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.
250 Indicates that there are no resumed threads left in the target (all
251 threads are stopped). The remote stub reports support for this stop
252 reply to GDB's qSupported query.
254 QCatchSyscalls:1 [;SYSNO]...
256 Enable ("QCatchSyscalls:1") or disable ("QCatchSyscalls:0")
257 catching syscalls from the inferior process.
259 syscall_entry stop reason
260 Indicates that a syscall was just called.
262 syscall_return stop reason
263 Indicates that a syscall just returned.
265 QCatchSyscalls:1 in qSupported
266 The qSupported packet may now include QCatchSyscalls:1 in the reply
267 to indicate support for catching syscalls.
269 * Extended-remote exec events
271 ** GDB now has support for exec events on extended-remote Linux targets.
272 For such targets with Linux kernels 2.5.46 and later, this enables
273 follow-exec-mode and exec catchpoints.
275 set remote exec-event-feature-packet
276 show remote exec-event-feature-packet
277 Set/show the use of the remote exec event feature.
279 * Thread names in remote protocol
281 The reply to qXfer:threads:read may now include a name attribute for each
284 * Target remote mode fork and exec events
286 ** GDB now has support for fork and exec events on target remote mode
287 Linux targets. For such targets with Linux kernels 2.5.46 and later,
288 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
289 fork and exec catchpoints.
291 * Remote syscall events
293 ** GDB now has support for catch syscall on remote Linux targets,
294 currently enabled on x86/x86_64 architectures.
296 set remote catch-syscall-packet
297 show remote catch-syscall-packet
298 Set/show the use of the remote catch syscall feature.
302 ** The -var-set-format command now accepts the zero-hexadecimal
303 format. It outputs data in hexadecimal format with zero-padding on the
308 ** gdb.InferiorThread objects have a new attribute "global_num",
309 which refers to the thread's global thread ID. The existing
310 "num" attribute now refers to the thread's per-inferior number.
311 See "Per-inferior thread numbers" above.
312 ** gdb.InferiorThread objects have a new attribute "inferior", which
313 is the Inferior object the thread belongs to.
315 *** Changes in GDB 7.10
317 * Support for process record-replay and reverse debugging on aarch64*-linux*
318 targets has been added. GDB now supports recording of A64 instruction set
319 including advance SIMD instructions.
321 * Support for Sun's version of the "stabs" debug file format has been removed.
323 * GDB now honors the content of the file /proc/PID/coredump_filter
324 (PID is the process ID) on GNU/Linux systems. This file can be used
325 to specify the types of memory mappings that will be included in a
326 corefile. For more information, please refer to the manual page of
327 "core(5)". GDB also has a new command: "set use-coredump-filter
328 on|off". It allows to set whether GDB will read the content of the
329 /proc/PID/coredump_filter file when generating a corefile.
331 * The "info os" command on GNU/Linux can now display information on
333 "info os cpus" Listing of all cpus/cores on the system
335 * GDB has two new commands: "set serial parity odd|even|none" and
336 "show serial parity". These allows to set or show parity for the
339 * The "info source" command now displays the producer string if it was
340 present in the debug info. This typically includes the compiler version
341 and may include things like its command line arguments.
343 * The "info dll", an alias of the "info sharedlibrary" command,
344 is now available on all platforms.
346 * Directory names supplied to the "set sysroot" commands may be
347 prefixed with "target:" to tell GDB to access shared libraries from
348 the target system, be it local or remote. This replaces the prefix
349 "remote:". The default sysroot has been changed from "" to
350 "target:". "remote:" is automatically converted to "target:" for
351 backward compatibility.
353 * The system root specified by "set sysroot" will be prepended to the
354 filename of the main executable (if reported to GDB as absolute by
355 the operating system) when starting processes remotely, and when
356 attaching to already-running local or remote processes.
358 * GDB now supports automatic location and retrieval of executable
359 files from remote targets. Remote debugging can now be initiated
360 using only a "target remote" or "target extended-remote" command
361 (no "set sysroot" or "file" commands are required). See "New remote
364 * The "dump" command now supports verilog hex format.
366 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
368 * On GNU/Linux, GDB and gdbserver are now able to access executable
369 and shared library files without a "set sysroot" command when
370 attaching to processes running in different mount namespaces from
371 the debugger. This makes it possible to attach to processes in
372 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
373 See "New remote packets" below.
375 * The "tui reg" command now provides completion for all of the
376 available register groups, including target specific groups.
378 * The HISTSIZE environment variable is no longer read when determining
379 the size of GDB's command history. GDB now instead reads the dedicated
380 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
381 disables truncation of command history. Non-numeric values of GDBHISTSIZE
386 ** Memory ports can now be unbuffered.
390 ** gdb.Objfile objects have a new attribute "username",
391 which is the name of the objfile as specified by the user,
392 without, for example, resolving symlinks.
393 ** You can now write frame unwinders in Python.
394 ** gdb.Type objects have a new method "optimized_out",
395 returning optimized out gdb.Value instance of this type.
396 ** gdb.Value objects have new methods "reference_value" and
397 "const_value" which return a reference to the value and a
398 "const" version of the value respectively.
402 maint print symbol-cache
403 Print the contents of the symbol cache.
405 maint print symbol-cache-statistics
406 Print statistics of symbol cache usage.
408 maint flush-symbol-cache
409 Flush the contents of the symbol cache.
413 Start branch trace recording using Branch Trace Store (BTS) format.
416 Evaluate expression by using the compiler and print result.
420 Explicit commands for enabling and disabling tui mode.
423 set mpx bound on i386 and amd64
424 Support for bound table investigation on Intel MPX enabled applications.
428 Start branch trace recording using Intel Processor Trace format.
431 Print information about branch tracing internals.
433 maint btrace packet-history
434 Print the raw branch tracing data.
436 maint btrace clear-packet-history
437 Discard the stored raw branch tracing data.
440 Discard all branch tracing data. It will be fetched and processed
441 anew by the next "record" command.
446 Renamed from "set debug dwarf2-die".
448 Renamed from "show debug dwarf2-die".
451 Renamed from "set debug dwarf2-read".
452 show debug dwarf-read
453 Renamed from "show debug dwarf2-read".
455 maint set dwarf always-disassemble
456 Renamed from "maint set dwarf2 always-disassemble".
457 maint show dwarf always-disassemble
458 Renamed from "maint show dwarf2 always-disassemble".
460 maint set dwarf max-cache-age
461 Renamed from "maint set dwarf2 max-cache-age".
462 maint show dwarf max-cache-age
463 Renamed from "maint show dwarf2 max-cache-age".
466 show debug dwarf-line
467 Control display of debugging info regarding DWARF line processing.
471 Set the maximum number of candidates to be considered during
472 completion. The default value is 200. This limit allows GDB
473 to avoid generating large completion lists, the computation of
474 which can cause the debugger to become temporarily unresponsive.
476 set history remove-duplicates
477 show history remove-duplicates
478 Control the removal of duplicate history entries.
480 maint set symbol-cache-size
481 maint show symbol-cache-size
482 Control the size of the symbol cache.
484 set|show record btrace bts buffer-size
485 Set and show the size of the ring buffer used for branch tracing in
487 The obtained size may differ from the requested size. Use "info
488 record" to see the obtained buffer size.
490 set debug linux-namespaces
491 show debug linux-namespaces
492 Control display of debugging info regarding Linux namespaces.
494 set|show record btrace pt buffer-size
495 Set and show the size of the ring buffer used for branch tracing in
496 Intel Processor Trace format.
497 The obtained size may differ from the requested size. Use "info
498 record" to see the obtained buffer size.
500 maint set|show btrace pt skip-pad
501 Set and show whether PAD packets are skipped when computing the
504 * The command 'thread apply all' can now support new option '-ascending'
505 to call its specified command for all threads in ascending order.
507 * Python/Guile scripting
509 ** GDB now supports auto-loading of Python/Guile scripts contained in the
510 special section named `.debug_gdb_scripts'.
514 qXfer:btrace-conf:read
515 Return the branch trace configuration for the current thread.
517 Qbtrace-conf:bts:size
518 Set the requested ring buffer size for branch tracing in BTS format.
521 Enable Intel Procesor Trace-based branch tracing for the current
522 process. The remote stub reports support for this packet to GDB's
526 Set the requested ring buffer size for branch tracing in Intel Processor
530 Indicates a memory breakpoint instruction was executed, irrespective
531 of whether it was GDB that planted the breakpoint or the breakpoint
532 is hardcoded in the program. This is required for correct non-stop
536 Indicates the target stopped for a hardware breakpoint. This is
537 required for correct non-stop mode operation.
540 Return information about files on the remote system.
543 Return the full absolute name of the file that was executed to
544 create a process running on the remote system.
547 Select the filesystem on which vFile: operations with filename
548 arguments will operate. This is required for GDB to be able to
549 access files on remote targets where the remote stub does not
550 share a common filesystem with the inferior(s).
553 Indicates that a fork system call was executed.
556 Indicates that a vfork system call was executed.
558 vforkdone stop reason
559 Indicates that a vfork child of the specified process has executed
560 an exec or exit, allowing the vfork parent to resume execution.
562 fork-events and vfork-events features in qSupported
563 The qSupported packet allows GDB to request support for fork and
564 vfork events using new 'gdbfeatures' fork-events and vfork-events,
565 and the qSupported response can contain the corresponding
566 'stubfeatures'. Set and show commands can be used to display
567 whether these features are enabled.
569 * Extended-remote fork events
571 ** GDB now has support for fork events on extended-remote Linux
572 targets. For targets with Linux kernels 2.5.60 and later, this
573 enables follow-fork-mode and detach-on-fork for both fork and
574 vfork, as well as fork and vfork catchpoints.
576 * The info record command now shows the recording format and the
577 branch tracing configuration for the current thread when using
578 the btrace record target.
579 For the BTS format, it shows the ring buffer size.
581 * GDB now has support for DTrace USDT (Userland Static Defined
582 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
584 * GDB now supports access to vector registers on S/390 GNU/Linux
587 * Removed command line options
589 -xdb HP-UX XDB compatibility mode.
591 * Removed targets and native configurations
593 HP/PA running HP-UX hppa*-*-hpux*
594 Itanium running HP-UX ia64-*-hpux*
596 * New configure options
599 This configure option allows the user to build GDB with support for
600 Intel Processor Trace (default: auto). This requires libipt.
602 --with-libipt-prefix=PATH
603 Specify the path to the version of libipt that GDB should use.
604 $PATH/include should contain the intel-pt.h header and
605 $PATH/lib should contain the libipt.so library.
607 *** Changes in GDB 7.9.1
611 ** Xmethods can now specify a result type.
613 *** Changes in GDB 7.9
615 * GDB now supports hardware watchpoints on x86 GNU Hurd.
619 ** You can now access frame registers from Python scripts.
620 ** New attribute 'producer' for gdb.Symtab objects.
621 ** gdb.Objfile objects have a new attribute "progspace",
622 which is the gdb.Progspace object of the containing program space.
623 ** gdb.Objfile objects have a new attribute "owner".
624 ** gdb.Objfile objects have a new attribute "build_id",
625 which is the build ID generated when the file was built.
626 ** gdb.Objfile objects have a new method "add_separate_debug_file".
627 ** A new event "gdb.clear_objfiles" has been added, triggered when
628 selecting a new file to debug.
629 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
630 ** New function gdb.lookup_objfile.
632 New events which are triggered when GDB modifies the state of the
635 ** gdb.events.inferior_call_pre: Function call is about to be made.
636 ** gdb.events.inferior_call_post: Function call has just been made.
637 ** gdb.events.memory_changed: A memory location has been altered.
638 ** gdb.events.register_changed: A register has been altered.
640 * New Python-based convenience functions:
642 ** $_caller_is(name [, number_of_frames])
643 ** $_caller_matches(regexp [, number_of_frames])
644 ** $_any_caller_is(name [, number_of_frames])
645 ** $_any_caller_matches(regexp [, number_of_frames])
647 * GDB now supports the compilation and injection of source code into
648 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
649 to compile the source code to object code, and if successful, inject
650 and execute that code within the current context of the inferior.
651 Currently the C language is supported. The commands used to
652 interface with this new feature are:
654 compile code [-raw|-r] [--] [source code]
655 compile file [-raw|-r] filename
659 demangle [-l language] [--] name
660 Demangle "name" in the specified language, or the current language
661 if elided. This command is renamed from the "maint demangle" command.
662 The latter is kept as a no-op to avoid "maint demangle" being interpreted
663 as "maint demangler-warning".
665 queue-signal signal-name-or-number
666 Queue a signal to be delivered to the thread when it is resumed.
668 add-auto-load-scripts-directory directory
669 Add entries to the list of directories from which to load auto-loaded
672 maint print user-registers
673 List all currently available "user" registers.
675 compile code [-r|-raw] [--] [source code]
676 Compile, inject, and execute in the inferior the executable object
677 code produced by compiling the provided source code.
679 compile file [-r|-raw] filename
680 Compile and inject into the inferior the executable object code
681 produced by compiling the source code stored in the filename
684 * On resume, GDB now always passes the signal the program had stopped
685 for to the thread the signal was sent to, even if the user changed
686 threads before resuming. Previously GDB would often (but not
687 always) deliver the signal to the thread that happens to be current
690 * Conversely, the "signal" command now consistently delivers the
691 requested signal to the current thread. GDB now asks for
692 confirmation if the program had stopped for a signal and the user
693 switched threads meanwhile.
695 * "breakpoint always-inserted" modes "off" and "auto" merged.
697 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
698 won't remove breakpoints from the target until all threads stop,
699 even in non-stop mode. The "auto" mode has been removed, and "off"
700 is now the default mode.
704 set debug symbol-lookup
705 show debug symbol-lookup
706 Control display of debugging info regarding symbol lookup.
710 ** The -list-thread-groups command outputs an exit-code field for
711 inferiors that have exited.
715 MIPS SDE mips*-sde*-elf*
719 Support for these obsolete configurations has been removed.
721 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
722 SGI Irix-5.x mips-*-irix5*
723 SGI Irix-6.x mips-*-irix6*
724 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
725 VAX running Ultrix vax-*-ultrix*
727 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
728 and "assf"), have been removed. Use the "sharedlibrary" command, or
729 its alias "share", instead.
731 *** Changes in GDB 7.8
733 * New command line options
736 This is an alias for the --data-directory option.
738 * GDB supports printing and modifying of variable length automatic arrays
739 as specified in ISO C99.
741 * The ARM simulator now supports instruction level tracing
742 with or without disassembly.
746 GDB now has support for scripting using Guile. Whether this is
747 available is determined at configure time.
748 Guile version 2.0 or greater is required.
749 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
751 * New commands (for set/show, see "New options" below)
755 Invoke CODE by passing it to the Guile interpreter.
759 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
761 info auto-load guile-scripts [regexp]
762 Print the list of automatically loaded Guile scripts.
764 * The source command is now capable of sourcing Guile scripts.
765 This feature is dependent on the debugger being built with Guile support.
769 set print symbol-loading (off|brief|full)
770 show print symbol-loading
771 Control whether to print informational messages when loading symbol
772 information for a file. The default is "full", but when debugging
773 programs with large numbers of shared libraries the amount of output
776 set guile print-stack (none|message|full)
777 show guile print-stack
778 Show a stack trace when an error is encountered in a Guile script.
780 set auto-load guile-scripts (on|off)
781 show auto-load guile-scripts
782 Control auto-loading of Guile script files.
784 maint ada set ignore-descriptive-types (on|off)
785 maint ada show ignore-descriptive-types
786 Control whether the debugger should ignore descriptive types in Ada
787 programs. The default is not to ignore the descriptive types. See
788 the user manual for more details on descriptive types and the intended
789 usage of this option.
791 set auto-connect-native-target
793 Control whether GDB is allowed to automatically connect to the
794 native target for the run, attach, etc. commands when not connected
795 to any target yet. See also "target native" below.
797 set record btrace replay-memory-access (read-only|read-write)
798 show record btrace replay-memory-access
799 Control what memory accesses are allowed during replay.
801 maint set target-async (on|off)
802 maint show target-async
803 This controls whether GDB targets operate in synchronous or
804 asynchronous mode. Normally the default is asynchronous, if it is
805 available; but this can be changed to more easily debug problems
806 occurring only in synchronous mode.
808 set mi-async (on|off)
810 Control whether MI asynchronous mode is preferred. This supersedes
811 "set target-async" of previous GDB versions.
813 * "set target-async" is deprecated as a CLI option and is now an alias
814 for "set mi-async" (only puts MI into async mode).
816 * Background execution commands (e.g., "c&", "s&", etc.) are now
817 possible ``out of the box'' if the target supports them. Previously
818 the user would need to explicitly enable the possibility with the
819 "set target-async on" command.
821 * New features in the GDB remote stub, GDBserver
823 ** New option --debug-format=option1[,option2,...] allows one to add
824 additional text to each output. At present only timestamps
825 are supported: --debug-format=timestamps.
826 Timestamps can also be turned on with the
827 "monitor set debug-format timestamps" command from GDB.
829 * The 'record instruction-history' command now starts counting instructions
830 at one. This also affects the instruction ranges reported by the
831 'record function-call-history' command when given the /i modifier.
833 * The command 'record function-call-history' supports a new modifier '/c' to
834 indent the function names based on their call stack depth.
835 The fields for the '/i' and '/l' modifier have been reordered.
836 The source line range is now prefixed with 'at'.
837 The instruction range is now prefixed with 'inst'.
838 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
839 "record instruction-history" and "list" commands.
841 * The ranges given as arguments to the 'record function-call-history' and
842 'record instruction-history' commands are now inclusive.
844 * The btrace record target now supports the 'record goto' command.
845 For locations inside the execution trace, the back trace is computed
846 based on the information stored in the execution trace.
848 * The btrace record target supports limited reverse execution and replay.
849 The target does not record data and therefore does not allow reading
852 * The "catch syscall" command now works on s390*-linux* targets.
854 * The "compare-sections" command is no longer specific to target
855 remote. It now works with all targets.
857 * All native targets are now consistently called "native".
858 Consequently, the "target child", "target GNU", "target djgpp",
859 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
860 commands have been replaced with "target native". The QNX/NTO port
861 leaves the "procfs" target in place and adds a "native" target for
862 consistency with other ports. The impact on users should be minimal
863 as these commands previously either throwed an error, or were
864 no-ops. The target's name is visible in the output of the following
865 commands: "help target", "info target", "info files", "maint print
868 * The "target native" command now connects to the native target. This
869 can be used to launch native programs even when "set
870 auto-connect-native-target" is set to off.
872 * GDB now supports access to Intel MPX registers on GNU/Linux.
874 * Support for Intel AVX-512 registers on GNU/Linux.
875 Support displaying and modifying Intel AVX-512 registers
876 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
880 qXfer:btrace:read's annex
881 The qXfer:btrace:read packet supports a new annex 'delta' to read
882 branch trace incrementally.
886 ** Valid Python operations on gdb.Value objects representing
887 structs/classes invoke the corresponding overloaded operators if
889 ** New `Xmethods' feature in the Python API. Xmethods are
890 additional methods or replacements for existing methods of a C++
891 class. This feature is useful for those cases where a method
892 defined in C++ source code could be inlined or optimized out by
893 the compiler, making it unavailable to GDB.
896 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
898 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
899 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
900 its alias "share", instead.
902 * The commands "set remotebaud" and "show remotebaud" are no longer
903 supported. Use "set serial baud" and "show serial baud" (respectively)
908 ** A new option "-gdb-set mi-async" replaces "-gdb-set
909 target-async". The latter is left as a deprecated alias of the
910 former for backward compatibility. If the target supports it,
911 CLI background execution commands are now always possible by
912 default, independently of whether the frontend stated a
913 preference for asynchronous execution with "-gdb-set mi-async".
914 Previously "-gdb-set target-async off" affected both MI execution
915 commands and CLI execution commands.
917 *** Changes in GDB 7.7
919 * Improved support for process record-replay and reverse debugging on
920 arm*-linux* targets. Support for thumb32 and syscall instruction
921 recording has been added.
923 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
925 * GDB now supports Fission DWP file format version 2.
926 http://gcc.gnu.org/wiki/DebugFission
928 * New convenience function "$_isvoid", to check whether an expression
929 is void. A void expression is an expression where the type of the
930 result is "void". For example, some convenience variables may be
931 "void" when evaluated (e.g., "$_exitcode" before the execution of
932 the program being debugged; or an undefined convenience variable).
933 Another example, when calling a function whose return type is
936 * The "maintenance print objfiles" command now takes an optional regexp.
938 * The "catch syscall" command now works on arm*-linux* targets.
940 * GDB now consistently shows "<not saved>" when printing values of
941 registers the debug info indicates have not been saved in the frame
942 and there's nowhere to retrieve them from
943 (callee-saved/call-clobbered registers):
948 (gdb) info registers rax
951 Before, the former would print "<optimized out>", and the latter
952 "*value not available*".
954 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
959 ** Frame filters and frame decorators have been added.
960 ** Temporary breakpoints are now supported.
961 ** Line tables representation has been added.
962 ** New attribute 'parent_type' for gdb.Field objects.
963 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
964 ** New attribute 'name' for gdb.Type objects.
968 Nios II ELF nios2*-*-elf
969 Nios II GNU/Linux nios2*-*-linux
970 Texas Instruments MSP430 msp430*-*-elf
972 * Removed native configurations
974 Support for these a.out NetBSD and OpenBSD obsolete configurations has
975 been removed. ELF variants of these configurations are kept supported.
977 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
978 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
979 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
980 i[34567]86-*-openbsd3.[0-3]
981 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
982 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
983 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
987 Like "catch throw", but catches a re-thrown exception.
989 Renamed from old "maint check-symtabs".
991 Perform consistency checks on symtabs.
993 Expand symtabs matching an optional regexp.
996 Display the details of GDB configure-time options.
998 maint set|show per-command
999 maint set|show per-command space
1000 maint set|show per-command time
1001 maint set|show per-command symtab
1002 Enable display of per-command gdb resource usage.
1004 remove-symbol-file FILENAME
1005 remove-symbol-file -a ADDRESS
1006 Remove a symbol file added via add-symbol-file. The file to remove
1007 can be identified by its filename or by an address that lies within
1008 the boundaries of this symbol file in memory.
1011 info exceptions REGEXP
1012 Display the list of Ada exceptions defined in the program being
1013 debugged. If provided, only the exceptions whose names match REGEXP
1018 set debug symfile off|on
1020 Control display of debugging info regarding reading symbol files and
1021 symbol tables within those files
1023 set print raw frame-arguments
1024 show print raw frame-arguments
1025 Set/show whether to print frame arguments in raw mode,
1026 disregarding any defined pretty-printers.
1028 set remote trace-status-packet
1029 show remote trace-status-packet
1030 Set/show the use of remote protocol qTStatus packet.
1034 Control display of debugging messages related to Nios II targets.
1038 Control whether target-assisted range stepping is enabled.
1040 set startup-with-shell
1041 show startup-with-shell
1042 Specifies whether Unix child processes are started via a shell or
1047 Use the target memory cache for accesses to the code segment. This
1048 improves performance of remote debugging (particularly disassembly).
1050 * You can now use a literal value 'unlimited' for options that
1051 interpret 0 or -1 as meaning "unlimited". E.g., "set
1052 trace-buffer-size unlimited" is now an alias for "set
1053 trace-buffer-size -1" and "set height unlimited" is now an alias for
1056 * The "set debug symtab-create" debugging option of GDB has been changed to
1057 accept a verbosity level. 0 means "off", 1 provides basic debugging
1058 output, and values of 2 or greater provides more verbose output.
