1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.11
6 * GDB now supports multibit bitfields and enums in target register
9 * New Python-based convenience function $_as_string(val), which returns
10 the textual representation of a value. This function is especially
11 useful to obtain the text label of an enum value.
13 * Intel MPX bound violation handling.
15 Segmentation faults caused by a Intel MPX boundary violation
16 now display the kind of violation (upper or lower), the memory
17 address accessed and the memory bounds, along with the usual
18 signal received and code location.
22 Program received signal SIGSEGV, Segmentation fault
23 Upper bound violation while accessing address 0x7fffffffc3b3
24 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
25 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
30 skip -gfile file-glob-pattern
31 skip -function function
32 skip -rfunction regular-expression
33 A generalized form of the skip command, with new support for
34 glob-style file names and regular expressions for function names.
35 Additionally, a file spec and a function spec may now be combined.
37 maint info line-table REGEXP
38 Display the contents of GDB's internal line table data struture.
40 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
41 was added in GDBserver, including JIT compiling fast tracepoint's
42 conditional expression bytecode into native code.
44 *** Changes in GDB 7.11
46 * GDB now supports debugging kernel-based threads on FreeBSD.
48 * Per-inferior thread numbers
50 Thread numbers are now per inferior instead of global. If you're
51 debugging multiple inferiors, GDB displays thread IDs using a
52 qualified INF_NUM.THR_NUM form. For example:
56 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
57 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
58 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
59 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
61 As consequence, thread numbers as visible in the $_thread
62 convenience variable and in Python's InferiorThread.num attribute
63 are no longer unique between inferiors.
65 GDB now maintains a second thread ID per thread, referred to as the
66 global thread ID, which is the new equivalent of thread numbers in
67 previous releases. See also $_gthread below.
69 For backwards compatibility, MI's thread IDs always refer to global
72 * Commands that accept thread IDs now accept the qualified
73 INF_NUM.THR_NUM form as well. For example:
76 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
79 * In commands that accept a list of thread IDs, you can now refer to
80 all threads of an inferior using a star wildcard. GDB accepts
81 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
82 refer to all threads of the current inferior. For example, "info
85 * You can use "info threads -gid" to display the global thread ID of
88 * The new convenience variable $_gthread holds the global number of
91 * The new convenience variable $_inferior holds the number of the
94 * GDB now displays the ID and name of the thread that hit a breakpoint
95 or received a signal, if your program is multi-threaded. For
98 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
99 Thread 1 "main" received signal SIGINT, Interrupt.
101 * Record btrace now supports non-stop mode.
103 * Support for tracepoints on aarch64-linux was added in GDBserver.
105 * The 'record instruction-history' command now indicates speculative execution
106 when using the Intel Processor Trace recording format.
108 * GDB now allows users to specify explicit locations, bypassing
109 the linespec parser. This feature is also available to GDB/MI
112 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
113 GDB now is able to debug both AArch64 applications and ARM applications
116 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
117 including JIT compiling fast tracepoint's conditional expression bytecode
120 * GDB now supports displaced stepping on AArch64 GNU/Linux.
122 * "info threads", "info inferiors", "info display", "info checkpoints"
123 and "maint info program-spaces" now list the corresponding items in
124 ascending ID order, for consistency with all other "info" commands.
126 * In Ada, the overloads selection menu has been enhanced to display the
127 parameter types and the return types for the matching overloaded subprograms.
131 maint set target-non-stop (on|off|auto)
132 maint show target-non-stop
133 Control whether GDB targets always operate in non-stop mode even if
134 "set non-stop" is "off". The default is "auto", meaning non-stop
135 mode is enabled if supported by the target.
137 maint set bfd-sharing
138 maint show bfd-sharing
139 Control the reuse of bfd objects.
143 Control display of debugging info regarding bfd caching.
147 Control display of debugging info regarding FreeBSD threads.
149 set remote multiprocess-extensions-packet
150 show remote multiprocess-extensions-packet
151 Set/show the use of the remote protocol multiprocess extensions.
153 set remote thread-events
154 show remote thread-events
155 Set/show the use of thread create/exit events.
157 set ada print-signatures on|off
158 show ada print-signatures"
159 Control whether parameter types and return types are displayed in overloads
160 selection menus. It is activaled (@code{on}) by default.
164 Controls the maximum size of memory, in bytes, that GDB will
165 allocate for value contents. Prevents incorrect programs from
166 causing GDB to allocate overly large buffers. Default is 64k.
168 * The "disassemble" command accepts a new modifier: /s.
169 It prints mixed source+disassembly like /m with two differences:
170 - disassembled instructions are now printed in program order, and
171 - and source for all relevant files is now printed.
172 The "/m" option is now considered deprecated: its "source-centric"
173 output hasn't proved useful in practice.
175 * The "record instruction-history" command accepts a new modifier: /s.
176 It behaves exactly like /m and prints mixed source+disassembly.
178 * The "set scheduler-locking" command supports a new mode "replay".
179 It behaves like "off" in record mode and like "on" in replay mode.
181 * Support for various ROM monitors has been removed:
183 target dbug dBUG ROM monitor for Motorola ColdFire
184 target picobug Motorola picobug monitor
185 target dink32 DINK32 ROM monitor for PowerPC
186 target m32r Renesas M32R/D ROM monitor
187 target mon2000 mon2000 ROM monitor
188 target ppcbug PPCBUG ROM monitor for PowerPC
190 * Support for reading/writing memory and extracting values on architectures
191 whose memory is addressable in units of any integral multiple of 8 bits.
196 Indicates that an exec system call was executed.
198 exec-events feature in qSupported
199 The qSupported packet allows GDB to request support for exec
200 events using the new 'gdbfeature' exec-event, and the qSupported
201 response can contain the corresponding 'stubfeature'. Set and
202 show commands can be used to display whether these features are enabled.
205 Equivalent to interrupting with the ^C character, but works in
208 thread created stop reason (T05 create:...)
209 Indicates that the thread was just created and is stopped at entry.
211 thread exit stop reply (w exitcode;tid)
212 Indicates that the thread has terminated.
215 Enables/disables thread create and exit event reporting. For
216 example, this is used in non-stop mode when GDB stops a set of
217 threads and synchronously waits for the their corresponding stop
218 replies. Without exit events, if one of the threads exits, GDB
219 would hang forever not knowing that it should no longer expect a
220 stop for that same thread.
224 Indicates that there are no resumed threads left in the target (all
225 threads are stopped). The remote stub reports support for this stop
226 reply to GDB's qSupported query.
228 QCatchSyscalls:1 [;SYSNO]...
230 Enable ("QCatchSyscalls:1") or disable ("QCatchSyscalls:0")
231 catching syscalls from the inferior process.
233 syscall_entry stop reason
234 Indicates that a syscall was just called.
236 syscall_return stop reason
237 Indicates that a syscall just returned.
239 QCatchSyscalls:1 in qSupported
240 The qSupported packet may now include QCatchSyscalls:1 in the reply
241 to indicate support for catching syscalls.
243 * Extended-remote exec events
245 ** GDB now has support for exec events on extended-remote Linux targets.
246 For such targets with Linux kernels 2.5.46 and later, this enables
247 follow-exec-mode and exec catchpoints.
249 set remote exec-event-feature-packet
250 show remote exec-event-feature-packet
251 Set/show the use of the remote exec event feature.
253 * Thread names in remote protocol
255 The reply to qXfer:threads:read may now include a name attribute for each
258 * Target remote mode fork and exec events
260 ** GDB now has support for fork and exec events on target remote mode
261 Linux targets. For such targets with Linux kernels 2.5.46 and later,
262 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
263 fork and exec catchpoints.
265 * Remote syscall events
267 ** GDB now has support for catch syscall on remote Linux targets,
268 currently enabled on x86/x86_64 architectures.
270 set remote catch-syscall-packet
271 show remote catch-syscall-packet
272 Set/show the use of the remote catch syscall feature.
276 ** The -var-set-format command now accepts the zero-hexadecimal
277 format. It outputs data in hexadecimal format with zero-padding on the
282 ** gdb.InferiorThread objects have a new attribute "global_num",
283 which refers to the thread's global thread ID. The existing
284 "num" attribute now refers to the thread's per-inferior number.
285 See "Per-inferior thread numbers" above.
286 ** gdb.InferiorThread objects have a new attribute "inferior", which
287 is the Inferior object the thread belongs to.
289 *** Changes in GDB 7.10
291 * Support for process record-replay and reverse debugging on aarch64*-linux*
292 targets has been added. GDB now supports recording of A64 instruction set
293 including advance SIMD instructions.
295 * Support for Sun's version of the "stabs" debug file format has been removed.
297 * GDB now honors the content of the file /proc/PID/coredump_filter
298 (PID is the process ID) on GNU/Linux systems. This file can be used
299 to specify the types of memory mappings that will be included in a
300 corefile. For more information, please refer to the manual page of
301 "core(5)". GDB also has a new command: "set use-coredump-filter
302 on|off". It allows to set whether GDB will read the content of the
303 /proc/PID/coredump_filter file when generating a corefile.
305 * The "info os" command on GNU/Linux can now display information on
307 "info os cpus" Listing of all cpus/cores on the system
309 * GDB has two new commands: "set serial parity odd|even|none" and
310 "show serial parity". These allows to set or show parity for the
313 * The "info source" command now displays the producer string if it was
314 present in the debug info. This typically includes the compiler version
315 and may include things like its command line arguments.
317 * The "info dll", an alias of the "info sharedlibrary" command,
318 is now available on all platforms.
320 * Directory names supplied to the "set sysroot" commands may be
321 prefixed with "target:" to tell GDB to access shared libraries from
322 the target system, be it local or remote. This replaces the prefix
323 "remote:". The default sysroot has been changed from "" to
324 "target:". "remote:" is automatically converted to "target:" for
325 backward compatibility.
327 * The system root specified by "set sysroot" will be prepended to the
328 filename of the main executable (if reported to GDB as absolute by
329 the operating system) when starting processes remotely, and when
330 attaching to already-running local or remote processes.
332 * GDB now supports automatic location and retrieval of executable
333 files from remote targets. Remote debugging can now be initiated
334 using only a "target remote" or "target extended-remote" command
335 (no "set sysroot" or "file" commands are required). See "New remote
338 * The "dump" command now supports verilog hex format.
340 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
342 * On GNU/Linux, GDB and gdbserver are now able to access executable
343 and shared library files without a "set sysroot" command when
344 attaching to processes running in different mount namespaces from
345 the debugger. This makes it possible to attach to processes in
346 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
347 See "New remote packets" below.
349 * The "tui reg" command now provides completion for all of the
350 available register groups, including target specific groups.
352 * The HISTSIZE environment variable is no longer read when determining
353 the size of GDB's command history. GDB now instead reads the dedicated
354 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
355 disables truncation of command history. Non-numeric values of GDBHISTSIZE
360 ** Memory ports can now be unbuffered.
364 ** gdb.Objfile objects have a new attribute "username",
365 which is the name of the objfile as specified by the user,
366 without, for example, resolving symlinks.
367 ** You can now write frame unwinders in Python.
368 ** gdb.Type objects have a new method "optimized_out",
369 returning optimized out gdb.Value instance of this type.
370 ** gdb.Value objects have new methods "reference_value" and
371 "const_value" which return a reference to the value and a
372 "const" version of the value respectively.
376 maint print symbol-cache
377 Print the contents of the symbol cache.
379 maint print symbol-cache-statistics
380 Print statistics of symbol cache usage.
382 maint flush-symbol-cache
383 Flush the contents of the symbol cache.
387 Start branch trace recording using Branch Trace Store (BTS) format.
390 Evaluate expression by using the compiler and print result.
394 Explicit commands for enabling and disabling tui mode.
397 set mpx bound on i386 and amd64
398 Support for bound table investigation on Intel MPX enabled applications.
402 Start branch trace recording using Intel Processor Trace format.
405 Print information about branch tracing internals.
407 maint btrace packet-history
408 Print the raw branch tracing data.
410 maint btrace clear-packet-history
411 Discard the stored raw branch tracing data.
414 Discard all branch tracing data. It will be fetched and processed
415 anew by the next "record" command.
420 Renamed from "set debug dwarf2-die".
422 Renamed from "show debug dwarf2-die".
425 Renamed from "set debug dwarf2-read".
426 show debug dwarf-read
427 Renamed from "show debug dwarf2-read".
429 maint set dwarf always-disassemble
430 Renamed from "maint set dwarf2 always-disassemble".
431 maint show dwarf always-disassemble
432 Renamed from "maint show dwarf2 always-disassemble".
434 maint set dwarf max-cache-age
435 Renamed from "maint set dwarf2 max-cache-age".
436 maint show dwarf max-cache-age
437 Renamed from "maint show dwarf2 max-cache-age".
440 show debug dwarf-line
441 Control display of debugging info regarding DWARF line processing.
445 Set the maximum number of candidates to be considered during
446 completion. The default value is 200. This limit allows GDB
447 to avoid generating large completion lists, the computation of
448 which can cause the debugger to become temporarily unresponsive.
450 set history remove-duplicates
451 show history remove-duplicates
452 Control the removal of duplicate history entries.
454 maint set symbol-cache-size
455 maint show symbol-cache-size
456 Control the size of the symbol cache.
458 set|show record btrace bts buffer-size
459 Set and show the size of the ring buffer used for branch tracing in
461 The obtained size may differ from the requested size. Use "info
462 record" to see the obtained buffer size.
464 set debug linux-namespaces
465 show debug linux-namespaces
466 Control display of debugging info regarding Linux namespaces.
468 set|show record btrace pt buffer-size
469 Set and show the size of the ring buffer used for branch tracing in
470 Intel Processor Trace format.
471 The obtained size may differ from the requested size. Use "info
472 record" to see the obtained buffer size.
474 maint set|show btrace pt skip-pad
475 Set and show whether PAD packets are skipped when computing the
478 * The command 'thread apply all' can now support new option '-ascending'
479 to call its specified command for all threads in ascending order.
481 * Python/Guile scripting
483 ** GDB now supports auto-loading of Python/Guile scripts contained in the
484 special section named `.debug_gdb_scripts'.
488 qXfer:btrace-conf:read
489 Return the branch trace configuration for the current thread.
491 Qbtrace-conf:bts:size
492 Set the requested ring buffer size for branch tracing in BTS format.
495 Enable Intel Procesor Trace-based branch tracing for the current
496 process. The remote stub reports support for this packet to GDB's
500 Set the requested ring buffer size for branch tracing in Intel Processor
504 Indicates a memory breakpoint instruction was executed, irrespective
505 of whether it was GDB that planted the breakpoint or the breakpoint
506 is hardcoded in the program. This is required for correct non-stop
510 Indicates the target stopped for a hardware breakpoint. This is
511 required for correct non-stop mode operation.
514 Return information about files on the remote system.
517 Return the full absolute name of the file that was executed to
518 create a process running on the remote system.
521 Select the filesystem on which vFile: operations with filename
522 arguments will operate. This is required for GDB to be able to
523 access files on remote targets where the remote stub does not
524 share a common filesystem with the inferior(s).
527 Indicates that a fork system call was executed.
530 Indicates that a vfork system call was executed.
532 vforkdone stop reason
533 Indicates that a vfork child of the specified process has executed
534 an exec or exit, allowing the vfork parent to resume execution.
536 fork-events and vfork-events features in qSupported
537 The qSupported packet allows GDB to request support for fork and
538 vfork events using new 'gdbfeatures' fork-events and vfork-events,
539 and the qSupported response can contain the corresponding
540 'stubfeatures'. Set and show commands can be used to display
541 whether these features are enabled.
543 * Extended-remote fork events
545 ** GDB now has support for fork events on extended-remote Linux
546 targets. For targets with Linux kernels 2.5.60 and later, this
547 enables follow-fork-mode and detach-on-fork for both fork and
548 vfork, as well as fork and vfork catchpoints.
550 * The info record command now shows the recording format and the
551 branch tracing configuration for the current thread when using
552 the btrace record target.
553 For the BTS format, it shows the ring buffer size.
555 * GDB now has support for DTrace USDT (Userland Static Defined
556 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
558 * GDB now supports access to vector registers on S/390 GNU/Linux
561 * Removed command line options
563 -xdb HP-UX XDB compatibility mode.
565 * Removed targets and native configurations
567 HP/PA running HP-UX hppa*-*-hpux*
568 Itanium running HP-UX ia64-*-hpux*
570 * New configure options
573 This configure option allows the user to build GDB with support for
574 Intel Processor Trace (default: auto). This requires libipt.
576 --with-libipt-prefix=PATH
577 Specify the path to the version of libipt that GDB should use.
578 $PATH/include should contain the intel-pt.h header and
579 $PATH/lib should contain the libipt.so library.
581 *** Changes in GDB 7.9.1
585 ** Xmethods can now specify a result type.
587 *** Changes in GDB 7.9
589 * GDB now supports hardware watchpoints on x86 GNU Hurd.
593 ** You can now access frame registers from Python scripts.
594 ** New attribute 'producer' for gdb.Symtab objects.
595 ** gdb.Objfile objects have a new attribute "progspace",
596 which is the gdb.Progspace object of the containing program space.
597 ** gdb.Objfile objects have a new attribute "owner".
598 ** gdb.Objfile objects have a new attribute "build_id",
599 which is the build ID generated when the file was built.
600 ** gdb.Objfile objects have a new method "add_separate_debug_file".
601 ** A new event "gdb.clear_objfiles" has been added, triggered when
602 selecting a new file to debug.
603 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
604 ** New function gdb.lookup_objfile.
606 New events which are triggered when GDB modifies the state of the
609 ** gdb.events.inferior_call_pre: Function call is about to be made.
610 ** gdb.events.inferior_call_post: Function call has just been made.
611 ** gdb.events.memory_changed: A memory location has been altered.
612 ** gdb.events.register_changed: A register has been altered.
614 * New Python-based convenience functions:
616 ** $_caller_is(name [, number_of_frames])
617 ** $_caller_matches(regexp [, number_of_frames])
618 ** $_any_caller_is(name [, number_of_frames])
619 ** $_any_caller_matches(regexp [, number_of_frames])
621 * GDB now supports the compilation and injection of source code into
622 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
623 to compile the source code to object code, and if successful, inject
624 and execute that code within the current context of the inferior.
625 Currently the C language is supported. The commands used to
626 interface with this new feature are:
628 compile code [-raw|-r] [--] [source code]
629 compile file [-raw|-r] filename
633 demangle [-l language] [--] name
634 Demangle "name" in the specified language, or the current language
635 if elided. This command is renamed from the "maint demangle" command.
636 The latter is kept as a no-op to avoid "maint demangle" being interpreted
637 as "maint demangler-warning".
639 queue-signal signal-name-or-number
640 Queue a signal to be delivered to the thread when it is resumed.
642 add-auto-load-scripts-directory directory
643 Add entries to the list of directories from which to load auto-loaded
646 maint print user-registers
647 List all currently available "user" registers.
649 compile code [-r|-raw] [--] [source code]
650 Compile, inject, and execute in the inferior the executable object
651 code produced by compiling the provided source code.
