1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.10
6 * Per-inferior thread numbers
8 Thread numbers are now per inferior instead of global. If you're
9 debugging multiple inferiors, GDB displays thread IDs using a
10 qualified INF_NUM.THR_NUM form. For example:
14 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
15 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
16 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
17 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
19 As consequence, thread numbers as visible in the $_thread
20 convenience variable and in Python's InferiorThread.num attribute
21 are no longer unique between inferiors.
23 GDB now maintains a second thread ID per thread, referred to as the
24 global thread ID, which is the new equivalent of thread numbers in
25 previous releases. See also $_gthread below.
27 For backwards compatibility, MI's thread IDs always refer to global
30 * Commands that accept thread IDs now accept the qualified
31 INF_NUM.THR_NUM form as well. For example:
34 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
37 * You can use "info threads -gid" to display the global thread ID of
40 * The new convenience variable $_gthread holds the global number of
43 * The new convenience variable $_inferior holds the number of the
46 * Record btrace now supports non-stop mode.
48 * Support for tracepoints on aarch64-linux was added in GDBserver.
50 * The 'record instruction-history' command now indicates speculative execution
51 when using the Intel Processor Trace recording format.
53 * GDB now allows users to specify explicit locations, bypassing
54 the linespec parser. This feature is also available to GDB/MI
57 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
58 GDB now is able to debug both AArch64 applications and ARM applications
61 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
62 including JIT compiling fast tracepoint's conditional expression bytecode
65 * GDB now supports displaced stepping on AArch64 GNU/Linux.
67 * "info threads", "info inferiors", "info display", "info checkpoints"
68 and "maint info program-spaces" now list the corresponding items in
69 ascending ID order, for consistency with all other "info" commands.
71 * In Ada, the overloads selection menu has been enhanced to display the
72 parameter types and the return types for the matching overloaded subprograms.
76 maint set target-non-stop (on|off|auto)
77 maint show target-non-stop
78 Control whether GDB targets always operate in non-stop mode even if
79 "set non-stop" is "off". The default is "auto", meaning non-stop
80 mode is enabled if supported by the target.
83 maint show bfd-sharing
84 Control the reuse of bfd objects.
88 Control display of debugging info regarding bfd caching.
90 set remote multiprocess-extensions-packet
91 show remote multiprocess-extensions-packet
92 Set/show the use of the remote protocol multiprocess extensions.
94 set remote thread-events
95 show remote thread-events
96 Set/show the use of thread create/exit events.
98 set ada print-signatures on|off
99 show ada print-signatures"
100 Control whether parameter types and return types are displayed in overloads
101 selection menus. It is activaled (@code{on}) by default.
103 * The "disassemble" command accepts a new modifier: /s.
104 It prints mixed source+disassembly like /m with two differences:
105 - disassembled instructions are now printed in program order, and
106 - and source for all relevant files is now printed.
107 The "/m" option is now considered deprecated: its "source-centric"
108 output hasn't proved useful in practice.
110 * The "record instruction-history" command accepts a new modifier: /s.
111 It behaves exactly like /m and prints mixed source+disassembly.
113 * The "set scheduler-locking" command supports a new mode "replay".
114 It behaves like "off" in record mode and like "on" in replay mode.
116 * Support for various ROM monitors has been removed:
118 target dbug dBUG ROM monitor for Motorola ColdFire
119 target picobug Motorola picobug monitor
120 target dink32 DINK32 ROM monitor for PowerPC
121 target m32r Renesas M32R/D ROM monitor
122 target mon2000 mon2000 ROM monitor
123 target ppcbug PPCBUG ROM monitor for PowerPC
125 * Support for reading/writing memory and extracting values on architectures
126 whose memory is addressable in units of any integral multiple of 8 bits.
131 Indicates that an exec system call was executed.
133 exec-events feature in qSupported
134 The qSupported packet allows GDB to request support for exec
135 events using the new 'gdbfeature' exec-event, and the qSupported
136 response can contain the corresponding 'stubfeature'. Set and
137 show commands can be used to display whether these features are enabled.
140 Equivalent to interrupting with the ^C character, but works in
143 thread created stop reason (T05 create:...)
144 Indicates that the thread was just created and is stopped at entry.
146 thread exit stop reply (w exitcode;tid)
147 Indicates that the thread has terminated.
150 Enables/disables thread create and exit event reporting. For
151 example, this is used in non-stop mode when GDB stops a set of
152 threads and synchronously waits for the their corresponding stop
153 replies. Without exit events, if one of the threads exits, GDB
154 would hang forever not knowing that it should no longer expect a
155 stop for that same thread.
159 Indicates that there are no resumed threads left in the target (all
160 threads are stopped). The remote stub reports support for this stop
161 reply to GDB's qSupported query.
163 QCatchSyscalls:1 [;SYSNO]...
165 Enable ("QCatchSyscalls:1") or disable ("QCatchSyscalls:0")
166 catching syscalls from the inferior process.
168 syscall_entry stop reason
169 Indicates that a syscall was just called.
171 syscall_return stop reason
172 Indicates that a syscall just returned.
174 QCatchSyscalls:1 in qSupported
175 The qSupported packet may now include QCatchSyscalls:1 in the reply
176 to indicate support for catching syscalls.
178 * Extended-remote exec events
180 ** GDB now has support for exec events on extended-remote Linux targets.
181 For such targets with Linux kernels 2.5.46 and later, this enables
182 follow-exec-mode and exec catchpoints.
184 set remote exec-event-feature-packet
185 show remote exec-event-feature-packet
186 Set/show the use of the remote exec event feature.
188 * Thread names in remote protocol
190 The reply to qXfer:threads:read may now include a name attribute for each
193 * Target remote mode fork and exec events
195 ** GDB now has support for fork and exec events on target remote mode
196 Linux targets. For such targets with Linux kernels 2.5.46 and later,
197 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
198 fork and exec catchpoints.
200 * Remote syscall events
202 ** GDB now has support for catch syscall on remote Linux targets,
203 currently enabled on x86/x86_64 architectures.
205 set remote catch-syscall-packet
206 show remote catch-syscall-packet
207 Set/show the use of the remote catch syscall feature.
211 ** The -var-set-format command now accepts the zero-hexadecimal
212 format. It outputs data in hexadecimal format with zero-padding on the
217 ** gdb.InferiorThread objects have a new attribute "global_num",
218 which refers to the thread's global thread ID. The existing
219 "num" attribute now refers to the thread's per-inferior number.
220 See "Per-inferior thread numbers" above.
221 ** gdb.InferiorThread objects have a new attribute "inferior", which
222 is the Inferior object the thread belongs to.
224 *** Changes in GDB 7.10
226 * Support for process record-replay and reverse debugging on aarch64*-linux*
227 targets has been added. GDB now supports recording of A64 instruction set
228 including advance SIMD instructions.
230 * Support for Sun's version of the "stabs" debug file format has been removed.
232 * GDB now honors the content of the file /proc/PID/coredump_filter
233 (PID is the process ID) on GNU/Linux systems. This file can be used
234 to specify the types of memory mappings that will be included in a
235 corefile. For more information, please refer to the manual page of
236 "core(5)". GDB also has a new command: "set use-coredump-filter
237 on|off". It allows to set whether GDB will read the content of the
238 /proc/PID/coredump_filter file when generating a corefile.
240 * The "info os" command on GNU/Linux can now display information on
242 "info os cpus" Listing of all cpus/cores on the system
244 * GDB has two new commands: "set serial parity odd|even|none" and
245 "show serial parity". These allows to set or show parity for the
248 * The "info source" command now displays the producer string if it was
249 present in the debug info. This typically includes the compiler version
250 and may include things like its command line arguments.
252 * The "info dll", an alias of the "info sharedlibrary" command,
253 is now available on all platforms.
255 * Directory names supplied to the "set sysroot" commands may be
256 prefixed with "target:" to tell GDB to access shared libraries from
257 the target system, be it local or remote. This replaces the prefix
258 "remote:". The default sysroot has been changed from "" to
259 "target:". "remote:" is automatically converted to "target:" for
260 backward compatibility.
262 * The system root specified by "set sysroot" will be prepended to the
263 filename of the main executable (if reported to GDB as absolute by
264 the operating system) when starting processes remotely, and when
265 attaching to already-running local or remote processes.
267 * GDB now supports automatic location and retrieval of executable
268 files from remote targets. Remote debugging can now be initiated
269 using only a "target remote" or "target extended-remote" command
270 (no "set sysroot" or "file" commands are required). See "New remote
273 * The "dump" command now supports verilog hex format.
275 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
277 * On GNU/Linux, GDB and gdbserver are now able to access executable
278 and shared library files without a "set sysroot" command when
279 attaching to processes running in different mount namespaces from
280 the debugger. This makes it possible to attach to processes in
281 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
282 See "New remote packets" below.
284 * The "tui reg" command now provides completion for all of the
285 available register groups, including target specific groups.
287 * The HISTSIZE environment variable is no longer read when determining
288 the size of GDB's command history. GDB now instead reads the dedicated
289 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
290 disables truncation of command history. Non-numeric values of GDBHISTSIZE
295 ** Memory ports can now be unbuffered.
299 ** gdb.Objfile objects have a new attribute "username",
300 which is the name of the objfile as specified by the user,
301 without, for example, resolving symlinks.
302 ** You can now write frame unwinders in Python.
303 ** gdb.Type objects have a new method "optimized_out",
304 returning optimized out gdb.Value instance of this type.
305 ** gdb.Value objects have new methods "reference_value" and
306 "const_value" which return a reference to the value and a
307 "const" version of the value respectively.
311 maint print symbol-cache
312 Print the contents of the symbol cache.
314 maint print symbol-cache-statistics
315 Print statistics of symbol cache usage.
317 maint flush-symbol-cache
318 Flush the contents of the symbol cache.
322 Start branch trace recording using Branch Trace Store (BTS) format.
325 Evaluate expression by using the compiler and print result.
329 Explicit commands for enabling and disabling tui mode.
332 set mpx bound on i386 and amd64
333 Support for bound table investigation on Intel MPX enabled applications.
337 Start branch trace recording using Intel Processor Trace format.
340 Print information about branch tracing internals.
342 maint btrace packet-history
343 Print the raw branch tracing data.
345 maint btrace clear-packet-history
346 Discard the stored raw branch tracing data.
349 Discard all branch tracing data. It will be fetched and processed
350 anew by the next "record" command.
355 Renamed from "set debug dwarf2-die".
357 Renamed from "show debug dwarf2-die".
360 Renamed from "set debug dwarf2-read".
361 show debug dwarf-read
362 Renamed from "show debug dwarf2-read".
364 maint set dwarf always-disassemble
365 Renamed from "maint set dwarf2 always-disassemble".
366 maint show dwarf always-disassemble
367 Renamed from "maint show dwarf2 always-disassemble".
369 maint set dwarf max-cache-age
370 Renamed from "maint set dwarf2 max-cache-age".
371 maint show dwarf max-cache-age
372 Renamed from "maint show dwarf2 max-cache-age".
375 show debug dwarf-line
376 Control display of debugging info regarding DWARF line processing.
380 Set the maximum number of candidates to be considered during
381 completion. The default value is 200. This limit allows GDB
382 to avoid generating large completion lists, the computation of
383 which can cause the debugger to become temporarily unresponsive.
385 set history remove-duplicates
386 show history remove-duplicates
387 Control the removal of duplicate history entries.
389 maint set symbol-cache-size
390 maint show symbol-cache-size
391 Control the size of the symbol cache.
393 set|show record btrace bts buffer-size
394 Set and show the size of the ring buffer used for branch tracing in
396 The obtained size may differ from the requested size. Use "info
397 record" to see the obtained buffer size.
399 set debug linux-namespaces
400 show debug linux-namespaces
401 Control display of debugging info regarding Linux namespaces.
403 set|show record btrace pt buffer-size
404 Set and show the size of the ring buffer used for branch tracing in
405 Intel Processor Trace format.
406 The obtained size may differ from the requested size. Use "info
407 record" to see the obtained buffer size.
409 maint set|show btrace pt skip-pad
410 Set and show whether PAD packets are skipped when computing the
413 * The command 'thread apply all' can now support new option '-ascending'
414 to call its specified command for all threads in ascending order.
416 * Python/Guile scripting
418 ** GDB now supports auto-loading of Python/Guile scripts contained in the
419 special section named `.debug_gdb_scripts'.
423 qXfer:btrace-conf:read
424 Return the branch trace configuration for the current thread.
426 Qbtrace-conf:bts:size
427 Set the requested ring buffer size for branch tracing in BTS format.
430 Enable Intel Procesor Trace-based branch tracing for the current
431 process. The remote stub reports support for this packet to GDB's
435 Set the requested ring buffer size for branch tracing in Intel Processor
439 Indicates a memory breakpoint instruction was executed, irrespective
440 of whether it was GDB that planted the breakpoint or the breakpoint
441 is hardcoded in the program. This is required for correct non-stop
445 Indicates the target stopped for a hardware breakpoint. This is
446 required for correct non-stop mode operation.
449 Return information about files on the remote system.
452 Return the full absolute name of the file that was executed to
453 create a process running on the remote system.
456 Select the filesystem on which vFile: operations with filename
457 arguments will operate. This is required for GDB to be able to
458 access files on remote targets where the remote stub does not
459 share a common filesystem with the inferior(s).
462 Indicates that a fork system call was executed.
465 Indicates that a vfork system call was executed.
467 vforkdone stop reason
468 Indicates that a vfork child of the specified process has executed
469 an exec or exit, allowing the vfork parent to resume execution.
471 fork-events and vfork-events features in qSupported
472 The qSupported packet allows GDB to request support for fork and
473 vfork events using new 'gdbfeatures' fork-events and vfork-events,
474 and the qSupported response can contain the corresponding
475 'stubfeatures'. Set and show commands can be used to display
476 whether these features are enabled.
478 * Extended-remote fork events
480 ** GDB now has support for fork events on extended-remote Linux
481 targets. For targets with Linux kernels 2.5.60 and later, this
482 enables follow-fork-mode and detach-on-fork for both fork and
483 vfork, as well as fork and vfork catchpoints.
485 * The info record command now shows the recording format and the
486 branch tracing configuration for the current thread when using
487 the btrace record target.
488 For the BTS format, it shows the ring buffer size.
490 * GDB now has support for DTrace USDT (Userland Static Defined
491 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
493 * GDB now supports access to vector registers on S/390 GNU/Linux
496 * Removed command line options
498 -xdb HP-UX XDB compatibility mode.
500 * Removed targets and native configurations
502 HP/PA running HP-UX hppa*-*-hpux*
503 Itanium running HP-UX ia64-*-hpux*
505 * New configure options
508 This configure option allows the user to build GDB with support for
509 Intel Processor Trace (default: auto). This requires libipt.
511 --with-libipt-prefix=PATH
512 Specify the path to the version of libipt that GDB should use.
513 $PATH/include should contain the intel-pt.h header and
514 $PATH/lib should contain the libipt.so library.
516 *** Changes in GDB 7.9.1
520 ** Xmethods can now specify a result type.
522 *** Changes in GDB 7.9
524 * GDB now supports hardware watchpoints on x86 GNU Hurd.
528 ** You can now access frame registers from Python scripts.
529 ** New attribute 'producer' for gdb.Symtab objects.
530 ** gdb.Objfile objects have a new attribute "progspace",
531 which is the gdb.Progspace object of the containing program space.
532 ** gdb.Objfile objects have a new attribute "owner".
533 ** gdb.Objfile objects have a new attribute "build_id",
534 which is the build ID generated when the file was built.
535 ** gdb.Objfile objects have a new method "add_separate_debug_file".
536 ** A new event "gdb.clear_objfiles" has been added, triggered when
537 selecting a new file to debug.
538 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
539 ** New function gdb.lookup_objfile.
541 New events which are triggered when GDB modifies the state of the
544 ** gdb.events.inferior_call_pre: Function call is about to be made.
545 ** gdb.events.inferior_call_post: Function call has just been made.
546 ** gdb.events.memory_changed: A memory location has been altered.
547 ** gdb.events.register_changed: A register has been altered.
549 * New Python-based convenience functions:
551 ** $_caller_is(name [, number_of_frames])
552 ** $_caller_matches(regexp [, number_of_frames])
553 ** $_any_caller_is(name [, number_of_frames])
554 ** $_any_caller_matches(regexp [, number_of_frames])
556 * GDB now supports the compilation and injection of source code into
557 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
558 to compile the source code to object code, and if successful, inject
559 and execute that code within the current context of the inferior.
560 Currently the C language is supported. The commands used to
561 interface with this new feature are:
563 compile code [-raw|-r] [--] [source code]
564 compile file [-raw|-r] filename
568 demangle [-l language] [--] name
569 Demangle "name" in the specified language, or the current language
570 if elided. This command is renamed from the "maint demangle" command.
571 The latter is kept as a no-op to avoid "maint demangle" being interpreted
572 as "maint demangler-warning".
574 queue-signal signal-name-or-number
575 Queue a signal to be delivered to the thread when it is resumed.
577 add-auto-load-scripts-directory directory
578 Add entries to the list of directories from which to load auto-loaded
581 maint print user-registers
582 List all currently available "user" registers.
584 compile code [-r|-raw] [--] [source code]
585 Compile, inject, and execute in the inferior the executable object
586 code produced by compiling the provided source code.
588 compile file [-r|-raw] filename
589 Compile and inject into the inferior the executable object code
590 produced by compiling the source code stored in the filename
593 * On resume, GDB now always passes the signal the program had stopped
594 for to the thread the signal was sent to, even if the user changed
595 threads before resuming. Previously GDB would often (but not
596 always) deliver the signal to the thread that happens to be current
599 * Conversely, the "signal" command now consistently delivers the
600 requested signal to the current thread. GDB now asks for
601 confirmation if the program had stopped for a signal and the user
602 switched threads meanwhile.
604 * "breakpoint always-inserted" modes "off" and "auto" merged.
606 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
607 won't remove breakpoints from the target until all threads stop,
608 even in non-stop mode. The "auto" mode has been removed, and "off"
609 is now the default mode.
613 set debug symbol-lookup
614 show debug symbol-lookup
615 Control display of debugging info regarding symbol lookup.
619 ** The -list-thread-groups command outputs an exit-code field for
620 inferiors that have exited.
624 MIPS SDE mips*-sde*-elf*
628 Support for these obsolete configurations has been removed.
630 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
631 SGI Irix-5.x mips-*-irix5*
632 SGI Irix-6.x mips-*-irix6*
633 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
634 VAX running Ultrix vax-*-ultrix*
636 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
637 and "assf"), have been removed. Use the "sharedlibrary" command, or
638 its alias "share", instead.
640 *** Changes in GDB 7.8
642 * New command line options
645 This is an alias for the --data-directory option.
647 * GDB supports printing and modifying of variable length automatic arrays
648 as specified in ISO C99.
650 * The ARM simulator now supports instruction level tracing
651 with or without disassembly.
655 GDB now has support for scripting using Guile. Whether this is
656 available is determined at configure time.
657 Guile version 2.0 or greater is required.
658 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
660 * New commands (for set/show, see "New options" below)
664 Invoke CODE by passing it to the Guile interpreter.
668 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
670 info auto-load guile-scripts [regexp]
671 Print the list of automatically loaded Guile scripts.
673 * The source command is now capable of sourcing Guile scripts.
674 This feature is dependent on the debugger being built with Guile support.
678 set print symbol-loading (off|brief|full)
679 show print symbol-loading
680 Control whether to print informational messages when loading symbol
681 information for a file. The default is "full", but when debugging
682 programs with large numbers of shared libraries the amount of output
685 set guile print-stack (none|message|full)
686 show guile print-stack
687 Show a stack trace when an error is encountered in a Guile script.
689 set auto-load guile-scripts (on|off)
690 show auto-load guile-scripts
691 Control auto-loading of Guile script files.
693 maint ada set ignore-descriptive-types (on|off)
694 maint ada show ignore-descriptive-types
695 Control whether the debugger should ignore descriptive types in Ada
696 programs. The default is not to ignore the descriptive types. See
697 the user manual for more details on descriptive types and the intended
698 usage of this option.
700 set auto-connect-native-target
702 Control whether GDB is allowed to automatically connect to the
703 native target for the run, attach, etc. commands when not connected
704 to any target yet. See also "target native" below.
706 set record btrace replay-memory-access (read-only|read-write)
707 show record btrace replay-memory-access
708 Control what memory accesses are allowed during replay.
710 maint set target-async (on|off)
711 maint show target-async
712 This controls whether GDB targets operate in synchronous or
713 asynchronous mode. Normally the default is asynchronous, if it is
714 available; but this can be changed to more easily debug problems
715 occurring only in synchronous mode.
717 set mi-async (on|off)
719 Control whether MI asynchronous mode is preferred. This supersedes
720 "set target-async" of previous GDB versions.
722 * "set target-async" is deprecated as a CLI option and is now an alias
723 for "set mi-async" (only puts MI into async mode).
725 * Background execution commands (e.g., "c&", "s&", etc.) are now
726 possible ``out of the box'' if the target supports them. Previously
727 the user would need to explicitly enable the possibility with the
728 "set target-async on" command.
730 * New features in the GDB remote stub, GDBserver
732 ** New option --debug-format=option1[,option2,...] allows one to add
733 additional text to each output. At present only timestamps
734 are supported: --debug-format=timestamps.
735 Timestamps can also be turned on with the
736 "monitor set debug-format timestamps" command from GDB.
738 * The 'record instruction-history' command now starts counting instructions
739 at one. This also affects the instruction ranges reported by the
740 'record function-call-history' command when given the /i modifier.
742 * The command 'record function-call-history' supports a new modifier '/c' to
743 indent the function names based on their call stack depth.
744 The fields for the '/i' and '/l' modifier have been reordered.
745 The source line range is now prefixed with 'at'.
746 The instruction range is now prefixed with 'inst'.
747 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
748 "record instruction-history" and "list" commands.
750 * The ranges given as arguments to the 'record function-call-history' and
751 'record instruction-history' commands are now inclusive.
753 * The btrace record target now supports the 'record goto' command.
754 For locations inside the execution trace, the back trace is computed
755 based on the information stored in the execution trace.
757 * The btrace record target supports limited reverse execution and replay.
758 The target does not record data and therefore does not allow reading
761 * The "catch syscall" command now works on s390*-linux* targets.
763 * The "compare-sections" command is no longer specific to target
764 remote. It now works with all targets.
766 * All native targets are now consistently called "native".
767 Consequently, the "target child", "target GNU", "target djgpp",
768 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
769 commands have been replaced with "target native". The QNX/NTO port
770 leaves the "procfs" target in place and adds a "native" target for
771 consistency with other ports. The impact on users should be minimal
772 as these commands previously either throwed an error, or were
773 no-ops. The target's name is visible in the output of the following
774 commands: "help target", "info target", "info files", "maint print
777 * The "target native" command now connects to the native target. This
778 can be used to launch native programs even when "set
779 auto-connect-native-target" is set to off.
781 * GDB now supports access to Intel MPX registers on GNU/Linux.
783 * Support for Intel AVX-512 registers on GNU/Linux.
784 Support displaying and modifying Intel AVX-512 registers
785 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
789 qXfer:btrace:read's annex
790 The qXfer:btrace:read packet supports a new annex 'delta' to read
791 branch trace incrementally.
795 ** Valid Python operations on gdb.Value objects representing
796 structs/classes invoke the corresponding overloaded operators if
798 ** New `Xmethods' feature in the Python API. Xmethods are
799 additional methods or replacements for existing methods of a C++
800 class. This feature is useful for those cases where a method
801 defined in C++ source code could be inlined or optimized out by
802 the compiler, making it unavailable to GDB.
805 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
807 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
808 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
809 its alias "share", instead.
811 * The commands "set remotebaud" and "show remotebaud" are no longer
812 supported. Use "set serial baud" and "show serial baud" (respectively)
817 ** A new option "-gdb-set mi-async" replaces "-gdb-set
818 target-async". The latter is left as a deprecated alias of the
819 former for backward compatibility. If the target supports it,
820 CLI background execution commands are now always possible by
821 default, independently of whether the frontend stated a
822 preference for asynchronous execution with "-gdb-set mi-async".
