1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.11
6 * GDB now supports a negative repeat count in the 'x' command to examine
7 memory backward from the given address. For example:
10 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
11 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
12 (gdb) x/-5i 0x0000000000400580
13 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
14 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
15 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
16 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
17 0x40057b <main(int, char**)+25>:
18 callq 0x400536 <Func1(int, char const*)>
20 * Fortran: Support structures with fields of dynamic types and
21 arrays of dynamic types.
23 * GDB now supports multibit bitfields and enums in target register
26 * New Python-based convenience function $_as_string(val), which returns
27 the textual representation of a value. This function is especially
28 useful to obtain the text label of an enum value.
30 * Intel MPX bound violation handling.
32 Segmentation faults caused by a Intel MPX boundary violation
33 now display the kind of violation (upper or lower), the memory
34 address accessed and the memory bounds, along with the usual
35 signal received and code location.
39 Program received signal SIGSEGV, Segmentation fault
40 Upper bound violation while accessing address 0x7fffffffc3b3
41 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
42 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
44 * Rust language support.
45 GDB now supports debugging programs written in the Rust programming
46 language. See https://www.rust-lang.org/ for more information about
52 skip -gfile file-glob-pattern
53 skip -function function
54 skip -rfunction regular-expression
55 A generalized form of the skip command, with new support for
56 glob-style file names and regular expressions for function names.
57 Additionally, a file spec and a function spec may now be combined.
59 maint info line-table REGEXP
60 Display the contents of GDB's internal line table data struture.
63 Run any GDB unit tests that were compiled in.
65 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
66 was added in GDBserver, including JIT compiling fast tracepoint's
67 conditional expression bytecode into native code.
69 * Support for various remote target protocols and ROM monitors has
72 target m32rsdi Remote M32R debugging over SDI
73 target mips MIPS remote debugging protocol
74 target pmon PMON ROM monitor
75 target ddb NEC's DDB variant of PMON for Vr4300
76 target rockhopper NEC RockHopper variant of PMON
77 target lsi LSI variant of PMO
79 * Support for tracepoints and fast tracepoints on powerpc-linux,
80 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
81 including JIT compiling fast tracepoint's conditional expression
82 bytecode into native code.
84 * MI async record =record-started now includes the method and format used for
85 recording. For example:
87 =record-started,thread-group="i1",method="btrace",format="bts"
89 *** Changes in GDB 7.11
91 * GDB now supports debugging kernel-based threads on FreeBSD.
93 * Per-inferior thread numbers
95 Thread numbers are now per inferior instead of global. If you're
96 debugging multiple inferiors, GDB displays thread IDs using a
97 qualified INF_NUM.THR_NUM form. For example:
101 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
102 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
103 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
104 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
106 As consequence, thread numbers as visible in the $_thread
107 convenience variable and in Python's InferiorThread.num attribute
108 are no longer unique between inferiors.
110 GDB now maintains a second thread ID per thread, referred to as the
111 global thread ID, which is the new equivalent of thread numbers in
112 previous releases. See also $_gthread below.
114 For backwards compatibility, MI's thread IDs always refer to global
117 * Commands that accept thread IDs now accept the qualified
118 INF_NUM.THR_NUM form as well. For example:
121 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
124 * In commands that accept a list of thread IDs, you can now refer to
125 all threads of an inferior using a star wildcard. GDB accepts
126 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
127 refer to all threads of the current inferior. For example, "info
130 * You can use "info threads -gid" to display the global thread ID of
133 * The new convenience variable $_gthread holds the global number of
136 * The new convenience variable $_inferior holds the number of the
139 * GDB now displays the ID and name of the thread that hit a breakpoint
140 or received a signal, if your program is multi-threaded. For
143 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
144 Thread 1 "main" received signal SIGINT, Interrupt.
146 * Record btrace now supports non-stop mode.
148 * Support for tracepoints on aarch64-linux was added in GDBserver.
150 * The 'record instruction-history' command now indicates speculative execution
151 when using the Intel Processor Trace recording format.
153 * GDB now allows users to specify explicit locations, bypassing
154 the linespec parser. This feature is also available to GDB/MI
157 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
158 GDB now is able to debug both AArch64 applications and ARM applications
161 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
162 including JIT compiling fast tracepoint's conditional expression bytecode
165 * GDB now supports displaced stepping on AArch64 GNU/Linux.
167 * "info threads", "info inferiors", "info display", "info checkpoints"
168 and "maint info program-spaces" now list the corresponding items in
169 ascending ID order, for consistency with all other "info" commands.
171 * In Ada, the overloads selection menu has been enhanced to display the
172 parameter types and the return types for the matching overloaded subprograms.
176 maint set target-non-stop (on|off|auto)
177 maint show target-non-stop
178 Control whether GDB targets always operate in non-stop mode even if
179 "set non-stop" is "off". The default is "auto", meaning non-stop
180 mode is enabled if supported by the target.
182 maint set bfd-sharing
183 maint show bfd-sharing
184 Control the reuse of bfd objects.
188 Control display of debugging info regarding bfd caching.
192 Control display of debugging info regarding FreeBSD threads.
194 set remote multiprocess-extensions-packet
195 show remote multiprocess-extensions-packet
196 Set/show the use of the remote protocol multiprocess extensions.
198 set remote thread-events
199 show remote thread-events
200 Set/show the use of thread create/exit events.
202 set ada print-signatures on|off
203 show ada print-signatures"
204 Control whether parameter types and return types are displayed in overloads
205 selection menus. It is activaled (@code{on}) by default.
209 Controls the maximum size of memory, in bytes, that GDB will
210 allocate for value contents. Prevents incorrect programs from
211 causing GDB to allocate overly large buffers. Default is 64k.
213 * The "disassemble" command accepts a new modifier: /s.
214 It prints mixed source+disassembly like /m with two differences:
215 - disassembled instructions are now printed in program order, and
216 - and source for all relevant files is now printed.
217 The "/m" option is now considered deprecated: its "source-centric"
218 output hasn't proved useful in practice.
220 * The "record instruction-history" command accepts a new modifier: /s.
221 It behaves exactly like /m and prints mixed source+disassembly.
223 * The "set scheduler-locking" command supports a new mode "replay".
224 It behaves like "off" in record mode and like "on" in replay mode.
226 * Support for various ROM monitors has been removed:
228 target dbug dBUG ROM monitor for Motorola ColdFire
229 target picobug Motorola picobug monitor
230 target dink32 DINK32 ROM monitor for PowerPC
231 target m32r Renesas M32R/D ROM monitor
232 target mon2000 mon2000 ROM monitor
233 target ppcbug PPCBUG ROM monitor for PowerPC
235 * Support for reading/writing memory and extracting values on architectures
236 whose memory is addressable in units of any integral multiple of 8 bits.
241 Indicates that an exec system call was executed.
243 exec-events feature in qSupported
244 The qSupported packet allows GDB to request support for exec
245 events using the new 'gdbfeature' exec-event, and the qSupported
246 response can contain the corresponding 'stubfeature'. Set and
247 show commands can be used to display whether these features are enabled.
250 Equivalent to interrupting with the ^C character, but works in
253 thread created stop reason (T05 create:...)
254 Indicates that the thread was just created and is stopped at entry.
256 thread exit stop reply (w exitcode;tid)
257 Indicates that the thread has terminated.
260 Enables/disables thread create and exit event reporting. For
261 example, this is used in non-stop mode when GDB stops a set of
262 threads and synchronously waits for the their corresponding stop
263 replies. Without exit events, if one of the threads exits, GDB
264 would hang forever not knowing that it should no longer expect a
265 stop for that same thread.
268 Indicates that there are no resumed threads left in the target (all
269 threads are stopped). The remote stub reports support for this stop
270 reply to GDB's qSupported query.
273 Enables/disables catching syscalls from the inferior process.
274 The remote stub reports support for this packet to GDB's qSupported query.
276 syscall_entry stop reason
277 Indicates that a syscall was just called.
279 syscall_return stop reason
280 Indicates that a syscall just returned.
282 * Extended-remote exec events
284 ** GDB now has support for exec events on extended-remote Linux targets.
285 For such targets with Linux kernels 2.5.46 and later, this enables
286 follow-exec-mode and exec catchpoints.
288 set remote exec-event-feature-packet
289 show remote exec-event-feature-packet
290 Set/show the use of the remote exec event feature.
292 * Thread names in remote protocol
294 The reply to qXfer:threads:read may now include a name attribute for each
297 * Target remote mode fork and exec events
299 ** GDB now has support for fork and exec events on target remote mode
300 Linux targets. For such targets with Linux kernels 2.5.46 and later,
301 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
302 fork and exec catchpoints.
304 * Remote syscall events
306 ** GDB now has support for catch syscall on remote Linux targets,
307 currently enabled on x86/x86_64 architectures.
309 set remote catch-syscall-packet
310 show remote catch-syscall-packet
311 Set/show the use of the remote catch syscall feature.
315 ** The -var-set-format command now accepts the zero-hexadecimal
316 format. It outputs data in hexadecimal format with zero-padding on the
321 ** gdb.InferiorThread objects have a new attribute "global_num",
322 which refers to the thread's global thread ID. The existing
323 "num" attribute now refers to the thread's per-inferior number.
324 See "Per-inferior thread numbers" above.
325 ** gdb.InferiorThread objects have a new attribute "inferior", which
326 is the Inferior object the thread belongs to.
328 *** Changes in GDB 7.10
330 * Support for process record-replay and reverse debugging on aarch64*-linux*
331 targets has been added. GDB now supports recording of A64 instruction set
332 including advance SIMD instructions.
334 * Support for Sun's version of the "stabs" debug file format has been removed.
336 * GDB now honors the content of the file /proc/PID/coredump_filter
337 (PID is the process ID) on GNU/Linux systems. This file can be used
338 to specify the types of memory mappings that will be included in a
339 corefile. For more information, please refer to the manual page of
340 "core(5)". GDB also has a new command: "set use-coredump-filter
341 on|off". It allows to set whether GDB will read the content of the
342 /proc/PID/coredump_filter file when generating a corefile.
344 * The "info os" command on GNU/Linux can now display information on
346 "info os cpus" Listing of all cpus/cores on the system
348 * GDB has two new commands: "set serial parity odd|even|none" and
349 "show serial parity". These allows to set or show parity for the
352 * The "info source" command now displays the producer string if it was
353 present in the debug info. This typically includes the compiler version
354 and may include things like its command line arguments.
356 * The "info dll", an alias of the "info sharedlibrary" command,
357 is now available on all platforms.
359 * Directory names supplied to the "set sysroot" commands may be
360 prefixed with "target:" to tell GDB to access shared libraries from
361 the target system, be it local or remote. This replaces the prefix
362 "remote:". The default sysroot has been changed from "" to
363 "target:". "remote:" is automatically converted to "target:" for
364 backward compatibility.
366 * The system root specified by "set sysroot" will be prepended to the
367 filename of the main executable (if reported to GDB as absolute by
368 the operating system) when starting processes remotely, and when
369 attaching to already-running local or remote processes.
371 * GDB now supports automatic location and retrieval of executable
372 files from remote targets. Remote debugging can now be initiated
373 using only a "target remote" or "target extended-remote" command
374 (no "set sysroot" or "file" commands are required). See "New remote
377 * The "dump" command now supports verilog hex format.
379 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
381 * On GNU/Linux, GDB and gdbserver are now able to access executable
382 and shared library files without a "set sysroot" command when
383 attaching to processes running in different mount namespaces from
384 the debugger. This makes it possible to attach to processes in
385 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
386 See "New remote packets" below.
388 * The "tui reg" command now provides completion for all of the
389 available register groups, including target specific groups.
391 * The HISTSIZE environment variable is no longer read when determining
392 the size of GDB's command history. GDB now instead reads the dedicated
393 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
394 disables truncation of command history. Non-numeric values of GDBHISTSIZE
399 ** Memory ports can now be unbuffered.
403 ** gdb.Objfile objects have a new attribute "username",
404 which is the name of the objfile as specified by the user,
405 without, for example, resolving symlinks.
406 ** You can now write frame unwinders in Python.
407 ** gdb.Type objects have a new method "optimized_out",
408 returning optimized out gdb.Value instance of this type.
409 ** gdb.Value objects have new methods "reference_value" and
410 "const_value" which return a reference to the value and a
411 "const" version of the value respectively.
415 maint print symbol-cache
416 Print the contents of the symbol cache.
418 maint print symbol-cache-statistics
419 Print statistics of symbol cache usage.
421 maint flush-symbol-cache
422 Flush the contents of the symbol cache.
426 Start branch trace recording using Branch Trace Store (BTS) format.
429 Evaluate expression by using the compiler and print result.
433 Explicit commands for enabling and disabling tui mode.
436 set mpx bound on i386 and amd64
437 Support for bound table investigation on Intel MPX enabled applications.
441 Start branch trace recording using Intel Processor Trace format.
444 Print information about branch tracing internals.
446 maint btrace packet-history
447 Print the raw branch tracing data.
449 maint btrace clear-packet-history
450 Discard the stored raw branch tracing data.
453 Discard all branch tracing data. It will be fetched and processed
454 anew by the next "record" command.
459 Renamed from "set debug dwarf2-die".
461 Renamed from "show debug dwarf2-die".
464 Renamed from "set debug dwarf2-read".
465 show debug dwarf-read
466 Renamed from "show debug dwarf2-read".
468 maint set dwarf always-disassemble
469 Renamed from "maint set dwarf2 always-disassemble".
470 maint show dwarf always-disassemble
471 Renamed from "maint show dwarf2 always-disassemble".
473 maint set dwarf max-cache-age
474 Renamed from "maint set dwarf2 max-cache-age".
475 maint show dwarf max-cache-age
476 Renamed from "maint show dwarf2 max-cache-age".
479 show debug dwarf-line
480 Control display of debugging info regarding DWARF line processing.
484 Set the maximum number of candidates to be considered during
485 completion. The default value is 200. This limit allows GDB
486 to avoid generating large completion lists, the computation of
487 which can cause the debugger to become temporarily unresponsive.
489 set history remove-duplicates
490 show history remove-duplicates
491 Control the removal of duplicate history entries.
493 maint set symbol-cache-size
494 maint show symbol-cache-size
495 Control the size of the symbol cache.
497 set|show record btrace bts buffer-size
498 Set and show the size of the ring buffer used for branch tracing in
500 The obtained size may differ from the requested size. Use "info
501 record" to see the obtained buffer size.
503 set debug linux-namespaces
504 show debug linux-namespaces
505 Control display of debugging info regarding Linux namespaces.
507 set|show record btrace pt buffer-size
508 Set and show the size of the ring buffer used for branch tracing in
509 Intel Processor Trace format.
510 The obtained size may differ from the requested size. Use "info
511 record" to see the obtained buffer size.
513 maint set|show btrace pt skip-pad
514 Set and show whether PAD packets are skipped when computing the
517 * The command 'thread apply all' can now support new option '-ascending'
518 to call its specified command for all threads in ascending order.
520 * Python/Guile scripting
522 ** GDB now supports auto-loading of Python/Guile scripts contained in the
523 special section named `.debug_gdb_scripts'.
527 qXfer:btrace-conf:read
528 Return the branch trace configuration for the current thread.
530 Qbtrace-conf:bts:size
531 Set the requested ring buffer size for branch tracing in BTS format.
534 Enable Intel Procesor Trace-based branch tracing for the current
535 process. The remote stub reports support for this packet to GDB's
539 Set the requested ring buffer size for branch tracing in Intel Processor
543 Indicates a memory breakpoint instruction was executed, irrespective
544 of whether it was GDB that planted the breakpoint or the breakpoint
545 is hardcoded in the program. This is required for correct non-stop
549 Indicates the target stopped for a hardware breakpoint. This is
550 required for correct non-stop mode operation.
553 Return information about files on the remote system.
556 Return the full absolute name of the file that was executed to
557 create a process running on the remote system.
560 Select the filesystem on which vFile: operations with filename
561 arguments will operate. This is required for GDB to be able to
562 access files on remote targets where the remote stub does not
563 share a common filesystem with the inferior(s).
566 Indicates that a fork system call was executed.
569 Indicates that a vfork system call was executed.
571 vforkdone stop reason
572 Indicates that a vfork child of the specified process has executed
573 an exec or exit, allowing the vfork parent to resume execution.
575 fork-events and vfork-events features in qSupported
576 The qSupported packet allows GDB to request support for fork and
577 vfork events using new 'gdbfeatures' fork-events and vfork-events,
578 and the qSupported response can contain the corresponding
579 'stubfeatures'. Set and show commands can be used to display
580 whether these features are enabled.
582 * Extended-remote fork events
584 ** GDB now has support for fork events on extended-remote Linux
585 targets. For targets with Linux kernels 2.5.60 and later, this
586 enables follow-fork-mode and detach-on-fork for both fork and
587 vfork, as well as fork and vfork catchpoints.
589 * The info record command now shows the recording format and the
590 branch tracing configuration for the current thread when using
591 the btrace record target.
592 For the BTS format, it shows the ring buffer size.
594 * GDB now has support for DTrace USDT (Userland Static Defined
595 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
597 * GDB now supports access to vector registers on S/390 GNU/Linux
600 * Removed command line options
602 -xdb HP-UX XDB compatibility mode.
604 * Removed targets and native configurations
606 HP/PA running HP-UX hppa*-*-hpux*
607 Itanium running HP-UX ia64-*-hpux*
609 * New configure options
612 This configure option allows the user to build GDB with support for
613 Intel Processor Trace (default: auto). This requires libipt.
615 --with-libipt-prefix=PATH
616 Specify the path to the version of libipt that GDB should use.
617 $PATH/include should contain the intel-pt.h header and
618 $PATH/lib should contain the libipt.so library.
620 *** Changes in GDB 7.9.1
624 ** Xmethods can now specify a result type.
626 *** Changes in GDB 7.9
628 * GDB now supports hardware watchpoints on x86 GNU Hurd.
632 ** You can now access frame registers from Python scripts.
633 ** New attribute 'producer' for gdb.Symtab objects.
634 ** gdb.Objfile objects have a new attribute "progspace",
635 which is the gdb.Progspace object of the containing program space.
636 ** gdb.Objfile objects have a new attribute "owner".
637 ** gdb.Objfile objects have a new attribute "build_id",
638 which is the build ID generated when the file was built.
639 ** gdb.Objfile objects have a new method "add_separate_debug_file".
640 ** A new event "gdb.clear_objfiles" has been added, triggered when
641 selecting a new file to debug.
642 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
643 ** New function gdb.lookup_objfile.
645 New events which are triggered when GDB modifies the state of the
648 ** gdb.events.inferior_call_pre: Function call is about to be made.
649 ** gdb.events.inferior_call_post: Function call has just been made.
650 ** gdb.events.memory_changed: A memory location has been altered.
651 ** gdb.events.register_changed: A register has been altered.
653 * New Python-based convenience functions:
655 ** $_caller_is(name [, number_of_frames])
656 ** $_caller_matches(regexp [, number_of_frames])
657 ** $_any_caller_is(name [, number_of_frames])
658 ** $_any_caller_matches(regexp [, number_of_frames])
660 * GDB now supports the compilation and injection of source code into
661 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
662 to compile the source code to object code, and if successful, inject
663 and execute that code within the current context of the inferior.
664 Currently the C language is supported. The commands used to
665 interface with this new feature are:
667 compile code [-raw|-r] [--] [source code]
668 compile file [-raw|-r] filename
672 demangle [-l language] [--] name
673 Demangle "name" in the specified language, or the current language
674 if elided. This command is renamed from the "maint demangle" command.
675 The latter is kept as a no-op to avoid "maint demangle" being interpreted
676 as "maint demangler-warning".
678 queue-signal signal-name-or-number
679 Queue a signal to be delivered to the thread when it is resumed.
681 add-auto-load-scripts-directory directory
682 Add entries to the list of directories from which to load auto-loaded
685 maint print user-registers
686 List all currently available "user" registers.
688 compile code [-r|-raw] [--] [source code]
689 Compile, inject, and execute in the inferior the executable object
690 code produced by compiling the provided source code.
692 compile file [-r|-raw] filename
693 Compile and inject into the inferior the executable object code
694 produced by compiling the source code stored in the filename
697 * On resume, GDB now always passes the signal the program had stopped
698 for to the thread the signal was sent to, even if the user changed
699 threads before resuming. Previously GDB would often (but not
700 always) deliver the signal to the thread that happens to be current
703 * Conversely, the "signal" command now consistently delivers the
704 requested signal to the current thread. GDB now asks for
705 confirmation if the program had stopped for a signal and the user
706 switched threads meanwhile.
708 * "breakpoint always-inserted" modes "off" and "auto" merged.
710 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
711 won't remove breakpoints from the target until all threads stop,
712 even in non-stop mode. The "auto" mode has been removed, and "off"
713 is now the default mode.
717 set debug symbol-lookup
718 show debug symbol-lookup
719 Control display of debugging info regarding symbol lookup.
723 ** The -list-thread-groups command outputs an exit-code field for
724 inferiors that have exited.
728 MIPS SDE mips*-sde*-elf*
732 Support for these obsolete configurations has been removed.
734 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
735 SGI Irix-5.x mips-*-irix5*
736 SGI Irix-6.x mips-*-irix6*
737 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
738 VAX running Ultrix vax-*-ultrix*
740 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
741 and "assf"), have been removed. Use the "sharedlibrary" command, or
742 its alias "share", instead.
744 *** Changes in GDB 7.8
746 * New command line options
749 This is an alias for the --data-directory option.
751 * GDB supports printing and modifying of variable length automatic arrays
752 as specified in ISO C99.
754 * The ARM simulator now supports instruction level tracing
755 with or without disassembly.
759 GDB now has support for scripting using Guile. Whether this is
760 available is determined at configure time.
761 Guile version 2.0 or greater is required.
762 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
764 * New commands (for set/show, see "New options" below)
768 Invoke CODE by passing it to the Guile interpreter.
772 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
774 info auto-load guile-scripts [regexp]
775 Print the list of automatically loaded Guile scripts.
777 * The source command is now capable of sourcing Guile scripts.
778 This feature is dependent on the debugger being built with Guile support.
782 set print symbol-loading (off|brief|full)
783 show print symbol-loading
784 Control whether to print informational messages when loading symbol
785 information for a file. The default is "full", but when debugging
786 programs with large numbers of shared libraries the amount of output
789 set guile print-stack (none|message|full)
790 show guile print-stack
791 Show a stack trace when an error is encountered in a Guile script.
793 set auto-load guile-scripts (on|off)
794 show auto-load guile-scripts
795 Control auto-loading of Guile script files.
797 maint ada set ignore-descriptive-types (on|off)
798 maint ada show ignore-descriptive-types
799 Control whether the debugger should ignore descriptive types in Ada
800 programs. The default is not to ignore the descriptive types. See
801 the user manual for more details on descriptive types and the intended
802 usage of this option.
804 set auto-connect-native-target
806 Control whether GDB is allowed to automatically connect to the
807 native target for the run, attach, etc. commands when not connected
808 to any target yet. See also "target native" below.
810 set record btrace replay-memory-access (read-only|read-write)
811 show record btrace replay-memory-access
812 Control what memory accesses are allowed during replay.
814 maint set target-async (on|off)
815 maint show target-async
816 This controls whether GDB targets operate in synchronous or
817 asynchronous mode. Normally the default is asynchronous, if it is
818 available; but this can be changed to more easily debug problems
819 occurring only in synchronous mode.
821 set mi-async (on|off)
823 Control whether MI asynchronous mode is preferred. This supersedes
824 "set target-async" of previous GDB versions.
826 * "set target-async" is deprecated as a CLI option and is now an alias
827 for "set mi-async" (only puts MI into async mode).
829 * Background execution commands (e.g., "c&", "s&", etc.) are now
830 possible ``out of the box'' if the target supports them. Previously
831 the user would need to explicitly enable the possibility with the
832 "set target-async on" command.
834 * New features in the GDB remote stub, GDBserver
836 ** New option --debug-format=option1[,option2,...] allows one to add
837 additional text to each output. At present only timestamps
838 are supported: --debug-format=timestamps.
839 Timestamps can also be turned on with the
840 "monitor set debug-format timestamps" command from GDB.
842 * The 'record instruction-history' command now starts counting instructions
843 at one. This also affects the instruction ranges reported by the
844 'record function-call-history' command when given the /i modifier.
846 * The command 'record function-call-history' supports a new modifier '/c' to
847 indent the function names based on their call stack depth.
