1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.11
6 * Intel MPX bound violation handling.
8 Segmentation faults caused by a Intel MPX boundary violation
9 now display the kind of violation (upper or lower), the memory
10 address accessed and the memory bounds, along with the usual
11 signal received and code location.
15 Program received signal SIGSEGV, Segmentation fault
16 Upper bound violation while accessing address 0x7fffffffc3b3
17 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
18 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
20 *** Changes in GDB 7.11
22 * GDB now supports debugging kernel-based threads on FreeBSD.
24 * Per-inferior thread numbers
26 Thread numbers are now per inferior instead of global. If you're
27 debugging multiple inferiors, GDB displays thread IDs using a
28 qualified INF_NUM.THR_NUM form. For example:
32 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
33 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
34 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
35 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
37 As consequence, thread numbers as visible in the $_thread
38 convenience variable and in Python's InferiorThread.num attribute
39 are no longer unique between inferiors.
41 GDB now maintains a second thread ID per thread, referred to as the
42 global thread ID, which is the new equivalent of thread numbers in
43 previous releases. See also $_gthread below.
45 For backwards compatibility, MI's thread IDs always refer to global
48 * Commands that accept thread IDs now accept the qualified
49 INF_NUM.THR_NUM form as well. For example:
52 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
55 * In commands that accept a list of thread IDs, you can now refer to
56 all threads of an inferior using a star wildcard. GDB accepts
57 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
58 refer to all threads of the current inferior. For example, "info
61 * You can use "info threads -gid" to display the global thread ID of
64 * The new convenience variable $_gthread holds the global number of
67 * The new convenience variable $_inferior holds the number of the
70 * GDB now displays the ID and name of the thread that hit a breakpoint
71 or received a signal, if your program is multi-threaded. For
74 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
75 Thread 1 "main" received signal SIGINT, Interrupt.
77 * Record btrace now supports non-stop mode.
79 * Support for tracepoints on aarch64-linux was added in GDBserver.
81 * The 'record instruction-history' command now indicates speculative execution
82 when using the Intel Processor Trace recording format.
84 * GDB now allows users to specify explicit locations, bypassing
85 the linespec parser. This feature is also available to GDB/MI
88 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
89 GDB now is able to debug both AArch64 applications and ARM applications
92 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
93 including JIT compiling fast tracepoint's conditional expression bytecode
96 * GDB now supports displaced stepping on AArch64 GNU/Linux.
98 * "info threads", "info inferiors", "info display", "info checkpoints"
99 and "maint info program-spaces" now list the corresponding items in
100 ascending ID order, for consistency with all other "info" commands.
102 * In Ada, the overloads selection menu has been enhanced to display the
103 parameter types and the return types for the matching overloaded subprograms.
107 maint set target-non-stop (on|off|auto)
108 maint show target-non-stop
109 Control whether GDB targets always operate in non-stop mode even if
110 "set non-stop" is "off". The default is "auto", meaning non-stop
111 mode is enabled if supported by the target.
113 maint set bfd-sharing
114 maint show bfd-sharing
115 Control the reuse of bfd objects.
119 Control display of debugging info regarding bfd caching.
123 Control display of debugging info regarding FreeBSD threads.
125 set remote multiprocess-extensions-packet
126 show remote multiprocess-extensions-packet
127 Set/show the use of the remote protocol multiprocess extensions.
129 set remote thread-events
130 show remote thread-events
131 Set/show the use of thread create/exit events.
133 set ada print-signatures on|off
134 show ada print-signatures"
135 Control whether parameter types and return types are displayed in overloads
136 selection menus. It is activaled (@code{on}) by default.
140 Controls the maximum size of memory, in bytes, that GDB will
141 allocate for value contents. Prevents incorrect programs from
142 causing GDB to allocate overly large buffers. Default is 64k.
145 skip -gfile file-glob-pattern
146 skip -function function
147 skip -rfunction regular-expression
148 A generalized form of the skip command, with new support for
149 glob-style file names and regular expressions for function names.
150 Additionally, a file spec and a function spec may now be combined.
152 * The "disassemble" command accepts a new modifier: /s.
153 It prints mixed source+disassembly like /m with two differences:
154 - disassembled instructions are now printed in program order, and
155 - and source for all relevant files is now printed.
156 The "/m" option is now considered deprecated: its "source-centric"
157 output hasn't proved useful in practice.
159 * The "record instruction-history" command accepts a new modifier: /s.
160 It behaves exactly like /m and prints mixed source+disassembly.
162 * The "set scheduler-locking" command supports a new mode "replay".
163 It behaves like "off" in record mode and like "on" in replay mode.
165 * Support for various ROM monitors has been removed:
167 target dbug dBUG ROM monitor for Motorola ColdFire
168 target picobug Motorola picobug monitor
169 target dink32 DINK32 ROM monitor for PowerPC
170 target m32r Renesas M32R/D ROM monitor
171 target mon2000 mon2000 ROM monitor
172 target ppcbug PPCBUG ROM monitor for PowerPC
174 * Support for reading/writing memory and extracting values on architectures
175 whose memory is addressable in units of any integral multiple of 8 bits.
180 Indicates that an exec system call was executed.
182 exec-events feature in qSupported
183 The qSupported packet allows GDB to request support for exec
184 events using the new 'gdbfeature' exec-event, and the qSupported
185 response can contain the corresponding 'stubfeature'. Set and
186 show commands can be used to display whether these features are enabled.
189 Equivalent to interrupting with the ^C character, but works in
192 thread created stop reason (T05 create:...)
193 Indicates that the thread was just created and is stopped at entry.
195 thread exit stop reply (w exitcode;tid)
196 Indicates that the thread has terminated.
199 Enables/disables thread create and exit event reporting. For
200 example, this is used in non-stop mode when GDB stops a set of
201 threads and synchronously waits for the their corresponding stop
202 replies. Without exit events, if one of the threads exits, GDB
203 would hang forever not knowing that it should no longer expect a
204 stop for that same thread.
208 Indicates that there are no resumed threads left in the target (all
209 threads are stopped). The remote stub reports support for this stop
210 reply to GDB's qSupported query.
212 QCatchSyscalls:1 [;SYSNO]...
214 Enable ("QCatchSyscalls:1") or disable ("QCatchSyscalls:0")
215 catching syscalls from the inferior process.
217 syscall_entry stop reason
218 Indicates that a syscall was just called.
220 syscall_return stop reason
221 Indicates that a syscall just returned.
223 QCatchSyscalls:1 in qSupported
224 The qSupported packet may now include QCatchSyscalls:1 in the reply
225 to indicate support for catching syscalls.
227 * Extended-remote exec events
229 ** GDB now has support for exec events on extended-remote Linux targets.
230 For such targets with Linux kernels 2.5.46 and later, this enables
231 follow-exec-mode and exec catchpoints.
233 set remote exec-event-feature-packet
234 show remote exec-event-feature-packet
235 Set/show the use of the remote exec event feature.
237 * Thread names in remote protocol
239 The reply to qXfer:threads:read may now include a name attribute for each
242 * Target remote mode fork and exec events
244 ** GDB now has support for fork and exec events on target remote mode
245 Linux targets. For such targets with Linux kernels 2.5.46 and later,
246 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
247 fork and exec catchpoints.
249 * Remote syscall events
251 ** GDB now has support for catch syscall on remote Linux targets,
252 currently enabled on x86/x86_64 architectures.
254 set remote catch-syscall-packet
255 show remote catch-syscall-packet
256 Set/show the use of the remote catch syscall feature.
260 ** The -var-set-format command now accepts the zero-hexadecimal
261 format. It outputs data in hexadecimal format with zero-padding on the
266 ** gdb.InferiorThread objects have a new attribute "global_num",
267 which refers to the thread's global thread ID. The existing
268 "num" attribute now refers to the thread's per-inferior number.
269 See "Per-inferior thread numbers" above.
270 ** gdb.InferiorThread objects have a new attribute "inferior", which
271 is the Inferior object the thread belongs to.
273 *** Changes in GDB 7.10
275 * Support for process record-replay and reverse debugging on aarch64*-linux*
276 targets has been added. GDB now supports recording of A64 instruction set
277 including advance SIMD instructions.
279 * Support for Sun's version of the "stabs" debug file format has been removed.
281 * GDB now honors the content of the file /proc/PID/coredump_filter
282 (PID is the process ID) on GNU/Linux systems. This file can be used
283 to specify the types of memory mappings that will be included in a
284 corefile. For more information, please refer to the manual page of
285 "core(5)". GDB also has a new command: "set use-coredump-filter
286 on|off". It allows to set whether GDB will read the content of the
287 /proc/PID/coredump_filter file when generating a corefile.
289 * The "info os" command on GNU/Linux can now display information on
291 "info os cpus" Listing of all cpus/cores on the system
293 * GDB has two new commands: "set serial parity odd|even|none" and
294 "show serial parity". These allows to set or show parity for the
297 * The "info source" command now displays the producer string if it was
298 present in the debug info. This typically includes the compiler version
299 and may include things like its command line arguments.
301 * The "info dll", an alias of the "info sharedlibrary" command,
302 is now available on all platforms.
304 * Directory names supplied to the "set sysroot" commands may be
305 prefixed with "target:" to tell GDB to access shared libraries from
306 the target system, be it local or remote. This replaces the prefix
307 "remote:". The default sysroot has been changed from "" to
308 "target:". "remote:" is automatically converted to "target:" for
309 backward compatibility.
311 * The system root specified by "set sysroot" will be prepended to the
312 filename of the main executable (if reported to GDB as absolute by
313 the operating system) when starting processes remotely, and when
314 attaching to already-running local or remote processes.
316 * GDB now supports automatic location and retrieval of executable
317 files from remote targets. Remote debugging can now be initiated
318 using only a "target remote" or "target extended-remote" command
319 (no "set sysroot" or "file" commands are required). See "New remote
322 * The "dump" command now supports verilog hex format.
324 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
326 * On GNU/Linux, GDB and gdbserver are now able to access executable
327 and shared library files without a "set sysroot" command when
328 attaching to processes running in different mount namespaces from
329 the debugger. This makes it possible to attach to processes in
330 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
331 See "New remote packets" below.
333 * The "tui reg" command now provides completion for all of the
334 available register groups, including target specific groups.
336 * The HISTSIZE environment variable is no longer read when determining
337 the size of GDB's command history. GDB now instead reads the dedicated
338 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
339 disables truncation of command history. Non-numeric values of GDBHISTSIZE
344 ** Memory ports can now be unbuffered.
348 ** gdb.Objfile objects have a new attribute "username",
349 which is the name of the objfile as specified by the user,
350 without, for example, resolving symlinks.
351 ** You can now write frame unwinders in Python.
352 ** gdb.Type objects have a new method "optimized_out",
353 returning optimized out gdb.Value instance of this type.
354 ** gdb.Value objects have new methods "reference_value" and
355 "const_value" which return a reference to the value and a
356 "const" version of the value respectively.
360 maint print symbol-cache
361 Print the contents of the symbol cache.
363 maint print symbol-cache-statistics
364 Print statistics of symbol cache usage.
366 maint flush-symbol-cache
367 Flush the contents of the symbol cache.
371 Start branch trace recording using Branch Trace Store (BTS) format.
374 Evaluate expression by using the compiler and print result.
378 Explicit commands for enabling and disabling tui mode.
381 set mpx bound on i386 and amd64
382 Support for bound table investigation on Intel MPX enabled applications.
386 Start branch trace recording using Intel Processor Trace format.
389 Print information about branch tracing internals.
391 maint btrace packet-history
392 Print the raw branch tracing data.
394 maint btrace clear-packet-history
395 Discard the stored raw branch tracing data.
398 Discard all branch tracing data. It will be fetched and processed
399 anew by the next "record" command.
404 Renamed from "set debug dwarf2-die".
406 Renamed from "show debug dwarf2-die".
409 Renamed from "set debug dwarf2-read".
410 show debug dwarf-read
411 Renamed from "show debug dwarf2-read".
413 maint set dwarf always-disassemble
414 Renamed from "maint set dwarf2 always-disassemble".
415 maint show dwarf always-disassemble
416 Renamed from "maint show dwarf2 always-disassemble".
418 maint set dwarf max-cache-age
419 Renamed from "maint set dwarf2 max-cache-age".
420 maint show dwarf max-cache-age
421 Renamed from "maint show dwarf2 max-cache-age".
424 show debug dwarf-line
425 Control display of debugging info regarding DWARF line processing.
429 Set the maximum number of candidates to be considered during
430 completion. The default value is 200. This limit allows GDB
431 to avoid generating large completion lists, the computation of
432 which can cause the debugger to become temporarily unresponsive.
434 set history remove-duplicates
435 show history remove-duplicates
436 Control the removal of duplicate history entries.
438 maint set symbol-cache-size
439 maint show symbol-cache-size
440 Control the size of the symbol cache.
442 set|show record btrace bts buffer-size
443 Set and show the size of the ring buffer used for branch tracing in
445 The obtained size may differ from the requested size. Use "info
446 record" to see the obtained buffer size.
448 set debug linux-namespaces
449 show debug linux-namespaces
450 Control display of debugging info regarding Linux namespaces.
452 set|show record btrace pt buffer-size
453 Set and show the size of the ring buffer used for branch tracing in
454 Intel Processor Trace format.
455 The obtained size may differ from the requested size. Use "info
456 record" to see the obtained buffer size.
458 maint set|show btrace pt skip-pad
459 Set and show whether PAD packets are skipped when computing the
462 * The command 'thread apply all' can now support new option '-ascending'
463 to call its specified command for all threads in ascending order.
465 * Python/Guile scripting
467 ** GDB now supports auto-loading of Python/Guile scripts contained in the
468 special section named `.debug_gdb_scripts'.
472 qXfer:btrace-conf:read
473 Return the branch trace configuration for the current thread.
475 Qbtrace-conf:bts:size
476 Set the requested ring buffer size for branch tracing in BTS format.
479 Enable Intel Procesor Trace-based branch tracing for the current
480 process. The remote stub reports support for this packet to GDB's
484 Set the requested ring buffer size for branch tracing in Intel Processor
488 Indicates a memory breakpoint instruction was executed, irrespective
489 of whether it was GDB that planted the breakpoint or the breakpoint
490 is hardcoded in the program. This is required for correct non-stop
494 Indicates the target stopped for a hardware breakpoint. This is
495 required for correct non-stop mode operation.
498 Return information about files on the remote system.
501 Return the full absolute name of the file that was executed to
502 create a process running on the remote system.
505 Select the filesystem on which vFile: operations with filename
506 arguments will operate. This is required for GDB to be able to
507 access files on remote targets where the remote stub does not
508 share a common filesystem with the inferior(s).
511 Indicates that a fork system call was executed.
514 Indicates that a vfork system call was executed.
516 vforkdone stop reason
517 Indicates that a vfork child of the specified process has executed
518 an exec or exit, allowing the vfork parent to resume execution.
520 fork-events and vfork-events features in qSupported
521 The qSupported packet allows GDB to request support for fork and
522 vfork events using new 'gdbfeatures' fork-events and vfork-events,
523 and the qSupported response can contain the corresponding
524 'stubfeatures'. Set and show commands can be used to display
525 whether these features are enabled.
527 * Extended-remote fork events
529 ** GDB now has support for fork events on extended-remote Linux
530 targets. For targets with Linux kernels 2.5.60 and later, this
531 enables follow-fork-mode and detach-on-fork for both fork and
532 vfork, as well as fork and vfork catchpoints.
534 * The info record command now shows the recording format and the
535 branch tracing configuration for the current thread when using
536 the btrace record target.
537 For the BTS format, it shows the ring buffer size.
539 * GDB now has support for DTrace USDT (Userland Static Defined
540 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
542 * GDB now supports access to vector registers on S/390 GNU/Linux
545 * Removed command line options
547 -xdb HP-UX XDB compatibility mode.
549 * Removed targets and native configurations
551 HP/PA running HP-UX hppa*-*-hpux*
552 Itanium running HP-UX ia64-*-hpux*
554 * New configure options
557 This configure option allows the user to build GDB with support for
558 Intel Processor Trace (default: auto). This requires libipt.
560 --with-libipt-prefix=PATH
561 Specify the path to the version of libipt that GDB should use.
562 $PATH/include should contain the intel-pt.h header and
563 $PATH/lib should contain the libipt.so library.
565 *** Changes in GDB 7.9.1
569 ** Xmethods can now specify a result type.
571 *** Changes in GDB 7.9
573 * GDB now supports hardware watchpoints on x86 GNU Hurd.
577 ** You can now access frame registers from Python scripts.
578 ** New attribute 'producer' for gdb.Symtab objects.
579 ** gdb.Objfile objects have a new attribute "progspace",
580 which is the gdb.Progspace object of the containing program space.
581 ** gdb.Objfile objects have a new attribute "owner".
582 ** gdb.Objfile objects have a new attribute "build_id",
583 which is the build ID generated when the file was built.
584 ** gdb.Objfile objects have a new method "add_separate_debug_file".
585 ** A new event "gdb.clear_objfiles" has been added, triggered when
586 selecting a new file to debug.
587 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
588 ** New function gdb.lookup_objfile.
590 New events which are triggered when GDB modifies the state of the
593 ** gdb.events.inferior_call_pre: Function call is about to be made.
594 ** gdb.events.inferior_call_post: Function call has just been made.
595 ** gdb.events.memory_changed: A memory location has been altered.
596 ** gdb.events.register_changed: A register has been altered.
598 * New Python-based convenience functions:
600 ** $_caller_is(name [, number_of_frames])
601 ** $_caller_matches(regexp [, number_of_frames])
602 ** $_any_caller_is(name [, number_of_frames])
603 ** $_any_caller_matches(regexp [, number_of_frames])
605 * GDB now supports the compilation and injection of source code into
606 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
607 to compile the source code to object code, and if successful, inject
608 and execute that code within the current context of the inferior.
609 Currently the C language is supported. The commands used to
610 interface with this new feature are:
612 compile code [-raw|-r] [--] [source code]
613 compile file [-raw|-r] filename
617 demangle [-l language] [--] name
618 Demangle "name" in the specified language, or the current language
619 if elided. This command is renamed from the "maint demangle" command.
620 The latter is kept as a no-op to avoid "maint demangle" being interpreted
621 as "maint demangler-warning".
623 queue-signal signal-name-or-number
624 Queue a signal to be delivered to the thread when it is resumed.
626 add-auto-load-scripts-directory directory
627 Add entries to the list of directories from which to load auto-loaded
630 maint print user-registers
631 List all currently available "user" registers.
633 compile code [-r|-raw] [--] [source code]
634 Compile, inject, and execute in the inferior the executable object
635 code produced by compiling the provided source code.
637 compile file [-r|-raw] filename
638 Compile and inject into the inferior the executable object code
639 produced by compiling the source code stored in the filename
642 * On resume, GDB now always passes the signal the program had stopped
643 for to the thread the signal was sent to, even if the user changed
644 threads before resuming. Previously GDB would often (but not
645 always) deliver the signal to the thread that happens to be current
648 * Conversely, the "signal" command now consistently delivers the
649 requested signal to the current thread. GDB now asks for
650 confirmation if the program had stopped for a signal and the user
651 switched threads meanwhile.
653 * "breakpoint always-inserted" modes "off" and "auto" merged.
655 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
656 won't remove breakpoints from the target until all threads stop,
657 even in non-stop mode. The "auto" mode has been removed, and "off"
658 is now the default mode.
662 set debug symbol-lookup
663 show debug symbol-lookup
664 Control display of debugging info regarding symbol lookup.
668 ** The -list-thread-groups command outputs an exit-code field for
669 inferiors that have exited.
673 MIPS SDE mips*-sde*-elf*
677 Support for these obsolete configurations has been removed.
679 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
680 SGI Irix-5.x mips-*-irix5*
681 SGI Irix-6.x mips-*-irix6*
682 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
683 VAX running Ultrix vax-*-ultrix*
685 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
686 and "assf"), have been removed. Use the "sharedlibrary" command, or
687 its alias "share", instead.
689 *** Changes in GDB 7.8
691 * New command line options
694 This is an alias for the --data-directory option.
696 * GDB supports printing and modifying of variable length automatic arrays
697 as specified in ISO C99.
699 * The ARM simulator now supports instruction level tracing
700 with or without disassembly.
704 GDB now has support for scripting using Guile. Whether this is
705 available is determined at configure time.
706 Guile version 2.0 or greater is required.
707 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
709 * New commands (for set/show, see "New options" below)
713 Invoke CODE by passing it to the Guile interpreter.
717 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
719 info auto-load guile-scripts [regexp]
720 Print the list of automatically loaded Guile scripts.
722 * The source command is now capable of sourcing Guile scripts.
723 This feature is dependent on the debugger being built with Guile support.
727 set print symbol-loading (off|brief|full)
728 show print symbol-loading
729 Control whether to print informational messages when loading symbol
730 information for a file. The default is "full", but when debugging
731 programs with large numbers of shared libraries the amount of output
734 set guile print-stack (none|message|full)
735 show guile print-stack
736 Show a stack trace when an error is encountered in a Guile script.
738 set auto-load guile-scripts (on|off)
739 show auto-load guile-scripts
740 Control auto-loading of Guile script files.
742 maint ada set ignore-descriptive-types (on|off)
743 maint ada show ignore-descriptive-types
744 Control whether the debugger should ignore descriptive types in Ada
745 programs. The default is not to ignore the descriptive types. See
746 the user manual for more details on descriptive types and the intended
747 usage of this option.
749 set auto-connect-native-target
751 Control whether GDB is allowed to automatically connect to the
752 native target for the run, attach, etc. commands when not connected
753 to any target yet. See also "target native" below.
755 set record btrace replay-memory-access (read-only|read-write)
756 show record btrace replay-memory-access
757 Control what memory accesses are allowed during replay.
759 maint set target-async (on|off)
760 maint show target-async
761 This controls whether GDB targets operate in synchronous or
762 asynchronous mode. Normally the default is asynchronous, if it is
763 available; but this can be changed to more easily debug problems
764 occurring only in synchronous mode.
766 set mi-async (on|off)
768 Control whether MI asynchronous mode is preferred. This supersedes
769 "set target-async" of previous GDB versions.
771 * "set target-async" is deprecated as a CLI option and is now an alias
772 for "set mi-async" (only puts MI into async mode).
774 * Background execution commands (e.g., "c&", "s&", etc.) are now
775 possible ``out of the box'' if the target supports them. Previously
776 the user would need to explicitly enable the possibility with the
777 "set target-async on" command.
779 * New features in the GDB remote stub, GDBserver
781 ** New option --debug-format=option1[,option2,...] allows one to add
782 additional text to each output. At present only timestamps
783 are supported: --debug-format=timestamps.
784 Timestamps can also be turned on with the
785 "monitor set debug-format timestamps" command from GDB.
787 * The 'record instruction-history' command now starts counting instructions
788 at one. This also affects the instruction ranges reported by the
789 'record function-call-history' command when given the /i modifier.
791 * The command 'record function-call-history' supports a new modifier '/c' to
792 indent the function names based on their call stack depth.
793 The fields for the '/i' and '/l' modifier have been reordered.
794 The source line range is now prefixed with 'at'.
795 The instruction range is now prefixed with 'inst'.
796 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
797 "record instruction-history" and "list" commands.
799 * The ranges given as arguments to the 'record function-call-history' and
800 'record instruction-history' commands are now inclusive.
802 * The btrace record target now supports the 'record goto' command.
803 For locations inside the execution trace, the back trace is computed
804 based on the information stored in the execution trace.
806 * The btrace record target supports limited reverse execution and replay.
807 The target does not record data and therefore does not allow reading
810 * The "catch syscall" command now works on s390*-linux* targets.
812 * The "compare-sections" command is no longer specific to target
813 remote. It now works with all targets.
815 * All native targets are now consistently called "native".
816 Consequently, the "target child", "target GNU", "target djgpp",
817 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
818 commands have been replaced with "target native". The QNX/NTO port
819 leaves the "procfs" target in place and adds a "native" target for
820 consistency with other ports. The impact on users should be minimal
821 as these commands previously either throwed an error, or were
822 no-ops. The target's name is visible in the output of the following
823 commands: "help target", "info target", "info files", "maint print
826 * The "target native" command now connects to the native target. This
827 can be used to launch native programs even when "set
828 auto-connect-native-target" is set to off.
