1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.10
6 * GDB now supports debugging kernel-based threads on FreeBSD.
8 * Per-inferior thread numbers
10 Thread numbers are now per inferior instead of global. If you're
11 debugging multiple inferiors, GDB displays thread IDs using a
12 qualified INF_NUM.THR_NUM form. For example:
16 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
17 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
18 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
19 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
21 As consequence, thread numbers as visible in the $_thread
22 convenience variable and in Python's InferiorThread.num attribute
23 are no longer unique between inferiors.
25 GDB now maintains a second thread ID per thread, referred to as the
26 global thread ID, which is the new equivalent of thread numbers in
27 previous releases. See also $_gthread below.
29 For backwards compatibility, MI's thread IDs always refer to global
32 * Commands that accept thread IDs now accept the qualified
33 INF_NUM.THR_NUM form as well. For example:
36 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
39 * In commands that accept a list of thread IDs, you can now refer to
40 all threads of an inferior using a star wildcard. GDB accepts
41 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
42 refer to all threads of the current inferior. For example, "info
45 * You can use "info threads -gid" to display the global thread ID of
48 * The new convenience variable $_gthread holds the global number of
51 * The new convenience variable $_inferior holds the number of the
54 * GDB now displays the ID and name of the thread that hit a breakpoint
55 or received a signal, if your program is multi-threaded. For
58 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
59 Thread 1 "main" received signal SIGINT, Interrupt.
61 * Record btrace now supports non-stop mode.
63 * Support for tracepoints on aarch64-linux was added in GDBserver.
65 * The 'record instruction-history' command now indicates speculative execution
66 when using the Intel Processor Trace recording format.
68 * GDB now allows users to specify explicit locations, bypassing
69 the linespec parser. This feature is also available to GDB/MI
72 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
73 GDB now is able to debug both AArch64 applications and ARM applications
76 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
77 including JIT compiling fast tracepoint's conditional expression bytecode
80 * GDB now supports displaced stepping on AArch64 GNU/Linux.
82 * "info threads", "info inferiors", "info display", "info checkpoints"
83 and "maint info program-spaces" now list the corresponding items in
84 ascending ID order, for consistency with all other "info" commands.
86 * In Ada, the overloads selection menu has been enhanced to display the
87 parameter types and the return types for the matching overloaded subprograms.
91 maint set target-non-stop (on|off|auto)
92 maint show target-non-stop
93 Control whether GDB targets always operate in non-stop mode even if
94 "set non-stop" is "off". The default is "auto", meaning non-stop
95 mode is enabled if supported by the target.
98 maint show bfd-sharing
99 Control the reuse of bfd objects.
103 Control display of debugging info regarding bfd caching.
107 Control display of debugging info regarding FreeBSD threads.
109 set remote multiprocess-extensions-packet
110 show remote multiprocess-extensions-packet
111 Set/show the use of the remote protocol multiprocess extensions.
113 set remote thread-events
114 show remote thread-events
115 Set/show the use of thread create/exit events.
117 set ada print-signatures on|off
118 show ada print-signatures"
119 Control whether parameter types and return types are displayed in overloads
120 selection menus. It is activaled (@code{on}) by default.
122 * The "disassemble" command accepts a new modifier: /s.
123 It prints mixed source+disassembly like /m with two differences:
124 - disassembled instructions are now printed in program order, and
125 - and source for all relevant files is now printed.
126 The "/m" option is now considered deprecated: its "source-centric"
127 output hasn't proved useful in practice.
129 * The "record instruction-history" command accepts a new modifier: /s.
130 It behaves exactly like /m and prints mixed source+disassembly.
132 * The "set scheduler-locking" command supports a new mode "replay".
133 It behaves like "off" in record mode and like "on" in replay mode.
135 * Support for various ROM monitors has been removed:
137 target dbug dBUG ROM monitor for Motorola ColdFire
138 target picobug Motorola picobug monitor
139 target dink32 DINK32 ROM monitor for PowerPC
140 target m32r Renesas M32R/D ROM monitor
141 target mon2000 mon2000 ROM monitor
142 target ppcbug PPCBUG ROM monitor for PowerPC
144 * Support for reading/writing memory and extracting values on architectures
145 whose memory is addressable in units of any integral multiple of 8 bits.
150 Indicates that an exec system call was executed.
152 exec-events feature in qSupported
153 The qSupported packet allows GDB to request support for exec
154 events using the new 'gdbfeature' exec-event, and the qSupported
155 response can contain the corresponding 'stubfeature'. Set and
156 show commands can be used to display whether these features are enabled.
159 Equivalent to interrupting with the ^C character, but works in
162 thread created stop reason (T05 create:...)
163 Indicates that the thread was just created and is stopped at entry.
165 thread exit stop reply (w exitcode;tid)
166 Indicates that the thread has terminated.
169 Enables/disables thread create and exit event reporting. For
170 example, this is used in non-stop mode when GDB stops a set of
171 threads and synchronously waits for the their corresponding stop
172 replies. Without exit events, if one of the threads exits, GDB
173 would hang forever not knowing that it should no longer expect a
174 stop for that same thread.
178 Indicates that there are no resumed threads left in the target (all
179 threads are stopped). The remote stub reports support for this stop
180 reply to GDB's qSupported query.
182 QCatchSyscalls:1 [;SYSNO]...
184 Enable ("QCatchSyscalls:1") or disable ("QCatchSyscalls:0")
185 catching syscalls from the inferior process.
187 syscall_entry stop reason
188 Indicates that a syscall was just called.
190 syscall_return stop reason
191 Indicates that a syscall just returned.
193 QCatchSyscalls:1 in qSupported
194 The qSupported packet may now include QCatchSyscalls:1 in the reply
195 to indicate support for catching syscalls.
197 * Extended-remote exec events
199 ** GDB now has support for exec events on extended-remote Linux targets.
200 For such targets with Linux kernels 2.5.46 and later, this enables
201 follow-exec-mode and exec catchpoints.
203 set remote exec-event-feature-packet
204 show remote exec-event-feature-packet
205 Set/show the use of the remote exec event feature.
207 * Thread names in remote protocol
209 The reply to qXfer:threads:read may now include a name attribute for each
212 * Target remote mode fork and exec events
214 ** GDB now has support for fork and exec events on target remote mode
215 Linux targets. For such targets with Linux kernels 2.5.46 and later,
216 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
217 fork and exec catchpoints.
219 * Remote syscall events
221 ** GDB now has support for catch syscall on remote Linux targets,
222 currently enabled on x86/x86_64 architectures.
224 set remote catch-syscall-packet
225 show remote catch-syscall-packet
226 Set/show the use of the remote catch syscall feature.
230 ** The -var-set-format command now accepts the zero-hexadecimal
231 format. It outputs data in hexadecimal format with zero-padding on the
236 ** gdb.InferiorThread objects have a new attribute "global_num",
237 which refers to the thread's global thread ID. The existing
238 "num" attribute now refers to the thread's per-inferior number.
239 See "Per-inferior thread numbers" above.
240 ** gdb.InferiorThread objects have a new attribute "inferior", which
241 is the Inferior object the thread belongs to.
243 *** Changes in GDB 7.10
245 * Support for process record-replay and reverse debugging on aarch64*-linux*
246 targets has been added. GDB now supports recording of A64 instruction set
247 including advance SIMD instructions.
249 * Support for Sun's version of the "stabs" debug file format has been removed.
251 * GDB now honors the content of the file /proc/PID/coredump_filter
252 (PID is the process ID) on GNU/Linux systems. This file can be used
253 to specify the types of memory mappings that will be included in a
254 corefile. For more information, please refer to the manual page of
255 "core(5)". GDB also has a new command: "set use-coredump-filter
256 on|off". It allows to set whether GDB will read the content of the
257 /proc/PID/coredump_filter file when generating a corefile.
259 * The "info os" command on GNU/Linux can now display information on
261 "info os cpus" Listing of all cpus/cores on the system
263 * GDB has two new commands: "set serial parity odd|even|none" and
264 "show serial parity". These allows to set or show parity for the
267 * The "info source" command now displays the producer string if it was
268 present in the debug info. This typically includes the compiler version
269 and may include things like its command line arguments.
271 * The "info dll", an alias of the "info sharedlibrary" command,
272 is now available on all platforms.
274 * Directory names supplied to the "set sysroot" commands may be
275 prefixed with "target:" to tell GDB to access shared libraries from
276 the target system, be it local or remote. This replaces the prefix
277 "remote:". The default sysroot has been changed from "" to
278 "target:". "remote:" is automatically converted to "target:" for
279 backward compatibility.
281 * The system root specified by "set sysroot" will be prepended to the
282 filename of the main executable (if reported to GDB as absolute by
283 the operating system) when starting processes remotely, and when
284 attaching to already-running local or remote processes.
286 * GDB now supports automatic location and retrieval of executable
287 files from remote targets. Remote debugging can now be initiated
288 using only a "target remote" or "target extended-remote" command
289 (no "set sysroot" or "file" commands are required). See "New remote
292 * The "dump" command now supports verilog hex format.
294 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
296 * On GNU/Linux, GDB and gdbserver are now able to access executable
297 and shared library files without a "set sysroot" command when
298 attaching to processes running in different mount namespaces from
299 the debugger. This makes it possible to attach to processes in
300 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
301 See "New remote packets" below.
303 * The "tui reg" command now provides completion for all of the
304 available register groups, including target specific groups.
306 * The HISTSIZE environment variable is no longer read when determining
307 the size of GDB's command history. GDB now instead reads the dedicated
308 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
309 disables truncation of command history. Non-numeric values of GDBHISTSIZE
314 ** Memory ports can now be unbuffered.
318 ** gdb.Objfile objects have a new attribute "username",
319 which is the name of the objfile as specified by the user,
320 without, for example, resolving symlinks.
321 ** You can now write frame unwinders in Python.
322 ** gdb.Type objects have a new method "optimized_out",
323 returning optimized out gdb.Value instance of this type.
324 ** gdb.Value objects have new methods "reference_value" and
325 "const_value" which return a reference to the value and a
326 "const" version of the value respectively.
330 maint print symbol-cache
331 Print the contents of the symbol cache.
333 maint print symbol-cache-statistics
334 Print statistics of symbol cache usage.
336 maint flush-symbol-cache
337 Flush the contents of the symbol cache.
341 Start branch trace recording using Branch Trace Store (BTS) format.
344 Evaluate expression by using the compiler and print result.
348 Explicit commands for enabling and disabling tui mode.
351 set mpx bound on i386 and amd64
352 Support for bound table investigation on Intel MPX enabled applications.
356 Start branch trace recording using Intel Processor Trace format.
359 Print information about branch tracing internals.
361 maint btrace packet-history
362 Print the raw branch tracing data.
364 maint btrace clear-packet-history
365 Discard the stored raw branch tracing data.
368 Discard all branch tracing data. It will be fetched and processed
369 anew by the next "record" command.
374 Renamed from "set debug dwarf2-die".
376 Renamed from "show debug dwarf2-die".
379 Renamed from "set debug dwarf2-read".
380 show debug dwarf-read
381 Renamed from "show debug dwarf2-read".
383 maint set dwarf always-disassemble
384 Renamed from "maint set dwarf2 always-disassemble".
385 maint show dwarf always-disassemble
386 Renamed from "maint show dwarf2 always-disassemble".
388 maint set dwarf max-cache-age
389 Renamed from "maint set dwarf2 max-cache-age".
390 maint show dwarf max-cache-age
391 Renamed from "maint show dwarf2 max-cache-age".
394 show debug dwarf-line
395 Control display of debugging info regarding DWARF line processing.
399 Set the maximum number of candidates to be considered during
400 completion. The default value is 200. This limit allows GDB
401 to avoid generating large completion lists, the computation of
402 which can cause the debugger to become temporarily unresponsive.
404 set history remove-duplicates
405 show history remove-duplicates
406 Control the removal of duplicate history entries.
408 maint set symbol-cache-size
409 maint show symbol-cache-size
410 Control the size of the symbol cache.
412 set|show record btrace bts buffer-size
413 Set and show the size of the ring buffer used for branch tracing in
415 The obtained size may differ from the requested size. Use "info
416 record" to see the obtained buffer size.
418 set debug linux-namespaces
419 show debug linux-namespaces
420 Control display of debugging info regarding Linux namespaces.
422 set|show record btrace pt buffer-size
423 Set and show the size of the ring buffer used for branch tracing in
424 Intel Processor Trace format.
425 The obtained size may differ from the requested size. Use "info
426 record" to see the obtained buffer size.
428 maint set|show btrace pt skip-pad
429 Set and show whether PAD packets are skipped when computing the
432 * The command 'thread apply all' can now support new option '-ascending'
433 to call its specified command for all threads in ascending order.
435 * Python/Guile scripting
437 ** GDB now supports auto-loading of Python/Guile scripts contained in the
438 special section named `.debug_gdb_scripts'.
442 qXfer:btrace-conf:read
443 Return the branch trace configuration for the current thread.
445 Qbtrace-conf:bts:size
446 Set the requested ring buffer size for branch tracing in BTS format.
449 Enable Intel Procesor Trace-based branch tracing for the current
450 process. The remote stub reports support for this packet to GDB's
454 Set the requested ring buffer size for branch tracing in Intel Processor
458 Indicates a memory breakpoint instruction was executed, irrespective
459 of whether it was GDB that planted the breakpoint or the breakpoint
460 is hardcoded in the program. This is required for correct non-stop
464 Indicates the target stopped for a hardware breakpoint. This is
465 required for correct non-stop mode operation.
468 Return information about files on the remote system.
471 Return the full absolute name of the file that was executed to
472 create a process running on the remote system.
475 Select the filesystem on which vFile: operations with filename
476 arguments will operate. This is required for GDB to be able to
477 access files on remote targets where the remote stub does not
478 share a common filesystem with the inferior(s).
481 Indicates that a fork system call was executed.
484 Indicates that a vfork system call was executed.
486 vforkdone stop reason
487 Indicates that a vfork child of the specified process has executed
488 an exec or exit, allowing the vfork parent to resume execution.
490 fork-events and vfork-events features in qSupported
491 The qSupported packet allows GDB to request support for fork and
492 vfork events using new 'gdbfeatures' fork-events and vfork-events,
493 and the qSupported response can contain the corresponding
494 'stubfeatures'. Set and show commands can be used to display
495 whether these features are enabled.
497 * Extended-remote fork events
499 ** GDB now has support for fork events on extended-remote Linux
500 targets. For targets with Linux kernels 2.5.60 and later, this
501 enables follow-fork-mode and detach-on-fork for both fork and
502 vfork, as well as fork and vfork catchpoints.
504 * The info record command now shows the recording format and the
505 branch tracing configuration for the current thread when using
506 the btrace record target.
507 For the BTS format, it shows the ring buffer size.
509 * GDB now has support for DTrace USDT (Userland Static Defined
510 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
512 * GDB now supports access to vector registers on S/390 GNU/Linux
515 * Removed command line options
517 -xdb HP-UX XDB compatibility mode.
519 * Removed targets and native configurations
521 HP/PA running HP-UX hppa*-*-hpux*
522 Itanium running HP-UX ia64-*-hpux*
524 * New configure options
527 This configure option allows the user to build GDB with support for
528 Intel Processor Trace (default: auto). This requires libipt.
530 --with-libipt-prefix=PATH
531 Specify the path to the version of libipt that GDB should use.
532 $PATH/include should contain the intel-pt.h header and
533 $PATH/lib should contain the libipt.so library.
535 *** Changes in GDB 7.9.1
539 ** Xmethods can now specify a result type.
541 *** Changes in GDB 7.9
543 * GDB now supports hardware watchpoints on x86 GNU Hurd.
547 ** You can now access frame registers from Python scripts.
548 ** New attribute 'producer' for gdb.Symtab objects.
549 ** gdb.Objfile objects have a new attribute "progspace",
550 which is the gdb.Progspace object of the containing program space.
551 ** gdb.Objfile objects have a new attribute "owner".
552 ** gdb.Objfile objects have a new attribute "build_id",
553 which is the build ID generated when the file was built.
554 ** gdb.Objfile objects have a new method "add_separate_debug_file".
555 ** A new event "gdb.clear_objfiles" has been added, triggered when
556 selecting a new file to debug.
557 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
558 ** New function gdb.lookup_objfile.
560 New events which are triggered when GDB modifies the state of the
563 ** gdb.events.inferior_call_pre: Function call is about to be made.
564 ** gdb.events.inferior_call_post: Function call has just been made.
565 ** gdb.events.memory_changed: A memory location has been altered.
566 ** gdb.events.register_changed: A register has been altered.
568 * New Python-based convenience functions:
570 ** $_caller_is(name [, number_of_frames])
571 ** $_caller_matches(regexp [, number_of_frames])
572 ** $_any_caller_is(name [, number_of_frames])
573 ** $_any_caller_matches(regexp [, number_of_frames])
575 * GDB now supports the compilation and injection of source code into
576 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
577 to compile the source code to object code, and if successful, inject
578 and execute that code within the current context of the inferior.
579 Currently the C language is supported. The commands used to
580 interface with this new feature are:
582 compile code [-raw|-r] [--] [source code]
583 compile file [-raw|-r] filename
587 demangle [-l language] [--] name
588 Demangle "name" in the specified language, or the current language
589 if elided. This command is renamed from the "maint demangle" command.
590 The latter is kept as a no-op to avoid "maint demangle" being interpreted
591 as "maint demangler-warning".
593 queue-signal signal-name-or-number
594 Queue a signal to be delivered to the thread when it is resumed.
596 add-auto-load-scripts-directory directory
597 Add entries to the list of directories from which to load auto-loaded
600 maint print user-registers
601 List all currently available "user" registers.
603 compile code [-r|-raw] [--] [source code]
604 Compile, inject, and execute in the inferior the executable object
605 code produced by compiling the provided source code.
607 compile file [-r|-raw] filename
608 Compile and inject into the inferior the executable object code
609 produced by compiling the source code stored in the filename
612 * On resume, GDB now always passes the signal the program had stopped
613 for to the thread the signal was sent to, even if the user changed
614 threads before resuming. Previously GDB would often (but not
615 always) deliver the signal to the thread that happens to be current
618 * Conversely, the "signal" command now consistently delivers the
619 requested signal to the current thread. GDB now asks for
620 confirmation if the program had stopped for a signal and the user
621 switched threads meanwhile.
623 * "breakpoint always-inserted" modes "off" and "auto" merged.
625 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
626 won't remove breakpoints from the target until all threads stop,
627 even in non-stop mode. The "auto" mode has been removed, and "off"
628 is now the default mode.
632 set debug symbol-lookup
633 show debug symbol-lookup
634 Control display of debugging info regarding symbol lookup.
638 ** The -list-thread-groups command outputs an exit-code field for
639 inferiors that have exited.
643 MIPS SDE mips*-sde*-elf*
647 Support for these obsolete configurations has been removed.
649 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
650 SGI Irix-5.x mips-*-irix5*
651 SGI Irix-6.x mips-*-irix6*
652 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
653 VAX running Ultrix vax-*-ultrix*
655 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
656 and "assf"), have been removed. Use the "sharedlibrary" command, or
657 its alias "share", instead.
659 *** Changes in GDB 7.8
661 * New command line options
664 This is an alias for the --data-directory option.
666 * GDB supports printing and modifying of variable length automatic arrays
667 as specified in ISO C99.
669 * The ARM simulator now supports instruction level tracing
670 with or without disassembly.
674 GDB now has support for scripting using Guile. Whether this is
675 available is determined at configure time.
676 Guile version 2.0 or greater is required.
677 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
679 * New commands (for set/show, see "New options" below)
683 Invoke CODE by passing it to the Guile interpreter.
687 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
689 info auto-load guile-scripts [regexp]
690 Print the list of automatically loaded Guile scripts.
692 * The source command is now capable of sourcing Guile scripts.
693 This feature is dependent on the debugger being built with Guile support.
697 set print symbol-loading (off|brief|full)
698 show print symbol-loading
699 Control whether to print informational messages when loading symbol
700 information for a file. The default is "full", but when debugging
701 programs with large numbers of shared libraries the amount of output
704 set guile print-stack (none|message|full)
705 show guile print-stack
706 Show a stack trace when an error is encountered in a Guile script.
708 set auto-load guile-scripts (on|off)
709 show auto-load guile-scripts
710 Control auto-loading of Guile script files.
712 maint ada set ignore-descriptive-types (on|off)
713 maint ada show ignore-descriptive-types
714 Control whether the debugger should ignore descriptive types in Ada
715 programs. The default is not to ignore the descriptive types. See
716 the user manual for more details on descriptive types and the intended
717 usage of this option.
719 set auto-connect-native-target
721 Control whether GDB is allowed to automatically connect to the
722 native target for the run, attach, etc. commands when not connected
723 to any target yet. See also "target native" below.
725 set record btrace replay-memory-access (read-only|read-write)
726 show record btrace replay-memory-access
727 Control what memory accesses are allowed during replay.
729 maint set target-async (on|off)
730 maint show target-async
731 This controls whether GDB targets operate in synchronous or
732 asynchronous mode. Normally the default is asynchronous, if it is
733 available; but this can be changed to more easily debug problems
734 occurring only in synchronous mode.
736 set mi-async (on|off)
738 Control whether MI asynchronous mode is preferred. This supersedes
739 "set target-async" of previous GDB versions.
741 * "set target-async" is deprecated as a CLI option and is now an alias
742 for "set mi-async" (only puts MI into async mode).
744 * Background execution commands (e.g., "c&", "s&", etc.) are now
745 possible ``out of the box'' if the target supports them. Previously
746 the user would need to explicitly enable the possibility with the
747 "set target-async on" command.
749 * New features in the GDB remote stub, GDBserver
751 ** New option --debug-format=option1[,option2,...] allows one to add
752 additional text to each output. At present only timestamps
753 are supported: --debug-format=timestamps.
754 Timestamps can also be turned on with the
755 "monitor set debug-format timestamps" command from GDB.
757 * The 'record instruction-history' command now starts counting instructions
758 at one. This also affects the instruction ranges reported by the
759 'record function-call-history' command when given the /i modifier.
761 * The command 'record function-call-history' supports a new modifier '/c' to
762 indent the function names based on their call stack depth.
763 The fields for the '/i' and '/l' modifier have been reordered.
764 The source line range is now prefixed with 'at'.
765 The instruction range is now prefixed with 'inst'.
766 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
767 "record instruction-history" and "list" commands.
769 * The ranges given as arguments to the 'record function-call-history' and
770 'record instruction-history' commands are now inclusive.
772 * The btrace record target now supports the 'record goto' command.
773 For locations inside the execution trace, the back trace is computed
774 based on the information stored in the execution trace.
776 * The btrace record target supports limited reverse execution and replay.
777 The target does not record data and therefore does not allow reading
780 * The "catch syscall" command now works on s390*-linux* targets.
782 * The "compare-sections" command is no longer specific to target
783 remote. It now works with all targets.
785 * All native targets are now consistently called "native".
786 Consequently, the "target child", "target GNU", "target djgpp",
787 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
788 commands have been replaced with "target native". The QNX/NTO port
789 leaves the "procfs" target in place and adds a "native" target for
790 consistency with other ports. The impact on users should be minimal
791 as these commands previously either throwed an error, or were
792 no-ops. The target's name is visible in the output of the following
793 commands: "help target", "info target", "info files", "maint print
796 * The "target native" command now connects to the native target. This
797 can be used to launch native programs even when "set
798 auto-connect-native-target" is set to off.
800 * GDB now supports access to Intel MPX registers on GNU/Linux.
802 * Support for Intel AVX-512 registers on GNU/Linux.
803 Support displaying and modifying Intel AVX-512 registers
804 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
808 qXfer:btrace:read's annex
809 The qXfer:btrace:read packet supports a new annex 'delta' to read
810 branch trace incrementally.
814 ** Valid Python operations on gdb.Value objects representing
815 structs/classes invoke the corresponding overloaded operators if
817 ** New `Xmethods' feature in the Python API. Xmethods are
818 additional methods or replacements for existing methods of a C++
819 class. This feature is useful for those cases where a method
820 defined in C++ source code could be inlined or optimized out by
821 the compiler, making it unavailable to GDB.
824 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
826 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
827 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
828 its alias "share", instead.