848 The fields for the '/i' and '/l' modifier have been reordered.
849 The source line range is now prefixed with 'at'.
850 The instruction range is now prefixed with 'inst'.
851 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
852 "record instruction-history" and "list" commands.
854 * The ranges given as arguments to the 'record function-call-history' and
855 'record instruction-history' commands are now inclusive.
857 * The btrace record target now supports the 'record goto' command.
858 For locations inside the execution trace, the back trace is computed
859 based on the information stored in the execution trace.
861 * The btrace record target supports limited reverse execution and replay.
862 The target does not record data and therefore does not allow reading
865 * The "catch syscall" command now works on s390*-linux* targets.
867 * The "compare-sections" command is no longer specific to target
868 remote. It now works with all targets.
870 * All native targets are now consistently called "native".
871 Consequently, the "target child", "target GNU", "target djgpp",
872 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
873 commands have been replaced with "target native". The QNX/NTO port
874 leaves the "procfs" target in place and adds a "native" target for
875 consistency with other ports. The impact on users should be minimal
876 as these commands previously either throwed an error, or were
877 no-ops. The target's name is visible in the output of the following
878 commands: "help target", "info target", "info files", "maint print
881 * The "target native" command now connects to the native target. This
882 can be used to launch native programs even when "set
883 auto-connect-native-target" is set to off.
885 * GDB now supports access to Intel MPX registers on GNU/Linux.
887 * Support for Intel AVX-512 registers on GNU/Linux.
888 Support displaying and modifying Intel AVX-512 registers
889 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
893 qXfer:btrace:read's annex
894 The qXfer:btrace:read packet supports a new annex 'delta' to read
895 branch trace incrementally.
899 ** Valid Python operations on gdb.Value objects representing
900 structs/classes invoke the corresponding overloaded operators if
902 ** New `Xmethods' feature in the Python API. Xmethods are
903 additional methods or replacements for existing methods of a C++
904 class. This feature is useful for those cases where a method
905 defined in C++ source code could be inlined or optimized out by
906 the compiler, making it unavailable to GDB.
909 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
911 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
912 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
913 its alias "share", instead.
915 * The commands "set remotebaud" and "show remotebaud" are no longer
916 supported. Use "set serial baud" and "show serial baud" (respectively)
921 ** A new option "-gdb-set mi-async" replaces "-gdb-set
922 target-async". The latter is left as a deprecated alias of the
923 former for backward compatibility. If the target supports it,
924 CLI background execution commands are now always possible by
925 default, independently of whether the frontend stated a
926 preference for asynchronous execution with "-gdb-set mi-async".
927 Previously "-gdb-set target-async off" affected both MI execution
928 commands and CLI execution commands.
930 *** Changes in GDB 7.7
932 * Improved support for process record-replay and reverse debugging on
933 arm*-linux* targets. Support for thumb32 and syscall instruction
934 recording has been added.
936 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
938 * GDB now supports Fission DWP file format version 2.
939 http://gcc.gnu.org/wiki/DebugFission
941 * New convenience function "$_isvoid", to check whether an expression
942 is void. A void expression is an expression where the type of the
943 result is "void". For example, some convenience variables may be
944 "void" when evaluated (e.g., "$_exitcode" before the execution of
945 the program being debugged; or an undefined convenience variable).
946 Another example, when calling a function whose return type is
949 * The "maintenance print objfiles" command now takes an optional regexp.
951 * The "catch syscall" command now works on arm*-linux* targets.
953 * GDB now consistently shows "<not saved>" when printing values of
954 registers the debug info indicates have not been saved in the frame
955 and there's nowhere to retrieve them from
956 (callee-saved/call-clobbered registers):
961 (gdb) info registers rax
964 Before, the former would print "<optimized out>", and the latter
965 "*value not available*".
967 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
972 ** Frame filters and frame decorators have been added.
973 ** Temporary breakpoints are now supported.
974 ** Line tables representation has been added.
975 ** New attribute 'parent_type' for gdb.Field objects.
976 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
977 ** New attribute 'name' for gdb.Type objects.
981 Nios II ELF nios2*-*-elf
982 Nios II GNU/Linux nios2*-*-linux
983 Texas Instruments MSP430 msp430*-*-elf
985 * Removed native configurations
987 Support for these a.out NetBSD and OpenBSD obsolete configurations has
988 been removed. ELF variants of these configurations are kept supported.
990 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
991 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
992 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
993 i[34567]86-*-openbsd3.[0-3]
994 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
995 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
996 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1000 Like "catch throw", but catches a re-thrown exception.
1001 maint check-psymtabs
1002 Renamed from old "maint check-symtabs".
1004 Perform consistency checks on symtabs.
1005 maint expand-symtabs
1006 Expand symtabs matching an optional regexp.
1009 Display the details of GDB configure-time options.
1011 maint set|show per-command
1012 maint set|show per-command space
1013 maint set|show per-command time
1014 maint set|show per-command symtab
1015 Enable display of per-command gdb resource usage.
1017 remove-symbol-file FILENAME
1018 remove-symbol-file -a ADDRESS
1019 Remove a symbol file added via add-symbol-file. The file to remove
1020 can be identified by its filename or by an address that lies within
1021 the boundaries of this symbol file in memory.
1024 info exceptions REGEXP
1025 Display the list of Ada exceptions defined in the program being
1026 debugged. If provided, only the exceptions whose names match REGEXP
1031 set debug symfile off|on
1033 Control display of debugging info regarding reading symbol files and
1034 symbol tables within those files
1036 set print raw frame-arguments
1037 show print raw frame-arguments
1038 Set/show whether to print frame arguments in raw mode,
1039 disregarding any defined pretty-printers.
1041 set remote trace-status-packet
1042 show remote trace-status-packet
1043 Set/show the use of remote protocol qTStatus packet.
1047 Control display of debugging messages related to Nios II targets.
1051 Control whether target-assisted range stepping is enabled.
1053 set startup-with-shell
1054 show startup-with-shell
1055 Specifies whether Unix child processes are started via a shell or
1060 Use the target memory cache for accesses to the code segment. This
1061 improves performance of remote debugging (particularly disassembly).
1063 * You can now use a literal value 'unlimited' for options that
1064 interpret 0 or -1 as meaning "unlimited". E.g., "set
1065 trace-buffer-size unlimited" is now an alias for "set
1066 trace-buffer-size -1" and "set height unlimited" is now an alias for
1069 * The "set debug symtab-create" debugging option of GDB has been changed to
1070 accept a verbosity level. 0 means "off", 1 provides basic debugging
1071 output, and values of 2 or greater provides more verbose output.
1073 * New command-line options
1075 Display the details of GDB configure-time options.
1077 * The command 'tsave' can now support new option '-ctf' to save trace
1078 buffer in Common Trace Format.
1080 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1083 * GDB now implements the the C++ 'typeid' operator.
1085 * The new convenience variable $_exception holds the exception being
1086 thrown or caught at an exception-related catchpoint.
1088 * The exception-related catchpoints, like "catch throw", now accept a
1089 regular expression which can be used to filter exceptions by type.
1091 * The new convenience variable $_exitsignal is automatically set to
1092 the terminating signal number when the program being debugged dies
1093 due to an uncaught signal.
1097 ** All MI commands now accept an optional "--language" option.
1098 Support for this feature can be verified by using the "-list-features"
1099 command, which should contain "language-option".
1101 ** The new command -info-gdb-mi-command allows the user to determine
1102 whether a GDB/MI command is supported or not.
1104 ** The "^error" result record returned when trying to execute an undefined
1105 GDB/MI command now provides a variable named "code" whose content is the
1106 "undefined-command" error code. Support for this feature can be verified
1107 by using the "-list-features" command, which should contain
1108 "undefined-command-error-code".
1110 ** The -trace-save MI command can optionally save trace buffer in Common
1113 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1115 ** The command -data-list-register-values now accepts an optional
1116 "--skip-unavailable" option. When used, only the available registers
1119 ** The new command -trace-frame-collected dumps collected variables,
1120 computed expressions, tvars, memory and registers in a traceframe.
1122 ** The commands -stack-list-locals, -stack-list-arguments and
1123 -stack-list-variables now accept an option "--skip-unavailable".
1124 When used, only the available locals or arguments are displayed.
1126 ** The -exec-run command now accepts an optional "--start" option.
1127 When used, the command follows the same semantics as the "start"
1128 command, stopping the program's execution at the start of its
1129 main subprogram. Support for this feature can be verified using
1130 the "-list-features" command, which should contain
1131 "exec-run-start-option".
1133 ** The new commands -catch-assert and -catch-exceptions insert
1134 catchpoints stopping the program when Ada exceptions are raised.
1136 ** The new command -info-ada-exceptions provides the equivalent of
1137 the new "info exceptions" command.
1139 * New system-wide configuration scripts
1140 A GDB installation now provides scripts suitable for use as system-wide
1141 configuration scripts for the following systems:
1145 * GDB now supports target-assigned range stepping with remote targets.
1146 This improves the performance of stepping source lines by reducing
1147 the number of control packets from/to GDB. See "New remote packets"
1150 * GDB now understands the element 'tvar' in the XML traceframe info.
1151 It has the id of the collected trace state variables.
1153 * On S/390 targets that provide the transactional-execution feature,
1154 the program interruption transaction diagnostic block (TDB) is now
1155 represented as a number of additional "registers" in GDB.
1157 * New remote packets
1161 The vCont packet supports a new 'r' action, that tells the remote
1162 stub to step through an address range itself, without GDB
1163 involvemement at each single-step.
1165 qXfer:libraries-svr4:read's annex
1166 The previously unused annex of the qXfer:libraries-svr4:read packet
1167 is now used to support passing an argument list. The remote stub
1168 reports support for this argument list to GDB's qSupported query.
1169 The defined arguments are "start" and "prev", used to reduce work
1170 necessary for library list updating, resulting in significant
1173 * New features in the GDB remote stub, GDBserver
1175 ** GDBserver now supports target-assisted range stepping. Currently
1176 enabled on x86/x86_64 GNU/Linux targets.
1178 ** GDBserver now adds element 'tvar' in the XML in the reply to
1179 'qXfer:traceframe-info:read'. It has the id of the collected
1180 trace state variables.
1182 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1185 * New 'z' formatter for printing and examining memory, this displays the
1186 value as hexadecimal zero padded on the left to the size of the type.
1188 * GDB can now use Windows x64 unwinding data.
1190 * The "set remotebaud" command has been replaced by "set serial baud".
1191 Similarly, "show remotebaud" has been replaced by "show serial baud".
1192 The "set remotebaud" and "show remotebaud" commands are still available
1193 to provide backward compatibility with older versions of GDB.
1195 *** Changes in GDB 7.6
1197 * Target record has been renamed to record-full.
1198 Record/replay is now enabled with the "record full" command.
1199 This also affects settings that are associated with full record/replay
1200 that have been moved from "set/show record" to "set/show record full":
1202 set|show record full insn-number-max
1203 set|show record full stop-at-limit
1204 set|show record full memory-query
1206 * A new record target "record-btrace" has been added. The new target
1207 uses hardware support to record the control-flow of a process. It
1208 does not support replaying the execution, but it implements the
1209 below new commands for investigating the recorded execution log.
1210 This new recording method can be enabled using:
1214 The "record-btrace" target is only available on Intel Atom processors
1215 and requires a Linux kernel 2.6.32 or later.
1217 * Two new commands have been added for record/replay to give information
1218 about the recorded execution without having to replay the execution.
1219 The commands are only supported by "record btrace".
1221 record instruction-history prints the execution history at
1222 instruction granularity
1224 record function-call-history prints the execution history at
1225 function granularity
1227 * New native configurations
1229 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1230 FreeBSD/powerpc powerpc*-*-freebsd
1231 x86_64/Cygwin x86_64-*-cygwin*
1232 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1236 ARM AArch64 aarch64*-*-elf
1237 ARM AArch64 GNU/Linux aarch64*-*-linux
1238 Lynx 178 PowerPC powerpc-*-lynx*178
1239 x86_64/Cygwin x86_64-*-cygwin*
1240 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1242 * If the configured location of system.gdbinit file (as given by the
1243 --with-system-gdbinit option at configure time) is in the
1244 data-directory (as specified by --with-gdb-datadir at configure
1245 time) or in one of its subdirectories, then GDB will look for the
1246 system-wide init file in the directory specified by the
1247 --data-directory command-line option.
1249 * New command line options:
1251 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1252 other initialization files, unlike -nx which disables all of them.
1254 * Removed command line options
1256 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1259 * The 'ptype' and 'whatis' commands now accept an argument to control
1262 * 'info proc' now works on some core files.
1266 ** Vectors can be created with gdb.Type.vector.
1268 ** Python's atexit.register now works in GDB.
1270 ** Types can be pretty-printed via a Python API.
1272 ** Python 3 is now supported (in addition to Python 2.4 or later)
1274 ** New class gdb.Architecture exposes GDB's internal representation
1275 of architecture in the Python API.
1277 ** New method Frame.architecture returns the gdb.Architecture object
1278 corresponding to the frame's architecture.
1280 * New Python-based convenience functions:
1282 ** $_memeq(buf1, buf2, length)
1283 ** $_streq(str1, str2)
1285 ** $_regex(str, regex)
1287 * The 'cd' command now defaults to using '~' (the home directory) if not
1290 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1291 default for GCC since November 2000.
1293 * The command 'forward-search' can now be abbreviated as 'fo'.
1295 * The command 'info tracepoints' can now display 'installed on target'
1296 or 'not installed on target' for each non-pending location of tracepoint.
1298 * New configure options
1300 --enable-libmcheck/--disable-libmcheck
1301 By default, development versions are built with -lmcheck on hosts
1302 that support it, in order to help track memory corruption issues.
1303 Release versions, on the other hand, are built without -lmcheck
1304 by default. The --enable-libmcheck/--disable-libmcheck configure
1305 options allow the user to override that default.
1306 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1307 This configure option allows the user to build GDB with
1308 libbabeltrace using which GDB can read Common Trace Format data.
1310 * New commands (for set/show, see "New options" below)
1313 Catch signals. This is similar to "handle", but allows commands and
1314 conditions to be attached.
1317 List the BFDs known to GDB.
1319 python-interactive [command]
1321 Start a Python interactive prompt, or evaluate the optional command
1322 and print the result of expressions.
1325 "py" is a new alias for "python".
1327 enable type-printer [name]...
1328 disable type-printer [name]...
1329 Enable or disable type printers.
1333 ** For the Renesas Super-H architecture, the "regs" command has been removed
1334 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1339 set print type methods (on|off)
1340 show print type methods
1341 Control whether method declarations are displayed by "ptype".
1342 The default is to show them.
1344 set print type typedefs (on|off)
1345 show print type typedefs
1346 Control whether typedef definitions are displayed by "ptype".
1347 The default is to show them.
1349 set filename-display basename|relative|absolute
1350 show filename-display
1351 Control the way in which filenames is displayed.
1352 The default is "relative", which preserves previous behavior.
1354 set trace-buffer-size
1355 show trace-buffer-size
1356 Request target to change the size of trace buffer.
1358 set remote trace-buffer-size-packet auto|on|off
1359 show remote trace-buffer-size-packet
1360 Control the use of the remote protocol `QTBuffer:size' packet.
1364 Control display of debugging messages related to ARM AArch64.
1367 set debug coff-pe-read
1368 show debug coff-pe-read
1369 Control display of debugging messages related to reading of COFF/PE
1374 Control display of debugging messages related to Mach-O symbols
1377 set debug notification
1378 show debug notification
1379 Control display of debugging info for async remote notification.
1383 ** Command parameter changes are now notified using new async record
1384 "=cmd-param-changed".
1385 ** Trace frame changes caused by command "tfind" are now notified using
1386 new async record "=traceframe-changed".
1387 ** The creation, deletion and modification of trace state variables
1388 are now notified using new async records "=tsv-created",
1389 "=tsv-deleted" and "=tsv-modified".
1390 ** The start and stop of process record are now notified using new
1391 async record "=record-started" and "=record-stopped".
1392 ** Memory changes are now notified using new async record
1394 ** The data-disassemble command response will include a "fullname" field
1395 containing the absolute file name when source has been requested.
1396 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1397 command, to allow pattern filling of memory areas.
1398 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1399 library load/unload events.
1400 ** The response to breakpoint commands and breakpoint async records
1401 includes an "installed" field containing a boolean state about each
1402 non-pending tracepoint location is whether installed on target or not.
1403 ** Output of the "-trace-status" command includes a "trace-file" field
1404 containing the name of the trace file being examined. This field is
1405 optional, and only present when examining a trace file.
1406 ** The "fullname" field is now always present along with the "file" field,
1407 even if the file cannot be found by GDB.
1409 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1410 You must have the LZMA library available when configuring GDB for this
1411 feature to be enabled. For more information, see:
1412 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1414 * New remote packets
1417 Set the size of trace buffer. The remote stub reports support for this
1418 packet to gdb's qSupported query.
1421 Enable Branch Trace Store (BTS)-based branch tracing for the current
1422 thread. The remote stub reports support for this packet to gdb's
1426 Disable branch tracing for the current thread. The remote stub reports
1427 support for this packet to gdb's qSupported query.
1430 Read the traced branches for the current thread. The remote stub
1431 reports support for this packet to gdb's qSupported query.
1433 *** Changes in GDB 7.5
1435 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1436 for more x32 ABI info.
1438 * GDB now supports access to MIPS DSP registers on Linux targets.
1440 * GDB now supports debugging microMIPS binaries.
1442 * The "info os" command on GNU/Linux can now display information on
1443 several new classes of objects managed by the operating system:
1444 "info os procgroups" lists process groups
1445 "info os files" lists file descriptors
1446 "info os sockets" lists internet-domain sockets
1447 "info os shm" lists shared-memory regions
1448 "info os semaphores" lists semaphores
1449 "info os msg" lists message queues
1450 "info os modules" lists loaded kernel modules
1452 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1453 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1454 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1455 options and inspect the probe arguments using the new $_probe_arg family
1456 of convenience variables. You can obtain more information about SystemTap
1457 in <http://sourceware.org/systemtap/>.
1459 * GDB now supports reversible debugging on ARM, it allows you to
1460 debug basic ARM and THUMB instructions, and provides
1461 record/replay support.
1463 * The option "symbol-reloading" has been deleted as it is no longer used.
1467 ** GDB commands implemented in Python can now be put in command class
1470 ** The "maint set python print-stack on|off" is now deleted.
1472 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1473 apply "flag enum"-style pretty-printing to any enum.
1475 ** gdb.lookup_symbol can now work when there is no current frame.
1477 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1478 the source at which the symbol was defined.
1480 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1481 method 'value'. The former indicates whether the symbol needs a
1482 frame in order to compute its value, and the latter computes the
1485 ** A new method 'referenced_value' on gdb.Value objects which can
1486 dereference pointer as well as C++ reference values.
1488 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1489 which return the global and static blocks (as gdb.Block objects),
1490 of the underlying symbol table, respectively.
1492 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1493 object associated with a PC value.
1495 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1496 of the address range occupied by code for the current source line.
1498 * Go language support.
1499 GDB now supports debugging programs written in the Go programming
1502 * GDBserver now supports stdio connections.
1503 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1505 * The binary "gdbtui" can no longer be built or installed.
1506 Use "gdb -tui" instead.
1508 * GDB will now print "flag" enums specially. A flag enum is one where
1509 all the enumerator values have no bits in common when pairwise
1510 "and"ed. When printing a value whose type is a flag enum, GDB will
1511 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1512 (gdb) print (enum E) 3
1515 * The filename part of a linespec will now match trailing components
1516 of a source file name. For example, "break gcc/expr.c:1000" will
1517 now set a breakpoint in build/gcc/expr.c, but not
1518 build/libcpp/expr.c.
1520 * The "info proc" and "generate-core-file" commands will now also
1521 work on remote targets connected to GDBserver on Linux.
1523 * The command "info catch" has been removed. It has been disabled
1524 since December 2007.
1526 * The "catch exception" and "catch assert" commands now accept
1527 a condition at the end of the command, much like the "break"
1528 command does. For instance:
1530 (gdb) catch exception Constraint_Error if Barrier = True
1532 Previously, it was possible to add a condition to such catchpoints,
1533 but it had to be done as a second step, after the catchpoint had been
1534 created, using the "condition" command.
1536 * The "info static-tracepoint-marker" command will now also work on
1537 native Linux targets with in-process agent.
1539 * GDB can now set breakpoints on inlined functions.
1541 * The .gdb_index section has been updated to include symbols for
1542 inlined functions. GDB will ignore older .gdb_index sections by
1543 default, which could cause symbol files to be loaded more slowly
1544 until their .gdb_index sections can be recreated. The new command
1545 "set use-deprecated-index-sections on" will cause GDB to use any older
1546 .gdb_index sections it finds. This will restore performance, but the
1547 ability to set breakpoints on inlined functions will be lost in symbol
1548 files with older .gdb_index sections.
1550 The .gdb_index section has also been updated to record more information
1551 about each symbol. This speeds up the "info variables", "info functions"
1552 and "info types" commands when used with programs having the .gdb_index
1553 section, as well as speeding up debugging with shared libraries using
1554 the .gdb_index section.
1556 * Ada support for GDB/MI Variable Objects has been added.
1558 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1563 ** New command -info-os is the MI equivalent of "info os".
1565 ** Output logs ("set logging" and related) now include MI output.
1569 ** "set use-deprecated-index-sections on|off"
1570 "show use-deprecated-index-sections on|off"
1571 Controls the use of deprecated .gdb_index sections.
1573 ** "catch load" and "catch unload" can be used to stop when a shared
1574 library is loaded or unloaded, respectively.
1576 ** "enable count" can be used to auto-disable a breakpoint after
1579 ** "info vtbl" can be used to show the virtual method tables for
1580 C++ and Java objects.
1582 ** "explore" and its sub commands "explore value" and "explore type"
1583 can be used to recursively explore values and types of
1584 expressions. These commands are available only if GDB is
1585 configured with '--with-python'.
1587 ** "info auto-load" shows status of all kinds of auto-loaded files,
1588 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1589 sequences of commands files, "info auto-load python-scripts"
1590 shows status of auto-loading Python script files,
1591 "info auto-load local-gdbinit" shows status of loading init file
1592 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1593 status of inferior specific thread debugging shared library loading.
1595 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1596 and "show auto-load-scripts" commands have been deprecated, use their
1597 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1598 and "show auto-load python-scripts" counterparts instead.
1600 ** "dprintf location,format,args..." creates a dynamic printf, which
1601 is basically a breakpoint that does a printf and immediately
1602 resumes your program's execution, so it is like a printf that you
1603 can insert dynamically at runtime instead of at compiletime.
1605 ** "set print symbol"
1607 Controls whether GDB attempts to display the symbol, if any,
1608 corresponding to addresses it prints. This defaults to "on", but
1609 you can set it to "off" to restore GDB's previous behavior.
1611 * Deprecated commands
1613 ** For the Renesas Super-H architecture, the "regs" command has been
1614 deprecated, and "info all-registers" should be used instead.
1618 Renesas RL78 rl78-*-elf
1619 HP OpenVMS ia64 ia64-hp-openvms*
1621 * GDBserver supports evaluation of breakpoint conditions. When
1622 support is advertised by GDBserver, GDB may be told to send the
1623 breakpoint conditions in bytecode form to GDBserver. GDBserver
1624 will only report the breakpoint trigger to GDB when its condition
1629 set mips compression
1630 show mips compression
1631 Select the compressed ISA encoding used in functions that have no symbol
1632 information available. The encoding can be set to either of:
1635 and is updated automatically from ELF file flags if available.
1637 set breakpoint condition-evaluation
1638 show breakpoint condition-evaluation
1639 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1640 GDBserver ("target"). Default option "auto" chooses the most efficient
1642 This option can improve debugger efficiency depending on the speed of the
1646 Disable auto-loading globally.
1649 Show auto-loading setting of all kinds of auto-loaded files.
1651 set auto-load gdb-scripts on|off
1652 show auto-load gdb-scripts
1653 Control auto-loading of GDB canned sequences of commands files.
1655 set auto-load python-scripts on|off
1656 show auto-load python-scripts
1657 Control auto-loading of Python script files.
1659 set auto-load local-gdbinit on|off
1660 show auto-load local-gdbinit
1661 Control loading of init file (.gdbinit) from current directory.
1663 set auto-load libthread-db on|off
1664 show auto-load libthread-db
1665 Control auto-loading of inferior specific thread debugging shared library.
1667 set auto-load scripts-directory <dir1>[:<dir2>...]