1060 * New command-line options
1062 Display the details of GDB configure-time options.
1064 * The command 'tsave' can now support new option '-ctf' to save trace
1065 buffer in Common Trace Format.
1067 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1070 * GDB now implements the the C++ 'typeid' operator.
1072 * The new convenience variable $_exception holds the exception being
1073 thrown or caught at an exception-related catchpoint.
1075 * The exception-related catchpoints, like "catch throw", now accept a
1076 regular expression which can be used to filter exceptions by type.
1078 * The new convenience variable $_exitsignal is automatically set to
1079 the terminating signal number when the program being debugged dies
1080 due to an uncaught signal.
1084 ** All MI commands now accept an optional "--language" option.
1085 Support for this feature can be verified by using the "-list-features"
1086 command, which should contain "language-option".
1088 ** The new command -info-gdb-mi-command allows the user to determine
1089 whether a GDB/MI command is supported or not.
1091 ** The "^error" result record returned when trying to execute an undefined
1092 GDB/MI command now provides a variable named "code" whose content is the
1093 "undefined-command" error code. Support for this feature can be verified
1094 by using the "-list-features" command, which should contain
1095 "undefined-command-error-code".
1097 ** The -trace-save MI command can optionally save trace buffer in Common
1100 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1102 ** The command -data-list-register-values now accepts an optional
1103 "--skip-unavailable" option. When used, only the available registers
1106 ** The new command -trace-frame-collected dumps collected variables,
1107 computed expressions, tvars, memory and registers in a traceframe.
1109 ** The commands -stack-list-locals, -stack-list-arguments and
1110 -stack-list-variables now accept an option "--skip-unavailable".
1111 When used, only the available locals or arguments are displayed.
1113 ** The -exec-run command now accepts an optional "--start" option.
1114 When used, the command follows the same semantics as the "start"
1115 command, stopping the program's execution at the start of its
1116 main subprogram. Support for this feature can be verified using
1117 the "-list-features" command, which should contain
1118 "exec-run-start-option".
1120 ** The new commands -catch-assert and -catch-exceptions insert
1121 catchpoints stopping the program when Ada exceptions are raised.
1123 ** The new command -info-ada-exceptions provides the equivalent of
1124 the new "info exceptions" command.
1126 * New system-wide configuration scripts
1127 A GDB installation now provides scripts suitable for use as system-wide
1128 configuration scripts for the following systems:
1132 * GDB now supports target-assigned range stepping with remote targets.
1133 This improves the performance of stepping source lines by reducing
1134 the number of control packets from/to GDB. See "New remote packets"
1137 * GDB now understands the element 'tvar' in the XML traceframe info.
1138 It has the id of the collected trace state variables.
1140 * On S/390 targets that provide the transactional-execution feature,
1141 the program interruption transaction diagnostic block (TDB) is now
1142 represented as a number of additional "registers" in GDB.
1144 * New remote packets
1148 The vCont packet supports a new 'r' action, that tells the remote
1149 stub to step through an address range itself, without GDB
1150 involvemement at each single-step.
1152 qXfer:libraries-svr4:read's annex
1153 The previously unused annex of the qXfer:libraries-svr4:read packet
1154 is now used to support passing an argument list. The remote stub
1155 reports support for this argument list to GDB's qSupported query.
1156 The defined arguments are "start" and "prev", used to reduce work
1157 necessary for library list updating, resulting in significant
1160 * New features in the GDB remote stub, GDBserver
1162 ** GDBserver now supports target-assisted range stepping. Currently
1163 enabled on x86/x86_64 GNU/Linux targets.
1165 ** GDBserver now adds element 'tvar' in the XML in the reply to
1166 'qXfer:traceframe-info:read'. It has the id of the collected
1167 trace state variables.
1169 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1172 * New 'z' formatter for printing and examining memory, this displays the
1173 value as hexadecimal zero padded on the left to the size of the type.
1175 * GDB can now use Windows x64 unwinding data.
1177 * The "set remotebaud" command has been replaced by "set serial baud".
1178 Similarly, "show remotebaud" has been replaced by "show serial baud".
1179 The "set remotebaud" and "show remotebaud" commands are still available
1180 to provide backward compatibility with older versions of GDB.
1182 *** Changes in GDB 7.6
1184 * Target record has been renamed to record-full.
1185 Record/replay is now enabled with the "record full" command.
1186 This also affects settings that are associated with full record/replay
1187 that have been moved from "set/show record" to "set/show record full":
1189 set|show record full insn-number-max
1190 set|show record full stop-at-limit
1191 set|show record full memory-query
1193 * A new record target "record-btrace" has been added. The new target
1194 uses hardware support to record the control-flow of a process. It
1195 does not support replaying the execution, but it implements the
1196 below new commands for investigating the recorded execution log.
1197 This new recording method can be enabled using:
1201 The "record-btrace" target is only available on Intel Atom processors
1202 and requires a Linux kernel 2.6.32 or later.
1204 * Two new commands have been added for record/replay to give information
1205 about the recorded execution without having to replay the execution.
1206 The commands are only supported by "record btrace".
1208 record instruction-history prints the execution history at
1209 instruction granularity
1211 record function-call-history prints the execution history at
1212 function granularity
1214 * New native configurations
1216 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1217 FreeBSD/powerpc powerpc*-*-freebsd
1218 x86_64/Cygwin x86_64-*-cygwin*
1219 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1223 ARM AArch64 aarch64*-*-elf
1224 ARM AArch64 GNU/Linux aarch64*-*-linux
1225 Lynx 178 PowerPC powerpc-*-lynx*178
1226 x86_64/Cygwin x86_64-*-cygwin*
1227 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1229 * If the configured location of system.gdbinit file (as given by the
1230 --with-system-gdbinit option at configure time) is in the
1231 data-directory (as specified by --with-gdb-datadir at configure
1232 time) or in one of its subdirectories, then GDB will look for the
1233 system-wide init file in the directory specified by the
1234 --data-directory command-line option.
1236 * New command line options:
1238 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1239 other initialization files, unlike -nx which disables all of them.
1241 * Removed command line options
1243 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1246 * The 'ptype' and 'whatis' commands now accept an argument to control
1249 * 'info proc' now works on some core files.
1253 ** Vectors can be created with gdb.Type.vector.
1255 ** Python's atexit.register now works in GDB.
1257 ** Types can be pretty-printed via a Python API.
1259 ** Python 3 is now supported (in addition to Python 2.4 or later)
1261 ** New class gdb.Architecture exposes GDB's internal representation
1262 of architecture in the Python API.
1264 ** New method Frame.architecture returns the gdb.Architecture object
1265 corresponding to the frame's architecture.
1267 * New Python-based convenience functions:
1269 ** $_memeq(buf1, buf2, length)
1270 ** $_streq(str1, str2)
1272 ** $_regex(str, regex)
1274 * The 'cd' command now defaults to using '~' (the home directory) if not
1277 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1278 default for GCC since November 2000.
1280 * The command 'forward-search' can now be abbreviated as 'fo'.
1282 * The command 'info tracepoints' can now display 'installed on target'
1283 or 'not installed on target' for each non-pending location of tracepoint.
1285 * New configure options
1287 --enable-libmcheck/--disable-libmcheck
1288 By default, development versions are built with -lmcheck on hosts
1289 that support it, in order to help track memory corruption issues.
1290 Release versions, on the other hand, are built without -lmcheck
1291 by default. The --enable-libmcheck/--disable-libmcheck configure
1292 options allow the user to override that default.
1293 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1294 This configure option allows the user to build GDB with
1295 libbabeltrace using which GDB can read Common Trace Format data.
1297 * New commands (for set/show, see "New options" below)
1300 Catch signals. This is similar to "handle", but allows commands and
1301 conditions to be attached.
1304 List the BFDs known to GDB.
1306 python-interactive [command]
1308 Start a Python interactive prompt, or evaluate the optional command
1309 and print the result of expressions.
1312 "py" is a new alias for "python".
1314 enable type-printer [name]...
1315 disable type-printer [name]...
1316 Enable or disable type printers.
1320 ** For the Renesas Super-H architecture, the "regs" command has been removed
1321 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1326 set print type methods (on|off)
1327 show print type methods
1328 Control whether method declarations are displayed by "ptype".
1329 The default is to show them.
1331 set print type typedefs (on|off)
1332 show print type typedefs
1333 Control whether typedef definitions are displayed by "ptype".
1334 The default is to show them.
1336 set filename-display basename|relative|absolute
1337 show filename-display
1338 Control the way in which filenames is displayed.
1339 The default is "relative", which preserves previous behavior.
1341 set trace-buffer-size
1342 show trace-buffer-size
1343 Request target to change the size of trace buffer.
1345 set remote trace-buffer-size-packet auto|on|off
1346 show remote trace-buffer-size-packet
1347 Control the use of the remote protocol `QTBuffer:size' packet.
1351 Control display of debugging messages related to ARM AArch64.
1354 set debug coff-pe-read
1355 show debug coff-pe-read
1356 Control display of debugging messages related to reading of COFF/PE
1361 Control display of debugging messages related to Mach-O symbols
1364 set debug notification
1365 show debug notification
1366 Control display of debugging info for async remote notification.
1370 ** Command parameter changes are now notified using new async record
1371 "=cmd-param-changed".
1372 ** Trace frame changes caused by command "tfind" are now notified using
1373 new async record "=traceframe-changed".
1374 ** The creation, deletion and modification of trace state variables
1375 are now notified using new async records "=tsv-created",
1376 "=tsv-deleted" and "=tsv-modified".
1377 ** The start and stop of process record are now notified using new
1378 async record "=record-started" and "=record-stopped".
1379 ** Memory changes are now notified using new async record
1381 ** The data-disassemble command response will include a "fullname" field
1382 containing the absolute file name when source has been requested.
1383 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1384 command, to allow pattern filling of memory areas.
1385 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1386 library load/unload events.
1387 ** The response to breakpoint commands and breakpoint async records
1388 includes an "installed" field containing a boolean state about each
1389 non-pending tracepoint location is whether installed on target or not.
1390 ** Output of the "-trace-status" command includes a "trace-file" field
1391 containing the name of the trace file being examined. This field is
1392 optional, and only present when examining a trace file.
1393 ** The "fullname" field is now always present along with the "file" field,
1394 even if the file cannot be found by GDB.
1396 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1397 You must have the LZMA library available when configuring GDB for this
1398 feature to be enabled. For more information, see:
1399 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1401 * New remote packets
1404 Set the size of trace buffer. The remote stub reports support for this
1405 packet to gdb's qSupported query.
1408 Enable Branch Trace Store (BTS)-based branch tracing for the current
1409 thread. The remote stub reports support for this packet to gdb's
1413 Disable branch tracing for the current thread. The remote stub reports
1414 support for this packet to gdb's qSupported query.
1417 Read the traced branches for the current thread. The remote stub
1418 reports support for this packet to gdb's qSupported query.
1420 *** Changes in GDB 7.5
1422 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1423 for more x32 ABI info.
1425 * GDB now supports access to MIPS DSP registers on Linux targets.
1427 * GDB now supports debugging microMIPS binaries.
1429 * The "info os" command on GNU/Linux can now display information on
1430 several new classes of objects managed by the operating system:
1431 "info os procgroups" lists process groups
1432 "info os files" lists file descriptors
1433 "info os sockets" lists internet-domain sockets
1434 "info os shm" lists shared-memory regions
1435 "info os semaphores" lists semaphores
1436 "info os msg" lists message queues
1437 "info os modules" lists loaded kernel modules
1439 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1440 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1441 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1442 options and inspect the probe arguments using the new $_probe_arg family
1443 of convenience variables. You can obtain more information about SystemTap
1444 in <http://sourceware.org/systemtap/>.
1446 * GDB now supports reversible debugging on ARM, it allows you to
1447 debug basic ARM and THUMB instructions, and provides
1448 record/replay support.
1450 * The option "symbol-reloading" has been deleted as it is no longer used.
1454 ** GDB commands implemented in Python can now be put in command class
1457 ** The "maint set python print-stack on|off" is now deleted.
1459 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1460 apply "flag enum"-style pretty-printing to any enum.
1462 ** gdb.lookup_symbol can now work when there is no current frame.
1464 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1465 the source at which the symbol was defined.
1467 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1468 method 'value'. The former indicates whether the symbol needs a
1469 frame in order to compute its value, and the latter computes the
1472 ** A new method 'referenced_value' on gdb.Value objects which can
1473 dereference pointer as well as C++ reference values.
1475 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1476 which return the global and static blocks (as gdb.Block objects),
1477 of the underlying symbol table, respectively.
1479 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1480 object associated with a PC value.
1482 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1483 of the address range occupied by code for the current source line.
1485 * Go language support.
1486 GDB now supports debugging programs written in the Go programming
1489 * GDBserver now supports stdio connections.
1490 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1492 * The binary "gdbtui" can no longer be built or installed.
1493 Use "gdb -tui" instead.
1495 * GDB will now print "flag" enums specially. A flag enum is one where
1496 all the enumerator values have no bits in common when pairwise
1497 "and"ed. When printing a value whose type is a flag enum, GDB will
1498 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1499 (gdb) print (enum E) 3
1502 * The filename part of a linespec will now match trailing components
1503 of a source file name. For example, "break gcc/expr.c:1000" will
1504 now set a breakpoint in build/gcc/expr.c, but not
1505 build/libcpp/expr.c.
1507 * The "info proc" and "generate-core-file" commands will now also
1508 work on remote targets connected to GDBserver on Linux.
1510 * The command "info catch" has been removed. It has been disabled
1511 since December 2007.
1513 * The "catch exception" and "catch assert" commands now accept
1514 a condition at the end of the command, much like the "break"
1515 command does. For instance:
1517 (gdb) catch exception Constraint_Error if Barrier = True
1519 Previously, it was possible to add a condition to such catchpoints,
1520 but it had to be done as a second step, after the catchpoint had been
1521 created, using the "condition" command.
1523 * The "info static-tracepoint-marker" command will now also work on
1524 native Linux targets with in-process agent.
1526 * GDB can now set breakpoints on inlined functions.
1528 * The .gdb_index section has been updated to include symbols for
1529 inlined functions. GDB will ignore older .gdb_index sections by
1530 default, which could cause symbol files to be loaded more slowly
1531 until their .gdb_index sections can be recreated. The new command
1532 "set use-deprecated-index-sections on" will cause GDB to use any older
1533 .gdb_index sections it finds. This will restore performance, but the
1534 ability to set breakpoints on inlined functions will be lost in symbol
1535 files with older .gdb_index sections.
1537 The .gdb_index section has also been updated to record more information
1538 about each symbol. This speeds up the "info variables", "info functions"
1539 and "info types" commands when used with programs having the .gdb_index
1540 section, as well as speeding up debugging with shared libraries using
1541 the .gdb_index section.
1543 * Ada support for GDB/MI Variable Objects has been added.
1545 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1550 ** New command -info-os is the MI equivalent of "info os".
1552 ** Output logs ("set logging" and related) now include MI output.
1556 ** "set use-deprecated-index-sections on|off"
1557 "show use-deprecated-index-sections on|off"
1558 Controls the use of deprecated .gdb_index sections.
1560 ** "catch load" and "catch unload" can be used to stop when a shared
1561 library is loaded or unloaded, respectively.
1563 ** "enable count" can be used to auto-disable a breakpoint after
1566 ** "info vtbl" can be used to show the virtual method tables for
1567 C++ and Java objects.
1569 ** "explore" and its sub commands "explore value" and "explore type"
1570 can be used to recursively explore values and types of
1571 expressions. These commands are available only if GDB is
1572 configured with '--with-python'.
1574 ** "info auto-load" shows status of all kinds of auto-loaded files,
1575 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1576 sequences of commands files, "info auto-load python-scripts"
1577 shows status of auto-loading Python script files,
1578 "info auto-load local-gdbinit" shows status of loading init file
1579 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1580 status of inferior specific thread debugging shared library loading.
1582 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1583 and "show auto-load-scripts" commands have been deprecated, use their
1584 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1585 and "show auto-load python-scripts" counterparts instead.
1587 ** "dprintf location,format,args..." creates a dynamic printf, which
1588 is basically a breakpoint that does a printf and immediately
1589 resumes your program's execution, so it is like a printf that you
1590 can insert dynamically at runtime instead of at compiletime.
1592 ** "set print symbol"
1594 Controls whether GDB attempts to display the symbol, if any,
1595 corresponding to addresses it prints. This defaults to "on", but
1596 you can set it to "off" to restore GDB's previous behavior.
1598 * Deprecated commands
1600 ** For the Renesas Super-H architecture, the "regs" command has been
1601 deprecated, and "info all-registers" should be used instead.
1605 Renesas RL78 rl78-*-elf
1606 HP OpenVMS ia64 ia64-hp-openvms*
1608 * GDBserver supports evaluation of breakpoint conditions. When
1609 support is advertised by GDBserver, GDB may be told to send the
1610 breakpoint conditions in bytecode form to GDBserver. GDBserver
1611 will only report the breakpoint trigger to GDB when its condition
1616 set mips compression
1617 show mips compression
1618 Select the compressed ISA encoding used in functions that have no symbol
1619 information available. The encoding can be set to either of:
1622 and is updated automatically from ELF file flags if available.
1624 set breakpoint condition-evaluation
1625 show breakpoint condition-evaluation
1626 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1627 GDBserver ("target"). Default option "auto" chooses the most efficient
1629 This option can improve debugger efficiency depending on the speed of the
1633 Disable auto-loading globally.
1636 Show auto-loading setting of all kinds of auto-loaded files.
1638 set auto-load gdb-scripts on|off
1639 show auto-load gdb-scripts
1640 Control auto-loading of GDB canned sequences of commands files.
1642 set auto-load python-scripts on|off
1643 show auto-load python-scripts
1644 Control auto-loading of Python script files.
1646 set auto-load local-gdbinit on|off
1647 show auto-load local-gdbinit
1648 Control loading of init file (.gdbinit) from current directory.
1650 set auto-load libthread-db on|off
1651 show auto-load libthread-db
1652 Control auto-loading of inferior specific thread debugging shared library.
1654 set auto-load scripts-directory <dir1>[:<dir2>...]
1655 show auto-load scripts-directory
1656 Set a list of directories from which to load auto-loaded scripts.
1657 Automatically loaded Python scripts and GDB scripts are located in one
1658 of the directories listed by this option.
1659 The delimiter (':' above) may differ according to the host platform.
1661 set auto-load safe-path <dir1>[:<dir2>...]
1662 show auto-load safe-path
1663 Set a list of directories from which it is safe to auto-load files.
1664 The delimiter (':' above) may differ according to the host platform.
1666 set debug auto-load on|off
1667 show debug auto-load
1668 Control display of debugging info for auto-loading the files above.
1670 set dprintf-style gdb|call|agent
1672 Control the way in which a dynamic printf is performed; "gdb"
1673 requests a GDB printf command, while "call" causes dprintf to call a
1674 function in the inferior. "agent" requests that the target agent
1675 (such as GDBserver) do the printing.
1677 set dprintf-function <expr>
1678 show dprintf-function
1679 set dprintf-channel <expr>
1680 show dprintf-channel
1681 Set the function and optional first argument to the call when using
1682 the "call" style of dynamic printf.
1684 set disconnected-dprintf on|off
1685 show disconnected-dprintf
1686 Control whether agent-style dynamic printfs continue to be in effect
1687 after GDB disconnects.
1689 * New configure options
1691 --with-auto-load-dir
1692 Configure default value for the 'set auto-load scripts-directory'
1693 setting above. It defaults to '$debugdir:$datadir/auto-load',
1694 $debugdir representing global debugging info directories (available
1695 via 'show debug-file-directory') and $datadir representing GDB's data
1696 directory (available via 'show data-directory').
1698 --with-auto-load-safe-path
1699 Configure default value for the 'set auto-load safe-path' setting
1700 above. It defaults to the --with-auto-load-dir setting.
1702 --without-auto-load-safe-path
1703 Set 'set auto-load safe-path' to '/', effectively disabling this
1706 * New remote packets
1708 z0/z1 conditional breakpoints extension
1710 The z0/z1 breakpoint insertion packets have been extended to carry
1711 a list of conditional expressions over to the remote stub depending on the
1712 condition evaluation mode. The use of this extension can be controlled
1713 via the "set remote conditional-breakpoints-packet" command.
1717 Specify the signals which the remote stub may pass to the debugged
1718 program without GDB involvement.
1720 * New command line options
1722 --init-command=FILE, -ix Like --command, -x but execute it
1723 before loading inferior.
1724 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1725 execute it before loading inferior.
1727 *** Changes in GDB 7.4
1729 * GDB now handles ambiguous linespecs more consistently; the existing
1730 FILE:LINE support has been expanded to other types of linespecs. A
1731 breakpoint will now be set on all matching locations in all
1732 inferiors, and locations will be added or removed according to
1735 * GDB now allows you to skip uninteresting functions and files when
1736 stepping with the "skip function" and "skip file" commands.
1738 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1739 and "show remote hardware-watchpoint-length-limit". These allows to
1740 set or show the maximum length limit (in bytes) of a remote
1741 target hardware watchpoint.
1743 This allows e.g. to use "unlimited" hardware watchpoints with the
1744 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1745 watchpoints are slower than real hardware watchpoints but are
1746 significantly faster than gdb software watchpoints.
1750 ** The register_pretty_printer function in module gdb.printing now takes
1751 an optional `replace' argument. If True, the new printer replaces any
1754 ** The "maint set python print-stack on|off" command has been
1755 deprecated and will be deleted in GDB 7.5.
1756 A new command: "set python print-stack none|full|message" has
1757 replaced it. Additionally, the default for "print-stack" is
1758 now "message", which just prints the error message without
1761 ** A prompt substitution hook (prompt_hook) is now available to the
1764 ** A new Python module, gdb.prompt has been added to the GDB Python
1765 modules library. This module provides functionality for
1766 escape sequences in prompts (used by set/show
1767 extended-prompt). These escape sequences are replaced by their
1768 corresponding value.
1770 ** Python commands and convenience-functions located in
1771 'data-directory'/python/gdb/command and
1772 'data-directory'/python/gdb/function are now automatically loaded
1775 ** Blocks now provide four new attributes. global_block and
1776 static_block will return the global and static blocks
1777 respectively. is_static and is_global are boolean attributes
1778 that indicate if the block is one of those two types.
1780 ** Symbols now provide the "type" attribute, the type of the symbol.
1782 ** The "gdb.breakpoint" function has been deprecated in favor of
1785 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1786 of a function. This class is based on the "finish" command
1787 available in the CLI.
1789 ** Type objects for struct and union types now allow access to
1790 the fields using standard Python dictionary (mapping) methods.
1791 For example, "some_type['myfield']" now works, as does
1792 "some_type.items()".
1794 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1797 ** A new function, "deep_items" has been added to the gdb.types
1798 module in the GDB Python modules library. This function returns
1799 an iterator over the fields of a struct or union type. Unlike
1800 the standard Python "iteritems" method, it will recursively traverse
1801 any anonymous fields.
1805 ** "*stopped" events can report several new "reason"s, such as
1808 ** Breakpoint changes are now notified using new async records, like
1809 "=breakpoint-modified".
1811 ** New command -ada-task-info.
1813 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1814 $sdir specifies the default system locations of shared libraries.
1815 $pdir specifies the directory where the libpthread used by the application
1818 GDB no longer looks in $sdir and $pdir after it has searched the directories
1819 mentioned in libthread-db-search-path. If you want to search those
1820 directories, they must be specified in libthread-db-search-path.
1821 The default value of libthread-db-search-path on GNU/Linux and Solaris
1822 systems is now "$sdir:$pdir".