830 * The commands "set remotebaud" and "show remotebaud" are no longer
831 supported. Use "set serial baud" and "show serial baud" (respectively)
836 ** A new option "-gdb-set mi-async" replaces "-gdb-set
837 target-async". The latter is left as a deprecated alias of the
838 former for backward compatibility. If the target supports it,
839 CLI background execution commands are now always possible by
840 default, independently of whether the frontend stated a
841 preference for asynchronous execution with "-gdb-set mi-async".
842 Previously "-gdb-set target-async off" affected both MI execution
843 commands and CLI execution commands.
845 *** Changes in GDB 7.7
847 * Improved support for process record-replay and reverse debugging on
848 arm*-linux* targets. Support for thumb32 and syscall instruction
849 recording has been added.
851 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
853 * GDB now supports Fission DWP file format version 2.
854 http://gcc.gnu.org/wiki/DebugFission
856 * New convenience function "$_isvoid", to check whether an expression
857 is void. A void expression is an expression where the type of the
858 result is "void". For example, some convenience variables may be
859 "void" when evaluated (e.g., "$_exitcode" before the execution of
860 the program being debugged; or an undefined convenience variable).
861 Another example, when calling a function whose return type is
864 * The "maintenance print objfiles" command now takes an optional regexp.
866 * The "catch syscall" command now works on arm*-linux* targets.
868 * GDB now consistently shows "<not saved>" when printing values of
869 registers the debug info indicates have not been saved in the frame
870 and there's nowhere to retrieve them from
871 (callee-saved/call-clobbered registers):
876 (gdb) info registers rax
879 Before, the former would print "<optimized out>", and the latter
880 "*value not available*".
882 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
887 ** Frame filters and frame decorators have been added.
888 ** Temporary breakpoints are now supported.
889 ** Line tables representation has been added.
890 ** New attribute 'parent_type' for gdb.Field objects.
891 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
892 ** New attribute 'name' for gdb.Type objects.
896 Nios II ELF nios2*-*-elf
897 Nios II GNU/Linux nios2*-*-linux
898 Texas Instruments MSP430 msp430*-*-elf
900 * Removed native configurations
902 Support for these a.out NetBSD and OpenBSD obsolete configurations has
903 been removed. ELF variants of these configurations are kept supported.
905 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
906 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
907 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
908 i[34567]86-*-openbsd3.[0-3]
909 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
910 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
911 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
915 Like "catch throw", but catches a re-thrown exception.
917 Renamed from old "maint check-symtabs".
919 Perform consistency checks on symtabs.
921 Expand symtabs matching an optional regexp.
924 Display the details of GDB configure-time options.
926 maint set|show per-command
927 maint set|show per-command space
928 maint set|show per-command time
929 maint set|show per-command symtab
930 Enable display of per-command gdb resource usage.
932 remove-symbol-file FILENAME
933 remove-symbol-file -a ADDRESS
934 Remove a symbol file added via add-symbol-file. The file to remove
935 can be identified by its filename or by an address that lies within
936 the boundaries of this symbol file in memory.
939 info exceptions REGEXP
940 Display the list of Ada exceptions defined in the program being
941 debugged. If provided, only the exceptions whose names match REGEXP
946 set debug symfile off|on
948 Control display of debugging info regarding reading symbol files and
949 symbol tables within those files
951 set print raw frame-arguments
952 show print raw frame-arguments
953 Set/show whether to print frame arguments in raw mode,
954 disregarding any defined pretty-printers.
956 set remote trace-status-packet
957 show remote trace-status-packet
958 Set/show the use of remote protocol qTStatus packet.
962 Control display of debugging messages related to Nios II targets.
966 Control whether target-assisted range stepping is enabled.
968 set startup-with-shell
969 show startup-with-shell
970 Specifies whether Unix child processes are started via a shell or
975 Use the target memory cache for accesses to the code segment. This
976 improves performance of remote debugging (particularly disassembly).
978 * You can now use a literal value 'unlimited' for options that
979 interpret 0 or -1 as meaning "unlimited". E.g., "set
980 trace-buffer-size unlimited" is now an alias for "set
981 trace-buffer-size -1" and "set height unlimited" is now an alias for
984 * The "set debug symtab-create" debugging option of GDB has been changed to
985 accept a verbosity level. 0 means "off", 1 provides basic debugging
986 output, and values of 2 or greater provides more verbose output.
988 * New command-line options
990 Display the details of GDB configure-time options.
992 * The command 'tsave' can now support new option '-ctf' to save trace
993 buffer in Common Trace Format.
995 * Newly installed $prefix/bin/gcore acts as a shell interface for the
998 * GDB now implements the the C++ 'typeid' operator.
1000 * The new convenience variable $_exception holds the exception being
1001 thrown or caught at an exception-related catchpoint.
1003 * The exception-related catchpoints, like "catch throw", now accept a
1004 regular expression which can be used to filter exceptions by type.
1006 * The new convenience variable $_exitsignal is automatically set to
1007 the terminating signal number when the program being debugged dies
1008 due to an uncaught signal.
1012 ** All MI commands now accept an optional "--language" option.
1013 Support for this feature can be verified by using the "-list-features"
1014 command, which should contain "language-option".
1016 ** The new command -info-gdb-mi-command allows the user to determine
1017 whether a GDB/MI command is supported or not.
1019 ** The "^error" result record returned when trying to execute an undefined
1020 GDB/MI command now provides a variable named "code" whose content is the
1021 "undefined-command" error code. Support for this feature can be verified
1022 by using the "-list-features" command, which should contain
1023 "undefined-command-error-code".
1025 ** The -trace-save MI command can optionally save trace buffer in Common
1028 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1030 ** The command -data-list-register-values now accepts an optional
1031 "--skip-unavailable" option. When used, only the available registers
1034 ** The new command -trace-frame-collected dumps collected variables,
1035 computed expressions, tvars, memory and registers in a traceframe.
1037 ** The commands -stack-list-locals, -stack-list-arguments and
1038 -stack-list-variables now accept an option "--skip-unavailable".
1039 When used, only the available locals or arguments are displayed.
1041 ** The -exec-run command now accepts an optional "--start" option.
1042 When used, the command follows the same semantics as the "start"
1043 command, stopping the program's execution at the start of its
1044 main subprogram. Support for this feature can be verified using
1045 the "-list-features" command, which should contain
1046 "exec-run-start-option".
1048 ** The new commands -catch-assert and -catch-exceptions insert
1049 catchpoints stopping the program when Ada exceptions are raised.
1051 ** The new command -info-ada-exceptions provides the equivalent of
1052 the new "info exceptions" command.
1054 * New system-wide configuration scripts
1055 A GDB installation now provides scripts suitable for use as system-wide
1056 configuration scripts for the following systems:
1060 * GDB now supports target-assigned range stepping with remote targets.
1061 This improves the performance of stepping source lines by reducing
1062 the number of control packets from/to GDB. See "New remote packets"
1065 * GDB now understands the element 'tvar' in the XML traceframe info.
1066 It has the id of the collected trace state variables.
1068 * On S/390 targets that provide the transactional-execution feature,
1069 the program interruption transaction diagnostic block (TDB) is now
1070 represented as a number of additional "registers" in GDB.
1072 * New remote packets
1076 The vCont packet supports a new 'r' action, that tells the remote
1077 stub to step through an address range itself, without GDB
1078 involvemement at each single-step.
1080 qXfer:libraries-svr4:read's annex
1081 The previously unused annex of the qXfer:libraries-svr4:read packet
1082 is now used to support passing an argument list. The remote stub
1083 reports support for this argument list to GDB's qSupported query.
1084 The defined arguments are "start" and "prev", used to reduce work
1085 necessary for library list updating, resulting in significant
1088 * New features in the GDB remote stub, GDBserver
1090 ** GDBserver now supports target-assisted range stepping. Currently
1091 enabled on x86/x86_64 GNU/Linux targets.
1093 ** GDBserver now adds element 'tvar' in the XML in the reply to
1094 'qXfer:traceframe-info:read'. It has the id of the collected
1095 trace state variables.
1097 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1100 * New 'z' formatter for printing and examining memory, this displays the
1101 value as hexadecimal zero padded on the left to the size of the type.
1103 * GDB can now use Windows x64 unwinding data.
1105 * The "set remotebaud" command has been replaced by "set serial baud".
1106 Similarly, "show remotebaud" has been replaced by "show serial baud".
1107 The "set remotebaud" and "show remotebaud" commands are still available
1108 to provide backward compatibility with older versions of GDB.
1110 *** Changes in GDB 7.6
1112 * Target record has been renamed to record-full.
1113 Record/replay is now enabled with the "record full" command.
1114 This also affects settings that are associated with full record/replay
1115 that have been moved from "set/show record" to "set/show record full":
1117 set|show record full insn-number-max
1118 set|show record full stop-at-limit
1119 set|show record full memory-query
1121 * A new record target "record-btrace" has been added. The new target
1122 uses hardware support to record the control-flow of a process. It
1123 does not support replaying the execution, but it implements the
1124 below new commands for investigating the recorded execution log.
1125 This new recording method can be enabled using:
1129 The "record-btrace" target is only available on Intel Atom processors
1130 and requires a Linux kernel 2.6.32 or later.
1132 * Two new commands have been added for record/replay to give information
1133 about the recorded execution without having to replay the execution.
1134 The commands are only supported by "record btrace".
1136 record instruction-history prints the execution history at
1137 instruction granularity
1139 record function-call-history prints the execution history at
1140 function granularity
1142 * New native configurations
1144 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1145 FreeBSD/powerpc powerpc*-*-freebsd
1146 x86_64/Cygwin x86_64-*-cygwin*
1147 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1151 ARM AArch64 aarch64*-*-elf
1152 ARM AArch64 GNU/Linux aarch64*-*-linux
1153 Lynx 178 PowerPC powerpc-*-lynx*178
1154 x86_64/Cygwin x86_64-*-cygwin*
1155 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1157 * If the configured location of system.gdbinit file (as given by the
1158 --with-system-gdbinit option at configure time) is in the
1159 data-directory (as specified by --with-gdb-datadir at configure
1160 time) or in one of its subdirectories, then GDB will look for the
1161 system-wide init file in the directory specified by the
1162 --data-directory command-line option.
1164 * New command line options:
1166 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1167 other initialization files, unlike -nx which disables all of them.
1169 * Removed command line options
1171 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1174 * The 'ptype' and 'whatis' commands now accept an argument to control
1177 * 'info proc' now works on some core files.
1181 ** Vectors can be created with gdb.Type.vector.
1183 ** Python's atexit.register now works in GDB.
1185 ** Types can be pretty-printed via a Python API.
1187 ** Python 3 is now supported (in addition to Python 2.4 or later)
1189 ** New class gdb.Architecture exposes GDB's internal representation
1190 of architecture in the Python API.
1192 ** New method Frame.architecture returns the gdb.Architecture object
1193 corresponding to the frame's architecture.
1195 * New Python-based convenience functions:
1197 ** $_memeq(buf1, buf2, length)
1198 ** $_streq(str1, str2)
1200 ** $_regex(str, regex)
1202 * The 'cd' command now defaults to using '~' (the home directory) if not
1205 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1206 default for GCC since November 2000.
1208 * The command 'forward-search' can now be abbreviated as 'fo'.
1210 * The command 'info tracepoints' can now display 'installed on target'
1211 or 'not installed on target' for each non-pending location of tracepoint.
1213 * New configure options
1215 --enable-libmcheck/--disable-libmcheck
1216 By default, development versions are built with -lmcheck on hosts
1217 that support it, in order to help track memory corruption issues.
1218 Release versions, on the other hand, are built without -lmcheck
1219 by default. The --enable-libmcheck/--disable-libmcheck configure
1220 options allow the user to override that default.
1221 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1222 This configure option allows the user to build GDB with
1223 libbabeltrace using which GDB can read Common Trace Format data.
1225 * New commands (for set/show, see "New options" below)
1228 Catch signals. This is similar to "handle", but allows commands and
1229 conditions to be attached.
1232 List the BFDs known to GDB.
1234 python-interactive [command]
1236 Start a Python interactive prompt, or evaluate the optional command
1237 and print the result of expressions.
1240 "py" is a new alias for "python".
1242 enable type-printer [name]...
1243 disable type-printer [name]...
1244 Enable or disable type printers.
1248 ** For the Renesas Super-H architecture, the "regs" command has been removed
1249 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1254 set print type methods (on|off)
1255 show print type methods
1256 Control whether method declarations are displayed by "ptype".
1257 The default is to show them.
1259 set print type typedefs (on|off)
1260 show print type typedefs
1261 Control whether typedef definitions are displayed by "ptype".
1262 The default is to show them.
1264 set filename-display basename|relative|absolute
1265 show filename-display
1266 Control the way in which filenames is displayed.
1267 The default is "relative", which preserves previous behavior.
1269 set trace-buffer-size
1270 show trace-buffer-size
1271 Request target to change the size of trace buffer.
1273 set remote trace-buffer-size-packet auto|on|off
1274 show remote trace-buffer-size-packet
1275 Control the use of the remote protocol `QTBuffer:size' packet.
1279 Control display of debugging messages related to ARM AArch64.
1282 set debug coff-pe-read
1283 show debug coff-pe-read
1284 Control display of debugging messages related to reading of COFF/PE
1289 Control display of debugging messages related to Mach-O symbols
1292 set debug notification
1293 show debug notification
1294 Control display of debugging info for async remote notification.
1298 ** Command parameter changes are now notified using new async record
1299 "=cmd-param-changed".
1300 ** Trace frame changes caused by command "tfind" are now notified using
1301 new async record "=traceframe-changed".
1302 ** The creation, deletion and modification of trace state variables
1303 are now notified using new async records "=tsv-created",
1304 "=tsv-deleted" and "=tsv-modified".
1305 ** The start and stop of process record are now notified using new
1306 async record "=record-started" and "=record-stopped".
1307 ** Memory changes are now notified using new async record
1309 ** The data-disassemble command response will include a "fullname" field
1310 containing the absolute file name when source has been requested.
1311 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1312 command, to allow pattern filling of memory areas.
1313 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1314 library load/unload events.
1315 ** The response to breakpoint commands and breakpoint async records
1316 includes an "installed" field containing a boolean state about each
1317 non-pending tracepoint location is whether installed on target or not.
1318 ** Output of the "-trace-status" command includes a "trace-file" field
1319 containing the name of the trace file being examined. This field is
1320 optional, and only present when examining a trace file.
1321 ** The "fullname" field is now always present along with the "file" field,
1322 even if the file cannot be found by GDB.
1324 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1325 You must have the LZMA library available when configuring GDB for this
1326 feature to be enabled. For more information, see:
1327 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1329 * New remote packets
1332 Set the size of trace buffer. The remote stub reports support for this
1333 packet to gdb's qSupported query.
1336 Enable Branch Trace Store (BTS)-based branch tracing for the current
1337 thread. The remote stub reports support for this packet to gdb's
1341 Disable branch tracing for the current thread. The remote stub reports
1342 support for this packet to gdb's qSupported query.
1345 Read the traced branches for the current thread. The remote stub
1346 reports support for this packet to gdb's qSupported query.
1348 *** Changes in GDB 7.5
1350 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1351 for more x32 ABI info.
1353 * GDB now supports access to MIPS DSP registers on Linux targets.
1355 * GDB now supports debugging microMIPS binaries.
1357 * The "info os" command on GNU/Linux can now display information on
1358 several new classes of objects managed by the operating system:
1359 "info os procgroups" lists process groups
1360 "info os files" lists file descriptors
1361 "info os sockets" lists internet-domain sockets
1362 "info os shm" lists shared-memory regions
1363 "info os semaphores" lists semaphores
1364 "info os msg" lists message queues
1365 "info os modules" lists loaded kernel modules
1367 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1368 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1369 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1370 options and inspect the probe arguments using the new $_probe_arg family
1371 of convenience variables. You can obtain more information about SystemTap
1372 in <http://sourceware.org/systemtap/>.
1374 * GDB now supports reversible debugging on ARM, it allows you to
1375 debug basic ARM and THUMB instructions, and provides
1376 record/replay support.
1378 * The option "symbol-reloading" has been deleted as it is no longer used.
1382 ** GDB commands implemented in Python can now be put in command class
1385 ** The "maint set python print-stack on|off" is now deleted.
1387 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1388 apply "flag enum"-style pretty-printing to any enum.
1390 ** gdb.lookup_symbol can now work when there is no current frame.
1392 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1393 the source at which the symbol was defined.
1395 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1396 method 'value'. The former indicates whether the symbol needs a
1397 frame in order to compute its value, and the latter computes the
1400 ** A new method 'referenced_value' on gdb.Value objects which can
1401 dereference pointer as well as C++ reference values.
1403 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1404 which return the global and static blocks (as gdb.Block objects),
1405 of the underlying symbol table, respectively.
1407 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1408 object associated with a PC value.
1410 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1411 of the address range occupied by code for the current source line.
1413 * Go language support.
1414 GDB now supports debugging programs written in the Go programming
1417 * GDBserver now supports stdio connections.
1418 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1420 * The binary "gdbtui" can no longer be built or installed.
1421 Use "gdb -tui" instead.
1423 * GDB will now print "flag" enums specially. A flag enum is one where
1424 all the enumerator values have no bits in common when pairwise
1425 "and"ed. When printing a value whose type is a flag enum, GDB will
1426 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1427 (gdb) print (enum E) 3
1430 * The filename part of a linespec will now match trailing components
1431 of a source file name. For example, "break gcc/expr.c:1000" will
1432 now set a breakpoint in build/gcc/expr.c, but not
1433 build/libcpp/expr.c.
1435 * The "info proc" and "generate-core-file" commands will now also
1436 work on remote targets connected to GDBserver on Linux.
1438 * The command "info catch" has been removed. It has been disabled
1439 since December 2007.
1441 * The "catch exception" and "catch assert" commands now accept
1442 a condition at the end of the command, much like the "break"
1443 command does. For instance:
1445 (gdb) catch exception Constraint_Error if Barrier = True
1447 Previously, it was possible to add a condition to such catchpoints,
1448 but it had to be done as a second step, after the catchpoint had been
1449 created, using the "condition" command.
1451 * The "info static-tracepoint-marker" command will now also work on
1452 native Linux targets with in-process agent.
1454 * GDB can now set breakpoints on inlined functions.
1456 * The .gdb_index section has been updated to include symbols for
1457 inlined functions. GDB will ignore older .gdb_index sections by
1458 default, which could cause symbol files to be loaded more slowly
1459 until their .gdb_index sections can be recreated. The new command
1460 "set use-deprecated-index-sections on" will cause GDB to use any older
1461 .gdb_index sections it finds. This will restore performance, but the
1462 ability to set breakpoints on inlined functions will be lost in symbol
1463 files with older .gdb_index sections.
1465 The .gdb_index section has also been updated to record more information
1466 about each symbol. This speeds up the "info variables", "info functions"
1467 and "info types" commands when used with programs having the .gdb_index
1468 section, as well as speeding up debugging with shared libraries using
1469 the .gdb_index section.
1471 * Ada support for GDB/MI Variable Objects has been added.
1473 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1478 ** New command -info-os is the MI equivalent of "info os".
1480 ** Output logs ("set logging" and related) now include MI output.
1484 ** "set use-deprecated-index-sections on|off"
1485 "show use-deprecated-index-sections on|off"
1486 Controls the use of deprecated .gdb_index sections.
1488 ** "catch load" and "catch unload" can be used to stop when a shared
1489 library is loaded or unloaded, respectively.
1491 ** "enable count" can be used to auto-disable a breakpoint after
1494 ** "info vtbl" can be used to show the virtual method tables for
1495 C++ and Java objects.
1497 ** "explore" and its sub commands "explore value" and "explore type"
1498 can be used to recursively explore values and types of
1499 expressions. These commands are available only if GDB is
1500 configured with '--with-python'.
1502 ** "info auto-load" shows status of all kinds of auto-loaded files,
1503 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1504 sequences of commands files, "info auto-load python-scripts"
1505 shows status of auto-loading Python script files,
1506 "info auto-load local-gdbinit" shows status of loading init file
1507 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1508 status of inferior specific thread debugging shared library loading.
1510 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1511 and "show auto-load-scripts" commands have been deprecated, use their
1512 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1513 and "show auto-load python-scripts" counterparts instead.
1515 ** "dprintf location,format,args..." creates a dynamic printf, which
1516 is basically a breakpoint that does a printf and immediately
1517 resumes your program's execution, so it is like a printf that you
1518 can insert dynamically at runtime instead of at compiletime.
1520 ** "set print symbol"
1522 Controls whether GDB attempts to display the symbol, if any,
1523 corresponding to addresses it prints. This defaults to "on", but
1524 you can set it to "off" to restore GDB's previous behavior.
1526 * Deprecated commands
1528 ** For the Renesas Super-H architecture, the "regs" command has been
1529 deprecated, and "info all-registers" should be used instead.
1533 Renesas RL78 rl78-*-elf
1534 HP OpenVMS ia64 ia64-hp-openvms*
1536 * GDBserver supports evaluation of breakpoint conditions. When
1537 support is advertised by GDBserver, GDB may be told to send the
1538 breakpoint conditions in bytecode form to GDBserver. GDBserver
1539 will only report the breakpoint trigger to GDB when its condition
1544 set mips compression
1545 show mips compression
1546 Select the compressed ISA encoding used in functions that have no symbol
1547 information available. The encoding can be set to either of:
1550 and is updated automatically from ELF file flags if available.
1552 set breakpoint condition-evaluation
1553 show breakpoint condition-evaluation
1554 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1555 GDBserver ("target"). Default option "auto" chooses the most efficient
1557 This option can improve debugger efficiency depending on the speed of the
1561 Disable auto-loading globally.
1564 Show auto-loading setting of all kinds of auto-loaded files.
1566 set auto-load gdb-scripts on|off
1567 show auto-load gdb-scripts
1568 Control auto-loading of GDB canned sequences of commands files.
1570 set auto-load python-scripts on|off
1571 show auto-load python-scripts
1572 Control auto-loading of Python script files.
1574 set auto-load local-gdbinit on|off
1575 show auto-load local-gdbinit
1576 Control loading of init file (.gdbinit) from current directory.
1578 set auto-load libthread-db on|off
1579 show auto-load libthread-db
1580 Control auto-loading of inferior specific thread debugging shared library.
1582 set auto-load scripts-directory <dir1>[:<dir2>...]
1583 show auto-load scripts-directory
1584 Set a list of directories from which to load auto-loaded scripts.
1585 Automatically loaded Python scripts and GDB scripts are located in one
1586 of the directories listed by this option.
1587 The delimiter (':' above) may differ according to the host platform.
1589 set auto-load safe-path <dir1>[:<dir2>...]
1590 show auto-load safe-path
1591 Set a list of directories from which it is safe to auto-load files.
1592 The delimiter (':' above) may differ according to the host platform.
1594 set debug auto-load on|off
1595 show debug auto-load
1596 Control display of debugging info for auto-loading the files above.
1598 set dprintf-style gdb|call|agent
1600 Control the way in which a dynamic printf is performed; "gdb"
1601 requests a GDB printf command, while "call" causes dprintf to call a
1602 function in the inferior. "agent" requests that the target agent
1603 (such as GDBserver) do the printing.
1605 set dprintf-function <expr>
1606 show dprintf-function
1607 set dprintf-channel <expr>
1608 show dprintf-channel
1609 Set the function and optional first argument to the call when using
1610 the "call" style of dynamic printf.
1612 set disconnected-dprintf on|off
1613 show disconnected-dprintf
1614 Control whether agent-style dynamic printfs continue to be in effect
1615 after GDB disconnects.
1617 * New configure options
1619 --with-auto-load-dir
1620 Configure default value for the 'set auto-load scripts-directory'
1621 setting above. It defaults to '$debugdir:$datadir/auto-load',
1622 $debugdir representing global debugging info directories (available
1623 via 'show debug-file-directory') and $datadir representing GDB's data
1624 directory (available via 'show data-directory').
1626 --with-auto-load-safe-path
1627 Configure default value for the 'set auto-load safe-path' setting
1628 above. It defaults to the --with-auto-load-dir setting.