1668 show auto-load scripts-directory
1669 Set a list of directories from which to load auto-loaded scripts.
1670 Automatically loaded Python scripts and GDB scripts are located in one
1671 of the directories listed by this option.
1672 The delimiter (':' above) may differ according to the host platform.
1674 set auto-load safe-path <dir1>[:<dir2>...]
1675 show auto-load safe-path
1676 Set a list of directories from which it is safe to auto-load files.
1677 The delimiter (':' above) may differ according to the host platform.
1679 set debug auto-load on|off
1680 show debug auto-load
1681 Control display of debugging info for auto-loading the files above.
1683 set dprintf-style gdb|call|agent
1685 Control the way in which a dynamic printf is performed; "gdb"
1686 requests a GDB printf command, while "call" causes dprintf to call a
1687 function in the inferior. "agent" requests that the target agent
1688 (such as GDBserver) do the printing.
1690 set dprintf-function <expr>
1691 show dprintf-function
1692 set dprintf-channel <expr>
1693 show dprintf-channel
1694 Set the function and optional first argument to the call when using
1695 the "call" style of dynamic printf.
1697 set disconnected-dprintf on|off
1698 show disconnected-dprintf
1699 Control whether agent-style dynamic printfs continue to be in effect
1700 after GDB disconnects.
1702 * New configure options
1704 --with-auto-load-dir
1705 Configure default value for the 'set auto-load scripts-directory'
1706 setting above. It defaults to '$debugdir:$datadir/auto-load',
1707 $debugdir representing global debugging info directories (available
1708 via 'show debug-file-directory') and $datadir representing GDB's data
1709 directory (available via 'show data-directory').
1711 --with-auto-load-safe-path
1712 Configure default value for the 'set auto-load safe-path' setting
1713 above. It defaults to the --with-auto-load-dir setting.
1715 --without-auto-load-safe-path
1716 Set 'set auto-load safe-path' to '/', effectively disabling this
1719 * New remote packets
1721 z0/z1 conditional breakpoints extension
1723 The z0/z1 breakpoint insertion packets have been extended to carry
1724 a list of conditional expressions over to the remote stub depending on the
1725 condition evaluation mode. The use of this extension can be controlled
1726 via the "set remote conditional-breakpoints-packet" command.
1730 Specify the signals which the remote stub may pass to the debugged
1731 program without GDB involvement.
1733 * New command line options
1735 --init-command=FILE, -ix Like --command, -x but execute it
1736 before loading inferior.
1737 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1738 execute it before loading inferior.
1740 *** Changes in GDB 7.4
1742 * GDB now handles ambiguous linespecs more consistently; the existing
1743 FILE:LINE support has been expanded to other types of linespecs. A
1744 breakpoint will now be set on all matching locations in all
1745 inferiors, and locations will be added or removed according to
1748 * GDB now allows you to skip uninteresting functions and files when
1749 stepping with the "skip function" and "skip file" commands.
1751 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1752 and "show remote hardware-watchpoint-length-limit". These allows to
1753 set or show the maximum length limit (in bytes) of a remote
1754 target hardware watchpoint.
1756 This allows e.g. to use "unlimited" hardware watchpoints with the
1757 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1758 watchpoints are slower than real hardware watchpoints but are
1759 significantly faster than gdb software watchpoints.
1763 ** The register_pretty_printer function in module gdb.printing now takes
1764 an optional `replace' argument. If True, the new printer replaces any
1767 ** The "maint set python print-stack on|off" command has been
1768 deprecated and will be deleted in GDB 7.5.
1769 A new command: "set python print-stack none|full|message" has
1770 replaced it. Additionally, the default for "print-stack" is
1771 now "message", which just prints the error message without
1774 ** A prompt substitution hook (prompt_hook) is now available to the
1777 ** A new Python module, gdb.prompt has been added to the GDB Python
1778 modules library. This module provides functionality for
1779 escape sequences in prompts (used by set/show
1780 extended-prompt). These escape sequences are replaced by their
1781 corresponding value.
1783 ** Python commands and convenience-functions located in
1784 'data-directory'/python/gdb/command and
1785 'data-directory'/python/gdb/function are now automatically loaded
1788 ** Blocks now provide four new attributes. global_block and
1789 static_block will return the global and static blocks
1790 respectively. is_static and is_global are boolean attributes
1791 that indicate if the block is one of those two types.
1793 ** Symbols now provide the "type" attribute, the type of the symbol.
1795 ** The "gdb.breakpoint" function has been deprecated in favor of
1798 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1799 of a function. This class is based on the "finish" command
1800 available in the CLI.
1802 ** Type objects for struct and union types now allow access to
1803 the fields using standard Python dictionary (mapping) methods.
1804 For example, "some_type['myfield']" now works, as does
1805 "some_type.items()".
1807 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1810 ** A new function, "deep_items" has been added to the gdb.types
1811 module in the GDB Python modules library. This function returns
1812 an iterator over the fields of a struct or union type. Unlike
1813 the standard Python "iteritems" method, it will recursively traverse
1814 any anonymous fields.
1818 ** "*stopped" events can report several new "reason"s, such as
1821 ** Breakpoint changes are now notified using new async records, like
1822 "=breakpoint-modified".
1824 ** New command -ada-task-info.
1826 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1827 $sdir specifies the default system locations of shared libraries.
1828 $pdir specifies the directory where the libpthread used by the application
1831 GDB no longer looks in $sdir and $pdir after it has searched the directories
1832 mentioned in libthread-db-search-path. If you want to search those
1833 directories, they must be specified in libthread-db-search-path.
1834 The default value of libthread-db-search-path on GNU/Linux and Solaris
1835 systems is now "$sdir:$pdir".
1837 $pdir is not supported by gdbserver, it is currently ignored.
1838 $sdir is supported by gdbserver.
1840 * New configure option --with-iconv-bin.
1841 When using the internationalization support like the one in the GNU C
1842 library, GDB will invoke the "iconv" program to get a list of supported
1843 character sets. If this program lives in a non-standard location, one can
1844 use this option to specify where to find it.
1846 * When natively debugging programs on PowerPC BookE processors running
1847 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1848 watchpoints, which specify a mask in addition to an address to watch.
1849 The mask specifies that some bits of an address (the bits which are
1850 reset in the mask) should be ignored when matching the address accessed
1851 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1852 section in the user manual for more details.
1854 * The new option --once causes GDBserver to stop listening for connections once
1855 the first connection is made. The listening port used by GDBserver will
1856 become available after that.
1858 * New commands "info macros" and "alias" have been added.
1860 * New function parameters suffix @entry specifies value of function parameter
1861 at the time the function got called. Entry values are available only since
1867 "!" is now an alias of the "shell" command.
1868 Note that no space is needed between "!" and SHELL COMMAND.
1872 watch EXPRESSION mask MASK_VALUE
1873 The watch command now supports the mask argument which allows creation
1874 of masked watchpoints, if the current architecture supports this feature.
1876 info auto-load-scripts [REGEXP]
1877 This command was formerly named "maintenance print section-scripts".
1878 It is now generally useful and is no longer a maintenance-only command.
1880 info macro [-all] [--] MACRO
1881 The info macro command has new options `-all' and `--'. The first for
1882 printing all definitions of a macro. The second for explicitly specifying
1883 the end of arguments and the beginning of the macro name in case the macro
1884 name starts with a hyphen.
1886 collect[/s] EXPRESSIONS
1887 The tracepoint collect command now takes an optional modifier "/s"
1888 that directs it to dereference pointer-to-character types and
1889 collect the bytes of memory up to a zero byte. The behavior is
1890 similar to what you see when you use the regular print command on a
1891 string. An optional integer following the "/s" sets a bound on the
1892 number of bytes that will be collected.
1895 The trace start command now interprets any supplied arguments as a
1896 note to be recorded with the trace run, with an effect similar to
1897 setting the variable trace-notes.
1900 The trace stop command now interprets any arguments as a note to be
1901 mentioned along with the tstatus report that the trace was stopped
1902 with a command. The effect is similar to setting the variable
1905 * Tracepoints can now be enabled and disabled at any time after a trace
1906 experiment has been started using the standard "enable" and "disable"
1907 commands. It is now possible to start a trace experiment with no enabled
1908 tracepoints; GDB will display a warning, but will allow the experiment to
1909 begin, assuming that tracepoints will be enabled as needed while the trace
1912 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1913 locations with 4-byte instructions, when they were previously
1914 limited to locations with instructions of 5 bytes or longer.
1918 set debug dwarf2-read
1919 show debug dwarf2-read
1920 Turns on or off display of debugging messages related to reading
1921 DWARF debug info. The default is off.
1923 set debug symtab-create
1924 show debug symtab-create
1925 Turns on or off display of debugging messages related to symbol table
1926 creation. The default is off.
1929 show extended-prompt
1930 Set the GDB prompt, and allow escape sequences to be inserted to
1931 display miscellaneous information (see 'help set extended-prompt'
1932 for the list of sequences). This prompt (and any information
1933 accessed through the escape sequences) is updated every time the
1934 prompt is displayed.
1936 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1937 show print entry-values
1938 Set printing of frame argument values at function entry. In some cases
1939 GDB can determine the value of function argument which was passed by the
1940 function caller, even if the value was modified inside the called function.
1942 set debug entry-values
1943 show debug entry-values
1944 Control display of debugging info for determining frame argument values at
1945 function entry and virtual tail call frames.
1947 set basenames-may-differ
1948 show basenames-may-differ
1949 Set whether a source file may have multiple base names.
1950 (A "base name" is the name of a file with the directory part removed.
1951 Example: The base name of "/home/user/hello.c" is "hello.c".)
1952 If set, GDB will canonicalize file names (e.g., expand symlinks)
1953 before comparing them. Canonicalization is an expensive operation,
1954 but it allows the same file be known by more than one base name.
1955 If not set (the default), all source files are assumed to have just
1956 one base name, and gdb will do file name comparisons more efficiently.
1962 Set a user name and notes for the current and any future trace runs.
1963 This is useful for long-running and/or disconnected traces, to
1964 inform others (or yourself) as to who is running the trace, supply
1965 contact information, or otherwise explain what is going on.
1967 set trace-stop-notes
1968 show trace-stop-notes
1969 Set a note attached to the trace run, that is displayed when the
1970 trace has been stopped by a tstop command. This is useful for
1971 instance as an explanation, if you are stopping a trace run that was
1972 started by someone else.
1974 * New remote packets
1978 Dynamically enable a tracepoint in a started trace experiment.
1982 Dynamically disable a tracepoint in a started trace experiment.
1986 Set the user and notes of the trace run.
1990 Query the current status of a tracepoint.
1994 Query the minimum length of instruction at which a fast tracepoint may
1997 * Dcache size (number of lines) and line-size are now runtime-configurable
1998 via "set dcache line" and "set dcache line-size" commands.
2002 Texas Instruments TMS320C6x tic6x-*-*
2006 Renesas RL78 rl78-*-elf
2008 *** Changes in GDB 7.3.1
2010 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2012 *** Changes in GDB 7.3
2014 * GDB has a new command: "thread find [REGEXP]".
2015 It finds the thread id whose name, target id, or thread extra info
2016 matches the given regular expression.
2018 * The "catch syscall" command now works on mips*-linux* targets.
2020 * The -data-disassemble MI command now supports modes 2 and 3 for
2021 dumping the instruction opcodes.
2023 * New command line options
2025 -data-directory DIR Specify DIR as the "data-directory".
2026 This is mostly for testing purposes.
2028 * The "maint set python auto-load on|off" command has been renamed to
2029 "set auto-load-scripts on|off".
2031 * GDB has a new command: "set directories".
2032 It is like the "dir" command except that it replaces the
2033 source path list instead of augmenting it.
2035 * GDB now understands thread names.
2037 On GNU/Linux, "info threads" will display the thread name as set by
2038 prctl or pthread_setname_np.
2040 There is also a new command, "thread name", which can be used to
2041 assign a name internally for GDB to display.
2044 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2045 has been integrated into GDB.
2049 ** The function gdb.Write now accepts an optional keyword 'stream'.
2050 This keyword, when provided, will direct the output to either
2051 stdout, stderr, or GDB's logging output.
2053 ** Parameters can now be be sub-classed in Python, and in particular
2054 you may implement the get_set_doc and get_show_doc functions.
2055 This improves how Parameter set/show documentation is processed
2056 and allows for more dynamic content.
2058 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2059 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2060 have an is_valid method.
2062 ** Breakpoints can now be sub-classed in Python, and in particular
2063 you may implement a 'stop' function that is executed each time
2064 the inferior reaches that breakpoint.
2066 ** New function gdb.lookup_global_symbol looks up a global symbol.
2068 ** GDB values in Python are now callable if the value represents a
2069 function. For example, if 'some_value' represents a function that
2070 takes two integer parameters and returns a value, you can call
2071 that function like so:
2073 result = some_value (10,20)
2075 ** Module gdb.types has been added.
2076 It contains a collection of utilities for working with gdb.Types objects:
2077 get_basic_type, has_field, make_enum_dict.
2079 ** Module gdb.printing has been added.
2080 It contains utilities for writing and registering pretty-printers.
2081 New classes: PrettyPrinter, SubPrettyPrinter,
2082 RegexpCollectionPrettyPrinter.
2083 New function: register_pretty_printer.
2085 ** New commands "info pretty-printers", "enable pretty-printer" and
2086 "disable pretty-printer" have been added.
2088 ** gdb.parameter("directories") is now available.
2090 ** New function gdb.newest_frame returns the newest frame in the
2093 ** The gdb.InferiorThread class has a new "name" attribute. This
2094 holds the thread's name.
2096 ** Python Support for Inferior events.
2097 Python scripts can add observers to be notified of events
2098 occurring in the process being debugged.
2099 The following events are currently supported:
2100 - gdb.events.cont Continue event.
2101 - gdb.events.exited Inferior exited event.
2102 - gdb.events.stop Signal received, and Breakpoint hit events.
2106 ** GDB now puts template parameters in scope when debugging in an
2107 instantiation. For example, if you have:
2109 template<int X> int func (void) { return X; }
2111 then if you step into func<5>, "print X" will show "5". This
2112 feature requires proper debuginfo support from the compiler; it
2113 was added to GCC 4.5.
2115 ** The motion commands "next", "finish", "until", and "advance" now
2116 work better when exceptions are thrown. In particular, GDB will
2117 no longer lose control of the inferior; instead, the GDB will
2118 stop the inferior at the point at which the exception is caught.
2119 This functionality requires a change in the exception handling
2120 code that was introduced in GCC 4.5.
2122 * GDB now follows GCC's rules on accessing volatile objects when
2123 reading or writing target state during expression evaluation.
2124 One notable difference to prior behavior is that "print x = 0"
2125 no longer generates a read of x; the value of the assignment is
2126 now always taken directly from the value being assigned.
2128 * GDB now has some support for using labels in the program's source in
2129 linespecs. For instance, you can use "advance label" to continue
2130 execution to a label.
2132 * GDB now has support for reading and writing a new .gdb_index
2133 section. This section holds a fast index of DWARF debugging
2134 information and can be used to greatly speed up GDB startup and
2135 operation. See the documentation for `save gdb-index' for details.
2137 * The "watch" command now accepts an optional "-location" argument.
2138 When used, this causes GDB to watch the memory referred to by the
2139 expression. Such a watchpoint is never deleted due to it going out
2142 * GDB now supports thread debugging of core dumps on GNU/Linux.
2144 GDB now activates thread debugging using the libthread_db library
2145 when debugging GNU/Linux core dumps, similarly to when debugging
2146 live processes. As a result, when debugging a core dump file, GDB
2147 is now able to display pthread_t ids of threads. For example, "info
2148 threads" shows the same output as when debugging the process when it
2149 was live. In earlier releases, you'd see something like this:
2152 * 1 LWP 6780 main () at main.c:10
2154 While now you see this:
2157 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2159 It is also now possible to inspect TLS variables when debugging core
2162 When debugging a core dump generated on a machine other than the one
2163 used to run GDB, you may need to point GDB at the correct
2164 libthread_db library with the "set libthread-db-search-path"
2165 command. See the user manual for more details on this command.
2167 * When natively debugging programs on PowerPC BookE processors running
2168 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2169 which stop execution of the inferior whenever it executes an instruction
2170 at any address within the specified range. See the "PowerPC Embedded"
2171 section in the user manual for more details.
2173 * New features in the GDB remote stub, GDBserver
2175 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2176 and i686 LynxOS (version 5.x).
2178 ** GDBserver is now supported on Blackfin Linux.
2180 * New native configurations
2182 ia64 HP-UX ia64-*-hpux*
2186 Analog Devices, Inc. Blackfin Processor bfin-*
2188 * Ada task switching is now supported on sparc-elf targets when
2189 debugging a program using the Ravenscar Profile. For more information,
2190 see the "Tasking Support when using the Ravenscar Profile" section
2191 in the GDB user manual.
2193 * Guile support was removed.
2195 * New features in the GNU simulator
2197 ** The --map-info flag lists all known core mappings.
2199 ** CFI flashes may be simulated via the "cfi" device.
2201 *** Changes in GDB 7.2
2203 * Shared library support for remote targets by default
2205 When GDB is configured for a generic, non-OS specific target, like
2206 for example, --target=arm-eabi or one of the many *-*-elf targets,
2207 GDB now queries remote stubs for loaded shared libraries using the
2208 `qXfer:libraries:read' packet. Previously, shared library support
2209 was always disabled for such configurations.
2213 ** Argument Dependent Lookup (ADL)
2215 In C++ ADL lookup directs function search to the namespaces of its
2216 arguments even if the namespace has not been imported.
2226 Here the compiler will search for `foo' in the namespace of 'b'
2227 and find A::foo. GDB now supports this. This construct is commonly
2228 used in the Standard Template Library for operators.
2230 ** Improved User Defined Operator Support
2232 In addition to member operators, GDB now supports lookup of operators
2233 defined in a namespace and imported with a `using' directive, operators
2234 defined in the global scope, operators imported implicitly from an
2235 anonymous namespace, and the ADL operators mentioned in the previous
2237 GDB now also supports proper overload resolution for all the previously
2238 mentioned flavors of operators.
2240 ** static const class members
2242 Printing of static const class members that are initialized in the
2243 class definition has been fixed.
2245 * Windows Thread Information Block access.
2247 On Windows targets, GDB now supports displaying the Windows Thread
2248 Information Block (TIB) structure. This structure is visible either
2249 by using the new command `info w32 thread-information-block' or, by
2250 dereferencing the new convenience variable named `$_tlb', a
2251 thread-specific pointer to the TIB. This feature is also supported
2252 when remote debugging using GDBserver.
2254 * Static tracepoints
2256 Static tracepoints are calls in the user program into a tracing
2257 library. One such library is a port of the LTTng kernel tracer to
2258 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2259 When debugging with GDBserver, GDB now supports combining the GDB
2260 tracepoint machinery with such libraries. For example: the user can
2261 use GDB to probe a static tracepoint marker (a call from the user
2262 program into the tracing library) with the new "strace" command (see
2263 "New commands" below). This creates a "static tracepoint" in the
2264 breakpoint list, that can be manipulated with the same feature set
2265 as fast and regular tracepoints. E.g., collect registers, local and
2266 global variables, collect trace state variables, and define
2267 tracepoint conditions. In addition, the user can collect extra
2268 static tracepoint marker specific data, by collecting the new
2269 $_sdata internal variable. When analyzing the trace buffer, you can
2270 inspect $_sdata like any other variable available to GDB. For more
2271 information, see the "Tracepoints" chapter in GDB user manual. New
2272 remote packets have been defined to support static tracepoints, see
2273 the "New remote packets" section below.
2275 * Better reconstruction of tracepoints after disconnected tracing
2277 GDB will attempt to download the original source form of tracepoint
2278 definitions when starting a trace run, and then will upload these
2279 upon reconnection to the target, resulting in a more accurate
2280 reconstruction of the tracepoints that are in use on the target.
2284 You can now exercise direct control over the ways that GDB can
2285 affect your program. For instance, you can disallow the setting of
2286 breakpoints, so that the program can run continuously (assuming
2287 non-stop mode). In addition, the "observer" variable is available
2288 to switch all of the different controls; in observer mode, GDB
2289 cannot affect the target's behavior at all, which is useful for
2290 tasks like diagnosing live systems in the field.
2292 * The new convenience variable $_thread holds the number of the
2295 * New remote packets
2299 Return the address of the Windows Thread Information Block of a given thread.
2303 In response to several of the tracepoint packets, the target may now
2304 also respond with a number of intermediate `qRelocInsn' request
2305 packets before the final result packet, to have GDB handle
2306 relocating an instruction to execute at a different address. This
2307 is particularly useful for stubs that support fast tracepoints. GDB
2308 reports support for this feature in the qSupported packet.
2312 List static tracepoint markers in the target program.
2316 List static tracepoint markers at a given address in the target
2319 qXfer:statictrace:read
2321 Read the static trace data collected (by a `collect $_sdata'
2322 tracepoint action). The remote stub reports support for this packet
2323 to gdb's qSupported query.
2327 Send the current settings of GDB's permission flags.
2331 Send part of the source (textual) form of a tracepoint definition,
2332 which includes location, conditional, and action list.
2334 * The source command now accepts a -s option to force searching for the
2335 script in the source search path even if the script name specifies
2338 * New features in the GDB remote stub, GDBserver
2340 - GDBserver now support tracepoints (including fast tracepoints, and
2341 static tracepoints). The feature is currently supported by the
2342 i386-linux and amd64-linux builds. See the "Tracepoints support
2343 in gdbserver" section in the manual for more information.
2345 GDBserver JIT compiles the tracepoint's conditional agent
2346 expression bytecode into native code whenever possible for low
2347 overhead dynamic tracepoints conditionals. For such tracepoints,
2348 an expression that examines program state is evaluated when the
2349 tracepoint is reached, in order to determine whether to capture
2350 trace data. If the condition is simple and false, processing the
2351 tracepoint finishes very quickly and no data is gathered.
2353 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2354 for static tracepoints support.
2356 - GDBserver now supports x86_64 Windows 64-bit debugging.
2358 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2359 it understands register description.
2361 * The --batch flag now disables pagination and queries.
2363 * X86 general purpose registers
2365 GDB now supports reading/writing byte, word and double-word x86
2366 general purpose registers directly. This means you can use, say,
2367 $ah or $ax to refer, respectively, to the byte register AH and
2368 16-bit word register AX that are actually portions of the 32-bit
2369 register EAX or 64-bit register RAX.
2371 * The `commands' command now accepts a range of breakpoints to modify.
2372 A plain `commands' following a command that creates multiple
2373 breakpoints affects all the breakpoints set by that command. This
2374 applies to breakpoints set by `rbreak', and also applies when a
2375 single `break' command creates multiple breakpoints (e.g.,
2376 breakpoints on overloaded c++ functions).
2378 * The `rbreak' command now accepts a filename specification as part of
2379 its argument, limiting the functions selected by the regex to those
2380 in the specified file.
2382 * Support for remote debugging Windows and SymbianOS shared libraries
2383 from Unix hosts has been improved. Non Windows GDB builds now can
2384 understand target reported file names that follow MS-DOS based file
2385 system semantics, such as file names that include drive letters and
2386 use the backslash character as directory separator. This makes it
2387 possible to transparently use the "set sysroot" and "set
2388 solib-search-path" on Unix hosts to point as host copies of the
2389 target's shared libraries. See the new command "set
2390 target-file-system-kind" described below, and the "Commands to
2391 specify files" section in the user manual for more information.
2395 eval template, expressions...
2396 Convert the values of one or more expressions under the control
2397 of the string template to a command line, and call it.
2399 set target-file-system-kind unix|dos-based|auto
2400 show target-file-system-kind
2401 Set or show the assumed file system kind for target reported file
2404 save breakpoints <filename>
2405 Save all current breakpoint definitions to a file suitable for use
2406 in a later debugging session. To read the saved breakpoint
2407 definitions, use the `source' command.
2409 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2412 info static-tracepoint-markers
2413 Display information about static tracepoint markers in the target.
2415 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2416 Define a static tracepoint by probing a marker at the given
2417 function, line, address, or marker ID.
2421 Enable and disable observer mode.
2423 set may-write-registers on|off
2424 set may-write-memory on|off
2425 set may-insert-breakpoints on|off
2426 set may-insert-tracepoints on|off
2427 set may-insert-fast-tracepoints on|off
2428 set may-interrupt on|off
2429 Set individual permissions for GDB effects on the target. Note that
2430 some of these settings can have undesirable or surprising
2431 consequences, particularly when changed in the middle of a session.
