1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.11
6 * GDB now supports multibit bitfields and enums in target register
9 * New Python-based convenience function $_as_string(val), which returns
10 the textual representation of a value. This function is especially
11 useful to obtain the text label of an enum value.
13 * Intel MPX bound violation handling.
15 Segmentation faults caused by a Intel MPX boundary violation
16 now display the kind of violation (upper or lower), the memory
17 address accessed and the memory bounds, along with the usual
18 signal received and code location.
22 Program received signal SIGSEGV, Segmentation fault
23 Upper bound violation while accessing address 0x7fffffffc3b3
24 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
25 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
30 skip -gfile file-glob-pattern
31 skip -function function
32 skip -rfunction regular-expression
33 A generalized form of the skip command, with new support for
34 glob-style file names and regular expressions for function names.
35 Additionally, a file spec and a function spec may now be combined.
37 maint info line-table REGEXP
38 Display the contents of GDB's internal line table data struture.
40 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
41 was added in GDBserver, including JIT compiling fast tracepoint's
42 conditional expression bytecode into native code.
44 * Support for various remote target protocols and ROM monitors has
47 target m32rsdi Remote M32R debugging over SDI
48 target mips MIPS remote debugging protocol
49 target pmon PMON ROM monitor
50 target ddb NEC's DDB variant of PMON for Vr4300
51 target rockhopper NEC RockHopper variant of PMON
52 target lsi LSI variant of PMO
54 * Support for tracepoints and fast tracepoints on powerpc-linux,
55 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
56 including JIT compiling fast tracepoint's conditional expression
57 bytecode into native code.
59 *** Changes in GDB 7.11
61 * GDB now supports debugging kernel-based threads on FreeBSD.
63 * Per-inferior thread numbers
65 Thread numbers are now per inferior instead of global. If you're
66 debugging multiple inferiors, GDB displays thread IDs using a
67 qualified INF_NUM.THR_NUM form. For example:
71 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
72 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
73 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
74 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
76 As consequence, thread numbers as visible in the $_thread
77 convenience variable and in Python's InferiorThread.num attribute
78 are no longer unique between inferiors.
80 GDB now maintains a second thread ID per thread, referred to as the
81 global thread ID, which is the new equivalent of thread numbers in
82 previous releases. See also $_gthread below.
84 For backwards compatibility, MI's thread IDs always refer to global
87 * Commands that accept thread IDs now accept the qualified
88 INF_NUM.THR_NUM form as well. For example:
91 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
94 * In commands that accept a list of thread IDs, you can now refer to
95 all threads of an inferior using a star wildcard. GDB accepts
96 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
97 refer to all threads of the current inferior. For example, "info
100 * You can use "info threads -gid" to display the global thread ID of
103 * The new convenience variable $_gthread holds the global number of
106 * The new convenience variable $_inferior holds the number of the
109 * GDB now displays the ID and name of the thread that hit a breakpoint
110 or received a signal, if your program is multi-threaded. For
113 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
114 Thread 1 "main" received signal SIGINT, Interrupt.
116 * Record btrace now supports non-stop mode.
118 * Support for tracepoints on aarch64-linux was added in GDBserver.
120 * The 'record instruction-history' command now indicates speculative execution
121 when using the Intel Processor Trace recording format.
123 * GDB now allows users to specify explicit locations, bypassing
124 the linespec parser. This feature is also available to GDB/MI
127 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
128 GDB now is able to debug both AArch64 applications and ARM applications
131 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
132 including JIT compiling fast tracepoint's conditional expression bytecode
135 * GDB now supports displaced stepping on AArch64 GNU/Linux.
137 * "info threads", "info inferiors", "info display", "info checkpoints"
138 and "maint info program-spaces" now list the corresponding items in
139 ascending ID order, for consistency with all other "info" commands.
141 * In Ada, the overloads selection menu has been enhanced to display the
142 parameter types and the return types for the matching overloaded subprograms.
146 maint set target-non-stop (on|off|auto)
147 maint show target-non-stop
148 Control whether GDB targets always operate in non-stop mode even if
149 "set non-stop" is "off". The default is "auto", meaning non-stop
150 mode is enabled if supported by the target.
152 maint set bfd-sharing
153 maint show bfd-sharing
154 Control the reuse of bfd objects.
158 Control display of debugging info regarding bfd caching.
162 Control display of debugging info regarding FreeBSD threads.
164 set remote multiprocess-extensions-packet
165 show remote multiprocess-extensions-packet
166 Set/show the use of the remote protocol multiprocess extensions.
168 set remote thread-events
169 show remote thread-events
170 Set/show the use of thread create/exit events.
172 set ada print-signatures on|off
173 show ada print-signatures"
174 Control whether parameter types and return types are displayed in overloads
175 selection menus. It is activaled (@code{on}) by default.
179 Controls the maximum size of memory, in bytes, that GDB will
180 allocate for value contents. Prevents incorrect programs from
181 causing GDB to allocate overly large buffers. Default is 64k.
183 * The "disassemble" command accepts a new modifier: /s.
184 It prints mixed source+disassembly like /m with two differences:
185 - disassembled instructions are now printed in program order, and
186 - and source for all relevant files is now printed.
187 The "/m" option is now considered deprecated: its "source-centric"
188 output hasn't proved useful in practice.
190 * The "record instruction-history" command accepts a new modifier: /s.
191 It behaves exactly like /m and prints mixed source+disassembly.
193 * The "set scheduler-locking" command supports a new mode "replay".
194 It behaves like "off" in record mode and like "on" in replay mode.
196 * Support for various ROM monitors has been removed:
198 target dbug dBUG ROM monitor for Motorola ColdFire
199 target picobug Motorola picobug monitor
200 target dink32 DINK32 ROM monitor for PowerPC
201 target m32r Renesas M32R/D ROM monitor
202 target mon2000 mon2000 ROM monitor
203 target ppcbug PPCBUG ROM monitor for PowerPC
205 * Support for reading/writing memory and extracting values on architectures
206 whose memory is addressable in units of any integral multiple of 8 bits.
211 Indicates that an exec system call was executed.
213 exec-events feature in qSupported
214 The qSupported packet allows GDB to request support for exec
215 events using the new 'gdbfeature' exec-event, and the qSupported
216 response can contain the corresponding 'stubfeature'. Set and
217 show commands can be used to display whether these features are enabled.
220 Equivalent to interrupting with the ^C character, but works in
223 thread created stop reason (T05 create:...)
224 Indicates that the thread was just created and is stopped at entry.
226 thread exit stop reply (w exitcode;tid)
227 Indicates that the thread has terminated.
230 Enables/disables thread create and exit event reporting. For
231 example, this is used in non-stop mode when GDB stops a set of
232 threads and synchronously waits for the their corresponding stop
233 replies. Without exit events, if one of the threads exits, GDB
234 would hang forever not knowing that it should no longer expect a
235 stop for that same thread.
239 Indicates that there are no resumed threads left in the target (all
240 threads are stopped). The remote stub reports support for this stop
241 reply to GDB's qSupported query.
243 QCatchSyscalls:1 [;SYSNO]...
245 Enable ("QCatchSyscalls:1") or disable ("QCatchSyscalls:0")
246 catching syscalls from the inferior process.
248 syscall_entry stop reason
249 Indicates that a syscall was just called.
251 syscall_return stop reason
252 Indicates that a syscall just returned.
254 QCatchSyscalls:1 in qSupported
255 The qSupported packet may now include QCatchSyscalls:1 in the reply
256 to indicate support for catching syscalls.
258 * Extended-remote exec events
260 ** GDB now has support for exec events on extended-remote Linux targets.
261 For such targets with Linux kernels 2.5.46 and later, this enables
262 follow-exec-mode and exec catchpoints.
264 set remote exec-event-feature-packet
265 show remote exec-event-feature-packet
266 Set/show the use of the remote exec event feature.
268 * Thread names in remote protocol
270 The reply to qXfer:threads:read may now include a name attribute for each
273 * Target remote mode fork and exec events
275 ** GDB now has support for fork and exec events on target remote mode
276 Linux targets. For such targets with Linux kernels 2.5.46 and later,
277 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
278 fork and exec catchpoints.
280 * Remote syscall events
282 ** GDB now has support for catch syscall on remote Linux targets,
283 currently enabled on x86/x86_64 architectures.
285 set remote catch-syscall-packet
286 show remote catch-syscall-packet
287 Set/show the use of the remote catch syscall feature.
291 ** The -var-set-format command now accepts the zero-hexadecimal
292 format. It outputs data in hexadecimal format with zero-padding on the
297 ** gdb.InferiorThread objects have a new attribute "global_num",
298 which refers to the thread's global thread ID. The existing
299 "num" attribute now refers to the thread's per-inferior number.
300 See "Per-inferior thread numbers" above.
301 ** gdb.InferiorThread objects have a new attribute "inferior", which
302 is the Inferior object the thread belongs to.
304 *** Changes in GDB 7.10
306 * Support for process record-replay and reverse debugging on aarch64*-linux*
307 targets has been added. GDB now supports recording of A64 instruction set
308 including advance SIMD instructions.
310 * Support for Sun's version of the "stabs" debug file format has been removed.
312 * GDB now honors the content of the file /proc/PID/coredump_filter
313 (PID is the process ID) on GNU/Linux systems. This file can be used
314 to specify the types of memory mappings that will be included in a
315 corefile. For more information, please refer to the manual page of
316 "core(5)". GDB also has a new command: "set use-coredump-filter
317 on|off". It allows to set whether GDB will read the content of the
318 /proc/PID/coredump_filter file when generating a corefile.
320 * The "info os" command on GNU/Linux can now display information on
322 "info os cpus" Listing of all cpus/cores on the system
324 * GDB has two new commands: "set serial parity odd|even|none" and
325 "show serial parity". These allows to set or show parity for the
328 * The "info source" command now displays the producer string if it was
329 present in the debug info. This typically includes the compiler version
330 and may include things like its command line arguments.
332 * The "info dll", an alias of the "info sharedlibrary" command,
333 is now available on all platforms.
335 * Directory names supplied to the "set sysroot" commands may be
336 prefixed with "target:" to tell GDB to access shared libraries from
337 the target system, be it local or remote. This replaces the prefix
338 "remote:". The default sysroot has been changed from "" to
339 "target:". "remote:" is automatically converted to "target:" for
340 backward compatibility.
342 * The system root specified by "set sysroot" will be prepended to the
343 filename of the main executable (if reported to GDB as absolute by
344 the operating system) when starting processes remotely, and when
345 attaching to already-running local or remote processes.
347 * GDB now supports automatic location and retrieval of executable
348 files from remote targets. Remote debugging can now be initiated
349 using only a "target remote" or "target extended-remote" command
350 (no "set sysroot" or "file" commands are required). See "New remote
353 * The "dump" command now supports verilog hex format.
355 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
357 * On GNU/Linux, GDB and gdbserver are now able to access executable
358 and shared library files without a "set sysroot" command when
359 attaching to processes running in different mount namespaces from
360 the debugger. This makes it possible to attach to processes in
361 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
362 See "New remote packets" below.
364 * The "tui reg" command now provides completion for all of the
365 available register groups, including target specific groups.
367 * The HISTSIZE environment variable is no longer read when determining
368 the size of GDB's command history. GDB now instead reads the dedicated
369 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
370 disables truncation of command history. Non-numeric values of GDBHISTSIZE
375 ** Memory ports can now be unbuffered.
379 ** gdb.Objfile objects have a new attribute "username",
380 which is the name of the objfile as specified by the user,
381 without, for example, resolving symlinks.
382 ** You can now write frame unwinders in Python.
383 ** gdb.Type objects have a new method "optimized_out",
384 returning optimized out gdb.Value instance of this type.
385 ** gdb.Value objects have new methods "reference_value" and
386 "const_value" which return a reference to the value and a
387 "const" version of the value respectively.
391 maint print symbol-cache
392 Print the contents of the symbol cache.
394 maint print symbol-cache-statistics
395 Print statistics of symbol cache usage.
397 maint flush-symbol-cache
398 Flush the contents of the symbol cache.
402 Start branch trace recording using Branch Trace Store (BTS) format.
405 Evaluate expression by using the compiler and print result.
409 Explicit commands for enabling and disabling tui mode.
412 set mpx bound on i386 and amd64
413 Support for bound table investigation on Intel MPX enabled applications.
417 Start branch trace recording using Intel Processor Trace format.
420 Print information about branch tracing internals.
422 maint btrace packet-history
423 Print the raw branch tracing data.
425 maint btrace clear-packet-history
426 Discard the stored raw branch tracing data.
429 Discard all branch tracing data. It will be fetched and processed
430 anew by the next "record" command.
435 Renamed from "set debug dwarf2-die".
437 Renamed from "show debug dwarf2-die".
440 Renamed from "set debug dwarf2-read".
441 show debug dwarf-read
442 Renamed from "show debug dwarf2-read".
444 maint set dwarf always-disassemble
445 Renamed from "maint set dwarf2 always-disassemble".
446 maint show dwarf always-disassemble
447 Renamed from "maint show dwarf2 always-disassemble".
449 maint set dwarf max-cache-age
450 Renamed from "maint set dwarf2 max-cache-age".
451 maint show dwarf max-cache-age
452 Renamed from "maint show dwarf2 max-cache-age".
455 show debug dwarf-line
456 Control display of debugging info regarding DWARF line processing.
460 Set the maximum number of candidates to be considered during
461 completion. The default value is 200. This limit allows GDB
462 to avoid generating large completion lists, the computation of
463 which can cause the debugger to become temporarily unresponsive.
465 set history remove-duplicates
466 show history remove-duplicates
467 Control the removal of duplicate history entries.
469 maint set symbol-cache-size
470 maint show symbol-cache-size
471 Control the size of the symbol cache.
473 set|show record btrace bts buffer-size
474 Set and show the size of the ring buffer used for branch tracing in
476 The obtained size may differ from the requested size. Use "info
477 record" to see the obtained buffer size.
479 set debug linux-namespaces
480 show debug linux-namespaces
481 Control display of debugging info regarding Linux namespaces.
483 set|show record btrace pt buffer-size
484 Set and show the size of the ring buffer used for branch tracing in
485 Intel Processor Trace format.
486 The obtained size may differ from the requested size. Use "info
487 record" to see the obtained buffer size.
489 maint set|show btrace pt skip-pad
490 Set and show whether PAD packets are skipped when computing the
493 * The command 'thread apply all' can now support new option '-ascending'
494 to call its specified command for all threads in ascending order.
496 * Python/Guile scripting
498 ** GDB now supports auto-loading of Python/Guile scripts contained in the
499 special section named `.debug_gdb_scripts'.
503 qXfer:btrace-conf:read
504 Return the branch trace configuration for the current thread.
506 Qbtrace-conf:bts:size
507 Set the requested ring buffer size for branch tracing in BTS format.
510 Enable Intel Procesor Trace-based branch tracing for the current
511 process. The remote stub reports support for this packet to GDB's
515 Set the requested ring buffer size for branch tracing in Intel Processor
519 Indicates a memory breakpoint instruction was executed, irrespective
520 of whether it was GDB that planted the breakpoint or the breakpoint
521 is hardcoded in the program. This is required for correct non-stop
525 Indicates the target stopped for a hardware breakpoint. This is
526 required for correct non-stop mode operation.
529 Return information about files on the remote system.
532 Return the full absolute name of the file that was executed to
533 create a process running on the remote system.
536 Select the filesystem on which vFile: operations with filename
537 arguments will operate. This is required for GDB to be able to
538 access files on remote targets where the remote stub does not
539 share a common filesystem with the inferior(s).
542 Indicates that a fork system call was executed.
545 Indicates that a vfork system call was executed.
547 vforkdone stop reason
548 Indicates that a vfork child of the specified process has executed
549 an exec or exit, allowing the vfork parent to resume execution.
551 fork-events and vfork-events features in qSupported
552 The qSupported packet allows GDB to request support for fork and
553 vfork events using new 'gdbfeatures' fork-events and vfork-events,
554 and the qSupported response can contain the corresponding
555 'stubfeatures'. Set and show commands can be used to display
556 whether these features are enabled.
558 * Extended-remote fork events
560 ** GDB now has support for fork events on extended-remote Linux
561 targets. For targets with Linux kernels 2.5.60 and later, this
562 enables follow-fork-mode and detach-on-fork for both fork and
563 vfork, as well as fork and vfork catchpoints.
565 * The info record command now shows the recording format and the
566 branch tracing configuration for the current thread when using
567 the btrace record target.
568 For the BTS format, it shows the ring buffer size.
570 * GDB now has support for DTrace USDT (Userland Static Defined
571 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
573 * GDB now supports access to vector registers on S/390 GNU/Linux
576 * Removed command line options
578 -xdb HP-UX XDB compatibility mode.
580 * Removed targets and native configurations
582 HP/PA running HP-UX hppa*-*-hpux*
583 Itanium running HP-UX ia64-*-hpux*
585 * New configure options
588 This configure option allows the user to build GDB with support for
589 Intel Processor Trace (default: auto). This requires libipt.
591 --with-libipt-prefix=PATH
592 Specify the path to the version of libipt that GDB should use.
593 $PATH/include should contain the intel-pt.h header and
594 $PATH/lib should contain the libipt.so library.
596 *** Changes in GDB 7.9.1
600 ** Xmethods can now specify a result type.
602 *** Changes in GDB 7.9
604 * GDB now supports hardware watchpoints on x86 GNU Hurd.
608 ** You can now access frame registers from Python scripts.
609 ** New attribute 'producer' for gdb.Symtab objects.
610 ** gdb.Objfile objects have a new attribute "progspace",
611 which is the gdb.Progspace object of the containing program space.
612 ** gdb.Objfile objects have a new attribute "owner".
613 ** gdb.Objfile objects have a new attribute "build_id",
614 which is the build ID generated when the file was built.
615 ** gdb.Objfile objects have a new method "add_separate_debug_file".
616 ** A new event "gdb.clear_objfiles" has been added, triggered when
617 selecting a new file to debug.
618 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
619 ** New function gdb.lookup_objfile.
621 New events which are triggered when GDB modifies the state of the
624 ** gdb.events.inferior_call_pre: Function call is about to be made.
625 ** gdb.events.inferior_call_post: Function call has just been made.
626 ** gdb.events.memory_changed: A memory location has been altered.
627 ** gdb.events.register_changed: A register has been altered.
629 * New Python-based convenience functions:
631 ** $_caller_is(name [, number_of_frames])
632 ** $_caller_matches(regexp [, number_of_frames])
633 ** $_any_caller_is(name [, number_of_frames])
634 ** $_any_caller_matches(regexp [, number_of_frames])
636 * GDB now supports the compilation and injection of source code into
637 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
638 to compile the source code to object code, and if successful, inject
639 and execute that code within the current context of the inferior.
640 Currently the C language is supported. The commands used to
641 interface with this new feature are:
643 compile code [-raw|-r] [--] [source code]
644 compile file [-raw|-r] filename
648 demangle [-l language] [--] name
649 Demangle "name" in the specified language, or the current language
650 if elided. This command is renamed from the "maint demangle" command.
651 The latter is kept as a no-op to avoid "maint demangle" being interpreted
652 as "maint demangler-warning".
654 queue-signal signal-name-or-number
655 Queue a signal to be delivered to the thread when it is resumed.
657 add-auto-load-scripts-directory directory
658 Add entries to the list of directories from which to load auto-loaded
661 maint print user-registers
662 List all currently available "user" registers.
664 compile code [-r|-raw] [--] [source code]
665 Compile, inject, and execute in the inferior the executable object
666 code produced by compiling the provided source code.
668 compile file [-r|-raw] filename
669 Compile and inject into the inferior the executable object code
670 produced by compiling the source code stored in the filename
673 * On resume, GDB now always passes the signal the program had stopped
674 for to the thread the signal was sent to, even if the user changed
675 threads before resuming. Previously GDB would often (but not
676 always) deliver the signal to the thread that happens to be current
679 * Conversely, the "signal" command now consistently delivers the
680 requested signal to the current thread. GDB now asks for
681 confirmation if the program had stopped for a signal and the user
682 switched threads meanwhile.
684 * "breakpoint always-inserted" modes "off" and "auto" merged.
686 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
687 won't remove breakpoints from the target until all threads stop,
688 even in non-stop mode. The "auto" mode has been removed, and "off"
689 is now the default mode.
693 set debug symbol-lookup
694 show debug symbol-lookup
695 Control display of debugging info regarding symbol lookup.
699 ** The -list-thread-groups command outputs an exit-code field for
700 inferiors that have exited.
704 MIPS SDE mips*-sde*-elf*
708 Support for these obsolete configurations has been removed.
710 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
711 SGI Irix-5.x mips-*-irix5*
712 SGI Irix-6.x mips-*-irix6*
713 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
714 VAX running Ultrix vax-*-ultrix*
716 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
717 and "assf"), have been removed. Use the "sharedlibrary" command, or
718 its alias "share", instead.
720 *** Changes in GDB 7.8
722 * New command line options
725 This is an alias for the --data-directory option.
727 * GDB supports printing and modifying of variable length automatic arrays
728 as specified in ISO C99.
730 * The ARM simulator now supports instruction level tracing
731 with or without disassembly.
735 GDB now has support for scripting using Guile. Whether this is
736 available is determined at configure time.
737 Guile version 2.0 or greater is required.
738 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
740 * New commands (for set/show, see "New options" below)
744 Invoke CODE by passing it to the Guile interpreter.
748 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
750 info auto-load guile-scripts [regexp]
751 Print the list of automatically loaded Guile scripts.
753 * The source command is now capable of sourcing Guile scripts.
754 This feature is dependent on the debugger being built with Guile support.
758 set print symbol-loading (off|brief|full)
759 show print symbol-loading
760 Control whether to print informational messages when loading symbol
761 information for a file. The default is "full", but when debugging
762 programs with large numbers of shared libraries the amount of output
765 set guile print-stack (none|message|full)
766 show guile print-stack
767 Show a stack trace when an error is encountered in a Guile script.
769 set auto-load guile-scripts (on|off)
770 show auto-load guile-scripts
771 Control auto-loading of Guile script files.
773 maint ada set ignore-descriptive-types (on|off)
774 maint ada show ignore-descriptive-types
775 Control whether the debugger should ignore descriptive types in Ada
776 programs. The default is not to ignore the descriptive types. See
777 the user manual for more details on descriptive types and the intended
778 usage of this option.
780 set auto-connect-native-target
782 Control whether GDB is allowed to automatically connect to the
783 native target for the run, attach, etc. commands when not connected
784 to any target yet. See also "target native" below.
786 set record btrace replay-memory-access (read-only|read-write)
787 show record btrace replay-memory-access
788 Control what memory accesses are allowed during replay.
790 maint set target-async (on|off)
791 maint show target-async
792 This controls whether GDB targets operate in synchronous or
793 asynchronous mode. Normally the default is asynchronous, if it is
794 available; but this can be changed to more easily debug problems
795 occurring only in synchronous mode.
797 set mi-async (on|off)
799 Control whether MI asynchronous mode is preferred. This supersedes
800 "set target-async" of previous GDB versions.
802 * "set target-async" is deprecated as a CLI option and is now an alias
803 for "set mi-async" (only puts MI into async mode).
805 * Background execution commands (e.g., "c&", "s&", etc.) are now
806 possible ``out of the box'' if the target supports them. Previously
807 the user would need to explicitly enable the possibility with the
808 "set target-async on" command.
810 * New features in the GDB remote stub, GDBserver
812 ** New option --debug-format=option1[,option2,...] allows one to add
813 additional text to each output. At present only timestamps
814 are supported: --debug-format=timestamps.
815 Timestamps can also be turned on with the
816 "monitor set debug-format timestamps" command from GDB.
818 * The 'record instruction-history' command now starts counting instructions
819 at one. This also affects the instruction ranges reported by the
820 'record function-call-history' command when given the /i modifier.
822 * The command 'record function-call-history' supports a new modifier '/c' to
823 indent the function names based on their call stack depth.
824 The fields for the '/i' and '/l' modifier have been reordered.
825 The source line range is now prefixed with 'at'.
826 The instruction range is now prefixed with 'inst'.
827 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
828 "record instruction-history" and "list" commands.
830 * The ranges given as arguments to the 'record function-call-history' and
831 'record instruction-history' commands are now inclusive.
833 * The btrace record target now supports the 'record goto' command.
834 For locations inside the execution trace, the back trace is computed
835 based on the information stored in the execution trace.