1824 $pdir is not supported by gdbserver, it is currently ignored.
1825 $sdir is supported by gdbserver.
1827 * New configure option --with-iconv-bin.
1828 When using the internationalization support like the one in the GNU C
1829 library, GDB will invoke the "iconv" program to get a list of supported
1830 character sets. If this program lives in a non-standard location, one can
1831 use this option to specify where to find it.
1833 * When natively debugging programs on PowerPC BookE processors running
1834 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1835 watchpoints, which specify a mask in addition to an address to watch.
1836 The mask specifies that some bits of an address (the bits which are
1837 reset in the mask) should be ignored when matching the address accessed
1838 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1839 section in the user manual for more details.
1841 * The new option --once causes GDBserver to stop listening for connections once
1842 the first connection is made. The listening port used by GDBserver will
1843 become available after that.
1845 * New commands "info macros" and "alias" have been added.
1847 * New function parameters suffix @entry specifies value of function parameter
1848 at the time the function got called. Entry values are available only since
1854 "!" is now an alias of the "shell" command.
1855 Note that no space is needed between "!" and SHELL COMMAND.
1859 watch EXPRESSION mask MASK_VALUE
1860 The watch command now supports the mask argument which allows creation
1861 of masked watchpoints, if the current architecture supports this feature.
1863 info auto-load-scripts [REGEXP]
1864 This command was formerly named "maintenance print section-scripts".
1865 It is now generally useful and is no longer a maintenance-only command.
1867 info macro [-all] [--] MACRO
1868 The info macro command has new options `-all' and `--'. The first for
1869 printing all definitions of a macro. The second for explicitly specifying
1870 the end of arguments and the beginning of the macro name in case the macro
1871 name starts with a hyphen.
1873 collect[/s] EXPRESSIONS
1874 The tracepoint collect command now takes an optional modifier "/s"
1875 that directs it to dereference pointer-to-character types and
1876 collect the bytes of memory up to a zero byte. The behavior is
1877 similar to what you see when you use the regular print command on a
1878 string. An optional integer following the "/s" sets a bound on the
1879 number of bytes that will be collected.
1882 The trace start command now interprets any supplied arguments as a
1883 note to be recorded with the trace run, with an effect similar to
1884 setting the variable trace-notes.
1887 The trace stop command now interprets any arguments as a note to be
1888 mentioned along with the tstatus report that the trace was stopped
1889 with a command. The effect is similar to setting the variable
1892 * Tracepoints can now be enabled and disabled at any time after a trace
1893 experiment has been started using the standard "enable" and "disable"
1894 commands. It is now possible to start a trace experiment with no enabled
1895 tracepoints; GDB will display a warning, but will allow the experiment to
1896 begin, assuming that tracepoints will be enabled as needed while the trace
1899 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1900 locations with 4-byte instructions, when they were previously
1901 limited to locations with instructions of 5 bytes or longer.
1905 set debug dwarf2-read
1906 show debug dwarf2-read
1907 Turns on or off display of debugging messages related to reading
1908 DWARF debug info. The default is off.
1910 set debug symtab-create
1911 show debug symtab-create
1912 Turns on or off display of debugging messages related to symbol table
1913 creation. The default is off.
1916 show extended-prompt
1917 Set the GDB prompt, and allow escape sequences to be inserted to
1918 display miscellaneous information (see 'help set extended-prompt'
1919 for the list of sequences). This prompt (and any information
1920 accessed through the escape sequences) is updated every time the
1921 prompt is displayed.
1923 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1924 show print entry-values
1925 Set printing of frame argument values at function entry. In some cases
1926 GDB can determine the value of function argument which was passed by the
1927 function caller, even if the value was modified inside the called function.
1929 set debug entry-values
1930 show debug entry-values
1931 Control display of debugging info for determining frame argument values at
1932 function entry and virtual tail call frames.
1934 set basenames-may-differ
1935 show basenames-may-differ
1936 Set whether a source file may have multiple base names.
1937 (A "base name" is the name of a file with the directory part removed.
1938 Example: The base name of "/home/user/hello.c" is "hello.c".)
1939 If set, GDB will canonicalize file names (e.g., expand symlinks)
1940 before comparing them. Canonicalization is an expensive operation,
1941 but it allows the same file be known by more than one base name.
1942 If not set (the default), all source files are assumed to have just
1943 one base name, and gdb will do file name comparisons more efficiently.
1949 Set a user name and notes for the current and any future trace runs.
1950 This is useful for long-running and/or disconnected traces, to
1951 inform others (or yourself) as to who is running the trace, supply
1952 contact information, or otherwise explain what is going on.
1954 set trace-stop-notes
1955 show trace-stop-notes
1956 Set a note attached to the trace run, that is displayed when the
1957 trace has been stopped by a tstop command. This is useful for
1958 instance as an explanation, if you are stopping a trace run that was
1959 started by someone else.
1961 * New remote packets
1965 Dynamically enable a tracepoint in a started trace experiment.
1969 Dynamically disable a tracepoint in a started trace experiment.
1973 Set the user and notes of the trace run.
1977 Query the current status of a tracepoint.
1981 Query the minimum length of instruction at which a fast tracepoint may
1984 * Dcache size (number of lines) and line-size are now runtime-configurable
1985 via "set dcache line" and "set dcache line-size" commands.
1989 Texas Instruments TMS320C6x tic6x-*-*
1993 Renesas RL78 rl78-*-elf
1995 *** Changes in GDB 7.3.1
1997 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1999 *** Changes in GDB 7.3
2001 * GDB has a new command: "thread find [REGEXP]".
2002 It finds the thread id whose name, target id, or thread extra info
2003 matches the given regular expression.
2005 * The "catch syscall" command now works on mips*-linux* targets.
2007 * The -data-disassemble MI command now supports modes 2 and 3 for
2008 dumping the instruction opcodes.
2010 * New command line options
2012 -data-directory DIR Specify DIR as the "data-directory".
2013 This is mostly for testing purposes.
2015 * The "maint set python auto-load on|off" command has been renamed to
2016 "set auto-load-scripts on|off".
2018 * GDB has a new command: "set directories".
2019 It is like the "dir" command except that it replaces the
2020 source path list instead of augmenting it.
2022 * GDB now understands thread names.
2024 On GNU/Linux, "info threads" will display the thread name as set by
2025 prctl or pthread_setname_np.
2027 There is also a new command, "thread name", which can be used to
2028 assign a name internally for GDB to display.
2031 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2032 has been integrated into GDB.
2036 ** The function gdb.Write now accepts an optional keyword 'stream'.
2037 This keyword, when provided, will direct the output to either
2038 stdout, stderr, or GDB's logging output.
2040 ** Parameters can now be be sub-classed in Python, and in particular
2041 you may implement the get_set_doc and get_show_doc functions.
2042 This improves how Parameter set/show documentation is processed
2043 and allows for more dynamic content.
2045 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2046 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2047 have an is_valid method.
2049 ** Breakpoints can now be sub-classed in Python, and in particular
2050 you may implement a 'stop' function that is executed each time
2051 the inferior reaches that breakpoint.
2053 ** New function gdb.lookup_global_symbol looks up a global symbol.
2055 ** GDB values in Python are now callable if the value represents a
2056 function. For example, if 'some_value' represents a function that
2057 takes two integer parameters and returns a value, you can call
2058 that function like so:
2060 result = some_value (10,20)
2062 ** Module gdb.types has been added.
2063 It contains a collection of utilities for working with gdb.Types objects:
2064 get_basic_type, has_field, make_enum_dict.
2066 ** Module gdb.printing has been added.
2067 It contains utilities for writing and registering pretty-printers.
2068 New classes: PrettyPrinter, SubPrettyPrinter,
2069 RegexpCollectionPrettyPrinter.
2070 New function: register_pretty_printer.
2072 ** New commands "info pretty-printers", "enable pretty-printer" and
2073 "disable pretty-printer" have been added.
2075 ** gdb.parameter("directories") is now available.
2077 ** New function gdb.newest_frame returns the newest frame in the
2080 ** The gdb.InferiorThread class has a new "name" attribute. This
2081 holds the thread's name.
2083 ** Python Support for Inferior events.
2084 Python scripts can add observers to be notified of events
2085 occurring in the process being debugged.
2086 The following events are currently supported:
2087 - gdb.events.cont Continue event.
2088 - gdb.events.exited Inferior exited event.
2089 - gdb.events.stop Signal received, and Breakpoint hit events.
2093 ** GDB now puts template parameters in scope when debugging in an
2094 instantiation. For example, if you have:
2096 template<int X> int func (void) { return X; }
2098 then if you step into func<5>, "print X" will show "5". This
2099 feature requires proper debuginfo support from the compiler; it
2100 was added to GCC 4.5.
2102 ** The motion commands "next", "finish", "until", and "advance" now
2103 work better when exceptions are thrown. In particular, GDB will
2104 no longer lose control of the inferior; instead, the GDB will
2105 stop the inferior at the point at which the exception is caught.
2106 This functionality requires a change in the exception handling
2107 code that was introduced in GCC 4.5.
2109 * GDB now follows GCC's rules on accessing volatile objects when
2110 reading or writing target state during expression evaluation.
2111 One notable difference to prior behavior is that "print x = 0"
2112 no longer generates a read of x; the value of the assignment is
2113 now always taken directly from the value being assigned.
2115 * GDB now has some support for using labels in the program's source in
2116 linespecs. For instance, you can use "advance label" to continue
2117 execution to a label.
2119 * GDB now has support for reading and writing a new .gdb_index
2120 section. This section holds a fast index of DWARF debugging
2121 information and can be used to greatly speed up GDB startup and
2122 operation. See the documentation for `save gdb-index' for details.
2124 * The "watch" command now accepts an optional "-location" argument.
2125 When used, this causes GDB to watch the memory referred to by the
2126 expression. Such a watchpoint is never deleted due to it going out
2129 * GDB now supports thread debugging of core dumps on GNU/Linux.
2131 GDB now activates thread debugging using the libthread_db library
2132 when debugging GNU/Linux core dumps, similarly to when debugging
2133 live processes. As a result, when debugging a core dump file, GDB
2134 is now able to display pthread_t ids of threads. For example, "info
2135 threads" shows the same output as when debugging the process when it
2136 was live. In earlier releases, you'd see something like this:
2139 * 1 LWP 6780 main () at main.c:10
2141 While now you see this:
2144 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2146 It is also now possible to inspect TLS variables when debugging core
2149 When debugging a core dump generated on a machine other than the one
2150 used to run GDB, you may need to point GDB at the correct
2151 libthread_db library with the "set libthread-db-search-path"
2152 command. See the user manual for more details on this command.
2154 * When natively debugging programs on PowerPC BookE processors running
2155 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2156 which stop execution of the inferior whenever it executes an instruction
2157 at any address within the specified range. See the "PowerPC Embedded"
2158 section in the user manual for more details.
2160 * New features in the GDB remote stub, GDBserver
2162 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2163 and i686 LynxOS (version 5.x).
2165 ** GDBserver is now supported on Blackfin Linux.
2167 * New native configurations
2169 ia64 HP-UX ia64-*-hpux*
2173 Analog Devices, Inc. Blackfin Processor bfin-*
2175 * Ada task switching is now supported on sparc-elf targets when
2176 debugging a program using the Ravenscar Profile. For more information,
2177 see the "Tasking Support when using the Ravenscar Profile" section
2178 in the GDB user manual.
2180 * Guile support was removed.
2182 * New features in the GNU simulator
2184 ** The --map-info flag lists all known core mappings.
2186 ** CFI flashes may be simulated via the "cfi" device.
2188 *** Changes in GDB 7.2
2190 * Shared library support for remote targets by default
2192 When GDB is configured for a generic, non-OS specific target, like
2193 for example, --target=arm-eabi or one of the many *-*-elf targets,
2194 GDB now queries remote stubs for loaded shared libraries using the
2195 `qXfer:libraries:read' packet. Previously, shared library support
2196 was always disabled for such configurations.
2200 ** Argument Dependent Lookup (ADL)
2202 In C++ ADL lookup directs function search to the namespaces of its
2203 arguments even if the namespace has not been imported.
2213 Here the compiler will search for `foo' in the namespace of 'b'
2214 and find A::foo. GDB now supports this. This construct is commonly
2215 used in the Standard Template Library for operators.
2217 ** Improved User Defined Operator Support
2219 In addition to member operators, GDB now supports lookup of operators
2220 defined in a namespace and imported with a `using' directive, operators
2221 defined in the global scope, operators imported implicitly from an
2222 anonymous namespace, and the ADL operators mentioned in the previous
2224 GDB now also supports proper overload resolution for all the previously
2225 mentioned flavors of operators.
2227 ** static const class members
2229 Printing of static const class members that are initialized in the
2230 class definition has been fixed.
2232 * Windows Thread Information Block access.
2234 On Windows targets, GDB now supports displaying the Windows Thread
2235 Information Block (TIB) structure. This structure is visible either
2236 by using the new command `info w32 thread-information-block' or, by
2237 dereferencing the new convenience variable named `$_tlb', a
2238 thread-specific pointer to the TIB. This feature is also supported
2239 when remote debugging using GDBserver.
2241 * Static tracepoints
2243 Static tracepoints are calls in the user program into a tracing
2244 library. One such library is a port of the LTTng kernel tracer to
2245 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2246 When debugging with GDBserver, GDB now supports combining the GDB
2247 tracepoint machinery with such libraries. For example: the user can
2248 use GDB to probe a static tracepoint marker (a call from the user
2249 program into the tracing library) with the new "strace" command (see
2250 "New commands" below). This creates a "static tracepoint" in the
2251 breakpoint list, that can be manipulated with the same feature set
2252 as fast and regular tracepoints. E.g., collect registers, local and
2253 global variables, collect trace state variables, and define
2254 tracepoint conditions. In addition, the user can collect extra
2255 static tracepoint marker specific data, by collecting the new
2256 $_sdata internal variable. When analyzing the trace buffer, you can
2257 inspect $_sdata like any other variable available to GDB. For more
2258 information, see the "Tracepoints" chapter in GDB user manual. New
2259 remote packets have been defined to support static tracepoints, see
2260 the "New remote packets" section below.
2262 * Better reconstruction of tracepoints after disconnected tracing
2264 GDB will attempt to download the original source form of tracepoint
2265 definitions when starting a trace run, and then will upload these
2266 upon reconnection to the target, resulting in a more accurate
2267 reconstruction of the tracepoints that are in use on the target.
2271 You can now exercise direct control over the ways that GDB can
2272 affect your program. For instance, you can disallow the setting of
2273 breakpoints, so that the program can run continuously (assuming
2274 non-stop mode). In addition, the "observer" variable is available
2275 to switch all of the different controls; in observer mode, GDB
2276 cannot affect the target's behavior at all, which is useful for
2277 tasks like diagnosing live systems in the field.
2279 * The new convenience variable $_thread holds the number of the
2282 * New remote packets
2286 Return the address of the Windows Thread Information Block of a given thread.
2290 In response to several of the tracepoint packets, the target may now
2291 also respond with a number of intermediate `qRelocInsn' request
2292 packets before the final result packet, to have GDB handle
2293 relocating an instruction to execute at a different address. This
2294 is particularly useful for stubs that support fast tracepoints. GDB
2295 reports support for this feature in the qSupported packet.
2299 List static tracepoint markers in the target program.
2303 List static tracepoint markers at a given address in the target
2306 qXfer:statictrace:read
2308 Read the static trace data collected (by a `collect $_sdata'
2309 tracepoint action). The remote stub reports support for this packet
2310 to gdb's qSupported query.
2314 Send the current settings of GDB's permission flags.
2318 Send part of the source (textual) form of a tracepoint definition,
2319 which includes location, conditional, and action list.
2321 * The source command now accepts a -s option to force searching for the
2322 script in the source search path even if the script name specifies
2325 * New features in the GDB remote stub, GDBserver
2327 - GDBserver now support tracepoints (including fast tracepoints, and
2328 static tracepoints). The feature is currently supported by the
2329 i386-linux and amd64-linux builds. See the "Tracepoints support
2330 in gdbserver" section in the manual for more information.
2332 GDBserver JIT compiles the tracepoint's conditional agent
2333 expression bytecode into native code whenever possible for low
2334 overhead dynamic tracepoints conditionals. For such tracepoints,
2335 an expression that examines program state is evaluated when the
2336 tracepoint is reached, in order to determine whether to capture
2337 trace data. If the condition is simple and false, processing the
2338 tracepoint finishes very quickly and no data is gathered.
2340 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2341 for static tracepoints support.
2343 - GDBserver now supports x86_64 Windows 64-bit debugging.
2345 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2346 it understands register description.
2348 * The --batch flag now disables pagination and queries.
2350 * X86 general purpose registers
2352 GDB now supports reading/writing byte, word and double-word x86
2353 general purpose registers directly. This means you can use, say,
2354 $ah or $ax to refer, respectively, to the byte register AH and
2355 16-bit word register AX that are actually portions of the 32-bit
2356 register EAX or 64-bit register RAX.
2358 * The `commands' command now accepts a range of breakpoints to modify.
2359 A plain `commands' following a command that creates multiple
2360 breakpoints affects all the breakpoints set by that command. This
2361 applies to breakpoints set by `rbreak', and also applies when a
2362 single `break' command creates multiple breakpoints (e.g.,
2363 breakpoints on overloaded c++ functions).
2365 * The `rbreak' command now accepts a filename specification as part of
2366 its argument, limiting the functions selected by the regex to those
2367 in the specified file.
2369 * Support for remote debugging Windows and SymbianOS shared libraries
2370 from Unix hosts has been improved. Non Windows GDB builds now can
2371 understand target reported file names that follow MS-DOS based file
2372 system semantics, such as file names that include drive letters and
2373 use the backslash character as directory separator. This makes it
2374 possible to transparently use the "set sysroot" and "set
2375 solib-search-path" on Unix hosts to point as host copies of the
2376 target's shared libraries. See the new command "set
2377 target-file-system-kind" described below, and the "Commands to
2378 specify files" section in the user manual for more information.
2382 eval template, expressions...
2383 Convert the values of one or more expressions under the control
2384 of the string template to a command line, and call it.
2386 set target-file-system-kind unix|dos-based|auto
2387 show target-file-system-kind
2388 Set or show the assumed file system kind for target reported file
2391 save breakpoints <filename>
2392 Save all current breakpoint definitions to a file suitable for use
2393 in a later debugging session. To read the saved breakpoint
2394 definitions, use the `source' command.
2396 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2399 info static-tracepoint-markers
2400 Display information about static tracepoint markers in the target.
2402 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2403 Define a static tracepoint by probing a marker at the given
2404 function, line, address, or marker ID.
2408 Enable and disable observer mode.
2410 set may-write-registers on|off
2411 set may-write-memory on|off
2412 set may-insert-breakpoints on|off
2413 set may-insert-tracepoints on|off
2414 set may-insert-fast-tracepoints on|off
2415 set may-interrupt on|off
2416 Set individual permissions for GDB effects on the target. Note that
2417 some of these settings can have undesirable or surprising
2418 consequences, particularly when changed in the middle of a session.
2419 For instance, disabling the writing of memory can prevent
2420 breakpoints from being inserted, cause single-stepping to fail, or
2421 even crash your program, if you disable after breakpoints have been
2422 inserted. However, GDB should not crash.
2424 set record memory-query on|off
2425 show record memory-query
2426 Control whether to stop the inferior if memory changes caused
2427 by an instruction cannot be recorded.
2432 The disassemble command now supports "start,+length" form of two arguments.
2436 ** GDB now provides a new directory location, called the python directory,
2437 where Python scripts written for GDB can be installed. The location
2438 of that directory is <data-directory>/python, where <data-directory>
2439 is the GDB data directory. For more details, see section `Scripting
2440 GDB using Python' in the manual.
2442 ** The GDB Python API now has access to breakpoints, symbols, symbol
2443 tables, program spaces, inferiors, threads and frame's code blocks.
2444 Additionally, GDB Parameters can now be created from the API, and
2445 manipulated via set/show in the CLI.
2447 ** New functions gdb.target_charset, gdb.target_wide_charset,
2448 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2450 ** New exception gdb.GdbError.
2452 ** Pretty-printers are now also looked up in the current program space.
2454 ** Pretty-printers can now be individually enabled and disabled.
2456 ** GDB now looks for names of Python scripts to auto-load in a
2457 special section named `.debug_gdb_scripts', in addition to looking
2458 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2460 * Tracepoint actions were unified with breakpoint commands. In particular,
2461 there are no longer differences in "info break" output for breakpoints and
2462 tracepoints and the "commands" command can be used for both tracepoints and
2463 regular breakpoints.
2467 ARM Symbian arm*-*-symbianelf*
2469 * D language support.
2470 GDB now supports debugging programs written in the D programming
2473 * GDB now supports the extended ptrace interface for PowerPC which is
2474 available since Linux kernel version 2.6.34. This automatically enables
2475 any hardware breakpoints and additional hardware watchpoints available in
2476 the processor. The old ptrace interface exposes just one hardware
2477 watchpoint and no hardware breakpoints.
2479 * GDB is now able to use the Data Value Compare (DVC) register available on
2480 embedded PowerPC processors to implement in hardware simple watchpoint
2481 conditions of the form:
2483 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2485 This works in native GDB running on Linux kernels with the extended ptrace
2486 interface mentioned above.
2488 *** Changes in GDB 7.1
2492 ** Namespace Support
2494 GDB now supports importing of namespaces in C++. This enables the
2495 user to inspect variables from imported namespaces. Support for
2496 namepace aliasing has also been added. So, if a namespace is
2497 aliased in the current scope (e.g. namepace C=A; ) the user can
2498 print variables using the alias (e.g. (gdb) print C::x).
2502 All known bugs relating to the printing of virtual base class were
2503 fixed. It is now possible to call overloaded static methods using a
2508 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2509 and reinterpret_cast<> are now handled by the C++ expression parser.
2513 Xilinx MicroBlaze microblaze-*-*
2518 Xilinx MicroBlaze microblaze
2521 * Multi-program debugging.
2523 GDB now has support for multi-program (a.k.a. multi-executable or
2524 multi-exec) debugging. This allows for debugging multiple inferiors
2525 simultaneously each running a different program under the same GDB
2526 session. See "Debugging Multiple Inferiors and Programs" in the
2527 manual for more information. This implied some user visible changes
2528 in the multi-inferior support. For example, "info inferiors" now
2529 lists inferiors that are not running yet or that have exited
2530 already. See also "New commands" and "New options" below.
2532 * New tracing features
2534 GDB's tracepoint facility now includes several new features:
2536 ** Trace state variables
2538 GDB tracepoints now include support for trace state variables, which
2539 are variables managed by the target agent during a tracing
2540 experiment. They are useful for tracepoints that trigger each
2541 other, so for instance one tracepoint can count hits in a variable,
2542 and then a second tracepoint has a condition that is true when the
2543 count reaches a particular value. Trace state variables share the
2544 $-syntax of GDB convenience variables, and can appear in both
2545 tracepoint actions and condition expressions. Use the "tvariable"
2546 command to create, and "info tvariables" to view; see "Trace State
2547 Variables" in the manual for more detail.
2551 GDB now includes an option for defining fast tracepoints, which
2552 targets may implement more efficiently, such as by installing a jump
2553 into the target agent rather than a trap instruction. The resulting
2554 speedup can be by two orders of magnitude or more, although the
2555 tradeoff is that some program locations on some target architectures
2556 might not allow fast tracepoint installation, for instance if the
2557 instruction to be replaced is shorter than the jump. To request a
2558 fast tracepoint, use the "ftrace" command, with syntax identical to
2559 the regular trace command.
