1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.11
6 * Fortran: Support structures with fields of dynamic types and
7 arrays of dynamic types.
9 * GDB now supports multibit bitfields and enums in target register
12 * New Python-based convenience function $_as_string(val), which returns
13 the textual representation of a value. This function is especially
14 useful to obtain the text label of an enum value.
16 * Intel MPX bound violation handling.
18 Segmentation faults caused by a Intel MPX boundary violation
19 now display the kind of violation (upper or lower), the memory
20 address accessed and the memory bounds, along with the usual
21 signal received and code location.
25 Program received signal SIGSEGV, Segmentation fault
26 Upper bound violation while accessing address 0x7fffffffc3b3
27 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
28 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
33 skip -gfile file-glob-pattern
34 skip -function function
35 skip -rfunction regular-expression
36 A generalized form of the skip command, with new support for
37 glob-style file names and regular expressions for function names.
38 Additionally, a file spec and a function spec may now be combined.
40 maint info line-table REGEXP
41 Display the contents of GDB's internal line table data struture.
44 Run any GDB unit tests that were compiled in.
46 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
47 was added in GDBserver, including JIT compiling fast tracepoint's
48 conditional expression bytecode into native code.
50 * Support for various remote target protocols and ROM monitors has
53 target m32rsdi Remote M32R debugging over SDI
54 target mips MIPS remote debugging protocol
55 target pmon PMON ROM monitor
56 target ddb NEC's DDB variant of PMON for Vr4300
57 target rockhopper NEC RockHopper variant of PMON
58 target lsi LSI variant of PMO
60 * Support for tracepoints and fast tracepoints on powerpc-linux,
61 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
62 including JIT compiling fast tracepoint's conditional expression
63 bytecode into native code.
65 *** Changes in GDB 7.11
67 * GDB now supports debugging kernel-based threads on FreeBSD.
69 * Per-inferior thread numbers
71 Thread numbers are now per inferior instead of global. If you're
72 debugging multiple inferiors, GDB displays thread IDs using a
73 qualified INF_NUM.THR_NUM form. For example:
77 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
78 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
79 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
80 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
82 As consequence, thread numbers as visible in the $_thread
83 convenience variable and in Python's InferiorThread.num attribute
84 are no longer unique between inferiors.
86 GDB now maintains a second thread ID per thread, referred to as the
87 global thread ID, which is the new equivalent of thread numbers in
88 previous releases. See also $_gthread below.
90 For backwards compatibility, MI's thread IDs always refer to global
93 * Commands that accept thread IDs now accept the qualified
94 INF_NUM.THR_NUM form as well. For example:
97 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
100 * In commands that accept a list of thread IDs, you can now refer to
101 all threads of an inferior using a star wildcard. GDB accepts
102 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
103 refer to all threads of the current inferior. For example, "info
106 * You can use "info threads -gid" to display the global thread ID of
109 * The new convenience variable $_gthread holds the global number of
112 * The new convenience variable $_inferior holds the number of the
115 * GDB now displays the ID and name of the thread that hit a breakpoint
116 or received a signal, if your program is multi-threaded. For
119 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
120 Thread 1 "main" received signal SIGINT, Interrupt.
122 * Record btrace now supports non-stop mode.
124 * Support for tracepoints on aarch64-linux was added in GDBserver.
126 * The 'record instruction-history' command now indicates speculative execution
127 when using the Intel Processor Trace recording format.
129 * GDB now allows users to specify explicit locations, bypassing
130 the linespec parser. This feature is also available to GDB/MI
133 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
134 GDB now is able to debug both AArch64 applications and ARM applications
137 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
138 including JIT compiling fast tracepoint's conditional expression bytecode
141 * GDB now supports displaced stepping on AArch64 GNU/Linux.
143 * "info threads", "info inferiors", "info display", "info checkpoints"
144 and "maint info program-spaces" now list the corresponding items in
145 ascending ID order, for consistency with all other "info" commands.
147 * In Ada, the overloads selection menu has been enhanced to display the
148 parameter types and the return types for the matching overloaded subprograms.
152 maint set target-non-stop (on|off|auto)
153 maint show target-non-stop
154 Control whether GDB targets always operate in non-stop mode even if
155 "set non-stop" is "off". The default is "auto", meaning non-stop
156 mode is enabled if supported by the target.
158 maint set bfd-sharing
159 maint show bfd-sharing
160 Control the reuse of bfd objects.
164 Control display of debugging info regarding bfd caching.
168 Control display of debugging info regarding FreeBSD threads.
170 set remote multiprocess-extensions-packet
171 show remote multiprocess-extensions-packet
172 Set/show the use of the remote protocol multiprocess extensions.
174 set remote thread-events
175 show remote thread-events
176 Set/show the use of thread create/exit events.
178 set ada print-signatures on|off
179 show ada print-signatures"
180 Control whether parameter types and return types are displayed in overloads
181 selection menus. It is activaled (@code{on}) by default.
185 Controls the maximum size of memory, in bytes, that GDB will
186 allocate for value contents. Prevents incorrect programs from
187 causing GDB to allocate overly large buffers. Default is 64k.
189 * The "disassemble" command accepts a new modifier: /s.
190 It prints mixed source+disassembly like /m with two differences:
191 - disassembled instructions are now printed in program order, and
192 - and source for all relevant files is now printed.
193 The "/m" option is now considered deprecated: its "source-centric"
194 output hasn't proved useful in practice.
196 * The "record instruction-history" command accepts a new modifier: /s.
197 It behaves exactly like /m and prints mixed source+disassembly.
199 * The "set scheduler-locking" command supports a new mode "replay".
200 It behaves like "off" in record mode and like "on" in replay mode.
202 * Support for various ROM monitors has been removed:
204 target dbug dBUG ROM monitor for Motorola ColdFire
205 target picobug Motorola picobug monitor
206 target dink32 DINK32 ROM monitor for PowerPC
207 target m32r Renesas M32R/D ROM monitor
208 target mon2000 mon2000 ROM monitor
209 target ppcbug PPCBUG ROM monitor for PowerPC
211 * Support for reading/writing memory and extracting values on architectures
212 whose memory is addressable in units of any integral multiple of 8 bits.
217 Indicates that an exec system call was executed.
219 exec-events feature in qSupported
220 The qSupported packet allows GDB to request support for exec
221 events using the new 'gdbfeature' exec-event, and the qSupported
222 response can contain the corresponding 'stubfeature'. Set and
223 show commands can be used to display whether these features are enabled.
226 Equivalent to interrupting with the ^C character, but works in
229 thread created stop reason (T05 create:...)
230 Indicates that the thread was just created and is stopped at entry.
232 thread exit stop reply (w exitcode;tid)
233 Indicates that the thread has terminated.
236 Enables/disables thread create and exit event reporting. For
237 example, this is used in non-stop mode when GDB stops a set of
238 threads and synchronously waits for the their corresponding stop
239 replies. Without exit events, if one of the threads exits, GDB
240 would hang forever not knowing that it should no longer expect a
241 stop for that same thread.
245 Indicates that there are no resumed threads left in the target (all
246 threads are stopped). The remote stub reports support for this stop
247 reply to GDB's qSupported query.
249 QCatchSyscalls:1 [;SYSNO]...
251 Enable ("QCatchSyscalls:1") or disable ("QCatchSyscalls:0")
252 catching syscalls from the inferior process.
254 syscall_entry stop reason
255 Indicates that a syscall was just called.
257 syscall_return stop reason
258 Indicates that a syscall just returned.
260 QCatchSyscalls:1 in qSupported
261 The qSupported packet may now include QCatchSyscalls:1 in the reply
262 to indicate support for catching syscalls.
264 * Extended-remote exec events
266 ** GDB now has support for exec events on extended-remote Linux targets.
267 For such targets with Linux kernels 2.5.46 and later, this enables
268 follow-exec-mode and exec catchpoints.
270 set remote exec-event-feature-packet
271 show remote exec-event-feature-packet
272 Set/show the use of the remote exec event feature.
274 * Thread names in remote protocol
276 The reply to qXfer:threads:read may now include a name attribute for each
279 * Target remote mode fork and exec events
281 ** GDB now has support for fork and exec events on target remote mode
282 Linux targets. For such targets with Linux kernels 2.5.46 and later,
283 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
284 fork and exec catchpoints.
286 * Remote syscall events
288 ** GDB now has support for catch syscall on remote Linux targets,
289 currently enabled on x86/x86_64 architectures.
291 set remote catch-syscall-packet
292 show remote catch-syscall-packet
293 Set/show the use of the remote catch syscall feature.
297 ** The -var-set-format command now accepts the zero-hexadecimal
298 format. It outputs data in hexadecimal format with zero-padding on the
303 ** gdb.InferiorThread objects have a new attribute "global_num",
304 which refers to the thread's global thread ID. The existing
305 "num" attribute now refers to the thread's per-inferior number.
306 See "Per-inferior thread numbers" above.
307 ** gdb.InferiorThread objects have a new attribute "inferior", which
308 is the Inferior object the thread belongs to.
310 *** Changes in GDB 7.10
312 * Support for process record-replay and reverse debugging on aarch64*-linux*
313 targets has been added. GDB now supports recording of A64 instruction set
314 including advance SIMD instructions.
316 * Support for Sun's version of the "stabs" debug file format has been removed.
318 * GDB now honors the content of the file /proc/PID/coredump_filter
319 (PID is the process ID) on GNU/Linux systems. This file can be used
320 to specify the types of memory mappings that will be included in a
321 corefile. For more information, please refer to the manual page of
322 "core(5)". GDB also has a new command: "set use-coredump-filter
323 on|off". It allows to set whether GDB will read the content of the
324 /proc/PID/coredump_filter file when generating a corefile.
326 * The "info os" command on GNU/Linux can now display information on
328 "info os cpus" Listing of all cpus/cores on the system
330 * GDB has two new commands: "set serial parity odd|even|none" and
331 "show serial parity". These allows to set or show parity for the
334 * The "info source" command now displays the producer string if it was
335 present in the debug info. This typically includes the compiler version
336 and may include things like its command line arguments.
338 * The "info dll", an alias of the "info sharedlibrary" command,
339 is now available on all platforms.
341 * Directory names supplied to the "set sysroot" commands may be
342 prefixed with "target:" to tell GDB to access shared libraries from
343 the target system, be it local or remote. This replaces the prefix
344 "remote:". The default sysroot has been changed from "" to
345 "target:". "remote:" is automatically converted to "target:" for
346 backward compatibility.
348 * The system root specified by "set sysroot" will be prepended to the
349 filename of the main executable (if reported to GDB as absolute by
350 the operating system) when starting processes remotely, and when
351 attaching to already-running local or remote processes.
353 * GDB now supports automatic location and retrieval of executable
354 files from remote targets. Remote debugging can now be initiated
355 using only a "target remote" or "target extended-remote" command
356 (no "set sysroot" or "file" commands are required). See "New remote
359 * The "dump" command now supports verilog hex format.
361 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
363 * On GNU/Linux, GDB and gdbserver are now able to access executable
364 and shared library files without a "set sysroot" command when
365 attaching to processes running in different mount namespaces from
366 the debugger. This makes it possible to attach to processes in
367 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
368 See "New remote packets" below.
370 * The "tui reg" command now provides completion for all of the
371 available register groups, including target specific groups.
373 * The HISTSIZE environment variable is no longer read when determining
374 the size of GDB's command history. GDB now instead reads the dedicated
375 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
376 disables truncation of command history. Non-numeric values of GDBHISTSIZE
381 ** Memory ports can now be unbuffered.
385 ** gdb.Objfile objects have a new attribute "username",
386 which is the name of the objfile as specified by the user,
387 without, for example, resolving symlinks.
388 ** You can now write frame unwinders in Python.
389 ** gdb.Type objects have a new method "optimized_out",
390 returning optimized out gdb.Value instance of this type.
391 ** gdb.Value objects have new methods "reference_value" and
392 "const_value" which return a reference to the value and a
393 "const" version of the value respectively.
397 maint print symbol-cache
398 Print the contents of the symbol cache.
400 maint print symbol-cache-statistics
401 Print statistics of symbol cache usage.
403 maint flush-symbol-cache
404 Flush the contents of the symbol cache.
408 Start branch trace recording using Branch Trace Store (BTS) format.
411 Evaluate expression by using the compiler and print result.
415 Explicit commands for enabling and disabling tui mode.
418 set mpx bound on i386 and amd64
419 Support for bound table investigation on Intel MPX enabled applications.
423 Start branch trace recording using Intel Processor Trace format.
426 Print information about branch tracing internals.
428 maint btrace packet-history
429 Print the raw branch tracing data.
431 maint btrace clear-packet-history
432 Discard the stored raw branch tracing data.
435 Discard all branch tracing data. It will be fetched and processed
436 anew by the next "record" command.
441 Renamed from "set debug dwarf2-die".
443 Renamed from "show debug dwarf2-die".
446 Renamed from "set debug dwarf2-read".
447 show debug dwarf-read
448 Renamed from "show debug dwarf2-read".
450 maint set dwarf always-disassemble
451 Renamed from "maint set dwarf2 always-disassemble".
452 maint show dwarf always-disassemble
453 Renamed from "maint show dwarf2 always-disassemble".
455 maint set dwarf max-cache-age
456 Renamed from "maint set dwarf2 max-cache-age".
457 maint show dwarf max-cache-age
458 Renamed from "maint show dwarf2 max-cache-age".
461 show debug dwarf-line
462 Control display of debugging info regarding DWARF line processing.
466 Set the maximum number of candidates to be considered during
467 completion. The default value is 200. This limit allows GDB
468 to avoid generating large completion lists, the computation of
469 which can cause the debugger to become temporarily unresponsive.
471 set history remove-duplicates
472 show history remove-duplicates
473 Control the removal of duplicate history entries.
475 maint set symbol-cache-size
476 maint show symbol-cache-size
477 Control the size of the symbol cache.
479 set|show record btrace bts buffer-size
480 Set and show the size of the ring buffer used for branch tracing in
482 The obtained size may differ from the requested size. Use "info
483 record" to see the obtained buffer size.
485 set debug linux-namespaces
486 show debug linux-namespaces
487 Control display of debugging info regarding Linux namespaces.
489 set|show record btrace pt buffer-size
490 Set and show the size of the ring buffer used for branch tracing in
491 Intel Processor Trace format.
492 The obtained size may differ from the requested size. Use "info
493 record" to see the obtained buffer size.
495 maint set|show btrace pt skip-pad
496 Set and show whether PAD packets are skipped when computing the
499 * The command 'thread apply all' can now support new option '-ascending'
500 to call its specified command for all threads in ascending order.
502 * Python/Guile scripting
504 ** GDB now supports auto-loading of Python/Guile scripts contained in the
505 special section named `.debug_gdb_scripts'.
509 qXfer:btrace-conf:read
510 Return the branch trace configuration for the current thread.
512 Qbtrace-conf:bts:size
513 Set the requested ring buffer size for branch tracing in BTS format.
516 Enable Intel Procesor Trace-based branch tracing for the current
517 process. The remote stub reports support for this packet to GDB's
521 Set the requested ring buffer size for branch tracing in Intel Processor
525 Indicates a memory breakpoint instruction was executed, irrespective
526 of whether it was GDB that planted the breakpoint or the breakpoint
527 is hardcoded in the program. This is required for correct non-stop
531 Indicates the target stopped for a hardware breakpoint. This is
532 required for correct non-stop mode operation.
535 Return information about files on the remote system.
538 Return the full absolute name of the file that was executed to
539 create a process running on the remote system.
542 Select the filesystem on which vFile: operations with filename
543 arguments will operate. This is required for GDB to be able to
544 access files on remote targets where the remote stub does not
545 share a common filesystem with the inferior(s).
548 Indicates that a fork system call was executed.
551 Indicates that a vfork system call was executed.
553 vforkdone stop reason
554 Indicates that a vfork child of the specified process has executed
555 an exec or exit, allowing the vfork parent to resume execution.
557 fork-events and vfork-events features in qSupported
558 The qSupported packet allows GDB to request support for fork and
559 vfork events using new 'gdbfeatures' fork-events and vfork-events,
560 and the qSupported response can contain the corresponding
561 'stubfeatures'. Set and show commands can be used to display
562 whether these features are enabled.
564 * Extended-remote fork events
566 ** GDB now has support for fork events on extended-remote Linux
567 targets. For targets with Linux kernels 2.5.60 and later, this
568 enables follow-fork-mode and detach-on-fork for both fork and
569 vfork, as well as fork and vfork catchpoints.
571 * The info record command now shows the recording format and the
572 branch tracing configuration for the current thread when using
573 the btrace record target.
574 For the BTS format, it shows the ring buffer size.
576 * GDB now has support for DTrace USDT (Userland Static Defined
577 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
579 * GDB now supports access to vector registers on S/390 GNU/Linux
582 * Removed command line options
584 -xdb HP-UX XDB compatibility mode.
586 * Removed targets and native configurations
588 HP/PA running HP-UX hppa*-*-hpux*
589 Itanium running HP-UX ia64-*-hpux*
591 * New configure options
594 This configure option allows the user to build GDB with support for
595 Intel Processor Trace (default: auto). This requires libipt.
597 --with-libipt-prefix=PATH
598 Specify the path to the version of libipt that GDB should use.
599 $PATH/include should contain the intel-pt.h header and
600 $PATH/lib should contain the libipt.so library.
602 *** Changes in GDB 7.9.1
606 ** Xmethods can now specify a result type.
608 *** Changes in GDB 7.9
610 * GDB now supports hardware watchpoints on x86 GNU Hurd.
614 ** You can now access frame registers from Python scripts.
615 ** New attribute 'producer' for gdb.Symtab objects.
616 ** gdb.Objfile objects have a new attribute "progspace",
617 which is the gdb.Progspace object of the containing program space.
618 ** gdb.Objfile objects have a new attribute "owner".
619 ** gdb.Objfile objects have a new attribute "build_id",
620 which is the build ID generated when the file was built.
621 ** gdb.Objfile objects have a new method "add_separate_debug_file".
622 ** A new event "gdb.clear_objfiles" has been added, triggered when
623 selecting a new file to debug.
624 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
625 ** New function gdb.lookup_objfile.
627 New events which are triggered when GDB modifies the state of the
630 ** gdb.events.inferior_call_pre: Function call is about to be made.
631 ** gdb.events.inferior_call_post: Function call has just been made.
632 ** gdb.events.memory_changed: A memory location has been altered.
633 ** gdb.events.register_changed: A register has been altered.
635 * New Python-based convenience functions:
637 ** $_caller_is(name [, number_of_frames])
638 ** $_caller_matches(regexp [, number_of_frames])
639 ** $_any_caller_is(name [, number_of_frames])
640 ** $_any_caller_matches(regexp [, number_of_frames])
642 * GDB now supports the compilation and injection of source code into
643 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
644 to compile the source code to object code, and if successful, inject
645 and execute that code within the current context of the inferior.
646 Currently the C language is supported. The commands used to
647 interface with this new feature are:
649 compile code [-raw|-r] [--] [source code]
650 compile file [-raw|-r] filename
654 demangle [-l language] [--] name
655 Demangle "name" in the specified language, or the current language
656 if elided. This command is renamed from the "maint demangle" command.
657 The latter is kept as a no-op to avoid "maint demangle" being interpreted
658 as "maint demangler-warning".
660 queue-signal signal-name-or-number
661 Queue a signal to be delivered to the thread when it is resumed.
663 add-auto-load-scripts-directory directory
664 Add entries to the list of directories from which to load auto-loaded
667 maint print user-registers
668 List all currently available "user" registers.
670 compile code [-r|-raw] [--] [source code]
671 Compile, inject, and execute in the inferior the executable object
672 code produced by compiling the provided source code.
674 compile file [-r|-raw] filename
675 Compile and inject into the inferior the executable object code
676 produced by compiling the source code stored in the filename
679 * On resume, GDB now always passes the signal the program had stopped
680 for to the thread the signal was sent to, even if the user changed
681 threads before resuming. Previously GDB would often (but not
682 always) deliver the signal to the thread that happens to be current
685 * Conversely, the "signal" command now consistently delivers the
686 requested signal to the current thread. GDB now asks for
687 confirmation if the program had stopped for a signal and the user
688 switched threads meanwhile.
690 * "breakpoint always-inserted" modes "off" and "auto" merged.
692 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
693 won't remove breakpoints from the target until all threads stop,
694 even in non-stop mode. The "auto" mode has been removed, and "off"
695 is now the default mode.
699 set debug symbol-lookup
700 show debug symbol-lookup
701 Control display of debugging info regarding symbol lookup.
705 ** The -list-thread-groups command outputs an exit-code field for
706 inferiors that have exited.
710 MIPS SDE mips*-sde*-elf*
714 Support for these obsolete configurations has been removed.
716 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
717 SGI Irix-5.x mips-*-irix5*
718 SGI Irix-6.x mips-*-irix6*
719 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
720 VAX running Ultrix vax-*-ultrix*
722 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
723 and "assf"), have been removed. Use the "sharedlibrary" command, or
724 its alias "share", instead.
726 *** Changes in GDB 7.8
728 * New command line options
731 This is an alias for the --data-directory option.
733 * GDB supports printing and modifying of variable length automatic arrays
734 as specified in ISO C99.
736 * The ARM simulator now supports instruction level tracing
737 with or without disassembly.
741 GDB now has support for scripting using Guile. Whether this is
742 available is determined at configure time.
743 Guile version 2.0 or greater is required.
744 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
746 * New commands (for set/show, see "New options" below)
750 Invoke CODE by passing it to the Guile interpreter.
754 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
756 info auto-load guile-scripts [regexp]
757 Print the list of automatically loaded Guile scripts.
759 * The source command is now capable of sourcing Guile scripts.
760 This feature is dependent on the debugger being built with Guile support.
764 set print symbol-loading (off|brief|full)
765 show print symbol-loading
766 Control whether to print informational messages when loading symbol
767 information for a file. The default is "full", but when debugging
768 programs with large numbers of shared libraries the amount of output
771 set guile print-stack (none|message|full)
772 show guile print-stack
773 Show a stack trace when an error is encountered in a Guile script.
775 set auto-load guile-scripts (on|off)
776 show auto-load guile-scripts
777 Control auto-loading of Guile script files.
779 maint ada set ignore-descriptive-types (on|off)
780 maint ada show ignore-descriptive-types
781 Control whether the debugger should ignore descriptive types in Ada
782 programs. The default is not to ignore the descriptive types. See
783 the user manual for more details on descriptive types and the intended
784 usage of this option.
786 set auto-connect-native-target
788 Control whether GDB is allowed to automatically connect to the
789 native target for the run, attach, etc. commands when not connected
790 to any target yet. See also "target native" below.
792 set record btrace replay-memory-access (read-only|read-write)
793 show record btrace replay-memory-access
794 Control what memory accesses are allowed during replay.
796 maint set target-async (on|off)
797 maint show target-async
798 This controls whether GDB targets operate in synchronous or
799 asynchronous mode. Normally the default is asynchronous, if it is
800 available; but this can be changed to more easily debug problems
801 occurring only in synchronous mode.
803 set mi-async (on|off)
805 Control whether MI asynchronous mode is preferred. This supersedes
806 "set target-async" of previous GDB versions.
808 * "set target-async" is deprecated as a CLI option and is now an alias
809 for "set mi-async" (only puts MI into async mode).
811 * Background execution commands (e.g., "c&", "s&", etc.) are now
812 possible ``out of the box'' if the target supports them. Previously
813 the user would need to explicitly enable the possibility with the
814 "set target-async on" command.
816 * New features in the GDB remote stub, GDBserver
818 ** New option --debug-format=option1[,option2,...] allows one to add
819 additional text to each output. At present only timestamps
820 are supported: --debug-format=timestamps.
821 Timestamps can also be turned on with the
822 "monitor set debug-format timestamps" command from GDB.
824 * The 'record instruction-history' command now starts counting instructions
825 at one. This also affects the instruction ranges reported by the
826 'record function-call-history' command when given the /i modifier.
828 * The command 'record function-call-history' supports a new modifier '/c' to
829 indent the function names based on their call stack depth.
830 The fields for the '/i' and '/l' modifier have been reordered.
831 The source line range is now prefixed with 'at'.
832 The instruction range is now prefixed with 'inst'.
833 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
834 "record instruction-history" and "list" commands.
836 * The ranges given as arguments to the 'record function-call-history' and
837 'record instruction-history' commands are now inclusive.
839 * The btrace record target now supports the 'record goto' command.
