1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.11
6 * Fortran: Support structures with fields of dynamic types and
7 arrays of dynamic types.
9 * GDB now supports multibit bitfields and enums in target register
12 * New Python-based convenience function $_as_string(val), which returns
13 the textual representation of a value. This function is especially
14 useful to obtain the text label of an enum value.
16 * Intel MPX bound violation handling.
18 Segmentation faults caused by a Intel MPX boundary violation
19 now display the kind of violation (upper or lower), the memory
20 address accessed and the memory bounds, along with the usual
21 signal received and code location.
25 Program received signal SIGSEGV, Segmentation fault
26 Upper bound violation while accessing address 0x7fffffffc3b3
27 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
28 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
30 * Rust language support.
31 GDB now supports debugging programs written in the Rust programming
32 language. See https://www.rust-lang.org/ for more information about
38 skip -gfile file-glob-pattern
39 skip -function function
40 skip -rfunction regular-expression
41 A generalized form of the skip command, with new support for
42 glob-style file names and regular expressions for function names.
43 Additionally, a file spec and a function spec may now be combined.
45 maint info line-table REGEXP
46 Display the contents of GDB's internal line table data struture.
49 Run any GDB unit tests that were compiled in.
51 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
52 was added in GDBserver, including JIT compiling fast tracepoint's
53 conditional expression bytecode into native code.
55 * Support for various remote target protocols and ROM monitors has
58 target m32rsdi Remote M32R debugging over SDI
59 target mips MIPS remote debugging protocol
60 target pmon PMON ROM monitor
61 target ddb NEC's DDB variant of PMON for Vr4300
62 target rockhopper NEC RockHopper variant of PMON
63 target lsi LSI variant of PMO
65 * Support for tracepoints and fast tracepoints on powerpc-linux,
66 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
67 including JIT compiling fast tracepoint's conditional expression
68 bytecode into native code.
70 *** Changes in GDB 7.11
72 * GDB now supports debugging kernel-based threads on FreeBSD.
74 * Per-inferior thread numbers
76 Thread numbers are now per inferior instead of global. If you're
77 debugging multiple inferiors, GDB displays thread IDs using a
78 qualified INF_NUM.THR_NUM form. For example:
82 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
83 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
84 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
85 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
87 As consequence, thread numbers as visible in the $_thread
88 convenience variable and in Python's InferiorThread.num attribute
89 are no longer unique between inferiors.
91 GDB now maintains a second thread ID per thread, referred to as the
92 global thread ID, which is the new equivalent of thread numbers in
93 previous releases. See also $_gthread below.
95 For backwards compatibility, MI's thread IDs always refer to global
98 * Commands that accept thread IDs now accept the qualified
99 INF_NUM.THR_NUM form as well. For example:
102 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
105 * In commands that accept a list of thread IDs, you can now refer to
106 all threads of an inferior using a star wildcard. GDB accepts
107 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
108 refer to all threads of the current inferior. For example, "info
111 * You can use "info threads -gid" to display the global thread ID of
114 * The new convenience variable $_gthread holds the global number of
117 * The new convenience variable $_inferior holds the number of the
120 * GDB now displays the ID and name of the thread that hit a breakpoint
121 or received a signal, if your program is multi-threaded. For
124 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
125 Thread 1 "main" received signal SIGINT, Interrupt.
127 * Record btrace now supports non-stop mode.
129 * Support for tracepoints on aarch64-linux was added in GDBserver.
131 * The 'record instruction-history' command now indicates speculative execution
132 when using the Intel Processor Trace recording format.
134 * GDB now allows users to specify explicit locations, bypassing
135 the linespec parser. This feature is also available to GDB/MI
138 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
139 GDB now is able to debug both AArch64 applications and ARM applications
142 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
143 including JIT compiling fast tracepoint's conditional expression bytecode
146 * GDB now supports displaced stepping on AArch64 GNU/Linux.
148 * "info threads", "info inferiors", "info display", "info checkpoints"
149 and "maint info program-spaces" now list the corresponding items in
150 ascending ID order, for consistency with all other "info" commands.
152 * In Ada, the overloads selection menu has been enhanced to display the
153 parameter types and the return types for the matching overloaded subprograms.
157 maint set target-non-stop (on|off|auto)
158 maint show target-non-stop
159 Control whether GDB targets always operate in non-stop mode even if
160 "set non-stop" is "off". The default is "auto", meaning non-stop
161 mode is enabled if supported by the target.
163 maint set bfd-sharing
164 maint show bfd-sharing
165 Control the reuse of bfd objects.
169 Control display of debugging info regarding bfd caching.
173 Control display of debugging info regarding FreeBSD threads.
175 set remote multiprocess-extensions-packet
176 show remote multiprocess-extensions-packet
177 Set/show the use of the remote protocol multiprocess extensions.
179 set remote thread-events
180 show remote thread-events
181 Set/show the use of thread create/exit events.
183 set ada print-signatures on|off
184 show ada print-signatures"
185 Control whether parameter types and return types are displayed in overloads
186 selection menus. It is activaled (@code{on}) by default.
190 Controls the maximum size of memory, in bytes, that GDB will
191 allocate for value contents. Prevents incorrect programs from
192 causing GDB to allocate overly large buffers. Default is 64k.
194 * The "disassemble" command accepts a new modifier: /s.
195 It prints mixed source+disassembly like /m with two differences:
196 - disassembled instructions are now printed in program order, and
197 - and source for all relevant files is now printed.
198 The "/m" option is now considered deprecated: its "source-centric"
199 output hasn't proved useful in practice.
201 * The "record instruction-history" command accepts a new modifier: /s.
202 It behaves exactly like /m and prints mixed source+disassembly.
204 * The "set scheduler-locking" command supports a new mode "replay".
205 It behaves like "off" in record mode and like "on" in replay mode.
207 * Support for various ROM monitors has been removed:
209 target dbug dBUG ROM monitor for Motorola ColdFire
210 target picobug Motorola picobug monitor
211 target dink32 DINK32 ROM monitor for PowerPC
212 target m32r Renesas M32R/D ROM monitor
213 target mon2000 mon2000 ROM monitor
214 target ppcbug PPCBUG ROM monitor for PowerPC
216 * Support for reading/writing memory and extracting values on architectures
217 whose memory is addressable in units of any integral multiple of 8 bits.
222 Indicates that an exec system call was executed.
224 exec-events feature in qSupported
225 The qSupported packet allows GDB to request support for exec
226 events using the new 'gdbfeature' exec-event, and the qSupported
227 response can contain the corresponding 'stubfeature'. Set and
228 show commands can be used to display whether these features are enabled.
231 Equivalent to interrupting with the ^C character, but works in
234 thread created stop reason (T05 create:...)
235 Indicates that the thread was just created and is stopped at entry.
237 thread exit stop reply (w exitcode;tid)
238 Indicates that the thread has terminated.
241 Enables/disables thread create and exit event reporting. For
242 example, this is used in non-stop mode when GDB stops a set of
243 threads and synchronously waits for the their corresponding stop
244 replies. Without exit events, if one of the threads exits, GDB
245 would hang forever not knowing that it should no longer expect a
246 stop for that same thread.
249 Indicates that there are no resumed threads left in the target (all
250 threads are stopped). The remote stub reports support for this stop
251 reply to GDB's qSupported query.
254 Enables/disables catching syscalls from the inferior process.
255 The remote stub reports support for this packet to GDB's qSupported query.
257 syscall_entry stop reason
258 Indicates that a syscall was just called.
260 syscall_return stop reason
261 Indicates that a syscall just returned.
263 * Extended-remote exec events
265 ** GDB now has support for exec events on extended-remote Linux targets.
266 For such targets with Linux kernels 2.5.46 and later, this enables
267 follow-exec-mode and exec catchpoints.
269 set remote exec-event-feature-packet
270 show remote exec-event-feature-packet
271 Set/show the use of the remote exec event feature.
273 * Thread names in remote protocol
275 The reply to qXfer:threads:read may now include a name attribute for each
278 * Target remote mode fork and exec events
280 ** GDB now has support for fork and exec events on target remote mode
281 Linux targets. For such targets with Linux kernels 2.5.46 and later,
282 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
283 fork and exec catchpoints.
285 * Remote syscall events
287 ** GDB now has support for catch syscall on remote Linux targets,
288 currently enabled on x86/x86_64 architectures.
290 set remote catch-syscall-packet
291 show remote catch-syscall-packet
292 Set/show the use of the remote catch syscall feature.
296 ** The -var-set-format command now accepts the zero-hexadecimal
297 format. It outputs data in hexadecimal format with zero-padding on the
302 ** gdb.InferiorThread objects have a new attribute "global_num",
303 which refers to the thread's global thread ID. The existing
304 "num" attribute now refers to the thread's per-inferior number.
305 See "Per-inferior thread numbers" above.
306 ** gdb.InferiorThread objects have a new attribute "inferior", which
307 is the Inferior object the thread belongs to.
309 *** Changes in GDB 7.10
311 * Support for process record-replay and reverse debugging on aarch64*-linux*
312 targets has been added. GDB now supports recording of A64 instruction set
313 including advance SIMD instructions.
315 * Support for Sun's version of the "stabs" debug file format has been removed.
317 * GDB now honors the content of the file /proc/PID/coredump_filter
318 (PID is the process ID) on GNU/Linux systems. This file can be used
319 to specify the types of memory mappings that will be included in a
320 corefile. For more information, please refer to the manual page of
321 "core(5)". GDB also has a new command: "set use-coredump-filter
322 on|off". It allows to set whether GDB will read the content of the
323 /proc/PID/coredump_filter file when generating a corefile.
325 * The "info os" command on GNU/Linux can now display information on
327 "info os cpus" Listing of all cpus/cores on the system
329 * GDB has two new commands: "set serial parity odd|even|none" and
330 "show serial parity". These allows to set or show parity for the
333 * The "info source" command now displays the producer string if it was
334 present in the debug info. This typically includes the compiler version
335 and may include things like its command line arguments.
337 * The "info dll", an alias of the "info sharedlibrary" command,
338 is now available on all platforms.
340 * Directory names supplied to the "set sysroot" commands may be
341 prefixed with "target:" to tell GDB to access shared libraries from
342 the target system, be it local or remote. This replaces the prefix
343 "remote:". The default sysroot has been changed from "" to
344 "target:". "remote:" is automatically converted to "target:" for
345 backward compatibility.
347 * The system root specified by "set sysroot" will be prepended to the
348 filename of the main executable (if reported to GDB as absolute by
349 the operating system) when starting processes remotely, and when
350 attaching to already-running local or remote processes.
352 * GDB now supports automatic location and retrieval of executable
353 files from remote targets. Remote debugging can now be initiated
354 using only a "target remote" or "target extended-remote" command
355 (no "set sysroot" or "file" commands are required). See "New remote
358 * The "dump" command now supports verilog hex format.
360 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
362 * On GNU/Linux, GDB and gdbserver are now able to access executable
363 and shared library files without a "set sysroot" command when
364 attaching to processes running in different mount namespaces from
365 the debugger. This makes it possible to attach to processes in
366 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
367 See "New remote packets" below.
369 * The "tui reg" command now provides completion for all of the
370 available register groups, including target specific groups.
372 * The HISTSIZE environment variable is no longer read when determining
373 the size of GDB's command history. GDB now instead reads the dedicated
374 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
375 disables truncation of command history. Non-numeric values of GDBHISTSIZE
380 ** Memory ports can now be unbuffered.
384 ** gdb.Objfile objects have a new attribute "username",
385 which is the name of the objfile as specified by the user,
386 without, for example, resolving symlinks.
387 ** You can now write frame unwinders in Python.
388 ** gdb.Type objects have a new method "optimized_out",
389 returning optimized out gdb.Value instance of this type.
390 ** gdb.Value objects have new methods "reference_value" and
391 "const_value" which return a reference to the value and a
392 "const" version of the value respectively.
396 maint print symbol-cache
397 Print the contents of the symbol cache.
399 maint print symbol-cache-statistics
400 Print statistics of symbol cache usage.
402 maint flush-symbol-cache
403 Flush the contents of the symbol cache.
407 Start branch trace recording using Branch Trace Store (BTS) format.
410 Evaluate expression by using the compiler and print result.
414 Explicit commands for enabling and disabling tui mode.
417 set mpx bound on i386 and amd64
418 Support for bound table investigation on Intel MPX enabled applications.
422 Start branch trace recording using Intel Processor Trace format.
425 Print information about branch tracing internals.
427 maint btrace packet-history
428 Print the raw branch tracing data.
430 maint btrace clear-packet-history
431 Discard the stored raw branch tracing data.
434 Discard all branch tracing data. It will be fetched and processed
435 anew by the next "record" command.
440 Renamed from "set debug dwarf2-die".
442 Renamed from "show debug dwarf2-die".
445 Renamed from "set debug dwarf2-read".
446 show debug dwarf-read
447 Renamed from "show debug dwarf2-read".
449 maint set dwarf always-disassemble
450 Renamed from "maint set dwarf2 always-disassemble".
451 maint show dwarf always-disassemble
452 Renamed from "maint show dwarf2 always-disassemble".
454 maint set dwarf max-cache-age
455 Renamed from "maint set dwarf2 max-cache-age".
456 maint show dwarf max-cache-age
457 Renamed from "maint show dwarf2 max-cache-age".
460 show debug dwarf-line
461 Control display of debugging info regarding DWARF line processing.
465 Set the maximum number of candidates to be considered during
466 completion. The default value is 200. This limit allows GDB
467 to avoid generating large completion lists, the computation of
468 which can cause the debugger to become temporarily unresponsive.
470 set history remove-duplicates
471 show history remove-duplicates
472 Control the removal of duplicate history entries.
474 maint set symbol-cache-size
475 maint show symbol-cache-size
476 Control the size of the symbol cache.
478 set|show record btrace bts buffer-size
479 Set and show the size of the ring buffer used for branch tracing in
481 The obtained size may differ from the requested size. Use "info
482 record" to see the obtained buffer size.
484 set debug linux-namespaces
485 show debug linux-namespaces
486 Control display of debugging info regarding Linux namespaces.
488 set|show record btrace pt buffer-size
489 Set and show the size of the ring buffer used for branch tracing in
490 Intel Processor Trace format.
491 The obtained size may differ from the requested size. Use "info
492 record" to see the obtained buffer size.
494 maint set|show btrace pt skip-pad
495 Set and show whether PAD packets are skipped when computing the
498 * The command 'thread apply all' can now support new option '-ascending'
499 to call its specified command for all threads in ascending order.
501 * Python/Guile scripting
503 ** GDB now supports auto-loading of Python/Guile scripts contained in the
504 special section named `.debug_gdb_scripts'.
508 qXfer:btrace-conf:read
509 Return the branch trace configuration for the current thread.
511 Qbtrace-conf:bts:size
512 Set the requested ring buffer size for branch tracing in BTS format.
515 Enable Intel Procesor Trace-based branch tracing for the current
516 process. The remote stub reports support for this packet to GDB's
520 Set the requested ring buffer size for branch tracing in Intel Processor
524 Indicates a memory breakpoint instruction was executed, irrespective
525 of whether it was GDB that planted the breakpoint or the breakpoint
526 is hardcoded in the program. This is required for correct non-stop
530 Indicates the target stopped for a hardware breakpoint. This is
531 required for correct non-stop mode operation.
534 Return information about files on the remote system.
537 Return the full absolute name of the file that was executed to
538 create a process running on the remote system.
541 Select the filesystem on which vFile: operations with filename
542 arguments will operate. This is required for GDB to be able to
543 access files on remote targets where the remote stub does not
544 share a common filesystem with the inferior(s).
547 Indicates that a fork system call was executed.
550 Indicates that a vfork system call was executed.
552 vforkdone stop reason
553 Indicates that a vfork child of the specified process has executed
554 an exec or exit, allowing the vfork parent to resume execution.
556 fork-events and vfork-events features in qSupported
557 The qSupported packet allows GDB to request support for fork and
558 vfork events using new 'gdbfeatures' fork-events and vfork-events,
559 and the qSupported response can contain the corresponding
560 'stubfeatures'. Set and show commands can be used to display
561 whether these features are enabled.
563 * Extended-remote fork events
565 ** GDB now has support for fork events on extended-remote Linux
566 targets. For targets with Linux kernels 2.5.60 and later, this
567 enables follow-fork-mode and detach-on-fork for both fork and
568 vfork, as well as fork and vfork catchpoints.
570 * The info record command now shows the recording format and the
571 branch tracing configuration for the current thread when using
572 the btrace record target.
573 For the BTS format, it shows the ring buffer size.
575 * GDB now has support for DTrace USDT (Userland Static Defined
576 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
578 * GDB now supports access to vector registers on S/390 GNU/Linux
581 * Removed command line options
583 -xdb HP-UX XDB compatibility mode.
585 * Removed targets and native configurations
587 HP/PA running HP-UX hppa*-*-hpux*
588 Itanium running HP-UX ia64-*-hpux*
590 * New configure options
593 This configure option allows the user to build GDB with support for
594 Intel Processor Trace (default: auto). This requires libipt.
596 --with-libipt-prefix=PATH
597 Specify the path to the version of libipt that GDB should use.
598 $PATH/include should contain the intel-pt.h header and
599 $PATH/lib should contain the libipt.so library.
601 *** Changes in GDB 7.9.1
605 ** Xmethods can now specify a result type.
607 *** Changes in GDB 7.9
609 * GDB now supports hardware watchpoints on x86 GNU Hurd.
613 ** You can now access frame registers from Python scripts.
614 ** New attribute 'producer' for gdb.Symtab objects.
615 ** gdb.Objfile objects have a new attribute "progspace",
616 which is the gdb.Progspace object of the containing program space.
617 ** gdb.Objfile objects have a new attribute "owner".
618 ** gdb.Objfile objects have a new attribute "build_id",
619 which is the build ID generated when the file was built.
620 ** gdb.Objfile objects have a new method "add_separate_debug_file".
621 ** A new event "gdb.clear_objfiles" has been added, triggered when
622 selecting a new file to debug.
623 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
624 ** New function gdb.lookup_objfile.
626 New events which are triggered when GDB modifies the state of the
629 ** gdb.events.inferior_call_pre: Function call is about to be made.
630 ** gdb.events.inferior_call_post: Function call has just been made.
631 ** gdb.events.memory_changed: A memory location has been altered.
632 ** gdb.events.register_changed: A register has been altered.
634 * New Python-based convenience functions:
636 ** $_caller_is(name [, number_of_frames])
637 ** $_caller_matches(regexp [, number_of_frames])
638 ** $_any_caller_is(name [, number_of_frames])
639 ** $_any_caller_matches(regexp [, number_of_frames])
641 * GDB now supports the compilation and injection of source code into
642 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
643 to compile the source code to object code, and if successful, inject
644 and execute that code within the current context of the inferior.
645 Currently the C language is supported. The commands used to
646 interface with this new feature are:
648 compile code [-raw|-r] [--] [source code]
649 compile file [-raw|-r] filename
653 demangle [-l language] [--] name
654 Demangle "name" in the specified language, or the current language
655 if elided. This command is renamed from the "maint demangle" command.
656 The latter is kept as a no-op to avoid "maint demangle" being interpreted
657 as "maint demangler-warning".
659 queue-signal signal-name-or-number
660 Queue a signal to be delivered to the thread when it is resumed.
662 add-auto-load-scripts-directory directory
663 Add entries to the list of directories from which to load auto-loaded
666 maint print user-registers
667 List all currently available "user" registers.
669 compile code [-r|-raw] [--] [source code]
670 Compile, inject, and execute in the inferior the executable object
671 code produced by compiling the provided source code.
673 compile file [-r|-raw] filename
674 Compile and inject into the inferior the executable object code
675 produced by compiling the source code stored in the filename
678 * On resume, GDB now always passes the signal the program had stopped
679 for to the thread the signal was sent to, even if the user changed
680 threads before resuming. Previously GDB would often (but not
681 always) deliver the signal to the thread that happens to be current
684 * Conversely, the "signal" command now consistently delivers the
685 requested signal to the current thread. GDB now asks for
686 confirmation if the program had stopped for a signal and the user
687 switched threads meanwhile.
689 * "breakpoint always-inserted" modes "off" and "auto" merged.
691 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
692 won't remove breakpoints from the target until all threads stop,
693 even in non-stop mode. The "auto" mode has been removed, and "off"
694 is now the default mode.
698 set debug symbol-lookup
699 show debug symbol-lookup
700 Control display of debugging info regarding symbol lookup.
704 ** The -list-thread-groups command outputs an exit-code field for
705 inferiors that have exited.
709 MIPS SDE mips*-sde*-elf*
713 Support for these obsolete configurations has been removed.
715 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
716 SGI Irix-5.x mips-*-irix5*
717 SGI Irix-6.x mips-*-irix6*
718 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
719 VAX running Ultrix vax-*-ultrix*
721 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
722 and "assf"), have been removed. Use the "sharedlibrary" command, or
723 its alias "share", instead.
725 *** Changes in GDB 7.8
727 * New command line options
730 This is an alias for the --data-directory option.
732 * GDB supports printing and modifying of variable length automatic arrays
733 as specified in ISO C99.
735 * The ARM simulator now supports instruction level tracing
736 with or without disassembly.
740 GDB now has support for scripting using Guile. Whether this is
741 available is determined at configure time.
742 Guile version 2.0 or greater is required.
743 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
745 * New commands (for set/show, see "New options" below)
749 Invoke CODE by passing it to the Guile interpreter.
753 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
755 info auto-load guile-scripts [regexp]
756 Print the list of automatically loaded Guile scripts.
758 * The source command is now capable of sourcing Guile scripts.
759 This feature is dependent on the debugger being built with Guile support.
763 set print symbol-loading (off|brief|full)
764 show print symbol-loading
765 Control whether to print informational messages when loading symbol
766 information for a file. The default is "full", but when debugging
767 programs with large numbers of shared libraries the amount of output
770 set guile print-stack (none|message|full)
771 show guile print-stack
772 Show a stack trace when an error is encountered in a Guile script.
774 set auto-load guile-scripts (on|off)
775 show auto-load guile-scripts
776 Control auto-loading of Guile script files.
778 maint ada set ignore-descriptive-types (on|off)
779 maint ada show ignore-descriptive-types
780 Control whether the debugger should ignore descriptive types in Ada
781 programs. The default is not to ignore the descriptive types. See
782 the user manual for more details on descriptive types and the intended
783 usage of this option.
785 set auto-connect-native-target
787 Control whether GDB is allowed to automatically connect to the
788 native target for the run, attach, etc. commands when not connected
789 to any target yet. See also "target native" below.
791 set record btrace replay-memory-access (read-only|read-write)
792 show record btrace replay-memory-access
793 Control what memory accesses are allowed during replay.
795 maint set target-async (on|off)
796 maint show target-async
797 This controls whether GDB targets operate in synchronous or
798 asynchronous mode. Normally the default is asynchronous, if it is
799 available; but this can be changed to more easily debug problems
800 occurring only in synchronous mode.
802 set mi-async (on|off)
804 Control whether MI asynchronous mode is preferred. This supersedes
805 "set target-async" of previous GDB versions.
807 * "set target-async" is deprecated as a CLI option and is now an alias
808 for "set mi-async" (only puts MI into async mode).
810 * Background execution commands (e.g., "c&", "s&", etc.) are now
811 possible ``out of the box'' if the target supports them. Previously
812 the user would need to explicitly enable the possibility with the
813 "set target-async on" command.
815 * New features in the GDB remote stub, GDBserver
817 ** New option --debug-format=option1[,option2,...] allows one to add
818 additional text to each output. At present only timestamps
819 are supported: --debug-format=timestamps.
820 Timestamps can also be turned on with the
821 "monitor set debug-format timestamps" command from GDB.
823 * The 'record instruction-history' command now starts counting instructions
824 at one. This also affects the instruction ranges reported by the
825 'record function-call-history' command when given the /i modifier.
827 * The command 'record function-call-history' supports a new modifier '/c' to
828 indent the function names based on their call stack depth.
829 The fields for the '/i' and '/l' modifier have been reordered.
830 The source line range is now prefixed with 'at'.
831 The instruction range is now prefixed with 'inst'.
832 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
833 "record instruction-history" and "list" commands.
835 * The ranges given as arguments to the 'record function-call-history' and
836 'record instruction-history' commands are now inclusive.
838 * The btrace record target now supports the 'record goto' command.
839 For locations inside the execution trace, the back trace is computed
840 based on the information stored in the execution trace.