653 compile file [-r|-raw] filename
654 Compile and inject into the inferior the executable object code
655 produced by compiling the source code stored in the filename
658 * On resume, GDB now always passes the signal the program had stopped
659 for to the thread the signal was sent to, even if the user changed
660 threads before resuming. Previously GDB would often (but not
661 always) deliver the signal to the thread that happens to be current
664 * Conversely, the "signal" command now consistently delivers the
665 requested signal to the current thread. GDB now asks for
666 confirmation if the program had stopped for a signal and the user
667 switched threads meanwhile.
669 * "breakpoint always-inserted" modes "off" and "auto" merged.
671 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
672 won't remove breakpoints from the target until all threads stop,
673 even in non-stop mode. The "auto" mode has been removed, and "off"
674 is now the default mode.
678 set debug symbol-lookup
679 show debug symbol-lookup
680 Control display of debugging info regarding symbol lookup.
684 ** The -list-thread-groups command outputs an exit-code field for
685 inferiors that have exited.
689 MIPS SDE mips*-sde*-elf*
693 Support for these obsolete configurations has been removed.
695 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
696 SGI Irix-5.x mips-*-irix5*
697 SGI Irix-6.x mips-*-irix6*
698 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
699 VAX running Ultrix vax-*-ultrix*
701 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
702 and "assf"), have been removed. Use the "sharedlibrary" command, or
703 its alias "share", instead.
705 *** Changes in GDB 7.8
707 * New command line options
710 This is an alias for the --data-directory option.
712 * GDB supports printing and modifying of variable length automatic arrays
713 as specified in ISO C99.
715 * The ARM simulator now supports instruction level tracing
716 with or without disassembly.
720 GDB now has support for scripting using Guile. Whether this is
721 available is determined at configure time.
722 Guile version 2.0 or greater is required.
723 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
725 * New commands (for set/show, see "New options" below)
729 Invoke CODE by passing it to the Guile interpreter.
733 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
735 info auto-load guile-scripts [regexp]
736 Print the list of automatically loaded Guile scripts.
738 * The source command is now capable of sourcing Guile scripts.
739 This feature is dependent on the debugger being built with Guile support.
743 set print symbol-loading (off|brief|full)
744 show print symbol-loading
745 Control whether to print informational messages when loading symbol
746 information for a file. The default is "full", but when debugging
747 programs with large numbers of shared libraries the amount of output
750 set guile print-stack (none|message|full)
751 show guile print-stack
752 Show a stack trace when an error is encountered in a Guile script.
754 set auto-load guile-scripts (on|off)
755 show auto-load guile-scripts
756 Control auto-loading of Guile script files.
758 maint ada set ignore-descriptive-types (on|off)
759 maint ada show ignore-descriptive-types
760 Control whether the debugger should ignore descriptive types in Ada
761 programs. The default is not to ignore the descriptive types. See
762 the user manual for more details on descriptive types and the intended
763 usage of this option.
765 set auto-connect-native-target
767 Control whether GDB is allowed to automatically connect to the
768 native target for the run, attach, etc. commands when not connected
769 to any target yet. See also "target native" below.
771 set record btrace replay-memory-access (read-only|read-write)
772 show record btrace replay-memory-access
773 Control what memory accesses are allowed during replay.
775 maint set target-async (on|off)
776 maint show target-async
777 This controls whether GDB targets operate in synchronous or
778 asynchronous mode. Normally the default is asynchronous, if it is
779 available; but this can be changed to more easily debug problems
780 occurring only in synchronous mode.
782 set mi-async (on|off)
784 Control whether MI asynchronous mode is preferred. This supersedes
785 "set target-async" of previous GDB versions.
787 * "set target-async" is deprecated as a CLI option and is now an alias
788 for "set mi-async" (only puts MI into async mode).
790 * Background execution commands (e.g., "c&", "s&", etc.) are now
791 possible ``out of the box'' if the target supports them. Previously
792 the user would need to explicitly enable the possibility with the
793 "set target-async on" command.
795 * New features in the GDB remote stub, GDBserver
797 ** New option --debug-format=option1[,option2,...] allows one to add
798 additional text to each output. At present only timestamps
799 are supported: --debug-format=timestamps.
800 Timestamps can also be turned on with the
801 "monitor set debug-format timestamps" command from GDB.
803 * The 'record instruction-history' command now starts counting instructions
804 at one. This also affects the instruction ranges reported by the
805 'record function-call-history' command when given the /i modifier.
807 * The command 'record function-call-history' supports a new modifier '/c' to
808 indent the function names based on their call stack depth.
809 The fields for the '/i' and '/l' modifier have been reordered.
810 The source line range is now prefixed with 'at'.
811 The instruction range is now prefixed with 'inst'.
812 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
813 "record instruction-history" and "list" commands.
815 * The ranges given as arguments to the 'record function-call-history' and
816 'record instruction-history' commands are now inclusive.
818 * The btrace record target now supports the 'record goto' command.
819 For locations inside the execution trace, the back trace is computed
820 based on the information stored in the execution trace.
822 * The btrace record target supports limited reverse execution and replay.
823 The target does not record data and therefore does not allow reading
826 * The "catch syscall" command now works on s390*-linux* targets.
828 * The "compare-sections" command is no longer specific to target
829 remote. It now works with all targets.
831 * All native targets are now consistently called "native".
832 Consequently, the "target child", "target GNU", "target djgpp",
833 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
834 commands have been replaced with "target native". The QNX/NTO port
835 leaves the "procfs" target in place and adds a "native" target for
836 consistency with other ports. The impact on users should be minimal
837 as these commands previously either throwed an error, or were
838 no-ops. The target's name is visible in the output of the following
839 commands: "help target", "info target", "info files", "maint print
842 * The "target native" command now connects to the native target. This
843 can be used to launch native programs even when "set
844 auto-connect-native-target" is set to off.
846 * GDB now supports access to Intel MPX registers on GNU/Linux.
848 * Support for Intel AVX-512 registers on GNU/Linux.
849 Support displaying and modifying Intel AVX-512 registers
850 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
854 qXfer:btrace:read's annex
855 The qXfer:btrace:read packet supports a new annex 'delta' to read
856 branch trace incrementally.
860 ** Valid Python operations on gdb.Value objects representing
861 structs/classes invoke the corresponding overloaded operators if
863 ** New `Xmethods' feature in the Python API. Xmethods are
864 additional methods or replacements for existing methods of a C++
865 class. This feature is useful for those cases where a method
866 defined in C++ source code could be inlined or optimized out by
867 the compiler, making it unavailable to GDB.
870 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
872 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
873 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
874 its alias "share", instead.
876 * The commands "set remotebaud" and "show remotebaud" are no longer
877 supported. Use "set serial baud" and "show serial baud" (respectively)
882 ** A new option "-gdb-set mi-async" replaces "-gdb-set
883 target-async". The latter is left as a deprecated alias of the
884 former for backward compatibility. If the target supports it,
885 CLI background execution commands are now always possible by
886 default, independently of whether the frontend stated a
887 preference for asynchronous execution with "-gdb-set mi-async".
888 Previously "-gdb-set target-async off" affected both MI execution
889 commands and CLI execution commands.
891 *** Changes in GDB 7.7
893 * Improved support for process record-replay and reverse debugging on
894 arm*-linux* targets. Support for thumb32 and syscall instruction
895 recording has been added.
897 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
899 * GDB now supports Fission DWP file format version 2.
900 http://gcc.gnu.org/wiki/DebugFission
902 * New convenience function "$_isvoid", to check whether an expression
903 is void. A void expression is an expression where the type of the
904 result is "void". For example, some convenience variables may be
905 "void" when evaluated (e.g., "$_exitcode" before the execution of
906 the program being debugged; or an undefined convenience variable).
907 Another example, when calling a function whose return type is
910 * The "maintenance print objfiles" command now takes an optional regexp.
912 * The "catch syscall" command now works on arm*-linux* targets.
914 * GDB now consistently shows "<not saved>" when printing values of
915 registers the debug info indicates have not been saved in the frame
916 and there's nowhere to retrieve them from
917 (callee-saved/call-clobbered registers):
922 (gdb) info registers rax
925 Before, the former would print "<optimized out>", and the latter
926 "*value not available*".
928 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
933 ** Frame filters and frame decorators have been added.
934 ** Temporary breakpoints are now supported.
935 ** Line tables representation has been added.
936 ** New attribute 'parent_type' for gdb.Field objects.
937 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
938 ** New attribute 'name' for gdb.Type objects.
942 Nios II ELF nios2*-*-elf
943 Nios II GNU/Linux nios2*-*-linux
944 Texas Instruments MSP430 msp430*-*-elf
946 * Removed native configurations
948 Support for these a.out NetBSD and OpenBSD obsolete configurations has
949 been removed. ELF variants of these configurations are kept supported.
951 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
952 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
953 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
954 i[34567]86-*-openbsd3.[0-3]
955 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
956 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
957 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
961 Like "catch throw", but catches a re-thrown exception.
963 Renamed from old "maint check-symtabs".
965 Perform consistency checks on symtabs.
967 Expand symtabs matching an optional regexp.
970 Display the details of GDB configure-time options.
972 maint set|show per-command
973 maint set|show per-command space
974 maint set|show per-command time
975 maint set|show per-command symtab
976 Enable display of per-command gdb resource usage.
978 remove-symbol-file FILENAME
979 remove-symbol-file -a ADDRESS
980 Remove a symbol file added via add-symbol-file. The file to remove
981 can be identified by its filename or by an address that lies within
982 the boundaries of this symbol file in memory.
985 info exceptions REGEXP
986 Display the list of Ada exceptions defined in the program being
987 debugged. If provided, only the exceptions whose names match REGEXP
992 set debug symfile off|on
994 Control display of debugging info regarding reading symbol files and
995 symbol tables within those files
997 set print raw frame-arguments
998 show print raw frame-arguments
999 Set/show whether to print frame arguments in raw mode,
1000 disregarding any defined pretty-printers.
1002 set remote trace-status-packet
1003 show remote trace-status-packet
1004 Set/show the use of remote protocol qTStatus packet.
1008 Control display of debugging messages related to Nios II targets.
1012 Control whether target-assisted range stepping is enabled.
1014 set startup-with-shell
1015 show startup-with-shell
1016 Specifies whether Unix child processes are started via a shell or
1021 Use the target memory cache for accesses to the code segment. This
1022 improves performance of remote debugging (particularly disassembly).
1024 * You can now use a literal value 'unlimited' for options that
1025 interpret 0 or -1 as meaning "unlimited". E.g., "set
1026 trace-buffer-size unlimited" is now an alias for "set
1027 trace-buffer-size -1" and "set height unlimited" is now an alias for
1030 * The "set debug symtab-create" debugging option of GDB has been changed to
1031 accept a verbosity level. 0 means "off", 1 provides basic debugging
1032 output, and values of 2 or greater provides more verbose output.
1034 * New command-line options
1036 Display the details of GDB configure-time options.
1038 * The command 'tsave' can now support new option '-ctf' to save trace
1039 buffer in Common Trace Format.
1041 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1044 * GDB now implements the the C++ 'typeid' operator.
1046 * The new convenience variable $_exception holds the exception being
1047 thrown or caught at an exception-related catchpoint.
1049 * The exception-related catchpoints, like "catch throw", now accept a
1050 regular expression which can be used to filter exceptions by type.
1052 * The new convenience variable $_exitsignal is automatically set to
1053 the terminating signal number when the program being debugged dies
1054 due to an uncaught signal.
1058 ** All MI commands now accept an optional "--language" option.
1059 Support for this feature can be verified by using the "-list-features"
1060 command, which should contain "language-option".
1062 ** The new command -info-gdb-mi-command allows the user to determine
1063 whether a GDB/MI command is supported or not.
1065 ** The "^error" result record returned when trying to execute an undefined
1066 GDB/MI command now provides a variable named "code" whose content is the
1067 "undefined-command" error code. Support for this feature can be verified
1068 by using the "-list-features" command, which should contain
1069 "undefined-command-error-code".
1071 ** The -trace-save MI command can optionally save trace buffer in Common
1074 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1076 ** The command -data-list-register-values now accepts an optional
1077 "--skip-unavailable" option. When used, only the available registers
1080 ** The new command -trace-frame-collected dumps collected variables,
1081 computed expressions, tvars, memory and registers in a traceframe.
1083 ** The commands -stack-list-locals, -stack-list-arguments and
1084 -stack-list-variables now accept an option "--skip-unavailable".
1085 When used, only the available locals or arguments are displayed.
1087 ** The -exec-run command now accepts an optional "--start" option.
1088 When used, the command follows the same semantics as the "start"
1089 command, stopping the program's execution at the start of its
1090 main subprogram. Support for this feature can be verified using
1091 the "-list-features" command, which should contain
1092 "exec-run-start-option".
1094 ** The new commands -catch-assert and -catch-exceptions insert
1095 catchpoints stopping the program when Ada exceptions are raised.
1097 ** The new command -info-ada-exceptions provides the equivalent of
1098 the new "info exceptions" command.
1100 * New system-wide configuration scripts
1101 A GDB installation now provides scripts suitable for use as system-wide
1102 configuration scripts for the following systems:
1106 * GDB now supports target-assigned range stepping with remote targets.
1107 This improves the performance of stepping source lines by reducing
1108 the number of control packets from/to GDB. See "New remote packets"
1111 * GDB now understands the element 'tvar' in the XML traceframe info.
1112 It has the id of the collected trace state variables.
1114 * On S/390 targets that provide the transactional-execution feature,
1115 the program interruption transaction diagnostic block (TDB) is now
1116 represented as a number of additional "registers" in GDB.
1118 * New remote packets
1122 The vCont packet supports a new 'r' action, that tells the remote
1123 stub to step through an address range itself, without GDB
1124 involvemement at each single-step.
1126 qXfer:libraries-svr4:read's annex
1127 The previously unused annex of the qXfer:libraries-svr4:read packet
1128 is now used to support passing an argument list. The remote stub
1129 reports support for this argument list to GDB's qSupported query.
1130 The defined arguments are "start" and "prev", used to reduce work
1131 necessary for library list updating, resulting in significant
1134 * New features in the GDB remote stub, GDBserver
1136 ** GDBserver now supports target-assisted range stepping. Currently
1137 enabled on x86/x86_64 GNU/Linux targets.
1139 ** GDBserver now adds element 'tvar' in the XML in the reply to
1140 'qXfer:traceframe-info:read'. It has the id of the collected
1141 trace state variables.
1143 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1146 * New 'z' formatter for printing and examining memory, this displays the
1147 value as hexadecimal zero padded on the left to the size of the type.
1149 * GDB can now use Windows x64 unwinding data.
1151 * The "set remotebaud" command has been replaced by "set serial baud".
1152 Similarly, "show remotebaud" has been replaced by "show serial baud".
1153 The "set remotebaud" and "show remotebaud" commands are still available
1154 to provide backward compatibility with older versions of GDB.
1156 *** Changes in GDB 7.6
1158 * Target record has been renamed to record-full.
1159 Record/replay is now enabled with the "record full" command.
1160 This also affects settings that are associated with full record/replay
1161 that have been moved from "set/show record" to "set/show record full":
1163 set|show record full insn-number-max
1164 set|show record full stop-at-limit
1165 set|show record full memory-query
1167 * A new record target "record-btrace" has been added. The new target
1168 uses hardware support to record the control-flow of a process. It
1169 does not support replaying the execution, but it implements the
1170 below new commands for investigating the recorded execution log.
1171 This new recording method can be enabled using:
1175 The "record-btrace" target is only available on Intel Atom processors
1176 and requires a Linux kernel 2.6.32 or later.
1178 * Two new commands have been added for record/replay to give information
1179 about the recorded execution without having to replay the execution.
1180 The commands are only supported by "record btrace".
1182 record instruction-history prints the execution history at
1183 instruction granularity
1185 record function-call-history prints the execution history at
1186 function granularity
1188 * New native configurations
1190 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1191 FreeBSD/powerpc powerpc*-*-freebsd
1192 x86_64/Cygwin x86_64-*-cygwin*
1193 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1197 ARM AArch64 aarch64*-*-elf
1198 ARM AArch64 GNU/Linux aarch64*-*-linux
1199 Lynx 178 PowerPC powerpc-*-lynx*178
1200 x86_64/Cygwin x86_64-*-cygwin*
1201 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1203 * If the configured location of system.gdbinit file (as given by the
1204 --with-system-gdbinit option at configure time) is in the
1205 data-directory (as specified by --with-gdb-datadir at configure
1206 time) or in one of its subdirectories, then GDB will look for the
1207 system-wide init file in the directory specified by the
1208 --data-directory command-line option.
1210 * New command line options:
1212 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1213 other initialization files, unlike -nx which disables all of them.
1215 * Removed command line options
1217 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1220 * The 'ptype' and 'whatis' commands now accept an argument to control
1223 * 'info proc' now works on some core files.
1227 ** Vectors can be created with gdb.Type.vector.
1229 ** Python's atexit.register now works in GDB.
1231 ** Types can be pretty-printed via a Python API.
1233 ** Python 3 is now supported (in addition to Python 2.4 or later)
1235 ** New class gdb.Architecture exposes GDB's internal representation
1236 of architecture in the Python API.
1238 ** New method Frame.architecture returns the gdb.Architecture object
1239 corresponding to the frame's architecture.
1241 * New Python-based convenience functions:
1243 ** $_memeq(buf1, buf2, length)
1244 ** $_streq(str1, str2)
1246 ** $_regex(str, regex)
1248 * The 'cd' command now defaults to using '~' (the home directory) if not
1251 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1252 default for GCC since November 2000.
1254 * The command 'forward-search' can now be abbreviated as 'fo'.
1256 * The command 'info tracepoints' can now display 'installed on target'
1257 or 'not installed on target' for each non-pending location of tracepoint.
1259 * New configure options
1261 --enable-libmcheck/--disable-libmcheck
1262 By default, development versions are built with -lmcheck on hosts
1263 that support it, in order to help track memory corruption issues.
1264 Release versions, on the other hand, are built without -lmcheck
1265 by default. The --enable-libmcheck/--disable-libmcheck configure
1266 options allow the user to override that default.
1267 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1268 This configure option allows the user to build GDB with
1269 libbabeltrace using which GDB can read Common Trace Format data.
1271 * New commands (for set/show, see "New options" below)
1274 Catch signals. This is similar to "handle", but allows commands and
1275 conditions to be attached.
1278 List the BFDs known to GDB.
1280 python-interactive [command]
1282 Start a Python interactive prompt, or evaluate the optional command
1283 and print the result of expressions.
1286 "py" is a new alias for "python".
1288 enable type-printer [name]...
1289 disable type-printer [name]...