837 * The btrace record target supports limited reverse execution and replay.
838 The target does not record data and therefore does not allow reading
841 * The "catch syscall" command now works on s390*-linux* targets.
843 * The "compare-sections" command is no longer specific to target
844 remote. It now works with all targets.
846 * All native targets are now consistently called "native".
847 Consequently, the "target child", "target GNU", "target djgpp",
848 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
849 commands have been replaced with "target native". The QNX/NTO port
850 leaves the "procfs" target in place and adds a "native" target for
851 consistency with other ports. The impact on users should be minimal
852 as these commands previously either throwed an error, or were
853 no-ops. The target's name is visible in the output of the following
854 commands: "help target", "info target", "info files", "maint print
857 * The "target native" command now connects to the native target. This
858 can be used to launch native programs even when "set
859 auto-connect-native-target" is set to off.
861 * GDB now supports access to Intel MPX registers on GNU/Linux.
863 * Support for Intel AVX-512 registers on GNU/Linux.
864 Support displaying and modifying Intel AVX-512 registers
865 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
869 qXfer:btrace:read's annex
870 The qXfer:btrace:read packet supports a new annex 'delta' to read
871 branch trace incrementally.
875 ** Valid Python operations on gdb.Value objects representing
876 structs/classes invoke the corresponding overloaded operators if
878 ** New `Xmethods' feature in the Python API. Xmethods are
879 additional methods or replacements for existing methods of a C++
880 class. This feature is useful for those cases where a method
881 defined in C++ source code could be inlined or optimized out by
882 the compiler, making it unavailable to GDB.
885 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
887 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
888 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
889 its alias "share", instead.
891 * The commands "set remotebaud" and "show remotebaud" are no longer
892 supported. Use "set serial baud" and "show serial baud" (respectively)
897 ** A new option "-gdb-set mi-async" replaces "-gdb-set
898 target-async". The latter is left as a deprecated alias of the
899 former for backward compatibility. If the target supports it,
900 CLI background execution commands are now always possible by
901 default, independently of whether the frontend stated a
902 preference for asynchronous execution with "-gdb-set mi-async".
903 Previously "-gdb-set target-async off" affected both MI execution
904 commands and CLI execution commands.
906 *** Changes in GDB 7.7
908 * Improved support for process record-replay and reverse debugging on
909 arm*-linux* targets. Support for thumb32 and syscall instruction
910 recording has been added.
912 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
914 * GDB now supports Fission DWP file format version 2.
915 http://gcc.gnu.org/wiki/DebugFission
917 * New convenience function "$_isvoid", to check whether an expression
918 is void. A void expression is an expression where the type of the
919 result is "void". For example, some convenience variables may be
920 "void" when evaluated (e.g., "$_exitcode" before the execution of
921 the program being debugged; or an undefined convenience variable).
922 Another example, when calling a function whose return type is
925 * The "maintenance print objfiles" command now takes an optional regexp.
927 * The "catch syscall" command now works on arm*-linux* targets.
929 * GDB now consistently shows "<not saved>" when printing values of
930 registers the debug info indicates have not been saved in the frame
931 and there's nowhere to retrieve them from
932 (callee-saved/call-clobbered registers):
937 (gdb) info registers rax
940 Before, the former would print "<optimized out>", and the latter
941 "*value not available*".
943 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
948 ** Frame filters and frame decorators have been added.
949 ** Temporary breakpoints are now supported.
950 ** Line tables representation has been added.
951 ** New attribute 'parent_type' for gdb.Field objects.
952 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
953 ** New attribute 'name' for gdb.Type objects.
957 Nios II ELF nios2*-*-elf
958 Nios II GNU/Linux nios2*-*-linux
959 Texas Instruments MSP430 msp430*-*-elf
961 * Removed native configurations
963 Support for these a.out NetBSD and OpenBSD obsolete configurations has
964 been removed. ELF variants of these configurations are kept supported.
966 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
967 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
968 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
969 i[34567]86-*-openbsd3.[0-3]
970 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
971 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
972 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
976 Like "catch throw", but catches a re-thrown exception.
978 Renamed from old "maint check-symtabs".
980 Perform consistency checks on symtabs.
982 Expand symtabs matching an optional regexp.
985 Display the details of GDB configure-time options.
987 maint set|show per-command
988 maint set|show per-command space
989 maint set|show per-command time
990 maint set|show per-command symtab
991 Enable display of per-command gdb resource usage.
993 remove-symbol-file FILENAME
994 remove-symbol-file -a ADDRESS
995 Remove a symbol file added via add-symbol-file. The file to remove
996 can be identified by its filename or by an address that lies within
997 the boundaries of this symbol file in memory.
1000 info exceptions REGEXP
1001 Display the list of Ada exceptions defined in the program being
1002 debugged. If provided, only the exceptions whose names match REGEXP
1007 set debug symfile off|on
1009 Control display of debugging info regarding reading symbol files and
1010 symbol tables within those files
1012 set print raw frame-arguments
1013 show print raw frame-arguments
1014 Set/show whether to print frame arguments in raw mode,
1015 disregarding any defined pretty-printers.
1017 set remote trace-status-packet
1018 show remote trace-status-packet
1019 Set/show the use of remote protocol qTStatus packet.
1023 Control display of debugging messages related to Nios II targets.
1027 Control whether target-assisted range stepping is enabled.
1029 set startup-with-shell
1030 show startup-with-shell
1031 Specifies whether Unix child processes are started via a shell or
1036 Use the target memory cache for accesses to the code segment. This
1037 improves performance of remote debugging (particularly disassembly).
1039 * You can now use a literal value 'unlimited' for options that
1040 interpret 0 or -1 as meaning "unlimited". E.g., "set
1041 trace-buffer-size unlimited" is now an alias for "set
1042 trace-buffer-size -1" and "set height unlimited" is now an alias for
1045 * The "set debug symtab-create" debugging option of GDB has been changed to
1046 accept a verbosity level. 0 means "off", 1 provides basic debugging
1047 output, and values of 2 or greater provides more verbose output.
1049 * New command-line options
1051 Display the details of GDB configure-time options.
1053 * The command 'tsave' can now support new option '-ctf' to save trace
1054 buffer in Common Trace Format.
1056 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1059 * GDB now implements the the C++ 'typeid' operator.
1061 * The new convenience variable $_exception holds the exception being
1062 thrown or caught at an exception-related catchpoint.
1064 * The exception-related catchpoints, like "catch throw", now accept a
1065 regular expression which can be used to filter exceptions by type.
1067 * The new convenience variable $_exitsignal is automatically set to
1068 the terminating signal number when the program being debugged dies
1069 due to an uncaught signal.
1073 ** All MI commands now accept an optional "--language" option.
1074 Support for this feature can be verified by using the "-list-features"
1075 command, which should contain "language-option".
1077 ** The new command -info-gdb-mi-command allows the user to determine
1078 whether a GDB/MI command is supported or not.
1080 ** The "^error" result record returned when trying to execute an undefined
1081 GDB/MI command now provides a variable named "code" whose content is the
1082 "undefined-command" error code. Support for this feature can be verified
1083 by using the "-list-features" command, which should contain
1084 "undefined-command-error-code".
1086 ** The -trace-save MI command can optionally save trace buffer in Common
1089 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1091 ** The command -data-list-register-values now accepts an optional
1092 "--skip-unavailable" option. When used, only the available registers
1095 ** The new command -trace-frame-collected dumps collected variables,
1096 computed expressions, tvars, memory and registers in a traceframe.
1098 ** The commands -stack-list-locals, -stack-list-arguments and
1099 -stack-list-variables now accept an option "--skip-unavailable".
1100 When used, only the available locals or arguments are displayed.
1102 ** The -exec-run command now accepts an optional "--start" option.
1103 When used, the command follows the same semantics as the "start"
1104 command, stopping the program's execution at the start of its
1105 main subprogram. Support for this feature can be verified using
1106 the "-list-features" command, which should contain
1107 "exec-run-start-option".
1109 ** The new commands -catch-assert and -catch-exceptions insert
1110 catchpoints stopping the program when Ada exceptions are raised.
1112 ** The new command -info-ada-exceptions provides the equivalent of
1113 the new "info exceptions" command.
1115 * New system-wide configuration scripts
1116 A GDB installation now provides scripts suitable for use as system-wide
1117 configuration scripts for the following systems:
1121 * GDB now supports target-assigned range stepping with remote targets.
1122 This improves the performance of stepping source lines by reducing
1123 the number of control packets from/to GDB. See "New remote packets"
1126 * GDB now understands the element 'tvar' in the XML traceframe info.
1127 It has the id of the collected trace state variables.
1129 * On S/390 targets that provide the transactional-execution feature,
1130 the program interruption transaction diagnostic block (TDB) is now
1131 represented as a number of additional "registers" in GDB.
1133 * New remote packets
1137 The vCont packet supports a new 'r' action, that tells the remote
1138 stub to step through an address range itself, without GDB
1139 involvemement at each single-step.
1141 qXfer:libraries-svr4:read's annex
1142 The previously unused annex of the qXfer:libraries-svr4:read packet
1143 is now used to support passing an argument list. The remote stub
1144 reports support for this argument list to GDB's qSupported query.
1145 The defined arguments are "start" and "prev", used to reduce work
1146 necessary for library list updating, resulting in significant
1149 * New features in the GDB remote stub, GDBserver
1151 ** GDBserver now supports target-assisted range stepping. Currently
1152 enabled on x86/x86_64 GNU/Linux targets.
1154 ** GDBserver now adds element 'tvar' in the XML in the reply to
1155 'qXfer:traceframe-info:read'. It has the id of the collected
1156 trace state variables.
1158 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1161 * New 'z' formatter for printing and examining memory, this displays the
1162 value as hexadecimal zero padded on the left to the size of the type.
1164 * GDB can now use Windows x64 unwinding data.
1166 * The "set remotebaud" command has been replaced by "set serial baud".
1167 Similarly, "show remotebaud" has been replaced by "show serial baud".
1168 The "set remotebaud" and "show remotebaud" commands are still available
1169 to provide backward compatibility with older versions of GDB.
1171 *** Changes in GDB 7.6
1173 * Target record has been renamed to record-full.
1174 Record/replay is now enabled with the "record full" command.
1175 This also affects settings that are associated with full record/replay
1176 that have been moved from "set/show record" to "set/show record full":
1178 set|show record full insn-number-max
1179 set|show record full stop-at-limit
1180 set|show record full memory-query
1182 * A new record target "record-btrace" has been added. The new target
1183 uses hardware support to record the control-flow of a process. It
1184 does not support replaying the execution, but it implements the
1185 below new commands for investigating the recorded execution log.
1186 This new recording method can be enabled using:
1190 The "record-btrace" target is only available on Intel Atom processors
1191 and requires a Linux kernel 2.6.32 or later.
1193 * Two new commands have been added for record/replay to give information
1194 about the recorded execution without having to replay the execution.
1195 The commands are only supported by "record btrace".
1197 record instruction-history prints the execution history at
1198 instruction granularity
1200 record function-call-history prints the execution history at
1201 function granularity
1203 * New native configurations
1205 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1206 FreeBSD/powerpc powerpc*-*-freebsd
1207 x86_64/Cygwin x86_64-*-cygwin*
1208 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1212 ARM AArch64 aarch64*-*-elf
1213 ARM AArch64 GNU/Linux aarch64*-*-linux
1214 Lynx 178 PowerPC powerpc-*-lynx*178
1215 x86_64/Cygwin x86_64-*-cygwin*
1216 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1218 * If the configured location of system.gdbinit file (as given by the
1219 --with-system-gdbinit option at configure time) is in the
1220 data-directory (as specified by --with-gdb-datadir at configure
1221 time) or in one of its subdirectories, then GDB will look for the
1222 system-wide init file in the directory specified by the
1223 --data-directory command-line option.
1225 * New command line options:
1227 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1228 other initialization files, unlike -nx which disables all of them.
1230 * Removed command line options
1232 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1235 * The 'ptype' and 'whatis' commands now accept an argument to control
1238 * 'info proc' now works on some core files.
1242 ** Vectors can be created with gdb.Type.vector.
1244 ** Python's atexit.register now works in GDB.
1246 ** Types can be pretty-printed via a Python API.
1248 ** Python 3 is now supported (in addition to Python 2.4 or later)
1250 ** New class gdb.Architecture exposes GDB's internal representation
1251 of architecture in the Python API.
1253 ** New method Frame.architecture returns the gdb.Architecture object
1254 corresponding to the frame's architecture.
1256 * New Python-based convenience functions:
1258 ** $_memeq(buf1, buf2, length)
1259 ** $_streq(str1, str2)
1261 ** $_regex(str, regex)
1263 * The 'cd' command now defaults to using '~' (the home directory) if not
1266 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1267 default for GCC since November 2000.
1269 * The command 'forward-search' can now be abbreviated as 'fo'.
1271 * The command 'info tracepoints' can now display 'installed on target'
1272 or 'not installed on target' for each non-pending location of tracepoint.
1274 * New configure options
1276 --enable-libmcheck/--disable-libmcheck
1277 By default, development versions are built with -lmcheck on hosts
1278 that support it, in order to help track memory corruption issues.
1279 Release versions, on the other hand, are built without -lmcheck
1280 by default. The --enable-libmcheck/--disable-libmcheck configure
1281 options allow the user to override that default.
1282 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1283 This configure option allows the user to build GDB with
1284 libbabeltrace using which GDB can read Common Trace Format data.
1286 * New commands (for set/show, see "New options" below)
1289 Catch signals. This is similar to "handle", but allows commands and
1290 conditions to be attached.
1293 List the BFDs known to GDB.
1295 python-interactive [command]
1297 Start a Python interactive prompt, or evaluate the optional command
1298 and print the result of expressions.
1301 "py" is a new alias for "python".
1303 enable type-printer [name]...
1304 disable type-printer [name]...
1305 Enable or disable type printers.
1309 ** For the Renesas Super-H architecture, the "regs" command has been removed
1310 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1315 set print type methods (on|off)
1316 show print type methods
1317 Control whether method declarations are displayed by "ptype".
1318 The default is to show them.
1320 set print type typedefs (on|off)
1321 show print type typedefs
1322 Control whether typedef definitions are displayed by "ptype".
1323 The default is to show them.
1325 set filename-display basename|relative|absolute
1326 show filename-display
1327 Control the way in which filenames is displayed.
1328 The default is "relative", which preserves previous behavior.
1330 set trace-buffer-size
1331 show trace-buffer-size
1332 Request target to change the size of trace buffer.
1334 set remote trace-buffer-size-packet auto|on|off
1335 show remote trace-buffer-size-packet
1336 Control the use of the remote protocol `QTBuffer:size' packet.
1340 Control display of debugging messages related to ARM AArch64.
1343 set debug coff-pe-read
1344 show debug coff-pe-read
1345 Control display of debugging messages related to reading of COFF/PE
1350 Control display of debugging messages related to Mach-O symbols
1353 set debug notification
1354 show debug notification
1355 Control display of debugging info for async remote notification.
1359 ** Command parameter changes are now notified using new async record
1360 "=cmd-param-changed".
1361 ** Trace frame changes caused by command "tfind" are now notified using
1362 new async record "=traceframe-changed".
1363 ** The creation, deletion and modification of trace state variables
1364 are now notified using new async records "=tsv-created",
1365 "=tsv-deleted" and "=tsv-modified".
1366 ** The start and stop of process record are now notified using new
1367 async record "=record-started" and "=record-stopped".
1368 ** Memory changes are now notified using new async record
1370 ** The data-disassemble command response will include a "fullname" field
1371 containing the absolute file name when source has been requested.
1372 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1373 command, to allow pattern filling of memory areas.
1374 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1375 library load/unload events.
1376 ** The response to breakpoint commands and breakpoint async records
1377 includes an "installed" field containing a boolean state about each
1378 non-pending tracepoint location is whether installed on target or not.
1379 ** Output of the "-trace-status" command includes a "trace-file" field
1380 containing the name of the trace file being examined. This field is
1381 optional, and only present when examining a trace file.
1382 ** The "fullname" field is now always present along with the "file" field,
1383 even if the file cannot be found by GDB.
1385 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1386 You must have the LZMA library available when configuring GDB for this
1387 feature to be enabled. For more information, see:
1388 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1390 * New remote packets
1393 Set the size of trace buffer. The remote stub reports support for this
1394 packet to gdb's qSupported query.
1397 Enable Branch Trace Store (BTS)-based branch tracing for the current
1398 thread. The remote stub reports support for this packet to gdb's
1402 Disable branch tracing for the current thread. The remote stub reports
1403 support for this packet to gdb's qSupported query.
1406 Read the traced branches for the current thread. The remote stub
1407 reports support for this packet to gdb's qSupported query.
1409 *** Changes in GDB 7.5
1411 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1412 for more x32 ABI info.
1414 * GDB now supports access to MIPS DSP registers on Linux targets.
1416 * GDB now supports debugging microMIPS binaries.
1418 * The "info os" command on GNU/Linux can now display information on
1419 several new classes of objects managed by the operating system:
1420 "info os procgroups" lists process groups
1421 "info os files" lists file descriptors
1422 "info os sockets" lists internet-domain sockets
1423 "info os shm" lists shared-memory regions
1424 "info os semaphores" lists semaphores
1425 "info os msg" lists message queues
1426 "info os modules" lists loaded kernel modules
1428 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1429 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1430 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1431 options and inspect the probe arguments using the new $_probe_arg family
1432 of convenience variables. You can obtain more information about SystemTap
1433 in <http://sourceware.org/systemtap/>.
1435 * GDB now supports reversible debugging on ARM, it allows you to
1436 debug basic ARM and THUMB instructions, and provides
1437 record/replay support.
1439 * The option "symbol-reloading" has been deleted as it is no longer used.
1443 ** GDB commands implemented in Python can now be put in command class
1446 ** The "maint set python print-stack on|off" is now deleted.
1448 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1449 apply "flag enum"-style pretty-printing to any enum.
1451 ** gdb.lookup_symbol can now work when there is no current frame.
1453 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1454 the source at which the symbol was defined.
1456 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1457 method 'value'. The former indicates whether the symbol needs a
1458 frame in order to compute its value, and the latter computes the
1461 ** A new method 'referenced_value' on gdb.Value objects which can
1462 dereference pointer as well as C++ reference values.
1464 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1465 which return the global and static blocks (as gdb.Block objects),
1466 of the underlying symbol table, respectively.
1468 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1469 object associated with a PC value.
1471 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1472 of the address range occupied by code for the current source line.
1474 * Go language support.
1475 GDB now supports debugging programs written in the Go programming
1478 * GDBserver now supports stdio connections.
1479 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1481 * The binary "gdbtui" can no longer be built or installed.
1482 Use "gdb -tui" instead.
1484 * GDB will now print "flag" enums specially. A flag enum is one where
1485 all the enumerator values have no bits in common when pairwise
1486 "and"ed. When printing a value whose type is a flag enum, GDB will
1487 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1488 (gdb) print (enum E) 3
1491 * The filename part of a linespec will now match trailing components
1492 of a source file name. For example, "break gcc/expr.c:1000" will
1493 now set a breakpoint in build/gcc/expr.c, but not
1494 build/libcpp/expr.c.
1496 * The "info proc" and "generate-core-file" commands will now also
1497 work on remote targets connected to GDBserver on Linux.
1499 * The command "info catch" has been removed. It has been disabled
1500 since December 2007.
1502 * The "catch exception" and "catch assert" commands now accept
1503 a condition at the end of the command, much like the "break"
1504 command does. For instance:
1506 (gdb) catch exception Constraint_Error if Barrier = True
1508 Previously, it was possible to add a condition to such catchpoints,
1509 but it had to be done as a second step, after the catchpoint had been
1510 created, using the "condition" command.
1512 * The "info static-tracepoint-marker" command will now also work on
1513 native Linux targets with in-process agent.
1515 * GDB can now set breakpoints on inlined functions.
1517 * The .gdb_index section has been updated to include symbols for
1518 inlined functions. GDB will ignore older .gdb_index sections by
1519 default, which could cause symbol files to be loaded more slowly
1520 until their .gdb_index sections can be recreated. The new command
1521 "set use-deprecated-index-sections on" will cause GDB to use any older
1522 .gdb_index sections it finds. This will restore performance, but the
1523 ability to set breakpoints on inlined functions will be lost in symbol
1524 files with older .gdb_index sections.
1526 The .gdb_index section has also been updated to record more information
1527 about each symbol. This speeds up the "info variables", "info functions"
1528 and "info types" commands when used with programs having the .gdb_index
1529 section, as well as speeding up debugging with shared libraries using
1530 the .gdb_index section.
1532 * Ada support for GDB/MI Variable Objects has been added.
1534 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1539 ** New command -info-os is the MI equivalent of "info os".
1541 ** Output logs ("set logging" and related) now include MI output.
1545 ** "set use-deprecated-index-sections on|off"
1546 "show use-deprecated-index-sections on|off"
1547 Controls the use of deprecated .gdb_index sections.
1549 ** "catch load" and "catch unload" can be used to stop when a shared
1550 library is loaded or unloaded, respectively.
1552 ** "enable count" can be used to auto-disable a breakpoint after
1555 ** "info vtbl" can be used to show the virtual method tables for
1556 C++ and Java objects.
1558 ** "explore" and its sub commands "explore value" and "explore type"
1559 can be used to recursively explore values and types of
1560 expressions. These commands are available only if GDB is
1561 configured with '--with-python'.
1563 ** "info auto-load" shows status of all kinds of auto-loaded files,
1564 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1565 sequences of commands files, "info auto-load python-scripts"
1566 shows status of auto-loading Python script files,
1567 "info auto-load local-gdbinit" shows status of loading init file
1568 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1569 status of inferior specific thread debugging shared library loading.
1571 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1572 and "show auto-load-scripts" commands have been deprecated, use their
1573 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1574 and "show auto-load python-scripts" counterparts instead.
1576 ** "dprintf location,format,args..." creates a dynamic printf, which
1577 is basically a breakpoint that does a printf and immediately
1578 resumes your program's execution, so it is like a printf that you
1579 can insert dynamically at runtime instead of at compiletime.
1581 ** "set print symbol"
1583 Controls whether GDB attempts to display the symbol, if any,
1584 corresponding to addresses it prints. This defaults to "on", but
1585 you can set it to "off" to restore GDB's previous behavior.
1587 * Deprecated commands
1589 ** For the Renesas Super-H architecture, the "regs" command has been
1590 deprecated, and "info all-registers" should be used instead.
1594 Renesas RL78 rl78-*-elf
1595 HP OpenVMS ia64 ia64-hp-openvms*
1597 * GDBserver supports evaluation of breakpoint conditions. When
1598 support is advertised by GDBserver, GDB may be told to send the
1599 breakpoint conditions in bytecode form to GDBserver. GDBserver
1600 will only report the breakpoint trigger to GDB when its condition
1605 set mips compression
1606 show mips compression
1607 Select the compressed ISA encoding used in functions that have no symbol
1608 information available. The encoding can be set to either of:
1611 and is updated automatically from ELF file flags if available.
1613 set breakpoint condition-evaluation
1614 show breakpoint condition-evaluation
1615 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1616 GDBserver ("target"). Default option "auto" chooses the most efficient
1618 This option can improve debugger efficiency depending on the speed of the
1622 Disable auto-loading globally.
1625 Show auto-loading setting of all kinds of auto-loaded files.
1627 set auto-load gdb-scripts on|off
1628 show auto-load gdb-scripts
1629 Control auto-loading of GDB canned sequences of commands files.
1631 set auto-load python-scripts on|off
1632 show auto-load python-scripts
1633 Control auto-loading of Python script files.
1635 set auto-load local-gdbinit on|off
1636 show auto-load local-gdbinit
1637 Control loading of init file (.gdbinit) from current directory.
1639 set auto-load libthread-db on|off
1640 show auto-load libthread-db
1641 Control auto-loading of inferior specific thread debugging shared library.
1643 set auto-load scripts-directory <dir1>[:<dir2>...]
1644 show auto-load scripts-directory
1645 Set a list of directories from which to load auto-loaded scripts.
1646 Automatically loaded Python scripts and GDB scripts are located in one
1647 of the directories listed by this option.
1648 The delimiter (':' above) may differ according to the host platform.
1650 set auto-load safe-path <dir1>[:<dir2>...]