842 * The btrace record target supports limited reverse execution and replay.
843 The target does not record data and therefore does not allow reading
846 * The "catch syscall" command now works on s390*-linux* targets.
848 * The "compare-sections" command is no longer specific to target
849 remote. It now works with all targets.
851 * All native targets are now consistently called "native".
852 Consequently, the "target child", "target GNU", "target djgpp",
853 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
854 commands have been replaced with "target native". The QNX/NTO port
855 leaves the "procfs" target in place and adds a "native" target for
856 consistency with other ports. The impact on users should be minimal
857 as these commands previously either throwed an error, or were
858 no-ops. The target's name is visible in the output of the following
859 commands: "help target", "info target", "info files", "maint print
862 * The "target native" command now connects to the native target. This
863 can be used to launch native programs even when "set
864 auto-connect-native-target" is set to off.
866 * GDB now supports access to Intel MPX registers on GNU/Linux.
868 * Support for Intel AVX-512 registers on GNU/Linux.
869 Support displaying and modifying Intel AVX-512 registers
870 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
874 qXfer:btrace:read's annex
875 The qXfer:btrace:read packet supports a new annex 'delta' to read
876 branch trace incrementally.
880 ** Valid Python operations on gdb.Value objects representing
881 structs/classes invoke the corresponding overloaded operators if
883 ** New `Xmethods' feature in the Python API. Xmethods are
884 additional methods or replacements for existing methods of a C++
885 class. This feature is useful for those cases where a method
886 defined in C++ source code could be inlined or optimized out by
887 the compiler, making it unavailable to GDB.
890 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
892 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
893 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
894 its alias "share", instead.
896 * The commands "set remotebaud" and "show remotebaud" are no longer
897 supported. Use "set serial baud" and "show serial baud" (respectively)
902 ** A new option "-gdb-set mi-async" replaces "-gdb-set
903 target-async". The latter is left as a deprecated alias of the
904 former for backward compatibility. If the target supports it,
905 CLI background execution commands are now always possible by
906 default, independently of whether the frontend stated a
907 preference for asynchronous execution with "-gdb-set mi-async".
908 Previously "-gdb-set target-async off" affected both MI execution
909 commands and CLI execution commands.
911 *** Changes in GDB 7.7
913 * Improved support for process record-replay and reverse debugging on
914 arm*-linux* targets. Support for thumb32 and syscall instruction
915 recording has been added.
917 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
919 * GDB now supports Fission DWP file format version 2.
920 http://gcc.gnu.org/wiki/DebugFission
922 * New convenience function "$_isvoid", to check whether an expression
923 is void. A void expression is an expression where the type of the
924 result is "void". For example, some convenience variables may be
925 "void" when evaluated (e.g., "$_exitcode" before the execution of
926 the program being debugged; or an undefined convenience variable).
927 Another example, when calling a function whose return type is
930 * The "maintenance print objfiles" command now takes an optional regexp.
932 * The "catch syscall" command now works on arm*-linux* targets.
934 * GDB now consistently shows "<not saved>" when printing values of
935 registers the debug info indicates have not been saved in the frame
936 and there's nowhere to retrieve them from
937 (callee-saved/call-clobbered registers):
942 (gdb) info registers rax
945 Before, the former would print "<optimized out>", and the latter
946 "*value not available*".
948 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
953 ** Frame filters and frame decorators have been added.
954 ** Temporary breakpoints are now supported.
955 ** Line tables representation has been added.
956 ** New attribute 'parent_type' for gdb.Field objects.
957 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
958 ** New attribute 'name' for gdb.Type objects.
962 Nios II ELF nios2*-*-elf
963 Nios II GNU/Linux nios2*-*-linux
964 Texas Instruments MSP430 msp430*-*-elf
966 * Removed native configurations
968 Support for these a.out NetBSD and OpenBSD obsolete configurations has
969 been removed. ELF variants of these configurations are kept supported.
971 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
972 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
973 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
974 i[34567]86-*-openbsd3.[0-3]
975 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
976 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
977 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
981 Like "catch throw", but catches a re-thrown exception.
983 Renamed from old "maint check-symtabs".
985 Perform consistency checks on symtabs.
987 Expand symtabs matching an optional regexp.
990 Display the details of GDB configure-time options.
992 maint set|show per-command
993 maint set|show per-command space
994 maint set|show per-command time
995 maint set|show per-command symtab
996 Enable display of per-command gdb resource usage.
998 remove-symbol-file FILENAME
999 remove-symbol-file -a ADDRESS
1000 Remove a symbol file added via add-symbol-file. The file to remove
1001 can be identified by its filename or by an address that lies within
1002 the boundaries of this symbol file in memory.
1005 info exceptions REGEXP
1006 Display the list of Ada exceptions defined in the program being
1007 debugged. If provided, only the exceptions whose names match REGEXP
1012 set debug symfile off|on
1014 Control display of debugging info regarding reading symbol files and
1015 symbol tables within those files
1017 set print raw frame-arguments
1018 show print raw frame-arguments
1019 Set/show whether to print frame arguments in raw mode,
1020 disregarding any defined pretty-printers.
1022 set remote trace-status-packet
1023 show remote trace-status-packet
1024 Set/show the use of remote protocol qTStatus packet.
1028 Control display of debugging messages related to Nios II targets.
1032 Control whether target-assisted range stepping is enabled.
1034 set startup-with-shell
1035 show startup-with-shell
1036 Specifies whether Unix child processes are started via a shell or
1041 Use the target memory cache for accesses to the code segment. This
1042 improves performance of remote debugging (particularly disassembly).
1044 * You can now use a literal value 'unlimited' for options that
1045 interpret 0 or -1 as meaning "unlimited". E.g., "set
1046 trace-buffer-size unlimited" is now an alias for "set
1047 trace-buffer-size -1" and "set height unlimited" is now an alias for
1050 * The "set debug symtab-create" debugging option of GDB has been changed to
1051 accept a verbosity level. 0 means "off", 1 provides basic debugging
1052 output, and values of 2 or greater provides more verbose output.
1054 * New command-line options
1056 Display the details of GDB configure-time options.
1058 * The command 'tsave' can now support new option '-ctf' to save trace
1059 buffer in Common Trace Format.
1061 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1064 * GDB now implements the the C++ 'typeid' operator.
1066 * The new convenience variable $_exception holds the exception being
1067 thrown or caught at an exception-related catchpoint.
1069 * The exception-related catchpoints, like "catch throw", now accept a
1070 regular expression which can be used to filter exceptions by type.
1072 * The new convenience variable $_exitsignal is automatically set to
1073 the terminating signal number when the program being debugged dies
1074 due to an uncaught signal.
1078 ** All MI commands now accept an optional "--language" option.
1079 Support for this feature can be verified by using the "-list-features"
1080 command, which should contain "language-option".
1082 ** The new command -info-gdb-mi-command allows the user to determine
1083 whether a GDB/MI command is supported or not.
1085 ** The "^error" result record returned when trying to execute an undefined
1086 GDB/MI command now provides a variable named "code" whose content is the
1087 "undefined-command" error code. Support for this feature can be verified
1088 by using the "-list-features" command, which should contain
1089 "undefined-command-error-code".
1091 ** The -trace-save MI command can optionally save trace buffer in Common
1094 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1096 ** The command -data-list-register-values now accepts an optional
1097 "--skip-unavailable" option. When used, only the available registers
1100 ** The new command -trace-frame-collected dumps collected variables,
1101 computed expressions, tvars, memory and registers in a traceframe.
1103 ** The commands -stack-list-locals, -stack-list-arguments and
1104 -stack-list-variables now accept an option "--skip-unavailable".
1105 When used, only the available locals or arguments are displayed.
1107 ** The -exec-run command now accepts an optional "--start" option.
1108 When used, the command follows the same semantics as the "start"
1109 command, stopping the program's execution at the start of its
1110 main subprogram. Support for this feature can be verified using
1111 the "-list-features" command, which should contain
1112 "exec-run-start-option".
1114 ** The new commands -catch-assert and -catch-exceptions insert
1115 catchpoints stopping the program when Ada exceptions are raised.
1117 ** The new command -info-ada-exceptions provides the equivalent of
1118 the new "info exceptions" command.
1120 * New system-wide configuration scripts
1121 A GDB installation now provides scripts suitable for use as system-wide
1122 configuration scripts for the following systems:
1126 * GDB now supports target-assigned range stepping with remote targets.
1127 This improves the performance of stepping source lines by reducing
1128 the number of control packets from/to GDB. See "New remote packets"
1131 * GDB now understands the element 'tvar' in the XML traceframe info.
1132 It has the id of the collected trace state variables.
1134 * On S/390 targets that provide the transactional-execution feature,
1135 the program interruption transaction diagnostic block (TDB) is now
1136 represented as a number of additional "registers" in GDB.
1138 * New remote packets
1142 The vCont packet supports a new 'r' action, that tells the remote
1143 stub to step through an address range itself, without GDB
1144 involvemement at each single-step.
1146 qXfer:libraries-svr4:read's annex
1147 The previously unused annex of the qXfer:libraries-svr4:read packet
1148 is now used to support passing an argument list. The remote stub
1149 reports support for this argument list to GDB's qSupported query.
1150 The defined arguments are "start" and "prev", used to reduce work
1151 necessary for library list updating, resulting in significant
1154 * New features in the GDB remote stub, GDBserver
1156 ** GDBserver now supports target-assisted range stepping. Currently
1157 enabled on x86/x86_64 GNU/Linux targets.
1159 ** GDBserver now adds element 'tvar' in the XML in the reply to
1160 'qXfer:traceframe-info:read'. It has the id of the collected
1161 trace state variables.
1163 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1166 * New 'z' formatter for printing and examining memory, this displays the
1167 value as hexadecimal zero padded on the left to the size of the type.
1169 * GDB can now use Windows x64 unwinding data.
1171 * The "set remotebaud" command has been replaced by "set serial baud".
1172 Similarly, "show remotebaud" has been replaced by "show serial baud".
1173 The "set remotebaud" and "show remotebaud" commands are still available
1174 to provide backward compatibility with older versions of GDB.
1176 *** Changes in GDB 7.6
1178 * Target record has been renamed to record-full.
1179 Record/replay is now enabled with the "record full" command.
1180 This also affects settings that are associated with full record/replay
1181 that have been moved from "set/show record" to "set/show record full":
1183 set|show record full insn-number-max
1184 set|show record full stop-at-limit
1185 set|show record full memory-query
1187 * A new record target "record-btrace" has been added. The new target
1188 uses hardware support to record the control-flow of a process. It
1189 does not support replaying the execution, but it implements the
1190 below new commands for investigating the recorded execution log.
1191 This new recording method can be enabled using:
1195 The "record-btrace" target is only available on Intel Atom processors
1196 and requires a Linux kernel 2.6.32 or later.
1198 * Two new commands have been added for record/replay to give information
1199 about the recorded execution without having to replay the execution.
1200 The commands are only supported by "record btrace".
1202 record instruction-history prints the execution history at
1203 instruction granularity
1205 record function-call-history prints the execution history at
1206 function granularity
1208 * New native configurations
1210 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1211 FreeBSD/powerpc powerpc*-*-freebsd
1212 x86_64/Cygwin x86_64-*-cygwin*
1213 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1217 ARM AArch64 aarch64*-*-elf
1218 ARM AArch64 GNU/Linux aarch64*-*-linux
1219 Lynx 178 PowerPC powerpc-*-lynx*178
1220 x86_64/Cygwin x86_64-*-cygwin*
1221 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1223 * If the configured location of system.gdbinit file (as given by the
1224 --with-system-gdbinit option at configure time) is in the
1225 data-directory (as specified by --with-gdb-datadir at configure
1226 time) or in one of its subdirectories, then GDB will look for the
1227 system-wide init file in the directory specified by the
1228 --data-directory command-line option.
1230 * New command line options:
1232 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1233 other initialization files, unlike -nx which disables all of them.
1235 * Removed command line options
1237 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1240 * The 'ptype' and 'whatis' commands now accept an argument to control
1243 * 'info proc' now works on some core files.
1247 ** Vectors can be created with gdb.Type.vector.
1249 ** Python's atexit.register now works in GDB.
1251 ** Types can be pretty-printed via a Python API.
1253 ** Python 3 is now supported (in addition to Python 2.4 or later)
1255 ** New class gdb.Architecture exposes GDB's internal representation
1256 of architecture in the Python API.
1258 ** New method Frame.architecture returns the gdb.Architecture object
1259 corresponding to the frame's architecture.
1261 * New Python-based convenience functions:
1263 ** $_memeq(buf1, buf2, length)
1264 ** $_streq(str1, str2)
1266 ** $_regex(str, regex)
1268 * The 'cd' command now defaults to using '~' (the home directory) if not
1271 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1272 default for GCC since November 2000.
1274 * The command 'forward-search' can now be abbreviated as 'fo'.
1276 * The command 'info tracepoints' can now display 'installed on target'
1277 or 'not installed on target' for each non-pending location of tracepoint.
1279 * New configure options
1281 --enable-libmcheck/--disable-libmcheck
1282 By default, development versions are built with -lmcheck on hosts
1283 that support it, in order to help track memory corruption issues.
1284 Release versions, on the other hand, are built without -lmcheck
1285 by default. The --enable-libmcheck/--disable-libmcheck configure
1286 options allow the user to override that default.
1287 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1288 This configure option allows the user to build GDB with
1289 libbabeltrace using which GDB can read Common Trace Format data.
1291 * New commands (for set/show, see "New options" below)
1294 Catch signals. This is similar to "handle", but allows commands and
1295 conditions to be attached.
1298 List the BFDs known to GDB.
1300 python-interactive [command]
1302 Start a Python interactive prompt, or evaluate the optional command
1303 and print the result of expressions.
1306 "py" is a new alias for "python".
1308 enable type-printer [name]...
1309 disable type-printer [name]...
1310 Enable or disable type printers.
1314 ** For the Renesas Super-H architecture, the "regs" command has been removed
1315 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1320 set print type methods (on|off)
1321 show print type methods
1322 Control whether method declarations are displayed by "ptype".
1323 The default is to show them.
1325 set print type typedefs (on|off)
1326 show print type typedefs
1327 Control whether typedef definitions are displayed by "ptype".
1328 The default is to show them.
1330 set filename-display basename|relative|absolute
1331 show filename-display
1332 Control the way in which filenames is displayed.
1333 The default is "relative", which preserves previous behavior.
1335 set trace-buffer-size
1336 show trace-buffer-size
1337 Request target to change the size of trace buffer.
1339 set remote trace-buffer-size-packet auto|on|off
1340 show remote trace-buffer-size-packet
1341 Control the use of the remote protocol `QTBuffer:size' packet.
1345 Control display of debugging messages related to ARM AArch64.
1348 set debug coff-pe-read
1349 show debug coff-pe-read
1350 Control display of debugging messages related to reading of COFF/PE
1355 Control display of debugging messages related to Mach-O symbols
1358 set debug notification
1359 show debug notification
1360 Control display of debugging info for async remote notification.
1364 ** Command parameter changes are now notified using new async record
1365 "=cmd-param-changed".
1366 ** Trace frame changes caused by command "tfind" are now notified using
1367 new async record "=traceframe-changed".
1368 ** The creation, deletion and modification of trace state variables
1369 are now notified using new async records "=tsv-created",
1370 "=tsv-deleted" and "=tsv-modified".
1371 ** The start and stop of process record are now notified using new
1372 async record "=record-started" and "=record-stopped".
1373 ** Memory changes are now notified using new async record
1375 ** The data-disassemble command response will include a "fullname" field
1376 containing the absolute file name when source has been requested.
1377 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1378 command, to allow pattern filling of memory areas.
1379 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1380 library load/unload events.
1381 ** The response to breakpoint commands and breakpoint async records
1382 includes an "installed" field containing a boolean state about each
1383 non-pending tracepoint location is whether installed on target or not.
1384 ** Output of the "-trace-status" command includes a "trace-file" field
1385 containing the name of the trace file being examined. This field is
1386 optional, and only present when examining a trace file.
1387 ** The "fullname" field is now always present along with the "file" field,
1388 even if the file cannot be found by GDB.
1390 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1391 You must have the LZMA library available when configuring GDB for this
1392 feature to be enabled. For more information, see:
1393 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1395 * New remote packets
1398 Set the size of trace buffer. The remote stub reports support for this
1399 packet to gdb's qSupported query.
1402 Enable Branch Trace Store (BTS)-based branch tracing for the current
1403 thread. The remote stub reports support for this packet to gdb's
1407 Disable branch tracing for the current thread. The remote stub reports
1408 support for this packet to gdb's qSupported query.
1411 Read the traced branches for the current thread. The remote stub
1412 reports support for this packet to gdb's qSupported query.
1414 *** Changes in GDB 7.5
1416 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1417 for more x32 ABI info.
1419 * GDB now supports access to MIPS DSP registers on Linux targets.
1421 * GDB now supports debugging microMIPS binaries.
1423 * The "info os" command on GNU/Linux can now display information on
1424 several new classes of objects managed by the operating system:
1425 "info os procgroups" lists process groups
1426 "info os files" lists file descriptors
1427 "info os sockets" lists internet-domain sockets
1428 "info os shm" lists shared-memory regions
1429 "info os semaphores" lists semaphores
1430 "info os msg" lists message queues
1431 "info os modules" lists loaded kernel modules
1433 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1434 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1435 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1436 options and inspect the probe arguments using the new $_probe_arg family
1437 of convenience variables. You can obtain more information about SystemTap
1438 in <http://sourceware.org/systemtap/>.
1440 * GDB now supports reversible debugging on ARM, it allows you to
1441 debug basic ARM and THUMB instructions, and provides
1442 record/replay support.
1444 * The option "symbol-reloading" has been deleted as it is no longer used.
1448 ** GDB commands implemented in Python can now be put in command class
1451 ** The "maint set python print-stack on|off" is now deleted.
1453 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1454 apply "flag enum"-style pretty-printing to any enum.
1456 ** gdb.lookup_symbol can now work when there is no current frame.
1458 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1459 the source at which the symbol was defined.
1461 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1462 method 'value'. The former indicates whether the symbol needs a
1463 frame in order to compute its value, and the latter computes the
1466 ** A new method 'referenced_value' on gdb.Value objects which can
1467 dereference pointer as well as C++ reference values.
1469 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1470 which return the global and static blocks (as gdb.Block objects),
1471 of the underlying symbol table, respectively.
1473 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1474 object associated with a PC value.
1476 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1477 of the address range occupied by code for the current source line.
1479 * Go language support.
1480 GDB now supports debugging programs written in the Go programming
1483 * GDBserver now supports stdio connections.
1484 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1486 * The binary "gdbtui" can no longer be built or installed.
1487 Use "gdb -tui" instead.
1489 * GDB will now print "flag" enums specially. A flag enum is one where
1490 all the enumerator values have no bits in common when pairwise
1491 "and"ed. When printing a value whose type is a flag enum, GDB will
1492 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1493 (gdb) print (enum E) 3
1496 * The filename part of a linespec will now match trailing components
1497 of a source file name. For example, "break gcc/expr.c:1000" will
1498 now set a breakpoint in build/gcc/expr.c, but not
1499 build/libcpp/expr.c.
1501 * The "info proc" and "generate-core-file" commands will now also
1502 work on remote targets connected to GDBserver on Linux.
1504 * The command "info catch" has been removed. It has been disabled
1505 since December 2007.
1507 * The "catch exception" and "catch assert" commands now accept
1508 a condition at the end of the command, much like the "break"
1509 command does. For instance:
1511 (gdb) catch exception Constraint_Error if Barrier = True
1513 Previously, it was possible to add a condition to such catchpoints,
1514 but it had to be done as a second step, after the catchpoint had been
1515 created, using the "condition" command.
1517 * The "info static-tracepoint-marker" command will now also work on
1518 native Linux targets with in-process agent.
1520 * GDB can now set breakpoints on inlined functions.
1522 * The .gdb_index section has been updated to include symbols for
1523 inlined functions. GDB will ignore older .gdb_index sections by
1524 default, which could cause symbol files to be loaded more slowly
1525 until their .gdb_index sections can be recreated. The new command
1526 "set use-deprecated-index-sections on" will cause GDB to use any older
1527 .gdb_index sections it finds. This will restore performance, but the
1528 ability to set breakpoints on inlined functions will be lost in symbol
1529 files with older .gdb_index sections.
1531 The .gdb_index section has also been updated to record more information
1532 about each symbol. This speeds up the "info variables", "info functions"
1533 and "info types" commands when used with programs having the .gdb_index
1534 section, as well as speeding up debugging with shared libraries using
1535 the .gdb_index section.
1537 * Ada support for GDB/MI Variable Objects has been added.
1539 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1544 ** New command -info-os is the MI equivalent of "info os".
1546 ** Output logs ("set logging" and related) now include MI output.
1550 ** "set use-deprecated-index-sections on|off"
1551 "show use-deprecated-index-sections on|off"
1552 Controls the use of deprecated .gdb_index sections.
1554 ** "catch load" and "catch unload" can be used to stop when a shared
1555 library is loaded or unloaded, respectively.
1557 ** "enable count" can be used to auto-disable a breakpoint after
1560 ** "info vtbl" can be used to show the virtual method tables for
1561 C++ and Java objects.
1563 ** "explore" and its sub commands "explore value" and "explore type"
1564 can be used to recursively explore values and types of
1565 expressions. These commands are available only if GDB is
1566 configured with '--with-python'.
1568 ** "info auto-load" shows status of all kinds of auto-loaded files,
1569 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1570 sequences of commands files, "info auto-load python-scripts"
1571 shows status of auto-loading Python script files,
1572 "info auto-load local-gdbinit" shows status of loading init file
1573 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1574 status of inferior specific thread debugging shared library loading.
1576 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1577 and "show auto-load-scripts" commands have been deprecated, use their
1578 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1579 and "show auto-load python-scripts" counterparts instead.
1581 ** "dprintf location,format,args..." creates a dynamic printf, which
1582 is basically a breakpoint that does a printf and immediately
1583 resumes your program's execution, so it is like a printf that you
1584 can insert dynamically at runtime instead of at compiletime.
1586 ** "set print symbol"
1588 Controls whether GDB attempts to display the symbol, if any,
1589 corresponding to addresses it prints. This defaults to "on", but
1590 you can set it to "off" to restore GDB's previous behavior.
1592 * Deprecated commands
1594 ** For the Renesas Super-H architecture, the "regs" command has been
1595 deprecated, and "info all-registers" should be used instead.
1599 Renesas RL78 rl78-*-elf
1600 HP OpenVMS ia64 ia64-hp-openvms*
1602 * GDBserver supports evaluation of breakpoint conditions. When
1603 support is advertised by GDBserver, GDB may be told to send the
1604 breakpoint conditions in bytecode form to GDBserver. GDBserver
1605 will only report the breakpoint trigger to GDB when its condition
1610 set mips compression
1611 show mips compression
1612 Select the compressed ISA encoding used in functions that have no symbol
1613 information available. The encoding can be set to either of:
1616 and is updated automatically from ELF file flags if available.
1618 set breakpoint condition-evaluation
1619 show breakpoint condition-evaluation
1620 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1621 GDBserver ("target"). Default option "auto" chooses the most efficient
1623 This option can improve debugger efficiency depending on the speed of the
1627 Disable auto-loading globally.
1630 Show auto-loading setting of all kinds of auto-loaded files.
1632 set auto-load gdb-scripts on|off
1633 show auto-load gdb-scripts
1634 Control auto-loading of GDB canned sequences of commands files.
1636 set auto-load python-scripts on|off
1637 show auto-load python-scripts
1638 Control auto-loading of Python script files.
1640 set auto-load local-gdbinit on|off
1641 show auto-load local-gdbinit
1642 Control loading of init file (.gdbinit) from current directory.
1644 set auto-load libthread-db on|off
1645 show auto-load libthread-db
1646 Control auto-loading of inferior specific thread debugging shared library.
1648 set auto-load scripts-directory <dir1>[:<dir2>...]
1649 show auto-load scripts-directory
1650 Set a list of directories from which to load auto-loaded scripts.
1651 Automatically loaded Python scripts and GDB scripts are located in one
1652 of the directories listed by this option.
1653 The delimiter (':' above) may differ according to the host platform.
1655 set auto-load safe-path <dir1>[:<dir2>...]