1290 Enable or disable type printers.
1294 ** For the Renesas Super-H architecture, the "regs" command has been removed
1295 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1300 set print type methods (on|off)
1301 show print type methods
1302 Control whether method declarations are displayed by "ptype".
1303 The default is to show them.
1305 set print type typedefs (on|off)
1306 show print type typedefs
1307 Control whether typedef definitions are displayed by "ptype".
1308 The default is to show them.
1310 set filename-display basename|relative|absolute
1311 show filename-display
1312 Control the way in which filenames is displayed.
1313 The default is "relative", which preserves previous behavior.
1315 set trace-buffer-size
1316 show trace-buffer-size
1317 Request target to change the size of trace buffer.
1319 set remote trace-buffer-size-packet auto|on|off
1320 show remote trace-buffer-size-packet
1321 Control the use of the remote protocol `QTBuffer:size' packet.
1325 Control display of debugging messages related to ARM AArch64.
1328 set debug coff-pe-read
1329 show debug coff-pe-read
1330 Control display of debugging messages related to reading of COFF/PE
1335 Control display of debugging messages related to Mach-O symbols
1338 set debug notification
1339 show debug notification
1340 Control display of debugging info for async remote notification.
1344 ** Command parameter changes are now notified using new async record
1345 "=cmd-param-changed".
1346 ** Trace frame changes caused by command "tfind" are now notified using
1347 new async record "=traceframe-changed".
1348 ** The creation, deletion and modification of trace state variables
1349 are now notified using new async records "=tsv-created",
1350 "=tsv-deleted" and "=tsv-modified".
1351 ** The start and stop of process record are now notified using new
1352 async record "=record-started" and "=record-stopped".
1353 ** Memory changes are now notified using new async record
1355 ** The data-disassemble command response will include a "fullname" field
1356 containing the absolute file name when source has been requested.
1357 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1358 command, to allow pattern filling of memory areas.
1359 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1360 library load/unload events.
1361 ** The response to breakpoint commands and breakpoint async records
1362 includes an "installed" field containing a boolean state about each
1363 non-pending tracepoint location is whether installed on target or not.
1364 ** Output of the "-trace-status" command includes a "trace-file" field
1365 containing the name of the trace file being examined. This field is
1366 optional, and only present when examining a trace file.
1367 ** The "fullname" field is now always present along with the "file" field,
1368 even if the file cannot be found by GDB.
1370 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1371 You must have the LZMA library available when configuring GDB for this
1372 feature to be enabled. For more information, see:
1373 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1375 * New remote packets
1378 Set the size of trace buffer. The remote stub reports support for this
1379 packet to gdb's qSupported query.
1382 Enable Branch Trace Store (BTS)-based branch tracing for the current
1383 thread. The remote stub reports support for this packet to gdb's
1387 Disable branch tracing for the current thread. The remote stub reports
1388 support for this packet to gdb's qSupported query.
1391 Read the traced branches for the current thread. The remote stub
1392 reports support for this packet to gdb's qSupported query.
1394 *** Changes in GDB 7.5
1396 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1397 for more x32 ABI info.
1399 * GDB now supports access to MIPS DSP registers on Linux targets.
1401 * GDB now supports debugging microMIPS binaries.
1403 * The "info os" command on GNU/Linux can now display information on
1404 several new classes of objects managed by the operating system:
1405 "info os procgroups" lists process groups
1406 "info os files" lists file descriptors
1407 "info os sockets" lists internet-domain sockets
1408 "info os shm" lists shared-memory regions
1409 "info os semaphores" lists semaphores
1410 "info os msg" lists message queues
1411 "info os modules" lists loaded kernel modules
1413 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1414 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1415 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1416 options and inspect the probe arguments using the new $_probe_arg family
1417 of convenience variables. You can obtain more information about SystemTap
1418 in <http://sourceware.org/systemtap/>.
1420 * GDB now supports reversible debugging on ARM, it allows you to
1421 debug basic ARM and THUMB instructions, and provides
1422 record/replay support.
1424 * The option "symbol-reloading" has been deleted as it is no longer used.
1428 ** GDB commands implemented in Python can now be put in command class
1431 ** The "maint set python print-stack on|off" is now deleted.
1433 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1434 apply "flag enum"-style pretty-printing to any enum.
1436 ** gdb.lookup_symbol can now work when there is no current frame.
1438 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1439 the source at which the symbol was defined.
1441 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1442 method 'value'. The former indicates whether the symbol needs a
1443 frame in order to compute its value, and the latter computes the
1446 ** A new method 'referenced_value' on gdb.Value objects which can
1447 dereference pointer as well as C++ reference values.
1449 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1450 which return the global and static blocks (as gdb.Block objects),
1451 of the underlying symbol table, respectively.
1453 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1454 object associated with a PC value.
1456 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1457 of the address range occupied by code for the current source line.
1459 * Go language support.
1460 GDB now supports debugging programs written in the Go programming
1463 * GDBserver now supports stdio connections.
1464 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1466 * The binary "gdbtui" can no longer be built or installed.
1467 Use "gdb -tui" instead.
1469 * GDB will now print "flag" enums specially. A flag enum is one where
1470 all the enumerator values have no bits in common when pairwise
1471 "and"ed. When printing a value whose type is a flag enum, GDB will
1472 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1473 (gdb) print (enum E) 3
1476 * The filename part of a linespec will now match trailing components
1477 of a source file name. For example, "break gcc/expr.c:1000" will
1478 now set a breakpoint in build/gcc/expr.c, but not
1479 build/libcpp/expr.c.
1481 * The "info proc" and "generate-core-file" commands will now also
1482 work on remote targets connected to GDBserver on Linux.
1484 * The command "info catch" has been removed. It has been disabled
1485 since December 2007.
1487 * The "catch exception" and "catch assert" commands now accept
1488 a condition at the end of the command, much like the "break"
1489 command does. For instance:
1491 (gdb) catch exception Constraint_Error if Barrier = True
1493 Previously, it was possible to add a condition to such catchpoints,
1494 but it had to be done as a second step, after the catchpoint had been
1495 created, using the "condition" command.
1497 * The "info static-tracepoint-marker" command will now also work on
1498 native Linux targets with in-process agent.
1500 * GDB can now set breakpoints on inlined functions.
1502 * The .gdb_index section has been updated to include symbols for
1503 inlined functions. GDB will ignore older .gdb_index sections by
1504 default, which could cause symbol files to be loaded more slowly
1505 until their .gdb_index sections can be recreated. The new command
1506 "set use-deprecated-index-sections on" will cause GDB to use any older
1507 .gdb_index sections it finds. This will restore performance, but the
1508 ability to set breakpoints on inlined functions will be lost in symbol
1509 files with older .gdb_index sections.
1511 The .gdb_index section has also been updated to record more information
1512 about each symbol. This speeds up the "info variables", "info functions"
1513 and "info types" commands when used with programs having the .gdb_index
1514 section, as well as speeding up debugging with shared libraries using
1515 the .gdb_index section.
1517 * Ada support for GDB/MI Variable Objects has been added.
1519 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1524 ** New command -info-os is the MI equivalent of "info os".
1526 ** Output logs ("set logging" and related) now include MI output.
1530 ** "set use-deprecated-index-sections on|off"
1531 "show use-deprecated-index-sections on|off"
1532 Controls the use of deprecated .gdb_index sections.
1534 ** "catch load" and "catch unload" can be used to stop when a shared
1535 library is loaded or unloaded, respectively.
1537 ** "enable count" can be used to auto-disable a breakpoint after
1540 ** "info vtbl" can be used to show the virtual method tables for
1541 C++ and Java objects.
1543 ** "explore" and its sub commands "explore value" and "explore type"
1544 can be used to recursively explore values and types of
1545 expressions. These commands are available only if GDB is
1546 configured with '--with-python'.
1548 ** "info auto-load" shows status of all kinds of auto-loaded files,
1549 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1550 sequences of commands files, "info auto-load python-scripts"
1551 shows status of auto-loading Python script files,
1552 "info auto-load local-gdbinit" shows status of loading init file
1553 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1554 status of inferior specific thread debugging shared library loading.
1556 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1557 and "show auto-load-scripts" commands have been deprecated, use their
1558 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1559 and "show auto-load python-scripts" counterparts instead.
1561 ** "dprintf location,format,args..." creates a dynamic printf, which
1562 is basically a breakpoint that does a printf and immediately
1563 resumes your program's execution, so it is like a printf that you
1564 can insert dynamically at runtime instead of at compiletime.
1566 ** "set print symbol"
1568 Controls whether GDB attempts to display the symbol, if any,
1569 corresponding to addresses it prints. This defaults to "on", but
1570 you can set it to "off" to restore GDB's previous behavior.
1572 * Deprecated commands
1574 ** For the Renesas Super-H architecture, the "regs" command has been
1575 deprecated, and "info all-registers" should be used instead.
1579 Renesas RL78 rl78-*-elf
1580 HP OpenVMS ia64 ia64-hp-openvms*
1582 * GDBserver supports evaluation of breakpoint conditions. When
1583 support is advertised by GDBserver, GDB may be told to send the
1584 breakpoint conditions in bytecode form to GDBserver. GDBserver
1585 will only report the breakpoint trigger to GDB when its condition
1590 set mips compression
1591 show mips compression
1592 Select the compressed ISA encoding used in functions that have no symbol
1593 information available. The encoding can be set to either of:
1596 and is updated automatically from ELF file flags if available.
1598 set breakpoint condition-evaluation
1599 show breakpoint condition-evaluation
1600 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1601 GDBserver ("target"). Default option "auto" chooses the most efficient
1603 This option can improve debugger efficiency depending on the speed of the
1607 Disable auto-loading globally.
1610 Show auto-loading setting of all kinds of auto-loaded files.
1612 set auto-load gdb-scripts on|off
1613 show auto-load gdb-scripts
1614 Control auto-loading of GDB canned sequences of commands files.
1616 set auto-load python-scripts on|off
1617 show auto-load python-scripts
1618 Control auto-loading of Python script files.
1620 set auto-load local-gdbinit on|off
1621 show auto-load local-gdbinit
1622 Control loading of init file (.gdbinit) from current directory.
1624 set auto-load libthread-db on|off
1625 show auto-load libthread-db
1626 Control auto-loading of inferior specific thread debugging shared library.
1628 set auto-load scripts-directory <dir1>[:<dir2>...]
1629 show auto-load scripts-directory
1630 Set a list of directories from which to load auto-loaded scripts.
1631 Automatically loaded Python scripts and GDB scripts are located in one
1632 of the directories listed by this option.
1633 The delimiter (':' above) may differ according to the host platform.
1635 set auto-load safe-path <dir1>[:<dir2>...]
1636 show auto-load safe-path
1637 Set a list of directories from which it is safe to auto-load files.
1638 The delimiter (':' above) may differ according to the host platform.
1640 set debug auto-load on|off
1641 show debug auto-load
1642 Control display of debugging info for auto-loading the files above.
1644 set dprintf-style gdb|call|agent
1646 Control the way in which a dynamic printf is performed; "gdb"
1647 requests a GDB printf command, while "call" causes dprintf to call a
1648 function in the inferior. "agent" requests that the target agent
1649 (such as GDBserver) do the printing.
1651 set dprintf-function <expr>
1652 show dprintf-function
1653 set dprintf-channel <expr>
1654 show dprintf-channel
1655 Set the function and optional first argument to the call when using
1656 the "call" style of dynamic printf.
1658 set disconnected-dprintf on|off
1659 show disconnected-dprintf
1660 Control whether agent-style dynamic printfs continue to be in effect
1661 after GDB disconnects.
1663 * New configure options
1665 --with-auto-load-dir
1666 Configure default value for the 'set auto-load scripts-directory'
1667 setting above. It defaults to '$debugdir:$datadir/auto-load',
1668 $debugdir representing global debugging info directories (available
1669 via 'show debug-file-directory') and $datadir representing GDB's data
1670 directory (available via 'show data-directory').
1672 --with-auto-load-safe-path
1673 Configure default value for the 'set auto-load safe-path' setting
1674 above. It defaults to the --with-auto-load-dir setting.
1676 --without-auto-load-safe-path
1677 Set 'set auto-load safe-path' to '/', effectively disabling this
1680 * New remote packets
1682 z0/z1 conditional breakpoints extension
1684 The z0/z1 breakpoint insertion packets have been extended to carry
1685 a list of conditional expressions over to the remote stub depending on the
1686 condition evaluation mode. The use of this extension can be controlled
1687 via the "set remote conditional-breakpoints-packet" command.
1691 Specify the signals which the remote stub may pass to the debugged
1692 program without GDB involvement.
1694 * New command line options
1696 --init-command=FILE, -ix Like --command, -x but execute it
1697 before loading inferior.
1698 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1699 execute it before loading inferior.
1701 *** Changes in GDB 7.4
1703 * GDB now handles ambiguous linespecs more consistently; the existing
1704 FILE:LINE support has been expanded to other types of linespecs. A
1705 breakpoint will now be set on all matching locations in all
1706 inferiors, and locations will be added or removed according to
1709 * GDB now allows you to skip uninteresting functions and files when
1710 stepping with the "skip function" and "skip file" commands.
1712 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1713 and "show remote hardware-watchpoint-length-limit". These allows to
1714 set or show the maximum length limit (in bytes) of a remote
1715 target hardware watchpoint.
1717 This allows e.g. to use "unlimited" hardware watchpoints with the
1718 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1719 watchpoints are slower than real hardware watchpoints but are
1720 significantly faster than gdb software watchpoints.
1724 ** The register_pretty_printer function in module gdb.printing now takes
1725 an optional `replace' argument. If True, the new printer replaces any
1728 ** The "maint set python print-stack on|off" command has been
1729 deprecated and will be deleted in GDB 7.5.
1730 A new command: "set python print-stack none|full|message" has
1731 replaced it. Additionally, the default for "print-stack" is
1732 now "message", which just prints the error message without
1735 ** A prompt substitution hook (prompt_hook) is now available to the
1738 ** A new Python module, gdb.prompt has been added to the GDB Python
1739 modules library. This module provides functionality for
1740 escape sequences in prompts (used by set/show
1741 extended-prompt). These escape sequences are replaced by their
1742 corresponding value.
1744 ** Python commands and convenience-functions located in
1745 'data-directory'/python/gdb/command and
1746 'data-directory'/python/gdb/function are now automatically loaded
1749 ** Blocks now provide four new attributes. global_block and
1750 static_block will return the global and static blocks
1751 respectively. is_static and is_global are boolean attributes
1752 that indicate if the block is one of those two types.
1754 ** Symbols now provide the "type" attribute, the type of the symbol.
1756 ** The "gdb.breakpoint" function has been deprecated in favor of
1759 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1760 of a function. This class is based on the "finish" command
1761 available in the CLI.
1763 ** Type objects for struct and union types now allow access to
1764 the fields using standard Python dictionary (mapping) methods.
1765 For example, "some_type['myfield']" now works, as does
1766 "some_type.items()".
1768 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1771 ** A new function, "deep_items" has been added to the gdb.types
1772 module in the GDB Python modules library. This function returns
1773 an iterator over the fields of a struct or union type. Unlike
1774 the standard Python "iteritems" method, it will recursively traverse
1775 any anonymous fields.
1779 ** "*stopped" events can report several new "reason"s, such as
1782 ** Breakpoint changes are now notified using new async records, like
1783 "=breakpoint-modified".
1785 ** New command -ada-task-info.
1787 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1788 $sdir specifies the default system locations of shared libraries.
1789 $pdir specifies the directory where the libpthread used by the application
1792 GDB no longer looks in $sdir and $pdir after it has searched the directories
1793 mentioned in libthread-db-search-path. If you want to search those
1794 directories, they must be specified in libthread-db-search-path.
1795 The default value of libthread-db-search-path on GNU/Linux and Solaris
1796 systems is now "$sdir:$pdir".
1798 $pdir is not supported by gdbserver, it is currently ignored.
1799 $sdir is supported by gdbserver.
1801 * New configure option --with-iconv-bin.
1802 When using the internationalization support like the one in the GNU C
1803 library, GDB will invoke the "iconv" program to get a list of supported
1804 character sets. If this program lives in a non-standard location, one can
1805 use this option to specify where to find it.
1807 * When natively debugging programs on PowerPC BookE processors running
1808 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1809 watchpoints, which specify a mask in addition to an address to watch.
1810 The mask specifies that some bits of an address (the bits which are
1811 reset in the mask) should be ignored when matching the address accessed
1812 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1813 section in the user manual for more details.
1815 * The new option --once causes GDBserver to stop listening for connections once
1816 the first connection is made. The listening port used by GDBserver will
1817 become available after that.
1819 * New commands "info macros" and "alias" have been added.
1821 * New function parameters suffix @entry specifies value of function parameter
1822 at the time the function got called. Entry values are available only since
1828 "!" is now an alias of the "shell" command.
1829 Note that no space is needed between "!" and SHELL COMMAND.
1833 watch EXPRESSION mask MASK_VALUE
1834 The watch command now supports the mask argument which allows creation
1835 of masked watchpoints, if the current architecture supports this feature.
1837 info auto-load-scripts [REGEXP]
1838 This command was formerly named "maintenance print section-scripts".
1839 It is now generally useful and is no longer a maintenance-only command.
1841 info macro [-all] [--] MACRO
1842 The info macro command has new options `-all' and `--'. The first for
1843 printing all definitions of a macro. The second for explicitly specifying
1844 the end of arguments and the beginning of the macro name in case the macro
1845 name starts with a hyphen.
1847 collect[/s] EXPRESSIONS
1848 The tracepoint collect command now takes an optional modifier "/s"
1849 that directs it to dereference pointer-to-character types and
1850 collect the bytes of memory up to a zero byte. The behavior is
1851 similar to what you see when you use the regular print command on a
1852 string. An optional integer following the "/s" sets a bound on the
1853 number of bytes that will be collected.
1856 The trace start command now interprets any supplied arguments as a
1857 note to be recorded with the trace run, with an effect similar to
1858 setting the variable trace-notes.
1861 The trace stop command now interprets any arguments as a note to be
1862 mentioned along with the tstatus report that the trace was stopped
1863 with a command. The effect is similar to setting the variable
1866 * Tracepoints can now be enabled and disabled at any time after a trace
1867 experiment has been started using the standard "enable" and "disable"
1868 commands. It is now possible to start a trace experiment with no enabled
1869 tracepoints; GDB will display a warning, but will allow the experiment to
1870 begin, assuming that tracepoints will be enabled as needed while the trace
1873 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1874 locations with 4-byte instructions, when they were previously
1875 limited to locations with instructions of 5 bytes or longer.
1879 set debug dwarf2-read
1880 show debug dwarf2-read
1881 Turns on or off display of debugging messages related to reading
1882 DWARF debug info. The default is off.
1884 set debug symtab-create
1885 show debug symtab-create
1886 Turns on or off display of debugging messages related to symbol table
1887 creation. The default is off.
1890 show extended-prompt
1891 Set the GDB prompt, and allow escape sequences to be inserted to
1892 display miscellaneous information (see 'help set extended-prompt'
1893 for the list of sequences). This prompt (and any information
1894 accessed through the escape sequences) is updated every time the
1895 prompt is displayed.
1897 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1898 show print entry-values
1899 Set printing of frame argument values at function entry. In some cases
1900 GDB can determine the value of function argument which was passed by the
1901 function caller, even if the value was modified inside the called function.
1903 set debug entry-values
1904 show debug entry-values
1905 Control display of debugging info for determining frame argument values at
1906 function entry and virtual tail call frames.