1651 show auto-load safe-path
1652 Set a list of directories from which it is safe to auto-load files.
1653 The delimiter (':' above) may differ according to the host platform.
1655 set debug auto-load on|off
1656 show debug auto-load
1657 Control display of debugging info for auto-loading the files above.
1659 set dprintf-style gdb|call|agent
1661 Control the way in which a dynamic printf is performed; "gdb"
1662 requests a GDB printf command, while "call" causes dprintf to call a
1663 function in the inferior. "agent" requests that the target agent
1664 (such as GDBserver) do the printing.
1666 set dprintf-function <expr>
1667 show dprintf-function
1668 set dprintf-channel <expr>
1669 show dprintf-channel
1670 Set the function and optional first argument to the call when using
1671 the "call" style of dynamic printf.
1673 set disconnected-dprintf on|off
1674 show disconnected-dprintf
1675 Control whether agent-style dynamic printfs continue to be in effect
1676 after GDB disconnects.
1678 * New configure options
1680 --with-auto-load-dir
1681 Configure default value for the 'set auto-load scripts-directory'
1682 setting above. It defaults to '$debugdir:$datadir/auto-load',
1683 $debugdir representing global debugging info directories (available
1684 via 'show debug-file-directory') and $datadir representing GDB's data
1685 directory (available via 'show data-directory').
1687 --with-auto-load-safe-path
1688 Configure default value for the 'set auto-load safe-path' setting
1689 above. It defaults to the --with-auto-load-dir setting.
1691 --without-auto-load-safe-path
1692 Set 'set auto-load safe-path' to '/', effectively disabling this
1695 * New remote packets
1697 z0/z1 conditional breakpoints extension
1699 The z0/z1 breakpoint insertion packets have been extended to carry
1700 a list of conditional expressions over to the remote stub depending on the
1701 condition evaluation mode. The use of this extension can be controlled
1702 via the "set remote conditional-breakpoints-packet" command.
1706 Specify the signals which the remote stub may pass to the debugged
1707 program without GDB involvement.
1709 * New command line options
1711 --init-command=FILE, -ix Like --command, -x but execute it
1712 before loading inferior.
1713 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1714 execute it before loading inferior.
1716 *** Changes in GDB 7.4
1718 * GDB now handles ambiguous linespecs more consistently; the existing
1719 FILE:LINE support has been expanded to other types of linespecs. A
1720 breakpoint will now be set on all matching locations in all
1721 inferiors, and locations will be added or removed according to
1724 * GDB now allows you to skip uninteresting functions and files when
1725 stepping with the "skip function" and "skip file" commands.
1727 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1728 and "show remote hardware-watchpoint-length-limit". These allows to
1729 set or show the maximum length limit (in bytes) of a remote
1730 target hardware watchpoint.
1732 This allows e.g. to use "unlimited" hardware watchpoints with the
1733 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1734 watchpoints are slower than real hardware watchpoints but are
1735 significantly faster than gdb software watchpoints.
1739 ** The register_pretty_printer function in module gdb.printing now takes
1740 an optional `replace' argument. If True, the new printer replaces any
1743 ** The "maint set python print-stack on|off" command has been
1744 deprecated and will be deleted in GDB 7.5.
1745 A new command: "set python print-stack none|full|message" has
1746 replaced it. Additionally, the default for "print-stack" is
1747 now "message", which just prints the error message without
1750 ** A prompt substitution hook (prompt_hook) is now available to the
1753 ** A new Python module, gdb.prompt has been added to the GDB Python
1754 modules library. This module provides functionality for
1755 escape sequences in prompts (used by set/show
1756 extended-prompt). These escape sequences are replaced by their
1757 corresponding value.
1759 ** Python commands and convenience-functions located in
1760 'data-directory'/python/gdb/command and
1761 'data-directory'/python/gdb/function are now automatically loaded
1764 ** Blocks now provide four new attributes. global_block and
1765 static_block will return the global and static blocks
1766 respectively. is_static and is_global are boolean attributes
1767 that indicate if the block is one of those two types.
1769 ** Symbols now provide the "type" attribute, the type of the symbol.
1771 ** The "gdb.breakpoint" function has been deprecated in favor of
1774 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1775 of a function. This class is based on the "finish" command
1776 available in the CLI.
1778 ** Type objects for struct and union types now allow access to
1779 the fields using standard Python dictionary (mapping) methods.
1780 For example, "some_type['myfield']" now works, as does
1781 "some_type.items()".
1783 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1786 ** A new function, "deep_items" has been added to the gdb.types
1787 module in the GDB Python modules library. This function returns
1788 an iterator over the fields of a struct or union type. Unlike
1789 the standard Python "iteritems" method, it will recursively traverse
1790 any anonymous fields.
1794 ** "*stopped" events can report several new "reason"s, such as
1797 ** Breakpoint changes are now notified using new async records, like
1798 "=breakpoint-modified".
1800 ** New command -ada-task-info.
1802 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1803 $sdir specifies the default system locations of shared libraries.
1804 $pdir specifies the directory where the libpthread used by the application
1807 GDB no longer looks in $sdir and $pdir after it has searched the directories
1808 mentioned in libthread-db-search-path. If you want to search those
1809 directories, they must be specified in libthread-db-search-path.
1810 The default value of libthread-db-search-path on GNU/Linux and Solaris
1811 systems is now "$sdir:$pdir".
1813 $pdir is not supported by gdbserver, it is currently ignored.
1814 $sdir is supported by gdbserver.
1816 * New configure option --with-iconv-bin.
1817 When using the internationalization support like the one in the GNU C
1818 library, GDB will invoke the "iconv" program to get a list of supported
1819 character sets. If this program lives in a non-standard location, one can
1820 use this option to specify where to find it.
1822 * When natively debugging programs on PowerPC BookE processors running
1823 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1824 watchpoints, which specify a mask in addition to an address to watch.
1825 The mask specifies that some bits of an address (the bits which are
1826 reset in the mask) should be ignored when matching the address accessed
1827 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1828 section in the user manual for more details.
1830 * The new option --once causes GDBserver to stop listening for connections once
1831 the first connection is made. The listening port used by GDBserver will
1832 become available after that.
1834 * New commands "info macros" and "alias" have been added.
1836 * New function parameters suffix @entry specifies value of function parameter
1837 at the time the function got called. Entry values are available only since
1843 "!" is now an alias of the "shell" command.
1844 Note that no space is needed between "!" and SHELL COMMAND.
1848 watch EXPRESSION mask MASK_VALUE
1849 The watch command now supports the mask argument which allows creation
1850 of masked watchpoints, if the current architecture supports this feature.
1852 info auto-load-scripts [REGEXP]
1853 This command was formerly named "maintenance print section-scripts".
1854 It is now generally useful and is no longer a maintenance-only command.
1856 info macro [-all] [--] MACRO
1857 The info macro command has new options `-all' and `--'. The first for
1858 printing all definitions of a macro. The second for explicitly specifying
1859 the end of arguments and the beginning of the macro name in case the macro
1860 name starts with a hyphen.
1862 collect[/s] EXPRESSIONS
1863 The tracepoint collect command now takes an optional modifier "/s"
1864 that directs it to dereference pointer-to-character types and
1865 collect the bytes of memory up to a zero byte. The behavior is
1866 similar to what you see when you use the regular print command on a
1867 string. An optional integer following the "/s" sets a bound on the
1868 number of bytes that will be collected.
1871 The trace start command now interprets any supplied arguments as a
1872 note to be recorded with the trace run, with an effect similar to
1873 setting the variable trace-notes.
1876 The trace stop command now interprets any arguments as a note to be
1877 mentioned along with the tstatus report that the trace was stopped
1878 with a command. The effect is similar to setting the variable
1881 * Tracepoints can now be enabled and disabled at any time after a trace
1882 experiment has been started using the standard "enable" and "disable"
1883 commands. It is now possible to start a trace experiment with no enabled
1884 tracepoints; GDB will display a warning, but will allow the experiment to
1885 begin, assuming that tracepoints will be enabled as needed while the trace
1888 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1889 locations with 4-byte instructions, when they were previously
1890 limited to locations with instructions of 5 bytes or longer.
1894 set debug dwarf2-read
1895 show debug dwarf2-read
1896 Turns on or off display of debugging messages related to reading
1897 DWARF debug info. The default is off.
1899 set debug symtab-create
1900 show debug symtab-create
1901 Turns on or off display of debugging messages related to symbol table
1902 creation. The default is off.
1905 show extended-prompt
1906 Set the GDB prompt, and allow escape sequences to be inserted to
1907 display miscellaneous information (see 'help set extended-prompt'
1908 for the list of sequences). This prompt (and any information
1909 accessed through the escape sequences) is updated every time the
1910 prompt is displayed.
1912 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1913 show print entry-values
1914 Set printing of frame argument values at function entry. In some cases
1915 GDB can determine the value of function argument which was passed by the
1916 function caller, even if the value was modified inside the called function.
1918 set debug entry-values
1919 show debug entry-values
1920 Control display of debugging info for determining frame argument values at
1921 function entry and virtual tail call frames.
1923 set basenames-may-differ
1924 show basenames-may-differ
1925 Set whether a source file may have multiple base names.
1926 (A "base name" is the name of a file with the directory part removed.
1927 Example: The base name of "/home/user/hello.c" is "hello.c".)
1928 If set, GDB will canonicalize file names (e.g., expand symlinks)
1929 before comparing them. Canonicalization is an expensive operation,
1930 but it allows the same file be known by more than one base name.
1931 If not set (the default), all source files are assumed to have just
1932 one base name, and gdb will do file name comparisons more efficiently.
1938 Set a user name and notes for the current and any future trace runs.
1939 This is useful for long-running and/or disconnected traces, to
1940 inform others (or yourself) as to who is running the trace, supply
1941 contact information, or otherwise explain what is going on.
1943 set trace-stop-notes
1944 show trace-stop-notes
1945 Set a note attached to the trace run, that is displayed when the
1946 trace has been stopped by a tstop command. This is useful for
1947 instance as an explanation, if you are stopping a trace run that was
1948 started by someone else.
1950 * New remote packets
1954 Dynamically enable a tracepoint in a started trace experiment.
1958 Dynamically disable a tracepoint in a started trace experiment.
1962 Set the user and notes of the trace run.
1966 Query the current status of a tracepoint.
1970 Query the minimum length of instruction at which a fast tracepoint may
1973 * Dcache size (number of lines) and line-size are now runtime-configurable
1974 via "set dcache line" and "set dcache line-size" commands.
1978 Texas Instruments TMS320C6x tic6x-*-*
1982 Renesas RL78 rl78-*-elf
1984 *** Changes in GDB 7.3.1
1986 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1988 *** Changes in GDB 7.3
1990 * GDB has a new command: "thread find [REGEXP]".
1991 It finds the thread id whose name, target id, or thread extra info
1992 matches the given regular expression.
1994 * The "catch syscall" command now works on mips*-linux* targets.
1996 * The -data-disassemble MI command now supports modes 2 and 3 for
1997 dumping the instruction opcodes.
1999 * New command line options
2001 -data-directory DIR Specify DIR as the "data-directory".
2002 This is mostly for testing purposes.
2004 * The "maint set python auto-load on|off" command has been renamed to
2005 "set auto-load-scripts on|off".
2007 * GDB has a new command: "set directories".
2008 It is like the "dir" command except that it replaces the
2009 source path list instead of augmenting it.
2011 * GDB now understands thread names.
2013 On GNU/Linux, "info threads" will display the thread name as set by
2014 prctl or pthread_setname_np.
2016 There is also a new command, "thread name", which can be used to
2017 assign a name internally for GDB to display.
2020 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2021 has been integrated into GDB.
2025 ** The function gdb.Write now accepts an optional keyword 'stream'.
2026 This keyword, when provided, will direct the output to either
2027 stdout, stderr, or GDB's logging output.
2029 ** Parameters can now be be sub-classed in Python, and in particular
2030 you may implement the get_set_doc and get_show_doc functions.
2031 This improves how Parameter set/show documentation is processed
2032 and allows for more dynamic content.
2034 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2035 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2036 have an is_valid method.
2038 ** Breakpoints can now be sub-classed in Python, and in particular
2039 you may implement a 'stop' function that is executed each time
2040 the inferior reaches that breakpoint.
2042 ** New function gdb.lookup_global_symbol looks up a global symbol.
2044 ** GDB values in Python are now callable if the value represents a
2045 function. For example, if 'some_value' represents a function that
2046 takes two integer parameters and returns a value, you can call
2047 that function like so:
2049 result = some_value (10,20)
2051 ** Module gdb.types has been added.
2052 It contains a collection of utilities for working with gdb.Types objects:
2053 get_basic_type, has_field, make_enum_dict.
2055 ** Module gdb.printing has been added.
2056 It contains utilities for writing and registering pretty-printers.
2057 New classes: PrettyPrinter, SubPrettyPrinter,
2058 RegexpCollectionPrettyPrinter.
2059 New function: register_pretty_printer.
2061 ** New commands "info pretty-printers", "enable pretty-printer" and
2062 "disable pretty-printer" have been added.
2064 ** gdb.parameter("directories") is now available.
2066 ** New function gdb.newest_frame returns the newest frame in the
2069 ** The gdb.InferiorThread class has a new "name" attribute. This
2070 holds the thread's name.
2072 ** Python Support for Inferior events.
2073 Python scripts can add observers to be notified of events
2074 occurring in the process being debugged.
2075 The following events are currently supported:
2076 - gdb.events.cont Continue event.
2077 - gdb.events.exited Inferior exited event.
2078 - gdb.events.stop Signal received, and Breakpoint hit events.
2082 ** GDB now puts template parameters in scope when debugging in an
2083 instantiation. For example, if you have:
2085 template<int X> int func (void) { return X; }
2087 then if you step into func<5>, "print X" will show "5". This
2088 feature requires proper debuginfo support from the compiler; it
2089 was added to GCC 4.5.
2091 ** The motion commands "next", "finish", "until", and "advance" now
2092 work better when exceptions are thrown. In particular, GDB will
2093 no longer lose control of the inferior; instead, the GDB will
2094 stop the inferior at the point at which the exception is caught.
2095 This functionality requires a change in the exception handling
2096 code that was introduced in GCC 4.5.
2098 * GDB now follows GCC's rules on accessing volatile objects when
2099 reading or writing target state during expression evaluation.
2100 One notable difference to prior behavior is that "print x = 0"
2101 no longer generates a read of x; the value of the assignment is
2102 now always taken directly from the value being assigned.
2104 * GDB now has some support for using labels in the program's source in
2105 linespecs. For instance, you can use "advance label" to continue
2106 execution to a label.
2108 * GDB now has support for reading and writing a new .gdb_index
2109 section. This section holds a fast index of DWARF debugging
2110 information and can be used to greatly speed up GDB startup and
2111 operation. See the documentation for `save gdb-index' for details.
2113 * The "watch" command now accepts an optional "-location" argument.
2114 When used, this causes GDB to watch the memory referred to by the
2115 expression. Such a watchpoint is never deleted due to it going out
2118 * GDB now supports thread debugging of core dumps on GNU/Linux.
2120 GDB now activates thread debugging using the libthread_db library
2121 when debugging GNU/Linux core dumps, similarly to when debugging
2122 live processes. As a result, when debugging a core dump file, GDB
2123 is now able to display pthread_t ids of threads. For example, "info
2124 threads" shows the same output as when debugging the process when it
2125 was live. In earlier releases, you'd see something like this:
2128 * 1 LWP 6780 main () at main.c:10
2130 While now you see this:
2133 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2135 It is also now possible to inspect TLS variables when debugging core
2138 When debugging a core dump generated on a machine other than the one
2139 used to run GDB, you may need to point GDB at the correct
2140 libthread_db library with the "set libthread-db-search-path"
2141 command. See the user manual for more details on this command.
2143 * When natively debugging programs on PowerPC BookE processors running
2144 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2145 which stop execution of the inferior whenever it executes an instruction
2146 at any address within the specified range. See the "PowerPC Embedded"
2147 section in the user manual for more details.
2149 * New features in the GDB remote stub, GDBserver
2151 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2152 and i686 LynxOS (version 5.x).
2154 ** GDBserver is now supported on Blackfin Linux.
2156 * New native configurations
2158 ia64 HP-UX ia64-*-hpux*
2162 Analog Devices, Inc. Blackfin Processor bfin-*
2164 * Ada task switching is now supported on sparc-elf targets when
2165 debugging a program using the Ravenscar Profile. For more information,
2166 see the "Tasking Support when using the Ravenscar Profile" section
2167 in the GDB user manual.
2169 * Guile support was removed.
2171 * New features in the GNU simulator
2173 ** The --map-info flag lists all known core mappings.
2175 ** CFI flashes may be simulated via the "cfi" device.
2177 *** Changes in GDB 7.2
2179 * Shared library support for remote targets by default
2181 When GDB is configured for a generic, non-OS specific target, like
2182 for example, --target=arm-eabi or one of the many *-*-elf targets,
2183 GDB now queries remote stubs for loaded shared libraries using the
2184 `qXfer:libraries:read' packet. Previously, shared library support
2185 was always disabled for such configurations.
2189 ** Argument Dependent Lookup (ADL)
2191 In C++ ADL lookup directs function search to the namespaces of its
2192 arguments even if the namespace has not been imported.
2202 Here the compiler will search for `foo' in the namespace of 'b'
2203 and find A::foo. GDB now supports this. This construct is commonly
2204 used in the Standard Template Library for operators.
2206 ** Improved User Defined Operator Support
2208 In addition to member operators, GDB now supports lookup of operators
2209 defined in a namespace and imported with a `using' directive, operators
2210 defined in the global scope, operators imported implicitly from an
2211 anonymous namespace, and the ADL operators mentioned in the previous
2213 GDB now also supports proper overload resolution for all the previously
2214 mentioned flavors of operators.
2216 ** static const class members
2218 Printing of static const class members that are initialized in the
2219 class definition has been fixed.
2221 * Windows Thread Information Block access.
2223 On Windows targets, GDB now supports displaying the Windows Thread
2224 Information Block (TIB) structure. This structure is visible either
2225 by using the new command `info w32 thread-information-block' or, by
2226 dereferencing the new convenience variable named `$_tlb', a
2227 thread-specific pointer to the TIB. This feature is also supported
2228 when remote debugging using GDBserver.
2230 * Static tracepoints
2232 Static tracepoints are calls in the user program into a tracing
2233 library. One such library is a port of the LTTng kernel tracer to
2234 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2235 When debugging with GDBserver, GDB now supports combining the GDB
2236 tracepoint machinery with such libraries. For example: the user can
2237 use GDB to probe a static tracepoint marker (a call from the user
2238 program into the tracing library) with the new "strace" command (see
2239 "New commands" below). This creates a "static tracepoint" in the
2240 breakpoint list, that can be manipulated with the same feature set
2241 as fast and regular tracepoints. E.g., collect registers, local and
2242 global variables, collect trace state variables, and define
2243 tracepoint conditions. In addition, the user can collect extra
2244 static tracepoint marker specific data, by collecting the new
2245 $_sdata internal variable. When analyzing the trace buffer, you can
2246 inspect $_sdata like any other variable available to GDB. For more
2247 information, see the "Tracepoints" chapter in GDB user manual. New
2248 remote packets have been defined to support static tracepoints, see
2249 the "New remote packets" section below.
2251 * Better reconstruction of tracepoints after disconnected tracing
2253 GDB will attempt to download the original source form of tracepoint
2254 definitions when starting a trace run, and then will upload these
2255 upon reconnection to the target, resulting in a more accurate
2256 reconstruction of the tracepoints that are in use on the target.
2260 You can now exercise direct control over the ways that GDB can
2261 affect your program. For instance, you can disallow the setting of
2262 breakpoints, so that the program can run continuously (assuming
2263 non-stop mode). In addition, the "observer" variable is available
2264 to switch all of the different controls; in observer mode, GDB
2265 cannot affect the target's behavior at all, which is useful for
2266 tasks like diagnosing live systems in the field.
2268 * The new convenience variable $_thread holds the number of the
2271 * New remote packets
2275 Return the address of the Windows Thread Information Block of a given thread.
2279 In response to several of the tracepoint packets, the target may now
2280 also respond with a number of intermediate `qRelocInsn' request
2281 packets before the final result packet, to have GDB handle
2282 relocating an instruction to execute at a different address. This
2283 is particularly useful for stubs that support fast tracepoints. GDB
2284 reports support for this feature in the qSupported packet.
2288 List static tracepoint markers in the target program.
2292 List static tracepoint markers at a given address in the target
2295 qXfer:statictrace:read
2297 Read the static trace data collected (by a `collect $_sdata'
2298 tracepoint action). The remote stub reports support for this packet
2299 to gdb's qSupported query.
2303 Send the current settings of GDB's permission flags.
2307 Send part of the source (textual) form of a tracepoint definition,
2308 which includes location, conditional, and action list.
2310 * The source command now accepts a -s option to force searching for the
2311 script in the source search path even if the script name specifies
2314 * New features in the GDB remote stub, GDBserver
2316 - GDBserver now support tracepoints (including fast tracepoints, and
2317 static tracepoints). The feature is currently supported by the
2318 i386-linux and amd64-linux builds. See the "Tracepoints support
2319 in gdbserver" section in the manual for more information.
2321 GDBserver JIT compiles the tracepoint's conditional agent
2322 expression bytecode into native code whenever possible for low
2323 overhead dynamic tracepoints conditionals. For such tracepoints,
2324 an expression that examines program state is evaluated when the
2325 tracepoint is reached, in order to determine whether to capture
2326 trace data. If the condition is simple and false, processing the
2327 tracepoint finishes very quickly and no data is gathered.
2329 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2330 for static tracepoints support.
2332 - GDBserver now supports x86_64 Windows 64-bit debugging.
2334 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2335 it understands register description.
2337 * The --batch flag now disables pagination and queries.
2339 * X86 general purpose registers
2341 GDB now supports reading/writing byte, word and double-word x86
2342 general purpose registers directly. This means you can use, say,
2343 $ah or $ax to refer, respectively, to the byte register AH and
2344 16-bit word register AX that are actually portions of the 32-bit
2345 register EAX or 64-bit register RAX.
2347 * The `commands' command now accepts a range of breakpoints to modify.
2348 A plain `commands' following a command that creates multiple
2349 breakpoints affects all the breakpoints set by that command. This
2350 applies to breakpoints set by `rbreak', and also applies when a
2351 single `break' command creates multiple breakpoints (e.g.,
2352 breakpoints on overloaded c++ functions).
2354 * The `rbreak' command now accepts a filename specification as part of
2355 its argument, limiting the functions selected by the regex to those
2356 in the specified file.
2358 * Support for remote debugging Windows and SymbianOS shared libraries
2359 from Unix hosts has been improved. Non Windows GDB builds now can
2360 understand target reported file names that follow MS-DOS based file
2361 system semantics, such as file names that include drive letters and
2362 use the backslash character as directory separator. This makes it
2363 possible to transparently use the "set sysroot" and "set
2364 solib-search-path" on Unix hosts to point as host copies of the
2365 target's shared libraries. See the new command "set
2366 target-file-system-kind" described below, and the "Commands to
2367 specify files" section in the user manual for more information.
2371 eval template, expressions...
2372 Convert the values of one or more expressions under the control
2373 of the string template to a command line, and call it.
2375 set target-file-system-kind unix|dos-based|auto
2376 show target-file-system-kind
2377 Set or show the assumed file system kind for target reported file
2380 save breakpoints <filename>
2381 Save all current breakpoint definitions to a file suitable for use
2382 in a later debugging session. To read the saved breakpoint
2383 definitions, use the `source' command.
2385 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2388 info static-tracepoint-markers
2389 Display information about static tracepoint markers in the target.
2391 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2392 Define a static tracepoint by probing a marker at the given
2393 function, line, address, or marker ID.
2397 Enable and disable observer mode.
2399 set may-write-registers on|off
2400 set may-write-memory on|off
2401 set may-insert-breakpoints on|off
2402 set may-insert-tracepoints on|off
2403 set may-insert-fast-tracepoints on|off
2404 set may-interrupt on|off
2405 Set individual permissions for GDB effects on the target. Note that
2406 some of these settings can have undesirable or surprising
2407 consequences, particularly when changed in the middle of a session.
2408 For instance, disabling the writing of memory can prevent
2409 breakpoints from being inserted, cause single-stepping to fail, or
2410 even crash your program, if you disable after breakpoints have been
2411 inserted. However, GDB should not crash.
2413 set record memory-query on|off
2414 show record memory-query
2415 Control whether to stop the inferior if memory changes caused
2416 by an instruction cannot be recorded.