830 * GDB now supports access to Intel MPX registers on GNU/Linux.
832 * Support for Intel AVX-512 registers on GNU/Linux.
833 Support displaying and modifying Intel AVX-512 registers
834 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
838 qXfer:btrace:read's annex
839 The qXfer:btrace:read packet supports a new annex 'delta' to read
840 branch trace incrementally.
844 ** Valid Python operations on gdb.Value objects representing
845 structs/classes invoke the corresponding overloaded operators if
847 ** New `Xmethods' feature in the Python API. Xmethods are
848 additional methods or replacements for existing methods of a C++
849 class. This feature is useful for those cases where a method
850 defined in C++ source code could be inlined or optimized out by
851 the compiler, making it unavailable to GDB.
854 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
856 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
857 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
858 its alias "share", instead.
860 * The commands "set remotebaud" and "show remotebaud" are no longer
861 supported. Use "set serial baud" and "show serial baud" (respectively)
866 ** A new option "-gdb-set mi-async" replaces "-gdb-set
867 target-async". The latter is left as a deprecated alias of the
868 former for backward compatibility. If the target supports it,
869 CLI background execution commands are now always possible by
870 default, independently of whether the frontend stated a
871 preference for asynchronous execution with "-gdb-set mi-async".
872 Previously "-gdb-set target-async off" affected both MI execution
873 commands and CLI execution commands.
875 *** Changes in GDB 7.7
877 * Improved support for process record-replay and reverse debugging on
878 arm*-linux* targets. Support for thumb32 and syscall instruction
879 recording has been added.
881 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
883 * GDB now supports Fission DWP file format version 2.
884 http://gcc.gnu.org/wiki/DebugFission
886 * New convenience function "$_isvoid", to check whether an expression
887 is void. A void expression is an expression where the type of the
888 result is "void". For example, some convenience variables may be
889 "void" when evaluated (e.g., "$_exitcode" before the execution of
890 the program being debugged; or an undefined convenience variable).
891 Another example, when calling a function whose return type is
894 * The "maintenance print objfiles" command now takes an optional regexp.
896 * The "catch syscall" command now works on arm*-linux* targets.
898 * GDB now consistently shows "<not saved>" when printing values of
899 registers the debug info indicates have not been saved in the frame
900 and there's nowhere to retrieve them from
901 (callee-saved/call-clobbered registers):
906 (gdb) info registers rax
909 Before, the former would print "<optimized out>", and the latter
910 "*value not available*".
912 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
917 ** Frame filters and frame decorators have been added.
918 ** Temporary breakpoints are now supported.
919 ** Line tables representation has been added.
920 ** New attribute 'parent_type' for gdb.Field objects.
921 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
922 ** New attribute 'name' for gdb.Type objects.
926 Nios II ELF nios2*-*-elf
927 Nios II GNU/Linux nios2*-*-linux
928 Texas Instruments MSP430 msp430*-*-elf
930 * Removed native configurations
932 Support for these a.out NetBSD and OpenBSD obsolete configurations has
933 been removed. ELF variants of these configurations are kept supported.
935 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
936 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
937 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
938 i[34567]86-*-openbsd3.[0-3]
939 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
940 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
941 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
945 Like "catch throw", but catches a re-thrown exception.
947 Renamed from old "maint check-symtabs".
949 Perform consistency checks on symtabs.
951 Expand symtabs matching an optional regexp.
954 Display the details of GDB configure-time options.
956 maint set|show per-command
957 maint set|show per-command space
958 maint set|show per-command time
959 maint set|show per-command symtab
960 Enable display of per-command gdb resource usage.
962 remove-symbol-file FILENAME
963 remove-symbol-file -a ADDRESS
964 Remove a symbol file added via add-symbol-file. The file to remove
965 can be identified by its filename or by an address that lies within
966 the boundaries of this symbol file in memory.
969 info exceptions REGEXP
970 Display the list of Ada exceptions defined in the program being
971 debugged. If provided, only the exceptions whose names match REGEXP
976 set debug symfile off|on
978 Control display of debugging info regarding reading symbol files and
979 symbol tables within those files
981 set print raw frame-arguments
982 show print raw frame-arguments
983 Set/show whether to print frame arguments in raw mode,
984 disregarding any defined pretty-printers.
986 set remote trace-status-packet
987 show remote trace-status-packet
988 Set/show the use of remote protocol qTStatus packet.
992 Control display of debugging messages related to Nios II targets.
996 Control whether target-assisted range stepping is enabled.
998 set startup-with-shell
999 show startup-with-shell
1000 Specifies whether Unix child processes are started via a shell or
1005 Use the target memory cache for accesses to the code segment. This
1006 improves performance of remote debugging (particularly disassembly).
1008 * You can now use a literal value 'unlimited' for options that
1009 interpret 0 or -1 as meaning "unlimited". E.g., "set
1010 trace-buffer-size unlimited" is now an alias for "set
1011 trace-buffer-size -1" and "set height unlimited" is now an alias for
1014 * The "set debug symtab-create" debugging option of GDB has been changed to
1015 accept a verbosity level. 0 means "off", 1 provides basic debugging
1016 output, and values of 2 or greater provides more verbose output.
1018 * New command-line options
1020 Display the details of GDB configure-time options.
1022 * The command 'tsave' can now support new option '-ctf' to save trace
1023 buffer in Common Trace Format.
1025 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1028 * GDB now implements the the C++ 'typeid' operator.
1030 * The new convenience variable $_exception holds the exception being
1031 thrown or caught at an exception-related catchpoint.
1033 * The exception-related catchpoints, like "catch throw", now accept a
1034 regular expression which can be used to filter exceptions by type.
1036 * The new convenience variable $_exitsignal is automatically set to
1037 the terminating signal number when the program being debugged dies
1038 due to an uncaught signal.
1042 ** All MI commands now accept an optional "--language" option.
1043 Support for this feature can be verified by using the "-list-features"
1044 command, which should contain "language-option".
1046 ** The new command -info-gdb-mi-command allows the user to determine
1047 whether a GDB/MI command is supported or not.
1049 ** The "^error" result record returned when trying to execute an undefined
1050 GDB/MI command now provides a variable named "code" whose content is the
1051 "undefined-command" error code. Support for this feature can be verified
1052 by using the "-list-features" command, which should contain
1053 "undefined-command-error-code".
1055 ** The -trace-save MI command can optionally save trace buffer in Common
1058 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1060 ** The command -data-list-register-values now accepts an optional
1061 "--skip-unavailable" option. When used, only the available registers
1064 ** The new command -trace-frame-collected dumps collected variables,
1065 computed expressions, tvars, memory and registers in a traceframe.
1067 ** The commands -stack-list-locals, -stack-list-arguments and
1068 -stack-list-variables now accept an option "--skip-unavailable".
1069 When used, only the available locals or arguments are displayed.
1071 ** The -exec-run command now accepts an optional "--start" option.
1072 When used, the command follows the same semantics as the "start"
1073 command, stopping the program's execution at the start of its
1074 main subprogram. Support for this feature can be verified using
1075 the "-list-features" command, which should contain
1076 "exec-run-start-option".
1078 ** The new commands -catch-assert and -catch-exceptions insert
1079 catchpoints stopping the program when Ada exceptions are raised.
1081 ** The new command -info-ada-exceptions provides the equivalent of
1082 the new "info exceptions" command.
1084 * New system-wide configuration scripts
1085 A GDB installation now provides scripts suitable for use as system-wide
1086 configuration scripts for the following systems:
1090 * GDB now supports target-assigned range stepping with remote targets.
1091 This improves the performance of stepping source lines by reducing
1092 the number of control packets from/to GDB. See "New remote packets"
1095 * GDB now understands the element 'tvar' in the XML traceframe info.
1096 It has the id of the collected trace state variables.
1098 * On S/390 targets that provide the transactional-execution feature,
1099 the program interruption transaction diagnostic block (TDB) is now
1100 represented as a number of additional "registers" in GDB.
1102 * New remote packets
1106 The vCont packet supports a new 'r' action, that tells the remote
1107 stub to step through an address range itself, without GDB
1108 involvemement at each single-step.
1110 qXfer:libraries-svr4:read's annex
1111 The previously unused annex of the qXfer:libraries-svr4:read packet
1112 is now used to support passing an argument list. The remote stub
1113 reports support for this argument list to GDB's qSupported query.
1114 The defined arguments are "start" and "prev", used to reduce work
1115 necessary for library list updating, resulting in significant
1118 * New features in the GDB remote stub, GDBserver
1120 ** GDBserver now supports target-assisted range stepping. Currently
1121 enabled on x86/x86_64 GNU/Linux targets.
1123 ** GDBserver now adds element 'tvar' in the XML in the reply to
1124 'qXfer:traceframe-info:read'. It has the id of the collected
1125 trace state variables.
1127 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1130 * New 'z' formatter for printing and examining memory, this displays the
1131 value as hexadecimal zero padded on the left to the size of the type.
1133 * GDB can now use Windows x64 unwinding data.
1135 * The "set remotebaud" command has been replaced by "set serial baud".
1136 Similarly, "show remotebaud" has been replaced by "show serial baud".
1137 The "set remotebaud" and "show remotebaud" commands are still available
1138 to provide backward compatibility with older versions of GDB.
1140 *** Changes in GDB 7.6
1142 * Target record has been renamed to record-full.
1143 Record/replay is now enabled with the "record full" command.
1144 This also affects settings that are associated with full record/replay
1145 that have been moved from "set/show record" to "set/show record full":
1147 set|show record full insn-number-max
1148 set|show record full stop-at-limit
1149 set|show record full memory-query
1151 * A new record target "record-btrace" has been added. The new target
1152 uses hardware support to record the control-flow of a process. It
1153 does not support replaying the execution, but it implements the
1154 below new commands for investigating the recorded execution log.
1155 This new recording method can be enabled using:
1159 The "record-btrace" target is only available on Intel Atom processors
1160 and requires a Linux kernel 2.6.32 or later.
1162 * Two new commands have been added for record/replay to give information
1163 about the recorded execution without having to replay the execution.
1164 The commands are only supported by "record btrace".
1166 record instruction-history prints the execution history at
1167 instruction granularity
1169 record function-call-history prints the execution history at
1170 function granularity
1172 * New native configurations
1174 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1175 FreeBSD/powerpc powerpc*-*-freebsd
1176 x86_64/Cygwin x86_64-*-cygwin*
1177 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1181 ARM AArch64 aarch64*-*-elf
1182 ARM AArch64 GNU/Linux aarch64*-*-linux
1183 Lynx 178 PowerPC powerpc-*-lynx*178
1184 x86_64/Cygwin x86_64-*-cygwin*
1185 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1187 * If the configured location of system.gdbinit file (as given by the
1188 --with-system-gdbinit option at configure time) is in the
1189 data-directory (as specified by --with-gdb-datadir at configure
1190 time) or in one of its subdirectories, then GDB will look for the
1191 system-wide init file in the directory specified by the
1192 --data-directory command-line option.
1194 * New command line options:
1196 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1197 other initialization files, unlike -nx which disables all of them.
1199 * Removed command line options
1201 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1204 * The 'ptype' and 'whatis' commands now accept an argument to control
1207 * 'info proc' now works on some core files.
1211 ** Vectors can be created with gdb.Type.vector.
1213 ** Python's atexit.register now works in GDB.
1215 ** Types can be pretty-printed via a Python API.
1217 ** Python 3 is now supported (in addition to Python 2.4 or later)
1219 ** New class gdb.Architecture exposes GDB's internal representation
1220 of architecture in the Python API.
1222 ** New method Frame.architecture returns the gdb.Architecture object
1223 corresponding to the frame's architecture.
1225 * New Python-based convenience functions:
1227 ** $_memeq(buf1, buf2, length)
1228 ** $_streq(str1, str2)
1230 ** $_regex(str, regex)
1232 * The 'cd' command now defaults to using '~' (the home directory) if not
1235 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1236 default for GCC since November 2000.
1238 * The command 'forward-search' can now be abbreviated as 'fo'.
1240 * The command 'info tracepoints' can now display 'installed on target'
1241 or 'not installed on target' for each non-pending location of tracepoint.
1243 * New configure options
1245 --enable-libmcheck/--disable-libmcheck
1246 By default, development versions are built with -lmcheck on hosts
1247 that support it, in order to help track memory corruption issues.
1248 Release versions, on the other hand, are built without -lmcheck
1249 by default. The --enable-libmcheck/--disable-libmcheck configure
1250 options allow the user to override that default.
1251 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1252 This configure option allows the user to build GDB with
1253 libbabeltrace using which GDB can read Common Trace Format data.
1255 * New commands (for set/show, see "New options" below)
1258 Catch signals. This is similar to "handle", but allows commands and
1259 conditions to be attached.
1262 List the BFDs known to GDB.
1264 python-interactive [command]
1266 Start a Python interactive prompt, or evaluate the optional command
1267 and print the result of expressions.
1270 "py" is a new alias for "python".
1272 enable type-printer [name]...
1273 disable type-printer [name]...
1274 Enable or disable type printers.
1278 ** For the Renesas Super-H architecture, the "regs" command has been removed
1279 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1284 set print type methods (on|off)
1285 show print type methods
1286 Control whether method declarations are displayed by "ptype".
1287 The default is to show them.
1289 set print type typedefs (on|off)
1290 show print type typedefs
1291 Control whether typedef definitions are displayed by "ptype".
1292 The default is to show them.
1294 set filename-display basename|relative|absolute
1295 show filename-display
1296 Control the way in which filenames is displayed.
1297 The default is "relative", which preserves previous behavior.
1299 set trace-buffer-size
1300 show trace-buffer-size
1301 Request target to change the size of trace buffer.
1303 set remote trace-buffer-size-packet auto|on|off
1304 show remote trace-buffer-size-packet
1305 Control the use of the remote protocol `QTBuffer:size' packet.
1309 Control display of debugging messages related to ARM AArch64.
1312 set debug coff-pe-read
1313 show debug coff-pe-read
1314 Control display of debugging messages related to reading of COFF/PE
1319 Control display of debugging messages related to Mach-O symbols
1322 set debug notification
1323 show debug notification
1324 Control display of debugging info for async remote notification.
1328 ** Command parameter changes are now notified using new async record
1329 "=cmd-param-changed".
1330 ** Trace frame changes caused by command "tfind" are now notified using
1331 new async record "=traceframe-changed".
1332 ** The creation, deletion and modification of trace state variables
1333 are now notified using new async records "=tsv-created",
1334 "=tsv-deleted" and "=tsv-modified".
1335 ** The start and stop of process record are now notified using new
1336 async record "=record-started" and "=record-stopped".
1337 ** Memory changes are now notified using new async record
1339 ** The data-disassemble command response will include a "fullname" field
1340 containing the absolute file name when source has been requested.
1341 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1342 command, to allow pattern filling of memory areas.
1343 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1344 library load/unload events.
1345 ** The response to breakpoint commands and breakpoint async records
1346 includes an "installed" field containing a boolean state about each
1347 non-pending tracepoint location is whether installed on target or not.
1348 ** Output of the "-trace-status" command includes a "trace-file" field
1349 containing the name of the trace file being examined. This field is
1350 optional, and only present when examining a trace file.
1351 ** The "fullname" field is now always present along with the "file" field,
1352 even if the file cannot be found by GDB.
1354 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1355 You must have the LZMA library available when configuring GDB for this
1356 feature to be enabled. For more information, see:
1357 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1359 * New remote packets
1362 Set the size of trace buffer. The remote stub reports support for this
1363 packet to gdb's qSupported query.
1366 Enable Branch Trace Store (BTS)-based branch tracing for the current
1367 thread. The remote stub reports support for this packet to gdb's
1371 Disable branch tracing for the current thread. The remote stub reports
1372 support for this packet to gdb's qSupported query.
1375 Read the traced branches for the current thread. The remote stub
1376 reports support for this packet to gdb's qSupported query.
1378 *** Changes in GDB 7.5
1380 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1381 for more x32 ABI info.
1383 * GDB now supports access to MIPS DSP registers on Linux targets.
1385 * GDB now supports debugging microMIPS binaries.
1387 * The "info os" command on GNU/Linux can now display information on
1388 several new classes of objects managed by the operating system:
1389 "info os procgroups" lists process groups
1390 "info os files" lists file descriptors
1391 "info os sockets" lists internet-domain sockets
1392 "info os shm" lists shared-memory regions
1393 "info os semaphores" lists semaphores
1394 "info os msg" lists message queues
1395 "info os modules" lists loaded kernel modules
1397 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1398 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1399 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1400 options and inspect the probe arguments using the new $_probe_arg family
1401 of convenience variables. You can obtain more information about SystemTap
1402 in <http://sourceware.org/systemtap/>.
1404 * GDB now supports reversible debugging on ARM, it allows you to
1405 debug basic ARM and THUMB instructions, and provides
1406 record/replay support.
1408 * The option "symbol-reloading" has been deleted as it is no longer used.
1412 ** GDB commands implemented in Python can now be put in command class
1415 ** The "maint set python print-stack on|off" is now deleted.
1417 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1418 apply "flag enum"-style pretty-printing to any enum.
1420 ** gdb.lookup_symbol can now work when there is no current frame.
1422 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1423 the source at which the symbol was defined.
1425 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1426 method 'value'. The former indicates whether the symbol needs a
1427 frame in order to compute its value, and the latter computes the
1430 ** A new method 'referenced_value' on gdb.Value objects which can
1431 dereference pointer as well as C++ reference values.
1433 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1434 which return the global and static blocks (as gdb.Block objects),
1435 of the underlying symbol table, respectively.
1437 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1438 object associated with a PC value.
1440 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1441 of the address range occupied by code for the current source line.
1443 * Go language support.
1444 GDB now supports debugging programs written in the Go programming
1447 * GDBserver now supports stdio connections.
1448 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1450 * The binary "gdbtui" can no longer be built or installed.
1451 Use "gdb -tui" instead.
1453 * GDB will now print "flag" enums specially. A flag enum is one where
1454 all the enumerator values have no bits in common when pairwise
1455 "and"ed. When printing a value whose type is a flag enum, GDB will
1456 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1457 (gdb) print (enum E) 3
1460 * The filename part of a linespec will now match trailing components
1461 of a source file name. For example, "break gcc/expr.c:1000" will
1462 now set a breakpoint in build/gcc/expr.c, but not
1463 build/libcpp/expr.c.
1465 * The "info proc" and "generate-core-file" commands will now also
1466 work on remote targets connected to GDBserver on Linux.
1468 * The command "info catch" has been removed. It has been disabled
1469 since December 2007.
1471 * The "catch exception" and "catch assert" commands now accept
1472 a condition at the end of the command, much like the "break"
1473 command does. For instance:
1475 (gdb) catch exception Constraint_Error if Barrier = True
1477 Previously, it was possible to add a condition to such catchpoints,
1478 but it had to be done as a second step, after the catchpoint had been
1479 created, using the "condition" command.
1481 * The "info static-tracepoint-marker" command will now also work on
1482 native Linux targets with in-process agent.
1484 * GDB can now set breakpoints on inlined functions.
1486 * The .gdb_index section has been updated to include symbols for
1487 inlined functions. GDB will ignore older .gdb_index sections by
1488 default, which could cause symbol files to be loaded more slowly
1489 until their .gdb_index sections can be recreated. The new command
1490 "set use-deprecated-index-sections on" will cause GDB to use any older
1491 .gdb_index sections it finds. This will restore performance, but the
1492 ability to set breakpoints on inlined functions will be lost in symbol
1493 files with older .gdb_index sections.
1495 The .gdb_index section has also been updated to record more information
1496 about each symbol. This speeds up the "info variables", "info functions"
1497 and "info types" commands when used with programs having the .gdb_index
1498 section, as well as speeding up debugging with shared libraries using
1499 the .gdb_index section.
1501 * Ada support for GDB/MI Variable Objects has been added.
1503 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1508 ** New command -info-os is the MI equivalent of "info os".
1510 ** Output logs ("set logging" and related) now include MI output.
1514 ** "set use-deprecated-index-sections on|off"
1515 "show use-deprecated-index-sections on|off"
1516 Controls the use of deprecated .gdb_index sections.
1518 ** "catch load" and "catch unload" can be used to stop when a shared
1519 library is loaded or unloaded, respectively.
1521 ** "enable count" can be used to auto-disable a breakpoint after
1524 ** "info vtbl" can be used to show the virtual method tables for
1525 C++ and Java objects.
1527 ** "explore" and its sub commands "explore value" and "explore type"
1528 can be used to recursively explore values and types of
1529 expressions. These commands are available only if GDB is
1530 configured with '--with-python'.
1532 ** "info auto-load" shows status of all kinds of auto-loaded files,
1533 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1534 sequences of commands files, "info auto-load python-scripts"
1535 shows status of auto-loading Python script files,
1536 "info auto-load local-gdbinit" shows status of loading init file
1537 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1538 status of inferior specific thread debugging shared library loading.
1540 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1541 and "show auto-load-scripts" commands have been deprecated, use their
1542 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1543 and "show auto-load python-scripts" counterparts instead.
1545 ** "dprintf location,format,args..." creates a dynamic printf, which
1546 is basically a breakpoint that does a printf and immediately
1547 resumes your program's execution, so it is like a printf that you
1548 can insert dynamically at runtime instead of at compiletime.
1550 ** "set print symbol"
1552 Controls whether GDB attempts to display the symbol, if any,
1553 corresponding to addresses it prints. This defaults to "on", but
1554 you can set it to "off" to restore GDB's previous behavior.
1556 * Deprecated commands
1558 ** For the Renesas Super-H architecture, the "regs" command has been
1559 deprecated, and "info all-registers" should be used instead.
1563 Renesas RL78 rl78-*-elf
1564 HP OpenVMS ia64 ia64-hp-openvms*
1566 * GDBserver supports evaluation of breakpoint conditions. When
1567 support is advertised by GDBserver, GDB may be told to send the
1568 breakpoint conditions in bytecode form to GDBserver. GDBserver
1569 will only report the breakpoint trigger to GDB when its condition
1574 set mips compression
1575 show mips compression
1576 Select the compressed ISA encoding used in functions that have no symbol
1577 information available. The encoding can be set to either of:
1580 and is updated automatically from ELF file flags if available.
1582 set breakpoint condition-evaluation
1583 show breakpoint condition-evaluation
1584 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1585 GDBserver ("target"). Default option "auto" chooses the most efficient
1587 This option can improve debugger efficiency depending on the speed of the
1591 Disable auto-loading globally.
1594 Show auto-loading setting of all kinds of auto-loaded files.
1596 set auto-load gdb-scripts on|off
1597 show auto-load gdb-scripts
1598 Control auto-loading of GDB canned sequences of commands files.
1600 set auto-load python-scripts on|off
1601 show auto-load python-scripts
1602 Control auto-loading of Python script files.
1604 set auto-load local-gdbinit on|off
1605 show auto-load local-gdbinit
1606 Control loading of init file (.gdbinit) from current directory.
1608 set auto-load libthread-db on|off
1609 show auto-load libthread-db
1610 Control auto-loading of inferior specific thread debugging shared library.
1612 set auto-load scripts-directory <dir1>[:<dir2>...]
1613 show auto-load scripts-directory
1614 Set a list of directories from which to load auto-loaded scripts.
1615 Automatically loaded Python scripts and GDB scripts are located in one
1616 of the directories listed by this option.
1617 The delimiter (':' above) may differ according to the host platform.
1619 set auto-load safe-path <dir1>[:<dir2>...]
1620 show auto-load safe-path
1621 Set a list of directories from which it is safe to auto-load files.
1622 The delimiter (':' above) may differ according to the host platform.
1624 set debug auto-load on|off
1625 show debug auto-load
1626 Control display of debugging info for auto-loading the files above.
1628 set dprintf-style gdb|call|agent
1630 Control the way in which a dynamic printf is performed; "gdb"
1631 requests a GDB printf command, while "call" causes dprintf to call a
1632 function in the inferior. "agent" requests that the target agent
1633 (such as GDBserver) do the printing.
1635 set dprintf-function <expr>
1636 show dprintf-function
1637 set dprintf-channel <expr>
1638 show dprintf-channel
1639 Set the function and optional first argument to the call when using
1640 the "call" style of dynamic printf.
1642 set disconnected-dprintf on|off
1643 show disconnected-dprintf
1644 Control whether agent-style dynamic printfs continue to be in effect
1645 after GDB disconnects.