1630 --without-auto-load-safe-path
1631 Set 'set auto-load safe-path' to '/', effectively disabling this
1634 * New remote packets
1636 z0/z1 conditional breakpoints extension
1638 The z0/z1 breakpoint insertion packets have been extended to carry
1639 a list of conditional expressions over to the remote stub depending on the
1640 condition evaluation mode. The use of this extension can be controlled
1641 via the "set remote conditional-breakpoints-packet" command.
1645 Specify the signals which the remote stub may pass to the debugged
1646 program without GDB involvement.
1648 * New command line options
1650 --init-command=FILE, -ix Like --command, -x but execute it
1651 before loading inferior.
1652 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1653 execute it before loading inferior.
1655 *** Changes in GDB 7.4
1657 * GDB now handles ambiguous linespecs more consistently; the existing
1658 FILE:LINE support has been expanded to other types of linespecs. A
1659 breakpoint will now be set on all matching locations in all
1660 inferiors, and locations will be added or removed according to
1663 * GDB now allows you to skip uninteresting functions and files when
1664 stepping with the "skip function" and "skip file" commands.
1666 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1667 and "show remote hardware-watchpoint-length-limit". These allows to
1668 set or show the maximum length limit (in bytes) of a remote
1669 target hardware watchpoint.
1671 This allows e.g. to use "unlimited" hardware watchpoints with the
1672 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1673 watchpoints are slower than real hardware watchpoints but are
1674 significantly faster than gdb software watchpoints.
1678 ** The register_pretty_printer function in module gdb.printing now takes
1679 an optional `replace' argument. If True, the new printer replaces any
1682 ** The "maint set python print-stack on|off" command has been
1683 deprecated and will be deleted in GDB 7.5.
1684 A new command: "set python print-stack none|full|message" has
1685 replaced it. Additionally, the default for "print-stack" is
1686 now "message", which just prints the error message without
1689 ** A prompt substitution hook (prompt_hook) is now available to the
1692 ** A new Python module, gdb.prompt has been added to the GDB Python
1693 modules library. This module provides functionality for
1694 escape sequences in prompts (used by set/show
1695 extended-prompt). These escape sequences are replaced by their
1696 corresponding value.
1698 ** Python commands and convenience-functions located in
1699 'data-directory'/python/gdb/command and
1700 'data-directory'/python/gdb/function are now automatically loaded
1703 ** Blocks now provide four new attributes. global_block and
1704 static_block will return the global and static blocks
1705 respectively. is_static and is_global are boolean attributes
1706 that indicate if the block is one of those two types.
1708 ** Symbols now provide the "type" attribute, the type of the symbol.
1710 ** The "gdb.breakpoint" function has been deprecated in favor of
1713 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1714 of a function. This class is based on the "finish" command
1715 available in the CLI.
1717 ** Type objects for struct and union types now allow access to
1718 the fields using standard Python dictionary (mapping) methods.
1719 For example, "some_type['myfield']" now works, as does
1720 "some_type.items()".
1722 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1725 ** A new function, "deep_items" has been added to the gdb.types
1726 module in the GDB Python modules library. This function returns
1727 an iterator over the fields of a struct or union type. Unlike
1728 the standard Python "iteritems" method, it will recursively traverse
1729 any anonymous fields.
1733 ** "*stopped" events can report several new "reason"s, such as
1736 ** Breakpoint changes are now notified using new async records, like
1737 "=breakpoint-modified".
1739 ** New command -ada-task-info.
1741 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1742 $sdir specifies the default system locations of shared libraries.
1743 $pdir specifies the directory where the libpthread used by the application
1746 GDB no longer looks in $sdir and $pdir after it has searched the directories
1747 mentioned in libthread-db-search-path. If you want to search those
1748 directories, they must be specified in libthread-db-search-path.
1749 The default value of libthread-db-search-path on GNU/Linux and Solaris
1750 systems is now "$sdir:$pdir".
1752 $pdir is not supported by gdbserver, it is currently ignored.
1753 $sdir is supported by gdbserver.
1755 * New configure option --with-iconv-bin.
1756 When using the internationalization support like the one in the GNU C
1757 library, GDB will invoke the "iconv" program to get a list of supported
1758 character sets. If this program lives in a non-standard location, one can
1759 use this option to specify where to find it.
1761 * When natively debugging programs on PowerPC BookE processors running
1762 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1763 watchpoints, which specify a mask in addition to an address to watch.
1764 The mask specifies that some bits of an address (the bits which are
1765 reset in the mask) should be ignored when matching the address accessed
1766 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1767 section in the user manual for more details.
1769 * The new option --once causes GDBserver to stop listening for connections once
1770 the first connection is made. The listening port used by GDBserver will
1771 become available after that.
1773 * New commands "info macros" and "alias" have been added.
1775 * New function parameters suffix @entry specifies value of function parameter
1776 at the time the function got called. Entry values are available only since
1782 "!" is now an alias of the "shell" command.
1783 Note that no space is needed between "!" and SHELL COMMAND.
1787 watch EXPRESSION mask MASK_VALUE
1788 The watch command now supports the mask argument which allows creation
1789 of masked watchpoints, if the current architecture supports this feature.
1791 info auto-load-scripts [REGEXP]
1792 This command was formerly named "maintenance print section-scripts".
1793 It is now generally useful and is no longer a maintenance-only command.
1795 info macro [-all] [--] MACRO
1796 The info macro command has new options `-all' and `--'. The first for
1797 printing all definitions of a macro. The second for explicitly specifying
1798 the end of arguments and the beginning of the macro name in case the macro
1799 name starts with a hyphen.
1801 collect[/s] EXPRESSIONS
1802 The tracepoint collect command now takes an optional modifier "/s"
1803 that directs it to dereference pointer-to-character types and
1804 collect the bytes of memory up to a zero byte. The behavior is
1805 similar to what you see when you use the regular print command on a
1806 string. An optional integer following the "/s" sets a bound on the
1807 number of bytes that will be collected.
1810 The trace start command now interprets any supplied arguments as a
1811 note to be recorded with the trace run, with an effect similar to
1812 setting the variable trace-notes.
1815 The trace stop command now interprets any arguments as a note to be
1816 mentioned along with the tstatus report that the trace was stopped
1817 with a command. The effect is similar to setting the variable
1820 * Tracepoints can now be enabled and disabled at any time after a trace
1821 experiment has been started using the standard "enable" and "disable"
1822 commands. It is now possible to start a trace experiment with no enabled
1823 tracepoints; GDB will display a warning, but will allow the experiment to
1824 begin, assuming that tracepoints will be enabled as needed while the trace
1827 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1828 locations with 4-byte instructions, when they were previously
1829 limited to locations with instructions of 5 bytes or longer.
1833 set debug dwarf2-read
1834 show debug dwarf2-read
1835 Turns on or off display of debugging messages related to reading
1836 DWARF debug info. The default is off.
1838 set debug symtab-create
1839 show debug symtab-create
1840 Turns on or off display of debugging messages related to symbol table
1841 creation. The default is off.
1844 show extended-prompt
1845 Set the GDB prompt, and allow escape sequences to be inserted to
1846 display miscellaneous information (see 'help set extended-prompt'
1847 for the list of sequences). This prompt (and any information
1848 accessed through the escape sequences) is updated every time the
1849 prompt is displayed.
1851 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1852 show print entry-values
1853 Set printing of frame argument values at function entry. In some cases
1854 GDB can determine the value of function argument which was passed by the
1855 function caller, even if the value was modified inside the called function.
1857 set debug entry-values
1858 show debug entry-values
1859 Control display of debugging info for determining frame argument values at
1860 function entry and virtual tail call frames.
1862 set basenames-may-differ
1863 show basenames-may-differ
1864 Set whether a source file may have multiple base names.
1865 (A "base name" is the name of a file with the directory part removed.
1866 Example: The base name of "/home/user/hello.c" is "hello.c".)
1867 If set, GDB will canonicalize file names (e.g., expand symlinks)
1868 before comparing them. Canonicalization is an expensive operation,
1869 but it allows the same file be known by more than one base name.
1870 If not set (the default), all source files are assumed to have just
1871 one base name, and gdb will do file name comparisons more efficiently.
1877 Set a user name and notes for the current and any future trace runs.
1878 This is useful for long-running and/or disconnected traces, to
1879 inform others (or yourself) as to who is running the trace, supply
1880 contact information, or otherwise explain what is going on.
1882 set trace-stop-notes
1883 show trace-stop-notes
1884 Set a note attached to the trace run, that is displayed when the
1885 trace has been stopped by a tstop command. This is useful for
1886 instance as an explanation, if you are stopping a trace run that was
1887 started by someone else.
1889 * New remote packets
1893 Dynamically enable a tracepoint in a started trace experiment.
1897 Dynamically disable a tracepoint in a started trace experiment.
1901 Set the user and notes of the trace run.
1905 Query the current status of a tracepoint.
1909 Query the minimum length of instruction at which a fast tracepoint may
1912 * Dcache size (number of lines) and line-size are now runtime-configurable
1913 via "set dcache line" and "set dcache line-size" commands.
1917 Texas Instruments TMS320C6x tic6x-*-*
1921 Renesas RL78 rl78-*-elf
1923 *** Changes in GDB 7.3.1
1925 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1927 *** Changes in GDB 7.3
1929 * GDB has a new command: "thread find [REGEXP]".
1930 It finds the thread id whose name, target id, or thread extra info
1931 matches the given regular expression.
1933 * The "catch syscall" command now works on mips*-linux* targets.
1935 * The -data-disassemble MI command now supports modes 2 and 3 for
1936 dumping the instruction opcodes.
1938 * New command line options
1940 -data-directory DIR Specify DIR as the "data-directory".
1941 This is mostly for testing purposes.
1943 * The "maint set python auto-load on|off" command has been renamed to
1944 "set auto-load-scripts on|off".
1946 * GDB has a new command: "set directories".
1947 It is like the "dir" command except that it replaces the
1948 source path list instead of augmenting it.
1950 * GDB now understands thread names.
1952 On GNU/Linux, "info threads" will display the thread name as set by
1953 prctl or pthread_setname_np.
1955 There is also a new command, "thread name", which can be used to
1956 assign a name internally for GDB to display.
1959 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1960 has been integrated into GDB.
1964 ** The function gdb.Write now accepts an optional keyword 'stream'.
1965 This keyword, when provided, will direct the output to either
1966 stdout, stderr, or GDB's logging output.
1968 ** Parameters can now be be sub-classed in Python, and in particular
1969 you may implement the get_set_doc and get_show_doc functions.
1970 This improves how Parameter set/show documentation is processed
1971 and allows for more dynamic content.
1973 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1974 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1975 have an is_valid method.
1977 ** Breakpoints can now be sub-classed in Python, and in particular
1978 you may implement a 'stop' function that is executed each time
1979 the inferior reaches that breakpoint.
1981 ** New function gdb.lookup_global_symbol looks up a global symbol.
1983 ** GDB values in Python are now callable if the value represents a
1984 function. For example, if 'some_value' represents a function that
1985 takes two integer parameters and returns a value, you can call
1986 that function like so:
1988 result = some_value (10,20)
1990 ** Module gdb.types has been added.
1991 It contains a collection of utilities for working with gdb.Types objects:
1992 get_basic_type, has_field, make_enum_dict.
1994 ** Module gdb.printing has been added.
1995 It contains utilities for writing and registering pretty-printers.
1996 New classes: PrettyPrinter, SubPrettyPrinter,
1997 RegexpCollectionPrettyPrinter.
1998 New function: register_pretty_printer.
2000 ** New commands "info pretty-printers", "enable pretty-printer" and
2001 "disable pretty-printer" have been added.
2003 ** gdb.parameter("directories") is now available.
2005 ** New function gdb.newest_frame returns the newest frame in the
2008 ** The gdb.InferiorThread class has a new "name" attribute. This
2009 holds the thread's name.
2011 ** Python Support for Inferior events.
2012 Python scripts can add observers to be notified of events
2013 occurring in the process being debugged.
2014 The following events are currently supported:
2015 - gdb.events.cont Continue event.
2016 - gdb.events.exited Inferior exited event.
2017 - gdb.events.stop Signal received, and Breakpoint hit events.
2021 ** GDB now puts template parameters in scope when debugging in an
2022 instantiation. For example, if you have:
2024 template<int X> int func (void) { return X; }
2026 then if you step into func<5>, "print X" will show "5". This
2027 feature requires proper debuginfo support from the compiler; it
2028 was added to GCC 4.5.
2030 ** The motion commands "next", "finish", "until", and "advance" now
2031 work better when exceptions are thrown. In particular, GDB will
2032 no longer lose control of the inferior; instead, the GDB will
2033 stop the inferior at the point at which the exception is caught.
2034 This functionality requires a change in the exception handling
2035 code that was introduced in GCC 4.5.
2037 * GDB now follows GCC's rules on accessing volatile objects when
2038 reading or writing target state during expression evaluation.
2039 One notable difference to prior behavior is that "print x = 0"
2040 no longer generates a read of x; the value of the assignment is
2041 now always taken directly from the value being assigned.
2043 * GDB now has some support for using labels in the program's source in
2044 linespecs. For instance, you can use "advance label" to continue
2045 execution to a label.
2047 * GDB now has support for reading and writing a new .gdb_index
2048 section. This section holds a fast index of DWARF debugging
2049 information and can be used to greatly speed up GDB startup and
2050 operation. See the documentation for `save gdb-index' for details.
2052 * The "watch" command now accepts an optional "-location" argument.
2053 When used, this causes GDB to watch the memory referred to by the
2054 expression. Such a watchpoint is never deleted due to it going out
2057 * GDB now supports thread debugging of core dumps on GNU/Linux.
2059 GDB now activates thread debugging using the libthread_db library
2060 when debugging GNU/Linux core dumps, similarly to when debugging
2061 live processes. As a result, when debugging a core dump file, GDB
2062 is now able to display pthread_t ids of threads. For example, "info
2063 threads" shows the same output as when debugging the process when it
2064 was live. In earlier releases, you'd see something like this:
2067 * 1 LWP 6780 main () at main.c:10
2069 While now you see this:
2072 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2074 It is also now possible to inspect TLS variables when debugging core
2077 When debugging a core dump generated on a machine other than the one
2078 used to run GDB, you may need to point GDB at the correct
2079 libthread_db library with the "set libthread-db-search-path"
2080 command. See the user manual for more details on this command.
2082 * When natively debugging programs on PowerPC BookE processors running
2083 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2084 which stop execution of the inferior whenever it executes an instruction
2085 at any address within the specified range. See the "PowerPC Embedded"
2086 section in the user manual for more details.
2088 * New features in the GDB remote stub, GDBserver
2090 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2091 and i686 LynxOS (version 5.x).
2093 ** GDBserver is now supported on Blackfin Linux.
2095 * New native configurations
2097 ia64 HP-UX ia64-*-hpux*
2101 Analog Devices, Inc. Blackfin Processor bfin-*
2103 * Ada task switching is now supported on sparc-elf targets when
2104 debugging a program using the Ravenscar Profile. For more information,
2105 see the "Tasking Support when using the Ravenscar Profile" section
2106 in the GDB user manual.
2108 * Guile support was removed.
2110 * New features in the GNU simulator
2112 ** The --map-info flag lists all known core mappings.
2114 ** CFI flashes may be simulated via the "cfi" device.
2116 *** Changes in GDB 7.2
2118 * Shared library support for remote targets by default
2120 When GDB is configured for a generic, non-OS specific target, like
2121 for example, --target=arm-eabi or one of the many *-*-elf targets,
2122 GDB now queries remote stubs for loaded shared libraries using the
2123 `qXfer:libraries:read' packet. Previously, shared library support
2124 was always disabled for such configurations.
2128 ** Argument Dependent Lookup (ADL)
2130 In C++ ADL lookup directs function search to the namespaces of its
2131 arguments even if the namespace has not been imported.
2141 Here the compiler will search for `foo' in the namespace of 'b'
2142 and find A::foo. GDB now supports this. This construct is commonly
2143 used in the Standard Template Library for operators.
2145 ** Improved User Defined Operator Support
2147 In addition to member operators, GDB now supports lookup of operators
2148 defined in a namespace and imported with a `using' directive, operators
2149 defined in the global scope, operators imported implicitly from an
2150 anonymous namespace, and the ADL operators mentioned in the previous
2152 GDB now also supports proper overload resolution for all the previously
2153 mentioned flavors of operators.
2155 ** static const class members
2157 Printing of static const class members that are initialized in the
2158 class definition has been fixed.
2160 * Windows Thread Information Block access.
2162 On Windows targets, GDB now supports displaying the Windows Thread
2163 Information Block (TIB) structure. This structure is visible either
2164 by using the new command `info w32 thread-information-block' or, by
2165 dereferencing the new convenience variable named `$_tlb', a
2166 thread-specific pointer to the TIB. This feature is also supported
2167 when remote debugging using GDBserver.
2169 * Static tracepoints
2171 Static tracepoints are calls in the user program into a tracing
2172 library. One such library is a port of the LTTng kernel tracer to
2173 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2174 When debugging with GDBserver, GDB now supports combining the GDB
2175 tracepoint machinery with such libraries. For example: the user can
2176 use GDB to probe a static tracepoint marker (a call from the user
2177 program into the tracing library) with the new "strace" command (see
2178 "New commands" below). This creates a "static tracepoint" in the
2179 breakpoint list, that can be manipulated with the same feature set
2180 as fast and regular tracepoints. E.g., collect registers, local and
2181 global variables, collect trace state variables, and define
2182 tracepoint conditions. In addition, the user can collect extra
2183 static tracepoint marker specific data, by collecting the new
2184 $_sdata internal variable. When analyzing the trace buffer, you can
2185 inspect $_sdata like any other variable available to GDB. For more
2186 information, see the "Tracepoints" chapter in GDB user manual. New
2187 remote packets have been defined to support static tracepoints, see
2188 the "New remote packets" section below.
2190 * Better reconstruction of tracepoints after disconnected tracing
2192 GDB will attempt to download the original source form of tracepoint
2193 definitions when starting a trace run, and then will upload these
2194 upon reconnection to the target, resulting in a more accurate
2195 reconstruction of the tracepoints that are in use on the target.
2199 You can now exercise direct control over the ways that GDB can
2200 affect your program. For instance, you can disallow the setting of
2201 breakpoints, so that the program can run continuously (assuming
2202 non-stop mode). In addition, the "observer" variable is available
2203 to switch all of the different controls; in observer mode, GDB
2204 cannot affect the target's behavior at all, which is useful for
2205 tasks like diagnosing live systems in the field.
2207 * The new convenience variable $_thread holds the number of the
2210 * New remote packets
2214 Return the address of the Windows Thread Information Block of a given thread.
2218 In response to several of the tracepoint packets, the target may now
2219 also respond with a number of intermediate `qRelocInsn' request
2220 packets before the final result packet, to have GDB handle
2221 relocating an instruction to execute at a different address. This
2222 is particularly useful for stubs that support fast tracepoints. GDB
2223 reports support for this feature in the qSupported packet.
2227 List static tracepoint markers in the target program.
2231 List static tracepoint markers at a given address in the target
2234 qXfer:statictrace:read
2236 Read the static trace data collected (by a `collect $_sdata'
2237 tracepoint action). The remote stub reports support for this packet
2238 to gdb's qSupported query.
2242 Send the current settings of GDB's permission flags.
2246 Send part of the source (textual) form of a tracepoint definition,
2247 which includes location, conditional, and action list.
2249 * The source command now accepts a -s option to force searching for the
2250 script in the source search path even if the script name specifies
2253 * New features in the GDB remote stub, GDBserver
2255 - GDBserver now support tracepoints (including fast tracepoints, and
2256 static tracepoints). The feature is currently supported by the
2257 i386-linux and amd64-linux builds. See the "Tracepoints support
2258 in gdbserver" section in the manual for more information.
2260 GDBserver JIT compiles the tracepoint's conditional agent
2261 expression bytecode into native code whenever possible for low
2262 overhead dynamic tracepoints conditionals. For such tracepoints,
2263 an expression that examines program state is evaluated when the
2264 tracepoint is reached, in order to determine whether to capture
2265 trace data. If the condition is simple and false, processing the
2266 tracepoint finishes very quickly and no data is gathered.
2268 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2269 for static tracepoints support.
2271 - GDBserver now supports x86_64 Windows 64-bit debugging.
2273 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2274 it understands register description.
2276 * The --batch flag now disables pagination and queries.
2278 * X86 general purpose registers
2280 GDB now supports reading/writing byte, word and double-word x86
2281 general purpose registers directly. This means you can use, say,
2282 $ah or $ax to refer, respectively, to the byte register AH and
2283 16-bit word register AX that are actually portions of the 32-bit
2284 register EAX or 64-bit register RAX.
2286 * The `commands' command now accepts a range of breakpoints to modify.
2287 A plain `commands' following a command that creates multiple
2288 breakpoints affects all the breakpoints set by that command. This
2289 applies to breakpoints set by `rbreak', and also applies when a
2290 single `break' command creates multiple breakpoints (e.g.,
2291 breakpoints on overloaded c++ functions).
2293 * The `rbreak' command now accepts a filename specification as part of
2294 its argument, limiting the functions selected by the regex to those
2295 in the specified file.
2297 * Support for remote debugging Windows and SymbianOS shared libraries
2298 from Unix hosts has been improved. Non Windows GDB builds now can
2299 understand target reported file names that follow MS-DOS based file
2300 system semantics, such as file names that include drive letters and
2301 use the backslash character as directory separator. This makes it
2302 possible to transparently use the "set sysroot" and "set
2303 solib-search-path" on Unix hosts to point as host copies of the
2304 target's shared libraries. See the new command "set
2305 target-file-system-kind" described below, and the "Commands to
2306 specify files" section in the user manual for more information.
2310 eval template, expressions...
2311 Convert the values of one or more expressions under the control
2312 of the string template to a command line, and call it.
2314 set target-file-system-kind unix|dos-based|auto
2315 show target-file-system-kind
2316 Set or show the assumed file system kind for target reported file
2319 save breakpoints <filename>
2320 Save all current breakpoint definitions to a file suitable for use
2321 in a later debugging session. To read the saved breakpoint
2322 definitions, use the `source' command.
2324 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2327 info static-tracepoint-markers
2328 Display information about static tracepoint markers in the target.
2330 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2331 Define a static tracepoint by probing a marker at the given
2332 function, line, address, or marker ID.
2336 Enable and disable observer mode.
2338 set may-write-registers on|off
2339 set may-write-memory on|off
2340 set may-insert-breakpoints on|off
2341 set may-insert-tracepoints on|off
2342 set may-insert-fast-tracepoints on|off
2343 set may-interrupt on|off
2344 Set individual permissions for GDB effects on the target. Note that
2345 some of these settings can have undesirable or surprising
2346 consequences, particularly when changed in the middle of a session.
2347 For instance, disabling the writing of memory can prevent
2348 breakpoints from being inserted, cause single-stepping to fail, or
2349 even crash your program, if you disable after breakpoints have been
2350 inserted. However, GDB should not crash.
2352 set record memory-query on|off
2353 show record memory-query
2354 Control whether to stop the inferior if memory changes caused
2355 by an instruction cannot be recorded.
2360 The disassemble command now supports "start,+length" form of two arguments.
2364 ** GDB now provides a new directory location, called the python directory,
2365 where Python scripts written for GDB can be installed. The location
2366 of that directory is <data-directory>/python, where <data-directory>
2367 is the GDB data directory. For more details, see section `Scripting
2368 GDB using Python' in the manual.
2370 ** The GDB Python API now has access to breakpoints, symbols, symbol
2371 tables, program spaces, inferiors, threads and frame's code blocks.
2372 Additionally, GDB Parameters can now be created from the API, and
2373 manipulated via set/show in the CLI.
2375 ** New functions gdb.target_charset, gdb.target_wide_charset,
2376 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2378 ** New exception gdb.GdbError.
2380 ** Pretty-printers are now also looked up in the current program space.
2382 ** Pretty-printers can now be individually enabled and disabled.
2384 ** GDB now looks for names of Python scripts to auto-load in a
2385 special section named `.debug_gdb_scripts', in addition to looking
2386 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2388 * Tracepoint actions were unified with breakpoint commands. In particular,
2389 there are no longer differences in "info break" output for breakpoints and
2390 tracepoints and the "commands" command can be used for both tracepoints and
2391 regular breakpoints.