2421 The disassemble command now supports "start,+length" form of two arguments.
2425 ** GDB now provides a new directory location, called the python directory,
2426 where Python scripts written for GDB can be installed. The location
2427 of that directory is <data-directory>/python, where <data-directory>
2428 is the GDB data directory. For more details, see section `Scripting
2429 GDB using Python' in the manual.
2431 ** The GDB Python API now has access to breakpoints, symbols, symbol
2432 tables, program spaces, inferiors, threads and frame's code blocks.
2433 Additionally, GDB Parameters can now be created from the API, and
2434 manipulated via set/show in the CLI.
2436 ** New functions gdb.target_charset, gdb.target_wide_charset,
2437 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2439 ** New exception gdb.GdbError.
2441 ** Pretty-printers are now also looked up in the current program space.
2443 ** Pretty-printers can now be individually enabled and disabled.
2445 ** GDB now looks for names of Python scripts to auto-load in a
2446 special section named `.debug_gdb_scripts', in addition to looking
2447 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2449 * Tracepoint actions were unified with breakpoint commands. In particular,
2450 there are no longer differences in "info break" output for breakpoints and
2451 tracepoints and the "commands" command can be used for both tracepoints and
2452 regular breakpoints.
2456 ARM Symbian arm*-*-symbianelf*
2458 * D language support.
2459 GDB now supports debugging programs written in the D programming
2462 * GDB now supports the extended ptrace interface for PowerPC which is
2463 available since Linux kernel version 2.6.34. This automatically enables
2464 any hardware breakpoints and additional hardware watchpoints available in
2465 the processor. The old ptrace interface exposes just one hardware
2466 watchpoint and no hardware breakpoints.
2468 * GDB is now able to use the Data Value Compare (DVC) register available on
2469 embedded PowerPC processors to implement in hardware simple watchpoint
2470 conditions of the form:
2472 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2474 This works in native GDB running on Linux kernels with the extended ptrace
2475 interface mentioned above.
2477 *** Changes in GDB 7.1
2481 ** Namespace Support
2483 GDB now supports importing of namespaces in C++. This enables the
2484 user to inspect variables from imported namespaces. Support for
2485 namepace aliasing has also been added. So, if a namespace is
2486 aliased in the current scope (e.g. namepace C=A; ) the user can
2487 print variables using the alias (e.g. (gdb) print C::x).
2491 All known bugs relating to the printing of virtual base class were
2492 fixed. It is now possible to call overloaded static methods using a
2497 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2498 and reinterpret_cast<> are now handled by the C++ expression parser.
2502 Xilinx MicroBlaze microblaze-*-*
2507 Xilinx MicroBlaze microblaze
2510 * Multi-program debugging.
2512 GDB now has support for multi-program (a.k.a. multi-executable or
2513 multi-exec) debugging. This allows for debugging multiple inferiors
2514 simultaneously each running a different program under the same GDB
2515 session. See "Debugging Multiple Inferiors and Programs" in the
2516 manual for more information. This implied some user visible changes
2517 in the multi-inferior support. For example, "info inferiors" now
2518 lists inferiors that are not running yet or that have exited
2519 already. See also "New commands" and "New options" below.
2521 * New tracing features
2523 GDB's tracepoint facility now includes several new features:
2525 ** Trace state variables
2527 GDB tracepoints now include support for trace state variables, which
2528 are variables managed by the target agent during a tracing
2529 experiment. They are useful for tracepoints that trigger each
2530 other, so for instance one tracepoint can count hits in a variable,
2531 and then a second tracepoint has a condition that is true when the
2532 count reaches a particular value. Trace state variables share the
2533 $-syntax of GDB convenience variables, and can appear in both
2534 tracepoint actions and condition expressions. Use the "tvariable"
2535 command to create, and "info tvariables" to view; see "Trace State
2536 Variables" in the manual for more detail.
2540 GDB now includes an option for defining fast tracepoints, which
2541 targets may implement more efficiently, such as by installing a jump
2542 into the target agent rather than a trap instruction. The resulting
2543 speedup can be by two orders of magnitude or more, although the
2544 tradeoff is that some program locations on some target architectures
2545 might not allow fast tracepoint installation, for instance if the
2546 instruction to be replaced is shorter than the jump. To request a
2547 fast tracepoint, use the "ftrace" command, with syntax identical to
2548 the regular trace command.
2550 ** Disconnected tracing
2552 It is now possible to detach GDB from the target while it is running
2553 a trace experiment, then reconnect later to see how the experiment
2554 is going. In addition, a new variable disconnected-tracing lets you
2555 tell the target agent whether to continue running a trace if the
2556 connection is lost unexpectedly.
2560 GDB now has the ability to save the trace buffer into a file, and
2561 then use that file as a target, similarly to you can do with
2562 corefiles. You can select trace frames, print data that was
2563 collected in them, and use tstatus to display the state of the
2564 tracing run at the moment that it was saved. To create a trace
2565 file, use "tsave <filename>", and to use it, do "target tfile
2568 ** Circular trace buffer
2570 You can ask the target agent to handle the trace buffer as a
2571 circular buffer, discarding the oldest trace frames to make room for
2572 newer ones, by setting circular-trace-buffer to on. This feature may
2573 not be available for all target agents.
2578 The disassemble command, when invoked with two arguments, now requires
2579 the arguments to be comma-separated.
2582 The info variables command now displays variable definitions. Files
2583 which only declare a variable are not shown.
2586 The source command is now capable of sourcing Python scripts.
2587 This feature is dependent on the debugger being build with Python
2590 Related to this enhancement is also the introduction of a new command
2591 "set script-extension" (see below).
2593 * New commands (for set/show, see "New options" below)
2595 record save [<FILENAME>]
2596 Save a file (in core file format) containing the process record
2597 execution log for replay debugging at a later time.
2599 record restore <FILENAME>
2600 Restore the process record execution log that was saved at an
2601 earlier time, for replay debugging.
2603 add-inferior [-copies <N>] [-exec <FILENAME>]
2606 clone-inferior [-copies <N>] [ID]
2607 Make a new inferior ready to execute the same program another
2608 inferior has loaded.
2613 maint info program-spaces
2614 List the program spaces loaded into GDB.
2616 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2617 show remote interrupt-sequence
2618 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2619 as the sequence to the remote target in order to interrupt the execution.
2620 Ctrl-C is a default. Some system prefers BREAK which is high level of
2621 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2622 Magic SysRq g. It is BREAK signal and character 'g'.
2624 set remote interrupt-on-connect [on | off]
2625 show remote interrupt-on-connect
2626 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2627 remote target when gdb connects to it. This is needed when you debug
2630 set remotebreak [on | off]
2632 Deprecated. Use "set/show remote interrupt-sequence" instead.
2634 tvariable $NAME [ = EXP ]
2635 Create or modify a trace state variable.
2638 List trace state variables and their values.
2640 delete tvariable $NAME ...
2641 Delete one or more trace state variables.
2644 Evaluate the given expressions without collecting anything into the
2645 trace buffer. (Valid in tracepoint actions only.)
2647 ftrace FN / FILE:LINE / *ADDR
2648 Define a fast tracepoint at the given function, line, or address.
2650 * New expression syntax
2652 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2653 GDB now parses 0b101010 identically with 42.
2657 set follow-exec-mode new|same
2658 show follow-exec-mode
2659 Control whether GDB reuses the same inferior across an exec call or
2660 creates a new one. This is useful to be able to restart the old
2661 executable after the inferior having done an exec call.
2663 set default-collect EXPR, ...
2664 show default-collect
2665 Define a list of expressions to be collected at each tracepoint.
2666 This is a useful way to ensure essential items are not overlooked,
2667 such as registers or a critical global variable.
2669 set disconnected-tracing
2670 show disconnected-tracing
2671 If set to 1, the target is instructed to continue tracing if it
2672 loses its connection to GDB. If 0, the target is to stop tracing
2675 set circular-trace-buffer
2676 show circular-trace-buffer
2677 If set to on, the target is instructed to use a circular trace buffer
2678 and discard the oldest trace frames instead of stopping the trace due
2679 to a full trace buffer. If set to off, the trace stops when the buffer
2680 fills up. Some targets may not support this.
2682 set script-extension off|soft|strict
2683 show script-extension
2684 If set to "off", the debugger does not perform any script language
2685 recognition, and all sourced files are assumed to be GDB scripts.
2686 If set to "soft" (the default), files are sourced according to
2687 filename extension, falling back to GDB scripts if the first
2689 If set to "strict", files are sourced according to filename extension.
2691 set ada trust-PAD-over-XVS on|off
2692 show ada trust-PAD-over-XVS
2693 If off, activate a workaround against a bug in the debugging information
2694 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2695 the GCC sources for more information about the GNAT encoding and
2696 PAD types in particular). It is always safe to set this option to
2697 off, but this introduces a slight performance penalty. The default
2700 * Python API Improvements
2702 ** GDB provides the new class gdb.LazyString. This is useful in
2703 some pretty-printing cases. The new method gdb.Value.lazy_string
2704 provides a simple way to create objects of this type.
2706 ** The fields returned by gdb.Type.fields now have an
2707 `is_base_class' attribute.
2709 ** The new method gdb.Type.range returns the range of an array type.
2711 ** The new method gdb.parse_and_eval can be used to parse and
2712 evaluate an expression.
2714 * New remote packets
2717 Define a trace state variable.
2720 Get the current value of a trace state variable.
2723 Set desired tracing behavior upon disconnection.
2726 Set the trace buffer to be linear or circular.
2729 Get data about the tracepoints currently in use.
2733 Process record now works correctly with hardware watchpoints.
2735 Multiple bug fixes have been made to the mips-irix port, making it
2736 much more reliable. In particular:
2737 - Debugging threaded applications is now possible again. Previously,
2738 GDB would hang while starting the program, or while waiting for
2739 the program to stop at a breakpoint.
2740 - Attaching to a running process no longer hangs.
2741 - An error occurring while loading a core file has been fixed.
2742 - Changing the value of the PC register now works again. This fixes
2743 problems observed when using the "jump" command, or when calling
2744 a function from GDB, or even when assigning a new value to $pc.
2745 - With the "finish" and "return" commands, the return value for functions
2746 returning a small array is now correctly printed.
2747 - It is now possible to break on shared library code which gets executed
2748 during a shared library init phase (code executed while executing
2749 their .init section). Previously, the breakpoint would have no effect.
2750 - GDB is now able to backtrace through the signal handler for
2751 non-threaded programs.
2753 PIE (Position Independent Executable) programs debugging is now supported.
2754 This includes debugging execution of PIC (Position Independent Code) shared
2755 libraries although for that, it should be possible to run such libraries as an
2758 *** Changes in GDB 7.0
2760 * GDB now has an interface for JIT compilation. Applications that
2761 dynamically generate code can create symbol files in memory and register
2762 them with GDB. For users, the feature should work transparently, and
2763 for JIT developers, the interface is documented in the GDB manual in the
2764 "JIT Compilation Interface" chapter.
2766 * Tracepoints may now be conditional. The syntax is as for
2767 breakpoints; either an "if" clause appended to the "trace" command,
2768 or the "condition" command is available. GDB sends the condition to
2769 the target for evaluation using the same bytecode format as is used
2770 for tracepoint actions.
2772 * The disassemble command now supports: an optional /r modifier, print the
2773 raw instructions in hex as well as in symbolic form, and an optional /m
2774 modifier to print mixed source+assembly.
2776 * Process record and replay
2778 In a architecture environment that supports ``process record and
2779 replay'', ``process record and replay'' target can record a log of
2780 the process execution, and replay it with both forward and reverse
2783 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2784 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2785 set execution-direction {forward|reverse}, for targets that support
2788 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2789 feature is available with a native GDB running on kernel version
2792 * GDB now has support for multi-byte and wide character sets on the
2793 target. Strings whose character type is wchar_t, char16_t, or
2794 char32_t are now correctly printed. GDB supports wide- and unicode-
2795 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2796 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2797 `printf'. This feature requires iconv to work properly; if your
2798 system does not have a working iconv, GDB can use GNU libiconv. See
2799 the installation instructions for more information.
2801 * GDB now supports automatic retrieval of shared library files from
2802 remote targets. To use this feature, specify a system root that begins
2803 with the `remote:' prefix, either via the `set sysroot' command or via
2804 the `--with-sysroot' configure-time option.
2806 * "info sharedlibrary" now takes an optional regex of libraries to show,
2807 and it now reports if a shared library has no debugging information.
2809 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2810 now complete on file names.
2812 * When completing in expressions, gdb will attempt to limit
2813 completions to allowable structure or union fields, where appropriate.
2814 For instance, consider:
2816 # struct example { int f1; double f2; };
2817 # struct example variable;
2820 If the user types TAB at the end of this command line, the available
2821 completions will be "f1" and "f2".
2823 * Inlined functions are now supported. They show up in backtraces, and
2824 the "step", "next", and "finish" commands handle them automatically.
2826 * GDB now supports the token-splicing (##) and stringification (#)
2827 operators when expanding macros. It also supports variable-arity
2830 * GDB now supports inspecting extra signal information, exported by
2831 the new $_siginfo convenience variable. The feature is currently
2832 implemented on linux ARM, i386 and amd64.
2834 * GDB can now display the VFP floating point registers and NEON vector
2835 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2836 can provide these registers (requires Linux 2.6.30 or later). Remote
2837 and simulator targets may also provide them.
2839 * New remote packets
2842 Search memory for a sequence of bytes.
2845 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2846 operation over reliable transport links. Use of this packet is
2847 controlled by the `set remote noack-packet' command.
2850 Kill the process with the specified process ID. Use this in preference
2851 to `k' when multiprocess protocol extensions are supported.
2854 Obtains additional operating system information
2858 Read or write additional signal information.
2860 * Removed remote protocol undocumented extension
2862 An undocumented extension to the remote protocol's `S' stop reply
2863 packet that permited the stub to pass a process id was removed.
2864 Remote servers should use the `T' stop reply packet instead.
2866 * GDB now supports multiple function calling conventions according to the
2867 DWARF-2 DW_AT_calling_convention function attribute.
2869 * The SH target utilizes the aforementioned change to distinguish between gcc
2870 and Renesas calling convention. It also adds the new CLI commands
2871 `set/show sh calling-convention'.
2873 * GDB can now read compressed debug sections, as produced by GNU gold
2874 with the --compress-debug-sections=zlib flag.
2876 * 64-bit core files are now supported on AIX.
2878 * Thread switching is now supported on Tru64.
2880 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2881 which will be allocated using malloc later in program execution.
2883 * The qXfer:libraries:read remote procotol packet now allows passing a
2884 list of section offsets.
2886 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2887 conditions handling signals delivered during attach or thread creation
2888 have also been fixed.
2890 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2891 From the user's standpoint, all unqualified instances of True and False
2892 are treated as the standard definitions, regardless of context.
2894 * GDB now parses C++ symbol and type names more flexibly. For
2897 template<typename T> class C { };
2900 GDB will now correctly handle all of:
2902 ptype C<char const *>
2903 ptype C<char const*>
2904 ptype C<const char *>
2905 ptype C<const char*>
2907 * New features in the GDB remote stub, gdbserver
2909 - The "--wrapper" command-line argument tells gdbserver to use a
2910 wrapper program to launch programs for debugging.
2912 - On PowerPC and S/390 targets, it is now possible to use a single
2913 gdbserver executable to debug both 32-bit and 64-bit programs.
2914 (This requires gdbserver itself to be built as a 64-bit executable.)
2916 - gdbserver uses the new noack protocol mode for TCP connections to
2917 reduce communications latency, if also supported and enabled in GDB.
2919 - Support for the sparc64-linux-gnu target is now included in
2922 - The amd64-linux build of gdbserver now supports debugging both
2923 32-bit and 64-bit programs.
2925 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2926 now support hardware watchpoints, and will use them automatically
2931 GDB now has support for scripting using Python. Whether this is
2932 available is determined at configure time.
2934 New GDB commands can now be written in Python.
2936 * Ada tasking support
2938 Ada tasks can now be inspected in GDB. The following commands have
2942 Print the list of Ada tasks.
2944 Print detailed information about task number N.
2946 Print the task number of the current task.
2948 Switch the context of debugging to task number N.
2950 * Support for user-defined prefixed commands. The "define" command can
2951 add new commands to existing prefixes, e.g. "target".
2953 * Multi-inferior, multi-process debugging.
2955 GDB now has generalized support for multi-inferior debugging. See
2956 "Debugging Multiple Inferiors" in the manual for more information.
2957 Although availability still depends on target support, the command
2958 set is more uniform now. The GNU/Linux specific multi-forks support
2959 has been migrated to this new framework. This implied some user
2960 visible changes; see "New commands" and also "Removed commands"
2963 * Target descriptions can now describe the target OS ABI. See the
2964 "Target Description Format" section in the user manual for more
2967 * Target descriptions can now describe "compatible" architectures
2968 to indicate that the target can execute applications for a different
2969 architecture in addition to those for the main target architecture.
2970 See the "Target Description Format" section in the user manual for
2973 * Multi-architecture debugging.
2975 GDB now includes general supports for debugging applications on
2976 hybrid systems that use more than one single processor architecture
2977 at the same time. Each such hybrid architecture still requires
2978 specific support to be added. The only hybrid architecture supported
2979 in this version of GDB is the Cell Broadband Engine.
2981 * GDB now supports integrated debugging of Cell/B.E. applications that
2982 use both the PPU and SPU architectures. To enable support for hybrid
2983 Cell/B.E. debugging, you need to configure GDB to support both the
2984 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2985 --enable-targets configure option.
2987 * Non-stop mode debugging.
2989 For some targets, GDB now supports an optional mode of operation in
2990 which you can examine stopped threads while other threads continue
2991 to execute freely. This is referred to as non-stop mode, with the
2992 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2993 section in the user manual for more information.
2995 To be able to support remote non-stop debugging, a remote stub needs
2996 to implement the non-stop mode remote protocol extensions, as
2997 described in the "Remote Non-Stop" section of the user manual. The
2998 GDB remote stub, gdbserver, has been adjusted to support these
2999 extensions on linux targets.
3001 * New commands (for set/show, see "New options" below)
3003 catch syscall [NAME(S) | NUMBER(S)]
3004 Catch system calls. Arguments, which should be names of system
3005 calls or their numbers, mean catch only those syscalls. Without
3006 arguments, every syscall will be caught. When the inferior issues
3007 any of the specified syscalls, GDB will stop and announce the system
3008 call, both when it is called and when its call returns. This
3009 feature is currently available with a native GDB running on the
3010 Linux Kernel, under the following architectures: x86, x86_64,
3011 PowerPC and PowerPC64.
3013 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3015 Search memory for a sequence of bytes.
3017 maint set python print-stack
3018 maint show python print-stack
3019 Show a stack trace when an error is encountered in a Python script.
3022 Invoke CODE by passing it to the Python interpreter.
3027 These allow macros to be defined, undefined, and listed
3031 Show operating system information about processes.
3034 List the inferiors currently under GDB's control.
3037 Switch focus to inferior number NUM.
3040 Detach from inferior number NUM.
3043 Kill inferior number NUM.
3047 set spu stop-on-load
3048 show spu stop-on-load
3049 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3051 set spu auto-flush-cache
3052 show spu auto-flush-cache
3053 Control whether to automatically flush the software-managed cache
3054 during Cell/B.E. debugging.
3056 set sh calling-convention
3057 show sh calling-convention
3058 Control the calling convention used when calling SH target functions.
3061 show debug timestamp
3062 Control display of timestamps with GDB debugging output.
3064 set disassemble-next-line
3065 show disassemble-next-line
3066 Control display of disassembled source lines or instructions when
3069 set remote noack-packet
3070 show remote noack-packet
3071 Set/show the use of remote protocol QStartNoAckMode packet. See above
3072 under "New remote packets."
3074 set remote query-attached-packet
3075 show remote query-attached-packet
3076 Control use of remote protocol `qAttached' (query-attached) packet.
3078 set remote read-siginfo-object
3079 show remote read-siginfo-object
3080 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3083 set remote write-siginfo-object
3084 show remote write-siginfo-object
3085 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3088 set remote reverse-continue
3089 show remote reverse-continue
3090 Control use of remote protocol 'bc' (reverse-continue) packet.
3092 set remote reverse-step
3093 show remote reverse-step
3094 Control use of remote protocol 'bs' (reverse-step) packet.
3096 set displaced-stepping
3097 show displaced-stepping
3098 Control displaced stepping mode. Displaced stepping is a way to
3099 single-step over breakpoints without removing them from the debuggee.
3100 Also known as "out-of-line single-stepping".
3103 show debug displaced
3104 Control display of debugging info for displaced stepping.
3106 maint set internal-error
3107 maint show internal-error
3108 Control what GDB does when an internal error is detected.
3110 maint set internal-warning
3111 maint show internal-warning
3112 Control what GDB does when an internal warning is detected.
3117 Use a wrapper program to launch programs for debugging.
3119 set multiple-symbols (all|ask|cancel)
3120 show multiple-symbols
3121 The value of this variable can be changed to adjust the debugger behavior
3122 when an expression or a breakpoint location contains an ambiguous symbol
3123 name (an overloaded function name, for instance).
3125 set breakpoint always-inserted
3126 show breakpoint always-inserted
3127 Keep breakpoints always inserted in the target, as opposed to inserting
3128 them when resuming the target, and removing them when the target stops.
3129 This option can improve debugger performance on slow remote targets.
3131 set arm fallback-mode (arm|thumb|auto)
3132 show arm fallback-mode
3133 set arm force-mode (arm|thumb|auto)
3135 These commands control how ARM GDB determines whether instructions
3136 are ARM or Thumb. The default for both settings is auto, which uses
3137 the current CPSR value for instructions without symbols; previous
3138 versions of GDB behaved as if "set arm fallback-mode arm".
3140 set disable-randomization
3141 show disable-randomization
3142 Standalone programs run with the virtual address space randomization enabled
3143 by default on some platforms. This option keeps the addresses stable across
3144 multiple debugging sessions.
3148 Control whether other threads are stopped or not when some thread hits
3153 Requests that asynchronous execution is enabled in the target, if available.
3154 In this case, it's possible to resume target in the background, and interact
3155 with GDB while the target is running. "show target-async" displays the
3156 current state of asynchronous execution of the target.
3158 set target-wide-charset
3159 show target-wide-charset
3160 The target-wide-charset is the name of the character set that GDB
3161 uses when printing characters whose type is wchar_t.
3163 set tcp auto-retry (on|off)
3165 set tcp connect-timeout
3166 show tcp connect-timeout
3167 These commands allow GDB to retry failed TCP connections to a remote stub
3168 with a specified timeout period; this is useful if the stub is launched
3169 in parallel with GDB but may not be ready to accept connections immediately.
3171 set libthread-db-search-path
3172 show libthread-db-search-path
3173 Control list of directories which GDB will search for appropriate
3176 set schedule-multiple (on|off)
3177 show schedule-multiple
3178 Allow GDB to resume all threads of all processes or only threads of
3179 the current process.
3183 Use more aggressive caching for accesses to the stack. This improves
3184 performance of remote debugging (particularly backtraces) without
3185 affecting correctness.
3187 set interactive-mode (on|off|auto)
3188 show interactive-mode
3189 Control whether GDB runs in interactive mode (on) or not (off).
3190 When in interactive mode, GDB waits for the user to answer all
3191 queries. Otherwise, GDB does not wait and assumes the default
3192 answer. When set to auto (the default), GDB determines which
3193 mode to use based on the stdin settings.
3198 For program forks, this is replaced by the new more generic `info
3199 inferiors' command. To list checkpoints, you can still use the
3200 `info checkpoints' command, which was an alias for the `info forks'
3204 Replaced by the new `inferior' command. To switch between
3205 checkpoints, you can still use the `restart' command, which was an
3206 alias for the `fork' command.
3209 This is removed, since some targets don't have a notion of
3210 processes. To switch between processes, you can still use the
3211 `inferior' command using GDB's own inferior number.
3214 For program forks, this is replaced by the new more generic `kill
3215 inferior' command. To delete a checkpoint, you can still use the
3216 `delete checkpoint' command, which was an alias for the `delete
3220 For program forks, this is replaced by the new more generic `detach
3221 inferior' command. To detach a checkpoint, you can still use the
3222 `detach checkpoint' command, which was an alias for the `detach
3225 * New native configurations
3227 x86/x86_64 Darwin i[34567]86-*-darwin*
3229 x86_64 MinGW x86_64-*-mingw*
3233 Lattice Mico32 lm32-*
3234 x86 DICOS i[34567]86-*-dicos*
3235 x86_64 DICOS x86_64-*-dicos*
3238 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3239 (mingw32ce) debugging.