823 Previously "-gdb-set target-async off" affected both MI execution
824 commands and CLI execution commands.
826 *** Changes in GDB 7.7
828 * Improved support for process record-replay and reverse debugging on
829 arm*-linux* targets. Support for thumb32 and syscall instruction
830 recording has been added.
832 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
834 * GDB now supports Fission DWP file format version 2.
835 http://gcc.gnu.org/wiki/DebugFission
837 * New convenience function "$_isvoid", to check whether an expression
838 is void. A void expression is an expression where the type of the
839 result is "void". For example, some convenience variables may be
840 "void" when evaluated (e.g., "$_exitcode" before the execution of
841 the program being debugged; or an undefined convenience variable).
842 Another example, when calling a function whose return type is
845 * The "maintenance print objfiles" command now takes an optional regexp.
847 * The "catch syscall" command now works on arm*-linux* targets.
849 * GDB now consistently shows "<not saved>" when printing values of
850 registers the debug info indicates have not been saved in the frame
851 and there's nowhere to retrieve them from
852 (callee-saved/call-clobbered registers):
857 (gdb) info registers rax
860 Before, the former would print "<optimized out>", and the latter
861 "*value not available*".
863 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
868 ** Frame filters and frame decorators have been added.
869 ** Temporary breakpoints are now supported.
870 ** Line tables representation has been added.
871 ** New attribute 'parent_type' for gdb.Field objects.
872 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
873 ** New attribute 'name' for gdb.Type objects.
877 Nios II ELF nios2*-*-elf
878 Nios II GNU/Linux nios2*-*-linux
879 Texas Instruments MSP430 msp430*-*-elf
881 * Removed native configurations
883 Support for these a.out NetBSD and OpenBSD obsolete configurations has
884 been removed. ELF variants of these configurations are kept supported.
886 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
887 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
888 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
889 i[34567]86-*-openbsd3.[0-3]
890 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
891 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
892 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
896 Like "catch throw", but catches a re-thrown exception.
898 Renamed from old "maint check-symtabs".
900 Perform consistency checks on symtabs.
902 Expand symtabs matching an optional regexp.
905 Display the details of GDB configure-time options.
907 maint set|show per-command
908 maint set|show per-command space
909 maint set|show per-command time
910 maint set|show per-command symtab
911 Enable display of per-command gdb resource usage.
913 remove-symbol-file FILENAME
914 remove-symbol-file -a ADDRESS
915 Remove a symbol file added via add-symbol-file. The file to remove
916 can be identified by its filename or by an address that lies within
917 the boundaries of this symbol file in memory.
920 info exceptions REGEXP
921 Display the list of Ada exceptions defined in the program being
922 debugged. If provided, only the exceptions whose names match REGEXP
927 set debug symfile off|on
929 Control display of debugging info regarding reading symbol files and
930 symbol tables within those files
932 set print raw frame-arguments
933 show print raw frame-arguments
934 Set/show whether to print frame arguments in raw mode,
935 disregarding any defined pretty-printers.
937 set remote trace-status-packet
938 show remote trace-status-packet
939 Set/show the use of remote protocol qTStatus packet.
943 Control display of debugging messages related to Nios II targets.
947 Control whether target-assisted range stepping is enabled.
949 set startup-with-shell
950 show startup-with-shell
951 Specifies whether Unix child processes are started via a shell or
956 Use the target memory cache for accesses to the code segment. This
957 improves performance of remote debugging (particularly disassembly).
959 * You can now use a literal value 'unlimited' for options that
960 interpret 0 or -1 as meaning "unlimited". E.g., "set
961 trace-buffer-size unlimited" is now an alias for "set
962 trace-buffer-size -1" and "set height unlimited" is now an alias for
965 * The "set debug symtab-create" debugging option of GDB has been changed to
966 accept a verbosity level. 0 means "off", 1 provides basic debugging
967 output, and values of 2 or greater provides more verbose output.
969 * New command-line options
971 Display the details of GDB configure-time options.
973 * The command 'tsave' can now support new option '-ctf' to save trace
974 buffer in Common Trace Format.
976 * Newly installed $prefix/bin/gcore acts as a shell interface for the
979 * GDB now implements the the C++ 'typeid' operator.
981 * The new convenience variable $_exception holds the exception being
982 thrown or caught at an exception-related catchpoint.
984 * The exception-related catchpoints, like "catch throw", now accept a
985 regular expression which can be used to filter exceptions by type.
987 * The new convenience variable $_exitsignal is automatically set to
988 the terminating signal number when the program being debugged dies
989 due to an uncaught signal.
993 ** All MI commands now accept an optional "--language" option.
994 Support for this feature can be verified by using the "-list-features"
995 command, which should contain "language-option".
997 ** The new command -info-gdb-mi-command allows the user to determine
998 whether a GDB/MI command is supported or not.
1000 ** The "^error" result record returned when trying to execute an undefined
1001 GDB/MI command now provides a variable named "code" whose content is the
1002 "undefined-command" error code. Support for this feature can be verified
1003 by using the "-list-features" command, which should contain
1004 "undefined-command-error-code".
1006 ** The -trace-save MI command can optionally save trace buffer in Common
1009 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1011 ** The command -data-list-register-values now accepts an optional
1012 "--skip-unavailable" option. When used, only the available registers
1015 ** The new command -trace-frame-collected dumps collected variables,
1016 computed expressions, tvars, memory and registers in a traceframe.
1018 ** The commands -stack-list-locals, -stack-list-arguments and
1019 -stack-list-variables now accept an option "--skip-unavailable".
1020 When used, only the available locals or arguments are displayed.
1022 ** The -exec-run command now accepts an optional "--start" option.
1023 When used, the command follows the same semantics as the "start"
1024 command, stopping the program's execution at the start of its
1025 main subprogram. Support for this feature can be verified using
1026 the "-list-features" command, which should contain
1027 "exec-run-start-option".
1029 ** The new commands -catch-assert and -catch-exceptions insert
1030 catchpoints stopping the program when Ada exceptions are raised.
1032 ** The new command -info-ada-exceptions provides the equivalent of
1033 the new "info exceptions" command.
1035 * New system-wide configuration scripts
1036 A GDB installation now provides scripts suitable for use as system-wide
1037 configuration scripts for the following systems:
1041 * GDB now supports target-assigned range stepping with remote targets.
1042 This improves the performance of stepping source lines by reducing
1043 the number of control packets from/to GDB. See "New remote packets"
1046 * GDB now understands the element 'tvar' in the XML traceframe info.
1047 It has the id of the collected trace state variables.
1049 * On S/390 targets that provide the transactional-execution feature,
1050 the program interruption transaction diagnostic block (TDB) is now
1051 represented as a number of additional "registers" in GDB.
1053 * New remote packets
1057 The vCont packet supports a new 'r' action, that tells the remote
1058 stub to step through an address range itself, without GDB
1059 involvemement at each single-step.
1061 qXfer:libraries-svr4:read's annex
1062 The previously unused annex of the qXfer:libraries-svr4:read packet
1063 is now used to support passing an argument list. The remote stub
1064 reports support for this argument list to GDB's qSupported query.
1065 The defined arguments are "start" and "prev", used to reduce work
1066 necessary for library list updating, resulting in significant
1069 * New features in the GDB remote stub, GDBserver
1071 ** GDBserver now supports target-assisted range stepping. Currently
1072 enabled on x86/x86_64 GNU/Linux targets.
1074 ** GDBserver now adds element 'tvar' in the XML in the reply to
1075 'qXfer:traceframe-info:read'. It has the id of the collected
1076 trace state variables.
1078 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1081 * New 'z' formatter for printing and examining memory, this displays the
1082 value as hexadecimal zero padded on the left to the size of the type.
1084 * GDB can now use Windows x64 unwinding data.
1086 * The "set remotebaud" command has been replaced by "set serial baud".
1087 Similarly, "show remotebaud" has been replaced by "show serial baud".
1088 The "set remotebaud" and "show remotebaud" commands are still available
1089 to provide backward compatibility with older versions of GDB.
1091 *** Changes in GDB 7.6
1093 * Target record has been renamed to record-full.
1094 Record/replay is now enabled with the "record full" command.
1095 This also affects settings that are associated with full record/replay
1096 that have been moved from "set/show record" to "set/show record full":
1098 set|show record full insn-number-max
1099 set|show record full stop-at-limit
1100 set|show record full memory-query
1102 * A new record target "record-btrace" has been added. The new target
1103 uses hardware support to record the control-flow of a process. It
1104 does not support replaying the execution, but it implements the
1105 below new commands for investigating the recorded execution log.
1106 This new recording method can be enabled using:
1110 The "record-btrace" target is only available on Intel Atom processors
1111 and requires a Linux kernel 2.6.32 or later.
1113 * Two new commands have been added for record/replay to give information
1114 about the recorded execution without having to replay the execution.
1115 The commands are only supported by "record btrace".
1117 record instruction-history prints the execution history at
1118 instruction granularity
1120 record function-call-history prints the execution history at
1121 function granularity
1123 * New native configurations
1125 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1126 FreeBSD/powerpc powerpc*-*-freebsd
1127 x86_64/Cygwin x86_64-*-cygwin*
1128 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1132 ARM AArch64 aarch64*-*-elf
1133 ARM AArch64 GNU/Linux aarch64*-*-linux
1134 Lynx 178 PowerPC powerpc-*-lynx*178
1135 x86_64/Cygwin x86_64-*-cygwin*
1136 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1138 * If the configured location of system.gdbinit file (as given by the
1139 --with-system-gdbinit option at configure time) is in the
1140 data-directory (as specified by --with-gdb-datadir at configure
1141 time) or in one of its subdirectories, then GDB will look for the
1142 system-wide init file in the directory specified by the
1143 --data-directory command-line option.
1145 * New command line options:
1147 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1148 other initialization files, unlike -nx which disables all of them.
1150 * Removed command line options
1152 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1155 * The 'ptype' and 'whatis' commands now accept an argument to control
1158 * 'info proc' now works on some core files.
1162 ** Vectors can be created with gdb.Type.vector.
1164 ** Python's atexit.register now works in GDB.
1166 ** Types can be pretty-printed via a Python API.
1168 ** Python 3 is now supported (in addition to Python 2.4 or later)
1170 ** New class gdb.Architecture exposes GDB's internal representation
1171 of architecture in the Python API.
1173 ** New method Frame.architecture returns the gdb.Architecture object
1174 corresponding to the frame's architecture.
1176 * New Python-based convenience functions:
1178 ** $_memeq(buf1, buf2, length)
1179 ** $_streq(str1, str2)
1181 ** $_regex(str, regex)
1183 * The 'cd' command now defaults to using '~' (the home directory) if not
1186 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1187 default for GCC since November 2000.
1189 * The command 'forward-search' can now be abbreviated as 'fo'.
1191 * The command 'info tracepoints' can now display 'installed on target'
1192 or 'not installed on target' for each non-pending location of tracepoint.
1194 * New configure options
1196 --enable-libmcheck/--disable-libmcheck
1197 By default, development versions are built with -lmcheck on hosts
1198 that support it, in order to help track memory corruption issues.
1199 Release versions, on the other hand, are built without -lmcheck
1200 by default. The --enable-libmcheck/--disable-libmcheck configure
1201 options allow the user to override that default.
1202 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1203 This configure option allows the user to build GDB with
1204 libbabeltrace using which GDB can read Common Trace Format data.
1206 * New commands (for set/show, see "New options" below)
1209 Catch signals. This is similar to "handle", but allows commands and
1210 conditions to be attached.
1213 List the BFDs known to GDB.
1215 python-interactive [command]
1217 Start a Python interactive prompt, or evaluate the optional command
1218 and print the result of expressions.
1221 "py" is a new alias for "python".
1223 enable type-printer [name]...
1224 disable type-printer [name]...
1225 Enable or disable type printers.
1229 ** For the Renesas Super-H architecture, the "regs" command has been removed
1230 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1235 set print type methods (on|off)
1236 show print type methods
1237 Control whether method declarations are displayed by "ptype".
1238 The default is to show them.
1240 set print type typedefs (on|off)
1241 show print type typedefs
1242 Control whether typedef definitions are displayed by "ptype".
1243 The default is to show them.
1245 set filename-display basename|relative|absolute
1246 show filename-display
1247 Control the way in which filenames is displayed.
1248 The default is "relative", which preserves previous behavior.
1250 set trace-buffer-size
1251 show trace-buffer-size
1252 Request target to change the size of trace buffer.
1254 set remote trace-buffer-size-packet auto|on|off
1255 show remote trace-buffer-size-packet
1256 Control the use of the remote protocol `QTBuffer:size' packet.
1260 Control display of debugging messages related to ARM AArch64.
1263 set debug coff-pe-read
1264 show debug coff-pe-read
1265 Control display of debugging messages related to reading of COFF/PE
1270 Control display of debugging messages related to Mach-O symbols
1273 set debug notification
1274 show debug notification
1275 Control display of debugging info for async remote notification.
1279 ** Command parameter changes are now notified using new async record
1280 "=cmd-param-changed".
1281 ** Trace frame changes caused by command "tfind" are now notified using
1282 new async record "=traceframe-changed".
1283 ** The creation, deletion and modification of trace state variables
1284 are now notified using new async records "=tsv-created",
1285 "=tsv-deleted" and "=tsv-modified".
1286 ** The start and stop of process record are now notified using new
1287 async record "=record-started" and "=record-stopped".
1288 ** Memory changes are now notified using new async record
1290 ** The data-disassemble command response will include a "fullname" field
1291 containing the absolute file name when source has been requested.
1292 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1293 command, to allow pattern filling of memory areas.
1294 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1295 library load/unload events.
1296 ** The response to breakpoint commands and breakpoint async records
1297 includes an "installed" field containing a boolean state about each
1298 non-pending tracepoint location is whether installed on target or not.
1299 ** Output of the "-trace-status" command includes a "trace-file" field
1300 containing the name of the trace file being examined. This field is
1301 optional, and only present when examining a trace file.
1302 ** The "fullname" field is now always present along with the "file" field,
1303 even if the file cannot be found by GDB.
1305 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1306 You must have the LZMA library available when configuring GDB for this
1307 feature to be enabled. For more information, see:
1308 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1310 * New remote packets
1313 Set the size of trace buffer. The remote stub reports support for this
1314 packet to gdb's qSupported query.
1317 Enable Branch Trace Store (BTS)-based branch tracing for the current
1318 thread. The remote stub reports support for this packet to gdb's
1322 Disable branch tracing for the current thread. The remote stub reports
1323 support for this packet to gdb's qSupported query.
1326 Read the traced branches for the current thread. The remote stub
1327 reports support for this packet to gdb's qSupported query.
1329 *** Changes in GDB 7.5
1331 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1332 for more x32 ABI info.
1334 * GDB now supports access to MIPS DSP registers on Linux targets.
1336 * GDB now supports debugging microMIPS binaries.
1338 * The "info os" command on GNU/Linux can now display information on
1339 several new classes of objects managed by the operating system:
1340 "info os procgroups" lists process groups
1341 "info os files" lists file descriptors
1342 "info os sockets" lists internet-domain sockets
1343 "info os shm" lists shared-memory regions
1344 "info os semaphores" lists semaphores
1345 "info os msg" lists message queues
1346 "info os modules" lists loaded kernel modules
1348 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1349 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1350 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1351 options and inspect the probe arguments using the new $_probe_arg family
1352 of convenience variables. You can obtain more information about SystemTap
1353 in <http://sourceware.org/systemtap/>.
1355 * GDB now supports reversible debugging on ARM, it allows you to
1356 debug basic ARM and THUMB instructions, and provides
1357 record/replay support.
1359 * The option "symbol-reloading" has been deleted as it is no longer used.
1363 ** GDB commands implemented in Python can now be put in command class
1366 ** The "maint set python print-stack on|off" is now deleted.
1368 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1369 apply "flag enum"-style pretty-printing to any enum.
1371 ** gdb.lookup_symbol can now work when there is no current frame.
1373 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1374 the source at which the symbol was defined.
1376 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1377 method 'value'. The former indicates whether the symbol needs a
1378 frame in order to compute its value, and the latter computes the
1381 ** A new method 'referenced_value' on gdb.Value objects which can
1382 dereference pointer as well as C++ reference values.
1384 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1385 which return the global and static blocks (as gdb.Block objects),
1386 of the underlying symbol table, respectively.
1388 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1389 object associated with a PC value.
1391 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1392 of the address range occupied by code for the current source line.
1394 * Go language support.
1395 GDB now supports debugging programs written in the Go programming
1398 * GDBserver now supports stdio connections.
1399 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1401 * The binary "gdbtui" can no longer be built or installed.
1402 Use "gdb -tui" instead.
1404 * GDB will now print "flag" enums specially. A flag enum is one where
1405 all the enumerator values have no bits in common when pairwise
1406 "and"ed. When printing a value whose type is a flag enum, GDB will
1407 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1408 (gdb) print (enum E) 3
1411 * The filename part of a linespec will now match trailing components
1412 of a source file name. For example, "break gcc/expr.c:1000" will
1413 now set a breakpoint in build/gcc/expr.c, but not
1414 build/libcpp/expr.c.
1416 * The "info proc" and "generate-core-file" commands will now also
1417 work on remote targets connected to GDBserver on Linux.
1419 * The command "info catch" has been removed. It has been disabled
1420 since December 2007.
1422 * The "catch exception" and "catch assert" commands now accept
1423 a condition at the end of the command, much like the "break"
1424 command does. For instance:
1426 (gdb) catch exception Constraint_Error if Barrier = True
1428 Previously, it was possible to add a condition to such catchpoints,
1429 but it had to be done as a second step, after the catchpoint had been
1430 created, using the "condition" command.
1432 * The "info static-tracepoint-marker" command will now also work on
1433 native Linux targets with in-process agent.
1435 * GDB can now set breakpoints on inlined functions.
1437 * The .gdb_index section has been updated to include symbols for
1438 inlined functions. GDB will ignore older .gdb_index sections by
1439 default, which could cause symbol files to be loaded more slowly
1440 until their .gdb_index sections can be recreated. The new command
1441 "set use-deprecated-index-sections on" will cause GDB to use any older
1442 .gdb_index sections it finds. This will restore performance, but the
1443 ability to set breakpoints on inlined functions will be lost in symbol
1444 files with older .gdb_index sections.
1446 The .gdb_index section has also been updated to record more information
1447 about each symbol. This speeds up the "info variables", "info functions"
1448 and "info types" commands when used with programs having the .gdb_index
1449 section, as well as speeding up debugging with shared libraries using
1450 the .gdb_index section.
1452 * Ada support for GDB/MI Variable Objects has been added.
1454 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1459 ** New command -info-os is the MI equivalent of "info os".
1461 ** Output logs ("set logging" and related) now include MI output.
1465 ** "set use-deprecated-index-sections on|off"
1466 "show use-deprecated-index-sections on|off"
1467 Controls the use of deprecated .gdb_index sections.
1469 ** "catch load" and "catch unload" can be used to stop when a shared
1470 library is loaded or unloaded, respectively.
1472 ** "enable count" can be used to auto-disable a breakpoint after
1475 ** "info vtbl" can be used to show the virtual method tables for
1476 C++ and Java objects.
1478 ** "explore" and its sub commands "explore value" and "explore type"
1479 can be used to recursively explore values and types of
1480 expressions. These commands are available only if GDB is
1481 configured with '--with-python'.
1483 ** "info auto-load" shows status of all kinds of auto-loaded files,
1484 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1485 sequences of commands files, "info auto-load python-scripts"
1486 shows status of auto-loading Python script files,
1487 "info auto-load local-gdbinit" shows status of loading init file
1488 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1489 status of inferior specific thread debugging shared library loading.
1491 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1492 and "show auto-load-scripts" commands have been deprecated, use their
1493 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1494 and "show auto-load python-scripts" counterparts instead.
1496 ** "dprintf location,format,args..." creates a dynamic printf, which
1497 is basically a breakpoint that does a printf and immediately
1498 resumes your program's execution, so it is like a printf that you
1499 can insert dynamically at runtime instead of at compiletime.
1501 ** "set print symbol"
1503 Controls whether GDB attempts to display the symbol, if any,
1504 corresponding to addresses it prints. This defaults to "on", but
1505 you can set it to "off" to restore GDB's previous behavior.
1507 * Deprecated commands
1509 ** For the Renesas Super-H architecture, the "regs" command has been
1510 deprecated, and "info all-registers" should be used instead.
1514 Renesas RL78 rl78-*-elf
1515 HP OpenVMS ia64 ia64-hp-openvms*
1517 * GDBserver supports evaluation of breakpoint conditions. When
1518 support is advertised by GDBserver, GDB may be told to send the
1519 breakpoint conditions in bytecode form to GDBserver. GDBserver
1520 will only report the breakpoint trigger to GDB when its condition
1525 set mips compression
1526 show mips compression
1527 Select the compressed ISA encoding used in functions that have no symbol
1528 information available. The encoding can be set to either of:
1531 and is updated automatically from ELF file flags if available.
1533 set breakpoint condition-evaluation
1534 show breakpoint condition-evaluation
1535 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1536 GDBserver ("target"). Default option "auto" chooses the most efficient
1538 This option can improve debugger efficiency depending on the speed of the
1542 Disable auto-loading globally.
1545 Show auto-loading setting of all kinds of auto-loaded files.
1547 set auto-load gdb-scripts on|off
1548 show auto-load gdb-scripts
1549 Control auto-loading of GDB canned sequences of commands files.
1551 set auto-load python-scripts on|off
1552 show auto-load python-scripts
1553 Control auto-loading of Python script files.
1555 set auto-load local-gdbinit on|off
1556 show auto-load local-gdbinit
1557 Control loading of init file (.gdbinit) from current directory.
1559 set auto-load libthread-db on|off
1560 show auto-load libthread-db
1561 Control auto-loading of inferior specific thread debugging shared library.
1563 set auto-load scripts-directory <dir1>[:<dir2>...]
1564 show auto-load scripts-directory
1565 Set a list of directories from which to load auto-loaded scripts.
1566 Automatically loaded Python scripts and GDB scripts are located in one
1567 of the directories listed by this option.
1568 The delimiter (':' above) may differ according to the host platform.
1570 set auto-load safe-path <dir1>[:<dir2>...]
1571 show auto-load safe-path
1572 Set a list of directories from which it is safe to auto-load files.
1573 The delimiter (':' above) may differ according to the host platform.
1575 set debug auto-load on|off
1576 show debug auto-load
1577 Control display of debugging info for auto-loading the files above.
1579 set dprintf-style gdb|call|agent
1581 Control the way in which a dynamic printf is performed; "gdb"
1582 requests a GDB printf command, while "call" causes dprintf to call a
1583 function in the inferior. "agent" requests that the target agent
1584 (such as GDBserver) do the printing.
1586 set dprintf-function <expr>
1587 show dprintf-function
1588 set dprintf-channel <expr>
1589 show dprintf-channel
1590 Set the function and optional first argument to the call when using
1591 the "call" style of dynamic printf.
1593 set disconnected-dprintf on|off
1594 show disconnected-dprintf
1595 Control whether agent-style dynamic printfs continue to be in effect
1596 after GDB disconnects.
1598 * New configure options
1600 --with-auto-load-dir
1601 Configure default value for the 'set auto-load scripts-directory'
1602 setting above. It defaults to '$debugdir:$datadir/auto-load',
1603 $debugdir representing global debugging info directories (available
1604 via 'show debug-file-directory') and $datadir representing GDB's data
1605 directory (available via 'show data-directory').
1607 --with-auto-load-safe-path
1608 Configure default value for the 'set auto-load safe-path' setting
1609 above. It defaults to the --with-auto-load-dir setting.
1611 --without-auto-load-safe-path
1612 Set 'set auto-load safe-path' to '/', effectively disabling this
1615 * New remote packets
1617 z0/z1 conditional breakpoints extension
1619 The z0/z1 breakpoint insertion packets have been extended to carry
1620 a list of conditional expressions over to the remote stub depending on the
1621 condition evaluation mode. The use of this extension can be controlled
1622 via the "set remote conditional-breakpoints-packet" command.
1626 Specify the signals which the remote stub may pass to the debugged
1627 program without GDB involvement.