1647 * New configure options
1649 --with-auto-load-dir
1650 Configure default value for the 'set auto-load scripts-directory'
1651 setting above. It defaults to '$debugdir:$datadir/auto-load',
1652 $debugdir representing global debugging info directories (available
1653 via 'show debug-file-directory') and $datadir representing GDB's data
1654 directory (available via 'show data-directory').
1656 --with-auto-load-safe-path
1657 Configure default value for the 'set auto-load safe-path' setting
1658 above. It defaults to the --with-auto-load-dir setting.
1660 --without-auto-load-safe-path
1661 Set 'set auto-load safe-path' to '/', effectively disabling this
1664 * New remote packets
1666 z0/z1 conditional breakpoints extension
1668 The z0/z1 breakpoint insertion packets have been extended to carry
1669 a list of conditional expressions over to the remote stub depending on the
1670 condition evaluation mode. The use of this extension can be controlled
1671 via the "set remote conditional-breakpoints-packet" command.
1675 Specify the signals which the remote stub may pass to the debugged
1676 program without GDB involvement.
1678 * New command line options
1680 --init-command=FILE, -ix Like --command, -x but execute it
1681 before loading inferior.
1682 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1683 execute it before loading inferior.
1685 *** Changes in GDB 7.4
1687 * GDB now handles ambiguous linespecs more consistently; the existing
1688 FILE:LINE support has been expanded to other types of linespecs. A
1689 breakpoint will now be set on all matching locations in all
1690 inferiors, and locations will be added or removed according to
1693 * GDB now allows you to skip uninteresting functions and files when
1694 stepping with the "skip function" and "skip file" commands.
1696 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1697 and "show remote hardware-watchpoint-length-limit". These allows to
1698 set or show the maximum length limit (in bytes) of a remote
1699 target hardware watchpoint.
1701 This allows e.g. to use "unlimited" hardware watchpoints with the
1702 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1703 watchpoints are slower than real hardware watchpoints but are
1704 significantly faster than gdb software watchpoints.
1708 ** The register_pretty_printer function in module gdb.printing now takes
1709 an optional `replace' argument. If True, the new printer replaces any
1712 ** The "maint set python print-stack on|off" command has been
1713 deprecated and will be deleted in GDB 7.5.
1714 A new command: "set python print-stack none|full|message" has
1715 replaced it. Additionally, the default for "print-stack" is
1716 now "message", which just prints the error message without
1719 ** A prompt substitution hook (prompt_hook) is now available to the
1722 ** A new Python module, gdb.prompt has been added to the GDB Python
1723 modules library. This module provides functionality for
1724 escape sequences in prompts (used by set/show
1725 extended-prompt). These escape sequences are replaced by their
1726 corresponding value.
1728 ** Python commands and convenience-functions located in
1729 'data-directory'/python/gdb/command and
1730 'data-directory'/python/gdb/function are now automatically loaded
1733 ** Blocks now provide four new attributes. global_block and
1734 static_block will return the global and static blocks
1735 respectively. is_static and is_global are boolean attributes
1736 that indicate if the block is one of those two types.
1738 ** Symbols now provide the "type" attribute, the type of the symbol.
1740 ** The "gdb.breakpoint" function has been deprecated in favor of
1743 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1744 of a function. This class is based on the "finish" command
1745 available in the CLI.
1747 ** Type objects for struct and union types now allow access to
1748 the fields using standard Python dictionary (mapping) methods.
1749 For example, "some_type['myfield']" now works, as does
1750 "some_type.items()".
1752 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1755 ** A new function, "deep_items" has been added to the gdb.types
1756 module in the GDB Python modules library. This function returns
1757 an iterator over the fields of a struct or union type. Unlike
1758 the standard Python "iteritems" method, it will recursively traverse
1759 any anonymous fields.
1763 ** "*stopped" events can report several new "reason"s, such as
1766 ** Breakpoint changes are now notified using new async records, like
1767 "=breakpoint-modified".
1769 ** New command -ada-task-info.
1771 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1772 $sdir specifies the default system locations of shared libraries.
1773 $pdir specifies the directory where the libpthread used by the application
1776 GDB no longer looks in $sdir and $pdir after it has searched the directories
1777 mentioned in libthread-db-search-path. If you want to search those
1778 directories, they must be specified in libthread-db-search-path.
1779 The default value of libthread-db-search-path on GNU/Linux and Solaris
1780 systems is now "$sdir:$pdir".
1782 $pdir is not supported by gdbserver, it is currently ignored.
1783 $sdir is supported by gdbserver.
1785 * New configure option --with-iconv-bin.
1786 When using the internationalization support like the one in the GNU C
1787 library, GDB will invoke the "iconv" program to get a list of supported
1788 character sets. If this program lives in a non-standard location, one can
1789 use this option to specify where to find it.
1791 * When natively debugging programs on PowerPC BookE processors running
1792 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1793 watchpoints, which specify a mask in addition to an address to watch.
1794 The mask specifies that some bits of an address (the bits which are
1795 reset in the mask) should be ignored when matching the address accessed
1796 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1797 section in the user manual for more details.
1799 * The new option --once causes GDBserver to stop listening for connections once
1800 the first connection is made. The listening port used by GDBserver will
1801 become available after that.
1803 * New commands "info macros" and "alias" have been added.
1805 * New function parameters suffix @entry specifies value of function parameter
1806 at the time the function got called. Entry values are available only since
1812 "!" is now an alias of the "shell" command.
1813 Note that no space is needed between "!" and SHELL COMMAND.
1817 watch EXPRESSION mask MASK_VALUE
1818 The watch command now supports the mask argument which allows creation
1819 of masked watchpoints, if the current architecture supports this feature.
1821 info auto-load-scripts [REGEXP]
1822 This command was formerly named "maintenance print section-scripts".
1823 It is now generally useful and is no longer a maintenance-only command.
1825 info macro [-all] [--] MACRO
1826 The info macro command has new options `-all' and `--'. The first for
1827 printing all definitions of a macro. The second for explicitly specifying
1828 the end of arguments and the beginning of the macro name in case the macro
1829 name starts with a hyphen.
1831 collect[/s] EXPRESSIONS
1832 The tracepoint collect command now takes an optional modifier "/s"
1833 that directs it to dereference pointer-to-character types and
1834 collect the bytes of memory up to a zero byte. The behavior is
1835 similar to what you see when you use the regular print command on a
1836 string. An optional integer following the "/s" sets a bound on the
1837 number of bytes that will be collected.
1840 The trace start command now interprets any supplied arguments as a
1841 note to be recorded with the trace run, with an effect similar to
1842 setting the variable trace-notes.
1845 The trace stop command now interprets any arguments as a note to be
1846 mentioned along with the tstatus report that the trace was stopped
1847 with a command. The effect is similar to setting the variable
1850 * Tracepoints can now be enabled and disabled at any time after a trace
1851 experiment has been started using the standard "enable" and "disable"
1852 commands. It is now possible to start a trace experiment with no enabled
1853 tracepoints; GDB will display a warning, but will allow the experiment to
1854 begin, assuming that tracepoints will be enabled as needed while the trace
1857 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1858 locations with 4-byte instructions, when they were previously
1859 limited to locations with instructions of 5 bytes or longer.
1863 set debug dwarf2-read
1864 show debug dwarf2-read
1865 Turns on or off display of debugging messages related to reading
1866 DWARF debug info. The default is off.
1868 set debug symtab-create
1869 show debug symtab-create
1870 Turns on or off display of debugging messages related to symbol table
1871 creation. The default is off.
1874 show extended-prompt
1875 Set the GDB prompt, and allow escape sequences to be inserted to
1876 display miscellaneous information (see 'help set extended-prompt'
1877 for the list of sequences). This prompt (and any information
1878 accessed through the escape sequences) is updated every time the
1879 prompt is displayed.
1881 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1882 show print entry-values
1883 Set printing of frame argument values at function entry. In some cases
1884 GDB can determine the value of function argument which was passed by the
1885 function caller, even if the value was modified inside the called function.
1887 set debug entry-values
1888 show debug entry-values
1889 Control display of debugging info for determining frame argument values at
1890 function entry and virtual tail call frames.
1892 set basenames-may-differ
1893 show basenames-may-differ
1894 Set whether a source file may have multiple base names.
1895 (A "base name" is the name of a file with the directory part removed.
1896 Example: The base name of "/home/user/hello.c" is "hello.c".)
1897 If set, GDB will canonicalize file names (e.g., expand symlinks)
1898 before comparing them. Canonicalization is an expensive operation,
1899 but it allows the same file be known by more than one base name.
1900 If not set (the default), all source files are assumed to have just
1901 one base name, and gdb will do file name comparisons more efficiently.
1907 Set a user name and notes for the current and any future trace runs.
1908 This is useful for long-running and/or disconnected traces, to
1909 inform others (or yourself) as to who is running the trace, supply
1910 contact information, or otherwise explain what is going on.
1912 set trace-stop-notes
1913 show trace-stop-notes
1914 Set a note attached to the trace run, that is displayed when the
1915 trace has been stopped by a tstop command. This is useful for
1916 instance as an explanation, if you are stopping a trace run that was
1917 started by someone else.
1919 * New remote packets
1923 Dynamically enable a tracepoint in a started trace experiment.
1927 Dynamically disable a tracepoint in a started trace experiment.
1931 Set the user and notes of the trace run.
1935 Query the current status of a tracepoint.
1939 Query the minimum length of instruction at which a fast tracepoint may
1942 * Dcache size (number of lines) and line-size are now runtime-configurable
1943 via "set dcache line" and "set dcache line-size" commands.
1947 Texas Instruments TMS320C6x tic6x-*-*
1951 Renesas RL78 rl78-*-elf
1953 *** Changes in GDB 7.3.1
1955 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1957 *** Changes in GDB 7.3
1959 * GDB has a new command: "thread find [REGEXP]".
1960 It finds the thread id whose name, target id, or thread extra info
1961 matches the given regular expression.
1963 * The "catch syscall" command now works on mips*-linux* targets.
1965 * The -data-disassemble MI command now supports modes 2 and 3 for
1966 dumping the instruction opcodes.
1968 * New command line options
1970 -data-directory DIR Specify DIR as the "data-directory".
1971 This is mostly for testing purposes.
1973 * The "maint set python auto-load on|off" command has been renamed to
1974 "set auto-load-scripts on|off".
1976 * GDB has a new command: "set directories".
1977 It is like the "dir" command except that it replaces the
1978 source path list instead of augmenting it.
1980 * GDB now understands thread names.
1982 On GNU/Linux, "info threads" will display the thread name as set by
1983 prctl or pthread_setname_np.
1985 There is also a new command, "thread name", which can be used to
1986 assign a name internally for GDB to display.
1989 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1990 has been integrated into GDB.
1994 ** The function gdb.Write now accepts an optional keyword 'stream'.
1995 This keyword, when provided, will direct the output to either
1996 stdout, stderr, or GDB's logging output.
1998 ** Parameters can now be be sub-classed in Python, and in particular
1999 you may implement the get_set_doc and get_show_doc functions.
2000 This improves how Parameter set/show documentation is processed
2001 and allows for more dynamic content.
2003 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2004 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2005 have an is_valid method.
2007 ** Breakpoints can now be sub-classed in Python, and in particular
2008 you may implement a 'stop' function that is executed each time
2009 the inferior reaches that breakpoint.
2011 ** New function gdb.lookup_global_symbol looks up a global symbol.
2013 ** GDB values in Python are now callable if the value represents a
2014 function. For example, if 'some_value' represents a function that
2015 takes two integer parameters and returns a value, you can call
2016 that function like so:
2018 result = some_value (10,20)
2020 ** Module gdb.types has been added.
2021 It contains a collection of utilities for working with gdb.Types objects:
2022 get_basic_type, has_field, make_enum_dict.
2024 ** Module gdb.printing has been added.
2025 It contains utilities for writing and registering pretty-printers.
2026 New classes: PrettyPrinter, SubPrettyPrinter,
2027 RegexpCollectionPrettyPrinter.
2028 New function: register_pretty_printer.
2030 ** New commands "info pretty-printers", "enable pretty-printer" and
2031 "disable pretty-printer" have been added.
2033 ** gdb.parameter("directories") is now available.
2035 ** New function gdb.newest_frame returns the newest frame in the
2038 ** The gdb.InferiorThread class has a new "name" attribute. This
2039 holds the thread's name.
2041 ** Python Support for Inferior events.
2042 Python scripts can add observers to be notified of events
2043 occurring in the process being debugged.
2044 The following events are currently supported:
2045 - gdb.events.cont Continue event.
2046 - gdb.events.exited Inferior exited event.
2047 - gdb.events.stop Signal received, and Breakpoint hit events.
2051 ** GDB now puts template parameters in scope when debugging in an
2052 instantiation. For example, if you have:
2054 template<int X> int func (void) { return X; }
2056 then if you step into func<5>, "print X" will show "5". This
2057 feature requires proper debuginfo support from the compiler; it
2058 was added to GCC 4.5.
2060 ** The motion commands "next", "finish", "until", and "advance" now
2061 work better when exceptions are thrown. In particular, GDB will
2062 no longer lose control of the inferior; instead, the GDB will
2063 stop the inferior at the point at which the exception is caught.
2064 This functionality requires a change in the exception handling
2065 code that was introduced in GCC 4.5.
2067 * GDB now follows GCC's rules on accessing volatile objects when
2068 reading or writing target state during expression evaluation.
2069 One notable difference to prior behavior is that "print x = 0"
2070 no longer generates a read of x; the value of the assignment is
2071 now always taken directly from the value being assigned.
2073 * GDB now has some support for using labels in the program's source in
2074 linespecs. For instance, you can use "advance label" to continue
2075 execution to a label.
2077 * GDB now has support for reading and writing a new .gdb_index
2078 section. This section holds a fast index of DWARF debugging
2079 information and can be used to greatly speed up GDB startup and
2080 operation. See the documentation for `save gdb-index' for details.
2082 * The "watch" command now accepts an optional "-location" argument.
2083 When used, this causes GDB to watch the memory referred to by the
2084 expression. Such a watchpoint is never deleted due to it going out
2087 * GDB now supports thread debugging of core dumps on GNU/Linux.
2089 GDB now activates thread debugging using the libthread_db library
2090 when debugging GNU/Linux core dumps, similarly to when debugging
2091 live processes. As a result, when debugging a core dump file, GDB
2092 is now able to display pthread_t ids of threads. For example, "info
2093 threads" shows the same output as when debugging the process when it
2094 was live. In earlier releases, you'd see something like this:
2097 * 1 LWP 6780 main () at main.c:10
2099 While now you see this:
2102 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2104 It is also now possible to inspect TLS variables when debugging core
2107 When debugging a core dump generated on a machine other than the one
2108 used to run GDB, you may need to point GDB at the correct
2109 libthread_db library with the "set libthread-db-search-path"
2110 command. See the user manual for more details on this command.
2112 * When natively debugging programs on PowerPC BookE processors running
2113 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2114 which stop execution of the inferior whenever it executes an instruction
2115 at any address within the specified range. See the "PowerPC Embedded"
2116 section in the user manual for more details.
2118 * New features in the GDB remote stub, GDBserver
2120 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2121 and i686 LynxOS (version 5.x).
2123 ** GDBserver is now supported on Blackfin Linux.
2125 * New native configurations
2127 ia64 HP-UX ia64-*-hpux*
2131 Analog Devices, Inc. Blackfin Processor bfin-*
2133 * Ada task switching is now supported on sparc-elf targets when
2134 debugging a program using the Ravenscar Profile. For more information,
2135 see the "Tasking Support when using the Ravenscar Profile" section
2136 in the GDB user manual.
2138 * Guile support was removed.
2140 * New features in the GNU simulator
2142 ** The --map-info flag lists all known core mappings.
2144 ** CFI flashes may be simulated via the "cfi" device.
2146 *** Changes in GDB 7.2
2148 * Shared library support for remote targets by default
2150 When GDB is configured for a generic, non-OS specific target, like
2151 for example, --target=arm-eabi or one of the many *-*-elf targets,
2152 GDB now queries remote stubs for loaded shared libraries using the
2153 `qXfer:libraries:read' packet. Previously, shared library support
2154 was always disabled for such configurations.
2158 ** Argument Dependent Lookup (ADL)
2160 In C++ ADL lookup directs function search to the namespaces of its
2161 arguments even if the namespace has not been imported.
2171 Here the compiler will search for `foo' in the namespace of 'b'
2172 and find A::foo. GDB now supports this. This construct is commonly
2173 used in the Standard Template Library for operators.
2175 ** Improved User Defined Operator Support
2177 In addition to member operators, GDB now supports lookup of operators
2178 defined in a namespace and imported with a `using' directive, operators
2179 defined in the global scope, operators imported implicitly from an
2180 anonymous namespace, and the ADL operators mentioned in the previous
2182 GDB now also supports proper overload resolution for all the previously
2183 mentioned flavors of operators.
2185 ** static const class members
2187 Printing of static const class members that are initialized in the
2188 class definition has been fixed.
2190 * Windows Thread Information Block access.
2192 On Windows targets, GDB now supports displaying the Windows Thread
2193 Information Block (TIB) structure. This structure is visible either
2194 by using the new command `info w32 thread-information-block' or, by
2195 dereferencing the new convenience variable named `$_tlb', a
2196 thread-specific pointer to the TIB. This feature is also supported
2197 when remote debugging using GDBserver.
2199 * Static tracepoints
2201 Static tracepoints are calls in the user program into a tracing
2202 library. One such library is a port of the LTTng kernel tracer to
2203 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2204 When debugging with GDBserver, GDB now supports combining the GDB
2205 tracepoint machinery with such libraries. For example: the user can
2206 use GDB to probe a static tracepoint marker (a call from the user
2207 program into the tracing library) with the new "strace" command (see
2208 "New commands" below). This creates a "static tracepoint" in the
2209 breakpoint list, that can be manipulated with the same feature set
2210 as fast and regular tracepoints. E.g., collect registers, local and
2211 global variables, collect trace state variables, and define
2212 tracepoint conditions. In addition, the user can collect extra
2213 static tracepoint marker specific data, by collecting the new
2214 $_sdata internal variable. When analyzing the trace buffer, you can
2215 inspect $_sdata like any other variable available to GDB. For more
2216 information, see the "Tracepoints" chapter in GDB user manual. New
2217 remote packets have been defined to support static tracepoints, see
2218 the "New remote packets" section below.
2220 * Better reconstruction of tracepoints after disconnected tracing
2222 GDB will attempt to download the original source form of tracepoint
2223 definitions when starting a trace run, and then will upload these
2224 upon reconnection to the target, resulting in a more accurate
2225 reconstruction of the tracepoints that are in use on the target.
2229 You can now exercise direct control over the ways that GDB can
2230 affect your program. For instance, you can disallow the setting of
2231 breakpoints, so that the program can run continuously (assuming
2232 non-stop mode). In addition, the "observer" variable is available
2233 to switch all of the different controls; in observer mode, GDB
2234 cannot affect the target's behavior at all, which is useful for
2235 tasks like diagnosing live systems in the field.
2237 * The new convenience variable $_thread holds the number of the
2240 * New remote packets
2244 Return the address of the Windows Thread Information Block of a given thread.
2248 In response to several of the tracepoint packets, the target may now
2249 also respond with a number of intermediate `qRelocInsn' request
2250 packets before the final result packet, to have GDB handle
2251 relocating an instruction to execute at a different address. This
2252 is particularly useful for stubs that support fast tracepoints. GDB
2253 reports support for this feature in the qSupported packet.
2257 List static tracepoint markers in the target program.
2261 List static tracepoint markers at a given address in the target
2264 qXfer:statictrace:read
2266 Read the static trace data collected (by a `collect $_sdata'
2267 tracepoint action). The remote stub reports support for this packet
2268 to gdb's qSupported query.
2272 Send the current settings of GDB's permission flags.
2276 Send part of the source (textual) form of a tracepoint definition,
2277 which includes location, conditional, and action list.
2279 * The source command now accepts a -s option to force searching for the
2280 script in the source search path even if the script name specifies
2283 * New features in the GDB remote stub, GDBserver
2285 - GDBserver now support tracepoints (including fast tracepoints, and
2286 static tracepoints). The feature is currently supported by the
2287 i386-linux and amd64-linux builds. See the "Tracepoints support
2288 in gdbserver" section in the manual for more information.
2290 GDBserver JIT compiles the tracepoint's conditional agent
2291 expression bytecode into native code whenever possible for low
2292 overhead dynamic tracepoints conditionals. For such tracepoints,
2293 an expression that examines program state is evaluated when the
2294 tracepoint is reached, in order to determine whether to capture
2295 trace data. If the condition is simple and false, processing the
2296 tracepoint finishes very quickly and no data is gathered.
2298 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2299 for static tracepoints support.
2301 - GDBserver now supports x86_64 Windows 64-bit debugging.
2303 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2304 it understands register description.
2306 * The --batch flag now disables pagination and queries.
2308 * X86 general purpose registers
2310 GDB now supports reading/writing byte, word and double-word x86
2311 general purpose registers directly. This means you can use, say,
2312 $ah or $ax to refer, respectively, to the byte register AH and
2313 16-bit word register AX that are actually portions of the 32-bit
2314 register EAX or 64-bit register RAX.
2316 * The `commands' command now accepts a range of breakpoints to modify.
2317 A plain `commands' following a command that creates multiple
2318 breakpoints affects all the breakpoints set by that command. This
2319 applies to breakpoints set by `rbreak', and also applies when a
2320 single `break' command creates multiple breakpoints (e.g.,
2321 breakpoints on overloaded c++ functions).
2323 * The `rbreak' command now accepts a filename specification as part of
2324 its argument, limiting the functions selected by the regex to those
2325 in the specified file.
2327 * Support for remote debugging Windows and SymbianOS shared libraries
2328 from Unix hosts has been improved. Non Windows GDB builds now can
2329 understand target reported file names that follow MS-DOS based file
2330 system semantics, such as file names that include drive letters and
2331 use the backslash character as directory separator. This makes it
2332 possible to transparently use the "set sysroot" and "set
2333 solib-search-path" on Unix hosts to point as host copies of the
2334 target's shared libraries. See the new command "set
2335 target-file-system-kind" described below, and the "Commands to
2336 specify files" section in the user manual for more information.
2340 eval template, expressions...
2341 Convert the values of one or more expressions under the control
2342 of the string template to a command line, and call it.
2344 set target-file-system-kind unix|dos-based|auto
2345 show target-file-system-kind
2346 Set or show the assumed file system kind for target reported file
2349 save breakpoints <filename>
2350 Save all current breakpoint definitions to a file suitable for use
2351 in a later debugging session. To read the saved breakpoint
2352 definitions, use the `source' command.
2354 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2357 info static-tracepoint-markers
2358 Display information about static tracepoint markers in the target.
2360 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2361 Define a static tracepoint by probing a marker at the given
2362 function, line, address, or marker ID.
2366 Enable and disable observer mode.
2368 set may-write-registers on|off
2369 set may-write-memory on|off
2370 set may-insert-breakpoints on|off
2371 set may-insert-tracepoints on|off
2372 set may-insert-fast-tracepoints on|off
2373 set may-interrupt on|off
2374 Set individual permissions for GDB effects on the target. Note that
2375 some of these settings can have undesirable or surprising
2376 consequences, particularly when changed in the middle of a session.
2377 For instance, disabling the writing of memory can prevent
2378 breakpoints from being inserted, cause single-stepping to fail, or
2379 even crash your program, if you disable after breakpoints have been
2380 inserted. However, GDB should not crash.
2382 set record memory-query on|off
2383 show record memory-query
2384 Control whether to stop the inferior if memory changes caused
2385 by an instruction cannot be recorded.
2390 The disassemble command now supports "start,+length" form of two arguments.
2394 ** GDB now provides a new directory location, called the python directory,
2395 where Python scripts written for GDB can be installed. The location
2396 of that directory is <data-directory>/python, where <data-directory>
2397 is the GDB data directory. For more details, see section `Scripting
2398 GDB using Python' in the manual.
2400 ** The GDB Python API now has access to breakpoints, symbols, symbol
2401 tables, program spaces, inferiors, threads and frame's code blocks.
2402 Additionally, GDB Parameters can now be created from the API, and
2403 manipulated via set/show in the CLI.