2395 ARM Symbian arm*-*-symbianelf*
2397 * D language support.
2398 GDB now supports debugging programs written in the D programming
2401 * GDB now supports the extended ptrace interface for PowerPC which is
2402 available since Linux kernel version 2.6.34. This automatically enables
2403 any hardware breakpoints and additional hardware watchpoints available in
2404 the processor. The old ptrace interface exposes just one hardware
2405 watchpoint and no hardware breakpoints.
2407 * GDB is now able to use the Data Value Compare (DVC) register available on
2408 embedded PowerPC processors to implement in hardware simple watchpoint
2409 conditions of the form:
2411 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2413 This works in native GDB running on Linux kernels with the extended ptrace
2414 interface mentioned above.
2416 *** Changes in GDB 7.1
2420 ** Namespace Support
2422 GDB now supports importing of namespaces in C++. This enables the
2423 user to inspect variables from imported namespaces. Support for
2424 namepace aliasing has also been added. So, if a namespace is
2425 aliased in the current scope (e.g. namepace C=A; ) the user can
2426 print variables using the alias (e.g. (gdb) print C::x).
2430 All known bugs relating to the printing of virtual base class were
2431 fixed. It is now possible to call overloaded static methods using a
2436 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2437 and reinterpret_cast<> are now handled by the C++ expression parser.
2441 Xilinx MicroBlaze microblaze-*-*
2446 Xilinx MicroBlaze microblaze
2449 * Multi-program debugging.
2451 GDB now has support for multi-program (a.k.a. multi-executable or
2452 multi-exec) debugging. This allows for debugging multiple inferiors
2453 simultaneously each running a different program under the same GDB
2454 session. See "Debugging Multiple Inferiors and Programs" in the
2455 manual for more information. This implied some user visible changes
2456 in the multi-inferior support. For example, "info inferiors" now
2457 lists inferiors that are not running yet or that have exited
2458 already. See also "New commands" and "New options" below.
2460 * New tracing features
2462 GDB's tracepoint facility now includes several new features:
2464 ** Trace state variables
2466 GDB tracepoints now include support for trace state variables, which
2467 are variables managed by the target agent during a tracing
2468 experiment. They are useful for tracepoints that trigger each
2469 other, so for instance one tracepoint can count hits in a variable,
2470 and then a second tracepoint has a condition that is true when the
2471 count reaches a particular value. Trace state variables share the
2472 $-syntax of GDB convenience variables, and can appear in both
2473 tracepoint actions and condition expressions. Use the "tvariable"
2474 command to create, and "info tvariables" to view; see "Trace State
2475 Variables" in the manual for more detail.
2479 GDB now includes an option for defining fast tracepoints, which
2480 targets may implement more efficiently, such as by installing a jump
2481 into the target agent rather than a trap instruction. The resulting
2482 speedup can be by two orders of magnitude or more, although the
2483 tradeoff is that some program locations on some target architectures
2484 might not allow fast tracepoint installation, for instance if the
2485 instruction to be replaced is shorter than the jump. To request a
2486 fast tracepoint, use the "ftrace" command, with syntax identical to
2487 the regular trace command.
2489 ** Disconnected tracing
2491 It is now possible to detach GDB from the target while it is running
2492 a trace experiment, then reconnect later to see how the experiment
2493 is going. In addition, a new variable disconnected-tracing lets you
2494 tell the target agent whether to continue running a trace if the
2495 connection is lost unexpectedly.
2499 GDB now has the ability to save the trace buffer into a file, and
2500 then use that file as a target, similarly to you can do with
2501 corefiles. You can select trace frames, print data that was
2502 collected in them, and use tstatus to display the state of the
2503 tracing run at the moment that it was saved. To create a trace
2504 file, use "tsave <filename>", and to use it, do "target tfile
2507 ** Circular trace buffer
2509 You can ask the target agent to handle the trace buffer as a
2510 circular buffer, discarding the oldest trace frames to make room for
2511 newer ones, by setting circular-trace-buffer to on. This feature may
2512 not be available for all target agents.
2517 The disassemble command, when invoked with two arguments, now requires
2518 the arguments to be comma-separated.
2521 The info variables command now displays variable definitions. Files
2522 which only declare a variable are not shown.
2525 The source command is now capable of sourcing Python scripts.
2526 This feature is dependent on the debugger being build with Python
2529 Related to this enhancement is also the introduction of a new command
2530 "set script-extension" (see below).
2532 * New commands (for set/show, see "New options" below)
2534 record save [<FILENAME>]
2535 Save a file (in core file format) containing the process record
2536 execution log for replay debugging at a later time.
2538 record restore <FILENAME>
2539 Restore the process record execution log that was saved at an
2540 earlier time, for replay debugging.
2542 add-inferior [-copies <N>] [-exec <FILENAME>]
2545 clone-inferior [-copies <N>] [ID]
2546 Make a new inferior ready to execute the same program another
2547 inferior has loaded.
2552 maint info program-spaces
2553 List the program spaces loaded into GDB.
2555 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2556 show remote interrupt-sequence
2557 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2558 as the sequence to the remote target in order to interrupt the execution.
2559 Ctrl-C is a default. Some system prefers BREAK which is high level of
2560 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2561 Magic SysRq g. It is BREAK signal and character 'g'.
2563 set remote interrupt-on-connect [on | off]
2564 show remote interrupt-on-connect
2565 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2566 remote target when gdb connects to it. This is needed when you debug
2569 set remotebreak [on | off]
2571 Deprecated. Use "set/show remote interrupt-sequence" instead.
2573 tvariable $NAME [ = EXP ]
2574 Create or modify a trace state variable.
2577 List trace state variables and their values.
2579 delete tvariable $NAME ...
2580 Delete one or more trace state variables.
2583 Evaluate the given expressions without collecting anything into the
2584 trace buffer. (Valid in tracepoint actions only.)
2586 ftrace FN / FILE:LINE / *ADDR
2587 Define a fast tracepoint at the given function, line, or address.
2589 * New expression syntax
2591 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2592 GDB now parses 0b101010 identically with 42.
2596 set follow-exec-mode new|same
2597 show follow-exec-mode
2598 Control whether GDB reuses the same inferior across an exec call or
2599 creates a new one. This is useful to be able to restart the old
2600 executable after the inferior having done an exec call.
2602 set default-collect EXPR, ...
2603 show default-collect
2604 Define a list of expressions to be collected at each tracepoint.
2605 This is a useful way to ensure essential items are not overlooked,
2606 such as registers or a critical global variable.
2608 set disconnected-tracing
2609 show disconnected-tracing
2610 If set to 1, the target is instructed to continue tracing if it
2611 loses its connection to GDB. If 0, the target is to stop tracing
2614 set circular-trace-buffer
2615 show circular-trace-buffer
2616 If set to on, the target is instructed to use a circular trace buffer
2617 and discard the oldest trace frames instead of stopping the trace due
2618 to a full trace buffer. If set to off, the trace stops when the buffer
2619 fills up. Some targets may not support this.
2621 set script-extension off|soft|strict
2622 show script-extension
2623 If set to "off", the debugger does not perform any script language
2624 recognition, and all sourced files are assumed to be GDB scripts.
2625 If set to "soft" (the default), files are sourced according to
2626 filename extension, falling back to GDB scripts if the first
2628 If set to "strict", files are sourced according to filename extension.
2630 set ada trust-PAD-over-XVS on|off
2631 show ada trust-PAD-over-XVS
2632 If off, activate a workaround against a bug in the debugging information
2633 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2634 the GCC sources for more information about the GNAT encoding and
2635 PAD types in particular). It is always safe to set this option to
2636 off, but this introduces a slight performance penalty. The default
2639 * Python API Improvements
2641 ** GDB provides the new class gdb.LazyString. This is useful in
2642 some pretty-printing cases. The new method gdb.Value.lazy_string
2643 provides a simple way to create objects of this type.
2645 ** The fields returned by gdb.Type.fields now have an
2646 `is_base_class' attribute.
2648 ** The new method gdb.Type.range returns the range of an array type.
2650 ** The new method gdb.parse_and_eval can be used to parse and
2651 evaluate an expression.
2653 * New remote packets
2656 Define a trace state variable.
2659 Get the current value of a trace state variable.
2662 Set desired tracing behavior upon disconnection.
2665 Set the trace buffer to be linear or circular.
2668 Get data about the tracepoints currently in use.
2672 Process record now works correctly with hardware watchpoints.
2674 Multiple bug fixes have been made to the mips-irix port, making it
2675 much more reliable. In particular:
2676 - Debugging threaded applications is now possible again. Previously,
2677 GDB would hang while starting the program, or while waiting for
2678 the program to stop at a breakpoint.
2679 - Attaching to a running process no longer hangs.
2680 - An error occurring while loading a core file has been fixed.
2681 - Changing the value of the PC register now works again. This fixes
2682 problems observed when using the "jump" command, or when calling
2683 a function from GDB, or even when assigning a new value to $pc.
2684 - With the "finish" and "return" commands, the return value for functions
2685 returning a small array is now correctly printed.
2686 - It is now possible to break on shared library code which gets executed
2687 during a shared library init phase (code executed while executing
2688 their .init section). Previously, the breakpoint would have no effect.
2689 - GDB is now able to backtrace through the signal handler for
2690 non-threaded programs.
2692 PIE (Position Independent Executable) programs debugging is now supported.
2693 This includes debugging execution of PIC (Position Independent Code) shared
2694 libraries although for that, it should be possible to run such libraries as an
2697 *** Changes in GDB 7.0
2699 * GDB now has an interface for JIT compilation. Applications that
2700 dynamically generate code can create symbol files in memory and register
2701 them with GDB. For users, the feature should work transparently, and
2702 for JIT developers, the interface is documented in the GDB manual in the
2703 "JIT Compilation Interface" chapter.
2705 * Tracepoints may now be conditional. The syntax is as for
2706 breakpoints; either an "if" clause appended to the "trace" command,
2707 or the "condition" command is available. GDB sends the condition to
2708 the target for evaluation using the same bytecode format as is used
2709 for tracepoint actions.
2711 * The disassemble command now supports: an optional /r modifier, print the
2712 raw instructions in hex as well as in symbolic form, and an optional /m
2713 modifier to print mixed source+assembly.
2715 * Process record and replay
2717 In a architecture environment that supports ``process record and
2718 replay'', ``process record and replay'' target can record a log of
2719 the process execution, and replay it with both forward and reverse
2722 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2723 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2724 set execution-direction {forward|reverse}, for targets that support
2727 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2728 feature is available with a native GDB running on kernel version
2731 * GDB now has support for multi-byte and wide character sets on the
2732 target. Strings whose character type is wchar_t, char16_t, or
2733 char32_t are now correctly printed. GDB supports wide- and unicode-
2734 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2735 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2736 `printf'. This feature requires iconv to work properly; if your
2737 system does not have a working iconv, GDB can use GNU libiconv. See
2738 the installation instructions for more information.
2740 * GDB now supports automatic retrieval of shared library files from
2741 remote targets. To use this feature, specify a system root that begins
2742 with the `remote:' prefix, either via the `set sysroot' command or via
2743 the `--with-sysroot' configure-time option.
2745 * "info sharedlibrary" now takes an optional regex of libraries to show,
2746 and it now reports if a shared library has no debugging information.
2748 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2749 now complete on file names.
2751 * When completing in expressions, gdb will attempt to limit
2752 completions to allowable structure or union fields, where appropriate.
2753 For instance, consider:
2755 # struct example { int f1; double f2; };
2756 # struct example variable;
2759 If the user types TAB at the end of this command line, the available
2760 completions will be "f1" and "f2".
2762 * Inlined functions are now supported. They show up in backtraces, and
2763 the "step", "next", and "finish" commands handle them automatically.
2765 * GDB now supports the token-splicing (##) and stringification (#)
2766 operators when expanding macros. It also supports variable-arity
2769 * GDB now supports inspecting extra signal information, exported by
2770 the new $_siginfo convenience variable. The feature is currently
2771 implemented on linux ARM, i386 and amd64.
2773 * GDB can now display the VFP floating point registers and NEON vector
2774 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2775 can provide these registers (requires Linux 2.6.30 or later). Remote
2776 and simulator targets may also provide them.
2778 * New remote packets
2781 Search memory for a sequence of bytes.
2784 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2785 operation over reliable transport links. Use of this packet is
2786 controlled by the `set remote noack-packet' command.
2789 Kill the process with the specified process ID. Use this in preference
2790 to `k' when multiprocess protocol extensions are supported.
2793 Obtains additional operating system information
2797 Read or write additional signal information.
2799 * Removed remote protocol undocumented extension
2801 An undocumented extension to the remote protocol's `S' stop reply
2802 packet that permited the stub to pass a process id was removed.
2803 Remote servers should use the `T' stop reply packet instead.
2805 * GDB now supports multiple function calling conventions according to the
2806 DWARF-2 DW_AT_calling_convention function attribute.
2808 * The SH target utilizes the aforementioned change to distinguish between gcc
2809 and Renesas calling convention. It also adds the new CLI commands
2810 `set/show sh calling-convention'.
2812 * GDB can now read compressed debug sections, as produced by GNU gold
2813 with the --compress-debug-sections=zlib flag.
2815 * 64-bit core files are now supported on AIX.
2817 * Thread switching is now supported on Tru64.
2819 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2820 which will be allocated using malloc later in program execution.
2822 * The qXfer:libraries:read remote procotol packet now allows passing a
2823 list of section offsets.
2825 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2826 conditions handling signals delivered during attach or thread creation
2827 have also been fixed.
2829 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2830 From the user's standpoint, all unqualified instances of True and False
2831 are treated as the standard definitions, regardless of context.
2833 * GDB now parses C++ symbol and type names more flexibly. For
2836 template<typename T> class C { };
2839 GDB will now correctly handle all of:
2841 ptype C<char const *>
2842 ptype C<char const*>
2843 ptype C<const char *>
2844 ptype C<const char*>
2846 * New features in the GDB remote stub, gdbserver
2848 - The "--wrapper" command-line argument tells gdbserver to use a
2849 wrapper program to launch programs for debugging.
2851 - On PowerPC and S/390 targets, it is now possible to use a single
2852 gdbserver executable to debug both 32-bit and 64-bit programs.
2853 (This requires gdbserver itself to be built as a 64-bit executable.)
2855 - gdbserver uses the new noack protocol mode for TCP connections to
2856 reduce communications latency, if also supported and enabled in GDB.
2858 - Support for the sparc64-linux-gnu target is now included in
2861 - The amd64-linux build of gdbserver now supports debugging both
2862 32-bit and 64-bit programs.
2864 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2865 now support hardware watchpoints, and will use them automatically
2870 GDB now has support for scripting using Python. Whether this is
2871 available is determined at configure time.
2873 New GDB commands can now be written in Python.
2875 * Ada tasking support
2877 Ada tasks can now be inspected in GDB. The following commands have
2881 Print the list of Ada tasks.
2883 Print detailed information about task number N.
2885 Print the task number of the current task.
2887 Switch the context of debugging to task number N.
2889 * Support for user-defined prefixed commands. The "define" command can
2890 add new commands to existing prefixes, e.g. "target".
2892 * Multi-inferior, multi-process debugging.
2894 GDB now has generalized support for multi-inferior debugging. See
2895 "Debugging Multiple Inferiors" in the manual for more information.
2896 Although availability still depends on target support, the command
2897 set is more uniform now. The GNU/Linux specific multi-forks support
2898 has been migrated to this new framework. This implied some user
2899 visible changes; see "New commands" and also "Removed commands"
2902 * Target descriptions can now describe the target OS ABI. See the
2903 "Target Description Format" section in the user manual for more
2906 * Target descriptions can now describe "compatible" architectures
2907 to indicate that the target can execute applications for a different
2908 architecture in addition to those for the main target architecture.
2909 See the "Target Description Format" section in the user manual for
2912 * Multi-architecture debugging.
2914 GDB now includes general supports for debugging applications on
2915 hybrid systems that use more than one single processor architecture
2916 at the same time. Each such hybrid architecture still requires
2917 specific support to be added. The only hybrid architecture supported
2918 in this version of GDB is the Cell Broadband Engine.
2920 * GDB now supports integrated debugging of Cell/B.E. applications that
2921 use both the PPU and SPU architectures. To enable support for hybrid
2922 Cell/B.E. debugging, you need to configure GDB to support both the
2923 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2924 --enable-targets configure option.
2926 * Non-stop mode debugging.
2928 For some targets, GDB now supports an optional mode of operation in
2929 which you can examine stopped threads while other threads continue
2930 to execute freely. This is referred to as non-stop mode, with the
2931 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2932 section in the user manual for more information.
2934 To be able to support remote non-stop debugging, a remote stub needs
2935 to implement the non-stop mode remote protocol extensions, as
2936 described in the "Remote Non-Stop" section of the user manual. The
2937 GDB remote stub, gdbserver, has been adjusted to support these
2938 extensions on linux targets.
2940 * New commands (for set/show, see "New options" below)
2942 catch syscall [NAME(S) | NUMBER(S)]
2943 Catch system calls. Arguments, which should be names of system
2944 calls or their numbers, mean catch only those syscalls. Without
2945 arguments, every syscall will be caught. When the inferior issues
2946 any of the specified syscalls, GDB will stop and announce the system
2947 call, both when it is called and when its call returns. This
2948 feature is currently available with a native GDB running on the
2949 Linux Kernel, under the following architectures: x86, x86_64,
2950 PowerPC and PowerPC64.
2952 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2954 Search memory for a sequence of bytes.
2956 maint set python print-stack
2957 maint show python print-stack
2958 Show a stack trace when an error is encountered in a Python script.
2961 Invoke CODE by passing it to the Python interpreter.
2966 These allow macros to be defined, undefined, and listed
2970 Show operating system information about processes.
2973 List the inferiors currently under GDB's control.
2976 Switch focus to inferior number NUM.
2979 Detach from inferior number NUM.
2982 Kill inferior number NUM.
2986 set spu stop-on-load
2987 show spu stop-on-load
2988 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2990 set spu auto-flush-cache
2991 show spu auto-flush-cache
2992 Control whether to automatically flush the software-managed cache
2993 during Cell/B.E. debugging.
2995 set sh calling-convention
2996 show sh calling-convention
2997 Control the calling convention used when calling SH target functions.
3000 show debug timestamp
3001 Control display of timestamps with GDB debugging output.
3003 set disassemble-next-line
3004 show disassemble-next-line
3005 Control display of disassembled source lines or instructions when
3008 set remote noack-packet
3009 show remote noack-packet
3010 Set/show the use of remote protocol QStartNoAckMode packet. See above
3011 under "New remote packets."
3013 set remote query-attached-packet
3014 show remote query-attached-packet
3015 Control use of remote protocol `qAttached' (query-attached) packet.
3017 set remote read-siginfo-object
3018 show remote read-siginfo-object
3019 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3022 set remote write-siginfo-object
3023 show remote write-siginfo-object
3024 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3027 set remote reverse-continue
3028 show remote reverse-continue
3029 Control use of remote protocol 'bc' (reverse-continue) packet.
3031 set remote reverse-step
3032 show remote reverse-step
3033 Control use of remote protocol 'bs' (reverse-step) packet.
3035 set displaced-stepping
3036 show displaced-stepping
3037 Control displaced stepping mode. Displaced stepping is a way to
3038 single-step over breakpoints without removing them from the debuggee.
3039 Also known as "out-of-line single-stepping".
3042 show debug displaced
3043 Control display of debugging info for displaced stepping.
3045 maint set internal-error
3046 maint show internal-error
3047 Control what GDB does when an internal error is detected.
3049 maint set internal-warning
3050 maint show internal-warning
3051 Control what GDB does when an internal warning is detected.
3056 Use a wrapper program to launch programs for debugging.
3058 set multiple-symbols (all|ask|cancel)
3059 show multiple-symbols
3060 The value of this variable can be changed to adjust the debugger behavior
3061 when an expression or a breakpoint location contains an ambiguous symbol
3062 name (an overloaded function name, for instance).
3064 set breakpoint always-inserted
3065 show breakpoint always-inserted
3066 Keep breakpoints always inserted in the target, as opposed to inserting
3067 them when resuming the target, and removing them when the target stops.
3068 This option can improve debugger performance on slow remote targets.
3070 set arm fallback-mode (arm|thumb|auto)
3071 show arm fallback-mode
3072 set arm force-mode (arm|thumb|auto)
3074 These commands control how ARM GDB determines whether instructions
3075 are ARM or Thumb. The default for both settings is auto, which uses
3076 the current CPSR value for instructions without symbols; previous
3077 versions of GDB behaved as if "set arm fallback-mode arm".
3079 set disable-randomization
3080 show disable-randomization
3081 Standalone programs run with the virtual address space randomization enabled
3082 by default on some platforms. This option keeps the addresses stable across
3083 multiple debugging sessions.
3087 Control whether other threads are stopped or not when some thread hits
3092 Requests that asynchronous execution is enabled in the target, if available.
3093 In this case, it's possible to resume target in the background, and interact
3094 with GDB while the target is running. "show target-async" displays the
3095 current state of asynchronous execution of the target.
3097 set target-wide-charset
3098 show target-wide-charset
3099 The target-wide-charset is the name of the character set that GDB
3100 uses when printing characters whose type is wchar_t.
3102 set tcp auto-retry (on|off)
3104 set tcp connect-timeout
3105 show tcp connect-timeout
3106 These commands allow GDB to retry failed TCP connections to a remote stub
3107 with a specified timeout period; this is useful if the stub is launched
3108 in parallel with GDB but may not be ready to accept connections immediately.
3110 set libthread-db-search-path
3111 show libthread-db-search-path
3112 Control list of directories which GDB will search for appropriate
3115 set schedule-multiple (on|off)
3116 show schedule-multiple
3117 Allow GDB to resume all threads of all processes or only threads of
3118 the current process.
3122 Use more aggressive caching for accesses to the stack. This improves
3123 performance of remote debugging (particularly backtraces) without
3124 affecting correctness.
3126 set interactive-mode (on|off|auto)
3127 show interactive-mode
3128 Control whether GDB runs in interactive mode (on) or not (off).
3129 When in interactive mode, GDB waits for the user to answer all
3130 queries. Otherwise, GDB does not wait and assumes the default
3131 answer. When set to auto (the default), GDB determines which
3132 mode to use based on the stdin settings.
3137 For program forks, this is replaced by the new more generic `info
3138 inferiors' command. To list checkpoints, you can still use the
3139 `info checkpoints' command, which was an alias for the `info forks'
3143 Replaced by the new `inferior' command. To switch between
3144 checkpoints, you can still use the `restart' command, which was an
3145 alias for the `fork' command.
3148 This is removed, since some targets don't have a notion of
3149 processes. To switch between processes, you can still use the
3150 `inferior' command using GDB's own inferior number.
3153 For program forks, this is replaced by the new more generic `kill
3154 inferior' command. To delete a checkpoint, you can still use the
3155 `delete checkpoint' command, which was an alias for the `delete
3159 For program forks, this is replaced by the new more generic `detach
3160 inferior' command. To detach a checkpoint, you can still use the
3161 `detach checkpoint' command, which was an alias for the `detach
3164 * New native configurations
3166 x86/x86_64 Darwin i[34567]86-*-darwin*
3168 x86_64 MinGW x86_64-*-mingw*
3172 Lattice Mico32 lm32-*
3173 x86 DICOS i[34567]86-*-dicos*
3174 x86_64 DICOS x86_64-*-dicos*
3177 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3178 (mingw32ce) debugging.
3184 These commands were actually not implemented on any target.
3186 *** Changes in GDB 6.8
3188 * New native configurations
3190 NetBSD/hppa hppa*-*netbsd*
3191 Xtensa GNU/Linux xtensa*-*-linux*
3195 NetBSD/hppa hppa*-*-netbsd*
3196 Xtensa GNU/Lunux xtensa*-*-linux*
3198 * Change in command line behavior -- corefiles vs. process ids.
3200 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3201 attaching to process NUMBER fails, GDB no longer attempts to open a
3202 core file named NUMBER. Attaching to a program using the -c option
3203 is no longer supported. Instead, use the '-p' or '--pid' options.