2432 For instance, disabling the writing of memory can prevent
2433 breakpoints from being inserted, cause single-stepping to fail, or
2434 even crash your program, if you disable after breakpoints have been
2435 inserted. However, GDB should not crash.
2437 set record memory-query on|off
2438 show record memory-query
2439 Control whether to stop the inferior if memory changes caused
2440 by an instruction cannot be recorded.
2445 The disassemble command now supports "start,+length" form of two arguments.
2449 ** GDB now provides a new directory location, called the python directory,
2450 where Python scripts written for GDB can be installed. The location
2451 of that directory is <data-directory>/python, where <data-directory>
2452 is the GDB data directory. For more details, see section `Scripting
2453 GDB using Python' in the manual.
2455 ** The GDB Python API now has access to breakpoints, symbols, symbol
2456 tables, program spaces, inferiors, threads and frame's code blocks.
2457 Additionally, GDB Parameters can now be created from the API, and
2458 manipulated via set/show in the CLI.
2460 ** New functions gdb.target_charset, gdb.target_wide_charset,
2461 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2463 ** New exception gdb.GdbError.
2465 ** Pretty-printers are now also looked up in the current program space.
2467 ** Pretty-printers can now be individually enabled and disabled.
2469 ** GDB now looks for names of Python scripts to auto-load in a
2470 special section named `.debug_gdb_scripts', in addition to looking
2471 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2473 * Tracepoint actions were unified with breakpoint commands. In particular,
2474 there are no longer differences in "info break" output for breakpoints and
2475 tracepoints and the "commands" command can be used for both tracepoints and
2476 regular breakpoints.
2480 ARM Symbian arm*-*-symbianelf*
2482 * D language support.
2483 GDB now supports debugging programs written in the D programming
2486 * GDB now supports the extended ptrace interface for PowerPC which is
2487 available since Linux kernel version 2.6.34. This automatically enables
2488 any hardware breakpoints and additional hardware watchpoints available in
2489 the processor. The old ptrace interface exposes just one hardware
2490 watchpoint and no hardware breakpoints.
2492 * GDB is now able to use the Data Value Compare (DVC) register available on
2493 embedded PowerPC processors to implement in hardware simple watchpoint
2494 conditions of the form:
2496 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2498 This works in native GDB running on Linux kernels with the extended ptrace
2499 interface mentioned above.
2501 *** Changes in GDB 7.1
2505 ** Namespace Support
2507 GDB now supports importing of namespaces in C++. This enables the
2508 user to inspect variables from imported namespaces. Support for
2509 namepace aliasing has also been added. So, if a namespace is
2510 aliased in the current scope (e.g. namepace C=A; ) the user can
2511 print variables using the alias (e.g. (gdb) print C::x).
2515 All known bugs relating to the printing of virtual base class were
2516 fixed. It is now possible to call overloaded static methods using a
2521 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2522 and reinterpret_cast<> are now handled by the C++ expression parser.
2526 Xilinx MicroBlaze microblaze-*-*
2531 Xilinx MicroBlaze microblaze
2534 * Multi-program debugging.
2536 GDB now has support for multi-program (a.k.a. multi-executable or
2537 multi-exec) debugging. This allows for debugging multiple inferiors
2538 simultaneously each running a different program under the same GDB
2539 session. See "Debugging Multiple Inferiors and Programs" in the
2540 manual for more information. This implied some user visible changes
2541 in the multi-inferior support. For example, "info inferiors" now
2542 lists inferiors that are not running yet or that have exited
2543 already. See also "New commands" and "New options" below.
2545 * New tracing features
2547 GDB's tracepoint facility now includes several new features:
2549 ** Trace state variables
2551 GDB tracepoints now include support for trace state variables, which
2552 are variables managed by the target agent during a tracing
2553 experiment. They are useful for tracepoints that trigger each
2554 other, so for instance one tracepoint can count hits in a variable,
2555 and then a second tracepoint has a condition that is true when the
2556 count reaches a particular value. Trace state variables share the
2557 $-syntax of GDB convenience variables, and can appear in both
2558 tracepoint actions and condition expressions. Use the "tvariable"
2559 command to create, and "info tvariables" to view; see "Trace State
2560 Variables" in the manual for more detail.
2564 GDB now includes an option for defining fast tracepoints, which
2565 targets may implement more efficiently, such as by installing a jump
2566 into the target agent rather than a trap instruction. The resulting
2567 speedup can be by two orders of magnitude or more, although the
2568 tradeoff is that some program locations on some target architectures
2569 might not allow fast tracepoint installation, for instance if the
2570 instruction to be replaced is shorter than the jump. To request a
2571 fast tracepoint, use the "ftrace" command, with syntax identical to
2572 the regular trace command.
2574 ** Disconnected tracing
2576 It is now possible to detach GDB from the target while it is running
2577 a trace experiment, then reconnect later to see how the experiment
2578 is going. In addition, a new variable disconnected-tracing lets you
2579 tell the target agent whether to continue running a trace if the
2580 connection is lost unexpectedly.
2584 GDB now has the ability to save the trace buffer into a file, and
2585 then use that file as a target, similarly to you can do with
2586 corefiles. You can select trace frames, print data that was
2587 collected in them, and use tstatus to display the state of the
2588 tracing run at the moment that it was saved. To create a trace
2589 file, use "tsave <filename>", and to use it, do "target tfile
2592 ** Circular trace buffer
2594 You can ask the target agent to handle the trace buffer as a
2595 circular buffer, discarding the oldest trace frames to make room for
2596 newer ones, by setting circular-trace-buffer to on. This feature may
2597 not be available for all target agents.
2602 The disassemble command, when invoked with two arguments, now requires
2603 the arguments to be comma-separated.
2606 The info variables command now displays variable definitions. Files
2607 which only declare a variable are not shown.
2610 The source command is now capable of sourcing Python scripts.
2611 This feature is dependent on the debugger being build with Python
2614 Related to this enhancement is also the introduction of a new command
2615 "set script-extension" (see below).
2617 * New commands (for set/show, see "New options" below)
2619 record save [<FILENAME>]
2620 Save a file (in core file format) containing the process record
2621 execution log for replay debugging at a later time.
2623 record restore <FILENAME>
2624 Restore the process record execution log that was saved at an
2625 earlier time, for replay debugging.
2627 add-inferior [-copies <N>] [-exec <FILENAME>]
2630 clone-inferior [-copies <N>] [ID]
2631 Make a new inferior ready to execute the same program another
2632 inferior has loaded.
2637 maint info program-spaces
2638 List the program spaces loaded into GDB.
2640 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2641 show remote interrupt-sequence
2642 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2643 as the sequence to the remote target in order to interrupt the execution.
2644 Ctrl-C is a default. Some system prefers BREAK which is high level of
2645 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2646 Magic SysRq g. It is BREAK signal and character 'g'.
2648 set remote interrupt-on-connect [on | off]
2649 show remote interrupt-on-connect
2650 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2651 remote target when gdb connects to it. This is needed when you debug
2654 set remotebreak [on | off]
2656 Deprecated. Use "set/show remote interrupt-sequence" instead.
2658 tvariable $NAME [ = EXP ]
2659 Create or modify a trace state variable.
2662 List trace state variables and their values.
2664 delete tvariable $NAME ...
2665 Delete one or more trace state variables.
2668 Evaluate the given expressions without collecting anything into the
2669 trace buffer. (Valid in tracepoint actions only.)
2671 ftrace FN / FILE:LINE / *ADDR
2672 Define a fast tracepoint at the given function, line, or address.
2674 * New expression syntax
2676 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2677 GDB now parses 0b101010 identically with 42.
2681 set follow-exec-mode new|same
2682 show follow-exec-mode
2683 Control whether GDB reuses the same inferior across an exec call or
2684 creates a new one. This is useful to be able to restart the old
2685 executable after the inferior having done an exec call.
2687 set default-collect EXPR, ...
2688 show default-collect
2689 Define a list of expressions to be collected at each tracepoint.
2690 This is a useful way to ensure essential items are not overlooked,
2691 such as registers or a critical global variable.
2693 set disconnected-tracing
2694 show disconnected-tracing
2695 If set to 1, the target is instructed to continue tracing if it
2696 loses its connection to GDB. If 0, the target is to stop tracing
2699 set circular-trace-buffer
2700 show circular-trace-buffer
2701 If set to on, the target is instructed to use a circular trace buffer
2702 and discard the oldest trace frames instead of stopping the trace due
2703 to a full trace buffer. If set to off, the trace stops when the buffer
2704 fills up. Some targets may not support this.
2706 set script-extension off|soft|strict
2707 show script-extension
2708 If set to "off", the debugger does not perform any script language
2709 recognition, and all sourced files are assumed to be GDB scripts.
2710 If set to "soft" (the default), files are sourced according to
2711 filename extension, falling back to GDB scripts if the first
2713 If set to "strict", files are sourced according to filename extension.
2715 set ada trust-PAD-over-XVS on|off
2716 show ada trust-PAD-over-XVS
2717 If off, activate a workaround against a bug in the debugging information
2718 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2719 the GCC sources for more information about the GNAT encoding and
2720 PAD types in particular). It is always safe to set this option to
2721 off, but this introduces a slight performance penalty. The default
2724 * Python API Improvements
2726 ** GDB provides the new class gdb.LazyString. This is useful in
2727 some pretty-printing cases. The new method gdb.Value.lazy_string
2728 provides a simple way to create objects of this type.
2730 ** The fields returned by gdb.Type.fields now have an
2731 `is_base_class' attribute.
2733 ** The new method gdb.Type.range returns the range of an array type.
2735 ** The new method gdb.parse_and_eval can be used to parse and
2736 evaluate an expression.
2738 * New remote packets
2741 Define a trace state variable.
2744 Get the current value of a trace state variable.
2747 Set desired tracing behavior upon disconnection.
2750 Set the trace buffer to be linear or circular.
2753 Get data about the tracepoints currently in use.
2757 Process record now works correctly with hardware watchpoints.
2759 Multiple bug fixes have been made to the mips-irix port, making it
2760 much more reliable. In particular:
2761 - Debugging threaded applications is now possible again. Previously,
2762 GDB would hang while starting the program, or while waiting for
2763 the program to stop at a breakpoint.
2764 - Attaching to a running process no longer hangs.
2765 - An error occurring while loading a core file has been fixed.
2766 - Changing the value of the PC register now works again. This fixes
2767 problems observed when using the "jump" command, or when calling
2768 a function from GDB, or even when assigning a new value to $pc.
2769 - With the "finish" and "return" commands, the return value for functions
2770 returning a small array is now correctly printed.
2771 - It is now possible to break on shared library code which gets executed
2772 during a shared library init phase (code executed while executing
2773 their .init section). Previously, the breakpoint would have no effect.
2774 - GDB is now able to backtrace through the signal handler for
2775 non-threaded programs.
2777 PIE (Position Independent Executable) programs debugging is now supported.
2778 This includes debugging execution of PIC (Position Independent Code) shared
2779 libraries although for that, it should be possible to run such libraries as an
2782 *** Changes in GDB 7.0
2784 * GDB now has an interface for JIT compilation. Applications that
2785 dynamically generate code can create symbol files in memory and register
2786 them with GDB. For users, the feature should work transparently, and
2787 for JIT developers, the interface is documented in the GDB manual in the
2788 "JIT Compilation Interface" chapter.
2790 * Tracepoints may now be conditional. The syntax is as for
2791 breakpoints; either an "if" clause appended to the "trace" command,
2792 or the "condition" command is available. GDB sends the condition to
2793 the target for evaluation using the same bytecode format as is used
2794 for tracepoint actions.
2796 * The disassemble command now supports: an optional /r modifier, print the
2797 raw instructions in hex as well as in symbolic form, and an optional /m
2798 modifier to print mixed source+assembly.
2800 * Process record and replay
2802 In a architecture environment that supports ``process record and
2803 replay'', ``process record and replay'' target can record a log of
2804 the process execution, and replay it with both forward and reverse
2807 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2808 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2809 set execution-direction {forward|reverse}, for targets that support
2812 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2813 feature is available with a native GDB running on kernel version
2816 * GDB now has support for multi-byte and wide character sets on the
2817 target. Strings whose character type is wchar_t, char16_t, or
2818 char32_t are now correctly printed. GDB supports wide- and unicode-
2819 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2820 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2821 `printf'. This feature requires iconv to work properly; if your
2822 system does not have a working iconv, GDB can use GNU libiconv. See
2823 the installation instructions for more information.
2825 * GDB now supports automatic retrieval of shared library files from
2826 remote targets. To use this feature, specify a system root that begins
2827 with the `remote:' prefix, either via the `set sysroot' command or via
2828 the `--with-sysroot' configure-time option.
2830 * "info sharedlibrary" now takes an optional regex of libraries to show,
2831 and it now reports if a shared library has no debugging information.
2833 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2834 now complete on file names.
2836 * When completing in expressions, gdb will attempt to limit
2837 completions to allowable structure or union fields, where appropriate.
2838 For instance, consider:
2840 # struct example { int f1; double f2; };
2841 # struct example variable;
2844 If the user types TAB at the end of this command line, the available
2845 completions will be "f1" and "f2".
2847 * Inlined functions are now supported. They show up in backtraces, and
2848 the "step", "next", and "finish" commands handle them automatically.
2850 * GDB now supports the token-splicing (##) and stringification (#)
2851 operators when expanding macros. It also supports variable-arity
2854 * GDB now supports inspecting extra signal information, exported by
2855 the new $_siginfo convenience variable. The feature is currently
2856 implemented on linux ARM, i386 and amd64.
2858 * GDB can now display the VFP floating point registers and NEON vector
2859 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2860 can provide these registers (requires Linux 2.6.30 or later). Remote
2861 and simulator targets may also provide them.
2863 * New remote packets
2866 Search memory for a sequence of bytes.
2869 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2870 operation over reliable transport links. Use of this packet is
2871 controlled by the `set remote noack-packet' command.
2874 Kill the process with the specified process ID. Use this in preference
2875 to `k' when multiprocess protocol extensions are supported.
2878 Obtains additional operating system information
2882 Read or write additional signal information.
2884 * Removed remote protocol undocumented extension
2886 An undocumented extension to the remote protocol's `S' stop reply
2887 packet that permited the stub to pass a process id was removed.
2888 Remote servers should use the `T' stop reply packet instead.
2890 * GDB now supports multiple function calling conventions according to the
2891 DWARF-2 DW_AT_calling_convention function attribute.
2893 * The SH target utilizes the aforementioned change to distinguish between gcc
2894 and Renesas calling convention. It also adds the new CLI commands
2895 `set/show sh calling-convention'.
2897 * GDB can now read compressed debug sections, as produced by GNU gold
2898 with the --compress-debug-sections=zlib flag.
2900 * 64-bit core files are now supported on AIX.
2902 * Thread switching is now supported on Tru64.
2904 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2905 which will be allocated using malloc later in program execution.
2907 * The qXfer:libraries:read remote procotol packet now allows passing a
2908 list of section offsets.
2910 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2911 conditions handling signals delivered during attach or thread creation
2912 have also been fixed.
2914 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2915 From the user's standpoint, all unqualified instances of True and False
2916 are treated as the standard definitions, regardless of context.
2918 * GDB now parses C++ symbol and type names more flexibly. For
2921 template<typename T> class C { };
2924 GDB will now correctly handle all of:
2926 ptype C<char const *>
2927 ptype C<char const*>
2928 ptype C<const char *>
2929 ptype C<const char*>
2931 * New features in the GDB remote stub, gdbserver
2933 - The "--wrapper" command-line argument tells gdbserver to use a
2934 wrapper program to launch programs for debugging.
2936 - On PowerPC and S/390 targets, it is now possible to use a single
2937 gdbserver executable to debug both 32-bit and 64-bit programs.
2938 (This requires gdbserver itself to be built as a 64-bit executable.)
2940 - gdbserver uses the new noack protocol mode for TCP connections to
2941 reduce communications latency, if also supported and enabled in GDB.
2943 - Support for the sparc64-linux-gnu target is now included in
2946 - The amd64-linux build of gdbserver now supports debugging both
2947 32-bit and 64-bit programs.
2949 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2950 now support hardware watchpoints, and will use them automatically
2955 GDB now has support for scripting using Python. Whether this is
2956 available is determined at configure time.
2958 New GDB commands can now be written in Python.
2960 * Ada tasking support
2962 Ada tasks can now be inspected in GDB. The following commands have
2966 Print the list of Ada tasks.
2968 Print detailed information about task number N.
2970 Print the task number of the current task.
2972 Switch the context of debugging to task number N.
2974 * Support for user-defined prefixed commands. The "define" command can
2975 add new commands to existing prefixes, e.g. "target".
2977 * Multi-inferior, multi-process debugging.
2979 GDB now has generalized support for multi-inferior debugging. See
2980 "Debugging Multiple Inferiors" in the manual for more information.
2981 Although availability still depends on target support, the command
2982 set is more uniform now. The GNU/Linux specific multi-forks support
2983 has been migrated to this new framework. This implied some user
2984 visible changes; see "New commands" and also "Removed commands"
2987 * Target descriptions can now describe the target OS ABI. See the
2988 "Target Description Format" section in the user manual for more
2991 * Target descriptions can now describe "compatible" architectures
2992 to indicate that the target can execute applications for a different
2993 architecture in addition to those for the main target architecture.
2994 See the "Target Description Format" section in the user manual for
2997 * Multi-architecture debugging.
2999 GDB now includes general supports for debugging applications on
3000 hybrid systems that use more than one single processor architecture
3001 at the same time. Each such hybrid architecture still requires
3002 specific support to be added. The only hybrid architecture supported
3003 in this version of GDB is the Cell Broadband Engine.
3005 * GDB now supports integrated debugging of Cell/B.E. applications that
3006 use both the PPU and SPU architectures. To enable support for hybrid
3007 Cell/B.E. debugging, you need to configure GDB to support both the
3008 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3009 --enable-targets configure option.
3011 * Non-stop mode debugging.
3013 For some targets, GDB now supports an optional mode of operation in
3014 which you can examine stopped threads while other threads continue
3015 to execute freely. This is referred to as non-stop mode, with the
3016 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3017 section in the user manual for more information.
3019 To be able to support remote non-stop debugging, a remote stub needs
3020 to implement the non-stop mode remote protocol extensions, as
3021 described in the "Remote Non-Stop" section of the user manual. The
3022 GDB remote stub, gdbserver, has been adjusted to support these
3023 extensions on linux targets.
3025 * New commands (for set/show, see "New options" below)
3027 catch syscall [NAME(S) | NUMBER(S)]
3028 Catch system calls. Arguments, which should be names of system
3029 calls or their numbers, mean catch only those syscalls. Without
3030 arguments, every syscall will be caught. When the inferior issues
3031 any of the specified syscalls, GDB will stop and announce the system
3032 call, both when it is called and when its call returns. This
3033 feature is currently available with a native GDB running on the
3034 Linux Kernel, under the following architectures: x86, x86_64,
3035 PowerPC and PowerPC64.
3037 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3039 Search memory for a sequence of bytes.
3041 maint set python print-stack
3042 maint show python print-stack
3043 Show a stack trace when an error is encountered in a Python script.
3046 Invoke CODE by passing it to the Python interpreter.
3051 These allow macros to be defined, undefined, and listed
3055 Show operating system information about processes.
3058 List the inferiors currently under GDB's control.
3061 Switch focus to inferior number NUM.
3064 Detach from inferior number NUM.
3067 Kill inferior number NUM.
3071 set spu stop-on-load
3072 show spu stop-on-load
3073 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3075 set spu auto-flush-cache
3076 show spu auto-flush-cache
3077 Control whether to automatically flush the software-managed cache
3078 during Cell/B.E. debugging.
3080 set sh calling-convention
3081 show sh calling-convention
3082 Control the calling convention used when calling SH target functions.
3085 show debug timestamp
3086 Control display of timestamps with GDB debugging output.
3088 set disassemble-next-line
3089 show disassemble-next-line
3090 Control display of disassembled source lines or instructions when
3093 set remote noack-packet
3094 show remote noack-packet
3095 Set/show the use of remote protocol QStartNoAckMode packet. See above
3096 under "New remote packets."
3098 set remote query-attached-packet
3099 show remote query-attached-packet
3100 Control use of remote protocol `qAttached' (query-attached) packet.
3102 set remote read-siginfo-object
3103 show remote read-siginfo-object
3104 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3107 set remote write-siginfo-object
3108 show remote write-siginfo-object
3109 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3112 set remote reverse-continue
3113 show remote reverse-continue
3114 Control use of remote protocol 'bc' (reverse-continue) packet.
3116 set remote reverse-step
3117 show remote reverse-step
3118 Control use of remote protocol 'bs' (reverse-step) packet.
3120 set displaced-stepping
3121 show displaced-stepping
3122 Control displaced stepping mode. Displaced stepping is a way to
3123 single-step over breakpoints without removing them from the debuggee.
3124 Also known as "out-of-line single-stepping".
3127 show debug displaced
3128 Control display of debugging info for displaced stepping.
3130 maint set internal-error
3131 maint show internal-error
3132 Control what GDB does when an internal error is detected.
3134 maint set internal-warning
3135 maint show internal-warning
3136 Control what GDB does when an internal warning is detected.
3141 Use a wrapper program to launch programs for debugging.
3143 set multiple-symbols (all|ask|cancel)
3144 show multiple-symbols
3145 The value of this variable can be changed to adjust the debugger behavior
3146 when an expression or a breakpoint location contains an ambiguous symbol
3147 name (an overloaded function name, for instance).
3149 set breakpoint always-inserted
3150 show breakpoint always-inserted
3151 Keep breakpoints always inserted in the target, as opposed to inserting
3152 them when resuming the target, and removing them when the target stops.
3153 This option can improve debugger performance on slow remote targets.
3155 set arm fallback-mode (arm|thumb|auto)
3156 show arm fallback-mode
3157 set arm force-mode (arm|thumb|auto)
3159 These commands control how ARM GDB determines whether instructions
3160 are ARM or Thumb. The default for both settings is auto, which uses
3161 the current CPSR value for instructions without symbols; previous
3162 versions of GDB behaved as if "set arm fallback-mode arm".
3164 set disable-randomization
3165 show disable-randomization
3166 Standalone programs run with the virtual address space randomization enabled
3167 by default on some platforms. This option keeps the addresses stable across
3168 multiple debugging sessions.
3172 Control whether other threads are stopped or not when some thread hits
3177 Requests that asynchronous execution is enabled in the target, if available.
3178 In this case, it's possible to resume target in the background, and interact
3179 with GDB while the target is running. "show target-async" displays the
3180 current state of asynchronous execution of the target.
3182 set target-wide-charset
3183 show target-wide-charset
3184 The target-wide-charset is the name of the character set that GDB
3185 uses when printing characters whose type is wchar_t.
3187 set tcp auto-retry (on|off)
3189 set tcp connect-timeout
3190 show tcp connect-timeout
3191 These commands allow GDB to retry failed TCP connections to a remote stub
3192 with a specified timeout period; this is useful if the stub is launched
3193 in parallel with GDB but may not be ready to accept connections immediately.
3195 set libthread-db-search-path
3196 show libthread-db-search-path
3197 Control list of directories which GDB will search for appropriate
3200 set schedule-multiple (on|off)
3201 show schedule-multiple
3202 Allow GDB to resume all threads of all processes or only threads of
3203 the current process.
3207 Use more aggressive caching for accesses to the stack. This improves
3208 performance of remote debugging (particularly backtraces) without
3209 affecting correctness.
3211 set interactive-mode (on|off|auto)
3212 show interactive-mode
3213 Control whether GDB runs in interactive mode (on) or not (off).
3214 When in interactive mode, GDB waits for the user to answer all
3215 queries. Otherwise, GDB does not wait and assumes the default
3216 answer. When set to auto (the default), GDB determines which
3217 mode to use based on the stdin settings.
3222 For program forks, this is replaced by the new more generic `info
3223 inferiors' command. To list checkpoints, you can still use the
3224 `info checkpoints' command, which was an alias for the `info forks'
3228 Replaced by the new `inferior' command. To switch between
3229 checkpoints, you can still use the `restart' command, which was an
3230 alias for the `fork' command.
3233 This is removed, since some targets don't have a notion of
3234 processes. To switch between processes, you can still use the
3235 `inferior' command using GDB's own inferior number.