1908 set basenames-may-differ
1909 show basenames-may-differ
1910 Set whether a source file may have multiple base names.
1911 (A "base name" is the name of a file with the directory part removed.
1912 Example: The base name of "/home/user/hello.c" is "hello.c".)
1913 If set, GDB will canonicalize file names (e.g., expand symlinks)
1914 before comparing them. Canonicalization is an expensive operation,
1915 but it allows the same file be known by more than one base name.
1916 If not set (the default), all source files are assumed to have just
1917 one base name, and gdb will do file name comparisons more efficiently.
1923 Set a user name and notes for the current and any future trace runs.
1924 This is useful for long-running and/or disconnected traces, to
1925 inform others (or yourself) as to who is running the trace, supply
1926 contact information, or otherwise explain what is going on.
1928 set trace-stop-notes
1929 show trace-stop-notes
1930 Set a note attached to the trace run, that is displayed when the
1931 trace has been stopped by a tstop command. This is useful for
1932 instance as an explanation, if you are stopping a trace run that was
1933 started by someone else.
1935 * New remote packets
1939 Dynamically enable a tracepoint in a started trace experiment.
1943 Dynamically disable a tracepoint in a started trace experiment.
1947 Set the user and notes of the trace run.
1951 Query the current status of a tracepoint.
1955 Query the minimum length of instruction at which a fast tracepoint may
1958 * Dcache size (number of lines) and line-size are now runtime-configurable
1959 via "set dcache line" and "set dcache line-size" commands.
1963 Texas Instruments TMS320C6x tic6x-*-*
1967 Renesas RL78 rl78-*-elf
1969 *** Changes in GDB 7.3.1
1971 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1973 *** Changes in GDB 7.3
1975 * GDB has a new command: "thread find [REGEXP]".
1976 It finds the thread id whose name, target id, or thread extra info
1977 matches the given regular expression.
1979 * The "catch syscall" command now works on mips*-linux* targets.
1981 * The -data-disassemble MI command now supports modes 2 and 3 for
1982 dumping the instruction opcodes.
1984 * New command line options
1986 -data-directory DIR Specify DIR as the "data-directory".
1987 This is mostly for testing purposes.
1989 * The "maint set python auto-load on|off" command has been renamed to
1990 "set auto-load-scripts on|off".
1992 * GDB has a new command: "set directories".
1993 It is like the "dir" command except that it replaces the
1994 source path list instead of augmenting it.
1996 * GDB now understands thread names.
1998 On GNU/Linux, "info threads" will display the thread name as set by
1999 prctl or pthread_setname_np.
2001 There is also a new command, "thread name", which can be used to
2002 assign a name internally for GDB to display.
2005 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2006 has been integrated into GDB.
2010 ** The function gdb.Write now accepts an optional keyword 'stream'.
2011 This keyword, when provided, will direct the output to either
2012 stdout, stderr, or GDB's logging output.
2014 ** Parameters can now be be sub-classed in Python, and in particular
2015 you may implement the get_set_doc and get_show_doc functions.
2016 This improves how Parameter set/show documentation is processed
2017 and allows for more dynamic content.
2019 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2020 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2021 have an is_valid method.
2023 ** Breakpoints can now be sub-classed in Python, and in particular
2024 you may implement a 'stop' function that is executed each time
2025 the inferior reaches that breakpoint.
2027 ** New function gdb.lookup_global_symbol looks up a global symbol.
2029 ** GDB values in Python are now callable if the value represents a
2030 function. For example, if 'some_value' represents a function that
2031 takes two integer parameters and returns a value, you can call
2032 that function like so:
2034 result = some_value (10,20)
2036 ** Module gdb.types has been added.
2037 It contains a collection of utilities for working with gdb.Types objects:
2038 get_basic_type, has_field, make_enum_dict.
2040 ** Module gdb.printing has been added.
2041 It contains utilities for writing and registering pretty-printers.
2042 New classes: PrettyPrinter, SubPrettyPrinter,
2043 RegexpCollectionPrettyPrinter.
2044 New function: register_pretty_printer.
2046 ** New commands "info pretty-printers", "enable pretty-printer" and
2047 "disable pretty-printer" have been added.
2049 ** gdb.parameter("directories") is now available.
2051 ** New function gdb.newest_frame returns the newest frame in the
2054 ** The gdb.InferiorThread class has a new "name" attribute. This
2055 holds the thread's name.
2057 ** Python Support for Inferior events.
2058 Python scripts can add observers to be notified of events
2059 occurring in the process being debugged.
2060 The following events are currently supported:
2061 - gdb.events.cont Continue event.
2062 - gdb.events.exited Inferior exited event.
2063 - gdb.events.stop Signal received, and Breakpoint hit events.
2067 ** GDB now puts template parameters in scope when debugging in an
2068 instantiation. For example, if you have:
2070 template<int X> int func (void) { return X; }
2072 then if you step into func<5>, "print X" will show "5". This
2073 feature requires proper debuginfo support from the compiler; it
2074 was added to GCC 4.5.
2076 ** The motion commands "next", "finish", "until", and "advance" now
2077 work better when exceptions are thrown. In particular, GDB will
2078 no longer lose control of the inferior; instead, the GDB will
2079 stop the inferior at the point at which the exception is caught.
2080 This functionality requires a change in the exception handling
2081 code that was introduced in GCC 4.5.
2083 * GDB now follows GCC's rules on accessing volatile objects when
2084 reading or writing target state during expression evaluation.
2085 One notable difference to prior behavior is that "print x = 0"
2086 no longer generates a read of x; the value of the assignment is
2087 now always taken directly from the value being assigned.
2089 * GDB now has some support for using labels in the program's source in
2090 linespecs. For instance, you can use "advance label" to continue
2091 execution to a label.
2093 * GDB now has support for reading and writing a new .gdb_index
2094 section. This section holds a fast index of DWARF debugging
2095 information and can be used to greatly speed up GDB startup and
2096 operation. See the documentation for `save gdb-index' for details.
2098 * The "watch" command now accepts an optional "-location" argument.
2099 When used, this causes GDB to watch the memory referred to by the
2100 expression. Such a watchpoint is never deleted due to it going out
2103 * GDB now supports thread debugging of core dumps on GNU/Linux.
2105 GDB now activates thread debugging using the libthread_db library
2106 when debugging GNU/Linux core dumps, similarly to when debugging
2107 live processes. As a result, when debugging a core dump file, GDB
2108 is now able to display pthread_t ids of threads. For example, "info
2109 threads" shows the same output as when debugging the process when it
2110 was live. In earlier releases, you'd see something like this:
2113 * 1 LWP 6780 main () at main.c:10
2115 While now you see this:
2118 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2120 It is also now possible to inspect TLS variables when debugging core
2123 When debugging a core dump generated on a machine other than the one
2124 used to run GDB, you may need to point GDB at the correct
2125 libthread_db library with the "set libthread-db-search-path"
2126 command. See the user manual for more details on this command.
2128 * When natively debugging programs on PowerPC BookE processors running
2129 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2130 which stop execution of the inferior whenever it executes an instruction
2131 at any address within the specified range. See the "PowerPC Embedded"
2132 section in the user manual for more details.
2134 * New features in the GDB remote stub, GDBserver
2136 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2137 and i686 LynxOS (version 5.x).
2139 ** GDBserver is now supported on Blackfin Linux.
2141 * New native configurations
2143 ia64 HP-UX ia64-*-hpux*
2147 Analog Devices, Inc. Blackfin Processor bfin-*
2149 * Ada task switching is now supported on sparc-elf targets when
2150 debugging a program using the Ravenscar Profile. For more information,
2151 see the "Tasking Support when using the Ravenscar Profile" section
2152 in the GDB user manual.
2154 * Guile support was removed.
2156 * New features in the GNU simulator
2158 ** The --map-info flag lists all known core mappings.
2160 ** CFI flashes may be simulated via the "cfi" device.
2162 *** Changes in GDB 7.2
2164 * Shared library support for remote targets by default
2166 When GDB is configured for a generic, non-OS specific target, like
2167 for example, --target=arm-eabi or one of the many *-*-elf targets,
2168 GDB now queries remote stubs for loaded shared libraries using the
2169 `qXfer:libraries:read' packet. Previously, shared library support
2170 was always disabled for such configurations.
2174 ** Argument Dependent Lookup (ADL)
2176 In C++ ADL lookup directs function search to the namespaces of its
2177 arguments even if the namespace has not been imported.
2187 Here the compiler will search for `foo' in the namespace of 'b'
2188 and find A::foo. GDB now supports this. This construct is commonly
2189 used in the Standard Template Library for operators.
2191 ** Improved User Defined Operator Support
2193 In addition to member operators, GDB now supports lookup of operators
2194 defined in a namespace and imported with a `using' directive, operators
2195 defined in the global scope, operators imported implicitly from an
2196 anonymous namespace, and the ADL operators mentioned in the previous
2198 GDB now also supports proper overload resolution for all the previously
2199 mentioned flavors of operators.
2201 ** static const class members
2203 Printing of static const class members that are initialized in the
2204 class definition has been fixed.
2206 * Windows Thread Information Block access.
2208 On Windows targets, GDB now supports displaying the Windows Thread
2209 Information Block (TIB) structure. This structure is visible either
2210 by using the new command `info w32 thread-information-block' or, by
2211 dereferencing the new convenience variable named `$_tlb', a
2212 thread-specific pointer to the TIB. This feature is also supported
2213 when remote debugging using GDBserver.
2215 * Static tracepoints
2217 Static tracepoints are calls in the user program into a tracing
2218 library. One such library is a port of the LTTng kernel tracer to
2219 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2220 When debugging with GDBserver, GDB now supports combining the GDB
2221 tracepoint machinery with such libraries. For example: the user can
2222 use GDB to probe a static tracepoint marker (a call from the user
2223 program into the tracing library) with the new "strace" command (see
2224 "New commands" below). This creates a "static tracepoint" in the
2225 breakpoint list, that can be manipulated with the same feature set
2226 as fast and regular tracepoints. E.g., collect registers, local and
2227 global variables, collect trace state variables, and define
2228 tracepoint conditions. In addition, the user can collect extra
2229 static tracepoint marker specific data, by collecting the new
2230 $_sdata internal variable. When analyzing the trace buffer, you can
2231 inspect $_sdata like any other variable available to GDB. For more
2232 information, see the "Tracepoints" chapter in GDB user manual. New
2233 remote packets have been defined to support static tracepoints, see
2234 the "New remote packets" section below.
2236 * Better reconstruction of tracepoints after disconnected tracing
2238 GDB will attempt to download the original source form of tracepoint
2239 definitions when starting a trace run, and then will upload these
2240 upon reconnection to the target, resulting in a more accurate
2241 reconstruction of the tracepoints that are in use on the target.
2245 You can now exercise direct control over the ways that GDB can
2246 affect your program. For instance, you can disallow the setting of
2247 breakpoints, so that the program can run continuously (assuming
2248 non-stop mode). In addition, the "observer" variable is available
2249 to switch all of the different controls; in observer mode, GDB
2250 cannot affect the target's behavior at all, which is useful for
2251 tasks like diagnosing live systems in the field.
2253 * The new convenience variable $_thread holds the number of the
2256 * New remote packets
2260 Return the address of the Windows Thread Information Block of a given thread.
2264 In response to several of the tracepoint packets, the target may now
2265 also respond with a number of intermediate `qRelocInsn' request
2266 packets before the final result packet, to have GDB handle
2267 relocating an instruction to execute at a different address. This
2268 is particularly useful for stubs that support fast tracepoints. GDB
2269 reports support for this feature in the qSupported packet.
2273 List static tracepoint markers in the target program.
2277 List static tracepoint markers at a given address in the target
2280 qXfer:statictrace:read
2282 Read the static trace data collected (by a `collect $_sdata'
2283 tracepoint action). The remote stub reports support for this packet
2284 to gdb's qSupported query.
2288 Send the current settings of GDB's permission flags.
2292 Send part of the source (textual) form of a tracepoint definition,
2293 which includes location, conditional, and action list.
2295 * The source command now accepts a -s option to force searching for the
2296 script in the source search path even if the script name specifies
2299 * New features in the GDB remote stub, GDBserver
2301 - GDBserver now support tracepoints (including fast tracepoints, and
2302 static tracepoints). The feature is currently supported by the
2303 i386-linux and amd64-linux builds. See the "Tracepoints support
2304 in gdbserver" section in the manual for more information.
2306 GDBserver JIT compiles the tracepoint's conditional agent
2307 expression bytecode into native code whenever possible for low
2308 overhead dynamic tracepoints conditionals. For such tracepoints,
2309 an expression that examines program state is evaluated when the
2310 tracepoint is reached, in order to determine whether to capture
2311 trace data. If the condition is simple and false, processing the
2312 tracepoint finishes very quickly and no data is gathered.
2314 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2315 for static tracepoints support.
2317 - GDBserver now supports x86_64 Windows 64-bit debugging.
2319 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2320 it understands register description.
2322 * The --batch flag now disables pagination and queries.
2324 * X86 general purpose registers
2326 GDB now supports reading/writing byte, word and double-word x86
2327 general purpose registers directly. This means you can use, say,
2328 $ah or $ax to refer, respectively, to the byte register AH and
2329 16-bit word register AX that are actually portions of the 32-bit
2330 register EAX or 64-bit register RAX.
2332 * The `commands' command now accepts a range of breakpoints to modify.
2333 A plain `commands' following a command that creates multiple
2334 breakpoints affects all the breakpoints set by that command. This
2335 applies to breakpoints set by `rbreak', and also applies when a
2336 single `break' command creates multiple breakpoints (e.g.,
2337 breakpoints on overloaded c++ functions).
2339 * The `rbreak' command now accepts a filename specification as part of
2340 its argument, limiting the functions selected by the regex to those
2341 in the specified file.
2343 * Support for remote debugging Windows and SymbianOS shared libraries
2344 from Unix hosts has been improved. Non Windows GDB builds now can
2345 understand target reported file names that follow MS-DOS based file
2346 system semantics, such as file names that include drive letters and
2347 use the backslash character as directory separator. This makes it
2348 possible to transparently use the "set sysroot" and "set
2349 solib-search-path" on Unix hosts to point as host copies of the
2350 target's shared libraries. See the new command "set
2351 target-file-system-kind" described below, and the "Commands to
2352 specify files" section in the user manual for more information.
2356 eval template, expressions...
2357 Convert the values of one or more expressions under the control
2358 of the string template to a command line, and call it.
2360 set target-file-system-kind unix|dos-based|auto
2361 show target-file-system-kind
2362 Set or show the assumed file system kind for target reported file
2365 save breakpoints <filename>
2366 Save all current breakpoint definitions to a file suitable for use
2367 in a later debugging session. To read the saved breakpoint
2368 definitions, use the `source' command.
2370 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2373 info static-tracepoint-markers
2374 Display information about static tracepoint markers in the target.
2376 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2377 Define a static tracepoint by probing a marker at the given
2378 function, line, address, or marker ID.
2382 Enable and disable observer mode.
2384 set may-write-registers on|off
2385 set may-write-memory on|off
2386 set may-insert-breakpoints on|off
2387 set may-insert-tracepoints on|off
2388 set may-insert-fast-tracepoints on|off
2389 set may-interrupt on|off
2390 Set individual permissions for GDB effects on the target. Note that
2391 some of these settings can have undesirable or surprising
2392 consequences, particularly when changed in the middle of a session.
2393 For instance, disabling the writing of memory can prevent
2394 breakpoints from being inserted, cause single-stepping to fail, or
2395 even crash your program, if you disable after breakpoints have been
2396 inserted. However, GDB should not crash.
2398 set record memory-query on|off
2399 show record memory-query
2400 Control whether to stop the inferior if memory changes caused
2401 by an instruction cannot be recorded.
2406 The disassemble command now supports "start,+length" form of two arguments.
2410 ** GDB now provides a new directory location, called the python directory,
2411 where Python scripts written for GDB can be installed. The location
2412 of that directory is <data-directory>/python, where <data-directory>
2413 is the GDB data directory. For more details, see section `Scripting
2414 GDB using Python' in the manual.
2416 ** The GDB Python API now has access to breakpoints, symbols, symbol
2417 tables, program spaces, inferiors, threads and frame's code blocks.
2418 Additionally, GDB Parameters can now be created from the API, and
2419 manipulated via set/show in the CLI.
2421 ** New functions gdb.target_charset, gdb.target_wide_charset,
2422 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2424 ** New exception gdb.GdbError.
2426 ** Pretty-printers are now also looked up in the current program space.
2428 ** Pretty-printers can now be individually enabled and disabled.
2430 ** GDB now looks for names of Python scripts to auto-load in a
2431 special section named `.debug_gdb_scripts', in addition to looking
2432 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2434 * Tracepoint actions were unified with breakpoint commands. In particular,
2435 there are no longer differences in "info break" output for breakpoints and
2436 tracepoints and the "commands" command can be used for both tracepoints and
2437 regular breakpoints.
2441 ARM Symbian arm*-*-symbianelf*
2443 * D language support.
2444 GDB now supports debugging programs written in the D programming
2447 * GDB now supports the extended ptrace interface for PowerPC which is
2448 available since Linux kernel version 2.6.34. This automatically enables
2449 any hardware breakpoints and additional hardware watchpoints available in
2450 the processor. The old ptrace interface exposes just one hardware
2451 watchpoint and no hardware breakpoints.
2453 * GDB is now able to use the Data Value Compare (DVC) register available on
2454 embedded PowerPC processors to implement in hardware simple watchpoint
2455 conditions of the form:
2457 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2459 This works in native GDB running on Linux kernels with the extended ptrace
2460 interface mentioned above.
2462 *** Changes in GDB 7.1
2466 ** Namespace Support
2468 GDB now supports importing of namespaces in C++. This enables the
2469 user to inspect variables from imported namespaces. Support for
2470 namepace aliasing has also been added. So, if a namespace is
2471 aliased in the current scope (e.g. namepace C=A; ) the user can
2472 print variables using the alias (e.g. (gdb) print C::x).
2476 All known bugs relating to the printing of virtual base class were
2477 fixed. It is now possible to call overloaded static methods using a
2482 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2483 and reinterpret_cast<> are now handled by the C++ expression parser.
2487 Xilinx MicroBlaze microblaze-*-*
2492 Xilinx MicroBlaze microblaze
2495 * Multi-program debugging.
2497 GDB now has support for multi-program (a.k.a. multi-executable or
2498 multi-exec) debugging. This allows for debugging multiple inferiors
2499 simultaneously each running a different program under the same GDB
2500 session. See "Debugging Multiple Inferiors and Programs" in the
2501 manual for more information. This implied some user visible changes
2502 in the multi-inferior support. For example, "info inferiors" now
2503 lists inferiors that are not running yet or that have exited
2504 already. See also "New commands" and "New options" below.