3205 * GDB can now be built as a native debugger for debugging Windows x86
3206 (mingw32) Portable Executable (PE) programs.
3208 * Pending breakpoints no longer change their number when their address
3211 * GDB now supports breakpoints with multiple locations,
3212 including breakpoints on C++ constructors, inside C++ templates,
3213 and in inlined functions.
3215 * GDB's ability to debug optimized code has been improved. GDB more
3216 accurately identifies function bodies and lexical blocks that occupy
3217 more than one contiguous range of addresses.
3219 * Target descriptions can now describe registers for PowerPC.
3221 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3222 registers on PowerPC targets.
3224 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3225 targets even when the libthread_db library is not available.
3227 * The GDB remote stub, gdbserver, now supports the new file transfer
3228 commands (remote put, remote get, and remote delete).
3230 * The GDB remote stub, gdbserver, now supports run and attach in
3231 extended-remote mode.
3233 * hppa*64*-*-hpux11* target broken
3234 The debugger is unable to start a program and fails with the following
3235 error: "Error trying to get information about dynamic linker".
3236 The gdb-6.7 release is also affected.
3238 * GDB now supports the --enable-targets= configure option to allow
3239 building a single GDB executable that supports multiple remote
3240 target architectures.
3242 * GDB now supports debugging C and C++ programs which use the
3243 Decimal Floating Point extension. In addition, the PowerPC target
3244 now has a set of pseudo-registers to inspect decimal float values
3245 stored in two consecutive float registers.
3247 * The -break-insert MI command can optionally create pending
3250 * Improved support for debugging Ada
3251 Many improvements to the Ada language support have been made. These
3253 - Better support for Ada2005 interface types
3254 - Improved handling of arrays and slices in general
3255 - Better support for Taft-amendment types
3256 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3258 - Improved command completion in Ada
3261 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3266 set print frame-arguments (all|scalars|none)
3267 show print frame-arguments
3268 The value of this variable can be changed to control which argument
3269 values should be printed by the debugger when displaying a frame.
3274 Transfer files to and from a remote target, and delete remote files.
3281 Transfer files to and from a remote target, and delete remote files.
3283 * New remote packets
3290 Open, close, read, write, and delete files on the remote system.
3293 Attach to an existing process on the remote system, in extended-remote
3297 Run a new process on the remote system, in extended-remote mode.
3299 *** Changes in GDB 6.7
3301 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3302 bfd, libiberty and opcodes, as revealed by static analysis donated by
3303 Coverity, Inc. (http://scan.coverity.com).
3305 * When looking up multiply-defined global symbols, GDB will now prefer the
3306 symbol definition in the current shared library if it was built using the
3307 -Bsymbolic linker option.
3309 * When the Text User Interface (TUI) is not configured, GDB will now
3310 recognize the -tui command-line option and print a message that the TUI
3313 * The GDB remote stub, gdbserver, now has lower overhead for high
3314 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3316 * GDB for MIPS targets now autodetects whether a remote target provides
3317 32-bit or 64-bit register values.
3319 * Support for C++ member pointers has been improved.
3321 * GDB now understands XML target descriptions, which specify the
3322 target's overall architecture. GDB can read a description from
3323 a local file or over the remote serial protocol.
3325 * Vectors of single-byte data use a new integer type which is not
3326 automatically displayed as character or string data.
3328 * The /s format now works with the print command. It displays
3329 arrays of single-byte integers and pointers to single-byte integers
3332 * Target descriptions can now describe target-specific registers,
3333 for architectures which have implemented the support (currently
3334 only ARM, M68K, and MIPS).
3336 * GDB and the GDB remote stub, gdbserver, now support the XScale
3339 * The GDB remote stub, gdbserver, has been updated to support
3340 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3341 has been rewritten to use the standard GDB remote protocol.
3343 * GDB can now step into C++ functions which are called through thunks.
3345 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3347 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3348 layout. It also supports a TextSeg= and DataSeg= response when only
3349 segment base addresses (rather than offsets) are available.
3351 * The /i format now outputs any trailing branch delay slot instructions
3352 immediately following the last instruction within the count specified.
3354 * The GDB remote protocol "T" stop reply packet now supports a
3355 "library" response. Combined with the new "qXfer:libraries:read"
3356 packet, this response allows GDB to debug shared libraries on targets
3357 where the operating system manages the list of loaded libraries (e.g.
3358 Windows and SymbianOS).
3360 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3361 (DLLs) on Windows and Windows CE targets.
3363 * GDB now supports a faster verification that a .debug file matches its binary
3364 according to its build-id signature, if the signature is present.
3370 Enable or disable hardware flow control (RTS/CTS) on the serial port
3371 when debugging using remote targets.
3373 set mem inaccessible-by-default
3374 show mem inaccessible-by-default
3375 If the target supplies a memory map, for instance via the remote
3376 protocol's "qXfer:memory-map:read" packet, setting this variable
3377 prevents GDB from accessing memory outside the memory map. This
3378 is useful for targets with memory mapped registers or which react
3379 badly to accesses of unmapped address space.
3381 set breakpoint auto-hw
3382 show breakpoint auto-hw
3383 If the target supplies a memory map, for instance via the remote
3384 protocol's "qXfer:memory-map:read" packet, setting this variable
3385 lets GDB use hardware breakpoints automatically for memory regions
3386 where it can not use software breakpoints. This covers both the
3387 "break" command and internal breakpoints used for other commands
3388 including "next" and "finish".
3391 catch exception unhandled
3392 Stop the program execution when Ada exceptions are raised.
3395 Stop the program execution when an Ada assertion failed.
3399 Set an alternate system root for target files. This is a more
3400 general version of "set solib-absolute-prefix", which is now
3401 an alias to "set sysroot".
3404 Provide extended SPU facility status information. This set of
3405 commands is available only when debugging the Cell/B.E. SPU
3408 * New native configurations
3410 OpenBSD/sh sh*-*openbsd*
3413 unset tdesc filename
3415 Use the specified local file as an XML target description, and do
3416 not query the target for its built-in description.
3420 OpenBSD/sh sh*-*-openbsd*
3421 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3422 Toshiba Media Processor mep-elf
3424 * New remote packets
3427 Ignore the specified signals; pass them directly to the debugged program
3428 without stopping other threads or reporting them to GDB.
3430 qXfer:features:read:
3431 Read an XML target description from the target, which describes its
3436 Read or write contents of an spufs file on the target system. These
3437 packets are available only on the Cell/B.E. SPU architecture.
3439 qXfer:libraries:read:
3440 Report the loaded shared libraries. Combined with new "T" packet
3441 response, this packet allows GDB to debug shared libraries on
3442 targets where the operating system manages the list of loaded
3443 libraries (e.g. Windows and SymbianOS).
3447 Support for these obsolete configurations has been removed.
3455 i[34567]86-*-lynxos*
3456 i[34567]86-*-netware*
3457 i[34567]86-*-sco3.2v5*
3458 i[34567]86-*-sco3.2v4*
3460 i[34567]86-*-sysv4.2*
3463 i[34567]86-*-unixware2*
3464 i[34567]86-*-unixware*
3473 * Other removed features
3480 Various m68k-only ROM monitors.
3487 Various Renesas ROM monitors and debugging interfaces for SH and
3492 Support for a Macraigor serial interface to on-chip debugging.
3493 GDB does not directly support the newer parallel or USB
3498 A debug information format. The predecessor to DWARF 2 and
3499 DWARF 3, which are still supported.
3501 Support for the HP aCC compiler on HP-UX/PA-RISC
3503 SOM-encapsulated symbolic debugging information, automatic
3504 invocation of pxdb, and the aCC custom C++ ABI. This does not
3505 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3506 with aCC can still be debugged on an assembly level.
3508 MIPS ".pdr" sections
3510 A MIPS-specific format used to describe stack frame layout
3511 in debugging information.
3515 GDB could work with an older version of Guile to debug
3516 the interpreter and Scheme programs running in it.
3518 set mips stack-arg-size
3519 set mips saved-gpreg-size
3521 Use "set mips abi" to control parameter passing for MIPS.
3523 *** Changes in GDB 6.6
3528 Cell Broadband Engine SPU spu-elf
3530 * GDB can now be configured as a cross-debugger targeting native Windows
3531 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3532 running on a Windows system over TCP/IP to debug Windows programs.
3534 * The GDB remote stub, gdbserver, has been updated to support Windows and
3535 Cygwin debugging. Both single-threaded and multi-threaded programs are
3538 * The "set trust-readonly-sections" command works again. This command was
3539 broken in GDB 6.3, 6.4, and 6.5.
3541 * The "load" command now supports writing to flash memory, if the remote
3542 stub provides the required support.
3544 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3545 longer requires symbolic debug information (e.g. DWARF-2).
3550 unset substitute-path
3551 show substitute-path
3552 Manage a list of substitution rules that GDB uses to rewrite the name
3553 of the directories where the sources are located. This can be useful
3554 for instance when the sources were moved to a different location
3555 between compilation and debugging.
3559 Print each CLI command as it is executed. Each command is prefixed with
3560 a number of `+' symbols representing the nesting depth.
3561 The source command now has a `-v' option to enable the same feature.
3565 The ARM Demon monitor support (RDP protocol, "target rdp").
3567 Kernel Object Display, an embedded debugging feature which only worked with
3568 an obsolete version of Cisco IOS.
3570 The 'set download-write-size' and 'show download-write-size' commands.
3572 * New remote packets
3575 Tell a stub about GDB client features, and request remote target features.
3576 The first feature implemented is PacketSize, which allows the target to
3577 specify the size of packets it can handle - to minimize the number of
3578 packets required and improve performance when connected to a remote
3582 Fetch an OS auxilliary vector from the remote stub. This packet is a
3583 more efficient replacement for qPart:auxv:read.
3585 qXfer:memory-map:read:
3586 Fetch a memory map from the remote stub, including information about
3587 RAM, ROM, and flash memory devices.
3592 Erase and program a flash memory device.
3594 * Removed remote packets
3597 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3598 used it, and only gdbserver implemented it.
3600 *** Changes in GDB 6.5
3604 Renesas M32C/M16C m32c-elf
3606 Morpho Technologies ms1 ms1-elf
3610 init-if-undefined Initialize a convenience variable, but
3611 only if it doesn't already have a value.
3613 The following commands are presently only implemented for native GNU/Linux:
3615 checkpoint Save a snapshot of the program state.
3617 restart <n> Return the program state to a
3618 previously saved state.
3620 info checkpoints List currently saved checkpoints.
3622 delete-checkpoint <n> Delete a previously saved checkpoint.
3624 set|show detach-on-fork Tell gdb whether to detach from a newly
3625 forked process, or to keep debugging it.
3627 info forks List forks of the user program that
3628 are available to be debugged.
3630 fork <n> Switch to debugging one of several
3631 forks of the user program that are
3632 available to be debugged.
3634 delete-fork <n> Delete a fork from the list of forks
3635 that are available to be debugged (and
3636 kill the forked process).
3638 detach-fork <n> Delete a fork from the list of forks
3639 that are available to be debugged (and
3640 allow the process to continue).
3644 Morpho Technologies ms2 ms1-elf
3646 * Improved Windows host support
3648 GDB now builds as a cross debugger hosted on i686-mingw32, including
3649 native console support, and remote communications using either
3650 network sockets or serial ports.
3652 * Improved Modula-2 language support
3654 GDB can now print most types in the Modula-2 syntax. This includes:
3655 basic types, set types, record types, enumerated types, range types,
3656 pointer types and ARRAY types. Procedure var parameters are correctly
3657 printed and hexadecimal addresses and character constants are also
3658 written in the Modula-2 syntax. Best results can be obtained by using
3659 GNU Modula-2 together with the -gdwarf-2 command line option.
3663 The ARM rdi-share module.
3665 The Netware NLM debug server.
3667 *** Changes in GDB 6.4
3669 * New native configurations
3671 OpenBSD/arm arm*-*-openbsd*
3672 OpenBSD/mips64 mips64-*-openbsd*
3676 Morpho Technologies ms1 ms1-elf
3678 * New command line options
3680 --batch-silent As for --batch, but totally silent.
3681 --return-child-result The debugger will exist with the same value
3682 the child (debugged) program exited with.
3683 --eval-command COMMAND, -ex COMMAND
3684 Execute a single GDB CLI command. This may be
3685 specified multiple times and in conjunction
3686 with the --command (-x) option.
3688 * Deprecated commands removed
3690 The following commands, that were deprecated in 2000, have been
3694 set|show arm disassembly-flavor set|show arm disassembler
3695 othernames set arm disassembler
3696 set|show remotedebug set|show debug remote
3697 set|show archdebug set|show debug arch
3698 set|show eventdebug set|show debug event
3701 * New BSD user-level threads support
3703 It is now possible to debug programs using the user-level threads
3704 library on OpenBSD and FreeBSD. Currently supported (target)
3707 FreeBSD/amd64 x86_64-*-freebsd*
3708 FreeBSD/i386 i386-*-freebsd*
3709 OpenBSD/i386 i386-*-openbsd*
3711 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3712 are not yet supported.
3714 * New support for Matsushita MN10300 w/sim added
3715 (Work in progress). mn10300-elf.
3717 * REMOVED configurations and files
3719 VxWorks and the XDR protocol *-*-vxworks
3720 Motorola MCORE mcore-*-*
3721 National Semiconductor NS32000 ns32k-*-*
3723 * New "set print array-indexes" command
3725 After turning this setting "on", GDB prints the index of each element
3726 when displaying arrays. The default is "off" to preserve the previous
3729 * VAX floating point support
3731 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3733 * User-defined command support
3735 In addition to using $arg0..$arg9 for argument passing, it is now possible
3736 to use $argc to determine now many arguments have been passed. See the
3737 section on user-defined commands in the user manual for more information.
3739 *** Changes in GDB 6.3:
3741 * New command line option
3743 GDB now accepts -l followed by a number to set the timeout for remote
3746 * GDB works with GCC -feliminate-dwarf2-dups
3748 GDB now supports a more compact representation of DWARF-2 debug
3749 information using DW_FORM_ref_addr references. These are produced
3750 by GCC with the option -feliminate-dwarf2-dups and also by some
3751 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3752 to use -feliminate-dwarf2-dups.
3754 * Internationalization
3756 When supported by the host system, GDB will be built with
3757 internationalization (libintl). The task of marking up the sources is
3758 continued, we're looking forward to our first translation.
3762 Initial support for debugging programs compiled with the GNAT
3763 implementation of the Ada programming language has been integrated
3764 into GDB. In this release, support is limited to expression evaluation.
3766 * New native configurations
3768 GNU/Linux/m32r m32r-*-linux-gnu
3772 GDB's remote protocol now includes support for the 'p' packet. This
3773 packet is used to fetch individual registers from a remote inferior.
3775 * END-OF-LIFE registers[] compatibility module
3777 GDB's internal register infrastructure has been completely rewritten.
3778 The new infrastructure making possible the implementation of key new
3779 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3782 GDB 6.3 will be the last release to include the the registers[]
3783 compatibility module that allowed out-of-date configurations to
3784 continue to work. This change directly impacts the following
3794 powerpc bdm protocol
3796 Unless there is activity to revive these configurations, they will be
3797 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3799 * OBSOLETE configurations and files
3801 Configurations that have been declared obsolete in this release have
3802 been commented out. Unless there is activity to revive these
3803 configurations, the next release of GDB will have their sources
3804 permanently REMOVED.
3813 *** Changes in GDB 6.2.1:
3815 * MIPS `break main; run' gave an heuristic-fence-post warning
3817 When attempting to run even a simple program, a warning about
3818 heuristic-fence-post being hit would be reported. This problem has
3821 * MIPS IRIX 'long double' crashed GDB
3823 When examining a long double variable, GDB would get a segmentation
3824 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3825 IRIX long double values).
3829 A bug in the VAX stack code was causing problems with the "next"
3830 command. This problem has been fixed.
3832 *** Changes in GDB 6.2:
3834 * Fix for ``many threads''
3836 On GNU/Linux systems that use the NPTL threads library, a program
3837 rapidly creating and deleting threads would confuse GDB leading to the
3840 ptrace: No such process.
3841 thread_db_get_info: cannot get thread info: generic error
3843 This problem has been fixed.
3845 * "-async" and "-noasync" options removed.
3847 Support for the broken "-noasync" option has been removed (it caused
3850 * New ``start'' command.
3852 This command runs the program until the begining of the main procedure.
3854 * New BSD Kernel Data Access Library (libkvm) interface
3856 Using ``target kvm'' it is now possible to debug kernel core dumps and
3857 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3858 platforms. Currently supported (native-only) configurations are:
3860 FreeBSD/amd64 x86_64-*-freebsd*
3861 FreeBSD/i386 i?86-*-freebsd*
3862 NetBSD/i386 i?86-*-netbsd*
3863 NetBSD/m68k m68*-*-netbsd*
3864 NetBSD/sparc sparc-*-netbsd*
3865 OpenBSD/amd64 x86_64-*-openbsd*
3866 OpenBSD/i386 i?86-*-openbsd*
3867 OpenBSD/m68k m68*-openbsd*
3868 OpenBSD/sparc sparc-*-openbsd*
3870 * Signal trampoline code overhauled
3872 Many generic problems with GDB's signal handling code have been fixed.
3873 These include: backtraces through non-contiguous stacks; recognition
3874 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3875 call; backtrace through a signal trampoline; step into and out of
3876 signal handlers; and single-stepping in the signal trampoline.
3878 Please note that kernel bugs are a limiting factor here. These
3879 features have been shown to work on an s390 GNU/Linux system that
3880 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3882 * Cygwin support for DWARF 2 added.
3884 * New native configurations
3886 GNU/Linux/hppa hppa*-*-linux*
3887 OpenBSD/hppa hppa*-*-openbsd*
3888 OpenBSD/m68k m68*-*-openbsd*
3889 OpenBSD/m88k m88*-*-openbsd*
3890 OpenBSD/powerpc powerpc-*-openbsd*
3891 NetBSD/vax vax-*-netbsd*
3892 OpenBSD/vax vax-*-openbsd*
3894 * END-OF-LIFE frame compatibility module
3896 GDB's internal frame infrastructure has been completely rewritten.
3897 The new infrastructure making it possible to support key new features
3898 including DWARF 2 Call Frame Information. To aid in the task of
3899 migrating old configurations to this new infrastructure, a
3900 compatibility module, that allowed old configurations to continue to
3901 work, was also included.
3903 GDB 6.2 will be the last release to include this frame compatibility
3904 module. This change directly impacts the following configurations:
3914 Unless there is activity to revive these configurations, they will be
3915 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3917 * REMOVED configurations and files
3919 Sun 3, running SunOS 3 m68*-*-sunos3*
3920 Sun 3, running SunOS 4 m68*-*-sunos4*
3921 Sun 2, running SunOS 3 m68000-*-sunos3*
3922 Sun 2, running SunOS 4 m68000-*-sunos4*
3923 Motorola 680x0 running LynxOS m68*-*-lynxos*
3924 AT&T 3b1/Unix pc m68*-att-*
3925 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3926 decstation mips-dec-* mips-little-*
3927 riscos mips-*-riscos* mips-*-sysv*
3928 sonymips mips-sony-*
3929 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3931 *** Changes in GDB 6.1.1:
3933 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3935 The TUI (Text-mode User Interface) is now built as part of a default
3936 GDB configuration. It is enabled by either selecting the TUI with the
3937 command line option "-i=tui" or by running the separate "gdbtui"
3938 program. For more information on the TUI, see the manual "Debugging
3941 * Pending breakpoint support (also included in GDB 6.1)
3943 Support has been added to allow you to specify breakpoints in shared
3944 libraries that have not yet been loaded. If a breakpoint location
3945 cannot be found, and the "breakpoint pending" option is set to auto,
3946 GDB queries you if you wish to make the breakpoint pending on a future
3947 shared-library load. If and when GDB resolves the breakpoint symbol,
3948 the pending breakpoint is removed as one or more regular breakpoints
3951 Pending breakpoints are very useful for GCJ Java debugging.
3953 * Fixed ISO-C build problems
3955 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3956 non ISO-C code that stopped them being built using a more strict ISO-C
3957 compiler (e.g., IBM's C compiler).
3959 * Fixed build problem on IRIX 5
3961 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3962 wasn't able to compile compile on an IRIX 5 system.
3964 * Added execute permission to gdb/gdbserver/configure
3966 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3967 permission. This bug would cause configure to fail on a number of
3968 systems (Solaris, IRIX). Ref: server/519.
3970 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3972 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3973 has been updated to use constant array sizes.
3975 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3977 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3978 its generated DWARF Call Frame Info. This encoding was causing GDB to
3979 panic, that panic has been fixed. Ref: gdb/1628.
3981 * Fixed a problem when examining parameters in shared library code.
3983 When examining parameters in optimized shared library code generated
3984 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3985 not available''. GDB now correctly displays the variable's value.
3987 *** Changes in GDB 6.1:
3989 * Removed --with-mmalloc
3991 Support for the mmalloc memory manager has been removed, as it
3992 conflicted with the internal gdb byte cache.
3994 * Changes in AMD64 configurations
3996 The AMD64 target now includes the %cs and %ss registers. As a result
3997 the AMD64 remote protocol has changed; this affects the floating-point
3998 and SSE registers. If you rely on those registers for your debugging,
3999 you should upgrade gdbserver on the remote side.
4001 * Revised SPARC target
4003 The SPARC target has been completely revised, incorporating the
4004 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4005 support for LynxOS and SunOS 4 has been dropped. Calling functions
4006 from within GDB on operating systems with a non-executable stack
4007 (Solaris, OpenBSD) now works.
4011 GDB has a new C++ demangler which does a better job on the mangled
4012 names generated by current versions of g++. It also runs faster, so
4013 with this and other changes gdb should now start faster on large C++
4016 * DWARF 2 Location Expressions
4018 GDB support for location expressions has been extended to support function
4019 arguments and frame bases. Older versions of GDB could crash when they
4022 * C++ nested types and namespaces
4024 GDB's support for nested types and namespaces in C++ has been
4025 improved, especially if you use the DWARF 2 debugging format. (This
4026 is the default for recent versions of GCC on most platforms.)
4027 Specifically, if you have a class "Inner" defined within a class or
4028 namespace "Outer", then GDB realizes that the class's name is
4029 "Outer::Inner", not simply "Inner". This should greatly reduce the
4030 frequency of complaints about not finding RTTI symbols. In addition,
4031 if you are stopped at inside of a function defined within a namespace,
4032 GDB modifies its name lookup accordingly.
4034 * New native configurations
4036 NetBSD/amd64 x86_64-*-netbsd*
4037 OpenBSD/amd64 x86_64-*-openbsd*
4038 OpenBSD/alpha alpha*-*-openbsd*
4039 OpenBSD/sparc sparc-*-openbsd*
4040 OpenBSD/sparc64 sparc64-*-openbsd*
4042 * New debugging protocols
4044 M32R with SDI protocol m32r-*-elf*
4046 * "set prompt-escape-char" command deleted.
4048 The command "set prompt-escape-char" has been deleted. This command,
4049 and its very obscure effet on GDB's prompt, was never documented,
4050 tested, nor mentioned in the NEWS file.
4052 * OBSOLETE configurations and files
4054 Configurations that have been declared obsolete in this release have
4055 been commented out. Unless there is activity to revive these
4056 configurations, the next release of GDB will have their sources
4057 permanently REMOVED.
4059 Sun 3, running SunOS 3 m68*-*-sunos3*
4060 Sun 3, running SunOS 4 m68*-*-sunos4*
4061 Sun 2, running SunOS 3 m68000-*-sunos3*
4062 Sun 2, running SunOS 4 m68000-*-sunos4*
4063 Motorola 680x0 running LynxOS m68*-*-lynxos*
4064 AT&T 3b1/Unix pc m68*-att-*
4065 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4066 decstation mips-dec-* mips-little-*
4067 riscos mips-*-riscos* mips-*-sysv*
4068 sonymips mips-sony-*
4069 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4071 * REMOVED configurations and files
4073 SGI Irix-4.x mips-sgi-irix4 or iris4
4074 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4075 Z8000 simulator z8k-zilog-none or z8ksim
4076 Matsushita MN10200 w/simulator mn10200-*-*
4077 H8/500 simulator h8500-hitachi-hms or h8500hms
4078 HP/PA running BSD hppa*-*-bsd*
4079 HP/PA running OSF/1 hppa*-*-osf*
4080 HP/PA Pro target hppa*-*-pro*
4081 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4082 386BSD i[3456]86-*-bsd*
4083 Sequent family i[3456]86-sequent-sysv4*
4084 i[3456]86-sequent-sysv*
4085 i[3456]86-sequent-bsd*
4086 SPARC running LynxOS sparc-*-lynxos*
4087 SPARC running SunOS 4 sparc-*-sunos4*
4088 Tsqware Sparclet sparclet-*-*
4089 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4091 *** Changes in GDB 6.0:
4095 Support for debugging the Objective-C programming language has been
4096 integrated into GDB.