2405 ** New functions gdb.target_charset, gdb.target_wide_charset,
2406 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2408 ** New exception gdb.GdbError.
2410 ** Pretty-printers are now also looked up in the current program space.
2412 ** Pretty-printers can now be individually enabled and disabled.
2414 ** GDB now looks for names of Python scripts to auto-load in a
2415 special section named `.debug_gdb_scripts', in addition to looking
2416 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2418 * Tracepoint actions were unified with breakpoint commands. In particular,
2419 there are no longer differences in "info break" output for breakpoints and
2420 tracepoints and the "commands" command can be used for both tracepoints and
2421 regular breakpoints.
2425 ARM Symbian arm*-*-symbianelf*
2427 * D language support.
2428 GDB now supports debugging programs written in the D programming
2431 * GDB now supports the extended ptrace interface for PowerPC which is
2432 available since Linux kernel version 2.6.34. This automatically enables
2433 any hardware breakpoints and additional hardware watchpoints available in
2434 the processor. The old ptrace interface exposes just one hardware
2435 watchpoint and no hardware breakpoints.
2437 * GDB is now able to use the Data Value Compare (DVC) register available on
2438 embedded PowerPC processors to implement in hardware simple watchpoint
2439 conditions of the form:
2441 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2443 This works in native GDB running on Linux kernels with the extended ptrace
2444 interface mentioned above.
2446 *** Changes in GDB 7.1
2450 ** Namespace Support
2452 GDB now supports importing of namespaces in C++. This enables the
2453 user to inspect variables from imported namespaces. Support for
2454 namepace aliasing has also been added. So, if a namespace is
2455 aliased in the current scope (e.g. namepace C=A; ) the user can
2456 print variables using the alias (e.g. (gdb) print C::x).
2460 All known bugs relating to the printing of virtual base class were
2461 fixed. It is now possible to call overloaded static methods using a
2466 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2467 and reinterpret_cast<> are now handled by the C++ expression parser.
2471 Xilinx MicroBlaze microblaze-*-*
2476 Xilinx MicroBlaze microblaze
2479 * Multi-program debugging.
2481 GDB now has support for multi-program (a.k.a. multi-executable or
2482 multi-exec) debugging. This allows for debugging multiple inferiors
2483 simultaneously each running a different program under the same GDB
2484 session. See "Debugging Multiple Inferiors and Programs" in the
2485 manual for more information. This implied some user visible changes
2486 in the multi-inferior support. For example, "info inferiors" now
2487 lists inferiors that are not running yet or that have exited
2488 already. See also "New commands" and "New options" below.
2490 * New tracing features
2492 GDB's tracepoint facility now includes several new features:
2494 ** Trace state variables
2496 GDB tracepoints now include support for trace state variables, which
2497 are variables managed by the target agent during a tracing
2498 experiment. They are useful for tracepoints that trigger each
2499 other, so for instance one tracepoint can count hits in a variable,
2500 and then a second tracepoint has a condition that is true when the
2501 count reaches a particular value. Trace state variables share the
2502 $-syntax of GDB convenience variables, and can appear in both
2503 tracepoint actions and condition expressions. Use the "tvariable"
2504 command to create, and "info tvariables" to view; see "Trace State
2505 Variables" in the manual for more detail.
2509 GDB now includes an option for defining fast tracepoints, which
2510 targets may implement more efficiently, such as by installing a jump
2511 into the target agent rather than a trap instruction. The resulting
2512 speedup can be by two orders of magnitude or more, although the
2513 tradeoff is that some program locations on some target architectures
2514 might not allow fast tracepoint installation, for instance if the
2515 instruction to be replaced is shorter than the jump. To request a
2516 fast tracepoint, use the "ftrace" command, with syntax identical to
2517 the regular trace command.
2519 ** Disconnected tracing
2521 It is now possible to detach GDB from the target while it is running
2522 a trace experiment, then reconnect later to see how the experiment
2523 is going. In addition, a new variable disconnected-tracing lets you
2524 tell the target agent whether to continue running a trace if the
2525 connection is lost unexpectedly.
2529 GDB now has the ability to save the trace buffer into a file, and
2530 then use that file as a target, similarly to you can do with
2531 corefiles. You can select trace frames, print data that was
2532 collected in them, and use tstatus to display the state of the
2533 tracing run at the moment that it was saved. To create a trace
2534 file, use "tsave <filename>", and to use it, do "target tfile
2537 ** Circular trace buffer
2539 You can ask the target agent to handle the trace buffer as a
2540 circular buffer, discarding the oldest trace frames to make room for
2541 newer ones, by setting circular-trace-buffer to on. This feature may
2542 not be available for all target agents.
2547 The disassemble command, when invoked with two arguments, now requires
2548 the arguments to be comma-separated.
2551 The info variables command now displays variable definitions. Files
2552 which only declare a variable are not shown.
2555 The source command is now capable of sourcing Python scripts.
2556 This feature is dependent on the debugger being build with Python
2559 Related to this enhancement is also the introduction of a new command
2560 "set script-extension" (see below).
2562 * New commands (for set/show, see "New options" below)
2564 record save [<FILENAME>]
2565 Save a file (in core file format) containing the process record
2566 execution log for replay debugging at a later time.
2568 record restore <FILENAME>
2569 Restore the process record execution log that was saved at an
2570 earlier time, for replay debugging.
2572 add-inferior [-copies <N>] [-exec <FILENAME>]
2575 clone-inferior [-copies <N>] [ID]
2576 Make a new inferior ready to execute the same program another
2577 inferior has loaded.
2582 maint info program-spaces
2583 List the program spaces loaded into GDB.
2585 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2586 show remote interrupt-sequence
2587 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2588 as the sequence to the remote target in order to interrupt the execution.
2589 Ctrl-C is a default. Some system prefers BREAK which is high level of
2590 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2591 Magic SysRq g. It is BREAK signal and character 'g'.
2593 set remote interrupt-on-connect [on | off]
2594 show remote interrupt-on-connect
2595 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2596 remote target when gdb connects to it. This is needed when you debug
2599 set remotebreak [on | off]
2601 Deprecated. Use "set/show remote interrupt-sequence" instead.
2603 tvariable $NAME [ = EXP ]
2604 Create or modify a trace state variable.
2607 List trace state variables and their values.
2609 delete tvariable $NAME ...
2610 Delete one or more trace state variables.
2613 Evaluate the given expressions without collecting anything into the
2614 trace buffer. (Valid in tracepoint actions only.)
2616 ftrace FN / FILE:LINE / *ADDR
2617 Define a fast tracepoint at the given function, line, or address.
2619 * New expression syntax
2621 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2622 GDB now parses 0b101010 identically with 42.
2626 set follow-exec-mode new|same
2627 show follow-exec-mode
2628 Control whether GDB reuses the same inferior across an exec call or
2629 creates a new one. This is useful to be able to restart the old
2630 executable after the inferior having done an exec call.
2632 set default-collect EXPR, ...
2633 show default-collect
2634 Define a list of expressions to be collected at each tracepoint.
2635 This is a useful way to ensure essential items are not overlooked,
2636 such as registers or a critical global variable.
2638 set disconnected-tracing
2639 show disconnected-tracing
2640 If set to 1, the target is instructed to continue tracing if it
2641 loses its connection to GDB. If 0, the target is to stop tracing
2644 set circular-trace-buffer
2645 show circular-trace-buffer
2646 If set to on, the target is instructed to use a circular trace buffer
2647 and discard the oldest trace frames instead of stopping the trace due
2648 to a full trace buffer. If set to off, the trace stops when the buffer
2649 fills up. Some targets may not support this.
2651 set script-extension off|soft|strict
2652 show script-extension
2653 If set to "off", the debugger does not perform any script language
2654 recognition, and all sourced files are assumed to be GDB scripts.
2655 If set to "soft" (the default), files are sourced according to
2656 filename extension, falling back to GDB scripts if the first
2658 If set to "strict", files are sourced according to filename extension.
2660 set ada trust-PAD-over-XVS on|off
2661 show ada trust-PAD-over-XVS
2662 If off, activate a workaround against a bug in the debugging information
2663 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2664 the GCC sources for more information about the GNAT encoding and
2665 PAD types in particular). It is always safe to set this option to
2666 off, but this introduces a slight performance penalty. The default
2669 * Python API Improvements
2671 ** GDB provides the new class gdb.LazyString. This is useful in
2672 some pretty-printing cases. The new method gdb.Value.lazy_string
2673 provides a simple way to create objects of this type.
2675 ** The fields returned by gdb.Type.fields now have an
2676 `is_base_class' attribute.
2678 ** The new method gdb.Type.range returns the range of an array type.
2680 ** The new method gdb.parse_and_eval can be used to parse and
2681 evaluate an expression.
2683 * New remote packets
2686 Define a trace state variable.
2689 Get the current value of a trace state variable.
2692 Set desired tracing behavior upon disconnection.
2695 Set the trace buffer to be linear or circular.
2698 Get data about the tracepoints currently in use.
2702 Process record now works correctly with hardware watchpoints.
2704 Multiple bug fixes have been made to the mips-irix port, making it
2705 much more reliable. In particular:
2706 - Debugging threaded applications is now possible again. Previously,
2707 GDB would hang while starting the program, or while waiting for
2708 the program to stop at a breakpoint.
2709 - Attaching to a running process no longer hangs.
2710 - An error occurring while loading a core file has been fixed.
2711 - Changing the value of the PC register now works again. This fixes
2712 problems observed when using the "jump" command, or when calling
2713 a function from GDB, or even when assigning a new value to $pc.
2714 - With the "finish" and "return" commands, the return value for functions
2715 returning a small array is now correctly printed.
2716 - It is now possible to break on shared library code which gets executed
2717 during a shared library init phase (code executed while executing
2718 their .init section). Previously, the breakpoint would have no effect.
2719 - GDB is now able to backtrace through the signal handler for
2720 non-threaded programs.
2722 PIE (Position Independent Executable) programs debugging is now supported.
2723 This includes debugging execution of PIC (Position Independent Code) shared
2724 libraries although for that, it should be possible to run such libraries as an
2727 *** Changes in GDB 7.0
2729 * GDB now has an interface for JIT compilation. Applications that
2730 dynamically generate code can create symbol files in memory and register
2731 them with GDB. For users, the feature should work transparently, and
2732 for JIT developers, the interface is documented in the GDB manual in the
2733 "JIT Compilation Interface" chapter.
2735 * Tracepoints may now be conditional. The syntax is as for
2736 breakpoints; either an "if" clause appended to the "trace" command,
2737 or the "condition" command is available. GDB sends the condition to
2738 the target for evaluation using the same bytecode format as is used
2739 for tracepoint actions.
2741 * The disassemble command now supports: an optional /r modifier, print the
2742 raw instructions in hex as well as in symbolic form, and an optional /m
2743 modifier to print mixed source+assembly.
2745 * Process record and replay
2747 In a architecture environment that supports ``process record and
2748 replay'', ``process record and replay'' target can record a log of
2749 the process execution, and replay it with both forward and reverse
2752 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2753 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2754 set execution-direction {forward|reverse}, for targets that support
2757 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2758 feature is available with a native GDB running on kernel version
2761 * GDB now has support for multi-byte and wide character sets on the
2762 target. Strings whose character type is wchar_t, char16_t, or
2763 char32_t are now correctly printed. GDB supports wide- and unicode-
2764 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2765 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2766 `printf'. This feature requires iconv to work properly; if your
2767 system does not have a working iconv, GDB can use GNU libiconv. See
2768 the installation instructions for more information.
2770 * GDB now supports automatic retrieval of shared library files from
2771 remote targets. To use this feature, specify a system root that begins
2772 with the `remote:' prefix, either via the `set sysroot' command or via
2773 the `--with-sysroot' configure-time option.
2775 * "info sharedlibrary" now takes an optional regex of libraries to show,
2776 and it now reports if a shared library has no debugging information.
2778 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2779 now complete on file names.
2781 * When completing in expressions, gdb will attempt to limit
2782 completions to allowable structure or union fields, where appropriate.
2783 For instance, consider:
2785 # struct example { int f1; double f2; };
2786 # struct example variable;
2789 If the user types TAB at the end of this command line, the available
2790 completions will be "f1" and "f2".
2792 * Inlined functions are now supported. They show up in backtraces, and
2793 the "step", "next", and "finish" commands handle them automatically.
2795 * GDB now supports the token-splicing (##) and stringification (#)
2796 operators when expanding macros. It also supports variable-arity
2799 * GDB now supports inspecting extra signal information, exported by
2800 the new $_siginfo convenience variable. The feature is currently
2801 implemented on linux ARM, i386 and amd64.
2803 * GDB can now display the VFP floating point registers and NEON vector
2804 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2805 can provide these registers (requires Linux 2.6.30 or later). Remote
2806 and simulator targets may also provide them.
2808 * New remote packets
2811 Search memory for a sequence of bytes.
2814 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2815 operation over reliable transport links. Use of this packet is
2816 controlled by the `set remote noack-packet' command.
2819 Kill the process with the specified process ID. Use this in preference
2820 to `k' when multiprocess protocol extensions are supported.
2823 Obtains additional operating system information
2827 Read or write additional signal information.
2829 * Removed remote protocol undocumented extension
2831 An undocumented extension to the remote protocol's `S' stop reply
2832 packet that permited the stub to pass a process id was removed.
2833 Remote servers should use the `T' stop reply packet instead.
2835 * GDB now supports multiple function calling conventions according to the
2836 DWARF-2 DW_AT_calling_convention function attribute.
2838 * The SH target utilizes the aforementioned change to distinguish between gcc
2839 and Renesas calling convention. It also adds the new CLI commands
2840 `set/show sh calling-convention'.
2842 * GDB can now read compressed debug sections, as produced by GNU gold
2843 with the --compress-debug-sections=zlib flag.
2845 * 64-bit core files are now supported on AIX.
2847 * Thread switching is now supported on Tru64.
2849 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2850 which will be allocated using malloc later in program execution.
2852 * The qXfer:libraries:read remote procotol packet now allows passing a
2853 list of section offsets.
2855 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2856 conditions handling signals delivered during attach or thread creation
2857 have also been fixed.
2859 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2860 From the user's standpoint, all unqualified instances of True and False
2861 are treated as the standard definitions, regardless of context.
2863 * GDB now parses C++ symbol and type names more flexibly. For
2866 template<typename T> class C { };
2869 GDB will now correctly handle all of:
2871 ptype C<char const *>
2872 ptype C<char const*>
2873 ptype C<const char *>
2874 ptype C<const char*>
2876 * New features in the GDB remote stub, gdbserver
2878 - The "--wrapper" command-line argument tells gdbserver to use a
2879 wrapper program to launch programs for debugging.
2881 - On PowerPC and S/390 targets, it is now possible to use a single
2882 gdbserver executable to debug both 32-bit and 64-bit programs.
2883 (This requires gdbserver itself to be built as a 64-bit executable.)
2885 - gdbserver uses the new noack protocol mode for TCP connections to
2886 reduce communications latency, if also supported and enabled in GDB.
2888 - Support for the sparc64-linux-gnu target is now included in
2891 - The amd64-linux build of gdbserver now supports debugging both
2892 32-bit and 64-bit programs.
2894 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2895 now support hardware watchpoints, and will use them automatically
2900 GDB now has support for scripting using Python. Whether this is
2901 available is determined at configure time.
2903 New GDB commands can now be written in Python.
2905 * Ada tasking support
2907 Ada tasks can now be inspected in GDB. The following commands have
2911 Print the list of Ada tasks.
2913 Print detailed information about task number N.
2915 Print the task number of the current task.
2917 Switch the context of debugging to task number N.
2919 * Support for user-defined prefixed commands. The "define" command can
2920 add new commands to existing prefixes, e.g. "target".
2922 * Multi-inferior, multi-process debugging.
2924 GDB now has generalized support for multi-inferior debugging. See
2925 "Debugging Multiple Inferiors" in the manual for more information.
2926 Although availability still depends on target support, the command
2927 set is more uniform now. The GNU/Linux specific multi-forks support
2928 has been migrated to this new framework. This implied some user
2929 visible changes; see "New commands" and also "Removed commands"
2932 * Target descriptions can now describe the target OS ABI. See the
2933 "Target Description Format" section in the user manual for more
2936 * Target descriptions can now describe "compatible" architectures
2937 to indicate that the target can execute applications for a different
2938 architecture in addition to those for the main target architecture.
2939 See the "Target Description Format" section in the user manual for
2942 * Multi-architecture debugging.
2944 GDB now includes general supports for debugging applications on
2945 hybrid systems that use more than one single processor architecture
2946 at the same time. Each such hybrid architecture still requires
2947 specific support to be added. The only hybrid architecture supported
2948 in this version of GDB is the Cell Broadband Engine.
2950 * GDB now supports integrated debugging of Cell/B.E. applications that
2951 use both the PPU and SPU architectures. To enable support for hybrid
2952 Cell/B.E. debugging, you need to configure GDB to support both the
2953 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2954 --enable-targets configure option.
2956 * Non-stop mode debugging.
2958 For some targets, GDB now supports an optional mode of operation in
2959 which you can examine stopped threads while other threads continue
2960 to execute freely. This is referred to as non-stop mode, with the
2961 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2962 section in the user manual for more information.
2964 To be able to support remote non-stop debugging, a remote stub needs
2965 to implement the non-stop mode remote protocol extensions, as
2966 described in the "Remote Non-Stop" section of the user manual. The
2967 GDB remote stub, gdbserver, has been adjusted to support these
2968 extensions on linux targets.
2970 * New commands (for set/show, see "New options" below)
2972 catch syscall [NAME(S) | NUMBER(S)]
2973 Catch system calls. Arguments, which should be names of system
2974 calls or their numbers, mean catch only those syscalls. Without
2975 arguments, every syscall will be caught. When the inferior issues
2976 any of the specified syscalls, GDB will stop and announce the system
2977 call, both when it is called and when its call returns. This
2978 feature is currently available with a native GDB running on the
2979 Linux Kernel, under the following architectures: x86, x86_64,
2980 PowerPC and PowerPC64.
2982 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2984 Search memory for a sequence of bytes.
2986 maint set python print-stack
2987 maint show python print-stack
2988 Show a stack trace when an error is encountered in a Python script.
2991 Invoke CODE by passing it to the Python interpreter.
2996 These allow macros to be defined, undefined, and listed
3000 Show operating system information about processes.
3003 List the inferiors currently under GDB's control.
3006 Switch focus to inferior number NUM.
3009 Detach from inferior number NUM.
3012 Kill inferior number NUM.
3016 set spu stop-on-load
3017 show spu stop-on-load
3018 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3020 set spu auto-flush-cache
3021 show spu auto-flush-cache
3022 Control whether to automatically flush the software-managed cache
3023 during Cell/B.E. debugging.
3025 set sh calling-convention
3026 show sh calling-convention
3027 Control the calling convention used when calling SH target functions.
3030 show debug timestamp
3031 Control display of timestamps with GDB debugging output.
3033 set disassemble-next-line
3034 show disassemble-next-line
3035 Control display of disassembled source lines or instructions when
3038 set remote noack-packet
3039 show remote noack-packet
3040 Set/show the use of remote protocol QStartNoAckMode packet. See above
3041 under "New remote packets."
3043 set remote query-attached-packet
3044 show remote query-attached-packet
3045 Control use of remote protocol `qAttached' (query-attached) packet.
3047 set remote read-siginfo-object
3048 show remote read-siginfo-object
3049 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3052 set remote write-siginfo-object
3053 show remote write-siginfo-object
3054 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3057 set remote reverse-continue
3058 show remote reverse-continue
3059 Control use of remote protocol 'bc' (reverse-continue) packet.
3061 set remote reverse-step
3062 show remote reverse-step
3063 Control use of remote protocol 'bs' (reverse-step) packet.
3065 set displaced-stepping
3066 show displaced-stepping
3067 Control displaced stepping mode. Displaced stepping is a way to
3068 single-step over breakpoints without removing them from the debuggee.
3069 Also known as "out-of-line single-stepping".
3072 show debug displaced
3073 Control display of debugging info for displaced stepping.
3075 maint set internal-error
3076 maint show internal-error
3077 Control what GDB does when an internal error is detected.
3079 maint set internal-warning
3080 maint show internal-warning
3081 Control what GDB does when an internal warning is detected.
3086 Use a wrapper program to launch programs for debugging.
3088 set multiple-symbols (all|ask|cancel)
3089 show multiple-symbols
3090 The value of this variable can be changed to adjust the debugger behavior
3091 when an expression or a breakpoint location contains an ambiguous symbol
3092 name (an overloaded function name, for instance).
3094 set breakpoint always-inserted
3095 show breakpoint always-inserted
3096 Keep breakpoints always inserted in the target, as opposed to inserting
3097 them when resuming the target, and removing them when the target stops.
3098 This option can improve debugger performance on slow remote targets.
3100 set arm fallback-mode (arm|thumb|auto)
3101 show arm fallback-mode
3102 set arm force-mode (arm|thumb|auto)
3104 These commands control how ARM GDB determines whether instructions
3105 are ARM or Thumb. The default for both settings is auto, which uses
3106 the current CPSR value for instructions without symbols; previous
3107 versions of GDB behaved as if "set arm fallback-mode arm".
3109 set disable-randomization
3110 show disable-randomization
3111 Standalone programs run with the virtual address space randomization enabled
3112 by default on some platforms. This option keeps the addresses stable across
3113 multiple debugging sessions.
3117 Control whether other threads are stopped or not when some thread hits
3122 Requests that asynchronous execution is enabled in the target, if available.
3123 In this case, it's possible to resume target in the background, and interact
3124 with GDB while the target is running. "show target-async" displays the
3125 current state of asynchronous execution of the target.
3127 set target-wide-charset
3128 show target-wide-charset
3129 The target-wide-charset is the name of the character set that GDB
3130 uses when printing characters whose type is wchar_t.
3132 set tcp auto-retry (on|off)
3134 set tcp connect-timeout
3135 show tcp connect-timeout
3136 These commands allow GDB to retry failed TCP connections to a remote stub
3137 with a specified timeout period; this is useful if the stub is launched
3138 in parallel with GDB but may not be ready to accept connections immediately.
3140 set libthread-db-search-path
3141 show libthread-db-search-path
3142 Control list of directories which GDB will search for appropriate
3145 set schedule-multiple (on|off)
3146 show schedule-multiple
3147 Allow GDB to resume all threads of all processes or only threads of
3148 the current process.
3152 Use more aggressive caching for accesses to the stack. This improves
3153 performance of remote debugging (particularly backtraces) without
3154 affecting correctness.
3156 set interactive-mode (on|off|auto)
3157 show interactive-mode
3158 Control whether GDB runs in interactive mode (on) or not (off).
3159 When in interactive mode, GDB waits for the user to answer all
3160 queries. Otherwise, GDB does not wait and assumes the default
3161 answer. When set to auto (the default), GDB determines which
3162 mode to use based on the stdin settings.
3167 For program forks, this is replaced by the new more generic `info
3168 inferiors' command. To list checkpoints, you can still use the
3169 `info checkpoints' command, which was an alias for the `info forks'
3173 Replaced by the new `inferior' command. To switch between
3174 checkpoints, you can still use the `restart' command, which was an
3175 alias for the `fork' command.
3178 This is removed, since some targets don't have a notion of
3179 processes. To switch between processes, you can still use the
3180 `inferior' command using GDB's own inferior number.
3183 For program forks, this is replaced by the new more generic `kill
3184 inferior' command. To delete a checkpoint, you can still use the
3185 `delete checkpoint' command, which was an alias for the `delete
3189 For program forks, this is replaced by the new more generic `detach
3190 inferior' command. To detach a checkpoint, you can still use the
3191 `detach checkpoint' command, which was an alias for the `detach
3194 * New native configurations
3196 x86/x86_64 Darwin i[34567]86-*-darwin*
3198 x86_64 MinGW x86_64-*-mingw*
3202 Lattice Mico32 lm32-*
3203 x86 DICOS i[34567]86-*-dicos*
3204 x86_64 DICOS x86_64-*-dicos*
3207 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3208 (mingw32ce) debugging.
3214 These commands were actually not implemented on any target.
3216 *** Changes in GDB 6.8
3218 * New native configurations
3220 NetBSD/hppa hppa*-*netbsd*
3221 Xtensa GNU/Linux xtensa*-*-linux*
3225 NetBSD/hppa hppa*-*-netbsd*
3226 Xtensa GNU/Lunux xtensa*-*-linux*
3228 * Change in command line behavior -- corefiles vs. process ids.