3238 For program forks, this is replaced by the new more generic `kill
3239 inferior' command. To delete a checkpoint, you can still use the
3240 `delete checkpoint' command, which was an alias for the `delete
3244 For program forks, this is replaced by the new more generic `detach
3245 inferior' command. To detach a checkpoint, you can still use the
3246 `detach checkpoint' command, which was an alias for the `detach
3249 * New native configurations
3251 x86/x86_64 Darwin i[34567]86-*-darwin*
3253 x86_64 MinGW x86_64-*-mingw*
3257 Lattice Mico32 lm32-*
3258 x86 DICOS i[34567]86-*-dicos*
3259 x86_64 DICOS x86_64-*-dicos*
3262 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3263 (mingw32ce) debugging.
3269 These commands were actually not implemented on any target.
3271 *** Changes in GDB 6.8
3273 * New native configurations
3275 NetBSD/hppa hppa*-*netbsd*
3276 Xtensa GNU/Linux xtensa*-*-linux*
3280 NetBSD/hppa hppa*-*-netbsd*
3281 Xtensa GNU/Lunux xtensa*-*-linux*
3283 * Change in command line behavior -- corefiles vs. process ids.
3285 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3286 attaching to process NUMBER fails, GDB no longer attempts to open a
3287 core file named NUMBER. Attaching to a program using the -c option
3288 is no longer supported. Instead, use the '-p' or '--pid' options.
3290 * GDB can now be built as a native debugger for debugging Windows x86
3291 (mingw32) Portable Executable (PE) programs.
3293 * Pending breakpoints no longer change their number when their address
3296 * GDB now supports breakpoints with multiple locations,
3297 including breakpoints on C++ constructors, inside C++ templates,
3298 and in inlined functions.
3300 * GDB's ability to debug optimized code has been improved. GDB more
3301 accurately identifies function bodies and lexical blocks that occupy
3302 more than one contiguous range of addresses.
3304 * Target descriptions can now describe registers for PowerPC.
3306 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3307 registers on PowerPC targets.
3309 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3310 targets even when the libthread_db library is not available.
3312 * The GDB remote stub, gdbserver, now supports the new file transfer
3313 commands (remote put, remote get, and remote delete).
3315 * The GDB remote stub, gdbserver, now supports run and attach in
3316 extended-remote mode.
3318 * hppa*64*-*-hpux11* target broken
3319 The debugger is unable to start a program and fails with the following
3320 error: "Error trying to get information about dynamic linker".
3321 The gdb-6.7 release is also affected.
3323 * GDB now supports the --enable-targets= configure option to allow
3324 building a single GDB executable that supports multiple remote
3325 target architectures.
3327 * GDB now supports debugging C and C++ programs which use the
3328 Decimal Floating Point extension. In addition, the PowerPC target
3329 now has a set of pseudo-registers to inspect decimal float values
3330 stored in two consecutive float registers.
3332 * The -break-insert MI command can optionally create pending
3335 * Improved support for debugging Ada
3336 Many improvements to the Ada language support have been made. These
3338 - Better support for Ada2005 interface types
3339 - Improved handling of arrays and slices in general
3340 - Better support for Taft-amendment types
3341 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3343 - Improved command completion in Ada
3346 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3351 set print frame-arguments (all|scalars|none)
3352 show print frame-arguments
3353 The value of this variable can be changed to control which argument
3354 values should be printed by the debugger when displaying a frame.
3359 Transfer files to and from a remote target, and delete remote files.
3366 Transfer files to and from a remote target, and delete remote files.
3368 * New remote packets
3375 Open, close, read, write, and delete files on the remote system.
3378 Attach to an existing process on the remote system, in extended-remote
3382 Run a new process on the remote system, in extended-remote mode.
3384 *** Changes in GDB 6.7
3386 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3387 bfd, libiberty and opcodes, as revealed by static analysis donated by
3388 Coverity, Inc. (http://scan.coverity.com).
3390 * When looking up multiply-defined global symbols, GDB will now prefer the
3391 symbol definition in the current shared library if it was built using the
3392 -Bsymbolic linker option.
3394 * When the Text User Interface (TUI) is not configured, GDB will now
3395 recognize the -tui command-line option and print a message that the TUI
3398 * The GDB remote stub, gdbserver, now has lower overhead for high
3399 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3401 * GDB for MIPS targets now autodetects whether a remote target provides
3402 32-bit or 64-bit register values.
3404 * Support for C++ member pointers has been improved.
3406 * GDB now understands XML target descriptions, which specify the
3407 target's overall architecture. GDB can read a description from
3408 a local file or over the remote serial protocol.
3410 * Vectors of single-byte data use a new integer type which is not
3411 automatically displayed as character or string data.
3413 * The /s format now works with the print command. It displays
3414 arrays of single-byte integers and pointers to single-byte integers
3417 * Target descriptions can now describe target-specific registers,
3418 for architectures which have implemented the support (currently
3419 only ARM, M68K, and MIPS).
3421 * GDB and the GDB remote stub, gdbserver, now support the XScale
3424 * The GDB remote stub, gdbserver, has been updated to support
3425 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3426 has been rewritten to use the standard GDB remote protocol.
3428 * GDB can now step into C++ functions which are called through thunks.
3430 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3432 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3433 layout. It also supports a TextSeg= and DataSeg= response when only
3434 segment base addresses (rather than offsets) are available.
3436 * The /i format now outputs any trailing branch delay slot instructions
3437 immediately following the last instruction within the count specified.
3439 * The GDB remote protocol "T" stop reply packet now supports a
3440 "library" response. Combined with the new "qXfer:libraries:read"
3441 packet, this response allows GDB to debug shared libraries on targets
3442 where the operating system manages the list of loaded libraries (e.g.
3443 Windows and SymbianOS).
3445 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3446 (DLLs) on Windows and Windows CE targets.
3448 * GDB now supports a faster verification that a .debug file matches its binary
3449 according to its build-id signature, if the signature is present.
3455 Enable or disable hardware flow control (RTS/CTS) on the serial port
3456 when debugging using remote targets.
3458 set mem inaccessible-by-default
3459 show mem inaccessible-by-default
3460 If the target supplies a memory map, for instance via the remote
3461 protocol's "qXfer:memory-map:read" packet, setting this variable
3462 prevents GDB from accessing memory outside the memory map. This
3463 is useful for targets with memory mapped registers or which react
3464 badly to accesses of unmapped address space.
3466 set breakpoint auto-hw
3467 show breakpoint auto-hw
3468 If the target supplies a memory map, for instance via the remote
3469 protocol's "qXfer:memory-map:read" packet, setting this variable
3470 lets GDB use hardware breakpoints automatically for memory regions
3471 where it can not use software breakpoints. This covers both the
3472 "break" command and internal breakpoints used for other commands
3473 including "next" and "finish".
3476 catch exception unhandled
3477 Stop the program execution when Ada exceptions are raised.
3480 Stop the program execution when an Ada assertion failed.
3484 Set an alternate system root for target files. This is a more
3485 general version of "set solib-absolute-prefix", which is now
3486 an alias to "set sysroot".
3489 Provide extended SPU facility status information. This set of
3490 commands is available only when debugging the Cell/B.E. SPU
3493 * New native configurations
3495 OpenBSD/sh sh*-*openbsd*
3498 unset tdesc filename
3500 Use the specified local file as an XML target description, and do
3501 not query the target for its built-in description.
3505 OpenBSD/sh sh*-*-openbsd*
3506 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3507 Toshiba Media Processor mep-elf
3509 * New remote packets
3512 Ignore the specified signals; pass them directly to the debugged program
3513 without stopping other threads or reporting them to GDB.
3515 qXfer:features:read:
3516 Read an XML target description from the target, which describes its
3521 Read or write contents of an spufs file on the target system. These
3522 packets are available only on the Cell/B.E. SPU architecture.
3524 qXfer:libraries:read:
3525 Report the loaded shared libraries. Combined with new "T" packet
3526 response, this packet allows GDB to debug shared libraries on
3527 targets where the operating system manages the list of loaded
3528 libraries (e.g. Windows and SymbianOS).
3532 Support for these obsolete configurations has been removed.
3540 i[34567]86-*-lynxos*
3541 i[34567]86-*-netware*
3542 i[34567]86-*-sco3.2v5*
3543 i[34567]86-*-sco3.2v4*
3545 i[34567]86-*-sysv4.2*
3548 i[34567]86-*-unixware2*
3549 i[34567]86-*-unixware*
3558 * Other removed features
3565 Various m68k-only ROM monitors.
3572 Various Renesas ROM monitors and debugging interfaces for SH and
3577 Support for a Macraigor serial interface to on-chip debugging.
3578 GDB does not directly support the newer parallel or USB
3583 A debug information format. The predecessor to DWARF 2 and
3584 DWARF 3, which are still supported.
3586 Support for the HP aCC compiler on HP-UX/PA-RISC
3588 SOM-encapsulated symbolic debugging information, automatic
3589 invocation of pxdb, and the aCC custom C++ ABI. This does not
3590 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3591 with aCC can still be debugged on an assembly level.
3593 MIPS ".pdr" sections
3595 A MIPS-specific format used to describe stack frame layout
3596 in debugging information.
3600 GDB could work with an older version of Guile to debug
3601 the interpreter and Scheme programs running in it.
3603 set mips stack-arg-size
3604 set mips saved-gpreg-size
3606 Use "set mips abi" to control parameter passing for MIPS.
3608 *** Changes in GDB 6.6
3613 Cell Broadband Engine SPU spu-elf
3615 * GDB can now be configured as a cross-debugger targeting native Windows
3616 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3617 running on a Windows system over TCP/IP to debug Windows programs.
3619 * The GDB remote stub, gdbserver, has been updated to support Windows and
3620 Cygwin debugging. Both single-threaded and multi-threaded programs are
3623 * The "set trust-readonly-sections" command works again. This command was
3624 broken in GDB 6.3, 6.4, and 6.5.
3626 * The "load" command now supports writing to flash memory, if the remote
3627 stub provides the required support.
3629 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3630 longer requires symbolic debug information (e.g. DWARF-2).
3635 unset substitute-path
3636 show substitute-path
3637 Manage a list of substitution rules that GDB uses to rewrite the name
3638 of the directories where the sources are located. This can be useful
3639 for instance when the sources were moved to a different location
3640 between compilation and debugging.
3644 Print each CLI command as it is executed. Each command is prefixed with
3645 a number of `+' symbols representing the nesting depth.
3646 The source command now has a `-v' option to enable the same feature.
3650 The ARM Demon monitor support (RDP protocol, "target rdp").
3652 Kernel Object Display, an embedded debugging feature which only worked with
3653 an obsolete version of Cisco IOS.
3655 The 'set download-write-size' and 'show download-write-size' commands.
3657 * New remote packets
3660 Tell a stub about GDB client features, and request remote target features.
3661 The first feature implemented is PacketSize, which allows the target to
3662 specify the size of packets it can handle - to minimize the number of
3663 packets required and improve performance when connected to a remote
3667 Fetch an OS auxilliary vector from the remote stub. This packet is a
3668 more efficient replacement for qPart:auxv:read.
3670 qXfer:memory-map:read:
3671 Fetch a memory map from the remote stub, including information about
3672 RAM, ROM, and flash memory devices.
3677 Erase and program a flash memory device.
3679 * Removed remote packets
3682 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3683 used it, and only gdbserver implemented it.
3685 *** Changes in GDB 6.5
3689 Renesas M32C/M16C m32c-elf
3691 Morpho Technologies ms1 ms1-elf
3695 init-if-undefined Initialize a convenience variable, but
3696 only if it doesn't already have a value.
3698 The following commands are presently only implemented for native GNU/Linux:
3700 checkpoint Save a snapshot of the program state.
3702 restart <n> Return the program state to a
3703 previously saved state.
3705 info checkpoints List currently saved checkpoints.
3707 delete-checkpoint <n> Delete a previously saved checkpoint.
3709 set|show detach-on-fork Tell gdb whether to detach from a newly
3710 forked process, or to keep debugging it.
3712 info forks List forks of the user program that
3713 are available to be debugged.
3715 fork <n> Switch to debugging one of several
3716 forks of the user program that are
3717 available to be debugged.
3719 delete-fork <n> Delete a fork from the list of forks
3720 that are available to be debugged (and
3721 kill the forked process).
3723 detach-fork <n> Delete a fork from the list of forks
3724 that are available to be debugged (and
3725 allow the process to continue).
3729 Morpho Technologies ms2 ms1-elf
3731 * Improved Windows host support
3733 GDB now builds as a cross debugger hosted on i686-mingw32, including
3734 native console support, and remote communications using either
3735 network sockets or serial ports.
3737 * Improved Modula-2 language support
3739 GDB can now print most types in the Modula-2 syntax. This includes:
3740 basic types, set types, record types, enumerated types, range types,
3741 pointer types and ARRAY types. Procedure var parameters are correctly
3742 printed and hexadecimal addresses and character constants are also
3743 written in the Modula-2 syntax. Best results can be obtained by using
3744 GNU Modula-2 together with the -gdwarf-2 command line option.
3748 The ARM rdi-share module.
3750 The Netware NLM debug server.
3752 *** Changes in GDB 6.4
3754 * New native configurations
3756 OpenBSD/arm arm*-*-openbsd*
3757 OpenBSD/mips64 mips64-*-openbsd*
3761 Morpho Technologies ms1 ms1-elf
3763 * New command line options
3765 --batch-silent As for --batch, but totally silent.
3766 --return-child-result The debugger will exist with the same value
3767 the child (debugged) program exited with.
3768 --eval-command COMMAND, -ex COMMAND
3769 Execute a single GDB CLI command. This may be
3770 specified multiple times and in conjunction
3771 with the --command (-x) option.
3773 * Deprecated commands removed
3775 The following commands, that were deprecated in 2000, have been
3779 set|show arm disassembly-flavor set|show arm disassembler
3780 othernames set arm disassembler
3781 set|show remotedebug set|show debug remote
3782 set|show archdebug set|show debug arch
3783 set|show eventdebug set|show debug event
3786 * New BSD user-level threads support
3788 It is now possible to debug programs using the user-level threads
3789 library on OpenBSD and FreeBSD. Currently supported (target)
3792 FreeBSD/amd64 x86_64-*-freebsd*
3793 FreeBSD/i386 i386-*-freebsd*
3794 OpenBSD/i386 i386-*-openbsd*
3796 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3797 are not yet supported.
3799 * New support for Matsushita MN10300 w/sim added
3800 (Work in progress). mn10300-elf.
3802 * REMOVED configurations and files
3804 VxWorks and the XDR protocol *-*-vxworks
3805 Motorola MCORE mcore-*-*
3806 National Semiconductor NS32000 ns32k-*-*
3808 * New "set print array-indexes" command
3810 After turning this setting "on", GDB prints the index of each element
3811 when displaying arrays. The default is "off" to preserve the previous
3814 * VAX floating point support
3816 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3818 * User-defined command support
3820 In addition to using $arg0..$arg9 for argument passing, it is now possible
3821 to use $argc to determine now many arguments have been passed. See the
3822 section on user-defined commands in the user manual for more information.
3824 *** Changes in GDB 6.3:
3826 * New command line option
3828 GDB now accepts -l followed by a number to set the timeout for remote
3831 * GDB works with GCC -feliminate-dwarf2-dups
3833 GDB now supports a more compact representation of DWARF-2 debug
3834 information using DW_FORM_ref_addr references. These are produced
3835 by GCC with the option -feliminate-dwarf2-dups and also by some
3836 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3837 to use -feliminate-dwarf2-dups.
3839 * Internationalization
3841 When supported by the host system, GDB will be built with
3842 internationalization (libintl). The task of marking up the sources is
3843 continued, we're looking forward to our first translation.
3847 Initial support for debugging programs compiled with the GNAT
3848 implementation of the Ada programming language has been integrated
3849 into GDB. In this release, support is limited to expression evaluation.
3851 * New native configurations
3853 GNU/Linux/m32r m32r-*-linux-gnu
3857 GDB's remote protocol now includes support for the 'p' packet. This
3858 packet is used to fetch individual registers from a remote inferior.
3860 * END-OF-LIFE registers[] compatibility module
3862 GDB's internal register infrastructure has been completely rewritten.
3863 The new infrastructure making possible the implementation of key new
3864 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3867 GDB 6.3 will be the last release to include the the registers[]
3868 compatibility module that allowed out-of-date configurations to
3869 continue to work. This change directly impacts the following
3879 powerpc bdm protocol
3881 Unless there is activity to revive these configurations, they will be
3882 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3884 * OBSOLETE configurations and files
3886 Configurations that have been declared obsolete in this release have
3887 been commented out. Unless there is activity to revive these
3888 configurations, the next release of GDB will have their sources
3889 permanently REMOVED.
3898 *** Changes in GDB 6.2.1:
3900 * MIPS `break main; run' gave an heuristic-fence-post warning
3902 When attempting to run even a simple program, a warning about
3903 heuristic-fence-post being hit would be reported. This problem has
3906 * MIPS IRIX 'long double' crashed GDB
3908 When examining a long double variable, GDB would get a segmentation
3909 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3910 IRIX long double values).
3914 A bug in the VAX stack code was causing problems with the "next"
3915 command. This problem has been fixed.
3917 *** Changes in GDB 6.2:
3919 * Fix for ``many threads''
3921 On GNU/Linux systems that use the NPTL threads library, a program
3922 rapidly creating and deleting threads would confuse GDB leading to the
3925 ptrace: No such process.
3926 thread_db_get_info: cannot get thread info: generic error
3928 This problem has been fixed.
3930 * "-async" and "-noasync" options removed.
3932 Support for the broken "-noasync" option has been removed (it caused
3935 * New ``start'' command.
3937 This command runs the program until the begining of the main procedure.
3939 * New BSD Kernel Data Access Library (libkvm) interface
3941 Using ``target kvm'' it is now possible to debug kernel core dumps and
3942 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3943 platforms. Currently supported (native-only) configurations are:
3945 FreeBSD/amd64 x86_64-*-freebsd*
3946 FreeBSD/i386 i?86-*-freebsd*
3947 NetBSD/i386 i?86-*-netbsd*
3948 NetBSD/m68k m68*-*-netbsd*
3949 NetBSD/sparc sparc-*-netbsd*
3950 OpenBSD/amd64 x86_64-*-openbsd*
3951 OpenBSD/i386 i?86-*-openbsd*
3952 OpenBSD/m68k m68*-openbsd*
3953 OpenBSD/sparc sparc-*-openbsd*
3955 * Signal trampoline code overhauled
3957 Many generic problems with GDB's signal handling code have been fixed.
3958 These include: backtraces through non-contiguous stacks; recognition
3959 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3960 call; backtrace through a signal trampoline; step into and out of
3961 signal handlers; and single-stepping in the signal trampoline.
3963 Please note that kernel bugs are a limiting factor here. These
3964 features have been shown to work on an s390 GNU/Linux system that
3965 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3967 * Cygwin support for DWARF 2 added.
3969 * New native configurations
3971 GNU/Linux/hppa hppa*-*-linux*
3972 OpenBSD/hppa hppa*-*-openbsd*
3973 OpenBSD/m68k m68*-*-openbsd*
3974 OpenBSD/m88k m88*-*-openbsd*
3975 OpenBSD/powerpc powerpc-*-openbsd*
3976 NetBSD/vax vax-*-netbsd*
3977 OpenBSD/vax vax-*-openbsd*
3979 * END-OF-LIFE frame compatibility module
3981 GDB's internal frame infrastructure has been completely rewritten.
3982 The new infrastructure making it possible to support key new features
3983 including DWARF 2 Call Frame Information. To aid in the task of
3984 migrating old configurations to this new infrastructure, a
3985 compatibility module, that allowed old configurations to continue to
3986 work, was also included.
3988 GDB 6.2 will be the last release to include this frame compatibility
3989 module. This change directly impacts the following configurations:
3999 Unless there is activity to revive these configurations, they will be
4000 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4002 * REMOVED configurations and files
4004 Sun 3, running SunOS 3 m68*-*-sunos3*
4005 Sun 3, running SunOS 4 m68*-*-sunos4*
4006 Sun 2, running SunOS 3 m68000-*-sunos3*
4007 Sun 2, running SunOS 4 m68000-*-sunos4*
4008 Motorola 680x0 running LynxOS m68*-*-lynxos*
4009 AT&T 3b1/Unix pc m68*-att-*
4010 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4011 decstation mips-dec-* mips-little-*
4012 riscos mips-*-riscos* mips-*-sysv*
4013 sonymips mips-sony-*
4014 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4016 *** Changes in GDB 6.1.1:
4018 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4020 The TUI (Text-mode User Interface) is now built as part of a default
4021 GDB configuration. It is enabled by either selecting the TUI with the
4022 command line option "-i=tui" or by running the separate "gdbtui"
4023 program. For more information on the TUI, see the manual "Debugging
4026 * Pending breakpoint support (also included in GDB 6.1)
4028 Support has been added to allow you to specify breakpoints in shared
4029 libraries that have not yet been loaded. If a breakpoint location
4030 cannot be found, and the "breakpoint pending" option is set to auto,
4031 GDB queries you if you wish to make the breakpoint pending on a future
4032 shared-library load. If and when GDB resolves the breakpoint symbol,
4033 the pending breakpoint is removed as one or more regular breakpoints
4036 Pending breakpoints are very useful for GCJ Java debugging.
4038 * Fixed ISO-C build problems
4040 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4041 non ISO-C code that stopped them being built using a more strict ISO-C
4042 compiler (e.g., IBM's C compiler).
4044 * Fixed build problem on IRIX 5
4046 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4047 wasn't able to compile compile on an IRIX 5 system.
4049 * Added execute permission to gdb/gdbserver/configure
4051 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4052 permission. This bug would cause configure to fail on a number of
4053 systems (Solaris, IRIX). Ref: server/519.
4055 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4057 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4058 has been updated to use constant array sizes.
4060 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4062 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4063 its generated DWARF Call Frame Info. This encoding was causing GDB to
4064 panic, that panic has been fixed. Ref: gdb/1628.
4066 * Fixed a problem when examining parameters in shared library code.
4068 When examining parameters in optimized shared library code generated
4069 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4070 not available''. GDB now correctly displays the variable's value.
4072 *** Changes in GDB 6.1:
4074 * Removed --with-mmalloc
4076 Support for the mmalloc memory manager has been removed, as it
4077 conflicted with the internal gdb byte cache.
4079 * Changes in AMD64 configurations
4081 The AMD64 target now includes the %cs and %ss registers. As a result
4082 the AMD64 remote protocol has changed; this affects the floating-point
4083 and SSE registers. If you rely on those registers for your debugging,
4084 you should upgrade gdbserver on the remote side.
4086 * Revised SPARC target
4088 The SPARC target has been completely revised, incorporating the
4089 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4090 support for LynxOS and SunOS 4 has been dropped. Calling functions
4091 from within GDB on operating systems with a non-executable stack
4092 (Solaris, OpenBSD) now works.
4096 GDB has a new C++ demangler which does a better job on the mangled
4097 names generated by current versions of g++. It also runs faster, so
4098 with this and other changes gdb should now start faster on large C++
4101 * DWARF 2 Location Expressions
4103 GDB support for location expressions has been extended to support function
4104 arguments and frame bases. Older versions of GDB could crash when they
4107 * C++ nested types and namespaces
4109 GDB's support for nested types and namespaces in C++ has been
4110 improved, especially if you use the DWARF 2 debugging format. (This
4111 is the default for recent versions of GCC on most platforms.)
4112 Specifically, if you have a class "Inner" defined within a class or
4113 namespace "Outer", then GDB realizes that the class's name is
4114 "Outer::Inner", not simply "Inner". This should greatly reduce the
4115 frequency of complaints about not finding RTTI symbols. In addition,
4116 if you are stopped at inside of a function defined within a namespace,
4117 GDB modifies its name lookup accordingly.
4119 * New native configurations
4121 NetBSD/amd64 x86_64-*-netbsd*
4122 OpenBSD/amd64 x86_64-*-openbsd*
4123 OpenBSD/alpha alpha*-*-openbsd*
4124 OpenBSD/sparc sparc-*-openbsd*
4125 OpenBSD/sparc64 sparc64-*-openbsd*
4127 * New debugging protocols
4129 M32R with SDI protocol m32r-*-elf*
4131 * "set prompt-escape-char" command deleted.
4133 The command "set prompt-escape-char" has been deleted. This command,
4134 and its very obscure effet on GDB's prompt, was never documented,
4135 tested, nor mentioned in the NEWS file.
4137 * OBSOLETE configurations and files
4139 Configurations that have been declared obsolete in this release have
4140 been commented out. Unless there is activity to revive these
4141 configurations, the next release of GDB will have their sources
4142 permanently REMOVED.