2506 * New tracing features
2508 GDB's tracepoint facility now includes several new features:
2510 ** Trace state variables
2512 GDB tracepoints now include support for trace state variables, which
2513 are variables managed by the target agent during a tracing
2514 experiment. They are useful for tracepoints that trigger each
2515 other, so for instance one tracepoint can count hits in a variable,
2516 and then a second tracepoint has a condition that is true when the
2517 count reaches a particular value. Trace state variables share the
2518 $-syntax of GDB convenience variables, and can appear in both
2519 tracepoint actions and condition expressions. Use the "tvariable"
2520 command to create, and "info tvariables" to view; see "Trace State
2521 Variables" in the manual for more detail.
2525 GDB now includes an option for defining fast tracepoints, which
2526 targets may implement more efficiently, such as by installing a jump
2527 into the target agent rather than a trap instruction. The resulting
2528 speedup can be by two orders of magnitude or more, although the
2529 tradeoff is that some program locations on some target architectures
2530 might not allow fast tracepoint installation, for instance if the
2531 instruction to be replaced is shorter than the jump. To request a
2532 fast tracepoint, use the "ftrace" command, with syntax identical to
2533 the regular trace command.
2535 ** Disconnected tracing
2537 It is now possible to detach GDB from the target while it is running
2538 a trace experiment, then reconnect later to see how the experiment
2539 is going. In addition, a new variable disconnected-tracing lets you
2540 tell the target agent whether to continue running a trace if the
2541 connection is lost unexpectedly.
2545 GDB now has the ability to save the trace buffer into a file, and
2546 then use that file as a target, similarly to you can do with
2547 corefiles. You can select trace frames, print data that was
2548 collected in them, and use tstatus to display the state of the
2549 tracing run at the moment that it was saved. To create a trace
2550 file, use "tsave <filename>", and to use it, do "target tfile
2553 ** Circular trace buffer
2555 You can ask the target agent to handle the trace buffer as a
2556 circular buffer, discarding the oldest trace frames to make room for
2557 newer ones, by setting circular-trace-buffer to on. This feature may
2558 not be available for all target agents.
2563 The disassemble command, when invoked with two arguments, now requires
2564 the arguments to be comma-separated.
2567 The info variables command now displays variable definitions. Files
2568 which only declare a variable are not shown.
2571 The source command is now capable of sourcing Python scripts.
2572 This feature is dependent on the debugger being build with Python
2575 Related to this enhancement is also the introduction of a new command
2576 "set script-extension" (see below).
2578 * New commands (for set/show, see "New options" below)
2580 record save [<FILENAME>]
2581 Save a file (in core file format) containing the process record
2582 execution log for replay debugging at a later time.
2584 record restore <FILENAME>
2585 Restore the process record execution log that was saved at an
2586 earlier time, for replay debugging.
2588 add-inferior [-copies <N>] [-exec <FILENAME>]
2591 clone-inferior [-copies <N>] [ID]
2592 Make a new inferior ready to execute the same program another
2593 inferior has loaded.
2598 maint info program-spaces
2599 List the program spaces loaded into GDB.
2601 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2602 show remote interrupt-sequence
2603 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2604 as the sequence to the remote target in order to interrupt the execution.
2605 Ctrl-C is a default. Some system prefers BREAK which is high level of
2606 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2607 Magic SysRq g. It is BREAK signal and character 'g'.
2609 set remote interrupt-on-connect [on | off]
2610 show remote interrupt-on-connect
2611 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2612 remote target when gdb connects to it. This is needed when you debug
2615 set remotebreak [on | off]
2617 Deprecated. Use "set/show remote interrupt-sequence" instead.
2619 tvariable $NAME [ = EXP ]
2620 Create or modify a trace state variable.
2623 List trace state variables and their values.
2625 delete tvariable $NAME ...
2626 Delete one or more trace state variables.
2629 Evaluate the given expressions without collecting anything into the
2630 trace buffer. (Valid in tracepoint actions only.)
2632 ftrace FN / FILE:LINE / *ADDR
2633 Define a fast tracepoint at the given function, line, or address.
2635 * New expression syntax
2637 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2638 GDB now parses 0b101010 identically with 42.
2642 set follow-exec-mode new|same
2643 show follow-exec-mode
2644 Control whether GDB reuses the same inferior across an exec call or
2645 creates a new one. This is useful to be able to restart the old
2646 executable after the inferior having done an exec call.
2648 set default-collect EXPR, ...
2649 show default-collect
2650 Define a list of expressions to be collected at each tracepoint.
2651 This is a useful way to ensure essential items are not overlooked,
2652 such as registers or a critical global variable.
2654 set disconnected-tracing
2655 show disconnected-tracing
2656 If set to 1, the target is instructed to continue tracing if it
2657 loses its connection to GDB. If 0, the target is to stop tracing
2660 set circular-trace-buffer
2661 show circular-trace-buffer
2662 If set to on, the target is instructed to use a circular trace buffer
2663 and discard the oldest trace frames instead of stopping the trace due
2664 to a full trace buffer. If set to off, the trace stops when the buffer
2665 fills up. Some targets may not support this.
2667 set script-extension off|soft|strict
2668 show script-extension
2669 If set to "off", the debugger does not perform any script language
2670 recognition, and all sourced files are assumed to be GDB scripts.
2671 If set to "soft" (the default), files are sourced according to
2672 filename extension, falling back to GDB scripts if the first
2674 If set to "strict", files are sourced according to filename extension.
2676 set ada trust-PAD-over-XVS on|off
2677 show ada trust-PAD-over-XVS
2678 If off, activate a workaround against a bug in the debugging information
2679 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2680 the GCC sources for more information about the GNAT encoding and
2681 PAD types in particular). It is always safe to set this option to
2682 off, but this introduces a slight performance penalty. The default
2685 * Python API Improvements
2687 ** GDB provides the new class gdb.LazyString. This is useful in
2688 some pretty-printing cases. The new method gdb.Value.lazy_string
2689 provides a simple way to create objects of this type.
2691 ** The fields returned by gdb.Type.fields now have an
2692 `is_base_class' attribute.
2694 ** The new method gdb.Type.range returns the range of an array type.
2696 ** The new method gdb.parse_and_eval can be used to parse and
2697 evaluate an expression.
2699 * New remote packets
2702 Define a trace state variable.
2705 Get the current value of a trace state variable.
2708 Set desired tracing behavior upon disconnection.
2711 Set the trace buffer to be linear or circular.
2714 Get data about the tracepoints currently in use.
2718 Process record now works correctly with hardware watchpoints.
2720 Multiple bug fixes have been made to the mips-irix port, making it
2721 much more reliable. In particular:
2722 - Debugging threaded applications is now possible again. Previously,
2723 GDB would hang while starting the program, or while waiting for
2724 the program to stop at a breakpoint.
2725 - Attaching to a running process no longer hangs.
2726 - An error occurring while loading a core file has been fixed.
2727 - Changing the value of the PC register now works again. This fixes
2728 problems observed when using the "jump" command, or when calling
2729 a function from GDB, or even when assigning a new value to $pc.
2730 - With the "finish" and "return" commands, the return value for functions
2731 returning a small array is now correctly printed.
2732 - It is now possible to break on shared library code which gets executed
2733 during a shared library init phase (code executed while executing
2734 their .init section). Previously, the breakpoint would have no effect.
2735 - GDB is now able to backtrace through the signal handler for
2736 non-threaded programs.
2738 PIE (Position Independent Executable) programs debugging is now supported.
2739 This includes debugging execution of PIC (Position Independent Code) shared
2740 libraries although for that, it should be possible to run such libraries as an
2743 *** Changes in GDB 7.0
2745 * GDB now has an interface for JIT compilation. Applications that
2746 dynamically generate code can create symbol files in memory and register
2747 them with GDB. For users, the feature should work transparently, and
2748 for JIT developers, the interface is documented in the GDB manual in the
2749 "JIT Compilation Interface" chapter.
2751 * Tracepoints may now be conditional. The syntax is as for
2752 breakpoints; either an "if" clause appended to the "trace" command,
2753 or the "condition" command is available. GDB sends the condition to
2754 the target for evaluation using the same bytecode format as is used
2755 for tracepoint actions.
2757 * The disassemble command now supports: an optional /r modifier, print the
2758 raw instructions in hex as well as in symbolic form, and an optional /m
2759 modifier to print mixed source+assembly.
2761 * Process record and replay
2763 In a architecture environment that supports ``process record and
2764 replay'', ``process record and replay'' target can record a log of
2765 the process execution, and replay it with both forward and reverse
2768 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2769 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2770 set execution-direction {forward|reverse}, for targets that support
2773 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2774 feature is available with a native GDB running on kernel version
2777 * GDB now has support for multi-byte and wide character sets on the
2778 target. Strings whose character type is wchar_t, char16_t, or
2779 char32_t are now correctly printed. GDB supports wide- and unicode-
2780 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2781 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2782 `printf'. This feature requires iconv to work properly; if your
2783 system does not have a working iconv, GDB can use GNU libiconv. See
2784 the installation instructions for more information.
2786 * GDB now supports automatic retrieval of shared library files from
2787 remote targets. To use this feature, specify a system root that begins
2788 with the `remote:' prefix, either via the `set sysroot' command or via
2789 the `--with-sysroot' configure-time option.
2791 * "info sharedlibrary" now takes an optional regex of libraries to show,
2792 and it now reports if a shared library has no debugging information.
2794 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2795 now complete on file names.
2797 * When completing in expressions, gdb will attempt to limit
2798 completions to allowable structure or union fields, where appropriate.
2799 For instance, consider:
2801 # struct example { int f1; double f2; };
2802 # struct example variable;
2805 If the user types TAB at the end of this command line, the available
2806 completions will be "f1" and "f2".
2808 * Inlined functions are now supported. They show up in backtraces, and
2809 the "step", "next", and "finish" commands handle them automatically.
2811 * GDB now supports the token-splicing (##) and stringification (#)
2812 operators when expanding macros. It also supports variable-arity
2815 * GDB now supports inspecting extra signal information, exported by
2816 the new $_siginfo convenience variable. The feature is currently
2817 implemented on linux ARM, i386 and amd64.
2819 * GDB can now display the VFP floating point registers and NEON vector
2820 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2821 can provide these registers (requires Linux 2.6.30 or later). Remote
2822 and simulator targets may also provide them.
2824 * New remote packets
2827 Search memory for a sequence of bytes.
2830 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2831 operation over reliable transport links. Use of this packet is
2832 controlled by the `set remote noack-packet' command.
2835 Kill the process with the specified process ID. Use this in preference
2836 to `k' when multiprocess protocol extensions are supported.
2839 Obtains additional operating system information
2843 Read or write additional signal information.
2845 * Removed remote protocol undocumented extension
2847 An undocumented extension to the remote protocol's `S' stop reply
2848 packet that permited the stub to pass a process id was removed.
2849 Remote servers should use the `T' stop reply packet instead.
2851 * GDB now supports multiple function calling conventions according to the
2852 DWARF-2 DW_AT_calling_convention function attribute.
2854 * The SH target utilizes the aforementioned change to distinguish between gcc
2855 and Renesas calling convention. It also adds the new CLI commands
2856 `set/show sh calling-convention'.
2858 * GDB can now read compressed debug sections, as produced by GNU gold
2859 with the --compress-debug-sections=zlib flag.
2861 * 64-bit core files are now supported on AIX.
2863 * Thread switching is now supported on Tru64.
2865 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2866 which will be allocated using malloc later in program execution.
2868 * The qXfer:libraries:read remote procotol packet now allows passing a
2869 list of section offsets.
2871 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2872 conditions handling signals delivered during attach or thread creation
2873 have also been fixed.
2875 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2876 From the user's standpoint, all unqualified instances of True and False
2877 are treated as the standard definitions, regardless of context.
2879 * GDB now parses C++ symbol and type names more flexibly. For
2882 template<typename T> class C { };
2885 GDB will now correctly handle all of:
2887 ptype C<char const *>
2888 ptype C<char const*>
2889 ptype C<const char *>
2890 ptype C<const char*>
2892 * New features in the GDB remote stub, gdbserver
2894 - The "--wrapper" command-line argument tells gdbserver to use a
2895 wrapper program to launch programs for debugging.
2897 - On PowerPC and S/390 targets, it is now possible to use a single
2898 gdbserver executable to debug both 32-bit and 64-bit programs.
2899 (This requires gdbserver itself to be built as a 64-bit executable.)
2901 - gdbserver uses the new noack protocol mode for TCP connections to
2902 reduce communications latency, if also supported and enabled in GDB.
2904 - Support for the sparc64-linux-gnu target is now included in
2907 - The amd64-linux build of gdbserver now supports debugging both
2908 32-bit and 64-bit programs.
2910 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2911 now support hardware watchpoints, and will use them automatically
2916 GDB now has support for scripting using Python. Whether this is
2917 available is determined at configure time.
2919 New GDB commands can now be written in Python.
2921 * Ada tasking support
2923 Ada tasks can now be inspected in GDB. The following commands have
2927 Print the list of Ada tasks.
2929 Print detailed information about task number N.
2931 Print the task number of the current task.
2933 Switch the context of debugging to task number N.
2935 * Support for user-defined prefixed commands. The "define" command can
2936 add new commands to existing prefixes, e.g. "target".
2938 * Multi-inferior, multi-process debugging.
2940 GDB now has generalized support for multi-inferior debugging. See
2941 "Debugging Multiple Inferiors" in the manual for more information.
2942 Although availability still depends on target support, the command
2943 set is more uniform now. The GNU/Linux specific multi-forks support
2944 has been migrated to this new framework. This implied some user
2945 visible changes; see "New commands" and also "Removed commands"
2948 * Target descriptions can now describe the target OS ABI. See the
2949 "Target Description Format" section in the user manual for more
2952 * Target descriptions can now describe "compatible" architectures
2953 to indicate that the target can execute applications for a different
2954 architecture in addition to those for the main target architecture.
2955 See the "Target Description Format" section in the user manual for
2958 * Multi-architecture debugging.
2960 GDB now includes general supports for debugging applications on
2961 hybrid systems that use more than one single processor architecture
2962 at the same time. Each such hybrid architecture still requires
2963 specific support to be added. The only hybrid architecture supported
2964 in this version of GDB is the Cell Broadband Engine.
2966 * GDB now supports integrated debugging of Cell/B.E. applications that
2967 use both the PPU and SPU architectures. To enable support for hybrid
2968 Cell/B.E. debugging, you need to configure GDB to support both the
2969 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2970 --enable-targets configure option.
2972 * Non-stop mode debugging.
2974 For some targets, GDB now supports an optional mode of operation in
2975 which you can examine stopped threads while other threads continue
2976 to execute freely. This is referred to as non-stop mode, with the
2977 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2978 section in the user manual for more information.
2980 To be able to support remote non-stop debugging, a remote stub needs
2981 to implement the non-stop mode remote protocol extensions, as
2982 described in the "Remote Non-Stop" section of the user manual. The
2983 GDB remote stub, gdbserver, has been adjusted to support these
2984 extensions on linux targets.
2986 * New commands (for set/show, see "New options" below)
2988 catch syscall [NAME(S) | NUMBER(S)]
2989 Catch system calls. Arguments, which should be names of system
2990 calls or their numbers, mean catch only those syscalls. Without
2991 arguments, every syscall will be caught. When the inferior issues
2992 any of the specified syscalls, GDB will stop and announce the system
2993 call, both when it is called and when its call returns. This
2994 feature is currently available with a native GDB running on the
2995 Linux Kernel, under the following architectures: x86, x86_64,
2996 PowerPC and PowerPC64.
2998 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3000 Search memory for a sequence of bytes.
3002 maint set python print-stack
3003 maint show python print-stack
3004 Show a stack trace when an error is encountered in a Python script.
3007 Invoke CODE by passing it to the Python interpreter.
3012 These allow macros to be defined, undefined, and listed
3016 Show operating system information about processes.
3019 List the inferiors currently under GDB's control.
3022 Switch focus to inferior number NUM.
3025 Detach from inferior number NUM.
3028 Kill inferior number NUM.
3032 set spu stop-on-load
3033 show spu stop-on-load
3034 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3036 set spu auto-flush-cache
3037 show spu auto-flush-cache
3038 Control whether to automatically flush the software-managed cache
3039 during Cell/B.E. debugging.
3041 set sh calling-convention
3042 show sh calling-convention
3043 Control the calling convention used when calling SH target functions.
3046 show debug timestamp
3047 Control display of timestamps with GDB debugging output.
3049 set disassemble-next-line
3050 show disassemble-next-line
3051 Control display of disassembled source lines or instructions when
3054 set remote noack-packet
3055 show remote noack-packet
3056 Set/show the use of remote protocol QStartNoAckMode packet. See above
3057 under "New remote packets."
3059 set remote query-attached-packet
3060 show remote query-attached-packet
3061 Control use of remote protocol `qAttached' (query-attached) packet.
3063 set remote read-siginfo-object
3064 show remote read-siginfo-object
3065 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3068 set remote write-siginfo-object
3069 show remote write-siginfo-object
3070 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3073 set remote reverse-continue
3074 show remote reverse-continue
3075 Control use of remote protocol 'bc' (reverse-continue) packet.
3077 set remote reverse-step
3078 show remote reverse-step
3079 Control use of remote protocol 'bs' (reverse-step) packet.
3081 set displaced-stepping
3082 show displaced-stepping
3083 Control displaced stepping mode. Displaced stepping is a way to
3084 single-step over breakpoints without removing them from the debuggee.
3085 Also known as "out-of-line single-stepping".
3088 show debug displaced
3089 Control display of debugging info for displaced stepping.
3091 maint set internal-error
3092 maint show internal-error
3093 Control what GDB does when an internal error is detected.
3095 maint set internal-warning
3096 maint show internal-warning
3097 Control what GDB does when an internal warning is detected.
3102 Use a wrapper program to launch programs for debugging.
3104 set multiple-symbols (all|ask|cancel)
3105 show multiple-symbols
3106 The value of this variable can be changed to adjust the debugger behavior
3107 when an expression or a breakpoint location contains an ambiguous symbol
3108 name (an overloaded function name, for instance).
3110 set breakpoint always-inserted
3111 show breakpoint always-inserted
3112 Keep breakpoints always inserted in the target, as opposed to inserting
3113 them when resuming the target, and removing them when the target stops.
3114 This option can improve debugger performance on slow remote targets.
3116 set arm fallback-mode (arm|thumb|auto)
3117 show arm fallback-mode
3118 set arm force-mode (arm|thumb|auto)
3120 These commands control how ARM GDB determines whether instructions
3121 are ARM or Thumb. The default for both settings is auto, which uses
3122 the current CPSR value for instructions without symbols; previous
3123 versions of GDB behaved as if "set arm fallback-mode arm".
3125 set disable-randomization
3126 show disable-randomization
3127 Standalone programs run with the virtual address space randomization enabled
3128 by default on some platforms. This option keeps the addresses stable across
3129 multiple debugging sessions.
3133 Control whether other threads are stopped or not when some thread hits
3138 Requests that asynchronous execution is enabled in the target, if available.
3139 In this case, it's possible to resume target in the background, and interact
3140 with GDB while the target is running. "show target-async" displays the
3141 current state of asynchronous execution of the target.
3143 set target-wide-charset
3144 show target-wide-charset
3145 The target-wide-charset is the name of the character set that GDB
3146 uses when printing characters whose type is wchar_t.