3230 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3231 attaching to process NUMBER fails, GDB no longer attempts to open a
3232 core file named NUMBER. Attaching to a program using the -c option
3233 is no longer supported. Instead, use the '-p' or '--pid' options.
3235 * GDB can now be built as a native debugger for debugging Windows x86
3236 (mingw32) Portable Executable (PE) programs.
3238 * Pending breakpoints no longer change their number when their address
3241 * GDB now supports breakpoints with multiple locations,
3242 including breakpoints on C++ constructors, inside C++ templates,
3243 and in inlined functions.
3245 * GDB's ability to debug optimized code has been improved. GDB more
3246 accurately identifies function bodies and lexical blocks that occupy
3247 more than one contiguous range of addresses.
3249 * Target descriptions can now describe registers for PowerPC.
3251 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3252 registers on PowerPC targets.
3254 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3255 targets even when the libthread_db library is not available.
3257 * The GDB remote stub, gdbserver, now supports the new file transfer
3258 commands (remote put, remote get, and remote delete).
3260 * The GDB remote stub, gdbserver, now supports run and attach in
3261 extended-remote mode.
3263 * hppa*64*-*-hpux11* target broken
3264 The debugger is unable to start a program and fails with the following
3265 error: "Error trying to get information about dynamic linker".
3266 The gdb-6.7 release is also affected.
3268 * GDB now supports the --enable-targets= configure option to allow
3269 building a single GDB executable that supports multiple remote
3270 target architectures.
3272 * GDB now supports debugging C and C++ programs which use the
3273 Decimal Floating Point extension. In addition, the PowerPC target
3274 now has a set of pseudo-registers to inspect decimal float values
3275 stored in two consecutive float registers.
3277 * The -break-insert MI command can optionally create pending
3280 * Improved support for debugging Ada
3281 Many improvements to the Ada language support have been made. These
3283 - Better support for Ada2005 interface types
3284 - Improved handling of arrays and slices in general
3285 - Better support for Taft-amendment types
3286 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3288 - Improved command completion in Ada
3291 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3296 set print frame-arguments (all|scalars|none)
3297 show print frame-arguments
3298 The value of this variable can be changed to control which argument
3299 values should be printed by the debugger when displaying a frame.
3304 Transfer files to and from a remote target, and delete remote files.
3311 Transfer files to and from a remote target, and delete remote files.
3313 * New remote packets
3320 Open, close, read, write, and delete files on the remote system.
3323 Attach to an existing process on the remote system, in extended-remote
3327 Run a new process on the remote system, in extended-remote mode.
3329 *** Changes in GDB 6.7
3331 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3332 bfd, libiberty and opcodes, as revealed by static analysis donated by
3333 Coverity, Inc. (http://scan.coverity.com).
3335 * When looking up multiply-defined global symbols, GDB will now prefer the
3336 symbol definition in the current shared library if it was built using the
3337 -Bsymbolic linker option.
3339 * When the Text User Interface (TUI) is not configured, GDB will now
3340 recognize the -tui command-line option and print a message that the TUI
3343 * The GDB remote stub, gdbserver, now has lower overhead for high
3344 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3346 * GDB for MIPS targets now autodetects whether a remote target provides
3347 32-bit or 64-bit register values.
3349 * Support for C++ member pointers has been improved.
3351 * GDB now understands XML target descriptions, which specify the
3352 target's overall architecture. GDB can read a description from
3353 a local file or over the remote serial protocol.
3355 * Vectors of single-byte data use a new integer type which is not
3356 automatically displayed as character or string data.
3358 * The /s format now works with the print command. It displays
3359 arrays of single-byte integers and pointers to single-byte integers
3362 * Target descriptions can now describe target-specific registers,
3363 for architectures which have implemented the support (currently
3364 only ARM, M68K, and MIPS).
3366 * GDB and the GDB remote stub, gdbserver, now support the XScale
3369 * The GDB remote stub, gdbserver, has been updated to support
3370 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3371 has been rewritten to use the standard GDB remote protocol.
3373 * GDB can now step into C++ functions which are called through thunks.
3375 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3377 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3378 layout. It also supports a TextSeg= and DataSeg= response when only
3379 segment base addresses (rather than offsets) are available.
3381 * The /i format now outputs any trailing branch delay slot instructions
3382 immediately following the last instruction within the count specified.
3384 * The GDB remote protocol "T" stop reply packet now supports a
3385 "library" response. Combined with the new "qXfer:libraries:read"
3386 packet, this response allows GDB to debug shared libraries on targets
3387 where the operating system manages the list of loaded libraries (e.g.
3388 Windows and SymbianOS).
3390 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3391 (DLLs) on Windows and Windows CE targets.
3393 * GDB now supports a faster verification that a .debug file matches its binary
3394 according to its build-id signature, if the signature is present.
3400 Enable or disable hardware flow control (RTS/CTS) on the serial port
3401 when debugging using remote targets.
3403 set mem inaccessible-by-default
3404 show mem inaccessible-by-default
3405 If the target supplies a memory map, for instance via the remote
3406 protocol's "qXfer:memory-map:read" packet, setting this variable
3407 prevents GDB from accessing memory outside the memory map. This
3408 is useful for targets with memory mapped registers or which react
3409 badly to accesses of unmapped address space.
3411 set breakpoint auto-hw
3412 show breakpoint auto-hw
3413 If the target supplies a memory map, for instance via the remote
3414 protocol's "qXfer:memory-map:read" packet, setting this variable
3415 lets GDB use hardware breakpoints automatically for memory regions
3416 where it can not use software breakpoints. This covers both the
3417 "break" command and internal breakpoints used for other commands
3418 including "next" and "finish".
3421 catch exception unhandled
3422 Stop the program execution when Ada exceptions are raised.
3425 Stop the program execution when an Ada assertion failed.
3429 Set an alternate system root for target files. This is a more
3430 general version of "set solib-absolute-prefix", which is now
3431 an alias to "set sysroot".
3434 Provide extended SPU facility status information. This set of
3435 commands is available only when debugging the Cell/B.E. SPU
3438 * New native configurations
3440 OpenBSD/sh sh*-*openbsd*
3443 unset tdesc filename
3445 Use the specified local file as an XML target description, and do
3446 not query the target for its built-in description.
3450 OpenBSD/sh sh*-*-openbsd*
3451 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3452 Toshiba Media Processor mep-elf
3454 * New remote packets
3457 Ignore the specified signals; pass them directly to the debugged program
3458 without stopping other threads or reporting them to GDB.
3460 qXfer:features:read:
3461 Read an XML target description from the target, which describes its
3466 Read or write contents of an spufs file on the target system. These
3467 packets are available only on the Cell/B.E. SPU architecture.
3469 qXfer:libraries:read:
3470 Report the loaded shared libraries. Combined with new "T" packet
3471 response, this packet allows GDB to debug shared libraries on
3472 targets where the operating system manages the list of loaded
3473 libraries (e.g. Windows and SymbianOS).
3477 Support for these obsolete configurations has been removed.
3485 i[34567]86-*-lynxos*
3486 i[34567]86-*-netware*
3487 i[34567]86-*-sco3.2v5*
3488 i[34567]86-*-sco3.2v4*
3490 i[34567]86-*-sysv4.2*
3493 i[34567]86-*-unixware2*
3494 i[34567]86-*-unixware*
3503 * Other removed features
3510 Various m68k-only ROM monitors.
3517 Various Renesas ROM monitors and debugging interfaces for SH and
3522 Support for a Macraigor serial interface to on-chip debugging.
3523 GDB does not directly support the newer parallel or USB
3528 A debug information format. The predecessor to DWARF 2 and
3529 DWARF 3, which are still supported.
3531 Support for the HP aCC compiler on HP-UX/PA-RISC
3533 SOM-encapsulated symbolic debugging information, automatic
3534 invocation of pxdb, and the aCC custom C++ ABI. This does not
3535 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3536 with aCC can still be debugged on an assembly level.
3538 MIPS ".pdr" sections
3540 A MIPS-specific format used to describe stack frame layout
3541 in debugging information.
3545 GDB could work with an older version of Guile to debug
3546 the interpreter and Scheme programs running in it.
3548 set mips stack-arg-size
3549 set mips saved-gpreg-size
3551 Use "set mips abi" to control parameter passing for MIPS.
3553 *** Changes in GDB 6.6
3558 Cell Broadband Engine SPU spu-elf
3560 * GDB can now be configured as a cross-debugger targeting native Windows
3561 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3562 running on a Windows system over TCP/IP to debug Windows programs.
3564 * The GDB remote stub, gdbserver, has been updated to support Windows and
3565 Cygwin debugging. Both single-threaded and multi-threaded programs are
3568 * The "set trust-readonly-sections" command works again. This command was
3569 broken in GDB 6.3, 6.4, and 6.5.
3571 * The "load" command now supports writing to flash memory, if the remote
3572 stub provides the required support.
3574 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3575 longer requires symbolic debug information (e.g. DWARF-2).
3580 unset substitute-path
3581 show substitute-path
3582 Manage a list of substitution rules that GDB uses to rewrite the name
3583 of the directories where the sources are located. This can be useful
3584 for instance when the sources were moved to a different location
3585 between compilation and debugging.
3589 Print each CLI command as it is executed. Each command is prefixed with
3590 a number of `+' symbols representing the nesting depth.
3591 The source command now has a `-v' option to enable the same feature.
3595 The ARM Demon monitor support (RDP protocol, "target rdp").
3597 Kernel Object Display, an embedded debugging feature which only worked with
3598 an obsolete version of Cisco IOS.
3600 The 'set download-write-size' and 'show download-write-size' commands.
3602 * New remote packets
3605 Tell a stub about GDB client features, and request remote target features.
3606 The first feature implemented is PacketSize, which allows the target to
3607 specify the size of packets it can handle - to minimize the number of
3608 packets required and improve performance when connected to a remote
3612 Fetch an OS auxilliary vector from the remote stub. This packet is a
3613 more efficient replacement for qPart:auxv:read.
3615 qXfer:memory-map:read:
3616 Fetch a memory map from the remote stub, including information about
3617 RAM, ROM, and flash memory devices.
3622 Erase and program a flash memory device.
3624 * Removed remote packets
3627 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3628 used it, and only gdbserver implemented it.
3630 *** Changes in GDB 6.5
3634 Renesas M32C/M16C m32c-elf
3636 Morpho Technologies ms1 ms1-elf
3640 init-if-undefined Initialize a convenience variable, but
3641 only if it doesn't already have a value.
3643 The following commands are presently only implemented for native GNU/Linux:
3645 checkpoint Save a snapshot of the program state.
3647 restart <n> Return the program state to a
3648 previously saved state.
3650 info checkpoints List currently saved checkpoints.
3652 delete-checkpoint <n> Delete a previously saved checkpoint.
3654 set|show detach-on-fork Tell gdb whether to detach from a newly
3655 forked process, or to keep debugging it.
3657 info forks List forks of the user program that
3658 are available to be debugged.
3660 fork <n> Switch to debugging one of several
3661 forks of the user program that are
3662 available to be debugged.
3664 delete-fork <n> Delete a fork from the list of forks
3665 that are available to be debugged (and
3666 kill the forked process).
3668 detach-fork <n> Delete a fork from the list of forks
3669 that are available to be debugged (and
3670 allow the process to continue).
3674 Morpho Technologies ms2 ms1-elf
3676 * Improved Windows host support
3678 GDB now builds as a cross debugger hosted on i686-mingw32, including
3679 native console support, and remote communications using either
3680 network sockets or serial ports.
3682 * Improved Modula-2 language support
3684 GDB can now print most types in the Modula-2 syntax. This includes:
3685 basic types, set types, record types, enumerated types, range types,
3686 pointer types and ARRAY types. Procedure var parameters are correctly
3687 printed and hexadecimal addresses and character constants are also
3688 written in the Modula-2 syntax. Best results can be obtained by using
3689 GNU Modula-2 together with the -gdwarf-2 command line option.
3693 The ARM rdi-share module.
3695 The Netware NLM debug server.
3697 *** Changes in GDB 6.4
3699 * New native configurations
3701 OpenBSD/arm arm*-*-openbsd*
3702 OpenBSD/mips64 mips64-*-openbsd*
3706 Morpho Technologies ms1 ms1-elf
3708 * New command line options
3710 --batch-silent As for --batch, but totally silent.
3711 --return-child-result The debugger will exist with the same value
3712 the child (debugged) program exited with.
3713 --eval-command COMMAND, -ex COMMAND
3714 Execute a single GDB CLI command. This may be
3715 specified multiple times and in conjunction
3716 with the --command (-x) option.
3718 * Deprecated commands removed
3720 The following commands, that were deprecated in 2000, have been
3724 set|show arm disassembly-flavor set|show arm disassembler
3725 othernames set arm disassembler
3726 set|show remotedebug set|show debug remote
3727 set|show archdebug set|show debug arch
3728 set|show eventdebug set|show debug event
3731 * New BSD user-level threads support
3733 It is now possible to debug programs using the user-level threads
3734 library on OpenBSD and FreeBSD. Currently supported (target)
3737 FreeBSD/amd64 x86_64-*-freebsd*
3738 FreeBSD/i386 i386-*-freebsd*
3739 OpenBSD/i386 i386-*-openbsd*
3741 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3742 are not yet supported.
3744 * New support for Matsushita MN10300 w/sim added
3745 (Work in progress). mn10300-elf.
3747 * REMOVED configurations and files
3749 VxWorks and the XDR protocol *-*-vxworks
3750 Motorola MCORE mcore-*-*
3751 National Semiconductor NS32000 ns32k-*-*
3753 * New "set print array-indexes" command
3755 After turning this setting "on", GDB prints the index of each element
3756 when displaying arrays. The default is "off" to preserve the previous
3759 * VAX floating point support
3761 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3763 * User-defined command support
3765 In addition to using $arg0..$arg9 for argument passing, it is now possible
3766 to use $argc to determine now many arguments have been passed. See the
3767 section on user-defined commands in the user manual for more information.
3769 *** Changes in GDB 6.3:
3771 * New command line option
3773 GDB now accepts -l followed by a number to set the timeout for remote
3776 * GDB works with GCC -feliminate-dwarf2-dups
3778 GDB now supports a more compact representation of DWARF-2 debug
3779 information using DW_FORM_ref_addr references. These are produced
3780 by GCC with the option -feliminate-dwarf2-dups and also by some
3781 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3782 to use -feliminate-dwarf2-dups.
3784 * Internationalization
3786 When supported by the host system, GDB will be built with
3787 internationalization (libintl). The task of marking up the sources is
3788 continued, we're looking forward to our first translation.
3792 Initial support for debugging programs compiled with the GNAT
3793 implementation of the Ada programming language has been integrated
3794 into GDB. In this release, support is limited to expression evaluation.
3796 * New native configurations
3798 GNU/Linux/m32r m32r-*-linux-gnu
3802 GDB's remote protocol now includes support for the 'p' packet. This
3803 packet is used to fetch individual registers from a remote inferior.
3805 * END-OF-LIFE registers[] compatibility module
3807 GDB's internal register infrastructure has been completely rewritten.
3808 The new infrastructure making possible the implementation of key new
3809 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3812 GDB 6.3 will be the last release to include the the registers[]
3813 compatibility module that allowed out-of-date configurations to
3814 continue to work. This change directly impacts the following
3824 powerpc bdm protocol
3826 Unless there is activity to revive these configurations, they will be
3827 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3829 * OBSOLETE configurations and files
3831 Configurations that have been declared obsolete in this release have
3832 been commented out. Unless there is activity to revive these
3833 configurations, the next release of GDB will have their sources
3834 permanently REMOVED.
3843 *** Changes in GDB 6.2.1:
3845 * MIPS `break main; run' gave an heuristic-fence-post warning
3847 When attempting to run even a simple program, a warning about
3848 heuristic-fence-post being hit would be reported. This problem has
3851 * MIPS IRIX 'long double' crashed GDB
3853 When examining a long double variable, GDB would get a segmentation
3854 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3855 IRIX long double values).
3859 A bug in the VAX stack code was causing problems with the "next"
3860 command. This problem has been fixed.
3862 *** Changes in GDB 6.2:
3864 * Fix for ``many threads''
3866 On GNU/Linux systems that use the NPTL threads library, a program
3867 rapidly creating and deleting threads would confuse GDB leading to the
3870 ptrace: No such process.
3871 thread_db_get_info: cannot get thread info: generic error
3873 This problem has been fixed.
3875 * "-async" and "-noasync" options removed.
3877 Support for the broken "-noasync" option has been removed (it caused
3880 * New ``start'' command.
3882 This command runs the program until the begining of the main procedure.
3884 * New BSD Kernel Data Access Library (libkvm) interface
3886 Using ``target kvm'' it is now possible to debug kernel core dumps and
3887 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3888 platforms. Currently supported (native-only) configurations are:
3890 FreeBSD/amd64 x86_64-*-freebsd*
3891 FreeBSD/i386 i?86-*-freebsd*
3892 NetBSD/i386 i?86-*-netbsd*
3893 NetBSD/m68k m68*-*-netbsd*
3894 NetBSD/sparc sparc-*-netbsd*
3895 OpenBSD/amd64 x86_64-*-openbsd*
3896 OpenBSD/i386 i?86-*-openbsd*
3897 OpenBSD/m68k m68*-openbsd*
3898 OpenBSD/sparc sparc-*-openbsd*
3900 * Signal trampoline code overhauled
3902 Many generic problems with GDB's signal handling code have been fixed.
3903 These include: backtraces through non-contiguous stacks; recognition
3904 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3905 call; backtrace through a signal trampoline; step into and out of
3906 signal handlers; and single-stepping in the signal trampoline.
3908 Please note that kernel bugs are a limiting factor here. These
3909 features have been shown to work on an s390 GNU/Linux system that
3910 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3912 * Cygwin support for DWARF 2 added.
3914 * New native configurations
3916 GNU/Linux/hppa hppa*-*-linux*
3917 OpenBSD/hppa hppa*-*-openbsd*
3918 OpenBSD/m68k m68*-*-openbsd*
3919 OpenBSD/m88k m88*-*-openbsd*
3920 OpenBSD/powerpc powerpc-*-openbsd*
3921 NetBSD/vax vax-*-netbsd*
3922 OpenBSD/vax vax-*-openbsd*
3924 * END-OF-LIFE frame compatibility module
3926 GDB's internal frame infrastructure has been completely rewritten.
3927 The new infrastructure making it possible to support key new features
3928 including DWARF 2 Call Frame Information. To aid in the task of
3929 migrating old configurations to this new infrastructure, a
3930 compatibility module, that allowed old configurations to continue to
3931 work, was also included.
3933 GDB 6.2 will be the last release to include this frame compatibility
3934 module. This change directly impacts the following configurations:
3944 Unless there is activity to revive these configurations, they will be
3945 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3947 * REMOVED configurations and files
3949 Sun 3, running SunOS 3 m68*-*-sunos3*
3950 Sun 3, running SunOS 4 m68*-*-sunos4*
3951 Sun 2, running SunOS 3 m68000-*-sunos3*
3952 Sun 2, running SunOS 4 m68000-*-sunos4*
3953 Motorola 680x0 running LynxOS m68*-*-lynxos*
3954 AT&T 3b1/Unix pc m68*-att-*
3955 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3956 decstation mips-dec-* mips-little-*
3957 riscos mips-*-riscos* mips-*-sysv*
3958 sonymips mips-sony-*
3959 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3961 *** Changes in GDB 6.1.1:
3963 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3965 The TUI (Text-mode User Interface) is now built as part of a default
3966 GDB configuration. It is enabled by either selecting the TUI with the
3967 command line option "-i=tui" or by running the separate "gdbtui"
3968 program. For more information on the TUI, see the manual "Debugging
3971 * Pending breakpoint support (also included in GDB 6.1)
3973 Support has been added to allow you to specify breakpoints in shared
3974 libraries that have not yet been loaded. If a breakpoint location
3975 cannot be found, and the "breakpoint pending" option is set to auto,
3976 GDB queries you if you wish to make the breakpoint pending on a future
3977 shared-library load. If and when GDB resolves the breakpoint symbol,
3978 the pending breakpoint is removed as one or more regular breakpoints
3981 Pending breakpoints are very useful for GCJ Java debugging.
3983 * Fixed ISO-C build problems
3985 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3986 non ISO-C code that stopped them being built using a more strict ISO-C
3987 compiler (e.g., IBM's C compiler).
3989 * Fixed build problem on IRIX 5
3991 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3992 wasn't able to compile compile on an IRIX 5 system.
3994 * Added execute permission to gdb/gdbserver/configure
3996 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3997 permission. This bug would cause configure to fail on a number of
3998 systems (Solaris, IRIX). Ref: server/519.
4000 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4002 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4003 has been updated to use constant array sizes.
4005 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4007 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4008 its generated DWARF Call Frame Info. This encoding was causing GDB to
4009 panic, that panic has been fixed. Ref: gdb/1628.
4011 * Fixed a problem when examining parameters in shared library code.
4013 When examining parameters in optimized shared library code generated
4014 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4015 not available''. GDB now correctly displays the variable's value.
4017 *** Changes in GDB 6.1:
4019 * Removed --with-mmalloc
4021 Support for the mmalloc memory manager has been removed, as it
4022 conflicted with the internal gdb byte cache.
4024 * Changes in AMD64 configurations
4026 The AMD64 target now includes the %cs and %ss registers. As a result
4027 the AMD64 remote protocol has changed; this affects the floating-point
4028 and SSE registers. If you rely on those registers for your debugging,
4029 you should upgrade gdbserver on the remote side.
4031 * Revised SPARC target
4033 The SPARC target has been completely revised, incorporating the
4034 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4035 support for LynxOS and SunOS 4 has been dropped. Calling functions
4036 from within GDB on operating systems with a non-executable stack
4037 (Solaris, OpenBSD) now works.
4041 GDB has a new C++ demangler which does a better job on the mangled
4042 names generated by current versions of g++. It also runs faster, so
4043 with this and other changes gdb should now start faster on large C++
4046 * DWARF 2 Location Expressions
4048 GDB support for location expressions has been extended to support function
4049 arguments and frame bases. Older versions of GDB could crash when they
4052 * C++ nested types and namespaces
4054 GDB's support for nested types and namespaces in C++ has been
4055 improved, especially if you use the DWARF 2 debugging format. (This
4056 is the default for recent versions of GCC on most platforms.)
4057 Specifically, if you have a class "Inner" defined within a class or
4058 namespace "Outer", then GDB realizes that the class's name is
4059 "Outer::Inner", not simply "Inner". This should greatly reduce the
4060 frequency of complaints about not finding RTTI symbols. In addition,
4061 if you are stopped at inside of a function defined within a namespace,
4062 GDB modifies its name lookup accordingly.
4064 * New native configurations
4066 NetBSD/amd64 x86_64-*-netbsd*
4067 OpenBSD/amd64 x86_64-*-openbsd*
4068 OpenBSD/alpha alpha*-*-openbsd*
4069 OpenBSD/sparc sparc-*-openbsd*
4070 OpenBSD/sparc64 sparc64-*-openbsd*
4072 * New debugging protocols
4074 M32R with SDI protocol m32r-*-elf*
4076 * "set prompt-escape-char" command deleted.
4078 The command "set prompt-escape-char" has been deleted. This command,
4079 and its very obscure effet on GDB's prompt, was never documented,
4080 tested, nor mentioned in the NEWS file.
4082 * OBSOLETE configurations and files
4084 Configurations that have been declared obsolete in this release have
4085 been commented out. Unless there is activity to revive these
4086 configurations, the next release of GDB will have their sources
4087 permanently REMOVED.