4098 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4100 DWARF 2's Call Frame Information makes available compiler generated
4101 information that more exactly describes the program's run-time stack.
4102 By using this information, GDB is able to provide more robust stack
4105 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4106 have been updated to use a new backtrace mechanism which includes
4107 DWARF 2 CFI support.
4111 GDB's remote protocol has been extended to include support for hosted
4112 file I/O (where the remote target uses GDB's file system). See GDB's
4113 remote protocol documentation for details.
4115 * All targets using the new architecture framework.
4117 All of GDB's targets have been updated to use the new internal
4118 architecture framework. The way is now open for future GDB releases
4119 to include cross-architecture native debugging support (i386 on amd64,
4122 * GNU/Linux's Thread Local Storage (TLS)
4124 GDB now includes support for for the GNU/Linux implementation of
4125 per-thread variables.
4127 * GNU/Linux's Native POSIX Thread Library (NPTL)
4129 GDB's thread code has been updated to work with either the new
4130 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4132 * Separate debug info.
4134 GDB, in conjunction with BINUTILS, now supports a mechanism for
4135 automatically loading debug information from a separate file. Instead
4136 of shipping full debug and non-debug versions of system libraries,
4137 system integrators can now instead ship just the stripped libraries
4138 and optional debug files.
4140 * DWARF 2 Location Expressions
4142 DWARF 2 Location Expressions allow the compiler to more completely
4143 describe the location of variables (even in optimized code) to the
4146 GDB now includes preliminary support for location expressions (support
4147 for DW_OP_piece is still missing).
4151 A number of long standing bugs that caused GDB to die while starting a
4152 Java application have been fixed. GDB's Java support is now
4153 considered "useable".
4155 * GNU/Linux support for fork, vfork, and exec.
4157 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4158 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4161 * GDB supports logging output to a file
4163 There are two new commands, "set logging" and "show logging", which can be
4164 used to capture GDB's output to a file.
4166 * The meaning of "detach" has changed for gdbserver
4168 The "detach" command will now resume the application, as documented. To
4169 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4172 * d10v, m68hc11 `regs' command deprecated
4174 The `info registers' command has been updated so that it displays the
4175 registers using a format identical to the old `regs' command.
4179 A new command, "maint set profile on/off", has been added. This command can
4180 be used to enable or disable profiling while running GDB, to profile a
4181 session or a set of commands. In addition there is a new configure switch,
4182 "--enable-profiling", which will cause GDB to be compiled with profiling
4183 data, for more informative profiling results.
4185 * Default MI syntax changed to "mi2".
4187 The default MI (machine interface) syntax, enabled by the command line
4188 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4189 "mi1", can be enabled by specifying the option "-i=mi1".
4191 Support for the original "mi0" syntax (included in GDB 5.0) has been
4194 Fix for gdb/192: removed extraneous space when displaying frame level.
4195 Fix for gdb/672: update changelist is now output in mi list format.
4196 Fix for gdb/702: a -var-assign that updates the value now shows up
4197 in a subsequent -var-update.
4199 * New native configurations.
4201 FreeBSD/amd64 x86_64-*-freebsd*
4203 * Multi-arched targets.
4205 HP/PA HPUX11 hppa*-*-hpux*
4206 Renesas M32R/D w/simulator m32r-*-elf*
4208 * OBSOLETE configurations and files
4210 Configurations that have been declared obsolete in this release have
4211 been commented out. Unless there is activity to revive these
4212 configurations, the next release of GDB will have their sources
4213 permanently REMOVED.
4215 Z8000 simulator z8k-zilog-none or z8ksim
4216 Matsushita MN10200 w/simulator mn10200-*-*
4217 H8/500 simulator h8500-hitachi-hms or h8500hms
4218 HP/PA running BSD hppa*-*-bsd*
4219 HP/PA running OSF/1 hppa*-*-osf*
4220 HP/PA Pro target hppa*-*-pro*
4221 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4222 Sequent family i[3456]86-sequent-sysv4*
4223 i[3456]86-sequent-sysv*
4224 i[3456]86-sequent-bsd*
4225 Tsqware Sparclet sparclet-*-*
4226 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4228 * REMOVED configurations and files
4231 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4232 IBM AIX PS/2 i[3456]86-*-aix
4233 i386 running Mach 3.0 i[3456]86-*-mach3*
4234 i386 running Mach i[3456]86-*-mach*
4235 i386 running OSF/1 i[3456]86-*osf1mk*
4236 HP/Apollo 68k Family m68*-apollo*-sysv*,
4238 m68*-hp-bsd*, m68*-hp-hpux*
4239 Argonaut Risc Chip (ARC) arc-*-*
4240 Mitsubishi D30V d30v-*-*
4241 Fujitsu FR30 fr30-*-elf*
4242 OS/9000 i[34]86-*-os9k
4243 I960 with MON960 i960-*-coff
4245 * MIPS $fp behavior changed
4247 The convenience variable $fp, for the MIPS, now consistently returns
4248 the address of the current frame's base. Previously, depending on the
4249 context, $fp could refer to either $sp or the current frame's base
4250 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4251 The GNU Source-Level Debugger''.
4253 *** Changes in GDB 5.3:
4255 * GNU/Linux shared library multi-threaded performance improved.
4257 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4258 `/proc', in preference to `ptrace' for memory reads. This may result
4259 in an improvement in the start-up time of multi-threaded, shared
4260 library applications when run under GDB. One GDB user writes: ``loads
4261 shared libs like mad''.
4263 * ``gdbserver'' now supports multi-threaded applications on some targets
4265 Support for debugging multi-threaded applications which use
4266 the GNU/Linux LinuxThreads package has been added for
4267 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4268 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4270 * GDB now supports C/C++ preprocessor macros.
4272 GDB now expands preprocessor macro invocations in C/C++ expressions,
4273 and provides various commands for showing macro definitions and how
4276 The new command `macro expand EXPRESSION' expands any macro
4277 invocations in expression, and shows the result.
4279 The new command `show macro MACRO-NAME' shows the definition of the
4280 macro named MACRO-NAME, and where it was defined.
4282 Most compilers don't include information about macros in the debugging
4283 information by default. In GCC 3.1, for example, you need to compile
4284 your program with the options `-gdwarf-2 -g3'. If the macro
4285 information is present in the executable, GDB will read it.
4287 * Multi-arched targets.
4289 DEC Alpha (partial) alpha*-*-*
4290 DEC VAX (partial) vax-*-*
4292 National Semiconductor NS32000 (partial) ns32k-*-*
4293 Motorola 68000 (partial) m68k-*-*
4294 Motorola MCORE mcore-*-*
4298 Fujitsu FRV architecture added by Red Hat frv*-*-*
4301 * New native configurations
4303 Alpha NetBSD alpha*-*-netbsd*
4304 SH NetBSD sh*-*-netbsdelf*
4305 MIPS NetBSD mips*-*-netbsd*
4306 UltraSPARC NetBSD sparc64-*-netbsd*
4308 * OBSOLETE configurations and files
4310 Configurations that have been declared obsolete in this release have
4311 been commented out. Unless there is activity to revive these
4312 configurations, the next release of GDB will have their sources
4313 permanently REMOVED.
4315 Mitsubishi D30V d30v-*-*
4316 OS/9000 i[34]86-*-os9k
4317 IBM AIX PS/2 i[3456]86-*-aix
4318 Fujitsu FR30 fr30-*-elf*
4319 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4320 Argonaut Risc Chip (ARC) arc-*-*
4321 i386 running Mach 3.0 i[3456]86-*-mach3*
4322 i386 running Mach i[3456]86-*-mach*
4323 i386 running OSF/1 i[3456]86-*osf1mk*
4324 HP/Apollo 68k Family m68*-apollo*-sysv*,
4326 m68*-hp-bsd*, m68*-hp-hpux*
4327 I960 with MON960 i960-*-coff
4329 * OBSOLETE languages
4331 CHILL, a Pascal like language used by telecommunications companies.
4333 * REMOVED configurations and files
4335 AMD 29k family via UDI a29k-amd-udi, udi29k
4336 A29K VxWorks a29k-*-vxworks
4337 AMD 29000 embedded, using EBMON a29k-none-none
4338 AMD 29000 embedded with COFF a29k-none-coff
4339 AMD 29000 embedded with a.out a29k-none-aout
4341 testsuite/gdb.hp/gdb.threads-hp/ directory
4343 * New command "set max-user-call-depth <nnn>"
4345 This command allows the user to limit the call depth of user-defined
4346 commands. The default is 1024.
4348 * Changes in FreeBSD/i386 native debugging.
4350 Support for the "generate-core-file" has been added.
4352 * New commands "dump", "append", and "restore".
4354 These commands allow data to be copied from target memory
4355 to a bfd-format or binary file (dump and append), and back
4356 from a file into memory (restore).
4358 * Improved "next/step" support on multi-processor Alpha Tru64.
4360 The previous single-step mechanism could cause unpredictable problems,
4361 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4362 of a software single-step mechanism prevents this.
4364 *** Changes in GDB 5.2.1:
4372 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4373 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4374 Fix, by Joel Brobecker imported from mainline.
4376 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4377 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4378 Fix, by Fred Fish, imported from mainline.
4380 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4381 Surprisingly enough, it works now.
4382 By Michal Ludvig, imported from mainline.
4384 i386 hardware watchpoint support:
4385 avoid misses on second run for some targets.
4386 By Pierre Muller, imported from mainline.
4388 *** Changes in GDB 5.2:
4390 * New command "set trust-readonly-sections on[off]".
4392 This command is a hint that tells gdb that read-only sections
4393 really are read-only (ie. that their contents will not change).
4394 In this mode, gdb will go to the object file rather than the
4395 target to read memory from read-only sections (such as ".text").
4396 This can be a significant performance improvement on some
4397 (notably embedded) targets.
4399 * New command "generate-core-file" (or "gcore").
4401 This new gdb command allows the user to drop a core file of the child
4402 process state at any time. So far it's been implemented only for
4403 GNU/Linux and Solaris, but should be relatively easily ported to other
4404 hosts. Argument is core file name (defaults to core.<pid>).
4406 * New command line option
4408 GDB now accepts --pid or -p followed by a process id.
4410 * Change in command line behavior -- corefiles vs. process ids.
4412 There is a subtle behavior in the way in which GDB handles
4413 command line arguments. The first non-flag argument is always
4414 a program to debug, but the second non-flag argument may either
4415 be a corefile or a process id. Previously, GDB would attempt to
4416 open the second argument as a corefile, and if that failed, would
4417 issue a superfluous error message and then attempt to attach it as
4418 a process. Now, if the second argument begins with a non-digit,
4419 it will be treated as a corefile. If it begins with a digit,
4420 GDB will attempt to attach it as a process, and if no such process
4421 is found, will then attempt to open it as a corefile.
4423 * Changes in ARM configurations.
4425 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4426 configuration is fully multi-arch.
4428 * New native configurations
4430 ARM NetBSD arm*-*-netbsd*
4431 x86 OpenBSD i[3456]86-*-openbsd*
4432 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4433 Sparc64 running FreeBSD sparc64-*-freebsd*
4437 Sanyo XStormy16 xstormy16-elf
4439 * OBSOLETE configurations and files
4441 Configurations that have been declared obsolete in this release have
4442 been commented out. Unless there is activity to revive these
4443 configurations, the next release of GDB will have their sources
4444 permanently REMOVED.
4446 AMD 29k family via UDI a29k-amd-udi, udi29k
4447 A29K VxWorks a29k-*-vxworks
4448 AMD 29000 embedded, using EBMON a29k-none-none
4449 AMD 29000 embedded with COFF a29k-none-coff
4450 AMD 29000 embedded with a.out a29k-none-aout
4452 testsuite/gdb.hp/gdb.threads-hp/ directory
4454 * REMOVED configurations and files
4456 TI TMS320C80 tic80-*-*
4458 PowerPC Solaris powerpcle-*-solaris*
4459 PowerPC Windows NT powerpcle-*-cygwin32
4460 PowerPC Netware powerpc-*-netware*
4461 Harris/CXUX m88k m88*-harris-cxux*
4462 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4463 ns32k-utek-sysv* ns32k-utek-*
4464 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4465 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4466 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4467 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4468 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4470 * Changes to command line processing
4472 The new `--args' feature can be used to specify command-line arguments
4473 for the inferior from gdb's command line.
4475 * Changes to key bindings
4477 There is a new `operate-and-get-next' function bound to `C-o'.
4479 *** Changes in GDB 5.1.1
4481 Fix compile problem on DJGPP.
4483 Fix a problem with floating-point registers on the i386 being
4486 Fix to stop GDB crashing on .debug_str debug info.
4488 Numerous documentation fixes.
4490 Numerous testsuite fixes.
4492 *** Changes in GDB 5.1:
4494 * New native configurations
4496 Alpha FreeBSD alpha*-*-freebsd*
4497 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4498 MIPS GNU/Linux mips*-*-linux*
4499 MIPS SGI Irix 6.x mips*-sgi-irix6*
4500 ia64 AIX ia64-*-aix*
4501 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4505 Motorola 68HC11 and 68HC12 m68hc11-elf
4507 UltraSparc running GNU/Linux sparc64-*-linux*
4509 * OBSOLETE configurations and files
4511 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4512 Harris/CXUX m88k m88*-harris-cxux*
4513 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4514 ns32k-utek-sysv* ns32k-utek-*
4515 TI TMS320C80 tic80-*-*
4517 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4518 PowerPC Solaris powerpcle-*-solaris*
4519 PowerPC Windows NT powerpcle-*-cygwin32
4520 PowerPC Netware powerpc-*-netware*
4521 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4522 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4523 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4524 Apple Macintosh (MPW) host N/A
4526 stuff.c (Program to stuff files into a specially prepared space in kdb)
4527 kdb-start.c (Main loop for the standalone kernel debugger)
4529 Configurations that have been declared obsolete in this release have
4530 been commented out. Unless there is activity to revive these
4531 configurations, the next release of GDB will have their sources
4532 permanently REMOVED.
4534 * REMOVED configurations and files
4536 Altos 3068 m68*-altos-*
4537 Convex c1-*-*, c2-*-*
4539 ARM RISCix arm-*-* (as host)
4543 * GDB has been converted to ISO C.
4545 GDB's source code has been converted to ISO C. In particular, the
4546 sources are fully protoized, and rely on standard headers being
4551 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4553 * The MI enabled by default.
4555 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4556 revised and enabled by default. Packages which use GDB as a debugging
4557 engine behind a UI or another front end are encouraged to switch to
4558 using the GDB/MI interface, instead of the old annotations interface
4559 which is now deprecated.
4561 * Support for debugging Pascal programs.
4563 GDB now includes support for debugging Pascal programs. The following
4564 main features are supported:
4566 - Pascal-specific data types such as sets;
4568 - automatic recognition of Pascal sources based on file-name
4571 - Pascal-style display of data types, variables, and functions;
4573 - a Pascal expression parser.
4575 However, some important features are not yet supported.
4577 - Pascal string operations are not supported at all;
4579 - there are some problems with boolean types;
4581 - Pascal type hexadecimal constants are not supported
4582 because they conflict with the internal variables format;
4584 - support for Pascal objects and classes is not full yet;
4586 - unlike Pascal, GDB is case-sensitive for symbol names.
4588 * Changes in completion.
4590 Commands such as `shell', `run' and `set args', which pass arguments
4591 to inferior programs, now complete on file names, similar to what
4592 users expect at the shell prompt.
4594 Commands which accept locations, such as `disassemble', `print',
4595 `breakpoint', `until', etc. now complete on filenames as well as
4596 program symbols. Thus, if you type "break foob TAB", and the source
4597 files linked into the programs include `foobar.c', that file name will
4598 be one of the candidates for completion. However, file names are not
4599 considered for completion after you typed a colon that delimits a file
4600 name from a name of a function in that file, as in "break foo.c:bar".
4602 `set demangle-style' completes on available demangling styles.
4604 * New platform-independent commands:
4606 It is now possible to define a post-hook for a command as well as a
4607 hook that runs before the command. For more details, see the
4608 documentation of `hookpost' in the GDB manual.
4610 * Changes in GNU/Linux native debugging.
4612 Support for debugging multi-threaded programs has been completely
4613 revised for all platforms except m68k and sparc. You can now debug as
4614 many threads as your system allows you to have.
4616 Attach/detach is supported for multi-threaded programs.
4618 Support for SSE registers was added for x86. This doesn't work for
4619 multi-threaded programs though.
4621 * Changes in MIPS configurations.
4623 Multi-arch support is enabled for all MIPS configurations.
4625 GDB can now be built as native debugger on SGI Irix 6.x systems for
4626 debugging n32 executables. (Debugging 64-bit executables is not yet
4629 * Unified support for hardware watchpoints in all x86 configurations.
4631 Most (if not all) native x86 configurations support hardware-assisted
4632 breakpoints and watchpoints in a unified manner. This support
4633 implements debug register sharing between watchpoints, which allows to
4634 put a virtually infinite number of watchpoints on the same address,
4635 and also supports watching regions up to 16 bytes with several debug
4638 The new maintenance command `maintenance show-debug-regs' toggles
4639 debugging print-outs in functions that insert, remove, and test
4640 watchpoints and hardware breakpoints.
4642 * Changes in the DJGPP native configuration.
4644 New command ``info dos sysinfo'' displays assorted information about
4645 the CPU, OS, memory, and DPMI server.
4647 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4648 display information about segment descriptors stored in GDT, LDT, and
4651 New commands ``info dos pde'' and ``info dos pte'' display entries
4652 from Page Directory and Page Tables (for now works with CWSDPMI only).
4653 New command ``info dos address-pte'' displays the Page Table entry for
4654 a given linear address.
4656 GDB can now pass command lines longer than 126 characters to the
4657 program being debugged (requires an update to the libdbg.a library
4658 which is part of the DJGPP development kit).
4660 DWARF2 debug info is now supported.
4662 It is now possible to `step' and `next' through calls to `longjmp'.
4664 * Changes in documentation.
4666 All GDB documentation was converted to GFDL, the GNU Free
4667 Documentation License.
4669 Tracepoints-related commands are now fully documented in the GDB
4672 TUI, the Text-mode User Interface, is now documented in the manual.
4674 Tracepoints-related commands are now fully documented in the GDB
4677 The "GDB Internals" manual now has an index. It also includes
4678 documentation of `ui_out' functions, GDB coding standards, x86
4679 hardware watchpoints, and memory region attributes.
4681 * GDB's version number moved to ``version.in''
4683 The Makefile variable VERSION has been replaced by the file
4684 ``version.in''. People creating GDB distributions should update the
4685 contents of this file.
4689 GUD support is now a standard part of the EMACS distribution.
4691 *** Changes in GDB 5.0:
4693 * Improved support for debugging FP programs on x86 targets
4695 Unified and much-improved support for debugging floating-point
4696 programs on all x86 targets. In particular, ``info float'' now
4697 displays the FP registers in the same format on all x86 targets, with
4698 greater level of detail.
4700 * Improvements and bugfixes in hardware-assisted watchpoints
4702 It is now possible to watch array elements, struct members, and
4703 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4704 on x86 targets no longer erroneously trigger when the address is
4707 * Improvements in the native DJGPP version of GDB
4709 The distribution now includes all the scripts and auxiliary files
4710 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4711 machines ``out of the box''.
4713 The DJGPP version can now debug programs that use signals. It is
4714 possible to catch signals that happened in the debuggee, deliver
4715 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4716 would kill the program being debugged.) Programs that hook hardware
4717 interrupts (keyboard, timer, etc.) can also be debugged.
4719 It is now possible to debug DJGPP programs that redirect their
4720 standard handles or switch them to raw (as opposed to cooked) mode, or
4721 even close them. The command ``run < foo > bar'' works as expected,
4722 and ``info terminal'' reports useful information about the debuggee's
4723 terminal, including raw/cooked mode, redirection, etc.
4725 The DJGPP version now uses termios functions for console I/O, which
4726 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4729 DOS-style file names with drive letters are now fully supported by
4732 It is now possible to debug DJGPP programs that switch their working
4733 directory. It is also possible to rerun the debuggee any number of
4734 times without restarting GDB; thus, you can use the same setup,
4735 breakpoints, etc. for many debugging sessions.
4737 * New native configurations
4739 ARM GNU/Linux arm*-*-linux*
4740 PowerPC GNU/Linux powerpc-*-linux*
4744 Motorola MCore mcore-*-*
4745 x86 VxWorks i[3456]86-*-vxworks*
4746 PowerPC VxWorks powerpc-*-vxworks*
4747 TI TMS320C80 tic80-*-*
4749 * OBSOLETE configurations
4751 Altos 3068 m68*-altos-*
4752 Convex c1-*-*, c2-*-*
4754 ARM RISCix arm-*-* (as host)
4757 Configurations that have been declared obsolete will be commented out,
4758 but the code will be left in place. If there is no activity to revive
4759 these configurations before the next release of GDB, the sources will
4760 be permanently REMOVED.
4762 * Gould support removed
4764 Support for the Gould PowerNode and NP1 has been removed.
4766 * New features for SVR4
4768 On SVR4 native platforms (such as Solaris), if you attach to a process
4769 without first loading a symbol file, GDB will now attempt to locate and
4770 load symbols from the running process's executable file.
4772 * Many C++ enhancements
4774 C++ support has been greatly improved. Overload resolution now works properly
4775 in almost all cases. RTTI support is on the way.
4777 * Remote targets can connect to a sub-program
4779 A popen(3) style serial-device has been added. This device starts a
4780 sub-process (such as a stand-alone simulator) and then communicates
4781 with that. The sub-program to run is specified using the syntax
4782 ``|<program> <args>'' vis:
4784 (gdb) set remotedebug 1
4785 (gdb) target extended-remote |mn10300-elf-sim program-args
4787 * MIPS 64 remote protocol
4789 A long standing bug in the mips64 remote protocol where by GDB
4790 expected certain 32 bit registers (ex SR) to be transfered as 32
4791 instead of 64 bits has been fixed.
4793 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4794 added to provide backward compatibility with older versions of GDB.
4796 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4798 The command ``set remotebinarydownload'' command has been replaced by
4799 ``set remote X-packet''. Other commands in ``set remote'' family
4800 include ``set remote P-packet''.
4802 * Breakpoint commands accept ranges.
4804 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4805 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4806 ``tracepoint passcount'' also accepts a range of tracepoints.
4808 * ``apropos'' command added.
4810 The ``apropos'' command searches through command names and
4811 documentation strings, printing out matches, making it much easier to
4812 try to find a command that does what you are looking for.
4816 A new machine oriented interface (MI) has been added to GDB. This
4817 interface is designed for debug environments running GDB as a separate
4818 process. This is part of the long term libGDB project. See the
4819 "GDB/MI" chapter of the GDB manual for further information. It can be
4820 enabled by configuring with:
4822 .../configure --enable-gdbmi
4824 *** Changes in GDB-4.18:
4826 * New native configurations
4828 HP-UX 10.20 hppa*-*-hpux10.20
4829 HP-UX 11.x hppa*-*-hpux11.0*
4830 M68K GNU/Linux m68*-*-linux*
4834 Fujitsu FR30 fr30-*-elf*
4835 Intel StrongARM strongarm-*-*
4836 Mitsubishi D30V d30v-*-*
4838 * OBSOLETE configurations
4840 Gould PowerNode, NP1 np1-*-*, pn-*-*
4842 Configurations that have been declared obsolete will be commented out,
4843 but the code will be left in place. If there is no activity to revive
4844 these configurations before the next release of GDB, the sources will
4845 be permanently REMOVED.