3148 set tcp auto-retry (on|off)
3150 set tcp connect-timeout
3151 show tcp connect-timeout
3152 These commands allow GDB to retry failed TCP connections to a remote stub
3153 with a specified timeout period; this is useful if the stub is launched
3154 in parallel with GDB but may not be ready to accept connections immediately.
3156 set libthread-db-search-path
3157 show libthread-db-search-path
3158 Control list of directories which GDB will search for appropriate
3161 set schedule-multiple (on|off)
3162 show schedule-multiple
3163 Allow GDB to resume all threads of all processes or only threads of
3164 the current process.
3168 Use more aggressive caching for accesses to the stack. This improves
3169 performance of remote debugging (particularly backtraces) without
3170 affecting correctness.
3172 set interactive-mode (on|off|auto)
3173 show interactive-mode
3174 Control whether GDB runs in interactive mode (on) or not (off).
3175 When in interactive mode, GDB waits for the user to answer all
3176 queries. Otherwise, GDB does not wait and assumes the default
3177 answer. When set to auto (the default), GDB determines which
3178 mode to use based on the stdin settings.
3183 For program forks, this is replaced by the new more generic `info
3184 inferiors' command. To list checkpoints, you can still use the
3185 `info checkpoints' command, which was an alias for the `info forks'
3189 Replaced by the new `inferior' command. To switch between
3190 checkpoints, you can still use the `restart' command, which was an
3191 alias for the `fork' command.
3194 This is removed, since some targets don't have a notion of
3195 processes. To switch between processes, you can still use the
3196 `inferior' command using GDB's own inferior number.
3199 For program forks, this is replaced by the new more generic `kill
3200 inferior' command. To delete a checkpoint, you can still use the
3201 `delete checkpoint' command, which was an alias for the `delete
3205 For program forks, this is replaced by the new more generic `detach
3206 inferior' command. To detach a checkpoint, you can still use the
3207 `detach checkpoint' command, which was an alias for the `detach
3210 * New native configurations
3212 x86/x86_64 Darwin i[34567]86-*-darwin*
3214 x86_64 MinGW x86_64-*-mingw*
3218 Lattice Mico32 lm32-*
3219 x86 DICOS i[34567]86-*-dicos*
3220 x86_64 DICOS x86_64-*-dicos*
3223 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3224 (mingw32ce) debugging.
3230 These commands were actually not implemented on any target.
3232 *** Changes in GDB 6.8
3234 * New native configurations
3236 NetBSD/hppa hppa*-*netbsd*
3237 Xtensa GNU/Linux xtensa*-*-linux*
3241 NetBSD/hppa hppa*-*-netbsd*
3242 Xtensa GNU/Lunux xtensa*-*-linux*
3244 * Change in command line behavior -- corefiles vs. process ids.
3246 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3247 attaching to process NUMBER fails, GDB no longer attempts to open a
3248 core file named NUMBER. Attaching to a program using the -c option
3249 is no longer supported. Instead, use the '-p' or '--pid' options.
3251 * GDB can now be built as a native debugger for debugging Windows x86
3252 (mingw32) Portable Executable (PE) programs.
3254 * Pending breakpoints no longer change their number when their address
3257 * GDB now supports breakpoints with multiple locations,
3258 including breakpoints on C++ constructors, inside C++ templates,
3259 and in inlined functions.
3261 * GDB's ability to debug optimized code has been improved. GDB more
3262 accurately identifies function bodies and lexical blocks that occupy
3263 more than one contiguous range of addresses.
3265 * Target descriptions can now describe registers for PowerPC.
3267 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3268 registers on PowerPC targets.
3270 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3271 targets even when the libthread_db library is not available.
3273 * The GDB remote stub, gdbserver, now supports the new file transfer
3274 commands (remote put, remote get, and remote delete).
3276 * The GDB remote stub, gdbserver, now supports run and attach in
3277 extended-remote mode.
3279 * hppa*64*-*-hpux11* target broken
3280 The debugger is unable to start a program and fails with the following
3281 error: "Error trying to get information about dynamic linker".
3282 The gdb-6.7 release is also affected.
3284 * GDB now supports the --enable-targets= configure option to allow
3285 building a single GDB executable that supports multiple remote
3286 target architectures.
3288 * GDB now supports debugging C and C++ programs which use the
3289 Decimal Floating Point extension. In addition, the PowerPC target
3290 now has a set of pseudo-registers to inspect decimal float values
3291 stored in two consecutive float registers.
3293 * The -break-insert MI command can optionally create pending
3296 * Improved support for debugging Ada
3297 Many improvements to the Ada language support have been made. These
3299 - Better support for Ada2005 interface types
3300 - Improved handling of arrays and slices in general
3301 - Better support for Taft-amendment types
3302 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3304 - Improved command completion in Ada
3307 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3312 set print frame-arguments (all|scalars|none)
3313 show print frame-arguments
3314 The value of this variable can be changed to control which argument
3315 values should be printed by the debugger when displaying a frame.
3320 Transfer files to and from a remote target, and delete remote files.
3327 Transfer files to and from a remote target, and delete remote files.
3329 * New remote packets
3336 Open, close, read, write, and delete files on the remote system.
3339 Attach to an existing process on the remote system, in extended-remote
3343 Run a new process on the remote system, in extended-remote mode.
3345 *** Changes in GDB 6.7
3347 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3348 bfd, libiberty and opcodes, as revealed by static analysis donated by
3349 Coverity, Inc. (http://scan.coverity.com).
3351 * When looking up multiply-defined global symbols, GDB will now prefer the
3352 symbol definition in the current shared library if it was built using the
3353 -Bsymbolic linker option.
3355 * When the Text User Interface (TUI) is not configured, GDB will now
3356 recognize the -tui command-line option and print a message that the TUI
3359 * The GDB remote stub, gdbserver, now has lower overhead for high
3360 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3362 * GDB for MIPS targets now autodetects whether a remote target provides
3363 32-bit or 64-bit register values.
3365 * Support for C++ member pointers has been improved.
3367 * GDB now understands XML target descriptions, which specify the
3368 target's overall architecture. GDB can read a description from
3369 a local file or over the remote serial protocol.
3371 * Vectors of single-byte data use a new integer type which is not
3372 automatically displayed as character or string data.
3374 * The /s format now works with the print command. It displays
3375 arrays of single-byte integers and pointers to single-byte integers
3378 * Target descriptions can now describe target-specific registers,
3379 for architectures which have implemented the support (currently
3380 only ARM, M68K, and MIPS).
3382 * GDB and the GDB remote stub, gdbserver, now support the XScale
3385 * The GDB remote stub, gdbserver, has been updated to support
3386 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3387 has been rewritten to use the standard GDB remote protocol.
3389 * GDB can now step into C++ functions which are called through thunks.
3391 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3393 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3394 layout. It also supports a TextSeg= and DataSeg= response when only
3395 segment base addresses (rather than offsets) are available.
3397 * The /i format now outputs any trailing branch delay slot instructions
3398 immediately following the last instruction within the count specified.
3400 * The GDB remote protocol "T" stop reply packet now supports a
3401 "library" response. Combined with the new "qXfer:libraries:read"
3402 packet, this response allows GDB to debug shared libraries on targets
3403 where the operating system manages the list of loaded libraries (e.g.
3404 Windows and SymbianOS).
3406 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3407 (DLLs) on Windows and Windows CE targets.
3409 * GDB now supports a faster verification that a .debug file matches its binary
3410 according to its build-id signature, if the signature is present.
3416 Enable or disable hardware flow control (RTS/CTS) on the serial port
3417 when debugging using remote targets.
3419 set mem inaccessible-by-default
3420 show mem inaccessible-by-default
3421 If the target supplies a memory map, for instance via the remote
3422 protocol's "qXfer:memory-map:read" packet, setting this variable
3423 prevents GDB from accessing memory outside the memory map. This
3424 is useful for targets with memory mapped registers or which react
3425 badly to accesses of unmapped address space.
3427 set breakpoint auto-hw
3428 show breakpoint auto-hw
3429 If the target supplies a memory map, for instance via the remote
3430 protocol's "qXfer:memory-map:read" packet, setting this variable
3431 lets GDB use hardware breakpoints automatically for memory regions
3432 where it can not use software breakpoints. This covers both the
3433 "break" command and internal breakpoints used for other commands
3434 including "next" and "finish".
3437 catch exception unhandled
3438 Stop the program execution when Ada exceptions are raised.
3441 Stop the program execution when an Ada assertion failed.
3445 Set an alternate system root for target files. This is a more
3446 general version of "set solib-absolute-prefix", which is now
3447 an alias to "set sysroot".
3450 Provide extended SPU facility status information. This set of
3451 commands is available only when debugging the Cell/B.E. SPU
3454 * New native configurations
3456 OpenBSD/sh sh*-*openbsd*
3459 unset tdesc filename
3461 Use the specified local file as an XML target description, and do
3462 not query the target for its built-in description.
3466 OpenBSD/sh sh*-*-openbsd*
3467 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3468 Toshiba Media Processor mep-elf
3470 * New remote packets
3473 Ignore the specified signals; pass them directly to the debugged program
3474 without stopping other threads or reporting them to GDB.
3476 qXfer:features:read:
3477 Read an XML target description from the target, which describes its
3482 Read or write contents of an spufs file on the target system. These
3483 packets are available only on the Cell/B.E. SPU architecture.
3485 qXfer:libraries:read:
3486 Report the loaded shared libraries. Combined with new "T" packet
3487 response, this packet allows GDB to debug shared libraries on
3488 targets where the operating system manages the list of loaded
3489 libraries (e.g. Windows and SymbianOS).
3493 Support for these obsolete configurations has been removed.
3501 i[34567]86-*-lynxos*
3502 i[34567]86-*-netware*
3503 i[34567]86-*-sco3.2v5*
3504 i[34567]86-*-sco3.2v4*
3506 i[34567]86-*-sysv4.2*
3509 i[34567]86-*-unixware2*
3510 i[34567]86-*-unixware*
3519 * Other removed features
3526 Various m68k-only ROM monitors.
3533 Various Renesas ROM monitors and debugging interfaces for SH and
3538 Support for a Macraigor serial interface to on-chip debugging.
3539 GDB does not directly support the newer parallel or USB
3544 A debug information format. The predecessor to DWARF 2 and
3545 DWARF 3, which are still supported.
3547 Support for the HP aCC compiler on HP-UX/PA-RISC
3549 SOM-encapsulated symbolic debugging information, automatic
3550 invocation of pxdb, and the aCC custom C++ ABI. This does not
3551 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3552 with aCC can still be debugged on an assembly level.
3554 MIPS ".pdr" sections
3556 A MIPS-specific format used to describe stack frame layout
3557 in debugging information.
3561 GDB could work with an older version of Guile to debug
3562 the interpreter and Scheme programs running in it.
3564 set mips stack-arg-size
3565 set mips saved-gpreg-size
3567 Use "set mips abi" to control parameter passing for MIPS.
3569 *** Changes in GDB 6.6
3574 Cell Broadband Engine SPU spu-elf
3576 * GDB can now be configured as a cross-debugger targeting native Windows
3577 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3578 running on a Windows system over TCP/IP to debug Windows programs.
3580 * The GDB remote stub, gdbserver, has been updated to support Windows and
3581 Cygwin debugging. Both single-threaded and multi-threaded programs are
3584 * The "set trust-readonly-sections" command works again. This command was
3585 broken in GDB 6.3, 6.4, and 6.5.
3587 * The "load" command now supports writing to flash memory, if the remote
3588 stub provides the required support.
3590 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3591 longer requires symbolic debug information (e.g. DWARF-2).
3596 unset substitute-path
3597 show substitute-path
3598 Manage a list of substitution rules that GDB uses to rewrite the name
3599 of the directories where the sources are located. This can be useful
3600 for instance when the sources were moved to a different location
3601 between compilation and debugging.
3605 Print each CLI command as it is executed. Each command is prefixed with
3606 a number of `+' symbols representing the nesting depth.
3607 The source command now has a `-v' option to enable the same feature.
3611 The ARM Demon monitor support (RDP protocol, "target rdp").
3613 Kernel Object Display, an embedded debugging feature which only worked with
3614 an obsolete version of Cisco IOS.
3616 The 'set download-write-size' and 'show download-write-size' commands.
3618 * New remote packets
3621 Tell a stub about GDB client features, and request remote target features.
3622 The first feature implemented is PacketSize, which allows the target to
3623 specify the size of packets it can handle - to minimize the number of
3624 packets required and improve performance when connected to a remote
3628 Fetch an OS auxilliary vector from the remote stub. This packet is a
3629 more efficient replacement for qPart:auxv:read.
3631 qXfer:memory-map:read:
3632 Fetch a memory map from the remote stub, including information about
3633 RAM, ROM, and flash memory devices.
3638 Erase and program a flash memory device.
3640 * Removed remote packets
3643 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3644 used it, and only gdbserver implemented it.
3646 *** Changes in GDB 6.5
3650 Renesas M32C/M16C m32c-elf
3652 Morpho Technologies ms1 ms1-elf
3656 init-if-undefined Initialize a convenience variable, but
3657 only if it doesn't already have a value.
3659 The following commands are presently only implemented for native GNU/Linux:
3661 checkpoint Save a snapshot of the program state.
3663 restart <n> Return the program state to a
3664 previously saved state.
3666 info checkpoints List currently saved checkpoints.
3668 delete-checkpoint <n> Delete a previously saved checkpoint.
3670 set|show detach-on-fork Tell gdb whether to detach from a newly
3671 forked process, or to keep debugging it.
3673 info forks List forks of the user program that
3674 are available to be debugged.
3676 fork <n> Switch to debugging one of several
3677 forks of the user program that are
3678 available to be debugged.
3680 delete-fork <n> Delete a fork from the list of forks
3681 that are available to be debugged (and
3682 kill the forked process).
3684 detach-fork <n> Delete a fork from the list of forks
3685 that are available to be debugged (and
3686 allow the process to continue).
3690 Morpho Technologies ms2 ms1-elf
3692 * Improved Windows host support
3694 GDB now builds as a cross debugger hosted on i686-mingw32, including
3695 native console support, and remote communications using either
3696 network sockets or serial ports.
3698 * Improved Modula-2 language support
3700 GDB can now print most types in the Modula-2 syntax. This includes:
3701 basic types, set types, record types, enumerated types, range types,
3702 pointer types and ARRAY types. Procedure var parameters are correctly
3703 printed and hexadecimal addresses and character constants are also
3704 written in the Modula-2 syntax. Best results can be obtained by using
3705 GNU Modula-2 together with the -gdwarf-2 command line option.
3709 The ARM rdi-share module.
3711 The Netware NLM debug server.
3713 *** Changes in GDB 6.4
3715 * New native configurations
3717 OpenBSD/arm arm*-*-openbsd*
3718 OpenBSD/mips64 mips64-*-openbsd*
3722 Morpho Technologies ms1 ms1-elf
3724 * New command line options
3726 --batch-silent As for --batch, but totally silent.
3727 --return-child-result The debugger will exist with the same value
3728 the child (debugged) program exited with.
3729 --eval-command COMMAND, -ex COMMAND
3730 Execute a single GDB CLI command. This may be
3731 specified multiple times and in conjunction
3732 with the --command (-x) option.
3734 * Deprecated commands removed
3736 The following commands, that were deprecated in 2000, have been
3740 set|show arm disassembly-flavor set|show arm disassembler
3741 othernames set arm disassembler
3742 set|show remotedebug set|show debug remote
3743 set|show archdebug set|show debug arch
3744 set|show eventdebug set|show debug event
3747 * New BSD user-level threads support
3749 It is now possible to debug programs using the user-level threads
3750 library on OpenBSD and FreeBSD. Currently supported (target)
3753 FreeBSD/amd64 x86_64-*-freebsd*
3754 FreeBSD/i386 i386-*-freebsd*
3755 OpenBSD/i386 i386-*-openbsd*
3757 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3758 are not yet supported.
3760 * New support for Matsushita MN10300 w/sim added
3761 (Work in progress). mn10300-elf.
3763 * REMOVED configurations and files
3765 VxWorks and the XDR protocol *-*-vxworks
3766 Motorola MCORE mcore-*-*
3767 National Semiconductor NS32000 ns32k-*-*
3769 * New "set print array-indexes" command
3771 After turning this setting "on", GDB prints the index of each element
3772 when displaying arrays. The default is "off" to preserve the previous
3775 * VAX floating point support
3777 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3779 * User-defined command support
3781 In addition to using $arg0..$arg9 for argument passing, it is now possible
3782 to use $argc to determine now many arguments have been passed. See the
3783 section on user-defined commands in the user manual for more information.
3785 *** Changes in GDB 6.3:
3787 * New command line option
3789 GDB now accepts -l followed by a number to set the timeout for remote
3792 * GDB works with GCC -feliminate-dwarf2-dups
3794 GDB now supports a more compact representation of DWARF-2 debug
3795 information using DW_FORM_ref_addr references. These are produced
3796 by GCC with the option -feliminate-dwarf2-dups and also by some
3797 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3798 to use -feliminate-dwarf2-dups.
3800 * Internationalization
3802 When supported by the host system, GDB will be built with
3803 internationalization (libintl). The task of marking up the sources is
3804 continued, we're looking forward to our first translation.
3808 Initial support for debugging programs compiled with the GNAT
3809 implementation of the Ada programming language has been integrated
3810 into GDB. In this release, support is limited to expression evaluation.
3812 * New native configurations
3814 GNU/Linux/m32r m32r-*-linux-gnu
3818 GDB's remote protocol now includes support for the 'p' packet. This
3819 packet is used to fetch individual registers from a remote inferior.
3821 * END-OF-LIFE registers[] compatibility module
3823 GDB's internal register infrastructure has been completely rewritten.
3824 The new infrastructure making possible the implementation of key new
3825 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3828 GDB 6.3 will be the last release to include the the registers[]
3829 compatibility module that allowed out-of-date configurations to
3830 continue to work. This change directly impacts the following
3840 powerpc bdm protocol
3842 Unless there is activity to revive these configurations, they will be
3843 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3845 * OBSOLETE configurations and files
3847 Configurations that have been declared obsolete in this release have
3848 been commented out. Unless there is activity to revive these
3849 configurations, the next release of GDB will have their sources
3850 permanently REMOVED.
3859 *** Changes in GDB 6.2.1:
3861 * MIPS `break main; run' gave an heuristic-fence-post warning
3863 When attempting to run even a simple program, a warning about
3864 heuristic-fence-post being hit would be reported. This problem has
3867 * MIPS IRIX 'long double' crashed GDB
3869 When examining a long double variable, GDB would get a segmentation
3870 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3871 IRIX long double values).
3875 A bug in the VAX stack code was causing problems with the "next"
3876 command. This problem has been fixed.
3878 *** Changes in GDB 6.2:
3880 * Fix for ``many threads''
3882 On GNU/Linux systems that use the NPTL threads library, a program
3883 rapidly creating and deleting threads would confuse GDB leading to the
3886 ptrace: No such process.
3887 thread_db_get_info: cannot get thread info: generic error
3889 This problem has been fixed.
3891 * "-async" and "-noasync" options removed.