2561 ** Disconnected tracing
2563 It is now possible to detach GDB from the target while it is running
2564 a trace experiment, then reconnect later to see how the experiment
2565 is going. In addition, a new variable disconnected-tracing lets you
2566 tell the target agent whether to continue running a trace if the
2567 connection is lost unexpectedly.
2571 GDB now has the ability to save the trace buffer into a file, and
2572 then use that file as a target, similarly to you can do with
2573 corefiles. You can select trace frames, print data that was
2574 collected in them, and use tstatus to display the state of the
2575 tracing run at the moment that it was saved. To create a trace
2576 file, use "tsave <filename>", and to use it, do "target tfile
2579 ** Circular trace buffer
2581 You can ask the target agent to handle the trace buffer as a
2582 circular buffer, discarding the oldest trace frames to make room for
2583 newer ones, by setting circular-trace-buffer to on. This feature may
2584 not be available for all target agents.
2589 The disassemble command, when invoked with two arguments, now requires
2590 the arguments to be comma-separated.
2593 The info variables command now displays variable definitions. Files
2594 which only declare a variable are not shown.
2597 The source command is now capable of sourcing Python scripts.
2598 This feature is dependent on the debugger being build with Python
2601 Related to this enhancement is also the introduction of a new command
2602 "set script-extension" (see below).
2604 * New commands (for set/show, see "New options" below)
2606 record save [<FILENAME>]
2607 Save a file (in core file format) containing the process record
2608 execution log for replay debugging at a later time.
2610 record restore <FILENAME>
2611 Restore the process record execution log that was saved at an
2612 earlier time, for replay debugging.
2614 add-inferior [-copies <N>] [-exec <FILENAME>]
2617 clone-inferior [-copies <N>] [ID]
2618 Make a new inferior ready to execute the same program another
2619 inferior has loaded.
2624 maint info program-spaces
2625 List the program spaces loaded into GDB.
2627 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2628 show remote interrupt-sequence
2629 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2630 as the sequence to the remote target in order to interrupt the execution.
2631 Ctrl-C is a default. Some system prefers BREAK which is high level of
2632 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2633 Magic SysRq g. It is BREAK signal and character 'g'.
2635 set remote interrupt-on-connect [on | off]
2636 show remote interrupt-on-connect
2637 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2638 remote target when gdb connects to it. This is needed when you debug
2641 set remotebreak [on | off]
2643 Deprecated. Use "set/show remote interrupt-sequence" instead.
2645 tvariable $NAME [ = EXP ]
2646 Create or modify a trace state variable.
2649 List trace state variables and their values.
2651 delete tvariable $NAME ...
2652 Delete one or more trace state variables.
2655 Evaluate the given expressions without collecting anything into the
2656 trace buffer. (Valid in tracepoint actions only.)
2658 ftrace FN / FILE:LINE / *ADDR
2659 Define a fast tracepoint at the given function, line, or address.
2661 * New expression syntax
2663 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2664 GDB now parses 0b101010 identically with 42.
2668 set follow-exec-mode new|same
2669 show follow-exec-mode
2670 Control whether GDB reuses the same inferior across an exec call or
2671 creates a new one. This is useful to be able to restart the old
2672 executable after the inferior having done an exec call.
2674 set default-collect EXPR, ...
2675 show default-collect
2676 Define a list of expressions to be collected at each tracepoint.
2677 This is a useful way to ensure essential items are not overlooked,
2678 such as registers or a critical global variable.
2680 set disconnected-tracing
2681 show disconnected-tracing
2682 If set to 1, the target is instructed to continue tracing if it
2683 loses its connection to GDB. If 0, the target is to stop tracing
2686 set circular-trace-buffer
2687 show circular-trace-buffer
2688 If set to on, the target is instructed to use a circular trace buffer
2689 and discard the oldest trace frames instead of stopping the trace due
2690 to a full trace buffer. If set to off, the trace stops when the buffer
2691 fills up. Some targets may not support this.
2693 set script-extension off|soft|strict
2694 show script-extension
2695 If set to "off", the debugger does not perform any script language
2696 recognition, and all sourced files are assumed to be GDB scripts.
2697 If set to "soft" (the default), files are sourced according to
2698 filename extension, falling back to GDB scripts if the first
2700 If set to "strict", files are sourced according to filename extension.
2702 set ada trust-PAD-over-XVS on|off
2703 show ada trust-PAD-over-XVS
2704 If off, activate a workaround against a bug in the debugging information
2705 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2706 the GCC sources for more information about the GNAT encoding and
2707 PAD types in particular). It is always safe to set this option to
2708 off, but this introduces a slight performance penalty. The default
2711 * Python API Improvements
2713 ** GDB provides the new class gdb.LazyString. This is useful in
2714 some pretty-printing cases. The new method gdb.Value.lazy_string
2715 provides a simple way to create objects of this type.
2717 ** The fields returned by gdb.Type.fields now have an
2718 `is_base_class' attribute.
2720 ** The new method gdb.Type.range returns the range of an array type.
2722 ** The new method gdb.parse_and_eval can be used to parse and
2723 evaluate an expression.
2725 * New remote packets
2728 Define a trace state variable.
2731 Get the current value of a trace state variable.
2734 Set desired tracing behavior upon disconnection.
2737 Set the trace buffer to be linear or circular.
2740 Get data about the tracepoints currently in use.
2744 Process record now works correctly with hardware watchpoints.
2746 Multiple bug fixes have been made to the mips-irix port, making it
2747 much more reliable. In particular:
2748 - Debugging threaded applications is now possible again. Previously,
2749 GDB would hang while starting the program, or while waiting for
2750 the program to stop at a breakpoint.
2751 - Attaching to a running process no longer hangs.
2752 - An error occurring while loading a core file has been fixed.
2753 - Changing the value of the PC register now works again. This fixes
2754 problems observed when using the "jump" command, or when calling
2755 a function from GDB, or even when assigning a new value to $pc.
2756 - With the "finish" and "return" commands, the return value for functions
2757 returning a small array is now correctly printed.
2758 - It is now possible to break on shared library code which gets executed
2759 during a shared library init phase (code executed while executing
2760 their .init section). Previously, the breakpoint would have no effect.
2761 - GDB is now able to backtrace through the signal handler for
2762 non-threaded programs.
2764 PIE (Position Independent Executable) programs debugging is now supported.
2765 This includes debugging execution of PIC (Position Independent Code) shared
2766 libraries although for that, it should be possible to run such libraries as an
2769 *** Changes in GDB 7.0
2771 * GDB now has an interface for JIT compilation. Applications that
2772 dynamically generate code can create symbol files in memory and register
2773 them with GDB. For users, the feature should work transparently, and
2774 for JIT developers, the interface is documented in the GDB manual in the
2775 "JIT Compilation Interface" chapter.
2777 * Tracepoints may now be conditional. The syntax is as for
2778 breakpoints; either an "if" clause appended to the "trace" command,
2779 or the "condition" command is available. GDB sends the condition to
2780 the target for evaluation using the same bytecode format as is used
2781 for tracepoint actions.
2783 * The disassemble command now supports: an optional /r modifier, print the
2784 raw instructions in hex as well as in symbolic form, and an optional /m
2785 modifier to print mixed source+assembly.
2787 * Process record and replay
2789 In a architecture environment that supports ``process record and
2790 replay'', ``process record and replay'' target can record a log of
2791 the process execution, and replay it with both forward and reverse
2794 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2795 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2796 set execution-direction {forward|reverse}, for targets that support
2799 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2800 feature is available with a native GDB running on kernel version
2803 * GDB now has support for multi-byte and wide character sets on the
2804 target. Strings whose character type is wchar_t, char16_t, or
2805 char32_t are now correctly printed. GDB supports wide- and unicode-
2806 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2807 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2808 `printf'. This feature requires iconv to work properly; if your
2809 system does not have a working iconv, GDB can use GNU libiconv. See
2810 the installation instructions for more information.
2812 * GDB now supports automatic retrieval of shared library files from
2813 remote targets. To use this feature, specify a system root that begins
2814 with the `remote:' prefix, either via the `set sysroot' command or via
2815 the `--with-sysroot' configure-time option.
2817 * "info sharedlibrary" now takes an optional regex of libraries to show,
2818 and it now reports if a shared library has no debugging information.
2820 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2821 now complete on file names.
2823 * When completing in expressions, gdb will attempt to limit
2824 completions to allowable structure or union fields, where appropriate.
2825 For instance, consider:
2827 # struct example { int f1; double f2; };
2828 # struct example variable;
2831 If the user types TAB at the end of this command line, the available
2832 completions will be "f1" and "f2".
2834 * Inlined functions are now supported. They show up in backtraces, and
2835 the "step", "next", and "finish" commands handle them automatically.
2837 * GDB now supports the token-splicing (##) and stringification (#)
2838 operators when expanding macros. It also supports variable-arity
2841 * GDB now supports inspecting extra signal information, exported by
2842 the new $_siginfo convenience variable. The feature is currently
2843 implemented on linux ARM, i386 and amd64.
2845 * GDB can now display the VFP floating point registers and NEON vector
2846 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2847 can provide these registers (requires Linux 2.6.30 or later). Remote
2848 and simulator targets may also provide them.
2850 * New remote packets
2853 Search memory for a sequence of bytes.
2856 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2857 operation over reliable transport links. Use of this packet is
2858 controlled by the `set remote noack-packet' command.
2861 Kill the process with the specified process ID. Use this in preference
2862 to `k' when multiprocess protocol extensions are supported.
2865 Obtains additional operating system information
2869 Read or write additional signal information.
2871 * Removed remote protocol undocumented extension
2873 An undocumented extension to the remote protocol's `S' stop reply
2874 packet that permited the stub to pass a process id was removed.
2875 Remote servers should use the `T' stop reply packet instead.
2877 * GDB now supports multiple function calling conventions according to the
2878 DWARF-2 DW_AT_calling_convention function attribute.
2880 * The SH target utilizes the aforementioned change to distinguish between gcc
2881 and Renesas calling convention. It also adds the new CLI commands
2882 `set/show sh calling-convention'.
2884 * GDB can now read compressed debug sections, as produced by GNU gold
2885 with the --compress-debug-sections=zlib flag.
2887 * 64-bit core files are now supported on AIX.
2889 * Thread switching is now supported on Tru64.
2891 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2892 which will be allocated using malloc later in program execution.
2894 * The qXfer:libraries:read remote procotol packet now allows passing a
2895 list of section offsets.
2897 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2898 conditions handling signals delivered during attach or thread creation
2899 have also been fixed.
2901 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2902 From the user's standpoint, all unqualified instances of True and False
2903 are treated as the standard definitions, regardless of context.
2905 * GDB now parses C++ symbol and type names more flexibly. For
2908 template<typename T> class C { };
2911 GDB will now correctly handle all of:
2913 ptype C<char const *>
2914 ptype C<char const*>
2915 ptype C<const char *>
2916 ptype C<const char*>
2918 * New features in the GDB remote stub, gdbserver
2920 - The "--wrapper" command-line argument tells gdbserver to use a
2921 wrapper program to launch programs for debugging.
2923 - On PowerPC and S/390 targets, it is now possible to use a single
2924 gdbserver executable to debug both 32-bit and 64-bit programs.
2925 (This requires gdbserver itself to be built as a 64-bit executable.)
2927 - gdbserver uses the new noack protocol mode for TCP connections to
2928 reduce communications latency, if also supported and enabled in GDB.
2930 - Support for the sparc64-linux-gnu target is now included in
2933 - The amd64-linux build of gdbserver now supports debugging both
2934 32-bit and 64-bit programs.
2936 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2937 now support hardware watchpoints, and will use them automatically
2942 GDB now has support for scripting using Python. Whether this is
2943 available is determined at configure time.
2945 New GDB commands can now be written in Python.
2947 * Ada tasking support
2949 Ada tasks can now be inspected in GDB. The following commands have
2953 Print the list of Ada tasks.
2955 Print detailed information about task number N.
2957 Print the task number of the current task.
2959 Switch the context of debugging to task number N.
2961 * Support for user-defined prefixed commands. The "define" command can
2962 add new commands to existing prefixes, e.g. "target".
2964 * Multi-inferior, multi-process debugging.
2966 GDB now has generalized support for multi-inferior debugging. See
2967 "Debugging Multiple Inferiors" in the manual for more information.
2968 Although availability still depends on target support, the command
2969 set is more uniform now. The GNU/Linux specific multi-forks support
2970 has been migrated to this new framework. This implied some user
2971 visible changes; see "New commands" and also "Removed commands"
2974 * Target descriptions can now describe the target OS ABI. See the
2975 "Target Description Format" section in the user manual for more
2978 * Target descriptions can now describe "compatible" architectures
2979 to indicate that the target can execute applications for a different
2980 architecture in addition to those for the main target architecture.
2981 See the "Target Description Format" section in the user manual for
2984 * Multi-architecture debugging.
2986 GDB now includes general supports for debugging applications on
2987 hybrid systems that use more than one single processor architecture
2988 at the same time. Each such hybrid architecture still requires
2989 specific support to be added. The only hybrid architecture supported
2990 in this version of GDB is the Cell Broadband Engine.
2992 * GDB now supports integrated debugging of Cell/B.E. applications that
2993 use both the PPU and SPU architectures. To enable support for hybrid
2994 Cell/B.E. debugging, you need to configure GDB to support both the
2995 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2996 --enable-targets configure option.
2998 * Non-stop mode debugging.
3000 For some targets, GDB now supports an optional mode of operation in
3001 which you can examine stopped threads while other threads continue
3002 to execute freely. This is referred to as non-stop mode, with the
3003 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3004 section in the user manual for more information.
3006 To be able to support remote non-stop debugging, a remote stub needs
3007 to implement the non-stop mode remote protocol extensions, as
3008 described in the "Remote Non-Stop" section of the user manual. The
3009 GDB remote stub, gdbserver, has been adjusted to support these
3010 extensions on linux targets.
3012 * New commands (for set/show, see "New options" below)
3014 catch syscall [NAME(S) | NUMBER(S)]
3015 Catch system calls. Arguments, which should be names of system
3016 calls or their numbers, mean catch only those syscalls. Without
3017 arguments, every syscall will be caught. When the inferior issues
3018 any of the specified syscalls, GDB will stop and announce the system
3019 call, both when it is called and when its call returns. This
3020 feature is currently available with a native GDB running on the
3021 Linux Kernel, under the following architectures: x86, x86_64,
3022 PowerPC and PowerPC64.
3024 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3026 Search memory for a sequence of bytes.
3028 maint set python print-stack
3029 maint show python print-stack
3030 Show a stack trace when an error is encountered in a Python script.
3033 Invoke CODE by passing it to the Python interpreter.
3038 These allow macros to be defined, undefined, and listed
3042 Show operating system information about processes.
3045 List the inferiors currently under GDB's control.
3048 Switch focus to inferior number NUM.
3051 Detach from inferior number NUM.
3054 Kill inferior number NUM.
3058 set spu stop-on-load
3059 show spu stop-on-load
3060 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3062 set spu auto-flush-cache
3063 show spu auto-flush-cache
3064 Control whether to automatically flush the software-managed cache
3065 during Cell/B.E. debugging.
3067 set sh calling-convention
3068 show sh calling-convention
3069 Control the calling convention used when calling SH target functions.
3072 show debug timestamp
3073 Control display of timestamps with GDB debugging output.
3075 set disassemble-next-line
3076 show disassemble-next-line
3077 Control display of disassembled source lines or instructions when
3080 set remote noack-packet
3081 show remote noack-packet
3082 Set/show the use of remote protocol QStartNoAckMode packet. See above
3083 under "New remote packets."
3085 set remote query-attached-packet
3086 show remote query-attached-packet
3087 Control use of remote protocol `qAttached' (query-attached) packet.
3089 set remote read-siginfo-object
3090 show remote read-siginfo-object
3091 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3094 set remote write-siginfo-object
3095 show remote write-siginfo-object
3096 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3099 set remote reverse-continue
3100 show remote reverse-continue
3101 Control use of remote protocol 'bc' (reverse-continue) packet.
3103 set remote reverse-step
3104 show remote reverse-step
3105 Control use of remote protocol 'bs' (reverse-step) packet.
3107 set displaced-stepping
3108 show displaced-stepping
3109 Control displaced stepping mode. Displaced stepping is a way to
3110 single-step over breakpoints without removing them from the debuggee.
3111 Also known as "out-of-line single-stepping".
3114 show debug displaced
3115 Control display of debugging info for displaced stepping.
3117 maint set internal-error
3118 maint show internal-error
3119 Control what GDB does when an internal error is detected.
3121 maint set internal-warning
3122 maint show internal-warning
3123 Control what GDB does when an internal warning is detected.
3128 Use a wrapper program to launch programs for debugging.
3130 set multiple-symbols (all|ask|cancel)
3131 show multiple-symbols
3132 The value of this variable can be changed to adjust the debugger behavior
3133 when an expression or a breakpoint location contains an ambiguous symbol
3134 name (an overloaded function name, for instance).
3136 set breakpoint always-inserted
3137 show breakpoint always-inserted
3138 Keep breakpoints always inserted in the target, as opposed to inserting
3139 them when resuming the target, and removing them when the target stops.
3140 This option can improve debugger performance on slow remote targets.
3142 set arm fallback-mode (arm|thumb|auto)
3143 show arm fallback-mode
3144 set arm force-mode (arm|thumb|auto)
3146 These commands control how ARM GDB determines whether instructions
3147 are ARM or Thumb. The default for both settings is auto, which uses
3148 the current CPSR value for instructions without symbols; previous
3149 versions of GDB behaved as if "set arm fallback-mode arm".
3151 set disable-randomization
3152 show disable-randomization
3153 Standalone programs run with the virtual address space randomization enabled
3154 by default on some platforms. This option keeps the addresses stable across
3155 multiple debugging sessions.
3159 Control whether other threads are stopped or not when some thread hits
3164 Requests that asynchronous execution is enabled in the target, if available.
3165 In this case, it's possible to resume target in the background, and interact
3166 with GDB while the target is running. "show target-async" displays the
3167 current state of asynchronous execution of the target.
3169 set target-wide-charset
3170 show target-wide-charset
3171 The target-wide-charset is the name of the character set that GDB
3172 uses when printing characters whose type is wchar_t.
3174 set tcp auto-retry (on|off)
3176 set tcp connect-timeout
3177 show tcp connect-timeout
3178 These commands allow GDB to retry failed TCP connections to a remote stub
3179 with a specified timeout period; this is useful if the stub is launched
3180 in parallel with GDB but may not be ready to accept connections immediately.
3182 set libthread-db-search-path
3183 show libthread-db-search-path
3184 Control list of directories which GDB will search for appropriate
3187 set schedule-multiple (on|off)
3188 show schedule-multiple
3189 Allow GDB to resume all threads of all processes or only threads of
3190 the current process.
3194 Use more aggressive caching for accesses to the stack. This improves
3195 performance of remote debugging (particularly backtraces) without
3196 affecting correctness.
3198 set interactive-mode (on|off|auto)
3199 show interactive-mode
3200 Control whether GDB runs in interactive mode (on) or not (off).
3201 When in interactive mode, GDB waits for the user to answer all
3202 queries. Otherwise, GDB does not wait and assumes the default
3203 answer. When set to auto (the default), GDB determines which
3204 mode to use based on the stdin settings.
3209 For program forks, this is replaced by the new more generic `info
3210 inferiors' command. To list checkpoints, you can still use the
3211 `info checkpoints' command, which was an alias for the `info forks'
3215 Replaced by the new `inferior' command. To switch between
3216 checkpoints, you can still use the `restart' command, which was an
3217 alias for the `fork' command.
3220 This is removed, since some targets don't have a notion of
3221 processes. To switch between processes, you can still use the
3222 `inferior' command using GDB's own inferior number.
3225 For program forks, this is replaced by the new more generic `kill
3226 inferior' command. To delete a checkpoint, you can still use the
3227 `delete checkpoint' command, which was an alias for the `delete
3231 For program forks, this is replaced by the new more generic `detach
3232 inferior' command. To detach a checkpoint, you can still use the
3233 `detach checkpoint' command, which was an alias for the `detach
3236 * New native configurations
3238 x86/x86_64 Darwin i[34567]86-*-darwin*
3240 x86_64 MinGW x86_64-*-mingw*
3244 Lattice Mico32 lm32-*
3245 x86 DICOS i[34567]86-*-dicos*
3246 x86_64 DICOS x86_64-*-dicos*
3249 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3250 (mingw32ce) debugging.
3256 These commands were actually not implemented on any target.
3258 *** Changes in GDB 6.8
3260 * New native configurations
3262 NetBSD/hppa hppa*-*netbsd*
3263 Xtensa GNU/Linux xtensa*-*-linux*
3267 NetBSD/hppa hppa*-*-netbsd*
3268 Xtensa GNU/Lunux xtensa*-*-linux*
3270 * Change in command line behavior -- corefiles vs. process ids.
3272 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3273 attaching to process NUMBER fails, GDB no longer attempts to open a
3274 core file named NUMBER. Attaching to a program using the -c option
3275 is no longer supported. Instead, use the '-p' or '--pid' options.
3277 * GDB can now be built as a native debugger for debugging Windows x86
3278 (mingw32) Portable Executable (PE) programs.
3280 * Pending breakpoints no longer change their number when their address
3283 * GDB now supports breakpoints with multiple locations,
3284 including breakpoints on C++ constructors, inside C++ templates,
3285 and in inlined functions.
3287 * GDB's ability to debug optimized code has been improved. GDB more
3288 accurately identifies function bodies and lexical blocks that occupy
3289 more than one contiguous range of addresses.
3291 * Target descriptions can now describe registers for PowerPC.
3293 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3294 registers on PowerPC targets.
3296 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3297 targets even when the libthread_db library is not available.
3299 * The GDB remote stub, gdbserver, now supports the new file transfer
3300 commands (remote put, remote get, and remote delete).
3302 * The GDB remote stub, gdbserver, now supports run and attach in
3303 extended-remote mode.
3305 * hppa*64*-*-hpux11* target broken
3306 The debugger is unable to start a program and fails with the following
3307 error: "Error trying to get information about dynamic linker".
3308 The gdb-6.7 release is also affected.
3310 * GDB now supports the --enable-targets= configure option to allow
3311 building a single GDB executable that supports multiple remote
3312 target architectures.
3314 * GDB now supports debugging C and C++ programs which use the
3315 Decimal Floating Point extension. In addition, the PowerPC target
3316 now has a set of pseudo-registers to inspect decimal float values
3317 stored in two consecutive float registers.
3319 * The -break-insert MI command can optionally create pending
3322 * Improved support for debugging Ada
3323 Many improvements to the Ada language support have been made. These
3325 - Better support for Ada2005 interface types
3326 - Improved handling of arrays and slices in general
3327 - Better support for Taft-amendment types
3328 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3330 - Improved command completion in Ada
3333 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3338 set print frame-arguments (all|scalars|none)
3339 show print frame-arguments
3340 The value of this variable can be changed to control which argument
3341 values should be printed by the debugger when displaying a frame.
3346 Transfer files to and from a remote target, and delete remote files.
3353 Transfer files to and from a remote target, and delete remote files.
3355 * New remote packets
3362 Open, close, read, write, and delete files on the remote system.
3365 Attach to an existing process on the remote system, in extended-remote
3369 Run a new process on the remote system, in extended-remote mode.
3371 *** Changes in GDB 6.7
3373 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3374 bfd, libiberty and opcodes, as revealed by static analysis donated by
3375 Coverity, Inc. (http://scan.coverity.com).
3377 * When looking up multiply-defined global symbols, GDB will now prefer the
3378 symbol definition in the current shared library if it was built using the
3379 -Bsymbolic linker option.