4144 Sun 3, running SunOS 3 m68*-*-sunos3*
4145 Sun 3, running SunOS 4 m68*-*-sunos4*
4146 Sun 2, running SunOS 3 m68000-*-sunos3*
4147 Sun 2, running SunOS 4 m68000-*-sunos4*
4148 Motorola 680x0 running LynxOS m68*-*-lynxos*
4149 AT&T 3b1/Unix pc m68*-att-*
4150 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4151 decstation mips-dec-* mips-little-*
4152 riscos mips-*-riscos* mips-*-sysv*
4153 sonymips mips-sony-*
4154 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4156 * REMOVED configurations and files
4158 SGI Irix-4.x mips-sgi-irix4 or iris4
4159 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4160 Z8000 simulator z8k-zilog-none or z8ksim
4161 Matsushita MN10200 w/simulator mn10200-*-*
4162 H8/500 simulator h8500-hitachi-hms or h8500hms
4163 HP/PA running BSD hppa*-*-bsd*
4164 HP/PA running OSF/1 hppa*-*-osf*
4165 HP/PA Pro target hppa*-*-pro*
4166 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4167 386BSD i[3456]86-*-bsd*
4168 Sequent family i[3456]86-sequent-sysv4*
4169 i[3456]86-sequent-sysv*
4170 i[3456]86-sequent-bsd*
4171 SPARC running LynxOS sparc-*-lynxos*
4172 SPARC running SunOS 4 sparc-*-sunos4*
4173 Tsqware Sparclet sparclet-*-*
4174 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4176 *** Changes in GDB 6.0:
4180 Support for debugging the Objective-C programming language has been
4181 integrated into GDB.
4183 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4185 DWARF 2's Call Frame Information makes available compiler generated
4186 information that more exactly describes the program's run-time stack.
4187 By using this information, GDB is able to provide more robust stack
4190 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4191 have been updated to use a new backtrace mechanism which includes
4192 DWARF 2 CFI support.
4196 GDB's remote protocol has been extended to include support for hosted
4197 file I/O (where the remote target uses GDB's file system). See GDB's
4198 remote protocol documentation for details.
4200 * All targets using the new architecture framework.
4202 All of GDB's targets have been updated to use the new internal
4203 architecture framework. The way is now open for future GDB releases
4204 to include cross-architecture native debugging support (i386 on amd64,
4207 * GNU/Linux's Thread Local Storage (TLS)
4209 GDB now includes support for for the GNU/Linux implementation of
4210 per-thread variables.
4212 * GNU/Linux's Native POSIX Thread Library (NPTL)
4214 GDB's thread code has been updated to work with either the new
4215 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4217 * Separate debug info.
4219 GDB, in conjunction with BINUTILS, now supports a mechanism for
4220 automatically loading debug information from a separate file. Instead
4221 of shipping full debug and non-debug versions of system libraries,
4222 system integrators can now instead ship just the stripped libraries
4223 and optional debug files.
4225 * DWARF 2 Location Expressions
4227 DWARF 2 Location Expressions allow the compiler to more completely
4228 describe the location of variables (even in optimized code) to the
4231 GDB now includes preliminary support for location expressions (support
4232 for DW_OP_piece is still missing).
4236 A number of long standing bugs that caused GDB to die while starting a
4237 Java application have been fixed. GDB's Java support is now
4238 considered "useable".
4240 * GNU/Linux support for fork, vfork, and exec.
4242 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4243 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4246 * GDB supports logging output to a file
4248 There are two new commands, "set logging" and "show logging", which can be
4249 used to capture GDB's output to a file.
4251 * The meaning of "detach" has changed for gdbserver
4253 The "detach" command will now resume the application, as documented. To
4254 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4257 * d10v, m68hc11 `regs' command deprecated
4259 The `info registers' command has been updated so that it displays the
4260 registers using a format identical to the old `regs' command.
4264 A new command, "maint set profile on/off", has been added. This command can
4265 be used to enable or disable profiling while running GDB, to profile a
4266 session or a set of commands. In addition there is a new configure switch,
4267 "--enable-profiling", which will cause GDB to be compiled with profiling
4268 data, for more informative profiling results.
4270 * Default MI syntax changed to "mi2".
4272 The default MI (machine interface) syntax, enabled by the command line
4273 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4274 "mi1", can be enabled by specifying the option "-i=mi1".
4276 Support for the original "mi0" syntax (included in GDB 5.0) has been
4279 Fix for gdb/192: removed extraneous space when displaying frame level.
4280 Fix for gdb/672: update changelist is now output in mi list format.
4281 Fix for gdb/702: a -var-assign that updates the value now shows up
4282 in a subsequent -var-update.
4284 * New native configurations.
4286 FreeBSD/amd64 x86_64-*-freebsd*
4288 * Multi-arched targets.
4290 HP/PA HPUX11 hppa*-*-hpux*
4291 Renesas M32R/D w/simulator m32r-*-elf*
4293 * OBSOLETE configurations and files
4295 Configurations that have been declared obsolete in this release have
4296 been commented out. Unless there is activity to revive these
4297 configurations, the next release of GDB will have their sources
4298 permanently REMOVED.
4300 Z8000 simulator z8k-zilog-none or z8ksim
4301 Matsushita MN10200 w/simulator mn10200-*-*
4302 H8/500 simulator h8500-hitachi-hms or h8500hms
4303 HP/PA running BSD hppa*-*-bsd*
4304 HP/PA running OSF/1 hppa*-*-osf*
4305 HP/PA Pro target hppa*-*-pro*
4306 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4307 Sequent family i[3456]86-sequent-sysv4*
4308 i[3456]86-sequent-sysv*
4309 i[3456]86-sequent-bsd*
4310 Tsqware Sparclet sparclet-*-*
4311 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4313 * REMOVED configurations and files
4316 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4317 IBM AIX PS/2 i[3456]86-*-aix
4318 i386 running Mach 3.0 i[3456]86-*-mach3*
4319 i386 running Mach i[3456]86-*-mach*
4320 i386 running OSF/1 i[3456]86-*osf1mk*
4321 HP/Apollo 68k Family m68*-apollo*-sysv*,
4323 m68*-hp-bsd*, m68*-hp-hpux*
4324 Argonaut Risc Chip (ARC) arc-*-*
4325 Mitsubishi D30V d30v-*-*
4326 Fujitsu FR30 fr30-*-elf*
4327 OS/9000 i[34]86-*-os9k
4328 I960 with MON960 i960-*-coff
4330 * MIPS $fp behavior changed
4332 The convenience variable $fp, for the MIPS, now consistently returns
4333 the address of the current frame's base. Previously, depending on the
4334 context, $fp could refer to either $sp or the current frame's base
4335 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4336 The GNU Source-Level Debugger''.
4338 *** Changes in GDB 5.3:
4340 * GNU/Linux shared library multi-threaded performance improved.
4342 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4343 `/proc', in preference to `ptrace' for memory reads. This may result
4344 in an improvement in the start-up time of multi-threaded, shared
4345 library applications when run under GDB. One GDB user writes: ``loads
4346 shared libs like mad''.
4348 * ``gdbserver'' now supports multi-threaded applications on some targets
4350 Support for debugging multi-threaded applications which use
4351 the GNU/Linux LinuxThreads package has been added for
4352 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4353 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4355 * GDB now supports C/C++ preprocessor macros.
4357 GDB now expands preprocessor macro invocations in C/C++ expressions,
4358 and provides various commands for showing macro definitions and how
4361 The new command `macro expand EXPRESSION' expands any macro
4362 invocations in expression, and shows the result.
4364 The new command `show macro MACRO-NAME' shows the definition of the
4365 macro named MACRO-NAME, and where it was defined.
4367 Most compilers don't include information about macros in the debugging
4368 information by default. In GCC 3.1, for example, you need to compile
4369 your program with the options `-gdwarf-2 -g3'. If the macro
4370 information is present in the executable, GDB will read it.
4372 * Multi-arched targets.
4374 DEC Alpha (partial) alpha*-*-*
4375 DEC VAX (partial) vax-*-*
4377 National Semiconductor NS32000 (partial) ns32k-*-*
4378 Motorola 68000 (partial) m68k-*-*
4379 Motorola MCORE mcore-*-*
4383 Fujitsu FRV architecture added by Red Hat frv*-*-*
4386 * New native configurations
4388 Alpha NetBSD alpha*-*-netbsd*
4389 SH NetBSD sh*-*-netbsdelf*
4390 MIPS NetBSD mips*-*-netbsd*
4391 UltraSPARC NetBSD sparc64-*-netbsd*
4393 * OBSOLETE configurations and files
4395 Configurations that have been declared obsolete in this release have
4396 been commented out. Unless there is activity to revive these
4397 configurations, the next release of GDB will have their sources
4398 permanently REMOVED.
4400 Mitsubishi D30V d30v-*-*
4401 OS/9000 i[34]86-*-os9k
4402 IBM AIX PS/2 i[3456]86-*-aix
4403 Fujitsu FR30 fr30-*-elf*
4404 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4405 Argonaut Risc Chip (ARC) arc-*-*
4406 i386 running Mach 3.0 i[3456]86-*-mach3*
4407 i386 running Mach i[3456]86-*-mach*
4408 i386 running OSF/1 i[3456]86-*osf1mk*
4409 HP/Apollo 68k Family m68*-apollo*-sysv*,
4411 m68*-hp-bsd*, m68*-hp-hpux*
4412 I960 with MON960 i960-*-coff
4414 * OBSOLETE languages
4416 CHILL, a Pascal like language used by telecommunications companies.
4418 * REMOVED configurations and files
4420 AMD 29k family via UDI a29k-amd-udi, udi29k
4421 A29K VxWorks a29k-*-vxworks
4422 AMD 29000 embedded, using EBMON a29k-none-none
4423 AMD 29000 embedded with COFF a29k-none-coff
4424 AMD 29000 embedded with a.out a29k-none-aout
4426 testsuite/gdb.hp/gdb.threads-hp/ directory
4428 * New command "set max-user-call-depth <nnn>"
4430 This command allows the user to limit the call depth of user-defined
4431 commands. The default is 1024.
4433 * Changes in FreeBSD/i386 native debugging.
4435 Support for the "generate-core-file" has been added.
4437 * New commands "dump", "append", and "restore".
4439 These commands allow data to be copied from target memory
4440 to a bfd-format or binary file (dump and append), and back
4441 from a file into memory (restore).
4443 * Improved "next/step" support on multi-processor Alpha Tru64.
4445 The previous single-step mechanism could cause unpredictable problems,
4446 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4447 of a software single-step mechanism prevents this.
4449 *** Changes in GDB 5.2.1:
4457 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4458 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4459 Fix, by Joel Brobecker imported from mainline.
4461 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4462 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4463 Fix, by Fred Fish, imported from mainline.
4465 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4466 Surprisingly enough, it works now.
4467 By Michal Ludvig, imported from mainline.
4469 i386 hardware watchpoint support:
4470 avoid misses on second run for some targets.
4471 By Pierre Muller, imported from mainline.
4473 *** Changes in GDB 5.2:
4475 * New command "set trust-readonly-sections on[off]".
4477 This command is a hint that tells gdb that read-only sections
4478 really are read-only (ie. that their contents will not change).
4479 In this mode, gdb will go to the object file rather than the
4480 target to read memory from read-only sections (such as ".text").
4481 This can be a significant performance improvement on some
4482 (notably embedded) targets.
4484 * New command "generate-core-file" (or "gcore").
4486 This new gdb command allows the user to drop a core file of the child
4487 process state at any time. So far it's been implemented only for
4488 GNU/Linux and Solaris, but should be relatively easily ported to other
4489 hosts. Argument is core file name (defaults to core.<pid>).
4491 * New command line option
4493 GDB now accepts --pid or -p followed by a process id.
4495 * Change in command line behavior -- corefiles vs. process ids.
4497 There is a subtle behavior in the way in which GDB handles
4498 command line arguments. The first non-flag argument is always
4499 a program to debug, but the second non-flag argument may either
4500 be a corefile or a process id. Previously, GDB would attempt to
4501 open the second argument as a corefile, and if that failed, would
4502 issue a superfluous error message and then attempt to attach it as
4503 a process. Now, if the second argument begins with a non-digit,
4504 it will be treated as a corefile. If it begins with a digit,
4505 GDB will attempt to attach it as a process, and if no such process
4506 is found, will then attempt to open it as a corefile.
4508 * Changes in ARM configurations.
4510 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4511 configuration is fully multi-arch.
4513 * New native configurations
4515 ARM NetBSD arm*-*-netbsd*
4516 x86 OpenBSD i[3456]86-*-openbsd*
4517 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4518 Sparc64 running FreeBSD sparc64-*-freebsd*
4522 Sanyo XStormy16 xstormy16-elf
4524 * OBSOLETE configurations and files
4526 Configurations that have been declared obsolete in this release have
4527 been commented out. Unless there is activity to revive these
4528 configurations, the next release of GDB will have their sources
4529 permanently REMOVED.
4531 AMD 29k family via UDI a29k-amd-udi, udi29k
4532 A29K VxWorks a29k-*-vxworks
4533 AMD 29000 embedded, using EBMON a29k-none-none
4534 AMD 29000 embedded with COFF a29k-none-coff
4535 AMD 29000 embedded with a.out a29k-none-aout
4537 testsuite/gdb.hp/gdb.threads-hp/ directory
4539 * REMOVED configurations and files
4541 TI TMS320C80 tic80-*-*
4543 PowerPC Solaris powerpcle-*-solaris*
4544 PowerPC Windows NT powerpcle-*-cygwin32
4545 PowerPC Netware powerpc-*-netware*
4546 Harris/CXUX m88k m88*-harris-cxux*
4547 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4548 ns32k-utek-sysv* ns32k-utek-*
4549 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4550 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4551 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4552 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4553 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4555 * Changes to command line processing
4557 The new `--args' feature can be used to specify command-line arguments
4558 for the inferior from gdb's command line.
4560 * Changes to key bindings
4562 There is a new `operate-and-get-next' function bound to `C-o'.
4564 *** Changes in GDB 5.1.1
4566 Fix compile problem on DJGPP.
4568 Fix a problem with floating-point registers on the i386 being
4571 Fix to stop GDB crashing on .debug_str debug info.
4573 Numerous documentation fixes.
4575 Numerous testsuite fixes.
4577 *** Changes in GDB 5.1:
4579 * New native configurations
4581 Alpha FreeBSD alpha*-*-freebsd*
4582 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4583 MIPS GNU/Linux mips*-*-linux*
4584 MIPS SGI Irix 6.x mips*-sgi-irix6*
4585 ia64 AIX ia64-*-aix*
4586 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4590 Motorola 68HC11 and 68HC12 m68hc11-elf
4592 UltraSparc running GNU/Linux sparc64-*-linux*
4594 * OBSOLETE configurations and files
4596 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4597 Harris/CXUX m88k m88*-harris-cxux*
4598 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4599 ns32k-utek-sysv* ns32k-utek-*
4600 TI TMS320C80 tic80-*-*
4602 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4603 PowerPC Solaris powerpcle-*-solaris*
4604 PowerPC Windows NT powerpcle-*-cygwin32
4605 PowerPC Netware powerpc-*-netware*
4606 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4607 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4608 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4609 Apple Macintosh (MPW) host N/A
4611 stuff.c (Program to stuff files into a specially prepared space in kdb)
4612 kdb-start.c (Main loop for the standalone kernel debugger)
4614 Configurations that have been declared obsolete in this release have
4615 been commented out. Unless there is activity to revive these
4616 configurations, the next release of GDB will have their sources
4617 permanently REMOVED.
4619 * REMOVED configurations and files
4621 Altos 3068 m68*-altos-*
4622 Convex c1-*-*, c2-*-*
4624 ARM RISCix arm-*-* (as host)
4628 * GDB has been converted to ISO C.
4630 GDB's source code has been converted to ISO C. In particular, the
4631 sources are fully protoized, and rely on standard headers being
4636 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4638 * The MI enabled by default.
4640 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4641 revised and enabled by default. Packages which use GDB as a debugging
4642 engine behind a UI or another front end are encouraged to switch to
4643 using the GDB/MI interface, instead of the old annotations interface
4644 which is now deprecated.
4646 * Support for debugging Pascal programs.
4648 GDB now includes support for debugging Pascal programs. The following
4649 main features are supported:
4651 - Pascal-specific data types such as sets;
4653 - automatic recognition of Pascal sources based on file-name
4656 - Pascal-style display of data types, variables, and functions;
4658 - a Pascal expression parser.
4660 However, some important features are not yet supported.
4662 - Pascal string operations are not supported at all;
4664 - there are some problems with boolean types;
4666 - Pascal type hexadecimal constants are not supported
4667 because they conflict with the internal variables format;
4669 - support for Pascal objects and classes is not full yet;
4671 - unlike Pascal, GDB is case-sensitive for symbol names.
4673 * Changes in completion.
4675 Commands such as `shell', `run' and `set args', which pass arguments
4676 to inferior programs, now complete on file names, similar to what
4677 users expect at the shell prompt.
4679 Commands which accept locations, such as `disassemble', `print',
4680 `breakpoint', `until', etc. now complete on filenames as well as
4681 program symbols. Thus, if you type "break foob TAB", and the source
4682 files linked into the programs include `foobar.c', that file name will
4683 be one of the candidates for completion. However, file names are not
4684 considered for completion after you typed a colon that delimits a file
4685 name from a name of a function in that file, as in "break foo.c:bar".
4687 `set demangle-style' completes on available demangling styles.
4689 * New platform-independent commands:
4691 It is now possible to define a post-hook for a command as well as a
4692 hook that runs before the command. For more details, see the
4693 documentation of `hookpost' in the GDB manual.
4695 * Changes in GNU/Linux native debugging.
4697 Support for debugging multi-threaded programs has been completely
4698 revised for all platforms except m68k and sparc. You can now debug as
4699 many threads as your system allows you to have.
4701 Attach/detach is supported for multi-threaded programs.
4703 Support for SSE registers was added for x86. This doesn't work for
4704 multi-threaded programs though.
4706 * Changes in MIPS configurations.
4708 Multi-arch support is enabled for all MIPS configurations.
4710 GDB can now be built as native debugger on SGI Irix 6.x systems for
4711 debugging n32 executables. (Debugging 64-bit executables is not yet
4714 * Unified support for hardware watchpoints in all x86 configurations.
4716 Most (if not all) native x86 configurations support hardware-assisted
4717 breakpoints and watchpoints in a unified manner. This support
4718 implements debug register sharing between watchpoints, which allows to
4719 put a virtually infinite number of watchpoints on the same address,
4720 and also supports watching regions up to 16 bytes with several debug
4723 The new maintenance command `maintenance show-debug-regs' toggles
4724 debugging print-outs in functions that insert, remove, and test
4725 watchpoints and hardware breakpoints.
4727 * Changes in the DJGPP native configuration.
4729 New command ``info dos sysinfo'' displays assorted information about
4730 the CPU, OS, memory, and DPMI server.
4732 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4733 display information about segment descriptors stored in GDT, LDT, and
4736 New commands ``info dos pde'' and ``info dos pte'' display entries
4737 from Page Directory and Page Tables (for now works with CWSDPMI only).
4738 New command ``info dos address-pte'' displays the Page Table entry for
4739 a given linear address.
4741 GDB can now pass command lines longer than 126 characters to the
4742 program being debugged (requires an update to the libdbg.a library
4743 which is part of the DJGPP development kit).
4745 DWARF2 debug info is now supported.
4747 It is now possible to `step' and `next' through calls to `longjmp'.
4749 * Changes in documentation.
4751 All GDB documentation was converted to GFDL, the GNU Free
4752 Documentation License.
4754 Tracepoints-related commands are now fully documented in the GDB
4757 TUI, the Text-mode User Interface, is now documented in the manual.
4759 Tracepoints-related commands are now fully documented in the GDB
4762 The "GDB Internals" manual now has an index. It also includes
4763 documentation of `ui_out' functions, GDB coding standards, x86
4764 hardware watchpoints, and memory region attributes.
4766 * GDB's version number moved to ``version.in''
4768 The Makefile variable VERSION has been replaced by the file
4769 ``version.in''. People creating GDB distributions should update the
4770 contents of this file.
4774 GUD support is now a standard part of the EMACS distribution.
4776 *** Changes in GDB 5.0:
4778 * Improved support for debugging FP programs on x86 targets
4780 Unified and much-improved support for debugging floating-point
4781 programs on all x86 targets. In particular, ``info float'' now
4782 displays the FP registers in the same format on all x86 targets, with
4783 greater level of detail.
4785 * Improvements and bugfixes in hardware-assisted watchpoints
4787 It is now possible to watch array elements, struct members, and
4788 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4789 on x86 targets no longer erroneously trigger when the address is
4792 * Improvements in the native DJGPP version of GDB
4794 The distribution now includes all the scripts and auxiliary files
4795 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4796 machines ``out of the box''.
4798 The DJGPP version can now debug programs that use signals. It is
4799 possible to catch signals that happened in the debuggee, deliver
4800 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4801 would kill the program being debugged.) Programs that hook hardware
4802 interrupts (keyboard, timer, etc.) can also be debugged.
4804 It is now possible to debug DJGPP programs that redirect their
4805 standard handles or switch them to raw (as opposed to cooked) mode, or
4806 even close them. The command ``run < foo > bar'' works as expected,
4807 and ``info terminal'' reports useful information about the debuggee's
4808 terminal, including raw/cooked mode, redirection, etc.
4810 The DJGPP version now uses termios functions for console I/O, which
4811 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4814 DOS-style file names with drive letters are now fully supported by
4817 It is now possible to debug DJGPP programs that switch their working
4818 directory. It is also possible to rerun the debuggee any number of
4819 times without restarting GDB; thus, you can use the same setup,
4820 breakpoints, etc. for many debugging sessions.
4822 * New native configurations
4824 ARM GNU/Linux arm*-*-linux*
4825 PowerPC GNU/Linux powerpc-*-linux*
4829 Motorola MCore mcore-*-*
4830 x86 VxWorks i[3456]86-*-vxworks*
4831 PowerPC VxWorks powerpc-*-vxworks*
4832 TI TMS320C80 tic80-*-*
4834 * OBSOLETE configurations
4836 Altos 3068 m68*-altos-*
4837 Convex c1-*-*, c2-*-*
4839 ARM RISCix arm-*-* (as host)
4842 Configurations that have been declared obsolete will be commented out,
4843 but the code will be left in place. If there is no activity to revive
4844 these configurations before the next release of GDB, the sources will
4845 be permanently REMOVED.
4847 * Gould support removed
4849 Support for the Gould PowerNode and NP1 has been removed.
4851 * New features for SVR4
4853 On SVR4 native platforms (such as Solaris), if you attach to a process
4854 without first loading a symbol file, GDB will now attempt to locate and
4855 load symbols from the running process's executable file.
4857 * Many C++ enhancements
4859 C++ support has been greatly improved. Overload resolution now works properly
4860 in almost all cases. RTTI support is on the way.
4862 * Remote targets can connect to a sub-program
4864 A popen(3) style serial-device has been added. This device starts a
4865 sub-process (such as a stand-alone simulator) and then communicates
4866 with that. The sub-program to run is specified using the syntax
4867 ``|<program> <args>'' vis:
4869 (gdb) set remotedebug 1
4870 (gdb) target extended-remote |mn10300-elf-sim program-args
4872 * MIPS 64 remote protocol
4874 A long standing bug in the mips64 remote protocol where by GDB
4875 expected certain 32 bit registers (ex SR) to be transfered as 32
4876 instead of 64 bits has been fixed.
4878 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4879 added to provide backward compatibility with older versions of GDB.
4881 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4883 The command ``set remotebinarydownload'' command has been replaced by
4884 ``set remote X-packet''. Other commands in ``set remote'' family
4885 include ``set remote P-packet''.
4887 * Breakpoint commands accept ranges.
4889 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4890 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4891 ``tracepoint passcount'' also accepts a range of tracepoints.
4893 * ``apropos'' command added.
4895 The ``apropos'' command searches through command names and
4896 documentation strings, printing out matches, making it much easier to
4897 try to find a command that does what you are looking for.