840 For locations inside the execution trace, the back trace is computed
841 based on the information stored in the execution trace.
843 * The btrace record target supports limited reverse execution and replay.
844 The target does not record data and therefore does not allow reading
847 * The "catch syscall" command now works on s390*-linux* targets.
849 * The "compare-sections" command is no longer specific to target
850 remote. It now works with all targets.
852 * All native targets are now consistently called "native".
853 Consequently, the "target child", "target GNU", "target djgpp",
854 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
855 commands have been replaced with "target native". The QNX/NTO port
856 leaves the "procfs" target in place and adds a "native" target for
857 consistency with other ports. The impact on users should be minimal
858 as these commands previously either throwed an error, or were
859 no-ops. The target's name is visible in the output of the following
860 commands: "help target", "info target", "info files", "maint print
863 * The "target native" command now connects to the native target. This
864 can be used to launch native programs even when "set
865 auto-connect-native-target" is set to off.
867 * GDB now supports access to Intel MPX registers on GNU/Linux.
869 * Support for Intel AVX-512 registers on GNU/Linux.
870 Support displaying and modifying Intel AVX-512 registers
871 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
875 qXfer:btrace:read's annex
876 The qXfer:btrace:read packet supports a new annex 'delta' to read
877 branch trace incrementally.
881 ** Valid Python operations on gdb.Value objects representing
882 structs/classes invoke the corresponding overloaded operators if
884 ** New `Xmethods' feature in the Python API. Xmethods are
885 additional methods or replacements for existing methods of a C++
886 class. This feature is useful for those cases where a method
887 defined in C++ source code could be inlined or optimized out by
888 the compiler, making it unavailable to GDB.
891 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
893 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
894 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
895 its alias "share", instead.
897 * The commands "set remotebaud" and "show remotebaud" are no longer
898 supported. Use "set serial baud" and "show serial baud" (respectively)
903 ** A new option "-gdb-set mi-async" replaces "-gdb-set
904 target-async". The latter is left as a deprecated alias of the
905 former for backward compatibility. If the target supports it,
906 CLI background execution commands are now always possible by
907 default, independently of whether the frontend stated a
908 preference for asynchronous execution with "-gdb-set mi-async".
909 Previously "-gdb-set target-async off" affected both MI execution
910 commands and CLI execution commands.
912 *** Changes in GDB 7.7
914 * Improved support for process record-replay and reverse debugging on
915 arm*-linux* targets. Support for thumb32 and syscall instruction
916 recording has been added.
918 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
920 * GDB now supports Fission DWP file format version 2.
921 http://gcc.gnu.org/wiki/DebugFission
923 * New convenience function "$_isvoid", to check whether an expression
924 is void. A void expression is an expression where the type of the
925 result is "void". For example, some convenience variables may be
926 "void" when evaluated (e.g., "$_exitcode" before the execution of
927 the program being debugged; or an undefined convenience variable).
928 Another example, when calling a function whose return type is
931 * The "maintenance print objfiles" command now takes an optional regexp.
933 * The "catch syscall" command now works on arm*-linux* targets.
935 * GDB now consistently shows "<not saved>" when printing values of
936 registers the debug info indicates have not been saved in the frame
937 and there's nowhere to retrieve them from
938 (callee-saved/call-clobbered registers):
943 (gdb) info registers rax
946 Before, the former would print "<optimized out>", and the latter
947 "*value not available*".
949 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
954 ** Frame filters and frame decorators have been added.
955 ** Temporary breakpoints are now supported.
956 ** Line tables representation has been added.
957 ** New attribute 'parent_type' for gdb.Field objects.
958 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
959 ** New attribute 'name' for gdb.Type objects.
963 Nios II ELF nios2*-*-elf
964 Nios II GNU/Linux nios2*-*-linux
965 Texas Instruments MSP430 msp430*-*-elf
967 * Removed native configurations
969 Support for these a.out NetBSD and OpenBSD obsolete configurations has
970 been removed. ELF variants of these configurations are kept supported.
972 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
973 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
974 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
975 i[34567]86-*-openbsd3.[0-3]
976 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
977 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
978 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
982 Like "catch throw", but catches a re-thrown exception.
984 Renamed from old "maint check-symtabs".
986 Perform consistency checks on symtabs.
988 Expand symtabs matching an optional regexp.
991 Display the details of GDB configure-time options.
993 maint set|show per-command
994 maint set|show per-command space
995 maint set|show per-command time
996 maint set|show per-command symtab
997 Enable display of per-command gdb resource usage.
999 remove-symbol-file FILENAME
1000 remove-symbol-file -a ADDRESS
1001 Remove a symbol file added via add-symbol-file. The file to remove
1002 can be identified by its filename or by an address that lies within
1003 the boundaries of this symbol file in memory.
1006 info exceptions REGEXP
1007 Display the list of Ada exceptions defined in the program being
1008 debugged. If provided, only the exceptions whose names match REGEXP
1013 set debug symfile off|on
1015 Control display of debugging info regarding reading symbol files and
1016 symbol tables within those files
1018 set print raw frame-arguments
1019 show print raw frame-arguments
1020 Set/show whether to print frame arguments in raw mode,
1021 disregarding any defined pretty-printers.
1023 set remote trace-status-packet
1024 show remote trace-status-packet
1025 Set/show the use of remote protocol qTStatus packet.
1029 Control display of debugging messages related to Nios II targets.
1033 Control whether target-assisted range stepping is enabled.
1035 set startup-with-shell
1036 show startup-with-shell
1037 Specifies whether Unix child processes are started via a shell or
1042 Use the target memory cache for accesses to the code segment. This
1043 improves performance of remote debugging (particularly disassembly).
1045 * You can now use a literal value 'unlimited' for options that
1046 interpret 0 or -1 as meaning "unlimited". E.g., "set
1047 trace-buffer-size unlimited" is now an alias for "set
1048 trace-buffer-size -1" and "set height unlimited" is now an alias for
1051 * The "set debug symtab-create" debugging option of GDB has been changed to
1052 accept a verbosity level. 0 means "off", 1 provides basic debugging
1053 output, and values of 2 or greater provides more verbose output.
1055 * New command-line options
1057 Display the details of GDB configure-time options.
1059 * The command 'tsave' can now support new option '-ctf' to save trace
1060 buffer in Common Trace Format.
1062 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1065 * GDB now implements the the C++ 'typeid' operator.
1067 * The new convenience variable $_exception holds the exception being
1068 thrown or caught at an exception-related catchpoint.
1070 * The exception-related catchpoints, like "catch throw", now accept a
1071 regular expression which can be used to filter exceptions by type.
1073 * The new convenience variable $_exitsignal is automatically set to
1074 the terminating signal number when the program being debugged dies
1075 due to an uncaught signal.
1079 ** All MI commands now accept an optional "--language" option.
1080 Support for this feature can be verified by using the "-list-features"
1081 command, which should contain "language-option".
1083 ** The new command -info-gdb-mi-command allows the user to determine
1084 whether a GDB/MI command is supported or not.
1086 ** The "^error" result record returned when trying to execute an undefined
1087 GDB/MI command now provides a variable named "code" whose content is the
1088 "undefined-command" error code. Support for this feature can be verified
1089 by using the "-list-features" command, which should contain
1090 "undefined-command-error-code".
1092 ** The -trace-save MI command can optionally save trace buffer in Common
1095 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1097 ** The command -data-list-register-values now accepts an optional
1098 "--skip-unavailable" option. When used, only the available registers
1101 ** The new command -trace-frame-collected dumps collected variables,
1102 computed expressions, tvars, memory and registers in a traceframe.
1104 ** The commands -stack-list-locals, -stack-list-arguments and
1105 -stack-list-variables now accept an option "--skip-unavailable".
1106 When used, only the available locals or arguments are displayed.
1108 ** The -exec-run command now accepts an optional "--start" option.
1109 When used, the command follows the same semantics as the "start"
1110 command, stopping the program's execution at the start of its
1111 main subprogram. Support for this feature can be verified using
1112 the "-list-features" command, which should contain
1113 "exec-run-start-option".
1115 ** The new commands -catch-assert and -catch-exceptions insert
1116 catchpoints stopping the program when Ada exceptions are raised.
1118 ** The new command -info-ada-exceptions provides the equivalent of
1119 the new "info exceptions" command.
1121 * New system-wide configuration scripts
1122 A GDB installation now provides scripts suitable for use as system-wide
1123 configuration scripts for the following systems:
1127 * GDB now supports target-assigned range stepping with remote targets.
1128 This improves the performance of stepping source lines by reducing
1129 the number of control packets from/to GDB. See "New remote packets"
1132 * GDB now understands the element 'tvar' in the XML traceframe info.
1133 It has the id of the collected trace state variables.
1135 * On S/390 targets that provide the transactional-execution feature,
1136 the program interruption transaction diagnostic block (TDB) is now
1137 represented as a number of additional "registers" in GDB.
1139 * New remote packets
1143 The vCont packet supports a new 'r' action, that tells the remote
1144 stub to step through an address range itself, without GDB
1145 involvemement at each single-step.
1147 qXfer:libraries-svr4:read's annex
1148 The previously unused annex of the qXfer:libraries-svr4:read packet
1149 is now used to support passing an argument list. The remote stub
1150 reports support for this argument list to GDB's qSupported query.
1151 The defined arguments are "start" and "prev", used to reduce work
1152 necessary for library list updating, resulting in significant
1155 * New features in the GDB remote stub, GDBserver
1157 ** GDBserver now supports target-assisted range stepping. Currently
1158 enabled on x86/x86_64 GNU/Linux targets.
1160 ** GDBserver now adds element 'tvar' in the XML in the reply to
1161 'qXfer:traceframe-info:read'. It has the id of the collected
1162 trace state variables.
1164 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1167 * New 'z' formatter for printing and examining memory, this displays the
1168 value as hexadecimal zero padded on the left to the size of the type.
1170 * GDB can now use Windows x64 unwinding data.
1172 * The "set remotebaud" command has been replaced by "set serial baud".
1173 Similarly, "show remotebaud" has been replaced by "show serial baud".
1174 The "set remotebaud" and "show remotebaud" commands are still available
1175 to provide backward compatibility with older versions of GDB.
1177 *** Changes in GDB 7.6
1179 * Target record has been renamed to record-full.
1180 Record/replay is now enabled with the "record full" command.
1181 This also affects settings that are associated with full record/replay
1182 that have been moved from "set/show record" to "set/show record full":
1184 set|show record full insn-number-max
1185 set|show record full stop-at-limit
1186 set|show record full memory-query
1188 * A new record target "record-btrace" has been added. The new target
1189 uses hardware support to record the control-flow of a process. It
1190 does not support replaying the execution, but it implements the
1191 below new commands for investigating the recorded execution log.
1192 This new recording method can be enabled using:
1196 The "record-btrace" target is only available on Intel Atom processors
1197 and requires a Linux kernel 2.6.32 or later.
1199 * Two new commands have been added for record/replay to give information
1200 about the recorded execution without having to replay the execution.
1201 The commands are only supported by "record btrace".
1203 record instruction-history prints the execution history at
1204 instruction granularity
1206 record function-call-history prints the execution history at
1207 function granularity
1209 * New native configurations
1211 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1212 FreeBSD/powerpc powerpc*-*-freebsd
1213 x86_64/Cygwin x86_64-*-cygwin*
1214 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1218 ARM AArch64 aarch64*-*-elf
1219 ARM AArch64 GNU/Linux aarch64*-*-linux
1220 Lynx 178 PowerPC powerpc-*-lynx*178
1221 x86_64/Cygwin x86_64-*-cygwin*
1222 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1224 * If the configured location of system.gdbinit file (as given by the
1225 --with-system-gdbinit option at configure time) is in the
1226 data-directory (as specified by --with-gdb-datadir at configure
1227 time) or in one of its subdirectories, then GDB will look for the
1228 system-wide init file in the directory specified by the
1229 --data-directory command-line option.
1231 * New command line options:
1233 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1234 other initialization files, unlike -nx which disables all of them.
1236 * Removed command line options
1238 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1241 * The 'ptype' and 'whatis' commands now accept an argument to control
1244 * 'info proc' now works on some core files.
1248 ** Vectors can be created with gdb.Type.vector.
1250 ** Python's atexit.register now works in GDB.
1252 ** Types can be pretty-printed via a Python API.
1254 ** Python 3 is now supported (in addition to Python 2.4 or later)
1256 ** New class gdb.Architecture exposes GDB's internal representation
1257 of architecture in the Python API.
1259 ** New method Frame.architecture returns the gdb.Architecture object
1260 corresponding to the frame's architecture.
1262 * New Python-based convenience functions:
1264 ** $_memeq(buf1, buf2, length)
1265 ** $_streq(str1, str2)
1267 ** $_regex(str, regex)
1269 * The 'cd' command now defaults to using '~' (the home directory) if not
1272 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1273 default for GCC since November 2000.
1275 * The command 'forward-search' can now be abbreviated as 'fo'.
1277 * The command 'info tracepoints' can now display 'installed on target'
1278 or 'not installed on target' for each non-pending location of tracepoint.
1280 * New configure options
1282 --enable-libmcheck/--disable-libmcheck
1283 By default, development versions are built with -lmcheck on hosts
1284 that support it, in order to help track memory corruption issues.
1285 Release versions, on the other hand, are built without -lmcheck
1286 by default. The --enable-libmcheck/--disable-libmcheck configure
1287 options allow the user to override that default.
1288 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1289 This configure option allows the user to build GDB with
1290 libbabeltrace using which GDB can read Common Trace Format data.
1292 * New commands (for set/show, see "New options" below)
1295 Catch signals. This is similar to "handle", but allows commands and
1296 conditions to be attached.
1299 List the BFDs known to GDB.
1301 python-interactive [command]
1303 Start a Python interactive prompt, or evaluate the optional command
1304 and print the result of expressions.
1307 "py" is a new alias for "python".
1309 enable type-printer [name]...
1310 disable type-printer [name]...
1311 Enable or disable type printers.
1315 ** For the Renesas Super-H architecture, the "regs" command has been removed
1316 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1321 set print type methods (on|off)
1322 show print type methods
1323 Control whether method declarations are displayed by "ptype".
1324 The default is to show them.
1326 set print type typedefs (on|off)
1327 show print type typedefs
1328 Control whether typedef definitions are displayed by "ptype".
1329 The default is to show them.
1331 set filename-display basename|relative|absolute
1332 show filename-display
1333 Control the way in which filenames is displayed.
1334 The default is "relative", which preserves previous behavior.
1336 set trace-buffer-size
1337 show trace-buffer-size
1338 Request target to change the size of trace buffer.
1340 set remote trace-buffer-size-packet auto|on|off
1341 show remote trace-buffer-size-packet
1342 Control the use of the remote protocol `QTBuffer:size' packet.
1346 Control display of debugging messages related to ARM AArch64.
1349 set debug coff-pe-read
1350 show debug coff-pe-read
1351 Control display of debugging messages related to reading of COFF/PE
1356 Control display of debugging messages related to Mach-O symbols
1359 set debug notification
1360 show debug notification
1361 Control display of debugging info for async remote notification.
1365 ** Command parameter changes are now notified using new async record
1366 "=cmd-param-changed".
1367 ** Trace frame changes caused by command "tfind" are now notified using
1368 new async record "=traceframe-changed".
1369 ** The creation, deletion and modification of trace state variables
1370 are now notified using new async records "=tsv-created",
1371 "=tsv-deleted" and "=tsv-modified".
1372 ** The start and stop of process record are now notified using new
1373 async record "=record-started" and "=record-stopped".
1374 ** Memory changes are now notified using new async record
1376 ** The data-disassemble command response will include a "fullname" field
1377 containing the absolute file name when source has been requested.
1378 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1379 command, to allow pattern filling of memory areas.
1380 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1381 library load/unload events.
1382 ** The response to breakpoint commands and breakpoint async records
1383 includes an "installed" field containing a boolean state about each
1384 non-pending tracepoint location is whether installed on target or not.
1385 ** Output of the "-trace-status" command includes a "trace-file" field
1386 containing the name of the trace file being examined. This field is
1387 optional, and only present when examining a trace file.
1388 ** The "fullname" field is now always present along with the "file" field,
1389 even if the file cannot be found by GDB.
1391 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1392 You must have the LZMA library available when configuring GDB for this
1393 feature to be enabled. For more information, see:
1394 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1396 * New remote packets
1399 Set the size of trace buffer. The remote stub reports support for this
1400 packet to gdb's qSupported query.
1403 Enable Branch Trace Store (BTS)-based branch tracing for the current
1404 thread. The remote stub reports support for this packet to gdb's
1408 Disable branch tracing for the current thread. The remote stub reports
1409 support for this packet to gdb's qSupported query.
1412 Read the traced branches for the current thread. The remote stub
1413 reports support for this packet to gdb's qSupported query.
1415 *** Changes in GDB 7.5
1417 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1418 for more x32 ABI info.
1420 * GDB now supports access to MIPS DSP registers on Linux targets.
1422 * GDB now supports debugging microMIPS binaries.
1424 * The "info os" command on GNU/Linux can now display information on
1425 several new classes of objects managed by the operating system:
1426 "info os procgroups" lists process groups
1427 "info os files" lists file descriptors
1428 "info os sockets" lists internet-domain sockets
1429 "info os shm" lists shared-memory regions
1430 "info os semaphores" lists semaphores
1431 "info os msg" lists message queues
1432 "info os modules" lists loaded kernel modules
1434 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1435 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1436 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1437 options and inspect the probe arguments using the new $_probe_arg family
1438 of convenience variables. You can obtain more information about SystemTap
1439 in <http://sourceware.org/systemtap/>.
1441 * GDB now supports reversible debugging on ARM, it allows you to
1442 debug basic ARM and THUMB instructions, and provides
1443 record/replay support.
1445 * The option "symbol-reloading" has been deleted as it is no longer used.
1449 ** GDB commands implemented in Python can now be put in command class
1452 ** The "maint set python print-stack on|off" is now deleted.
1454 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1455 apply "flag enum"-style pretty-printing to any enum.
1457 ** gdb.lookup_symbol can now work when there is no current frame.
1459 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1460 the source at which the symbol was defined.
1462 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1463 method 'value'. The former indicates whether the symbol needs a
1464 frame in order to compute its value, and the latter computes the
1467 ** A new method 'referenced_value' on gdb.Value objects which can
1468 dereference pointer as well as C++ reference values.
1470 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1471 which return the global and static blocks (as gdb.Block objects),
1472 of the underlying symbol table, respectively.
1474 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1475 object associated with a PC value.
1477 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1478 of the address range occupied by code for the current source line.
1480 * Go language support.
1481 GDB now supports debugging programs written in the Go programming
1484 * GDBserver now supports stdio connections.
1485 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1487 * The binary "gdbtui" can no longer be built or installed.
1488 Use "gdb -tui" instead.
1490 * GDB will now print "flag" enums specially. A flag enum is one where
1491 all the enumerator values have no bits in common when pairwise
1492 "and"ed. When printing a value whose type is a flag enum, GDB will
1493 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1494 (gdb) print (enum E) 3
1497 * The filename part of a linespec will now match trailing components
1498 of a source file name. For example, "break gcc/expr.c:1000" will
1499 now set a breakpoint in build/gcc/expr.c, but not
1500 build/libcpp/expr.c.
1502 * The "info proc" and "generate-core-file" commands will now also
1503 work on remote targets connected to GDBserver on Linux.
1505 * The command "info catch" has been removed. It has been disabled
1506 since December 2007.
1508 * The "catch exception" and "catch assert" commands now accept
1509 a condition at the end of the command, much like the "break"
1510 command does. For instance:
1512 (gdb) catch exception Constraint_Error if Barrier = True
1514 Previously, it was possible to add a condition to such catchpoints,
1515 but it had to be done as a second step, after the catchpoint had been
1516 created, using the "condition" command.
1518 * The "info static-tracepoint-marker" command will now also work on
1519 native Linux targets with in-process agent.
1521 * GDB can now set breakpoints on inlined functions.
1523 * The .gdb_index section has been updated to include symbols for
1524 inlined functions. GDB will ignore older .gdb_index sections by
1525 default, which could cause symbol files to be loaded more slowly
1526 until their .gdb_index sections can be recreated. The new command
1527 "set use-deprecated-index-sections on" will cause GDB to use any older
1528 .gdb_index sections it finds. This will restore performance, but the
1529 ability to set breakpoints on inlined functions will be lost in symbol
1530 files with older .gdb_index sections.
1532 The .gdb_index section has also been updated to record more information
1533 about each symbol. This speeds up the "info variables", "info functions"
1534 and "info types" commands when used with programs having the .gdb_index
1535 section, as well as speeding up debugging with shared libraries using
1536 the .gdb_index section.
1538 * Ada support for GDB/MI Variable Objects has been added.
1540 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1545 ** New command -info-os is the MI equivalent of "info os".
1547 ** Output logs ("set logging" and related) now include MI output.
1551 ** "set use-deprecated-index-sections on|off"
1552 "show use-deprecated-index-sections on|off"
1553 Controls the use of deprecated .gdb_index sections.
1555 ** "catch load" and "catch unload" can be used to stop when a shared
1556 library is loaded or unloaded, respectively.
1558 ** "enable count" can be used to auto-disable a breakpoint after
1561 ** "info vtbl" can be used to show the virtual method tables for
1562 C++ and Java objects.
1564 ** "explore" and its sub commands "explore value" and "explore type"
1565 can be used to recursively explore values and types of
1566 expressions. These commands are available only if GDB is
1567 configured with '--with-python'.
1569 ** "info auto-load" shows status of all kinds of auto-loaded files,
1570 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1571 sequences of commands files, "info auto-load python-scripts"
1572 shows status of auto-loading Python script files,
1573 "info auto-load local-gdbinit" shows status of loading init file
1574 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1575 status of inferior specific thread debugging shared library loading.
1577 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1578 and "show auto-load-scripts" commands have been deprecated, use their
1579 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1580 and "show auto-load python-scripts" counterparts instead.
1582 ** "dprintf location,format,args..." creates a dynamic printf, which
1583 is basically a breakpoint that does a printf and immediately
1584 resumes your program's execution, so it is like a printf that you
1585 can insert dynamically at runtime instead of at compiletime.
1587 ** "set print symbol"
1589 Controls whether GDB attempts to display the symbol, if any,
1590 corresponding to addresses it prints. This defaults to "on", but
1591 you can set it to "off" to restore GDB's previous behavior.
1593 * Deprecated commands
1595 ** For the Renesas Super-H architecture, the "regs" command has been
1596 deprecated, and "info all-registers" should be used instead.
1600 Renesas RL78 rl78-*-elf
1601 HP OpenVMS ia64 ia64-hp-openvms*
1603 * GDBserver supports evaluation of breakpoint conditions. When
1604 support is advertised by GDBserver, GDB may be told to send the
1605 breakpoint conditions in bytecode form to GDBserver. GDBserver
1606 will only report the breakpoint trigger to GDB when its condition
1611 set mips compression
1612 show mips compression
1613 Select the compressed ISA encoding used in functions that have no symbol
1614 information available. The encoding can be set to either of:
1617 and is updated automatically from ELF file flags if available.
1619 set breakpoint condition-evaluation
1620 show breakpoint condition-evaluation
1621 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1622 GDBserver ("target"). Default option "auto" chooses the most efficient
1624 This option can improve debugger efficiency depending on the speed of the
1628 Disable auto-loading globally.
1631 Show auto-loading setting of all kinds of auto-loaded files.
1633 set auto-load gdb-scripts on|off
1634 show auto-load gdb-scripts
1635 Control auto-loading of GDB canned sequences of commands files.
1637 set auto-load python-scripts on|off
1638 show auto-load python-scripts
1639 Control auto-loading of Python script files.
1641 set auto-load local-gdbinit on|off
1642 show auto-load local-gdbinit
1643 Control loading of init file (.gdbinit) from current directory.
1645 set auto-load libthread-db on|off
1646 show auto-load libthread-db
1647 Control auto-loading of inferior specific thread debugging shared library.
1649 set auto-load scripts-directory <dir1>[:<dir2>...]
1650 show auto-load scripts-directory
1651 Set a list of directories from which to load auto-loaded scripts.
1652 Automatically loaded Python scripts and GDB scripts are located in one
1653 of the directories listed by this option.
1654 The delimiter (':' above) may differ according to the host platform.
1656 set auto-load safe-path <dir1>[:<dir2>...]