4089 Sun 3, running SunOS 3 m68*-*-sunos3*
4090 Sun 3, running SunOS 4 m68*-*-sunos4*
4091 Sun 2, running SunOS 3 m68000-*-sunos3*
4092 Sun 2, running SunOS 4 m68000-*-sunos4*
4093 Motorola 680x0 running LynxOS m68*-*-lynxos*
4094 AT&T 3b1/Unix pc m68*-att-*
4095 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4096 decstation mips-dec-* mips-little-*
4097 riscos mips-*-riscos* mips-*-sysv*
4098 sonymips mips-sony-*
4099 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4101 * REMOVED configurations and files
4103 SGI Irix-4.x mips-sgi-irix4 or iris4
4104 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4105 Z8000 simulator z8k-zilog-none or z8ksim
4106 Matsushita MN10200 w/simulator mn10200-*-*
4107 H8/500 simulator h8500-hitachi-hms or h8500hms
4108 HP/PA running BSD hppa*-*-bsd*
4109 HP/PA running OSF/1 hppa*-*-osf*
4110 HP/PA Pro target hppa*-*-pro*
4111 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4112 386BSD i[3456]86-*-bsd*
4113 Sequent family i[3456]86-sequent-sysv4*
4114 i[3456]86-sequent-sysv*
4115 i[3456]86-sequent-bsd*
4116 SPARC running LynxOS sparc-*-lynxos*
4117 SPARC running SunOS 4 sparc-*-sunos4*
4118 Tsqware Sparclet sparclet-*-*
4119 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4121 *** Changes in GDB 6.0:
4125 Support for debugging the Objective-C programming language has been
4126 integrated into GDB.
4128 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4130 DWARF 2's Call Frame Information makes available compiler generated
4131 information that more exactly describes the program's run-time stack.
4132 By using this information, GDB is able to provide more robust stack
4135 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4136 have been updated to use a new backtrace mechanism which includes
4137 DWARF 2 CFI support.
4141 GDB's remote protocol has been extended to include support for hosted
4142 file I/O (where the remote target uses GDB's file system). See GDB's
4143 remote protocol documentation for details.
4145 * All targets using the new architecture framework.
4147 All of GDB's targets have been updated to use the new internal
4148 architecture framework. The way is now open for future GDB releases
4149 to include cross-architecture native debugging support (i386 on amd64,
4152 * GNU/Linux's Thread Local Storage (TLS)
4154 GDB now includes support for for the GNU/Linux implementation of
4155 per-thread variables.
4157 * GNU/Linux's Native POSIX Thread Library (NPTL)
4159 GDB's thread code has been updated to work with either the new
4160 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4162 * Separate debug info.
4164 GDB, in conjunction with BINUTILS, now supports a mechanism for
4165 automatically loading debug information from a separate file. Instead
4166 of shipping full debug and non-debug versions of system libraries,
4167 system integrators can now instead ship just the stripped libraries
4168 and optional debug files.
4170 * DWARF 2 Location Expressions
4172 DWARF 2 Location Expressions allow the compiler to more completely
4173 describe the location of variables (even in optimized code) to the
4176 GDB now includes preliminary support for location expressions (support
4177 for DW_OP_piece is still missing).
4181 A number of long standing bugs that caused GDB to die while starting a
4182 Java application have been fixed. GDB's Java support is now
4183 considered "useable".
4185 * GNU/Linux support for fork, vfork, and exec.
4187 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4188 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4191 * GDB supports logging output to a file
4193 There are two new commands, "set logging" and "show logging", which can be
4194 used to capture GDB's output to a file.
4196 * The meaning of "detach" has changed for gdbserver
4198 The "detach" command will now resume the application, as documented. To
4199 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4202 * d10v, m68hc11 `regs' command deprecated
4204 The `info registers' command has been updated so that it displays the
4205 registers using a format identical to the old `regs' command.
4209 A new command, "maint set profile on/off", has been added. This command can
4210 be used to enable or disable profiling while running GDB, to profile a
4211 session or a set of commands. In addition there is a new configure switch,
4212 "--enable-profiling", which will cause GDB to be compiled with profiling
4213 data, for more informative profiling results.
4215 * Default MI syntax changed to "mi2".
4217 The default MI (machine interface) syntax, enabled by the command line
4218 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4219 "mi1", can be enabled by specifying the option "-i=mi1".
4221 Support for the original "mi0" syntax (included in GDB 5.0) has been
4224 Fix for gdb/192: removed extraneous space when displaying frame level.
4225 Fix for gdb/672: update changelist is now output in mi list format.
4226 Fix for gdb/702: a -var-assign that updates the value now shows up
4227 in a subsequent -var-update.
4229 * New native configurations.
4231 FreeBSD/amd64 x86_64-*-freebsd*
4233 * Multi-arched targets.
4235 HP/PA HPUX11 hppa*-*-hpux*
4236 Renesas M32R/D w/simulator m32r-*-elf*
4238 * OBSOLETE configurations and files
4240 Configurations that have been declared obsolete in this release have
4241 been commented out. Unless there is activity to revive these
4242 configurations, the next release of GDB will have their sources
4243 permanently REMOVED.
4245 Z8000 simulator z8k-zilog-none or z8ksim
4246 Matsushita MN10200 w/simulator mn10200-*-*
4247 H8/500 simulator h8500-hitachi-hms or h8500hms
4248 HP/PA running BSD hppa*-*-bsd*
4249 HP/PA running OSF/1 hppa*-*-osf*
4250 HP/PA Pro target hppa*-*-pro*
4251 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4252 Sequent family i[3456]86-sequent-sysv4*
4253 i[3456]86-sequent-sysv*
4254 i[3456]86-sequent-bsd*
4255 Tsqware Sparclet sparclet-*-*
4256 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4258 * REMOVED configurations and files
4261 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4262 IBM AIX PS/2 i[3456]86-*-aix
4263 i386 running Mach 3.0 i[3456]86-*-mach3*
4264 i386 running Mach i[3456]86-*-mach*
4265 i386 running OSF/1 i[3456]86-*osf1mk*
4266 HP/Apollo 68k Family m68*-apollo*-sysv*,
4268 m68*-hp-bsd*, m68*-hp-hpux*
4269 Argonaut Risc Chip (ARC) arc-*-*
4270 Mitsubishi D30V d30v-*-*
4271 Fujitsu FR30 fr30-*-elf*
4272 OS/9000 i[34]86-*-os9k
4273 I960 with MON960 i960-*-coff
4275 * MIPS $fp behavior changed
4277 The convenience variable $fp, for the MIPS, now consistently returns
4278 the address of the current frame's base. Previously, depending on the
4279 context, $fp could refer to either $sp or the current frame's base
4280 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4281 The GNU Source-Level Debugger''.
4283 *** Changes in GDB 5.3:
4285 * GNU/Linux shared library multi-threaded performance improved.
4287 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4288 `/proc', in preference to `ptrace' for memory reads. This may result
4289 in an improvement in the start-up time of multi-threaded, shared
4290 library applications when run under GDB. One GDB user writes: ``loads
4291 shared libs like mad''.
4293 * ``gdbserver'' now supports multi-threaded applications on some targets
4295 Support for debugging multi-threaded applications which use
4296 the GNU/Linux LinuxThreads package has been added for
4297 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4298 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4300 * GDB now supports C/C++ preprocessor macros.
4302 GDB now expands preprocessor macro invocations in C/C++ expressions,
4303 and provides various commands for showing macro definitions and how
4306 The new command `macro expand EXPRESSION' expands any macro
4307 invocations in expression, and shows the result.
4309 The new command `show macro MACRO-NAME' shows the definition of the
4310 macro named MACRO-NAME, and where it was defined.
4312 Most compilers don't include information about macros in the debugging
4313 information by default. In GCC 3.1, for example, you need to compile
4314 your program with the options `-gdwarf-2 -g3'. If the macro
4315 information is present in the executable, GDB will read it.
4317 * Multi-arched targets.
4319 DEC Alpha (partial) alpha*-*-*
4320 DEC VAX (partial) vax-*-*
4322 National Semiconductor NS32000 (partial) ns32k-*-*
4323 Motorola 68000 (partial) m68k-*-*
4324 Motorola MCORE mcore-*-*
4328 Fujitsu FRV architecture added by Red Hat frv*-*-*
4331 * New native configurations
4333 Alpha NetBSD alpha*-*-netbsd*
4334 SH NetBSD sh*-*-netbsdelf*
4335 MIPS NetBSD mips*-*-netbsd*
4336 UltraSPARC NetBSD sparc64-*-netbsd*
4338 * OBSOLETE configurations and files
4340 Configurations that have been declared obsolete in this release have
4341 been commented out. Unless there is activity to revive these
4342 configurations, the next release of GDB will have their sources
4343 permanently REMOVED.
4345 Mitsubishi D30V d30v-*-*
4346 OS/9000 i[34]86-*-os9k
4347 IBM AIX PS/2 i[3456]86-*-aix
4348 Fujitsu FR30 fr30-*-elf*
4349 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4350 Argonaut Risc Chip (ARC) arc-*-*
4351 i386 running Mach 3.0 i[3456]86-*-mach3*
4352 i386 running Mach i[3456]86-*-mach*
4353 i386 running OSF/1 i[3456]86-*osf1mk*
4354 HP/Apollo 68k Family m68*-apollo*-sysv*,
4356 m68*-hp-bsd*, m68*-hp-hpux*
4357 I960 with MON960 i960-*-coff
4359 * OBSOLETE languages
4361 CHILL, a Pascal like language used by telecommunications companies.
4363 * REMOVED configurations and files
4365 AMD 29k family via UDI a29k-amd-udi, udi29k
4366 A29K VxWorks a29k-*-vxworks
4367 AMD 29000 embedded, using EBMON a29k-none-none
4368 AMD 29000 embedded with COFF a29k-none-coff
4369 AMD 29000 embedded with a.out a29k-none-aout
4371 testsuite/gdb.hp/gdb.threads-hp/ directory
4373 * New command "set max-user-call-depth <nnn>"
4375 This command allows the user to limit the call depth of user-defined
4376 commands. The default is 1024.
4378 * Changes in FreeBSD/i386 native debugging.
4380 Support for the "generate-core-file" has been added.
4382 * New commands "dump", "append", and "restore".
4384 These commands allow data to be copied from target memory
4385 to a bfd-format or binary file (dump and append), and back
4386 from a file into memory (restore).
4388 * Improved "next/step" support on multi-processor Alpha Tru64.
4390 The previous single-step mechanism could cause unpredictable problems,
4391 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4392 of a software single-step mechanism prevents this.
4394 *** Changes in GDB 5.2.1:
4402 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4403 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4404 Fix, by Joel Brobecker imported from mainline.
4406 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4407 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4408 Fix, by Fred Fish, imported from mainline.
4410 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4411 Surprisingly enough, it works now.
4412 By Michal Ludvig, imported from mainline.
4414 i386 hardware watchpoint support:
4415 avoid misses on second run for some targets.
4416 By Pierre Muller, imported from mainline.
4418 *** Changes in GDB 5.2:
4420 * New command "set trust-readonly-sections on[off]".
4422 This command is a hint that tells gdb that read-only sections
4423 really are read-only (ie. that their contents will not change).
4424 In this mode, gdb will go to the object file rather than the
4425 target to read memory from read-only sections (such as ".text").
4426 This can be a significant performance improvement on some
4427 (notably embedded) targets.
4429 * New command "generate-core-file" (or "gcore").
4431 This new gdb command allows the user to drop a core file of the child
4432 process state at any time. So far it's been implemented only for
4433 GNU/Linux and Solaris, but should be relatively easily ported to other
4434 hosts. Argument is core file name (defaults to core.<pid>).
4436 * New command line option
4438 GDB now accepts --pid or -p followed by a process id.
4440 * Change in command line behavior -- corefiles vs. process ids.
4442 There is a subtle behavior in the way in which GDB handles
4443 command line arguments. The first non-flag argument is always
4444 a program to debug, but the second non-flag argument may either
4445 be a corefile or a process id. Previously, GDB would attempt to
4446 open the second argument as a corefile, and if that failed, would
4447 issue a superfluous error message and then attempt to attach it as
4448 a process. Now, if the second argument begins with a non-digit,
4449 it will be treated as a corefile. If it begins with a digit,
4450 GDB will attempt to attach it as a process, and if no such process
4451 is found, will then attempt to open it as a corefile.
4453 * Changes in ARM configurations.
4455 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4456 configuration is fully multi-arch.
4458 * New native configurations
4460 ARM NetBSD arm*-*-netbsd*
4461 x86 OpenBSD i[3456]86-*-openbsd*
4462 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4463 Sparc64 running FreeBSD sparc64-*-freebsd*
4467 Sanyo XStormy16 xstormy16-elf
4469 * OBSOLETE configurations and files
4471 Configurations that have been declared obsolete in this release have
4472 been commented out. Unless there is activity to revive these
4473 configurations, the next release of GDB will have their sources
4474 permanently REMOVED.
4476 AMD 29k family via UDI a29k-amd-udi, udi29k
4477 A29K VxWorks a29k-*-vxworks
4478 AMD 29000 embedded, using EBMON a29k-none-none
4479 AMD 29000 embedded with COFF a29k-none-coff
4480 AMD 29000 embedded with a.out a29k-none-aout
4482 testsuite/gdb.hp/gdb.threads-hp/ directory
4484 * REMOVED configurations and files
4486 TI TMS320C80 tic80-*-*
4488 PowerPC Solaris powerpcle-*-solaris*
4489 PowerPC Windows NT powerpcle-*-cygwin32
4490 PowerPC Netware powerpc-*-netware*
4491 Harris/CXUX m88k m88*-harris-cxux*
4492 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4493 ns32k-utek-sysv* ns32k-utek-*
4494 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4495 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4496 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4497 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4498 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4500 * Changes to command line processing
4502 The new `--args' feature can be used to specify command-line arguments
4503 for the inferior from gdb's command line.
4505 * Changes to key bindings
4507 There is a new `operate-and-get-next' function bound to `C-o'.
4509 *** Changes in GDB 5.1.1
4511 Fix compile problem on DJGPP.
4513 Fix a problem with floating-point registers on the i386 being
4516 Fix to stop GDB crashing on .debug_str debug info.
4518 Numerous documentation fixes.
4520 Numerous testsuite fixes.
4522 *** Changes in GDB 5.1:
4524 * New native configurations
4526 Alpha FreeBSD alpha*-*-freebsd*
4527 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4528 MIPS GNU/Linux mips*-*-linux*
4529 MIPS SGI Irix 6.x mips*-sgi-irix6*
4530 ia64 AIX ia64-*-aix*
4531 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4535 Motorola 68HC11 and 68HC12 m68hc11-elf
4537 UltraSparc running GNU/Linux sparc64-*-linux*
4539 * OBSOLETE configurations and files
4541 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4542 Harris/CXUX m88k m88*-harris-cxux*
4543 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4544 ns32k-utek-sysv* ns32k-utek-*
4545 TI TMS320C80 tic80-*-*
4547 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4548 PowerPC Solaris powerpcle-*-solaris*
4549 PowerPC Windows NT powerpcle-*-cygwin32
4550 PowerPC Netware powerpc-*-netware*
4551 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4552 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4553 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4554 Apple Macintosh (MPW) host N/A
4556 stuff.c (Program to stuff files into a specially prepared space in kdb)
4557 kdb-start.c (Main loop for the standalone kernel debugger)
4559 Configurations that have been declared obsolete in this release have
4560 been commented out. Unless there is activity to revive these
4561 configurations, the next release of GDB will have their sources
4562 permanently REMOVED.
4564 * REMOVED configurations and files
4566 Altos 3068 m68*-altos-*
4567 Convex c1-*-*, c2-*-*
4569 ARM RISCix arm-*-* (as host)
4573 * GDB has been converted to ISO C.
4575 GDB's source code has been converted to ISO C. In particular, the
4576 sources are fully protoized, and rely on standard headers being
4581 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4583 * The MI enabled by default.
4585 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4586 revised and enabled by default. Packages which use GDB as a debugging
4587 engine behind a UI or another front end are encouraged to switch to
4588 using the GDB/MI interface, instead of the old annotations interface
4589 which is now deprecated.
4591 * Support for debugging Pascal programs.
4593 GDB now includes support for debugging Pascal programs. The following
4594 main features are supported:
4596 - Pascal-specific data types such as sets;
4598 - automatic recognition of Pascal sources based on file-name
4601 - Pascal-style display of data types, variables, and functions;
4603 - a Pascal expression parser.
4605 However, some important features are not yet supported.
4607 - Pascal string operations are not supported at all;
4609 - there are some problems with boolean types;
4611 - Pascal type hexadecimal constants are not supported
4612 because they conflict with the internal variables format;
4614 - support for Pascal objects and classes is not full yet;
4616 - unlike Pascal, GDB is case-sensitive for symbol names.
4618 * Changes in completion.
4620 Commands such as `shell', `run' and `set args', which pass arguments
4621 to inferior programs, now complete on file names, similar to what
4622 users expect at the shell prompt.
4624 Commands which accept locations, such as `disassemble', `print',
4625 `breakpoint', `until', etc. now complete on filenames as well as
4626 program symbols. Thus, if you type "break foob TAB", and the source
4627 files linked into the programs include `foobar.c', that file name will
4628 be one of the candidates for completion. However, file names are not
4629 considered for completion after you typed a colon that delimits a file
4630 name from a name of a function in that file, as in "break foo.c:bar".
4632 `set demangle-style' completes on available demangling styles.
4634 * New platform-independent commands:
4636 It is now possible to define a post-hook for a command as well as a
4637 hook that runs before the command. For more details, see the
4638 documentation of `hookpost' in the GDB manual.
4640 * Changes in GNU/Linux native debugging.
4642 Support for debugging multi-threaded programs has been completely
4643 revised for all platforms except m68k and sparc. You can now debug as
4644 many threads as your system allows you to have.
4646 Attach/detach is supported for multi-threaded programs.
4648 Support for SSE registers was added for x86. This doesn't work for
4649 multi-threaded programs though.
4651 * Changes in MIPS configurations.
4653 Multi-arch support is enabled for all MIPS configurations.
4655 GDB can now be built as native debugger on SGI Irix 6.x systems for
4656 debugging n32 executables. (Debugging 64-bit executables is not yet
4659 * Unified support for hardware watchpoints in all x86 configurations.
4661 Most (if not all) native x86 configurations support hardware-assisted
4662 breakpoints and watchpoints in a unified manner. This support
4663 implements debug register sharing between watchpoints, which allows to
4664 put a virtually infinite number of watchpoints on the same address,
4665 and also supports watching regions up to 16 bytes with several debug
4668 The new maintenance command `maintenance show-debug-regs' toggles
4669 debugging print-outs in functions that insert, remove, and test
4670 watchpoints and hardware breakpoints.
4672 * Changes in the DJGPP native configuration.
4674 New command ``info dos sysinfo'' displays assorted information about
4675 the CPU, OS, memory, and DPMI server.
4677 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4678 display information about segment descriptors stored in GDT, LDT, and
4681 New commands ``info dos pde'' and ``info dos pte'' display entries
4682 from Page Directory and Page Tables (for now works with CWSDPMI only).
4683 New command ``info dos address-pte'' displays the Page Table entry for
4684 a given linear address.
4686 GDB can now pass command lines longer than 126 characters to the
4687 program being debugged (requires an update to the libdbg.a library
4688 which is part of the DJGPP development kit).
4690 DWARF2 debug info is now supported.
4692 It is now possible to `step' and `next' through calls to `longjmp'.
4694 * Changes in documentation.
4696 All GDB documentation was converted to GFDL, the GNU Free
4697 Documentation License.
4699 Tracepoints-related commands are now fully documented in the GDB
4702 TUI, the Text-mode User Interface, is now documented in the manual.
4704 Tracepoints-related commands are now fully documented in the GDB
4707 The "GDB Internals" manual now has an index. It also includes
4708 documentation of `ui_out' functions, GDB coding standards, x86
4709 hardware watchpoints, and memory region attributes.
4711 * GDB's version number moved to ``version.in''
4713 The Makefile variable VERSION has been replaced by the file
4714 ``version.in''. People creating GDB distributions should update the
4715 contents of this file.
4719 GUD support is now a standard part of the EMACS distribution.
4721 *** Changes in GDB 5.0:
4723 * Improved support for debugging FP programs on x86 targets
4725 Unified and much-improved support for debugging floating-point
4726 programs on all x86 targets. In particular, ``info float'' now
4727 displays the FP registers in the same format on all x86 targets, with
4728 greater level of detail.
4730 * Improvements and bugfixes in hardware-assisted watchpoints
4732 It is now possible to watch array elements, struct members, and
4733 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4734 on x86 targets no longer erroneously trigger when the address is
4737 * Improvements in the native DJGPP version of GDB
4739 The distribution now includes all the scripts and auxiliary files
4740 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4741 machines ``out of the box''.
4743 The DJGPP version can now debug programs that use signals. It is
4744 possible to catch signals that happened in the debuggee, deliver
4745 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4746 would kill the program being debugged.) Programs that hook hardware
4747 interrupts (keyboard, timer, etc.) can also be debugged.
4749 It is now possible to debug DJGPP programs that redirect their
4750 standard handles or switch them to raw (as opposed to cooked) mode, or
4751 even close them. The command ``run < foo > bar'' works as expected,
4752 and ``info terminal'' reports useful information about the debuggee's
4753 terminal, including raw/cooked mode, redirection, etc.
4755 The DJGPP version now uses termios functions for console I/O, which
4756 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4759 DOS-style file names with drive letters are now fully supported by
4762 It is now possible to debug DJGPP programs that switch their working
4763 directory. It is also possible to rerun the debuggee any number of
4764 times without restarting GDB; thus, you can use the same setup,
4765 breakpoints, etc. for many debugging sessions.
4767 * New native configurations
4769 ARM GNU/Linux arm*-*-linux*
4770 PowerPC GNU/Linux powerpc-*-linux*
4774 Motorola MCore mcore-*-*
4775 x86 VxWorks i[3456]86-*-vxworks*
4776 PowerPC VxWorks powerpc-*-vxworks*
4777 TI TMS320C80 tic80-*-*
4779 * OBSOLETE configurations
4781 Altos 3068 m68*-altos-*
4782 Convex c1-*-*, c2-*-*
4784 ARM RISCix arm-*-* (as host)
4787 Configurations that have been declared obsolete will be commented out,
4788 but the code will be left in place. If there is no activity to revive
4789 these configurations before the next release of GDB, the sources will
4790 be permanently REMOVED.
4792 * Gould support removed
4794 Support for the Gould PowerNode and NP1 has been removed.
4796 * New features for SVR4
4798 On SVR4 native platforms (such as Solaris), if you attach to a process
4799 without first loading a symbol file, GDB will now attempt to locate and
4800 load symbols from the running process's executable file.
4802 * Many C++ enhancements
4804 C++ support has been greatly improved. Overload resolution now works properly
4805 in almost all cases. RTTI support is on the way.
4807 * Remote targets can connect to a sub-program
4809 A popen(3) style serial-device has been added. This device starts a
4810 sub-process (such as a stand-alone simulator) and then communicates
4811 with that. The sub-program to run is specified using the syntax
4812 ``|<program> <args>'' vis:
4814 (gdb) set remotedebug 1
4815 (gdb) target extended-remote |mn10300-elf-sim program-args
4817 * MIPS 64 remote protocol
4819 A long standing bug in the mips64 remote protocol where by GDB
4820 expected certain 32 bit registers (ex SR) to be transfered as 32
4821 instead of 64 bits has been fixed.
4823 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4824 added to provide backward compatibility with older versions of GDB.
4826 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4828 The command ``set remotebinarydownload'' command has been replaced by
4829 ``set remote X-packet''. Other commands in ``set remote'' family
4830 include ``set remote P-packet''.
4832 * Breakpoint commands accept ranges.
4834 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4835 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4836 ``tracepoint passcount'' also accepts a range of tracepoints.
4838 * ``apropos'' command added.
4840 The ``apropos'' command searches through command names and
4841 documentation strings, printing out matches, making it much easier to
4842 try to find a command that does what you are looking for.
4846 A new machine oriented interface (MI) has been added to GDB. This
4847 interface is designed for debug environments running GDB as a separate
4848 process. This is part of the long term libGDB project. See the
4849 "GDB/MI" chapter of the GDB manual for further information. It can be
4850 enabled by configuring with:
4852 .../configure --enable-gdbmi
4854 *** Changes in GDB-4.18:
4856 * New native configurations
4858 HP-UX 10.20 hppa*-*-hpux10.20
4859 HP-UX 11.x hppa*-*-hpux11.0*
4860 M68K GNU/Linux m68*-*-linux*
4864 Fujitsu FR30 fr30-*-elf*
4865 Intel StrongARM strongarm-*-*
4866 Mitsubishi D30V d30v-*-*
4868 * OBSOLETE configurations
4870 Gould PowerNode, NP1 np1-*-*, pn-*-*
4872 Configurations that have been declared obsolete will be commented out,
4873 but the code will be left in place. If there is no activity to revive
4874 these configurations before the next release of GDB, the sources will
4875 be permanently REMOVED.