4901 A new machine oriented interface (MI) has been added to GDB. This
4902 interface is designed for debug environments running GDB as a separate
4903 process. This is part of the long term libGDB project. See the
4904 "GDB/MI" chapter of the GDB manual for further information. It can be
4905 enabled by configuring with:
4907 .../configure --enable-gdbmi
4909 *** Changes in GDB-4.18:
4911 * New native configurations
4913 HP-UX 10.20 hppa*-*-hpux10.20
4914 HP-UX 11.x hppa*-*-hpux11.0*
4915 M68K GNU/Linux m68*-*-linux*
4919 Fujitsu FR30 fr30-*-elf*
4920 Intel StrongARM strongarm-*-*
4921 Mitsubishi D30V d30v-*-*
4923 * OBSOLETE configurations
4925 Gould PowerNode, NP1 np1-*-*, pn-*-*
4927 Configurations that have been declared obsolete will be commented out,
4928 but the code will be left in place. If there is no activity to revive
4929 these configurations before the next release of GDB, the sources will
4930 be permanently REMOVED.
4934 As a compatibility experiment, GDB's source files buildsym.h and
4935 buildsym.c have been converted to pure standard C, no longer
4936 containing any K&R compatibility code. We believe that all systems in
4937 use today either come with a standard C compiler, or have a GCC port
4938 available. If this is not true, please report the affected
4939 configuration to bug-gdb@gnu.org immediately. See the README file for
4940 information about getting a standard C compiler if you don't have one
4945 GDB now uses readline 2.2.
4947 * set extension-language
4949 You can now control the mapping between filename extensions and source
4950 languages by using the `set extension-language' command. For instance,
4951 you can ask GDB to treat .c files as C++ by saying
4952 set extension-language .c c++
4953 The command `info extensions' lists all of the recognized extensions
4954 and their associated languages.
4956 * Setting processor type for PowerPC and RS/6000
4958 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4959 you can use the `set processor' command to specify what variant of the
4960 PowerPC family you are debugging. The command
4964 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4965 following PowerPC and RS6000 variants:
4967 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4968 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4970 403GC IBM PowerPC 403GC
4971 505 Motorola PowerPC 505
4972 860 Motorola PowerPC 860 or 850
4973 601 Motorola PowerPC 601
4974 602 Motorola PowerPC 602
4975 603 Motorola/IBM PowerPC 603 or 603e
4976 604 Motorola PowerPC 604 or 604e
4977 750 Motorola/IBM PowerPC 750 or 750
4979 At the moment, this command just tells GDB what to name the
4980 special-purpose processor registers. Since almost all the affected
4981 registers are inaccessible to user-level programs, this command is
4982 only useful for remote debugging in its present form.
4986 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4987 more extensive support for HP-UX. Added features include shared
4988 library support, kernel threads and hardware watchpoints for 11.00,
4989 support for HP's ANSI C and C++ compilers, and a compatibility mode
4990 for xdb and dbx commands.
4994 HP's donation includes the new concept of catchpoints, which is a
4995 generalization of the old catch command. On HP-UX, it is now possible
4996 to catch exec, fork, and vfork, as well as library loading.
4998 This means that the existing catch command has changed; its first
4999 argument now specifies the type of catch to be set up. See the
5000 output of "help catch" for a list of catchpoint types.
5002 * Debugging across forks
5004 On HP-UX, you can choose which process to debug when a fork() happens
5009 HP has donated a curses-based terminal user interface (TUI). To get
5010 it, build with --enable-tui. Although this can be enabled for any
5011 configuration, at present it only works for native HP debugging.
5013 * GDB remote protocol additions
5015 A new protocol packet 'X' that writes binary data is now available.
5016 Default behavior is to try 'X', then drop back to 'M' if the stub
5017 fails to respond. The settable variable `remotebinarydownload'
5018 allows explicit control over the use of 'X'.
5020 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5021 full 64-bit address. The command
5023 set remoteaddresssize 32
5025 can be used to revert to the old behaviour. For existing remote stubs
5026 the change should not be noticed, as the additional address information
5029 In order to assist in debugging stubs, you may use the maintenance
5030 command `packet' to send any text string to the stub. For instance,
5032 maint packet heythere
5034 sends the packet "$heythere#<checksum>". Note that it is very easy to
5035 disrupt a debugging session by sending the wrong packet at the wrong
5038 The compare-sections command allows you to compare section data on the
5039 target to what is in the executable file without uploading or
5040 downloading, by comparing CRC checksums.
5042 * Tracing can collect general expressions
5044 You may now collect general expressions at tracepoints. This requires
5045 further additions to the target-side stub; see tracepoint.c and
5046 doc/agentexpr.texi for further details.
5048 * mask-address variable for Mips
5050 For Mips targets, you may control the zeroing of the upper 32 bits of
5051 a 64-bit address by entering `set mask-address on'. This is mainly
5052 of interest to users of embedded R4xxx and R5xxx processors.
5054 * Higher serial baud rates
5056 GDB's serial code now allows you to specify baud rates 57600, 115200,
5057 230400, and 460800 baud. (Note that your host system may not be able
5058 to achieve all of these rates.)
5062 The i960 configuration now includes an initial implementation of a
5063 builtin simulator, contributed by Jim Wilson.
5066 *** Changes in GDB-4.17:
5068 * New native configurations
5070 Alpha GNU/Linux alpha*-*-linux*
5071 Unixware 2.x i[3456]86-unixware2*
5072 Irix 6.x mips*-sgi-irix6*
5073 PowerPC GNU/Linux powerpc-*-linux*
5074 PowerPC Solaris powerpcle-*-solaris*
5075 Sparc GNU/Linux sparc-*-linux*
5076 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5080 Argonaut Risc Chip (ARC) arc-*-*
5081 Hitachi H8/300S h8300*-*-*
5082 Matsushita MN10200 w/simulator mn10200-*-*
5083 Matsushita MN10300 w/simulator mn10300-*-*
5084 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5085 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5086 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5087 Mitsubishi D10V w/simulator d10v-*-*
5088 Mitsubishi M32R/D w/simulator m32r-*-elf*
5089 Tsqware Sparclet sparclet-*-*
5090 NEC V850 w/simulator v850-*-*
5092 * New debugging protocols
5094 ARM with RDI protocol arm*-*-*
5095 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5096 DDB and LSI variants of PMON protocol mips*-*-*
5097 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5098 PowerPC with SDS protocol powerpc{,le}-*-eabi
5099 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5103 All configurations can now understand and use the DWARF 2 debugging
5104 format. The choice is automatic, if the symbol file contains DWARF 2
5109 GDB now includes basic Java language support. This support is
5110 only useful with Java compilers that produce native machine code.
5112 * solib-absolute-prefix and solib-search-path
5114 For SunOS and SVR4 shared libraries, you may now set the prefix for
5115 loading absolute shared library symbol files, and the search path for
5116 locating non-absolute shared library symbol files.
5118 * Live range splitting
5120 GDB can now effectively debug code for which GCC has performed live
5121 range splitting as part of its optimization. See gdb/doc/LRS for
5122 more details on the expected format of the stabs information.
5126 GDB's support for the GNU Hurd, including thread debugging, has been
5127 updated to work with current versions of the Hurd.
5131 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5132 instruction set. ARM GDB automatically detects when Thumb
5133 instructions are in use, and adjusts disassembly and backtracing
5138 GDB's MIPS target configurations now handle the MIP16 16-bit
5143 GDB now includes support for overlays; if an executable has been
5144 linked such that multiple sections are based at the same address, GDB
5145 will decide which section to use for symbolic info. You can choose to
5146 control the decision manually, using overlay commands, or implement
5147 additional target-side support and use "overlay load-target" to bring
5148 in the overlay mapping. Do "help overlay" for more detail.
5152 The command "info symbol <address>" displays information about
5153 the symbol at the specified address.
5157 The standard remote protocol now includes an extension that allows
5158 asynchronous collection and display of trace data. This requires
5159 extensive support in the target-side debugging stub. Tracing mode
5160 includes a new interaction mode in GDB and new commands: see the
5161 file tracepoint.c for more details.
5165 Configurations for embedded MIPS now include a simulator contributed
5166 by Cygnus Solutions. The simulator supports the instruction sets
5167 of most MIPS variants.
5171 Sparc configurations may now include the ERC32 simulator contributed
5172 by the European Space Agency. The simulator is not built into
5173 Sparc targets by default; configure with --enable-sim to include it.
5177 For target configurations that may include multiple variants of a
5178 basic architecture (such as MIPS and SH), you may now set the
5179 architecture explicitly. "set arch" sets, "info arch" lists
5180 the possible architectures.
5182 *** Changes in GDB-4.16:
5184 * New native configurations
5186 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5187 M68K NetBSD m68k-*-netbsd*
5188 PowerPC AIX 4.x powerpc-*-aix*
5189 PowerPC MacOS powerpc-*-macos*
5190 PowerPC Windows NT powerpcle-*-cygwin32
5191 RS/6000 AIX 4.x rs6000-*-aix4*
5195 ARM with RDP protocol arm-*-*
5196 I960 with MON960 i960-*-coff
5197 MIPS VxWorks mips*-*-vxworks*
5198 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5199 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5201 Matra Sparclet sparclet-*-*
5205 The powerpc-eabi configuration now includes the PSIM simulator,
5206 contributed by Andrew Cagney, with assistance from Mike Meissner.
5207 PSIM is a very elaborate model of the PowerPC, including not only
5208 basic instruction set execution, but also details of execution unit
5209 performance and I/O hardware. See sim/ppc/README for more details.
5213 GDB now works with Solaris 2.5.
5215 * Windows 95/NT native
5217 GDB will now work as a native debugger on Windows 95 and Windows NT.
5218 To build it from source, you must use the "gnu-win32" environment,
5219 which uses a DLL to emulate enough of Unix to run the GNU tools.
5220 Further information, binaries, and sources are available at
5221 ftp.cygnus.com, under pub/gnu-win32.
5223 * dont-repeat command
5225 If a user-defined command includes the command `dont-repeat', then the
5226 command will not be repeated if the user just types return. This is
5227 useful if the command is time-consuming to run, so that accidental
5228 extra keystrokes don't run the same command many times.
5230 * Send break instead of ^C
5232 The standard remote protocol now includes an option to send a break
5233 rather than a ^C to the target in order to interrupt it. By default,
5234 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5236 * Remote protocol timeout
5238 The standard remote protocol includes a new variable `remotetimeout'
5239 that allows you to set the number of seconds before GDB gives up trying
5240 to read from the target. The default value is 2.
5242 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5244 By default GDB will automatically keep track of objects as they are
5245 loaded and unloaded by the dynamic linker. By using the command `set
5246 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5247 when shared library events occur, thus allowing you to set breakpoints
5248 in shared libraries which are explicitly loaded by the inferior.
5250 Note this feature does not work on hpux8. On hpux9 you must link
5251 /usr/lib/end.o into your program. This feature should work
5252 automatically on hpux10.
5254 * Irix 5.x hardware watchpoint support
5256 Irix 5 configurations now support the use of hardware watchpoints.
5258 * Mips protocol "SYN garbage limit"
5260 When debugging a Mips target using the `target mips' protocol, you
5261 may set the number of characters that GDB will ignore by setting
5262 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5263 every character. The default value is 1050.
5265 * Recording and replaying remote debug sessions
5267 If you set `remotelogfile' to the name of a file, gdb will write to it
5268 a recording of a remote debug session. This recording may then be
5269 replayed back to gdb using "gdbreplay". See gdbserver/README for
5270 details. This is useful when you have a problem with GDB while doing
5271 remote debugging; you can make a recording of the session and send it
5272 to someone else, who can then recreate the problem.
5274 * Speedups for remote debugging
5276 GDB includes speedups for downloading and stepping MIPS systems using
5277 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5278 and more efficient S-record downloading.
5280 * Memory use reductions and statistics collection
5282 GDB now uses less memory and reports statistics about memory usage.
5283 Try the `maint print statistics' command, for example.
5285 *** Changes in GDB-4.15:
5287 * Psymtabs for XCOFF
5289 The symbol reader for AIX GDB now uses partial symbol tables. This
5290 can greatly improve startup time, especially for large executables.
5292 * Remote targets use caching
5294 Remote targets now use a data cache to speed up communication with the
5295 remote side. The data cache could lead to incorrect results because
5296 it doesn't know about volatile variables, thus making it impossible to
5297 debug targets which use memory mapped I/O devices. `set remotecache
5298 off' turns the the data cache off.
5300 * Remote targets may have threads
5302 The standard remote protocol now includes support for multiple threads
5303 in the target system, using new protocol commands 'H' and 'T'. See
5304 gdb/remote.c for details.
5308 If GDB is configured with `--enable-netrom', then it will include
5309 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5310 acts as though it is a bank of ROM on the target board, but you can
5311 write into it over the network. GDB's support consists only of
5312 support for fast loading into the emulated ROM; to debug, you must use
5313 another protocol, such as standard remote protocol. The usual
5314 sequence is something like
5316 target nrom <netrom-hostname>
5318 target remote <netrom-hostname>:1235
5322 GDB now includes support for the Apple Macintosh, as a host only. It
5323 may be run as either an MPW tool or as a standalone application, and
5324 it can debug through the serial port. All the usual GDB commands are
5325 available, but to the target command, you must supply "serial" as the
5326 device type instead of "/dev/ttyXX". See mpw-README in the main
5327 directory for more information on how to build. The MPW configuration
5328 scripts */mpw-config.in support only a few targets, and only the
5329 mips-idt-ecoff target has been tested.
5333 GDB configuration now uses autoconf. This is not user-visible,
5334 but does simplify configuration and building.
5338 GDB now supports hpux10.
5340 *** Changes in GDB-4.14:
5342 * New native configurations
5344 x86 FreeBSD i[345]86-*-freebsd
5345 x86 NetBSD i[345]86-*-netbsd
5346 NS32k NetBSD ns32k-*-netbsd
5347 Sparc NetBSD sparc-*-netbsd
5351 A29K VxWorks a29k-*-vxworks
5352 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5353 CPU32 EST-300 emulator m68*-*-est*
5354 PowerPC ELF powerpc-*-elf
5357 * Alpha OSF/1 support for procfs
5359 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5360 possible to attach to running processes. As the mounting of the /proc
5361 filesystem is optional on the Alpha, GDB automatically determines
5362 the availability of /proc during startup. This can lead to problems
5363 if /proc is unmounted after GDB has been started.
5365 * Arguments to user-defined commands
5367 User commands may accept up to 10 arguments separated by whitespace.
5368 Arguments are accessed within the user command via $arg0..$arg9. A
5371 print $arg0 + $arg1 + $arg2
5373 To execute the command use:
5376 Defines the command "adder" which prints the sum of its three arguments.
5377 Note the arguments are text substitutions, so they may reference variables,
5378 use complex expressions, or even perform inferior function calls.
5380 * New `if' and `while' commands
5382 This makes it possible to write more sophisticated user-defined
5383 commands. Both commands take a single argument, which is the
5384 expression to evaluate, and must be followed by the commands to
5385 execute, one per line, if the expression is nonzero, the list being
5386 terminated by the word `end'. The `if' command list may include an
5387 `else' word, which causes the following commands to be executed only
5388 if the expression is zero.
5390 * Fortran source language mode
5392 GDB now includes partial support for Fortran 77. It will recognize
5393 Fortran programs and can evaluate a subset of Fortran expressions, but
5394 variables and functions may not be handled correctly. GDB will work
5395 with G77, but does not yet know much about symbols emitted by other
5398 * Better HPUX support
5400 Most debugging facilities now work on dynamic executables for HPPAs
5401 running hpux9 or later. You can attach to running dynamically linked
5402 processes, but by default the dynamic libraries will be read-only, so
5403 for instance you won't be able to put breakpoints in them. To change
5404 that behavior do the following before running the program:
5410 This will cause the libraries to be mapped private and read-write.
5411 To revert to the normal behavior, do this:
5417 You cannot set breakpoints or examine data in the library until after
5418 the library is loaded if the function/data symbols do not have
5421 GDB can now also read debug symbols produced by the HP C compiler on
5422 HPPAs (sorry, no C++, Fortran or 68k support).
5424 * Target byte order now dynamically selectable
5426 You can choose which byte order to use with a target system, via the
5427 commands "set endian big" and "set endian little", and you can see the
5428 current setting by using "show endian". You can also give the command
5429 "set endian auto", in which case GDB will use the byte order
5430 associated with the executable. Currently, only embedded MIPS
5431 configurations support dynamic selection of target byte order.
5433 * New DOS host serial code
5435 This version uses DPMI interrupts to handle buffered I/O, so you
5436 no longer need to run asynctsr when debugging boards connected to
5439 *** Changes in GDB-4.13:
5441 * New "complete" command
5443 This lists all the possible completions for the rest of the line, if it
5444 were to be given as a command itself. This is intended for use by emacs.
5446 * Trailing space optional in prompt
5448 "set prompt" no longer adds a space for you after the prompt you set. This
5449 allows you to set a prompt which ends in a space or one that does not.
5451 * Breakpoint hit counts
5453 "info break" now displays a count of the number of times the breakpoint
5454 has been hit. This is especially useful in conjunction with "ignore"; you
5455 can ignore a large number of breakpoint hits, look at the breakpoint info
5456 to see how many times the breakpoint was hit, then run again, ignoring one
5457 less than that number, and this will get you quickly to the last hit of
5460 * Ability to stop printing at NULL character
5462 "set print null-stop" will cause GDB to stop printing the characters of
5463 an array when the first NULL is encountered. This is useful when large
5464 arrays actually contain only short strings.
5466 * Shared library breakpoints
5468 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5469 breakpoints in shared libraries before the executable is run.
5471 * Hardware watchpoints
5473 There is a new hardware breakpoint for the watch command for sparclite
5474 targets. See gdb/sparclite/hw_breakpoint.note.
5476 Hardware watchpoints are also now supported under GNU/Linux.
5480 Annotations have been added. These are for use with graphical interfaces,
5481 and are still experimental. Currently only gdba.el uses these.
5483 * Improved Irix 5 support
5485 GDB now works properly with Irix 5.2.
5487 * Improved HPPA support
5489 GDB now works properly with the latest GCC and GAS.
5491 * New native configurations
5493 Sequent PTX4 i[34]86-sequent-ptx4
5494 HPPA running OSF/1 hppa*-*-osf*
5495 Atari TT running SVR4 m68*-*-sysv4*
5496 RS/6000 LynxOS rs6000-*-lynxos*
5500 OS/9000 i[34]86-*-os9k
5501 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5504 * Hitachi SH7000 and E7000-PC ICE support
5506 There is now support for communicating with the Hitachi E7000-PC ICE.
5507 This is available automatically when GDB is configured for the SH.
5511 As usual, a variety of small fixes and improvements, both generic
5512 and configuration-specific. See the ChangeLog for more detail.
5514 *** Changes in GDB-4.12:
5516 * Irix 5 is now supported
5520 GDB-4.12 on the HPPA has a number of changes which make it unable
5521 to debug the output from the currently released versions of GCC and
5522 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5523 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5524 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5527 *** Changes in GDB-4.11:
5529 * User visible changes:
5533 The "set remotedebug" option is now consistent between the mips remote
5534 target, remote targets using the gdb-specific protocol, UDI (AMD's
5535 debug protocol for the 29k) and the 88k bug monitor. It is now an
5536 integer specifying a debug level (normally 0 or 1, but 2 means more
5537 debugging info for the mips target).
5539 * DEC Alpha native support
5541 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5542 debug info, but GDB works fairly well with the DEC compiler and should
5543 work with a future GCC release. See the README file for a few
5544 Alpha-specific notes.
5546 * Preliminary thread implementation
5548 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5550 * LynxOS native and target support for 386
5552 This release has been hosted on LynxOS 2.2, and also can be configured
5553 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5556 * Improvements in C++ mangling/demangling.
5558 This release has much better g++ debugging, specifically in name
5559 mangling/demangling, virtual function calls, print virtual table,
5560 call methods, ...etc.
5562 *** Changes in GDB-4.10:
5564 * User visible changes:
5566 Remote debugging using the GDB-specific (`target remote') protocol now
5567 supports the `load' command. This is only useful if you have some
5568 other way of getting the stub to the target system, and you can put it
5569 somewhere in memory where it won't get clobbered by the download.
5571 Filename completion now works.
5573 When run under emacs mode, the "info line" command now causes the
5574 arrow to point to the line specified. Also, "info line" prints
5575 addresses in symbolic form (as well as hex).
5577 All vxworks based targets now support a user settable option, called
5578 vxworks-timeout. This option represents the number of seconds gdb
5579 should wait for responses to rpc's. You might want to use this if
5580 your vxworks target is, perhaps, a slow software simulator or happens
5581 to be on the far side of a thin network line.
5585 This release contains support for using a DEC alpha as a GDB host for
5586 cross debugging. Native alpha debugging is not supported yet.
5589 *** Changes in GDB-4.9:
5593 This is the first GDB release which is accompanied by a matching testsuite.
5594 The testsuite requires installation of dejagnu, which should be available
5595 via ftp from most sites that carry GNU software.
5599 'Cfront' style demangling has had its name changed to 'ARM' style, to
5600 emphasize that it was written from the specifications in the C++ Annotated
5601 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5602 disclaimers, it still generated too much confusion with users attempting to
5603 use gdb with AT&T cfront.
5607 GDB now uses a standard remote interface to a simulator library.
5608 So far, the library contains simulators for the Zilog Z8001/2, the
5609 Hitachi H8/300, H8/500 and Super-H.
5611 * New targets supported
5613 H8/300 simulator h8300-hitachi-hms or h8300hms
5614 H8/500 simulator h8500-hitachi-hms or h8500hms
5615 SH simulator sh-hitachi-hms or sh
5616 Z8000 simulator z8k-zilog-none or z8ksim
5617 IDT MIPS board over serial line mips-idt-ecoff
5619 Cross-debugging to GO32 targets is supported. It requires a custom
5620 version of the i386-stub.c module which is integrated with the
5621 GO32 memory extender.
5623 * New remote protocols
5625 MIPS remote debugging protocol.
5627 * New source languages supported
5629 This version includes preliminary support for Chill, a Pascal like language
5630 used by telecommunications companies. Chill support is also being integrated
5631 into the GNU compiler, but we don't know when it will be publically available.
5634 *** Changes in GDB-4.8:
5636 * HP Precision Architecture supported
5638 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5639 version of this support was available as a set of patches from the
5640 University of Utah. GDB does not support debugging of programs
5641 compiled with the HP compiler, because HP will not document their file
5642 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5643 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5645 Many problems in the preliminary version have been fixed.
5647 * Faster and better demangling
5649 We have improved template demangling and fixed numerous bugs in the GNU style
5650 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5651 character types (wchar_t) are now supported. Demangling of each symbol is now
5652 only done once, and is cached when the symbol table for a file is read in.
5653 This results in a small increase in memory usage for C programs, a moderate
5654 increase in memory usage for C++ programs, and a fantastic speedup in
5657 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5658 from the specifications in the Annotated Reference Manual, which AT&T's
5659 compiler does not actually implement.
5661 * G++ multiple inheritance compiler problem
5663 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5664 inheritance lattices was reworked to properly discover ambiguities. We
5665 recently found an example which causes this new algorithm to fail in a
5666 very subtle way, producing bad debug information for those classes.
5667 The file 'gcc.patch' (in this directory) can be applied to gcc to
5668 circumvent the problem. A future GCC release will contain a complete
5671 The previous G++ debug info problem (mentioned below for the gdb-4.7
5672 release) is fixed in gcc version 2.3.2.
5674 * Improved configure script
5676 The `configure' script will now attempt to guess your system type if
5677 you don't supply a host system type. The old scheme of supplying a
5678 host system triplet is preferable over using this. All the magic is
5679 done in the new `config.guess' script. Examine it for details.
5681 We have also brought our configure script much more in line with the FSF's
5682 version. It now supports the --with-xxx options. In particular,
5683 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5684 The resulting GDB will not be able to read arbitrary object file formats --
5685 only the format ``expected'' to be used on the configured target system.
5686 We hope to make this the default in a future release.
5688 * Documentation improvements
5690 There's new internal documentation on how to modify GDB, and how to
5691 produce clean changes to the code. We implore people to read it
5692 before submitting changes.
5694 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5695 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5696 `info' files are also provided. To build `info' files from scratch,
5697 you will need the latest `makeinfo' release, which will be available in
5698 a future texinfo-X.Y release.
5700 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5701 We're not sure exactly which versions have this problem, but it has
5702 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5703 or better. If that isn't possible, there is a patch in
5704 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5705 around this problem.
5709 GDB now supports array constants that can be used in expressions typed in by
5710 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5711 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5714 The new directory `gdb/sparclite' contains a program that demonstrates
5715 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5717 * New native hosts supported
5719 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5720 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5722 * New targets supported
5724 AMD 29k family via UDI a29k-amd-udi or udi29k
5726 * New file formats supported
5728 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5729 HPUX core files, and SCO 3.2v2 core files.