1657 show auto-load safe-path
1658 Set a list of directories from which it is safe to auto-load files.
1659 The delimiter (':' above) may differ according to the host platform.
1661 set debug auto-load on|off
1662 show debug auto-load
1663 Control display of debugging info for auto-loading the files above.
1665 set dprintf-style gdb|call|agent
1667 Control the way in which a dynamic printf is performed; "gdb"
1668 requests a GDB printf command, while "call" causes dprintf to call a
1669 function in the inferior. "agent" requests that the target agent
1670 (such as GDBserver) do the printing.
1672 set dprintf-function <expr>
1673 show dprintf-function
1674 set dprintf-channel <expr>
1675 show dprintf-channel
1676 Set the function and optional first argument to the call when using
1677 the "call" style of dynamic printf.
1679 set disconnected-dprintf on|off
1680 show disconnected-dprintf
1681 Control whether agent-style dynamic printfs continue to be in effect
1682 after GDB disconnects.
1684 * New configure options
1686 --with-auto-load-dir
1687 Configure default value for the 'set auto-load scripts-directory'
1688 setting above. It defaults to '$debugdir:$datadir/auto-load',
1689 $debugdir representing global debugging info directories (available
1690 via 'show debug-file-directory') and $datadir representing GDB's data
1691 directory (available via 'show data-directory').
1693 --with-auto-load-safe-path
1694 Configure default value for the 'set auto-load safe-path' setting
1695 above. It defaults to the --with-auto-load-dir setting.
1697 --without-auto-load-safe-path
1698 Set 'set auto-load safe-path' to '/', effectively disabling this
1701 * New remote packets
1703 z0/z1 conditional breakpoints extension
1705 The z0/z1 breakpoint insertion packets have been extended to carry
1706 a list of conditional expressions over to the remote stub depending on the
1707 condition evaluation mode. The use of this extension can be controlled
1708 via the "set remote conditional-breakpoints-packet" command.
1712 Specify the signals which the remote stub may pass to the debugged
1713 program without GDB involvement.
1715 * New command line options
1717 --init-command=FILE, -ix Like --command, -x but execute it
1718 before loading inferior.
1719 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1720 execute it before loading inferior.
1722 *** Changes in GDB 7.4
1724 * GDB now handles ambiguous linespecs more consistently; the existing
1725 FILE:LINE support has been expanded to other types of linespecs. A
1726 breakpoint will now be set on all matching locations in all
1727 inferiors, and locations will be added or removed according to
1730 * GDB now allows you to skip uninteresting functions and files when
1731 stepping with the "skip function" and "skip file" commands.
1733 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1734 and "show remote hardware-watchpoint-length-limit". These allows to
1735 set or show the maximum length limit (in bytes) of a remote
1736 target hardware watchpoint.
1738 This allows e.g. to use "unlimited" hardware watchpoints with the
1739 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1740 watchpoints are slower than real hardware watchpoints but are
1741 significantly faster than gdb software watchpoints.
1745 ** The register_pretty_printer function in module gdb.printing now takes
1746 an optional `replace' argument. If True, the new printer replaces any
1749 ** The "maint set python print-stack on|off" command has been
1750 deprecated and will be deleted in GDB 7.5.
1751 A new command: "set python print-stack none|full|message" has
1752 replaced it. Additionally, the default for "print-stack" is
1753 now "message", which just prints the error message without
1756 ** A prompt substitution hook (prompt_hook) is now available to the
1759 ** A new Python module, gdb.prompt has been added to the GDB Python
1760 modules library. This module provides functionality for
1761 escape sequences in prompts (used by set/show
1762 extended-prompt). These escape sequences are replaced by their
1763 corresponding value.
1765 ** Python commands and convenience-functions located in
1766 'data-directory'/python/gdb/command and
1767 'data-directory'/python/gdb/function are now automatically loaded
1770 ** Blocks now provide four new attributes. global_block and
1771 static_block will return the global and static blocks
1772 respectively. is_static and is_global are boolean attributes
1773 that indicate if the block is one of those two types.
1775 ** Symbols now provide the "type" attribute, the type of the symbol.
1777 ** The "gdb.breakpoint" function has been deprecated in favor of
1780 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1781 of a function. This class is based on the "finish" command
1782 available in the CLI.
1784 ** Type objects for struct and union types now allow access to
1785 the fields using standard Python dictionary (mapping) methods.
1786 For example, "some_type['myfield']" now works, as does
1787 "some_type.items()".
1789 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1792 ** A new function, "deep_items" has been added to the gdb.types
1793 module in the GDB Python modules library. This function returns
1794 an iterator over the fields of a struct or union type. Unlike
1795 the standard Python "iteritems" method, it will recursively traverse
1796 any anonymous fields.
1800 ** "*stopped" events can report several new "reason"s, such as
1803 ** Breakpoint changes are now notified using new async records, like
1804 "=breakpoint-modified".
1806 ** New command -ada-task-info.
1808 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1809 $sdir specifies the default system locations of shared libraries.
1810 $pdir specifies the directory where the libpthread used by the application
1813 GDB no longer looks in $sdir and $pdir after it has searched the directories
1814 mentioned in libthread-db-search-path. If you want to search those
1815 directories, they must be specified in libthread-db-search-path.
1816 The default value of libthread-db-search-path on GNU/Linux and Solaris
1817 systems is now "$sdir:$pdir".
1819 $pdir is not supported by gdbserver, it is currently ignored.
1820 $sdir is supported by gdbserver.
1822 * New configure option --with-iconv-bin.
1823 When using the internationalization support like the one in the GNU C
1824 library, GDB will invoke the "iconv" program to get a list of supported
1825 character sets. If this program lives in a non-standard location, one can
1826 use this option to specify where to find it.
1828 * When natively debugging programs on PowerPC BookE processors running
1829 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1830 watchpoints, which specify a mask in addition to an address to watch.
1831 The mask specifies that some bits of an address (the bits which are
1832 reset in the mask) should be ignored when matching the address accessed
1833 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1834 section in the user manual for more details.
1836 * The new option --once causes GDBserver to stop listening for connections once
1837 the first connection is made. The listening port used by GDBserver will
1838 become available after that.
1840 * New commands "info macros" and "alias" have been added.
1842 * New function parameters suffix @entry specifies value of function parameter
1843 at the time the function got called. Entry values are available only since
1849 "!" is now an alias of the "shell" command.
1850 Note that no space is needed between "!" and SHELL COMMAND.
1854 watch EXPRESSION mask MASK_VALUE
1855 The watch command now supports the mask argument which allows creation
1856 of masked watchpoints, if the current architecture supports this feature.
1858 info auto-load-scripts [REGEXP]
1859 This command was formerly named "maintenance print section-scripts".
1860 It is now generally useful and is no longer a maintenance-only command.
1862 info macro [-all] [--] MACRO
1863 The info macro command has new options `-all' and `--'. The first for
1864 printing all definitions of a macro. The second for explicitly specifying
1865 the end of arguments and the beginning of the macro name in case the macro
1866 name starts with a hyphen.
1868 collect[/s] EXPRESSIONS
1869 The tracepoint collect command now takes an optional modifier "/s"
1870 that directs it to dereference pointer-to-character types and
1871 collect the bytes of memory up to a zero byte. The behavior is
1872 similar to what you see when you use the regular print command on a
1873 string. An optional integer following the "/s" sets a bound on the
1874 number of bytes that will be collected.
1877 The trace start command now interprets any supplied arguments as a
1878 note to be recorded with the trace run, with an effect similar to
1879 setting the variable trace-notes.
1882 The trace stop command now interprets any arguments as a note to be
1883 mentioned along with the tstatus report that the trace was stopped
1884 with a command. The effect is similar to setting the variable
1887 * Tracepoints can now be enabled and disabled at any time after a trace
1888 experiment has been started using the standard "enable" and "disable"
1889 commands. It is now possible to start a trace experiment with no enabled
1890 tracepoints; GDB will display a warning, but will allow the experiment to
1891 begin, assuming that tracepoints will be enabled as needed while the trace
1894 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1895 locations with 4-byte instructions, when they were previously
1896 limited to locations with instructions of 5 bytes or longer.
1900 set debug dwarf2-read
1901 show debug dwarf2-read
1902 Turns on or off display of debugging messages related to reading
1903 DWARF debug info. The default is off.
1905 set debug symtab-create
1906 show debug symtab-create
1907 Turns on or off display of debugging messages related to symbol table
1908 creation. The default is off.
1911 show extended-prompt
1912 Set the GDB prompt, and allow escape sequences to be inserted to
1913 display miscellaneous information (see 'help set extended-prompt'
1914 for the list of sequences). This prompt (and any information
1915 accessed through the escape sequences) is updated every time the
1916 prompt is displayed.
1918 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1919 show print entry-values
1920 Set printing of frame argument values at function entry. In some cases
1921 GDB can determine the value of function argument which was passed by the
1922 function caller, even if the value was modified inside the called function.
1924 set debug entry-values
1925 show debug entry-values
1926 Control display of debugging info for determining frame argument values at
1927 function entry and virtual tail call frames.
1929 set basenames-may-differ
1930 show basenames-may-differ
1931 Set whether a source file may have multiple base names.
1932 (A "base name" is the name of a file with the directory part removed.
1933 Example: The base name of "/home/user/hello.c" is "hello.c".)
1934 If set, GDB will canonicalize file names (e.g., expand symlinks)
1935 before comparing them. Canonicalization is an expensive operation,
1936 but it allows the same file be known by more than one base name.
1937 If not set (the default), all source files are assumed to have just
1938 one base name, and gdb will do file name comparisons more efficiently.
1944 Set a user name and notes for the current and any future trace runs.
1945 This is useful for long-running and/or disconnected traces, to
1946 inform others (or yourself) as to who is running the trace, supply
1947 contact information, or otherwise explain what is going on.
1949 set trace-stop-notes
1950 show trace-stop-notes
1951 Set a note attached to the trace run, that is displayed when the
1952 trace has been stopped by a tstop command. This is useful for
1953 instance as an explanation, if you are stopping a trace run that was
1954 started by someone else.
1956 * New remote packets
1960 Dynamically enable a tracepoint in a started trace experiment.
1964 Dynamically disable a tracepoint in a started trace experiment.
1968 Set the user and notes of the trace run.
1972 Query the current status of a tracepoint.
1976 Query the minimum length of instruction at which a fast tracepoint may
1979 * Dcache size (number of lines) and line-size are now runtime-configurable
1980 via "set dcache line" and "set dcache line-size" commands.
1984 Texas Instruments TMS320C6x tic6x-*-*
1988 Renesas RL78 rl78-*-elf
1990 *** Changes in GDB 7.3.1
1992 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1994 *** Changes in GDB 7.3
1996 * GDB has a new command: "thread find [REGEXP]".
1997 It finds the thread id whose name, target id, or thread extra info
1998 matches the given regular expression.
2000 * The "catch syscall" command now works on mips*-linux* targets.
2002 * The -data-disassemble MI command now supports modes 2 and 3 for
2003 dumping the instruction opcodes.
2005 * New command line options
2007 -data-directory DIR Specify DIR as the "data-directory".
2008 This is mostly for testing purposes.
2010 * The "maint set python auto-load on|off" command has been renamed to
2011 "set auto-load-scripts on|off".
2013 * GDB has a new command: "set directories".
2014 It is like the "dir" command except that it replaces the
2015 source path list instead of augmenting it.
2017 * GDB now understands thread names.
2019 On GNU/Linux, "info threads" will display the thread name as set by
2020 prctl or pthread_setname_np.
2022 There is also a new command, "thread name", which can be used to
2023 assign a name internally for GDB to display.
2026 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2027 has been integrated into GDB.
2031 ** The function gdb.Write now accepts an optional keyword 'stream'.
2032 This keyword, when provided, will direct the output to either
2033 stdout, stderr, or GDB's logging output.
2035 ** Parameters can now be be sub-classed in Python, and in particular
2036 you may implement the get_set_doc and get_show_doc functions.
2037 This improves how Parameter set/show documentation is processed
2038 and allows for more dynamic content.
2040 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2041 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2042 have an is_valid method.
2044 ** Breakpoints can now be sub-classed in Python, and in particular
2045 you may implement a 'stop' function that is executed each time
2046 the inferior reaches that breakpoint.
2048 ** New function gdb.lookup_global_symbol looks up a global symbol.
2050 ** GDB values in Python are now callable if the value represents a
2051 function. For example, if 'some_value' represents a function that
2052 takes two integer parameters and returns a value, you can call
2053 that function like so:
2055 result = some_value (10,20)
2057 ** Module gdb.types has been added.
2058 It contains a collection of utilities for working with gdb.Types objects:
2059 get_basic_type, has_field, make_enum_dict.
2061 ** Module gdb.printing has been added.
2062 It contains utilities for writing and registering pretty-printers.
2063 New classes: PrettyPrinter, SubPrettyPrinter,
2064 RegexpCollectionPrettyPrinter.
2065 New function: register_pretty_printer.
2067 ** New commands "info pretty-printers", "enable pretty-printer" and
2068 "disable pretty-printer" have been added.
2070 ** gdb.parameter("directories") is now available.
2072 ** New function gdb.newest_frame returns the newest frame in the
2075 ** The gdb.InferiorThread class has a new "name" attribute. This
2076 holds the thread's name.
2078 ** Python Support for Inferior events.
2079 Python scripts can add observers to be notified of events
2080 occurring in the process being debugged.
2081 The following events are currently supported:
2082 - gdb.events.cont Continue event.
2083 - gdb.events.exited Inferior exited event.
2084 - gdb.events.stop Signal received, and Breakpoint hit events.
2088 ** GDB now puts template parameters in scope when debugging in an
2089 instantiation. For example, if you have:
2091 template<int X> int func (void) { return X; }
2093 then if you step into func<5>, "print X" will show "5". This
2094 feature requires proper debuginfo support from the compiler; it
2095 was added to GCC 4.5.
2097 ** The motion commands "next", "finish", "until", and "advance" now
2098 work better when exceptions are thrown. In particular, GDB will
2099 no longer lose control of the inferior; instead, the GDB will
2100 stop the inferior at the point at which the exception is caught.
2101 This functionality requires a change in the exception handling
2102 code that was introduced in GCC 4.5.
2104 * GDB now follows GCC's rules on accessing volatile objects when
2105 reading or writing target state during expression evaluation.
2106 One notable difference to prior behavior is that "print x = 0"
2107 no longer generates a read of x; the value of the assignment is
2108 now always taken directly from the value being assigned.
2110 * GDB now has some support for using labels in the program's source in
2111 linespecs. For instance, you can use "advance label" to continue
2112 execution to a label.
2114 * GDB now has support for reading and writing a new .gdb_index
2115 section. This section holds a fast index of DWARF debugging
2116 information and can be used to greatly speed up GDB startup and
2117 operation. See the documentation for `save gdb-index' for details.
2119 * The "watch" command now accepts an optional "-location" argument.
2120 When used, this causes GDB to watch the memory referred to by the
2121 expression. Such a watchpoint is never deleted due to it going out
2124 * GDB now supports thread debugging of core dumps on GNU/Linux.
2126 GDB now activates thread debugging using the libthread_db library
2127 when debugging GNU/Linux core dumps, similarly to when debugging
2128 live processes. As a result, when debugging a core dump file, GDB
2129 is now able to display pthread_t ids of threads. For example, "info
2130 threads" shows the same output as when debugging the process when it
2131 was live. In earlier releases, you'd see something like this:
2134 * 1 LWP 6780 main () at main.c:10
2136 While now you see this:
2139 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2141 It is also now possible to inspect TLS variables when debugging core
2144 When debugging a core dump generated on a machine other than the one
2145 used to run GDB, you may need to point GDB at the correct
2146 libthread_db library with the "set libthread-db-search-path"
2147 command. See the user manual for more details on this command.
2149 * When natively debugging programs on PowerPC BookE processors running
2150 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2151 which stop execution of the inferior whenever it executes an instruction
2152 at any address within the specified range. See the "PowerPC Embedded"
2153 section in the user manual for more details.
2155 * New features in the GDB remote stub, GDBserver
2157 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2158 and i686 LynxOS (version 5.x).
2160 ** GDBserver is now supported on Blackfin Linux.
2162 * New native configurations
2164 ia64 HP-UX ia64-*-hpux*
2168 Analog Devices, Inc. Blackfin Processor bfin-*
2170 * Ada task switching is now supported on sparc-elf targets when
2171 debugging a program using the Ravenscar Profile. For more information,
2172 see the "Tasking Support when using the Ravenscar Profile" section
2173 in the GDB user manual.
2175 * Guile support was removed.
2177 * New features in the GNU simulator
2179 ** The --map-info flag lists all known core mappings.
2181 ** CFI flashes may be simulated via the "cfi" device.
2183 *** Changes in GDB 7.2
2185 * Shared library support for remote targets by default
2187 When GDB is configured for a generic, non-OS specific target, like
2188 for example, --target=arm-eabi or one of the many *-*-elf targets,
2189 GDB now queries remote stubs for loaded shared libraries using the
2190 `qXfer:libraries:read' packet. Previously, shared library support
2191 was always disabled for such configurations.
2195 ** Argument Dependent Lookup (ADL)
2197 In C++ ADL lookup directs function search to the namespaces of its
2198 arguments even if the namespace has not been imported.
2208 Here the compiler will search for `foo' in the namespace of 'b'
2209 and find A::foo. GDB now supports this. This construct is commonly
2210 used in the Standard Template Library for operators.
2212 ** Improved User Defined Operator Support
2214 In addition to member operators, GDB now supports lookup of operators
2215 defined in a namespace and imported with a `using' directive, operators
2216 defined in the global scope, operators imported implicitly from an
2217 anonymous namespace, and the ADL operators mentioned in the previous
2219 GDB now also supports proper overload resolution for all the previously
2220 mentioned flavors of operators.
2222 ** static const class members
2224 Printing of static const class members that are initialized in the
2225 class definition has been fixed.
2227 * Windows Thread Information Block access.
2229 On Windows targets, GDB now supports displaying the Windows Thread
2230 Information Block (TIB) structure. This structure is visible either
2231 by using the new command `info w32 thread-information-block' or, by
2232 dereferencing the new convenience variable named `$_tlb', a
2233 thread-specific pointer to the TIB. This feature is also supported
2234 when remote debugging using GDBserver.
2236 * Static tracepoints
2238 Static tracepoints are calls in the user program into a tracing
2239 library. One such library is a port of the LTTng kernel tracer to
2240 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2241 When debugging with GDBserver, GDB now supports combining the GDB
2242 tracepoint machinery with such libraries. For example: the user can
2243 use GDB to probe a static tracepoint marker (a call from the user
2244 program into the tracing library) with the new "strace" command (see
2245 "New commands" below). This creates a "static tracepoint" in the
2246 breakpoint list, that can be manipulated with the same feature set
2247 as fast and regular tracepoints. E.g., collect registers, local and
2248 global variables, collect trace state variables, and define
2249 tracepoint conditions. In addition, the user can collect extra
2250 static tracepoint marker specific data, by collecting the new
2251 $_sdata internal variable. When analyzing the trace buffer, you can
2252 inspect $_sdata like any other variable available to GDB. For more
2253 information, see the "Tracepoints" chapter in GDB user manual. New
2254 remote packets have been defined to support static tracepoints, see
2255 the "New remote packets" section below.
2257 * Better reconstruction of tracepoints after disconnected tracing
2259 GDB will attempt to download the original source form of tracepoint
2260 definitions when starting a trace run, and then will upload these
2261 upon reconnection to the target, resulting in a more accurate
2262 reconstruction of the tracepoints that are in use on the target.
2266 You can now exercise direct control over the ways that GDB can
2267 affect your program. For instance, you can disallow the setting of
2268 breakpoints, so that the program can run continuously (assuming
2269 non-stop mode). In addition, the "observer" variable is available
2270 to switch all of the different controls; in observer mode, GDB
2271 cannot affect the target's behavior at all, which is useful for
2272 tasks like diagnosing live systems in the field.
2274 * The new convenience variable $_thread holds the number of the
2277 * New remote packets
2281 Return the address of the Windows Thread Information Block of a given thread.
2285 In response to several of the tracepoint packets, the target may now
2286 also respond with a number of intermediate `qRelocInsn' request
2287 packets before the final result packet, to have GDB handle
2288 relocating an instruction to execute at a different address. This
2289 is particularly useful for stubs that support fast tracepoints. GDB
2290 reports support for this feature in the qSupported packet.
2294 List static tracepoint markers in the target program.
2298 List static tracepoint markers at a given address in the target
2301 qXfer:statictrace:read
2303 Read the static trace data collected (by a `collect $_sdata'
2304 tracepoint action). The remote stub reports support for this packet
2305 to gdb's qSupported query.
2309 Send the current settings of GDB's permission flags.
2313 Send part of the source (textual) form of a tracepoint definition,
2314 which includes location, conditional, and action list.
2316 * The source command now accepts a -s option to force searching for the
2317 script in the source search path even if the script name specifies
2320 * New features in the GDB remote stub, GDBserver
2322 - GDBserver now support tracepoints (including fast tracepoints, and
2323 static tracepoints). The feature is currently supported by the
2324 i386-linux and amd64-linux builds. See the "Tracepoints support
2325 in gdbserver" section in the manual for more information.
2327 GDBserver JIT compiles the tracepoint's conditional agent
2328 expression bytecode into native code whenever possible for low
2329 overhead dynamic tracepoints conditionals. For such tracepoints,
2330 an expression that examines program state is evaluated when the
2331 tracepoint is reached, in order to determine whether to capture
2332 trace data. If the condition is simple and false, processing the
2333 tracepoint finishes very quickly and no data is gathered.
2335 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2336 for static tracepoints support.
2338 - GDBserver now supports x86_64 Windows 64-bit debugging.
2340 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2341 it understands register description.
2343 * The --batch flag now disables pagination and queries.
2345 * X86 general purpose registers
2347 GDB now supports reading/writing byte, word and double-word x86
2348 general purpose registers directly. This means you can use, say,
2349 $ah or $ax to refer, respectively, to the byte register AH and
2350 16-bit word register AX that are actually portions of the 32-bit
2351 register EAX or 64-bit register RAX.
2353 * The `commands' command now accepts a range of breakpoints to modify.
2354 A plain `commands' following a command that creates multiple
2355 breakpoints affects all the breakpoints set by that command. This
2356 applies to breakpoints set by `rbreak', and also applies when a
2357 single `break' command creates multiple breakpoints (e.g.,
2358 breakpoints on overloaded c++ functions).
2360 * The `rbreak' command now accepts a filename specification as part of
2361 its argument, limiting the functions selected by the regex to those
2362 in the specified file.
2364 * Support for remote debugging Windows and SymbianOS shared libraries
2365 from Unix hosts has been improved. Non Windows GDB builds now can
2366 understand target reported file names that follow MS-DOS based file
2367 system semantics, such as file names that include drive letters and
2368 use the backslash character as directory separator. This makes it
2369 possible to transparently use the "set sysroot" and "set
2370 solib-search-path" on Unix hosts to point as host copies of the
2371 target's shared libraries. See the new command "set
2372 target-file-system-kind" described below, and the "Commands to
2373 specify files" section in the user manual for more information.
2377 eval template, expressions...
2378 Convert the values of one or more expressions under the control
2379 of the string template to a command line, and call it.
2381 set target-file-system-kind unix|dos-based|auto
2382 show target-file-system-kind
2383 Set or show the assumed file system kind for target reported file
2386 save breakpoints <filename>
2387 Save all current breakpoint definitions to a file suitable for use
2388 in a later debugging session. To read the saved breakpoint
2389 definitions, use the `source' command.
2391 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2394 info static-tracepoint-markers
2395 Display information about static tracepoint markers in the target.
2397 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2398 Define a static tracepoint by probing a marker at the given
2399 function, line, address, or marker ID.
2403 Enable and disable observer mode.
2405 set may-write-registers on|off
2406 set may-write-memory on|off
2407 set may-insert-breakpoints on|off
2408 set may-insert-tracepoints on|off
2409 set may-insert-fast-tracepoints on|off
2410 set may-interrupt on|off
2411 Set individual permissions for GDB effects on the target. Note that
2412 some of these settings can have undesirable or surprising
2413 consequences, particularly when changed in the middle of a session.
2414 For instance, disabling the writing of memory can prevent
2415 breakpoints from being inserted, cause single-stepping to fail, or
2416 even crash your program, if you disable after breakpoints have been
2417 inserted. However, GDB should not crash.