3381 * When the Text User Interface (TUI) is not configured, GDB will now
3382 recognize the -tui command-line option and print a message that the TUI
3385 * The GDB remote stub, gdbserver, now has lower overhead for high
3386 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3388 * GDB for MIPS targets now autodetects whether a remote target provides
3389 32-bit or 64-bit register values.
3391 * Support for C++ member pointers has been improved.
3393 * GDB now understands XML target descriptions, which specify the
3394 target's overall architecture. GDB can read a description from
3395 a local file or over the remote serial protocol.
3397 * Vectors of single-byte data use a new integer type which is not
3398 automatically displayed as character or string data.
3400 * The /s format now works with the print command. It displays
3401 arrays of single-byte integers and pointers to single-byte integers
3404 * Target descriptions can now describe target-specific registers,
3405 for architectures which have implemented the support (currently
3406 only ARM, M68K, and MIPS).
3408 * GDB and the GDB remote stub, gdbserver, now support the XScale
3411 * The GDB remote stub, gdbserver, has been updated to support
3412 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3413 has been rewritten to use the standard GDB remote protocol.
3415 * GDB can now step into C++ functions which are called through thunks.
3417 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3419 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3420 layout. It also supports a TextSeg= and DataSeg= response when only
3421 segment base addresses (rather than offsets) are available.
3423 * The /i format now outputs any trailing branch delay slot instructions
3424 immediately following the last instruction within the count specified.
3426 * The GDB remote protocol "T" stop reply packet now supports a
3427 "library" response. Combined with the new "qXfer:libraries:read"
3428 packet, this response allows GDB to debug shared libraries on targets
3429 where the operating system manages the list of loaded libraries (e.g.
3430 Windows and SymbianOS).
3432 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3433 (DLLs) on Windows and Windows CE targets.
3435 * GDB now supports a faster verification that a .debug file matches its binary
3436 according to its build-id signature, if the signature is present.
3442 Enable or disable hardware flow control (RTS/CTS) on the serial port
3443 when debugging using remote targets.
3445 set mem inaccessible-by-default
3446 show mem inaccessible-by-default
3447 If the target supplies a memory map, for instance via the remote
3448 protocol's "qXfer:memory-map:read" packet, setting this variable
3449 prevents GDB from accessing memory outside the memory map. This
3450 is useful for targets with memory mapped registers or which react
3451 badly to accesses of unmapped address space.
3453 set breakpoint auto-hw
3454 show breakpoint auto-hw
3455 If the target supplies a memory map, for instance via the remote
3456 protocol's "qXfer:memory-map:read" packet, setting this variable
3457 lets GDB use hardware breakpoints automatically for memory regions
3458 where it can not use software breakpoints. This covers both the
3459 "break" command and internal breakpoints used for other commands
3460 including "next" and "finish".
3463 catch exception unhandled
3464 Stop the program execution when Ada exceptions are raised.
3467 Stop the program execution when an Ada assertion failed.
3471 Set an alternate system root for target files. This is a more
3472 general version of "set solib-absolute-prefix", which is now
3473 an alias to "set sysroot".
3476 Provide extended SPU facility status information. This set of
3477 commands is available only when debugging the Cell/B.E. SPU
3480 * New native configurations
3482 OpenBSD/sh sh*-*openbsd*
3485 unset tdesc filename
3487 Use the specified local file as an XML target description, and do
3488 not query the target for its built-in description.
3492 OpenBSD/sh sh*-*-openbsd*
3493 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3494 Toshiba Media Processor mep-elf
3496 * New remote packets
3499 Ignore the specified signals; pass them directly to the debugged program
3500 without stopping other threads or reporting them to GDB.
3502 qXfer:features:read:
3503 Read an XML target description from the target, which describes its
3508 Read or write contents of an spufs file on the target system. These
3509 packets are available only on the Cell/B.E. SPU architecture.
3511 qXfer:libraries:read:
3512 Report the loaded shared libraries. Combined with new "T" packet
3513 response, this packet allows GDB to debug shared libraries on
3514 targets where the operating system manages the list of loaded
3515 libraries (e.g. Windows and SymbianOS).
3519 Support for these obsolete configurations has been removed.
3527 i[34567]86-*-lynxos*
3528 i[34567]86-*-netware*
3529 i[34567]86-*-sco3.2v5*
3530 i[34567]86-*-sco3.2v4*
3532 i[34567]86-*-sysv4.2*
3535 i[34567]86-*-unixware2*
3536 i[34567]86-*-unixware*
3545 * Other removed features
3552 Various m68k-only ROM monitors.
3559 Various Renesas ROM monitors and debugging interfaces for SH and
3564 Support for a Macraigor serial interface to on-chip debugging.
3565 GDB does not directly support the newer parallel or USB
3570 A debug information format. The predecessor to DWARF 2 and
3571 DWARF 3, which are still supported.
3573 Support for the HP aCC compiler on HP-UX/PA-RISC
3575 SOM-encapsulated symbolic debugging information, automatic
3576 invocation of pxdb, and the aCC custom C++ ABI. This does not
3577 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3578 with aCC can still be debugged on an assembly level.
3580 MIPS ".pdr" sections
3582 A MIPS-specific format used to describe stack frame layout
3583 in debugging information.
3587 GDB could work with an older version of Guile to debug
3588 the interpreter and Scheme programs running in it.
3590 set mips stack-arg-size
3591 set mips saved-gpreg-size
3593 Use "set mips abi" to control parameter passing for MIPS.
3595 *** Changes in GDB 6.6
3600 Cell Broadband Engine SPU spu-elf
3602 * GDB can now be configured as a cross-debugger targeting native Windows
3603 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3604 running on a Windows system over TCP/IP to debug Windows programs.
3606 * The GDB remote stub, gdbserver, has been updated to support Windows and
3607 Cygwin debugging. Both single-threaded and multi-threaded programs are
3610 * The "set trust-readonly-sections" command works again. This command was
3611 broken in GDB 6.3, 6.4, and 6.5.
3613 * The "load" command now supports writing to flash memory, if the remote
3614 stub provides the required support.
3616 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3617 longer requires symbolic debug information (e.g. DWARF-2).
3622 unset substitute-path
3623 show substitute-path
3624 Manage a list of substitution rules that GDB uses to rewrite the name
3625 of the directories where the sources are located. This can be useful
3626 for instance when the sources were moved to a different location
3627 between compilation and debugging.
3631 Print each CLI command as it is executed. Each command is prefixed with
3632 a number of `+' symbols representing the nesting depth.
3633 The source command now has a `-v' option to enable the same feature.
3637 The ARM Demon monitor support (RDP protocol, "target rdp").
3639 Kernel Object Display, an embedded debugging feature which only worked with
3640 an obsolete version of Cisco IOS.
3642 The 'set download-write-size' and 'show download-write-size' commands.
3644 * New remote packets
3647 Tell a stub about GDB client features, and request remote target features.
3648 The first feature implemented is PacketSize, which allows the target to
3649 specify the size of packets it can handle - to minimize the number of
3650 packets required and improve performance when connected to a remote
3654 Fetch an OS auxilliary vector from the remote stub. This packet is a
3655 more efficient replacement for qPart:auxv:read.
3657 qXfer:memory-map:read:
3658 Fetch a memory map from the remote stub, including information about
3659 RAM, ROM, and flash memory devices.
3664 Erase and program a flash memory device.
3666 * Removed remote packets
3669 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3670 used it, and only gdbserver implemented it.
3672 *** Changes in GDB 6.5
3676 Renesas M32C/M16C m32c-elf
3678 Morpho Technologies ms1 ms1-elf
3682 init-if-undefined Initialize a convenience variable, but
3683 only if it doesn't already have a value.
3685 The following commands are presently only implemented for native GNU/Linux:
3687 checkpoint Save a snapshot of the program state.
3689 restart <n> Return the program state to a
3690 previously saved state.
3692 info checkpoints List currently saved checkpoints.
3694 delete-checkpoint <n> Delete a previously saved checkpoint.
3696 set|show detach-on-fork Tell gdb whether to detach from a newly
3697 forked process, or to keep debugging it.
3699 info forks List forks of the user program that
3700 are available to be debugged.
3702 fork <n> Switch to debugging one of several
3703 forks of the user program that are
3704 available to be debugged.
3706 delete-fork <n> Delete a fork from the list of forks
3707 that are available to be debugged (and
3708 kill the forked process).
3710 detach-fork <n> Delete a fork from the list of forks
3711 that are available to be debugged (and
3712 allow the process to continue).
3716 Morpho Technologies ms2 ms1-elf
3718 * Improved Windows host support
3720 GDB now builds as a cross debugger hosted on i686-mingw32, including
3721 native console support, and remote communications using either
3722 network sockets or serial ports.
3724 * Improved Modula-2 language support
3726 GDB can now print most types in the Modula-2 syntax. This includes:
3727 basic types, set types, record types, enumerated types, range types,
3728 pointer types and ARRAY types. Procedure var parameters are correctly
3729 printed and hexadecimal addresses and character constants are also
3730 written in the Modula-2 syntax. Best results can be obtained by using
3731 GNU Modula-2 together with the -gdwarf-2 command line option.
3735 The ARM rdi-share module.
3737 The Netware NLM debug server.
3739 *** Changes in GDB 6.4
3741 * New native configurations
3743 OpenBSD/arm arm*-*-openbsd*
3744 OpenBSD/mips64 mips64-*-openbsd*
3748 Morpho Technologies ms1 ms1-elf
3750 * New command line options
3752 --batch-silent As for --batch, but totally silent.
3753 --return-child-result The debugger will exist with the same value
3754 the child (debugged) program exited with.
3755 --eval-command COMMAND, -ex COMMAND
3756 Execute a single GDB CLI command. This may be
3757 specified multiple times and in conjunction
3758 with the --command (-x) option.
3760 * Deprecated commands removed
3762 The following commands, that were deprecated in 2000, have been
3766 set|show arm disassembly-flavor set|show arm disassembler
3767 othernames set arm disassembler
3768 set|show remotedebug set|show debug remote
3769 set|show archdebug set|show debug arch
3770 set|show eventdebug set|show debug event
3773 * New BSD user-level threads support
3775 It is now possible to debug programs using the user-level threads
3776 library on OpenBSD and FreeBSD. Currently supported (target)
3779 FreeBSD/amd64 x86_64-*-freebsd*
3780 FreeBSD/i386 i386-*-freebsd*
3781 OpenBSD/i386 i386-*-openbsd*
3783 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3784 are not yet supported.
3786 * New support for Matsushita MN10300 w/sim added
3787 (Work in progress). mn10300-elf.
3789 * REMOVED configurations and files
3791 VxWorks and the XDR protocol *-*-vxworks
3792 Motorola MCORE mcore-*-*
3793 National Semiconductor NS32000 ns32k-*-*
3795 * New "set print array-indexes" command
3797 After turning this setting "on", GDB prints the index of each element
3798 when displaying arrays. The default is "off" to preserve the previous
3801 * VAX floating point support
3803 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3805 * User-defined command support
3807 In addition to using $arg0..$arg9 for argument passing, it is now possible
3808 to use $argc to determine now many arguments have been passed. See the
3809 section on user-defined commands in the user manual for more information.
3811 *** Changes in GDB 6.3:
3813 * New command line option
3815 GDB now accepts -l followed by a number to set the timeout for remote
3818 * GDB works with GCC -feliminate-dwarf2-dups
3820 GDB now supports a more compact representation of DWARF-2 debug
3821 information using DW_FORM_ref_addr references. These are produced
3822 by GCC with the option -feliminate-dwarf2-dups and also by some
3823 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3824 to use -feliminate-dwarf2-dups.
3826 * Internationalization
3828 When supported by the host system, GDB will be built with
3829 internationalization (libintl). The task of marking up the sources is
3830 continued, we're looking forward to our first translation.
3834 Initial support for debugging programs compiled with the GNAT
3835 implementation of the Ada programming language has been integrated
3836 into GDB. In this release, support is limited to expression evaluation.
3838 * New native configurations
3840 GNU/Linux/m32r m32r-*-linux-gnu
3844 GDB's remote protocol now includes support for the 'p' packet. This
3845 packet is used to fetch individual registers from a remote inferior.
3847 * END-OF-LIFE registers[] compatibility module
3849 GDB's internal register infrastructure has been completely rewritten.
3850 The new infrastructure making possible the implementation of key new
3851 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3854 GDB 6.3 will be the last release to include the the registers[]
3855 compatibility module that allowed out-of-date configurations to
3856 continue to work. This change directly impacts the following
3866 powerpc bdm protocol
3868 Unless there is activity to revive these configurations, they will be
3869 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3871 * OBSOLETE configurations and files
3873 Configurations that have been declared obsolete in this release have
3874 been commented out. Unless there is activity to revive these
3875 configurations, the next release of GDB will have their sources
3876 permanently REMOVED.
3885 *** Changes in GDB 6.2.1:
3887 * MIPS `break main; run' gave an heuristic-fence-post warning
3889 When attempting to run even a simple program, a warning about
3890 heuristic-fence-post being hit would be reported. This problem has
3893 * MIPS IRIX 'long double' crashed GDB
3895 When examining a long double variable, GDB would get a segmentation
3896 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3897 IRIX long double values).
3901 A bug in the VAX stack code was causing problems with the "next"
3902 command. This problem has been fixed.
3904 *** Changes in GDB 6.2:
3906 * Fix for ``many threads''
3908 On GNU/Linux systems that use the NPTL threads library, a program
3909 rapidly creating and deleting threads would confuse GDB leading to the
3912 ptrace: No such process.
3913 thread_db_get_info: cannot get thread info: generic error
3915 This problem has been fixed.
3917 * "-async" and "-noasync" options removed.
3919 Support for the broken "-noasync" option has been removed (it caused
3922 * New ``start'' command.
3924 This command runs the program until the begining of the main procedure.
3926 * New BSD Kernel Data Access Library (libkvm) interface
3928 Using ``target kvm'' it is now possible to debug kernel core dumps and
3929 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3930 platforms. Currently supported (native-only) configurations are:
3932 FreeBSD/amd64 x86_64-*-freebsd*
3933 FreeBSD/i386 i?86-*-freebsd*
3934 NetBSD/i386 i?86-*-netbsd*
3935 NetBSD/m68k m68*-*-netbsd*
3936 NetBSD/sparc sparc-*-netbsd*
3937 OpenBSD/amd64 x86_64-*-openbsd*
3938 OpenBSD/i386 i?86-*-openbsd*
3939 OpenBSD/m68k m68*-openbsd*
3940 OpenBSD/sparc sparc-*-openbsd*
3942 * Signal trampoline code overhauled
3944 Many generic problems with GDB's signal handling code have been fixed.
3945 These include: backtraces through non-contiguous stacks; recognition
3946 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3947 call; backtrace through a signal trampoline; step into and out of
3948 signal handlers; and single-stepping in the signal trampoline.
3950 Please note that kernel bugs are a limiting factor here. These
3951 features have been shown to work on an s390 GNU/Linux system that
3952 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3954 * Cygwin support for DWARF 2 added.
3956 * New native configurations
3958 GNU/Linux/hppa hppa*-*-linux*
3959 OpenBSD/hppa hppa*-*-openbsd*
3960 OpenBSD/m68k m68*-*-openbsd*
3961 OpenBSD/m88k m88*-*-openbsd*
3962 OpenBSD/powerpc powerpc-*-openbsd*
3963 NetBSD/vax vax-*-netbsd*
3964 OpenBSD/vax vax-*-openbsd*
3966 * END-OF-LIFE frame compatibility module
3968 GDB's internal frame infrastructure has been completely rewritten.
3969 The new infrastructure making it possible to support key new features
3970 including DWARF 2 Call Frame Information. To aid in the task of
3971 migrating old configurations to this new infrastructure, a
3972 compatibility module, that allowed old configurations to continue to
3973 work, was also included.
3975 GDB 6.2 will be the last release to include this frame compatibility
3976 module. This change directly impacts the following configurations:
3986 Unless there is activity to revive these configurations, they will be
3987 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3989 * REMOVED configurations and files
3991 Sun 3, running SunOS 3 m68*-*-sunos3*
3992 Sun 3, running SunOS 4 m68*-*-sunos4*
3993 Sun 2, running SunOS 3 m68000-*-sunos3*
3994 Sun 2, running SunOS 4 m68000-*-sunos4*
3995 Motorola 680x0 running LynxOS m68*-*-lynxos*
3996 AT&T 3b1/Unix pc m68*-att-*
3997 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3998 decstation mips-dec-* mips-little-*
3999 riscos mips-*-riscos* mips-*-sysv*
4000 sonymips mips-sony-*
4001 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4003 *** Changes in GDB 6.1.1:
4005 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4007 The TUI (Text-mode User Interface) is now built as part of a default
4008 GDB configuration. It is enabled by either selecting the TUI with the
4009 command line option "-i=tui" or by running the separate "gdbtui"
4010 program. For more information on the TUI, see the manual "Debugging
4013 * Pending breakpoint support (also included in GDB 6.1)
4015 Support has been added to allow you to specify breakpoints in shared
4016 libraries that have not yet been loaded. If a breakpoint location
4017 cannot be found, and the "breakpoint pending" option is set to auto,
4018 GDB queries you if you wish to make the breakpoint pending on a future
4019 shared-library load. If and when GDB resolves the breakpoint symbol,
4020 the pending breakpoint is removed as one or more regular breakpoints
4023 Pending breakpoints are very useful for GCJ Java debugging.
4025 * Fixed ISO-C build problems
4027 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4028 non ISO-C code that stopped them being built using a more strict ISO-C
4029 compiler (e.g., IBM's C compiler).
4031 * Fixed build problem on IRIX 5
4033 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4034 wasn't able to compile compile on an IRIX 5 system.
4036 * Added execute permission to gdb/gdbserver/configure
4038 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4039 permission. This bug would cause configure to fail on a number of
4040 systems (Solaris, IRIX). Ref: server/519.
4042 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4044 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4045 has been updated to use constant array sizes.
4047 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4049 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4050 its generated DWARF Call Frame Info. This encoding was causing GDB to
4051 panic, that panic has been fixed. Ref: gdb/1628.
4053 * Fixed a problem when examining parameters in shared library code.
4055 When examining parameters in optimized shared library code generated
4056 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4057 not available''. GDB now correctly displays the variable's value.
4059 *** Changes in GDB 6.1:
4061 * Removed --with-mmalloc
4063 Support for the mmalloc memory manager has been removed, as it
4064 conflicted with the internal gdb byte cache.
4066 * Changes in AMD64 configurations
4068 The AMD64 target now includes the %cs and %ss registers. As a result
4069 the AMD64 remote protocol has changed; this affects the floating-point
4070 and SSE registers. If you rely on those registers for your debugging,
4071 you should upgrade gdbserver on the remote side.
4073 * Revised SPARC target
4075 The SPARC target has been completely revised, incorporating the
4076 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4077 support for LynxOS and SunOS 4 has been dropped. Calling functions
4078 from within GDB on operating systems with a non-executable stack
4079 (Solaris, OpenBSD) now works.
4083 GDB has a new C++ demangler which does a better job on the mangled
4084 names generated by current versions of g++. It also runs faster, so
4085 with this and other changes gdb should now start faster on large C++
4088 * DWARF 2 Location Expressions
4090 GDB support for location expressions has been extended to support function
4091 arguments and frame bases. Older versions of GDB could crash when they
4094 * C++ nested types and namespaces
4096 GDB's support for nested types and namespaces in C++ has been
4097 improved, especially if you use the DWARF 2 debugging format. (This
4098 is the default for recent versions of GCC on most platforms.)
4099 Specifically, if you have a class "Inner" defined within a class or
4100 namespace "Outer", then GDB realizes that the class's name is
4101 "Outer::Inner", not simply "Inner". This should greatly reduce the
4102 frequency of complaints about not finding RTTI symbols. In addition,
4103 if you are stopped at inside of a function defined within a namespace,
4104 GDB modifies its name lookup accordingly.
4106 * New native configurations
4108 NetBSD/amd64 x86_64-*-netbsd*
4109 OpenBSD/amd64 x86_64-*-openbsd*
4110 OpenBSD/alpha alpha*-*-openbsd*
4111 OpenBSD/sparc sparc-*-openbsd*
4112 OpenBSD/sparc64 sparc64-*-openbsd*
4114 * New debugging protocols
4116 M32R with SDI protocol m32r-*-elf*
4118 * "set prompt-escape-char" command deleted.
4120 The command "set prompt-escape-char" has been deleted. This command,
4121 and its very obscure effet on GDB's prompt, was never documented,
4122 tested, nor mentioned in the NEWS file.
4124 * OBSOLETE configurations and files
4126 Configurations that have been declared obsolete in this release have
4127 been commented out. Unless there is activity to revive these
4128 configurations, the next release of GDB will have their sources
4129 permanently REMOVED.
4131 Sun 3, running SunOS 3 m68*-*-sunos3*
4132 Sun 3, running SunOS 4 m68*-*-sunos4*
4133 Sun 2, running SunOS 3 m68000-*-sunos3*
4134 Sun 2, running SunOS 4 m68000-*-sunos4*
4135 Motorola 680x0 running LynxOS m68*-*-lynxos*
4136 AT&T 3b1/Unix pc m68*-att-*
4137 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4138 decstation mips-dec-* mips-little-*
4139 riscos mips-*-riscos* mips-*-sysv*
4140 sonymips mips-sony-*
4141 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4143 * REMOVED configurations and files
4145 SGI Irix-4.x mips-sgi-irix4 or iris4
4146 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4147 Z8000 simulator z8k-zilog-none or z8ksim
4148 Matsushita MN10200 w/simulator mn10200-*-*
4149 H8/500 simulator h8500-hitachi-hms or h8500hms
4150 HP/PA running BSD hppa*-*-bsd*
4151 HP/PA running OSF/1 hppa*-*-osf*
4152 HP/PA Pro target hppa*-*-pro*
4153 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4154 386BSD i[3456]86-*-bsd*
4155 Sequent family i[3456]86-sequent-sysv4*
4156 i[3456]86-sequent-sysv*
4157 i[3456]86-sequent-bsd*
4158 SPARC running LynxOS sparc-*-lynxos*
4159 SPARC running SunOS 4 sparc-*-sunos4*
4160 Tsqware Sparclet sparclet-*-*
4161 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4163 *** Changes in GDB 6.0:
4167 Support for debugging the Objective-C programming language has been
4168 integrated into GDB.
4170 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4172 DWARF 2's Call Frame Information makes available compiler generated
4173 information that more exactly describes the program's run-time stack.
4174 By using this information, GDB is able to provide more robust stack
4177 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4178 have been updated to use a new backtrace mechanism which includes
4179 DWARF 2 CFI support.
4183 GDB's remote protocol has been extended to include support for hosted
4184 file I/O (where the remote target uses GDB's file system). See GDB's
4185 remote protocol documentation for details.
4187 * All targets using the new architecture framework.
4189 All of GDB's targets have been updated to use the new internal
4190 architecture framework. The way is now open for future GDB releases
4191 to include cross-architecture native debugging support (i386 on amd64,
4194 * GNU/Linux's Thread Local Storage (TLS)
4196 GDB now includes support for for the GNU/Linux implementation of
4197 per-thread variables.
4199 * GNU/Linux's Native POSIX Thread Library (NPTL)
4201 GDB's thread code has been updated to work with either the new
4202 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4204 * Separate debug info.