3245 These commands were actually not implemented on any target.
3247 *** Changes in GDB 6.8
3249 * New native configurations
3251 NetBSD/hppa hppa*-*netbsd*
3252 Xtensa GNU/Linux xtensa*-*-linux*
3256 NetBSD/hppa hppa*-*-netbsd*
3257 Xtensa GNU/Lunux xtensa*-*-linux*
3259 * Change in command line behavior -- corefiles vs. process ids.
3261 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3262 attaching to process NUMBER fails, GDB no longer attempts to open a
3263 core file named NUMBER. Attaching to a program using the -c option
3264 is no longer supported. Instead, use the '-p' or '--pid' options.
3266 * GDB can now be built as a native debugger for debugging Windows x86
3267 (mingw32) Portable Executable (PE) programs.
3269 * Pending breakpoints no longer change their number when their address
3272 * GDB now supports breakpoints with multiple locations,
3273 including breakpoints on C++ constructors, inside C++ templates,
3274 and in inlined functions.
3276 * GDB's ability to debug optimized code has been improved. GDB more
3277 accurately identifies function bodies and lexical blocks that occupy
3278 more than one contiguous range of addresses.
3280 * Target descriptions can now describe registers for PowerPC.
3282 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3283 registers on PowerPC targets.
3285 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3286 targets even when the libthread_db library is not available.
3288 * The GDB remote stub, gdbserver, now supports the new file transfer
3289 commands (remote put, remote get, and remote delete).
3291 * The GDB remote stub, gdbserver, now supports run and attach in
3292 extended-remote mode.
3294 * hppa*64*-*-hpux11* target broken
3295 The debugger is unable to start a program and fails with the following
3296 error: "Error trying to get information about dynamic linker".
3297 The gdb-6.7 release is also affected.
3299 * GDB now supports the --enable-targets= configure option to allow
3300 building a single GDB executable that supports multiple remote
3301 target architectures.
3303 * GDB now supports debugging C and C++ programs which use the
3304 Decimal Floating Point extension. In addition, the PowerPC target
3305 now has a set of pseudo-registers to inspect decimal float values
3306 stored in two consecutive float registers.
3308 * The -break-insert MI command can optionally create pending
3311 * Improved support for debugging Ada
3312 Many improvements to the Ada language support have been made. These
3314 - Better support for Ada2005 interface types
3315 - Improved handling of arrays and slices in general
3316 - Better support for Taft-amendment types
3317 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3319 - Improved command completion in Ada
3322 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3327 set print frame-arguments (all|scalars|none)
3328 show print frame-arguments
3329 The value of this variable can be changed to control which argument
3330 values should be printed by the debugger when displaying a frame.
3335 Transfer files to and from a remote target, and delete remote files.
3342 Transfer files to and from a remote target, and delete remote files.
3344 * New remote packets
3351 Open, close, read, write, and delete files on the remote system.
3354 Attach to an existing process on the remote system, in extended-remote
3358 Run a new process on the remote system, in extended-remote mode.
3360 *** Changes in GDB 6.7
3362 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3363 bfd, libiberty and opcodes, as revealed by static analysis donated by
3364 Coverity, Inc. (http://scan.coverity.com).
3366 * When looking up multiply-defined global symbols, GDB will now prefer the
3367 symbol definition in the current shared library if it was built using the
3368 -Bsymbolic linker option.
3370 * When the Text User Interface (TUI) is not configured, GDB will now
3371 recognize the -tui command-line option and print a message that the TUI
3374 * The GDB remote stub, gdbserver, now has lower overhead for high
3375 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3377 * GDB for MIPS targets now autodetects whether a remote target provides
3378 32-bit or 64-bit register values.
3380 * Support for C++ member pointers has been improved.
3382 * GDB now understands XML target descriptions, which specify the
3383 target's overall architecture. GDB can read a description from
3384 a local file or over the remote serial protocol.
3386 * Vectors of single-byte data use a new integer type which is not
3387 automatically displayed as character or string data.
3389 * The /s format now works with the print command. It displays
3390 arrays of single-byte integers and pointers to single-byte integers
3393 * Target descriptions can now describe target-specific registers,
3394 for architectures which have implemented the support (currently
3395 only ARM, M68K, and MIPS).
3397 * GDB and the GDB remote stub, gdbserver, now support the XScale
3400 * The GDB remote stub, gdbserver, has been updated to support
3401 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3402 has been rewritten to use the standard GDB remote protocol.
3404 * GDB can now step into C++ functions which are called through thunks.
3406 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3408 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3409 layout. It also supports a TextSeg= and DataSeg= response when only
3410 segment base addresses (rather than offsets) are available.
3412 * The /i format now outputs any trailing branch delay slot instructions
3413 immediately following the last instruction within the count specified.
3415 * The GDB remote protocol "T" stop reply packet now supports a
3416 "library" response. Combined with the new "qXfer:libraries:read"
3417 packet, this response allows GDB to debug shared libraries on targets
3418 where the operating system manages the list of loaded libraries (e.g.
3419 Windows and SymbianOS).
3421 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3422 (DLLs) on Windows and Windows CE targets.
3424 * GDB now supports a faster verification that a .debug file matches its binary
3425 according to its build-id signature, if the signature is present.
3431 Enable or disable hardware flow control (RTS/CTS) on the serial port
3432 when debugging using remote targets.
3434 set mem inaccessible-by-default
3435 show mem inaccessible-by-default
3436 If the target supplies a memory map, for instance via the remote
3437 protocol's "qXfer:memory-map:read" packet, setting this variable
3438 prevents GDB from accessing memory outside the memory map. This
3439 is useful for targets with memory mapped registers or which react
3440 badly to accesses of unmapped address space.
3442 set breakpoint auto-hw
3443 show breakpoint auto-hw
3444 If the target supplies a memory map, for instance via the remote
3445 protocol's "qXfer:memory-map:read" packet, setting this variable
3446 lets GDB use hardware breakpoints automatically for memory regions
3447 where it can not use software breakpoints. This covers both the
3448 "break" command and internal breakpoints used for other commands
3449 including "next" and "finish".
3452 catch exception unhandled
3453 Stop the program execution when Ada exceptions are raised.
3456 Stop the program execution when an Ada assertion failed.
3460 Set an alternate system root for target files. This is a more
3461 general version of "set solib-absolute-prefix", which is now
3462 an alias to "set sysroot".
3465 Provide extended SPU facility status information. This set of
3466 commands is available only when debugging the Cell/B.E. SPU
3469 * New native configurations
3471 OpenBSD/sh sh*-*openbsd*
3474 unset tdesc filename
3476 Use the specified local file as an XML target description, and do
3477 not query the target for its built-in description.
3481 OpenBSD/sh sh*-*-openbsd*
3482 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3483 Toshiba Media Processor mep-elf
3485 * New remote packets
3488 Ignore the specified signals; pass them directly to the debugged program
3489 without stopping other threads or reporting them to GDB.
3491 qXfer:features:read:
3492 Read an XML target description from the target, which describes its
3497 Read or write contents of an spufs file on the target system. These
3498 packets are available only on the Cell/B.E. SPU architecture.
3500 qXfer:libraries:read:
3501 Report the loaded shared libraries. Combined with new "T" packet
3502 response, this packet allows GDB to debug shared libraries on
3503 targets where the operating system manages the list of loaded
3504 libraries (e.g. Windows and SymbianOS).
3508 Support for these obsolete configurations has been removed.
3516 i[34567]86-*-lynxos*
3517 i[34567]86-*-netware*
3518 i[34567]86-*-sco3.2v5*
3519 i[34567]86-*-sco3.2v4*
3521 i[34567]86-*-sysv4.2*
3524 i[34567]86-*-unixware2*
3525 i[34567]86-*-unixware*
3534 * Other removed features
3541 Various m68k-only ROM monitors.
3548 Various Renesas ROM monitors and debugging interfaces for SH and
3553 Support for a Macraigor serial interface to on-chip debugging.
3554 GDB does not directly support the newer parallel or USB
3559 A debug information format. The predecessor to DWARF 2 and
3560 DWARF 3, which are still supported.
3562 Support for the HP aCC compiler on HP-UX/PA-RISC
3564 SOM-encapsulated symbolic debugging information, automatic
3565 invocation of pxdb, and the aCC custom C++ ABI. This does not
3566 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3567 with aCC can still be debugged on an assembly level.
3569 MIPS ".pdr" sections
3571 A MIPS-specific format used to describe stack frame layout
3572 in debugging information.
3576 GDB could work with an older version of Guile to debug
3577 the interpreter and Scheme programs running in it.
3579 set mips stack-arg-size
3580 set mips saved-gpreg-size
3582 Use "set mips abi" to control parameter passing for MIPS.
3584 *** Changes in GDB 6.6
3589 Cell Broadband Engine SPU spu-elf
3591 * GDB can now be configured as a cross-debugger targeting native Windows
3592 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3593 running on a Windows system over TCP/IP to debug Windows programs.
3595 * The GDB remote stub, gdbserver, has been updated to support Windows and
3596 Cygwin debugging. Both single-threaded and multi-threaded programs are
3599 * The "set trust-readonly-sections" command works again. This command was
3600 broken in GDB 6.3, 6.4, and 6.5.
3602 * The "load" command now supports writing to flash memory, if the remote
3603 stub provides the required support.
3605 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3606 longer requires symbolic debug information (e.g. DWARF-2).
3611 unset substitute-path
3612 show substitute-path
3613 Manage a list of substitution rules that GDB uses to rewrite the name
3614 of the directories where the sources are located. This can be useful
3615 for instance when the sources were moved to a different location
3616 between compilation and debugging.
3620 Print each CLI command as it is executed. Each command is prefixed with
3621 a number of `+' symbols representing the nesting depth.
3622 The source command now has a `-v' option to enable the same feature.
3626 The ARM Demon monitor support (RDP protocol, "target rdp").
3628 Kernel Object Display, an embedded debugging feature which only worked with
3629 an obsolete version of Cisco IOS.
3631 The 'set download-write-size' and 'show download-write-size' commands.
3633 * New remote packets
3636 Tell a stub about GDB client features, and request remote target features.
3637 The first feature implemented is PacketSize, which allows the target to
3638 specify the size of packets it can handle - to minimize the number of
3639 packets required and improve performance when connected to a remote
3643 Fetch an OS auxilliary vector from the remote stub. This packet is a
3644 more efficient replacement for qPart:auxv:read.
3646 qXfer:memory-map:read:
3647 Fetch a memory map from the remote stub, including information about
3648 RAM, ROM, and flash memory devices.
3653 Erase and program a flash memory device.
3655 * Removed remote packets
3658 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3659 used it, and only gdbserver implemented it.
3661 *** Changes in GDB 6.5
3665 Renesas M32C/M16C m32c-elf
3667 Morpho Technologies ms1 ms1-elf
3671 init-if-undefined Initialize a convenience variable, but
3672 only if it doesn't already have a value.
3674 The following commands are presently only implemented for native GNU/Linux:
3676 checkpoint Save a snapshot of the program state.
3678 restart <n> Return the program state to a
3679 previously saved state.
3681 info checkpoints List currently saved checkpoints.
3683 delete-checkpoint <n> Delete a previously saved checkpoint.
3685 set|show detach-on-fork Tell gdb whether to detach from a newly
3686 forked process, or to keep debugging it.
3688 info forks List forks of the user program that
3689 are available to be debugged.
3691 fork <n> Switch to debugging one of several
3692 forks of the user program that are
3693 available to be debugged.
3695 delete-fork <n> Delete a fork from the list of forks
3696 that are available to be debugged (and
3697 kill the forked process).
3699 detach-fork <n> Delete a fork from the list of forks
3700 that are available to be debugged (and
3701 allow the process to continue).
3705 Morpho Technologies ms2 ms1-elf
3707 * Improved Windows host support
3709 GDB now builds as a cross debugger hosted on i686-mingw32, including
3710 native console support, and remote communications using either
3711 network sockets or serial ports.
3713 * Improved Modula-2 language support
3715 GDB can now print most types in the Modula-2 syntax. This includes:
3716 basic types, set types, record types, enumerated types, range types,
3717 pointer types and ARRAY types. Procedure var parameters are correctly
3718 printed and hexadecimal addresses and character constants are also
3719 written in the Modula-2 syntax. Best results can be obtained by using
3720 GNU Modula-2 together with the -gdwarf-2 command line option.
3724 The ARM rdi-share module.
3726 The Netware NLM debug server.
3728 *** Changes in GDB 6.4
3730 * New native configurations
3732 OpenBSD/arm arm*-*-openbsd*
3733 OpenBSD/mips64 mips64-*-openbsd*
3737 Morpho Technologies ms1 ms1-elf
3739 * New command line options
3741 --batch-silent As for --batch, but totally silent.
3742 --return-child-result The debugger will exist with the same value
3743 the child (debugged) program exited with.
3744 --eval-command COMMAND, -ex COMMAND
3745 Execute a single GDB CLI command. This may be
3746 specified multiple times and in conjunction
3747 with the --command (-x) option.
3749 * Deprecated commands removed
3751 The following commands, that were deprecated in 2000, have been
3755 set|show arm disassembly-flavor set|show arm disassembler
3756 othernames set arm disassembler
3757 set|show remotedebug set|show debug remote
3758 set|show archdebug set|show debug arch
3759 set|show eventdebug set|show debug event
3762 * New BSD user-level threads support
3764 It is now possible to debug programs using the user-level threads
3765 library on OpenBSD and FreeBSD. Currently supported (target)
3768 FreeBSD/amd64 x86_64-*-freebsd*
3769 FreeBSD/i386 i386-*-freebsd*
3770 OpenBSD/i386 i386-*-openbsd*
3772 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3773 are not yet supported.
3775 * New support for Matsushita MN10300 w/sim added
3776 (Work in progress). mn10300-elf.
3778 * REMOVED configurations and files
3780 VxWorks and the XDR protocol *-*-vxworks
3781 Motorola MCORE mcore-*-*
3782 National Semiconductor NS32000 ns32k-*-*
3784 * New "set print array-indexes" command
3786 After turning this setting "on", GDB prints the index of each element
3787 when displaying arrays. The default is "off" to preserve the previous
3790 * VAX floating point support
3792 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3794 * User-defined command support
3796 In addition to using $arg0..$arg9 for argument passing, it is now possible
3797 to use $argc to determine now many arguments have been passed. See the
3798 section on user-defined commands in the user manual for more information.
3800 *** Changes in GDB 6.3:
3802 * New command line option
3804 GDB now accepts -l followed by a number to set the timeout for remote
3807 * GDB works with GCC -feliminate-dwarf2-dups
3809 GDB now supports a more compact representation of DWARF-2 debug
3810 information using DW_FORM_ref_addr references. These are produced
3811 by GCC with the option -feliminate-dwarf2-dups and also by some
3812 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3813 to use -feliminate-dwarf2-dups.
3815 * Internationalization
3817 When supported by the host system, GDB will be built with
3818 internationalization (libintl). The task of marking up the sources is
3819 continued, we're looking forward to our first translation.
3823 Initial support for debugging programs compiled with the GNAT
3824 implementation of the Ada programming language has been integrated
3825 into GDB. In this release, support is limited to expression evaluation.
3827 * New native configurations
3829 GNU/Linux/m32r m32r-*-linux-gnu
3833 GDB's remote protocol now includes support for the 'p' packet. This
3834 packet is used to fetch individual registers from a remote inferior.
3836 * END-OF-LIFE registers[] compatibility module
3838 GDB's internal register infrastructure has been completely rewritten.
3839 The new infrastructure making possible the implementation of key new
3840 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3843 GDB 6.3 will be the last release to include the the registers[]
3844 compatibility module that allowed out-of-date configurations to
3845 continue to work. This change directly impacts the following
3855 powerpc bdm protocol
3857 Unless there is activity to revive these configurations, they will be
3858 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3860 * OBSOLETE configurations and files
3862 Configurations that have been declared obsolete in this release have
3863 been commented out. Unless there is activity to revive these
3864 configurations, the next release of GDB will have their sources
3865 permanently REMOVED.
3874 *** Changes in GDB 6.2.1:
3876 * MIPS `break main; run' gave an heuristic-fence-post warning
3878 When attempting to run even a simple program, a warning about
3879 heuristic-fence-post being hit would be reported. This problem has
3882 * MIPS IRIX 'long double' crashed GDB
3884 When examining a long double variable, GDB would get a segmentation
3885 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3886 IRIX long double values).
3890 A bug in the VAX stack code was causing problems with the "next"
3891 command. This problem has been fixed.
3893 *** Changes in GDB 6.2:
3895 * Fix for ``many threads''
3897 On GNU/Linux systems that use the NPTL threads library, a program
3898 rapidly creating and deleting threads would confuse GDB leading to the
3901 ptrace: No such process.
3902 thread_db_get_info: cannot get thread info: generic error
3904 This problem has been fixed.
3906 * "-async" and "-noasync" options removed.
3908 Support for the broken "-noasync" option has been removed (it caused
3911 * New ``start'' command.
3913 This command runs the program until the begining of the main procedure.
3915 * New BSD Kernel Data Access Library (libkvm) interface
3917 Using ``target kvm'' it is now possible to debug kernel core dumps and
3918 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3919 platforms. Currently supported (native-only) configurations are:
3921 FreeBSD/amd64 x86_64-*-freebsd*
3922 FreeBSD/i386 i?86-*-freebsd*
3923 NetBSD/i386 i?86-*-netbsd*
3924 NetBSD/m68k m68*-*-netbsd*
3925 NetBSD/sparc sparc-*-netbsd*
3926 OpenBSD/amd64 x86_64-*-openbsd*
3927 OpenBSD/i386 i?86-*-openbsd*
3928 OpenBSD/m68k m68*-openbsd*
3929 OpenBSD/sparc sparc-*-openbsd*
3931 * Signal trampoline code overhauled
3933 Many generic problems with GDB's signal handling code have been fixed.
3934 These include: backtraces through non-contiguous stacks; recognition
3935 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3936 call; backtrace through a signal trampoline; step into and out of
3937 signal handlers; and single-stepping in the signal trampoline.
3939 Please note that kernel bugs are a limiting factor here. These
3940 features have been shown to work on an s390 GNU/Linux system that
3941 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3943 * Cygwin support for DWARF 2 added.
3945 * New native configurations
3947 GNU/Linux/hppa hppa*-*-linux*
3948 OpenBSD/hppa hppa*-*-openbsd*
3949 OpenBSD/m68k m68*-*-openbsd*
3950 OpenBSD/m88k m88*-*-openbsd*
3951 OpenBSD/powerpc powerpc-*-openbsd*
3952 NetBSD/vax vax-*-netbsd*
3953 OpenBSD/vax vax-*-openbsd*
3955 * END-OF-LIFE frame compatibility module
3957 GDB's internal frame infrastructure has been completely rewritten.
3958 The new infrastructure making it possible to support key new features
3959 including DWARF 2 Call Frame Information. To aid in the task of
3960 migrating old configurations to this new infrastructure, a
3961 compatibility module, that allowed old configurations to continue to
3962 work, was also included.
3964 GDB 6.2 will be the last release to include this frame compatibility
3965 module. This change directly impacts the following configurations:
3975 Unless there is activity to revive these configurations, they will be
3976 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3978 * REMOVED configurations and files
3980 Sun 3, running SunOS 3 m68*-*-sunos3*
3981 Sun 3, running SunOS 4 m68*-*-sunos4*
3982 Sun 2, running SunOS 3 m68000-*-sunos3*
3983 Sun 2, running SunOS 4 m68000-*-sunos4*
3984 Motorola 680x0 running LynxOS m68*-*-lynxos*
3985 AT&T 3b1/Unix pc m68*-att-*
3986 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3987 decstation mips-dec-* mips-little-*
3988 riscos mips-*-riscos* mips-*-sysv*
3989 sonymips mips-sony-*
3990 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3992 *** Changes in GDB 6.1.1:
3994 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3996 The TUI (Text-mode User Interface) is now built as part of a default
3997 GDB configuration. It is enabled by either selecting the TUI with the
3998 command line option "-i=tui" or by running the separate "gdbtui"
3999 program. For more information on the TUI, see the manual "Debugging
4002 * Pending breakpoint support (also included in GDB 6.1)
4004 Support has been added to allow you to specify breakpoints in shared
4005 libraries that have not yet been loaded. If a breakpoint location
4006 cannot be found, and the "breakpoint pending" option is set to auto,
4007 GDB queries you if you wish to make the breakpoint pending on a future
4008 shared-library load. If and when GDB resolves the breakpoint symbol,
4009 the pending breakpoint is removed as one or more regular breakpoints
4012 Pending breakpoints are very useful for GCJ Java debugging.
4014 * Fixed ISO-C build problems
4016 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4017 non ISO-C code that stopped them being built using a more strict ISO-C
4018 compiler (e.g., IBM's C compiler).
4020 * Fixed build problem on IRIX 5
4022 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4023 wasn't able to compile compile on an IRIX 5 system.
4025 * Added execute permission to gdb/gdbserver/configure
4027 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4028 permission. This bug would cause configure to fail on a number of
4029 systems (Solaris, IRIX). Ref: server/519.
4031 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4033 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4034 has been updated to use constant array sizes.
4036 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4038 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4039 its generated DWARF Call Frame Info. This encoding was causing GDB to
4040 panic, that panic has been fixed. Ref: gdb/1628.
4042 * Fixed a problem when examining parameters in shared library code.
4044 When examining parameters in optimized shared library code generated
4045 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4046 not available''. GDB now correctly displays the variable's value.
4048 *** Changes in GDB 6.1:
4050 * Removed --with-mmalloc
4052 Support for the mmalloc memory manager has been removed, as it
4053 conflicted with the internal gdb byte cache.
4055 * Changes in AMD64 configurations
4057 The AMD64 target now includes the %cs and %ss registers. As a result
4058 the AMD64 remote protocol has changed; this affects the floating-point
4059 and SSE registers. If you rely on those registers for your debugging,
4060 you should upgrade gdbserver on the remote side.
4062 * Revised SPARC target
4064 The SPARC target has been completely revised, incorporating the
4065 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4066 support for LynxOS and SunOS 4 has been dropped. Calling functions
4067 from within GDB on operating systems with a non-executable stack
4068 (Solaris, OpenBSD) now works.
4072 GDB has a new C++ demangler which does a better job on the mangled
4073 names generated by current versions of g++. It also runs faster, so
4074 with this and other changes gdb should now start faster on large C++
4077 * DWARF 2 Location Expressions
4079 GDB support for location expressions has been extended to support function
4080 arguments and frame bases. Older versions of GDB could crash when they
4083 * C++ nested types and namespaces
4085 GDB's support for nested types and namespaces in C++ has been
4086 improved, especially if you use the DWARF 2 debugging format. (This
4087 is the default for recent versions of GCC on most platforms.)
4088 Specifically, if you have a class "Inner" defined within a class or
4089 namespace "Outer", then GDB realizes that the class's name is
4090 "Outer::Inner", not simply "Inner". This should greatly reduce the
4091 frequency of complaints about not finding RTTI symbols. In addition,
4092 if you are stopped at inside of a function defined within a namespace,
4093 GDB modifies its name lookup accordingly.
4095 * New native configurations
4097 NetBSD/amd64 x86_64-*-netbsd*
4098 OpenBSD/amd64 x86_64-*-openbsd*
4099 OpenBSD/alpha alpha*-*-openbsd*
4100 OpenBSD/sparc sparc-*-openbsd*
4101 OpenBSD/sparc64 sparc64-*-openbsd*
4103 * New debugging protocols
4105 M32R with SDI protocol m32r-*-elf*
4107 * "set prompt-escape-char" command deleted.
4109 The command "set prompt-escape-char" has been deleted. This command,
4110 and its very obscure effet on GDB's prompt, was never documented,
4111 tested, nor mentioned in the NEWS file.
4113 * OBSOLETE configurations and files
4115 Configurations that have been declared obsolete in this release have
4116 been commented out. Unless there is activity to revive these
4117 configurations, the next release of GDB will have their sources
4118 permanently REMOVED.