2419 set record memory-query on|off
2420 show record memory-query
2421 Control whether to stop the inferior if memory changes caused
2422 by an instruction cannot be recorded.
2427 The disassemble command now supports "start,+length" form of two arguments.
2431 ** GDB now provides a new directory location, called the python directory,
2432 where Python scripts written for GDB can be installed. The location
2433 of that directory is <data-directory>/python, where <data-directory>
2434 is the GDB data directory. For more details, see section `Scripting
2435 GDB using Python' in the manual.
2437 ** The GDB Python API now has access to breakpoints, symbols, symbol
2438 tables, program spaces, inferiors, threads and frame's code blocks.
2439 Additionally, GDB Parameters can now be created from the API, and
2440 manipulated via set/show in the CLI.
2442 ** New functions gdb.target_charset, gdb.target_wide_charset,
2443 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2445 ** New exception gdb.GdbError.
2447 ** Pretty-printers are now also looked up in the current program space.
2449 ** Pretty-printers can now be individually enabled and disabled.
2451 ** GDB now looks for names of Python scripts to auto-load in a
2452 special section named `.debug_gdb_scripts', in addition to looking
2453 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2455 * Tracepoint actions were unified with breakpoint commands. In particular,
2456 there are no longer differences in "info break" output for breakpoints and
2457 tracepoints and the "commands" command can be used for both tracepoints and
2458 regular breakpoints.
2462 ARM Symbian arm*-*-symbianelf*
2464 * D language support.
2465 GDB now supports debugging programs written in the D programming
2468 * GDB now supports the extended ptrace interface for PowerPC which is
2469 available since Linux kernel version 2.6.34. This automatically enables
2470 any hardware breakpoints and additional hardware watchpoints available in
2471 the processor. The old ptrace interface exposes just one hardware
2472 watchpoint and no hardware breakpoints.
2474 * GDB is now able to use the Data Value Compare (DVC) register available on
2475 embedded PowerPC processors to implement in hardware simple watchpoint
2476 conditions of the form:
2478 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2480 This works in native GDB running on Linux kernels with the extended ptrace
2481 interface mentioned above.
2483 *** Changes in GDB 7.1
2487 ** Namespace Support
2489 GDB now supports importing of namespaces in C++. This enables the
2490 user to inspect variables from imported namespaces. Support for
2491 namepace aliasing has also been added. So, if a namespace is
2492 aliased in the current scope (e.g. namepace C=A; ) the user can
2493 print variables using the alias (e.g. (gdb) print C::x).
2497 All known bugs relating to the printing of virtual base class were
2498 fixed. It is now possible to call overloaded static methods using a
2503 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2504 and reinterpret_cast<> are now handled by the C++ expression parser.
2508 Xilinx MicroBlaze microblaze-*-*
2513 Xilinx MicroBlaze microblaze
2516 * Multi-program debugging.
2518 GDB now has support for multi-program (a.k.a. multi-executable or
2519 multi-exec) debugging. This allows for debugging multiple inferiors
2520 simultaneously each running a different program under the same GDB
2521 session. See "Debugging Multiple Inferiors and Programs" in the
2522 manual for more information. This implied some user visible changes
2523 in the multi-inferior support. For example, "info inferiors" now
2524 lists inferiors that are not running yet or that have exited
2525 already. See also "New commands" and "New options" below.
2527 * New tracing features
2529 GDB's tracepoint facility now includes several new features:
2531 ** Trace state variables
2533 GDB tracepoints now include support for trace state variables, which
2534 are variables managed by the target agent during a tracing
2535 experiment. They are useful for tracepoints that trigger each
2536 other, so for instance one tracepoint can count hits in a variable,
2537 and then a second tracepoint has a condition that is true when the
2538 count reaches a particular value. Trace state variables share the
2539 $-syntax of GDB convenience variables, and can appear in both
2540 tracepoint actions and condition expressions. Use the "tvariable"
2541 command to create, and "info tvariables" to view; see "Trace State
2542 Variables" in the manual for more detail.
2546 GDB now includes an option for defining fast tracepoints, which
2547 targets may implement more efficiently, such as by installing a jump
2548 into the target agent rather than a trap instruction. The resulting
2549 speedup can be by two orders of magnitude or more, although the
2550 tradeoff is that some program locations on some target architectures
2551 might not allow fast tracepoint installation, for instance if the
2552 instruction to be replaced is shorter than the jump. To request a
2553 fast tracepoint, use the "ftrace" command, with syntax identical to
2554 the regular trace command.
2556 ** Disconnected tracing
2558 It is now possible to detach GDB from the target while it is running
2559 a trace experiment, then reconnect later to see how the experiment
2560 is going. In addition, a new variable disconnected-tracing lets you
2561 tell the target agent whether to continue running a trace if the
2562 connection is lost unexpectedly.
2566 GDB now has the ability to save the trace buffer into a file, and
2567 then use that file as a target, similarly to you can do with
2568 corefiles. You can select trace frames, print data that was
2569 collected in them, and use tstatus to display the state of the
2570 tracing run at the moment that it was saved. To create a trace
2571 file, use "tsave <filename>", and to use it, do "target tfile
2574 ** Circular trace buffer
2576 You can ask the target agent to handle the trace buffer as a
2577 circular buffer, discarding the oldest trace frames to make room for
2578 newer ones, by setting circular-trace-buffer to on. This feature may
2579 not be available for all target agents.
2584 The disassemble command, when invoked with two arguments, now requires
2585 the arguments to be comma-separated.
2588 The info variables command now displays variable definitions. Files
2589 which only declare a variable are not shown.
2592 The source command is now capable of sourcing Python scripts.
2593 This feature is dependent on the debugger being build with Python
2596 Related to this enhancement is also the introduction of a new command
2597 "set script-extension" (see below).
2599 * New commands (for set/show, see "New options" below)
2601 record save [<FILENAME>]
2602 Save a file (in core file format) containing the process record
2603 execution log for replay debugging at a later time.
2605 record restore <FILENAME>
2606 Restore the process record execution log that was saved at an
2607 earlier time, for replay debugging.
2609 add-inferior [-copies <N>] [-exec <FILENAME>]
2612 clone-inferior [-copies <N>] [ID]
2613 Make a new inferior ready to execute the same program another
2614 inferior has loaded.
2619 maint info program-spaces
2620 List the program spaces loaded into GDB.
2622 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2623 show remote interrupt-sequence
2624 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2625 as the sequence to the remote target in order to interrupt the execution.
2626 Ctrl-C is a default. Some system prefers BREAK which is high level of
2627 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2628 Magic SysRq g. It is BREAK signal and character 'g'.
2630 set remote interrupt-on-connect [on | off]
2631 show remote interrupt-on-connect
2632 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2633 remote target when gdb connects to it. This is needed when you debug
2636 set remotebreak [on | off]
2638 Deprecated. Use "set/show remote interrupt-sequence" instead.
2640 tvariable $NAME [ = EXP ]
2641 Create or modify a trace state variable.
2644 List trace state variables and their values.
2646 delete tvariable $NAME ...
2647 Delete one or more trace state variables.
2650 Evaluate the given expressions without collecting anything into the
2651 trace buffer. (Valid in tracepoint actions only.)
2653 ftrace FN / FILE:LINE / *ADDR
2654 Define a fast tracepoint at the given function, line, or address.
2656 * New expression syntax
2658 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2659 GDB now parses 0b101010 identically with 42.
2663 set follow-exec-mode new|same
2664 show follow-exec-mode
2665 Control whether GDB reuses the same inferior across an exec call or
2666 creates a new one. This is useful to be able to restart the old
2667 executable after the inferior having done an exec call.
2669 set default-collect EXPR, ...
2670 show default-collect
2671 Define a list of expressions to be collected at each tracepoint.
2672 This is a useful way to ensure essential items are not overlooked,
2673 such as registers or a critical global variable.
2675 set disconnected-tracing
2676 show disconnected-tracing
2677 If set to 1, the target is instructed to continue tracing if it
2678 loses its connection to GDB. If 0, the target is to stop tracing
2681 set circular-trace-buffer
2682 show circular-trace-buffer
2683 If set to on, the target is instructed to use a circular trace buffer
2684 and discard the oldest trace frames instead of stopping the trace due
2685 to a full trace buffer. If set to off, the trace stops when the buffer
2686 fills up. Some targets may not support this.
2688 set script-extension off|soft|strict
2689 show script-extension
2690 If set to "off", the debugger does not perform any script language
2691 recognition, and all sourced files are assumed to be GDB scripts.
2692 If set to "soft" (the default), files are sourced according to
2693 filename extension, falling back to GDB scripts if the first
2695 If set to "strict", files are sourced according to filename extension.
2697 set ada trust-PAD-over-XVS on|off
2698 show ada trust-PAD-over-XVS
2699 If off, activate a workaround against a bug in the debugging information
2700 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2701 the GCC sources for more information about the GNAT encoding and
2702 PAD types in particular). It is always safe to set this option to
2703 off, but this introduces a slight performance penalty. The default
2706 * Python API Improvements
2708 ** GDB provides the new class gdb.LazyString. This is useful in
2709 some pretty-printing cases. The new method gdb.Value.lazy_string
2710 provides a simple way to create objects of this type.
2712 ** The fields returned by gdb.Type.fields now have an
2713 `is_base_class' attribute.
2715 ** The new method gdb.Type.range returns the range of an array type.
2717 ** The new method gdb.parse_and_eval can be used to parse and
2718 evaluate an expression.
2720 * New remote packets
2723 Define a trace state variable.
2726 Get the current value of a trace state variable.
2729 Set desired tracing behavior upon disconnection.
2732 Set the trace buffer to be linear or circular.
2735 Get data about the tracepoints currently in use.
2739 Process record now works correctly with hardware watchpoints.
2741 Multiple bug fixes have been made to the mips-irix port, making it
2742 much more reliable. In particular:
2743 - Debugging threaded applications is now possible again. Previously,
2744 GDB would hang while starting the program, or while waiting for
2745 the program to stop at a breakpoint.
2746 - Attaching to a running process no longer hangs.
2747 - An error occurring while loading a core file has been fixed.
2748 - Changing the value of the PC register now works again. This fixes
2749 problems observed when using the "jump" command, or when calling
2750 a function from GDB, or even when assigning a new value to $pc.
2751 - With the "finish" and "return" commands, the return value for functions
2752 returning a small array is now correctly printed.
2753 - It is now possible to break on shared library code which gets executed
2754 during a shared library init phase (code executed while executing
2755 their .init section). Previously, the breakpoint would have no effect.
2756 - GDB is now able to backtrace through the signal handler for
2757 non-threaded programs.
2759 PIE (Position Independent Executable) programs debugging is now supported.
2760 This includes debugging execution of PIC (Position Independent Code) shared
2761 libraries although for that, it should be possible to run such libraries as an
2764 *** Changes in GDB 7.0
2766 * GDB now has an interface for JIT compilation. Applications that
2767 dynamically generate code can create symbol files in memory and register
2768 them with GDB. For users, the feature should work transparently, and
2769 for JIT developers, the interface is documented in the GDB manual in the
2770 "JIT Compilation Interface" chapter.
2772 * Tracepoints may now be conditional. The syntax is as for
2773 breakpoints; either an "if" clause appended to the "trace" command,
2774 or the "condition" command is available. GDB sends the condition to
2775 the target for evaluation using the same bytecode format as is used
2776 for tracepoint actions.
2778 * The disassemble command now supports: an optional /r modifier, print the
2779 raw instructions in hex as well as in symbolic form, and an optional /m
2780 modifier to print mixed source+assembly.
2782 * Process record and replay
2784 In a architecture environment that supports ``process record and
2785 replay'', ``process record and replay'' target can record a log of
2786 the process execution, and replay it with both forward and reverse
2789 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2790 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2791 set execution-direction {forward|reverse}, for targets that support
2794 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2795 feature is available with a native GDB running on kernel version
2798 * GDB now has support for multi-byte and wide character sets on the
2799 target. Strings whose character type is wchar_t, char16_t, or
2800 char32_t are now correctly printed. GDB supports wide- and unicode-
2801 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2802 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2803 `printf'. This feature requires iconv to work properly; if your
2804 system does not have a working iconv, GDB can use GNU libiconv. See
2805 the installation instructions for more information.
2807 * GDB now supports automatic retrieval of shared library files from
2808 remote targets. To use this feature, specify a system root that begins
2809 with the `remote:' prefix, either via the `set sysroot' command or via
2810 the `--with-sysroot' configure-time option.
2812 * "info sharedlibrary" now takes an optional regex of libraries to show,
2813 and it now reports if a shared library has no debugging information.
2815 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2816 now complete on file names.
2818 * When completing in expressions, gdb will attempt to limit
2819 completions to allowable structure or union fields, where appropriate.
2820 For instance, consider:
2822 # struct example { int f1; double f2; };
2823 # struct example variable;
2826 If the user types TAB at the end of this command line, the available
2827 completions will be "f1" and "f2".
2829 * Inlined functions are now supported. They show up in backtraces, and
2830 the "step", "next", and "finish" commands handle them automatically.
2832 * GDB now supports the token-splicing (##) and stringification (#)
2833 operators when expanding macros. It also supports variable-arity
2836 * GDB now supports inspecting extra signal information, exported by
2837 the new $_siginfo convenience variable. The feature is currently
2838 implemented on linux ARM, i386 and amd64.
2840 * GDB can now display the VFP floating point registers and NEON vector
2841 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2842 can provide these registers (requires Linux 2.6.30 or later). Remote
2843 and simulator targets may also provide them.
2845 * New remote packets
2848 Search memory for a sequence of bytes.
2851 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2852 operation over reliable transport links. Use of this packet is
2853 controlled by the `set remote noack-packet' command.
2856 Kill the process with the specified process ID. Use this in preference
2857 to `k' when multiprocess protocol extensions are supported.
2860 Obtains additional operating system information
2864 Read or write additional signal information.
2866 * Removed remote protocol undocumented extension
2868 An undocumented extension to the remote protocol's `S' stop reply
2869 packet that permited the stub to pass a process id was removed.
2870 Remote servers should use the `T' stop reply packet instead.
2872 * GDB now supports multiple function calling conventions according to the
2873 DWARF-2 DW_AT_calling_convention function attribute.
2875 * The SH target utilizes the aforementioned change to distinguish between gcc
2876 and Renesas calling convention. It also adds the new CLI commands
2877 `set/show sh calling-convention'.
2879 * GDB can now read compressed debug sections, as produced by GNU gold
2880 with the --compress-debug-sections=zlib flag.
2882 * 64-bit core files are now supported on AIX.
2884 * Thread switching is now supported on Tru64.
2886 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2887 which will be allocated using malloc later in program execution.
2889 * The qXfer:libraries:read remote procotol packet now allows passing a
2890 list of section offsets.
2892 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2893 conditions handling signals delivered during attach or thread creation
2894 have also been fixed.
2896 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2897 From the user's standpoint, all unqualified instances of True and False
2898 are treated as the standard definitions, regardless of context.
2900 * GDB now parses C++ symbol and type names more flexibly. For
2903 template<typename T> class C { };
2906 GDB will now correctly handle all of:
2908 ptype C<char const *>
2909 ptype C<char const*>
2910 ptype C<const char *>
2911 ptype C<const char*>
2913 * New features in the GDB remote stub, gdbserver
2915 - The "--wrapper" command-line argument tells gdbserver to use a
2916 wrapper program to launch programs for debugging.
2918 - On PowerPC and S/390 targets, it is now possible to use a single
2919 gdbserver executable to debug both 32-bit and 64-bit programs.
2920 (This requires gdbserver itself to be built as a 64-bit executable.)
2922 - gdbserver uses the new noack protocol mode for TCP connections to
2923 reduce communications latency, if also supported and enabled in GDB.
2925 - Support for the sparc64-linux-gnu target is now included in
2928 - The amd64-linux build of gdbserver now supports debugging both
2929 32-bit and 64-bit programs.
2931 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2932 now support hardware watchpoints, and will use them automatically
2937 GDB now has support for scripting using Python. Whether this is
2938 available is determined at configure time.
2940 New GDB commands can now be written in Python.
2942 * Ada tasking support
2944 Ada tasks can now be inspected in GDB. The following commands have
2948 Print the list of Ada tasks.
2950 Print detailed information about task number N.
2952 Print the task number of the current task.
2954 Switch the context of debugging to task number N.
2956 * Support for user-defined prefixed commands. The "define" command can
2957 add new commands to existing prefixes, e.g. "target".
2959 * Multi-inferior, multi-process debugging.
2961 GDB now has generalized support for multi-inferior debugging. See
2962 "Debugging Multiple Inferiors" in the manual for more information.
2963 Although availability still depends on target support, the command
2964 set is more uniform now. The GNU/Linux specific multi-forks support
2965 has been migrated to this new framework. This implied some user
2966 visible changes; see "New commands" and also "Removed commands"
2969 * Target descriptions can now describe the target OS ABI. See the
2970 "Target Description Format" section in the user manual for more
2973 * Target descriptions can now describe "compatible" architectures
2974 to indicate that the target can execute applications for a different
2975 architecture in addition to those for the main target architecture.
2976 See the "Target Description Format" section in the user manual for
2979 * Multi-architecture debugging.
2981 GDB now includes general supports for debugging applications on
2982 hybrid systems that use more than one single processor architecture
2983 at the same time. Each such hybrid architecture still requires
2984 specific support to be added. The only hybrid architecture supported
2985 in this version of GDB is the Cell Broadband Engine.
2987 * GDB now supports integrated debugging of Cell/B.E. applications that
2988 use both the PPU and SPU architectures. To enable support for hybrid
2989 Cell/B.E. debugging, you need to configure GDB to support both the
2990 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2991 --enable-targets configure option.
2993 * Non-stop mode debugging.
2995 For some targets, GDB now supports an optional mode of operation in
2996 which you can examine stopped threads while other threads continue
2997 to execute freely. This is referred to as non-stop mode, with the
2998 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2999 section in the user manual for more information.
3001 To be able to support remote non-stop debugging, a remote stub needs
3002 to implement the non-stop mode remote protocol extensions, as
3003 described in the "Remote Non-Stop" section of the user manual. The
3004 GDB remote stub, gdbserver, has been adjusted to support these
3005 extensions on linux targets.
3007 * New commands (for set/show, see "New options" below)
3009 catch syscall [NAME(S) | NUMBER(S)]
3010 Catch system calls. Arguments, which should be names of system
3011 calls or their numbers, mean catch only those syscalls. Without
3012 arguments, every syscall will be caught. When the inferior issues
3013 any of the specified syscalls, GDB will stop and announce the system
3014 call, both when it is called and when its call returns. This
3015 feature is currently available with a native GDB running on the
3016 Linux Kernel, under the following architectures: x86, x86_64,
3017 PowerPC and PowerPC64.
3019 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3021 Search memory for a sequence of bytes.
3023 maint set python print-stack
3024 maint show python print-stack
3025 Show a stack trace when an error is encountered in a Python script.
3028 Invoke CODE by passing it to the Python interpreter.
3033 These allow macros to be defined, undefined, and listed
3037 Show operating system information about processes.
3040 List the inferiors currently under GDB's control.
3043 Switch focus to inferior number NUM.
3046 Detach from inferior number NUM.
3049 Kill inferior number NUM.
3053 set spu stop-on-load
3054 show spu stop-on-load
3055 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3057 set spu auto-flush-cache
3058 show spu auto-flush-cache
3059 Control whether to automatically flush the software-managed cache
3060 during Cell/B.E. debugging.
3062 set sh calling-convention
3063 show sh calling-convention
3064 Control the calling convention used when calling SH target functions.
3067 show debug timestamp
3068 Control display of timestamps with GDB debugging output.
3070 set disassemble-next-line
3071 show disassemble-next-line
3072 Control display of disassembled source lines or instructions when
3075 set remote noack-packet
3076 show remote noack-packet
3077 Set/show the use of remote protocol QStartNoAckMode packet. See above
3078 under "New remote packets."
3080 set remote query-attached-packet
3081 show remote query-attached-packet
3082 Control use of remote protocol `qAttached' (query-attached) packet.
3084 set remote read-siginfo-object
3085 show remote read-siginfo-object
3086 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3089 set remote write-siginfo-object
3090 show remote write-siginfo-object
3091 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3094 set remote reverse-continue
3095 show remote reverse-continue
3096 Control use of remote protocol 'bc' (reverse-continue) packet.
3098 set remote reverse-step
3099 show remote reverse-step
3100 Control use of remote protocol 'bs' (reverse-step) packet.
3102 set displaced-stepping
3103 show displaced-stepping
3104 Control displaced stepping mode. Displaced stepping is a way to
3105 single-step over breakpoints without removing them from the debuggee.
3106 Also known as "out-of-line single-stepping".
3109 show debug displaced
3110 Control display of debugging info for displaced stepping.
3112 maint set internal-error
3113 maint show internal-error
3114 Control what GDB does when an internal error is detected.
3116 maint set internal-warning
3117 maint show internal-warning
3118 Control what GDB does when an internal warning is detected.
3123 Use a wrapper program to launch programs for debugging.
3125 set multiple-symbols (all|ask|cancel)
3126 show multiple-symbols
3127 The value of this variable can be changed to adjust the debugger behavior
3128 when an expression or a breakpoint location contains an ambiguous symbol
3129 name (an overloaded function name, for instance).
3131 set breakpoint always-inserted
3132 show breakpoint always-inserted
3133 Keep breakpoints always inserted in the target, as opposed to inserting
3134 them when resuming the target, and removing them when the target stops.
3135 This option can improve debugger performance on slow remote targets.
3137 set arm fallback-mode (arm|thumb|auto)
3138 show arm fallback-mode
3139 set arm force-mode (arm|thumb|auto)
3141 These commands control how ARM GDB determines whether instructions
3142 are ARM or Thumb. The default for both settings is auto, which uses
3143 the current CPSR value for instructions without symbols; previous
3144 versions of GDB behaved as if "set arm fallback-mode arm".
3146 set disable-randomization
3147 show disable-randomization
3148 Standalone programs run with the virtual address space randomization enabled
3149 by default on some platforms. This option keeps the addresses stable across
3150 multiple debugging sessions.
3154 Control whether other threads are stopped or not when some thread hits
3159 Requests that asynchronous execution is enabled in the target, if available.
3160 In this case, it's possible to resume target in the background, and interact
3161 with GDB while the target is running. "show target-async" displays the
3162 current state of asynchronous execution of the target.
3164 set target-wide-charset
3165 show target-wide-charset
3166 The target-wide-charset is the name of the character set that GDB
3167 uses when printing characters whose type is wchar_t.
3169 set tcp auto-retry (on|off)
3171 set tcp connect-timeout
3172 show tcp connect-timeout
3173 These commands allow GDB to retry failed TCP connections to a remote stub
3174 with a specified timeout period; this is useful if the stub is launched
3175 in parallel with GDB but may not be ready to accept connections immediately.
3177 set libthread-db-search-path
3178 show libthread-db-search-path
3179 Control list of directories which GDB will search for appropriate
3182 set schedule-multiple (on|off)
3183 show schedule-multiple
3184 Allow GDB to resume all threads of all processes or only threads of
3185 the current process.
3189 Use more aggressive caching for accesses to the stack. This improves
3190 performance of remote debugging (particularly backtraces) without
3191 affecting correctness.
3193 set interactive-mode (on|off|auto)
3194 show interactive-mode
3195 Control whether GDB runs in interactive mode (on) or not (off).
3196 When in interactive mode, GDB waits for the user to answer all
3197 queries. Otherwise, GDB does not wait and assumes the default
3198 answer. When set to auto (the default), GDB determines which
3199 mode to use based on the stdin settings.
3204 For program forks, this is replaced by the new more generic `info
3205 inferiors' command. To list checkpoints, you can still use the
3206 `info checkpoints' command, which was an alias for the `info forks'
3210 Replaced by the new `inferior' command. To switch between
3211 checkpoints, you can still use the `restart' command, which was an
3212 alias for the `fork' command.
3215 This is removed, since some targets don't have a notion of
3216 processes. To switch between processes, you can still use the
3217 `inferior' command using GDB's own inferior number.
3220 For program forks, this is replaced by the new more generic `kill
3221 inferior' command. To delete a checkpoint, you can still use the
3222 `delete checkpoint' command, which was an alias for the `delete
3226 For program forks, this is replaced by the new more generic `detach
3227 inferior' command. To detach a checkpoint, you can still use the
3228 `detach checkpoint' command, which was an alias for the `detach
3231 * New native configurations
3233 x86/x86_64 Darwin i[34567]86-*-darwin*
3235 x86_64 MinGW x86_64-*-mingw*
3239 Lattice Mico32 lm32-*
3240 x86 DICOS i[34567]86-*-dicos*
3241 x86_64 DICOS x86_64-*-dicos*
3244 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3245 (mingw32ce) debugging.