1656 show auto-load safe-path
1657 Set a list of directories from which it is safe to auto-load files.
1658 The delimiter (':' above) may differ according to the host platform.
1660 set debug auto-load on|off
1661 show debug auto-load
1662 Control display of debugging info for auto-loading the files above.
1664 set dprintf-style gdb|call|agent
1666 Control the way in which a dynamic printf is performed; "gdb"
1667 requests a GDB printf command, while "call" causes dprintf to call a
1668 function in the inferior. "agent" requests that the target agent
1669 (such as GDBserver) do the printing.
1671 set dprintf-function <expr>
1672 show dprintf-function
1673 set dprintf-channel <expr>
1674 show dprintf-channel
1675 Set the function and optional first argument to the call when using
1676 the "call" style of dynamic printf.
1678 set disconnected-dprintf on|off
1679 show disconnected-dprintf
1680 Control whether agent-style dynamic printfs continue to be in effect
1681 after GDB disconnects.
1683 * New configure options
1685 --with-auto-load-dir
1686 Configure default value for the 'set auto-load scripts-directory'
1687 setting above. It defaults to '$debugdir:$datadir/auto-load',
1688 $debugdir representing global debugging info directories (available
1689 via 'show debug-file-directory') and $datadir representing GDB's data
1690 directory (available via 'show data-directory').
1692 --with-auto-load-safe-path
1693 Configure default value for the 'set auto-load safe-path' setting
1694 above. It defaults to the --with-auto-load-dir setting.
1696 --without-auto-load-safe-path
1697 Set 'set auto-load safe-path' to '/', effectively disabling this
1700 * New remote packets
1702 z0/z1 conditional breakpoints extension
1704 The z0/z1 breakpoint insertion packets have been extended to carry
1705 a list of conditional expressions over to the remote stub depending on the
1706 condition evaluation mode. The use of this extension can be controlled
1707 via the "set remote conditional-breakpoints-packet" command.
1711 Specify the signals which the remote stub may pass to the debugged
1712 program without GDB involvement.
1714 * New command line options
1716 --init-command=FILE, -ix Like --command, -x but execute it
1717 before loading inferior.
1718 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1719 execute it before loading inferior.
1721 *** Changes in GDB 7.4
1723 * GDB now handles ambiguous linespecs more consistently; the existing
1724 FILE:LINE support has been expanded to other types of linespecs. A
1725 breakpoint will now be set on all matching locations in all
1726 inferiors, and locations will be added or removed according to
1729 * GDB now allows you to skip uninteresting functions and files when
1730 stepping with the "skip function" and "skip file" commands.
1732 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1733 and "show remote hardware-watchpoint-length-limit". These allows to
1734 set or show the maximum length limit (in bytes) of a remote
1735 target hardware watchpoint.
1737 This allows e.g. to use "unlimited" hardware watchpoints with the
1738 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1739 watchpoints are slower than real hardware watchpoints but are
1740 significantly faster than gdb software watchpoints.
1744 ** The register_pretty_printer function in module gdb.printing now takes
1745 an optional `replace' argument. If True, the new printer replaces any
1748 ** The "maint set python print-stack on|off" command has been
1749 deprecated and will be deleted in GDB 7.5.
1750 A new command: "set python print-stack none|full|message" has
1751 replaced it. Additionally, the default for "print-stack" is
1752 now "message", which just prints the error message without
1755 ** A prompt substitution hook (prompt_hook) is now available to the
1758 ** A new Python module, gdb.prompt has been added to the GDB Python
1759 modules library. This module provides functionality for
1760 escape sequences in prompts (used by set/show
1761 extended-prompt). These escape sequences are replaced by their
1762 corresponding value.
1764 ** Python commands and convenience-functions located in
1765 'data-directory'/python/gdb/command and
1766 'data-directory'/python/gdb/function are now automatically loaded
1769 ** Blocks now provide four new attributes. global_block and
1770 static_block will return the global and static blocks
1771 respectively. is_static and is_global are boolean attributes
1772 that indicate if the block is one of those two types.
1774 ** Symbols now provide the "type" attribute, the type of the symbol.
1776 ** The "gdb.breakpoint" function has been deprecated in favor of
1779 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1780 of a function. This class is based on the "finish" command
1781 available in the CLI.
1783 ** Type objects for struct and union types now allow access to
1784 the fields using standard Python dictionary (mapping) methods.
1785 For example, "some_type['myfield']" now works, as does
1786 "some_type.items()".
1788 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1791 ** A new function, "deep_items" has been added to the gdb.types
1792 module in the GDB Python modules library. This function returns
1793 an iterator over the fields of a struct or union type. Unlike
1794 the standard Python "iteritems" method, it will recursively traverse
1795 any anonymous fields.
1799 ** "*stopped" events can report several new "reason"s, such as
1802 ** Breakpoint changes are now notified using new async records, like
1803 "=breakpoint-modified".
1805 ** New command -ada-task-info.
1807 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1808 $sdir specifies the default system locations of shared libraries.
1809 $pdir specifies the directory where the libpthread used by the application
1812 GDB no longer looks in $sdir and $pdir after it has searched the directories
1813 mentioned in libthread-db-search-path. If you want to search those
1814 directories, they must be specified in libthread-db-search-path.
1815 The default value of libthread-db-search-path on GNU/Linux and Solaris
1816 systems is now "$sdir:$pdir".
1818 $pdir is not supported by gdbserver, it is currently ignored.
1819 $sdir is supported by gdbserver.
1821 * New configure option --with-iconv-bin.
1822 When using the internationalization support like the one in the GNU C
1823 library, GDB will invoke the "iconv" program to get a list of supported
1824 character sets. If this program lives in a non-standard location, one can
1825 use this option to specify where to find it.
1827 * When natively debugging programs on PowerPC BookE processors running
1828 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1829 watchpoints, which specify a mask in addition to an address to watch.
1830 The mask specifies that some bits of an address (the bits which are
1831 reset in the mask) should be ignored when matching the address accessed
1832 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1833 section in the user manual for more details.
1835 * The new option --once causes GDBserver to stop listening for connections once
1836 the first connection is made. The listening port used by GDBserver will
1837 become available after that.
1839 * New commands "info macros" and "alias" have been added.
1841 * New function parameters suffix @entry specifies value of function parameter
1842 at the time the function got called. Entry values are available only since
1848 "!" is now an alias of the "shell" command.
1849 Note that no space is needed between "!" and SHELL COMMAND.
1853 watch EXPRESSION mask MASK_VALUE
1854 The watch command now supports the mask argument which allows creation
1855 of masked watchpoints, if the current architecture supports this feature.
1857 info auto-load-scripts [REGEXP]
1858 This command was formerly named "maintenance print section-scripts".
1859 It is now generally useful and is no longer a maintenance-only command.
1861 info macro [-all] [--] MACRO
1862 The info macro command has new options `-all' and `--'. The first for
1863 printing all definitions of a macro. The second for explicitly specifying
1864 the end of arguments and the beginning of the macro name in case the macro
1865 name starts with a hyphen.
1867 collect[/s] EXPRESSIONS
1868 The tracepoint collect command now takes an optional modifier "/s"
1869 that directs it to dereference pointer-to-character types and
1870 collect the bytes of memory up to a zero byte. The behavior is
1871 similar to what you see when you use the regular print command on a
1872 string. An optional integer following the "/s" sets a bound on the
1873 number of bytes that will be collected.
1876 The trace start command now interprets any supplied arguments as a
1877 note to be recorded with the trace run, with an effect similar to
1878 setting the variable trace-notes.
1881 The trace stop command now interprets any arguments as a note to be
1882 mentioned along with the tstatus report that the trace was stopped
1883 with a command. The effect is similar to setting the variable
1886 * Tracepoints can now be enabled and disabled at any time after a trace
1887 experiment has been started using the standard "enable" and "disable"
1888 commands. It is now possible to start a trace experiment with no enabled
1889 tracepoints; GDB will display a warning, but will allow the experiment to
1890 begin, assuming that tracepoints will be enabled as needed while the trace
1893 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1894 locations with 4-byte instructions, when they were previously
1895 limited to locations with instructions of 5 bytes or longer.
1899 set debug dwarf2-read
1900 show debug dwarf2-read
1901 Turns on or off display of debugging messages related to reading
1902 DWARF debug info. The default is off.
1904 set debug symtab-create
1905 show debug symtab-create
1906 Turns on or off display of debugging messages related to symbol table
1907 creation. The default is off.
1910 show extended-prompt
1911 Set the GDB prompt, and allow escape sequences to be inserted to
1912 display miscellaneous information (see 'help set extended-prompt'
1913 for the list of sequences). This prompt (and any information
1914 accessed through the escape sequences) is updated every time the
1915 prompt is displayed.
1917 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1918 show print entry-values
1919 Set printing of frame argument values at function entry. In some cases
1920 GDB can determine the value of function argument which was passed by the
1921 function caller, even if the value was modified inside the called function.
1923 set debug entry-values
1924 show debug entry-values
1925 Control display of debugging info for determining frame argument values at
1926 function entry and virtual tail call frames.
1928 set basenames-may-differ
1929 show basenames-may-differ
1930 Set whether a source file may have multiple base names.
1931 (A "base name" is the name of a file with the directory part removed.
1932 Example: The base name of "/home/user/hello.c" is "hello.c".)
1933 If set, GDB will canonicalize file names (e.g., expand symlinks)
1934 before comparing them. Canonicalization is an expensive operation,
1935 but it allows the same file be known by more than one base name.
1936 If not set (the default), all source files are assumed to have just
1937 one base name, and gdb will do file name comparisons more efficiently.
1943 Set a user name and notes for the current and any future trace runs.
1944 This is useful for long-running and/or disconnected traces, to
1945 inform others (or yourself) as to who is running the trace, supply
1946 contact information, or otherwise explain what is going on.
1948 set trace-stop-notes
1949 show trace-stop-notes
1950 Set a note attached to the trace run, that is displayed when the
1951 trace has been stopped by a tstop command. This is useful for
1952 instance as an explanation, if you are stopping a trace run that was
1953 started by someone else.
1955 * New remote packets
1959 Dynamically enable a tracepoint in a started trace experiment.
1963 Dynamically disable a tracepoint in a started trace experiment.
1967 Set the user and notes of the trace run.
1971 Query the current status of a tracepoint.
1975 Query the minimum length of instruction at which a fast tracepoint may
1978 * Dcache size (number of lines) and line-size are now runtime-configurable
1979 via "set dcache line" and "set dcache line-size" commands.
1983 Texas Instruments TMS320C6x tic6x-*-*
1987 Renesas RL78 rl78-*-elf
1989 *** Changes in GDB 7.3.1
1991 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1993 *** Changes in GDB 7.3
1995 * GDB has a new command: "thread find [REGEXP]".
1996 It finds the thread id whose name, target id, or thread extra info
1997 matches the given regular expression.
1999 * The "catch syscall" command now works on mips*-linux* targets.
2001 * The -data-disassemble MI command now supports modes 2 and 3 for
2002 dumping the instruction opcodes.
2004 * New command line options
2006 -data-directory DIR Specify DIR as the "data-directory".
2007 This is mostly for testing purposes.
2009 * The "maint set python auto-load on|off" command has been renamed to
2010 "set auto-load-scripts on|off".
2012 * GDB has a new command: "set directories".
2013 It is like the "dir" command except that it replaces the
2014 source path list instead of augmenting it.
2016 * GDB now understands thread names.
2018 On GNU/Linux, "info threads" will display the thread name as set by
2019 prctl or pthread_setname_np.
2021 There is also a new command, "thread name", which can be used to
2022 assign a name internally for GDB to display.
2025 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2026 has been integrated into GDB.
2030 ** The function gdb.Write now accepts an optional keyword 'stream'.
2031 This keyword, when provided, will direct the output to either
2032 stdout, stderr, or GDB's logging output.
2034 ** Parameters can now be be sub-classed in Python, and in particular
2035 you may implement the get_set_doc and get_show_doc functions.
2036 This improves how Parameter set/show documentation is processed
2037 and allows for more dynamic content.
2039 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2040 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2041 have an is_valid method.
2043 ** Breakpoints can now be sub-classed in Python, and in particular
2044 you may implement a 'stop' function that is executed each time
2045 the inferior reaches that breakpoint.
2047 ** New function gdb.lookup_global_symbol looks up a global symbol.
2049 ** GDB values in Python are now callable if the value represents a
2050 function. For example, if 'some_value' represents a function that
2051 takes two integer parameters and returns a value, you can call
2052 that function like so:
2054 result = some_value (10,20)
2056 ** Module gdb.types has been added.
2057 It contains a collection of utilities for working with gdb.Types objects:
2058 get_basic_type, has_field, make_enum_dict.
2060 ** Module gdb.printing has been added.
2061 It contains utilities for writing and registering pretty-printers.
2062 New classes: PrettyPrinter, SubPrettyPrinter,
2063 RegexpCollectionPrettyPrinter.
2064 New function: register_pretty_printer.
2066 ** New commands "info pretty-printers", "enable pretty-printer" and
2067 "disable pretty-printer" have been added.
2069 ** gdb.parameter("directories") is now available.
2071 ** New function gdb.newest_frame returns the newest frame in the
2074 ** The gdb.InferiorThread class has a new "name" attribute. This
2075 holds the thread's name.
2077 ** Python Support for Inferior events.
2078 Python scripts can add observers to be notified of events
2079 occurring in the process being debugged.
2080 The following events are currently supported:
2081 - gdb.events.cont Continue event.
2082 - gdb.events.exited Inferior exited event.
2083 - gdb.events.stop Signal received, and Breakpoint hit events.
2087 ** GDB now puts template parameters in scope when debugging in an
2088 instantiation. For example, if you have:
2090 template<int X> int func (void) { return X; }
2092 then if you step into func<5>, "print X" will show "5". This
2093 feature requires proper debuginfo support from the compiler; it
2094 was added to GCC 4.5.
2096 ** The motion commands "next", "finish", "until", and "advance" now
2097 work better when exceptions are thrown. In particular, GDB will
2098 no longer lose control of the inferior; instead, the GDB will
2099 stop the inferior at the point at which the exception is caught.
2100 This functionality requires a change in the exception handling
2101 code that was introduced in GCC 4.5.
2103 * GDB now follows GCC's rules on accessing volatile objects when
2104 reading or writing target state during expression evaluation.
2105 One notable difference to prior behavior is that "print x = 0"
2106 no longer generates a read of x; the value of the assignment is
2107 now always taken directly from the value being assigned.
2109 * GDB now has some support for using labels in the program's source in
2110 linespecs. For instance, you can use "advance label" to continue
2111 execution to a label.
2113 * GDB now has support for reading and writing a new .gdb_index
2114 section. This section holds a fast index of DWARF debugging
2115 information and can be used to greatly speed up GDB startup and
2116 operation. See the documentation for `save gdb-index' for details.
2118 * The "watch" command now accepts an optional "-location" argument.
2119 When used, this causes GDB to watch the memory referred to by the
2120 expression. Such a watchpoint is never deleted due to it going out
2123 * GDB now supports thread debugging of core dumps on GNU/Linux.
2125 GDB now activates thread debugging using the libthread_db library
2126 when debugging GNU/Linux core dumps, similarly to when debugging
2127 live processes. As a result, when debugging a core dump file, GDB
2128 is now able to display pthread_t ids of threads. For example, "info
2129 threads" shows the same output as when debugging the process when it
2130 was live. In earlier releases, you'd see something like this:
2133 * 1 LWP 6780 main () at main.c:10
2135 While now you see this:
2138 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2140 It is also now possible to inspect TLS variables when debugging core
2143 When debugging a core dump generated on a machine other than the one
2144 used to run GDB, you may need to point GDB at the correct
2145 libthread_db library with the "set libthread-db-search-path"
2146 command. See the user manual for more details on this command.
2148 * When natively debugging programs on PowerPC BookE processors running
2149 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2150 which stop execution of the inferior whenever it executes an instruction
2151 at any address within the specified range. See the "PowerPC Embedded"
2152 section in the user manual for more details.
2154 * New features in the GDB remote stub, GDBserver
2156 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2157 and i686 LynxOS (version 5.x).
2159 ** GDBserver is now supported on Blackfin Linux.
2161 * New native configurations
2163 ia64 HP-UX ia64-*-hpux*
2167 Analog Devices, Inc. Blackfin Processor bfin-*
2169 * Ada task switching is now supported on sparc-elf targets when
2170 debugging a program using the Ravenscar Profile. For more information,
2171 see the "Tasking Support when using the Ravenscar Profile" section
2172 in the GDB user manual.
2174 * Guile support was removed.
2176 * New features in the GNU simulator
2178 ** The --map-info flag lists all known core mappings.
2180 ** CFI flashes may be simulated via the "cfi" device.
2182 *** Changes in GDB 7.2
2184 * Shared library support for remote targets by default
2186 When GDB is configured for a generic, non-OS specific target, like
2187 for example, --target=arm-eabi or one of the many *-*-elf targets,
2188 GDB now queries remote stubs for loaded shared libraries using the
2189 `qXfer:libraries:read' packet. Previously, shared library support
2190 was always disabled for such configurations.
2194 ** Argument Dependent Lookup (ADL)
2196 In C++ ADL lookup directs function search to the namespaces of its
2197 arguments even if the namespace has not been imported.
2207 Here the compiler will search for `foo' in the namespace of 'b'
2208 and find A::foo. GDB now supports this. This construct is commonly
2209 used in the Standard Template Library for operators.
2211 ** Improved User Defined Operator Support
2213 In addition to member operators, GDB now supports lookup of operators
2214 defined in a namespace and imported with a `using' directive, operators
2215 defined in the global scope, operators imported implicitly from an
2216 anonymous namespace, and the ADL operators mentioned in the previous
2218 GDB now also supports proper overload resolution for all the previously
2219 mentioned flavors of operators.
2221 ** static const class members
2223 Printing of static const class members that are initialized in the
2224 class definition has been fixed.
2226 * Windows Thread Information Block access.
2228 On Windows targets, GDB now supports displaying the Windows Thread
2229 Information Block (TIB) structure. This structure is visible either
2230 by using the new command `info w32 thread-information-block' or, by
2231 dereferencing the new convenience variable named `$_tlb', a
2232 thread-specific pointer to the TIB. This feature is also supported
2233 when remote debugging using GDBserver.
2235 * Static tracepoints
2237 Static tracepoints are calls in the user program into a tracing
2238 library. One such library is a port of the LTTng kernel tracer to
2239 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2240 When debugging with GDBserver, GDB now supports combining the GDB
2241 tracepoint machinery with such libraries. For example: the user can
2242 use GDB to probe a static tracepoint marker (a call from the user
2243 program into the tracing library) with the new "strace" command (see
2244 "New commands" below). This creates a "static tracepoint" in the
2245 breakpoint list, that can be manipulated with the same feature set
2246 as fast and regular tracepoints. E.g., collect registers, local and
2247 global variables, collect trace state variables, and define
2248 tracepoint conditions. In addition, the user can collect extra
2249 static tracepoint marker specific data, by collecting the new
2250 $_sdata internal variable. When analyzing the trace buffer, you can
2251 inspect $_sdata like any other variable available to GDB. For more
2252 information, see the "Tracepoints" chapter in GDB user manual. New
2253 remote packets have been defined to support static tracepoints, see
2254 the "New remote packets" section below.
2256 * Better reconstruction of tracepoints after disconnected tracing
2258 GDB will attempt to download the original source form of tracepoint
2259 definitions when starting a trace run, and then will upload these
2260 upon reconnection to the target, resulting in a more accurate
2261 reconstruction of the tracepoints that are in use on the target.
2265 You can now exercise direct control over the ways that GDB can
2266 affect your program. For instance, you can disallow the setting of
2267 breakpoints, so that the program can run continuously (assuming
2268 non-stop mode). In addition, the "observer" variable is available
2269 to switch all of the different controls; in observer mode, GDB
2270 cannot affect the target's behavior at all, which is useful for
2271 tasks like diagnosing live systems in the field.
2273 * The new convenience variable $_thread holds the number of the
2276 * New remote packets
2280 Return the address of the Windows Thread Information Block of a given thread.
2284 In response to several of the tracepoint packets, the target may now
2285 also respond with a number of intermediate `qRelocInsn' request
2286 packets before the final result packet, to have GDB handle
2287 relocating an instruction to execute at a different address. This
2288 is particularly useful for stubs that support fast tracepoints. GDB
2289 reports support for this feature in the qSupported packet.
2293 List static tracepoint markers in the target program.
2297 List static tracepoint markers at a given address in the target
2300 qXfer:statictrace:read
2302 Read the static trace data collected (by a `collect $_sdata'
2303 tracepoint action). The remote stub reports support for this packet
2304 to gdb's qSupported query.
2308 Send the current settings of GDB's permission flags.
2312 Send part of the source (textual) form of a tracepoint definition,
2313 which includes location, conditional, and action list.
2315 * The source command now accepts a -s option to force searching for the
2316 script in the source search path even if the script name specifies
2319 * New features in the GDB remote stub, GDBserver
2321 - GDBserver now support tracepoints (including fast tracepoints, and
2322 static tracepoints). The feature is currently supported by the
2323 i386-linux and amd64-linux builds. See the "Tracepoints support
2324 in gdbserver" section in the manual for more information.
2326 GDBserver JIT compiles the tracepoint's conditional agent
2327 expression bytecode into native code whenever possible for low
2328 overhead dynamic tracepoints conditionals. For such tracepoints,
2329 an expression that examines program state is evaluated when the
2330 tracepoint is reached, in order to determine whether to capture
2331 trace data. If the condition is simple and false, processing the
2332 tracepoint finishes very quickly and no data is gathered.
2334 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2335 for static tracepoints support.
2337 - GDBserver now supports x86_64 Windows 64-bit debugging.
2339 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2340 it understands register description.
2342 * The --batch flag now disables pagination and queries.
2344 * X86 general purpose registers
2346 GDB now supports reading/writing byte, word and double-word x86
2347 general purpose registers directly. This means you can use, say,
2348 $ah or $ax to refer, respectively, to the byte register AH and
2349 16-bit word register AX that are actually portions of the 32-bit
2350 register EAX or 64-bit register RAX.
2352 * The `commands' command now accepts a range of breakpoints to modify.
2353 A plain `commands' following a command that creates multiple
2354 breakpoints affects all the breakpoints set by that command. This
2355 applies to breakpoints set by `rbreak', and also applies when a
2356 single `break' command creates multiple breakpoints (e.g.,
2357 breakpoints on overloaded c++ functions).
2359 * The `rbreak' command now accepts a filename specification as part of
2360 its argument, limiting the functions selected by the regex to those
2361 in the specified file.
2363 * Support for remote debugging Windows and SymbianOS shared libraries
2364 from Unix hosts has been improved. Non Windows GDB builds now can
2365 understand target reported file names that follow MS-DOS based file
2366 system semantics, such as file names that include drive letters and
2367 use the backslash character as directory separator. This makes it
2368 possible to transparently use the "set sysroot" and "set
2369 solib-search-path" on Unix hosts to point as host copies of the
2370 target's shared libraries. See the new command "set
2371 target-file-system-kind" described below, and the "Commands to
2372 specify files" section in the user manual for more information.
2376 eval template, expressions...
2377 Convert the values of one or more expressions under the control
2378 of the string template to a command line, and call it.
2380 set target-file-system-kind unix|dos-based|auto
2381 show target-file-system-kind
2382 Set or show the assumed file system kind for target reported file
2385 save breakpoints <filename>
2386 Save all current breakpoint definitions to a file suitable for use
2387 in a later debugging session. To read the saved breakpoint
2388 definitions, use the `source' command.
2390 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2393 info static-tracepoint-markers
2394 Display information about static tracepoint markers in the target.
2396 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2397 Define a static tracepoint by probing a marker at the given
2398 function, line, address, or marker ID.
2402 Enable and disable observer mode.
2404 set may-write-registers on|off
2405 set may-write-memory on|off
2406 set may-insert-breakpoints on|off
2407 set may-insert-tracepoints on|off
2408 set may-insert-fast-tracepoints on|off
2409 set may-interrupt on|off
2410 Set individual permissions for GDB effects on the target. Note that
2411 some of these settings can have undesirable or surprising
2412 consequences, particularly when changed in the middle of a session.
2413 For instance, disabling the writing of memory can prevent
2414 breakpoints from being inserted, cause single-stepping to fail, or
2415 even crash your program, if you disable after breakpoints have been
2416 inserted. However, GDB should not crash.
2418 set record memory-query on|off
2419 show record memory-query
2420 Control whether to stop the inferior if memory changes caused
2421 by an instruction cannot be recorded.