1629 * New command line options
1631 --init-command=FILE, -ix Like --command, -x but execute it
1632 before loading inferior.
1633 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1634 execute it before loading inferior.
1636 *** Changes in GDB 7.4
1638 * GDB now handles ambiguous linespecs more consistently; the existing
1639 FILE:LINE support has been expanded to other types of linespecs. A
1640 breakpoint will now be set on all matching locations in all
1641 inferiors, and locations will be added or removed according to
1644 * GDB now allows you to skip uninteresting functions and files when
1645 stepping with the "skip function" and "skip file" commands.
1647 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1648 and "show remote hardware-watchpoint-length-limit". These allows to
1649 set or show the maximum length limit (in bytes) of a remote
1650 target hardware watchpoint.
1652 This allows e.g. to use "unlimited" hardware watchpoints with the
1653 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1654 watchpoints are slower than real hardware watchpoints but are
1655 significantly faster than gdb software watchpoints.
1659 ** The register_pretty_printer function in module gdb.printing now takes
1660 an optional `replace' argument. If True, the new printer replaces any
1663 ** The "maint set python print-stack on|off" command has been
1664 deprecated and will be deleted in GDB 7.5.
1665 A new command: "set python print-stack none|full|message" has
1666 replaced it. Additionally, the default for "print-stack" is
1667 now "message", which just prints the error message without
1670 ** A prompt substitution hook (prompt_hook) is now available to the
1673 ** A new Python module, gdb.prompt has been added to the GDB Python
1674 modules library. This module provides functionality for
1675 escape sequences in prompts (used by set/show
1676 extended-prompt). These escape sequences are replaced by their
1677 corresponding value.
1679 ** Python commands and convenience-functions located in
1680 'data-directory'/python/gdb/command and
1681 'data-directory'/python/gdb/function are now automatically loaded
1684 ** Blocks now provide four new attributes. global_block and
1685 static_block will return the global and static blocks
1686 respectively. is_static and is_global are boolean attributes
1687 that indicate if the block is one of those two types.
1689 ** Symbols now provide the "type" attribute, the type of the symbol.
1691 ** The "gdb.breakpoint" function has been deprecated in favor of
1694 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1695 of a function. This class is based on the "finish" command
1696 available in the CLI.
1698 ** Type objects for struct and union types now allow access to
1699 the fields using standard Python dictionary (mapping) methods.
1700 For example, "some_type['myfield']" now works, as does
1701 "some_type.items()".
1703 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1706 ** A new function, "deep_items" has been added to the gdb.types
1707 module in the GDB Python modules library. This function returns
1708 an iterator over the fields of a struct or union type. Unlike
1709 the standard Python "iteritems" method, it will recursively traverse
1710 any anonymous fields.
1714 ** "*stopped" events can report several new "reason"s, such as
1717 ** Breakpoint changes are now notified using new async records, like
1718 "=breakpoint-modified".
1720 ** New command -ada-task-info.
1722 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1723 $sdir specifies the default system locations of shared libraries.
1724 $pdir specifies the directory where the libpthread used by the application
1727 GDB no longer looks in $sdir and $pdir after it has searched the directories
1728 mentioned in libthread-db-search-path. If you want to search those
1729 directories, they must be specified in libthread-db-search-path.
1730 The default value of libthread-db-search-path on GNU/Linux and Solaris
1731 systems is now "$sdir:$pdir".
1733 $pdir is not supported by gdbserver, it is currently ignored.
1734 $sdir is supported by gdbserver.
1736 * New configure option --with-iconv-bin.
1737 When using the internationalization support like the one in the GNU C
1738 library, GDB will invoke the "iconv" program to get a list of supported
1739 character sets. If this program lives in a non-standard location, one can
1740 use this option to specify where to find it.
1742 * When natively debugging programs on PowerPC BookE processors running
1743 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1744 watchpoints, which specify a mask in addition to an address to watch.
1745 The mask specifies that some bits of an address (the bits which are
1746 reset in the mask) should be ignored when matching the address accessed
1747 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1748 section in the user manual for more details.
1750 * The new option --once causes GDBserver to stop listening for connections once
1751 the first connection is made. The listening port used by GDBserver will
1752 become available after that.
1754 * New commands "info macros" and "alias" have been added.
1756 * New function parameters suffix @entry specifies value of function parameter
1757 at the time the function got called. Entry values are available only since
1763 "!" is now an alias of the "shell" command.
1764 Note that no space is needed between "!" and SHELL COMMAND.
1768 watch EXPRESSION mask MASK_VALUE
1769 The watch command now supports the mask argument which allows creation
1770 of masked watchpoints, if the current architecture supports this feature.
1772 info auto-load-scripts [REGEXP]
1773 This command was formerly named "maintenance print section-scripts".
1774 It is now generally useful and is no longer a maintenance-only command.
1776 info macro [-all] [--] MACRO
1777 The info macro command has new options `-all' and `--'. The first for
1778 printing all definitions of a macro. The second for explicitly specifying
1779 the end of arguments and the beginning of the macro name in case the macro
1780 name starts with a hyphen.
1782 collect[/s] EXPRESSIONS
1783 The tracepoint collect command now takes an optional modifier "/s"
1784 that directs it to dereference pointer-to-character types and
1785 collect the bytes of memory up to a zero byte. The behavior is
1786 similar to what you see when you use the regular print command on a
1787 string. An optional integer following the "/s" sets a bound on the
1788 number of bytes that will be collected.
1791 The trace start command now interprets any supplied arguments as a
1792 note to be recorded with the trace run, with an effect similar to
1793 setting the variable trace-notes.
1796 The trace stop command now interprets any arguments as a note to be
1797 mentioned along with the tstatus report that the trace was stopped
1798 with a command. The effect is similar to setting the variable
1801 * Tracepoints can now be enabled and disabled at any time after a trace
1802 experiment has been started using the standard "enable" and "disable"
1803 commands. It is now possible to start a trace experiment with no enabled
1804 tracepoints; GDB will display a warning, but will allow the experiment to
1805 begin, assuming that tracepoints will be enabled as needed while the trace
1808 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1809 locations with 4-byte instructions, when they were previously
1810 limited to locations with instructions of 5 bytes or longer.
1814 set debug dwarf2-read
1815 show debug dwarf2-read
1816 Turns on or off display of debugging messages related to reading
1817 DWARF debug info. The default is off.
1819 set debug symtab-create
1820 show debug symtab-create
1821 Turns on or off display of debugging messages related to symbol table
1822 creation. The default is off.
1825 show extended-prompt
1826 Set the GDB prompt, and allow escape sequences to be inserted to
1827 display miscellaneous information (see 'help set extended-prompt'
1828 for the list of sequences). This prompt (and any information
1829 accessed through the escape sequences) is updated every time the
1830 prompt is displayed.
1832 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1833 show print entry-values
1834 Set printing of frame argument values at function entry. In some cases
1835 GDB can determine the value of function argument which was passed by the
1836 function caller, even if the value was modified inside the called function.
1838 set debug entry-values
1839 show debug entry-values
1840 Control display of debugging info for determining frame argument values at
1841 function entry and virtual tail call frames.
1843 set basenames-may-differ
1844 show basenames-may-differ
1845 Set whether a source file may have multiple base names.
1846 (A "base name" is the name of a file with the directory part removed.
1847 Example: The base name of "/home/user/hello.c" is "hello.c".)
1848 If set, GDB will canonicalize file names (e.g., expand symlinks)
1849 before comparing them. Canonicalization is an expensive operation,
1850 but it allows the same file be known by more than one base name.
1851 If not set (the default), all source files are assumed to have just
1852 one base name, and gdb will do file name comparisons more efficiently.
1858 Set a user name and notes for the current and any future trace runs.
1859 This is useful for long-running and/or disconnected traces, to
1860 inform others (or yourself) as to who is running the trace, supply
1861 contact information, or otherwise explain what is going on.
1863 set trace-stop-notes
1864 show trace-stop-notes
1865 Set a note attached to the trace run, that is displayed when the
1866 trace has been stopped by a tstop command. This is useful for
1867 instance as an explanation, if you are stopping a trace run that was
1868 started by someone else.
1870 * New remote packets
1874 Dynamically enable a tracepoint in a started trace experiment.
1878 Dynamically disable a tracepoint in a started trace experiment.
1882 Set the user and notes of the trace run.
1886 Query the current status of a tracepoint.
1890 Query the minimum length of instruction at which a fast tracepoint may
1893 * Dcache size (number of lines) and line-size are now runtime-configurable
1894 via "set dcache line" and "set dcache line-size" commands.
1898 Texas Instruments TMS320C6x tic6x-*-*
1902 Renesas RL78 rl78-*-elf
1904 *** Changes in GDB 7.3.1
1906 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1908 *** Changes in GDB 7.3
1910 * GDB has a new command: "thread find [REGEXP]".
1911 It finds the thread id whose name, target id, or thread extra info
1912 matches the given regular expression.
1914 * The "catch syscall" command now works on mips*-linux* targets.
1916 * The -data-disassemble MI command now supports modes 2 and 3 for
1917 dumping the instruction opcodes.
1919 * New command line options
1921 -data-directory DIR Specify DIR as the "data-directory".
1922 This is mostly for testing purposes.
1924 * The "maint set python auto-load on|off" command has been renamed to
1925 "set auto-load-scripts on|off".
1927 * GDB has a new command: "set directories".
1928 It is like the "dir" command except that it replaces the
1929 source path list instead of augmenting it.
1931 * GDB now understands thread names.
1933 On GNU/Linux, "info threads" will display the thread name as set by
1934 prctl or pthread_setname_np.
1936 There is also a new command, "thread name", which can be used to
1937 assign a name internally for GDB to display.
1940 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1941 has been integrated into GDB.
1945 ** The function gdb.Write now accepts an optional keyword 'stream'.
1946 This keyword, when provided, will direct the output to either
1947 stdout, stderr, or GDB's logging output.
1949 ** Parameters can now be be sub-classed in Python, and in particular
1950 you may implement the get_set_doc and get_show_doc functions.
1951 This improves how Parameter set/show documentation is processed
1952 and allows for more dynamic content.
1954 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1955 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1956 have an is_valid method.
1958 ** Breakpoints can now be sub-classed in Python, and in particular
1959 you may implement a 'stop' function that is executed each time
1960 the inferior reaches that breakpoint.
1962 ** New function gdb.lookup_global_symbol looks up a global symbol.
1964 ** GDB values in Python are now callable if the value represents a
1965 function. For example, if 'some_value' represents a function that
1966 takes two integer parameters and returns a value, you can call
1967 that function like so:
1969 result = some_value (10,20)
1971 ** Module gdb.types has been added.
1972 It contains a collection of utilities for working with gdb.Types objects:
1973 get_basic_type, has_field, make_enum_dict.
1975 ** Module gdb.printing has been added.
1976 It contains utilities for writing and registering pretty-printers.
1977 New classes: PrettyPrinter, SubPrettyPrinter,
1978 RegexpCollectionPrettyPrinter.
1979 New function: register_pretty_printer.
1981 ** New commands "info pretty-printers", "enable pretty-printer" and
1982 "disable pretty-printer" have been added.
1984 ** gdb.parameter("directories") is now available.
1986 ** New function gdb.newest_frame returns the newest frame in the
1989 ** The gdb.InferiorThread class has a new "name" attribute. This
1990 holds the thread's name.
1992 ** Python Support for Inferior events.
1993 Python scripts can add observers to be notified of events
1994 occurring in the process being debugged.
1995 The following events are currently supported:
1996 - gdb.events.cont Continue event.
1997 - gdb.events.exited Inferior exited event.
1998 - gdb.events.stop Signal received, and Breakpoint hit events.
2002 ** GDB now puts template parameters in scope when debugging in an
2003 instantiation. For example, if you have:
2005 template<int X> int func (void) { return X; }
2007 then if you step into func<5>, "print X" will show "5". This
2008 feature requires proper debuginfo support from the compiler; it
2009 was added to GCC 4.5.
2011 ** The motion commands "next", "finish", "until", and "advance" now
2012 work better when exceptions are thrown. In particular, GDB will
2013 no longer lose control of the inferior; instead, the GDB will
2014 stop the inferior at the point at which the exception is caught.
2015 This functionality requires a change in the exception handling
2016 code that was introduced in GCC 4.5.
2018 * GDB now follows GCC's rules on accessing volatile objects when
2019 reading or writing target state during expression evaluation.
2020 One notable difference to prior behavior is that "print x = 0"
2021 no longer generates a read of x; the value of the assignment is
2022 now always taken directly from the value being assigned.
2024 * GDB now has some support for using labels in the program's source in
2025 linespecs. For instance, you can use "advance label" to continue
2026 execution to a label.
2028 * GDB now has support for reading and writing a new .gdb_index
2029 section. This section holds a fast index of DWARF debugging
2030 information and can be used to greatly speed up GDB startup and
2031 operation. See the documentation for `save gdb-index' for details.
2033 * The "watch" command now accepts an optional "-location" argument.
2034 When used, this causes GDB to watch the memory referred to by the
2035 expression. Such a watchpoint is never deleted due to it going out
2038 * GDB now supports thread debugging of core dumps on GNU/Linux.
2040 GDB now activates thread debugging using the libthread_db library
2041 when debugging GNU/Linux core dumps, similarly to when debugging
2042 live processes. As a result, when debugging a core dump file, GDB
2043 is now able to display pthread_t ids of threads. For example, "info
2044 threads" shows the same output as when debugging the process when it
2045 was live. In earlier releases, you'd see something like this:
2048 * 1 LWP 6780 main () at main.c:10
2050 While now you see this:
2053 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2055 It is also now possible to inspect TLS variables when debugging core
2058 When debugging a core dump generated on a machine other than the one
2059 used to run GDB, you may need to point GDB at the correct
2060 libthread_db library with the "set libthread-db-search-path"
2061 command. See the user manual for more details on this command.
2063 * When natively debugging programs on PowerPC BookE processors running
2064 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2065 which stop execution of the inferior whenever it executes an instruction
2066 at any address within the specified range. See the "PowerPC Embedded"
2067 section in the user manual for more details.
2069 * New features in the GDB remote stub, GDBserver
2071 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2072 and i686 LynxOS (version 5.x).
2074 ** GDBserver is now supported on Blackfin Linux.
2076 * New native configurations
2078 ia64 HP-UX ia64-*-hpux*
2082 Analog Devices, Inc. Blackfin Processor bfin-*
2084 * Ada task switching is now supported on sparc-elf targets when
2085 debugging a program using the Ravenscar Profile. For more information,
2086 see the "Tasking Support when using the Ravenscar Profile" section
2087 in the GDB user manual.
2089 * Guile support was removed.
2091 * New features in the GNU simulator
2093 ** The --map-info flag lists all known core mappings.
2095 ** CFI flashes may be simulated via the "cfi" device.
2097 *** Changes in GDB 7.2
2099 * Shared library support for remote targets by default
2101 When GDB is configured for a generic, non-OS specific target, like
2102 for example, --target=arm-eabi or one of the many *-*-elf targets,
2103 GDB now queries remote stubs for loaded shared libraries using the
2104 `qXfer:libraries:read' packet. Previously, shared library support
2105 was always disabled for such configurations.
2109 ** Argument Dependent Lookup (ADL)
2111 In C++ ADL lookup directs function search to the namespaces of its
2112 arguments even if the namespace has not been imported.
2122 Here the compiler will search for `foo' in the namespace of 'b'
2123 and find A::foo. GDB now supports this. This construct is commonly
2124 used in the Standard Template Library for operators.
2126 ** Improved User Defined Operator Support
2128 In addition to member operators, GDB now supports lookup of operators
2129 defined in a namespace and imported with a `using' directive, operators
2130 defined in the global scope, operators imported implicitly from an
2131 anonymous namespace, and the ADL operators mentioned in the previous
2133 GDB now also supports proper overload resolution for all the previously
2134 mentioned flavors of operators.
2136 ** static const class members
2138 Printing of static const class members that are initialized in the
2139 class definition has been fixed.
2141 * Windows Thread Information Block access.
2143 On Windows targets, GDB now supports displaying the Windows Thread
2144 Information Block (TIB) structure. This structure is visible either
2145 by using the new command `info w32 thread-information-block' or, by
2146 dereferencing the new convenience variable named `$_tlb', a
2147 thread-specific pointer to the TIB. This feature is also supported
2148 when remote debugging using GDBserver.
2150 * Static tracepoints
2152 Static tracepoints are calls in the user program into a tracing
2153 library. One such library is a port of the LTTng kernel tracer to
2154 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2155 When debugging with GDBserver, GDB now supports combining the GDB
2156 tracepoint machinery with such libraries. For example: the user can
2157 use GDB to probe a static tracepoint marker (a call from the user
2158 program into the tracing library) with the new "strace" command (see
2159 "New commands" below). This creates a "static tracepoint" in the
2160 breakpoint list, that can be manipulated with the same feature set
2161 as fast and regular tracepoints. E.g., collect registers, local and
2162 global variables, collect trace state variables, and define
2163 tracepoint conditions. In addition, the user can collect extra
2164 static tracepoint marker specific data, by collecting the new
2165 $_sdata internal variable. When analyzing the trace buffer, you can
2166 inspect $_sdata like any other variable available to GDB. For more
2167 information, see the "Tracepoints" chapter in GDB user manual. New
2168 remote packets have been defined to support static tracepoints, see
2169 the "New remote packets" section below.
2171 * Better reconstruction of tracepoints after disconnected tracing
2173 GDB will attempt to download the original source form of tracepoint
2174 definitions when starting a trace run, and then will upload these
2175 upon reconnection to the target, resulting in a more accurate
2176 reconstruction of the tracepoints that are in use on the target.
2180 You can now exercise direct control over the ways that GDB can
2181 affect your program. For instance, you can disallow the setting of
2182 breakpoints, so that the program can run continuously (assuming
2183 non-stop mode). In addition, the "observer" variable is available
2184 to switch all of the different controls; in observer mode, GDB
2185 cannot affect the target's behavior at all, which is useful for
2186 tasks like diagnosing live systems in the field.
2188 * The new convenience variable $_thread holds the number of the
2191 * New remote packets
2195 Return the address of the Windows Thread Information Block of a given thread.
2199 In response to several of the tracepoint packets, the target may now
2200 also respond with a number of intermediate `qRelocInsn' request
2201 packets before the final result packet, to have GDB handle
2202 relocating an instruction to execute at a different address. This
2203 is particularly useful for stubs that support fast tracepoints. GDB
2204 reports support for this feature in the qSupported packet.
2208 List static tracepoint markers in the target program.
2212 List static tracepoint markers at a given address in the target
2215 qXfer:statictrace:read
2217 Read the static trace data collected (by a `collect $_sdata'
2218 tracepoint action). The remote stub reports support for this packet
2219 to gdb's qSupported query.
2223 Send the current settings of GDB's permission flags.
2227 Send part of the source (textual) form of a tracepoint definition,
2228 which includes location, conditional, and action list.
2230 * The source command now accepts a -s option to force searching for the
2231 script in the source search path even if the script name specifies
2234 * New features in the GDB remote stub, GDBserver
2236 - GDBserver now support tracepoints (including fast tracepoints, and
2237 static tracepoints). The feature is currently supported by the
2238 i386-linux and amd64-linux builds. See the "Tracepoints support
2239 in gdbserver" section in the manual for more information.
2241 GDBserver JIT compiles the tracepoint's conditional agent
2242 expression bytecode into native code whenever possible for low
2243 overhead dynamic tracepoints conditionals. For such tracepoints,
2244 an expression that examines program state is evaluated when the
2245 tracepoint is reached, in order to determine whether to capture
2246 trace data. If the condition is simple and false, processing the
2247 tracepoint finishes very quickly and no data is gathered.
2249 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2250 for static tracepoints support.
2252 - GDBserver now supports x86_64 Windows 64-bit debugging.
2254 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2255 it understands register description.
2257 * The --batch flag now disables pagination and queries.
2259 * X86 general purpose registers
2261 GDB now supports reading/writing byte, word and double-word x86
2262 general purpose registers directly. This means you can use, say,
2263 $ah or $ax to refer, respectively, to the byte register AH and
2264 16-bit word register AX that are actually portions of the 32-bit
2265 register EAX or 64-bit register RAX.
2267 * The `commands' command now accepts a range of breakpoints to modify.
2268 A plain `commands' following a command that creates multiple
2269 breakpoints affects all the breakpoints set by that command. This
2270 applies to breakpoints set by `rbreak', and also applies when a
2271 single `break' command creates multiple breakpoints (e.g.,
2272 breakpoints on overloaded c++ functions).
2274 * The `rbreak' command now accepts a filename specification as part of
2275 its argument, limiting the functions selected by the regex to those
2276 in the specified file.
2278 * Support for remote debugging Windows and SymbianOS shared libraries
2279 from Unix hosts has been improved. Non Windows GDB builds now can
2280 understand target reported file names that follow MS-DOS based file
2281 system semantics, such as file names that include drive letters and
2282 use the backslash character as directory separator. This makes it
2283 possible to transparently use the "set sysroot" and "set
2284 solib-search-path" on Unix hosts to point as host copies of the
2285 target's shared libraries. See the new command "set
2286 target-file-system-kind" described below, and the "Commands to
2287 specify files" section in the user manual for more information.
2291 eval template, expressions...
2292 Convert the values of one or more expressions under the control
2293 of the string template to a command line, and call it.
2295 set target-file-system-kind unix|dos-based|auto
2296 show target-file-system-kind
2297 Set or show the assumed file system kind for target reported file
2300 save breakpoints <filename>
2301 Save all current breakpoint definitions to a file suitable for use
2302 in a later debugging session. To read the saved breakpoint
2303 definitions, use the `source' command.
2305 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2308 info static-tracepoint-markers
2309 Display information about static tracepoint markers in the target.
2311 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2312 Define a static tracepoint by probing a marker at the given
2313 function, line, address, or marker ID.
2317 Enable and disable observer mode.
2319 set may-write-registers on|off
2320 set may-write-memory on|off
2321 set may-insert-breakpoints on|off
2322 set may-insert-tracepoints on|off
2323 set may-insert-fast-tracepoints on|off
2324 set may-interrupt on|off
2325 Set individual permissions for GDB effects on the target. Note that
2326 some of these settings can have undesirable or surprising
2327 consequences, particularly when changed in the middle of a session.
2328 For instance, disabling the writing of memory can prevent
2329 breakpoints from being inserted, cause single-stepping to fail, or
2330 even crash your program, if you disable after breakpoints have been
2331 inserted. However, GDB should not crash.
2333 set record memory-query on|off
2334 show record memory-query
2335 Control whether to stop the inferior if memory changes caused
2336 by an instruction cannot be recorded.
2341 The disassemble command now supports "start,+length" form of two arguments.
2345 ** GDB now provides a new directory location, called the python directory,
2346 where Python scripts written for GDB can be installed. The location
2347 of that directory is <data-directory>/python, where <data-directory>
2348 is the GDB data directory. For more details, see section `Scripting
2349 GDB using Python' in the manual.
2351 ** The GDB Python API now has access to breakpoints, symbols, symbol
2352 tables, program spaces, inferiors, threads and frame's code blocks.
2353 Additionally, GDB Parameters can now be created from the API, and
2354 manipulated via set/show in the CLI.
2356 ** New functions gdb.target_charset, gdb.target_wide_charset,
2357 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2359 ** New exception gdb.GdbError.
2361 ** Pretty-printers are now also looked up in the current program space.
2363 ** Pretty-printers can now be individually enabled and disabled.
2365 ** GDB now looks for names of Python scripts to auto-load in a
2366 special section named `.debug_gdb_scripts', in addition to looking
2367 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2369 * Tracepoint actions were unified with breakpoint commands. In particular,
2370 there are no longer differences in "info break" output for breakpoints and
2371 tracepoints and the "commands" command can be used for both tracepoints and
2372 regular breakpoints.
2376 ARM Symbian arm*-*-symbianelf*
2378 * D language support.
2379 GDB now supports debugging programs written in the D programming
2382 * GDB now supports the extended ptrace interface for PowerPC which is
2383 available since Linux kernel version 2.6.34. This automatically enables
2384 any hardware breakpoints and additional hardware watchpoints available in
2385 the processor. The old ptrace interface exposes just one hardware
2386 watchpoint and no hardware breakpoints.