3251 These commands were actually not implemented on any target.
3253 *** Changes in GDB 6.8
3255 * New native configurations
3257 NetBSD/hppa hppa*-*netbsd*
3258 Xtensa GNU/Linux xtensa*-*-linux*
3262 NetBSD/hppa hppa*-*-netbsd*
3263 Xtensa GNU/Lunux xtensa*-*-linux*
3265 * Change in command line behavior -- corefiles vs. process ids.
3267 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3268 attaching to process NUMBER fails, GDB no longer attempts to open a
3269 core file named NUMBER. Attaching to a program using the -c option
3270 is no longer supported. Instead, use the '-p' or '--pid' options.
3272 * GDB can now be built as a native debugger for debugging Windows x86
3273 (mingw32) Portable Executable (PE) programs.
3275 * Pending breakpoints no longer change their number when their address
3278 * GDB now supports breakpoints with multiple locations,
3279 including breakpoints on C++ constructors, inside C++ templates,
3280 and in inlined functions.
3282 * GDB's ability to debug optimized code has been improved. GDB more
3283 accurately identifies function bodies and lexical blocks that occupy
3284 more than one contiguous range of addresses.
3286 * Target descriptions can now describe registers for PowerPC.
3288 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3289 registers on PowerPC targets.
3291 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3292 targets even when the libthread_db library is not available.
3294 * The GDB remote stub, gdbserver, now supports the new file transfer
3295 commands (remote put, remote get, and remote delete).
3297 * The GDB remote stub, gdbserver, now supports run and attach in
3298 extended-remote mode.
3300 * hppa*64*-*-hpux11* target broken
3301 The debugger is unable to start a program and fails with the following
3302 error: "Error trying to get information about dynamic linker".
3303 The gdb-6.7 release is also affected.
3305 * GDB now supports the --enable-targets= configure option to allow
3306 building a single GDB executable that supports multiple remote
3307 target architectures.
3309 * GDB now supports debugging C and C++ programs which use the
3310 Decimal Floating Point extension. In addition, the PowerPC target
3311 now has a set of pseudo-registers to inspect decimal float values
3312 stored in two consecutive float registers.
3314 * The -break-insert MI command can optionally create pending
3317 * Improved support for debugging Ada
3318 Many improvements to the Ada language support have been made. These
3320 - Better support for Ada2005 interface types
3321 - Improved handling of arrays and slices in general
3322 - Better support for Taft-amendment types
3323 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3325 - Improved command completion in Ada
3328 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3333 set print frame-arguments (all|scalars|none)
3334 show print frame-arguments
3335 The value of this variable can be changed to control which argument
3336 values should be printed by the debugger when displaying a frame.
3341 Transfer files to and from a remote target, and delete remote files.
3348 Transfer files to and from a remote target, and delete remote files.
3350 * New remote packets
3357 Open, close, read, write, and delete files on the remote system.
3360 Attach to an existing process on the remote system, in extended-remote
3364 Run a new process on the remote system, in extended-remote mode.
3366 *** Changes in GDB 6.7
3368 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3369 bfd, libiberty and opcodes, as revealed by static analysis donated by
3370 Coverity, Inc. (http://scan.coverity.com).
3372 * When looking up multiply-defined global symbols, GDB will now prefer the
3373 symbol definition in the current shared library if it was built using the
3374 -Bsymbolic linker option.
3376 * When the Text User Interface (TUI) is not configured, GDB will now
3377 recognize the -tui command-line option and print a message that the TUI
3380 * The GDB remote stub, gdbserver, now has lower overhead for high
3381 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3383 * GDB for MIPS targets now autodetects whether a remote target provides
3384 32-bit or 64-bit register values.
3386 * Support for C++ member pointers has been improved.
3388 * GDB now understands XML target descriptions, which specify the
3389 target's overall architecture. GDB can read a description from
3390 a local file or over the remote serial protocol.
3392 * Vectors of single-byte data use a new integer type which is not
3393 automatically displayed as character or string data.
3395 * The /s format now works with the print command. It displays
3396 arrays of single-byte integers and pointers to single-byte integers
3399 * Target descriptions can now describe target-specific registers,
3400 for architectures which have implemented the support (currently
3401 only ARM, M68K, and MIPS).
3403 * GDB and the GDB remote stub, gdbserver, now support the XScale
3406 * The GDB remote stub, gdbserver, has been updated to support
3407 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3408 has been rewritten to use the standard GDB remote protocol.
3410 * GDB can now step into C++ functions which are called through thunks.
3412 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3414 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3415 layout. It also supports a TextSeg= and DataSeg= response when only
3416 segment base addresses (rather than offsets) are available.
3418 * The /i format now outputs any trailing branch delay slot instructions
3419 immediately following the last instruction within the count specified.
3421 * The GDB remote protocol "T" stop reply packet now supports a
3422 "library" response. Combined with the new "qXfer:libraries:read"
3423 packet, this response allows GDB to debug shared libraries on targets
3424 where the operating system manages the list of loaded libraries (e.g.
3425 Windows and SymbianOS).
3427 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3428 (DLLs) on Windows and Windows CE targets.
3430 * GDB now supports a faster verification that a .debug file matches its binary
3431 according to its build-id signature, if the signature is present.
3437 Enable or disable hardware flow control (RTS/CTS) on the serial port
3438 when debugging using remote targets.
3440 set mem inaccessible-by-default
3441 show mem inaccessible-by-default
3442 If the target supplies a memory map, for instance via the remote
3443 protocol's "qXfer:memory-map:read" packet, setting this variable
3444 prevents GDB from accessing memory outside the memory map. This
3445 is useful for targets with memory mapped registers or which react
3446 badly to accesses of unmapped address space.
3448 set breakpoint auto-hw
3449 show breakpoint auto-hw
3450 If the target supplies a memory map, for instance via the remote
3451 protocol's "qXfer:memory-map:read" packet, setting this variable
3452 lets GDB use hardware breakpoints automatically for memory regions
3453 where it can not use software breakpoints. This covers both the
3454 "break" command and internal breakpoints used for other commands
3455 including "next" and "finish".
3458 catch exception unhandled
3459 Stop the program execution when Ada exceptions are raised.
3462 Stop the program execution when an Ada assertion failed.
3466 Set an alternate system root for target files. This is a more
3467 general version of "set solib-absolute-prefix", which is now
3468 an alias to "set sysroot".
3471 Provide extended SPU facility status information. This set of
3472 commands is available only when debugging the Cell/B.E. SPU
3475 * New native configurations
3477 OpenBSD/sh sh*-*openbsd*
3480 unset tdesc filename
3482 Use the specified local file as an XML target description, and do
3483 not query the target for its built-in description.
3487 OpenBSD/sh sh*-*-openbsd*
3488 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3489 Toshiba Media Processor mep-elf
3491 * New remote packets
3494 Ignore the specified signals; pass them directly to the debugged program
3495 without stopping other threads or reporting them to GDB.
3497 qXfer:features:read:
3498 Read an XML target description from the target, which describes its
3503 Read or write contents of an spufs file on the target system. These
3504 packets are available only on the Cell/B.E. SPU architecture.
3506 qXfer:libraries:read:
3507 Report the loaded shared libraries. Combined with new "T" packet
3508 response, this packet allows GDB to debug shared libraries on
3509 targets where the operating system manages the list of loaded
3510 libraries (e.g. Windows and SymbianOS).
3514 Support for these obsolete configurations has been removed.
3522 i[34567]86-*-lynxos*
3523 i[34567]86-*-netware*
3524 i[34567]86-*-sco3.2v5*
3525 i[34567]86-*-sco3.2v4*
3527 i[34567]86-*-sysv4.2*
3530 i[34567]86-*-unixware2*
3531 i[34567]86-*-unixware*
3540 * Other removed features
3547 Various m68k-only ROM monitors.
3554 Various Renesas ROM monitors and debugging interfaces for SH and
3559 Support for a Macraigor serial interface to on-chip debugging.
3560 GDB does not directly support the newer parallel or USB
3565 A debug information format. The predecessor to DWARF 2 and
3566 DWARF 3, which are still supported.
3568 Support for the HP aCC compiler on HP-UX/PA-RISC
3570 SOM-encapsulated symbolic debugging information, automatic
3571 invocation of pxdb, and the aCC custom C++ ABI. This does not
3572 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3573 with aCC can still be debugged on an assembly level.
3575 MIPS ".pdr" sections
3577 A MIPS-specific format used to describe stack frame layout
3578 in debugging information.
3582 GDB could work with an older version of Guile to debug
3583 the interpreter and Scheme programs running in it.
3585 set mips stack-arg-size
3586 set mips saved-gpreg-size
3588 Use "set mips abi" to control parameter passing for MIPS.
3590 *** Changes in GDB 6.6
3595 Cell Broadband Engine SPU spu-elf
3597 * GDB can now be configured as a cross-debugger targeting native Windows
3598 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3599 running on a Windows system over TCP/IP to debug Windows programs.
3601 * The GDB remote stub, gdbserver, has been updated to support Windows and
3602 Cygwin debugging. Both single-threaded and multi-threaded programs are
3605 * The "set trust-readonly-sections" command works again. This command was
3606 broken in GDB 6.3, 6.4, and 6.5.
3608 * The "load" command now supports writing to flash memory, if the remote
3609 stub provides the required support.
3611 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3612 longer requires symbolic debug information (e.g. DWARF-2).
3617 unset substitute-path
3618 show substitute-path
3619 Manage a list of substitution rules that GDB uses to rewrite the name
3620 of the directories where the sources are located. This can be useful
3621 for instance when the sources were moved to a different location
3622 between compilation and debugging.
3626 Print each CLI command as it is executed. Each command is prefixed with
3627 a number of `+' symbols representing the nesting depth.
3628 The source command now has a `-v' option to enable the same feature.
3632 The ARM Demon monitor support (RDP protocol, "target rdp").
3634 Kernel Object Display, an embedded debugging feature which only worked with
3635 an obsolete version of Cisco IOS.
3637 The 'set download-write-size' and 'show download-write-size' commands.
3639 * New remote packets
3642 Tell a stub about GDB client features, and request remote target features.
3643 The first feature implemented is PacketSize, which allows the target to
3644 specify the size of packets it can handle - to minimize the number of
3645 packets required and improve performance when connected to a remote
3649 Fetch an OS auxilliary vector from the remote stub. This packet is a
3650 more efficient replacement for qPart:auxv:read.
3652 qXfer:memory-map:read:
3653 Fetch a memory map from the remote stub, including information about
3654 RAM, ROM, and flash memory devices.
3659 Erase and program a flash memory device.
3661 * Removed remote packets
3664 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3665 used it, and only gdbserver implemented it.
3667 *** Changes in GDB 6.5
3671 Renesas M32C/M16C m32c-elf
3673 Morpho Technologies ms1 ms1-elf
3677 init-if-undefined Initialize a convenience variable, but
3678 only if it doesn't already have a value.
3680 The following commands are presently only implemented for native GNU/Linux:
3682 checkpoint Save a snapshot of the program state.
3684 restart <n> Return the program state to a
3685 previously saved state.
3687 info checkpoints List currently saved checkpoints.
3689 delete-checkpoint <n> Delete a previously saved checkpoint.
3691 set|show detach-on-fork Tell gdb whether to detach from a newly
3692 forked process, or to keep debugging it.
3694 info forks List forks of the user program that
3695 are available to be debugged.
3697 fork <n> Switch to debugging one of several
3698 forks of the user program that are
3699 available to be debugged.
3701 delete-fork <n> Delete a fork from the list of forks
3702 that are available to be debugged (and
3703 kill the forked process).
3705 detach-fork <n> Delete a fork from the list of forks
3706 that are available to be debugged (and
3707 allow the process to continue).
3711 Morpho Technologies ms2 ms1-elf
3713 * Improved Windows host support
3715 GDB now builds as a cross debugger hosted on i686-mingw32, including
3716 native console support, and remote communications using either
3717 network sockets or serial ports.
3719 * Improved Modula-2 language support
3721 GDB can now print most types in the Modula-2 syntax. This includes:
3722 basic types, set types, record types, enumerated types, range types,
3723 pointer types and ARRAY types. Procedure var parameters are correctly
3724 printed and hexadecimal addresses and character constants are also
3725 written in the Modula-2 syntax. Best results can be obtained by using
3726 GNU Modula-2 together with the -gdwarf-2 command line option.
3730 The ARM rdi-share module.
3732 The Netware NLM debug server.
3734 *** Changes in GDB 6.4
3736 * New native configurations
3738 OpenBSD/arm arm*-*-openbsd*
3739 OpenBSD/mips64 mips64-*-openbsd*
3743 Morpho Technologies ms1 ms1-elf
3745 * New command line options
3747 --batch-silent As for --batch, but totally silent.
3748 --return-child-result The debugger will exist with the same value
3749 the child (debugged) program exited with.
3750 --eval-command COMMAND, -ex COMMAND
3751 Execute a single GDB CLI command. This may be
3752 specified multiple times and in conjunction
3753 with the --command (-x) option.
3755 * Deprecated commands removed
3757 The following commands, that were deprecated in 2000, have been
3761 set|show arm disassembly-flavor set|show arm disassembler
3762 othernames set arm disassembler
3763 set|show remotedebug set|show debug remote
3764 set|show archdebug set|show debug arch
3765 set|show eventdebug set|show debug event
3768 * New BSD user-level threads support
3770 It is now possible to debug programs using the user-level threads
3771 library on OpenBSD and FreeBSD. Currently supported (target)
3774 FreeBSD/amd64 x86_64-*-freebsd*
3775 FreeBSD/i386 i386-*-freebsd*
3776 OpenBSD/i386 i386-*-openbsd*
3778 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3779 are not yet supported.
3781 * New support for Matsushita MN10300 w/sim added
3782 (Work in progress). mn10300-elf.
3784 * REMOVED configurations and files
3786 VxWorks and the XDR protocol *-*-vxworks
3787 Motorola MCORE mcore-*-*
3788 National Semiconductor NS32000 ns32k-*-*
3790 * New "set print array-indexes" command
3792 After turning this setting "on", GDB prints the index of each element
3793 when displaying arrays. The default is "off" to preserve the previous
3796 * VAX floating point support
3798 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3800 * User-defined command support
3802 In addition to using $arg0..$arg9 for argument passing, it is now possible
3803 to use $argc to determine now many arguments have been passed. See the
3804 section on user-defined commands in the user manual for more information.
3806 *** Changes in GDB 6.3:
3808 * New command line option
3810 GDB now accepts -l followed by a number to set the timeout for remote
3813 * GDB works with GCC -feliminate-dwarf2-dups
3815 GDB now supports a more compact representation of DWARF-2 debug
3816 information using DW_FORM_ref_addr references. These are produced
3817 by GCC with the option -feliminate-dwarf2-dups and also by some
3818 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3819 to use -feliminate-dwarf2-dups.
3821 * Internationalization
3823 When supported by the host system, GDB will be built with
3824 internationalization (libintl). The task of marking up the sources is
3825 continued, we're looking forward to our first translation.
3829 Initial support for debugging programs compiled with the GNAT
3830 implementation of the Ada programming language has been integrated
3831 into GDB. In this release, support is limited to expression evaluation.
3833 * New native configurations
3835 GNU/Linux/m32r m32r-*-linux-gnu
3839 GDB's remote protocol now includes support for the 'p' packet. This
3840 packet is used to fetch individual registers from a remote inferior.
3842 * END-OF-LIFE registers[] compatibility module
3844 GDB's internal register infrastructure has been completely rewritten.
3845 The new infrastructure making possible the implementation of key new
3846 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3849 GDB 6.3 will be the last release to include the the registers[]
3850 compatibility module that allowed out-of-date configurations to
3851 continue to work. This change directly impacts the following
3861 powerpc bdm protocol
3863 Unless there is activity to revive these configurations, they will be
3864 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3866 * OBSOLETE configurations and files
3868 Configurations that have been declared obsolete in this release have
3869 been commented out. Unless there is activity to revive these
3870 configurations, the next release of GDB will have their sources
3871 permanently REMOVED.
3880 *** Changes in GDB 6.2.1:
3882 * MIPS `break main; run' gave an heuristic-fence-post warning
3884 When attempting to run even a simple program, a warning about
3885 heuristic-fence-post being hit would be reported. This problem has
3888 * MIPS IRIX 'long double' crashed GDB
3890 When examining a long double variable, GDB would get a segmentation
3891 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3892 IRIX long double values).
3896 A bug in the VAX stack code was causing problems with the "next"
3897 command. This problem has been fixed.
3899 *** Changes in GDB 6.2:
3901 * Fix for ``many threads''
3903 On GNU/Linux systems that use the NPTL threads library, a program
3904 rapidly creating and deleting threads would confuse GDB leading to the
3907 ptrace: No such process.
3908 thread_db_get_info: cannot get thread info: generic error
3910 This problem has been fixed.
3912 * "-async" and "-noasync" options removed.
3914 Support for the broken "-noasync" option has been removed (it caused
3917 * New ``start'' command.
3919 This command runs the program until the begining of the main procedure.
3921 * New BSD Kernel Data Access Library (libkvm) interface
3923 Using ``target kvm'' it is now possible to debug kernel core dumps and
3924 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3925 platforms. Currently supported (native-only) configurations are:
3927 FreeBSD/amd64 x86_64-*-freebsd*
3928 FreeBSD/i386 i?86-*-freebsd*
3929 NetBSD/i386 i?86-*-netbsd*
3930 NetBSD/m68k m68*-*-netbsd*
3931 NetBSD/sparc sparc-*-netbsd*
3932 OpenBSD/amd64 x86_64-*-openbsd*
3933 OpenBSD/i386 i?86-*-openbsd*
3934 OpenBSD/m68k m68*-openbsd*
3935 OpenBSD/sparc sparc-*-openbsd*
3937 * Signal trampoline code overhauled
3939 Many generic problems with GDB's signal handling code have been fixed.
3940 These include: backtraces through non-contiguous stacks; recognition
3941 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3942 call; backtrace through a signal trampoline; step into and out of
3943 signal handlers; and single-stepping in the signal trampoline.
3945 Please note that kernel bugs are a limiting factor here. These
3946 features have been shown to work on an s390 GNU/Linux system that
3947 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3949 * Cygwin support for DWARF 2 added.
3951 * New native configurations
3953 GNU/Linux/hppa hppa*-*-linux*
3954 OpenBSD/hppa hppa*-*-openbsd*
3955 OpenBSD/m68k m68*-*-openbsd*
3956 OpenBSD/m88k m88*-*-openbsd*
3957 OpenBSD/powerpc powerpc-*-openbsd*
3958 NetBSD/vax vax-*-netbsd*
3959 OpenBSD/vax vax-*-openbsd*
3961 * END-OF-LIFE frame compatibility module
3963 GDB's internal frame infrastructure has been completely rewritten.
3964 The new infrastructure making it possible to support key new features
3965 including DWARF 2 Call Frame Information. To aid in the task of
3966 migrating old configurations to this new infrastructure, a
3967 compatibility module, that allowed old configurations to continue to
3968 work, was also included.
3970 GDB 6.2 will be the last release to include this frame compatibility
3971 module. This change directly impacts the following configurations:
3981 Unless there is activity to revive these configurations, they will be
3982 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3984 * REMOVED configurations and files
3986 Sun 3, running SunOS 3 m68*-*-sunos3*
3987 Sun 3, running SunOS 4 m68*-*-sunos4*
3988 Sun 2, running SunOS 3 m68000-*-sunos3*
3989 Sun 2, running SunOS 4 m68000-*-sunos4*
3990 Motorola 680x0 running LynxOS m68*-*-lynxos*
3991 AT&T 3b1/Unix pc m68*-att-*
3992 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3993 decstation mips-dec-* mips-little-*
3994 riscos mips-*-riscos* mips-*-sysv*
3995 sonymips mips-sony-*
3996 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3998 *** Changes in GDB 6.1.1:
4000 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4002 The TUI (Text-mode User Interface) is now built as part of a default
4003 GDB configuration. It is enabled by either selecting the TUI with the
4004 command line option "-i=tui" or by running the separate "gdbtui"
4005 program. For more information on the TUI, see the manual "Debugging
4008 * Pending breakpoint support (also included in GDB 6.1)
4010 Support has been added to allow you to specify breakpoints in shared
4011 libraries that have not yet been loaded. If a breakpoint location
4012 cannot be found, and the "breakpoint pending" option is set to auto,
4013 GDB queries you if you wish to make the breakpoint pending on a future
4014 shared-library load. If and when GDB resolves the breakpoint symbol,
4015 the pending breakpoint is removed as one or more regular breakpoints
4018 Pending breakpoints are very useful for GCJ Java debugging.
4020 * Fixed ISO-C build problems
4022 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4023 non ISO-C code that stopped them being built using a more strict ISO-C
4024 compiler (e.g., IBM's C compiler).
4026 * Fixed build problem on IRIX 5
4028 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4029 wasn't able to compile compile on an IRIX 5 system.
4031 * Added execute permission to gdb/gdbserver/configure
4033 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4034 permission. This bug would cause configure to fail on a number of
4035 systems (Solaris, IRIX). Ref: server/519.
4037 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4039 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4040 has been updated to use constant array sizes.
4042 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4044 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4045 its generated DWARF Call Frame Info. This encoding was causing GDB to
4046 panic, that panic has been fixed. Ref: gdb/1628.
4048 * Fixed a problem when examining parameters in shared library code.
4050 When examining parameters in optimized shared library code generated
4051 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4052 not available''. GDB now correctly displays the variable's value.
4054 *** Changes in GDB 6.1:
4056 * Removed --with-mmalloc
4058 Support for the mmalloc memory manager has been removed, as it
4059 conflicted with the internal gdb byte cache.
4061 * Changes in AMD64 configurations
4063 The AMD64 target now includes the %cs and %ss registers. As a result
4064 the AMD64 remote protocol has changed; this affects the floating-point
4065 and SSE registers. If you rely on those registers for your debugging,
4066 you should upgrade gdbserver on the remote side.
4068 * Revised SPARC target
4070 The SPARC target has been completely revised, incorporating the
4071 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4072 support for LynxOS and SunOS 4 has been dropped. Calling functions
4073 from within GDB on operating systems with a non-executable stack
4074 (Solaris, OpenBSD) now works.
4078 GDB has a new C++ demangler which does a better job on the mangled
4079 names generated by current versions of g++. It also runs faster, so
4080 with this and other changes gdb should now start faster on large C++
4083 * DWARF 2 Location Expressions
4085 GDB support for location expressions has been extended to support function
4086 arguments and frame bases. Older versions of GDB could crash when they
4089 * C++ nested types and namespaces
4091 GDB's support for nested types and namespaces in C++ has been
4092 improved, especially if you use the DWARF 2 debugging format. (This
4093 is the default for recent versions of GCC on most platforms.)
4094 Specifically, if you have a class "Inner" defined within a class or
4095 namespace "Outer", then GDB realizes that the class's name is
4096 "Outer::Inner", not simply "Inner". This should greatly reduce the
4097 frequency of complaints about not finding RTTI symbols. In addition,
4098 if you are stopped at inside of a function defined within a namespace,
4099 GDB modifies its name lookup accordingly.
4101 * New native configurations
4103 NetBSD/amd64 x86_64-*-netbsd*
4104 OpenBSD/amd64 x86_64-*-openbsd*
4105 OpenBSD/alpha alpha*-*-openbsd*
4106 OpenBSD/sparc sparc-*-openbsd*
4107 OpenBSD/sparc64 sparc64-*-openbsd*
4109 * New debugging protocols
4111 M32R with SDI protocol m32r-*-elf*
4113 * "set prompt-escape-char" command deleted.
4115 The command "set prompt-escape-char" has been deleted. This command,
4116 and its very obscure effet on GDB's prompt, was never documented,
4117 tested, nor mentioned in the NEWS file.
4119 * OBSOLETE configurations and files
4121 Configurations that have been declared obsolete in this release have
4122 been commented out. Unless there is activity to revive these
4123 configurations, the next release of GDB will have their sources
4124 permanently REMOVED.