2426 The disassemble command now supports "start,+length" form of two arguments.
2430 ** GDB now provides a new directory location, called the python directory,
2431 where Python scripts written for GDB can be installed. The location
2432 of that directory is <data-directory>/python, where <data-directory>
2433 is the GDB data directory. For more details, see section `Scripting
2434 GDB using Python' in the manual.
2436 ** The GDB Python API now has access to breakpoints, symbols, symbol
2437 tables, program spaces, inferiors, threads and frame's code blocks.
2438 Additionally, GDB Parameters can now be created from the API, and
2439 manipulated via set/show in the CLI.
2441 ** New functions gdb.target_charset, gdb.target_wide_charset,
2442 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2444 ** New exception gdb.GdbError.
2446 ** Pretty-printers are now also looked up in the current program space.
2448 ** Pretty-printers can now be individually enabled and disabled.
2450 ** GDB now looks for names of Python scripts to auto-load in a
2451 special section named `.debug_gdb_scripts', in addition to looking
2452 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2454 * Tracepoint actions were unified with breakpoint commands. In particular,
2455 there are no longer differences in "info break" output for breakpoints and
2456 tracepoints and the "commands" command can be used for both tracepoints and
2457 regular breakpoints.
2461 ARM Symbian arm*-*-symbianelf*
2463 * D language support.
2464 GDB now supports debugging programs written in the D programming
2467 * GDB now supports the extended ptrace interface for PowerPC which is
2468 available since Linux kernel version 2.6.34. This automatically enables
2469 any hardware breakpoints and additional hardware watchpoints available in
2470 the processor. The old ptrace interface exposes just one hardware
2471 watchpoint and no hardware breakpoints.
2473 * GDB is now able to use the Data Value Compare (DVC) register available on
2474 embedded PowerPC processors to implement in hardware simple watchpoint
2475 conditions of the form:
2477 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2479 This works in native GDB running on Linux kernels with the extended ptrace
2480 interface mentioned above.
2482 *** Changes in GDB 7.1
2486 ** Namespace Support
2488 GDB now supports importing of namespaces in C++. This enables the
2489 user to inspect variables from imported namespaces. Support for
2490 namepace aliasing has also been added. So, if a namespace is
2491 aliased in the current scope (e.g. namepace C=A; ) the user can
2492 print variables using the alias (e.g. (gdb) print C::x).
2496 All known bugs relating to the printing of virtual base class were
2497 fixed. It is now possible to call overloaded static methods using a
2502 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2503 and reinterpret_cast<> are now handled by the C++ expression parser.
2507 Xilinx MicroBlaze microblaze-*-*
2512 Xilinx MicroBlaze microblaze
2515 * Multi-program debugging.
2517 GDB now has support for multi-program (a.k.a. multi-executable or
2518 multi-exec) debugging. This allows for debugging multiple inferiors
2519 simultaneously each running a different program under the same GDB
2520 session. See "Debugging Multiple Inferiors and Programs" in the
2521 manual for more information. This implied some user visible changes
2522 in the multi-inferior support. For example, "info inferiors" now
2523 lists inferiors that are not running yet or that have exited
2524 already. See also "New commands" and "New options" below.
2526 * New tracing features
2528 GDB's tracepoint facility now includes several new features:
2530 ** Trace state variables
2532 GDB tracepoints now include support for trace state variables, which
2533 are variables managed by the target agent during a tracing
2534 experiment. They are useful for tracepoints that trigger each
2535 other, so for instance one tracepoint can count hits in a variable,
2536 and then a second tracepoint has a condition that is true when the
2537 count reaches a particular value. Trace state variables share the
2538 $-syntax of GDB convenience variables, and can appear in both
2539 tracepoint actions and condition expressions. Use the "tvariable"
2540 command to create, and "info tvariables" to view; see "Trace State
2541 Variables" in the manual for more detail.
2545 GDB now includes an option for defining fast tracepoints, which
2546 targets may implement more efficiently, such as by installing a jump
2547 into the target agent rather than a trap instruction. The resulting
2548 speedup can be by two orders of magnitude or more, although the
2549 tradeoff is that some program locations on some target architectures
2550 might not allow fast tracepoint installation, for instance if the
2551 instruction to be replaced is shorter than the jump. To request a
2552 fast tracepoint, use the "ftrace" command, with syntax identical to
2553 the regular trace command.
2555 ** Disconnected tracing
2557 It is now possible to detach GDB from the target while it is running
2558 a trace experiment, then reconnect later to see how the experiment
2559 is going. In addition, a new variable disconnected-tracing lets you
2560 tell the target agent whether to continue running a trace if the
2561 connection is lost unexpectedly.
2565 GDB now has the ability to save the trace buffer into a file, and
2566 then use that file as a target, similarly to you can do with
2567 corefiles. You can select trace frames, print data that was
2568 collected in them, and use tstatus to display the state of the
2569 tracing run at the moment that it was saved. To create a trace
2570 file, use "tsave <filename>", and to use it, do "target tfile
2573 ** Circular trace buffer
2575 You can ask the target agent to handle the trace buffer as a
2576 circular buffer, discarding the oldest trace frames to make room for
2577 newer ones, by setting circular-trace-buffer to on. This feature may
2578 not be available for all target agents.
2583 The disassemble command, when invoked with two arguments, now requires
2584 the arguments to be comma-separated.
2587 The info variables command now displays variable definitions. Files
2588 which only declare a variable are not shown.
2591 The source command is now capable of sourcing Python scripts.
2592 This feature is dependent on the debugger being build with Python
2595 Related to this enhancement is also the introduction of a new command
2596 "set script-extension" (see below).
2598 * New commands (for set/show, see "New options" below)
2600 record save [<FILENAME>]
2601 Save a file (in core file format) containing the process record
2602 execution log for replay debugging at a later time.
2604 record restore <FILENAME>
2605 Restore the process record execution log that was saved at an
2606 earlier time, for replay debugging.
2608 add-inferior [-copies <N>] [-exec <FILENAME>]
2611 clone-inferior [-copies <N>] [ID]
2612 Make a new inferior ready to execute the same program another
2613 inferior has loaded.
2618 maint info program-spaces
2619 List the program spaces loaded into GDB.
2621 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2622 show remote interrupt-sequence
2623 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2624 as the sequence to the remote target in order to interrupt the execution.
2625 Ctrl-C is a default. Some system prefers BREAK which is high level of
2626 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2627 Magic SysRq g. It is BREAK signal and character 'g'.
2629 set remote interrupt-on-connect [on | off]
2630 show remote interrupt-on-connect
2631 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2632 remote target when gdb connects to it. This is needed when you debug
2635 set remotebreak [on | off]
2637 Deprecated. Use "set/show remote interrupt-sequence" instead.
2639 tvariable $NAME [ = EXP ]
2640 Create or modify a trace state variable.
2643 List trace state variables and their values.
2645 delete tvariable $NAME ...
2646 Delete one or more trace state variables.
2649 Evaluate the given expressions without collecting anything into the
2650 trace buffer. (Valid in tracepoint actions only.)
2652 ftrace FN / FILE:LINE / *ADDR
2653 Define a fast tracepoint at the given function, line, or address.
2655 * New expression syntax
2657 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2658 GDB now parses 0b101010 identically with 42.
2662 set follow-exec-mode new|same
2663 show follow-exec-mode
2664 Control whether GDB reuses the same inferior across an exec call or
2665 creates a new one. This is useful to be able to restart the old
2666 executable after the inferior having done an exec call.
2668 set default-collect EXPR, ...
2669 show default-collect
2670 Define a list of expressions to be collected at each tracepoint.
2671 This is a useful way to ensure essential items are not overlooked,
2672 such as registers or a critical global variable.
2674 set disconnected-tracing
2675 show disconnected-tracing
2676 If set to 1, the target is instructed to continue tracing if it
2677 loses its connection to GDB. If 0, the target is to stop tracing
2680 set circular-trace-buffer
2681 show circular-trace-buffer
2682 If set to on, the target is instructed to use a circular trace buffer
2683 and discard the oldest trace frames instead of stopping the trace due
2684 to a full trace buffer. If set to off, the trace stops when the buffer
2685 fills up. Some targets may not support this.
2687 set script-extension off|soft|strict
2688 show script-extension
2689 If set to "off", the debugger does not perform any script language
2690 recognition, and all sourced files are assumed to be GDB scripts.
2691 If set to "soft" (the default), files are sourced according to
2692 filename extension, falling back to GDB scripts if the first
2694 If set to "strict", files are sourced according to filename extension.
2696 set ada trust-PAD-over-XVS on|off
2697 show ada trust-PAD-over-XVS
2698 If off, activate a workaround against a bug in the debugging information
2699 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2700 the GCC sources for more information about the GNAT encoding and
2701 PAD types in particular). It is always safe to set this option to
2702 off, but this introduces a slight performance penalty. The default
2705 * Python API Improvements
2707 ** GDB provides the new class gdb.LazyString. This is useful in
2708 some pretty-printing cases. The new method gdb.Value.lazy_string
2709 provides a simple way to create objects of this type.
2711 ** The fields returned by gdb.Type.fields now have an
2712 `is_base_class' attribute.
2714 ** The new method gdb.Type.range returns the range of an array type.
2716 ** The new method gdb.parse_and_eval can be used to parse and
2717 evaluate an expression.
2719 * New remote packets
2722 Define a trace state variable.
2725 Get the current value of a trace state variable.
2728 Set desired tracing behavior upon disconnection.
2731 Set the trace buffer to be linear or circular.
2734 Get data about the tracepoints currently in use.
2738 Process record now works correctly with hardware watchpoints.
2740 Multiple bug fixes have been made to the mips-irix port, making it
2741 much more reliable. In particular:
2742 - Debugging threaded applications is now possible again. Previously,
2743 GDB would hang while starting the program, or while waiting for
2744 the program to stop at a breakpoint.
2745 - Attaching to a running process no longer hangs.
2746 - An error occurring while loading a core file has been fixed.
2747 - Changing the value of the PC register now works again. This fixes
2748 problems observed when using the "jump" command, or when calling
2749 a function from GDB, or even when assigning a new value to $pc.
2750 - With the "finish" and "return" commands, the return value for functions
2751 returning a small array is now correctly printed.
2752 - It is now possible to break on shared library code which gets executed
2753 during a shared library init phase (code executed while executing
2754 their .init section). Previously, the breakpoint would have no effect.
2755 - GDB is now able to backtrace through the signal handler for
2756 non-threaded programs.
2758 PIE (Position Independent Executable) programs debugging is now supported.
2759 This includes debugging execution of PIC (Position Independent Code) shared
2760 libraries although for that, it should be possible to run such libraries as an
2763 *** Changes in GDB 7.0
2765 * GDB now has an interface for JIT compilation. Applications that
2766 dynamically generate code can create symbol files in memory and register
2767 them with GDB. For users, the feature should work transparently, and
2768 for JIT developers, the interface is documented in the GDB manual in the
2769 "JIT Compilation Interface" chapter.
2771 * Tracepoints may now be conditional. The syntax is as for
2772 breakpoints; either an "if" clause appended to the "trace" command,
2773 or the "condition" command is available. GDB sends the condition to
2774 the target for evaluation using the same bytecode format as is used
2775 for tracepoint actions.
2777 * The disassemble command now supports: an optional /r modifier, print the
2778 raw instructions in hex as well as in symbolic form, and an optional /m
2779 modifier to print mixed source+assembly.
2781 * Process record and replay
2783 In a architecture environment that supports ``process record and
2784 replay'', ``process record and replay'' target can record a log of
2785 the process execution, and replay it with both forward and reverse
2788 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2789 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2790 set execution-direction {forward|reverse}, for targets that support
2793 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2794 feature is available with a native GDB running on kernel version
2797 * GDB now has support for multi-byte and wide character sets on the
2798 target. Strings whose character type is wchar_t, char16_t, or
2799 char32_t are now correctly printed. GDB supports wide- and unicode-
2800 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2801 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2802 `printf'. This feature requires iconv to work properly; if your
2803 system does not have a working iconv, GDB can use GNU libiconv. See
2804 the installation instructions for more information.
2806 * GDB now supports automatic retrieval of shared library files from
2807 remote targets. To use this feature, specify a system root that begins
2808 with the `remote:' prefix, either via the `set sysroot' command or via
2809 the `--with-sysroot' configure-time option.
2811 * "info sharedlibrary" now takes an optional regex of libraries to show,
2812 and it now reports if a shared library has no debugging information.
2814 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2815 now complete on file names.
2817 * When completing in expressions, gdb will attempt to limit
2818 completions to allowable structure or union fields, where appropriate.
2819 For instance, consider:
2821 # struct example { int f1; double f2; };
2822 # struct example variable;
2825 If the user types TAB at the end of this command line, the available
2826 completions will be "f1" and "f2".
2828 * Inlined functions are now supported. They show up in backtraces, and
2829 the "step", "next", and "finish" commands handle them automatically.
2831 * GDB now supports the token-splicing (##) and stringification (#)
2832 operators when expanding macros. It also supports variable-arity
2835 * GDB now supports inspecting extra signal information, exported by
2836 the new $_siginfo convenience variable. The feature is currently
2837 implemented on linux ARM, i386 and amd64.
2839 * GDB can now display the VFP floating point registers and NEON vector
2840 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2841 can provide these registers (requires Linux 2.6.30 or later). Remote
2842 and simulator targets may also provide them.
2844 * New remote packets
2847 Search memory for a sequence of bytes.
2850 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2851 operation over reliable transport links. Use of this packet is
2852 controlled by the `set remote noack-packet' command.
2855 Kill the process with the specified process ID. Use this in preference
2856 to `k' when multiprocess protocol extensions are supported.
2859 Obtains additional operating system information
2863 Read or write additional signal information.
2865 * Removed remote protocol undocumented extension
2867 An undocumented extension to the remote protocol's `S' stop reply
2868 packet that permited the stub to pass a process id was removed.
2869 Remote servers should use the `T' stop reply packet instead.
2871 * GDB now supports multiple function calling conventions according to the
2872 DWARF-2 DW_AT_calling_convention function attribute.
2874 * The SH target utilizes the aforementioned change to distinguish between gcc
2875 and Renesas calling convention. It also adds the new CLI commands
2876 `set/show sh calling-convention'.
2878 * GDB can now read compressed debug sections, as produced by GNU gold
2879 with the --compress-debug-sections=zlib flag.
2881 * 64-bit core files are now supported on AIX.
2883 * Thread switching is now supported on Tru64.
2885 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2886 which will be allocated using malloc later in program execution.
2888 * The qXfer:libraries:read remote procotol packet now allows passing a
2889 list of section offsets.
2891 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2892 conditions handling signals delivered during attach or thread creation
2893 have also been fixed.
2895 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2896 From the user's standpoint, all unqualified instances of True and False
2897 are treated as the standard definitions, regardless of context.
2899 * GDB now parses C++ symbol and type names more flexibly. For
2902 template<typename T> class C { };
2905 GDB will now correctly handle all of:
2907 ptype C<char const *>
2908 ptype C<char const*>
2909 ptype C<const char *>
2910 ptype C<const char*>
2912 * New features in the GDB remote stub, gdbserver
2914 - The "--wrapper" command-line argument tells gdbserver to use a
2915 wrapper program to launch programs for debugging.
2917 - On PowerPC and S/390 targets, it is now possible to use a single
2918 gdbserver executable to debug both 32-bit and 64-bit programs.
2919 (This requires gdbserver itself to be built as a 64-bit executable.)
2921 - gdbserver uses the new noack protocol mode for TCP connections to
2922 reduce communications latency, if also supported and enabled in GDB.
2924 - Support for the sparc64-linux-gnu target is now included in
2927 - The amd64-linux build of gdbserver now supports debugging both
2928 32-bit and 64-bit programs.
2930 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2931 now support hardware watchpoints, and will use them automatically
2936 GDB now has support for scripting using Python. Whether this is
2937 available is determined at configure time.
2939 New GDB commands can now be written in Python.
2941 * Ada tasking support
2943 Ada tasks can now be inspected in GDB. The following commands have
2947 Print the list of Ada tasks.
2949 Print detailed information about task number N.
2951 Print the task number of the current task.
2953 Switch the context of debugging to task number N.
2955 * Support for user-defined prefixed commands. The "define" command can
2956 add new commands to existing prefixes, e.g. "target".
2958 * Multi-inferior, multi-process debugging.
2960 GDB now has generalized support for multi-inferior debugging. See
2961 "Debugging Multiple Inferiors" in the manual for more information.
2962 Although availability still depends on target support, the command
2963 set is more uniform now. The GNU/Linux specific multi-forks support
2964 has been migrated to this new framework. This implied some user
2965 visible changes; see "New commands" and also "Removed commands"
2968 * Target descriptions can now describe the target OS ABI. See the
2969 "Target Description Format" section in the user manual for more
2972 * Target descriptions can now describe "compatible" architectures
2973 to indicate that the target can execute applications for a different
2974 architecture in addition to those for the main target architecture.
2975 See the "Target Description Format" section in the user manual for
2978 * Multi-architecture debugging.
2980 GDB now includes general supports for debugging applications on
2981 hybrid systems that use more than one single processor architecture
2982 at the same time. Each such hybrid architecture still requires
2983 specific support to be added. The only hybrid architecture supported
2984 in this version of GDB is the Cell Broadband Engine.
2986 * GDB now supports integrated debugging of Cell/B.E. applications that
2987 use both the PPU and SPU architectures. To enable support for hybrid
2988 Cell/B.E. debugging, you need to configure GDB to support both the
2989 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2990 --enable-targets configure option.
2992 * Non-stop mode debugging.
2994 For some targets, GDB now supports an optional mode of operation in
2995 which you can examine stopped threads while other threads continue
2996 to execute freely. This is referred to as non-stop mode, with the
2997 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2998 section in the user manual for more information.
3000 To be able to support remote non-stop debugging, a remote stub needs
3001 to implement the non-stop mode remote protocol extensions, as
3002 described in the "Remote Non-Stop" section of the user manual. The
3003 GDB remote stub, gdbserver, has been adjusted to support these
3004 extensions on linux targets.
3006 * New commands (for set/show, see "New options" below)
3008 catch syscall [NAME(S) | NUMBER(S)]
3009 Catch system calls. Arguments, which should be names of system
3010 calls or their numbers, mean catch only those syscalls. Without
3011 arguments, every syscall will be caught. When the inferior issues
3012 any of the specified syscalls, GDB will stop and announce the system
3013 call, both when it is called and when its call returns. This
3014 feature is currently available with a native GDB running on the
3015 Linux Kernel, under the following architectures: x86, x86_64,
3016 PowerPC and PowerPC64.
3018 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3020 Search memory for a sequence of bytes.
3022 maint set python print-stack
3023 maint show python print-stack
3024 Show a stack trace when an error is encountered in a Python script.
3027 Invoke CODE by passing it to the Python interpreter.
3032 These allow macros to be defined, undefined, and listed
3036 Show operating system information about processes.
3039 List the inferiors currently under GDB's control.
3042 Switch focus to inferior number NUM.
3045 Detach from inferior number NUM.
3048 Kill inferior number NUM.
3052 set spu stop-on-load
3053 show spu stop-on-load
3054 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3056 set spu auto-flush-cache
3057 show spu auto-flush-cache
3058 Control whether to automatically flush the software-managed cache
3059 during Cell/B.E. debugging.
3061 set sh calling-convention
3062 show sh calling-convention
3063 Control the calling convention used when calling SH target functions.
3066 show debug timestamp
3067 Control display of timestamps with GDB debugging output.
3069 set disassemble-next-line
3070 show disassemble-next-line
3071 Control display of disassembled source lines or instructions when
3074 set remote noack-packet
3075 show remote noack-packet
3076 Set/show the use of remote protocol QStartNoAckMode packet. See above
3077 under "New remote packets."
3079 set remote query-attached-packet
3080 show remote query-attached-packet
3081 Control use of remote protocol `qAttached' (query-attached) packet.
3083 set remote read-siginfo-object
3084 show remote read-siginfo-object
3085 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3088 set remote write-siginfo-object
3089 show remote write-siginfo-object
3090 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3093 set remote reverse-continue
3094 show remote reverse-continue
3095 Control use of remote protocol 'bc' (reverse-continue) packet.
3097 set remote reverse-step
3098 show remote reverse-step
3099 Control use of remote protocol 'bs' (reverse-step) packet.
3101 set displaced-stepping
3102 show displaced-stepping
3103 Control displaced stepping mode. Displaced stepping is a way to
3104 single-step over breakpoints without removing them from the debuggee.
3105 Also known as "out-of-line single-stepping".
3108 show debug displaced
3109 Control display of debugging info for displaced stepping.
3111 maint set internal-error
3112 maint show internal-error
3113 Control what GDB does when an internal error is detected.
3115 maint set internal-warning
3116 maint show internal-warning
3117 Control what GDB does when an internal warning is detected.
3122 Use a wrapper program to launch programs for debugging.
3124 set multiple-symbols (all|ask|cancel)
3125 show multiple-symbols
3126 The value of this variable can be changed to adjust the debugger behavior
3127 when an expression or a breakpoint location contains an ambiguous symbol
3128 name (an overloaded function name, for instance).
3130 set breakpoint always-inserted
3131 show breakpoint always-inserted
3132 Keep breakpoints always inserted in the target, as opposed to inserting
3133 them when resuming the target, and removing them when the target stops.
3134 This option can improve debugger performance on slow remote targets.
3136 set arm fallback-mode (arm|thumb|auto)
3137 show arm fallback-mode
3138 set arm force-mode (arm|thumb|auto)
3140 These commands control how ARM GDB determines whether instructions
3141 are ARM or Thumb. The default for both settings is auto, which uses
3142 the current CPSR value for instructions without symbols; previous
3143 versions of GDB behaved as if "set arm fallback-mode arm".
3145 set disable-randomization
3146 show disable-randomization
3147 Standalone programs run with the virtual address space randomization enabled
3148 by default on some platforms. This option keeps the addresses stable across
3149 multiple debugging sessions.
3153 Control whether other threads are stopped or not when some thread hits
3158 Requests that asynchronous execution is enabled in the target, if available.
3159 In this case, it's possible to resume target in the background, and interact
3160 with GDB while the target is running. "show target-async" displays the
3161 current state of asynchronous execution of the target.
3163 set target-wide-charset
3164 show target-wide-charset
3165 The target-wide-charset is the name of the character set that GDB
3166 uses when printing characters whose type is wchar_t.
3168 set tcp auto-retry (on|off)
3170 set tcp connect-timeout
3171 show tcp connect-timeout
3172 These commands allow GDB to retry failed TCP connections to a remote stub
3173 with a specified timeout period; this is useful if the stub is launched
3174 in parallel with GDB but may not be ready to accept connections immediately.
3176 set libthread-db-search-path
3177 show libthread-db-search-path
3178 Control list of directories which GDB will search for appropriate
3181 set schedule-multiple (on|off)
3182 show schedule-multiple
3183 Allow GDB to resume all threads of all processes or only threads of
3184 the current process.
3188 Use more aggressive caching for accesses to the stack. This improves
3189 performance of remote debugging (particularly backtraces) without
3190 affecting correctness.
3192 set interactive-mode (on|off|auto)
3193 show interactive-mode
3194 Control whether GDB runs in interactive mode (on) or not (off).
3195 When in interactive mode, GDB waits for the user to answer all
3196 queries. Otherwise, GDB does not wait and assumes the default
3197 answer. When set to auto (the default), GDB determines which
3198 mode to use based on the stdin settings.
3203 For program forks, this is replaced by the new more generic `info
3204 inferiors' command. To list checkpoints, you can still use the
3205 `info checkpoints' command, which was an alias for the `info forks'
3209 Replaced by the new `inferior' command. To switch between
3210 checkpoints, you can still use the `restart' command, which was an
3211 alias for the `fork' command.
3214 This is removed, since some targets don't have a notion of
3215 processes. To switch between processes, you can still use the
3216 `inferior' command using GDB's own inferior number.
3219 For program forks, this is replaced by the new more generic `kill
3220 inferior' command. To delete a checkpoint, you can still use the
3221 `delete checkpoint' command, which was an alias for the `delete
3225 For program forks, this is replaced by the new more generic `detach
3226 inferior' command. To detach a checkpoint, you can still use the
3227 `detach checkpoint' command, which was an alias for the `detach
3230 * New native configurations
3232 x86/x86_64 Darwin i[34567]86-*-darwin*
3234 x86_64 MinGW x86_64-*-mingw*
3238 Lattice Mico32 lm32-*
3239 x86 DICOS i[34567]86-*-dicos*
3240 x86_64 DICOS x86_64-*-dicos*
3243 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3244 (mingw32ce) debugging.