4849 As a compatibility experiment, GDB's source files buildsym.h and
4850 buildsym.c have been converted to pure standard C, no longer
4851 containing any K&R compatibility code. We believe that all systems in
4852 use today either come with a standard C compiler, or have a GCC port
4853 available. If this is not true, please report the affected
4854 configuration to bug-gdb@gnu.org immediately. See the README file for
4855 information about getting a standard C compiler if you don't have one
4860 GDB now uses readline 2.2.
4862 * set extension-language
4864 You can now control the mapping between filename extensions and source
4865 languages by using the `set extension-language' command. For instance,
4866 you can ask GDB to treat .c files as C++ by saying
4867 set extension-language .c c++
4868 The command `info extensions' lists all of the recognized extensions
4869 and their associated languages.
4871 * Setting processor type for PowerPC and RS/6000
4873 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4874 you can use the `set processor' command to specify what variant of the
4875 PowerPC family you are debugging. The command
4879 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4880 following PowerPC and RS6000 variants:
4882 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4883 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4885 403GC IBM PowerPC 403GC
4886 505 Motorola PowerPC 505
4887 860 Motorola PowerPC 860 or 850
4888 601 Motorola PowerPC 601
4889 602 Motorola PowerPC 602
4890 603 Motorola/IBM PowerPC 603 or 603e
4891 604 Motorola PowerPC 604 or 604e
4892 750 Motorola/IBM PowerPC 750 or 750
4894 At the moment, this command just tells GDB what to name the
4895 special-purpose processor registers. Since almost all the affected
4896 registers are inaccessible to user-level programs, this command is
4897 only useful for remote debugging in its present form.
4901 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4902 more extensive support for HP-UX. Added features include shared
4903 library support, kernel threads and hardware watchpoints for 11.00,
4904 support for HP's ANSI C and C++ compilers, and a compatibility mode
4905 for xdb and dbx commands.
4909 HP's donation includes the new concept of catchpoints, which is a
4910 generalization of the old catch command. On HP-UX, it is now possible
4911 to catch exec, fork, and vfork, as well as library loading.
4913 This means that the existing catch command has changed; its first
4914 argument now specifies the type of catch to be set up. See the
4915 output of "help catch" for a list of catchpoint types.
4917 * Debugging across forks
4919 On HP-UX, you can choose which process to debug when a fork() happens
4924 HP has donated a curses-based terminal user interface (TUI). To get
4925 it, build with --enable-tui. Although this can be enabled for any
4926 configuration, at present it only works for native HP debugging.
4928 * GDB remote protocol additions
4930 A new protocol packet 'X' that writes binary data is now available.
4931 Default behavior is to try 'X', then drop back to 'M' if the stub
4932 fails to respond. The settable variable `remotebinarydownload'
4933 allows explicit control over the use of 'X'.
4935 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4936 full 64-bit address. The command
4938 set remoteaddresssize 32
4940 can be used to revert to the old behaviour. For existing remote stubs
4941 the change should not be noticed, as the additional address information
4944 In order to assist in debugging stubs, you may use the maintenance
4945 command `packet' to send any text string to the stub. For instance,
4947 maint packet heythere
4949 sends the packet "$heythere#<checksum>". Note that it is very easy to
4950 disrupt a debugging session by sending the wrong packet at the wrong
4953 The compare-sections command allows you to compare section data on the
4954 target to what is in the executable file without uploading or
4955 downloading, by comparing CRC checksums.
4957 * Tracing can collect general expressions
4959 You may now collect general expressions at tracepoints. This requires
4960 further additions to the target-side stub; see tracepoint.c and
4961 doc/agentexpr.texi for further details.
4963 * mask-address variable for Mips
4965 For Mips targets, you may control the zeroing of the upper 32 bits of
4966 a 64-bit address by entering `set mask-address on'. This is mainly
4967 of interest to users of embedded R4xxx and R5xxx processors.
4969 * Higher serial baud rates
4971 GDB's serial code now allows you to specify baud rates 57600, 115200,
4972 230400, and 460800 baud. (Note that your host system may not be able
4973 to achieve all of these rates.)
4977 The i960 configuration now includes an initial implementation of a
4978 builtin simulator, contributed by Jim Wilson.
4981 *** Changes in GDB-4.17:
4983 * New native configurations
4985 Alpha GNU/Linux alpha*-*-linux*
4986 Unixware 2.x i[3456]86-unixware2*
4987 Irix 6.x mips*-sgi-irix6*
4988 PowerPC GNU/Linux powerpc-*-linux*
4989 PowerPC Solaris powerpcle-*-solaris*
4990 Sparc GNU/Linux sparc-*-linux*
4991 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4995 Argonaut Risc Chip (ARC) arc-*-*
4996 Hitachi H8/300S h8300*-*-*
4997 Matsushita MN10200 w/simulator mn10200-*-*
4998 Matsushita MN10300 w/simulator mn10300-*-*
4999 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5000 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5001 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5002 Mitsubishi D10V w/simulator d10v-*-*
5003 Mitsubishi M32R/D w/simulator m32r-*-elf*
5004 Tsqware Sparclet sparclet-*-*
5005 NEC V850 w/simulator v850-*-*
5007 * New debugging protocols
5009 ARM with RDI protocol arm*-*-*
5010 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5011 DDB and LSI variants of PMON protocol mips*-*-*
5012 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5013 PowerPC with SDS protocol powerpc{,le}-*-eabi
5014 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5018 All configurations can now understand and use the DWARF 2 debugging
5019 format. The choice is automatic, if the symbol file contains DWARF 2
5024 GDB now includes basic Java language support. This support is
5025 only useful with Java compilers that produce native machine code.
5027 * solib-absolute-prefix and solib-search-path
5029 For SunOS and SVR4 shared libraries, you may now set the prefix for
5030 loading absolute shared library symbol files, and the search path for
5031 locating non-absolute shared library symbol files.
5033 * Live range splitting
5035 GDB can now effectively debug code for which GCC has performed live
5036 range splitting as part of its optimization. See gdb/doc/LRS for
5037 more details on the expected format of the stabs information.
5041 GDB's support for the GNU Hurd, including thread debugging, has been
5042 updated to work with current versions of the Hurd.
5046 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5047 instruction set. ARM GDB automatically detects when Thumb
5048 instructions are in use, and adjusts disassembly and backtracing
5053 GDB's MIPS target configurations now handle the MIP16 16-bit
5058 GDB now includes support for overlays; if an executable has been
5059 linked such that multiple sections are based at the same address, GDB
5060 will decide which section to use for symbolic info. You can choose to
5061 control the decision manually, using overlay commands, or implement
5062 additional target-side support and use "overlay load-target" to bring
5063 in the overlay mapping. Do "help overlay" for more detail.
5067 The command "info symbol <address>" displays information about
5068 the symbol at the specified address.
5072 The standard remote protocol now includes an extension that allows
5073 asynchronous collection and display of trace data. This requires
5074 extensive support in the target-side debugging stub. Tracing mode
5075 includes a new interaction mode in GDB and new commands: see the
5076 file tracepoint.c for more details.
5080 Configurations for embedded MIPS now include a simulator contributed
5081 by Cygnus Solutions. The simulator supports the instruction sets
5082 of most MIPS variants.
5086 Sparc configurations may now include the ERC32 simulator contributed
5087 by the European Space Agency. The simulator is not built into
5088 Sparc targets by default; configure with --enable-sim to include it.
5092 For target configurations that may include multiple variants of a
5093 basic architecture (such as MIPS and SH), you may now set the
5094 architecture explicitly. "set arch" sets, "info arch" lists
5095 the possible architectures.
5097 *** Changes in GDB-4.16:
5099 * New native configurations
5101 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5102 M68K NetBSD m68k-*-netbsd*
5103 PowerPC AIX 4.x powerpc-*-aix*
5104 PowerPC MacOS powerpc-*-macos*
5105 PowerPC Windows NT powerpcle-*-cygwin32
5106 RS/6000 AIX 4.x rs6000-*-aix4*
5110 ARM with RDP protocol arm-*-*
5111 I960 with MON960 i960-*-coff
5112 MIPS VxWorks mips*-*-vxworks*
5113 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5114 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5116 Matra Sparclet sparclet-*-*
5120 The powerpc-eabi configuration now includes the PSIM simulator,
5121 contributed by Andrew Cagney, with assistance from Mike Meissner.
5122 PSIM is a very elaborate model of the PowerPC, including not only
5123 basic instruction set execution, but also details of execution unit
5124 performance and I/O hardware. See sim/ppc/README for more details.
5128 GDB now works with Solaris 2.5.
5130 * Windows 95/NT native
5132 GDB will now work as a native debugger on Windows 95 and Windows NT.
5133 To build it from source, you must use the "gnu-win32" environment,
5134 which uses a DLL to emulate enough of Unix to run the GNU tools.
5135 Further information, binaries, and sources are available at
5136 ftp.cygnus.com, under pub/gnu-win32.
5138 * dont-repeat command
5140 If a user-defined command includes the command `dont-repeat', then the
5141 command will not be repeated if the user just types return. This is
5142 useful if the command is time-consuming to run, so that accidental
5143 extra keystrokes don't run the same command many times.
5145 * Send break instead of ^C
5147 The standard remote protocol now includes an option to send a break
5148 rather than a ^C to the target in order to interrupt it. By default,
5149 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5151 * Remote protocol timeout
5153 The standard remote protocol includes a new variable `remotetimeout'
5154 that allows you to set the number of seconds before GDB gives up trying
5155 to read from the target. The default value is 2.
5157 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5159 By default GDB will automatically keep track of objects as they are
5160 loaded and unloaded by the dynamic linker. By using the command `set
5161 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5162 when shared library events occur, thus allowing you to set breakpoints
5163 in shared libraries which are explicitly loaded by the inferior.
5165 Note this feature does not work on hpux8. On hpux9 you must link
5166 /usr/lib/end.o into your program. This feature should work
5167 automatically on hpux10.
5169 * Irix 5.x hardware watchpoint support
5171 Irix 5 configurations now support the use of hardware watchpoints.
5173 * Mips protocol "SYN garbage limit"
5175 When debugging a Mips target using the `target mips' protocol, you
5176 may set the number of characters that GDB will ignore by setting
5177 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5178 every character. The default value is 1050.
5180 * Recording and replaying remote debug sessions
5182 If you set `remotelogfile' to the name of a file, gdb will write to it
5183 a recording of a remote debug session. This recording may then be
5184 replayed back to gdb using "gdbreplay". See gdbserver/README for
5185 details. This is useful when you have a problem with GDB while doing
5186 remote debugging; you can make a recording of the session and send it
5187 to someone else, who can then recreate the problem.
5189 * Speedups for remote debugging
5191 GDB includes speedups for downloading and stepping MIPS systems using
5192 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5193 and more efficient S-record downloading.
5195 * Memory use reductions and statistics collection
5197 GDB now uses less memory and reports statistics about memory usage.
5198 Try the `maint print statistics' command, for example.
5200 *** Changes in GDB-4.15:
5202 * Psymtabs for XCOFF
5204 The symbol reader for AIX GDB now uses partial symbol tables. This
5205 can greatly improve startup time, especially for large executables.
5207 * Remote targets use caching
5209 Remote targets now use a data cache to speed up communication with the
5210 remote side. The data cache could lead to incorrect results because
5211 it doesn't know about volatile variables, thus making it impossible to
5212 debug targets which use memory mapped I/O devices. `set remotecache
5213 off' turns the the data cache off.
5215 * Remote targets may have threads
5217 The standard remote protocol now includes support for multiple threads
5218 in the target system, using new protocol commands 'H' and 'T'. See
5219 gdb/remote.c for details.
5223 If GDB is configured with `--enable-netrom', then it will include
5224 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5225 acts as though it is a bank of ROM on the target board, but you can
5226 write into it over the network. GDB's support consists only of
5227 support for fast loading into the emulated ROM; to debug, you must use
5228 another protocol, such as standard remote protocol. The usual
5229 sequence is something like
5231 target nrom <netrom-hostname>
5233 target remote <netrom-hostname>:1235
5237 GDB now includes support for the Apple Macintosh, as a host only. It
5238 may be run as either an MPW tool or as a standalone application, and
5239 it can debug through the serial port. All the usual GDB commands are
5240 available, but to the target command, you must supply "serial" as the
5241 device type instead of "/dev/ttyXX". See mpw-README in the main
5242 directory for more information on how to build. The MPW configuration
5243 scripts */mpw-config.in support only a few targets, and only the
5244 mips-idt-ecoff target has been tested.
5248 GDB configuration now uses autoconf. This is not user-visible,
5249 but does simplify configuration and building.
5253 GDB now supports hpux10.
5255 *** Changes in GDB-4.14:
5257 * New native configurations
5259 x86 FreeBSD i[345]86-*-freebsd
5260 x86 NetBSD i[345]86-*-netbsd
5261 NS32k NetBSD ns32k-*-netbsd
5262 Sparc NetBSD sparc-*-netbsd
5266 A29K VxWorks a29k-*-vxworks
5267 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5268 CPU32 EST-300 emulator m68*-*-est*
5269 PowerPC ELF powerpc-*-elf
5272 * Alpha OSF/1 support for procfs
5274 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5275 possible to attach to running processes. As the mounting of the /proc
5276 filesystem is optional on the Alpha, GDB automatically determines
5277 the availability of /proc during startup. This can lead to problems
5278 if /proc is unmounted after GDB has been started.
5280 * Arguments to user-defined commands
5282 User commands may accept up to 10 arguments separated by whitespace.
5283 Arguments are accessed within the user command via $arg0..$arg9. A
5286 print $arg0 + $arg1 + $arg2
5288 To execute the command use:
5291 Defines the command "adder" which prints the sum of its three arguments.
5292 Note the arguments are text substitutions, so they may reference variables,
5293 use complex expressions, or even perform inferior function calls.
5295 * New `if' and `while' commands
5297 This makes it possible to write more sophisticated user-defined
5298 commands. Both commands take a single argument, which is the
5299 expression to evaluate, and must be followed by the commands to
5300 execute, one per line, if the expression is nonzero, the list being
5301 terminated by the word `end'. The `if' command list may include an
5302 `else' word, which causes the following commands to be executed only
5303 if the expression is zero.
5305 * Fortran source language mode
5307 GDB now includes partial support for Fortran 77. It will recognize
5308 Fortran programs and can evaluate a subset of Fortran expressions, but
5309 variables and functions may not be handled correctly. GDB will work
5310 with G77, but does not yet know much about symbols emitted by other
5313 * Better HPUX support
5315 Most debugging facilities now work on dynamic executables for HPPAs
5316 running hpux9 or later. You can attach to running dynamically linked
5317 processes, but by default the dynamic libraries will be read-only, so
5318 for instance you won't be able to put breakpoints in them. To change
5319 that behavior do the following before running the program:
5325 This will cause the libraries to be mapped private and read-write.
5326 To revert to the normal behavior, do this:
5332 You cannot set breakpoints or examine data in the library until after
5333 the library is loaded if the function/data symbols do not have
5336 GDB can now also read debug symbols produced by the HP C compiler on
5337 HPPAs (sorry, no C++, Fortran or 68k support).
5339 * Target byte order now dynamically selectable
5341 You can choose which byte order to use with a target system, via the
5342 commands "set endian big" and "set endian little", and you can see the
5343 current setting by using "show endian". You can also give the command
5344 "set endian auto", in which case GDB will use the byte order
5345 associated with the executable. Currently, only embedded MIPS
5346 configurations support dynamic selection of target byte order.
5348 * New DOS host serial code
5350 This version uses DPMI interrupts to handle buffered I/O, so you
5351 no longer need to run asynctsr when debugging boards connected to
5354 *** Changes in GDB-4.13:
5356 * New "complete" command
5358 This lists all the possible completions for the rest of the line, if it
5359 were to be given as a command itself. This is intended for use by emacs.
5361 * Trailing space optional in prompt
5363 "set prompt" no longer adds a space for you after the prompt you set. This
5364 allows you to set a prompt which ends in a space or one that does not.
5366 * Breakpoint hit counts
5368 "info break" now displays a count of the number of times the breakpoint
5369 has been hit. This is especially useful in conjunction with "ignore"; you
5370 can ignore a large number of breakpoint hits, look at the breakpoint info
5371 to see how many times the breakpoint was hit, then run again, ignoring one
5372 less than that number, and this will get you quickly to the last hit of
5375 * Ability to stop printing at NULL character
5377 "set print null-stop" will cause GDB to stop printing the characters of
5378 an array when the first NULL is encountered. This is useful when large
5379 arrays actually contain only short strings.
5381 * Shared library breakpoints
5383 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5384 breakpoints in shared libraries before the executable is run.
5386 * Hardware watchpoints
5388 There is a new hardware breakpoint for the watch command for sparclite
5389 targets. See gdb/sparclite/hw_breakpoint.note.
5391 Hardware watchpoints are also now supported under GNU/Linux.
5395 Annotations have been added. These are for use with graphical interfaces,
5396 and are still experimental. Currently only gdba.el uses these.
5398 * Improved Irix 5 support
5400 GDB now works properly with Irix 5.2.
5402 * Improved HPPA support
5404 GDB now works properly with the latest GCC and GAS.
5406 * New native configurations
5408 Sequent PTX4 i[34]86-sequent-ptx4
5409 HPPA running OSF/1 hppa*-*-osf*
5410 Atari TT running SVR4 m68*-*-sysv4*
5411 RS/6000 LynxOS rs6000-*-lynxos*
5415 OS/9000 i[34]86-*-os9k
5416 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5419 * Hitachi SH7000 and E7000-PC ICE support
5421 There is now support for communicating with the Hitachi E7000-PC ICE.
5422 This is available automatically when GDB is configured for the SH.
5426 As usual, a variety of small fixes and improvements, both generic
5427 and configuration-specific. See the ChangeLog for more detail.
5429 *** Changes in GDB-4.12:
5431 * Irix 5 is now supported
5435 GDB-4.12 on the HPPA has a number of changes which make it unable
5436 to debug the output from the currently released versions of GCC and
5437 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5438 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5439 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5442 *** Changes in GDB-4.11:
5444 * User visible changes:
5448 The "set remotedebug" option is now consistent between the mips remote
5449 target, remote targets using the gdb-specific protocol, UDI (AMD's
5450 debug protocol for the 29k) and the 88k bug monitor. It is now an
5451 integer specifying a debug level (normally 0 or 1, but 2 means more
5452 debugging info for the mips target).
5454 * DEC Alpha native support
5456 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5457 debug info, but GDB works fairly well with the DEC compiler and should
5458 work with a future GCC release. See the README file for a few
5459 Alpha-specific notes.
5461 * Preliminary thread implementation
5463 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5465 * LynxOS native and target support for 386
5467 This release has been hosted on LynxOS 2.2, and also can be configured
5468 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5471 * Improvements in C++ mangling/demangling.
5473 This release has much better g++ debugging, specifically in name
5474 mangling/demangling, virtual function calls, print virtual table,
5475 call methods, ...etc.
5477 *** Changes in GDB-4.10:
5479 * User visible changes:
5481 Remote debugging using the GDB-specific (`target remote') protocol now
5482 supports the `load' command. This is only useful if you have some
5483 other way of getting the stub to the target system, and you can put it
5484 somewhere in memory where it won't get clobbered by the download.
5486 Filename completion now works.
5488 When run under emacs mode, the "info line" command now causes the
5489 arrow to point to the line specified. Also, "info line" prints
5490 addresses in symbolic form (as well as hex).
5492 All vxworks based targets now support a user settable option, called
5493 vxworks-timeout. This option represents the number of seconds gdb
5494 should wait for responses to rpc's. You might want to use this if
5495 your vxworks target is, perhaps, a slow software simulator or happens
5496 to be on the far side of a thin network line.
5500 This release contains support for using a DEC alpha as a GDB host for
5501 cross debugging. Native alpha debugging is not supported yet.
5504 *** Changes in GDB-4.9:
5508 This is the first GDB release which is accompanied by a matching testsuite.
5509 The testsuite requires installation of dejagnu, which should be available
5510 via ftp from most sites that carry GNU software.
5514 'Cfront' style demangling has had its name changed to 'ARM' style, to
5515 emphasize that it was written from the specifications in the C++ Annotated
5516 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5517 disclaimers, it still generated too much confusion with users attempting to
5518 use gdb with AT&T cfront.
5522 GDB now uses a standard remote interface to a simulator library.
5523 So far, the library contains simulators for the Zilog Z8001/2, the
5524 Hitachi H8/300, H8/500 and Super-H.
5526 * New targets supported
5528 H8/300 simulator h8300-hitachi-hms or h8300hms
5529 H8/500 simulator h8500-hitachi-hms or h8500hms
5530 SH simulator sh-hitachi-hms or sh
5531 Z8000 simulator z8k-zilog-none or z8ksim
5532 IDT MIPS board over serial line mips-idt-ecoff
5534 Cross-debugging to GO32 targets is supported. It requires a custom
5535 version of the i386-stub.c module which is integrated with the
5536 GO32 memory extender.
5538 * New remote protocols
5540 MIPS remote debugging protocol.
5542 * New source languages supported
5544 This version includes preliminary support for Chill, a Pascal like language
5545 used by telecommunications companies. Chill support is also being integrated
5546 into the GNU compiler, but we don't know when it will be publically available.
5549 *** Changes in GDB-4.8:
5551 * HP Precision Architecture supported
5553 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5554 version of this support was available as a set of patches from the
5555 University of Utah. GDB does not support debugging of programs
5556 compiled with the HP compiler, because HP will not document their file
5557 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5558 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5560 Many problems in the preliminary version have been fixed.
5562 * Faster and better demangling
5564 We have improved template demangling and fixed numerous bugs in the GNU style
5565 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5566 character types (wchar_t) are now supported. Demangling of each symbol is now
5567 only done once, and is cached when the symbol table for a file is read in.
5568 This results in a small increase in memory usage for C programs, a moderate
5569 increase in memory usage for C++ programs, and a fantastic speedup in
5572 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5573 from the specifications in the Annotated Reference Manual, which AT&T's
5574 compiler does not actually implement.
5576 * G++ multiple inheritance compiler problem
5578 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5579 inheritance lattices was reworked to properly discover ambiguities. We
5580 recently found an example which causes this new algorithm to fail in a
5581 very subtle way, producing bad debug information for those classes.
5582 The file 'gcc.patch' (in this directory) can be applied to gcc to
5583 circumvent the problem. A future GCC release will contain a complete
5586 The previous G++ debug info problem (mentioned below for the gdb-4.7
5587 release) is fixed in gcc version 2.3.2.
5589 * Improved configure script
5591 The `configure' script will now attempt to guess your system type if
5592 you don't supply a host system type. The old scheme of supplying a
5593 host system triplet is preferable over using this. All the magic is
5594 done in the new `config.guess' script. Examine it for details.
5596 We have also brought our configure script much more in line with the FSF's
5597 version. It now supports the --with-xxx options. In particular,
5598 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5599 The resulting GDB will not be able to read arbitrary object file formats --
5600 only the format ``expected'' to be used on the configured target system.
5601 We hope to make this the default in a future release.
5603 * Documentation improvements
5605 There's new internal documentation on how to modify GDB, and how to
5606 produce clean changes to the code. We implore people to read it
5607 before submitting changes.
5609 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5610 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5611 `info' files are also provided. To build `info' files from scratch,
5612 you will need the latest `makeinfo' release, which will be available in
5613 a future texinfo-X.Y release.
5615 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5616 We're not sure exactly which versions have this problem, but it has
5617 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5618 or better. If that isn't possible, there is a patch in
5619 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5620 around this problem.
5624 GDB now supports array constants that can be used in expressions typed in by
5625 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5626 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5629 The new directory `gdb/sparclite' contains a program that demonstrates
5630 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5632 * New native hosts supported
5634 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5635 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5637 * New targets supported
5639 AMD 29k family via UDI a29k-amd-udi or udi29k
5641 * New file formats supported
5643 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5644 HPUX core files, and SCO 3.2v2 core files.
5648 Attaching to processes now works again; thanks for the many bug reports.
5650 We have also stomped on a bunch of core dumps caused by
5651 printf_filtered("%s") problems.