4879 As a compatibility experiment, GDB's source files buildsym.h and
4880 buildsym.c have been converted to pure standard C, no longer
4881 containing any K&R compatibility code. We believe that all systems in
4882 use today either come with a standard C compiler, or have a GCC port
4883 available. If this is not true, please report the affected
4884 configuration to bug-gdb@gnu.org immediately. See the README file for
4885 information about getting a standard C compiler if you don't have one
4890 GDB now uses readline 2.2.
4892 * set extension-language
4894 You can now control the mapping between filename extensions and source
4895 languages by using the `set extension-language' command. For instance,
4896 you can ask GDB to treat .c files as C++ by saying
4897 set extension-language .c c++
4898 The command `info extensions' lists all of the recognized extensions
4899 and their associated languages.
4901 * Setting processor type for PowerPC and RS/6000
4903 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4904 you can use the `set processor' command to specify what variant of the
4905 PowerPC family you are debugging. The command
4909 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4910 following PowerPC and RS6000 variants:
4912 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4913 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4915 403GC IBM PowerPC 403GC
4916 505 Motorola PowerPC 505
4917 860 Motorola PowerPC 860 or 850
4918 601 Motorola PowerPC 601
4919 602 Motorola PowerPC 602
4920 603 Motorola/IBM PowerPC 603 or 603e
4921 604 Motorola PowerPC 604 or 604e
4922 750 Motorola/IBM PowerPC 750 or 750
4924 At the moment, this command just tells GDB what to name the
4925 special-purpose processor registers. Since almost all the affected
4926 registers are inaccessible to user-level programs, this command is
4927 only useful for remote debugging in its present form.
4931 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4932 more extensive support for HP-UX. Added features include shared
4933 library support, kernel threads and hardware watchpoints for 11.00,
4934 support for HP's ANSI C and C++ compilers, and a compatibility mode
4935 for xdb and dbx commands.
4939 HP's donation includes the new concept of catchpoints, which is a
4940 generalization of the old catch command. On HP-UX, it is now possible
4941 to catch exec, fork, and vfork, as well as library loading.
4943 This means that the existing catch command has changed; its first
4944 argument now specifies the type of catch to be set up. See the
4945 output of "help catch" for a list of catchpoint types.
4947 * Debugging across forks
4949 On HP-UX, you can choose which process to debug when a fork() happens
4954 HP has donated a curses-based terminal user interface (TUI). To get
4955 it, build with --enable-tui. Although this can be enabled for any
4956 configuration, at present it only works for native HP debugging.
4958 * GDB remote protocol additions
4960 A new protocol packet 'X' that writes binary data is now available.
4961 Default behavior is to try 'X', then drop back to 'M' if the stub
4962 fails to respond. The settable variable `remotebinarydownload'
4963 allows explicit control over the use of 'X'.
4965 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4966 full 64-bit address. The command
4968 set remoteaddresssize 32
4970 can be used to revert to the old behaviour. For existing remote stubs
4971 the change should not be noticed, as the additional address information
4974 In order to assist in debugging stubs, you may use the maintenance
4975 command `packet' to send any text string to the stub. For instance,
4977 maint packet heythere
4979 sends the packet "$heythere#<checksum>". Note that it is very easy to
4980 disrupt a debugging session by sending the wrong packet at the wrong
4983 The compare-sections command allows you to compare section data on the
4984 target to what is in the executable file without uploading or
4985 downloading, by comparing CRC checksums.
4987 * Tracing can collect general expressions
4989 You may now collect general expressions at tracepoints. This requires
4990 further additions to the target-side stub; see tracepoint.c and
4991 doc/agentexpr.texi for further details.
4993 * mask-address variable for Mips
4995 For Mips targets, you may control the zeroing of the upper 32 bits of
4996 a 64-bit address by entering `set mask-address on'. This is mainly
4997 of interest to users of embedded R4xxx and R5xxx processors.
4999 * Higher serial baud rates
5001 GDB's serial code now allows you to specify baud rates 57600, 115200,
5002 230400, and 460800 baud. (Note that your host system may not be able
5003 to achieve all of these rates.)
5007 The i960 configuration now includes an initial implementation of a
5008 builtin simulator, contributed by Jim Wilson.
5011 *** Changes in GDB-4.17:
5013 * New native configurations
5015 Alpha GNU/Linux alpha*-*-linux*
5016 Unixware 2.x i[3456]86-unixware2*
5017 Irix 6.x mips*-sgi-irix6*
5018 PowerPC GNU/Linux powerpc-*-linux*
5019 PowerPC Solaris powerpcle-*-solaris*
5020 Sparc GNU/Linux sparc-*-linux*
5021 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5025 Argonaut Risc Chip (ARC) arc-*-*
5026 Hitachi H8/300S h8300*-*-*
5027 Matsushita MN10200 w/simulator mn10200-*-*
5028 Matsushita MN10300 w/simulator mn10300-*-*
5029 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5030 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5031 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5032 Mitsubishi D10V w/simulator d10v-*-*
5033 Mitsubishi M32R/D w/simulator m32r-*-elf*
5034 Tsqware Sparclet sparclet-*-*
5035 NEC V850 w/simulator v850-*-*
5037 * New debugging protocols
5039 ARM with RDI protocol arm*-*-*
5040 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5041 DDB and LSI variants of PMON protocol mips*-*-*
5042 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5043 PowerPC with SDS protocol powerpc{,le}-*-eabi
5044 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5048 All configurations can now understand and use the DWARF 2 debugging
5049 format. The choice is automatic, if the symbol file contains DWARF 2
5054 GDB now includes basic Java language support. This support is
5055 only useful with Java compilers that produce native machine code.
5057 * solib-absolute-prefix and solib-search-path
5059 For SunOS and SVR4 shared libraries, you may now set the prefix for
5060 loading absolute shared library symbol files, and the search path for
5061 locating non-absolute shared library symbol files.
5063 * Live range splitting
5065 GDB can now effectively debug code for which GCC has performed live
5066 range splitting as part of its optimization. See gdb/doc/LRS for
5067 more details on the expected format of the stabs information.
5071 GDB's support for the GNU Hurd, including thread debugging, has been
5072 updated to work with current versions of the Hurd.
5076 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5077 instruction set. ARM GDB automatically detects when Thumb
5078 instructions are in use, and adjusts disassembly and backtracing
5083 GDB's MIPS target configurations now handle the MIP16 16-bit
5088 GDB now includes support for overlays; if an executable has been
5089 linked such that multiple sections are based at the same address, GDB
5090 will decide which section to use for symbolic info. You can choose to
5091 control the decision manually, using overlay commands, or implement
5092 additional target-side support and use "overlay load-target" to bring
5093 in the overlay mapping. Do "help overlay" for more detail.
5097 The command "info symbol <address>" displays information about
5098 the symbol at the specified address.
5102 The standard remote protocol now includes an extension that allows
5103 asynchronous collection and display of trace data. This requires
5104 extensive support in the target-side debugging stub. Tracing mode
5105 includes a new interaction mode in GDB and new commands: see the
5106 file tracepoint.c for more details.
5110 Configurations for embedded MIPS now include a simulator contributed
5111 by Cygnus Solutions. The simulator supports the instruction sets
5112 of most MIPS variants.
5116 Sparc configurations may now include the ERC32 simulator contributed
5117 by the European Space Agency. The simulator is not built into
5118 Sparc targets by default; configure with --enable-sim to include it.
5122 For target configurations that may include multiple variants of a
5123 basic architecture (such as MIPS and SH), you may now set the
5124 architecture explicitly. "set arch" sets, "info arch" lists
5125 the possible architectures.
5127 *** Changes in GDB-4.16:
5129 * New native configurations
5131 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5132 M68K NetBSD m68k-*-netbsd*
5133 PowerPC AIX 4.x powerpc-*-aix*
5134 PowerPC MacOS powerpc-*-macos*
5135 PowerPC Windows NT powerpcle-*-cygwin32
5136 RS/6000 AIX 4.x rs6000-*-aix4*
5140 ARM with RDP protocol arm-*-*
5141 I960 with MON960 i960-*-coff
5142 MIPS VxWorks mips*-*-vxworks*
5143 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5144 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5146 Matra Sparclet sparclet-*-*
5150 The powerpc-eabi configuration now includes the PSIM simulator,
5151 contributed by Andrew Cagney, with assistance from Mike Meissner.
5152 PSIM is a very elaborate model of the PowerPC, including not only
5153 basic instruction set execution, but also details of execution unit
5154 performance and I/O hardware. See sim/ppc/README for more details.
5158 GDB now works with Solaris 2.5.
5160 * Windows 95/NT native
5162 GDB will now work as a native debugger on Windows 95 and Windows NT.
5163 To build it from source, you must use the "gnu-win32" environment,
5164 which uses a DLL to emulate enough of Unix to run the GNU tools.
5165 Further information, binaries, and sources are available at
5166 ftp.cygnus.com, under pub/gnu-win32.
5168 * dont-repeat command
5170 If a user-defined command includes the command `dont-repeat', then the
5171 command will not be repeated if the user just types return. This is
5172 useful if the command is time-consuming to run, so that accidental
5173 extra keystrokes don't run the same command many times.
5175 * Send break instead of ^C
5177 The standard remote protocol now includes an option to send a break
5178 rather than a ^C to the target in order to interrupt it. By default,
5179 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5181 * Remote protocol timeout
5183 The standard remote protocol includes a new variable `remotetimeout'
5184 that allows you to set the number of seconds before GDB gives up trying
5185 to read from the target. The default value is 2.
5187 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5189 By default GDB will automatically keep track of objects as they are
5190 loaded and unloaded by the dynamic linker. By using the command `set
5191 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5192 when shared library events occur, thus allowing you to set breakpoints
5193 in shared libraries which are explicitly loaded by the inferior.
5195 Note this feature does not work on hpux8. On hpux9 you must link
5196 /usr/lib/end.o into your program. This feature should work
5197 automatically on hpux10.
5199 * Irix 5.x hardware watchpoint support
5201 Irix 5 configurations now support the use of hardware watchpoints.
5203 * Mips protocol "SYN garbage limit"
5205 When debugging a Mips target using the `target mips' protocol, you
5206 may set the number of characters that GDB will ignore by setting
5207 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5208 every character. The default value is 1050.
5210 * Recording and replaying remote debug sessions
5212 If you set `remotelogfile' to the name of a file, gdb will write to it
5213 a recording of a remote debug session. This recording may then be
5214 replayed back to gdb using "gdbreplay". See gdbserver/README for
5215 details. This is useful when you have a problem with GDB while doing
5216 remote debugging; you can make a recording of the session and send it
5217 to someone else, who can then recreate the problem.
5219 * Speedups for remote debugging
5221 GDB includes speedups for downloading and stepping MIPS systems using
5222 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5223 and more efficient S-record downloading.
5225 * Memory use reductions and statistics collection
5227 GDB now uses less memory and reports statistics about memory usage.
5228 Try the `maint print statistics' command, for example.
5230 *** Changes in GDB-4.15:
5232 * Psymtabs for XCOFF
5234 The symbol reader for AIX GDB now uses partial symbol tables. This
5235 can greatly improve startup time, especially for large executables.
5237 * Remote targets use caching
5239 Remote targets now use a data cache to speed up communication with the
5240 remote side. The data cache could lead to incorrect results because
5241 it doesn't know about volatile variables, thus making it impossible to
5242 debug targets which use memory mapped I/O devices. `set remotecache
5243 off' turns the the data cache off.
5245 * Remote targets may have threads
5247 The standard remote protocol now includes support for multiple threads
5248 in the target system, using new protocol commands 'H' and 'T'. See
5249 gdb/remote.c for details.
5253 If GDB is configured with `--enable-netrom', then it will include
5254 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5255 acts as though it is a bank of ROM on the target board, but you can
5256 write into it over the network. GDB's support consists only of
5257 support for fast loading into the emulated ROM; to debug, you must use
5258 another protocol, such as standard remote protocol. The usual
5259 sequence is something like
5261 target nrom <netrom-hostname>
5263 target remote <netrom-hostname>:1235
5267 GDB now includes support for the Apple Macintosh, as a host only. It
5268 may be run as either an MPW tool or as a standalone application, and
5269 it can debug through the serial port. All the usual GDB commands are
5270 available, but to the target command, you must supply "serial" as the
5271 device type instead of "/dev/ttyXX". See mpw-README in the main
5272 directory for more information on how to build. The MPW configuration
5273 scripts */mpw-config.in support only a few targets, and only the
5274 mips-idt-ecoff target has been tested.
5278 GDB configuration now uses autoconf. This is not user-visible,
5279 but does simplify configuration and building.
5283 GDB now supports hpux10.
5285 *** Changes in GDB-4.14:
5287 * New native configurations
5289 x86 FreeBSD i[345]86-*-freebsd
5290 x86 NetBSD i[345]86-*-netbsd
5291 NS32k NetBSD ns32k-*-netbsd
5292 Sparc NetBSD sparc-*-netbsd
5296 A29K VxWorks a29k-*-vxworks
5297 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5298 CPU32 EST-300 emulator m68*-*-est*
5299 PowerPC ELF powerpc-*-elf
5302 * Alpha OSF/1 support for procfs
5304 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5305 possible to attach to running processes. As the mounting of the /proc
5306 filesystem is optional on the Alpha, GDB automatically determines
5307 the availability of /proc during startup. This can lead to problems
5308 if /proc is unmounted after GDB has been started.
5310 * Arguments to user-defined commands
5312 User commands may accept up to 10 arguments separated by whitespace.
5313 Arguments are accessed within the user command via $arg0..$arg9. A
5316 print $arg0 + $arg1 + $arg2
5318 To execute the command use:
5321 Defines the command "adder" which prints the sum of its three arguments.
5322 Note the arguments are text substitutions, so they may reference variables,
5323 use complex expressions, or even perform inferior function calls.
5325 * New `if' and `while' commands
5327 This makes it possible to write more sophisticated user-defined
5328 commands. Both commands take a single argument, which is the
5329 expression to evaluate, and must be followed by the commands to
5330 execute, one per line, if the expression is nonzero, the list being
5331 terminated by the word `end'. The `if' command list may include an
5332 `else' word, which causes the following commands to be executed only
5333 if the expression is zero.
5335 * Fortran source language mode
5337 GDB now includes partial support for Fortran 77. It will recognize
5338 Fortran programs and can evaluate a subset of Fortran expressions, but
5339 variables and functions may not be handled correctly. GDB will work
5340 with G77, but does not yet know much about symbols emitted by other
5343 * Better HPUX support
5345 Most debugging facilities now work on dynamic executables for HPPAs
5346 running hpux9 or later. You can attach to running dynamically linked
5347 processes, but by default the dynamic libraries will be read-only, so
5348 for instance you won't be able to put breakpoints in them. To change
5349 that behavior do the following before running the program:
5355 This will cause the libraries to be mapped private and read-write.
5356 To revert to the normal behavior, do this:
5362 You cannot set breakpoints or examine data in the library until after
5363 the library is loaded if the function/data symbols do not have
5366 GDB can now also read debug symbols produced by the HP C compiler on
5367 HPPAs (sorry, no C++, Fortran or 68k support).
5369 * Target byte order now dynamically selectable
5371 You can choose which byte order to use with a target system, via the
5372 commands "set endian big" and "set endian little", and you can see the
5373 current setting by using "show endian". You can also give the command
5374 "set endian auto", in which case GDB will use the byte order
5375 associated with the executable. Currently, only embedded MIPS
5376 configurations support dynamic selection of target byte order.
5378 * New DOS host serial code
5380 This version uses DPMI interrupts to handle buffered I/O, so you
5381 no longer need to run asynctsr when debugging boards connected to
5384 *** Changes in GDB-4.13:
5386 * New "complete" command
5388 This lists all the possible completions for the rest of the line, if it
5389 were to be given as a command itself. This is intended for use by emacs.
5391 * Trailing space optional in prompt
5393 "set prompt" no longer adds a space for you after the prompt you set. This
5394 allows you to set a prompt which ends in a space or one that does not.
5396 * Breakpoint hit counts
5398 "info break" now displays a count of the number of times the breakpoint
5399 has been hit. This is especially useful in conjunction with "ignore"; you
5400 can ignore a large number of breakpoint hits, look at the breakpoint info
5401 to see how many times the breakpoint was hit, then run again, ignoring one
5402 less than that number, and this will get you quickly to the last hit of
5405 * Ability to stop printing at NULL character
5407 "set print null-stop" will cause GDB to stop printing the characters of
5408 an array when the first NULL is encountered. This is useful when large
5409 arrays actually contain only short strings.
5411 * Shared library breakpoints
5413 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5414 breakpoints in shared libraries before the executable is run.
5416 * Hardware watchpoints
5418 There is a new hardware breakpoint for the watch command for sparclite
5419 targets. See gdb/sparclite/hw_breakpoint.note.
5421 Hardware watchpoints are also now supported under GNU/Linux.
5425 Annotations have been added. These are for use with graphical interfaces,
5426 and are still experimental. Currently only gdba.el uses these.
5428 * Improved Irix 5 support
5430 GDB now works properly with Irix 5.2.
5432 * Improved HPPA support
5434 GDB now works properly with the latest GCC and GAS.
5436 * New native configurations
5438 Sequent PTX4 i[34]86-sequent-ptx4
5439 HPPA running OSF/1 hppa*-*-osf*
5440 Atari TT running SVR4 m68*-*-sysv4*
5441 RS/6000 LynxOS rs6000-*-lynxos*
5445 OS/9000 i[34]86-*-os9k
5446 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5449 * Hitachi SH7000 and E7000-PC ICE support
5451 There is now support for communicating with the Hitachi E7000-PC ICE.
5452 This is available automatically when GDB is configured for the SH.
5456 As usual, a variety of small fixes and improvements, both generic
5457 and configuration-specific. See the ChangeLog for more detail.
5459 *** Changes in GDB-4.12:
5461 * Irix 5 is now supported
5465 GDB-4.12 on the HPPA has a number of changes which make it unable
5466 to debug the output from the currently released versions of GCC and
5467 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5468 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5469 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5472 *** Changes in GDB-4.11:
5474 * User visible changes:
5478 The "set remotedebug" option is now consistent between the mips remote
5479 target, remote targets using the gdb-specific protocol, UDI (AMD's
5480 debug protocol for the 29k) and the 88k bug monitor. It is now an
5481 integer specifying a debug level (normally 0 or 1, but 2 means more
5482 debugging info for the mips target).
5484 * DEC Alpha native support
5486 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5487 debug info, but GDB works fairly well with the DEC compiler and should
5488 work with a future GCC release. See the README file for a few
5489 Alpha-specific notes.
5491 * Preliminary thread implementation
5493 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5495 * LynxOS native and target support for 386
5497 This release has been hosted on LynxOS 2.2, and also can be configured
5498 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5501 * Improvements in C++ mangling/demangling.
5503 This release has much better g++ debugging, specifically in name
5504 mangling/demangling, virtual function calls, print virtual table,
5505 call methods, ...etc.
5507 *** Changes in GDB-4.10:
5509 * User visible changes:
5511 Remote debugging using the GDB-specific (`target remote') protocol now
5512 supports the `load' command. This is only useful if you have some
5513 other way of getting the stub to the target system, and you can put it
5514 somewhere in memory where it won't get clobbered by the download.
5516 Filename completion now works.
5518 When run under emacs mode, the "info line" command now causes the
5519 arrow to point to the line specified. Also, "info line" prints
5520 addresses in symbolic form (as well as hex).
5522 All vxworks based targets now support a user settable option, called
5523 vxworks-timeout. This option represents the number of seconds gdb
5524 should wait for responses to rpc's. You might want to use this if
5525 your vxworks target is, perhaps, a slow software simulator or happens
5526 to be on the far side of a thin network line.
5530 This release contains support for using a DEC alpha as a GDB host for
5531 cross debugging. Native alpha debugging is not supported yet.
5534 *** Changes in GDB-4.9:
5538 This is the first GDB release which is accompanied by a matching testsuite.
5539 The testsuite requires installation of dejagnu, which should be available
5540 via ftp from most sites that carry GNU software.
5544 'Cfront' style demangling has had its name changed to 'ARM' style, to
5545 emphasize that it was written from the specifications in the C++ Annotated
5546 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5547 disclaimers, it still generated too much confusion with users attempting to
5548 use gdb with AT&T cfront.
5552 GDB now uses a standard remote interface to a simulator library.
5553 So far, the library contains simulators for the Zilog Z8001/2, the
5554 Hitachi H8/300, H8/500 and Super-H.
5556 * New targets supported
5558 H8/300 simulator h8300-hitachi-hms or h8300hms
5559 H8/500 simulator h8500-hitachi-hms or h8500hms
5560 SH simulator sh-hitachi-hms or sh
5561 Z8000 simulator z8k-zilog-none or z8ksim
5562 IDT MIPS board over serial line mips-idt-ecoff
5564 Cross-debugging to GO32 targets is supported. It requires a custom
5565 version of the i386-stub.c module which is integrated with the
5566 GO32 memory extender.
5568 * New remote protocols
5570 MIPS remote debugging protocol.
5572 * New source languages supported
5574 This version includes preliminary support for Chill, a Pascal like language
5575 used by telecommunications companies. Chill support is also being integrated
5576 into the GNU compiler, but we don't know when it will be publically available.
5579 *** Changes in GDB-4.8:
5581 * HP Precision Architecture supported
5583 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5584 version of this support was available as a set of patches from the
5585 University of Utah. GDB does not support debugging of programs
5586 compiled with the HP compiler, because HP will not document their file
5587 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5588 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5590 Many problems in the preliminary version have been fixed.
5592 * Faster and better demangling
5594 We have improved template demangling and fixed numerous bugs in the GNU style
5595 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5596 character types (wchar_t) are now supported. Demangling of each symbol is now
5597 only done once, and is cached when the symbol table for a file is read in.
5598 This results in a small increase in memory usage for C programs, a moderate
5599 increase in memory usage for C++ programs, and a fantastic speedup in
5602 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5603 from the specifications in the Annotated Reference Manual, which AT&T's
5604 compiler does not actually implement.
5606 * G++ multiple inheritance compiler problem
5608 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5609 inheritance lattices was reworked to properly discover ambiguities. We
5610 recently found an example which causes this new algorithm to fail in a
5611 very subtle way, producing bad debug information for those classes.
5612 The file 'gcc.patch' (in this directory) can be applied to gcc to
5613 circumvent the problem. A future GCC release will contain a complete
5616 The previous G++ debug info problem (mentioned below for the gdb-4.7
5617 release) is fixed in gcc version 2.3.2.
5619 * Improved configure script
5621 The `configure' script will now attempt to guess your system type if
5622 you don't supply a host system type. The old scheme of supplying a
5623 host system triplet is preferable over using this. All the magic is
5624 done in the new `config.guess' script. Examine it for details.
5626 We have also brought our configure script much more in line with the FSF's
5627 version. It now supports the --with-xxx options. In particular,
5628 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5629 The resulting GDB will not be able to read arbitrary object file formats --
5630 only the format ``expected'' to be used on the configured target system.
5631 We hope to make this the default in a future release.
5633 * Documentation improvements
5635 There's new internal documentation on how to modify GDB, and how to
5636 produce clean changes to the code. We implore people to read it
5637 before submitting changes.
5639 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5640 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5641 `info' files are also provided. To build `info' files from scratch,
5642 you will need the latest `makeinfo' release, which will be available in
5643 a future texinfo-X.Y release.
5645 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5646 We're not sure exactly which versions have this problem, but it has
5647 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5648 or better. If that isn't possible, there is a patch in
5649 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5650 around this problem.
5654 GDB now supports array constants that can be used in expressions typed in by
5655 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5656 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5659 The new directory `gdb/sparclite' contains a program that demonstrates
5660 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5662 * New native hosts supported
5664 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5665 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5667 * New targets supported
5669 AMD 29k family via UDI a29k-amd-udi or udi29k
5671 * New file formats supported
5673 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5674 HPUX core files, and SCO 3.2v2 core files.