3250 These commands were actually not implemented on any target.
3252 *** Changes in GDB 6.8
3254 * New native configurations
3256 NetBSD/hppa hppa*-*netbsd*
3257 Xtensa GNU/Linux xtensa*-*-linux*
3261 NetBSD/hppa hppa*-*-netbsd*
3262 Xtensa GNU/Lunux xtensa*-*-linux*
3264 * Change in command line behavior -- corefiles vs. process ids.
3266 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3267 attaching to process NUMBER fails, GDB no longer attempts to open a
3268 core file named NUMBER. Attaching to a program using the -c option
3269 is no longer supported. Instead, use the '-p' or '--pid' options.
3271 * GDB can now be built as a native debugger for debugging Windows x86
3272 (mingw32) Portable Executable (PE) programs.
3274 * Pending breakpoints no longer change their number when their address
3277 * GDB now supports breakpoints with multiple locations,
3278 including breakpoints on C++ constructors, inside C++ templates,
3279 and in inlined functions.
3281 * GDB's ability to debug optimized code has been improved. GDB more
3282 accurately identifies function bodies and lexical blocks that occupy
3283 more than one contiguous range of addresses.
3285 * Target descriptions can now describe registers for PowerPC.
3287 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3288 registers on PowerPC targets.
3290 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3291 targets even when the libthread_db library is not available.
3293 * The GDB remote stub, gdbserver, now supports the new file transfer
3294 commands (remote put, remote get, and remote delete).
3296 * The GDB remote stub, gdbserver, now supports run and attach in
3297 extended-remote mode.
3299 * hppa*64*-*-hpux11* target broken
3300 The debugger is unable to start a program and fails with the following
3301 error: "Error trying to get information about dynamic linker".
3302 The gdb-6.7 release is also affected.
3304 * GDB now supports the --enable-targets= configure option to allow
3305 building a single GDB executable that supports multiple remote
3306 target architectures.
3308 * GDB now supports debugging C and C++ programs which use the
3309 Decimal Floating Point extension. In addition, the PowerPC target
3310 now has a set of pseudo-registers to inspect decimal float values
3311 stored in two consecutive float registers.
3313 * The -break-insert MI command can optionally create pending
3316 * Improved support for debugging Ada
3317 Many improvements to the Ada language support have been made. These
3319 - Better support for Ada2005 interface types
3320 - Improved handling of arrays and slices in general
3321 - Better support for Taft-amendment types
3322 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3324 - Improved command completion in Ada
3327 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3332 set print frame-arguments (all|scalars|none)
3333 show print frame-arguments
3334 The value of this variable can be changed to control which argument
3335 values should be printed by the debugger when displaying a frame.
3340 Transfer files to and from a remote target, and delete remote files.
3347 Transfer files to and from a remote target, and delete remote files.
3349 * New remote packets
3356 Open, close, read, write, and delete files on the remote system.
3359 Attach to an existing process on the remote system, in extended-remote
3363 Run a new process on the remote system, in extended-remote mode.
3365 *** Changes in GDB 6.7
3367 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3368 bfd, libiberty and opcodes, as revealed by static analysis donated by
3369 Coverity, Inc. (http://scan.coverity.com).
3371 * When looking up multiply-defined global symbols, GDB will now prefer the
3372 symbol definition in the current shared library if it was built using the
3373 -Bsymbolic linker option.
3375 * When the Text User Interface (TUI) is not configured, GDB will now
3376 recognize the -tui command-line option and print a message that the TUI
3379 * The GDB remote stub, gdbserver, now has lower overhead for high
3380 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3382 * GDB for MIPS targets now autodetects whether a remote target provides
3383 32-bit or 64-bit register values.
3385 * Support for C++ member pointers has been improved.
3387 * GDB now understands XML target descriptions, which specify the
3388 target's overall architecture. GDB can read a description from
3389 a local file or over the remote serial protocol.
3391 * Vectors of single-byte data use a new integer type which is not
3392 automatically displayed as character or string data.
3394 * The /s format now works with the print command. It displays
3395 arrays of single-byte integers and pointers to single-byte integers
3398 * Target descriptions can now describe target-specific registers,
3399 for architectures which have implemented the support (currently
3400 only ARM, M68K, and MIPS).
3402 * GDB and the GDB remote stub, gdbserver, now support the XScale
3405 * The GDB remote stub, gdbserver, has been updated to support
3406 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3407 has been rewritten to use the standard GDB remote protocol.
3409 * GDB can now step into C++ functions which are called through thunks.
3411 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3413 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3414 layout. It also supports a TextSeg= and DataSeg= response when only
3415 segment base addresses (rather than offsets) are available.
3417 * The /i format now outputs any trailing branch delay slot instructions
3418 immediately following the last instruction within the count specified.
3420 * The GDB remote protocol "T" stop reply packet now supports a
3421 "library" response. Combined with the new "qXfer:libraries:read"
3422 packet, this response allows GDB to debug shared libraries on targets
3423 where the operating system manages the list of loaded libraries (e.g.
3424 Windows and SymbianOS).
3426 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3427 (DLLs) on Windows and Windows CE targets.
3429 * GDB now supports a faster verification that a .debug file matches its binary
3430 according to its build-id signature, if the signature is present.
3436 Enable or disable hardware flow control (RTS/CTS) on the serial port
3437 when debugging using remote targets.
3439 set mem inaccessible-by-default
3440 show mem inaccessible-by-default
3441 If the target supplies a memory map, for instance via the remote
3442 protocol's "qXfer:memory-map:read" packet, setting this variable
3443 prevents GDB from accessing memory outside the memory map. This
3444 is useful for targets with memory mapped registers or which react
3445 badly to accesses of unmapped address space.
3447 set breakpoint auto-hw
3448 show breakpoint auto-hw
3449 If the target supplies a memory map, for instance via the remote
3450 protocol's "qXfer:memory-map:read" packet, setting this variable
3451 lets GDB use hardware breakpoints automatically for memory regions
3452 where it can not use software breakpoints. This covers both the
3453 "break" command and internal breakpoints used for other commands
3454 including "next" and "finish".
3457 catch exception unhandled
3458 Stop the program execution when Ada exceptions are raised.
3461 Stop the program execution when an Ada assertion failed.
3465 Set an alternate system root for target files. This is a more
3466 general version of "set solib-absolute-prefix", which is now
3467 an alias to "set sysroot".
3470 Provide extended SPU facility status information. This set of
3471 commands is available only when debugging the Cell/B.E. SPU
3474 * New native configurations
3476 OpenBSD/sh sh*-*openbsd*
3479 unset tdesc filename
3481 Use the specified local file as an XML target description, and do
3482 not query the target for its built-in description.
3486 OpenBSD/sh sh*-*-openbsd*
3487 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3488 Toshiba Media Processor mep-elf
3490 * New remote packets
3493 Ignore the specified signals; pass them directly to the debugged program
3494 without stopping other threads or reporting them to GDB.
3496 qXfer:features:read:
3497 Read an XML target description from the target, which describes its
3502 Read or write contents of an spufs file on the target system. These
3503 packets are available only on the Cell/B.E. SPU architecture.
3505 qXfer:libraries:read:
3506 Report the loaded shared libraries. Combined with new "T" packet
3507 response, this packet allows GDB to debug shared libraries on
3508 targets where the operating system manages the list of loaded
3509 libraries (e.g. Windows and SymbianOS).
3513 Support for these obsolete configurations has been removed.
3521 i[34567]86-*-lynxos*
3522 i[34567]86-*-netware*
3523 i[34567]86-*-sco3.2v5*
3524 i[34567]86-*-sco3.2v4*
3526 i[34567]86-*-sysv4.2*
3529 i[34567]86-*-unixware2*
3530 i[34567]86-*-unixware*
3539 * Other removed features
3546 Various m68k-only ROM monitors.
3553 Various Renesas ROM monitors and debugging interfaces for SH and
3558 Support for a Macraigor serial interface to on-chip debugging.
3559 GDB does not directly support the newer parallel or USB
3564 A debug information format. The predecessor to DWARF 2 and
3565 DWARF 3, which are still supported.
3567 Support for the HP aCC compiler on HP-UX/PA-RISC
3569 SOM-encapsulated symbolic debugging information, automatic
3570 invocation of pxdb, and the aCC custom C++ ABI. This does not
3571 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3572 with aCC can still be debugged on an assembly level.
3574 MIPS ".pdr" sections
3576 A MIPS-specific format used to describe stack frame layout
3577 in debugging information.
3581 GDB could work with an older version of Guile to debug
3582 the interpreter and Scheme programs running in it.
3584 set mips stack-arg-size
3585 set mips saved-gpreg-size
3587 Use "set mips abi" to control parameter passing for MIPS.
3589 *** Changes in GDB 6.6
3594 Cell Broadband Engine SPU spu-elf
3596 * GDB can now be configured as a cross-debugger targeting native Windows
3597 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3598 running on a Windows system over TCP/IP to debug Windows programs.
3600 * The GDB remote stub, gdbserver, has been updated to support Windows and
3601 Cygwin debugging. Both single-threaded and multi-threaded programs are
3604 * The "set trust-readonly-sections" command works again. This command was
3605 broken in GDB 6.3, 6.4, and 6.5.
3607 * The "load" command now supports writing to flash memory, if the remote
3608 stub provides the required support.
3610 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3611 longer requires symbolic debug information (e.g. DWARF-2).
3616 unset substitute-path
3617 show substitute-path
3618 Manage a list of substitution rules that GDB uses to rewrite the name
3619 of the directories where the sources are located. This can be useful
3620 for instance when the sources were moved to a different location
3621 between compilation and debugging.
3625 Print each CLI command as it is executed. Each command is prefixed with
3626 a number of `+' symbols representing the nesting depth.
3627 The source command now has a `-v' option to enable the same feature.
3631 The ARM Demon monitor support (RDP protocol, "target rdp").
3633 Kernel Object Display, an embedded debugging feature which only worked with
3634 an obsolete version of Cisco IOS.
3636 The 'set download-write-size' and 'show download-write-size' commands.
3638 * New remote packets
3641 Tell a stub about GDB client features, and request remote target features.
3642 The first feature implemented is PacketSize, which allows the target to
3643 specify the size of packets it can handle - to minimize the number of
3644 packets required and improve performance when connected to a remote
3648 Fetch an OS auxilliary vector from the remote stub. This packet is a
3649 more efficient replacement for qPart:auxv:read.
3651 qXfer:memory-map:read:
3652 Fetch a memory map from the remote stub, including information about
3653 RAM, ROM, and flash memory devices.
3658 Erase and program a flash memory device.
3660 * Removed remote packets
3663 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3664 used it, and only gdbserver implemented it.
3666 *** Changes in GDB 6.5
3670 Renesas M32C/M16C m32c-elf
3672 Morpho Technologies ms1 ms1-elf
3676 init-if-undefined Initialize a convenience variable, but
3677 only if it doesn't already have a value.
3679 The following commands are presently only implemented for native GNU/Linux:
3681 checkpoint Save a snapshot of the program state.
3683 restart <n> Return the program state to a
3684 previously saved state.
3686 info checkpoints List currently saved checkpoints.
3688 delete-checkpoint <n> Delete a previously saved checkpoint.
3690 set|show detach-on-fork Tell gdb whether to detach from a newly
3691 forked process, or to keep debugging it.
3693 info forks List forks of the user program that
3694 are available to be debugged.
3696 fork <n> Switch to debugging one of several
3697 forks of the user program that are
3698 available to be debugged.
3700 delete-fork <n> Delete a fork from the list of forks
3701 that are available to be debugged (and
3702 kill the forked process).
3704 detach-fork <n> Delete a fork from the list of forks
3705 that are available to be debugged (and
3706 allow the process to continue).
3710 Morpho Technologies ms2 ms1-elf
3712 * Improved Windows host support
3714 GDB now builds as a cross debugger hosted on i686-mingw32, including
3715 native console support, and remote communications using either
3716 network sockets or serial ports.
3718 * Improved Modula-2 language support
3720 GDB can now print most types in the Modula-2 syntax. This includes:
3721 basic types, set types, record types, enumerated types, range types,
3722 pointer types and ARRAY types. Procedure var parameters are correctly
3723 printed and hexadecimal addresses and character constants are also
3724 written in the Modula-2 syntax. Best results can be obtained by using
3725 GNU Modula-2 together with the -gdwarf-2 command line option.
3729 The ARM rdi-share module.
3731 The Netware NLM debug server.
3733 *** Changes in GDB 6.4
3735 * New native configurations
3737 OpenBSD/arm arm*-*-openbsd*
3738 OpenBSD/mips64 mips64-*-openbsd*
3742 Morpho Technologies ms1 ms1-elf
3744 * New command line options
3746 --batch-silent As for --batch, but totally silent.
3747 --return-child-result The debugger will exist with the same value
3748 the child (debugged) program exited with.
3749 --eval-command COMMAND, -ex COMMAND
3750 Execute a single GDB CLI command. This may be
3751 specified multiple times and in conjunction
3752 with the --command (-x) option.
3754 * Deprecated commands removed
3756 The following commands, that were deprecated in 2000, have been
3760 set|show arm disassembly-flavor set|show arm disassembler
3761 othernames set arm disassembler
3762 set|show remotedebug set|show debug remote
3763 set|show archdebug set|show debug arch
3764 set|show eventdebug set|show debug event
3767 * New BSD user-level threads support
3769 It is now possible to debug programs using the user-level threads
3770 library on OpenBSD and FreeBSD. Currently supported (target)
3773 FreeBSD/amd64 x86_64-*-freebsd*
3774 FreeBSD/i386 i386-*-freebsd*
3775 OpenBSD/i386 i386-*-openbsd*
3777 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3778 are not yet supported.
3780 * New support for Matsushita MN10300 w/sim added
3781 (Work in progress). mn10300-elf.
3783 * REMOVED configurations and files
3785 VxWorks and the XDR protocol *-*-vxworks
3786 Motorola MCORE mcore-*-*
3787 National Semiconductor NS32000 ns32k-*-*
3789 * New "set print array-indexes" command
3791 After turning this setting "on", GDB prints the index of each element
3792 when displaying arrays. The default is "off" to preserve the previous
3795 * VAX floating point support
3797 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3799 * User-defined command support
3801 In addition to using $arg0..$arg9 for argument passing, it is now possible
3802 to use $argc to determine now many arguments have been passed. See the
3803 section on user-defined commands in the user manual for more information.
3805 *** Changes in GDB 6.3:
3807 * New command line option
3809 GDB now accepts -l followed by a number to set the timeout for remote
3812 * GDB works with GCC -feliminate-dwarf2-dups
3814 GDB now supports a more compact representation of DWARF-2 debug
3815 information using DW_FORM_ref_addr references. These are produced
3816 by GCC with the option -feliminate-dwarf2-dups and also by some
3817 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3818 to use -feliminate-dwarf2-dups.
3820 * Internationalization
3822 When supported by the host system, GDB will be built with
3823 internationalization (libintl). The task of marking up the sources is
3824 continued, we're looking forward to our first translation.
3828 Initial support for debugging programs compiled with the GNAT
3829 implementation of the Ada programming language has been integrated
3830 into GDB. In this release, support is limited to expression evaluation.
3832 * New native configurations
3834 GNU/Linux/m32r m32r-*-linux-gnu
3838 GDB's remote protocol now includes support for the 'p' packet. This
3839 packet is used to fetch individual registers from a remote inferior.
3841 * END-OF-LIFE registers[] compatibility module
3843 GDB's internal register infrastructure has been completely rewritten.
3844 The new infrastructure making possible the implementation of key new
3845 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3848 GDB 6.3 will be the last release to include the the registers[]
3849 compatibility module that allowed out-of-date configurations to
3850 continue to work. This change directly impacts the following
3860 powerpc bdm protocol
3862 Unless there is activity to revive these configurations, they will be
3863 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3865 * OBSOLETE configurations and files
3867 Configurations that have been declared obsolete in this release have
3868 been commented out. Unless there is activity to revive these
3869 configurations, the next release of GDB will have their sources
3870 permanently REMOVED.
3879 *** Changes in GDB 6.2.1:
3881 * MIPS `break main; run' gave an heuristic-fence-post warning
3883 When attempting to run even a simple program, a warning about
3884 heuristic-fence-post being hit would be reported. This problem has
3887 * MIPS IRIX 'long double' crashed GDB
3889 When examining a long double variable, GDB would get a segmentation
3890 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3891 IRIX long double values).
3895 A bug in the VAX stack code was causing problems with the "next"
3896 command. This problem has been fixed.
3898 *** Changes in GDB 6.2:
3900 * Fix for ``many threads''
3902 On GNU/Linux systems that use the NPTL threads library, a program
3903 rapidly creating and deleting threads would confuse GDB leading to the
3906 ptrace: No such process.
3907 thread_db_get_info: cannot get thread info: generic error
3909 This problem has been fixed.
3911 * "-async" and "-noasync" options removed.
3913 Support for the broken "-noasync" option has been removed (it caused
3916 * New ``start'' command.
3918 This command runs the program until the begining of the main procedure.
3920 * New BSD Kernel Data Access Library (libkvm) interface
3922 Using ``target kvm'' it is now possible to debug kernel core dumps and
3923 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3924 platforms. Currently supported (native-only) configurations are:
3926 FreeBSD/amd64 x86_64-*-freebsd*
3927 FreeBSD/i386 i?86-*-freebsd*
3928 NetBSD/i386 i?86-*-netbsd*
3929 NetBSD/m68k m68*-*-netbsd*
3930 NetBSD/sparc sparc-*-netbsd*
3931 OpenBSD/amd64 x86_64-*-openbsd*
3932 OpenBSD/i386 i?86-*-openbsd*
3933 OpenBSD/m68k m68*-openbsd*
3934 OpenBSD/sparc sparc-*-openbsd*
3936 * Signal trampoline code overhauled
3938 Many generic problems with GDB's signal handling code have been fixed.
3939 These include: backtraces through non-contiguous stacks; recognition
3940 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3941 call; backtrace through a signal trampoline; step into and out of
3942 signal handlers; and single-stepping in the signal trampoline.
3944 Please note that kernel bugs are a limiting factor here. These
3945 features have been shown to work on an s390 GNU/Linux system that
3946 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3948 * Cygwin support for DWARF 2 added.
3950 * New native configurations
3952 GNU/Linux/hppa hppa*-*-linux*
3953 OpenBSD/hppa hppa*-*-openbsd*
3954 OpenBSD/m68k m68*-*-openbsd*
3955 OpenBSD/m88k m88*-*-openbsd*
3956 OpenBSD/powerpc powerpc-*-openbsd*
3957 NetBSD/vax vax-*-netbsd*
3958 OpenBSD/vax vax-*-openbsd*
3960 * END-OF-LIFE frame compatibility module
3962 GDB's internal frame infrastructure has been completely rewritten.
3963 The new infrastructure making it possible to support key new features
3964 including DWARF 2 Call Frame Information. To aid in the task of
3965 migrating old configurations to this new infrastructure, a
3966 compatibility module, that allowed old configurations to continue to
3967 work, was also included.
3969 GDB 6.2 will be the last release to include this frame compatibility
3970 module. This change directly impacts the following configurations:
3980 Unless there is activity to revive these configurations, they will be
3981 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3983 * REMOVED configurations and files
3985 Sun 3, running SunOS 3 m68*-*-sunos3*
3986 Sun 3, running SunOS 4 m68*-*-sunos4*
3987 Sun 2, running SunOS 3 m68000-*-sunos3*
3988 Sun 2, running SunOS 4 m68000-*-sunos4*
3989 Motorola 680x0 running LynxOS m68*-*-lynxos*
3990 AT&T 3b1/Unix pc m68*-att-*
3991 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3992 decstation mips-dec-* mips-little-*
3993 riscos mips-*-riscos* mips-*-sysv*
3994 sonymips mips-sony-*
3995 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3997 *** Changes in GDB 6.1.1:
3999 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4001 The TUI (Text-mode User Interface) is now built as part of a default
4002 GDB configuration. It is enabled by either selecting the TUI with the
4003 command line option "-i=tui" or by running the separate "gdbtui"
4004 program. For more information on the TUI, see the manual "Debugging
4007 * Pending breakpoint support (also included in GDB 6.1)
4009 Support has been added to allow you to specify breakpoints in shared
4010 libraries that have not yet been loaded. If a breakpoint location
4011 cannot be found, and the "breakpoint pending" option is set to auto,
4012 GDB queries you if you wish to make the breakpoint pending on a future
4013 shared-library load. If and when GDB resolves the breakpoint symbol,
4014 the pending breakpoint is removed as one or more regular breakpoints
4017 Pending breakpoints are very useful for GCJ Java debugging.
4019 * Fixed ISO-C build problems
4021 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4022 non ISO-C code that stopped them being built using a more strict ISO-C
4023 compiler (e.g., IBM's C compiler).
4025 * Fixed build problem on IRIX 5
4027 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4028 wasn't able to compile compile on an IRIX 5 system.
4030 * Added execute permission to gdb/gdbserver/configure
4032 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4033 permission. This bug would cause configure to fail on a number of
4034 systems (Solaris, IRIX). Ref: server/519.
4036 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4038 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4039 has been updated to use constant array sizes.
4041 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4043 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4044 its generated DWARF Call Frame Info. This encoding was causing GDB to
4045 panic, that panic has been fixed. Ref: gdb/1628.
4047 * Fixed a problem when examining parameters in shared library code.
4049 When examining parameters in optimized shared library code generated
4050 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4051 not available''. GDB now correctly displays the variable's value.
4053 *** Changes in GDB 6.1:
4055 * Removed --with-mmalloc
4057 Support for the mmalloc memory manager has been removed, as it
4058 conflicted with the internal gdb byte cache.
4060 * Changes in AMD64 configurations
4062 The AMD64 target now includes the %cs and %ss registers. As a result
4063 the AMD64 remote protocol has changed; this affects the floating-point
4064 and SSE registers. If you rely on those registers for your debugging,
4065 you should upgrade gdbserver on the remote side.
4067 * Revised SPARC target
4069 The SPARC target has been completely revised, incorporating the
4070 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4071 support for LynxOS and SunOS 4 has been dropped. Calling functions
4072 from within GDB on operating systems with a non-executable stack
4073 (Solaris, OpenBSD) now works.
4077 GDB has a new C++ demangler which does a better job on the mangled
4078 names generated by current versions of g++. It also runs faster, so
4079 with this and other changes gdb should now start faster on large C++
4082 * DWARF 2 Location Expressions
4084 GDB support for location expressions has been extended to support function
4085 arguments and frame bases. Older versions of GDB could crash when they
4088 * C++ nested types and namespaces
4090 GDB's support for nested types and namespaces in C++ has been
4091 improved, especially if you use the DWARF 2 debugging format. (This
4092 is the default for recent versions of GCC on most platforms.)
4093 Specifically, if you have a class "Inner" defined within a class or
4094 namespace "Outer", then GDB realizes that the class's name is
4095 "Outer::Inner", not simply "Inner". This should greatly reduce the
4096 frequency of complaints about not finding RTTI symbols. In addition,
4097 if you are stopped at inside of a function defined within a namespace,
4098 GDB modifies its name lookup accordingly.
4100 * New native configurations
4102 NetBSD/amd64 x86_64-*-netbsd*
4103 OpenBSD/amd64 x86_64-*-openbsd*
4104 OpenBSD/alpha alpha*-*-openbsd*
4105 OpenBSD/sparc sparc-*-openbsd*
4106 OpenBSD/sparc64 sparc64-*-openbsd*
4108 * New debugging protocols
4110 M32R with SDI protocol m32r-*-elf*
4112 * "set prompt-escape-char" command deleted.
4114 The command "set prompt-escape-char" has been deleted. This command,
4115 and its very obscure effet on GDB's prompt, was never documented,
4116 tested, nor mentioned in the NEWS file.
4118 * OBSOLETE configurations and files
4120 Configurations that have been declared obsolete in this release have
4121 been commented out. Unless there is activity to revive these
4122 configurations, the next release of GDB will have their sources
4123 permanently REMOVED.