4126 Sun 3, running SunOS 3 m68*-*-sunos3*
4127 Sun 3, running SunOS 4 m68*-*-sunos4*
4128 Sun 2, running SunOS 3 m68000-*-sunos3*
4129 Sun 2, running SunOS 4 m68000-*-sunos4*
4130 Motorola 680x0 running LynxOS m68*-*-lynxos*
4131 AT&T 3b1/Unix pc m68*-att-*
4132 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4133 decstation mips-dec-* mips-little-*
4134 riscos mips-*-riscos* mips-*-sysv*
4135 sonymips mips-sony-*
4136 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4138 * REMOVED configurations and files
4140 SGI Irix-4.x mips-sgi-irix4 or iris4
4141 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4142 Z8000 simulator z8k-zilog-none or z8ksim
4143 Matsushita MN10200 w/simulator mn10200-*-*
4144 H8/500 simulator h8500-hitachi-hms or h8500hms
4145 HP/PA running BSD hppa*-*-bsd*
4146 HP/PA running OSF/1 hppa*-*-osf*
4147 HP/PA Pro target hppa*-*-pro*
4148 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4149 386BSD i[3456]86-*-bsd*
4150 Sequent family i[3456]86-sequent-sysv4*
4151 i[3456]86-sequent-sysv*
4152 i[3456]86-sequent-bsd*
4153 SPARC running LynxOS sparc-*-lynxos*
4154 SPARC running SunOS 4 sparc-*-sunos4*
4155 Tsqware Sparclet sparclet-*-*
4156 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4158 *** Changes in GDB 6.0:
4162 Support for debugging the Objective-C programming language has been
4163 integrated into GDB.
4165 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4167 DWARF 2's Call Frame Information makes available compiler generated
4168 information that more exactly describes the program's run-time stack.
4169 By using this information, GDB is able to provide more robust stack
4172 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4173 have been updated to use a new backtrace mechanism which includes
4174 DWARF 2 CFI support.
4178 GDB's remote protocol has been extended to include support for hosted
4179 file I/O (where the remote target uses GDB's file system). See GDB's
4180 remote protocol documentation for details.
4182 * All targets using the new architecture framework.
4184 All of GDB's targets have been updated to use the new internal
4185 architecture framework. The way is now open for future GDB releases
4186 to include cross-architecture native debugging support (i386 on amd64,
4189 * GNU/Linux's Thread Local Storage (TLS)
4191 GDB now includes support for for the GNU/Linux implementation of
4192 per-thread variables.
4194 * GNU/Linux's Native POSIX Thread Library (NPTL)
4196 GDB's thread code has been updated to work with either the new
4197 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4199 * Separate debug info.
4201 GDB, in conjunction with BINUTILS, now supports a mechanism for
4202 automatically loading debug information from a separate file. Instead
4203 of shipping full debug and non-debug versions of system libraries,
4204 system integrators can now instead ship just the stripped libraries
4205 and optional debug files.
4207 * DWARF 2 Location Expressions
4209 DWARF 2 Location Expressions allow the compiler to more completely
4210 describe the location of variables (even in optimized code) to the
4213 GDB now includes preliminary support for location expressions (support
4214 for DW_OP_piece is still missing).
4218 A number of long standing bugs that caused GDB to die while starting a
4219 Java application have been fixed. GDB's Java support is now
4220 considered "useable".
4222 * GNU/Linux support for fork, vfork, and exec.
4224 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4225 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4228 * GDB supports logging output to a file
4230 There are two new commands, "set logging" and "show logging", which can be
4231 used to capture GDB's output to a file.
4233 * The meaning of "detach" has changed for gdbserver
4235 The "detach" command will now resume the application, as documented. To
4236 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4239 * d10v, m68hc11 `regs' command deprecated
4241 The `info registers' command has been updated so that it displays the
4242 registers using a format identical to the old `regs' command.
4246 A new command, "maint set profile on/off", has been added. This command can
4247 be used to enable or disable profiling while running GDB, to profile a
4248 session or a set of commands. In addition there is a new configure switch,
4249 "--enable-profiling", which will cause GDB to be compiled with profiling
4250 data, for more informative profiling results.
4252 * Default MI syntax changed to "mi2".
4254 The default MI (machine interface) syntax, enabled by the command line
4255 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4256 "mi1", can be enabled by specifying the option "-i=mi1".
4258 Support for the original "mi0" syntax (included in GDB 5.0) has been
4261 Fix for gdb/192: removed extraneous space when displaying frame level.
4262 Fix for gdb/672: update changelist is now output in mi list format.
4263 Fix for gdb/702: a -var-assign that updates the value now shows up
4264 in a subsequent -var-update.
4266 * New native configurations.
4268 FreeBSD/amd64 x86_64-*-freebsd*
4270 * Multi-arched targets.
4272 HP/PA HPUX11 hppa*-*-hpux*
4273 Renesas M32R/D w/simulator m32r-*-elf*
4275 * OBSOLETE configurations and files
4277 Configurations that have been declared obsolete in this release have
4278 been commented out. Unless there is activity to revive these
4279 configurations, the next release of GDB will have their sources
4280 permanently REMOVED.
4282 Z8000 simulator z8k-zilog-none or z8ksim
4283 Matsushita MN10200 w/simulator mn10200-*-*
4284 H8/500 simulator h8500-hitachi-hms or h8500hms
4285 HP/PA running BSD hppa*-*-bsd*
4286 HP/PA running OSF/1 hppa*-*-osf*
4287 HP/PA Pro target hppa*-*-pro*
4288 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4289 Sequent family i[3456]86-sequent-sysv4*
4290 i[3456]86-sequent-sysv*
4291 i[3456]86-sequent-bsd*
4292 Tsqware Sparclet sparclet-*-*
4293 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4295 * REMOVED configurations and files
4298 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4299 IBM AIX PS/2 i[3456]86-*-aix
4300 i386 running Mach 3.0 i[3456]86-*-mach3*
4301 i386 running Mach i[3456]86-*-mach*
4302 i386 running OSF/1 i[3456]86-*osf1mk*
4303 HP/Apollo 68k Family m68*-apollo*-sysv*,
4305 m68*-hp-bsd*, m68*-hp-hpux*
4306 Argonaut Risc Chip (ARC) arc-*-*
4307 Mitsubishi D30V d30v-*-*
4308 Fujitsu FR30 fr30-*-elf*
4309 OS/9000 i[34]86-*-os9k
4310 I960 with MON960 i960-*-coff
4312 * MIPS $fp behavior changed
4314 The convenience variable $fp, for the MIPS, now consistently returns
4315 the address of the current frame's base. Previously, depending on the
4316 context, $fp could refer to either $sp or the current frame's base
4317 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4318 The GNU Source-Level Debugger''.
4320 *** Changes in GDB 5.3:
4322 * GNU/Linux shared library multi-threaded performance improved.
4324 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4325 `/proc', in preference to `ptrace' for memory reads. This may result
4326 in an improvement in the start-up time of multi-threaded, shared
4327 library applications when run under GDB. One GDB user writes: ``loads
4328 shared libs like mad''.
4330 * ``gdbserver'' now supports multi-threaded applications on some targets
4332 Support for debugging multi-threaded applications which use
4333 the GNU/Linux LinuxThreads package has been added for
4334 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4335 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4337 * GDB now supports C/C++ preprocessor macros.
4339 GDB now expands preprocessor macro invocations in C/C++ expressions,
4340 and provides various commands for showing macro definitions and how
4343 The new command `macro expand EXPRESSION' expands any macro
4344 invocations in expression, and shows the result.
4346 The new command `show macro MACRO-NAME' shows the definition of the
4347 macro named MACRO-NAME, and where it was defined.
4349 Most compilers don't include information about macros in the debugging
4350 information by default. In GCC 3.1, for example, you need to compile
4351 your program with the options `-gdwarf-2 -g3'. If the macro
4352 information is present in the executable, GDB will read it.
4354 * Multi-arched targets.
4356 DEC Alpha (partial) alpha*-*-*
4357 DEC VAX (partial) vax-*-*
4359 National Semiconductor NS32000 (partial) ns32k-*-*
4360 Motorola 68000 (partial) m68k-*-*
4361 Motorola MCORE mcore-*-*
4365 Fujitsu FRV architecture added by Red Hat frv*-*-*
4368 * New native configurations
4370 Alpha NetBSD alpha*-*-netbsd*
4371 SH NetBSD sh*-*-netbsdelf*
4372 MIPS NetBSD mips*-*-netbsd*
4373 UltraSPARC NetBSD sparc64-*-netbsd*
4375 * OBSOLETE configurations and files
4377 Configurations that have been declared obsolete in this release have
4378 been commented out. Unless there is activity to revive these
4379 configurations, the next release of GDB will have their sources
4380 permanently REMOVED.
4382 Mitsubishi D30V d30v-*-*
4383 OS/9000 i[34]86-*-os9k
4384 IBM AIX PS/2 i[3456]86-*-aix
4385 Fujitsu FR30 fr30-*-elf*
4386 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4387 Argonaut Risc Chip (ARC) arc-*-*
4388 i386 running Mach 3.0 i[3456]86-*-mach3*
4389 i386 running Mach i[3456]86-*-mach*
4390 i386 running OSF/1 i[3456]86-*osf1mk*
4391 HP/Apollo 68k Family m68*-apollo*-sysv*,
4393 m68*-hp-bsd*, m68*-hp-hpux*
4394 I960 with MON960 i960-*-coff
4396 * OBSOLETE languages
4398 CHILL, a Pascal like language used by telecommunications companies.
4400 * REMOVED configurations and files
4402 AMD 29k family via UDI a29k-amd-udi, udi29k
4403 A29K VxWorks a29k-*-vxworks
4404 AMD 29000 embedded, using EBMON a29k-none-none
4405 AMD 29000 embedded with COFF a29k-none-coff
4406 AMD 29000 embedded with a.out a29k-none-aout
4408 testsuite/gdb.hp/gdb.threads-hp/ directory
4410 * New command "set max-user-call-depth <nnn>"
4412 This command allows the user to limit the call depth of user-defined
4413 commands. The default is 1024.
4415 * Changes in FreeBSD/i386 native debugging.
4417 Support for the "generate-core-file" has been added.
4419 * New commands "dump", "append", and "restore".
4421 These commands allow data to be copied from target memory
4422 to a bfd-format or binary file (dump and append), and back
4423 from a file into memory (restore).
4425 * Improved "next/step" support on multi-processor Alpha Tru64.
4427 The previous single-step mechanism could cause unpredictable problems,
4428 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4429 of a software single-step mechanism prevents this.
4431 *** Changes in GDB 5.2.1:
4439 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4440 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4441 Fix, by Joel Brobecker imported from mainline.
4443 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4444 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4445 Fix, by Fred Fish, imported from mainline.
4447 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4448 Surprisingly enough, it works now.
4449 By Michal Ludvig, imported from mainline.
4451 i386 hardware watchpoint support:
4452 avoid misses on second run for some targets.
4453 By Pierre Muller, imported from mainline.
4455 *** Changes in GDB 5.2:
4457 * New command "set trust-readonly-sections on[off]".
4459 This command is a hint that tells gdb that read-only sections
4460 really are read-only (ie. that their contents will not change).
4461 In this mode, gdb will go to the object file rather than the
4462 target to read memory from read-only sections (such as ".text").
4463 This can be a significant performance improvement on some
4464 (notably embedded) targets.
4466 * New command "generate-core-file" (or "gcore").
4468 This new gdb command allows the user to drop a core file of the child
4469 process state at any time. So far it's been implemented only for
4470 GNU/Linux and Solaris, but should be relatively easily ported to other
4471 hosts. Argument is core file name (defaults to core.<pid>).
4473 * New command line option
4475 GDB now accepts --pid or -p followed by a process id.
4477 * Change in command line behavior -- corefiles vs. process ids.
4479 There is a subtle behavior in the way in which GDB handles
4480 command line arguments. The first non-flag argument is always
4481 a program to debug, but the second non-flag argument may either
4482 be a corefile or a process id. Previously, GDB would attempt to
4483 open the second argument as a corefile, and if that failed, would
4484 issue a superfluous error message and then attempt to attach it as
4485 a process. Now, if the second argument begins with a non-digit,
4486 it will be treated as a corefile. If it begins with a digit,
4487 GDB will attempt to attach it as a process, and if no such process
4488 is found, will then attempt to open it as a corefile.
4490 * Changes in ARM configurations.
4492 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4493 configuration is fully multi-arch.
4495 * New native configurations
4497 ARM NetBSD arm*-*-netbsd*
4498 x86 OpenBSD i[3456]86-*-openbsd*
4499 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4500 Sparc64 running FreeBSD sparc64-*-freebsd*
4504 Sanyo XStormy16 xstormy16-elf
4506 * OBSOLETE configurations and files
4508 Configurations that have been declared obsolete in this release have
4509 been commented out. Unless there is activity to revive these
4510 configurations, the next release of GDB will have their sources
4511 permanently REMOVED.
4513 AMD 29k family via UDI a29k-amd-udi, udi29k
4514 A29K VxWorks a29k-*-vxworks
4515 AMD 29000 embedded, using EBMON a29k-none-none
4516 AMD 29000 embedded with COFF a29k-none-coff
4517 AMD 29000 embedded with a.out a29k-none-aout
4519 testsuite/gdb.hp/gdb.threads-hp/ directory
4521 * REMOVED configurations and files
4523 TI TMS320C80 tic80-*-*
4525 PowerPC Solaris powerpcle-*-solaris*
4526 PowerPC Windows NT powerpcle-*-cygwin32
4527 PowerPC Netware powerpc-*-netware*
4528 Harris/CXUX m88k m88*-harris-cxux*
4529 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4530 ns32k-utek-sysv* ns32k-utek-*
4531 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4532 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4533 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4534 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4535 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4537 * Changes to command line processing
4539 The new `--args' feature can be used to specify command-line arguments
4540 for the inferior from gdb's command line.
4542 * Changes to key bindings
4544 There is a new `operate-and-get-next' function bound to `C-o'.
4546 *** Changes in GDB 5.1.1
4548 Fix compile problem on DJGPP.
4550 Fix a problem with floating-point registers on the i386 being
4553 Fix to stop GDB crashing on .debug_str debug info.
4555 Numerous documentation fixes.
4557 Numerous testsuite fixes.
4559 *** Changes in GDB 5.1:
4561 * New native configurations
4563 Alpha FreeBSD alpha*-*-freebsd*
4564 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4565 MIPS GNU/Linux mips*-*-linux*
4566 MIPS SGI Irix 6.x mips*-sgi-irix6*
4567 ia64 AIX ia64-*-aix*
4568 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4572 Motorola 68HC11 and 68HC12 m68hc11-elf
4574 UltraSparc running GNU/Linux sparc64-*-linux*
4576 * OBSOLETE configurations and files
4578 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4579 Harris/CXUX m88k m88*-harris-cxux*
4580 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4581 ns32k-utek-sysv* ns32k-utek-*
4582 TI TMS320C80 tic80-*-*
4584 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4585 PowerPC Solaris powerpcle-*-solaris*
4586 PowerPC Windows NT powerpcle-*-cygwin32
4587 PowerPC Netware powerpc-*-netware*
4588 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4589 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4590 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4591 Apple Macintosh (MPW) host N/A
4593 stuff.c (Program to stuff files into a specially prepared space in kdb)
4594 kdb-start.c (Main loop for the standalone kernel debugger)
4596 Configurations that have been declared obsolete in this release have
4597 been commented out. Unless there is activity to revive these
4598 configurations, the next release of GDB will have their sources
4599 permanently REMOVED.
4601 * REMOVED configurations and files
4603 Altos 3068 m68*-altos-*
4604 Convex c1-*-*, c2-*-*
4606 ARM RISCix arm-*-* (as host)
4610 * GDB has been converted to ISO C.
4612 GDB's source code has been converted to ISO C. In particular, the
4613 sources are fully protoized, and rely on standard headers being
4618 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4620 * The MI enabled by default.
4622 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4623 revised and enabled by default. Packages which use GDB as a debugging
4624 engine behind a UI or another front end are encouraged to switch to
4625 using the GDB/MI interface, instead of the old annotations interface
4626 which is now deprecated.
4628 * Support for debugging Pascal programs.
4630 GDB now includes support for debugging Pascal programs. The following
4631 main features are supported:
4633 - Pascal-specific data types such as sets;
4635 - automatic recognition of Pascal sources based on file-name
4638 - Pascal-style display of data types, variables, and functions;
4640 - a Pascal expression parser.
4642 However, some important features are not yet supported.
4644 - Pascal string operations are not supported at all;
4646 - there are some problems with boolean types;
4648 - Pascal type hexadecimal constants are not supported
4649 because they conflict with the internal variables format;
4651 - support for Pascal objects and classes is not full yet;
4653 - unlike Pascal, GDB is case-sensitive for symbol names.
4655 * Changes in completion.
4657 Commands such as `shell', `run' and `set args', which pass arguments
4658 to inferior programs, now complete on file names, similar to what
4659 users expect at the shell prompt.
4661 Commands which accept locations, such as `disassemble', `print',
4662 `breakpoint', `until', etc. now complete on filenames as well as
4663 program symbols. Thus, if you type "break foob TAB", and the source
4664 files linked into the programs include `foobar.c', that file name will
4665 be one of the candidates for completion. However, file names are not
4666 considered for completion after you typed a colon that delimits a file
4667 name from a name of a function in that file, as in "break foo.c:bar".
4669 `set demangle-style' completes on available demangling styles.
4671 * New platform-independent commands:
4673 It is now possible to define a post-hook for a command as well as a
4674 hook that runs before the command. For more details, see the
4675 documentation of `hookpost' in the GDB manual.
4677 * Changes in GNU/Linux native debugging.
4679 Support for debugging multi-threaded programs has been completely
4680 revised for all platforms except m68k and sparc. You can now debug as
4681 many threads as your system allows you to have.
4683 Attach/detach is supported for multi-threaded programs.
4685 Support for SSE registers was added for x86. This doesn't work for
4686 multi-threaded programs though.
4688 * Changes in MIPS configurations.
4690 Multi-arch support is enabled for all MIPS configurations.
4692 GDB can now be built as native debugger on SGI Irix 6.x systems for
4693 debugging n32 executables. (Debugging 64-bit executables is not yet
4696 * Unified support for hardware watchpoints in all x86 configurations.
4698 Most (if not all) native x86 configurations support hardware-assisted
4699 breakpoints and watchpoints in a unified manner. This support
4700 implements debug register sharing between watchpoints, which allows to
4701 put a virtually infinite number of watchpoints on the same address,
4702 and also supports watching regions up to 16 bytes with several debug
4705 The new maintenance command `maintenance show-debug-regs' toggles
4706 debugging print-outs in functions that insert, remove, and test
4707 watchpoints and hardware breakpoints.
4709 * Changes in the DJGPP native configuration.
4711 New command ``info dos sysinfo'' displays assorted information about
4712 the CPU, OS, memory, and DPMI server.
4714 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4715 display information about segment descriptors stored in GDT, LDT, and
4718 New commands ``info dos pde'' and ``info dos pte'' display entries
4719 from Page Directory and Page Tables (for now works with CWSDPMI only).
4720 New command ``info dos address-pte'' displays the Page Table entry for
4721 a given linear address.
4723 GDB can now pass command lines longer than 126 characters to the
4724 program being debugged (requires an update to the libdbg.a library
4725 which is part of the DJGPP development kit).
4727 DWARF2 debug info is now supported.
4729 It is now possible to `step' and `next' through calls to `longjmp'.
4731 * Changes in documentation.
4733 All GDB documentation was converted to GFDL, the GNU Free
4734 Documentation License.
4736 Tracepoints-related commands are now fully documented in the GDB
4739 TUI, the Text-mode User Interface, is now documented in the manual.
4741 Tracepoints-related commands are now fully documented in the GDB
4744 The "GDB Internals" manual now has an index. It also includes
4745 documentation of `ui_out' functions, GDB coding standards, x86
4746 hardware watchpoints, and memory region attributes.
4748 * GDB's version number moved to ``version.in''
4750 The Makefile variable VERSION has been replaced by the file
4751 ``version.in''. People creating GDB distributions should update the
4752 contents of this file.
4756 GUD support is now a standard part of the EMACS distribution.
4758 *** Changes in GDB 5.0:
4760 * Improved support for debugging FP programs on x86 targets
4762 Unified and much-improved support for debugging floating-point
4763 programs on all x86 targets. In particular, ``info float'' now
4764 displays the FP registers in the same format on all x86 targets, with
4765 greater level of detail.
4767 * Improvements and bugfixes in hardware-assisted watchpoints
4769 It is now possible to watch array elements, struct members, and
4770 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4771 on x86 targets no longer erroneously trigger when the address is
4774 * Improvements in the native DJGPP version of GDB
4776 The distribution now includes all the scripts and auxiliary files
4777 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4778 machines ``out of the box''.
4780 The DJGPP version can now debug programs that use signals. It is
4781 possible to catch signals that happened in the debuggee, deliver
4782 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4783 would kill the program being debugged.) Programs that hook hardware
4784 interrupts (keyboard, timer, etc.) can also be debugged.
4786 It is now possible to debug DJGPP programs that redirect their
4787 standard handles or switch them to raw (as opposed to cooked) mode, or
4788 even close them. The command ``run < foo > bar'' works as expected,
4789 and ``info terminal'' reports useful information about the debuggee's
4790 terminal, including raw/cooked mode, redirection, etc.
4792 The DJGPP version now uses termios functions for console I/O, which
4793 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4796 DOS-style file names with drive letters are now fully supported by
4799 It is now possible to debug DJGPP programs that switch their working
4800 directory. It is also possible to rerun the debuggee any number of
4801 times without restarting GDB; thus, you can use the same setup,
4802 breakpoints, etc. for many debugging sessions.
4804 * New native configurations
4806 ARM GNU/Linux arm*-*-linux*
4807 PowerPC GNU/Linux powerpc-*-linux*
4811 Motorola MCore mcore-*-*
4812 x86 VxWorks i[3456]86-*-vxworks*
4813 PowerPC VxWorks powerpc-*-vxworks*
4814 TI TMS320C80 tic80-*-*
4816 * OBSOLETE configurations
4818 Altos 3068 m68*-altos-*
4819 Convex c1-*-*, c2-*-*
4821 ARM RISCix arm-*-* (as host)
4824 Configurations that have been declared obsolete will be commented out,
4825 but the code will be left in place. If there is no activity to revive
4826 these configurations before the next release of GDB, the sources will
4827 be permanently REMOVED.
4829 * Gould support removed
4831 Support for the Gould PowerNode and NP1 has been removed.
4833 * New features for SVR4
4835 On SVR4 native platforms (such as Solaris), if you attach to a process
4836 without first loading a symbol file, GDB will now attempt to locate and
4837 load symbols from the running process's executable file.
4839 * Many C++ enhancements
4841 C++ support has been greatly improved. Overload resolution now works properly
4842 in almost all cases. RTTI support is on the way.
4844 * Remote targets can connect to a sub-program
4846 A popen(3) style serial-device has been added. This device starts a
4847 sub-process (such as a stand-alone simulator) and then communicates
4848 with that. The sub-program to run is specified using the syntax
4849 ``|<program> <args>'' vis:
4851 (gdb) set remotedebug 1
4852 (gdb) target extended-remote |mn10300-elf-sim program-args
4854 * MIPS 64 remote protocol
4856 A long standing bug in the mips64 remote protocol where by GDB
4857 expected certain 32 bit registers (ex SR) to be transfered as 32
4858 instead of 64 bits has been fixed.
4860 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4861 added to provide backward compatibility with older versions of GDB.
4863 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4865 The command ``set remotebinarydownload'' command has been replaced by
4866 ``set remote X-packet''. Other commands in ``set remote'' family
4867 include ``set remote P-packet''.
4869 * Breakpoint commands accept ranges.
4871 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4872 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4873 ``tracepoint passcount'' also accepts a range of tracepoints.
4875 * ``apropos'' command added.
4877 The ``apropos'' command searches through command names and
4878 documentation strings, printing out matches, making it much easier to
4879 try to find a command that does what you are looking for.