2388 * GDB is now able to use the Data Value Compare (DVC) register available on
2389 embedded PowerPC processors to implement in hardware simple watchpoint
2390 conditions of the form:
2392 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2394 This works in native GDB running on Linux kernels with the extended ptrace
2395 interface mentioned above.
2397 *** Changes in GDB 7.1
2401 ** Namespace Support
2403 GDB now supports importing of namespaces in C++. This enables the
2404 user to inspect variables from imported namespaces. Support for
2405 namepace aliasing has also been added. So, if a namespace is
2406 aliased in the current scope (e.g. namepace C=A; ) the user can
2407 print variables using the alias (e.g. (gdb) print C::x).
2411 All known bugs relating to the printing of virtual base class were
2412 fixed. It is now possible to call overloaded static methods using a
2417 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2418 and reinterpret_cast<> are now handled by the C++ expression parser.
2422 Xilinx MicroBlaze microblaze-*-*
2427 Xilinx MicroBlaze microblaze
2430 * Multi-program debugging.
2432 GDB now has support for multi-program (a.k.a. multi-executable or
2433 multi-exec) debugging. This allows for debugging multiple inferiors
2434 simultaneously each running a different program under the same GDB
2435 session. See "Debugging Multiple Inferiors and Programs" in the
2436 manual for more information. This implied some user visible changes
2437 in the multi-inferior support. For example, "info inferiors" now
2438 lists inferiors that are not running yet or that have exited
2439 already. See also "New commands" and "New options" below.
2441 * New tracing features
2443 GDB's tracepoint facility now includes several new features:
2445 ** Trace state variables
2447 GDB tracepoints now include support for trace state variables, which
2448 are variables managed by the target agent during a tracing
2449 experiment. They are useful for tracepoints that trigger each
2450 other, so for instance one tracepoint can count hits in a variable,
2451 and then a second tracepoint has a condition that is true when the
2452 count reaches a particular value. Trace state variables share the
2453 $-syntax of GDB convenience variables, and can appear in both
2454 tracepoint actions and condition expressions. Use the "tvariable"
2455 command to create, and "info tvariables" to view; see "Trace State
2456 Variables" in the manual for more detail.
2460 GDB now includes an option for defining fast tracepoints, which
2461 targets may implement more efficiently, such as by installing a jump
2462 into the target agent rather than a trap instruction. The resulting
2463 speedup can be by two orders of magnitude or more, although the
2464 tradeoff is that some program locations on some target architectures
2465 might not allow fast tracepoint installation, for instance if the
2466 instruction to be replaced is shorter than the jump. To request a
2467 fast tracepoint, use the "ftrace" command, with syntax identical to
2468 the regular trace command.
2470 ** Disconnected tracing
2472 It is now possible to detach GDB from the target while it is running
2473 a trace experiment, then reconnect later to see how the experiment
2474 is going. In addition, a new variable disconnected-tracing lets you
2475 tell the target agent whether to continue running a trace if the
2476 connection is lost unexpectedly.
2480 GDB now has the ability to save the trace buffer into a file, and
2481 then use that file as a target, similarly to you can do with
2482 corefiles. You can select trace frames, print data that was
2483 collected in them, and use tstatus to display the state of the
2484 tracing run at the moment that it was saved. To create a trace
2485 file, use "tsave <filename>", and to use it, do "target tfile
2488 ** Circular trace buffer
2490 You can ask the target agent to handle the trace buffer as a
2491 circular buffer, discarding the oldest trace frames to make room for
2492 newer ones, by setting circular-trace-buffer to on. This feature may
2493 not be available for all target agents.
2498 The disassemble command, when invoked with two arguments, now requires
2499 the arguments to be comma-separated.
2502 The info variables command now displays variable definitions. Files
2503 which only declare a variable are not shown.
2506 The source command is now capable of sourcing Python scripts.
2507 This feature is dependent on the debugger being build with Python
2510 Related to this enhancement is also the introduction of a new command
2511 "set script-extension" (see below).
2513 * New commands (for set/show, see "New options" below)
2515 record save [<FILENAME>]
2516 Save a file (in core file format) containing the process record
2517 execution log for replay debugging at a later time.
2519 record restore <FILENAME>
2520 Restore the process record execution log that was saved at an
2521 earlier time, for replay debugging.
2523 add-inferior [-copies <N>] [-exec <FILENAME>]
2526 clone-inferior [-copies <N>] [ID]
2527 Make a new inferior ready to execute the same program another
2528 inferior has loaded.
2533 maint info program-spaces
2534 List the program spaces loaded into GDB.
2536 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2537 show remote interrupt-sequence
2538 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2539 as the sequence to the remote target in order to interrupt the execution.
2540 Ctrl-C is a default. Some system prefers BREAK which is high level of
2541 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2542 Magic SysRq g. It is BREAK signal and character 'g'.
2544 set remote interrupt-on-connect [on | off]
2545 show remote interrupt-on-connect
2546 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2547 remote target when gdb connects to it. This is needed when you debug
2550 set remotebreak [on | off]
2552 Deprecated. Use "set/show remote interrupt-sequence" instead.
2554 tvariable $NAME [ = EXP ]
2555 Create or modify a trace state variable.
2558 List trace state variables and their values.
2560 delete tvariable $NAME ...
2561 Delete one or more trace state variables.
2564 Evaluate the given expressions without collecting anything into the
2565 trace buffer. (Valid in tracepoint actions only.)
2567 ftrace FN / FILE:LINE / *ADDR
2568 Define a fast tracepoint at the given function, line, or address.
2570 * New expression syntax
2572 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2573 GDB now parses 0b101010 identically with 42.
2577 set follow-exec-mode new|same
2578 show follow-exec-mode
2579 Control whether GDB reuses the same inferior across an exec call or
2580 creates a new one. This is useful to be able to restart the old
2581 executable after the inferior having done an exec call.
2583 set default-collect EXPR, ...
2584 show default-collect
2585 Define a list of expressions to be collected at each tracepoint.
2586 This is a useful way to ensure essential items are not overlooked,
2587 such as registers or a critical global variable.
2589 set disconnected-tracing
2590 show disconnected-tracing
2591 If set to 1, the target is instructed to continue tracing if it
2592 loses its connection to GDB. If 0, the target is to stop tracing
2595 set circular-trace-buffer
2596 show circular-trace-buffer
2597 If set to on, the target is instructed to use a circular trace buffer
2598 and discard the oldest trace frames instead of stopping the trace due
2599 to a full trace buffer. If set to off, the trace stops when the buffer
2600 fills up. Some targets may not support this.
2602 set script-extension off|soft|strict
2603 show script-extension
2604 If set to "off", the debugger does not perform any script language
2605 recognition, and all sourced files are assumed to be GDB scripts.
2606 If set to "soft" (the default), files are sourced according to
2607 filename extension, falling back to GDB scripts if the first
2609 If set to "strict", files are sourced according to filename extension.
2611 set ada trust-PAD-over-XVS on|off
2612 show ada trust-PAD-over-XVS
2613 If off, activate a workaround against a bug in the debugging information
2614 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2615 the GCC sources for more information about the GNAT encoding and
2616 PAD types in particular). It is always safe to set this option to
2617 off, but this introduces a slight performance penalty. The default
2620 * Python API Improvements
2622 ** GDB provides the new class gdb.LazyString. This is useful in
2623 some pretty-printing cases. The new method gdb.Value.lazy_string
2624 provides a simple way to create objects of this type.
2626 ** The fields returned by gdb.Type.fields now have an
2627 `is_base_class' attribute.
2629 ** The new method gdb.Type.range returns the range of an array type.
2631 ** The new method gdb.parse_and_eval can be used to parse and
2632 evaluate an expression.
2634 * New remote packets
2637 Define a trace state variable.
2640 Get the current value of a trace state variable.
2643 Set desired tracing behavior upon disconnection.
2646 Set the trace buffer to be linear or circular.
2649 Get data about the tracepoints currently in use.
2653 Process record now works correctly with hardware watchpoints.
2655 Multiple bug fixes have been made to the mips-irix port, making it
2656 much more reliable. In particular:
2657 - Debugging threaded applications is now possible again. Previously,
2658 GDB would hang while starting the program, or while waiting for
2659 the program to stop at a breakpoint.
2660 - Attaching to a running process no longer hangs.
2661 - An error occurring while loading a core file has been fixed.
2662 - Changing the value of the PC register now works again. This fixes
2663 problems observed when using the "jump" command, or when calling
2664 a function from GDB, or even when assigning a new value to $pc.
2665 - With the "finish" and "return" commands, the return value for functions
2666 returning a small array is now correctly printed.
2667 - It is now possible to break on shared library code which gets executed
2668 during a shared library init phase (code executed while executing
2669 their .init section). Previously, the breakpoint would have no effect.
2670 - GDB is now able to backtrace through the signal handler for
2671 non-threaded programs.
2673 PIE (Position Independent Executable) programs debugging is now supported.
2674 This includes debugging execution of PIC (Position Independent Code) shared
2675 libraries although for that, it should be possible to run such libraries as an
2678 *** Changes in GDB 7.0
2680 * GDB now has an interface for JIT compilation. Applications that
2681 dynamically generate code can create symbol files in memory and register
2682 them with GDB. For users, the feature should work transparently, and
2683 for JIT developers, the interface is documented in the GDB manual in the
2684 "JIT Compilation Interface" chapter.
2686 * Tracepoints may now be conditional. The syntax is as for
2687 breakpoints; either an "if" clause appended to the "trace" command,
2688 or the "condition" command is available. GDB sends the condition to
2689 the target for evaluation using the same bytecode format as is used
2690 for tracepoint actions.
2692 * The disassemble command now supports: an optional /r modifier, print the
2693 raw instructions in hex as well as in symbolic form, and an optional /m
2694 modifier to print mixed source+assembly.
2696 * Process record and replay
2698 In a architecture environment that supports ``process record and
2699 replay'', ``process record and replay'' target can record a log of
2700 the process execution, and replay it with both forward and reverse
2703 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2704 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2705 set execution-direction {forward|reverse}, for targets that support
2708 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2709 feature is available with a native GDB running on kernel version
2712 * GDB now has support for multi-byte and wide character sets on the
2713 target. Strings whose character type is wchar_t, char16_t, or
2714 char32_t are now correctly printed. GDB supports wide- and unicode-
2715 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2716 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2717 `printf'. This feature requires iconv to work properly; if your
2718 system does not have a working iconv, GDB can use GNU libiconv. See
2719 the installation instructions for more information.
2721 * GDB now supports automatic retrieval of shared library files from
2722 remote targets. To use this feature, specify a system root that begins
2723 with the `remote:' prefix, either via the `set sysroot' command or via
2724 the `--with-sysroot' configure-time option.
2726 * "info sharedlibrary" now takes an optional regex of libraries to show,
2727 and it now reports if a shared library has no debugging information.
2729 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2730 now complete on file names.
2732 * When completing in expressions, gdb will attempt to limit
2733 completions to allowable structure or union fields, where appropriate.
2734 For instance, consider:
2736 # struct example { int f1; double f2; };
2737 # struct example variable;
2740 If the user types TAB at the end of this command line, the available
2741 completions will be "f1" and "f2".
2743 * Inlined functions are now supported. They show up in backtraces, and
2744 the "step", "next", and "finish" commands handle them automatically.
2746 * GDB now supports the token-splicing (##) and stringification (#)
2747 operators when expanding macros. It also supports variable-arity
2750 * GDB now supports inspecting extra signal information, exported by
2751 the new $_siginfo convenience variable. The feature is currently
2752 implemented on linux ARM, i386 and amd64.
2754 * GDB can now display the VFP floating point registers and NEON vector
2755 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2756 can provide these registers (requires Linux 2.6.30 or later). Remote
2757 and simulator targets may also provide them.
2759 * New remote packets
2762 Search memory for a sequence of bytes.
2765 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2766 operation over reliable transport links. Use of this packet is
2767 controlled by the `set remote noack-packet' command.
2770 Kill the process with the specified process ID. Use this in preference
2771 to `k' when multiprocess protocol extensions are supported.
2774 Obtains additional operating system information
2778 Read or write additional signal information.
2780 * Removed remote protocol undocumented extension
2782 An undocumented extension to the remote protocol's `S' stop reply
2783 packet that permited the stub to pass a process id was removed.
2784 Remote servers should use the `T' stop reply packet instead.
2786 * GDB now supports multiple function calling conventions according to the
2787 DWARF-2 DW_AT_calling_convention function attribute.
2789 * The SH target utilizes the aforementioned change to distinguish between gcc
2790 and Renesas calling convention. It also adds the new CLI commands
2791 `set/show sh calling-convention'.
2793 * GDB can now read compressed debug sections, as produced by GNU gold
2794 with the --compress-debug-sections=zlib flag.
2796 * 64-bit core files are now supported on AIX.
2798 * Thread switching is now supported on Tru64.
2800 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2801 which will be allocated using malloc later in program execution.
2803 * The qXfer:libraries:read remote procotol packet now allows passing a
2804 list of section offsets.
2806 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2807 conditions handling signals delivered during attach or thread creation
2808 have also been fixed.
2810 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2811 From the user's standpoint, all unqualified instances of True and False
2812 are treated as the standard definitions, regardless of context.
2814 * GDB now parses C++ symbol and type names more flexibly. For
2817 template<typename T> class C { };
2820 GDB will now correctly handle all of:
2822 ptype C<char const *>
2823 ptype C<char const*>
2824 ptype C<const char *>
2825 ptype C<const char*>
2827 * New features in the GDB remote stub, gdbserver
2829 - The "--wrapper" command-line argument tells gdbserver to use a
2830 wrapper program to launch programs for debugging.
2832 - On PowerPC and S/390 targets, it is now possible to use a single
2833 gdbserver executable to debug both 32-bit and 64-bit programs.
2834 (This requires gdbserver itself to be built as a 64-bit executable.)
2836 - gdbserver uses the new noack protocol mode for TCP connections to
2837 reduce communications latency, if also supported and enabled in GDB.
2839 - Support for the sparc64-linux-gnu target is now included in
2842 - The amd64-linux build of gdbserver now supports debugging both
2843 32-bit and 64-bit programs.
2845 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2846 now support hardware watchpoints, and will use them automatically
2851 GDB now has support for scripting using Python. Whether this is
2852 available is determined at configure time.
2854 New GDB commands can now be written in Python.
2856 * Ada tasking support
2858 Ada tasks can now be inspected in GDB. The following commands have
2862 Print the list of Ada tasks.
2864 Print detailed information about task number N.
2866 Print the task number of the current task.
2868 Switch the context of debugging to task number N.
2870 * Support for user-defined prefixed commands. The "define" command can
2871 add new commands to existing prefixes, e.g. "target".
2873 * Multi-inferior, multi-process debugging.
2875 GDB now has generalized support for multi-inferior debugging. See
2876 "Debugging Multiple Inferiors" in the manual for more information.
2877 Although availability still depends on target support, the command
2878 set is more uniform now. The GNU/Linux specific multi-forks support
2879 has been migrated to this new framework. This implied some user
2880 visible changes; see "New commands" and also "Removed commands"
2883 * Target descriptions can now describe the target OS ABI. See the
2884 "Target Description Format" section in the user manual for more
2887 * Target descriptions can now describe "compatible" architectures
2888 to indicate that the target can execute applications for a different
2889 architecture in addition to those for the main target architecture.
2890 See the "Target Description Format" section in the user manual for
2893 * Multi-architecture debugging.
2895 GDB now includes general supports for debugging applications on
2896 hybrid systems that use more than one single processor architecture
2897 at the same time. Each such hybrid architecture still requires
2898 specific support to be added. The only hybrid architecture supported
2899 in this version of GDB is the Cell Broadband Engine.
2901 * GDB now supports integrated debugging of Cell/B.E. applications that
2902 use both the PPU and SPU architectures. To enable support for hybrid
2903 Cell/B.E. debugging, you need to configure GDB to support both the
2904 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2905 --enable-targets configure option.
2907 * Non-stop mode debugging.
2909 For some targets, GDB now supports an optional mode of operation in
2910 which you can examine stopped threads while other threads continue
2911 to execute freely. This is referred to as non-stop mode, with the
2912 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2913 section in the user manual for more information.
2915 To be able to support remote non-stop debugging, a remote stub needs
2916 to implement the non-stop mode remote protocol extensions, as
2917 described in the "Remote Non-Stop" section of the user manual. The
2918 GDB remote stub, gdbserver, has been adjusted to support these
2919 extensions on linux targets.
2921 * New commands (for set/show, see "New options" below)
2923 catch syscall [NAME(S) | NUMBER(S)]
2924 Catch system calls. Arguments, which should be names of system
2925 calls or their numbers, mean catch only those syscalls. Without
2926 arguments, every syscall will be caught. When the inferior issues
2927 any of the specified syscalls, GDB will stop and announce the system
2928 call, both when it is called and when its call returns. This
2929 feature is currently available with a native GDB running on the
2930 Linux Kernel, under the following architectures: x86, x86_64,
2931 PowerPC and PowerPC64.
2933 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2935 Search memory for a sequence of bytes.
2937 maint set python print-stack
2938 maint show python print-stack
2939 Show a stack trace when an error is encountered in a Python script.
2942 Invoke CODE by passing it to the Python interpreter.
2947 These allow macros to be defined, undefined, and listed
2951 Show operating system information about processes.
2954 List the inferiors currently under GDB's control.
2957 Switch focus to inferior number NUM.
2960 Detach from inferior number NUM.
2963 Kill inferior number NUM.
2967 set spu stop-on-load
2968 show spu stop-on-load
2969 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2971 set spu auto-flush-cache
2972 show spu auto-flush-cache
2973 Control whether to automatically flush the software-managed cache
2974 during Cell/B.E. debugging.
2976 set sh calling-convention
2977 show sh calling-convention
2978 Control the calling convention used when calling SH target functions.
2981 show debug timestamp
2982 Control display of timestamps with GDB debugging output.
2984 set disassemble-next-line
2985 show disassemble-next-line
2986 Control display of disassembled source lines or instructions when
2989 set remote noack-packet
2990 show remote noack-packet
2991 Set/show the use of remote protocol QStartNoAckMode packet. See above
2992 under "New remote packets."
2994 set remote query-attached-packet
2995 show remote query-attached-packet
2996 Control use of remote protocol `qAttached' (query-attached) packet.
2998 set remote read-siginfo-object
2999 show remote read-siginfo-object
3000 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3003 set remote write-siginfo-object
3004 show remote write-siginfo-object
3005 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3008 set remote reverse-continue
3009 show remote reverse-continue
3010 Control use of remote protocol 'bc' (reverse-continue) packet.
3012 set remote reverse-step
3013 show remote reverse-step
3014 Control use of remote protocol 'bs' (reverse-step) packet.
3016 set displaced-stepping
3017 show displaced-stepping
3018 Control displaced stepping mode. Displaced stepping is a way to
3019 single-step over breakpoints without removing them from the debuggee.
3020 Also known as "out-of-line single-stepping".
3023 show debug displaced
3024 Control display of debugging info for displaced stepping.
3026 maint set internal-error
3027 maint show internal-error
3028 Control what GDB does when an internal error is detected.
3030 maint set internal-warning
3031 maint show internal-warning
3032 Control what GDB does when an internal warning is detected.
3037 Use a wrapper program to launch programs for debugging.
3039 set multiple-symbols (all|ask|cancel)
3040 show multiple-symbols
3041 The value of this variable can be changed to adjust the debugger behavior
3042 when an expression or a breakpoint location contains an ambiguous symbol
3043 name (an overloaded function name, for instance).
3045 set breakpoint always-inserted
3046 show breakpoint always-inserted
3047 Keep breakpoints always inserted in the target, as opposed to inserting
3048 them when resuming the target, and removing them when the target stops.
3049 This option can improve debugger performance on slow remote targets.
3051 set arm fallback-mode (arm|thumb|auto)
3052 show arm fallback-mode
3053 set arm force-mode (arm|thumb|auto)
3055 These commands control how ARM GDB determines whether instructions
3056 are ARM or Thumb. The default for both settings is auto, which uses
3057 the current CPSR value for instructions without symbols; previous
3058 versions of GDB behaved as if "set arm fallback-mode arm".
3060 set disable-randomization
3061 show disable-randomization
3062 Standalone programs run with the virtual address space randomization enabled
3063 by default on some platforms. This option keeps the addresses stable across
3064 multiple debugging sessions.
3068 Control whether other threads are stopped or not when some thread hits
3073 Requests that asynchronous execution is enabled in the target, if available.
3074 In this case, it's possible to resume target in the background, and interact
3075 with GDB while the target is running. "show target-async" displays the
3076 current state of asynchronous execution of the target.
3078 set target-wide-charset
3079 show target-wide-charset
3080 The target-wide-charset is the name of the character set that GDB
3081 uses when printing characters whose type is wchar_t.
3083 set tcp auto-retry (on|off)
3085 set tcp connect-timeout
3086 show tcp connect-timeout
3087 These commands allow GDB to retry failed TCP connections to a remote stub
3088 with a specified timeout period; this is useful if the stub is launched
3089 in parallel with GDB but may not be ready to accept connections immediately.
3091 set libthread-db-search-path
3092 show libthread-db-search-path
3093 Control list of directories which GDB will search for appropriate
3096 set schedule-multiple (on|off)
3097 show schedule-multiple
3098 Allow GDB to resume all threads of all processes or only threads of
3099 the current process.
3103 Use more aggressive caching for accesses to the stack. This improves
3104 performance of remote debugging (particularly backtraces) without
3105 affecting correctness.
3107 set interactive-mode (on|off|auto)
3108 show interactive-mode
3109 Control whether GDB runs in interactive mode (on) or not (off).
3110 When in interactive mode, GDB waits for the user to answer all
3111 queries. Otherwise, GDB does not wait and assumes the default
3112 answer. When set to auto (the default), GDB determines which
3113 mode to use based on the stdin settings.
3118 For program forks, this is replaced by the new more generic `info
3119 inferiors' command. To list checkpoints, you can still use the
3120 `info checkpoints' command, which was an alias for the `info forks'
3124 Replaced by the new `inferior' command. To switch between
3125 checkpoints, you can still use the `restart' command, which was an
3126 alias for the `fork' command.
3129 This is removed, since some targets don't have a notion of
3130 processes. To switch between processes, you can still use the
3131 `inferior' command using GDB's own inferior number.
3134 For program forks, this is replaced by the new more generic `kill
3135 inferior' command. To delete a checkpoint, you can still use the
3136 `delete checkpoint' command, which was an alias for the `delete
3140 For program forks, this is replaced by the new more generic `detach
3141 inferior' command. To detach a checkpoint, you can still use the
3142 `detach checkpoint' command, which was an alias for the `detach
3145 * New native configurations
3147 x86/x86_64 Darwin i[34567]86-*-darwin*
3149 x86_64 MinGW x86_64-*-mingw*
3153 Lattice Mico32 lm32-*
3154 x86 DICOS i[34567]86-*-dicos*
3155 x86_64 DICOS x86_64-*-dicos*
3158 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3159 (mingw32ce) debugging.
3165 These commands were actually not implemented on any target.
3167 *** Changes in GDB 6.8
3169 * New native configurations
3171 NetBSD/hppa hppa*-*netbsd*
3172 Xtensa GNU/Linux xtensa*-*-linux*
3176 NetBSD/hppa hppa*-*-netbsd*
3177 Xtensa GNU/Lunux xtensa*-*-linux*
3179 * Change in command line behavior -- corefiles vs. process ids.
3181 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3182 attaching to process NUMBER fails, GDB no longer attempts to open a
3183 core file named NUMBER. Attaching to a program using the -c option
3184 is no longer supported. Instead, use the '-p' or '--pid' options.
3186 * GDB can now be built as a native debugger for debugging Windows x86
3187 (mingw32) Portable Executable (PE) programs.
3189 * Pending breakpoints no longer change their number when their address
3192 * GDB now supports breakpoints with multiple locations,
3193 including breakpoints on C++ constructors, inside C++ templates,
3194 and in inlined functions.