5733 Attaching to processes now works again; thanks for the many bug reports.
5735 We have also stomped on a bunch of core dumps caused by
5736 printf_filtered("%s") problems.
5738 We eliminated a copyright problem on the rpc and ptrace header files
5739 for VxWorks, which was discovered at the last minute during the 4.7
5740 release. You should now be able to build a VxWorks GDB.
5742 You can now interrupt gdb while an attached process is running. This
5743 will cause the attached process to stop, and give control back to GDB.
5745 We fixed problems caused by using too many file descriptors
5746 for reading symbols from object files and libraries. This was
5747 especially a problem for programs that used many (~100) shared
5750 The `step' command now only enters a subroutine if there is line number
5751 information for the subroutine. Otherwise it acts like the `next'
5752 command. Previously, `step' would enter subroutines if there was
5753 any debugging information about the routine. This avoids problems
5754 when using `cc -g1' on MIPS machines.
5756 * Internal improvements
5758 GDB's internal interfaces have been improved to make it easier to support
5759 debugging of multiple languages in the future.
5761 GDB now uses a common structure for symbol information internally.
5762 Minimal symbols (derived from linkage symbols in object files), partial
5763 symbols (from a quick scan of debug information), and full symbols
5764 contain a common subset of information, making it easier to write
5765 shared code that handles any of them.
5767 * New command line options
5769 We now accept --silent as an alias for --quiet.
5773 The memory-mapped-malloc library is now licensed under the GNU Library
5774 General Public License.
5776 *** Changes in GDB-4.7:
5778 * Host/native/target split
5780 GDB has had some major internal surgery to untangle the support for
5781 hosts and remote targets. Now, when you configure GDB for a remote
5782 target, it will no longer load in all of the support for debugging
5783 local programs on the host. When fully completed and tested, this will
5784 ensure that arbitrary host/target combinations are possible.
5786 The primary conceptual shift is to separate the non-portable code in
5787 GDB into three categories. Host specific code is required any time GDB
5788 is compiled on that host, regardless of the target. Target specific
5789 code relates to the peculiarities of the target, but can be compiled on
5790 any host. Native specific code is everything else: it can only be
5791 built when the host and target are the same system. Child process
5792 handling and core file support are two common `native' examples.
5794 GDB's use of /proc for controlling Unix child processes is now cleaner.
5795 It has been split out into a single module under the `target_ops' vector,
5796 plus two native-dependent functions for each system that uses /proc.
5798 * New hosts supported
5800 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5801 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5802 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5804 * New targets supported
5806 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5807 68030 and CPU32 m68030-*-*, m68332-*-*
5809 * New native hosts supported
5811 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5812 (386bsd is not well tested yet)
5813 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5815 * New file formats supported
5817 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5818 supports reading of `a.out.adobe' object files, which are an a.out
5819 format extended with minimal information about multiple sections.
5823 `show copying' is the same as the old `info copying'.
5824 `show warranty' is the same as `info warrantee'.
5825 These were renamed for consistency. The old commands continue to work.
5827 `info handle' is a new alias for `info signals'.
5829 You can now define pre-command hooks, which attach arbitrary command
5830 scripts to any command. The commands in the hook will be executed
5831 prior to the user's command. You can also create a hook which will be
5832 executed whenever the program stops. See gdb.texinfo.
5836 We now deal with Cfront style name mangling, and can even extract type
5837 info from mangled symbols. GDB can automatically figure out which
5838 symbol mangling style your C++ compiler uses.
5840 Calling of methods and virtual functions has been improved as well.
5844 The crash that occured when debugging Sun Ansi-C compiled binaries is
5845 fixed. This was due to mishandling of the extra N_SO stabs output
5848 We also finally got Ultrix 4.2 running in house, and fixed core file
5849 support, with help from a dozen people on the net.
5851 John M. Farrell discovered that the reason that single-stepping was so
5852 slow on all of the Mips based platforms (primarily SGI and DEC) was
5853 that we were trying to demangle and lookup a symbol used for internal
5854 purposes on every instruction that was being stepped through. Changing
5855 the name of that symbol so that it couldn't be mistaken for a C++
5856 mangled symbol sped things up a great deal.
5858 Rich Pixley sped up symbol lookups in general by getting much smarter
5859 about when C++ symbol mangling is necessary. This should make symbol
5860 completion (TAB on the command line) much faster. It's not as fast as
5861 we'd like, but it's significantly faster than gdb-4.6.
5865 A new user controllable variable 'call_scratch_address' can
5866 specify the location of a scratch area to be used when GDB
5867 calls a function in the target. This is necessary because the
5868 usual method of putting the scratch area on the stack does not work
5869 in systems that have separate instruction and data spaces.
5871 We integrated changes to support the 29k UDI (Universal Debugger
5872 Interface), but discovered at the last minute that we didn't have all
5873 of the appropriate copyright paperwork. We are working with AMD to
5874 resolve this, and hope to have it available soon.
5878 We have sped up the remote serial line protocol, especially for targets
5879 with lots of registers. It now supports a new `expedited status' ('T')
5880 message which can be used in place of the existing 'S' status message.
5881 This allows the remote stub to send only the registers that GDB
5882 needs to make a quick decision about single-stepping or conditional
5883 breakpoints, eliminating the need to fetch the entire register set for
5884 each instruction being stepped through.
5886 The GDB remote serial protocol now implements a write-through cache for
5887 registers, only re-reading the registers if the target has run.
5889 There is also a new remote serial stub for SPARC processors. You can
5890 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5891 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5892 processor with a serial port.
5896 Configure.in files have become much easier to read and modify. A new
5897 `table driven' format makes it more obvious what configurations are
5898 supported, and what files each one uses.
5902 There is a new opcodes library which will eventually contain all of the
5903 disassembly routines and opcode tables. At present, it only contains
5904 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5905 disassembler (binutils/objdump) to share these routines.
5907 The libiberty library is now copylefted under the GNU Library General
5908 Public License. This allows more liberal use, and was done so libg++
5909 can use it. This makes no difference to GDB, since the Library License
5910 grants all the rights from the General Public License.
5914 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5915 reference to the stabs symbol info used by the debugger. It is (as far
5916 as we know) the only published document on this fascinating topic. We
5917 encourage you to read it, compare it to the stabs information on your
5918 system, and send improvements on the document in general (to
5919 bug-gdb@prep.ai.mit.edu).
5921 And, of course, many bugs have been fixed.
5924 *** Changes in GDB-4.6:
5926 * Better support for C++ function names
5928 GDB now accepts as input the "demangled form" of C++ overloaded function
5929 names and member function names, and can do command completion on such names
5930 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5931 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5932 Make use of command completion, it is your friend.
5934 GDB also now accepts a variety of C++ mangled symbol formats. They are
5935 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5936 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5937 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5938 for the list of formats.
5940 * G++ symbol mangling problem
5942 Recent versions of gcc have a bug in how they emit debugging information for
5943 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5944 directory) can be applied to gcc to fix the problem. Alternatively, if you
5945 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5946 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5947 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5950 * New 'maintenance' command
5952 All of the commands related to hacking GDB internals have been moved out of
5953 the main command set, and now live behind the 'maintenance' command. This
5954 can also be abbreviated as 'mt'. The following changes were made:
5956 dump-me -> maintenance dump-me
5957 info all-breakpoints -> maintenance info breakpoints
5958 printmsyms -> maintenance print msyms
5959 printobjfiles -> maintenance print objfiles
5960 printpsyms -> maintenance print psymbols
5961 printsyms -> maintenance print symbols
5963 The following commands are new:
5965 maintenance demangle Call internal GDB demangler routine to
5966 demangle a C++ link name and prints the result.
5967 maintenance print type Print a type chain for a given symbol
5969 * Change to .gdbinit file processing
5971 We now read the $HOME/.gdbinit file before processing the argv arguments
5972 (e.g. reading symbol files or core files). This allows global parameters to
5973 be set, which will apply during the symbol reading. The ./.gdbinit is still
5974 read after argv processing.
5976 * New hosts supported
5978 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5980 GNU/Linux support i386-unknown-linux or linux
5982 We are also including code to support the HP/PA running BSD and HPUX. This
5983 is almost guaranteed not to work, as we didn't have time to test or build it
5984 for this release. We are including it so that the more adventurous (or
5985 masochistic) of you can play with it. We also had major problems with the
5986 fact that the compiler that we got from HP doesn't support the -g option.
5989 * New targets supported
5991 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5993 * More smarts about finding #include files
5995 GDB now remembers the compilation directory for all include files, and for
5996 all files from which C is generated (like yacc and lex sources). This
5997 greatly improves GDB's ability to find yacc/lex sources, and include files,
5998 especially if you are debugging your program from a directory different from
5999 the one that contains your sources.
6001 We also fixed a bug which caused difficulty with listing and setting
6002 breakpoints in include files which contain C code. (In the past, you had to
6003 try twice in order to list an include file that you hadn't looked at before.)
6005 * Interesting infernals change
6007 GDB now deals with arbitrary numbers of sections, where the symbols for each
6008 section must be relocated relative to that section's landing place in the
6009 target's address space. This work was needed to support ELF with embedded
6010 stabs used by Solaris-2.0.
6012 * Bug fixes (of course!)
6014 There have been loads of fixes for the following things:
6015 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6016 i960, stabs, DOS(GO32), procfs, etc...
6018 See the ChangeLog for details.
6020 *** Changes in GDB-4.5:
6022 * New machines supported (host and target)
6024 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6026 SGI Irix-4.x mips-sgi-irix4 or iris4
6028 * New malloc package
6030 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6031 Mmalloc is capable of handling mutiple heaps of memory. It is also
6032 capable of saving a heap to a file, and then mapping it back in later.
6033 This can be used to greatly speedup the startup of GDB by using a
6034 pre-parsed symbol table which lives in a mmalloc managed heap. For
6035 more details, please read mmalloc/mmalloc.texi.
6039 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6040 'help info proc' for details.
6042 * MIPS ecoff symbol table format
6044 The code that reads MIPS symbol table format is now supported on all hosts.
6045 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6048 * File name changes for MS-DOS
6050 Many files in the config directories have been renamed to make it easier to
6051 support GDB on MS-DOSe systems (which have very restrictive file name
6052 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6053 environment) is close to working but has some remaining problems. Note
6054 that debugging of DOS programs is not supported, due to limitations
6055 in the ``operating system'', but it can be used to host cross-debugging.
6057 * Cross byte order fixes
6059 Many fixes have been made to support cross debugging of Sparc and MIPS
6060 targets from hosts whose byte order differs.
6062 * New -mapped and -readnow options
6064 If memory-mapped files are available on your system through the 'mmap'
6065 system call, you can use the -mapped option on the `file' or
6066 `symbol-file' commands to cause GDB to write the symbols from your
6067 program into a reusable file. If the program you are debugging is
6068 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6069 Future GDB debugging sessions will notice the presence of this file,
6070 and will quickly map in symbol information from it, rather than reading
6071 the symbol table from the executable program. Using the '-mapped'
6072 option in a GDB `file' or `symbol-file' command has the same effect as
6073 starting GDB with the '-mapped' command-line option.
6075 You can cause GDB to read the entire symbol table immediately by using
6076 the '-readnow' option with any of the commands that load symbol table
6077 information (or on the GDB command line). This makes the command
6078 slower, but makes future operations faster.
6080 The -mapped and -readnow options are typically combined in order to
6081 build a `fred.syms' file that contains complete symbol information.
6082 A simple GDB invocation to do nothing but build a `.syms' file for future
6085 gdb -batch -nx -mapped -readnow programname
6087 The `.syms' file is specific to the host machine on which GDB is run.
6088 It holds an exact image of GDB's internal symbol table. It cannot be
6089 shared across multiple host platforms.
6091 * longjmp() handling
6093 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6094 siglongjmp() without losing control. This feature has not yet been ported to
6095 all systems. It currently works on many 386 platforms, all MIPS-based
6096 platforms (SGI, DECstation, etc), and Sun3/4.
6100 Preliminary work has been put in to support the new Solaris OS from Sun. At
6101 this time, it can control and debug processes, but it is not capable of
6106 As always, many many bug fixes. The major areas were with g++, and mipsread.
6107 People using the MIPS-based platforms should experience fewer mysterious
6108 crashes and trashed symbol tables.
6110 *** Changes in GDB-4.4:
6112 * New machines supported (host and target)
6114 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6116 BSD Reno on Vax vax-dec-bsd
6117 Ultrix on Vax vax-dec-ultrix
6119 * New machines supported (target)
6121 AMD 29000 embedded, using EBMON a29k-none-none
6125 GDB continues to improve its handling of C++. `References' work better.
6126 The demangler has also been improved, and now deals with symbols mangled as
6127 per the Annotated C++ Reference Guide.
6129 GDB also now handles `stabs' symbol information embedded in MIPS
6130 `ecoff' symbol tables. Since the ecoff format was not easily
6131 extensible to handle new languages such as C++, this appeared to be a
6132 good way to put C++ debugging info into MIPS binaries. This option
6133 will be supported in the GNU C compiler, version 2, when it is
6136 * New features for SVR4
6138 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6139 shared libraries. Debugging dynamically linked programs should present
6140 only minor differences from debugging statically linked programs.
6142 The `info proc' command will print out information about any process
6143 on an SVR4 system (including the one you are debugging). At the moment,
6144 it prints the address mappings of the process.
6146 If you bring up GDB on another SVR4 system, please send mail to
6147 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6149 * Better dynamic linking support in SunOS
6151 Reading symbols from shared libraries which contain debugging symbols
6152 now works properly. However, there remain issues such as automatic
6153 skipping of `transfer vector' code during function calls, which
6154 make it harder to debug code in a shared library, than to debug the
6155 same code linked statically.
6159 GDB is now using the latest `getopt' routines from the FSF. This
6160 version accepts the -- prefix for options with long names. GDB will
6161 continue to accept the old forms (-option and +option) as well.
6162 Various single letter abbreviations for options have been explicity
6163 added to the option table so that they won't get overshadowed in the
6164 future by other options that begin with the same letter.
6168 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6169 Many assorted bugs have been handled. Many more remain to be handled.
6170 See the various ChangeLog files (primarily in gdb and bfd) for details.
6173 *** Changes in GDB-4.3:
6175 * New machines supported (host and target)
6177 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6178 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6179 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6181 * Almost SCO Unix support
6183 We had hoped to support:
6184 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6185 (except for core file support), but we discovered very late in the release
6186 that it has problems with process groups that render gdb unusable. Sorry
6187 about that. I encourage people to fix it and post the fixes.
6189 * Preliminary ELF and DWARF support
6191 GDB can read ELF object files on System V Release 4, and can handle
6192 debugging records for C, in DWARF format, in ELF files. This support
6193 is preliminary. If you bring up GDB on another SVR4 system, please
6194 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6199 GDB now uses the latest `readline' library. One user-visible change
6200 is that two tabs will list possible command completions, which previously
6201 required typing M-? (meta-question mark, or ESC ?).
6205 The `stepi' bug that many of you noticed has been squashed.
6206 Many bugs in C++ have been handled. Many more remain to be handled.
6207 See the various ChangeLog files (primarily in gdb and bfd) for details.
6209 * State of the MIPS world (in case you wondered):
6211 GDB can understand the symbol tables emitted by the compilers
6212 supplied by most vendors of MIPS-based machines, including DEC. These
6213 symbol tables are in a format that essentially nobody else uses.
6215 Some versions of gcc come with an assembler post-processor called
6216 mips-tfile. This program is required if you want to do source-level
6217 debugging of gcc-compiled programs. I believe FSF does not ship
6218 mips-tfile with gcc version 1, but it will eventually come with gcc
6221 Debugging of g++ output remains a problem. g++ version 1.xx does not
6222 really support it at all. (If you're lucky, you should be able to get
6223 line numbers and stack traces to work, but no parameters or local
6224 variables.) With some work it should be possible to improve the
6227 When gcc version 2 is released, you will have somewhat better luck.
6228 However, even then you will get confusing results for inheritance and
6231 We will eventually provide full debugging of g++ output on
6232 DECstations. This will probably involve some kind of stabs-in-ecoff
6233 encapulation, but the details have not been worked out yet.
6236 *** Changes in GDB-4.2:
6238 * Improved configuration
6240 Only one copy of `configure' exists now, and it is not self-modifying.
6241 Porting BFD is simpler.
6245 The `step' and `next' commands now only stop at the first instruction
6246 of a source line. This prevents the multiple stops that used to occur
6247 in switch statements, for-loops, etc. `Step' continues to stop if a
6248 function that has debugging information is called within the line.
6252 Lots of small bugs fixed. More remain.
6254 * New host supported (not target)
6256 Intel 386 PC clone running Mach i386-none-mach
6259 *** Changes in GDB-4.1:
6261 * Multiple source language support
6263 GDB now has internal scaffolding to handle several source languages.
6264 It determines the type of each source file from its filename extension,
6265 and will switch expression parsing and number formatting to match the
6266 language of the function in the currently selected stack frame.
6267 You can also specifically set the language to be used, with
6268 `set language c' or `set language modula-2'.
6272 GDB now has preliminary support for the GNU Modula-2 compiler,
6273 currently under development at the State University of New York at
6274 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6275 continue through the fall of 1991 and into 1992.
6277 Other Modula-2 compilers are currently not supported, and attempting to
6278 debug programs compiled with them will likely result in an error as the
6279 symbol table is read. Feel free to work on it, though!
6281 There are hooks in GDB for strict type checking and range checking,
6282 in the `Modula-2 philosophy', but they do not currently work.
6286 GDB can now write to executable and core files (e.g. patch
6287 a variable's value). You must turn this switch on, specify
6288 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6289 by assigning a new value to a variable. Modifications take
6292 * Automatic SunOS shared library reading
6294 When you run your program, GDB automatically determines where its
6295 shared libraries (if any) have been loaded, and reads their symbols.
6296 The `share' command is no longer needed. This also works when
6297 examining core files.
6301 You can specify the number of lines that the `list' command shows.
6304 * New machines supported (host and target)
6306 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6307 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6308 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6310 * New hosts supported (not targets)
6312 IBM RT/PC: romp-ibm-aix or rtpc
6314 * New targets supported (not hosts)
6316 AMD 29000 embedded with COFF a29k-none-coff
6317 AMD 29000 embedded with a.out a29k-none-aout
6318 Ultracomputer remote kernel debug a29k-nyu-kern
6320 * New remote interfaces
6326 *** Changes in GDB-4.0:
6330 Wide output is wrapped at good places to make the output more readable.
6332 Gdb now supports cross-debugging from a host machine of one type to a
6333 target machine of another type. Communication with the target system
6334 is over serial lines. The ``target'' command handles connecting to the
6335 remote system; the ``load'' command will download a program into the
6336 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6337 also supports debugging of realtime processes running under VxWorks,
6338 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6339 stub on the target system.
6341 New CPUs supported include the AMD 29000 and Intel 960.
6343 GDB now reads object files and symbol tables via a ``binary file''
6344 library, which allows a single copy of GDB to debug programs of multiple
6345 object file types such as a.out and coff.
6347 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6348 refcard.dvi and refcard.ps are available to format it).
6351 * Control-Variable user interface simplified
6353 All variables that control the operation of the debugger can be set
6354 by the ``set'' command, and displayed by the ``show'' command.
6356 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6357 ``Show prompt'' produces the response:
6358 Gdb's prompt is new-gdb=>.
6360 What follows are the NEW set commands. The command ``help set'' will
6361 print a complete list of old and new set commands. ``help set FOO''
6362 will give a longer description of the variable FOO. ``show'' will show
6363 all of the variable descriptions and their current settings.
6365 confirm on/off: Enables warning questions for operations that are
6366 hard to recover from, e.g. rerunning the program while
6367 it is already running. Default is ON.
6369 editing on/off: Enables EMACS style command line editing
6370 of input. Previous lines can be recalled with
6371 control-P, the current line can be edited with control-B,
6372 you can search for commands with control-R, etc.
6375 history filename NAME: NAME is where the gdb command history
6376 will be stored. The default is .gdb_history,
6377 or the value of the environment variable
6380 history size N: The size, in commands, of the command history. The
6381 default is 256, or the value of the environment variable
6384 history save on/off: If this value is set to ON, the history file will
6385 be saved after exiting gdb. If set to OFF, the
6386 file will not be saved. The default is OFF.
6388 history expansion on/off: If this value is set to ON, then csh-like
6389 history expansion will be performed on
6390 command line input. The default is OFF.
6392 radix N: Sets the default radix for input and output. It can be set
6393 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6394 in the current radix, so "set radix 10" is always a no-op.
6396 height N: This integer value is the number of lines on a page. Default
6397 is 24, the current `stty rows'' setting, or the ``li#''
6398 setting from the termcap entry matching the environment
6401 width N: This integer value is the number of characters on a line.
6402 Default is 80, the current `stty cols'' setting, or the ``co#''
6403 setting from the termcap entry matching the environment
6406 Note: ``set screensize'' is obsolete. Use ``set height'' and
6407 ``set width'' instead.
6409 print address on/off: Print memory addresses in various command displays,
6410 such as stack traces and structure values. Gdb looks
6411 more ``symbolic'' if you turn this off; it looks more
6412 ``machine level'' with it on. Default is ON.
6414 print array on/off: Prettyprint arrays. New convenient format! Default
6417 print demangle on/off: Print C++ symbols in "source" form if on,
6420 print asm-demangle on/off: Same, for assembler level printouts
6423 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6426 * Support for Epoch Environment.
6428 The epoch environment is a version of Emacs v18 with windowing. One
6429 new command, ``inspect'', is identical to ``print'', except that if you
6430 are running in the epoch environment, the value is printed in its own
6434 * Support for Shared Libraries
6436 GDB can now debug programs and core files that use SunOS shared libraries.
6437 Symbols from a shared library cannot be referenced
6438 before the shared library has been linked with the program (this
6439 happens after you type ``run'' and before the function main() is entered).
6440 At any time after this linking (including when examining core files
6441 from dynamically linked programs), gdb reads the symbols from each
6442 shared library when you type the ``sharedlibrary'' command.
6443 It can be abbreviated ``share''.
6445 sharedlibrary REGEXP: Load shared object library symbols for files
6446 matching a unix regular expression. No argument
6447 indicates to load symbols for all shared libraries.
6449 info sharedlibrary: Status of loaded shared libraries.
6454 A watchpoint stops execution of a program whenever the value of an
6455 expression changes. Checking for this slows down execution
6456 tremendously whenever you are in the scope of the expression, but is
6457 quite useful for catching tough ``bit-spreader'' or pointer misuse
6458 problems. Some machines such as the 386 have hardware for doing this
6459 more quickly, and future versions of gdb will use this hardware.
6461 watch EXP: Set a watchpoint (breakpoint) for an expression.
6463 info watchpoints: Information about your watchpoints.
6465 delete N: Deletes watchpoint number N (same as breakpoints).
6466 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6467 enable N: Re-enables watchpoint number N (same as breakpoints).
6470 * C++ multiple inheritance
6472 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6475 * C++ exception handling
6477 Gdb now supports limited C++ exception handling. Besides the existing
6478 ability to breakpoint on an exception handler, gdb can breakpoint on
6479 the raising of an exception (before the stack is peeled back to the
6482 catch FOO: If there is a FOO exception handler in the dynamic scope,
6483 set a breakpoint to catch exceptions which may be raised there.
6484 Multiple exceptions (``catch foo bar baz'') may be caught.
6486 info catch: Lists all exceptions which may be caught in the
6487 current stack frame.
6490 * Minor command changes
6492 The command ``call func (arg, arg, ...)'' now acts like the print
6493 command, except it does not print or save a value if the function's result
6494 is void. This is similar to dbx usage.
6496 The ``up'' and ``down'' commands now always print the frame they end up
6497 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6498 frames without printing.
6500 * New directory command
6502 'dir' now adds directories to the FRONT of the source search path.
6503 The path starts off empty. Source files that contain debug information
6504 about the directory in which they were compiled can be found even
6505 with an empty path; Sun CC and GCC include this information. If GDB can't
6506 find your source file in the current directory, type "dir .".
6508 * Configuring GDB for compilation
6510 For normal use, type ``./configure host''. See README or gdb.texinfo
6513 GDB now handles cross debugging. If you are remotely debugging between
6514 two different machines, type ``./configure host -target=targ''.
6515 Host is the machine where GDB will run; targ is the machine
6516 where the program that you are debugging will run.