5678 Attaching to processes now works again; thanks for the many bug reports.
5680 We have also stomped on a bunch of core dumps caused by
5681 printf_filtered("%s") problems.
5683 We eliminated a copyright problem on the rpc and ptrace header files
5684 for VxWorks, which was discovered at the last minute during the 4.7
5685 release. You should now be able to build a VxWorks GDB.
5687 You can now interrupt gdb while an attached process is running. This
5688 will cause the attached process to stop, and give control back to GDB.
5690 We fixed problems caused by using too many file descriptors
5691 for reading symbols from object files and libraries. This was
5692 especially a problem for programs that used many (~100) shared
5695 The `step' command now only enters a subroutine if there is line number
5696 information for the subroutine. Otherwise it acts like the `next'
5697 command. Previously, `step' would enter subroutines if there was
5698 any debugging information about the routine. This avoids problems
5699 when using `cc -g1' on MIPS machines.
5701 * Internal improvements
5703 GDB's internal interfaces have been improved to make it easier to support
5704 debugging of multiple languages in the future.
5706 GDB now uses a common structure for symbol information internally.
5707 Minimal symbols (derived from linkage symbols in object files), partial
5708 symbols (from a quick scan of debug information), and full symbols
5709 contain a common subset of information, making it easier to write
5710 shared code that handles any of them.
5712 * New command line options
5714 We now accept --silent as an alias for --quiet.
5718 The memory-mapped-malloc library is now licensed under the GNU Library
5719 General Public License.
5721 *** Changes in GDB-4.7:
5723 * Host/native/target split
5725 GDB has had some major internal surgery to untangle the support for
5726 hosts and remote targets. Now, when you configure GDB for a remote
5727 target, it will no longer load in all of the support for debugging
5728 local programs on the host. When fully completed and tested, this will
5729 ensure that arbitrary host/target combinations are possible.
5731 The primary conceptual shift is to separate the non-portable code in
5732 GDB into three categories. Host specific code is required any time GDB
5733 is compiled on that host, regardless of the target. Target specific
5734 code relates to the peculiarities of the target, but can be compiled on
5735 any host. Native specific code is everything else: it can only be
5736 built when the host and target are the same system. Child process
5737 handling and core file support are two common `native' examples.
5739 GDB's use of /proc for controlling Unix child processes is now cleaner.
5740 It has been split out into a single module under the `target_ops' vector,
5741 plus two native-dependent functions for each system that uses /proc.
5743 * New hosts supported
5745 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5746 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5747 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5749 * New targets supported
5751 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5752 68030 and CPU32 m68030-*-*, m68332-*-*
5754 * New native hosts supported
5756 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5757 (386bsd is not well tested yet)
5758 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5760 * New file formats supported
5762 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5763 supports reading of `a.out.adobe' object files, which are an a.out
5764 format extended with minimal information about multiple sections.
5768 `show copying' is the same as the old `info copying'.
5769 `show warranty' is the same as `info warrantee'.
5770 These were renamed for consistency. The old commands continue to work.
5772 `info handle' is a new alias for `info signals'.
5774 You can now define pre-command hooks, which attach arbitrary command
5775 scripts to any command. The commands in the hook will be executed
5776 prior to the user's command. You can also create a hook which will be
5777 executed whenever the program stops. See gdb.texinfo.
5781 We now deal with Cfront style name mangling, and can even extract type
5782 info from mangled symbols. GDB can automatically figure out which
5783 symbol mangling style your C++ compiler uses.
5785 Calling of methods and virtual functions has been improved as well.
5789 The crash that occured when debugging Sun Ansi-C compiled binaries is
5790 fixed. This was due to mishandling of the extra N_SO stabs output
5793 We also finally got Ultrix 4.2 running in house, and fixed core file
5794 support, with help from a dozen people on the net.
5796 John M. Farrell discovered that the reason that single-stepping was so
5797 slow on all of the Mips based platforms (primarily SGI and DEC) was
5798 that we were trying to demangle and lookup a symbol used for internal
5799 purposes on every instruction that was being stepped through. Changing
5800 the name of that symbol so that it couldn't be mistaken for a C++
5801 mangled symbol sped things up a great deal.
5803 Rich Pixley sped up symbol lookups in general by getting much smarter
5804 about when C++ symbol mangling is necessary. This should make symbol
5805 completion (TAB on the command line) much faster. It's not as fast as
5806 we'd like, but it's significantly faster than gdb-4.6.
5810 A new user controllable variable 'call_scratch_address' can
5811 specify the location of a scratch area to be used when GDB
5812 calls a function in the target. This is necessary because the
5813 usual method of putting the scratch area on the stack does not work
5814 in systems that have separate instruction and data spaces.
5816 We integrated changes to support the 29k UDI (Universal Debugger
5817 Interface), but discovered at the last minute that we didn't have all
5818 of the appropriate copyright paperwork. We are working with AMD to
5819 resolve this, and hope to have it available soon.
5823 We have sped up the remote serial line protocol, especially for targets
5824 with lots of registers. It now supports a new `expedited status' ('T')
5825 message which can be used in place of the existing 'S' status message.
5826 This allows the remote stub to send only the registers that GDB
5827 needs to make a quick decision about single-stepping or conditional
5828 breakpoints, eliminating the need to fetch the entire register set for
5829 each instruction being stepped through.
5831 The GDB remote serial protocol now implements a write-through cache for
5832 registers, only re-reading the registers if the target has run.
5834 There is also a new remote serial stub for SPARC processors. You can
5835 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5836 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5837 processor with a serial port.
5841 Configure.in files have become much easier to read and modify. A new
5842 `table driven' format makes it more obvious what configurations are
5843 supported, and what files each one uses.
5847 There is a new opcodes library which will eventually contain all of the
5848 disassembly routines and opcode tables. At present, it only contains
5849 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5850 disassembler (binutils/objdump) to share these routines.
5852 The libiberty library is now copylefted under the GNU Library General
5853 Public License. This allows more liberal use, and was done so libg++
5854 can use it. This makes no difference to GDB, since the Library License
5855 grants all the rights from the General Public License.
5859 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5860 reference to the stabs symbol info used by the debugger. It is (as far
5861 as we know) the only published document on this fascinating topic. We
5862 encourage you to read it, compare it to the stabs information on your
5863 system, and send improvements on the document in general (to
5864 bug-gdb@prep.ai.mit.edu).
5866 And, of course, many bugs have been fixed.
5869 *** Changes in GDB-4.6:
5871 * Better support for C++ function names
5873 GDB now accepts as input the "demangled form" of C++ overloaded function
5874 names and member function names, and can do command completion on such names
5875 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5876 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5877 Make use of command completion, it is your friend.
5879 GDB also now accepts a variety of C++ mangled symbol formats. They are
5880 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5881 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5882 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5883 for the list of formats.
5885 * G++ symbol mangling problem
5887 Recent versions of gcc have a bug in how they emit debugging information for
5888 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5889 directory) can be applied to gcc to fix the problem. Alternatively, if you
5890 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5891 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5892 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5895 * New 'maintenance' command
5897 All of the commands related to hacking GDB internals have been moved out of
5898 the main command set, and now live behind the 'maintenance' command. This
5899 can also be abbreviated as 'mt'. The following changes were made:
5901 dump-me -> maintenance dump-me
5902 info all-breakpoints -> maintenance info breakpoints
5903 printmsyms -> maintenance print msyms
5904 printobjfiles -> maintenance print objfiles
5905 printpsyms -> maintenance print psymbols
5906 printsyms -> maintenance print symbols
5908 The following commands are new:
5910 maintenance demangle Call internal GDB demangler routine to
5911 demangle a C++ link name and prints the result.
5912 maintenance print type Print a type chain for a given symbol
5914 * Change to .gdbinit file processing
5916 We now read the $HOME/.gdbinit file before processing the argv arguments
5917 (e.g. reading symbol files or core files). This allows global parameters to
5918 be set, which will apply during the symbol reading. The ./.gdbinit is still
5919 read after argv processing.
5921 * New hosts supported
5923 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5925 GNU/Linux support i386-unknown-linux or linux
5927 We are also including code to support the HP/PA running BSD and HPUX. This
5928 is almost guaranteed not to work, as we didn't have time to test or build it
5929 for this release. We are including it so that the more adventurous (or
5930 masochistic) of you can play with it. We also had major problems with the
5931 fact that the compiler that we got from HP doesn't support the -g option.
5934 * New targets supported
5936 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5938 * More smarts about finding #include files
5940 GDB now remembers the compilation directory for all include files, and for
5941 all files from which C is generated (like yacc and lex sources). This
5942 greatly improves GDB's ability to find yacc/lex sources, and include files,
5943 especially if you are debugging your program from a directory different from
5944 the one that contains your sources.
5946 We also fixed a bug which caused difficulty with listing and setting
5947 breakpoints in include files which contain C code. (In the past, you had to
5948 try twice in order to list an include file that you hadn't looked at before.)
5950 * Interesting infernals change
5952 GDB now deals with arbitrary numbers of sections, where the symbols for each
5953 section must be relocated relative to that section's landing place in the
5954 target's address space. This work was needed to support ELF with embedded
5955 stabs used by Solaris-2.0.
5957 * Bug fixes (of course!)
5959 There have been loads of fixes for the following things:
5960 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5961 i960, stabs, DOS(GO32), procfs, etc...
5963 See the ChangeLog for details.
5965 *** Changes in GDB-4.5:
5967 * New machines supported (host and target)
5969 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5971 SGI Irix-4.x mips-sgi-irix4 or iris4
5973 * New malloc package
5975 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5976 Mmalloc is capable of handling mutiple heaps of memory. It is also
5977 capable of saving a heap to a file, and then mapping it back in later.
5978 This can be used to greatly speedup the startup of GDB by using a
5979 pre-parsed symbol table which lives in a mmalloc managed heap. For
5980 more details, please read mmalloc/mmalloc.texi.
5984 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5985 'help info proc' for details.
5987 * MIPS ecoff symbol table format
5989 The code that reads MIPS symbol table format is now supported on all hosts.
5990 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5993 * File name changes for MS-DOS
5995 Many files in the config directories have been renamed to make it easier to
5996 support GDB on MS-DOSe systems (which have very restrictive file name
5997 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5998 environment) is close to working but has some remaining problems. Note
5999 that debugging of DOS programs is not supported, due to limitations
6000 in the ``operating system'', but it can be used to host cross-debugging.
6002 * Cross byte order fixes
6004 Many fixes have been made to support cross debugging of Sparc and MIPS
6005 targets from hosts whose byte order differs.
6007 * New -mapped and -readnow options
6009 If memory-mapped files are available on your system through the 'mmap'
6010 system call, you can use the -mapped option on the `file' or
6011 `symbol-file' commands to cause GDB to write the symbols from your
6012 program into a reusable file. If the program you are debugging is
6013 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6014 Future GDB debugging sessions will notice the presence of this file,
6015 and will quickly map in symbol information from it, rather than reading
6016 the symbol table from the executable program. Using the '-mapped'
6017 option in a GDB `file' or `symbol-file' command has the same effect as
6018 starting GDB with the '-mapped' command-line option.
6020 You can cause GDB to read the entire symbol table immediately by using
6021 the '-readnow' option with any of the commands that load symbol table
6022 information (or on the GDB command line). This makes the command
6023 slower, but makes future operations faster.
6025 The -mapped and -readnow options are typically combined in order to
6026 build a `fred.syms' file that contains complete symbol information.
6027 A simple GDB invocation to do nothing but build a `.syms' file for future
6030 gdb -batch -nx -mapped -readnow programname
6032 The `.syms' file is specific to the host machine on which GDB is run.
6033 It holds an exact image of GDB's internal symbol table. It cannot be
6034 shared across multiple host platforms.
6036 * longjmp() handling
6038 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6039 siglongjmp() without losing control. This feature has not yet been ported to
6040 all systems. It currently works on many 386 platforms, all MIPS-based
6041 platforms (SGI, DECstation, etc), and Sun3/4.
6045 Preliminary work has been put in to support the new Solaris OS from Sun. At
6046 this time, it can control and debug processes, but it is not capable of
6051 As always, many many bug fixes. The major areas were with g++, and mipsread.
6052 People using the MIPS-based platforms should experience fewer mysterious
6053 crashes and trashed symbol tables.
6055 *** Changes in GDB-4.4:
6057 * New machines supported (host and target)
6059 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6061 BSD Reno on Vax vax-dec-bsd
6062 Ultrix on Vax vax-dec-ultrix
6064 * New machines supported (target)
6066 AMD 29000 embedded, using EBMON a29k-none-none
6070 GDB continues to improve its handling of C++. `References' work better.
6071 The demangler has also been improved, and now deals with symbols mangled as
6072 per the Annotated C++ Reference Guide.
6074 GDB also now handles `stabs' symbol information embedded in MIPS
6075 `ecoff' symbol tables. Since the ecoff format was not easily
6076 extensible to handle new languages such as C++, this appeared to be a
6077 good way to put C++ debugging info into MIPS binaries. This option
6078 will be supported in the GNU C compiler, version 2, when it is
6081 * New features for SVR4
6083 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6084 shared libraries. Debugging dynamically linked programs should present
6085 only minor differences from debugging statically linked programs.
6087 The `info proc' command will print out information about any process
6088 on an SVR4 system (including the one you are debugging). At the moment,
6089 it prints the address mappings of the process.
6091 If you bring up GDB on another SVR4 system, please send mail to
6092 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6094 * Better dynamic linking support in SunOS
6096 Reading symbols from shared libraries which contain debugging symbols
6097 now works properly. However, there remain issues such as automatic
6098 skipping of `transfer vector' code during function calls, which
6099 make it harder to debug code in a shared library, than to debug the
6100 same code linked statically.
6104 GDB is now using the latest `getopt' routines from the FSF. This
6105 version accepts the -- prefix for options with long names. GDB will
6106 continue to accept the old forms (-option and +option) as well.
6107 Various single letter abbreviations for options have been explicity
6108 added to the option table so that they won't get overshadowed in the
6109 future by other options that begin with the same letter.
6113 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6114 Many assorted bugs have been handled. Many more remain to be handled.
6115 See the various ChangeLog files (primarily in gdb and bfd) for details.
6118 *** Changes in GDB-4.3:
6120 * New machines supported (host and target)
6122 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6123 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6124 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6126 * Almost SCO Unix support
6128 We had hoped to support:
6129 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6130 (except for core file support), but we discovered very late in the release
6131 that it has problems with process groups that render gdb unusable. Sorry
6132 about that. I encourage people to fix it and post the fixes.
6134 * Preliminary ELF and DWARF support
6136 GDB can read ELF object files on System V Release 4, and can handle
6137 debugging records for C, in DWARF format, in ELF files. This support
6138 is preliminary. If you bring up GDB on another SVR4 system, please
6139 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6144 GDB now uses the latest `readline' library. One user-visible change
6145 is that two tabs will list possible command completions, which previously
6146 required typing M-? (meta-question mark, or ESC ?).
6150 The `stepi' bug that many of you noticed has been squashed.
6151 Many bugs in C++ have been handled. Many more remain to be handled.
6152 See the various ChangeLog files (primarily in gdb and bfd) for details.
6154 * State of the MIPS world (in case you wondered):
6156 GDB can understand the symbol tables emitted by the compilers
6157 supplied by most vendors of MIPS-based machines, including DEC. These
6158 symbol tables are in a format that essentially nobody else uses.
6160 Some versions of gcc come with an assembler post-processor called
6161 mips-tfile. This program is required if you want to do source-level
6162 debugging of gcc-compiled programs. I believe FSF does not ship
6163 mips-tfile with gcc version 1, but it will eventually come with gcc
6166 Debugging of g++ output remains a problem. g++ version 1.xx does not
6167 really support it at all. (If you're lucky, you should be able to get
6168 line numbers and stack traces to work, but no parameters or local
6169 variables.) With some work it should be possible to improve the
6172 When gcc version 2 is released, you will have somewhat better luck.
6173 However, even then you will get confusing results for inheritance and
6176 We will eventually provide full debugging of g++ output on
6177 DECstations. This will probably involve some kind of stabs-in-ecoff
6178 encapulation, but the details have not been worked out yet.
6181 *** Changes in GDB-4.2:
6183 * Improved configuration
6185 Only one copy of `configure' exists now, and it is not self-modifying.
6186 Porting BFD is simpler.
6190 The `step' and `next' commands now only stop at the first instruction
6191 of a source line. This prevents the multiple stops that used to occur
6192 in switch statements, for-loops, etc. `Step' continues to stop if a
6193 function that has debugging information is called within the line.
6197 Lots of small bugs fixed. More remain.
6199 * New host supported (not target)
6201 Intel 386 PC clone running Mach i386-none-mach
6204 *** Changes in GDB-4.1:
6206 * Multiple source language support
6208 GDB now has internal scaffolding to handle several source languages.
6209 It determines the type of each source file from its filename extension,
6210 and will switch expression parsing and number formatting to match the
6211 language of the function in the currently selected stack frame.
6212 You can also specifically set the language to be used, with
6213 `set language c' or `set language modula-2'.
6217 GDB now has preliminary support for the GNU Modula-2 compiler,
6218 currently under development at the State University of New York at
6219 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6220 continue through the fall of 1991 and into 1992.
6222 Other Modula-2 compilers are currently not supported, and attempting to
6223 debug programs compiled with them will likely result in an error as the
6224 symbol table is read. Feel free to work on it, though!
6226 There are hooks in GDB for strict type checking and range checking,
6227 in the `Modula-2 philosophy', but they do not currently work.
6231 GDB can now write to executable and core files (e.g. patch
6232 a variable's value). You must turn this switch on, specify
6233 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6234 by assigning a new value to a variable. Modifications take
6237 * Automatic SunOS shared library reading
6239 When you run your program, GDB automatically determines where its
6240 shared libraries (if any) have been loaded, and reads their symbols.
6241 The `share' command is no longer needed. This also works when
6242 examining core files.
6246 You can specify the number of lines that the `list' command shows.
6249 * New machines supported (host and target)
6251 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6252 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6253 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6255 * New hosts supported (not targets)
6257 IBM RT/PC: romp-ibm-aix or rtpc
6259 * New targets supported (not hosts)
6261 AMD 29000 embedded with COFF a29k-none-coff
6262 AMD 29000 embedded with a.out a29k-none-aout
6263 Ultracomputer remote kernel debug a29k-nyu-kern
6265 * New remote interfaces
6271 *** Changes in GDB-4.0:
6275 Wide output is wrapped at good places to make the output more readable.
6277 Gdb now supports cross-debugging from a host machine of one type to a
6278 target machine of another type. Communication with the target system
6279 is over serial lines. The ``target'' command handles connecting to the
6280 remote system; the ``load'' command will download a program into the
6281 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6282 also supports debugging of realtime processes running under VxWorks,
6283 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6284 stub on the target system.
6286 New CPUs supported include the AMD 29000 and Intel 960.
6288 GDB now reads object files and symbol tables via a ``binary file''
6289 library, which allows a single copy of GDB to debug programs of multiple
6290 object file types such as a.out and coff.
6292 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6293 refcard.dvi and refcard.ps are available to format it).
6296 * Control-Variable user interface simplified
6298 All variables that control the operation of the debugger can be set
6299 by the ``set'' command, and displayed by the ``show'' command.
6301 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6302 ``Show prompt'' produces the response:
6303 Gdb's prompt is new-gdb=>.
6305 What follows are the NEW set commands. The command ``help set'' will
6306 print a complete list of old and new set commands. ``help set FOO''
6307 will give a longer description of the variable FOO. ``show'' will show
6308 all of the variable descriptions and their current settings.
6310 confirm on/off: Enables warning questions for operations that are
6311 hard to recover from, e.g. rerunning the program while
6312 it is already running. Default is ON.
6314 editing on/off: Enables EMACS style command line editing
6315 of input. Previous lines can be recalled with
6316 control-P, the current line can be edited with control-B,
6317 you can search for commands with control-R, etc.
6320 history filename NAME: NAME is where the gdb command history
6321 will be stored. The default is .gdb_history,
6322 or the value of the environment variable
6325 history size N: The size, in commands, of the command history. The
6326 default is 256, or the value of the environment variable
6329 history save on/off: If this value is set to ON, the history file will
6330 be saved after exiting gdb. If set to OFF, the
6331 file will not be saved. The default is OFF.
6333 history expansion on/off: If this value is set to ON, then csh-like
6334 history expansion will be performed on
6335 command line input. The default is OFF.
6337 radix N: Sets the default radix for input and output. It can be set
6338 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6339 in the current radix, so "set radix 10" is always a no-op.
6341 height N: This integer value is the number of lines on a page. Default
6342 is 24, the current `stty rows'' setting, or the ``li#''
6343 setting from the termcap entry matching the environment
6346 width N: This integer value is the number of characters on a line.
6347 Default is 80, the current `stty cols'' setting, or the ``co#''
6348 setting from the termcap entry matching the environment
6351 Note: ``set screensize'' is obsolete. Use ``set height'' and
6352 ``set width'' instead.
6354 print address on/off: Print memory addresses in various command displays,
6355 such as stack traces and structure values. Gdb looks
6356 more ``symbolic'' if you turn this off; it looks more
6357 ``machine level'' with it on. Default is ON.
6359 print array on/off: Prettyprint arrays. New convenient format! Default
6362 print demangle on/off: Print C++ symbols in "source" form if on,
6365 print asm-demangle on/off: Same, for assembler level printouts
6368 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6371 * Support for Epoch Environment.
6373 The epoch environment is a version of Emacs v18 with windowing. One
6374 new command, ``inspect'', is identical to ``print'', except that if you
6375 are running in the epoch environment, the value is printed in its own
6379 * Support for Shared Libraries
6381 GDB can now debug programs and core files that use SunOS shared libraries.
6382 Symbols from a shared library cannot be referenced
6383 before the shared library has been linked with the program (this
6384 happens after you type ``run'' and before the function main() is entered).
6385 At any time after this linking (including when examining core files
6386 from dynamically linked programs), gdb reads the symbols from each
6387 shared library when you type the ``sharedlibrary'' command.
6388 It can be abbreviated ``share''.
6390 sharedlibrary REGEXP: Load shared object library symbols for files
6391 matching a unix regular expression. No argument
6392 indicates to load symbols for all shared libraries.
6394 info sharedlibrary: Status of loaded shared libraries.
6399 A watchpoint stops execution of a program whenever the value of an
6400 expression changes. Checking for this slows down execution
6401 tremendously whenever you are in the scope of the expression, but is
6402 quite useful for catching tough ``bit-spreader'' or pointer misuse
6403 problems. Some machines such as the 386 have hardware for doing this
6404 more quickly, and future versions of gdb will use this hardware.
6406 watch EXP: Set a watchpoint (breakpoint) for an expression.
6408 info watchpoints: Information about your watchpoints.
6410 delete N: Deletes watchpoint number N (same as breakpoints).
6411 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6412 enable N: Re-enables watchpoint number N (same as breakpoints).
6415 * C++ multiple inheritance
6417 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6420 * C++ exception handling
6422 Gdb now supports limited C++ exception handling. Besides the existing
6423 ability to breakpoint on an exception handler, gdb can breakpoint on
6424 the raising of an exception (before the stack is peeled back to the
6427 catch FOO: If there is a FOO exception handler in the dynamic scope,
6428 set a breakpoint to catch exceptions which may be raised there.
6429 Multiple exceptions (``catch foo bar baz'') may be caught.
6431 info catch: Lists all exceptions which may be caught in the
6432 current stack frame.
6435 * Minor command changes
6437 The command ``call func (arg, arg, ...)'' now acts like the print
6438 command, except it does not print or save a value if the function's result
6439 is void. This is similar to dbx usage.
6441 The ``up'' and ``down'' commands now always print the frame they end up
6442 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6443 frames without printing.
6445 * New directory command
6447 'dir' now adds directories to the FRONT of the source search path.
6448 The path starts off empty. Source files that contain debug information
6449 about the directory in which they were compiled can be found even
6450 with an empty path; Sun CC and GCC include this information. If GDB can't
6451 find your source file in the current directory, type "dir .".
6453 * Configuring GDB for compilation
6455 For normal use, type ``./configure host''. See README or gdb.texinfo
6458 GDB now handles cross debugging. If you are remotely debugging between
6459 two different machines, type ``./configure host -target=targ''.
6460 Host is the machine where GDB will run; targ is the machine
6461 where the program that you are debugging will run.