4883 A new machine oriented interface (MI) has been added to GDB. This
4884 interface is designed for debug environments running GDB as a separate
4885 process. This is part of the long term libGDB project. See the
4886 "GDB/MI" chapter of the GDB manual for further information. It can be
4887 enabled by configuring with:
4889 .../configure --enable-gdbmi
4891 *** Changes in GDB-4.18:
4893 * New native configurations
4895 HP-UX 10.20 hppa*-*-hpux10.20
4896 HP-UX 11.x hppa*-*-hpux11.0*
4897 M68K GNU/Linux m68*-*-linux*
4901 Fujitsu FR30 fr30-*-elf*
4902 Intel StrongARM strongarm-*-*
4903 Mitsubishi D30V d30v-*-*
4905 * OBSOLETE configurations
4907 Gould PowerNode, NP1 np1-*-*, pn-*-*
4909 Configurations that have been declared obsolete will be commented out,
4910 but the code will be left in place. If there is no activity to revive
4911 these configurations before the next release of GDB, the sources will
4912 be permanently REMOVED.
4916 As a compatibility experiment, GDB's source files buildsym.h and
4917 buildsym.c have been converted to pure standard C, no longer
4918 containing any K&R compatibility code. We believe that all systems in
4919 use today either come with a standard C compiler, or have a GCC port
4920 available. If this is not true, please report the affected
4921 configuration to bug-gdb@gnu.org immediately. See the README file for
4922 information about getting a standard C compiler if you don't have one
4927 GDB now uses readline 2.2.
4929 * set extension-language
4931 You can now control the mapping between filename extensions and source
4932 languages by using the `set extension-language' command. For instance,
4933 you can ask GDB to treat .c files as C++ by saying
4934 set extension-language .c c++
4935 The command `info extensions' lists all of the recognized extensions
4936 and their associated languages.
4938 * Setting processor type for PowerPC and RS/6000
4940 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4941 you can use the `set processor' command to specify what variant of the
4942 PowerPC family you are debugging. The command
4946 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4947 following PowerPC and RS6000 variants:
4949 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4950 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4952 403GC IBM PowerPC 403GC
4953 505 Motorola PowerPC 505
4954 860 Motorola PowerPC 860 or 850
4955 601 Motorola PowerPC 601
4956 602 Motorola PowerPC 602
4957 603 Motorola/IBM PowerPC 603 or 603e
4958 604 Motorola PowerPC 604 or 604e
4959 750 Motorola/IBM PowerPC 750 or 750
4961 At the moment, this command just tells GDB what to name the
4962 special-purpose processor registers. Since almost all the affected
4963 registers are inaccessible to user-level programs, this command is
4964 only useful for remote debugging in its present form.
4968 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4969 more extensive support for HP-UX. Added features include shared
4970 library support, kernel threads and hardware watchpoints for 11.00,
4971 support for HP's ANSI C and C++ compilers, and a compatibility mode
4972 for xdb and dbx commands.
4976 HP's donation includes the new concept of catchpoints, which is a
4977 generalization of the old catch command. On HP-UX, it is now possible
4978 to catch exec, fork, and vfork, as well as library loading.
4980 This means that the existing catch command has changed; its first
4981 argument now specifies the type of catch to be set up. See the
4982 output of "help catch" for a list of catchpoint types.
4984 * Debugging across forks
4986 On HP-UX, you can choose which process to debug when a fork() happens
4991 HP has donated a curses-based terminal user interface (TUI). To get
4992 it, build with --enable-tui. Although this can be enabled for any
4993 configuration, at present it only works for native HP debugging.
4995 * GDB remote protocol additions
4997 A new protocol packet 'X' that writes binary data is now available.
4998 Default behavior is to try 'X', then drop back to 'M' if the stub
4999 fails to respond. The settable variable `remotebinarydownload'
5000 allows explicit control over the use of 'X'.
5002 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5003 full 64-bit address. The command
5005 set remoteaddresssize 32
5007 can be used to revert to the old behaviour. For existing remote stubs
5008 the change should not be noticed, as the additional address information
5011 In order to assist in debugging stubs, you may use the maintenance
5012 command `packet' to send any text string to the stub. For instance,
5014 maint packet heythere
5016 sends the packet "$heythere#<checksum>". Note that it is very easy to
5017 disrupt a debugging session by sending the wrong packet at the wrong
5020 The compare-sections command allows you to compare section data on the
5021 target to what is in the executable file without uploading or
5022 downloading, by comparing CRC checksums.
5024 * Tracing can collect general expressions
5026 You may now collect general expressions at tracepoints. This requires
5027 further additions to the target-side stub; see tracepoint.c and
5028 doc/agentexpr.texi for further details.
5030 * mask-address variable for Mips
5032 For Mips targets, you may control the zeroing of the upper 32 bits of
5033 a 64-bit address by entering `set mask-address on'. This is mainly
5034 of interest to users of embedded R4xxx and R5xxx processors.
5036 * Higher serial baud rates
5038 GDB's serial code now allows you to specify baud rates 57600, 115200,
5039 230400, and 460800 baud. (Note that your host system may not be able
5040 to achieve all of these rates.)
5044 The i960 configuration now includes an initial implementation of a
5045 builtin simulator, contributed by Jim Wilson.
5048 *** Changes in GDB-4.17:
5050 * New native configurations
5052 Alpha GNU/Linux alpha*-*-linux*
5053 Unixware 2.x i[3456]86-unixware2*
5054 Irix 6.x mips*-sgi-irix6*
5055 PowerPC GNU/Linux powerpc-*-linux*
5056 PowerPC Solaris powerpcle-*-solaris*
5057 Sparc GNU/Linux sparc-*-linux*
5058 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5062 Argonaut Risc Chip (ARC) arc-*-*
5063 Hitachi H8/300S h8300*-*-*
5064 Matsushita MN10200 w/simulator mn10200-*-*
5065 Matsushita MN10300 w/simulator mn10300-*-*
5066 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5067 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5068 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5069 Mitsubishi D10V w/simulator d10v-*-*
5070 Mitsubishi M32R/D w/simulator m32r-*-elf*
5071 Tsqware Sparclet sparclet-*-*
5072 NEC V850 w/simulator v850-*-*
5074 * New debugging protocols
5076 ARM with RDI protocol arm*-*-*
5077 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5078 DDB and LSI variants of PMON protocol mips*-*-*
5079 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5080 PowerPC with SDS protocol powerpc{,le}-*-eabi
5081 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5085 All configurations can now understand and use the DWARF 2 debugging
5086 format. The choice is automatic, if the symbol file contains DWARF 2
5091 GDB now includes basic Java language support. This support is
5092 only useful with Java compilers that produce native machine code.
5094 * solib-absolute-prefix and solib-search-path
5096 For SunOS and SVR4 shared libraries, you may now set the prefix for
5097 loading absolute shared library symbol files, and the search path for
5098 locating non-absolute shared library symbol files.
5100 * Live range splitting
5102 GDB can now effectively debug code for which GCC has performed live
5103 range splitting as part of its optimization. See gdb/doc/LRS for
5104 more details on the expected format of the stabs information.
5108 GDB's support for the GNU Hurd, including thread debugging, has been
5109 updated to work with current versions of the Hurd.
5113 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5114 instruction set. ARM GDB automatically detects when Thumb
5115 instructions are in use, and adjusts disassembly and backtracing
5120 GDB's MIPS target configurations now handle the MIP16 16-bit
5125 GDB now includes support for overlays; if an executable has been
5126 linked such that multiple sections are based at the same address, GDB
5127 will decide which section to use for symbolic info. You can choose to
5128 control the decision manually, using overlay commands, or implement
5129 additional target-side support and use "overlay load-target" to bring
5130 in the overlay mapping. Do "help overlay" for more detail.
5134 The command "info symbol <address>" displays information about
5135 the symbol at the specified address.
5139 The standard remote protocol now includes an extension that allows
5140 asynchronous collection and display of trace data. This requires
5141 extensive support in the target-side debugging stub. Tracing mode
5142 includes a new interaction mode in GDB and new commands: see the
5143 file tracepoint.c for more details.
5147 Configurations for embedded MIPS now include a simulator contributed
5148 by Cygnus Solutions. The simulator supports the instruction sets
5149 of most MIPS variants.
5153 Sparc configurations may now include the ERC32 simulator contributed
5154 by the European Space Agency. The simulator is not built into
5155 Sparc targets by default; configure with --enable-sim to include it.
5159 For target configurations that may include multiple variants of a
5160 basic architecture (such as MIPS and SH), you may now set the
5161 architecture explicitly. "set arch" sets, "info arch" lists
5162 the possible architectures.
5164 *** Changes in GDB-4.16:
5166 * New native configurations
5168 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5169 M68K NetBSD m68k-*-netbsd*
5170 PowerPC AIX 4.x powerpc-*-aix*
5171 PowerPC MacOS powerpc-*-macos*
5172 PowerPC Windows NT powerpcle-*-cygwin32
5173 RS/6000 AIX 4.x rs6000-*-aix4*
5177 ARM with RDP protocol arm-*-*
5178 I960 with MON960 i960-*-coff
5179 MIPS VxWorks mips*-*-vxworks*
5180 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5181 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5183 Matra Sparclet sparclet-*-*
5187 The powerpc-eabi configuration now includes the PSIM simulator,
5188 contributed by Andrew Cagney, with assistance from Mike Meissner.
5189 PSIM is a very elaborate model of the PowerPC, including not only
5190 basic instruction set execution, but also details of execution unit
5191 performance and I/O hardware. See sim/ppc/README for more details.
5195 GDB now works with Solaris 2.5.
5197 * Windows 95/NT native
5199 GDB will now work as a native debugger on Windows 95 and Windows NT.
5200 To build it from source, you must use the "gnu-win32" environment,
5201 which uses a DLL to emulate enough of Unix to run the GNU tools.
5202 Further information, binaries, and sources are available at
5203 ftp.cygnus.com, under pub/gnu-win32.
5205 * dont-repeat command
5207 If a user-defined command includes the command `dont-repeat', then the
5208 command will not be repeated if the user just types return. This is
5209 useful if the command is time-consuming to run, so that accidental
5210 extra keystrokes don't run the same command many times.
5212 * Send break instead of ^C
5214 The standard remote protocol now includes an option to send a break
5215 rather than a ^C to the target in order to interrupt it. By default,
5216 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5218 * Remote protocol timeout
5220 The standard remote protocol includes a new variable `remotetimeout'
5221 that allows you to set the number of seconds before GDB gives up trying
5222 to read from the target. The default value is 2.
5224 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5226 By default GDB will automatically keep track of objects as they are
5227 loaded and unloaded by the dynamic linker. By using the command `set
5228 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5229 when shared library events occur, thus allowing you to set breakpoints
5230 in shared libraries which are explicitly loaded by the inferior.
5232 Note this feature does not work on hpux8. On hpux9 you must link
5233 /usr/lib/end.o into your program. This feature should work
5234 automatically on hpux10.
5236 * Irix 5.x hardware watchpoint support
5238 Irix 5 configurations now support the use of hardware watchpoints.
5240 * Mips protocol "SYN garbage limit"
5242 When debugging a Mips target using the `target mips' protocol, you
5243 may set the number of characters that GDB will ignore by setting
5244 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5245 every character. The default value is 1050.
5247 * Recording and replaying remote debug sessions
5249 If you set `remotelogfile' to the name of a file, gdb will write to it
5250 a recording of a remote debug session. This recording may then be
5251 replayed back to gdb using "gdbreplay". See gdbserver/README for
5252 details. This is useful when you have a problem with GDB while doing
5253 remote debugging; you can make a recording of the session and send it
5254 to someone else, who can then recreate the problem.
5256 * Speedups for remote debugging
5258 GDB includes speedups for downloading and stepping MIPS systems using
5259 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5260 and more efficient S-record downloading.
5262 * Memory use reductions and statistics collection
5264 GDB now uses less memory and reports statistics about memory usage.
5265 Try the `maint print statistics' command, for example.
5267 *** Changes in GDB-4.15:
5269 * Psymtabs for XCOFF
5271 The symbol reader for AIX GDB now uses partial symbol tables. This
5272 can greatly improve startup time, especially for large executables.
5274 * Remote targets use caching
5276 Remote targets now use a data cache to speed up communication with the
5277 remote side. The data cache could lead to incorrect results because
5278 it doesn't know about volatile variables, thus making it impossible to
5279 debug targets which use memory mapped I/O devices. `set remotecache
5280 off' turns the the data cache off.
5282 * Remote targets may have threads
5284 The standard remote protocol now includes support for multiple threads
5285 in the target system, using new protocol commands 'H' and 'T'. See
5286 gdb/remote.c for details.
5290 If GDB is configured with `--enable-netrom', then it will include
5291 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5292 acts as though it is a bank of ROM on the target board, but you can
5293 write into it over the network. GDB's support consists only of
5294 support for fast loading into the emulated ROM; to debug, you must use
5295 another protocol, such as standard remote protocol. The usual
5296 sequence is something like
5298 target nrom <netrom-hostname>
5300 target remote <netrom-hostname>:1235
5304 GDB now includes support for the Apple Macintosh, as a host only. It
5305 may be run as either an MPW tool or as a standalone application, and
5306 it can debug through the serial port. All the usual GDB commands are
5307 available, but to the target command, you must supply "serial" as the
5308 device type instead of "/dev/ttyXX". See mpw-README in the main
5309 directory for more information on how to build. The MPW configuration
5310 scripts */mpw-config.in support only a few targets, and only the
5311 mips-idt-ecoff target has been tested.
5315 GDB configuration now uses autoconf. This is not user-visible,
5316 but does simplify configuration and building.
5320 GDB now supports hpux10.
5322 *** Changes in GDB-4.14:
5324 * New native configurations
5326 x86 FreeBSD i[345]86-*-freebsd
5327 x86 NetBSD i[345]86-*-netbsd
5328 NS32k NetBSD ns32k-*-netbsd
5329 Sparc NetBSD sparc-*-netbsd
5333 A29K VxWorks a29k-*-vxworks
5334 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5335 CPU32 EST-300 emulator m68*-*-est*
5336 PowerPC ELF powerpc-*-elf
5339 * Alpha OSF/1 support for procfs
5341 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5342 possible to attach to running processes. As the mounting of the /proc
5343 filesystem is optional on the Alpha, GDB automatically determines
5344 the availability of /proc during startup. This can lead to problems
5345 if /proc is unmounted after GDB has been started.
5347 * Arguments to user-defined commands
5349 User commands may accept up to 10 arguments separated by whitespace.
5350 Arguments are accessed within the user command via $arg0..$arg9. A
5353 print $arg0 + $arg1 + $arg2
5355 To execute the command use:
5358 Defines the command "adder" which prints the sum of its three arguments.
5359 Note the arguments are text substitutions, so they may reference variables,
5360 use complex expressions, or even perform inferior function calls.
5362 * New `if' and `while' commands
5364 This makes it possible to write more sophisticated user-defined
5365 commands. Both commands take a single argument, which is the
5366 expression to evaluate, and must be followed by the commands to
5367 execute, one per line, if the expression is nonzero, the list being
5368 terminated by the word `end'. The `if' command list may include an
5369 `else' word, which causes the following commands to be executed only
5370 if the expression is zero.
5372 * Fortran source language mode
5374 GDB now includes partial support for Fortran 77. It will recognize
5375 Fortran programs and can evaluate a subset of Fortran expressions, but
5376 variables and functions may not be handled correctly. GDB will work
5377 with G77, but does not yet know much about symbols emitted by other
5380 * Better HPUX support
5382 Most debugging facilities now work on dynamic executables for HPPAs
5383 running hpux9 or later. You can attach to running dynamically linked
5384 processes, but by default the dynamic libraries will be read-only, so
5385 for instance you won't be able to put breakpoints in them. To change
5386 that behavior do the following before running the program:
5392 This will cause the libraries to be mapped private and read-write.
5393 To revert to the normal behavior, do this:
5399 You cannot set breakpoints or examine data in the library until after
5400 the library is loaded if the function/data symbols do not have
5403 GDB can now also read debug symbols produced by the HP C compiler on
5404 HPPAs (sorry, no C++, Fortran or 68k support).
5406 * Target byte order now dynamically selectable
5408 You can choose which byte order to use with a target system, via the
5409 commands "set endian big" and "set endian little", and you can see the
5410 current setting by using "show endian". You can also give the command
5411 "set endian auto", in which case GDB will use the byte order
5412 associated with the executable. Currently, only embedded MIPS
5413 configurations support dynamic selection of target byte order.
5415 * New DOS host serial code
5417 This version uses DPMI interrupts to handle buffered I/O, so you
5418 no longer need to run asynctsr when debugging boards connected to
5421 *** Changes in GDB-4.13:
5423 * New "complete" command
5425 This lists all the possible completions for the rest of the line, if it
5426 were to be given as a command itself. This is intended for use by emacs.
5428 * Trailing space optional in prompt
5430 "set prompt" no longer adds a space for you after the prompt you set. This
5431 allows you to set a prompt which ends in a space or one that does not.
5433 * Breakpoint hit counts
5435 "info break" now displays a count of the number of times the breakpoint
5436 has been hit. This is especially useful in conjunction with "ignore"; you
5437 can ignore a large number of breakpoint hits, look at the breakpoint info
5438 to see how many times the breakpoint was hit, then run again, ignoring one
5439 less than that number, and this will get you quickly to the last hit of
5442 * Ability to stop printing at NULL character
5444 "set print null-stop" will cause GDB to stop printing the characters of
5445 an array when the first NULL is encountered. This is useful when large
5446 arrays actually contain only short strings.
5448 * Shared library breakpoints
5450 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5451 breakpoints in shared libraries before the executable is run.
5453 * Hardware watchpoints
5455 There is a new hardware breakpoint for the watch command for sparclite
5456 targets. See gdb/sparclite/hw_breakpoint.note.
5458 Hardware watchpoints are also now supported under GNU/Linux.
5462 Annotations have been added. These are for use with graphical interfaces,
5463 and are still experimental. Currently only gdba.el uses these.
5465 * Improved Irix 5 support
5467 GDB now works properly with Irix 5.2.
5469 * Improved HPPA support
5471 GDB now works properly with the latest GCC and GAS.
5473 * New native configurations
5475 Sequent PTX4 i[34]86-sequent-ptx4
5476 HPPA running OSF/1 hppa*-*-osf*
5477 Atari TT running SVR4 m68*-*-sysv4*
5478 RS/6000 LynxOS rs6000-*-lynxos*
5482 OS/9000 i[34]86-*-os9k
5483 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5486 * Hitachi SH7000 and E7000-PC ICE support
5488 There is now support for communicating with the Hitachi E7000-PC ICE.
5489 This is available automatically when GDB is configured for the SH.
5493 As usual, a variety of small fixes and improvements, both generic
5494 and configuration-specific. See the ChangeLog for more detail.
5496 *** Changes in GDB-4.12:
5498 * Irix 5 is now supported
5502 GDB-4.12 on the HPPA has a number of changes which make it unable
5503 to debug the output from the currently released versions of GCC and
5504 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5505 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5506 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5509 *** Changes in GDB-4.11:
5511 * User visible changes:
5515 The "set remotedebug" option is now consistent between the mips remote
5516 target, remote targets using the gdb-specific protocol, UDI (AMD's
5517 debug protocol for the 29k) and the 88k bug monitor. It is now an
5518 integer specifying a debug level (normally 0 or 1, but 2 means more
5519 debugging info for the mips target).
5521 * DEC Alpha native support
5523 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5524 debug info, but GDB works fairly well with the DEC compiler and should
5525 work with a future GCC release. See the README file for a few
5526 Alpha-specific notes.
5528 * Preliminary thread implementation
5530 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5532 * LynxOS native and target support for 386
5534 This release has been hosted on LynxOS 2.2, and also can be configured
5535 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5538 * Improvements in C++ mangling/demangling.
5540 This release has much better g++ debugging, specifically in name
5541 mangling/demangling, virtual function calls, print virtual table,
5542 call methods, ...etc.
5544 *** Changes in GDB-4.10:
5546 * User visible changes:
5548 Remote debugging using the GDB-specific (`target remote') protocol now
5549 supports the `load' command. This is only useful if you have some
5550 other way of getting the stub to the target system, and you can put it
5551 somewhere in memory where it won't get clobbered by the download.
5553 Filename completion now works.
5555 When run under emacs mode, the "info line" command now causes the
5556 arrow to point to the line specified. Also, "info line" prints
5557 addresses in symbolic form (as well as hex).
5559 All vxworks based targets now support a user settable option, called
5560 vxworks-timeout. This option represents the number of seconds gdb
5561 should wait for responses to rpc's. You might want to use this if
5562 your vxworks target is, perhaps, a slow software simulator or happens
5563 to be on the far side of a thin network line.
5567 This release contains support for using a DEC alpha as a GDB host for
5568 cross debugging. Native alpha debugging is not supported yet.
5571 *** Changes in GDB-4.9:
5575 This is the first GDB release which is accompanied by a matching testsuite.
5576 The testsuite requires installation of dejagnu, which should be available
5577 via ftp from most sites that carry GNU software.
5581 'Cfront' style demangling has had its name changed to 'ARM' style, to
5582 emphasize that it was written from the specifications in the C++ Annotated
5583 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5584 disclaimers, it still generated too much confusion with users attempting to
5585 use gdb with AT&T cfront.
5589 GDB now uses a standard remote interface to a simulator library.
5590 So far, the library contains simulators for the Zilog Z8001/2, the
5591 Hitachi H8/300, H8/500 and Super-H.
5593 * New targets supported
5595 H8/300 simulator h8300-hitachi-hms or h8300hms
5596 H8/500 simulator h8500-hitachi-hms or h8500hms
5597 SH simulator sh-hitachi-hms or sh
5598 Z8000 simulator z8k-zilog-none or z8ksim
5599 IDT MIPS board over serial line mips-idt-ecoff
5601 Cross-debugging to GO32 targets is supported. It requires a custom
5602 version of the i386-stub.c module which is integrated with the
5603 GO32 memory extender.
5605 * New remote protocols
5607 MIPS remote debugging protocol.
5609 * New source languages supported
5611 This version includes preliminary support for Chill, a Pascal like language
5612 used by telecommunications companies. Chill support is also being integrated
5613 into the GNU compiler, but we don't know when it will be publically available.
5616 *** Changes in GDB-4.8:
5618 * HP Precision Architecture supported
5620 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5621 version of this support was available as a set of patches from the
5622 University of Utah. GDB does not support debugging of programs
5623 compiled with the HP compiler, because HP will not document their file
5624 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5625 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5627 Many problems in the preliminary version have been fixed.
5629 * Faster and better demangling
5631 We have improved template demangling and fixed numerous bugs in the GNU style
5632 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5633 character types (wchar_t) are now supported. Demangling of each symbol is now
5634 only done once, and is cached when the symbol table for a file is read in.
5635 This results in a small increase in memory usage for C programs, a moderate
5636 increase in memory usage for C++ programs, and a fantastic speedup in
5639 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5640 from the specifications in the Annotated Reference Manual, which AT&T's
5641 compiler does not actually implement.
5643 * G++ multiple inheritance compiler problem
5645 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5646 inheritance lattices was reworked to properly discover ambiguities. We
5647 recently found an example which causes this new algorithm to fail in a
5648 very subtle way, producing bad debug information for those classes.
5649 The file 'gcc.patch' (in this directory) can be applied to gcc to
5650 circumvent the problem. A future GCC release will contain a complete
5653 The previous G++ debug info problem (mentioned below for the gdb-4.7
5654 release) is fixed in gcc version 2.3.2.
5656 * Improved configure script
5658 The `configure' script will now attempt to guess your system type if
5659 you don't supply a host system type. The old scheme of supplying a
5660 host system triplet is preferable over using this. All the magic is
5661 done in the new `config.guess' script. Examine it for details.
5663 We have also brought our configure script much more in line with the FSF's
5664 version. It now supports the --with-xxx options. In particular,
5665 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5666 The resulting GDB will not be able to read arbitrary object file formats --
5667 only the format ``expected'' to be used on the configured target system.
5668 We hope to make this the default in a future release.
5670 * Documentation improvements
5672 There's new internal documentation on how to modify GDB, and how to
5673 produce clean changes to the code. We implore people to read it
5674 before submitting changes.
5676 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5677 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5678 `info' files are also provided. To build `info' files from scratch,
5679 you will need the latest `makeinfo' release, which will be available in
5680 a future texinfo-X.Y release.
5682 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5683 We're not sure exactly which versions have this problem, but it has
5684 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5685 or better. If that isn't possible, there is a patch in
5686 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5687 around this problem.
5691 GDB now supports array constants that can be used in expressions typed in by
5692 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5693 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5696 The new directory `gdb/sparclite' contains a program that demonstrates
5697 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5699 * New native hosts supported
5701 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5702 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5704 * New targets supported
5706 AMD 29k family via UDI a29k-amd-udi or udi29k
5708 * New file formats supported
5710 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5711 HPUX core files, and SCO 3.2v2 core files.