3196 * GDB's ability to debug optimized code has been improved. GDB more
3197 accurately identifies function bodies and lexical blocks that occupy
3198 more than one contiguous range of addresses.
3200 * Target descriptions can now describe registers for PowerPC.
3202 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3203 registers on PowerPC targets.
3205 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3206 targets even when the libthread_db library is not available.
3208 * The GDB remote stub, gdbserver, now supports the new file transfer
3209 commands (remote put, remote get, and remote delete).
3211 * The GDB remote stub, gdbserver, now supports run and attach in
3212 extended-remote mode.
3214 * hppa*64*-*-hpux11* target broken
3215 The debugger is unable to start a program and fails with the following
3216 error: "Error trying to get information about dynamic linker".
3217 The gdb-6.7 release is also affected.
3219 * GDB now supports the --enable-targets= configure option to allow
3220 building a single GDB executable that supports multiple remote
3221 target architectures.
3223 * GDB now supports debugging C and C++ programs which use the
3224 Decimal Floating Point extension. In addition, the PowerPC target
3225 now has a set of pseudo-registers to inspect decimal float values
3226 stored in two consecutive float registers.
3228 * The -break-insert MI command can optionally create pending
3231 * Improved support for debugging Ada
3232 Many improvements to the Ada language support have been made. These
3234 - Better support for Ada2005 interface types
3235 - Improved handling of arrays and slices in general
3236 - Better support for Taft-amendment types
3237 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3239 - Improved command completion in Ada
3242 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3247 set print frame-arguments (all|scalars|none)
3248 show print frame-arguments
3249 The value of this variable can be changed to control which argument
3250 values should be printed by the debugger when displaying a frame.
3255 Transfer files to and from a remote target, and delete remote files.
3262 Transfer files to and from a remote target, and delete remote files.
3264 * New remote packets
3271 Open, close, read, write, and delete files on the remote system.
3274 Attach to an existing process on the remote system, in extended-remote
3278 Run a new process on the remote system, in extended-remote mode.
3280 *** Changes in GDB 6.7
3282 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3283 bfd, libiberty and opcodes, as revealed by static analysis donated by
3284 Coverity, Inc. (http://scan.coverity.com).
3286 * When looking up multiply-defined global symbols, GDB will now prefer the
3287 symbol definition in the current shared library if it was built using the
3288 -Bsymbolic linker option.
3290 * When the Text User Interface (TUI) is not configured, GDB will now
3291 recognize the -tui command-line option and print a message that the TUI
3294 * The GDB remote stub, gdbserver, now has lower overhead for high
3295 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3297 * GDB for MIPS targets now autodetects whether a remote target provides
3298 32-bit or 64-bit register values.
3300 * Support for C++ member pointers has been improved.
3302 * GDB now understands XML target descriptions, which specify the
3303 target's overall architecture. GDB can read a description from
3304 a local file or over the remote serial protocol.
3306 * Vectors of single-byte data use a new integer type which is not
3307 automatically displayed as character or string data.
3309 * The /s format now works with the print command. It displays
3310 arrays of single-byte integers and pointers to single-byte integers
3313 * Target descriptions can now describe target-specific registers,
3314 for architectures which have implemented the support (currently
3315 only ARM, M68K, and MIPS).
3317 * GDB and the GDB remote stub, gdbserver, now support the XScale
3320 * The GDB remote stub, gdbserver, has been updated to support
3321 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3322 has been rewritten to use the standard GDB remote protocol.
3324 * GDB can now step into C++ functions which are called through thunks.
3326 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3328 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3329 layout. It also supports a TextSeg= and DataSeg= response when only
3330 segment base addresses (rather than offsets) are available.
3332 * The /i format now outputs any trailing branch delay slot instructions
3333 immediately following the last instruction within the count specified.
3335 * The GDB remote protocol "T" stop reply packet now supports a
3336 "library" response. Combined with the new "qXfer:libraries:read"
3337 packet, this response allows GDB to debug shared libraries on targets
3338 where the operating system manages the list of loaded libraries (e.g.
3339 Windows and SymbianOS).
3341 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3342 (DLLs) on Windows and Windows CE targets.
3344 * GDB now supports a faster verification that a .debug file matches its binary
3345 according to its build-id signature, if the signature is present.
3351 Enable or disable hardware flow control (RTS/CTS) on the serial port
3352 when debugging using remote targets.
3354 set mem inaccessible-by-default
3355 show mem inaccessible-by-default
3356 If the target supplies a memory map, for instance via the remote
3357 protocol's "qXfer:memory-map:read" packet, setting this variable
3358 prevents GDB from accessing memory outside the memory map. This
3359 is useful for targets with memory mapped registers or which react
3360 badly to accesses of unmapped address space.
3362 set breakpoint auto-hw
3363 show breakpoint auto-hw
3364 If the target supplies a memory map, for instance via the remote
3365 protocol's "qXfer:memory-map:read" packet, setting this variable
3366 lets GDB use hardware breakpoints automatically for memory regions
3367 where it can not use software breakpoints. This covers both the
3368 "break" command and internal breakpoints used for other commands
3369 including "next" and "finish".
3372 catch exception unhandled
3373 Stop the program execution when Ada exceptions are raised.
3376 Stop the program execution when an Ada assertion failed.
3380 Set an alternate system root for target files. This is a more
3381 general version of "set solib-absolute-prefix", which is now
3382 an alias to "set sysroot".
3385 Provide extended SPU facility status information. This set of
3386 commands is available only when debugging the Cell/B.E. SPU
3389 * New native configurations
3391 OpenBSD/sh sh*-*openbsd*
3394 unset tdesc filename
3396 Use the specified local file as an XML target description, and do
3397 not query the target for its built-in description.
3401 OpenBSD/sh sh*-*-openbsd*
3402 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3403 Toshiba Media Processor mep-elf
3405 * New remote packets
3408 Ignore the specified signals; pass them directly to the debugged program
3409 without stopping other threads or reporting them to GDB.
3411 qXfer:features:read:
3412 Read an XML target description from the target, which describes its
3417 Read or write contents of an spufs file on the target system. These
3418 packets are available only on the Cell/B.E. SPU architecture.
3420 qXfer:libraries:read:
3421 Report the loaded shared libraries. Combined with new "T" packet
3422 response, this packet allows GDB to debug shared libraries on
3423 targets where the operating system manages the list of loaded
3424 libraries (e.g. Windows and SymbianOS).
3428 Support for these obsolete configurations has been removed.
3436 i[34567]86-*-lynxos*
3437 i[34567]86-*-netware*
3438 i[34567]86-*-sco3.2v5*
3439 i[34567]86-*-sco3.2v4*
3441 i[34567]86-*-sysv4.2*
3444 i[34567]86-*-unixware2*
3445 i[34567]86-*-unixware*
3454 * Other removed features
3461 Various m68k-only ROM monitors.
3468 Various Renesas ROM monitors and debugging interfaces for SH and
3473 Support for a Macraigor serial interface to on-chip debugging.
3474 GDB does not directly support the newer parallel or USB
3479 A debug information format. The predecessor to DWARF 2 and
3480 DWARF 3, which are still supported.
3482 Support for the HP aCC compiler on HP-UX/PA-RISC
3484 SOM-encapsulated symbolic debugging information, automatic
3485 invocation of pxdb, and the aCC custom C++ ABI. This does not
3486 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3487 with aCC can still be debugged on an assembly level.
3489 MIPS ".pdr" sections
3491 A MIPS-specific format used to describe stack frame layout
3492 in debugging information.
3496 GDB could work with an older version of Guile to debug
3497 the interpreter and Scheme programs running in it.
3499 set mips stack-arg-size
3500 set mips saved-gpreg-size
3502 Use "set mips abi" to control parameter passing for MIPS.
3504 *** Changes in GDB 6.6
3509 Cell Broadband Engine SPU spu-elf
3511 * GDB can now be configured as a cross-debugger targeting native Windows
3512 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3513 running on a Windows system over TCP/IP to debug Windows programs.
3515 * The GDB remote stub, gdbserver, has been updated to support Windows and
3516 Cygwin debugging. Both single-threaded and multi-threaded programs are
3519 * The "set trust-readonly-sections" command works again. This command was
3520 broken in GDB 6.3, 6.4, and 6.5.
3522 * The "load" command now supports writing to flash memory, if the remote
3523 stub provides the required support.
3525 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3526 longer requires symbolic debug information (e.g. DWARF-2).
3531 unset substitute-path
3532 show substitute-path
3533 Manage a list of substitution rules that GDB uses to rewrite the name
3534 of the directories where the sources are located. This can be useful
3535 for instance when the sources were moved to a different location
3536 between compilation and debugging.
3540 Print each CLI command as it is executed. Each command is prefixed with
3541 a number of `+' symbols representing the nesting depth.
3542 The source command now has a `-v' option to enable the same feature.
3546 The ARM Demon monitor support (RDP protocol, "target rdp").
3548 Kernel Object Display, an embedded debugging feature which only worked with
3549 an obsolete version of Cisco IOS.
3551 The 'set download-write-size' and 'show download-write-size' commands.
3553 * New remote packets
3556 Tell a stub about GDB client features, and request remote target features.
3557 The first feature implemented is PacketSize, which allows the target to
3558 specify the size of packets it can handle - to minimize the number of
3559 packets required and improve performance when connected to a remote
3563 Fetch an OS auxilliary vector from the remote stub. This packet is a
3564 more efficient replacement for qPart:auxv:read.
3566 qXfer:memory-map:read:
3567 Fetch a memory map from the remote stub, including information about
3568 RAM, ROM, and flash memory devices.
3573 Erase and program a flash memory device.
3575 * Removed remote packets
3578 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3579 used it, and only gdbserver implemented it.
3581 *** Changes in GDB 6.5
3585 Renesas M32C/M16C m32c-elf
3587 Morpho Technologies ms1 ms1-elf
3591 init-if-undefined Initialize a convenience variable, but
3592 only if it doesn't already have a value.
3594 The following commands are presently only implemented for native GNU/Linux:
3596 checkpoint Save a snapshot of the program state.
3598 restart <n> Return the program state to a
3599 previously saved state.
3601 info checkpoints List currently saved checkpoints.
3603 delete-checkpoint <n> Delete a previously saved checkpoint.
3605 set|show detach-on-fork Tell gdb whether to detach from a newly
3606 forked process, or to keep debugging it.
3608 info forks List forks of the user program that
3609 are available to be debugged.
3611 fork <n> Switch to debugging one of several
3612 forks of the user program that are
3613 available to be debugged.
3615 delete-fork <n> Delete a fork from the list of forks
3616 that are available to be debugged (and
3617 kill the forked process).
3619 detach-fork <n> Delete a fork from the list of forks
3620 that are available to be debugged (and
3621 allow the process to continue).
3625 Morpho Technologies ms2 ms1-elf
3627 * Improved Windows host support
3629 GDB now builds as a cross debugger hosted on i686-mingw32, including
3630 native console support, and remote communications using either
3631 network sockets or serial ports.
3633 * Improved Modula-2 language support
3635 GDB can now print most types in the Modula-2 syntax. This includes:
3636 basic types, set types, record types, enumerated types, range types,
3637 pointer types and ARRAY types. Procedure var parameters are correctly
3638 printed and hexadecimal addresses and character constants are also
3639 written in the Modula-2 syntax. Best results can be obtained by using
3640 GNU Modula-2 together with the -gdwarf-2 command line option.
3644 The ARM rdi-share module.
3646 The Netware NLM debug server.
3648 *** Changes in GDB 6.4
3650 * New native configurations
3652 OpenBSD/arm arm*-*-openbsd*
3653 OpenBSD/mips64 mips64-*-openbsd*
3657 Morpho Technologies ms1 ms1-elf
3659 * New command line options
3661 --batch-silent As for --batch, but totally silent.
3662 --return-child-result The debugger will exist with the same value
3663 the child (debugged) program exited with.
3664 --eval-command COMMAND, -ex COMMAND
3665 Execute a single GDB CLI command. This may be
3666 specified multiple times and in conjunction
3667 with the --command (-x) option.
3669 * Deprecated commands removed
3671 The following commands, that were deprecated in 2000, have been
3675 set|show arm disassembly-flavor set|show arm disassembler
3676 othernames set arm disassembler
3677 set|show remotedebug set|show debug remote
3678 set|show archdebug set|show debug arch
3679 set|show eventdebug set|show debug event
3682 * New BSD user-level threads support
3684 It is now possible to debug programs using the user-level threads
3685 library on OpenBSD and FreeBSD. Currently supported (target)
3688 FreeBSD/amd64 x86_64-*-freebsd*
3689 FreeBSD/i386 i386-*-freebsd*
3690 OpenBSD/i386 i386-*-openbsd*
3692 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3693 are not yet supported.
3695 * New support for Matsushita MN10300 w/sim added
3696 (Work in progress). mn10300-elf.
3698 * REMOVED configurations and files
3700 VxWorks and the XDR protocol *-*-vxworks
3701 Motorola MCORE mcore-*-*
3702 National Semiconductor NS32000 ns32k-*-*
3704 * New "set print array-indexes" command
3706 After turning this setting "on", GDB prints the index of each element
3707 when displaying arrays. The default is "off" to preserve the previous
3710 * VAX floating point support
3712 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3714 * User-defined command support
3716 In addition to using $arg0..$arg9 for argument passing, it is now possible
3717 to use $argc to determine now many arguments have been passed. See the
3718 section on user-defined commands in the user manual for more information.
3720 *** Changes in GDB 6.3:
3722 * New command line option
3724 GDB now accepts -l followed by a number to set the timeout for remote
3727 * GDB works with GCC -feliminate-dwarf2-dups
3729 GDB now supports a more compact representation of DWARF-2 debug
3730 information using DW_FORM_ref_addr references. These are produced
3731 by GCC with the option -feliminate-dwarf2-dups and also by some
3732 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3733 to use -feliminate-dwarf2-dups.
3735 * Internationalization
3737 When supported by the host system, GDB will be built with
3738 internationalization (libintl). The task of marking up the sources is
3739 continued, we're looking forward to our first translation.
3743 Initial support for debugging programs compiled with the GNAT
3744 implementation of the Ada programming language has been integrated
3745 into GDB. In this release, support is limited to expression evaluation.
3747 * New native configurations
3749 GNU/Linux/m32r m32r-*-linux-gnu
3753 GDB's remote protocol now includes support for the 'p' packet. This
3754 packet is used to fetch individual registers from a remote inferior.
3756 * END-OF-LIFE registers[] compatibility module
3758 GDB's internal register infrastructure has been completely rewritten.
3759 The new infrastructure making possible the implementation of key new
3760 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3763 GDB 6.3 will be the last release to include the the registers[]
3764 compatibility module that allowed out-of-date configurations to
3765 continue to work. This change directly impacts the following
3775 powerpc bdm protocol
3777 Unless there is activity to revive these configurations, they will be
3778 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3780 * OBSOLETE configurations and files
3782 Configurations that have been declared obsolete in this release have
3783 been commented out. Unless there is activity to revive these
3784 configurations, the next release of GDB will have their sources
3785 permanently REMOVED.
3794 *** Changes in GDB 6.2.1:
3796 * MIPS `break main; run' gave an heuristic-fence-post warning
3798 When attempting to run even a simple program, a warning about
3799 heuristic-fence-post being hit would be reported. This problem has
3802 * MIPS IRIX 'long double' crashed GDB
3804 When examining a long double variable, GDB would get a segmentation
3805 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3806 IRIX long double values).
3810 A bug in the VAX stack code was causing problems with the "next"
3811 command. This problem has been fixed.
3813 *** Changes in GDB 6.2:
3815 * Fix for ``many threads''
3817 On GNU/Linux systems that use the NPTL threads library, a program
3818 rapidly creating and deleting threads would confuse GDB leading to the
3821 ptrace: No such process.
3822 thread_db_get_info: cannot get thread info: generic error
3824 This problem has been fixed.
3826 * "-async" and "-noasync" options removed.
3828 Support for the broken "-noasync" option has been removed (it caused
3831 * New ``start'' command.
3833 This command runs the program until the begining of the main procedure.
3835 * New BSD Kernel Data Access Library (libkvm) interface
3837 Using ``target kvm'' it is now possible to debug kernel core dumps and
3838 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3839 platforms. Currently supported (native-only) configurations are:
3841 FreeBSD/amd64 x86_64-*-freebsd*
3842 FreeBSD/i386 i?86-*-freebsd*
3843 NetBSD/i386 i?86-*-netbsd*
3844 NetBSD/m68k m68*-*-netbsd*
3845 NetBSD/sparc sparc-*-netbsd*
3846 OpenBSD/amd64 x86_64-*-openbsd*
3847 OpenBSD/i386 i?86-*-openbsd*
3848 OpenBSD/m68k m68*-openbsd*
3849 OpenBSD/sparc sparc-*-openbsd*
3851 * Signal trampoline code overhauled
3853 Many generic problems with GDB's signal handling code have been fixed.
3854 These include: backtraces through non-contiguous stacks; recognition
3855 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3856 call; backtrace through a signal trampoline; step into and out of
3857 signal handlers; and single-stepping in the signal trampoline.
3859 Please note that kernel bugs are a limiting factor here. These
3860 features have been shown to work on an s390 GNU/Linux system that
3861 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3863 * Cygwin support for DWARF 2 added.
3865 * New native configurations
3867 GNU/Linux/hppa hppa*-*-linux*
3868 OpenBSD/hppa hppa*-*-openbsd*
3869 OpenBSD/m68k m68*-*-openbsd*
3870 OpenBSD/m88k m88*-*-openbsd*
3871 OpenBSD/powerpc powerpc-*-openbsd*
3872 NetBSD/vax vax-*-netbsd*
3873 OpenBSD/vax vax-*-openbsd*
3875 * END-OF-LIFE frame compatibility module
3877 GDB's internal frame infrastructure has been completely rewritten.
3878 The new infrastructure making it possible to support key new features
3879 including DWARF 2 Call Frame Information. To aid in the task of
3880 migrating old configurations to this new infrastructure, a
3881 compatibility module, that allowed old configurations to continue to
3882 work, was also included.
3884 GDB 6.2 will be the last release to include this frame compatibility
3885 module. This change directly impacts the following configurations:
3895 Unless there is activity to revive these configurations, they will be
3896 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3898 * REMOVED configurations and files
3900 Sun 3, running SunOS 3 m68*-*-sunos3*
3901 Sun 3, running SunOS 4 m68*-*-sunos4*
3902 Sun 2, running SunOS 3 m68000-*-sunos3*
3903 Sun 2, running SunOS 4 m68000-*-sunos4*
3904 Motorola 680x0 running LynxOS m68*-*-lynxos*
3905 AT&T 3b1/Unix pc m68*-att-*
3906 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3907 decstation mips-dec-* mips-little-*
3908 riscos mips-*-riscos* mips-*-sysv*
3909 sonymips mips-sony-*
3910 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3912 *** Changes in GDB 6.1.1:
3914 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3916 The TUI (Text-mode User Interface) is now built as part of a default
3917 GDB configuration. It is enabled by either selecting the TUI with the
3918 command line option "-i=tui" or by running the separate "gdbtui"
3919 program. For more information on the TUI, see the manual "Debugging
3922 * Pending breakpoint support (also included in GDB 6.1)
3924 Support has been added to allow you to specify breakpoints in shared
3925 libraries that have not yet been loaded. If a breakpoint location
3926 cannot be found, and the "breakpoint pending" option is set to auto,
3927 GDB queries you if you wish to make the breakpoint pending on a future
3928 shared-library load. If and when GDB resolves the breakpoint symbol,
3929 the pending breakpoint is removed as one or more regular breakpoints
3932 Pending breakpoints are very useful for GCJ Java debugging.
3934 * Fixed ISO-C build problems
3936 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3937 non ISO-C code that stopped them being built using a more strict ISO-C
3938 compiler (e.g., IBM's C compiler).
3940 * Fixed build problem on IRIX 5
3942 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3943 wasn't able to compile compile on an IRIX 5 system.
3945 * Added execute permission to gdb/gdbserver/configure
3947 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3948 permission. This bug would cause configure to fail on a number of
3949 systems (Solaris, IRIX). Ref: server/519.
3951 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3953 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3954 has been updated to use constant array sizes.
3956 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3958 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3959 its generated DWARF Call Frame Info. This encoding was causing GDB to
3960 panic, that panic has been fixed. Ref: gdb/1628.
3962 * Fixed a problem when examining parameters in shared library code.
3964 When examining parameters in optimized shared library code generated
3965 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3966 not available''. GDB now correctly displays the variable's value.
3968 *** Changes in GDB 6.1:
3970 * Removed --with-mmalloc
3972 Support for the mmalloc memory manager has been removed, as it
3973 conflicted with the internal gdb byte cache.
3975 * Changes in AMD64 configurations
3977 The AMD64 target now includes the %cs and %ss registers. As a result
3978 the AMD64 remote protocol has changed; this affects the floating-point
3979 and SSE registers. If you rely on those registers for your debugging,
3980 you should upgrade gdbserver on the remote side.
3982 * Revised SPARC target
3984 The SPARC target has been completely revised, incorporating the
3985 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3986 support for LynxOS and SunOS 4 has been dropped. Calling functions
3987 from within GDB on operating systems with a non-executable stack
3988 (Solaris, OpenBSD) now works.
3992 GDB has a new C++ demangler which does a better job on the mangled
3993 names generated by current versions of g++. It also runs faster, so
3994 with this and other changes gdb should now start faster on large C++
3997 * DWARF 2 Location Expressions
3999 GDB support for location expressions has been extended to support function
4000 arguments and frame bases. Older versions of GDB could crash when they
4003 * C++ nested types and namespaces
4005 GDB's support for nested types and namespaces in C++ has been
4006 improved, especially if you use the DWARF 2 debugging format. (This
4007 is the default for recent versions of GCC on most platforms.)
4008 Specifically, if you have a class "Inner" defined within a class or
4009 namespace "Outer", then GDB realizes that the class's name is
4010 "Outer::Inner", not simply "Inner". This should greatly reduce the
4011 frequency of complaints about not finding RTTI symbols. In addition,
4012 if you are stopped at inside of a function defined within a namespace,
4013 GDB modifies its name lookup accordingly.
4015 * New native configurations
4017 NetBSD/amd64 x86_64-*-netbsd*
4018 OpenBSD/amd64 x86_64-*-openbsd*
4019 OpenBSD/alpha alpha*-*-openbsd*
4020 OpenBSD/sparc sparc-*-openbsd*
4021 OpenBSD/sparc64 sparc64-*-openbsd*
4023 * New debugging protocols
4025 M32R with SDI protocol m32r-*-elf*
4027 * "set prompt-escape-char" command deleted.
4029 The command "set prompt-escape-char" has been deleted. This command,
4030 and its very obscure effet on GDB's prompt, was never documented,
4031 tested, nor mentioned in the NEWS file.
4033 * OBSOLETE configurations and files
4035 Configurations that have been declared obsolete in this release have
4036 been commented out. Unless there is activity to revive these
4037 configurations, the next release of GDB will have their sources
4038 permanently REMOVED.
4040 Sun 3, running SunOS 3 m68*-*-sunos3*
4041 Sun 3, running SunOS 4 m68*-*-sunos4*
4042 Sun 2, running SunOS 3 m68000-*-sunos3*
4043 Sun 2, running SunOS 4 m68000-*-sunos4*
4044 Motorola 680x0 running LynxOS m68*-*-lynxos*
4045 AT&T 3b1/Unix pc m68*-att-*
4046 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4047 decstation mips-dec-* mips-little-*
4048 riscos mips-*-riscos* mips-*-sysv*
4049 sonymips mips-sony-*
4050 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4052 * REMOVED configurations and files
4054 SGI Irix-4.x mips-sgi-irix4 or iris4
4055 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4056 Z8000 simulator z8k-zilog-none or z8ksim
4057 Matsushita MN10200 w/simulator mn10200-*-*
4058 H8/500 simulator h8500-hitachi-hms or h8500hms
4059 HP/PA running BSD hppa*-*-bsd*
4060 HP/PA running OSF/1 hppa*-*-osf*
4061 HP/PA Pro target hppa*-*-pro*
4062 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4063 386BSD i[3456]86-*-bsd*
4064 Sequent family i[3456]86-sequent-sysv4*
4065 i[3456]86-sequent-sysv*
4066 i[3456]86-sequent-bsd*
4067 SPARC running LynxOS sparc-*-lynxos*
4068 SPARC running SunOS 4 sparc-*-sunos4*
4069 Tsqware Sparclet sparclet-*-*
4070 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4072 *** Changes in GDB 6.0:
4076 Support for debugging the Objective-C programming language has been
4077 integrated into GDB.