4125 Sun 3, running SunOS 3 m68*-*-sunos3*
4126 Sun 3, running SunOS 4 m68*-*-sunos4*
4127 Sun 2, running SunOS 3 m68000-*-sunos3*
4128 Sun 2, running SunOS 4 m68000-*-sunos4*
4129 Motorola 680x0 running LynxOS m68*-*-lynxos*
4130 AT&T 3b1/Unix pc m68*-att-*
4131 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4132 decstation mips-dec-* mips-little-*
4133 riscos mips-*-riscos* mips-*-sysv*
4134 sonymips mips-sony-*
4135 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4137 * REMOVED configurations and files
4139 SGI Irix-4.x mips-sgi-irix4 or iris4
4140 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4141 Z8000 simulator z8k-zilog-none or z8ksim
4142 Matsushita MN10200 w/simulator mn10200-*-*
4143 H8/500 simulator h8500-hitachi-hms or h8500hms
4144 HP/PA running BSD hppa*-*-bsd*
4145 HP/PA running OSF/1 hppa*-*-osf*
4146 HP/PA Pro target hppa*-*-pro*
4147 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4148 386BSD i[3456]86-*-bsd*
4149 Sequent family i[3456]86-sequent-sysv4*
4150 i[3456]86-sequent-sysv*
4151 i[3456]86-sequent-bsd*
4152 SPARC running LynxOS sparc-*-lynxos*
4153 SPARC running SunOS 4 sparc-*-sunos4*
4154 Tsqware Sparclet sparclet-*-*
4155 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4157 *** Changes in GDB 6.0:
4161 Support for debugging the Objective-C programming language has been
4162 integrated into GDB.
4164 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4166 DWARF 2's Call Frame Information makes available compiler generated
4167 information that more exactly describes the program's run-time stack.
4168 By using this information, GDB is able to provide more robust stack
4171 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4172 have been updated to use a new backtrace mechanism which includes
4173 DWARF 2 CFI support.
4177 GDB's remote protocol has been extended to include support for hosted
4178 file I/O (where the remote target uses GDB's file system). See GDB's
4179 remote protocol documentation for details.
4181 * All targets using the new architecture framework.
4183 All of GDB's targets have been updated to use the new internal
4184 architecture framework. The way is now open for future GDB releases
4185 to include cross-architecture native debugging support (i386 on amd64,
4188 * GNU/Linux's Thread Local Storage (TLS)
4190 GDB now includes support for for the GNU/Linux implementation of
4191 per-thread variables.
4193 * GNU/Linux's Native POSIX Thread Library (NPTL)
4195 GDB's thread code has been updated to work with either the new
4196 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4198 * Separate debug info.
4200 GDB, in conjunction with BINUTILS, now supports a mechanism for
4201 automatically loading debug information from a separate file. Instead
4202 of shipping full debug and non-debug versions of system libraries,
4203 system integrators can now instead ship just the stripped libraries
4204 and optional debug files.
4206 * DWARF 2 Location Expressions
4208 DWARF 2 Location Expressions allow the compiler to more completely
4209 describe the location of variables (even in optimized code) to the
4212 GDB now includes preliminary support for location expressions (support
4213 for DW_OP_piece is still missing).
4217 A number of long standing bugs that caused GDB to die while starting a
4218 Java application have been fixed. GDB's Java support is now
4219 considered "useable".
4221 * GNU/Linux support for fork, vfork, and exec.
4223 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4224 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4227 * GDB supports logging output to a file
4229 There are two new commands, "set logging" and "show logging", which can be
4230 used to capture GDB's output to a file.
4232 * The meaning of "detach" has changed for gdbserver
4234 The "detach" command will now resume the application, as documented. To
4235 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4238 * d10v, m68hc11 `regs' command deprecated
4240 The `info registers' command has been updated so that it displays the
4241 registers using a format identical to the old `regs' command.
4245 A new command, "maint set profile on/off", has been added. This command can
4246 be used to enable or disable profiling while running GDB, to profile a
4247 session or a set of commands. In addition there is a new configure switch,
4248 "--enable-profiling", which will cause GDB to be compiled with profiling
4249 data, for more informative profiling results.
4251 * Default MI syntax changed to "mi2".
4253 The default MI (machine interface) syntax, enabled by the command line
4254 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4255 "mi1", can be enabled by specifying the option "-i=mi1".
4257 Support for the original "mi0" syntax (included in GDB 5.0) has been
4260 Fix for gdb/192: removed extraneous space when displaying frame level.
4261 Fix for gdb/672: update changelist is now output in mi list format.
4262 Fix for gdb/702: a -var-assign that updates the value now shows up
4263 in a subsequent -var-update.
4265 * New native configurations.
4267 FreeBSD/amd64 x86_64-*-freebsd*
4269 * Multi-arched targets.
4271 HP/PA HPUX11 hppa*-*-hpux*
4272 Renesas M32R/D w/simulator m32r-*-elf*
4274 * OBSOLETE configurations and files
4276 Configurations that have been declared obsolete in this release have
4277 been commented out. Unless there is activity to revive these
4278 configurations, the next release of GDB will have their sources
4279 permanently REMOVED.
4281 Z8000 simulator z8k-zilog-none or z8ksim
4282 Matsushita MN10200 w/simulator mn10200-*-*
4283 H8/500 simulator h8500-hitachi-hms or h8500hms
4284 HP/PA running BSD hppa*-*-bsd*
4285 HP/PA running OSF/1 hppa*-*-osf*
4286 HP/PA Pro target hppa*-*-pro*
4287 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4288 Sequent family i[3456]86-sequent-sysv4*
4289 i[3456]86-sequent-sysv*
4290 i[3456]86-sequent-bsd*
4291 Tsqware Sparclet sparclet-*-*
4292 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4294 * REMOVED configurations and files
4297 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4298 IBM AIX PS/2 i[3456]86-*-aix
4299 i386 running Mach 3.0 i[3456]86-*-mach3*
4300 i386 running Mach i[3456]86-*-mach*
4301 i386 running OSF/1 i[3456]86-*osf1mk*
4302 HP/Apollo 68k Family m68*-apollo*-sysv*,
4304 m68*-hp-bsd*, m68*-hp-hpux*
4305 Argonaut Risc Chip (ARC) arc-*-*
4306 Mitsubishi D30V d30v-*-*
4307 Fujitsu FR30 fr30-*-elf*
4308 OS/9000 i[34]86-*-os9k
4309 I960 with MON960 i960-*-coff
4311 * MIPS $fp behavior changed
4313 The convenience variable $fp, for the MIPS, now consistently returns
4314 the address of the current frame's base. Previously, depending on the
4315 context, $fp could refer to either $sp or the current frame's base
4316 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4317 The GNU Source-Level Debugger''.
4319 *** Changes in GDB 5.3:
4321 * GNU/Linux shared library multi-threaded performance improved.
4323 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4324 `/proc', in preference to `ptrace' for memory reads. This may result
4325 in an improvement in the start-up time of multi-threaded, shared
4326 library applications when run under GDB. One GDB user writes: ``loads
4327 shared libs like mad''.
4329 * ``gdbserver'' now supports multi-threaded applications on some targets
4331 Support for debugging multi-threaded applications which use
4332 the GNU/Linux LinuxThreads package has been added for
4333 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4334 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4336 * GDB now supports C/C++ preprocessor macros.
4338 GDB now expands preprocessor macro invocations in C/C++ expressions,
4339 and provides various commands for showing macro definitions and how
4342 The new command `macro expand EXPRESSION' expands any macro
4343 invocations in expression, and shows the result.
4345 The new command `show macro MACRO-NAME' shows the definition of the
4346 macro named MACRO-NAME, and where it was defined.
4348 Most compilers don't include information about macros in the debugging
4349 information by default. In GCC 3.1, for example, you need to compile
4350 your program with the options `-gdwarf-2 -g3'. If the macro
4351 information is present in the executable, GDB will read it.
4353 * Multi-arched targets.
4355 DEC Alpha (partial) alpha*-*-*
4356 DEC VAX (partial) vax-*-*
4358 National Semiconductor NS32000 (partial) ns32k-*-*
4359 Motorola 68000 (partial) m68k-*-*
4360 Motorola MCORE mcore-*-*
4364 Fujitsu FRV architecture added by Red Hat frv*-*-*
4367 * New native configurations
4369 Alpha NetBSD alpha*-*-netbsd*
4370 SH NetBSD sh*-*-netbsdelf*
4371 MIPS NetBSD mips*-*-netbsd*
4372 UltraSPARC NetBSD sparc64-*-netbsd*
4374 * OBSOLETE configurations and files
4376 Configurations that have been declared obsolete in this release have
4377 been commented out. Unless there is activity to revive these
4378 configurations, the next release of GDB will have their sources
4379 permanently REMOVED.
4381 Mitsubishi D30V d30v-*-*
4382 OS/9000 i[34]86-*-os9k
4383 IBM AIX PS/2 i[3456]86-*-aix
4384 Fujitsu FR30 fr30-*-elf*
4385 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4386 Argonaut Risc Chip (ARC) arc-*-*
4387 i386 running Mach 3.0 i[3456]86-*-mach3*
4388 i386 running Mach i[3456]86-*-mach*
4389 i386 running OSF/1 i[3456]86-*osf1mk*
4390 HP/Apollo 68k Family m68*-apollo*-sysv*,
4392 m68*-hp-bsd*, m68*-hp-hpux*
4393 I960 with MON960 i960-*-coff
4395 * OBSOLETE languages
4397 CHILL, a Pascal like language used by telecommunications companies.
4399 * REMOVED configurations and files
4401 AMD 29k family via UDI a29k-amd-udi, udi29k
4402 A29K VxWorks a29k-*-vxworks
4403 AMD 29000 embedded, using EBMON a29k-none-none
4404 AMD 29000 embedded with COFF a29k-none-coff
4405 AMD 29000 embedded with a.out a29k-none-aout
4407 testsuite/gdb.hp/gdb.threads-hp/ directory
4409 * New command "set max-user-call-depth <nnn>"
4411 This command allows the user to limit the call depth of user-defined
4412 commands. The default is 1024.
4414 * Changes in FreeBSD/i386 native debugging.
4416 Support for the "generate-core-file" has been added.
4418 * New commands "dump", "append", and "restore".
4420 These commands allow data to be copied from target memory
4421 to a bfd-format or binary file (dump and append), and back
4422 from a file into memory (restore).
4424 * Improved "next/step" support on multi-processor Alpha Tru64.
4426 The previous single-step mechanism could cause unpredictable problems,
4427 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4428 of a software single-step mechanism prevents this.
4430 *** Changes in GDB 5.2.1:
4438 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4439 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4440 Fix, by Joel Brobecker imported from mainline.
4442 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4443 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4444 Fix, by Fred Fish, imported from mainline.
4446 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4447 Surprisingly enough, it works now.
4448 By Michal Ludvig, imported from mainline.
4450 i386 hardware watchpoint support:
4451 avoid misses on second run for some targets.
4452 By Pierre Muller, imported from mainline.
4454 *** Changes in GDB 5.2:
4456 * New command "set trust-readonly-sections on[off]".
4458 This command is a hint that tells gdb that read-only sections
4459 really are read-only (ie. that their contents will not change).
4460 In this mode, gdb will go to the object file rather than the
4461 target to read memory from read-only sections (such as ".text").
4462 This can be a significant performance improvement on some
4463 (notably embedded) targets.
4465 * New command "generate-core-file" (or "gcore").
4467 This new gdb command allows the user to drop a core file of the child
4468 process state at any time. So far it's been implemented only for
4469 GNU/Linux and Solaris, but should be relatively easily ported to other
4470 hosts. Argument is core file name (defaults to core.<pid>).
4472 * New command line option
4474 GDB now accepts --pid or -p followed by a process id.
4476 * Change in command line behavior -- corefiles vs. process ids.
4478 There is a subtle behavior in the way in which GDB handles
4479 command line arguments. The first non-flag argument is always
4480 a program to debug, but the second non-flag argument may either
4481 be a corefile or a process id. Previously, GDB would attempt to
4482 open the second argument as a corefile, and if that failed, would
4483 issue a superfluous error message and then attempt to attach it as
4484 a process. Now, if the second argument begins with a non-digit,
4485 it will be treated as a corefile. If it begins with a digit,
4486 GDB will attempt to attach it as a process, and if no such process
4487 is found, will then attempt to open it as a corefile.
4489 * Changes in ARM configurations.
4491 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4492 configuration is fully multi-arch.
4494 * New native configurations
4496 ARM NetBSD arm*-*-netbsd*
4497 x86 OpenBSD i[3456]86-*-openbsd*
4498 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4499 Sparc64 running FreeBSD sparc64-*-freebsd*
4503 Sanyo XStormy16 xstormy16-elf
4505 * OBSOLETE configurations and files
4507 Configurations that have been declared obsolete in this release have
4508 been commented out. Unless there is activity to revive these
4509 configurations, the next release of GDB will have their sources
4510 permanently REMOVED.
4512 AMD 29k family via UDI a29k-amd-udi, udi29k
4513 A29K VxWorks a29k-*-vxworks
4514 AMD 29000 embedded, using EBMON a29k-none-none
4515 AMD 29000 embedded with COFF a29k-none-coff
4516 AMD 29000 embedded with a.out a29k-none-aout
4518 testsuite/gdb.hp/gdb.threads-hp/ directory
4520 * REMOVED configurations and files
4522 TI TMS320C80 tic80-*-*
4524 PowerPC Solaris powerpcle-*-solaris*
4525 PowerPC Windows NT powerpcle-*-cygwin32
4526 PowerPC Netware powerpc-*-netware*
4527 Harris/CXUX m88k m88*-harris-cxux*
4528 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4529 ns32k-utek-sysv* ns32k-utek-*
4530 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4531 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4532 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4533 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4534 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4536 * Changes to command line processing
4538 The new `--args' feature can be used to specify command-line arguments
4539 for the inferior from gdb's command line.
4541 * Changes to key bindings
4543 There is a new `operate-and-get-next' function bound to `C-o'.
4545 *** Changes in GDB 5.1.1
4547 Fix compile problem on DJGPP.
4549 Fix a problem with floating-point registers on the i386 being
4552 Fix to stop GDB crashing on .debug_str debug info.
4554 Numerous documentation fixes.
4556 Numerous testsuite fixes.
4558 *** Changes in GDB 5.1:
4560 * New native configurations
4562 Alpha FreeBSD alpha*-*-freebsd*
4563 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4564 MIPS GNU/Linux mips*-*-linux*
4565 MIPS SGI Irix 6.x mips*-sgi-irix6*
4566 ia64 AIX ia64-*-aix*
4567 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4571 Motorola 68HC11 and 68HC12 m68hc11-elf
4573 UltraSparc running GNU/Linux sparc64-*-linux*
4575 * OBSOLETE configurations and files
4577 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4578 Harris/CXUX m88k m88*-harris-cxux*
4579 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4580 ns32k-utek-sysv* ns32k-utek-*
4581 TI TMS320C80 tic80-*-*
4583 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4584 PowerPC Solaris powerpcle-*-solaris*
4585 PowerPC Windows NT powerpcle-*-cygwin32
4586 PowerPC Netware powerpc-*-netware*
4587 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4588 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4589 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4590 Apple Macintosh (MPW) host N/A
4592 stuff.c (Program to stuff files into a specially prepared space in kdb)
4593 kdb-start.c (Main loop for the standalone kernel debugger)
4595 Configurations that have been declared obsolete in this release have
4596 been commented out. Unless there is activity to revive these
4597 configurations, the next release of GDB will have their sources
4598 permanently REMOVED.
4600 * REMOVED configurations and files
4602 Altos 3068 m68*-altos-*
4603 Convex c1-*-*, c2-*-*
4605 ARM RISCix arm-*-* (as host)
4609 * GDB has been converted to ISO C.
4611 GDB's source code has been converted to ISO C. In particular, the
4612 sources are fully protoized, and rely on standard headers being
4617 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4619 * The MI enabled by default.
4621 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4622 revised and enabled by default. Packages which use GDB as a debugging
4623 engine behind a UI or another front end are encouraged to switch to
4624 using the GDB/MI interface, instead of the old annotations interface
4625 which is now deprecated.
4627 * Support for debugging Pascal programs.
4629 GDB now includes support for debugging Pascal programs. The following
4630 main features are supported:
4632 - Pascal-specific data types such as sets;
4634 - automatic recognition of Pascal sources based on file-name
4637 - Pascal-style display of data types, variables, and functions;
4639 - a Pascal expression parser.
4641 However, some important features are not yet supported.
4643 - Pascal string operations are not supported at all;
4645 - there are some problems with boolean types;
4647 - Pascal type hexadecimal constants are not supported
4648 because they conflict with the internal variables format;
4650 - support for Pascal objects and classes is not full yet;
4652 - unlike Pascal, GDB is case-sensitive for symbol names.
4654 * Changes in completion.
4656 Commands such as `shell', `run' and `set args', which pass arguments
4657 to inferior programs, now complete on file names, similar to what
4658 users expect at the shell prompt.
4660 Commands which accept locations, such as `disassemble', `print',
4661 `breakpoint', `until', etc. now complete on filenames as well as
4662 program symbols. Thus, if you type "break foob TAB", and the source
4663 files linked into the programs include `foobar.c', that file name will
4664 be one of the candidates for completion. However, file names are not
4665 considered for completion after you typed a colon that delimits a file
4666 name from a name of a function in that file, as in "break foo.c:bar".
4668 `set demangle-style' completes on available demangling styles.
4670 * New platform-independent commands:
4672 It is now possible to define a post-hook for a command as well as a
4673 hook that runs before the command. For more details, see the
4674 documentation of `hookpost' in the GDB manual.
4676 * Changes in GNU/Linux native debugging.
4678 Support for debugging multi-threaded programs has been completely
4679 revised for all platforms except m68k and sparc. You can now debug as
4680 many threads as your system allows you to have.
4682 Attach/detach is supported for multi-threaded programs.
4684 Support for SSE registers was added for x86. This doesn't work for
4685 multi-threaded programs though.
4687 * Changes in MIPS configurations.
4689 Multi-arch support is enabled for all MIPS configurations.
4691 GDB can now be built as native debugger on SGI Irix 6.x systems for
4692 debugging n32 executables. (Debugging 64-bit executables is not yet
4695 * Unified support for hardware watchpoints in all x86 configurations.
4697 Most (if not all) native x86 configurations support hardware-assisted
4698 breakpoints and watchpoints in a unified manner. This support
4699 implements debug register sharing between watchpoints, which allows to
4700 put a virtually infinite number of watchpoints on the same address,
4701 and also supports watching regions up to 16 bytes with several debug
4704 The new maintenance command `maintenance show-debug-regs' toggles
4705 debugging print-outs in functions that insert, remove, and test
4706 watchpoints and hardware breakpoints.
4708 * Changes in the DJGPP native configuration.
4710 New command ``info dos sysinfo'' displays assorted information about
4711 the CPU, OS, memory, and DPMI server.
4713 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4714 display information about segment descriptors stored in GDT, LDT, and
4717 New commands ``info dos pde'' and ``info dos pte'' display entries
4718 from Page Directory and Page Tables (for now works with CWSDPMI only).
4719 New command ``info dos address-pte'' displays the Page Table entry for
4720 a given linear address.
4722 GDB can now pass command lines longer than 126 characters to the
4723 program being debugged (requires an update to the libdbg.a library
4724 which is part of the DJGPP development kit).
4726 DWARF2 debug info is now supported.
4728 It is now possible to `step' and `next' through calls to `longjmp'.
4730 * Changes in documentation.
4732 All GDB documentation was converted to GFDL, the GNU Free
4733 Documentation License.
4735 Tracepoints-related commands are now fully documented in the GDB
4738 TUI, the Text-mode User Interface, is now documented in the manual.
4740 Tracepoints-related commands are now fully documented in the GDB
4743 The "GDB Internals" manual now has an index. It also includes
4744 documentation of `ui_out' functions, GDB coding standards, x86
4745 hardware watchpoints, and memory region attributes.
4747 * GDB's version number moved to ``version.in''
4749 The Makefile variable VERSION has been replaced by the file
4750 ``version.in''. People creating GDB distributions should update the
4751 contents of this file.
4755 GUD support is now a standard part of the EMACS distribution.
4757 *** Changes in GDB 5.0:
4759 * Improved support for debugging FP programs on x86 targets
4761 Unified and much-improved support for debugging floating-point
4762 programs on all x86 targets. In particular, ``info float'' now
4763 displays the FP registers in the same format on all x86 targets, with
4764 greater level of detail.
4766 * Improvements and bugfixes in hardware-assisted watchpoints
4768 It is now possible to watch array elements, struct members, and
4769 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4770 on x86 targets no longer erroneously trigger when the address is
4773 * Improvements in the native DJGPP version of GDB
4775 The distribution now includes all the scripts and auxiliary files
4776 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4777 machines ``out of the box''.
4779 The DJGPP version can now debug programs that use signals. It is
4780 possible to catch signals that happened in the debuggee, deliver
4781 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4782 would kill the program being debugged.) Programs that hook hardware
4783 interrupts (keyboard, timer, etc.) can also be debugged.
4785 It is now possible to debug DJGPP programs that redirect their
4786 standard handles or switch them to raw (as opposed to cooked) mode, or
4787 even close them. The command ``run < foo > bar'' works as expected,
4788 and ``info terminal'' reports useful information about the debuggee's
4789 terminal, including raw/cooked mode, redirection, etc.
4791 The DJGPP version now uses termios functions for console I/O, which
4792 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4795 DOS-style file names with drive letters are now fully supported by
4798 It is now possible to debug DJGPP programs that switch their working
4799 directory. It is also possible to rerun the debuggee any number of
4800 times without restarting GDB; thus, you can use the same setup,
4801 breakpoints, etc. for many debugging sessions.
4803 * New native configurations
4805 ARM GNU/Linux arm*-*-linux*
4806 PowerPC GNU/Linux powerpc-*-linux*
4810 Motorola MCore mcore-*-*
4811 x86 VxWorks i[3456]86-*-vxworks*
4812 PowerPC VxWorks powerpc-*-vxworks*
4813 TI TMS320C80 tic80-*-*
4815 * OBSOLETE configurations
4817 Altos 3068 m68*-altos-*
4818 Convex c1-*-*, c2-*-*
4820 ARM RISCix arm-*-* (as host)
4823 Configurations that have been declared obsolete will be commented out,
4824 but the code will be left in place. If there is no activity to revive
4825 these configurations before the next release of GDB, the sources will
4826 be permanently REMOVED.
4828 * Gould support removed
4830 Support for the Gould PowerNode and NP1 has been removed.
4832 * New features for SVR4
4834 On SVR4 native platforms (such as Solaris), if you attach to a process
4835 without first loading a symbol file, GDB will now attempt to locate and
4836 load symbols from the running process's executable file.
4838 * Many C++ enhancements
4840 C++ support has been greatly improved. Overload resolution now works properly
4841 in almost all cases. RTTI support is on the way.
4843 * Remote targets can connect to a sub-program
4845 A popen(3) style serial-device has been added. This device starts a
4846 sub-process (such as a stand-alone simulator) and then communicates
4847 with that. The sub-program to run is specified using the syntax
4848 ``|<program> <args>'' vis:
4850 (gdb) set remotedebug 1
4851 (gdb) target extended-remote |mn10300-elf-sim program-args
4853 * MIPS 64 remote protocol
4855 A long standing bug in the mips64 remote protocol where by GDB
4856 expected certain 32 bit registers (ex SR) to be transfered as 32
4857 instead of 64 bits has been fixed.
4859 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4860 added to provide backward compatibility with older versions of GDB.
4862 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4864 The command ``set remotebinarydownload'' command has been replaced by
4865 ``set remote X-packet''. Other commands in ``set remote'' family
4866 include ``set remote P-packet''.
4868 * Breakpoint commands accept ranges.
4870 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4871 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4872 ``tracepoint passcount'' also accepts a range of tracepoints.
4874 * ``apropos'' command added.
4876 The ``apropos'' command searches through command names and
4877 documentation strings, printing out matches, making it much easier to
4878 try to find a command that does what you are looking for.
4882 A new machine oriented interface (MI) has been added to GDB. This
4883 interface is designed for debug environments running GDB as a separate
4884 process. This is part of the long term libGDB project. See the
4885 "GDB/MI" chapter of the GDB manual for further information. It can be
4886 enabled by configuring with:
4888 .../configure --enable-gdbmi
4890 *** Changes in GDB-4.18:
4892 * New native configurations
4894 HP-UX 10.20 hppa*-*-hpux10.20
4895 HP-UX 11.x hppa*-*-hpux11.0*
4896 M68K GNU/Linux m68*-*-linux*
4900 Fujitsu FR30 fr30-*-elf*
4901 Intel StrongARM strongarm-*-*
4902 Mitsubishi D30V d30v-*-*
4904 * OBSOLETE configurations
4906 Gould PowerNode, NP1 np1-*-*, pn-*-*
4908 Configurations that have been declared obsolete will be commented out,
4909 but the code will be left in place. If there is no activity to revive
4910 these configurations before the next release of GDB, the sources will
4911 be permanently REMOVED.