4206 GDB, in conjunction with BINUTILS, now supports a mechanism for
4207 automatically loading debug information from a separate file. Instead
4208 of shipping full debug and non-debug versions of system libraries,
4209 system integrators can now instead ship just the stripped libraries
4210 and optional debug files.
4212 * DWARF 2 Location Expressions
4214 DWARF 2 Location Expressions allow the compiler to more completely
4215 describe the location of variables (even in optimized code) to the
4218 GDB now includes preliminary support for location expressions (support
4219 for DW_OP_piece is still missing).
4223 A number of long standing bugs that caused GDB to die while starting a
4224 Java application have been fixed. GDB's Java support is now
4225 considered "useable".
4227 * GNU/Linux support for fork, vfork, and exec.
4229 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4230 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4233 * GDB supports logging output to a file
4235 There are two new commands, "set logging" and "show logging", which can be
4236 used to capture GDB's output to a file.
4238 * The meaning of "detach" has changed for gdbserver
4240 The "detach" command will now resume the application, as documented. To
4241 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4244 * d10v, m68hc11 `regs' command deprecated
4246 The `info registers' command has been updated so that it displays the
4247 registers using a format identical to the old `regs' command.
4251 A new command, "maint set profile on/off", has been added. This command can
4252 be used to enable or disable profiling while running GDB, to profile a
4253 session or a set of commands. In addition there is a new configure switch,
4254 "--enable-profiling", which will cause GDB to be compiled with profiling
4255 data, for more informative profiling results.
4257 * Default MI syntax changed to "mi2".
4259 The default MI (machine interface) syntax, enabled by the command line
4260 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4261 "mi1", can be enabled by specifying the option "-i=mi1".
4263 Support for the original "mi0" syntax (included in GDB 5.0) has been
4266 Fix for gdb/192: removed extraneous space when displaying frame level.
4267 Fix for gdb/672: update changelist is now output in mi list format.
4268 Fix for gdb/702: a -var-assign that updates the value now shows up
4269 in a subsequent -var-update.
4271 * New native configurations.
4273 FreeBSD/amd64 x86_64-*-freebsd*
4275 * Multi-arched targets.
4277 HP/PA HPUX11 hppa*-*-hpux*
4278 Renesas M32R/D w/simulator m32r-*-elf*
4280 * OBSOLETE configurations and files
4282 Configurations that have been declared obsolete in this release have
4283 been commented out. Unless there is activity to revive these
4284 configurations, the next release of GDB will have their sources
4285 permanently REMOVED.
4287 Z8000 simulator z8k-zilog-none or z8ksim
4288 Matsushita MN10200 w/simulator mn10200-*-*
4289 H8/500 simulator h8500-hitachi-hms or h8500hms
4290 HP/PA running BSD hppa*-*-bsd*
4291 HP/PA running OSF/1 hppa*-*-osf*
4292 HP/PA Pro target hppa*-*-pro*
4293 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4294 Sequent family i[3456]86-sequent-sysv4*
4295 i[3456]86-sequent-sysv*
4296 i[3456]86-sequent-bsd*
4297 Tsqware Sparclet sparclet-*-*
4298 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4300 * REMOVED configurations and files
4303 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4304 IBM AIX PS/2 i[3456]86-*-aix
4305 i386 running Mach 3.0 i[3456]86-*-mach3*
4306 i386 running Mach i[3456]86-*-mach*
4307 i386 running OSF/1 i[3456]86-*osf1mk*
4308 HP/Apollo 68k Family m68*-apollo*-sysv*,
4310 m68*-hp-bsd*, m68*-hp-hpux*
4311 Argonaut Risc Chip (ARC) arc-*-*
4312 Mitsubishi D30V d30v-*-*
4313 Fujitsu FR30 fr30-*-elf*
4314 OS/9000 i[34]86-*-os9k
4315 I960 with MON960 i960-*-coff
4317 * MIPS $fp behavior changed
4319 The convenience variable $fp, for the MIPS, now consistently returns
4320 the address of the current frame's base. Previously, depending on the
4321 context, $fp could refer to either $sp or the current frame's base
4322 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4323 The GNU Source-Level Debugger''.
4325 *** Changes in GDB 5.3:
4327 * GNU/Linux shared library multi-threaded performance improved.
4329 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4330 `/proc', in preference to `ptrace' for memory reads. This may result
4331 in an improvement in the start-up time of multi-threaded, shared
4332 library applications when run under GDB. One GDB user writes: ``loads
4333 shared libs like mad''.
4335 * ``gdbserver'' now supports multi-threaded applications on some targets
4337 Support for debugging multi-threaded applications which use
4338 the GNU/Linux LinuxThreads package has been added for
4339 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4340 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4342 * GDB now supports C/C++ preprocessor macros.
4344 GDB now expands preprocessor macro invocations in C/C++ expressions,
4345 and provides various commands for showing macro definitions and how
4348 The new command `macro expand EXPRESSION' expands any macro
4349 invocations in expression, and shows the result.
4351 The new command `show macro MACRO-NAME' shows the definition of the
4352 macro named MACRO-NAME, and where it was defined.
4354 Most compilers don't include information about macros in the debugging
4355 information by default. In GCC 3.1, for example, you need to compile
4356 your program with the options `-gdwarf-2 -g3'. If the macro
4357 information is present in the executable, GDB will read it.
4359 * Multi-arched targets.
4361 DEC Alpha (partial) alpha*-*-*
4362 DEC VAX (partial) vax-*-*
4364 National Semiconductor NS32000 (partial) ns32k-*-*
4365 Motorola 68000 (partial) m68k-*-*
4366 Motorola MCORE mcore-*-*
4370 Fujitsu FRV architecture added by Red Hat frv*-*-*
4373 * New native configurations
4375 Alpha NetBSD alpha*-*-netbsd*
4376 SH NetBSD sh*-*-netbsdelf*
4377 MIPS NetBSD mips*-*-netbsd*
4378 UltraSPARC NetBSD sparc64-*-netbsd*
4380 * OBSOLETE configurations and files
4382 Configurations that have been declared obsolete in this release have
4383 been commented out. Unless there is activity to revive these
4384 configurations, the next release of GDB will have their sources
4385 permanently REMOVED.
4387 Mitsubishi D30V d30v-*-*
4388 OS/9000 i[34]86-*-os9k
4389 IBM AIX PS/2 i[3456]86-*-aix
4390 Fujitsu FR30 fr30-*-elf*
4391 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4392 Argonaut Risc Chip (ARC) arc-*-*
4393 i386 running Mach 3.0 i[3456]86-*-mach3*
4394 i386 running Mach i[3456]86-*-mach*
4395 i386 running OSF/1 i[3456]86-*osf1mk*
4396 HP/Apollo 68k Family m68*-apollo*-sysv*,
4398 m68*-hp-bsd*, m68*-hp-hpux*
4399 I960 with MON960 i960-*-coff
4401 * OBSOLETE languages
4403 CHILL, a Pascal like language used by telecommunications companies.
4405 * REMOVED configurations and files
4407 AMD 29k family via UDI a29k-amd-udi, udi29k
4408 A29K VxWorks a29k-*-vxworks
4409 AMD 29000 embedded, using EBMON a29k-none-none
4410 AMD 29000 embedded with COFF a29k-none-coff
4411 AMD 29000 embedded with a.out a29k-none-aout
4413 testsuite/gdb.hp/gdb.threads-hp/ directory
4415 * New command "set max-user-call-depth <nnn>"
4417 This command allows the user to limit the call depth of user-defined
4418 commands. The default is 1024.
4420 * Changes in FreeBSD/i386 native debugging.
4422 Support for the "generate-core-file" has been added.
4424 * New commands "dump", "append", and "restore".
4426 These commands allow data to be copied from target memory
4427 to a bfd-format or binary file (dump and append), and back
4428 from a file into memory (restore).
4430 * Improved "next/step" support on multi-processor Alpha Tru64.
4432 The previous single-step mechanism could cause unpredictable problems,
4433 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4434 of a software single-step mechanism prevents this.
4436 *** Changes in GDB 5.2.1:
4444 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4445 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4446 Fix, by Joel Brobecker imported from mainline.
4448 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4449 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4450 Fix, by Fred Fish, imported from mainline.
4452 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4453 Surprisingly enough, it works now.
4454 By Michal Ludvig, imported from mainline.
4456 i386 hardware watchpoint support:
4457 avoid misses on second run for some targets.
4458 By Pierre Muller, imported from mainline.
4460 *** Changes in GDB 5.2:
4462 * New command "set trust-readonly-sections on[off]".
4464 This command is a hint that tells gdb that read-only sections
4465 really are read-only (ie. that their contents will not change).
4466 In this mode, gdb will go to the object file rather than the
4467 target to read memory from read-only sections (such as ".text").
4468 This can be a significant performance improvement on some
4469 (notably embedded) targets.
4471 * New command "generate-core-file" (or "gcore").
4473 This new gdb command allows the user to drop a core file of the child
4474 process state at any time. So far it's been implemented only for
4475 GNU/Linux and Solaris, but should be relatively easily ported to other
4476 hosts. Argument is core file name (defaults to core.<pid>).
4478 * New command line option
4480 GDB now accepts --pid or -p followed by a process id.
4482 * Change in command line behavior -- corefiles vs. process ids.
4484 There is a subtle behavior in the way in which GDB handles
4485 command line arguments. The first non-flag argument is always
4486 a program to debug, but the second non-flag argument may either
4487 be a corefile or a process id. Previously, GDB would attempt to
4488 open the second argument as a corefile, and if that failed, would
4489 issue a superfluous error message and then attempt to attach it as
4490 a process. Now, if the second argument begins with a non-digit,
4491 it will be treated as a corefile. If it begins with a digit,
4492 GDB will attempt to attach it as a process, and if no such process
4493 is found, will then attempt to open it as a corefile.
4495 * Changes in ARM configurations.
4497 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4498 configuration is fully multi-arch.
4500 * New native configurations
4502 ARM NetBSD arm*-*-netbsd*
4503 x86 OpenBSD i[3456]86-*-openbsd*
4504 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4505 Sparc64 running FreeBSD sparc64-*-freebsd*
4509 Sanyo XStormy16 xstormy16-elf
4511 * OBSOLETE configurations and files
4513 Configurations that have been declared obsolete in this release have
4514 been commented out. Unless there is activity to revive these
4515 configurations, the next release of GDB will have their sources
4516 permanently REMOVED.
4518 AMD 29k family via UDI a29k-amd-udi, udi29k
4519 A29K VxWorks a29k-*-vxworks
4520 AMD 29000 embedded, using EBMON a29k-none-none
4521 AMD 29000 embedded with COFF a29k-none-coff
4522 AMD 29000 embedded with a.out a29k-none-aout
4524 testsuite/gdb.hp/gdb.threads-hp/ directory
4526 * REMOVED configurations and files
4528 TI TMS320C80 tic80-*-*
4530 PowerPC Solaris powerpcle-*-solaris*
4531 PowerPC Windows NT powerpcle-*-cygwin32
4532 PowerPC Netware powerpc-*-netware*
4533 Harris/CXUX m88k m88*-harris-cxux*
4534 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4535 ns32k-utek-sysv* ns32k-utek-*
4536 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4537 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4538 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4539 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4540 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4542 * Changes to command line processing
4544 The new `--args' feature can be used to specify command-line arguments
4545 for the inferior from gdb's command line.
4547 * Changes to key bindings
4549 There is a new `operate-and-get-next' function bound to `C-o'.
4551 *** Changes in GDB 5.1.1
4553 Fix compile problem on DJGPP.
4555 Fix a problem with floating-point registers on the i386 being
4558 Fix to stop GDB crashing on .debug_str debug info.
4560 Numerous documentation fixes.
4562 Numerous testsuite fixes.
4564 *** Changes in GDB 5.1:
4566 * New native configurations
4568 Alpha FreeBSD alpha*-*-freebsd*
4569 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4570 MIPS GNU/Linux mips*-*-linux*
4571 MIPS SGI Irix 6.x mips*-sgi-irix6*
4572 ia64 AIX ia64-*-aix*
4573 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4577 Motorola 68HC11 and 68HC12 m68hc11-elf
4579 UltraSparc running GNU/Linux sparc64-*-linux*
4581 * OBSOLETE configurations and files
4583 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4584 Harris/CXUX m88k m88*-harris-cxux*
4585 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4586 ns32k-utek-sysv* ns32k-utek-*
4587 TI TMS320C80 tic80-*-*
4589 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4590 PowerPC Solaris powerpcle-*-solaris*
4591 PowerPC Windows NT powerpcle-*-cygwin32
4592 PowerPC Netware powerpc-*-netware*
4593 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4594 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4595 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4596 Apple Macintosh (MPW) host N/A
4598 stuff.c (Program to stuff files into a specially prepared space in kdb)
4599 kdb-start.c (Main loop for the standalone kernel debugger)
4601 Configurations that have been declared obsolete in this release have
4602 been commented out. Unless there is activity to revive these
4603 configurations, the next release of GDB will have their sources
4604 permanently REMOVED.
4606 * REMOVED configurations and files
4608 Altos 3068 m68*-altos-*
4609 Convex c1-*-*, c2-*-*
4611 ARM RISCix arm-*-* (as host)
4615 * GDB has been converted to ISO C.
4617 GDB's source code has been converted to ISO C. In particular, the
4618 sources are fully protoized, and rely on standard headers being
4623 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4625 * The MI enabled by default.
4627 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4628 revised and enabled by default. Packages which use GDB as a debugging
4629 engine behind a UI or another front end are encouraged to switch to
4630 using the GDB/MI interface, instead of the old annotations interface
4631 which is now deprecated.
4633 * Support for debugging Pascal programs.
4635 GDB now includes support for debugging Pascal programs. The following
4636 main features are supported:
4638 - Pascal-specific data types such as sets;
4640 - automatic recognition of Pascal sources based on file-name
4643 - Pascal-style display of data types, variables, and functions;
4645 - a Pascal expression parser.
4647 However, some important features are not yet supported.
4649 - Pascal string operations are not supported at all;
4651 - there are some problems with boolean types;
4653 - Pascal type hexadecimal constants are not supported
4654 because they conflict with the internal variables format;
4656 - support for Pascal objects and classes is not full yet;
4658 - unlike Pascal, GDB is case-sensitive for symbol names.
4660 * Changes in completion.
4662 Commands such as `shell', `run' and `set args', which pass arguments
4663 to inferior programs, now complete on file names, similar to what
4664 users expect at the shell prompt.
4666 Commands which accept locations, such as `disassemble', `print',
4667 `breakpoint', `until', etc. now complete on filenames as well as
4668 program symbols. Thus, if you type "break foob TAB", and the source
4669 files linked into the programs include `foobar.c', that file name will
4670 be one of the candidates for completion. However, file names are not
4671 considered for completion after you typed a colon that delimits a file
4672 name from a name of a function in that file, as in "break foo.c:bar".
4674 `set demangle-style' completes on available demangling styles.
4676 * New platform-independent commands:
4678 It is now possible to define a post-hook for a command as well as a
4679 hook that runs before the command. For more details, see the
4680 documentation of `hookpost' in the GDB manual.
4682 * Changes in GNU/Linux native debugging.
4684 Support for debugging multi-threaded programs has been completely
4685 revised for all platforms except m68k and sparc. You can now debug as
4686 many threads as your system allows you to have.
4688 Attach/detach is supported for multi-threaded programs.
4690 Support for SSE registers was added for x86. This doesn't work for
4691 multi-threaded programs though.
4693 * Changes in MIPS configurations.
4695 Multi-arch support is enabled for all MIPS configurations.
4697 GDB can now be built as native debugger on SGI Irix 6.x systems for
4698 debugging n32 executables. (Debugging 64-bit executables is not yet
4701 * Unified support for hardware watchpoints in all x86 configurations.
4703 Most (if not all) native x86 configurations support hardware-assisted
4704 breakpoints and watchpoints in a unified manner. This support
4705 implements debug register sharing between watchpoints, which allows to
4706 put a virtually infinite number of watchpoints on the same address,
4707 and also supports watching regions up to 16 bytes with several debug
4710 The new maintenance command `maintenance show-debug-regs' toggles
4711 debugging print-outs in functions that insert, remove, and test
4712 watchpoints and hardware breakpoints.
4714 * Changes in the DJGPP native configuration.
4716 New command ``info dos sysinfo'' displays assorted information about
4717 the CPU, OS, memory, and DPMI server.
4719 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4720 display information about segment descriptors stored in GDT, LDT, and
4723 New commands ``info dos pde'' and ``info dos pte'' display entries
4724 from Page Directory and Page Tables (for now works with CWSDPMI only).
4725 New command ``info dos address-pte'' displays the Page Table entry for
4726 a given linear address.
4728 GDB can now pass command lines longer than 126 characters to the
4729 program being debugged (requires an update to the libdbg.a library
4730 which is part of the DJGPP development kit).
4732 DWARF2 debug info is now supported.
4734 It is now possible to `step' and `next' through calls to `longjmp'.
4736 * Changes in documentation.
4738 All GDB documentation was converted to GFDL, the GNU Free
4739 Documentation License.
4741 Tracepoints-related commands are now fully documented in the GDB
4744 TUI, the Text-mode User Interface, is now documented in the manual.
4746 Tracepoints-related commands are now fully documented in the GDB
4749 The "GDB Internals" manual now has an index. It also includes
4750 documentation of `ui_out' functions, GDB coding standards, x86
4751 hardware watchpoints, and memory region attributes.
4753 * GDB's version number moved to ``version.in''
4755 The Makefile variable VERSION has been replaced by the file
4756 ``version.in''. People creating GDB distributions should update the
4757 contents of this file.
4761 GUD support is now a standard part of the EMACS distribution.
4763 *** Changes in GDB 5.0:
4765 * Improved support for debugging FP programs on x86 targets
4767 Unified and much-improved support for debugging floating-point
4768 programs on all x86 targets. In particular, ``info float'' now
4769 displays the FP registers in the same format on all x86 targets, with
4770 greater level of detail.
4772 * Improvements and bugfixes in hardware-assisted watchpoints
4774 It is now possible to watch array elements, struct members, and
4775 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4776 on x86 targets no longer erroneously trigger when the address is
4779 * Improvements in the native DJGPP version of GDB
4781 The distribution now includes all the scripts and auxiliary files
4782 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4783 machines ``out of the box''.
4785 The DJGPP version can now debug programs that use signals. It is
4786 possible to catch signals that happened in the debuggee, deliver
4787 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4788 would kill the program being debugged.) Programs that hook hardware
4789 interrupts (keyboard, timer, etc.) can also be debugged.
4791 It is now possible to debug DJGPP programs that redirect their
4792 standard handles or switch them to raw (as opposed to cooked) mode, or
4793 even close them. The command ``run < foo > bar'' works as expected,
4794 and ``info terminal'' reports useful information about the debuggee's
4795 terminal, including raw/cooked mode, redirection, etc.
4797 The DJGPP version now uses termios functions for console I/O, which
4798 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4801 DOS-style file names with drive letters are now fully supported by
4804 It is now possible to debug DJGPP programs that switch their working
4805 directory. It is also possible to rerun the debuggee any number of
4806 times without restarting GDB; thus, you can use the same setup,
4807 breakpoints, etc. for many debugging sessions.
4809 * New native configurations
4811 ARM GNU/Linux arm*-*-linux*
4812 PowerPC GNU/Linux powerpc-*-linux*
4816 Motorola MCore mcore-*-*
4817 x86 VxWorks i[3456]86-*-vxworks*
4818 PowerPC VxWorks powerpc-*-vxworks*
4819 TI TMS320C80 tic80-*-*
4821 * OBSOLETE configurations
4823 Altos 3068 m68*-altos-*
4824 Convex c1-*-*, c2-*-*
4826 ARM RISCix arm-*-* (as host)
4829 Configurations that have been declared obsolete will be commented out,
4830 but the code will be left in place. If there is no activity to revive
4831 these configurations before the next release of GDB, the sources will
4832 be permanently REMOVED.
4834 * Gould support removed
4836 Support for the Gould PowerNode and NP1 has been removed.
4838 * New features for SVR4
4840 On SVR4 native platforms (such as Solaris), if you attach to a process
4841 without first loading a symbol file, GDB will now attempt to locate and
4842 load symbols from the running process's executable file.
4844 * Many C++ enhancements
4846 C++ support has been greatly improved. Overload resolution now works properly
4847 in almost all cases. RTTI support is on the way.
4849 * Remote targets can connect to a sub-program
4851 A popen(3) style serial-device has been added. This device starts a
4852 sub-process (such as a stand-alone simulator) and then communicates
4853 with that. The sub-program to run is specified using the syntax
4854 ``|<program> <args>'' vis:
4856 (gdb) set remotedebug 1
4857 (gdb) target extended-remote |mn10300-elf-sim program-args
4859 * MIPS 64 remote protocol
4861 A long standing bug in the mips64 remote protocol where by GDB
4862 expected certain 32 bit registers (ex SR) to be transfered as 32
4863 instead of 64 bits has been fixed.
4865 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4866 added to provide backward compatibility with older versions of GDB.
4868 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4870 The command ``set remotebinarydownload'' command has been replaced by
4871 ``set remote X-packet''. Other commands in ``set remote'' family
4872 include ``set remote P-packet''.
4874 * Breakpoint commands accept ranges.
4876 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4877 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4878 ``tracepoint passcount'' also accepts a range of tracepoints.
4880 * ``apropos'' command added.
4882 The ``apropos'' command searches through command names and
4883 documentation strings, printing out matches, making it much easier to
4884 try to find a command that does what you are looking for.
4888 A new machine oriented interface (MI) has been added to GDB. This
4889 interface is designed for debug environments running GDB as a separate
4890 process. This is part of the long term libGDB project. See the
4891 "GDB/MI" chapter of the GDB manual for further information. It can be
4892 enabled by configuring with:
4894 .../configure --enable-gdbmi
4896 *** Changes in GDB-4.18:
4898 * New native configurations
4900 HP-UX 10.20 hppa*-*-hpux10.20
4901 HP-UX 11.x hppa*-*-hpux11.0*
4902 M68K GNU/Linux m68*-*-linux*
4906 Fujitsu FR30 fr30-*-elf*
4907 Intel StrongARM strongarm-*-*
4908 Mitsubishi D30V d30v-*-*
4910 * OBSOLETE configurations
4912 Gould PowerNode, NP1 np1-*-*, pn-*-*
4914 Configurations that have been declared obsolete will be commented out,
4915 but the code will be left in place. If there is no activity to revive
4916 these configurations before the next release of GDB, the sources will
4917 be permanently REMOVED.
4921 As a compatibility experiment, GDB's source files buildsym.h and
4922 buildsym.c have been converted to pure standard C, no longer
4923 containing any K&R compatibility code. We believe that all systems in
4924 use today either come with a standard C compiler, or have a GCC port
4925 available. If this is not true, please report the affected
4926 configuration to bug-gdb@gnu.org immediately. See the README file for
4927 information about getting a standard C compiler if you don't have one
4932 GDB now uses readline 2.2.
4934 * set extension-language
4936 You can now control the mapping between filename extensions and source
4937 languages by using the `set extension-language' command. For instance,
4938 you can ask GDB to treat .c files as C++ by saying
4939 set extension-language .c c++
4940 The command `info extensions' lists all of the recognized extensions
4941 and their associated languages.