4079 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4081 DWARF 2's Call Frame Information makes available compiler generated
4082 information that more exactly describes the program's run-time stack.
4083 By using this information, GDB is able to provide more robust stack
4086 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4087 have been updated to use a new backtrace mechanism which includes
4088 DWARF 2 CFI support.
4092 GDB's remote protocol has been extended to include support for hosted
4093 file I/O (where the remote target uses GDB's file system). See GDB's
4094 remote protocol documentation for details.
4096 * All targets using the new architecture framework.
4098 All of GDB's targets have been updated to use the new internal
4099 architecture framework. The way is now open for future GDB releases
4100 to include cross-architecture native debugging support (i386 on amd64,
4103 * GNU/Linux's Thread Local Storage (TLS)
4105 GDB now includes support for for the GNU/Linux implementation of
4106 per-thread variables.
4108 * GNU/Linux's Native POSIX Thread Library (NPTL)
4110 GDB's thread code has been updated to work with either the new
4111 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4113 * Separate debug info.
4115 GDB, in conjunction with BINUTILS, now supports a mechanism for
4116 automatically loading debug information from a separate file. Instead
4117 of shipping full debug and non-debug versions of system libraries,
4118 system integrators can now instead ship just the stripped libraries
4119 and optional debug files.
4121 * DWARF 2 Location Expressions
4123 DWARF 2 Location Expressions allow the compiler to more completely
4124 describe the location of variables (even in optimized code) to the
4127 GDB now includes preliminary support for location expressions (support
4128 for DW_OP_piece is still missing).
4132 A number of long standing bugs that caused GDB to die while starting a
4133 Java application have been fixed. GDB's Java support is now
4134 considered "useable".
4136 * GNU/Linux support for fork, vfork, and exec.
4138 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4139 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4142 * GDB supports logging output to a file
4144 There are two new commands, "set logging" and "show logging", which can be
4145 used to capture GDB's output to a file.
4147 * The meaning of "detach" has changed for gdbserver
4149 The "detach" command will now resume the application, as documented. To
4150 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4153 * d10v, m68hc11 `regs' command deprecated
4155 The `info registers' command has been updated so that it displays the
4156 registers using a format identical to the old `regs' command.
4160 A new command, "maint set profile on/off", has been added. This command can
4161 be used to enable or disable profiling while running GDB, to profile a
4162 session or a set of commands. In addition there is a new configure switch,
4163 "--enable-profiling", which will cause GDB to be compiled with profiling
4164 data, for more informative profiling results.
4166 * Default MI syntax changed to "mi2".
4168 The default MI (machine interface) syntax, enabled by the command line
4169 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4170 "mi1", can be enabled by specifying the option "-i=mi1".
4172 Support for the original "mi0" syntax (included in GDB 5.0) has been
4175 Fix for gdb/192: removed extraneous space when displaying frame level.
4176 Fix for gdb/672: update changelist is now output in mi list format.
4177 Fix for gdb/702: a -var-assign that updates the value now shows up
4178 in a subsequent -var-update.
4180 * New native configurations.
4182 FreeBSD/amd64 x86_64-*-freebsd*
4184 * Multi-arched targets.
4186 HP/PA HPUX11 hppa*-*-hpux*
4187 Renesas M32R/D w/simulator m32r-*-elf*
4189 * OBSOLETE configurations and files
4191 Configurations that have been declared obsolete in this release have
4192 been commented out. Unless there is activity to revive these
4193 configurations, the next release of GDB will have their sources
4194 permanently REMOVED.
4196 Z8000 simulator z8k-zilog-none or z8ksim
4197 Matsushita MN10200 w/simulator mn10200-*-*
4198 H8/500 simulator h8500-hitachi-hms or h8500hms
4199 HP/PA running BSD hppa*-*-bsd*
4200 HP/PA running OSF/1 hppa*-*-osf*
4201 HP/PA Pro target hppa*-*-pro*
4202 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4203 Sequent family i[3456]86-sequent-sysv4*
4204 i[3456]86-sequent-sysv*
4205 i[3456]86-sequent-bsd*
4206 Tsqware Sparclet sparclet-*-*
4207 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4209 * REMOVED configurations and files
4212 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4213 IBM AIX PS/2 i[3456]86-*-aix
4214 i386 running Mach 3.0 i[3456]86-*-mach3*
4215 i386 running Mach i[3456]86-*-mach*
4216 i386 running OSF/1 i[3456]86-*osf1mk*
4217 HP/Apollo 68k Family m68*-apollo*-sysv*,
4219 m68*-hp-bsd*, m68*-hp-hpux*
4220 Argonaut Risc Chip (ARC) arc-*-*
4221 Mitsubishi D30V d30v-*-*
4222 Fujitsu FR30 fr30-*-elf*
4223 OS/9000 i[34]86-*-os9k
4224 I960 with MON960 i960-*-coff
4226 * MIPS $fp behavior changed
4228 The convenience variable $fp, for the MIPS, now consistently returns
4229 the address of the current frame's base. Previously, depending on the
4230 context, $fp could refer to either $sp or the current frame's base
4231 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4232 The GNU Source-Level Debugger''.
4234 *** Changes in GDB 5.3:
4236 * GNU/Linux shared library multi-threaded performance improved.
4238 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4239 `/proc', in preference to `ptrace' for memory reads. This may result
4240 in an improvement in the start-up time of multi-threaded, shared
4241 library applications when run under GDB. One GDB user writes: ``loads
4242 shared libs like mad''.
4244 * ``gdbserver'' now supports multi-threaded applications on some targets
4246 Support for debugging multi-threaded applications which use
4247 the GNU/Linux LinuxThreads package has been added for
4248 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4249 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4251 * GDB now supports C/C++ preprocessor macros.
4253 GDB now expands preprocessor macro invocations in C/C++ expressions,
4254 and provides various commands for showing macro definitions and how
4257 The new command `macro expand EXPRESSION' expands any macro
4258 invocations in expression, and shows the result.
4260 The new command `show macro MACRO-NAME' shows the definition of the
4261 macro named MACRO-NAME, and where it was defined.
4263 Most compilers don't include information about macros in the debugging
4264 information by default. In GCC 3.1, for example, you need to compile
4265 your program with the options `-gdwarf-2 -g3'. If the macro
4266 information is present in the executable, GDB will read it.
4268 * Multi-arched targets.
4270 DEC Alpha (partial) alpha*-*-*
4271 DEC VAX (partial) vax-*-*
4273 National Semiconductor NS32000 (partial) ns32k-*-*
4274 Motorola 68000 (partial) m68k-*-*
4275 Motorola MCORE mcore-*-*
4279 Fujitsu FRV architecture added by Red Hat frv*-*-*
4282 * New native configurations
4284 Alpha NetBSD alpha*-*-netbsd*
4285 SH NetBSD sh*-*-netbsdelf*
4286 MIPS NetBSD mips*-*-netbsd*
4287 UltraSPARC NetBSD sparc64-*-netbsd*
4289 * OBSOLETE configurations and files
4291 Configurations that have been declared obsolete in this release have
4292 been commented out. Unless there is activity to revive these
4293 configurations, the next release of GDB will have their sources
4294 permanently REMOVED.
4296 Mitsubishi D30V d30v-*-*
4297 OS/9000 i[34]86-*-os9k
4298 IBM AIX PS/2 i[3456]86-*-aix
4299 Fujitsu FR30 fr30-*-elf*
4300 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4301 Argonaut Risc Chip (ARC) arc-*-*
4302 i386 running Mach 3.0 i[3456]86-*-mach3*
4303 i386 running Mach i[3456]86-*-mach*
4304 i386 running OSF/1 i[3456]86-*osf1mk*
4305 HP/Apollo 68k Family m68*-apollo*-sysv*,
4307 m68*-hp-bsd*, m68*-hp-hpux*
4308 I960 with MON960 i960-*-coff
4310 * OBSOLETE languages
4312 CHILL, a Pascal like language used by telecommunications companies.
4314 * REMOVED configurations and files
4316 AMD 29k family via UDI a29k-amd-udi, udi29k
4317 A29K VxWorks a29k-*-vxworks
4318 AMD 29000 embedded, using EBMON a29k-none-none
4319 AMD 29000 embedded with COFF a29k-none-coff
4320 AMD 29000 embedded with a.out a29k-none-aout
4322 testsuite/gdb.hp/gdb.threads-hp/ directory
4324 * New command "set max-user-call-depth <nnn>"
4326 This command allows the user to limit the call depth of user-defined
4327 commands. The default is 1024.
4329 * Changes in FreeBSD/i386 native debugging.
4331 Support for the "generate-core-file" has been added.
4333 * New commands "dump", "append", and "restore".
4335 These commands allow data to be copied from target memory
4336 to a bfd-format or binary file (dump and append), and back
4337 from a file into memory (restore).
4339 * Improved "next/step" support on multi-processor Alpha Tru64.
4341 The previous single-step mechanism could cause unpredictable problems,
4342 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4343 of a software single-step mechanism prevents this.
4345 *** Changes in GDB 5.2.1:
4353 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4354 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4355 Fix, by Joel Brobecker imported from mainline.
4357 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4358 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4359 Fix, by Fred Fish, imported from mainline.
4361 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4362 Surprisingly enough, it works now.
4363 By Michal Ludvig, imported from mainline.
4365 i386 hardware watchpoint support:
4366 avoid misses on second run for some targets.
4367 By Pierre Muller, imported from mainline.
4369 *** Changes in GDB 5.2:
4371 * New command "set trust-readonly-sections on[off]".
4373 This command is a hint that tells gdb that read-only sections
4374 really are read-only (ie. that their contents will not change).
4375 In this mode, gdb will go to the object file rather than the
4376 target to read memory from read-only sections (such as ".text").
4377 This can be a significant performance improvement on some
4378 (notably embedded) targets.
4380 * New command "generate-core-file" (or "gcore").
4382 This new gdb command allows the user to drop a core file of the child
4383 process state at any time. So far it's been implemented only for
4384 GNU/Linux and Solaris, but should be relatively easily ported to other
4385 hosts. Argument is core file name (defaults to core.<pid>).
4387 * New command line option
4389 GDB now accepts --pid or -p followed by a process id.
4391 * Change in command line behavior -- corefiles vs. process ids.
4393 There is a subtle behavior in the way in which GDB handles
4394 command line arguments. The first non-flag argument is always
4395 a program to debug, but the second non-flag argument may either
4396 be a corefile or a process id. Previously, GDB would attempt to
4397 open the second argument as a corefile, and if that failed, would
4398 issue a superfluous error message and then attempt to attach it as
4399 a process. Now, if the second argument begins with a non-digit,
4400 it will be treated as a corefile. If it begins with a digit,
4401 GDB will attempt to attach it as a process, and if no such process
4402 is found, will then attempt to open it as a corefile.
4404 * Changes in ARM configurations.
4406 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4407 configuration is fully multi-arch.
4409 * New native configurations
4411 ARM NetBSD arm*-*-netbsd*
4412 x86 OpenBSD i[3456]86-*-openbsd*
4413 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4414 Sparc64 running FreeBSD sparc64-*-freebsd*
4418 Sanyo XStormy16 xstormy16-elf
4420 * OBSOLETE configurations and files
4422 Configurations that have been declared obsolete in this release have
4423 been commented out. Unless there is activity to revive these
4424 configurations, the next release of GDB will have their sources
4425 permanently REMOVED.
4427 AMD 29k family via UDI a29k-amd-udi, udi29k
4428 A29K VxWorks a29k-*-vxworks
4429 AMD 29000 embedded, using EBMON a29k-none-none
4430 AMD 29000 embedded with COFF a29k-none-coff
4431 AMD 29000 embedded with a.out a29k-none-aout
4433 testsuite/gdb.hp/gdb.threads-hp/ directory
4435 * REMOVED configurations and files
4437 TI TMS320C80 tic80-*-*
4439 PowerPC Solaris powerpcle-*-solaris*
4440 PowerPC Windows NT powerpcle-*-cygwin32
4441 PowerPC Netware powerpc-*-netware*
4442 Harris/CXUX m88k m88*-harris-cxux*
4443 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4444 ns32k-utek-sysv* ns32k-utek-*
4445 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4446 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4447 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4448 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4449 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4451 * Changes to command line processing
4453 The new `--args' feature can be used to specify command-line arguments
4454 for the inferior from gdb's command line.
4456 * Changes to key bindings
4458 There is a new `operate-and-get-next' function bound to `C-o'.
4460 *** Changes in GDB 5.1.1
4462 Fix compile problem on DJGPP.
4464 Fix a problem with floating-point registers on the i386 being
4467 Fix to stop GDB crashing on .debug_str debug info.
4469 Numerous documentation fixes.
4471 Numerous testsuite fixes.
4473 *** Changes in GDB 5.1:
4475 * New native configurations
4477 Alpha FreeBSD alpha*-*-freebsd*
4478 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4479 MIPS GNU/Linux mips*-*-linux*
4480 MIPS SGI Irix 6.x mips*-sgi-irix6*
4481 ia64 AIX ia64-*-aix*
4482 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4486 Motorola 68HC11 and 68HC12 m68hc11-elf
4488 UltraSparc running GNU/Linux sparc64-*-linux*
4490 * OBSOLETE configurations and files
4492 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4493 Harris/CXUX m88k m88*-harris-cxux*
4494 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4495 ns32k-utek-sysv* ns32k-utek-*
4496 TI TMS320C80 tic80-*-*
4498 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4499 PowerPC Solaris powerpcle-*-solaris*
4500 PowerPC Windows NT powerpcle-*-cygwin32
4501 PowerPC Netware powerpc-*-netware*
4502 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4503 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4504 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4505 Apple Macintosh (MPW) host N/A
4507 stuff.c (Program to stuff files into a specially prepared space in kdb)
4508 kdb-start.c (Main loop for the standalone kernel debugger)
4510 Configurations that have been declared obsolete in this release have
4511 been commented out. Unless there is activity to revive these
4512 configurations, the next release of GDB will have their sources
4513 permanently REMOVED.
4515 * REMOVED configurations and files
4517 Altos 3068 m68*-altos-*
4518 Convex c1-*-*, c2-*-*
4520 ARM RISCix arm-*-* (as host)
4524 * GDB has been converted to ISO C.
4526 GDB's source code has been converted to ISO C. In particular, the
4527 sources are fully protoized, and rely on standard headers being
4532 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4534 * The MI enabled by default.
4536 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4537 revised and enabled by default. Packages which use GDB as a debugging
4538 engine behind a UI or another front end are encouraged to switch to
4539 using the GDB/MI interface, instead of the old annotations interface
4540 which is now deprecated.
4542 * Support for debugging Pascal programs.
4544 GDB now includes support for debugging Pascal programs. The following
4545 main features are supported:
4547 - Pascal-specific data types such as sets;
4549 - automatic recognition of Pascal sources based on file-name
4552 - Pascal-style display of data types, variables, and functions;
4554 - a Pascal expression parser.
4556 However, some important features are not yet supported.
4558 - Pascal string operations are not supported at all;
4560 - there are some problems with boolean types;
4562 - Pascal type hexadecimal constants are not supported
4563 because they conflict with the internal variables format;
4565 - support for Pascal objects and classes is not full yet;
4567 - unlike Pascal, GDB is case-sensitive for symbol names.
4569 * Changes in completion.
4571 Commands such as `shell', `run' and `set args', which pass arguments
4572 to inferior programs, now complete on file names, similar to what
4573 users expect at the shell prompt.
4575 Commands which accept locations, such as `disassemble', `print',
4576 `breakpoint', `until', etc. now complete on filenames as well as
4577 program symbols. Thus, if you type "break foob TAB", and the source
4578 files linked into the programs include `foobar.c', that file name will
4579 be one of the candidates for completion. However, file names are not
4580 considered for completion after you typed a colon that delimits a file
4581 name from a name of a function in that file, as in "break foo.c:bar".
4583 `set demangle-style' completes on available demangling styles.
4585 * New platform-independent commands:
4587 It is now possible to define a post-hook for a command as well as a
4588 hook that runs before the command. For more details, see the
4589 documentation of `hookpost' in the GDB manual.
4591 * Changes in GNU/Linux native debugging.
4593 Support for debugging multi-threaded programs has been completely
4594 revised for all platforms except m68k and sparc. You can now debug as
4595 many threads as your system allows you to have.
4597 Attach/detach is supported for multi-threaded programs.
4599 Support for SSE registers was added for x86. This doesn't work for
4600 multi-threaded programs though.
4602 * Changes in MIPS configurations.
4604 Multi-arch support is enabled for all MIPS configurations.
4606 GDB can now be built as native debugger on SGI Irix 6.x systems for
4607 debugging n32 executables. (Debugging 64-bit executables is not yet
4610 * Unified support for hardware watchpoints in all x86 configurations.
4612 Most (if not all) native x86 configurations support hardware-assisted
4613 breakpoints and watchpoints in a unified manner. This support
4614 implements debug register sharing between watchpoints, which allows to
4615 put a virtually infinite number of watchpoints on the same address,
4616 and also supports watching regions up to 16 bytes with several debug
4619 The new maintenance command `maintenance show-debug-regs' toggles
4620 debugging print-outs in functions that insert, remove, and test
4621 watchpoints and hardware breakpoints.
4623 * Changes in the DJGPP native configuration.
4625 New command ``info dos sysinfo'' displays assorted information about
4626 the CPU, OS, memory, and DPMI server.
4628 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4629 display information about segment descriptors stored in GDT, LDT, and
4632 New commands ``info dos pde'' and ``info dos pte'' display entries
4633 from Page Directory and Page Tables (for now works with CWSDPMI only).
4634 New command ``info dos address-pte'' displays the Page Table entry for
4635 a given linear address.
4637 GDB can now pass command lines longer than 126 characters to the
4638 program being debugged (requires an update to the libdbg.a library
4639 which is part of the DJGPP development kit).
4641 DWARF2 debug info is now supported.
4643 It is now possible to `step' and `next' through calls to `longjmp'.
4645 * Changes in documentation.
4647 All GDB documentation was converted to GFDL, the GNU Free
4648 Documentation License.
4650 Tracepoints-related commands are now fully documented in the GDB
4653 TUI, the Text-mode User Interface, is now documented in the manual.
4655 Tracepoints-related commands are now fully documented in the GDB
4658 The "GDB Internals" manual now has an index. It also includes
4659 documentation of `ui_out' functions, GDB coding standards, x86
4660 hardware watchpoints, and memory region attributes.
4662 * GDB's version number moved to ``version.in''
4664 The Makefile variable VERSION has been replaced by the file
4665 ``version.in''. People creating GDB distributions should update the
4666 contents of this file.
4670 GUD support is now a standard part of the EMACS distribution.
4672 *** Changes in GDB 5.0:
4674 * Improved support for debugging FP programs on x86 targets
4676 Unified and much-improved support for debugging floating-point
4677 programs on all x86 targets. In particular, ``info float'' now
4678 displays the FP registers in the same format on all x86 targets, with
4679 greater level of detail.
4681 * Improvements and bugfixes in hardware-assisted watchpoints
4683 It is now possible to watch array elements, struct members, and
4684 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4685 on x86 targets no longer erroneously trigger when the address is
4688 * Improvements in the native DJGPP version of GDB
4690 The distribution now includes all the scripts and auxiliary files
4691 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4692 machines ``out of the box''.
4694 The DJGPP version can now debug programs that use signals. It is
4695 possible to catch signals that happened in the debuggee, deliver
4696 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4697 would kill the program being debugged.) Programs that hook hardware
4698 interrupts (keyboard, timer, etc.) can also be debugged.
4700 It is now possible to debug DJGPP programs that redirect their
4701 standard handles or switch them to raw (as opposed to cooked) mode, or
4702 even close them. The command ``run < foo > bar'' works as expected,
4703 and ``info terminal'' reports useful information about the debuggee's
4704 terminal, including raw/cooked mode, redirection, etc.
4706 The DJGPP version now uses termios functions for console I/O, which
4707 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4710 DOS-style file names with drive letters are now fully supported by
4713 It is now possible to debug DJGPP programs that switch their working
4714 directory. It is also possible to rerun the debuggee any number of
4715 times without restarting GDB; thus, you can use the same setup,
4716 breakpoints, etc. for many debugging sessions.
4718 * New native configurations
4720 ARM GNU/Linux arm*-*-linux*
4721 PowerPC GNU/Linux powerpc-*-linux*
4725 Motorola MCore mcore-*-*
4726 x86 VxWorks i[3456]86-*-vxworks*
4727 PowerPC VxWorks powerpc-*-vxworks*
4728 TI TMS320C80 tic80-*-*
4730 * OBSOLETE configurations
4732 Altos 3068 m68*-altos-*
4733 Convex c1-*-*, c2-*-*
4735 ARM RISCix arm-*-* (as host)
4738 Configurations that have been declared obsolete will be commented out,
4739 but the code will be left in place. If there is no activity to revive
4740 these configurations before the next release of GDB, the sources will
4741 be permanently REMOVED.
4743 * Gould support removed
4745 Support for the Gould PowerNode and NP1 has been removed.
4747 * New features for SVR4
4749 On SVR4 native platforms (such as Solaris), if you attach to a process
4750 without first loading a symbol file, GDB will now attempt to locate and
4751 load symbols from the running process's executable file.
4753 * Many C++ enhancements
4755 C++ support has been greatly improved. Overload resolution now works properly
4756 in almost all cases. RTTI support is on the way.
4758 * Remote targets can connect to a sub-program
4760 A popen(3) style serial-device has been added. This device starts a
4761 sub-process (such as a stand-alone simulator) and then communicates
4762 with that. The sub-program to run is specified using the syntax
4763 ``|<program> <args>'' vis:
4765 (gdb) set remotedebug 1
4766 (gdb) target extended-remote |mn10300-elf-sim program-args
4768 * MIPS 64 remote protocol
4770 A long standing bug in the mips64 remote protocol where by GDB
4771 expected certain 32 bit registers (ex SR) to be transfered as 32
4772 instead of 64 bits has been fixed.
4774 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4775 added to provide backward compatibility with older versions of GDB.
4777 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4779 The command ``set remotebinarydownload'' command has been replaced by
4780 ``set remote X-packet''. Other commands in ``set remote'' family
4781 include ``set remote P-packet''.
4783 * Breakpoint commands accept ranges.
4785 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4786 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4787 ``tracepoint passcount'' also accepts a range of tracepoints.
4789 * ``apropos'' command added.
4791 The ``apropos'' command searches through command names and
4792 documentation strings, printing out matches, making it much easier to
4793 try to find a command that does what you are looking for.
4797 A new machine oriented interface (MI) has been added to GDB. This
4798 interface is designed for debug environments running GDB as a separate
4799 process. This is part of the long term libGDB project. See the
4800 "GDB/MI" chapter of the GDB manual for further information. It can be
4801 enabled by configuring with:
4803 .../configure --enable-gdbmi
4805 *** Changes in GDB-4.18:
4807 * New native configurations
4809 HP-UX 10.20 hppa*-*-hpux10.20
4810 HP-UX 11.x hppa*-*-hpux11.0*
4811 M68K GNU/Linux m68*-*-linux*
4815 Fujitsu FR30 fr30-*-elf*
4816 Intel StrongARM strongarm-*-*
4817 Mitsubishi D30V d30v-*-*
4819 * OBSOLETE configurations
4821 Gould PowerNode, NP1 np1-*-*, pn-*-*
4823 Configurations that have been declared obsolete will be commented out,
4824 but the code will be left in place. If there is no activity to revive
4825 these configurations before the next release of GDB, the sources will
4826 be permanently REMOVED.