4915 As a compatibility experiment, GDB's source files buildsym.h and
4916 buildsym.c have been converted to pure standard C, no longer
4917 containing any K&R compatibility code. We believe that all systems in
4918 use today either come with a standard C compiler, or have a GCC port
4919 available. If this is not true, please report the affected
4920 configuration to bug-gdb@gnu.org immediately. See the README file for
4921 information about getting a standard C compiler if you don't have one
4926 GDB now uses readline 2.2.
4928 * set extension-language
4930 You can now control the mapping between filename extensions and source
4931 languages by using the `set extension-language' command. For instance,
4932 you can ask GDB to treat .c files as C++ by saying
4933 set extension-language .c c++
4934 The command `info extensions' lists all of the recognized extensions
4935 and their associated languages.
4937 * Setting processor type for PowerPC and RS/6000
4939 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4940 you can use the `set processor' command to specify what variant of the
4941 PowerPC family you are debugging. The command
4945 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4946 following PowerPC and RS6000 variants:
4948 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4949 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4951 403GC IBM PowerPC 403GC
4952 505 Motorola PowerPC 505
4953 860 Motorola PowerPC 860 or 850
4954 601 Motorola PowerPC 601
4955 602 Motorola PowerPC 602
4956 603 Motorola/IBM PowerPC 603 or 603e
4957 604 Motorola PowerPC 604 or 604e
4958 750 Motorola/IBM PowerPC 750 or 750
4960 At the moment, this command just tells GDB what to name the
4961 special-purpose processor registers. Since almost all the affected
4962 registers are inaccessible to user-level programs, this command is
4963 only useful for remote debugging in its present form.
4967 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4968 more extensive support for HP-UX. Added features include shared
4969 library support, kernel threads and hardware watchpoints for 11.00,
4970 support for HP's ANSI C and C++ compilers, and a compatibility mode
4971 for xdb and dbx commands.
4975 HP's donation includes the new concept of catchpoints, which is a
4976 generalization of the old catch command. On HP-UX, it is now possible
4977 to catch exec, fork, and vfork, as well as library loading.
4979 This means that the existing catch command has changed; its first
4980 argument now specifies the type of catch to be set up. See the
4981 output of "help catch" for a list of catchpoint types.
4983 * Debugging across forks
4985 On HP-UX, you can choose which process to debug when a fork() happens
4990 HP has donated a curses-based terminal user interface (TUI). To get
4991 it, build with --enable-tui. Although this can be enabled for any
4992 configuration, at present it only works for native HP debugging.
4994 * GDB remote protocol additions
4996 A new protocol packet 'X' that writes binary data is now available.
4997 Default behavior is to try 'X', then drop back to 'M' if the stub
4998 fails to respond. The settable variable `remotebinarydownload'
4999 allows explicit control over the use of 'X'.
5001 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5002 full 64-bit address. The command
5004 set remoteaddresssize 32
5006 can be used to revert to the old behaviour. For existing remote stubs
5007 the change should not be noticed, as the additional address information
5010 In order to assist in debugging stubs, you may use the maintenance
5011 command `packet' to send any text string to the stub. For instance,
5013 maint packet heythere
5015 sends the packet "$heythere#<checksum>". Note that it is very easy to
5016 disrupt a debugging session by sending the wrong packet at the wrong
5019 The compare-sections command allows you to compare section data on the
5020 target to what is in the executable file without uploading or
5021 downloading, by comparing CRC checksums.
5023 * Tracing can collect general expressions
5025 You may now collect general expressions at tracepoints. This requires
5026 further additions to the target-side stub; see tracepoint.c and
5027 doc/agentexpr.texi for further details.
5029 * mask-address variable for Mips
5031 For Mips targets, you may control the zeroing of the upper 32 bits of
5032 a 64-bit address by entering `set mask-address on'. This is mainly
5033 of interest to users of embedded R4xxx and R5xxx processors.
5035 * Higher serial baud rates
5037 GDB's serial code now allows you to specify baud rates 57600, 115200,
5038 230400, and 460800 baud. (Note that your host system may not be able
5039 to achieve all of these rates.)
5043 The i960 configuration now includes an initial implementation of a
5044 builtin simulator, contributed by Jim Wilson.
5047 *** Changes in GDB-4.17:
5049 * New native configurations
5051 Alpha GNU/Linux alpha*-*-linux*
5052 Unixware 2.x i[3456]86-unixware2*
5053 Irix 6.x mips*-sgi-irix6*
5054 PowerPC GNU/Linux powerpc-*-linux*
5055 PowerPC Solaris powerpcle-*-solaris*
5056 Sparc GNU/Linux sparc-*-linux*
5057 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5061 Argonaut Risc Chip (ARC) arc-*-*
5062 Hitachi H8/300S h8300*-*-*
5063 Matsushita MN10200 w/simulator mn10200-*-*
5064 Matsushita MN10300 w/simulator mn10300-*-*
5065 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5066 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5067 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5068 Mitsubishi D10V w/simulator d10v-*-*
5069 Mitsubishi M32R/D w/simulator m32r-*-elf*
5070 Tsqware Sparclet sparclet-*-*
5071 NEC V850 w/simulator v850-*-*
5073 * New debugging protocols
5075 ARM with RDI protocol arm*-*-*
5076 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5077 DDB and LSI variants of PMON protocol mips*-*-*
5078 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5079 PowerPC with SDS protocol powerpc{,le}-*-eabi
5080 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5084 All configurations can now understand and use the DWARF 2 debugging
5085 format. The choice is automatic, if the symbol file contains DWARF 2
5090 GDB now includes basic Java language support. This support is
5091 only useful with Java compilers that produce native machine code.
5093 * solib-absolute-prefix and solib-search-path
5095 For SunOS and SVR4 shared libraries, you may now set the prefix for
5096 loading absolute shared library symbol files, and the search path for
5097 locating non-absolute shared library symbol files.
5099 * Live range splitting
5101 GDB can now effectively debug code for which GCC has performed live
5102 range splitting as part of its optimization. See gdb/doc/LRS for
5103 more details on the expected format of the stabs information.
5107 GDB's support for the GNU Hurd, including thread debugging, has been
5108 updated to work with current versions of the Hurd.
5112 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5113 instruction set. ARM GDB automatically detects when Thumb
5114 instructions are in use, and adjusts disassembly and backtracing
5119 GDB's MIPS target configurations now handle the MIP16 16-bit
5124 GDB now includes support for overlays; if an executable has been
5125 linked such that multiple sections are based at the same address, GDB
5126 will decide which section to use for symbolic info. You can choose to
5127 control the decision manually, using overlay commands, or implement
5128 additional target-side support and use "overlay load-target" to bring
5129 in the overlay mapping. Do "help overlay" for more detail.
5133 The command "info symbol <address>" displays information about
5134 the symbol at the specified address.
5138 The standard remote protocol now includes an extension that allows
5139 asynchronous collection and display of trace data. This requires
5140 extensive support in the target-side debugging stub. Tracing mode
5141 includes a new interaction mode in GDB and new commands: see the
5142 file tracepoint.c for more details.
5146 Configurations for embedded MIPS now include a simulator contributed
5147 by Cygnus Solutions. The simulator supports the instruction sets
5148 of most MIPS variants.
5152 Sparc configurations may now include the ERC32 simulator contributed
5153 by the European Space Agency. The simulator is not built into
5154 Sparc targets by default; configure with --enable-sim to include it.
5158 For target configurations that may include multiple variants of a
5159 basic architecture (such as MIPS and SH), you may now set the
5160 architecture explicitly. "set arch" sets, "info arch" lists
5161 the possible architectures.
5163 *** Changes in GDB-4.16:
5165 * New native configurations
5167 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5168 M68K NetBSD m68k-*-netbsd*
5169 PowerPC AIX 4.x powerpc-*-aix*
5170 PowerPC MacOS powerpc-*-macos*
5171 PowerPC Windows NT powerpcle-*-cygwin32
5172 RS/6000 AIX 4.x rs6000-*-aix4*
5176 ARM with RDP protocol arm-*-*
5177 I960 with MON960 i960-*-coff
5178 MIPS VxWorks mips*-*-vxworks*
5179 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5180 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5182 Matra Sparclet sparclet-*-*
5186 The powerpc-eabi configuration now includes the PSIM simulator,
5187 contributed by Andrew Cagney, with assistance from Mike Meissner.
5188 PSIM is a very elaborate model of the PowerPC, including not only
5189 basic instruction set execution, but also details of execution unit
5190 performance and I/O hardware. See sim/ppc/README for more details.
5194 GDB now works with Solaris 2.5.
5196 * Windows 95/NT native
5198 GDB will now work as a native debugger on Windows 95 and Windows NT.
5199 To build it from source, you must use the "gnu-win32" environment,
5200 which uses a DLL to emulate enough of Unix to run the GNU tools.
5201 Further information, binaries, and sources are available at
5202 ftp.cygnus.com, under pub/gnu-win32.
5204 * dont-repeat command
5206 If a user-defined command includes the command `dont-repeat', then the
5207 command will not be repeated if the user just types return. This is
5208 useful if the command is time-consuming to run, so that accidental
5209 extra keystrokes don't run the same command many times.
5211 * Send break instead of ^C
5213 The standard remote protocol now includes an option to send a break
5214 rather than a ^C to the target in order to interrupt it. By default,
5215 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5217 * Remote protocol timeout
5219 The standard remote protocol includes a new variable `remotetimeout'
5220 that allows you to set the number of seconds before GDB gives up trying
5221 to read from the target. The default value is 2.
5223 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5225 By default GDB will automatically keep track of objects as they are
5226 loaded and unloaded by the dynamic linker. By using the command `set
5227 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5228 when shared library events occur, thus allowing you to set breakpoints
5229 in shared libraries which are explicitly loaded by the inferior.
5231 Note this feature does not work on hpux8. On hpux9 you must link
5232 /usr/lib/end.o into your program. This feature should work
5233 automatically on hpux10.
5235 * Irix 5.x hardware watchpoint support
5237 Irix 5 configurations now support the use of hardware watchpoints.
5239 * Mips protocol "SYN garbage limit"
5241 When debugging a Mips target using the `target mips' protocol, you
5242 may set the number of characters that GDB will ignore by setting
5243 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5244 every character. The default value is 1050.
5246 * Recording and replaying remote debug sessions
5248 If you set `remotelogfile' to the name of a file, gdb will write to it
5249 a recording of a remote debug session. This recording may then be
5250 replayed back to gdb using "gdbreplay". See gdbserver/README for
5251 details. This is useful when you have a problem with GDB while doing
5252 remote debugging; you can make a recording of the session and send it
5253 to someone else, who can then recreate the problem.
5255 * Speedups for remote debugging
5257 GDB includes speedups for downloading and stepping MIPS systems using
5258 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5259 and more efficient S-record downloading.
5261 * Memory use reductions and statistics collection
5263 GDB now uses less memory and reports statistics about memory usage.
5264 Try the `maint print statistics' command, for example.
5266 *** Changes in GDB-4.15:
5268 * Psymtabs for XCOFF
5270 The symbol reader for AIX GDB now uses partial symbol tables. This
5271 can greatly improve startup time, especially for large executables.
5273 * Remote targets use caching
5275 Remote targets now use a data cache to speed up communication with the
5276 remote side. The data cache could lead to incorrect results because
5277 it doesn't know about volatile variables, thus making it impossible to
5278 debug targets which use memory mapped I/O devices. `set remotecache
5279 off' turns the the data cache off.
5281 * Remote targets may have threads
5283 The standard remote protocol now includes support for multiple threads
5284 in the target system, using new protocol commands 'H' and 'T'. See
5285 gdb/remote.c for details.
5289 If GDB is configured with `--enable-netrom', then it will include
5290 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5291 acts as though it is a bank of ROM on the target board, but you can
5292 write into it over the network. GDB's support consists only of
5293 support for fast loading into the emulated ROM; to debug, you must use
5294 another protocol, such as standard remote protocol. The usual
5295 sequence is something like
5297 target nrom <netrom-hostname>
5299 target remote <netrom-hostname>:1235
5303 GDB now includes support for the Apple Macintosh, as a host only. It
5304 may be run as either an MPW tool or as a standalone application, and
5305 it can debug through the serial port. All the usual GDB commands are
5306 available, but to the target command, you must supply "serial" as the
5307 device type instead of "/dev/ttyXX". See mpw-README in the main
5308 directory for more information on how to build. The MPW configuration
5309 scripts */mpw-config.in support only a few targets, and only the
5310 mips-idt-ecoff target has been tested.
5314 GDB configuration now uses autoconf. This is not user-visible,
5315 but does simplify configuration and building.
5319 GDB now supports hpux10.
5321 *** Changes in GDB-4.14:
5323 * New native configurations
5325 x86 FreeBSD i[345]86-*-freebsd
5326 x86 NetBSD i[345]86-*-netbsd
5327 NS32k NetBSD ns32k-*-netbsd
5328 Sparc NetBSD sparc-*-netbsd
5332 A29K VxWorks a29k-*-vxworks
5333 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5334 CPU32 EST-300 emulator m68*-*-est*
5335 PowerPC ELF powerpc-*-elf
5338 * Alpha OSF/1 support for procfs
5340 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5341 possible to attach to running processes. As the mounting of the /proc
5342 filesystem is optional on the Alpha, GDB automatically determines
5343 the availability of /proc during startup. This can lead to problems
5344 if /proc is unmounted after GDB has been started.
5346 * Arguments to user-defined commands
5348 User commands may accept up to 10 arguments separated by whitespace.
5349 Arguments are accessed within the user command via $arg0..$arg9. A
5352 print $arg0 + $arg1 + $arg2
5354 To execute the command use:
5357 Defines the command "adder" which prints the sum of its three arguments.
5358 Note the arguments are text substitutions, so they may reference variables,
5359 use complex expressions, or even perform inferior function calls.
5361 * New `if' and `while' commands
5363 This makes it possible to write more sophisticated user-defined
5364 commands. Both commands take a single argument, which is the
5365 expression to evaluate, and must be followed by the commands to
5366 execute, one per line, if the expression is nonzero, the list being
5367 terminated by the word `end'. The `if' command list may include an
5368 `else' word, which causes the following commands to be executed only
5369 if the expression is zero.
5371 * Fortran source language mode
5373 GDB now includes partial support for Fortran 77. It will recognize
5374 Fortran programs and can evaluate a subset of Fortran expressions, but
5375 variables and functions may not be handled correctly. GDB will work
5376 with G77, but does not yet know much about symbols emitted by other
5379 * Better HPUX support
5381 Most debugging facilities now work on dynamic executables for HPPAs
5382 running hpux9 or later. You can attach to running dynamically linked
5383 processes, but by default the dynamic libraries will be read-only, so
5384 for instance you won't be able to put breakpoints in them. To change
5385 that behavior do the following before running the program:
5391 This will cause the libraries to be mapped private and read-write.
5392 To revert to the normal behavior, do this:
5398 You cannot set breakpoints or examine data in the library until after
5399 the library is loaded if the function/data symbols do not have
5402 GDB can now also read debug symbols produced by the HP C compiler on
5403 HPPAs (sorry, no C++, Fortran or 68k support).
5405 * Target byte order now dynamically selectable
5407 You can choose which byte order to use with a target system, via the
5408 commands "set endian big" and "set endian little", and you can see the
5409 current setting by using "show endian". You can also give the command
5410 "set endian auto", in which case GDB will use the byte order
5411 associated with the executable. Currently, only embedded MIPS
5412 configurations support dynamic selection of target byte order.
5414 * New DOS host serial code
5416 This version uses DPMI interrupts to handle buffered I/O, so you
5417 no longer need to run asynctsr when debugging boards connected to
5420 *** Changes in GDB-4.13:
5422 * New "complete" command
5424 This lists all the possible completions for the rest of the line, if it
5425 were to be given as a command itself. This is intended for use by emacs.
5427 * Trailing space optional in prompt
5429 "set prompt" no longer adds a space for you after the prompt you set. This
5430 allows you to set a prompt which ends in a space or one that does not.
5432 * Breakpoint hit counts
5434 "info break" now displays a count of the number of times the breakpoint
5435 has been hit. This is especially useful in conjunction with "ignore"; you
5436 can ignore a large number of breakpoint hits, look at the breakpoint info
5437 to see how many times the breakpoint was hit, then run again, ignoring one
5438 less than that number, and this will get you quickly to the last hit of
5441 * Ability to stop printing at NULL character
5443 "set print null-stop" will cause GDB to stop printing the characters of
5444 an array when the first NULL is encountered. This is useful when large
5445 arrays actually contain only short strings.
5447 * Shared library breakpoints
5449 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5450 breakpoints in shared libraries before the executable is run.
5452 * Hardware watchpoints
5454 There is a new hardware breakpoint for the watch command for sparclite
5455 targets. See gdb/sparclite/hw_breakpoint.note.
5457 Hardware watchpoints are also now supported under GNU/Linux.
5461 Annotations have been added. These are for use with graphical interfaces,
5462 and are still experimental. Currently only gdba.el uses these.
5464 * Improved Irix 5 support
5466 GDB now works properly with Irix 5.2.
5468 * Improved HPPA support
5470 GDB now works properly with the latest GCC and GAS.
5472 * New native configurations
5474 Sequent PTX4 i[34]86-sequent-ptx4
5475 HPPA running OSF/1 hppa*-*-osf*
5476 Atari TT running SVR4 m68*-*-sysv4*
5477 RS/6000 LynxOS rs6000-*-lynxos*
5481 OS/9000 i[34]86-*-os9k
5482 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5485 * Hitachi SH7000 and E7000-PC ICE support
5487 There is now support for communicating with the Hitachi E7000-PC ICE.
5488 This is available automatically when GDB is configured for the SH.
5492 As usual, a variety of small fixes and improvements, both generic
5493 and configuration-specific. See the ChangeLog for more detail.
5495 *** Changes in GDB-4.12:
5497 * Irix 5 is now supported
5501 GDB-4.12 on the HPPA has a number of changes which make it unable
5502 to debug the output from the currently released versions of GCC and
5503 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5504 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5505 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5508 *** Changes in GDB-4.11:
5510 * User visible changes:
5514 The "set remotedebug" option is now consistent between the mips remote
5515 target, remote targets using the gdb-specific protocol, UDI (AMD's
5516 debug protocol for the 29k) and the 88k bug monitor. It is now an
5517 integer specifying a debug level (normally 0 or 1, but 2 means more
5518 debugging info for the mips target).
5520 * DEC Alpha native support
5522 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5523 debug info, but GDB works fairly well with the DEC compiler and should
5524 work with a future GCC release. See the README file for a few
5525 Alpha-specific notes.
5527 * Preliminary thread implementation
5529 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5531 * LynxOS native and target support for 386
5533 This release has been hosted on LynxOS 2.2, and also can be configured
5534 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5537 * Improvements in C++ mangling/demangling.
5539 This release has much better g++ debugging, specifically in name
5540 mangling/demangling, virtual function calls, print virtual table,
5541 call methods, ...etc.
5543 *** Changes in GDB-4.10:
5545 * User visible changes:
5547 Remote debugging using the GDB-specific (`target remote') protocol now
5548 supports the `load' command. This is only useful if you have some
5549 other way of getting the stub to the target system, and you can put it
5550 somewhere in memory where it won't get clobbered by the download.
5552 Filename completion now works.
5554 When run under emacs mode, the "info line" command now causes the
5555 arrow to point to the line specified. Also, "info line" prints
5556 addresses in symbolic form (as well as hex).
5558 All vxworks based targets now support a user settable option, called
5559 vxworks-timeout. This option represents the number of seconds gdb
5560 should wait for responses to rpc's. You might want to use this if
5561 your vxworks target is, perhaps, a slow software simulator or happens
5562 to be on the far side of a thin network line.
5566 This release contains support for using a DEC alpha as a GDB host for
5567 cross debugging. Native alpha debugging is not supported yet.
5570 *** Changes in GDB-4.9:
5574 This is the first GDB release which is accompanied by a matching testsuite.
5575 The testsuite requires installation of dejagnu, which should be available
5576 via ftp from most sites that carry GNU software.
5580 'Cfront' style demangling has had its name changed to 'ARM' style, to
5581 emphasize that it was written from the specifications in the C++ Annotated
5582 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5583 disclaimers, it still generated too much confusion with users attempting to
5584 use gdb with AT&T cfront.
5588 GDB now uses a standard remote interface to a simulator library.
5589 So far, the library contains simulators for the Zilog Z8001/2, the
5590 Hitachi H8/300, H8/500 and Super-H.
5592 * New targets supported
5594 H8/300 simulator h8300-hitachi-hms or h8300hms
5595 H8/500 simulator h8500-hitachi-hms or h8500hms
5596 SH simulator sh-hitachi-hms or sh
5597 Z8000 simulator z8k-zilog-none or z8ksim
5598 IDT MIPS board over serial line mips-idt-ecoff
5600 Cross-debugging to GO32 targets is supported. It requires a custom
5601 version of the i386-stub.c module which is integrated with the
5602 GO32 memory extender.
5604 * New remote protocols
5606 MIPS remote debugging protocol.
5608 * New source languages supported
5610 This version includes preliminary support for Chill, a Pascal like language
5611 used by telecommunications companies. Chill support is also being integrated
5612 into the GNU compiler, but we don't know when it will be publically available.
5615 *** Changes in GDB-4.8:
5617 * HP Precision Architecture supported
5619 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5620 version of this support was available as a set of patches from the
5621 University of Utah. GDB does not support debugging of programs
5622 compiled with the HP compiler, because HP will not document their file
5623 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5624 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5626 Many problems in the preliminary version have been fixed.
5628 * Faster and better demangling
5630 We have improved template demangling and fixed numerous bugs in the GNU style
5631 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5632 character types (wchar_t) are now supported. Demangling of each symbol is now
5633 only done once, and is cached when the symbol table for a file is read in.
5634 This results in a small increase in memory usage for C programs, a moderate
5635 increase in memory usage for C++ programs, and a fantastic speedup in
5638 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5639 from the specifications in the Annotated Reference Manual, which AT&T's
5640 compiler does not actually implement.
5642 * G++ multiple inheritance compiler problem
5644 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5645 inheritance lattices was reworked to properly discover ambiguities. We
5646 recently found an example which causes this new algorithm to fail in a
5647 very subtle way, producing bad debug information for those classes.
5648 The file 'gcc.patch' (in this directory) can be applied to gcc to
5649 circumvent the problem. A future GCC release will contain a complete
5652 The previous G++ debug info problem (mentioned below for the gdb-4.7
5653 release) is fixed in gcc version 2.3.2.
5655 * Improved configure script
5657 The `configure' script will now attempt to guess your system type if
5658 you don't supply a host system type. The old scheme of supplying a
5659 host system triplet is preferable over using this. All the magic is
5660 done in the new `config.guess' script. Examine it for details.
5662 We have also brought our configure script much more in line with the FSF's
5663 version. It now supports the --with-xxx options. In particular,
5664 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5665 The resulting GDB will not be able to read arbitrary object file formats --
5666 only the format ``expected'' to be used on the configured target system.
5667 We hope to make this the default in a future release.
5669 * Documentation improvements
5671 There's new internal documentation on how to modify GDB, and how to
5672 produce clean changes to the code. We implore people to read it
5673 before submitting changes.
5675 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5676 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5677 `info' files are also provided. To build `info' files from scratch,
5678 you will need the latest `makeinfo' release, which will be available in
5679 a future texinfo-X.Y release.
5681 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5682 We're not sure exactly which versions have this problem, but it has
5683 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5684 or better. If that isn't possible, there is a patch in
5685 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5686 around this problem.
5690 GDB now supports array constants that can be used in expressions typed in by
5691 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5692 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5695 The new directory `gdb/sparclite' contains a program that demonstrates
5696 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5698 * New native hosts supported
5700 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5701 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5703 * New targets supported
5705 AMD 29k family via UDI a29k-amd-udi or udi29k
5707 * New file formats supported
5709 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5710 HPUX core files, and SCO 3.2v2 core files.