5653 We eliminated a copyright problem on the rpc and ptrace header files
5654 for VxWorks, which was discovered at the last minute during the 4.7
5655 release. You should now be able to build a VxWorks GDB.
5657 You can now interrupt gdb while an attached process is running. This
5658 will cause the attached process to stop, and give control back to GDB.
5660 We fixed problems caused by using too many file descriptors
5661 for reading symbols from object files and libraries. This was
5662 especially a problem for programs that used many (~100) shared
5665 The `step' command now only enters a subroutine if there is line number
5666 information for the subroutine. Otherwise it acts like the `next'
5667 command. Previously, `step' would enter subroutines if there was
5668 any debugging information about the routine. This avoids problems
5669 when using `cc -g1' on MIPS machines.
5671 * Internal improvements
5673 GDB's internal interfaces have been improved to make it easier to support
5674 debugging of multiple languages in the future.
5676 GDB now uses a common structure for symbol information internally.
5677 Minimal symbols (derived from linkage symbols in object files), partial
5678 symbols (from a quick scan of debug information), and full symbols
5679 contain a common subset of information, making it easier to write
5680 shared code that handles any of them.
5682 * New command line options
5684 We now accept --silent as an alias for --quiet.
5688 The memory-mapped-malloc library is now licensed under the GNU Library
5689 General Public License.
5691 *** Changes in GDB-4.7:
5693 * Host/native/target split
5695 GDB has had some major internal surgery to untangle the support for
5696 hosts and remote targets. Now, when you configure GDB for a remote
5697 target, it will no longer load in all of the support for debugging
5698 local programs on the host. When fully completed and tested, this will
5699 ensure that arbitrary host/target combinations are possible.
5701 The primary conceptual shift is to separate the non-portable code in
5702 GDB into three categories. Host specific code is required any time GDB
5703 is compiled on that host, regardless of the target. Target specific
5704 code relates to the peculiarities of the target, but can be compiled on
5705 any host. Native specific code is everything else: it can only be
5706 built when the host and target are the same system. Child process
5707 handling and core file support are two common `native' examples.
5709 GDB's use of /proc for controlling Unix child processes is now cleaner.
5710 It has been split out into a single module under the `target_ops' vector,
5711 plus two native-dependent functions for each system that uses /proc.
5713 * New hosts supported
5715 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5716 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5717 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5719 * New targets supported
5721 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5722 68030 and CPU32 m68030-*-*, m68332-*-*
5724 * New native hosts supported
5726 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5727 (386bsd is not well tested yet)
5728 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5730 * New file formats supported
5732 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5733 supports reading of `a.out.adobe' object files, which are an a.out
5734 format extended with minimal information about multiple sections.
5738 `show copying' is the same as the old `info copying'.
5739 `show warranty' is the same as `info warrantee'.
5740 These were renamed for consistency. The old commands continue to work.
5742 `info handle' is a new alias for `info signals'.
5744 You can now define pre-command hooks, which attach arbitrary command
5745 scripts to any command. The commands in the hook will be executed
5746 prior to the user's command. You can also create a hook which will be
5747 executed whenever the program stops. See gdb.texinfo.
5751 We now deal with Cfront style name mangling, and can even extract type
5752 info from mangled symbols. GDB can automatically figure out which
5753 symbol mangling style your C++ compiler uses.
5755 Calling of methods and virtual functions has been improved as well.
5759 The crash that occured when debugging Sun Ansi-C compiled binaries is
5760 fixed. This was due to mishandling of the extra N_SO stabs output
5763 We also finally got Ultrix 4.2 running in house, and fixed core file
5764 support, with help from a dozen people on the net.
5766 John M. Farrell discovered that the reason that single-stepping was so
5767 slow on all of the Mips based platforms (primarily SGI and DEC) was
5768 that we were trying to demangle and lookup a symbol used for internal
5769 purposes on every instruction that was being stepped through. Changing
5770 the name of that symbol so that it couldn't be mistaken for a C++
5771 mangled symbol sped things up a great deal.
5773 Rich Pixley sped up symbol lookups in general by getting much smarter
5774 about when C++ symbol mangling is necessary. This should make symbol
5775 completion (TAB on the command line) much faster. It's not as fast as
5776 we'd like, but it's significantly faster than gdb-4.6.
5780 A new user controllable variable 'call_scratch_address' can
5781 specify the location of a scratch area to be used when GDB
5782 calls a function in the target. This is necessary because the
5783 usual method of putting the scratch area on the stack does not work
5784 in systems that have separate instruction and data spaces.
5786 We integrated changes to support the 29k UDI (Universal Debugger
5787 Interface), but discovered at the last minute that we didn't have all
5788 of the appropriate copyright paperwork. We are working with AMD to
5789 resolve this, and hope to have it available soon.
5793 We have sped up the remote serial line protocol, especially for targets
5794 with lots of registers. It now supports a new `expedited status' ('T')
5795 message which can be used in place of the existing 'S' status message.
5796 This allows the remote stub to send only the registers that GDB
5797 needs to make a quick decision about single-stepping or conditional
5798 breakpoints, eliminating the need to fetch the entire register set for
5799 each instruction being stepped through.
5801 The GDB remote serial protocol now implements a write-through cache for
5802 registers, only re-reading the registers if the target has run.
5804 There is also a new remote serial stub for SPARC processors. You can
5805 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5806 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5807 processor with a serial port.
5811 Configure.in files have become much easier to read and modify. A new
5812 `table driven' format makes it more obvious what configurations are
5813 supported, and what files each one uses.
5817 There is a new opcodes library which will eventually contain all of the
5818 disassembly routines and opcode tables. At present, it only contains
5819 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5820 disassembler (binutils/objdump) to share these routines.
5822 The libiberty library is now copylefted under the GNU Library General
5823 Public License. This allows more liberal use, and was done so libg++
5824 can use it. This makes no difference to GDB, since the Library License
5825 grants all the rights from the General Public License.
5829 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5830 reference to the stabs symbol info used by the debugger. It is (as far
5831 as we know) the only published document on this fascinating topic. We
5832 encourage you to read it, compare it to the stabs information on your
5833 system, and send improvements on the document in general (to
5834 bug-gdb@prep.ai.mit.edu).
5836 And, of course, many bugs have been fixed.
5839 *** Changes in GDB-4.6:
5841 * Better support for C++ function names
5843 GDB now accepts as input the "demangled form" of C++ overloaded function
5844 names and member function names, and can do command completion on such names
5845 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5846 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5847 Make use of command completion, it is your friend.
5849 GDB also now accepts a variety of C++ mangled symbol formats. They are
5850 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5851 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5852 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5853 for the list of formats.
5855 * G++ symbol mangling problem
5857 Recent versions of gcc have a bug in how they emit debugging information for
5858 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5859 directory) can be applied to gcc to fix the problem. Alternatively, if you
5860 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5861 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5862 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5865 * New 'maintenance' command
5867 All of the commands related to hacking GDB internals have been moved out of
5868 the main command set, and now live behind the 'maintenance' command. This
5869 can also be abbreviated as 'mt'. The following changes were made:
5871 dump-me -> maintenance dump-me
5872 info all-breakpoints -> maintenance info breakpoints
5873 printmsyms -> maintenance print msyms
5874 printobjfiles -> maintenance print objfiles
5875 printpsyms -> maintenance print psymbols
5876 printsyms -> maintenance print symbols
5878 The following commands are new:
5880 maintenance demangle Call internal GDB demangler routine to
5881 demangle a C++ link name and prints the result.
5882 maintenance print type Print a type chain for a given symbol
5884 * Change to .gdbinit file processing
5886 We now read the $HOME/.gdbinit file before processing the argv arguments
5887 (e.g. reading symbol files or core files). This allows global parameters to
5888 be set, which will apply during the symbol reading. The ./.gdbinit is still
5889 read after argv processing.
5891 * New hosts supported
5893 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5895 GNU/Linux support i386-unknown-linux or linux
5897 We are also including code to support the HP/PA running BSD and HPUX. This
5898 is almost guaranteed not to work, as we didn't have time to test or build it
5899 for this release. We are including it so that the more adventurous (or
5900 masochistic) of you can play with it. We also had major problems with the
5901 fact that the compiler that we got from HP doesn't support the -g option.
5904 * New targets supported
5906 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5908 * More smarts about finding #include files
5910 GDB now remembers the compilation directory for all include files, and for
5911 all files from which C is generated (like yacc and lex sources). This
5912 greatly improves GDB's ability to find yacc/lex sources, and include files,
5913 especially if you are debugging your program from a directory different from
5914 the one that contains your sources.
5916 We also fixed a bug which caused difficulty with listing and setting
5917 breakpoints in include files which contain C code. (In the past, you had to
5918 try twice in order to list an include file that you hadn't looked at before.)
5920 * Interesting infernals change
5922 GDB now deals with arbitrary numbers of sections, where the symbols for each
5923 section must be relocated relative to that section's landing place in the
5924 target's address space. This work was needed to support ELF with embedded
5925 stabs used by Solaris-2.0.
5927 * Bug fixes (of course!)
5929 There have been loads of fixes for the following things:
5930 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5931 i960, stabs, DOS(GO32), procfs, etc...
5933 See the ChangeLog for details.
5935 *** Changes in GDB-4.5:
5937 * New machines supported (host and target)
5939 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5941 SGI Irix-4.x mips-sgi-irix4 or iris4
5943 * New malloc package
5945 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5946 Mmalloc is capable of handling mutiple heaps of memory. It is also
5947 capable of saving a heap to a file, and then mapping it back in later.
5948 This can be used to greatly speedup the startup of GDB by using a
5949 pre-parsed symbol table which lives in a mmalloc managed heap. For
5950 more details, please read mmalloc/mmalloc.texi.
5954 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5955 'help info proc' for details.
5957 * MIPS ecoff symbol table format
5959 The code that reads MIPS symbol table format is now supported on all hosts.
5960 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5963 * File name changes for MS-DOS
5965 Many files in the config directories have been renamed to make it easier to
5966 support GDB on MS-DOSe systems (which have very restrictive file name
5967 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5968 environment) is close to working but has some remaining problems. Note
5969 that debugging of DOS programs is not supported, due to limitations
5970 in the ``operating system'', but it can be used to host cross-debugging.
5972 * Cross byte order fixes
5974 Many fixes have been made to support cross debugging of Sparc and MIPS
5975 targets from hosts whose byte order differs.
5977 * New -mapped and -readnow options
5979 If memory-mapped files are available on your system through the 'mmap'
5980 system call, you can use the -mapped option on the `file' or
5981 `symbol-file' commands to cause GDB to write the symbols from your
5982 program into a reusable file. If the program you are debugging is
5983 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5984 Future GDB debugging sessions will notice the presence of this file,
5985 and will quickly map in symbol information from it, rather than reading
5986 the symbol table from the executable program. Using the '-mapped'
5987 option in a GDB `file' or `symbol-file' command has the same effect as
5988 starting GDB with the '-mapped' command-line option.
5990 You can cause GDB to read the entire symbol table immediately by using
5991 the '-readnow' option with any of the commands that load symbol table
5992 information (or on the GDB command line). This makes the command
5993 slower, but makes future operations faster.
5995 The -mapped and -readnow options are typically combined in order to
5996 build a `fred.syms' file that contains complete symbol information.
5997 A simple GDB invocation to do nothing but build a `.syms' file for future
6000 gdb -batch -nx -mapped -readnow programname
6002 The `.syms' file is specific to the host machine on which GDB is run.
6003 It holds an exact image of GDB's internal symbol table. It cannot be
6004 shared across multiple host platforms.
6006 * longjmp() handling
6008 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6009 siglongjmp() without losing control. This feature has not yet been ported to
6010 all systems. It currently works on many 386 platforms, all MIPS-based
6011 platforms (SGI, DECstation, etc), and Sun3/4.
6015 Preliminary work has been put in to support the new Solaris OS from Sun. At
6016 this time, it can control and debug processes, but it is not capable of
6021 As always, many many bug fixes. The major areas were with g++, and mipsread.
6022 People using the MIPS-based platforms should experience fewer mysterious
6023 crashes and trashed symbol tables.
6025 *** Changes in GDB-4.4:
6027 * New machines supported (host and target)
6029 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6031 BSD Reno on Vax vax-dec-bsd
6032 Ultrix on Vax vax-dec-ultrix
6034 * New machines supported (target)
6036 AMD 29000 embedded, using EBMON a29k-none-none
6040 GDB continues to improve its handling of C++. `References' work better.
6041 The demangler has also been improved, and now deals with symbols mangled as
6042 per the Annotated C++ Reference Guide.
6044 GDB also now handles `stabs' symbol information embedded in MIPS
6045 `ecoff' symbol tables. Since the ecoff format was not easily
6046 extensible to handle new languages such as C++, this appeared to be a
6047 good way to put C++ debugging info into MIPS binaries. This option
6048 will be supported in the GNU C compiler, version 2, when it is
6051 * New features for SVR4
6053 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6054 shared libraries. Debugging dynamically linked programs should present
6055 only minor differences from debugging statically linked programs.
6057 The `info proc' command will print out information about any process
6058 on an SVR4 system (including the one you are debugging). At the moment,
6059 it prints the address mappings of the process.
6061 If you bring up GDB on another SVR4 system, please send mail to
6062 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6064 * Better dynamic linking support in SunOS
6066 Reading symbols from shared libraries which contain debugging symbols
6067 now works properly. However, there remain issues such as automatic
6068 skipping of `transfer vector' code during function calls, which
6069 make it harder to debug code in a shared library, than to debug the
6070 same code linked statically.
6074 GDB is now using the latest `getopt' routines from the FSF. This
6075 version accepts the -- prefix for options with long names. GDB will
6076 continue to accept the old forms (-option and +option) as well.
6077 Various single letter abbreviations for options have been explicity
6078 added to the option table so that they won't get overshadowed in the
6079 future by other options that begin with the same letter.
6083 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6084 Many assorted bugs have been handled. Many more remain to be handled.
6085 See the various ChangeLog files (primarily in gdb and bfd) for details.
6088 *** Changes in GDB-4.3:
6090 * New machines supported (host and target)
6092 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6093 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6094 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6096 * Almost SCO Unix support
6098 We had hoped to support:
6099 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6100 (except for core file support), but we discovered very late in the release
6101 that it has problems with process groups that render gdb unusable. Sorry
6102 about that. I encourage people to fix it and post the fixes.
6104 * Preliminary ELF and DWARF support
6106 GDB can read ELF object files on System V Release 4, and can handle
6107 debugging records for C, in DWARF format, in ELF files. This support
6108 is preliminary. If you bring up GDB on another SVR4 system, please
6109 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6114 GDB now uses the latest `readline' library. One user-visible change
6115 is that two tabs will list possible command completions, which previously
6116 required typing M-? (meta-question mark, or ESC ?).
6120 The `stepi' bug that many of you noticed has been squashed.
6121 Many bugs in C++ have been handled. Many more remain to be handled.
6122 See the various ChangeLog files (primarily in gdb and bfd) for details.
6124 * State of the MIPS world (in case you wondered):
6126 GDB can understand the symbol tables emitted by the compilers
6127 supplied by most vendors of MIPS-based machines, including DEC. These
6128 symbol tables are in a format that essentially nobody else uses.
6130 Some versions of gcc come with an assembler post-processor called
6131 mips-tfile. This program is required if you want to do source-level
6132 debugging of gcc-compiled programs. I believe FSF does not ship
6133 mips-tfile with gcc version 1, but it will eventually come with gcc
6136 Debugging of g++ output remains a problem. g++ version 1.xx does not
6137 really support it at all. (If you're lucky, you should be able to get
6138 line numbers and stack traces to work, but no parameters or local
6139 variables.) With some work it should be possible to improve the
6142 When gcc version 2 is released, you will have somewhat better luck.
6143 However, even then you will get confusing results for inheritance and
6146 We will eventually provide full debugging of g++ output on
6147 DECstations. This will probably involve some kind of stabs-in-ecoff
6148 encapulation, but the details have not been worked out yet.
6151 *** Changes in GDB-4.2:
6153 * Improved configuration
6155 Only one copy of `configure' exists now, and it is not self-modifying.
6156 Porting BFD is simpler.
6160 The `step' and `next' commands now only stop at the first instruction
6161 of a source line. This prevents the multiple stops that used to occur
6162 in switch statements, for-loops, etc. `Step' continues to stop if a
6163 function that has debugging information is called within the line.
6167 Lots of small bugs fixed. More remain.
6169 * New host supported (not target)
6171 Intel 386 PC clone running Mach i386-none-mach
6174 *** Changes in GDB-4.1:
6176 * Multiple source language support
6178 GDB now has internal scaffolding to handle several source languages.
6179 It determines the type of each source file from its filename extension,
6180 and will switch expression parsing and number formatting to match the
6181 language of the function in the currently selected stack frame.
6182 You can also specifically set the language to be used, with
6183 `set language c' or `set language modula-2'.
6187 GDB now has preliminary support for the GNU Modula-2 compiler,
6188 currently under development at the State University of New York at
6189 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6190 continue through the fall of 1991 and into 1992.
6192 Other Modula-2 compilers are currently not supported, and attempting to
6193 debug programs compiled with them will likely result in an error as the
6194 symbol table is read. Feel free to work on it, though!
6196 There are hooks in GDB for strict type checking and range checking,
6197 in the `Modula-2 philosophy', but they do not currently work.
6201 GDB can now write to executable and core files (e.g. patch
6202 a variable's value). You must turn this switch on, specify
6203 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6204 by assigning a new value to a variable. Modifications take
6207 * Automatic SunOS shared library reading
6209 When you run your program, GDB automatically determines where its
6210 shared libraries (if any) have been loaded, and reads their symbols.
6211 The `share' command is no longer needed. This also works when
6212 examining core files.
6216 You can specify the number of lines that the `list' command shows.
6219 * New machines supported (host and target)
6221 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6222 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6223 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6225 * New hosts supported (not targets)
6227 IBM RT/PC: romp-ibm-aix or rtpc
6229 * New targets supported (not hosts)
6231 AMD 29000 embedded with COFF a29k-none-coff
6232 AMD 29000 embedded with a.out a29k-none-aout
6233 Ultracomputer remote kernel debug a29k-nyu-kern
6235 * New remote interfaces
6241 *** Changes in GDB-4.0:
6245 Wide output is wrapped at good places to make the output more readable.
6247 Gdb now supports cross-debugging from a host machine of one type to a
6248 target machine of another type. Communication with the target system
6249 is over serial lines. The ``target'' command handles connecting to the
6250 remote system; the ``load'' command will download a program into the
6251 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6252 also supports debugging of realtime processes running under VxWorks,
6253 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6254 stub on the target system.
6256 New CPUs supported include the AMD 29000 and Intel 960.
6258 GDB now reads object files and symbol tables via a ``binary file''
6259 library, which allows a single copy of GDB to debug programs of multiple
6260 object file types such as a.out and coff.
6262 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6263 refcard.dvi and refcard.ps are available to format it).
6266 * Control-Variable user interface simplified
6268 All variables that control the operation of the debugger can be set
6269 by the ``set'' command, and displayed by the ``show'' command.
6271 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6272 ``Show prompt'' produces the response:
6273 Gdb's prompt is new-gdb=>.
6275 What follows are the NEW set commands. The command ``help set'' will
6276 print a complete list of old and new set commands. ``help set FOO''
6277 will give a longer description of the variable FOO. ``show'' will show
6278 all of the variable descriptions and their current settings.
6280 confirm on/off: Enables warning questions for operations that are
6281 hard to recover from, e.g. rerunning the program while
6282 it is already running. Default is ON.
6284 editing on/off: Enables EMACS style command line editing
6285 of input. Previous lines can be recalled with
6286 control-P, the current line can be edited with control-B,
6287 you can search for commands with control-R, etc.
6290 history filename NAME: NAME is where the gdb command history
6291 will be stored. The default is .gdb_history,
6292 or the value of the environment variable
6295 history size N: The size, in commands, of the command history. The
6296 default is 256, or the value of the environment variable
6299 history save on/off: If this value is set to ON, the history file will
6300 be saved after exiting gdb. If set to OFF, the
6301 file will not be saved. The default is OFF.
6303 history expansion on/off: If this value is set to ON, then csh-like
6304 history expansion will be performed on
6305 command line input. The default is OFF.
6307 radix N: Sets the default radix for input and output. It can be set
6308 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6309 in the current radix, so "set radix 10" is always a no-op.
6311 height N: This integer value is the number of lines on a page. Default
6312 is 24, the current `stty rows'' setting, or the ``li#''
6313 setting from the termcap entry matching the environment
6316 width N: This integer value is the number of characters on a line.
6317 Default is 80, the current `stty cols'' setting, or the ``co#''
6318 setting from the termcap entry matching the environment
6321 Note: ``set screensize'' is obsolete. Use ``set height'' and
6322 ``set width'' instead.
6324 print address on/off: Print memory addresses in various command displays,
6325 such as stack traces and structure values. Gdb looks
6326 more ``symbolic'' if you turn this off; it looks more
6327 ``machine level'' with it on. Default is ON.
6329 print array on/off: Prettyprint arrays. New convenient format! Default
6332 print demangle on/off: Print C++ symbols in "source" form if on,
6335 print asm-demangle on/off: Same, for assembler level printouts
6338 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6341 * Support for Epoch Environment.
6343 The epoch environment is a version of Emacs v18 with windowing. One
6344 new command, ``inspect'', is identical to ``print'', except that if you
6345 are running in the epoch environment, the value is printed in its own
6349 * Support for Shared Libraries
6351 GDB can now debug programs and core files that use SunOS shared libraries.
6352 Symbols from a shared library cannot be referenced
6353 before the shared library has been linked with the program (this
6354 happens after you type ``run'' and before the function main() is entered).
6355 At any time after this linking (including when examining core files
6356 from dynamically linked programs), gdb reads the symbols from each
6357 shared library when you type the ``sharedlibrary'' command.
6358 It can be abbreviated ``share''.
6360 sharedlibrary REGEXP: Load shared object library symbols for files
6361 matching a unix regular expression. No argument
6362 indicates to load symbols for all shared libraries.
6364 info sharedlibrary: Status of loaded shared libraries.
6369 A watchpoint stops execution of a program whenever the value of an
6370 expression changes. Checking for this slows down execution
6371 tremendously whenever you are in the scope of the expression, but is
6372 quite useful for catching tough ``bit-spreader'' or pointer misuse
6373 problems. Some machines such as the 386 have hardware for doing this
6374 more quickly, and future versions of gdb will use this hardware.
6376 watch EXP: Set a watchpoint (breakpoint) for an expression.
6378 info watchpoints: Information about your watchpoints.
6380 delete N: Deletes watchpoint number N (same as breakpoints).
6381 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6382 enable N: Re-enables watchpoint number N (same as breakpoints).
6385 * C++ multiple inheritance
6387 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6390 * C++ exception handling
6392 Gdb now supports limited C++ exception handling. Besides the existing
6393 ability to breakpoint on an exception handler, gdb can breakpoint on
6394 the raising of an exception (before the stack is peeled back to the
6397 catch FOO: If there is a FOO exception handler in the dynamic scope,
6398 set a breakpoint to catch exceptions which may be raised there.
6399 Multiple exceptions (``catch foo bar baz'') may be caught.
6401 info catch: Lists all exceptions which may be caught in the
6402 current stack frame.
6405 * Minor command changes
6407 The command ``call func (arg, arg, ...)'' now acts like the print
6408 command, except it does not print or save a value if the function's result
6409 is void. This is similar to dbx usage.
6411 The ``up'' and ``down'' commands now always print the frame they end up
6412 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6413 frames without printing.
6415 * New directory command
6417 'dir' now adds directories to the FRONT of the source search path.
6418 The path starts off empty. Source files that contain debug information
6419 about the directory in which they were compiled can be found even
6420 with an empty path; Sun CC and GCC include this information. If GDB can't
6421 find your source file in the current directory, type "dir .".
6423 * Configuring GDB for compilation
6425 For normal use, type ``./configure host''. See README or gdb.texinfo
6428 GDB now handles cross debugging. If you are remotely debugging between
6429 two different machines, type ``./configure host -target=targ''.
6430 Host is the machine where GDB will run; targ is the machine
6431 where the program that you are debugging will run.
projects / external / binutils.git / blob