4830 As a compatibility experiment, GDB's source files buildsym.h and
4831 buildsym.c have been converted to pure standard C, no longer
4832 containing any K&R compatibility code. We believe that all systems in
4833 use today either come with a standard C compiler, or have a GCC port
4834 available. If this is not true, please report the affected
4835 configuration to bug-gdb@gnu.org immediately. See the README file for
4836 information about getting a standard C compiler if you don't have one
4841 GDB now uses readline 2.2.
4843 * set extension-language
4845 You can now control the mapping between filename extensions and source
4846 languages by using the `set extension-language' command. For instance,
4847 you can ask GDB to treat .c files as C++ by saying
4848 set extension-language .c c++
4849 The command `info extensions' lists all of the recognized extensions
4850 and their associated languages.
4852 * Setting processor type for PowerPC and RS/6000
4854 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4855 you can use the `set processor' command to specify what variant of the
4856 PowerPC family you are debugging. The command
4860 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4861 following PowerPC and RS6000 variants:
4863 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4864 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4866 403GC IBM PowerPC 403GC
4867 505 Motorola PowerPC 505
4868 860 Motorola PowerPC 860 or 850
4869 601 Motorola PowerPC 601
4870 602 Motorola PowerPC 602
4871 603 Motorola/IBM PowerPC 603 or 603e
4872 604 Motorola PowerPC 604 or 604e
4873 750 Motorola/IBM PowerPC 750 or 750
4875 At the moment, this command just tells GDB what to name the
4876 special-purpose processor registers. Since almost all the affected
4877 registers are inaccessible to user-level programs, this command is
4878 only useful for remote debugging in its present form.
4882 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4883 more extensive support for HP-UX. Added features include shared
4884 library support, kernel threads and hardware watchpoints for 11.00,
4885 support for HP's ANSI C and C++ compilers, and a compatibility mode
4886 for xdb and dbx commands.
4890 HP's donation includes the new concept of catchpoints, which is a
4891 generalization of the old catch command. On HP-UX, it is now possible
4892 to catch exec, fork, and vfork, as well as library loading.
4894 This means that the existing catch command has changed; its first
4895 argument now specifies the type of catch to be set up. See the
4896 output of "help catch" for a list of catchpoint types.
4898 * Debugging across forks
4900 On HP-UX, you can choose which process to debug when a fork() happens
4905 HP has donated a curses-based terminal user interface (TUI). To get
4906 it, build with --enable-tui. Although this can be enabled for any
4907 configuration, at present it only works for native HP debugging.
4909 * GDB remote protocol additions
4911 A new protocol packet 'X' that writes binary data is now available.
4912 Default behavior is to try 'X', then drop back to 'M' if the stub
4913 fails to respond. The settable variable `remotebinarydownload'
4914 allows explicit control over the use of 'X'.
4916 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4917 full 64-bit address. The command
4919 set remoteaddresssize 32
4921 can be used to revert to the old behaviour. For existing remote stubs
4922 the change should not be noticed, as the additional address information
4925 In order to assist in debugging stubs, you may use the maintenance
4926 command `packet' to send any text string to the stub. For instance,
4928 maint packet heythere
4930 sends the packet "$heythere#<checksum>". Note that it is very easy to
4931 disrupt a debugging session by sending the wrong packet at the wrong
4934 The compare-sections command allows you to compare section data on the
4935 target to what is in the executable file without uploading or
4936 downloading, by comparing CRC checksums.
4938 * Tracing can collect general expressions
4940 You may now collect general expressions at tracepoints. This requires
4941 further additions to the target-side stub; see tracepoint.c and
4942 doc/agentexpr.texi for further details.
4944 * mask-address variable for Mips
4946 For Mips targets, you may control the zeroing of the upper 32 bits of
4947 a 64-bit address by entering `set mask-address on'. This is mainly
4948 of interest to users of embedded R4xxx and R5xxx processors.
4950 * Higher serial baud rates
4952 GDB's serial code now allows you to specify baud rates 57600, 115200,
4953 230400, and 460800 baud. (Note that your host system may not be able
4954 to achieve all of these rates.)
4958 The i960 configuration now includes an initial implementation of a
4959 builtin simulator, contributed by Jim Wilson.
4962 *** Changes in GDB-4.17:
4964 * New native configurations
4966 Alpha GNU/Linux alpha*-*-linux*
4967 Unixware 2.x i[3456]86-unixware2*
4968 Irix 6.x mips*-sgi-irix6*
4969 PowerPC GNU/Linux powerpc-*-linux*
4970 PowerPC Solaris powerpcle-*-solaris*
4971 Sparc GNU/Linux sparc-*-linux*
4972 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4976 Argonaut Risc Chip (ARC) arc-*-*
4977 Hitachi H8/300S h8300*-*-*
4978 Matsushita MN10200 w/simulator mn10200-*-*
4979 Matsushita MN10300 w/simulator mn10300-*-*
4980 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4981 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4982 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4983 Mitsubishi D10V w/simulator d10v-*-*
4984 Mitsubishi M32R/D w/simulator m32r-*-elf*
4985 Tsqware Sparclet sparclet-*-*
4986 NEC V850 w/simulator v850-*-*
4988 * New debugging protocols
4990 ARM with RDI protocol arm*-*-*
4991 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4992 DDB and LSI variants of PMON protocol mips*-*-*
4993 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4994 PowerPC with SDS protocol powerpc{,le}-*-eabi
4995 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4999 All configurations can now understand and use the DWARF 2 debugging
5000 format. The choice is automatic, if the symbol file contains DWARF 2
5005 GDB now includes basic Java language support. This support is
5006 only useful with Java compilers that produce native machine code.
5008 * solib-absolute-prefix and solib-search-path
5010 For SunOS and SVR4 shared libraries, you may now set the prefix for
5011 loading absolute shared library symbol files, and the search path for
5012 locating non-absolute shared library symbol files.
5014 * Live range splitting
5016 GDB can now effectively debug code for which GCC has performed live
5017 range splitting as part of its optimization. See gdb/doc/LRS for
5018 more details on the expected format of the stabs information.
5022 GDB's support for the GNU Hurd, including thread debugging, has been
5023 updated to work with current versions of the Hurd.
5027 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5028 instruction set. ARM GDB automatically detects when Thumb
5029 instructions are in use, and adjusts disassembly and backtracing
5034 GDB's MIPS target configurations now handle the MIP16 16-bit
5039 GDB now includes support for overlays; if an executable has been
5040 linked such that multiple sections are based at the same address, GDB
5041 will decide which section to use for symbolic info. You can choose to
5042 control the decision manually, using overlay commands, or implement
5043 additional target-side support and use "overlay load-target" to bring
5044 in the overlay mapping. Do "help overlay" for more detail.
5048 The command "info symbol <address>" displays information about
5049 the symbol at the specified address.
5053 The standard remote protocol now includes an extension that allows
5054 asynchronous collection and display of trace data. This requires
5055 extensive support in the target-side debugging stub. Tracing mode
5056 includes a new interaction mode in GDB and new commands: see the
5057 file tracepoint.c for more details.
5061 Configurations for embedded MIPS now include a simulator contributed
5062 by Cygnus Solutions. The simulator supports the instruction sets
5063 of most MIPS variants.
5067 Sparc configurations may now include the ERC32 simulator contributed
5068 by the European Space Agency. The simulator is not built into
5069 Sparc targets by default; configure with --enable-sim to include it.
5073 For target configurations that may include multiple variants of a
5074 basic architecture (such as MIPS and SH), you may now set the
5075 architecture explicitly. "set arch" sets, "info arch" lists
5076 the possible architectures.
5078 *** Changes in GDB-4.16:
5080 * New native configurations
5082 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5083 M68K NetBSD m68k-*-netbsd*
5084 PowerPC AIX 4.x powerpc-*-aix*
5085 PowerPC MacOS powerpc-*-macos*
5086 PowerPC Windows NT powerpcle-*-cygwin32
5087 RS/6000 AIX 4.x rs6000-*-aix4*
5091 ARM with RDP protocol arm-*-*
5092 I960 with MON960 i960-*-coff
5093 MIPS VxWorks mips*-*-vxworks*
5094 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5095 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5097 Matra Sparclet sparclet-*-*
5101 The powerpc-eabi configuration now includes the PSIM simulator,
5102 contributed by Andrew Cagney, with assistance from Mike Meissner.
5103 PSIM is a very elaborate model of the PowerPC, including not only
5104 basic instruction set execution, but also details of execution unit
5105 performance and I/O hardware. See sim/ppc/README for more details.
5109 GDB now works with Solaris 2.5.
5111 * Windows 95/NT native
5113 GDB will now work as a native debugger on Windows 95 and Windows NT.
5114 To build it from source, you must use the "gnu-win32" environment,
5115 which uses a DLL to emulate enough of Unix to run the GNU tools.
5116 Further information, binaries, and sources are available at
5117 ftp.cygnus.com, under pub/gnu-win32.
5119 * dont-repeat command
5121 If a user-defined command includes the command `dont-repeat', then the
5122 command will not be repeated if the user just types return. This is
5123 useful if the command is time-consuming to run, so that accidental
5124 extra keystrokes don't run the same command many times.
5126 * Send break instead of ^C
5128 The standard remote protocol now includes an option to send a break
5129 rather than a ^C to the target in order to interrupt it. By default,
5130 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5132 * Remote protocol timeout
5134 The standard remote protocol includes a new variable `remotetimeout'
5135 that allows you to set the number of seconds before GDB gives up trying
5136 to read from the target. The default value is 2.
5138 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5140 By default GDB will automatically keep track of objects as they are
5141 loaded and unloaded by the dynamic linker. By using the command `set
5142 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5143 when shared library events occur, thus allowing you to set breakpoints
5144 in shared libraries which are explicitly loaded by the inferior.
5146 Note this feature does not work on hpux8. On hpux9 you must link
5147 /usr/lib/end.o into your program. This feature should work
5148 automatically on hpux10.
5150 * Irix 5.x hardware watchpoint support
5152 Irix 5 configurations now support the use of hardware watchpoints.
5154 * Mips protocol "SYN garbage limit"
5156 When debugging a Mips target using the `target mips' protocol, you
5157 may set the number of characters that GDB will ignore by setting
5158 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5159 every character. The default value is 1050.
5161 * Recording and replaying remote debug sessions
5163 If you set `remotelogfile' to the name of a file, gdb will write to it
5164 a recording of a remote debug session. This recording may then be
5165 replayed back to gdb using "gdbreplay". See gdbserver/README for
5166 details. This is useful when you have a problem with GDB while doing
5167 remote debugging; you can make a recording of the session and send it
5168 to someone else, who can then recreate the problem.
5170 * Speedups for remote debugging
5172 GDB includes speedups for downloading and stepping MIPS systems using
5173 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5174 and more efficient S-record downloading.
5176 * Memory use reductions and statistics collection
5178 GDB now uses less memory and reports statistics about memory usage.
5179 Try the `maint print statistics' command, for example.
5181 *** Changes in GDB-4.15:
5183 * Psymtabs for XCOFF
5185 The symbol reader for AIX GDB now uses partial symbol tables. This
5186 can greatly improve startup time, especially for large executables.
5188 * Remote targets use caching
5190 Remote targets now use a data cache to speed up communication with the
5191 remote side. The data cache could lead to incorrect results because
5192 it doesn't know about volatile variables, thus making it impossible to
5193 debug targets which use memory mapped I/O devices. `set remotecache
5194 off' turns the the data cache off.
5196 * Remote targets may have threads
5198 The standard remote protocol now includes support for multiple threads
5199 in the target system, using new protocol commands 'H' and 'T'. See
5200 gdb/remote.c for details.
5204 If GDB is configured with `--enable-netrom', then it will include
5205 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5206 acts as though it is a bank of ROM on the target board, but you can
5207 write into it over the network. GDB's support consists only of
5208 support for fast loading into the emulated ROM; to debug, you must use
5209 another protocol, such as standard remote protocol. The usual
5210 sequence is something like
5212 target nrom <netrom-hostname>
5214 target remote <netrom-hostname>:1235
5218 GDB now includes support for the Apple Macintosh, as a host only. It
5219 may be run as either an MPW tool or as a standalone application, and
5220 it can debug through the serial port. All the usual GDB commands are
5221 available, but to the target command, you must supply "serial" as the
5222 device type instead of "/dev/ttyXX". See mpw-README in the main
5223 directory for more information on how to build. The MPW configuration
5224 scripts */mpw-config.in support only a few targets, and only the
5225 mips-idt-ecoff target has been tested.
5229 GDB configuration now uses autoconf. This is not user-visible,
5230 but does simplify configuration and building.
5234 GDB now supports hpux10.
5236 *** Changes in GDB-4.14:
5238 * New native configurations
5240 x86 FreeBSD i[345]86-*-freebsd
5241 x86 NetBSD i[345]86-*-netbsd
5242 NS32k NetBSD ns32k-*-netbsd
5243 Sparc NetBSD sparc-*-netbsd
5247 A29K VxWorks a29k-*-vxworks
5248 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5249 CPU32 EST-300 emulator m68*-*-est*
5250 PowerPC ELF powerpc-*-elf
5253 * Alpha OSF/1 support for procfs
5255 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5256 possible to attach to running processes. As the mounting of the /proc
5257 filesystem is optional on the Alpha, GDB automatically determines
5258 the availability of /proc during startup. This can lead to problems
5259 if /proc is unmounted after GDB has been started.
5261 * Arguments to user-defined commands
5263 User commands may accept up to 10 arguments separated by whitespace.
5264 Arguments are accessed within the user command via $arg0..$arg9. A
5267 print $arg0 + $arg1 + $arg2
5269 To execute the command use:
5272 Defines the command "adder" which prints the sum of its three arguments.
5273 Note the arguments are text substitutions, so they may reference variables,
5274 use complex expressions, or even perform inferior function calls.
5276 * New `if' and `while' commands
5278 This makes it possible to write more sophisticated user-defined
5279 commands. Both commands take a single argument, which is the
5280 expression to evaluate, and must be followed by the commands to
5281 execute, one per line, if the expression is nonzero, the list being
5282 terminated by the word `end'. The `if' command list may include an
5283 `else' word, which causes the following commands to be executed only
5284 if the expression is zero.
5286 * Fortran source language mode
5288 GDB now includes partial support for Fortran 77. It will recognize
5289 Fortran programs and can evaluate a subset of Fortran expressions, but
5290 variables and functions may not be handled correctly. GDB will work
5291 with G77, but does not yet know much about symbols emitted by other
5294 * Better HPUX support
5296 Most debugging facilities now work on dynamic executables for HPPAs
5297 running hpux9 or later. You can attach to running dynamically linked
5298 processes, but by default the dynamic libraries will be read-only, so
5299 for instance you won't be able to put breakpoints in them. To change
5300 that behavior do the following before running the program:
5306 This will cause the libraries to be mapped private and read-write.
5307 To revert to the normal behavior, do this:
5313 You cannot set breakpoints or examine data in the library until after
5314 the library is loaded if the function/data symbols do not have
5317 GDB can now also read debug symbols produced by the HP C compiler on
5318 HPPAs (sorry, no C++, Fortran or 68k support).
5320 * Target byte order now dynamically selectable
5322 You can choose which byte order to use with a target system, via the
5323 commands "set endian big" and "set endian little", and you can see the
5324 current setting by using "show endian". You can also give the command
5325 "set endian auto", in which case GDB will use the byte order
5326 associated with the executable. Currently, only embedded MIPS
5327 configurations support dynamic selection of target byte order.
5329 * New DOS host serial code
5331 This version uses DPMI interrupts to handle buffered I/O, so you
5332 no longer need to run asynctsr when debugging boards connected to
5335 *** Changes in GDB-4.13:
5337 * New "complete" command
5339 This lists all the possible completions for the rest of the line, if it
5340 were to be given as a command itself. This is intended for use by emacs.
5342 * Trailing space optional in prompt
5344 "set prompt" no longer adds a space for you after the prompt you set. This
5345 allows you to set a prompt which ends in a space or one that does not.
5347 * Breakpoint hit counts
5349 "info break" now displays a count of the number of times the breakpoint
5350 has been hit. This is especially useful in conjunction with "ignore"; you
5351 can ignore a large number of breakpoint hits, look at the breakpoint info
5352 to see how many times the breakpoint was hit, then run again, ignoring one
5353 less than that number, and this will get you quickly to the last hit of
5356 * Ability to stop printing at NULL character
5358 "set print null-stop" will cause GDB to stop printing the characters of
5359 an array when the first NULL is encountered. This is useful when large
5360 arrays actually contain only short strings.
5362 * Shared library breakpoints
5364 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5365 breakpoints in shared libraries before the executable is run.
5367 * Hardware watchpoints
5369 There is a new hardware breakpoint for the watch command for sparclite
5370 targets. See gdb/sparclite/hw_breakpoint.note.
5372 Hardware watchpoints are also now supported under GNU/Linux.
5376 Annotations have been added. These are for use with graphical interfaces,
5377 and are still experimental. Currently only gdba.el uses these.
5379 * Improved Irix 5 support
5381 GDB now works properly with Irix 5.2.
5383 * Improved HPPA support
5385 GDB now works properly with the latest GCC and GAS.
5387 * New native configurations
5389 Sequent PTX4 i[34]86-sequent-ptx4
5390 HPPA running OSF/1 hppa*-*-osf*
5391 Atari TT running SVR4 m68*-*-sysv4*
5392 RS/6000 LynxOS rs6000-*-lynxos*
5396 OS/9000 i[34]86-*-os9k
5397 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5400 * Hitachi SH7000 and E7000-PC ICE support
5402 There is now support for communicating with the Hitachi E7000-PC ICE.
5403 This is available automatically when GDB is configured for the SH.
5407 As usual, a variety of small fixes and improvements, both generic
5408 and configuration-specific. See the ChangeLog for more detail.
5410 *** Changes in GDB-4.12:
5412 * Irix 5 is now supported
5416 GDB-4.12 on the HPPA has a number of changes which make it unable
5417 to debug the output from the currently released versions of GCC and
5418 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5419 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5420 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5423 *** Changes in GDB-4.11:
5425 * User visible changes:
5429 The "set remotedebug" option is now consistent between the mips remote
5430 target, remote targets using the gdb-specific protocol, UDI (AMD's
5431 debug protocol for the 29k) and the 88k bug monitor. It is now an
5432 integer specifying a debug level (normally 0 or 1, but 2 means more
5433 debugging info for the mips target).
5435 * DEC Alpha native support
5437 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5438 debug info, but GDB works fairly well with the DEC compiler and should
5439 work with a future GCC release. See the README file for a few
5440 Alpha-specific notes.
5442 * Preliminary thread implementation
5444 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5446 * LynxOS native and target support for 386
5448 This release has been hosted on LynxOS 2.2, and also can be configured
5449 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5452 * Improvements in C++ mangling/demangling.
5454 This release has much better g++ debugging, specifically in name
5455 mangling/demangling, virtual function calls, print virtual table,
5456 call methods, ...etc.
5458 *** Changes in GDB-4.10:
5460 * User visible changes:
5462 Remote debugging using the GDB-specific (`target remote') protocol now
5463 supports the `load' command. This is only useful if you have some
5464 other way of getting the stub to the target system, and you can put it
5465 somewhere in memory where it won't get clobbered by the download.
5467 Filename completion now works.
5469 When run under emacs mode, the "info line" command now causes the
5470 arrow to point to the line specified. Also, "info line" prints
5471 addresses in symbolic form (as well as hex).
5473 All vxworks based targets now support a user settable option, called
5474 vxworks-timeout. This option represents the number of seconds gdb
5475 should wait for responses to rpc's. You might want to use this if
5476 your vxworks target is, perhaps, a slow software simulator or happens
5477 to be on the far side of a thin network line.
5481 This release contains support for using a DEC alpha as a GDB host for
5482 cross debugging. Native alpha debugging is not supported yet.
5485 *** Changes in GDB-4.9:
5489 This is the first GDB release which is accompanied by a matching testsuite.
5490 The testsuite requires installation of dejagnu, which should be available
5491 via ftp from most sites that carry GNU software.
5495 'Cfront' style demangling has had its name changed to 'ARM' style, to
5496 emphasize that it was written from the specifications in the C++ Annotated
5497 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5498 disclaimers, it still generated too much confusion with users attempting to
5499 use gdb with AT&T cfront.
5503 GDB now uses a standard remote interface to a simulator library.
5504 So far, the library contains simulators for the Zilog Z8001/2, the
5505 Hitachi H8/300, H8/500 and Super-H.
5507 * New targets supported
5509 H8/300 simulator h8300-hitachi-hms or h8300hms
5510 H8/500 simulator h8500-hitachi-hms or h8500hms
5511 SH simulator sh-hitachi-hms or sh
5512 Z8000 simulator z8k-zilog-none or z8ksim
5513 IDT MIPS board over serial line mips-idt-ecoff
5515 Cross-debugging to GO32 targets is supported. It requires a custom
5516 version of the i386-stub.c module which is integrated with the
5517 GO32 memory extender.
5519 * New remote protocols
5521 MIPS remote debugging protocol.
5523 * New source languages supported
5525 This version includes preliminary support for Chill, a Pascal like language
5526 used by telecommunications companies. Chill support is also being integrated
5527 into the GNU compiler, but we don't know when it will be publically available.
5530 *** Changes in GDB-4.8:
5532 * HP Precision Architecture supported
5534 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5535 version of this support was available as a set of patches from the
5536 University of Utah. GDB does not support debugging of programs
5537 compiled with the HP compiler, because HP will not document their file
5538 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5539 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5541 Many problems in the preliminary version have been fixed.
5543 * Faster and better demangling
5545 We have improved template demangling and fixed numerous bugs in the GNU style
5546 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5547 character types (wchar_t) are now supported. Demangling of each symbol is now
5548 only done once, and is cached when the symbol table for a file is read in.
5549 This results in a small increase in memory usage for C programs, a moderate
5550 increase in memory usage for C++ programs, and a fantastic speedup in
5553 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5554 from the specifications in the Annotated Reference Manual, which AT&T's
5555 compiler does not actually implement.
5557 * G++ multiple inheritance compiler problem
5559 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5560 inheritance lattices was reworked to properly discover ambiguities. We
5561 recently found an example which causes this new algorithm to fail in a
5562 very subtle way, producing bad debug information for those classes.
5563 The file 'gcc.patch' (in this directory) can be applied to gcc to
5564 circumvent the problem. A future GCC release will contain a complete
5567 The previous G++ debug info problem (mentioned below for the gdb-4.7
5568 release) is fixed in gcc version 2.3.2.
5570 * Improved configure script
5572 The `configure' script will now attempt to guess your system type if
5573 you don't supply a host system type. The old scheme of supplying a
5574 host system triplet is preferable over using this. All the magic is
5575 done in the new `config.guess' script. Examine it for details.
5577 We have also brought our configure script much more in line with the FSF's
5578 version. It now supports the --with-xxx options. In particular,
5579 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5580 The resulting GDB will not be able to read arbitrary object file formats --
5581 only the format ``expected'' to be used on the configured target system.
5582 We hope to make this the default in a future release.
5584 * Documentation improvements
5586 There's new internal documentation on how to modify GDB, and how to
5587 produce clean changes to the code. We implore people to read it
5588 before submitting changes.
5590 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5591 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5592 `info' files are also provided. To build `info' files from scratch,
5593 you will need the latest `makeinfo' release, which will be available in
5594 a future texinfo-X.Y release.
5596 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5597 We're not sure exactly which versions have this problem, but it has
5598 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5599 or better. If that isn't possible, there is a patch in
5600 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5601 around this problem.
5605 GDB now supports array constants that can be used in expressions typed in by
5606 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5607 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5610 The new directory `gdb/sparclite' contains a program that demonstrates
5611 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5613 * New native hosts supported
5615 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5616 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5618 * New targets supported
5620 AMD 29k family via UDI a29k-amd-udi or udi29k
5622 * New file formats supported
5624 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5625 HPUX core files, and SCO 3.2v2 core files.
5629 Attaching to processes now works again; thanks for the many bug reports.
5631 We have also stomped on a bunch of core dumps caused by
5632 printf_filtered("%s") problems.
5634 We eliminated a copyright problem on the rpc and ptrace header files
5635 for VxWorks, which was discovered at the last minute during the 4.7
5636 release. You should now be able to build a VxWorks GDB.