4120 Sun 3, running SunOS 3 m68*-*-sunos3*
4121 Sun 3, running SunOS 4 m68*-*-sunos4*
4122 Sun 2, running SunOS 3 m68000-*-sunos3*
4123 Sun 2, running SunOS 4 m68000-*-sunos4*
4124 Motorola 680x0 running LynxOS m68*-*-lynxos*
4125 AT&T 3b1/Unix pc m68*-att-*
4126 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4127 decstation mips-dec-* mips-little-*
4128 riscos mips-*-riscos* mips-*-sysv*
4129 sonymips mips-sony-*
4130 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4132 * REMOVED configurations and files
4134 SGI Irix-4.x mips-sgi-irix4 or iris4
4135 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4136 Z8000 simulator z8k-zilog-none or z8ksim
4137 Matsushita MN10200 w/simulator mn10200-*-*
4138 H8/500 simulator h8500-hitachi-hms or h8500hms
4139 HP/PA running BSD hppa*-*-bsd*
4140 HP/PA running OSF/1 hppa*-*-osf*
4141 HP/PA Pro target hppa*-*-pro*
4142 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4143 386BSD i[3456]86-*-bsd*
4144 Sequent family i[3456]86-sequent-sysv4*
4145 i[3456]86-sequent-sysv*
4146 i[3456]86-sequent-bsd*
4147 SPARC running LynxOS sparc-*-lynxos*
4148 SPARC running SunOS 4 sparc-*-sunos4*
4149 Tsqware Sparclet sparclet-*-*
4150 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4152 *** Changes in GDB 6.0:
4156 Support for debugging the Objective-C programming language has been
4157 integrated into GDB.
4159 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4161 DWARF 2's Call Frame Information makes available compiler generated
4162 information that more exactly describes the program's run-time stack.
4163 By using this information, GDB is able to provide more robust stack
4166 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4167 have been updated to use a new backtrace mechanism which includes
4168 DWARF 2 CFI support.
4172 GDB's remote protocol has been extended to include support for hosted
4173 file I/O (where the remote target uses GDB's file system). See GDB's
4174 remote protocol documentation for details.
4176 * All targets using the new architecture framework.
4178 All of GDB's targets have been updated to use the new internal
4179 architecture framework. The way is now open for future GDB releases
4180 to include cross-architecture native debugging support (i386 on amd64,
4183 * GNU/Linux's Thread Local Storage (TLS)
4185 GDB now includes support for for the GNU/Linux implementation of
4186 per-thread variables.
4188 * GNU/Linux's Native POSIX Thread Library (NPTL)
4190 GDB's thread code has been updated to work with either the new
4191 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4193 * Separate debug info.
4195 GDB, in conjunction with BINUTILS, now supports a mechanism for
4196 automatically loading debug information from a separate file. Instead
4197 of shipping full debug and non-debug versions of system libraries,
4198 system integrators can now instead ship just the stripped libraries
4199 and optional debug files.
4201 * DWARF 2 Location Expressions
4203 DWARF 2 Location Expressions allow the compiler to more completely
4204 describe the location of variables (even in optimized code) to the
4207 GDB now includes preliminary support for location expressions (support
4208 for DW_OP_piece is still missing).
4212 A number of long standing bugs that caused GDB to die while starting a
4213 Java application have been fixed. GDB's Java support is now
4214 considered "useable".
4216 * GNU/Linux support for fork, vfork, and exec.
4218 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4219 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4222 * GDB supports logging output to a file
4224 There are two new commands, "set logging" and "show logging", which can be
4225 used to capture GDB's output to a file.
4227 * The meaning of "detach" has changed for gdbserver
4229 The "detach" command will now resume the application, as documented. To
4230 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4233 * d10v, m68hc11 `regs' command deprecated
4235 The `info registers' command has been updated so that it displays the
4236 registers using a format identical to the old `regs' command.
4240 A new command, "maint set profile on/off", has been added. This command can
4241 be used to enable or disable profiling while running GDB, to profile a
4242 session or a set of commands. In addition there is a new configure switch,
4243 "--enable-profiling", which will cause GDB to be compiled with profiling
4244 data, for more informative profiling results.
4246 * Default MI syntax changed to "mi2".
4248 The default MI (machine interface) syntax, enabled by the command line
4249 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4250 "mi1", can be enabled by specifying the option "-i=mi1".
4252 Support for the original "mi0" syntax (included in GDB 5.0) has been
4255 Fix for gdb/192: removed extraneous space when displaying frame level.
4256 Fix for gdb/672: update changelist is now output in mi list format.
4257 Fix for gdb/702: a -var-assign that updates the value now shows up
4258 in a subsequent -var-update.
4260 * New native configurations.
4262 FreeBSD/amd64 x86_64-*-freebsd*
4264 * Multi-arched targets.
4266 HP/PA HPUX11 hppa*-*-hpux*
4267 Renesas M32R/D w/simulator m32r-*-elf*
4269 * OBSOLETE configurations and files
4271 Configurations that have been declared obsolete in this release have
4272 been commented out. Unless there is activity to revive these
4273 configurations, the next release of GDB will have their sources
4274 permanently REMOVED.
4276 Z8000 simulator z8k-zilog-none or z8ksim
4277 Matsushita MN10200 w/simulator mn10200-*-*
4278 H8/500 simulator h8500-hitachi-hms or h8500hms
4279 HP/PA running BSD hppa*-*-bsd*
4280 HP/PA running OSF/1 hppa*-*-osf*
4281 HP/PA Pro target hppa*-*-pro*
4282 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4283 Sequent family i[3456]86-sequent-sysv4*
4284 i[3456]86-sequent-sysv*
4285 i[3456]86-sequent-bsd*
4286 Tsqware Sparclet sparclet-*-*
4287 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4289 * REMOVED configurations and files
4292 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4293 IBM AIX PS/2 i[3456]86-*-aix
4294 i386 running Mach 3.0 i[3456]86-*-mach3*
4295 i386 running Mach i[3456]86-*-mach*
4296 i386 running OSF/1 i[3456]86-*osf1mk*
4297 HP/Apollo 68k Family m68*-apollo*-sysv*,
4299 m68*-hp-bsd*, m68*-hp-hpux*
4300 Argonaut Risc Chip (ARC) arc-*-*
4301 Mitsubishi D30V d30v-*-*
4302 Fujitsu FR30 fr30-*-elf*
4303 OS/9000 i[34]86-*-os9k
4304 I960 with MON960 i960-*-coff
4306 * MIPS $fp behavior changed
4308 The convenience variable $fp, for the MIPS, now consistently returns
4309 the address of the current frame's base. Previously, depending on the
4310 context, $fp could refer to either $sp or the current frame's base
4311 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4312 The GNU Source-Level Debugger''.
4314 *** Changes in GDB 5.3:
4316 * GNU/Linux shared library multi-threaded performance improved.
4318 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4319 `/proc', in preference to `ptrace' for memory reads. This may result
4320 in an improvement in the start-up time of multi-threaded, shared
4321 library applications when run under GDB. One GDB user writes: ``loads
4322 shared libs like mad''.
4324 * ``gdbserver'' now supports multi-threaded applications on some targets
4326 Support for debugging multi-threaded applications which use
4327 the GNU/Linux LinuxThreads package has been added for
4328 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4329 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4331 * GDB now supports C/C++ preprocessor macros.
4333 GDB now expands preprocessor macro invocations in C/C++ expressions,
4334 and provides various commands for showing macro definitions and how
4337 The new command `macro expand EXPRESSION' expands any macro
4338 invocations in expression, and shows the result.
4340 The new command `show macro MACRO-NAME' shows the definition of the
4341 macro named MACRO-NAME, and where it was defined.
4343 Most compilers don't include information about macros in the debugging
4344 information by default. In GCC 3.1, for example, you need to compile
4345 your program with the options `-gdwarf-2 -g3'. If the macro
4346 information is present in the executable, GDB will read it.
4348 * Multi-arched targets.
4350 DEC Alpha (partial) alpha*-*-*
4351 DEC VAX (partial) vax-*-*
4353 National Semiconductor NS32000 (partial) ns32k-*-*
4354 Motorola 68000 (partial) m68k-*-*
4355 Motorola MCORE mcore-*-*
4359 Fujitsu FRV architecture added by Red Hat frv*-*-*
4362 * New native configurations
4364 Alpha NetBSD alpha*-*-netbsd*
4365 SH NetBSD sh*-*-netbsdelf*
4366 MIPS NetBSD mips*-*-netbsd*
4367 UltraSPARC NetBSD sparc64-*-netbsd*
4369 * OBSOLETE configurations and files
4371 Configurations that have been declared obsolete in this release have
4372 been commented out. Unless there is activity to revive these
4373 configurations, the next release of GDB will have their sources
4374 permanently REMOVED.
4376 Mitsubishi D30V d30v-*-*
4377 OS/9000 i[34]86-*-os9k
4378 IBM AIX PS/2 i[3456]86-*-aix
4379 Fujitsu FR30 fr30-*-elf*
4380 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4381 Argonaut Risc Chip (ARC) arc-*-*
4382 i386 running Mach 3.0 i[3456]86-*-mach3*
4383 i386 running Mach i[3456]86-*-mach*
4384 i386 running OSF/1 i[3456]86-*osf1mk*
4385 HP/Apollo 68k Family m68*-apollo*-sysv*,
4387 m68*-hp-bsd*, m68*-hp-hpux*
4388 I960 with MON960 i960-*-coff
4390 * OBSOLETE languages
4392 CHILL, a Pascal like language used by telecommunications companies.
4394 * REMOVED configurations and files
4396 AMD 29k family via UDI a29k-amd-udi, udi29k
4397 A29K VxWorks a29k-*-vxworks
4398 AMD 29000 embedded, using EBMON a29k-none-none
4399 AMD 29000 embedded with COFF a29k-none-coff
4400 AMD 29000 embedded with a.out a29k-none-aout
4402 testsuite/gdb.hp/gdb.threads-hp/ directory
4404 * New command "set max-user-call-depth <nnn>"
4406 This command allows the user to limit the call depth of user-defined
4407 commands. The default is 1024.
4409 * Changes in FreeBSD/i386 native debugging.
4411 Support for the "generate-core-file" has been added.
4413 * New commands "dump", "append", and "restore".
4415 These commands allow data to be copied from target memory
4416 to a bfd-format or binary file (dump and append), and back
4417 from a file into memory (restore).
4419 * Improved "next/step" support on multi-processor Alpha Tru64.
4421 The previous single-step mechanism could cause unpredictable problems,
4422 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4423 of a software single-step mechanism prevents this.
4425 *** Changes in GDB 5.2.1:
4433 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4434 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4435 Fix, by Joel Brobecker imported from mainline.
4437 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4438 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4439 Fix, by Fred Fish, imported from mainline.
4441 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4442 Surprisingly enough, it works now.
4443 By Michal Ludvig, imported from mainline.
4445 i386 hardware watchpoint support:
4446 avoid misses on second run for some targets.
4447 By Pierre Muller, imported from mainline.
4449 *** Changes in GDB 5.2:
4451 * New command "set trust-readonly-sections on[off]".
4453 This command is a hint that tells gdb that read-only sections
4454 really are read-only (ie. that their contents will not change).
4455 In this mode, gdb will go to the object file rather than the
4456 target to read memory from read-only sections (such as ".text").
4457 This can be a significant performance improvement on some
4458 (notably embedded) targets.
4460 * New command "generate-core-file" (or "gcore").
4462 This new gdb command allows the user to drop a core file of the child
4463 process state at any time. So far it's been implemented only for
4464 GNU/Linux and Solaris, but should be relatively easily ported to other
4465 hosts. Argument is core file name (defaults to core.<pid>).
4467 * New command line option
4469 GDB now accepts --pid or -p followed by a process id.
4471 * Change in command line behavior -- corefiles vs. process ids.
4473 There is a subtle behavior in the way in which GDB handles
4474 command line arguments. The first non-flag argument is always
4475 a program to debug, but the second non-flag argument may either
4476 be a corefile or a process id. Previously, GDB would attempt to
4477 open the second argument as a corefile, and if that failed, would
4478 issue a superfluous error message and then attempt to attach it as
4479 a process. Now, if the second argument begins with a non-digit,
4480 it will be treated as a corefile. If it begins with a digit,
4481 GDB will attempt to attach it as a process, and if no such process
4482 is found, will then attempt to open it as a corefile.
4484 * Changes in ARM configurations.
4486 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4487 configuration is fully multi-arch.
4489 * New native configurations
4491 ARM NetBSD arm*-*-netbsd*
4492 x86 OpenBSD i[3456]86-*-openbsd*
4493 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4494 Sparc64 running FreeBSD sparc64-*-freebsd*
4498 Sanyo XStormy16 xstormy16-elf
4500 * OBSOLETE configurations and files
4502 Configurations that have been declared obsolete in this release have
4503 been commented out. Unless there is activity to revive these
4504 configurations, the next release of GDB will have their sources
4505 permanently REMOVED.
4507 AMD 29k family via UDI a29k-amd-udi, udi29k
4508 A29K VxWorks a29k-*-vxworks
4509 AMD 29000 embedded, using EBMON a29k-none-none
4510 AMD 29000 embedded with COFF a29k-none-coff
4511 AMD 29000 embedded with a.out a29k-none-aout
4513 testsuite/gdb.hp/gdb.threads-hp/ directory
4515 * REMOVED configurations and files
4517 TI TMS320C80 tic80-*-*
4519 PowerPC Solaris powerpcle-*-solaris*
4520 PowerPC Windows NT powerpcle-*-cygwin32
4521 PowerPC Netware powerpc-*-netware*
4522 Harris/CXUX m88k m88*-harris-cxux*
4523 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4524 ns32k-utek-sysv* ns32k-utek-*
4525 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4526 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4527 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4528 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4529 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4531 * Changes to command line processing
4533 The new `--args' feature can be used to specify command-line arguments
4534 for the inferior from gdb's command line.
4536 * Changes to key bindings
4538 There is a new `operate-and-get-next' function bound to `C-o'.
4540 *** Changes in GDB 5.1.1
4542 Fix compile problem on DJGPP.
4544 Fix a problem with floating-point registers on the i386 being
4547 Fix to stop GDB crashing on .debug_str debug info.
4549 Numerous documentation fixes.
4551 Numerous testsuite fixes.
4553 *** Changes in GDB 5.1:
4555 * New native configurations
4557 Alpha FreeBSD alpha*-*-freebsd*
4558 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4559 MIPS GNU/Linux mips*-*-linux*
4560 MIPS SGI Irix 6.x mips*-sgi-irix6*
4561 ia64 AIX ia64-*-aix*
4562 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4566 Motorola 68HC11 and 68HC12 m68hc11-elf
4568 UltraSparc running GNU/Linux sparc64-*-linux*
4570 * OBSOLETE configurations and files
4572 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4573 Harris/CXUX m88k m88*-harris-cxux*
4574 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4575 ns32k-utek-sysv* ns32k-utek-*
4576 TI TMS320C80 tic80-*-*
4578 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4579 PowerPC Solaris powerpcle-*-solaris*
4580 PowerPC Windows NT powerpcle-*-cygwin32
4581 PowerPC Netware powerpc-*-netware*
4582 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4583 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4584 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4585 Apple Macintosh (MPW) host N/A
4587 stuff.c (Program to stuff files into a specially prepared space in kdb)
4588 kdb-start.c (Main loop for the standalone kernel debugger)
4590 Configurations that have been declared obsolete in this release have
4591 been commented out. Unless there is activity to revive these
4592 configurations, the next release of GDB will have their sources
4593 permanently REMOVED.
4595 * REMOVED configurations and files
4597 Altos 3068 m68*-altos-*
4598 Convex c1-*-*, c2-*-*
4600 ARM RISCix arm-*-* (as host)
4604 * GDB has been converted to ISO C.
4606 GDB's source code has been converted to ISO C. In particular, the
4607 sources are fully protoized, and rely on standard headers being
4612 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4614 * The MI enabled by default.
4616 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4617 revised and enabled by default. Packages which use GDB as a debugging
4618 engine behind a UI or another front end are encouraged to switch to
4619 using the GDB/MI interface, instead of the old annotations interface
4620 which is now deprecated.
4622 * Support for debugging Pascal programs.
4624 GDB now includes support for debugging Pascal programs. The following
4625 main features are supported:
4627 - Pascal-specific data types such as sets;
4629 - automatic recognition of Pascal sources based on file-name
4632 - Pascal-style display of data types, variables, and functions;
4634 - a Pascal expression parser.
4636 However, some important features are not yet supported.
4638 - Pascal string operations are not supported at all;
4640 - there are some problems with boolean types;
4642 - Pascal type hexadecimal constants are not supported
4643 because they conflict with the internal variables format;
4645 - support for Pascal objects and classes is not full yet;
4647 - unlike Pascal, GDB is case-sensitive for symbol names.
4649 * Changes in completion.
4651 Commands such as `shell', `run' and `set args', which pass arguments
4652 to inferior programs, now complete on file names, similar to what
4653 users expect at the shell prompt.
4655 Commands which accept locations, such as `disassemble', `print',
4656 `breakpoint', `until', etc. now complete on filenames as well as
4657 program symbols. Thus, if you type "break foob TAB", and the source
4658 files linked into the programs include `foobar.c', that file name will
4659 be one of the candidates for completion. However, file names are not
4660 considered for completion after you typed a colon that delimits a file
4661 name from a name of a function in that file, as in "break foo.c:bar".
4663 `set demangle-style' completes on available demangling styles.
4665 * New platform-independent commands:
4667 It is now possible to define a post-hook for a command as well as a
4668 hook that runs before the command. For more details, see the
4669 documentation of `hookpost' in the GDB manual.
4671 * Changes in GNU/Linux native debugging.
4673 Support for debugging multi-threaded programs has been completely
4674 revised for all platforms except m68k and sparc. You can now debug as
4675 many threads as your system allows you to have.
4677 Attach/detach is supported for multi-threaded programs.
4679 Support for SSE registers was added for x86. This doesn't work for
4680 multi-threaded programs though.
4682 * Changes in MIPS configurations.
4684 Multi-arch support is enabled for all MIPS configurations.
4686 GDB can now be built as native debugger on SGI Irix 6.x systems for
4687 debugging n32 executables. (Debugging 64-bit executables is not yet
4690 * Unified support for hardware watchpoints in all x86 configurations.
4692 Most (if not all) native x86 configurations support hardware-assisted
4693 breakpoints and watchpoints in a unified manner. This support
4694 implements debug register sharing between watchpoints, which allows to
4695 put a virtually infinite number of watchpoints on the same address,
4696 and also supports watching regions up to 16 bytes with several debug
4699 The new maintenance command `maintenance show-debug-regs' toggles
4700 debugging print-outs in functions that insert, remove, and test
4701 watchpoints and hardware breakpoints.
4703 * Changes in the DJGPP native configuration.
4705 New command ``info dos sysinfo'' displays assorted information about
4706 the CPU, OS, memory, and DPMI server.
4708 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4709 display information about segment descriptors stored in GDT, LDT, and
4712 New commands ``info dos pde'' and ``info dos pte'' display entries
4713 from Page Directory and Page Tables (for now works with CWSDPMI only).
4714 New command ``info dos address-pte'' displays the Page Table entry for
4715 a given linear address.
4717 GDB can now pass command lines longer than 126 characters to the
4718 program being debugged (requires an update to the libdbg.a library
4719 which is part of the DJGPP development kit).
4721 DWARF2 debug info is now supported.
4723 It is now possible to `step' and `next' through calls to `longjmp'.
4725 * Changes in documentation.
4727 All GDB documentation was converted to GFDL, the GNU Free
4728 Documentation License.
4730 Tracepoints-related commands are now fully documented in the GDB
4733 TUI, the Text-mode User Interface, is now documented in the manual.
4735 Tracepoints-related commands are now fully documented in the GDB
4738 The "GDB Internals" manual now has an index. It also includes
4739 documentation of `ui_out' functions, GDB coding standards, x86
4740 hardware watchpoints, and memory region attributes.
4742 * GDB's version number moved to ``version.in''
4744 The Makefile variable VERSION has been replaced by the file
4745 ``version.in''. People creating GDB distributions should update the
4746 contents of this file.
4750 GUD support is now a standard part of the EMACS distribution.
4752 *** Changes in GDB 5.0:
4754 * Improved support for debugging FP programs on x86 targets
4756 Unified and much-improved support for debugging floating-point
4757 programs on all x86 targets. In particular, ``info float'' now
4758 displays the FP registers in the same format on all x86 targets, with
4759 greater level of detail.
4761 * Improvements and bugfixes in hardware-assisted watchpoints
4763 It is now possible to watch array elements, struct members, and
4764 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4765 on x86 targets no longer erroneously trigger when the address is
4768 * Improvements in the native DJGPP version of GDB
4770 The distribution now includes all the scripts and auxiliary files
4771 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4772 machines ``out of the box''.
4774 The DJGPP version can now debug programs that use signals. It is
4775 possible to catch signals that happened in the debuggee, deliver
4776 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4777 would kill the program being debugged.) Programs that hook hardware
4778 interrupts (keyboard, timer, etc.) can also be debugged.
4780 It is now possible to debug DJGPP programs that redirect their
4781 standard handles or switch them to raw (as opposed to cooked) mode, or
4782 even close them. The command ``run < foo > bar'' works as expected,
4783 and ``info terminal'' reports useful information about the debuggee's
4784 terminal, including raw/cooked mode, redirection, etc.
4786 The DJGPP version now uses termios functions for console I/O, which
4787 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4790 DOS-style file names with drive letters are now fully supported by
4793 It is now possible to debug DJGPP programs that switch their working
4794 directory. It is also possible to rerun the debuggee any number of
4795 times without restarting GDB; thus, you can use the same setup,
4796 breakpoints, etc. for many debugging sessions.
4798 * New native configurations
4800 ARM GNU/Linux arm*-*-linux*
4801 PowerPC GNU/Linux powerpc-*-linux*
4805 Motorola MCore mcore-*-*
4806 x86 VxWorks i[3456]86-*-vxworks*
4807 PowerPC VxWorks powerpc-*-vxworks*
4808 TI TMS320C80 tic80-*-*
4810 * OBSOLETE configurations
4812 Altos 3068 m68*-altos-*
4813 Convex c1-*-*, c2-*-*
4815 ARM RISCix arm-*-* (as host)
4818 Configurations that have been declared obsolete will be commented out,
4819 but the code will be left in place. If there is no activity to revive
4820 these configurations before the next release of GDB, the sources will
4821 be permanently REMOVED.
4823 * Gould support removed
4825 Support for the Gould PowerNode and NP1 has been removed.
4827 * New features for SVR4
4829 On SVR4 native platforms (such as Solaris), if you attach to a process
4830 without first loading a symbol file, GDB will now attempt to locate and
4831 load symbols from the running process's executable file.
4833 * Many C++ enhancements
4835 C++ support has been greatly improved. Overload resolution now works properly
4836 in almost all cases. RTTI support is on the way.
4838 * Remote targets can connect to a sub-program
4840 A popen(3) style serial-device has been added. This device starts a
4841 sub-process (such as a stand-alone simulator) and then communicates
4842 with that. The sub-program to run is specified using the syntax
4843 ``|<program> <args>'' vis:
4845 (gdb) set remotedebug 1
4846 (gdb) target extended-remote |mn10300-elf-sim program-args
4848 * MIPS 64 remote protocol
4850 A long standing bug in the mips64 remote protocol where by GDB
4851 expected certain 32 bit registers (ex SR) to be transfered as 32
4852 instead of 64 bits has been fixed.
4854 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4855 added to provide backward compatibility with older versions of GDB.
4857 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4859 The command ``set remotebinarydownload'' command has been replaced by
4860 ``set remote X-packet''. Other commands in ``set remote'' family
4861 include ``set remote P-packet''.
4863 * Breakpoint commands accept ranges.
4865 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4866 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4867 ``tracepoint passcount'' also accepts a range of tracepoints.
4869 * ``apropos'' command added.
4871 The ``apropos'' command searches through command names and
4872 documentation strings, printing out matches, making it much easier to
4873 try to find a command that does what you are looking for.