4943 * Setting processor type for PowerPC and RS/6000
4945 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4946 you can use the `set processor' command to specify what variant of the
4947 PowerPC family you are debugging. The command
4951 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4952 following PowerPC and RS6000 variants:
4954 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4955 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4957 403GC IBM PowerPC 403GC
4958 505 Motorola PowerPC 505
4959 860 Motorola PowerPC 860 or 850
4960 601 Motorola PowerPC 601
4961 602 Motorola PowerPC 602
4962 603 Motorola/IBM PowerPC 603 or 603e
4963 604 Motorola PowerPC 604 or 604e
4964 750 Motorola/IBM PowerPC 750 or 750
4966 At the moment, this command just tells GDB what to name the
4967 special-purpose processor registers. Since almost all the affected
4968 registers are inaccessible to user-level programs, this command is
4969 only useful for remote debugging in its present form.
4973 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4974 more extensive support for HP-UX. Added features include shared
4975 library support, kernel threads and hardware watchpoints for 11.00,
4976 support for HP's ANSI C and C++ compilers, and a compatibility mode
4977 for xdb and dbx commands.
4981 HP's donation includes the new concept of catchpoints, which is a
4982 generalization of the old catch command. On HP-UX, it is now possible
4983 to catch exec, fork, and vfork, as well as library loading.
4985 This means that the existing catch command has changed; its first
4986 argument now specifies the type of catch to be set up. See the
4987 output of "help catch" for a list of catchpoint types.
4989 * Debugging across forks
4991 On HP-UX, you can choose which process to debug when a fork() happens
4996 HP has donated a curses-based terminal user interface (TUI). To get
4997 it, build with --enable-tui. Although this can be enabled for any
4998 configuration, at present it only works for native HP debugging.
5000 * GDB remote protocol additions
5002 A new protocol packet 'X' that writes binary data is now available.
5003 Default behavior is to try 'X', then drop back to 'M' if the stub
5004 fails to respond. The settable variable `remotebinarydownload'
5005 allows explicit control over the use of 'X'.
5007 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5008 full 64-bit address. The command
5010 set remoteaddresssize 32
5012 can be used to revert to the old behaviour. For existing remote stubs
5013 the change should not be noticed, as the additional address information
5016 In order to assist in debugging stubs, you may use the maintenance
5017 command `packet' to send any text string to the stub. For instance,
5019 maint packet heythere
5021 sends the packet "$heythere#<checksum>". Note that it is very easy to
5022 disrupt a debugging session by sending the wrong packet at the wrong
5025 The compare-sections command allows you to compare section data on the
5026 target to what is in the executable file without uploading or
5027 downloading, by comparing CRC checksums.
5029 * Tracing can collect general expressions
5031 You may now collect general expressions at tracepoints. This requires
5032 further additions to the target-side stub; see tracepoint.c and
5033 doc/agentexpr.texi for further details.
5035 * mask-address variable for Mips
5037 For Mips targets, you may control the zeroing of the upper 32 bits of
5038 a 64-bit address by entering `set mask-address on'. This is mainly
5039 of interest to users of embedded R4xxx and R5xxx processors.
5041 * Higher serial baud rates
5043 GDB's serial code now allows you to specify baud rates 57600, 115200,
5044 230400, and 460800 baud. (Note that your host system may not be able
5045 to achieve all of these rates.)
5049 The i960 configuration now includes an initial implementation of a
5050 builtin simulator, contributed by Jim Wilson.
5053 *** Changes in GDB-4.17:
5055 * New native configurations
5057 Alpha GNU/Linux alpha*-*-linux*
5058 Unixware 2.x i[3456]86-unixware2*
5059 Irix 6.x mips*-sgi-irix6*
5060 PowerPC GNU/Linux powerpc-*-linux*
5061 PowerPC Solaris powerpcle-*-solaris*
5062 Sparc GNU/Linux sparc-*-linux*
5063 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5067 Argonaut Risc Chip (ARC) arc-*-*
5068 Hitachi H8/300S h8300*-*-*
5069 Matsushita MN10200 w/simulator mn10200-*-*
5070 Matsushita MN10300 w/simulator mn10300-*-*
5071 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5072 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5073 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5074 Mitsubishi D10V w/simulator d10v-*-*
5075 Mitsubishi M32R/D w/simulator m32r-*-elf*
5076 Tsqware Sparclet sparclet-*-*
5077 NEC V850 w/simulator v850-*-*
5079 * New debugging protocols
5081 ARM with RDI protocol arm*-*-*
5082 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5083 DDB and LSI variants of PMON protocol mips*-*-*
5084 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5085 PowerPC with SDS protocol powerpc{,le}-*-eabi
5086 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5090 All configurations can now understand and use the DWARF 2 debugging
5091 format. The choice is automatic, if the symbol file contains DWARF 2
5096 GDB now includes basic Java language support. This support is
5097 only useful with Java compilers that produce native machine code.
5099 * solib-absolute-prefix and solib-search-path
5101 For SunOS and SVR4 shared libraries, you may now set the prefix for
5102 loading absolute shared library symbol files, and the search path for
5103 locating non-absolute shared library symbol files.
5105 * Live range splitting
5107 GDB can now effectively debug code for which GCC has performed live
5108 range splitting as part of its optimization. See gdb/doc/LRS for
5109 more details on the expected format of the stabs information.
5113 GDB's support for the GNU Hurd, including thread debugging, has been
5114 updated to work with current versions of the Hurd.
5118 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5119 instruction set. ARM GDB automatically detects when Thumb
5120 instructions are in use, and adjusts disassembly and backtracing
5125 GDB's MIPS target configurations now handle the MIP16 16-bit
5130 GDB now includes support for overlays; if an executable has been
5131 linked such that multiple sections are based at the same address, GDB
5132 will decide which section to use for symbolic info. You can choose to
5133 control the decision manually, using overlay commands, or implement
5134 additional target-side support and use "overlay load-target" to bring
5135 in the overlay mapping. Do "help overlay" for more detail.
5139 The command "info symbol <address>" displays information about
5140 the symbol at the specified address.
5144 The standard remote protocol now includes an extension that allows
5145 asynchronous collection and display of trace data. This requires
5146 extensive support in the target-side debugging stub. Tracing mode
5147 includes a new interaction mode in GDB and new commands: see the
5148 file tracepoint.c for more details.
5152 Configurations for embedded MIPS now include a simulator contributed
5153 by Cygnus Solutions. The simulator supports the instruction sets
5154 of most MIPS variants.
5158 Sparc configurations may now include the ERC32 simulator contributed
5159 by the European Space Agency. The simulator is not built into
5160 Sparc targets by default; configure with --enable-sim to include it.
5164 For target configurations that may include multiple variants of a
5165 basic architecture (such as MIPS and SH), you may now set the
5166 architecture explicitly. "set arch" sets, "info arch" lists
5167 the possible architectures.
5169 *** Changes in GDB-4.16:
5171 * New native configurations
5173 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5174 M68K NetBSD m68k-*-netbsd*
5175 PowerPC AIX 4.x powerpc-*-aix*
5176 PowerPC MacOS powerpc-*-macos*
5177 PowerPC Windows NT powerpcle-*-cygwin32
5178 RS/6000 AIX 4.x rs6000-*-aix4*
5182 ARM with RDP protocol arm-*-*
5183 I960 with MON960 i960-*-coff
5184 MIPS VxWorks mips*-*-vxworks*
5185 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5186 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5188 Matra Sparclet sparclet-*-*
5192 The powerpc-eabi configuration now includes the PSIM simulator,
5193 contributed by Andrew Cagney, with assistance from Mike Meissner.
5194 PSIM is a very elaborate model of the PowerPC, including not only
5195 basic instruction set execution, but also details of execution unit
5196 performance and I/O hardware. See sim/ppc/README for more details.
5200 GDB now works with Solaris 2.5.
5202 * Windows 95/NT native
5204 GDB will now work as a native debugger on Windows 95 and Windows NT.
5205 To build it from source, you must use the "gnu-win32" environment,
5206 which uses a DLL to emulate enough of Unix to run the GNU tools.
5207 Further information, binaries, and sources are available at
5208 ftp.cygnus.com, under pub/gnu-win32.
5210 * dont-repeat command
5212 If a user-defined command includes the command `dont-repeat', then the
5213 command will not be repeated if the user just types return. This is
5214 useful if the command is time-consuming to run, so that accidental
5215 extra keystrokes don't run the same command many times.
5217 * Send break instead of ^C
5219 The standard remote protocol now includes an option to send a break
5220 rather than a ^C to the target in order to interrupt it. By default,
5221 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5223 * Remote protocol timeout
5225 The standard remote protocol includes a new variable `remotetimeout'
5226 that allows you to set the number of seconds before GDB gives up trying
5227 to read from the target. The default value is 2.
5229 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5231 By default GDB will automatically keep track of objects as they are
5232 loaded and unloaded by the dynamic linker. By using the command `set
5233 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5234 when shared library events occur, thus allowing you to set breakpoints
5235 in shared libraries which are explicitly loaded by the inferior.
5237 Note this feature does not work on hpux8. On hpux9 you must link
5238 /usr/lib/end.o into your program. This feature should work
5239 automatically on hpux10.
5241 * Irix 5.x hardware watchpoint support
5243 Irix 5 configurations now support the use of hardware watchpoints.
5245 * Mips protocol "SYN garbage limit"
5247 When debugging a Mips target using the `target mips' protocol, you
5248 may set the number of characters that GDB will ignore by setting
5249 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5250 every character. The default value is 1050.
5252 * Recording and replaying remote debug sessions
5254 If you set `remotelogfile' to the name of a file, gdb will write to it
5255 a recording of a remote debug session. This recording may then be
5256 replayed back to gdb using "gdbreplay". See gdbserver/README for
5257 details. This is useful when you have a problem with GDB while doing
5258 remote debugging; you can make a recording of the session and send it
5259 to someone else, who can then recreate the problem.
5261 * Speedups for remote debugging
5263 GDB includes speedups for downloading and stepping MIPS systems using
5264 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5265 and more efficient S-record downloading.
5267 * Memory use reductions and statistics collection
5269 GDB now uses less memory and reports statistics about memory usage.
5270 Try the `maint print statistics' command, for example.
5272 *** Changes in GDB-4.15:
5274 * Psymtabs for XCOFF
5276 The symbol reader for AIX GDB now uses partial symbol tables. This
5277 can greatly improve startup time, especially for large executables.
5279 * Remote targets use caching
5281 Remote targets now use a data cache to speed up communication with the
5282 remote side. The data cache could lead to incorrect results because
5283 it doesn't know about volatile variables, thus making it impossible to
5284 debug targets which use memory mapped I/O devices. `set remotecache
5285 off' turns the the data cache off.
5287 * Remote targets may have threads
5289 The standard remote protocol now includes support for multiple threads
5290 in the target system, using new protocol commands 'H' and 'T'. See
5291 gdb/remote.c for details.
5295 If GDB is configured with `--enable-netrom', then it will include
5296 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5297 acts as though it is a bank of ROM on the target board, but you can
5298 write into it over the network. GDB's support consists only of
5299 support for fast loading into the emulated ROM; to debug, you must use
5300 another protocol, such as standard remote protocol. The usual
5301 sequence is something like
5303 target nrom <netrom-hostname>
5305 target remote <netrom-hostname>:1235
5309 GDB now includes support for the Apple Macintosh, as a host only. It
5310 may be run as either an MPW tool or as a standalone application, and
5311 it can debug through the serial port. All the usual GDB commands are
5312 available, but to the target command, you must supply "serial" as the
5313 device type instead of "/dev/ttyXX". See mpw-README in the main
5314 directory for more information on how to build. The MPW configuration
5315 scripts */mpw-config.in support only a few targets, and only the
5316 mips-idt-ecoff target has been tested.
5320 GDB configuration now uses autoconf. This is not user-visible,
5321 but does simplify configuration and building.
5325 GDB now supports hpux10.
5327 *** Changes in GDB-4.14:
5329 * New native configurations
5331 x86 FreeBSD i[345]86-*-freebsd
5332 x86 NetBSD i[345]86-*-netbsd
5333 NS32k NetBSD ns32k-*-netbsd
5334 Sparc NetBSD sparc-*-netbsd
5338 A29K VxWorks a29k-*-vxworks
5339 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5340 CPU32 EST-300 emulator m68*-*-est*
5341 PowerPC ELF powerpc-*-elf
5344 * Alpha OSF/1 support for procfs
5346 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5347 possible to attach to running processes. As the mounting of the /proc
5348 filesystem is optional on the Alpha, GDB automatically determines
5349 the availability of /proc during startup. This can lead to problems
5350 if /proc is unmounted after GDB has been started.
5352 * Arguments to user-defined commands
5354 User commands may accept up to 10 arguments separated by whitespace.
5355 Arguments are accessed within the user command via $arg0..$arg9. A
5358 print $arg0 + $arg1 + $arg2
5360 To execute the command use:
5363 Defines the command "adder" which prints the sum of its three arguments.
5364 Note the arguments are text substitutions, so they may reference variables,
5365 use complex expressions, or even perform inferior function calls.
5367 * New `if' and `while' commands
5369 This makes it possible to write more sophisticated user-defined
5370 commands. Both commands take a single argument, which is the
5371 expression to evaluate, and must be followed by the commands to
5372 execute, one per line, if the expression is nonzero, the list being
5373 terminated by the word `end'. The `if' command list may include an
5374 `else' word, which causes the following commands to be executed only
5375 if the expression is zero.
5377 * Fortran source language mode
5379 GDB now includes partial support for Fortran 77. It will recognize
5380 Fortran programs and can evaluate a subset of Fortran expressions, but
5381 variables and functions may not be handled correctly. GDB will work
5382 with G77, but does not yet know much about symbols emitted by other
5385 * Better HPUX support
5387 Most debugging facilities now work on dynamic executables for HPPAs
5388 running hpux9 or later. You can attach to running dynamically linked
5389 processes, but by default the dynamic libraries will be read-only, so
5390 for instance you won't be able to put breakpoints in them. To change
5391 that behavior do the following before running the program:
5397 This will cause the libraries to be mapped private and read-write.
5398 To revert to the normal behavior, do this:
5404 You cannot set breakpoints or examine data in the library until after
5405 the library is loaded if the function/data symbols do not have
5408 GDB can now also read debug symbols produced by the HP C compiler on
5409 HPPAs (sorry, no C++, Fortran or 68k support).
5411 * Target byte order now dynamically selectable
5413 You can choose which byte order to use with a target system, via the
5414 commands "set endian big" and "set endian little", and you can see the
5415 current setting by using "show endian". You can also give the command
5416 "set endian auto", in which case GDB will use the byte order
5417 associated with the executable. Currently, only embedded MIPS
5418 configurations support dynamic selection of target byte order.
5420 * New DOS host serial code
5422 This version uses DPMI interrupts to handle buffered I/O, so you
5423 no longer need to run asynctsr when debugging boards connected to
5426 *** Changes in GDB-4.13:
5428 * New "complete" command
5430 This lists all the possible completions for the rest of the line, if it
5431 were to be given as a command itself. This is intended for use by emacs.
5433 * Trailing space optional in prompt
5435 "set prompt" no longer adds a space for you after the prompt you set. This
5436 allows you to set a prompt which ends in a space or one that does not.
5438 * Breakpoint hit counts
5440 "info break" now displays a count of the number of times the breakpoint
5441 has been hit. This is especially useful in conjunction with "ignore"; you
5442 can ignore a large number of breakpoint hits, look at the breakpoint info
5443 to see how many times the breakpoint was hit, then run again, ignoring one
5444 less than that number, and this will get you quickly to the last hit of
5447 * Ability to stop printing at NULL character
5449 "set print null-stop" will cause GDB to stop printing the characters of
5450 an array when the first NULL is encountered. This is useful when large
5451 arrays actually contain only short strings.
5453 * Shared library breakpoints
5455 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5456 breakpoints in shared libraries before the executable is run.
5458 * Hardware watchpoints
5460 There is a new hardware breakpoint for the watch command for sparclite
5461 targets. See gdb/sparclite/hw_breakpoint.note.
5463 Hardware watchpoints are also now supported under GNU/Linux.
5467 Annotations have been added. These are for use with graphical interfaces,
5468 and are still experimental. Currently only gdba.el uses these.
5470 * Improved Irix 5 support
5472 GDB now works properly with Irix 5.2.
5474 * Improved HPPA support
5476 GDB now works properly with the latest GCC and GAS.
5478 * New native configurations
5480 Sequent PTX4 i[34]86-sequent-ptx4
5481 HPPA running OSF/1 hppa*-*-osf*
5482 Atari TT running SVR4 m68*-*-sysv4*
5483 RS/6000 LynxOS rs6000-*-lynxos*
5487 OS/9000 i[34]86-*-os9k
5488 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5491 * Hitachi SH7000 and E7000-PC ICE support
5493 There is now support for communicating with the Hitachi E7000-PC ICE.
5494 This is available automatically when GDB is configured for the SH.
5498 As usual, a variety of small fixes and improvements, both generic
5499 and configuration-specific. See the ChangeLog for more detail.
5501 *** Changes in GDB-4.12:
5503 * Irix 5 is now supported
5507 GDB-4.12 on the HPPA has a number of changes which make it unable
5508 to debug the output from the currently released versions of GCC and
5509 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5510 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5511 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5514 *** Changes in GDB-4.11:
5516 * User visible changes:
5520 The "set remotedebug" option is now consistent between the mips remote
5521 target, remote targets using the gdb-specific protocol, UDI (AMD's
5522 debug protocol for the 29k) and the 88k bug monitor. It is now an
5523 integer specifying a debug level (normally 0 or 1, but 2 means more
5524 debugging info for the mips target).
5526 * DEC Alpha native support
5528 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5529 debug info, but GDB works fairly well with the DEC compiler and should
5530 work with a future GCC release. See the README file for a few
5531 Alpha-specific notes.
5533 * Preliminary thread implementation
5535 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5537 * LynxOS native and target support for 386
5539 This release has been hosted on LynxOS 2.2, and also can be configured
5540 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5543 * Improvements in C++ mangling/demangling.
5545 This release has much better g++ debugging, specifically in name
5546 mangling/demangling, virtual function calls, print virtual table,
5547 call methods, ...etc.
5549 *** Changes in GDB-4.10:
5551 * User visible changes:
5553 Remote debugging using the GDB-specific (`target remote') protocol now
5554 supports the `load' command. This is only useful if you have some
5555 other way of getting the stub to the target system, and you can put it
5556 somewhere in memory where it won't get clobbered by the download.
5558 Filename completion now works.
5560 When run under emacs mode, the "info line" command now causes the
5561 arrow to point to the line specified. Also, "info line" prints
5562 addresses in symbolic form (as well as hex).
5564 All vxworks based targets now support a user settable option, called
5565 vxworks-timeout. This option represents the number of seconds gdb
5566 should wait for responses to rpc's. You might want to use this if
5567 your vxworks target is, perhaps, a slow software simulator or happens
5568 to be on the far side of a thin network line.
5572 This release contains support for using a DEC alpha as a GDB host for
5573 cross debugging. Native alpha debugging is not supported yet.
5576 *** Changes in GDB-4.9:
5580 This is the first GDB release which is accompanied by a matching testsuite.
5581 The testsuite requires installation of dejagnu, which should be available
5582 via ftp from most sites that carry GNU software.
5586 'Cfront' style demangling has had its name changed to 'ARM' style, to
5587 emphasize that it was written from the specifications in the C++ Annotated
5588 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5589 disclaimers, it still generated too much confusion with users attempting to
5590 use gdb with AT&T cfront.
5594 GDB now uses a standard remote interface to a simulator library.
5595 So far, the library contains simulators for the Zilog Z8001/2, the
5596 Hitachi H8/300, H8/500 and Super-H.
5598 * New targets supported
5600 H8/300 simulator h8300-hitachi-hms or h8300hms
5601 H8/500 simulator h8500-hitachi-hms or h8500hms
5602 SH simulator sh-hitachi-hms or sh
5603 Z8000 simulator z8k-zilog-none or z8ksim
5604 IDT MIPS board over serial line mips-idt-ecoff
5606 Cross-debugging to GO32 targets is supported. It requires a custom
5607 version of the i386-stub.c module which is integrated with the
5608 GO32 memory extender.
5610 * New remote protocols
5612 MIPS remote debugging protocol.
5614 * New source languages supported
5616 This version includes preliminary support for Chill, a Pascal like language
5617 used by telecommunications companies. Chill support is also being integrated
5618 into the GNU compiler, but we don't know when it will be publically available.
5621 *** Changes in GDB-4.8:
5623 * HP Precision Architecture supported
5625 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5626 version of this support was available as a set of patches from the
5627 University of Utah. GDB does not support debugging of programs
5628 compiled with the HP compiler, because HP will not document their file
5629 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5630 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5632 Many problems in the preliminary version have been fixed.
5634 * Faster and better demangling
5636 We have improved template demangling and fixed numerous bugs in the GNU style
5637 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5638 character types (wchar_t) are now supported. Demangling of each symbol is now
5639 only done once, and is cached when the symbol table for a file is read in.
5640 This results in a small increase in memory usage for C programs, a moderate
5641 increase in memory usage for C++ programs, and a fantastic speedup in
5644 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5645 from the specifications in the Annotated Reference Manual, which AT&T's
5646 compiler does not actually implement.
5648 * G++ multiple inheritance compiler problem
5650 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5651 inheritance lattices was reworked to properly discover ambiguities. We
5652 recently found an example which causes this new algorithm to fail in a
5653 very subtle way, producing bad debug information for those classes.
5654 The file 'gcc.patch' (in this directory) can be applied to gcc to
5655 circumvent the problem. A future GCC release will contain a complete
5658 The previous G++ debug info problem (mentioned below for the gdb-4.7
5659 release) is fixed in gcc version 2.3.2.
5661 * Improved configure script
5663 The `configure' script will now attempt to guess your system type if
5664 you don't supply a host system type. The old scheme of supplying a
5665 host system triplet is preferable over using this. All the magic is
5666 done in the new `config.guess' script. Examine it for details.
5668 We have also brought our configure script much more in line with the FSF's
5669 version. It now supports the --with-xxx options. In particular,
5670 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5671 The resulting GDB will not be able to read arbitrary object file formats --
5672 only the format ``expected'' to be used on the configured target system.
5673 We hope to make this the default in a future release.
5675 * Documentation improvements
5677 There's new internal documentation on how to modify GDB, and how to
5678 produce clean changes to the code. We implore people to read it
5679 before submitting changes.
5681 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5682 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5683 `info' files are also provided. To build `info' files from scratch,
5684 you will need the latest `makeinfo' release, which will be available in
5685 a future texinfo-X.Y release.
5687 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5688 We're not sure exactly which versions have this problem, but it has
5689 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5690 or better. If that isn't possible, there is a patch in
5691 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5692 around this problem.
5696 GDB now supports array constants that can be used in expressions typed in by
5697 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5698 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5701 The new directory `gdb/sparclite' contains a program that demonstrates
5702 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5704 * New native hosts supported
5706 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5707 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5709 * New targets supported
5711 AMD 29k family via UDI a29k-amd-udi or udi29k
5713 * New file formats supported
5715 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5716 HPUX core files, and SCO 3.2v2 core files.
5720 Attaching to processes now works again; thanks for the many bug reports.
5722 We have also stomped on a bunch of core dumps caused by
5723 printf_filtered("%s") problems.
5725 We eliminated a copyright problem on the rpc and ptrace header files
5726 for VxWorks, which was discovered at the last minute during the 4.7
5727 release. You should now be able to build a VxWorks GDB.
5729 You can now interrupt gdb while an attached process is running. This
5730 will cause the attached process to stop, and give control back to GDB.
5732 We fixed problems caused by using too many file descriptors
5733 for reading symbols from object files and libraries. This was
5734 especially a problem for programs that used many (~100) shared
5737 The `step' command now only enters a subroutine if there is line number
5738 information for the subroutine. Otherwise it acts like the `next'
5739 command. Previously, `step' would enter subroutines if there was
5740 any debugging information about the routine. This avoids problems
5741 when using `cc -g1' on MIPS machines.