5715 Attaching to processes now works again; thanks for the many bug reports.
5717 We have also stomped on a bunch of core dumps caused by
5718 printf_filtered("%s") problems.
5720 We eliminated a copyright problem on the rpc and ptrace header files
5721 for VxWorks, which was discovered at the last minute during the 4.7
5722 release. You should now be able to build a VxWorks GDB.
5724 You can now interrupt gdb while an attached process is running. This
5725 will cause the attached process to stop, and give control back to GDB.
5727 We fixed problems caused by using too many file descriptors
5728 for reading symbols from object files and libraries. This was
5729 especially a problem for programs that used many (~100) shared
5732 The `step' command now only enters a subroutine if there is line number
5733 information for the subroutine. Otherwise it acts like the `next'
5734 command. Previously, `step' would enter subroutines if there was
5735 any debugging information about the routine. This avoids problems
5736 when using `cc -g1' on MIPS machines.
5738 * Internal improvements
5740 GDB's internal interfaces have been improved to make it easier to support
5741 debugging of multiple languages in the future.
5743 GDB now uses a common structure for symbol information internally.
5744 Minimal symbols (derived from linkage symbols in object files), partial
5745 symbols (from a quick scan of debug information), and full symbols
5746 contain a common subset of information, making it easier to write
5747 shared code that handles any of them.
5749 * New command line options
5751 We now accept --silent as an alias for --quiet.
5755 The memory-mapped-malloc library is now licensed under the GNU Library
5756 General Public License.
5758 *** Changes in GDB-4.7:
5760 * Host/native/target split
5762 GDB has had some major internal surgery to untangle the support for
5763 hosts and remote targets. Now, when you configure GDB for a remote
5764 target, it will no longer load in all of the support for debugging
5765 local programs on the host. When fully completed and tested, this will
5766 ensure that arbitrary host/target combinations are possible.
5768 The primary conceptual shift is to separate the non-portable code in
5769 GDB into three categories. Host specific code is required any time GDB
5770 is compiled on that host, regardless of the target. Target specific
5771 code relates to the peculiarities of the target, but can be compiled on
5772 any host. Native specific code is everything else: it can only be
5773 built when the host and target are the same system. Child process
5774 handling and core file support are two common `native' examples.
5776 GDB's use of /proc for controlling Unix child processes is now cleaner.
5777 It has been split out into a single module under the `target_ops' vector,
5778 plus two native-dependent functions for each system that uses /proc.
5780 * New hosts supported
5782 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5783 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5784 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5786 * New targets supported
5788 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5789 68030 and CPU32 m68030-*-*, m68332-*-*
5791 * New native hosts supported
5793 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5794 (386bsd is not well tested yet)
5795 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5797 * New file formats supported
5799 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5800 supports reading of `a.out.adobe' object files, which are an a.out
5801 format extended with minimal information about multiple sections.
5805 `show copying' is the same as the old `info copying'.
5806 `show warranty' is the same as `info warrantee'.
5807 These were renamed for consistency. The old commands continue to work.
5809 `info handle' is a new alias for `info signals'.
5811 You can now define pre-command hooks, which attach arbitrary command
5812 scripts to any command. The commands in the hook will be executed
5813 prior to the user's command. You can also create a hook which will be
5814 executed whenever the program stops. See gdb.texinfo.
5818 We now deal with Cfront style name mangling, and can even extract type
5819 info from mangled symbols. GDB can automatically figure out which
5820 symbol mangling style your C++ compiler uses.
5822 Calling of methods and virtual functions has been improved as well.
5826 The crash that occured when debugging Sun Ansi-C compiled binaries is
5827 fixed. This was due to mishandling of the extra N_SO stabs output
5830 We also finally got Ultrix 4.2 running in house, and fixed core file
5831 support, with help from a dozen people on the net.
5833 John M. Farrell discovered that the reason that single-stepping was so
5834 slow on all of the Mips based platforms (primarily SGI and DEC) was
5835 that we were trying to demangle and lookup a symbol used for internal
5836 purposes on every instruction that was being stepped through. Changing
5837 the name of that symbol so that it couldn't be mistaken for a C++
5838 mangled symbol sped things up a great deal.
5840 Rich Pixley sped up symbol lookups in general by getting much smarter
5841 about when C++ symbol mangling is necessary. This should make symbol
5842 completion (TAB on the command line) much faster. It's not as fast as
5843 we'd like, but it's significantly faster than gdb-4.6.
5847 A new user controllable variable 'call_scratch_address' can
5848 specify the location of a scratch area to be used when GDB
5849 calls a function in the target. This is necessary because the
5850 usual method of putting the scratch area on the stack does not work
5851 in systems that have separate instruction and data spaces.
5853 We integrated changes to support the 29k UDI (Universal Debugger
5854 Interface), but discovered at the last minute that we didn't have all
5855 of the appropriate copyright paperwork. We are working with AMD to
5856 resolve this, and hope to have it available soon.
5860 We have sped up the remote serial line protocol, especially for targets
5861 with lots of registers. It now supports a new `expedited status' ('T')
5862 message which can be used in place of the existing 'S' status message.
5863 This allows the remote stub to send only the registers that GDB
5864 needs to make a quick decision about single-stepping or conditional
5865 breakpoints, eliminating the need to fetch the entire register set for
5866 each instruction being stepped through.
5868 The GDB remote serial protocol now implements a write-through cache for
5869 registers, only re-reading the registers if the target has run.
5871 There is also a new remote serial stub for SPARC processors. You can
5872 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5873 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5874 processor with a serial port.
5878 Configure.in files have become much easier to read and modify. A new
5879 `table driven' format makes it more obvious what configurations are
5880 supported, and what files each one uses.
5884 There is a new opcodes library which will eventually contain all of the
5885 disassembly routines and opcode tables. At present, it only contains
5886 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5887 disassembler (binutils/objdump) to share these routines.
5889 The libiberty library is now copylefted under the GNU Library General
5890 Public License. This allows more liberal use, and was done so libg++
5891 can use it. This makes no difference to GDB, since the Library License
5892 grants all the rights from the General Public License.
5896 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5897 reference to the stabs symbol info used by the debugger. It is (as far
5898 as we know) the only published document on this fascinating topic. We
5899 encourage you to read it, compare it to the stabs information on your
5900 system, and send improvements on the document in general (to
5901 bug-gdb@prep.ai.mit.edu).
5903 And, of course, many bugs have been fixed.
5906 *** Changes in GDB-4.6:
5908 * Better support for C++ function names
5910 GDB now accepts as input the "demangled form" of C++ overloaded function
5911 names and member function names, and can do command completion on such names
5912 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5913 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5914 Make use of command completion, it is your friend.
5916 GDB also now accepts a variety of C++ mangled symbol formats. They are
5917 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5918 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5919 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5920 for the list of formats.
5922 * G++ symbol mangling problem
5924 Recent versions of gcc have a bug in how they emit debugging information for
5925 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5926 directory) can be applied to gcc to fix the problem. Alternatively, if you
5927 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5928 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5929 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5932 * New 'maintenance' command
5934 All of the commands related to hacking GDB internals have been moved out of
5935 the main command set, and now live behind the 'maintenance' command. This
5936 can also be abbreviated as 'mt'. The following changes were made:
5938 dump-me -> maintenance dump-me
5939 info all-breakpoints -> maintenance info breakpoints
5940 printmsyms -> maintenance print msyms
5941 printobjfiles -> maintenance print objfiles
5942 printpsyms -> maintenance print psymbols
5943 printsyms -> maintenance print symbols
5945 The following commands are new:
5947 maintenance demangle Call internal GDB demangler routine to
5948 demangle a C++ link name and prints the result.
5949 maintenance print type Print a type chain for a given symbol
5951 * Change to .gdbinit file processing
5953 We now read the $HOME/.gdbinit file before processing the argv arguments
5954 (e.g. reading symbol files or core files). This allows global parameters to
5955 be set, which will apply during the symbol reading. The ./.gdbinit is still
5956 read after argv processing.
5958 * New hosts supported
5960 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5962 GNU/Linux support i386-unknown-linux or linux
5964 We are also including code to support the HP/PA running BSD and HPUX. This
5965 is almost guaranteed not to work, as we didn't have time to test or build it
5966 for this release. We are including it so that the more adventurous (or
5967 masochistic) of you can play with it. We also had major problems with the
5968 fact that the compiler that we got from HP doesn't support the -g option.
5971 * New targets supported
5973 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5975 * More smarts about finding #include files
5977 GDB now remembers the compilation directory for all include files, and for
5978 all files from which C is generated (like yacc and lex sources). This
5979 greatly improves GDB's ability to find yacc/lex sources, and include files,
5980 especially if you are debugging your program from a directory different from
5981 the one that contains your sources.
5983 We also fixed a bug which caused difficulty with listing and setting
5984 breakpoints in include files which contain C code. (In the past, you had to
5985 try twice in order to list an include file that you hadn't looked at before.)
5987 * Interesting infernals change
5989 GDB now deals with arbitrary numbers of sections, where the symbols for each
5990 section must be relocated relative to that section's landing place in the
5991 target's address space. This work was needed to support ELF with embedded
5992 stabs used by Solaris-2.0.
5994 * Bug fixes (of course!)
5996 There have been loads of fixes for the following things:
5997 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5998 i960, stabs, DOS(GO32), procfs, etc...
6000 See the ChangeLog for details.
6002 *** Changes in GDB-4.5:
6004 * New machines supported (host and target)
6006 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6008 SGI Irix-4.x mips-sgi-irix4 or iris4
6010 * New malloc package
6012 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6013 Mmalloc is capable of handling mutiple heaps of memory. It is also
6014 capable of saving a heap to a file, and then mapping it back in later.
6015 This can be used to greatly speedup the startup of GDB by using a
6016 pre-parsed symbol table which lives in a mmalloc managed heap. For
6017 more details, please read mmalloc/mmalloc.texi.
6021 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6022 'help info proc' for details.
6024 * MIPS ecoff symbol table format
6026 The code that reads MIPS symbol table format is now supported on all hosts.
6027 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6030 * File name changes for MS-DOS
6032 Many files in the config directories have been renamed to make it easier to
6033 support GDB on MS-DOSe systems (which have very restrictive file name
6034 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6035 environment) is close to working but has some remaining problems. Note
6036 that debugging of DOS programs is not supported, due to limitations
6037 in the ``operating system'', but it can be used to host cross-debugging.
6039 * Cross byte order fixes
6041 Many fixes have been made to support cross debugging of Sparc and MIPS
6042 targets from hosts whose byte order differs.
6044 * New -mapped and -readnow options
6046 If memory-mapped files are available on your system through the 'mmap'
6047 system call, you can use the -mapped option on the `file' or
6048 `symbol-file' commands to cause GDB to write the symbols from your
6049 program into a reusable file. If the program you are debugging is
6050 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6051 Future GDB debugging sessions will notice the presence of this file,
6052 and will quickly map in symbol information from it, rather than reading
6053 the symbol table from the executable program. Using the '-mapped'
6054 option in a GDB `file' or `symbol-file' command has the same effect as
6055 starting GDB with the '-mapped' command-line option.
6057 You can cause GDB to read the entire symbol table immediately by using
6058 the '-readnow' option with any of the commands that load symbol table
6059 information (or on the GDB command line). This makes the command
6060 slower, but makes future operations faster.
6062 The -mapped and -readnow options are typically combined in order to
6063 build a `fred.syms' file that contains complete symbol information.
6064 A simple GDB invocation to do nothing but build a `.syms' file for future
6067 gdb -batch -nx -mapped -readnow programname
6069 The `.syms' file is specific to the host machine on which GDB is run.
6070 It holds an exact image of GDB's internal symbol table. It cannot be
6071 shared across multiple host platforms.
6073 * longjmp() handling
6075 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6076 siglongjmp() without losing control. This feature has not yet been ported to
6077 all systems. It currently works on many 386 platforms, all MIPS-based
6078 platforms (SGI, DECstation, etc), and Sun3/4.
6082 Preliminary work has been put in to support the new Solaris OS from Sun. At
6083 this time, it can control and debug processes, but it is not capable of
6088 As always, many many bug fixes. The major areas were with g++, and mipsread.
6089 People using the MIPS-based platforms should experience fewer mysterious
6090 crashes and trashed symbol tables.
6092 *** Changes in GDB-4.4:
6094 * New machines supported (host and target)
6096 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6098 BSD Reno on Vax vax-dec-bsd
6099 Ultrix on Vax vax-dec-ultrix
6101 * New machines supported (target)
6103 AMD 29000 embedded, using EBMON a29k-none-none
6107 GDB continues to improve its handling of C++. `References' work better.
6108 The demangler has also been improved, and now deals with symbols mangled as
6109 per the Annotated C++ Reference Guide.
6111 GDB also now handles `stabs' symbol information embedded in MIPS
6112 `ecoff' symbol tables. Since the ecoff format was not easily
6113 extensible to handle new languages such as C++, this appeared to be a
6114 good way to put C++ debugging info into MIPS binaries. This option
6115 will be supported in the GNU C compiler, version 2, when it is
6118 * New features for SVR4
6120 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6121 shared libraries. Debugging dynamically linked programs should present
6122 only minor differences from debugging statically linked programs.
6124 The `info proc' command will print out information about any process
6125 on an SVR4 system (including the one you are debugging). At the moment,
6126 it prints the address mappings of the process.
6128 If you bring up GDB on another SVR4 system, please send mail to
6129 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6131 * Better dynamic linking support in SunOS
6133 Reading symbols from shared libraries which contain debugging symbols
6134 now works properly. However, there remain issues such as automatic
6135 skipping of `transfer vector' code during function calls, which
6136 make it harder to debug code in a shared library, than to debug the
6137 same code linked statically.
6141 GDB is now using the latest `getopt' routines from the FSF. This
6142 version accepts the -- prefix for options with long names. GDB will
6143 continue to accept the old forms (-option and +option) as well.
6144 Various single letter abbreviations for options have been explicity
6145 added to the option table so that they won't get overshadowed in the
6146 future by other options that begin with the same letter.
6150 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6151 Many assorted bugs have been handled. Many more remain to be handled.
6152 See the various ChangeLog files (primarily in gdb and bfd) for details.
6155 *** Changes in GDB-4.3:
6157 * New machines supported (host and target)
6159 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6160 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6161 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6163 * Almost SCO Unix support
6165 We had hoped to support:
6166 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6167 (except for core file support), but we discovered very late in the release
6168 that it has problems with process groups that render gdb unusable. Sorry
6169 about that. I encourage people to fix it and post the fixes.
6171 * Preliminary ELF and DWARF support
6173 GDB can read ELF object files on System V Release 4, and can handle
6174 debugging records for C, in DWARF format, in ELF files. This support
6175 is preliminary. If you bring up GDB on another SVR4 system, please
6176 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6181 GDB now uses the latest `readline' library. One user-visible change
6182 is that two tabs will list possible command completions, which previously
6183 required typing M-? (meta-question mark, or ESC ?).
6187 The `stepi' bug that many of you noticed has been squashed.
6188 Many bugs in C++ have been handled. Many more remain to be handled.
6189 See the various ChangeLog files (primarily in gdb and bfd) for details.
6191 * State of the MIPS world (in case you wondered):
6193 GDB can understand the symbol tables emitted by the compilers
6194 supplied by most vendors of MIPS-based machines, including DEC. These
6195 symbol tables are in a format that essentially nobody else uses.
6197 Some versions of gcc come with an assembler post-processor called
6198 mips-tfile. This program is required if you want to do source-level
6199 debugging of gcc-compiled programs. I believe FSF does not ship
6200 mips-tfile with gcc version 1, but it will eventually come with gcc
6203 Debugging of g++ output remains a problem. g++ version 1.xx does not
6204 really support it at all. (If you're lucky, you should be able to get
6205 line numbers and stack traces to work, but no parameters or local
6206 variables.) With some work it should be possible to improve the
6209 When gcc version 2 is released, you will have somewhat better luck.
6210 However, even then you will get confusing results for inheritance and
6213 We will eventually provide full debugging of g++ output on
6214 DECstations. This will probably involve some kind of stabs-in-ecoff
6215 encapulation, but the details have not been worked out yet.
6218 *** Changes in GDB-4.2:
6220 * Improved configuration
6222 Only one copy of `configure' exists now, and it is not self-modifying.
6223 Porting BFD is simpler.
6227 The `step' and `next' commands now only stop at the first instruction
6228 of a source line. This prevents the multiple stops that used to occur
6229 in switch statements, for-loops, etc. `Step' continues to stop if a
6230 function that has debugging information is called within the line.
6234 Lots of small bugs fixed. More remain.
6236 * New host supported (not target)
6238 Intel 386 PC clone running Mach i386-none-mach
6241 *** Changes in GDB-4.1:
6243 * Multiple source language support
6245 GDB now has internal scaffolding to handle several source languages.
6246 It determines the type of each source file from its filename extension,
6247 and will switch expression parsing and number formatting to match the
6248 language of the function in the currently selected stack frame.
6249 You can also specifically set the language to be used, with
6250 `set language c' or `set language modula-2'.
6254 GDB now has preliminary support for the GNU Modula-2 compiler,
6255 currently under development at the State University of New York at
6256 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6257 continue through the fall of 1991 and into 1992.
6259 Other Modula-2 compilers are currently not supported, and attempting to
6260 debug programs compiled with them will likely result in an error as the
6261 symbol table is read. Feel free to work on it, though!
6263 There are hooks in GDB for strict type checking and range checking,
6264 in the `Modula-2 philosophy', but they do not currently work.
6268 GDB can now write to executable and core files (e.g. patch
6269 a variable's value). You must turn this switch on, specify
6270 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6271 by assigning a new value to a variable. Modifications take
6274 * Automatic SunOS shared library reading
6276 When you run your program, GDB automatically determines where its
6277 shared libraries (if any) have been loaded, and reads their symbols.
6278 The `share' command is no longer needed. This also works when
6279 examining core files.
6283 You can specify the number of lines that the `list' command shows.
6286 * New machines supported (host and target)
6288 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6289 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6290 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6292 * New hosts supported (not targets)
6294 IBM RT/PC: romp-ibm-aix or rtpc
6296 * New targets supported (not hosts)
6298 AMD 29000 embedded with COFF a29k-none-coff
6299 AMD 29000 embedded with a.out a29k-none-aout
6300 Ultracomputer remote kernel debug a29k-nyu-kern
6302 * New remote interfaces
6308 *** Changes in GDB-4.0:
6312 Wide output is wrapped at good places to make the output more readable.
6314 Gdb now supports cross-debugging from a host machine of one type to a
6315 target machine of another type. Communication with the target system
6316 is over serial lines. The ``target'' command handles connecting to the
6317 remote system; the ``load'' command will download a program into the
6318 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6319 also supports debugging of realtime processes running under VxWorks,
6320 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6321 stub on the target system.
6323 New CPUs supported include the AMD 29000 and Intel 960.
6325 GDB now reads object files and symbol tables via a ``binary file''
6326 library, which allows a single copy of GDB to debug programs of multiple
6327 object file types such as a.out and coff.
6329 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6330 refcard.dvi and refcard.ps are available to format it).
6333 * Control-Variable user interface simplified
6335 All variables that control the operation of the debugger can be set
6336 by the ``set'' command, and displayed by the ``show'' command.
6338 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6339 ``Show prompt'' produces the response:
6340 Gdb's prompt is new-gdb=>.
6342 What follows are the NEW set commands. The command ``help set'' will
6343 print a complete list of old and new set commands. ``help set FOO''
6344 will give a longer description of the variable FOO. ``show'' will show
6345 all of the variable descriptions and their current settings.
6347 confirm on/off: Enables warning questions for operations that are
6348 hard to recover from, e.g. rerunning the program while
6349 it is already running. Default is ON.
6351 editing on/off: Enables EMACS style command line editing
6352 of input. Previous lines can be recalled with
6353 control-P, the current line can be edited with control-B,
6354 you can search for commands with control-R, etc.
6357 history filename NAME: NAME is where the gdb command history
6358 will be stored. The default is .gdb_history,
6359 or the value of the environment variable
6362 history size N: The size, in commands, of the command history. The
6363 default is 256, or the value of the environment variable
6366 history save on/off: If this value is set to ON, the history file will
6367 be saved after exiting gdb. If set to OFF, the
6368 file will not be saved. The default is OFF.
6370 history expansion on/off: If this value is set to ON, then csh-like
6371 history expansion will be performed on
6372 command line input. The default is OFF.
6374 radix N: Sets the default radix for input and output. It can be set
6375 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6376 in the current radix, so "set radix 10" is always a no-op.
6378 height N: This integer value is the number of lines on a page. Default
6379 is 24, the current `stty rows'' setting, or the ``li#''
6380 setting from the termcap entry matching the environment
6383 width N: This integer value is the number of characters on a line.
6384 Default is 80, the current `stty cols'' setting, or the ``co#''
6385 setting from the termcap entry matching the environment
6388 Note: ``set screensize'' is obsolete. Use ``set height'' and
6389 ``set width'' instead.
6391 print address on/off: Print memory addresses in various command displays,
6392 such as stack traces and structure values. Gdb looks
6393 more ``symbolic'' if you turn this off; it looks more
6394 ``machine level'' with it on. Default is ON.
6396 print array on/off: Prettyprint arrays. New convenient format! Default
6399 print demangle on/off: Print C++ symbols in "source" form if on,
6402 print asm-demangle on/off: Same, for assembler level printouts
6405 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6408 * Support for Epoch Environment.
6410 The epoch environment is a version of Emacs v18 with windowing. One
6411 new command, ``inspect'', is identical to ``print'', except that if you
6412 are running in the epoch environment, the value is printed in its own
6416 * Support for Shared Libraries
6418 GDB can now debug programs and core files that use SunOS shared libraries.
6419 Symbols from a shared library cannot be referenced
6420 before the shared library has been linked with the program (this
6421 happens after you type ``run'' and before the function main() is entered).
6422 At any time after this linking (including when examining core files
6423 from dynamically linked programs), gdb reads the symbols from each
6424 shared library when you type the ``sharedlibrary'' command.
6425 It can be abbreviated ``share''.
6427 sharedlibrary REGEXP: Load shared object library symbols for files
6428 matching a unix regular expression. No argument
6429 indicates to load symbols for all shared libraries.
6431 info sharedlibrary: Status of loaded shared libraries.
6436 A watchpoint stops execution of a program whenever the value of an
6437 expression changes. Checking for this slows down execution
6438 tremendously whenever you are in the scope of the expression, but is
6439 quite useful for catching tough ``bit-spreader'' or pointer misuse
6440 problems. Some machines such as the 386 have hardware for doing this
6441 more quickly, and future versions of gdb will use this hardware.
6443 watch EXP: Set a watchpoint (breakpoint) for an expression.
6445 info watchpoints: Information about your watchpoints.
6447 delete N: Deletes watchpoint number N (same as breakpoints).
6448 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6449 enable N: Re-enables watchpoint number N (same as breakpoints).
6452 * C++ multiple inheritance
6454 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6457 * C++ exception handling
6459 Gdb now supports limited C++ exception handling. Besides the existing
6460 ability to breakpoint on an exception handler, gdb can breakpoint on
6461 the raising of an exception (before the stack is peeled back to the
6464 catch FOO: If there is a FOO exception handler in the dynamic scope,
6465 set a breakpoint to catch exceptions which may be raised there.
6466 Multiple exceptions (``catch foo bar baz'') may be caught.
6468 info catch: Lists all exceptions which may be caught in the
6469 current stack frame.
6472 * Minor command changes
6474 The command ``call func (arg, arg, ...)'' now acts like the print
6475 command, except it does not print or save a value if the function's result
6476 is void. This is similar to dbx usage.
6478 The ``up'' and ``down'' commands now always print the frame they end up
6479 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6480 frames without printing.
6482 * New directory command
6484 'dir' now adds directories to the FRONT of the source search path.
6485 The path starts off empty. Source files that contain debug information
6486 about the directory in which they were compiled can be found even
6487 with an empty path; Sun CC and GCC include this information. If GDB can't
6488 find your source file in the current directory, type "dir .".
6490 * Configuring GDB for compilation
6492 For normal use, type ``./configure host''. See README or gdb.texinfo
6495 GDB now handles cross debugging. If you are remotely debugging between
6496 two different machines, type ``./configure host -target=targ''.
6497 Host is the machine where GDB will run; targ is the machine
6498 where the program that you are debugging will run.