5714 Attaching to processes now works again; thanks for the many bug reports.
5716 We have also stomped on a bunch of core dumps caused by
5717 printf_filtered("%s") problems.
5719 We eliminated a copyright problem on the rpc and ptrace header files
5720 for VxWorks, which was discovered at the last minute during the 4.7
5721 release. You should now be able to build a VxWorks GDB.
5723 You can now interrupt gdb while an attached process is running. This
5724 will cause the attached process to stop, and give control back to GDB.
5726 We fixed problems caused by using too many file descriptors
5727 for reading symbols from object files and libraries. This was
5728 especially a problem for programs that used many (~100) shared
5731 The `step' command now only enters a subroutine if there is line number
5732 information for the subroutine. Otherwise it acts like the `next'
5733 command. Previously, `step' would enter subroutines if there was
5734 any debugging information about the routine. This avoids problems
5735 when using `cc -g1' on MIPS machines.
5737 * Internal improvements
5739 GDB's internal interfaces have been improved to make it easier to support
5740 debugging of multiple languages in the future.
5742 GDB now uses a common structure for symbol information internally.
5743 Minimal symbols (derived from linkage symbols in object files), partial
5744 symbols (from a quick scan of debug information), and full symbols
5745 contain a common subset of information, making it easier to write
5746 shared code that handles any of them.
5748 * New command line options
5750 We now accept --silent as an alias for --quiet.
5754 The memory-mapped-malloc library is now licensed under the GNU Library
5755 General Public License.
5757 *** Changes in GDB-4.7:
5759 * Host/native/target split
5761 GDB has had some major internal surgery to untangle the support for
5762 hosts and remote targets. Now, when you configure GDB for a remote
5763 target, it will no longer load in all of the support for debugging
5764 local programs on the host. When fully completed and tested, this will
5765 ensure that arbitrary host/target combinations are possible.
5767 The primary conceptual shift is to separate the non-portable code in
5768 GDB into three categories. Host specific code is required any time GDB
5769 is compiled on that host, regardless of the target. Target specific
5770 code relates to the peculiarities of the target, but can be compiled on
5771 any host. Native specific code is everything else: it can only be
5772 built when the host and target are the same system. Child process
5773 handling and core file support are two common `native' examples.
5775 GDB's use of /proc for controlling Unix child processes is now cleaner.
5776 It has been split out into a single module under the `target_ops' vector,
5777 plus two native-dependent functions for each system that uses /proc.
5779 * New hosts supported
5781 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5782 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5783 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5785 * New targets supported
5787 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5788 68030 and CPU32 m68030-*-*, m68332-*-*
5790 * New native hosts supported
5792 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5793 (386bsd is not well tested yet)
5794 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5796 * New file formats supported
5798 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5799 supports reading of `a.out.adobe' object files, which are an a.out
5800 format extended with minimal information about multiple sections.
5804 `show copying' is the same as the old `info copying'.
5805 `show warranty' is the same as `info warrantee'.
5806 These were renamed for consistency. The old commands continue to work.
5808 `info handle' is a new alias for `info signals'.
5810 You can now define pre-command hooks, which attach arbitrary command
5811 scripts to any command. The commands in the hook will be executed
5812 prior to the user's command. You can also create a hook which will be
5813 executed whenever the program stops. See gdb.texinfo.
5817 We now deal with Cfront style name mangling, and can even extract type
5818 info from mangled symbols. GDB can automatically figure out which
5819 symbol mangling style your C++ compiler uses.
5821 Calling of methods and virtual functions has been improved as well.
5825 The crash that occured when debugging Sun Ansi-C compiled binaries is
5826 fixed. This was due to mishandling of the extra N_SO stabs output
5829 We also finally got Ultrix 4.2 running in house, and fixed core file
5830 support, with help from a dozen people on the net.
5832 John M. Farrell discovered that the reason that single-stepping was so
5833 slow on all of the Mips based platforms (primarily SGI and DEC) was
5834 that we were trying to demangle and lookup a symbol used for internal
5835 purposes on every instruction that was being stepped through. Changing
5836 the name of that symbol so that it couldn't be mistaken for a C++
5837 mangled symbol sped things up a great deal.
5839 Rich Pixley sped up symbol lookups in general by getting much smarter
5840 about when C++ symbol mangling is necessary. This should make symbol
5841 completion (TAB on the command line) much faster. It's not as fast as
5842 we'd like, but it's significantly faster than gdb-4.6.
5846 A new user controllable variable 'call_scratch_address' can
5847 specify the location of a scratch area to be used when GDB
5848 calls a function in the target. This is necessary because the
5849 usual method of putting the scratch area on the stack does not work
5850 in systems that have separate instruction and data spaces.
5852 We integrated changes to support the 29k UDI (Universal Debugger
5853 Interface), but discovered at the last minute that we didn't have all
5854 of the appropriate copyright paperwork. We are working with AMD to
5855 resolve this, and hope to have it available soon.
5859 We have sped up the remote serial line protocol, especially for targets
5860 with lots of registers. It now supports a new `expedited status' ('T')
5861 message which can be used in place of the existing 'S' status message.
5862 This allows the remote stub to send only the registers that GDB
5863 needs to make a quick decision about single-stepping or conditional
5864 breakpoints, eliminating the need to fetch the entire register set for
5865 each instruction being stepped through.
5867 The GDB remote serial protocol now implements a write-through cache for
5868 registers, only re-reading the registers if the target has run.
5870 There is also a new remote serial stub for SPARC processors. You can
5871 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5872 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5873 processor with a serial port.
5877 Configure.in files have become much easier to read and modify. A new
5878 `table driven' format makes it more obvious what configurations are
5879 supported, and what files each one uses.
5883 There is a new opcodes library which will eventually contain all of the
5884 disassembly routines and opcode tables. At present, it only contains
5885 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5886 disassembler (binutils/objdump) to share these routines.
5888 The libiberty library is now copylefted under the GNU Library General
5889 Public License. This allows more liberal use, and was done so libg++
5890 can use it. This makes no difference to GDB, since the Library License
5891 grants all the rights from the General Public License.
5895 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5896 reference to the stabs symbol info used by the debugger. It is (as far
5897 as we know) the only published document on this fascinating topic. We
5898 encourage you to read it, compare it to the stabs information on your
5899 system, and send improvements on the document in general (to
5900 bug-gdb@prep.ai.mit.edu).
5902 And, of course, many bugs have been fixed.
5905 *** Changes in GDB-4.6:
5907 * Better support for C++ function names
5909 GDB now accepts as input the "demangled form" of C++ overloaded function
5910 names and member function names, and can do command completion on such names
5911 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5912 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5913 Make use of command completion, it is your friend.
5915 GDB also now accepts a variety of C++ mangled symbol formats. They are
5916 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5917 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5918 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5919 for the list of formats.
5921 * G++ symbol mangling problem
5923 Recent versions of gcc have a bug in how they emit debugging information for
5924 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5925 directory) can be applied to gcc to fix the problem. Alternatively, if you
5926 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5927 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5928 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5931 * New 'maintenance' command
5933 All of the commands related to hacking GDB internals have been moved out of
5934 the main command set, and now live behind the 'maintenance' command. This
5935 can also be abbreviated as 'mt'. The following changes were made:
5937 dump-me -> maintenance dump-me
5938 info all-breakpoints -> maintenance info breakpoints
5939 printmsyms -> maintenance print msyms
5940 printobjfiles -> maintenance print objfiles
5941 printpsyms -> maintenance print psymbols
5942 printsyms -> maintenance print symbols
5944 The following commands are new:
5946 maintenance demangle Call internal GDB demangler routine to
5947 demangle a C++ link name and prints the result.
5948 maintenance print type Print a type chain for a given symbol
5950 * Change to .gdbinit file processing
5952 We now read the $HOME/.gdbinit file before processing the argv arguments
5953 (e.g. reading symbol files or core files). This allows global parameters to
5954 be set, which will apply during the symbol reading. The ./.gdbinit is still
5955 read after argv processing.
5957 * New hosts supported
5959 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5961 GNU/Linux support i386-unknown-linux or linux
5963 We are also including code to support the HP/PA running BSD and HPUX. This
5964 is almost guaranteed not to work, as we didn't have time to test or build it
5965 for this release. We are including it so that the more adventurous (or
5966 masochistic) of you can play with it. We also had major problems with the
5967 fact that the compiler that we got from HP doesn't support the -g option.
5970 * New targets supported
5972 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5974 * More smarts about finding #include files
5976 GDB now remembers the compilation directory for all include files, and for
5977 all files from which C is generated (like yacc and lex sources). This
5978 greatly improves GDB's ability to find yacc/lex sources, and include files,
5979 especially if you are debugging your program from a directory different from
5980 the one that contains your sources.
5982 We also fixed a bug which caused difficulty with listing and setting
5983 breakpoints in include files which contain C code. (In the past, you had to
5984 try twice in order to list an include file that you hadn't looked at before.)
5986 * Interesting infernals change
5988 GDB now deals with arbitrary numbers of sections, where the symbols for each
5989 section must be relocated relative to that section's landing place in the
5990 target's address space. This work was needed to support ELF with embedded
5991 stabs used by Solaris-2.0.
5993 * Bug fixes (of course!)
5995 There have been loads of fixes for the following things:
5996 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5997 i960, stabs, DOS(GO32), procfs, etc...
5999 See the ChangeLog for details.
6001 *** Changes in GDB-4.5:
6003 * New machines supported (host and target)
6005 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6007 SGI Irix-4.x mips-sgi-irix4 or iris4
6009 * New malloc package
6011 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6012 Mmalloc is capable of handling mutiple heaps of memory. It is also
6013 capable of saving a heap to a file, and then mapping it back in later.
6014 This can be used to greatly speedup the startup of GDB by using a
6015 pre-parsed symbol table which lives in a mmalloc managed heap. For
6016 more details, please read mmalloc/mmalloc.texi.
6020 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6021 'help info proc' for details.
6023 * MIPS ecoff symbol table format
6025 The code that reads MIPS symbol table format is now supported on all hosts.
6026 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6029 * File name changes for MS-DOS
6031 Many files in the config directories have been renamed to make it easier to
6032 support GDB on MS-DOSe systems (which have very restrictive file name
6033 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6034 environment) is close to working but has some remaining problems. Note
6035 that debugging of DOS programs is not supported, due to limitations
6036 in the ``operating system'', but it can be used to host cross-debugging.
6038 * Cross byte order fixes
6040 Many fixes have been made to support cross debugging of Sparc and MIPS
6041 targets from hosts whose byte order differs.
6043 * New -mapped and -readnow options
6045 If memory-mapped files are available on your system through the 'mmap'
6046 system call, you can use the -mapped option on the `file' or
6047 `symbol-file' commands to cause GDB to write the symbols from your
6048 program into a reusable file. If the program you are debugging is
6049 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6050 Future GDB debugging sessions will notice the presence of this file,
6051 and will quickly map in symbol information from it, rather than reading
6052 the symbol table from the executable program. Using the '-mapped'
6053 option in a GDB `file' or `symbol-file' command has the same effect as
6054 starting GDB with the '-mapped' command-line option.
6056 You can cause GDB to read the entire symbol table immediately by using
6057 the '-readnow' option with any of the commands that load symbol table
6058 information (or on the GDB command line). This makes the command
6059 slower, but makes future operations faster.
6061 The -mapped and -readnow options are typically combined in order to
6062 build a `fred.syms' file that contains complete symbol information.
6063 A simple GDB invocation to do nothing but build a `.syms' file for future
6066 gdb -batch -nx -mapped -readnow programname
6068 The `.syms' file is specific to the host machine on which GDB is run.
6069 It holds an exact image of GDB's internal symbol table. It cannot be
6070 shared across multiple host platforms.
6072 * longjmp() handling
6074 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6075 siglongjmp() without losing control. This feature has not yet been ported to
6076 all systems. It currently works on many 386 platforms, all MIPS-based
6077 platforms (SGI, DECstation, etc), and Sun3/4.
6081 Preliminary work has been put in to support the new Solaris OS from Sun. At
6082 this time, it can control and debug processes, but it is not capable of
6087 As always, many many bug fixes. The major areas were with g++, and mipsread.
6088 People using the MIPS-based platforms should experience fewer mysterious
6089 crashes and trashed symbol tables.
6091 *** Changes in GDB-4.4:
6093 * New machines supported (host and target)
6095 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6097 BSD Reno on Vax vax-dec-bsd
6098 Ultrix on Vax vax-dec-ultrix
6100 * New machines supported (target)
6102 AMD 29000 embedded, using EBMON a29k-none-none
6106 GDB continues to improve its handling of C++. `References' work better.
6107 The demangler has also been improved, and now deals with symbols mangled as
6108 per the Annotated C++ Reference Guide.
6110 GDB also now handles `stabs' symbol information embedded in MIPS
6111 `ecoff' symbol tables. Since the ecoff format was not easily
6112 extensible to handle new languages such as C++, this appeared to be a
6113 good way to put C++ debugging info into MIPS binaries. This option
6114 will be supported in the GNU C compiler, version 2, when it is
6117 * New features for SVR4
6119 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6120 shared libraries. Debugging dynamically linked programs should present
6121 only minor differences from debugging statically linked programs.
6123 The `info proc' command will print out information about any process
6124 on an SVR4 system (including the one you are debugging). At the moment,
6125 it prints the address mappings of the process.
6127 If you bring up GDB on another SVR4 system, please send mail to
6128 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6130 * Better dynamic linking support in SunOS
6132 Reading symbols from shared libraries which contain debugging symbols
6133 now works properly. However, there remain issues such as automatic
6134 skipping of `transfer vector' code during function calls, which
6135 make it harder to debug code in a shared library, than to debug the
6136 same code linked statically.
6140 GDB is now using the latest `getopt' routines from the FSF. This
6141 version accepts the -- prefix for options with long names. GDB will
6142 continue to accept the old forms (-option and +option) as well.
6143 Various single letter abbreviations for options have been explicity
6144 added to the option table so that they won't get overshadowed in the
6145 future by other options that begin with the same letter.
6149 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6150 Many assorted bugs have been handled. Many more remain to be handled.
6151 See the various ChangeLog files (primarily in gdb and bfd) for details.
6154 *** Changes in GDB-4.3:
6156 * New machines supported (host and target)
6158 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6159 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6160 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6162 * Almost SCO Unix support
6164 We had hoped to support:
6165 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6166 (except for core file support), but we discovered very late in the release
6167 that it has problems with process groups that render gdb unusable. Sorry
6168 about that. I encourage people to fix it and post the fixes.
6170 * Preliminary ELF and DWARF support
6172 GDB can read ELF object files on System V Release 4, and can handle
6173 debugging records for C, in DWARF format, in ELF files. This support
6174 is preliminary. If you bring up GDB on another SVR4 system, please
6175 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6180 GDB now uses the latest `readline' library. One user-visible change
6181 is that two tabs will list possible command completions, which previously
6182 required typing M-? (meta-question mark, or ESC ?).
6186 The `stepi' bug that many of you noticed has been squashed.
6187 Many bugs in C++ have been handled. Many more remain to be handled.
6188 See the various ChangeLog files (primarily in gdb and bfd) for details.
6190 * State of the MIPS world (in case you wondered):
6192 GDB can understand the symbol tables emitted by the compilers
6193 supplied by most vendors of MIPS-based machines, including DEC. These
6194 symbol tables are in a format that essentially nobody else uses.
6196 Some versions of gcc come with an assembler post-processor called
6197 mips-tfile. This program is required if you want to do source-level
6198 debugging of gcc-compiled programs. I believe FSF does not ship
6199 mips-tfile with gcc version 1, but it will eventually come with gcc
6202 Debugging of g++ output remains a problem. g++ version 1.xx does not
6203 really support it at all. (If you're lucky, you should be able to get
6204 line numbers and stack traces to work, but no parameters or local
6205 variables.) With some work it should be possible to improve the
6208 When gcc version 2 is released, you will have somewhat better luck.
6209 However, even then you will get confusing results for inheritance and
6212 We will eventually provide full debugging of g++ output on
6213 DECstations. This will probably involve some kind of stabs-in-ecoff
6214 encapulation, but the details have not been worked out yet.
6217 *** Changes in GDB-4.2:
6219 * Improved configuration
6221 Only one copy of `configure' exists now, and it is not self-modifying.
6222 Porting BFD is simpler.
6226 The `step' and `next' commands now only stop at the first instruction
6227 of a source line. This prevents the multiple stops that used to occur
6228 in switch statements, for-loops, etc. `Step' continues to stop if a
6229 function that has debugging information is called within the line.
6233 Lots of small bugs fixed. More remain.
6235 * New host supported (not target)
6237 Intel 386 PC clone running Mach i386-none-mach
6240 *** Changes in GDB-4.1:
6242 * Multiple source language support
6244 GDB now has internal scaffolding to handle several source languages.
6245 It determines the type of each source file from its filename extension,
6246 and will switch expression parsing and number formatting to match the
6247 language of the function in the currently selected stack frame.
6248 You can also specifically set the language to be used, with
6249 `set language c' or `set language modula-2'.
6253 GDB now has preliminary support for the GNU Modula-2 compiler,
6254 currently under development at the State University of New York at
6255 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6256 continue through the fall of 1991 and into 1992.
6258 Other Modula-2 compilers are currently not supported, and attempting to
6259 debug programs compiled with them will likely result in an error as the
6260 symbol table is read. Feel free to work on it, though!
6262 There are hooks in GDB for strict type checking and range checking,
6263 in the `Modula-2 philosophy', but they do not currently work.
6267 GDB can now write to executable and core files (e.g. patch
6268 a variable's value). You must turn this switch on, specify
6269 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6270 by assigning a new value to a variable. Modifications take
6273 * Automatic SunOS shared library reading
6275 When you run your program, GDB automatically determines where its
6276 shared libraries (if any) have been loaded, and reads their symbols.
6277 The `share' command is no longer needed. This also works when
6278 examining core files.
6282 You can specify the number of lines that the `list' command shows.
6285 * New machines supported (host and target)
6287 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6288 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6289 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6291 * New hosts supported (not targets)
6293 IBM RT/PC: romp-ibm-aix or rtpc
6295 * New targets supported (not hosts)
6297 AMD 29000 embedded with COFF a29k-none-coff
6298 AMD 29000 embedded with a.out a29k-none-aout
6299 Ultracomputer remote kernel debug a29k-nyu-kern
6301 * New remote interfaces
6307 *** Changes in GDB-4.0:
6311 Wide output is wrapped at good places to make the output more readable.
6313 Gdb now supports cross-debugging from a host machine of one type to a
6314 target machine of another type. Communication with the target system
6315 is over serial lines. The ``target'' command handles connecting to the
6316 remote system; the ``load'' command will download a program into the
6317 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6318 also supports debugging of realtime processes running under VxWorks,
6319 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6320 stub on the target system.
6322 New CPUs supported include the AMD 29000 and Intel 960.
6324 GDB now reads object files and symbol tables via a ``binary file''
6325 library, which allows a single copy of GDB to debug programs of multiple
6326 object file types such as a.out and coff.
6328 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6329 refcard.dvi and refcard.ps are available to format it).
6332 * Control-Variable user interface simplified
6334 All variables that control the operation of the debugger can be set
6335 by the ``set'' command, and displayed by the ``show'' command.
6337 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6338 ``Show prompt'' produces the response:
6339 Gdb's prompt is new-gdb=>.
6341 What follows are the NEW set commands. The command ``help set'' will
6342 print a complete list of old and new set commands. ``help set FOO''
6343 will give a longer description of the variable FOO. ``show'' will show
6344 all of the variable descriptions and their current settings.
6346 confirm on/off: Enables warning questions for operations that are
6347 hard to recover from, e.g. rerunning the program while
6348 it is already running. Default is ON.
6350 editing on/off: Enables EMACS style command line editing
6351 of input. Previous lines can be recalled with
6352 control-P, the current line can be edited with control-B,
6353 you can search for commands with control-R, etc.
6356 history filename NAME: NAME is where the gdb command history
6357 will be stored. The default is .gdb_history,
6358 or the value of the environment variable
6361 history size N: The size, in commands, of the command history. The
6362 default is 256, or the value of the environment variable
6365 history save on/off: If this value is set to ON, the history file will
6366 be saved after exiting gdb. If set to OFF, the
6367 file will not be saved. The default is OFF.
6369 history expansion on/off: If this value is set to ON, then csh-like
6370 history expansion will be performed on
6371 command line input. The default is OFF.
6373 radix N: Sets the default radix for input and output. It can be set
6374 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6375 in the current radix, so "set radix 10" is always a no-op.
6377 height N: This integer value is the number of lines on a page. Default
6378 is 24, the current `stty rows'' setting, or the ``li#''
6379 setting from the termcap entry matching the environment
6382 width N: This integer value is the number of characters on a line.
6383 Default is 80, the current `stty cols'' setting, or the ``co#''
6384 setting from the termcap entry matching the environment
6387 Note: ``set screensize'' is obsolete. Use ``set height'' and
6388 ``set width'' instead.
6390 print address on/off: Print memory addresses in various command displays,
6391 such as stack traces and structure values. Gdb looks
6392 more ``symbolic'' if you turn this off; it looks more
6393 ``machine level'' with it on. Default is ON.
6395 print array on/off: Prettyprint arrays. New convenient format! Default
6398 print demangle on/off: Print C++ symbols in "source" form if on,
6401 print asm-demangle on/off: Same, for assembler level printouts
6404 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6407 * Support for Epoch Environment.
6409 The epoch environment is a version of Emacs v18 with windowing. One
6410 new command, ``inspect'', is identical to ``print'', except that if you
6411 are running in the epoch environment, the value is printed in its own
6415 * Support for Shared Libraries
6417 GDB can now debug programs and core files that use SunOS shared libraries.
6418 Symbols from a shared library cannot be referenced
6419 before the shared library has been linked with the program (this
6420 happens after you type ``run'' and before the function main() is entered).
6421 At any time after this linking (including when examining core files
6422 from dynamically linked programs), gdb reads the symbols from each
6423 shared library when you type the ``sharedlibrary'' command.
6424 It can be abbreviated ``share''.
6426 sharedlibrary REGEXP: Load shared object library symbols for files
6427 matching a unix regular expression. No argument
6428 indicates to load symbols for all shared libraries.
6430 info sharedlibrary: Status of loaded shared libraries.
6435 A watchpoint stops execution of a program whenever the value of an
6436 expression changes. Checking for this slows down execution
6437 tremendously whenever you are in the scope of the expression, but is
6438 quite useful for catching tough ``bit-spreader'' or pointer misuse
6439 problems. Some machines such as the 386 have hardware for doing this
6440 more quickly, and future versions of gdb will use this hardware.
6442 watch EXP: Set a watchpoint (breakpoint) for an expression.
6444 info watchpoints: Information about your watchpoints.
6446 delete N: Deletes watchpoint number N (same as breakpoints).
6447 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6448 enable N: Re-enables watchpoint number N (same as breakpoints).
6451 * C++ multiple inheritance
6453 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6456 * C++ exception handling
6458 Gdb now supports limited C++ exception handling. Besides the existing
6459 ability to breakpoint on an exception handler, gdb can breakpoint on
6460 the raising of an exception (before the stack is peeled back to the
6463 catch FOO: If there is a FOO exception handler in the dynamic scope,
6464 set a breakpoint to catch exceptions which may be raised there.
6465 Multiple exceptions (``catch foo bar baz'') may be caught.
6467 info catch: Lists all exceptions which may be caught in the
6468 current stack frame.
6471 * Minor command changes
6473 The command ``call func (arg, arg, ...)'' now acts like the print
6474 command, except it does not print or save a value if the function's result
6475 is void. This is similar to dbx usage.
6477 The ``up'' and ``down'' commands now always print the frame they end up
6478 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6479 frames without printing.
6481 * New directory command
6483 'dir' now adds directories to the FRONT of the source search path.
6484 The path starts off empty. Source files that contain debug information
6485 about the directory in which they were compiled can be found even
6486 with an empty path; Sun CC and GCC include this information. If GDB can't
6487 find your source file in the current directory, type "dir .".
6489 * Configuring GDB for compilation
6491 For normal use, type ``./configure host''. See README or gdb.texinfo
6494 GDB now handles cross debugging. If you are remotely debugging between
6495 two different machines, type ``./configure host -target=targ''.
6496 Host is the machine where GDB will run; targ is the machine
6497 where the program that you are debugging will run.
projects / external / binutils.git / blob