5743 * Internal improvements
5745 GDB's internal interfaces have been improved to make it easier to support
5746 debugging of multiple languages in the future.
5748 GDB now uses a common structure for symbol information internally.
5749 Minimal symbols (derived from linkage symbols in object files), partial
5750 symbols (from a quick scan of debug information), and full symbols
5751 contain a common subset of information, making it easier to write
5752 shared code that handles any of them.
5754 * New command line options
5756 We now accept --silent as an alias for --quiet.
5760 The memory-mapped-malloc library is now licensed under the GNU Library
5761 General Public License.
5763 *** Changes in GDB-4.7:
5765 * Host/native/target split
5767 GDB has had some major internal surgery to untangle the support for
5768 hosts and remote targets. Now, when you configure GDB for a remote
5769 target, it will no longer load in all of the support for debugging
5770 local programs on the host. When fully completed and tested, this will
5771 ensure that arbitrary host/target combinations are possible.
5773 The primary conceptual shift is to separate the non-portable code in
5774 GDB into three categories. Host specific code is required any time GDB
5775 is compiled on that host, regardless of the target. Target specific
5776 code relates to the peculiarities of the target, but can be compiled on
5777 any host. Native specific code is everything else: it can only be
5778 built when the host and target are the same system. Child process
5779 handling and core file support are two common `native' examples.
5781 GDB's use of /proc for controlling Unix child processes is now cleaner.
5782 It has been split out into a single module under the `target_ops' vector,
5783 plus two native-dependent functions for each system that uses /proc.
5785 * New hosts supported
5787 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5788 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5789 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5791 * New targets supported
5793 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5794 68030 and CPU32 m68030-*-*, m68332-*-*
5796 * New native hosts supported
5798 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5799 (386bsd is not well tested yet)
5800 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5802 * New file formats supported
5804 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5805 supports reading of `a.out.adobe' object files, which are an a.out
5806 format extended with minimal information about multiple sections.
5810 `show copying' is the same as the old `info copying'.
5811 `show warranty' is the same as `info warrantee'.
5812 These were renamed for consistency. The old commands continue to work.
5814 `info handle' is a new alias for `info signals'.
5816 You can now define pre-command hooks, which attach arbitrary command
5817 scripts to any command. The commands in the hook will be executed
5818 prior to the user's command. You can also create a hook which will be
5819 executed whenever the program stops. See gdb.texinfo.
5823 We now deal with Cfront style name mangling, and can even extract type
5824 info from mangled symbols. GDB can automatically figure out which
5825 symbol mangling style your C++ compiler uses.
5827 Calling of methods and virtual functions has been improved as well.
5831 The crash that occured when debugging Sun Ansi-C compiled binaries is
5832 fixed. This was due to mishandling of the extra N_SO stabs output
5835 We also finally got Ultrix 4.2 running in house, and fixed core file
5836 support, with help from a dozen people on the net.
5838 John M. Farrell discovered that the reason that single-stepping was so
5839 slow on all of the Mips based platforms (primarily SGI and DEC) was
5840 that we were trying to demangle and lookup a symbol used for internal
5841 purposes on every instruction that was being stepped through. Changing
5842 the name of that symbol so that it couldn't be mistaken for a C++
5843 mangled symbol sped things up a great deal.
5845 Rich Pixley sped up symbol lookups in general by getting much smarter
5846 about when C++ symbol mangling is necessary. This should make symbol
5847 completion (TAB on the command line) much faster. It's not as fast as
5848 we'd like, but it's significantly faster than gdb-4.6.
5852 A new user controllable variable 'call_scratch_address' can
5853 specify the location of a scratch area to be used when GDB
5854 calls a function in the target. This is necessary because the
5855 usual method of putting the scratch area on the stack does not work
5856 in systems that have separate instruction and data spaces.
5858 We integrated changes to support the 29k UDI (Universal Debugger
5859 Interface), but discovered at the last minute that we didn't have all
5860 of the appropriate copyright paperwork. We are working with AMD to
5861 resolve this, and hope to have it available soon.
5865 We have sped up the remote serial line protocol, especially for targets
5866 with lots of registers. It now supports a new `expedited status' ('T')
5867 message which can be used in place of the existing 'S' status message.
5868 This allows the remote stub to send only the registers that GDB
5869 needs to make a quick decision about single-stepping or conditional
5870 breakpoints, eliminating the need to fetch the entire register set for
5871 each instruction being stepped through.
5873 The GDB remote serial protocol now implements a write-through cache for
5874 registers, only re-reading the registers if the target has run.
5876 There is also a new remote serial stub for SPARC processors. You can
5877 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5878 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5879 processor with a serial port.
5883 Configure.in files have become much easier to read and modify. A new
5884 `table driven' format makes it more obvious what configurations are
5885 supported, and what files each one uses.
5889 There is a new opcodes library which will eventually contain all of the
5890 disassembly routines and opcode tables. At present, it only contains
5891 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5892 disassembler (binutils/objdump) to share these routines.
5894 The libiberty library is now copylefted under the GNU Library General
5895 Public License. This allows more liberal use, and was done so libg++
5896 can use it. This makes no difference to GDB, since the Library License
5897 grants all the rights from the General Public License.
5901 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5902 reference to the stabs symbol info used by the debugger. It is (as far
5903 as we know) the only published document on this fascinating topic. We
5904 encourage you to read it, compare it to the stabs information on your
5905 system, and send improvements on the document in general (to
5906 bug-gdb@prep.ai.mit.edu).
5908 And, of course, many bugs have been fixed.
5911 *** Changes in GDB-4.6:
5913 * Better support for C++ function names
5915 GDB now accepts as input the "demangled form" of C++ overloaded function
5916 names and member function names, and can do command completion on such names
5917 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5918 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5919 Make use of command completion, it is your friend.
5921 GDB also now accepts a variety of C++ mangled symbol formats. They are
5922 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5923 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5924 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5925 for the list of formats.
5927 * G++ symbol mangling problem
5929 Recent versions of gcc have a bug in how they emit debugging information for
5930 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5931 directory) can be applied to gcc to fix the problem. Alternatively, if you
5932 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5933 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5934 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5937 * New 'maintenance' command
5939 All of the commands related to hacking GDB internals have been moved out of
5940 the main command set, and now live behind the 'maintenance' command. This
5941 can also be abbreviated as 'mt'. The following changes were made:
5943 dump-me -> maintenance dump-me
5944 info all-breakpoints -> maintenance info breakpoints
5945 printmsyms -> maintenance print msyms
5946 printobjfiles -> maintenance print objfiles
5947 printpsyms -> maintenance print psymbols
5948 printsyms -> maintenance print symbols
5950 The following commands are new:
5952 maintenance demangle Call internal GDB demangler routine to
5953 demangle a C++ link name and prints the result.
5954 maintenance print type Print a type chain for a given symbol
5956 * Change to .gdbinit file processing
5958 We now read the $HOME/.gdbinit file before processing the argv arguments
5959 (e.g. reading symbol files or core files). This allows global parameters to
5960 be set, which will apply during the symbol reading. The ./.gdbinit is still
5961 read after argv processing.
5963 * New hosts supported
5965 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5967 GNU/Linux support i386-unknown-linux or linux
5969 We are also including code to support the HP/PA running BSD and HPUX. This
5970 is almost guaranteed not to work, as we didn't have time to test or build it
5971 for this release. We are including it so that the more adventurous (or
5972 masochistic) of you can play with it. We also had major problems with the
5973 fact that the compiler that we got from HP doesn't support the -g option.
5976 * New targets supported
5978 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5980 * More smarts about finding #include files
5982 GDB now remembers the compilation directory for all include files, and for
5983 all files from which C is generated (like yacc and lex sources). This
5984 greatly improves GDB's ability to find yacc/lex sources, and include files,
5985 especially if you are debugging your program from a directory different from
5986 the one that contains your sources.
5988 We also fixed a bug which caused difficulty with listing and setting
5989 breakpoints in include files which contain C code. (In the past, you had to
5990 try twice in order to list an include file that you hadn't looked at before.)
5992 * Interesting infernals change
5994 GDB now deals with arbitrary numbers of sections, where the symbols for each
5995 section must be relocated relative to that section's landing place in the
5996 target's address space. This work was needed to support ELF with embedded
5997 stabs used by Solaris-2.0.
5999 * Bug fixes (of course!)
6001 There have been loads of fixes for the following things:
6002 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6003 i960, stabs, DOS(GO32), procfs, etc...
6005 See the ChangeLog for details.
6007 *** Changes in GDB-4.5:
6009 * New machines supported (host and target)
6011 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6013 SGI Irix-4.x mips-sgi-irix4 or iris4
6015 * New malloc package
6017 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6018 Mmalloc is capable of handling mutiple heaps of memory. It is also
6019 capable of saving a heap to a file, and then mapping it back in later.
6020 This can be used to greatly speedup the startup of GDB by using a
6021 pre-parsed symbol table which lives in a mmalloc managed heap. For
6022 more details, please read mmalloc/mmalloc.texi.
6026 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6027 'help info proc' for details.
6029 * MIPS ecoff symbol table format
6031 The code that reads MIPS symbol table format is now supported on all hosts.
6032 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6035 * File name changes for MS-DOS
6037 Many files in the config directories have been renamed to make it easier to
6038 support GDB on MS-DOSe systems (which have very restrictive file name
6039 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6040 environment) is close to working but has some remaining problems. Note
6041 that debugging of DOS programs is not supported, due to limitations
6042 in the ``operating system'', but it can be used to host cross-debugging.
6044 * Cross byte order fixes
6046 Many fixes have been made to support cross debugging of Sparc and MIPS
6047 targets from hosts whose byte order differs.
6049 * New -mapped and -readnow options
6051 If memory-mapped files are available on your system through the 'mmap'
6052 system call, you can use the -mapped option on the `file' or
6053 `symbol-file' commands to cause GDB to write the symbols from your
6054 program into a reusable file. If the program you are debugging is
6055 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6056 Future GDB debugging sessions will notice the presence of this file,
6057 and will quickly map in symbol information from it, rather than reading
6058 the symbol table from the executable program. Using the '-mapped'
6059 option in a GDB `file' or `symbol-file' command has the same effect as
6060 starting GDB with the '-mapped' command-line option.
6062 You can cause GDB to read the entire symbol table immediately by using
6063 the '-readnow' option with any of the commands that load symbol table
6064 information (or on the GDB command line). This makes the command
6065 slower, but makes future operations faster.
6067 The -mapped and -readnow options are typically combined in order to
6068 build a `fred.syms' file that contains complete symbol information.
6069 A simple GDB invocation to do nothing but build a `.syms' file for future
6072 gdb -batch -nx -mapped -readnow programname
6074 The `.syms' file is specific to the host machine on which GDB is run.
6075 It holds an exact image of GDB's internal symbol table. It cannot be
6076 shared across multiple host platforms.
6078 * longjmp() handling
6080 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6081 siglongjmp() without losing control. This feature has not yet been ported to
6082 all systems. It currently works on many 386 platforms, all MIPS-based
6083 platforms (SGI, DECstation, etc), and Sun3/4.
6087 Preliminary work has been put in to support the new Solaris OS from Sun. At
6088 this time, it can control and debug processes, but it is not capable of
6093 As always, many many bug fixes. The major areas were with g++, and mipsread.
6094 People using the MIPS-based platforms should experience fewer mysterious
6095 crashes and trashed symbol tables.
6097 *** Changes in GDB-4.4:
6099 * New machines supported (host and target)
6101 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6103 BSD Reno on Vax vax-dec-bsd
6104 Ultrix on Vax vax-dec-ultrix
6106 * New machines supported (target)
6108 AMD 29000 embedded, using EBMON a29k-none-none
6112 GDB continues to improve its handling of C++. `References' work better.
6113 The demangler has also been improved, and now deals with symbols mangled as
6114 per the Annotated C++ Reference Guide.
6116 GDB also now handles `stabs' symbol information embedded in MIPS
6117 `ecoff' symbol tables. Since the ecoff format was not easily
6118 extensible to handle new languages such as C++, this appeared to be a
6119 good way to put C++ debugging info into MIPS binaries. This option
6120 will be supported in the GNU C compiler, version 2, when it is
6123 * New features for SVR4
6125 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6126 shared libraries. Debugging dynamically linked programs should present
6127 only minor differences from debugging statically linked programs.
6129 The `info proc' command will print out information about any process
6130 on an SVR4 system (including the one you are debugging). At the moment,
6131 it prints the address mappings of the process.
6133 If you bring up GDB on another SVR4 system, please send mail to
6134 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6136 * Better dynamic linking support in SunOS
6138 Reading symbols from shared libraries which contain debugging symbols
6139 now works properly. However, there remain issues such as automatic
6140 skipping of `transfer vector' code during function calls, which
6141 make it harder to debug code in a shared library, than to debug the
6142 same code linked statically.
6146 GDB is now using the latest `getopt' routines from the FSF. This
6147 version accepts the -- prefix for options with long names. GDB will
6148 continue to accept the old forms (-option and +option) as well.
6149 Various single letter abbreviations for options have been explicity
6150 added to the option table so that they won't get overshadowed in the
6151 future by other options that begin with the same letter.
6155 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6156 Many assorted bugs have been handled. Many more remain to be handled.
6157 See the various ChangeLog files (primarily in gdb and bfd) for details.
6160 *** Changes in GDB-4.3:
6162 * New machines supported (host and target)
6164 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6165 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6166 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6168 * Almost SCO Unix support
6170 We had hoped to support:
6171 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6172 (except for core file support), but we discovered very late in the release
6173 that it has problems with process groups that render gdb unusable. Sorry
6174 about that. I encourage people to fix it and post the fixes.
6176 * Preliminary ELF and DWARF support
6178 GDB can read ELF object files on System V Release 4, and can handle
6179 debugging records for C, in DWARF format, in ELF files. This support
6180 is preliminary. If you bring up GDB on another SVR4 system, please
6181 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6186 GDB now uses the latest `readline' library. One user-visible change
6187 is that two tabs will list possible command completions, which previously
6188 required typing M-? (meta-question mark, or ESC ?).
6192 The `stepi' bug that many of you noticed has been squashed.
6193 Many bugs in C++ have been handled. Many more remain to be handled.
6194 See the various ChangeLog files (primarily in gdb and bfd) for details.
6196 * State of the MIPS world (in case you wondered):
6198 GDB can understand the symbol tables emitted by the compilers
6199 supplied by most vendors of MIPS-based machines, including DEC. These
6200 symbol tables are in a format that essentially nobody else uses.
6202 Some versions of gcc come with an assembler post-processor called
6203 mips-tfile. This program is required if you want to do source-level
6204 debugging of gcc-compiled programs. I believe FSF does not ship
6205 mips-tfile with gcc version 1, but it will eventually come with gcc
6208 Debugging of g++ output remains a problem. g++ version 1.xx does not
6209 really support it at all. (If you're lucky, you should be able to get
6210 line numbers and stack traces to work, but no parameters or local
6211 variables.) With some work it should be possible to improve the
6214 When gcc version 2 is released, you will have somewhat better luck.
6215 However, even then you will get confusing results for inheritance and
6218 We will eventually provide full debugging of g++ output on
6219 DECstations. This will probably involve some kind of stabs-in-ecoff
6220 encapulation, but the details have not been worked out yet.
6223 *** Changes in GDB-4.2:
6225 * Improved configuration
6227 Only one copy of `configure' exists now, and it is not self-modifying.
6228 Porting BFD is simpler.
6232 The `step' and `next' commands now only stop at the first instruction
6233 of a source line. This prevents the multiple stops that used to occur
6234 in switch statements, for-loops, etc. `Step' continues to stop if a
6235 function that has debugging information is called within the line.
6239 Lots of small bugs fixed. More remain.
6241 * New host supported (not target)
6243 Intel 386 PC clone running Mach i386-none-mach
6246 *** Changes in GDB-4.1:
6248 * Multiple source language support
6250 GDB now has internal scaffolding to handle several source languages.
6251 It determines the type of each source file from its filename extension,
6252 and will switch expression parsing and number formatting to match the
6253 language of the function in the currently selected stack frame.
6254 You can also specifically set the language to be used, with
6255 `set language c' or `set language modula-2'.
6259 GDB now has preliminary support for the GNU Modula-2 compiler,
6260 currently under development at the State University of New York at
6261 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6262 continue through the fall of 1991 and into 1992.
6264 Other Modula-2 compilers are currently not supported, and attempting to
6265 debug programs compiled with them will likely result in an error as the
6266 symbol table is read. Feel free to work on it, though!
6268 There are hooks in GDB for strict type checking and range checking,
6269 in the `Modula-2 philosophy', but they do not currently work.
6273 GDB can now write to executable and core files (e.g. patch
6274 a variable's value). You must turn this switch on, specify
6275 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6276 by assigning a new value to a variable. Modifications take
6279 * Automatic SunOS shared library reading
6281 When you run your program, GDB automatically determines where its
6282 shared libraries (if any) have been loaded, and reads their symbols.
6283 The `share' command is no longer needed. This also works when
6284 examining core files.
6288 You can specify the number of lines that the `list' command shows.
6291 * New machines supported (host and target)
6293 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6294 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6295 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6297 * New hosts supported (not targets)
6299 IBM RT/PC: romp-ibm-aix or rtpc
6301 * New targets supported (not hosts)
6303 AMD 29000 embedded with COFF a29k-none-coff
6304 AMD 29000 embedded with a.out a29k-none-aout
6305 Ultracomputer remote kernel debug a29k-nyu-kern
6307 * New remote interfaces
6313 *** Changes in GDB-4.0:
6317 Wide output is wrapped at good places to make the output more readable.
6319 Gdb now supports cross-debugging from a host machine of one type to a
6320 target machine of another type. Communication with the target system
6321 is over serial lines. The ``target'' command handles connecting to the
6322 remote system; the ``load'' command will download a program into the
6323 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6324 also supports debugging of realtime processes running under VxWorks,
6325 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6326 stub on the target system.
6328 New CPUs supported include the AMD 29000 and Intel 960.
6330 GDB now reads object files and symbol tables via a ``binary file''
6331 library, which allows a single copy of GDB to debug programs of multiple
6332 object file types such as a.out and coff.
6334 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6335 refcard.dvi and refcard.ps are available to format it).
6338 * Control-Variable user interface simplified
6340 All variables that control the operation of the debugger can be set
6341 by the ``set'' command, and displayed by the ``show'' command.
6343 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6344 ``Show prompt'' produces the response:
6345 Gdb's prompt is new-gdb=>.
6347 What follows are the NEW set commands. The command ``help set'' will
6348 print a complete list of old and new set commands. ``help set FOO''
6349 will give a longer description of the variable FOO. ``show'' will show
6350 all of the variable descriptions and their current settings.
6352 confirm on/off: Enables warning questions for operations that are
6353 hard to recover from, e.g. rerunning the program while
6354 it is already running. Default is ON.
6356 editing on/off: Enables EMACS style command line editing
6357 of input. Previous lines can be recalled with
6358 control-P, the current line can be edited with control-B,
6359 you can search for commands with control-R, etc.
6362 history filename NAME: NAME is where the gdb command history
6363 will be stored. The default is .gdb_history,
6364 or the value of the environment variable
6367 history size N: The size, in commands, of the command history. The
6368 default is 256, or the value of the environment variable
6371 history save on/off: If this value is set to ON, the history file will
6372 be saved after exiting gdb. If set to OFF, the
6373 file will not be saved. The default is OFF.
6375 history expansion on/off: If this value is set to ON, then csh-like
6376 history expansion will be performed on
6377 command line input. The default is OFF.
6379 radix N: Sets the default radix for input and output. It can be set
6380 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6381 in the current radix, so "set radix 10" is always a no-op.
6383 height N: This integer value is the number of lines on a page. Default
6384 is 24, the current `stty rows'' setting, or the ``li#''
6385 setting from the termcap entry matching the environment
6388 width N: This integer value is the number of characters on a line.
6389 Default is 80, the current `stty cols'' setting, or the ``co#''
6390 setting from the termcap entry matching the environment
6393 Note: ``set screensize'' is obsolete. Use ``set height'' and
6394 ``set width'' instead.
6396 print address on/off: Print memory addresses in various command displays,
6397 such as stack traces and structure values. Gdb looks
6398 more ``symbolic'' if you turn this off; it looks more
6399 ``machine level'' with it on. Default is ON.
6401 print array on/off: Prettyprint arrays. New convenient format! Default
6404 print demangle on/off: Print C++ symbols in "source" form if on,
6407 print asm-demangle on/off: Same, for assembler level printouts
6410 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6413 * Support for Epoch Environment.
6415 The epoch environment is a version of Emacs v18 with windowing. One
6416 new command, ``inspect'', is identical to ``print'', except that if you
6417 are running in the epoch environment, the value is printed in its own
6421 * Support for Shared Libraries
6423 GDB can now debug programs and core files that use SunOS shared libraries.
6424 Symbols from a shared library cannot be referenced
6425 before the shared library has been linked with the program (this
6426 happens after you type ``run'' and before the function main() is entered).
6427 At any time after this linking (including when examining core files
6428 from dynamically linked programs), gdb reads the symbols from each
6429 shared library when you type the ``sharedlibrary'' command.
6430 It can be abbreviated ``share''.
6432 sharedlibrary REGEXP: Load shared object library symbols for files
6433 matching a unix regular expression. No argument
6434 indicates to load symbols for all shared libraries.
6436 info sharedlibrary: Status of loaded shared libraries.
6441 A watchpoint stops execution of a program whenever the value of an
6442 expression changes. Checking for this slows down execution
6443 tremendously whenever you are in the scope of the expression, but is
6444 quite useful for catching tough ``bit-spreader'' or pointer misuse
6445 problems. Some machines such as the 386 have hardware for doing this
6446 more quickly, and future versions of gdb will use this hardware.
6448 watch EXP: Set a watchpoint (breakpoint) for an expression.
6450 info watchpoints: Information about your watchpoints.
6452 delete N: Deletes watchpoint number N (same as breakpoints).
6453 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6454 enable N: Re-enables watchpoint number N (same as breakpoints).
6457 * C++ multiple inheritance
6459 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6462 * C++ exception handling
6464 Gdb now supports limited C++ exception handling. Besides the existing
6465 ability to breakpoint on an exception handler, gdb can breakpoint on
6466 the raising of an exception (before the stack is peeled back to the
6469 catch FOO: If there is a FOO exception handler in the dynamic scope,
6470 set a breakpoint to catch exceptions which may be raised there.
6471 Multiple exceptions (``catch foo bar baz'') may be caught.
6473 info catch: Lists all exceptions which may be caught in the
6474 current stack frame.
6477 * Minor command changes
6479 The command ``call func (arg, arg, ...)'' now acts like the print
6480 command, except it does not print or save a value if the function's result
6481 is void. This is similar to dbx usage.
6483 The ``up'' and ``down'' commands now always print the frame they end up
6484 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6485 frames without printing.
6487 * New directory command
6489 'dir' now adds directories to the FRONT of the source search path.
6490 The path starts off empty. Source files that contain debug information
6491 about the directory in which they were compiled can be found even
6492 with an empty path; Sun CC and GCC include this information. If GDB can't
6493 find your source file in the current directory, type "dir .".
6495 * Configuring GDB for compilation
6497 For normal use, type ``./configure host''. See README or gdb.texinfo
6500 GDB now handles cross debugging. If you are remotely debugging between
6501 two different machines, type ``./configure host -target=targ''.
6502 Host is the machine where GDB will run; targ is the machine
6503 where the program that you are debugging will run.