5638 You can now interrupt gdb while an attached process is running. This
5639 will cause the attached process to stop, and give control back to GDB.
5641 We fixed problems caused by using too many file descriptors
5642 for reading symbols from object files and libraries. This was
5643 especially a problem for programs that used many (~100) shared
5646 The `step' command now only enters a subroutine if there is line number
5647 information for the subroutine. Otherwise it acts like the `next'
5648 command. Previously, `step' would enter subroutines if there was
5649 any debugging information about the routine. This avoids problems
5650 when using `cc -g1' on MIPS machines.
5652 * Internal improvements
5654 GDB's internal interfaces have been improved to make it easier to support
5655 debugging of multiple languages in the future.
5657 GDB now uses a common structure for symbol information internally.
5658 Minimal symbols (derived from linkage symbols in object files), partial
5659 symbols (from a quick scan of debug information), and full symbols
5660 contain a common subset of information, making it easier to write
5661 shared code that handles any of them.
5663 * New command line options
5665 We now accept --silent as an alias for --quiet.
5669 The memory-mapped-malloc library is now licensed under the GNU Library
5670 General Public License.
5672 *** Changes in GDB-4.7:
5674 * Host/native/target split
5676 GDB has had some major internal surgery to untangle the support for
5677 hosts and remote targets. Now, when you configure GDB for a remote
5678 target, it will no longer load in all of the support for debugging
5679 local programs on the host. When fully completed and tested, this will
5680 ensure that arbitrary host/target combinations are possible.
5682 The primary conceptual shift is to separate the non-portable code in
5683 GDB into three categories. Host specific code is required any time GDB
5684 is compiled on that host, regardless of the target. Target specific
5685 code relates to the peculiarities of the target, but can be compiled on
5686 any host. Native specific code is everything else: it can only be
5687 built when the host and target are the same system. Child process
5688 handling and core file support are two common `native' examples.
5690 GDB's use of /proc for controlling Unix child processes is now cleaner.
5691 It has been split out into a single module under the `target_ops' vector,
5692 plus two native-dependent functions for each system that uses /proc.
5694 * New hosts supported
5696 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5697 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5698 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5700 * New targets supported
5702 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5703 68030 and CPU32 m68030-*-*, m68332-*-*
5705 * New native hosts supported
5707 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5708 (386bsd is not well tested yet)
5709 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5711 * New file formats supported
5713 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5714 supports reading of `a.out.adobe' object files, which are an a.out
5715 format extended with minimal information about multiple sections.
5719 `show copying' is the same as the old `info copying'.
5720 `show warranty' is the same as `info warrantee'.
5721 These were renamed for consistency. The old commands continue to work.
5723 `info handle' is a new alias for `info signals'.
5725 You can now define pre-command hooks, which attach arbitrary command
5726 scripts to any command. The commands in the hook will be executed
5727 prior to the user's command. You can also create a hook which will be
5728 executed whenever the program stops. See gdb.texinfo.
5732 We now deal with Cfront style name mangling, and can even extract type
5733 info from mangled symbols. GDB can automatically figure out which
5734 symbol mangling style your C++ compiler uses.
5736 Calling of methods and virtual functions has been improved as well.
5740 The crash that occured when debugging Sun Ansi-C compiled binaries is
5741 fixed. This was due to mishandling of the extra N_SO stabs output
5744 We also finally got Ultrix 4.2 running in house, and fixed core file
5745 support, with help from a dozen people on the net.
5747 John M. Farrell discovered that the reason that single-stepping was so
5748 slow on all of the Mips based platforms (primarily SGI and DEC) was
5749 that we were trying to demangle and lookup a symbol used for internal
5750 purposes on every instruction that was being stepped through. Changing
5751 the name of that symbol so that it couldn't be mistaken for a C++
5752 mangled symbol sped things up a great deal.
5754 Rich Pixley sped up symbol lookups in general by getting much smarter
5755 about when C++ symbol mangling is necessary. This should make symbol
5756 completion (TAB on the command line) much faster. It's not as fast as
5757 we'd like, but it's significantly faster than gdb-4.6.
5761 A new user controllable variable 'call_scratch_address' can
5762 specify the location of a scratch area to be used when GDB
5763 calls a function in the target. This is necessary because the
5764 usual method of putting the scratch area on the stack does not work
5765 in systems that have separate instruction and data spaces.
5767 We integrated changes to support the 29k UDI (Universal Debugger
5768 Interface), but discovered at the last minute that we didn't have all
5769 of the appropriate copyright paperwork. We are working with AMD to
5770 resolve this, and hope to have it available soon.
5774 We have sped up the remote serial line protocol, especially for targets
5775 with lots of registers. It now supports a new `expedited status' ('T')
5776 message which can be used in place of the existing 'S' status message.
5777 This allows the remote stub to send only the registers that GDB
5778 needs to make a quick decision about single-stepping or conditional
5779 breakpoints, eliminating the need to fetch the entire register set for
5780 each instruction being stepped through.
5782 The GDB remote serial protocol now implements a write-through cache for
5783 registers, only re-reading the registers if the target has run.
5785 There is also a new remote serial stub for SPARC processors. You can
5786 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5787 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5788 processor with a serial port.
5792 Configure.in files have become much easier to read and modify. A new
5793 `table driven' format makes it more obvious what configurations are
5794 supported, and what files each one uses.
5798 There is a new opcodes library which will eventually contain all of the
5799 disassembly routines and opcode tables. At present, it only contains
5800 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5801 disassembler (binutils/objdump) to share these routines.
5803 The libiberty library is now copylefted under the GNU Library General
5804 Public License. This allows more liberal use, and was done so libg++
5805 can use it. This makes no difference to GDB, since the Library License
5806 grants all the rights from the General Public License.
5810 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5811 reference to the stabs symbol info used by the debugger. It is (as far
5812 as we know) the only published document on this fascinating topic. We
5813 encourage you to read it, compare it to the stabs information on your
5814 system, and send improvements on the document in general (to
5815 bug-gdb@prep.ai.mit.edu).
5817 And, of course, many bugs have been fixed.
5820 *** Changes in GDB-4.6:
5822 * Better support for C++ function names
5824 GDB now accepts as input the "demangled form" of C++ overloaded function
5825 names and member function names, and can do command completion on such names
5826 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5827 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5828 Make use of command completion, it is your friend.
5830 GDB also now accepts a variety of C++ mangled symbol formats. They are
5831 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5832 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5833 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5834 for the list of formats.
5836 * G++ symbol mangling problem
5838 Recent versions of gcc have a bug in how they emit debugging information for
5839 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5840 directory) can be applied to gcc to fix the problem. Alternatively, if you
5841 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5842 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5843 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5846 * New 'maintenance' command
5848 All of the commands related to hacking GDB internals have been moved out of
5849 the main command set, and now live behind the 'maintenance' command. This
5850 can also be abbreviated as 'mt'. The following changes were made:
5852 dump-me -> maintenance dump-me
5853 info all-breakpoints -> maintenance info breakpoints
5854 printmsyms -> maintenance print msyms
5855 printobjfiles -> maintenance print objfiles
5856 printpsyms -> maintenance print psymbols
5857 printsyms -> maintenance print symbols
5859 The following commands are new:
5861 maintenance demangle Call internal GDB demangler routine to
5862 demangle a C++ link name and prints the result.
5863 maintenance print type Print a type chain for a given symbol
5865 * Change to .gdbinit file processing
5867 We now read the $HOME/.gdbinit file before processing the argv arguments
5868 (e.g. reading symbol files or core files). This allows global parameters to
5869 be set, which will apply during the symbol reading. The ./.gdbinit is still
5870 read after argv processing.
5872 * New hosts supported
5874 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5876 GNU/Linux support i386-unknown-linux or linux
5878 We are also including code to support the HP/PA running BSD and HPUX. This
5879 is almost guaranteed not to work, as we didn't have time to test or build it
5880 for this release. We are including it so that the more adventurous (or
5881 masochistic) of you can play with it. We also had major problems with the
5882 fact that the compiler that we got from HP doesn't support the -g option.
5885 * New targets supported
5887 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5889 * More smarts about finding #include files
5891 GDB now remembers the compilation directory for all include files, and for
5892 all files from which C is generated (like yacc and lex sources). This
5893 greatly improves GDB's ability to find yacc/lex sources, and include files,
5894 especially if you are debugging your program from a directory different from
5895 the one that contains your sources.
5897 We also fixed a bug which caused difficulty with listing and setting
5898 breakpoints in include files which contain C code. (In the past, you had to
5899 try twice in order to list an include file that you hadn't looked at before.)
5901 * Interesting infernals change
5903 GDB now deals with arbitrary numbers of sections, where the symbols for each
5904 section must be relocated relative to that section's landing place in the
5905 target's address space. This work was needed to support ELF with embedded
5906 stabs used by Solaris-2.0.
5908 * Bug fixes (of course!)
5910 There have been loads of fixes for the following things:
5911 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5912 i960, stabs, DOS(GO32), procfs, etc...
5914 See the ChangeLog for details.
5916 *** Changes in GDB-4.5:
5918 * New machines supported (host and target)
5920 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5922 SGI Irix-4.x mips-sgi-irix4 or iris4
5924 * New malloc package
5926 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5927 Mmalloc is capable of handling mutiple heaps of memory. It is also
5928 capable of saving a heap to a file, and then mapping it back in later.
5929 This can be used to greatly speedup the startup of GDB by using a
5930 pre-parsed symbol table which lives in a mmalloc managed heap. For
5931 more details, please read mmalloc/mmalloc.texi.
5935 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5936 'help info proc' for details.
5938 * MIPS ecoff symbol table format
5940 The code that reads MIPS symbol table format is now supported on all hosts.
5941 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5944 * File name changes for MS-DOS
5946 Many files in the config directories have been renamed to make it easier to
5947 support GDB on MS-DOSe systems (which have very restrictive file name
5948 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5949 environment) is close to working but has some remaining problems. Note
5950 that debugging of DOS programs is not supported, due to limitations
5951 in the ``operating system'', but it can be used to host cross-debugging.
5953 * Cross byte order fixes
5955 Many fixes have been made to support cross debugging of Sparc and MIPS
5956 targets from hosts whose byte order differs.
5958 * New -mapped and -readnow options
5960 If memory-mapped files are available on your system through the 'mmap'
5961 system call, you can use the -mapped option on the `file' or
5962 `symbol-file' commands to cause GDB to write the symbols from your
5963 program into a reusable file. If the program you are debugging is
5964 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5965 Future GDB debugging sessions will notice the presence of this file,
5966 and will quickly map in symbol information from it, rather than reading
5967 the symbol table from the executable program. Using the '-mapped'
5968 option in a GDB `file' or `symbol-file' command has the same effect as
5969 starting GDB with the '-mapped' command-line option.
5971 You can cause GDB to read the entire symbol table immediately by using
5972 the '-readnow' option with any of the commands that load symbol table
5973 information (or on the GDB command line). This makes the command
5974 slower, but makes future operations faster.
5976 The -mapped and -readnow options are typically combined in order to
5977 build a `fred.syms' file that contains complete symbol information.
5978 A simple GDB invocation to do nothing but build a `.syms' file for future
5981 gdb -batch -nx -mapped -readnow programname
5983 The `.syms' file is specific to the host machine on which GDB is run.
5984 It holds an exact image of GDB's internal symbol table. It cannot be
5985 shared across multiple host platforms.
5987 * longjmp() handling
5989 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5990 siglongjmp() without losing control. This feature has not yet been ported to
5991 all systems. It currently works on many 386 platforms, all MIPS-based
5992 platforms (SGI, DECstation, etc), and Sun3/4.
5996 Preliminary work has been put in to support the new Solaris OS from Sun. At
5997 this time, it can control and debug processes, but it is not capable of
6002 As always, many many bug fixes. The major areas were with g++, and mipsread.
6003 People using the MIPS-based platforms should experience fewer mysterious
6004 crashes and trashed symbol tables.
6006 *** Changes in GDB-4.4:
6008 * New machines supported (host and target)
6010 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6012 BSD Reno on Vax vax-dec-bsd
6013 Ultrix on Vax vax-dec-ultrix
6015 * New machines supported (target)
6017 AMD 29000 embedded, using EBMON a29k-none-none
6021 GDB continues to improve its handling of C++. `References' work better.
6022 The demangler has also been improved, and now deals with symbols mangled as
6023 per the Annotated C++ Reference Guide.
6025 GDB also now handles `stabs' symbol information embedded in MIPS
6026 `ecoff' symbol tables. Since the ecoff format was not easily
6027 extensible to handle new languages such as C++, this appeared to be a
6028 good way to put C++ debugging info into MIPS binaries. This option
6029 will be supported in the GNU C compiler, version 2, when it is
6032 * New features for SVR4
6034 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6035 shared libraries. Debugging dynamically linked programs should present
6036 only minor differences from debugging statically linked programs.
6038 The `info proc' command will print out information about any process
6039 on an SVR4 system (including the one you are debugging). At the moment,
6040 it prints the address mappings of the process.
6042 If you bring up GDB on another SVR4 system, please send mail to
6043 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6045 * Better dynamic linking support in SunOS
6047 Reading symbols from shared libraries which contain debugging symbols
6048 now works properly. However, there remain issues such as automatic
6049 skipping of `transfer vector' code during function calls, which
6050 make it harder to debug code in a shared library, than to debug the
6051 same code linked statically.
6055 GDB is now using the latest `getopt' routines from the FSF. This
6056 version accepts the -- prefix for options with long names. GDB will
6057 continue to accept the old forms (-option and +option) as well.
6058 Various single letter abbreviations for options have been explicity
6059 added to the option table so that they won't get overshadowed in the
6060 future by other options that begin with the same letter.
6064 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6065 Many assorted bugs have been handled. Many more remain to be handled.
6066 See the various ChangeLog files (primarily in gdb and bfd) for details.
6069 *** Changes in GDB-4.3:
6071 * New machines supported (host and target)
6073 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6074 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6075 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6077 * Almost SCO Unix support
6079 We had hoped to support:
6080 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6081 (except for core file support), but we discovered very late in the release
6082 that it has problems with process groups that render gdb unusable. Sorry
6083 about that. I encourage people to fix it and post the fixes.
6085 * Preliminary ELF and DWARF support
6087 GDB can read ELF object files on System V Release 4, and can handle
6088 debugging records for C, in DWARF format, in ELF files. This support
6089 is preliminary. If you bring up GDB on another SVR4 system, please
6090 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6095 GDB now uses the latest `readline' library. One user-visible change
6096 is that two tabs will list possible command completions, which previously
6097 required typing M-? (meta-question mark, or ESC ?).
6101 The `stepi' bug that many of you noticed has been squashed.
6102 Many bugs in C++ have been handled. Many more remain to be handled.
6103 See the various ChangeLog files (primarily in gdb and bfd) for details.
6105 * State of the MIPS world (in case you wondered):
6107 GDB can understand the symbol tables emitted by the compilers
6108 supplied by most vendors of MIPS-based machines, including DEC. These
6109 symbol tables are in a format that essentially nobody else uses.
6111 Some versions of gcc come with an assembler post-processor called
6112 mips-tfile. This program is required if you want to do source-level
6113 debugging of gcc-compiled programs. I believe FSF does not ship
6114 mips-tfile with gcc version 1, but it will eventually come with gcc
6117 Debugging of g++ output remains a problem. g++ version 1.xx does not
6118 really support it at all. (If you're lucky, you should be able to get
6119 line numbers and stack traces to work, but no parameters or local
6120 variables.) With some work it should be possible to improve the
6123 When gcc version 2 is released, you will have somewhat better luck.
6124 However, even then you will get confusing results for inheritance and
6127 We will eventually provide full debugging of g++ output on
6128 DECstations. This will probably involve some kind of stabs-in-ecoff
6129 encapulation, but the details have not been worked out yet.
6132 *** Changes in GDB-4.2:
6134 * Improved configuration
6136 Only one copy of `configure' exists now, and it is not self-modifying.
6137 Porting BFD is simpler.
6141 The `step' and `next' commands now only stop at the first instruction
6142 of a source line. This prevents the multiple stops that used to occur
6143 in switch statements, for-loops, etc. `Step' continues to stop if a
6144 function that has debugging information is called within the line.
6148 Lots of small bugs fixed. More remain.
6150 * New host supported (not target)
6152 Intel 386 PC clone running Mach i386-none-mach
6155 *** Changes in GDB-4.1:
6157 * Multiple source language support
6159 GDB now has internal scaffolding to handle several source languages.
6160 It determines the type of each source file from its filename extension,
6161 and will switch expression parsing and number formatting to match the
6162 language of the function in the currently selected stack frame.
6163 You can also specifically set the language to be used, with
6164 `set language c' or `set language modula-2'.
6168 GDB now has preliminary support for the GNU Modula-2 compiler,
6169 currently under development at the State University of New York at
6170 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6171 continue through the fall of 1991 and into 1992.
6173 Other Modula-2 compilers are currently not supported, and attempting to
6174 debug programs compiled with them will likely result in an error as the
6175 symbol table is read. Feel free to work on it, though!
6177 There are hooks in GDB for strict type checking and range checking,
6178 in the `Modula-2 philosophy', but they do not currently work.
6182 GDB can now write to executable and core files (e.g. patch
6183 a variable's value). You must turn this switch on, specify
6184 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6185 by assigning a new value to a variable. Modifications take
6188 * Automatic SunOS shared library reading
6190 When you run your program, GDB automatically determines where its
6191 shared libraries (if any) have been loaded, and reads their symbols.
6192 The `share' command is no longer needed. This also works when
6193 examining core files.
6197 You can specify the number of lines that the `list' command shows.
6200 * New machines supported (host and target)
6202 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6203 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6204 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6206 * New hosts supported (not targets)
6208 IBM RT/PC: romp-ibm-aix or rtpc
6210 * New targets supported (not hosts)
6212 AMD 29000 embedded with COFF a29k-none-coff
6213 AMD 29000 embedded with a.out a29k-none-aout
6214 Ultracomputer remote kernel debug a29k-nyu-kern
6216 * New remote interfaces
6222 *** Changes in GDB-4.0:
6226 Wide output is wrapped at good places to make the output more readable.
6228 Gdb now supports cross-debugging from a host machine of one type to a
6229 target machine of another type. Communication with the target system
6230 is over serial lines. The ``target'' command handles connecting to the
6231 remote system; the ``load'' command will download a program into the
6232 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6233 also supports debugging of realtime processes running under VxWorks,
6234 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6235 stub on the target system.
6237 New CPUs supported include the AMD 29000 and Intel 960.
6239 GDB now reads object files and symbol tables via a ``binary file''
6240 library, which allows a single copy of GDB to debug programs of multiple
6241 object file types such as a.out and coff.
6243 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6244 refcard.dvi and refcard.ps are available to format it).
6247 * Control-Variable user interface simplified
6249 All variables that control the operation of the debugger can be set
6250 by the ``set'' command, and displayed by the ``show'' command.
6252 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6253 ``Show prompt'' produces the response:
6254 Gdb's prompt is new-gdb=>.
6256 What follows are the NEW set commands. The command ``help set'' will
6257 print a complete list of old and new set commands. ``help set FOO''
6258 will give a longer description of the variable FOO. ``show'' will show
6259 all of the variable descriptions and their current settings.
6261 confirm on/off: Enables warning questions for operations that are
6262 hard to recover from, e.g. rerunning the program while
6263 it is already running. Default is ON.
6265 editing on/off: Enables EMACS style command line editing
6266 of input. Previous lines can be recalled with
6267 control-P, the current line can be edited with control-B,
6268 you can search for commands with control-R, etc.
6271 history filename NAME: NAME is where the gdb command history
6272 will be stored. The default is .gdb_history,
6273 or the value of the environment variable
6276 history size N: The size, in commands, of the command history. The
6277 default is 256, or the value of the environment variable
6280 history save on/off: If this value is set to ON, the history file will
6281 be saved after exiting gdb. If set to OFF, the
6282 file will not be saved. The default is OFF.
6284 history expansion on/off: If this value is set to ON, then csh-like
6285 history expansion will be performed on
6286 command line input. The default is OFF.
6288 radix N: Sets the default radix for input and output. It can be set
6289 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6290 in the current radix, so "set radix 10" is always a no-op.
6292 height N: This integer value is the number of lines on a page. Default
6293 is 24, the current `stty rows'' setting, or the ``li#''
6294 setting from the termcap entry matching the environment
6297 width N: This integer value is the number of characters on a line.
6298 Default is 80, the current `stty cols'' setting, or the ``co#''
6299 setting from the termcap entry matching the environment
6302 Note: ``set screensize'' is obsolete. Use ``set height'' and
6303 ``set width'' instead.
6305 print address on/off: Print memory addresses in various command displays,
6306 such as stack traces and structure values. Gdb looks
6307 more ``symbolic'' if you turn this off; it looks more
6308 ``machine level'' with it on. Default is ON.
6310 print array on/off: Prettyprint arrays. New convenient format! Default
6313 print demangle on/off: Print C++ symbols in "source" form if on,
6316 print asm-demangle on/off: Same, for assembler level printouts
6319 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6322 * Support for Epoch Environment.
6324 The epoch environment is a version of Emacs v18 with windowing. One
6325 new command, ``inspect'', is identical to ``print'', except that if you
6326 are running in the epoch environment, the value is printed in its own
6330 * Support for Shared Libraries
6332 GDB can now debug programs and core files that use SunOS shared libraries.
6333 Symbols from a shared library cannot be referenced
6334 before the shared library has been linked with the program (this
6335 happens after you type ``run'' and before the function main() is entered).
6336 At any time after this linking (including when examining core files
6337 from dynamically linked programs), gdb reads the symbols from each
6338 shared library when you type the ``sharedlibrary'' command.
6339 It can be abbreviated ``share''.
6341 sharedlibrary REGEXP: Load shared object library symbols for files
6342 matching a unix regular expression. No argument
6343 indicates to load symbols for all shared libraries.
6345 info sharedlibrary: Status of loaded shared libraries.
6350 A watchpoint stops execution of a program whenever the value of an
6351 expression changes. Checking for this slows down execution
6352 tremendously whenever you are in the scope of the expression, but is
6353 quite useful for catching tough ``bit-spreader'' or pointer misuse
6354 problems. Some machines such as the 386 have hardware for doing this
6355 more quickly, and future versions of gdb will use this hardware.
6357 watch EXP: Set a watchpoint (breakpoint) for an expression.
6359 info watchpoints: Information about your watchpoints.
6361 delete N: Deletes watchpoint number N (same as breakpoints).
6362 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6363 enable N: Re-enables watchpoint number N (same as breakpoints).
6366 * C++ multiple inheritance
6368 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6371 * C++ exception handling
6373 Gdb now supports limited C++ exception handling. Besides the existing
6374 ability to breakpoint on an exception handler, gdb can breakpoint on
6375 the raising of an exception (before the stack is peeled back to the
6378 catch FOO: If there is a FOO exception handler in the dynamic scope,
6379 set a breakpoint to catch exceptions which may be raised there.
6380 Multiple exceptions (``catch foo bar baz'') may be caught.
6382 info catch: Lists all exceptions which may be caught in the
6383 current stack frame.
6386 * Minor command changes
6388 The command ``call func (arg, arg, ...)'' now acts like the print
6389 command, except it does not print or save a value if the function's result
6390 is void. This is similar to dbx usage.
6392 The ``up'' and ``down'' commands now always print the frame they end up
6393 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6394 frames without printing.
6396 * New directory command
6398 'dir' now adds directories to the FRONT of the source search path.
6399 The path starts off empty. Source files that contain debug information
6400 about the directory in which they were compiled can be found even
6401 with an empty path; Sun CC and GCC include this information. If GDB can't
6402 find your source file in the current directory, type "dir .".
6404 * Configuring GDB for compilation
6406 For normal use, type ``./configure host''. See README or gdb.texinfo
6409 GDB now handles cross debugging. If you are remotely debugging between
6410 two different machines, type ``./configure host -target=targ''.
6411 Host is the machine where GDB will run; targ is the machine
6412 where the program that you are debugging will run.
projects / external / binutils.git / blob