3893 Support for the broken "-noasync" option has been removed (it caused
3896 * New ``start'' command.
3898 This command runs the program until the begining of the main procedure.
3900 * New BSD Kernel Data Access Library (libkvm) interface
3902 Using ``target kvm'' it is now possible to debug kernel core dumps and
3903 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3904 platforms. Currently supported (native-only) configurations are:
3906 FreeBSD/amd64 x86_64-*-freebsd*
3907 FreeBSD/i386 i?86-*-freebsd*
3908 NetBSD/i386 i?86-*-netbsd*
3909 NetBSD/m68k m68*-*-netbsd*
3910 NetBSD/sparc sparc-*-netbsd*
3911 OpenBSD/amd64 x86_64-*-openbsd*
3912 OpenBSD/i386 i?86-*-openbsd*
3913 OpenBSD/m68k m68*-openbsd*
3914 OpenBSD/sparc sparc-*-openbsd*
3916 * Signal trampoline code overhauled
3918 Many generic problems with GDB's signal handling code have been fixed.
3919 These include: backtraces through non-contiguous stacks; recognition
3920 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3921 call; backtrace through a signal trampoline; step into and out of
3922 signal handlers; and single-stepping in the signal trampoline.
3924 Please note that kernel bugs are a limiting factor here. These
3925 features have been shown to work on an s390 GNU/Linux system that
3926 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3928 * Cygwin support for DWARF 2 added.
3930 * New native configurations
3932 GNU/Linux/hppa hppa*-*-linux*
3933 OpenBSD/hppa hppa*-*-openbsd*
3934 OpenBSD/m68k m68*-*-openbsd*
3935 OpenBSD/m88k m88*-*-openbsd*
3936 OpenBSD/powerpc powerpc-*-openbsd*
3937 NetBSD/vax vax-*-netbsd*
3938 OpenBSD/vax vax-*-openbsd*
3940 * END-OF-LIFE frame compatibility module
3942 GDB's internal frame infrastructure has been completely rewritten.
3943 The new infrastructure making it possible to support key new features
3944 including DWARF 2 Call Frame Information. To aid in the task of
3945 migrating old configurations to this new infrastructure, a
3946 compatibility module, that allowed old configurations to continue to
3947 work, was also included.
3949 GDB 6.2 will be the last release to include this frame compatibility
3950 module. This change directly impacts the following configurations:
3960 Unless there is activity to revive these configurations, they will be
3961 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3963 * REMOVED configurations and files
3965 Sun 3, running SunOS 3 m68*-*-sunos3*
3966 Sun 3, running SunOS 4 m68*-*-sunos4*
3967 Sun 2, running SunOS 3 m68000-*-sunos3*
3968 Sun 2, running SunOS 4 m68000-*-sunos4*
3969 Motorola 680x0 running LynxOS m68*-*-lynxos*
3970 AT&T 3b1/Unix pc m68*-att-*
3971 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3972 decstation mips-dec-* mips-little-*
3973 riscos mips-*-riscos* mips-*-sysv*
3974 sonymips mips-sony-*
3975 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3977 *** Changes in GDB 6.1.1:
3979 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3981 The TUI (Text-mode User Interface) is now built as part of a default
3982 GDB configuration. It is enabled by either selecting the TUI with the
3983 command line option "-i=tui" or by running the separate "gdbtui"
3984 program. For more information on the TUI, see the manual "Debugging
3987 * Pending breakpoint support (also included in GDB 6.1)
3989 Support has been added to allow you to specify breakpoints in shared
3990 libraries that have not yet been loaded. If a breakpoint location
3991 cannot be found, and the "breakpoint pending" option is set to auto,
3992 GDB queries you if you wish to make the breakpoint pending on a future
3993 shared-library load. If and when GDB resolves the breakpoint symbol,
3994 the pending breakpoint is removed as one or more regular breakpoints
3997 Pending breakpoints are very useful for GCJ Java debugging.
3999 * Fixed ISO-C build problems
4001 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4002 non ISO-C code that stopped them being built using a more strict ISO-C
4003 compiler (e.g., IBM's C compiler).
4005 * Fixed build problem on IRIX 5
4007 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4008 wasn't able to compile compile on an IRIX 5 system.
4010 * Added execute permission to gdb/gdbserver/configure
4012 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4013 permission. This bug would cause configure to fail on a number of
4014 systems (Solaris, IRIX). Ref: server/519.
4016 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4018 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4019 has been updated to use constant array sizes.
4021 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4023 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4024 its generated DWARF Call Frame Info. This encoding was causing GDB to
4025 panic, that panic has been fixed. Ref: gdb/1628.
4027 * Fixed a problem when examining parameters in shared library code.
4029 When examining parameters in optimized shared library code generated
4030 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4031 not available''. GDB now correctly displays the variable's value.
4033 *** Changes in GDB 6.1:
4035 * Removed --with-mmalloc
4037 Support for the mmalloc memory manager has been removed, as it
4038 conflicted with the internal gdb byte cache.
4040 * Changes in AMD64 configurations
4042 The AMD64 target now includes the %cs and %ss registers. As a result
4043 the AMD64 remote protocol has changed; this affects the floating-point
4044 and SSE registers. If you rely on those registers for your debugging,
4045 you should upgrade gdbserver on the remote side.
4047 * Revised SPARC target
4049 The SPARC target has been completely revised, incorporating the
4050 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4051 support for LynxOS and SunOS 4 has been dropped. Calling functions
4052 from within GDB on operating systems with a non-executable stack
4053 (Solaris, OpenBSD) now works.
4057 GDB has a new C++ demangler which does a better job on the mangled
4058 names generated by current versions of g++. It also runs faster, so
4059 with this and other changes gdb should now start faster on large C++
4062 * DWARF 2 Location Expressions
4064 GDB support for location expressions has been extended to support function
4065 arguments and frame bases. Older versions of GDB could crash when they
4068 * C++ nested types and namespaces
4070 GDB's support for nested types and namespaces in C++ has been
4071 improved, especially if you use the DWARF 2 debugging format. (This
4072 is the default for recent versions of GCC on most platforms.)
4073 Specifically, if you have a class "Inner" defined within a class or
4074 namespace "Outer", then GDB realizes that the class's name is
4075 "Outer::Inner", not simply "Inner". This should greatly reduce the
4076 frequency of complaints about not finding RTTI symbols. In addition,
4077 if you are stopped at inside of a function defined within a namespace,
4078 GDB modifies its name lookup accordingly.
4080 * New native configurations
4082 NetBSD/amd64 x86_64-*-netbsd*
4083 OpenBSD/amd64 x86_64-*-openbsd*
4084 OpenBSD/alpha alpha*-*-openbsd*
4085 OpenBSD/sparc sparc-*-openbsd*
4086 OpenBSD/sparc64 sparc64-*-openbsd*
4088 * New debugging protocols
4090 M32R with SDI protocol m32r-*-elf*
4092 * "set prompt-escape-char" command deleted.
4094 The command "set prompt-escape-char" has been deleted. This command,
4095 and its very obscure effet on GDB's prompt, was never documented,
4096 tested, nor mentioned in the NEWS file.
4098 * OBSOLETE configurations and files
4100 Configurations that have been declared obsolete in this release have
4101 been commented out. Unless there is activity to revive these
4102 configurations, the next release of GDB will have their sources
4103 permanently REMOVED.
4105 Sun 3, running SunOS 3 m68*-*-sunos3*
4106 Sun 3, running SunOS 4 m68*-*-sunos4*
4107 Sun 2, running SunOS 3 m68000-*-sunos3*
4108 Sun 2, running SunOS 4 m68000-*-sunos4*
4109 Motorola 680x0 running LynxOS m68*-*-lynxos*
4110 AT&T 3b1/Unix pc m68*-att-*
4111 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4112 decstation mips-dec-* mips-little-*
4113 riscos mips-*-riscos* mips-*-sysv*
4114 sonymips mips-sony-*
4115 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4117 * REMOVED configurations and files
4119 SGI Irix-4.x mips-sgi-irix4 or iris4
4120 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4121 Z8000 simulator z8k-zilog-none or z8ksim
4122 Matsushita MN10200 w/simulator mn10200-*-*
4123 H8/500 simulator h8500-hitachi-hms or h8500hms
4124 HP/PA running BSD hppa*-*-bsd*
4125 HP/PA running OSF/1 hppa*-*-osf*
4126 HP/PA Pro target hppa*-*-pro*
4127 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4128 386BSD i[3456]86-*-bsd*
4129 Sequent family i[3456]86-sequent-sysv4*
4130 i[3456]86-sequent-sysv*
4131 i[3456]86-sequent-bsd*
4132 SPARC running LynxOS sparc-*-lynxos*
4133 SPARC running SunOS 4 sparc-*-sunos4*
4134 Tsqware Sparclet sparclet-*-*
4135 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4137 *** Changes in GDB 6.0:
4141 Support for debugging the Objective-C programming language has been
4142 integrated into GDB.
4144 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4146 DWARF 2's Call Frame Information makes available compiler generated
4147 information that more exactly describes the program's run-time stack.
4148 By using this information, GDB is able to provide more robust stack
4151 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4152 have been updated to use a new backtrace mechanism which includes
4153 DWARF 2 CFI support.
4157 GDB's remote protocol has been extended to include support for hosted
4158 file I/O (where the remote target uses GDB's file system). See GDB's
4159 remote protocol documentation for details.
4161 * All targets using the new architecture framework.
4163 All of GDB's targets have been updated to use the new internal
4164 architecture framework. The way is now open for future GDB releases
4165 to include cross-architecture native debugging support (i386 on amd64,
4168 * GNU/Linux's Thread Local Storage (TLS)
4170 GDB now includes support for for the GNU/Linux implementation of
4171 per-thread variables.
4173 * GNU/Linux's Native POSIX Thread Library (NPTL)
4175 GDB's thread code has been updated to work with either the new
4176 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4178 * Separate debug info.
4180 GDB, in conjunction with BINUTILS, now supports a mechanism for
4181 automatically loading debug information from a separate file. Instead
4182 of shipping full debug and non-debug versions of system libraries,
4183 system integrators can now instead ship just the stripped libraries
4184 and optional debug files.
4186 * DWARF 2 Location Expressions
4188 DWARF 2 Location Expressions allow the compiler to more completely
4189 describe the location of variables (even in optimized code) to the
4192 GDB now includes preliminary support for location expressions (support
4193 for DW_OP_piece is still missing).
4197 A number of long standing bugs that caused GDB to die while starting a
4198 Java application have been fixed. GDB's Java support is now
4199 considered "useable".
4201 * GNU/Linux support for fork, vfork, and exec.
4203 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4204 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4207 * GDB supports logging output to a file
4209 There are two new commands, "set logging" and "show logging", which can be
4210 used to capture GDB's output to a file.
4212 * The meaning of "detach" has changed for gdbserver
4214 The "detach" command will now resume the application, as documented. To
4215 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4218 * d10v, m68hc11 `regs' command deprecated
4220 The `info registers' command has been updated so that it displays the
4221 registers using a format identical to the old `regs' command.
4225 A new command, "maint set profile on/off", has been added. This command can
4226 be used to enable or disable profiling while running GDB, to profile a
4227 session or a set of commands. In addition there is a new configure switch,
4228 "--enable-profiling", which will cause GDB to be compiled with profiling
4229 data, for more informative profiling results.
4231 * Default MI syntax changed to "mi2".
4233 The default MI (machine interface) syntax, enabled by the command line
4234 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4235 "mi1", can be enabled by specifying the option "-i=mi1".
4237 Support for the original "mi0" syntax (included in GDB 5.0) has been
4240 Fix for gdb/192: removed extraneous space when displaying frame level.
4241 Fix for gdb/672: update changelist is now output in mi list format.
4242 Fix for gdb/702: a -var-assign that updates the value now shows up
4243 in a subsequent -var-update.
4245 * New native configurations.
4247 FreeBSD/amd64 x86_64-*-freebsd*
4249 * Multi-arched targets.
4251 HP/PA HPUX11 hppa*-*-hpux*
4252 Renesas M32R/D w/simulator m32r-*-elf*
4254 * OBSOLETE configurations and files
4256 Configurations that have been declared obsolete in this release have
4257 been commented out. Unless there is activity to revive these
4258 configurations, the next release of GDB will have their sources
4259 permanently REMOVED.
4261 Z8000 simulator z8k-zilog-none or z8ksim
4262 Matsushita MN10200 w/simulator mn10200-*-*
4263 H8/500 simulator h8500-hitachi-hms or h8500hms
4264 HP/PA running BSD hppa*-*-bsd*
4265 HP/PA running OSF/1 hppa*-*-osf*
4266 HP/PA Pro target hppa*-*-pro*
4267 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4268 Sequent family i[3456]86-sequent-sysv4*
4269 i[3456]86-sequent-sysv*
4270 i[3456]86-sequent-bsd*
4271 Tsqware Sparclet sparclet-*-*
4272 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4274 * REMOVED configurations and files
4277 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4278 IBM AIX PS/2 i[3456]86-*-aix
4279 i386 running Mach 3.0 i[3456]86-*-mach3*
4280 i386 running Mach i[3456]86-*-mach*
4281 i386 running OSF/1 i[3456]86-*osf1mk*
4282 HP/Apollo 68k Family m68*-apollo*-sysv*,
4284 m68*-hp-bsd*, m68*-hp-hpux*
4285 Argonaut Risc Chip (ARC) arc-*-*
4286 Mitsubishi D30V d30v-*-*
4287 Fujitsu FR30 fr30-*-elf*
4288 OS/9000 i[34]86-*-os9k
4289 I960 with MON960 i960-*-coff
4291 * MIPS $fp behavior changed
4293 The convenience variable $fp, for the MIPS, now consistently returns
4294 the address of the current frame's base. Previously, depending on the
4295 context, $fp could refer to either $sp or the current frame's base
4296 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4297 The GNU Source-Level Debugger''.
4299 *** Changes in GDB 5.3:
4301 * GNU/Linux shared library multi-threaded performance improved.
4303 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4304 `/proc', in preference to `ptrace' for memory reads. This may result
4305 in an improvement in the start-up time of multi-threaded, shared
4306 library applications when run under GDB. One GDB user writes: ``loads
4307 shared libs like mad''.
4309 * ``gdbserver'' now supports multi-threaded applications on some targets
4311 Support for debugging multi-threaded applications which use
4312 the GNU/Linux LinuxThreads package has been added for
4313 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4314 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4316 * GDB now supports C/C++ preprocessor macros.
4318 GDB now expands preprocessor macro invocations in C/C++ expressions,
4319 and provides various commands for showing macro definitions and how
4322 The new command `macro expand EXPRESSION' expands any macro
4323 invocations in expression, and shows the result.
4325 The new command `show macro MACRO-NAME' shows the definition of the
4326 macro named MACRO-NAME, and where it was defined.
4328 Most compilers don't include information about macros in the debugging
4329 information by default. In GCC 3.1, for example, you need to compile
4330 your program with the options `-gdwarf-2 -g3'. If the macro
4331 information is present in the executable, GDB will read it.
4333 * Multi-arched targets.
4335 DEC Alpha (partial) alpha*-*-*
4336 DEC VAX (partial) vax-*-*
4338 National Semiconductor NS32000 (partial) ns32k-*-*
4339 Motorola 68000 (partial) m68k-*-*
4340 Motorola MCORE mcore-*-*
4344 Fujitsu FRV architecture added by Red Hat frv*-*-*
4347 * New native configurations
4349 Alpha NetBSD alpha*-*-netbsd*
4350 SH NetBSD sh*-*-netbsdelf*
4351 MIPS NetBSD mips*-*-netbsd*
4352 UltraSPARC NetBSD sparc64-*-netbsd*
4354 * OBSOLETE configurations and files
4356 Configurations that have been declared obsolete in this release have
4357 been commented out. Unless there is activity to revive these
4358 configurations, the next release of GDB will have their sources
4359 permanently REMOVED.
4361 Mitsubishi D30V d30v-*-*
4362 OS/9000 i[34]86-*-os9k
4363 IBM AIX PS/2 i[3456]86-*-aix
4364 Fujitsu FR30 fr30-*-elf*
4365 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4366 Argonaut Risc Chip (ARC) arc-*-*
4367 i386 running Mach 3.0 i[3456]86-*-mach3*
4368 i386 running Mach i[3456]86-*-mach*
4369 i386 running OSF/1 i[3456]86-*osf1mk*
4370 HP/Apollo 68k Family m68*-apollo*-sysv*,
4372 m68*-hp-bsd*, m68*-hp-hpux*
4373 I960 with MON960 i960-*-coff
4375 * OBSOLETE languages
4377 CHILL, a Pascal like language used by telecommunications companies.
4379 * REMOVED configurations and files
4381 AMD 29k family via UDI a29k-amd-udi, udi29k
4382 A29K VxWorks a29k-*-vxworks
4383 AMD 29000 embedded, using EBMON a29k-none-none
4384 AMD 29000 embedded with COFF a29k-none-coff
4385 AMD 29000 embedded with a.out a29k-none-aout
4387 testsuite/gdb.hp/gdb.threads-hp/ directory
4389 * New command "set max-user-call-depth <nnn>"
4391 This command allows the user to limit the call depth of user-defined
4392 commands. The default is 1024.
4394 * Changes in FreeBSD/i386 native debugging.
4396 Support for the "generate-core-file" has been added.
4398 * New commands "dump", "append", and "restore".
4400 These commands allow data to be copied from target memory
4401 to a bfd-format or binary file (dump and append), and back
4402 from a file into memory (restore).
4404 * Improved "next/step" support on multi-processor Alpha Tru64.
4406 The previous single-step mechanism could cause unpredictable problems,
4407 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4408 of a software single-step mechanism prevents this.
4410 *** Changes in GDB 5.2.1:
4418 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4419 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4420 Fix, by Joel Brobecker imported from mainline.
4422 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4423 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4424 Fix, by Fred Fish, imported from mainline.
4426 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4427 Surprisingly enough, it works now.
4428 By Michal Ludvig, imported from mainline.
4430 i386 hardware watchpoint support:
4431 avoid misses on second run for some targets.
4432 By Pierre Muller, imported from mainline.
4434 *** Changes in GDB 5.2:
4436 * New command "set trust-readonly-sections on[off]".
4438 This command is a hint that tells gdb that read-only sections
4439 really are read-only (ie. that their contents will not change).
4440 In this mode, gdb will go to the object file rather than the
4441 target to read memory from read-only sections (such as ".text").
4442 This can be a significant performance improvement on some
4443 (notably embedded) targets.
4445 * New command "generate-core-file" (or "gcore").
4447 This new gdb command allows the user to drop a core file of the child
4448 process state at any time. So far it's been implemented only for
4449 GNU/Linux and Solaris, but should be relatively easily ported to other
4450 hosts. Argument is core file name (defaults to core.<pid>).
4452 * New command line option
4454 GDB now accepts --pid or -p followed by a process id.
4456 * Change in command line behavior -- corefiles vs. process ids.