4877 A new machine oriented interface (MI) has been added to GDB. This
4878 interface is designed for debug environments running GDB as a separate
4879 process. This is part of the long term libGDB project. See the
4880 "GDB/MI" chapter of the GDB manual for further information. It can be
4881 enabled by configuring with:
4883 .../configure --enable-gdbmi
4885 *** Changes in GDB-4.18:
4887 * New native configurations
4889 HP-UX 10.20 hppa*-*-hpux10.20
4890 HP-UX 11.x hppa*-*-hpux11.0*
4891 M68K GNU/Linux m68*-*-linux*
4895 Fujitsu FR30 fr30-*-elf*
4896 Intel StrongARM strongarm-*-*
4897 Mitsubishi D30V d30v-*-*
4899 * OBSOLETE configurations
4901 Gould PowerNode, NP1 np1-*-*, pn-*-*
4903 Configurations that have been declared obsolete will be commented out,
4904 but the code will be left in place. If there is no activity to revive
4905 these configurations before the next release of GDB, the sources will
4906 be permanently REMOVED.
4910 As a compatibility experiment, GDB's source files buildsym.h and
4911 buildsym.c have been converted to pure standard C, no longer
4912 containing any K&R compatibility code. We believe that all systems in
4913 use today either come with a standard C compiler, or have a GCC port
4914 available. If this is not true, please report the affected
4915 configuration to bug-gdb@gnu.org immediately. See the README file for
4916 information about getting a standard C compiler if you don't have one
4921 GDB now uses readline 2.2.
4923 * set extension-language
4925 You can now control the mapping between filename extensions and source
4926 languages by using the `set extension-language' command. For instance,
4927 you can ask GDB to treat .c files as C++ by saying
4928 set extension-language .c c++
4929 The command `info extensions' lists all of the recognized extensions
4930 and their associated languages.
4932 * Setting processor type for PowerPC and RS/6000
4934 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4935 you can use the `set processor' command to specify what variant of the
4936 PowerPC family you are debugging. The command
4940 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4941 following PowerPC and RS6000 variants:
4943 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4944 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4946 403GC IBM PowerPC 403GC
4947 505 Motorola PowerPC 505
4948 860 Motorola PowerPC 860 or 850
4949 601 Motorola PowerPC 601
4950 602 Motorola PowerPC 602
4951 603 Motorola/IBM PowerPC 603 or 603e
4952 604 Motorola PowerPC 604 or 604e
4953 750 Motorola/IBM PowerPC 750 or 750
4955 At the moment, this command just tells GDB what to name the
4956 special-purpose processor registers. Since almost all the affected
4957 registers are inaccessible to user-level programs, this command is
4958 only useful for remote debugging in its present form.
4962 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4963 more extensive support for HP-UX. Added features include shared
4964 library support, kernel threads and hardware watchpoints for 11.00,
4965 support for HP's ANSI C and C++ compilers, and a compatibility mode
4966 for xdb and dbx commands.
4970 HP's donation includes the new concept of catchpoints, which is a
4971 generalization of the old catch command. On HP-UX, it is now possible
4972 to catch exec, fork, and vfork, as well as library loading.
4974 This means that the existing catch command has changed; its first
4975 argument now specifies the type of catch to be set up. See the
4976 output of "help catch" for a list of catchpoint types.
4978 * Debugging across forks
4980 On HP-UX, you can choose which process to debug when a fork() happens
4985 HP has donated a curses-based terminal user interface (TUI). To get
4986 it, build with --enable-tui. Although this can be enabled for any
4987 configuration, at present it only works for native HP debugging.
4989 * GDB remote protocol additions
4991 A new protocol packet 'X' that writes binary data is now available.
4992 Default behavior is to try 'X', then drop back to 'M' if the stub
4993 fails to respond. The settable variable `remotebinarydownload'
4994 allows explicit control over the use of 'X'.
4996 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4997 full 64-bit address. The command
4999 set remoteaddresssize 32
5001 can be used to revert to the old behaviour. For existing remote stubs
5002 the change should not be noticed, as the additional address information
5005 In order to assist in debugging stubs, you may use the maintenance
5006 command `packet' to send any text string to the stub. For instance,
5008 maint packet heythere
5010 sends the packet "$heythere#<checksum>". Note that it is very easy to
5011 disrupt a debugging session by sending the wrong packet at the wrong
5014 The compare-sections command allows you to compare section data on the
5015 target to what is in the executable file without uploading or
5016 downloading, by comparing CRC checksums.
5018 * Tracing can collect general expressions
5020 You may now collect general expressions at tracepoints. This requires
5021 further additions to the target-side stub; see tracepoint.c and
5022 doc/agentexpr.texi for further details.
5024 * mask-address variable for Mips
5026 For Mips targets, you may control the zeroing of the upper 32 bits of
5027 a 64-bit address by entering `set mask-address on'. This is mainly
5028 of interest to users of embedded R4xxx and R5xxx processors.
5030 * Higher serial baud rates
5032 GDB's serial code now allows you to specify baud rates 57600, 115200,
5033 230400, and 460800 baud. (Note that your host system may not be able
5034 to achieve all of these rates.)
5038 The i960 configuration now includes an initial implementation of a
5039 builtin simulator, contributed by Jim Wilson.
5042 *** Changes in GDB-4.17:
5044 * New native configurations
5046 Alpha GNU/Linux alpha*-*-linux*
5047 Unixware 2.x i[3456]86-unixware2*
5048 Irix 6.x mips*-sgi-irix6*
5049 PowerPC GNU/Linux powerpc-*-linux*
5050 PowerPC Solaris powerpcle-*-solaris*
5051 Sparc GNU/Linux sparc-*-linux*
5052 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5056 Argonaut Risc Chip (ARC) arc-*-*
5057 Hitachi H8/300S h8300*-*-*
5058 Matsushita MN10200 w/simulator mn10200-*-*
5059 Matsushita MN10300 w/simulator mn10300-*-*
5060 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5061 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5062 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5063 Mitsubishi D10V w/simulator d10v-*-*
5064 Mitsubishi M32R/D w/simulator m32r-*-elf*
5065 Tsqware Sparclet sparclet-*-*
5066 NEC V850 w/simulator v850-*-*
5068 * New debugging protocols
5070 ARM with RDI protocol arm*-*-*
5071 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5072 DDB and LSI variants of PMON protocol mips*-*-*
5073 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5074 PowerPC with SDS protocol powerpc{,le}-*-eabi
5075 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5079 All configurations can now understand and use the DWARF 2 debugging
5080 format. The choice is automatic, if the symbol file contains DWARF 2
5085 GDB now includes basic Java language support. This support is
5086 only useful with Java compilers that produce native machine code.
5088 * solib-absolute-prefix and solib-search-path
5090 For SunOS and SVR4 shared libraries, you may now set the prefix for
5091 loading absolute shared library symbol files, and the search path for
5092 locating non-absolute shared library symbol files.
5094 * Live range splitting
5096 GDB can now effectively debug code for which GCC has performed live
5097 range splitting as part of its optimization. See gdb/doc/LRS for
5098 more details on the expected format of the stabs information.
5102 GDB's support for the GNU Hurd, including thread debugging, has been
5103 updated to work with current versions of the Hurd.
5107 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5108 instruction set. ARM GDB automatically detects when Thumb
5109 instructions are in use, and adjusts disassembly and backtracing
5114 GDB's MIPS target configurations now handle the MIP16 16-bit
5119 GDB now includes support for overlays; if an executable has been
5120 linked such that multiple sections are based at the same address, GDB
5121 will decide which section to use for symbolic info. You can choose to
5122 control the decision manually, using overlay commands, or implement
5123 additional target-side support and use "overlay load-target" to bring
5124 in the overlay mapping. Do "help overlay" for more detail.
5128 The command "info symbol <address>" displays information about
5129 the symbol at the specified address.
5133 The standard remote protocol now includes an extension that allows
5134 asynchronous collection and display of trace data. This requires
5135 extensive support in the target-side debugging stub. Tracing mode
5136 includes a new interaction mode in GDB and new commands: see the
5137 file tracepoint.c for more details.
5141 Configurations for embedded MIPS now include a simulator contributed
5142 by Cygnus Solutions. The simulator supports the instruction sets
5143 of most MIPS variants.
5147 Sparc configurations may now include the ERC32 simulator contributed
5148 by the European Space Agency. The simulator is not built into
5149 Sparc targets by default; configure with --enable-sim to include it.
5153 For target configurations that may include multiple variants of a
5154 basic architecture (such as MIPS and SH), you may now set the
5155 architecture explicitly. "set arch" sets, "info arch" lists
5156 the possible architectures.
5158 *** Changes in GDB-4.16:
5160 * New native configurations
5162 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5163 M68K NetBSD m68k-*-netbsd*
5164 PowerPC AIX 4.x powerpc-*-aix*
5165 PowerPC MacOS powerpc-*-macos*
5166 PowerPC Windows NT powerpcle-*-cygwin32
5167 RS/6000 AIX 4.x rs6000-*-aix4*
5171 ARM with RDP protocol arm-*-*
5172 I960 with MON960 i960-*-coff
5173 MIPS VxWorks mips*-*-vxworks*
5174 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5175 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5177 Matra Sparclet sparclet-*-*
5181 The powerpc-eabi configuration now includes the PSIM simulator,
5182 contributed by Andrew Cagney, with assistance from Mike Meissner.
5183 PSIM is a very elaborate model of the PowerPC, including not only
5184 basic instruction set execution, but also details of execution unit
5185 performance and I/O hardware. See sim/ppc/README for more details.
5189 GDB now works with Solaris 2.5.
5191 * Windows 95/NT native
5193 GDB will now work as a native debugger on Windows 95 and Windows NT.
5194 To build it from source, you must use the "gnu-win32" environment,
5195 which uses a DLL to emulate enough of Unix to run the GNU tools.
5196 Further information, binaries, and sources are available at
5197 ftp.cygnus.com, under pub/gnu-win32.
5199 * dont-repeat command
5201 If a user-defined command includes the command `dont-repeat', then the
5202 command will not be repeated if the user just types return. This is
5203 useful if the command is time-consuming to run, so that accidental
5204 extra keystrokes don't run the same command many times.
5206 * Send break instead of ^C
5208 The standard remote protocol now includes an option to send a break
5209 rather than a ^C to the target in order to interrupt it. By default,
5210 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5212 * Remote protocol timeout
5214 The standard remote protocol includes a new variable `remotetimeout'
5215 that allows you to set the number of seconds before GDB gives up trying
5216 to read from the target. The default value is 2.
5218 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5220 By default GDB will automatically keep track of objects as they are
5221 loaded and unloaded by the dynamic linker. By using the command `set
5222 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5223 when shared library events occur, thus allowing you to set breakpoints
5224 in shared libraries which are explicitly loaded by the inferior.
5226 Note this feature does not work on hpux8. On hpux9 you must link
5227 /usr/lib/end.o into your program. This feature should work
5228 automatically on hpux10.
5230 * Irix 5.x hardware watchpoint support
5232 Irix 5 configurations now support the use of hardware watchpoints.
5234 * Mips protocol "SYN garbage limit"
5236 When debugging a Mips target using the `target mips' protocol, you
5237 may set the number of characters that GDB will ignore by setting
5238 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5239 every character. The default value is 1050.
5241 * Recording and replaying remote debug sessions
5243 If you set `remotelogfile' to the name of a file, gdb will write to it
5244 a recording of a remote debug session. This recording may then be
5245 replayed back to gdb using "gdbreplay". See gdbserver/README for
5246 details. This is useful when you have a problem with GDB while doing
5247 remote debugging; you can make a recording of the session and send it
5248 to someone else, who can then recreate the problem.
5250 * Speedups for remote debugging
5252 GDB includes speedups for downloading and stepping MIPS systems using
5253 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5254 and more efficient S-record downloading.
5256 * Memory use reductions and statistics collection
5258 GDB now uses less memory and reports statistics about memory usage.
5259 Try the `maint print statistics' command, for example.
5261 *** Changes in GDB-4.15:
5263 * Psymtabs for XCOFF
5265 The symbol reader for AIX GDB now uses partial symbol tables. This
5266 can greatly improve startup time, especially for large executables.
5268 * Remote targets use caching
5270 Remote targets now use a data cache to speed up communication with the
5271 remote side. The data cache could lead to incorrect results because
5272 it doesn't know about volatile variables, thus making it impossible to
5273 debug targets which use memory mapped I/O devices. `set remotecache
5274 off' turns the the data cache off.
5276 * Remote targets may have threads
5278 The standard remote protocol now includes support for multiple threads
5279 in the target system, using new protocol commands 'H' and 'T'. See
5280 gdb/remote.c for details.
5284 If GDB is configured with `--enable-netrom', then it will include
5285 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5286 acts as though it is a bank of ROM on the target board, but you can
5287 write into it over the network. GDB's support consists only of
5288 support for fast loading into the emulated ROM; to debug, you must use
5289 another protocol, such as standard remote protocol. The usual
5290 sequence is something like
5292 target nrom <netrom-hostname>
5294 target remote <netrom-hostname>:1235
5298 GDB now includes support for the Apple Macintosh, as a host only. It
5299 may be run as either an MPW tool or as a standalone application, and
5300 it can debug through the serial port. All the usual GDB commands are
5301 available, but to the target command, you must supply "serial" as the
5302 device type instead of "/dev/ttyXX". See mpw-README in the main
5303 directory for more information on how to build. The MPW configuration
5304 scripts */mpw-config.in support only a few targets, and only the
5305 mips-idt-ecoff target has been tested.
5309 GDB configuration now uses autoconf. This is not user-visible,
5310 but does simplify configuration and building.
5314 GDB now supports hpux10.
5316 *** Changes in GDB-4.14:
5318 * New native configurations
5320 x86 FreeBSD i[345]86-*-freebsd
5321 x86 NetBSD i[345]86-*-netbsd
5322 NS32k NetBSD ns32k-*-netbsd
5323 Sparc NetBSD sparc-*-netbsd
5327 A29K VxWorks a29k-*-vxworks
5328 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5329 CPU32 EST-300 emulator m68*-*-est*
5330 PowerPC ELF powerpc-*-elf
5333 * Alpha OSF/1 support for procfs
5335 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5336 possible to attach to running processes. As the mounting of the /proc
5337 filesystem is optional on the Alpha, GDB automatically determines
5338 the availability of /proc during startup. This can lead to problems
5339 if /proc is unmounted after GDB has been started.
5341 * Arguments to user-defined commands
5343 User commands may accept up to 10 arguments separated by whitespace.
5344 Arguments are accessed within the user command via $arg0..$arg9. A
5347 print $arg0 + $arg1 + $arg2
5349 To execute the command use:
5352 Defines the command "adder" which prints the sum of its three arguments.
5353 Note the arguments are text substitutions, so they may reference variables,
5354 use complex expressions, or even perform inferior function calls.
5356 * New `if' and `while' commands
5358 This makes it possible to write more sophisticated user-defined
5359 commands. Both commands take a single argument, which is the
5360 expression to evaluate, and must be followed by the commands to
5361 execute, one per line, if the expression is nonzero, the list being
5362 terminated by the word `end'. The `if' command list may include an
5363 `else' word, which causes the following commands to be executed only
5364 if the expression is zero.
5366 * Fortran source language mode
5368 GDB now includes partial support for Fortran 77. It will recognize
5369 Fortran programs and can evaluate a subset of Fortran expressions, but
5370 variables and functions may not be handled correctly. GDB will work
5371 with G77, but does not yet know much about symbols emitted by other
5374 * Better HPUX support
5376 Most debugging facilities now work on dynamic executables for HPPAs
5377 running hpux9 or later. You can attach to running dynamically linked
5378 processes, but by default the dynamic libraries will be read-only, so
5379 for instance you won't be able to put breakpoints in them. To change
5380 that behavior do the following before running the program:
5386 This will cause the libraries to be mapped private and read-write.
5387 To revert to the normal behavior, do this:
5393 You cannot set breakpoints or examine data in the library until after
5394 the library is loaded if the function/data symbols do not have
5397 GDB can now also read debug symbols produced by the HP C compiler on
5398 HPPAs (sorry, no C++, Fortran or 68k support).
5400 * Target byte order now dynamically selectable
5402 You can choose which byte order to use with a target system, via the
5403 commands "set endian big" and "set endian little", and you can see the
5404 current setting by using "show endian". You can also give the command
5405 "set endian auto", in which case GDB will use the byte order
5406 associated with the executable. Currently, only embedded MIPS
5407 configurations support dynamic selection of target byte order.
5409 * New DOS host serial code
5411 This version uses DPMI interrupts to handle buffered I/O, so you
5412 no longer need to run asynctsr when debugging boards connected to
5415 *** Changes in GDB-4.13:
5417 * New "complete" command
5419 This lists all the possible completions for the rest of the line, if it
5420 were to be given as a command itself. This is intended for use by emacs.
5422 * Trailing space optional in prompt
5424 "set prompt" no longer adds a space for you after the prompt you set. This
5425 allows you to set a prompt which ends in a space or one that does not.
5427 * Breakpoint hit counts
5429 "info break" now displays a count of the number of times the breakpoint
5430 has been hit. This is especially useful in conjunction with "ignore"; you
5431 can ignore a large number of breakpoint hits, look at the breakpoint info
5432 to see how many times the breakpoint was hit, then run again, ignoring one
5433 less than that number, and this will get you quickly to the last hit of
5436 * Ability to stop printing at NULL character
5438 "set print null-stop" will cause GDB to stop printing the characters of
5439 an array when the first NULL is encountered. This is useful when large
5440 arrays actually contain only short strings.
5442 * Shared library breakpoints
5444 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5445 breakpoints in shared libraries before the executable is run.
5447 * Hardware watchpoints
5449 There is a new hardware breakpoint for the watch command for sparclite
5450 targets. See gdb/sparclite/hw_breakpoint.note.
5452 Hardware watchpoints are also now supported under GNU/Linux.
5456 Annotations have been added. These are for use with graphical interfaces,
5457 and are still experimental. Currently only gdba.el uses these.
5459 * Improved Irix 5 support
5461 GDB now works properly with Irix 5.2.
5463 * Improved HPPA support
5465 GDB now works properly with the latest GCC and GAS.
5467 * New native configurations
5469 Sequent PTX4 i[34]86-sequent-ptx4
5470 HPPA running OSF/1 hppa*-*-osf*
5471 Atari TT running SVR4 m68*-*-sysv4*
5472 RS/6000 LynxOS rs6000-*-lynxos*
5476 OS/9000 i[34]86-*-os9k
5477 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5480 * Hitachi SH7000 and E7000-PC ICE support
5482 There is now support for communicating with the Hitachi E7000-PC ICE.
5483 This is available automatically when GDB is configured for the SH.
5487 As usual, a variety of small fixes and improvements, both generic
5488 and configuration-specific. See the ChangeLog for more detail.
5490 *** Changes in GDB-4.12:
5492 * Irix 5 is now supported
5496 GDB-4.12 on the HPPA has a number of changes which make it unable
5497 to debug the output from the currently released versions of GCC and
5498 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5499 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5500 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5503 *** Changes in GDB-4.11:
5505 * User visible changes:
5509 The "set remotedebug" option is now consistent between the mips remote
5510 target, remote targets using the gdb-specific protocol, UDI (AMD's
5511 debug protocol for the 29k) and the 88k bug monitor. It is now an
5512 integer specifying a debug level (normally 0 or 1, but 2 means more
5513 debugging info for the mips target).
5515 * DEC Alpha native support
5517 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5518 debug info, but GDB works fairly well with the DEC compiler and should
5519 work with a future GCC release. See the README file for a few
5520 Alpha-specific notes.
5522 * Preliminary thread implementation
5524 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5526 * LynxOS native and target support for 386
5528 This release has been hosted on LynxOS 2.2, and also can be configured
5529 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5532 * Improvements in C++ mangling/demangling.
5534 This release has much better g++ debugging, specifically in name
5535 mangling/demangling, virtual function calls, print virtual table,
5536 call methods, ...etc.
5538 *** Changes in GDB-4.10:
5540 * User visible changes:
5542 Remote debugging using the GDB-specific (`target remote') protocol now
5543 supports the `load' command. This is only useful if you have some
5544 other way of getting the stub to the target system, and you can put it
5545 somewhere in memory where it won't get clobbered by the download.
5547 Filename completion now works.
5549 When run under emacs mode, the "info line" command now causes the
5550 arrow to point to the line specified. Also, "info line" prints
5551 addresses in symbolic form (as well as hex).
5553 All vxworks based targets now support a user settable option, called
5554 vxworks-timeout. This option represents the number of seconds gdb
5555 should wait for responses to rpc's. You might want to use this if
5556 your vxworks target is, perhaps, a slow software simulator or happens
5557 to be on the far side of a thin network line.
5561 This release contains support for using a DEC alpha as a GDB host for
5562 cross debugging. Native alpha debugging is not supported yet.
5565 *** Changes in GDB-4.9:
5569 This is the first GDB release which is accompanied by a matching testsuite.
5570 The testsuite requires installation of dejagnu, which should be available
5571 via ftp from most sites that carry GNU software.
5575 'Cfront' style demangling has had its name changed to 'ARM' style, to
5576 emphasize that it was written from the specifications in the C++ Annotated
5577 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5578 disclaimers, it still generated too much confusion with users attempting to
5579 use gdb with AT&T cfront.
5583 GDB now uses a standard remote interface to a simulator library.
5584 So far, the library contains simulators for the Zilog Z8001/2, the
5585 Hitachi H8/300, H8/500 and Super-H.
5587 * New targets supported
5589 H8/300 simulator h8300-hitachi-hms or h8300hms
5590 H8/500 simulator h8500-hitachi-hms or h8500hms
5591 SH simulator sh-hitachi-hms or sh
5592 Z8000 simulator z8k-zilog-none or z8ksim
5593 IDT MIPS board over serial line mips-idt-ecoff
5595 Cross-debugging to GO32 targets is supported. It requires a custom
5596 version of the i386-stub.c module which is integrated with the
5597 GO32 memory extender.
5599 * New remote protocols
5601 MIPS remote debugging protocol.
5603 * New source languages supported
5605 This version includes preliminary support for Chill, a Pascal like language
5606 used by telecommunications companies. Chill support is also being integrated
5607 into the GNU compiler, but we don't know when it will be publically available.
5610 *** Changes in GDB-4.8:
5612 * HP Precision Architecture supported
5614 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5615 version of this support was available as a set of patches from the
5616 University of Utah. GDB does not support debugging of programs
5617 compiled with the HP compiler, because HP will not document their file
5618 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5619 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5621 Many problems in the preliminary version have been fixed.
5623 * Faster and better demangling
5625 We have improved template demangling and fixed numerous bugs in the GNU style
5626 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5627 character types (wchar_t) are now supported. Demangling of each symbol is now
5628 only done once, and is cached when the symbol table for a file is read in.
5629 This results in a small increase in memory usage for C programs, a moderate
5630 increase in memory usage for C++ programs, and a fantastic speedup in
5633 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5634 from the specifications in the Annotated Reference Manual, which AT&T's
5635 compiler does not actually implement.
5637 * G++ multiple inheritance compiler problem
5639 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5640 inheritance lattices was reworked to properly discover ambiguities. We
5641 recently found an example which causes this new algorithm to fail in a
5642 very subtle way, producing bad debug information for those classes.
5643 The file 'gcc.patch' (in this directory) can be applied to gcc to
5644 circumvent the problem. A future GCC release will contain a complete
5647 The previous G++ debug info problem (mentioned below for the gdb-4.7
5648 release) is fixed in gcc version 2.3.2.
5650 * Improved configure script
5652 The `configure' script will now attempt to guess your system type if
5653 you don't supply a host system type. The old scheme of supplying a
5654 host system triplet is preferable over using this. All the magic is
5655 done in the new `config.guess' script. Examine it for details.
5657 We have also brought our configure script much more in line with the FSF's
5658 version. It now supports the --with-xxx options. In particular,
5659 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5660 The resulting GDB will not be able to read arbitrary object file formats --
5661 only the format ``expected'' to be used on the configured target system.
5662 We hope to make this the default in a future release.
5664 * Documentation improvements
5666 There's new internal documentation on how to modify GDB, and how to
5667 produce clean changes to the code. We implore people to read it
5668 before submitting changes.
5670 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5671 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5672 `info' files are also provided. To build `info' files from scratch,
5673 you will need the latest `makeinfo' release, which will be available in
5674 a future texinfo-X.Y release.
5676 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5677 We're not sure exactly which versions have this problem, but it has
5678 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5679 or better. If that isn't possible, there is a patch in
5680 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5681 around this problem.
5685 GDB now supports array constants that can be used in expressions typed in by
5686 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5687 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5690 The new directory `gdb/sparclite' contains a program that demonstrates
5691 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5693 * New native hosts supported
5695 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5696 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5698 * New targets supported
5700 AMD 29k family via UDI a29k-amd-udi or udi29k
5702 * New file formats supported
5704 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5705 HPUX core files, and SCO 3.2v2 core files.
5709 Attaching to processes now works again; thanks for the many bug reports.
5711 We have also stomped on a bunch of core dumps caused by
5712 printf_filtered("%s") problems.
5714 We eliminated a copyright problem on the rpc and ptrace header files
5715 for VxWorks, which was discovered at the last minute during the 4.7
5716 release. You should now be able to build a VxWorks GDB.
5718 You can now interrupt gdb while an attached process is running. This
5719 will cause the attached process to stop, and give control back to GDB.
5721 We fixed problems caused by using too many file descriptors
5722 for reading symbols from object files and libraries. This was
5723 especially a problem for programs that used many (~100) shared
5726 The `step' command now only enters a subroutine if there is line number
5727 information for the subroutine. Otherwise it acts like the `next'
5728 command. Previously, `step' would enter subroutines if there was
5729 any debugging information about the routine. This avoids problems
5730 when using `cc -g1' on MIPS machines.
5732 * Internal improvements
5734 GDB's internal interfaces have been improved to make it easier to support
5735 debugging of multiple languages in the future.
5737 GDB now uses a common structure for symbol information internally.
5738 Minimal symbols (derived from linkage symbols in object files), partial
5739 symbols (from a quick scan of debug information), and full symbols
5740 contain a common subset of information, making it easier to write
5741 shared code that handles any of them.
5743 * New command line options
5745 We now accept --silent as an alias for --quiet.
5749 The memory-mapped-malloc library is now licensed under the GNU Library
5750 General Public License.
5752 *** Changes in GDB-4.7:
5754 * Host/native/target split
5756 GDB has had some major internal surgery to untangle the support for
5757 hosts and remote targets. Now, when you configure GDB for a remote
5758 target, it will no longer load in all of the support for debugging
5759 local programs on the host. When fully completed and tested, this will
5760 ensure that arbitrary host/target combinations are possible.
5762 The primary conceptual shift is to separate the non-portable code in
5763 GDB into three categories. Host specific code is required any time GDB
5764 is compiled on that host, regardless of the target. Target specific
5765 code relates to the peculiarities of the target, but can be compiled on
5766 any host. Native specific code is everything else: it can only be
5767 built when the host and target are the same system. Child process
5768 handling and core file support are two common `native' examples.
5770 GDB's use of /proc for controlling Unix child processes is now cleaner.
5771 It has been split out into a single module under the `target_ops' vector,
5772 plus two native-dependent functions for each system that uses /proc.
5774 * New hosts supported
5776 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5777 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5778 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5780 * New targets supported
5782 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5783 68030 and CPU32 m68030-*-*, m68332-*-*
5785 * New native hosts supported
5787 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5788 (386bsd is not well tested yet)
5789 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5791 * New file formats supported
5793 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5794 supports reading of `a.out.adobe' object files, which are an a.out
5795 format extended with minimal information about multiple sections.
5799 `show copying' is the same as the old `info copying'.
5800 `show warranty' is the same as `info warrantee'.
5801 These were renamed for consistency. The old commands continue to work.
5803 `info handle' is a new alias for `info signals'.
5805 You can now define pre-command hooks, which attach arbitrary command
5806 scripts to any command. The commands in the hook will be executed
5807 prior to the user's command. You can also create a hook which will be
5808 executed whenever the program stops. See gdb.texinfo.
5812 We now deal with Cfront style name mangling, and can even extract type
5813 info from mangled symbols. GDB can automatically figure out which
5814 symbol mangling style your C++ compiler uses.
5816 Calling of methods and virtual functions has been improved as well.
5820 The crash that occured when debugging Sun Ansi-C compiled binaries is
5821 fixed. This was due to mishandling of the extra N_SO stabs output
5824 We also finally got Ultrix 4.2 running in house, and fixed core file
5825 support, with help from a dozen people on the net.
5827 John M. Farrell discovered that the reason that single-stepping was so
5828 slow on all of the Mips based platforms (primarily SGI and DEC) was
5829 that we were trying to demangle and lookup a symbol used for internal
5830 purposes on every instruction that was being stepped through. Changing
5831 the name of that symbol so that it couldn't be mistaken for a C++
5832 mangled symbol sped things up a great deal.
5834 Rich Pixley sped up symbol lookups in general by getting much smarter
5835 about when C++ symbol mangling is necessary. This should make symbol
5836 completion (TAB on the command line) much faster. It's not as fast as
5837 we'd like, but it's significantly faster than gdb-4.6.
5841 A new user controllable variable 'call_scratch_address' can
5842 specify the location of a scratch area to be used when GDB
5843 calls a function in the target. This is necessary because the
5844 usual method of putting the scratch area on the stack does not work
5845 in systems that have separate instruction and data spaces.
5847 We integrated changes to support the 29k UDI (Universal Debugger
5848 Interface), but discovered at the last minute that we didn't have all
5849 of the appropriate copyright paperwork. We are working with AMD to
5850 resolve this, and hope to have it available soon.
5854 We have sped up the remote serial line protocol, especially for targets
5855 with lots of registers. It now supports a new `expedited status' ('T')
5856 message which can be used in place of the existing 'S' status message.
5857 This allows the remote stub to send only the registers that GDB
5858 needs to make a quick decision about single-stepping or conditional
5859 breakpoints, eliminating the need to fetch the entire register set for
5860 each instruction being stepped through.
5862 The GDB remote serial protocol now implements a write-through cache for
5863 registers, only re-reading the registers if the target has run.
5865 There is also a new remote serial stub for SPARC processors. You can
5866 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5867 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5868 processor with a serial port.
5872 Configure.in files have become much easier to read and modify. A new
5873 `table driven' format makes it more obvious what configurations are
5874 supported, and what files each one uses.
5878 There is a new opcodes library which will eventually contain all of the
5879 disassembly routines and opcode tables. At present, it only contains
5880 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5881 disassembler (binutils/objdump) to share these routines.
5883 The libiberty library is now copylefted under the GNU Library General
5884 Public License. This allows more liberal use, and was done so libg++
5885 can use it. This makes no difference to GDB, since the Library License
5886 grants all the rights from the General Public License.
5890 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5891 reference to the stabs symbol info used by the debugger. It is (as far
5892 as we know) the only published document on this fascinating topic. We
5893 encourage you to read it, compare it to the stabs information on your
5894 system, and send improvements on the document in general (to
5895 bug-gdb@prep.ai.mit.edu).
5897 And, of course, many bugs have been fixed.
5900 *** Changes in GDB-4.6:
5902 * Better support for C++ function names
5904 GDB now accepts as input the "demangled form" of C++ overloaded function
5905 names and member function names, and can do command completion on such names
5906 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5907 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5908 Make use of command completion, it is your friend.
5910 GDB also now accepts a variety of C++ mangled symbol formats. They are
5911 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5912 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5913 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5914 for the list of formats.
5916 * G++ symbol mangling problem
5918 Recent versions of gcc have a bug in how they emit debugging information for
5919 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5920 directory) can be applied to gcc to fix the problem. Alternatively, if you
5921 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5922 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5923 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5926 * New 'maintenance' command
5928 All of the commands related to hacking GDB internals have been moved out of
5929 the main command set, and now live behind the 'maintenance' command. This
5930 can also be abbreviated as 'mt'. The following changes were made:
5932 dump-me -> maintenance dump-me
5933 info all-breakpoints -> maintenance info breakpoints
5934 printmsyms -> maintenance print msyms
5935 printobjfiles -> maintenance print objfiles
5936 printpsyms -> maintenance print psymbols
5937 printsyms -> maintenance print symbols
5939 The following commands are new:
5941 maintenance demangle Call internal GDB demangler routine to
5942 demangle a C++ link name and prints the result.
5943 maintenance print type Print a type chain for a given symbol
5945 * Change to .gdbinit file processing
5947 We now read the $HOME/.gdbinit file before processing the argv arguments
5948 (e.g. reading symbol files or core files). This allows global parameters to
5949 be set, which will apply during the symbol reading. The ./.gdbinit is still
5950 read after argv processing.
5952 * New hosts supported
5954 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5956 GNU/Linux support i386-unknown-linux or linux
5958 We are also including code to support the HP/PA running BSD and HPUX. This
5959 is almost guaranteed not to work, as we didn't have time to test or build it
5960 for this release. We are including it so that the more adventurous (or
5961 masochistic) of you can play with it. We also had major problems with the
5962 fact that the compiler that we got from HP doesn't support the -g option.
5965 * New targets supported
5967 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5969 * More smarts about finding #include files
5971 GDB now remembers the compilation directory for all include files, and for
5972 all files from which C is generated (like yacc and lex sources). This
5973 greatly improves GDB's ability to find yacc/lex sources, and include files,
5974 especially if you are debugging your program from a directory different from
5975 the one that contains your sources.
5977 We also fixed a bug which caused difficulty with listing and setting
5978 breakpoints in include files which contain C code. (In the past, you had to
5979 try twice in order to list an include file that you hadn't looked at before.)
5981 * Interesting infernals change
5983 GDB now deals with arbitrary numbers of sections, where the symbols for each
5984 section must be relocated relative to that section's landing place in the
5985 target's address space. This work was needed to support ELF with embedded
5986 stabs used by Solaris-2.0.
5988 * Bug fixes (of course!)
5990 There have been loads of fixes for the following things:
5991 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5992 i960, stabs, DOS(GO32), procfs, etc...
5994 See the ChangeLog for details.
5996 *** Changes in GDB-4.5:
5998 * New machines supported (host and target)
6000 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6002 SGI Irix-4.x mips-sgi-irix4 or iris4
6004 * New malloc package
6006 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6007 Mmalloc is capable of handling mutiple heaps of memory. It is also
6008 capable of saving a heap to a file, and then mapping it back in later.
6009 This can be used to greatly speedup the startup of GDB by using a
6010 pre-parsed symbol table which lives in a mmalloc managed heap. For
6011 more details, please read mmalloc/mmalloc.texi.
6015 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6016 'help info proc' for details.
6018 * MIPS ecoff symbol table format
6020 The code that reads MIPS symbol table format is now supported on all hosts.
6021 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6024 * File name changes for MS-DOS
6026 Many files in the config directories have been renamed to make it easier to
6027 support GDB on MS-DOSe systems (which have very restrictive file name
6028 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6029 environment) is close to working but has some remaining problems. Note
6030 that debugging of DOS programs is not supported, due to limitations
6031 in the ``operating system'', but it can be used to host cross-debugging.
6033 * Cross byte order fixes
6035 Many fixes have been made to support cross debugging of Sparc and MIPS
6036 targets from hosts whose byte order differs.
6038 * New -mapped and -readnow options
6040 If memory-mapped files are available on your system through the 'mmap'
6041 system call, you can use the -mapped option on the `file' or
6042 `symbol-file' commands to cause GDB to write the symbols from your
6043 program into a reusable file. If the program you are debugging is
6044 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6045 Future GDB debugging sessions will notice the presence of this file,
6046 and will quickly map in symbol information from it, rather than reading
6047 the symbol table from the executable program. Using the '-mapped'
6048 option in a GDB `file' or `symbol-file' command has the same effect as
6049 starting GDB with the '-mapped' command-line option.
6051 You can cause GDB to read the entire symbol table immediately by using
6052 the '-readnow' option with any of the commands that load symbol table
6053 information (or on the GDB command line). This makes the command
6054 slower, but makes future operations faster.
6056 The -mapped and -readnow options are typically combined in order to
6057 build a `fred.syms' file that contains complete symbol information.
6058 A simple GDB invocation to do nothing but build a `.syms' file for future
6061 gdb -batch -nx -mapped -readnow programname
6063 The `.syms' file is specific to the host machine on which GDB is run.
6064 It holds an exact image of GDB's internal symbol table. It cannot be
6065 shared across multiple host platforms.
6067 * longjmp() handling
6069 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6070 siglongjmp() without losing control. This feature has not yet been ported to
6071 all systems. It currently works on many 386 platforms, all MIPS-based
6072 platforms (SGI, DECstation, etc), and Sun3/4.
6076 Preliminary work has been put in to support the new Solaris OS from Sun. At
6077 this time, it can control and debug processes, but it is not capable of
6082 As always, many many bug fixes. The major areas were with g++, and mipsread.
6083 People using the MIPS-based platforms should experience fewer mysterious
6084 crashes and trashed symbol tables.
6086 *** Changes in GDB-4.4:
6088 * New machines supported (host and target)
6090 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6092 BSD Reno on Vax vax-dec-bsd
6093 Ultrix on Vax vax-dec-ultrix
6095 * New machines supported (target)
6097 AMD 29000 embedded, using EBMON a29k-none-none
6101 GDB continues to improve its handling of C++. `References' work better.
6102 The demangler has also been improved, and now deals with symbols mangled as
6103 per the Annotated C++ Reference Guide.
6105 GDB also now handles `stabs' symbol information embedded in MIPS
6106 `ecoff' symbol tables. Since the ecoff format was not easily
6107 extensible to handle new languages such as C++, this appeared to be a
6108 good way to put C++ debugging info into MIPS binaries. This option
6109 will be supported in the GNU C compiler, version 2, when it is
6112 * New features for SVR4
6114 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6115 shared libraries. Debugging dynamically linked programs should present
6116 only minor differences from debugging statically linked programs.
6118 The `info proc' command will print out information about any process
6119 on an SVR4 system (including the one you are debugging). At the moment,
6120 it prints the address mappings of the process.
6122 If you bring up GDB on another SVR4 system, please send mail to
6123 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6125 * Better dynamic linking support in SunOS
6127 Reading symbols from shared libraries which contain debugging symbols
6128 now works properly. However, there remain issues such as automatic
6129 skipping of `transfer vector' code during function calls, which
6130 make it harder to debug code in a shared library, than to debug the
6131 same code linked statically.
6135 GDB is now using the latest `getopt' routines from the FSF. This
6136 version accepts the -- prefix for options with long names. GDB will
6137 continue to accept the old forms (-option and +option) as well.
6138 Various single letter abbreviations for options have been explicity
6139 added to the option table so that they won't get overshadowed in the
6140 future by other options that begin with the same letter.
6144 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6145 Many assorted bugs have been handled. Many more remain to be handled.
6146 See the various ChangeLog files (primarily in gdb and bfd) for details.
6149 *** Changes in GDB-4.3:
6151 * New machines supported (host and target)
6153 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6154 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6155 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6157 * Almost SCO Unix support
6159 We had hoped to support:
6160 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6161 (except for core file support), but we discovered very late in the release
6162 that it has problems with process groups that render gdb unusable. Sorry
6163 about that. I encourage people to fix it and post the fixes.
6165 * Preliminary ELF and DWARF support
6167 GDB can read ELF object files on System V Release 4, and can handle
6168 debugging records for C, in DWARF format, in ELF files. This support
6169 is preliminary. If you bring up GDB on another SVR4 system, please
6170 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6175 GDB now uses the latest `readline' library. One user-visible change
6176 is that two tabs will list possible command completions, which previously
6177 required typing M-? (meta-question mark, or ESC ?).
6181 The `stepi' bug that many of you noticed has been squashed.
6182 Many bugs in C++ have been handled. Many more remain to be handled.
6183 See the various ChangeLog files (primarily in gdb and bfd) for details.
6185 * State of the MIPS world (in case you wondered):
6187 GDB can understand the symbol tables emitted by the compilers
6188 supplied by most vendors of MIPS-based machines, including DEC. These
6189 symbol tables are in a format that essentially nobody else uses.
6191 Some versions of gcc come with an assembler post-processor called
6192 mips-tfile. This program is required if you want to do source-level
6193 debugging of gcc-compiled programs. I believe FSF does not ship
6194 mips-tfile with gcc version 1, but it will eventually come with gcc
6197 Debugging of g++ output remains a problem. g++ version 1.xx does not
6198 really support it at all. (If you're lucky, you should be able to get
6199 line numbers and stack traces to work, but no parameters or local
6200 variables.) With some work it should be possible to improve the
6203 When gcc version 2 is released, you will have somewhat better luck.
6204 However, even then you will get confusing results for inheritance and
6207 We will eventually provide full debugging of g++ output on
6208 DECstations. This will probably involve some kind of stabs-in-ecoff
6209 encapulation, but the details have not been worked out yet.
6212 *** Changes in GDB-4.2:
6214 * Improved configuration
6216 Only one copy of `configure' exists now, and it is not self-modifying.
6217 Porting BFD is simpler.
6221 The `step' and `next' commands now only stop at the first instruction
6222 of a source line. This prevents the multiple stops that used to occur
6223 in switch statements, for-loops, etc. `Step' continues to stop if a
6224 function that has debugging information is called within the line.
6228 Lots of small bugs fixed. More remain.
6230 * New host supported (not target)
6232 Intel 386 PC clone running Mach i386-none-mach
6235 *** Changes in GDB-4.1:
6237 * Multiple source language support
6239 GDB now has internal scaffolding to handle several source languages.
6240 It determines the type of each source file from its filename extension,
6241 and will switch expression parsing and number formatting to match the
6242 language of the function in the currently selected stack frame.
6243 You can also specifically set the language to be used, with
6244 `set language c' or `set language modula-2'.
6248 GDB now has preliminary support for the GNU Modula-2 compiler,
6249 currently under development at the State University of New York at
6250 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6251 continue through the fall of 1991 and into 1992.
6253 Other Modula-2 compilers are currently not supported, and attempting to
6254 debug programs compiled with them will likely result in an error as the
6255 symbol table is read. Feel free to work on it, though!
6257 There are hooks in GDB for strict type checking and range checking,
6258 in the `Modula-2 philosophy', but they do not currently work.
6262 GDB can now write to executable and core files (e.g. patch
6263 a variable's value). You must turn this switch on, specify
6264 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6265 by assigning a new value to a variable. Modifications take
6268 * Automatic SunOS shared library reading
6270 When you run your program, GDB automatically determines where its
6271 shared libraries (if any) have been loaded, and reads their symbols.
6272 The `share' command is no longer needed. This also works when
6273 examining core files.
6277 You can specify the number of lines that the `list' command shows.
6280 * New machines supported (host and target)
6282 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6283 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6284 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6286 * New hosts supported (not targets)
6288 IBM RT/PC: romp-ibm-aix or rtpc
6290 * New targets supported (not hosts)
6292 AMD 29000 embedded with COFF a29k-none-coff
6293 AMD 29000 embedded with a.out a29k-none-aout
6294 Ultracomputer remote kernel debug a29k-nyu-kern
6296 * New remote interfaces
6302 *** Changes in GDB-4.0:
6306 Wide output is wrapped at good places to make the output more readable.
6308 Gdb now supports cross-debugging from a host machine of one type to a
6309 target machine of another type. Communication with the target system
6310 is over serial lines. The ``target'' command handles connecting to the
6311 remote system; the ``load'' command will download a program into the
6312 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6313 also supports debugging of realtime processes running under VxWorks,
6314 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6315 stub on the target system.
6317 New CPUs supported include the AMD 29000 and Intel 960.
6319 GDB now reads object files and symbol tables via a ``binary file''
6320 library, which allows a single copy of GDB to debug programs of multiple
6321 object file types such as a.out and coff.
6323 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6324 refcard.dvi and refcard.ps are available to format it).
6327 * Control-Variable user interface simplified
6329 All variables that control the operation of the debugger can be set
6330 by the ``set'' command, and displayed by the ``show'' command.
6332 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6333 ``Show prompt'' produces the response:
6334 Gdb's prompt is new-gdb=>.
6336 What follows are the NEW set commands. The command ``help set'' will
6337 print a complete list of old and new set commands. ``help set FOO''
6338 will give a longer description of the variable FOO. ``show'' will show
6339 all of the variable descriptions and their current settings.
6341 confirm on/off: Enables warning questions for operations that are
6342 hard to recover from, e.g. rerunning the program while
6343 it is already running. Default is ON.
6345 editing on/off: Enables EMACS style command line editing
6346 of input. Previous lines can be recalled with
6347 control-P, the current line can be edited with control-B,
6348 you can search for commands with control-R, etc.
6351 history filename NAME: NAME is where the gdb command history
6352 will be stored. The default is .gdb_history,
6353 or the value of the environment variable
6356 history size N: The size, in commands, of the command history. The
6357 default is 256, or the value of the environment variable
6360 history save on/off: If this value is set to ON, the history file will
6361 be saved after exiting gdb. If set to OFF, the
6362 file will not be saved. The default is OFF.
6364 history expansion on/off: If this value is set to ON, then csh-like
6365 history expansion will be performed on
6366 command line input. The default is OFF.
6368 radix N: Sets the default radix for input and output. It can be set
6369 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6370 in the current radix, so "set radix 10" is always a no-op.
6372 height N: This integer value is the number of lines on a page. Default
6373 is 24, the current `stty rows'' setting, or the ``li#''
6374 setting from the termcap entry matching the environment
6377 width N: This integer value is the number of characters on a line.
6378 Default is 80, the current `stty cols'' setting, or the ``co#''
6379 setting from the termcap entry matching the environment
6382 Note: ``set screensize'' is obsolete. Use ``set height'' and
6383 ``set width'' instead.
6385 print address on/off: Print memory addresses in various command displays,
6386 such as stack traces and structure values. Gdb looks
6387 more ``symbolic'' if you turn this off; it looks more
6388 ``machine level'' with it on. Default is ON.
6390 print array on/off: Prettyprint arrays. New convenient format! Default
6393 print demangle on/off: Print C++ symbols in "source" form if on,
6396 print asm-demangle on/off: Same, for assembler level printouts
6399 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6402 * Support for Epoch Environment.
6404 The epoch environment is a version of Emacs v18 with windowing. One
6405 new command, ``inspect'', is identical to ``print'', except that if you
6406 are running in the epoch environment, the value is printed in its own
6410 * Support for Shared Libraries
6412 GDB can now debug programs and core files that use SunOS shared libraries.
6413 Symbols from a shared library cannot be referenced
6414 before the shared library has been linked with the program (this
6415 happens after you type ``run'' and before the function main() is entered).
6416 At any time after this linking (including when examining core files
6417 from dynamically linked programs), gdb reads the symbols from each
6418 shared library when you type the ``sharedlibrary'' command.
6419 It can be abbreviated ``share''.
6421 sharedlibrary REGEXP: Load shared object library symbols for files
6422 matching a unix regular expression. No argument
6423 indicates to load symbols for all shared libraries.
6425 info sharedlibrary: Status of loaded shared libraries.
6430 A watchpoint stops execution of a program whenever the value of an
6431 expression changes. Checking for this slows down execution
6432 tremendously whenever you are in the scope of the expression, but is
6433 quite useful for catching tough ``bit-spreader'' or pointer misuse
6434 problems. Some machines such as the 386 have hardware for doing this
6435 more quickly, and future versions of gdb will use this hardware.
6437 watch EXP: Set a watchpoint (breakpoint) for an expression.
6439 info watchpoints: Information about your watchpoints.
6441 delete N: Deletes watchpoint number N (same as breakpoints).
6442 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6443 enable N: Re-enables watchpoint number N (same as breakpoints).
6446 * C++ multiple inheritance
6448 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6451 * C++ exception handling
6453 Gdb now supports limited C++ exception handling. Besides the existing
6454 ability to breakpoint on an exception handler, gdb can breakpoint on
6455 the raising of an exception (before the stack is peeled back to the
6458 catch FOO: If there is a FOO exception handler in the dynamic scope,
6459 set a breakpoint to catch exceptions which may be raised there.
6460 Multiple exceptions (``catch foo bar baz'') may be caught.
6462 info catch: Lists all exceptions which may be caught in the
6463 current stack frame.
6466 * Minor command changes
6468 The command ``call func (arg, arg, ...)'' now acts like the print
6469 command, except it does not print or save a value if the function's result
6470 is void. This is similar to dbx usage.
6472 The ``up'' and ``down'' commands now always print the frame they end up
6473 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6474 frames without printing.
6476 * New directory command
6478 'dir' now adds directories to the FRONT of the source search path.
6479 The path starts off empty. Source files that contain debug information
6480 about the directory in which they were compiled can be found even
6481 with an empty path; Sun CC and GCC include this information. If GDB can't
6482 find your source file in the current directory, type "dir .".
6484 * Configuring GDB for compilation
6486 For normal use, type ``./configure host''. See README or gdb.texinfo
6489 GDB now handles cross debugging. If you are remotely debugging between
6490 two different machines, type ``./configure host -target=targ''.
6491 Host is the machine where GDB will run; targ is the machine
6492 where the program that you are debugging will run.