4458 There is a subtle behavior in the way in which GDB handles
4459 command line arguments. The first non-flag argument is always
4460 a program to debug, but the second non-flag argument may either
4461 be a corefile or a process id. Previously, GDB would attempt to
4462 open the second argument as a corefile, and if that failed, would
4463 issue a superfluous error message and then attempt to attach it as
4464 a process. Now, if the second argument begins with a non-digit,
4465 it will be treated as a corefile. If it begins with a digit,
4466 GDB will attempt to attach it as a process, and if no such process
4467 is found, will then attempt to open it as a corefile.
4469 * Changes in ARM configurations.
4471 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4472 configuration is fully multi-arch.
4474 * New native configurations
4476 ARM NetBSD arm*-*-netbsd*
4477 x86 OpenBSD i[3456]86-*-openbsd*
4478 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4479 Sparc64 running FreeBSD sparc64-*-freebsd*
4483 Sanyo XStormy16 xstormy16-elf
4485 * OBSOLETE configurations and files
4487 Configurations that have been declared obsolete in this release have
4488 been commented out. Unless there is activity to revive these
4489 configurations, the next release of GDB will have their sources
4490 permanently REMOVED.
4492 AMD 29k family via UDI a29k-amd-udi, udi29k
4493 A29K VxWorks a29k-*-vxworks
4494 AMD 29000 embedded, using EBMON a29k-none-none
4495 AMD 29000 embedded with COFF a29k-none-coff
4496 AMD 29000 embedded with a.out a29k-none-aout
4498 testsuite/gdb.hp/gdb.threads-hp/ directory
4500 * REMOVED configurations and files
4502 TI TMS320C80 tic80-*-*
4504 PowerPC Solaris powerpcle-*-solaris*
4505 PowerPC Windows NT powerpcle-*-cygwin32
4506 PowerPC Netware powerpc-*-netware*
4507 Harris/CXUX m88k m88*-harris-cxux*
4508 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4509 ns32k-utek-sysv* ns32k-utek-*
4510 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4511 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4512 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4513 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4514 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4516 * Changes to command line processing
4518 The new `--args' feature can be used to specify command-line arguments
4519 for the inferior from gdb's command line.
4521 * Changes to key bindings
4523 There is a new `operate-and-get-next' function bound to `C-o'.
4525 *** Changes in GDB 5.1.1
4527 Fix compile problem on DJGPP.
4529 Fix a problem with floating-point registers on the i386 being
4532 Fix to stop GDB crashing on .debug_str debug info.
4534 Numerous documentation fixes.
4536 Numerous testsuite fixes.
4538 *** Changes in GDB 5.1:
4540 * New native configurations
4542 Alpha FreeBSD alpha*-*-freebsd*
4543 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4544 MIPS GNU/Linux mips*-*-linux*
4545 MIPS SGI Irix 6.x mips*-sgi-irix6*
4546 ia64 AIX ia64-*-aix*
4547 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4551 Motorola 68HC11 and 68HC12 m68hc11-elf
4553 UltraSparc running GNU/Linux sparc64-*-linux*
4555 * OBSOLETE configurations and files
4557 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4558 Harris/CXUX m88k m88*-harris-cxux*
4559 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4560 ns32k-utek-sysv* ns32k-utek-*
4561 TI TMS320C80 tic80-*-*
4563 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4564 PowerPC Solaris powerpcle-*-solaris*
4565 PowerPC Windows NT powerpcle-*-cygwin32
4566 PowerPC Netware powerpc-*-netware*
4567 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4568 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4569 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4570 Apple Macintosh (MPW) host N/A
4572 stuff.c (Program to stuff files into a specially prepared space in kdb)
4573 kdb-start.c (Main loop for the standalone kernel debugger)
4575 Configurations that have been declared obsolete in this release have
4576 been commented out. Unless there is activity to revive these
4577 configurations, the next release of GDB will have their sources
4578 permanently REMOVED.
4580 * REMOVED configurations and files
4582 Altos 3068 m68*-altos-*
4583 Convex c1-*-*, c2-*-*
4585 ARM RISCix arm-*-* (as host)
4589 * GDB has been converted to ISO C.
4591 GDB's source code has been converted to ISO C. In particular, the
4592 sources are fully protoized, and rely on standard headers being
4597 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4599 * The MI enabled by default.
4601 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4602 revised and enabled by default. Packages which use GDB as a debugging
4603 engine behind a UI or another front end are encouraged to switch to
4604 using the GDB/MI interface, instead of the old annotations interface
4605 which is now deprecated.
4607 * Support for debugging Pascal programs.
4609 GDB now includes support for debugging Pascal programs. The following
4610 main features are supported:
4612 - Pascal-specific data types such as sets;
4614 - automatic recognition of Pascal sources based on file-name
4617 - Pascal-style display of data types, variables, and functions;
4619 - a Pascal expression parser.
4621 However, some important features are not yet supported.
4623 - Pascal string operations are not supported at all;
4625 - there are some problems with boolean types;
4627 - Pascal type hexadecimal constants are not supported
4628 because they conflict with the internal variables format;
4630 - support for Pascal objects and classes is not full yet;
4632 - unlike Pascal, GDB is case-sensitive for symbol names.
4634 * Changes in completion.
4636 Commands such as `shell', `run' and `set args', which pass arguments
4637 to inferior programs, now complete on file names, similar to what
4638 users expect at the shell prompt.
4640 Commands which accept locations, such as `disassemble', `print',
4641 `breakpoint', `until', etc. now complete on filenames as well as
4642 program symbols. Thus, if you type "break foob TAB", and the source
4643 files linked into the programs include `foobar.c', that file name will
4644 be one of the candidates for completion. However, file names are not
4645 considered for completion after you typed a colon that delimits a file
4646 name from a name of a function in that file, as in "break foo.c:bar".
4648 `set demangle-style' completes on available demangling styles.
4650 * New platform-independent commands:
4652 It is now possible to define a post-hook for a command as well as a
4653 hook that runs before the command. For more details, see the
4654 documentation of `hookpost' in the GDB manual.
4656 * Changes in GNU/Linux native debugging.
4658 Support for debugging multi-threaded programs has been completely
4659 revised for all platforms except m68k and sparc. You can now debug as
4660 many threads as your system allows you to have.
4662 Attach/detach is supported for multi-threaded programs.
4664 Support for SSE registers was added for x86. This doesn't work for
4665 multi-threaded programs though.
4667 * Changes in MIPS configurations.
4669 Multi-arch support is enabled for all MIPS configurations.
4671 GDB can now be built as native debugger on SGI Irix 6.x systems for
4672 debugging n32 executables. (Debugging 64-bit executables is not yet
4675 * Unified support for hardware watchpoints in all x86 configurations.
4677 Most (if not all) native x86 configurations support hardware-assisted
4678 breakpoints and watchpoints in a unified manner. This support
4679 implements debug register sharing between watchpoints, which allows to
4680 put a virtually infinite number of watchpoints on the same address,
4681 and also supports watching regions up to 16 bytes with several debug
4684 The new maintenance command `maintenance show-debug-regs' toggles
4685 debugging print-outs in functions that insert, remove, and test
4686 watchpoints and hardware breakpoints.
4688 * Changes in the DJGPP native configuration.
4690 New command ``info dos sysinfo'' displays assorted information about
4691 the CPU, OS, memory, and DPMI server.
4693 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4694 display information about segment descriptors stored in GDT, LDT, and
4697 New commands ``info dos pde'' and ``info dos pte'' display entries
4698 from Page Directory and Page Tables (for now works with CWSDPMI only).
4699 New command ``info dos address-pte'' displays the Page Table entry for
4700 a given linear address.
4702 GDB can now pass command lines longer than 126 characters to the
4703 program being debugged (requires an update to the libdbg.a library
4704 which is part of the DJGPP development kit).
4706 DWARF2 debug info is now supported.
4708 It is now possible to `step' and `next' through calls to `longjmp'.
4710 * Changes in documentation.
4712 All GDB documentation was converted to GFDL, the GNU Free
4713 Documentation License.
4715 Tracepoints-related commands are now fully documented in the GDB
4718 TUI, the Text-mode User Interface, is now documented in the manual.
4720 Tracepoints-related commands are now fully documented in the GDB
4723 The "GDB Internals" manual now has an index. It also includes
4724 documentation of `ui_out' functions, GDB coding standards, x86
4725 hardware watchpoints, and memory region attributes.
4727 * GDB's version number moved to ``version.in''
4729 The Makefile variable VERSION has been replaced by the file
4730 ``version.in''. People creating GDB distributions should update the
4731 contents of this file.
4735 GUD support is now a standard part of the EMACS distribution.
4737 *** Changes in GDB 5.0:
4739 * Improved support for debugging FP programs on x86 targets
4741 Unified and much-improved support for debugging floating-point
4742 programs on all x86 targets. In particular, ``info float'' now
4743 displays the FP registers in the same format on all x86 targets, with
4744 greater level of detail.
4746 * Improvements and bugfixes in hardware-assisted watchpoints
4748 It is now possible to watch array elements, struct members, and
4749 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4750 on x86 targets no longer erroneously trigger when the address is
4753 * Improvements in the native DJGPP version of GDB
4755 The distribution now includes all the scripts and auxiliary files
4756 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4757 machines ``out of the box''.
4759 The DJGPP version can now debug programs that use signals. It is
4760 possible to catch signals that happened in the debuggee, deliver
4761 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4762 would kill the program being debugged.) Programs that hook hardware
4763 interrupts (keyboard, timer, etc.) can also be debugged.
4765 It is now possible to debug DJGPP programs that redirect their
4766 standard handles or switch them to raw (as opposed to cooked) mode, or
4767 even close them. The command ``run < foo > bar'' works as expected,
4768 and ``info terminal'' reports useful information about the debuggee's
4769 terminal, including raw/cooked mode, redirection, etc.
4771 The DJGPP version now uses termios functions for console I/O, which
4772 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4775 DOS-style file names with drive letters are now fully supported by
4778 It is now possible to debug DJGPP programs that switch their working
4779 directory. It is also possible to rerun the debuggee any number of
4780 times without restarting GDB; thus, you can use the same setup,
4781 breakpoints, etc. for many debugging sessions.
4783 * New native configurations
4785 ARM GNU/Linux arm*-*-linux*
4786 PowerPC GNU/Linux powerpc-*-linux*
4790 Motorola MCore mcore-*-*
4791 x86 VxWorks i[3456]86-*-vxworks*
4792 PowerPC VxWorks powerpc-*-vxworks*
4793 TI TMS320C80 tic80-*-*
4795 * OBSOLETE configurations
4797 Altos 3068 m68*-altos-*
4798 Convex c1-*-*, c2-*-*
4800 ARM RISCix arm-*-* (as host)
4803 Configurations that have been declared obsolete will be commented out,
4804 but the code will be left in place. If there is no activity to revive
4805 these configurations before the next release of GDB, the sources will
4806 be permanently REMOVED.
4808 * Gould support removed
4810 Support for the Gould PowerNode and NP1 has been removed.
4812 * New features for SVR4
4814 On SVR4 native platforms (such as Solaris), if you attach to a process
4815 without first loading a symbol file, GDB will now attempt to locate and
4816 load symbols from the running process's executable file.
4818 * Many C++ enhancements
4820 C++ support has been greatly improved. Overload resolution now works properly
4821 in almost all cases. RTTI support is on the way.
4823 * Remote targets can connect to a sub-program
4825 A popen(3) style serial-device has been added. This device starts a
4826 sub-process (such as a stand-alone simulator) and then communicates
4827 with that. The sub-program to run is specified using the syntax
4828 ``|<program> <args>'' vis:
4830 (gdb) set remotedebug 1
4831 (gdb) target extended-remote |mn10300-elf-sim program-args
4833 * MIPS 64 remote protocol
4835 A long standing bug in the mips64 remote protocol where by GDB
4836 expected certain 32 bit registers (ex SR) to be transfered as 32
4837 instead of 64 bits has been fixed.
4839 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4840 added to provide backward compatibility with older versions of GDB.
4842 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4844 The command ``set remotebinarydownload'' command has been replaced by
4845 ``set remote X-packet''. Other commands in ``set remote'' family
4846 include ``set remote P-packet''.
4848 * Breakpoint commands accept ranges.
4850 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4851 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4852 ``tracepoint passcount'' also accepts a range of tracepoints.
4854 * ``apropos'' command added.
4856 The ``apropos'' command searches through command names and
4857 documentation strings, printing out matches, making it much easier to
4858 try to find a command that does what you are looking for.
4862 A new machine oriented interface (MI) has been added to GDB. This
4863 interface is designed for debug environments running GDB as a separate
4864 process. This is part of the long term libGDB project. See the
4865 "GDB/MI" chapter of the GDB manual for further information. It can be
4866 enabled by configuring with:
4868 .../configure --enable-gdbmi
4870 *** Changes in GDB-4.18:
4872 * New native configurations
4874 HP-UX 10.20 hppa*-*-hpux10.20
4875 HP-UX 11.x hppa*-*-hpux11.0*
4876 M68K GNU/Linux m68*-*-linux*
4880 Fujitsu FR30 fr30-*-elf*
4881 Intel StrongARM strongarm-*-*
4882 Mitsubishi D30V d30v-*-*
4884 * OBSOLETE configurations
4886 Gould PowerNode, NP1 np1-*-*, pn-*-*
4888 Configurations that have been declared obsolete will be commented out,
4889 but the code will be left in place. If there is no activity to revive
4890 these configurations before the next release of GDB, the sources will
4891 be permanently REMOVED.
4895 As a compatibility experiment, GDB's source files buildsym.h and
4896 buildsym.c have been converted to pure standard C, no longer
4897 containing any K&R compatibility code. We believe that all systems in
4898 use today either come with a standard C compiler, or have a GCC port
4899 available. If this is not true, please report the affected
4900 configuration to bug-gdb@gnu.org immediately. See the README file for
4901 information about getting a standard C compiler if you don't have one
4906 GDB now uses readline 2.2.
4908 * set extension-language
4910 You can now control the mapping between filename extensions and source
4911 languages by using the `set extension-language' command. For instance,
4912 you can ask GDB to treat .c files as C++ by saying
4913 set extension-language .c c++
4914 The command `info extensions' lists all of the recognized extensions
4915 and their associated languages.
4917 * Setting processor type for PowerPC and RS/6000
4919 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4920 you can use the `set processor' command to specify what variant of the
4921 PowerPC family you are debugging. The command
4925 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4926 following PowerPC and RS6000 variants:
4928 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4929 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4931 403GC IBM PowerPC 403GC
4932 505 Motorola PowerPC 505
4933 860 Motorola PowerPC 860 or 850
4934 601 Motorola PowerPC 601
4935 602 Motorola PowerPC 602
4936 603 Motorola/IBM PowerPC 603 or 603e
4937 604 Motorola PowerPC 604 or 604e
4938 750 Motorola/IBM PowerPC 750 or 750
4940 At the moment, this command just tells GDB what to name the
4941 special-purpose processor registers. Since almost all the affected
4942 registers are inaccessible to user-level programs, this command is
4943 only useful for remote debugging in its present form.
4947 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4948 more extensive support for HP-UX. Added features include shared
4949 library support, kernel threads and hardware watchpoints for 11.00,
4950 support for HP's ANSI C and C++ compilers, and a compatibility mode
4951 for xdb and dbx commands.
4955 HP's donation includes the new concept of catchpoints, which is a
4956 generalization of the old catch command. On HP-UX, it is now possible
4957 to catch exec, fork, and vfork, as well as library loading.
4959 This means that the existing catch command has changed; its first
4960 argument now specifies the type of catch to be set up. See the
4961 output of "help catch" for a list of catchpoint types.
4963 * Debugging across forks
4965 On HP-UX, you can choose which process to debug when a fork() happens
4970 HP has donated a curses-based terminal user interface (TUI). To get
4971 it, build with --enable-tui. Although this can be enabled for any
4972 configuration, at present it only works for native HP debugging.
4974 * GDB remote protocol additions
4976 A new protocol packet 'X' that writes binary data is now available.
4977 Default behavior is to try 'X', then drop back to 'M' if the stub
4978 fails to respond. The settable variable `remotebinarydownload'
4979 allows explicit control over the use of 'X'.
4981 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4982 full 64-bit address. The command
4984 set remoteaddresssize 32
4986 can be used to revert to the old behaviour. For existing remote stubs
4987 the change should not be noticed, as the additional address information
4990 In order to assist in debugging stubs, you may use the maintenance
4991 command `packet' to send any text string to the stub. For instance,
4993 maint packet heythere
4995 sends the packet "$heythere#<checksum>". Note that it is very easy to
4996 disrupt a debugging session by sending the wrong packet at the wrong
4999 The compare-sections command allows you to compare section data on the
5000 target to what is in the executable file without uploading or
5001 downloading, by comparing CRC checksums.
5003 * Tracing can collect general expressions
5005 You may now collect general expressions at tracepoints. This requires
5006 further additions to the target-side stub; see tracepoint.c and
5007 doc/agentexpr.texi for further details.
5009 * mask-address variable for Mips
5011 For Mips targets, you may control the zeroing of the upper 32 bits of
5012 a 64-bit address by entering `set mask-address on'. This is mainly
5013 of interest to users of embedded R4xxx and R5xxx processors.
5015 * Higher serial baud rates
5017 GDB's serial code now allows you to specify baud rates 57600, 115200,
5018 230400, and 460800 baud. (Note that your host system may not be able
5019 to achieve all of these rates.)
5023 The i960 configuration now includes an initial implementation of a
5024 builtin simulator, contributed by Jim Wilson.
5027 *** Changes in GDB-4.17:
5029 * New native configurations
5031 Alpha GNU/Linux alpha*-*-linux*
5032 Unixware 2.x i[3456]86-unixware2*
5033 Irix 6.x mips*-sgi-irix6*
5034 PowerPC GNU/Linux powerpc-*-linux*
5035 PowerPC Solaris powerpcle-*-solaris*
5036 Sparc GNU/Linux sparc-*-linux*
5037 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5041 Argonaut Risc Chip (ARC) arc-*-*
5042 Hitachi H8/300S h8300*-*-*
5043 Matsushita MN10200 w/simulator mn10200-*-*
5044 Matsushita MN10300 w/simulator mn10300-*-*
5045 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5046 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5047 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5048 Mitsubishi D10V w/simulator d10v-*-*
5049 Mitsubishi M32R/D w/simulator m32r-*-elf*
5050 Tsqware Sparclet sparclet-*-*
5051 NEC V850 w/simulator v850-*-*
5053 * New debugging protocols
5055 ARM with RDI protocol arm*-*-*
5056 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5057 DDB and LSI variants of PMON protocol mips*-*-*
5058 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5059 PowerPC with SDS protocol powerpc{,le}-*-eabi
5060 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5064 All configurations can now understand and use the DWARF 2 debugging
5065 format. The choice is automatic, if the symbol file contains DWARF 2
5070 GDB now includes basic Java language support. This support is
5071 only useful with Java compilers that produce native machine code.
5073 * solib-absolute-prefix and solib-search-path
5075 For SunOS and SVR4 shared libraries, you may now set the prefix for
5076 loading absolute shared library symbol files, and the search path for
5077 locating non-absolute shared library symbol files.
5079 * Live range splitting
5081 GDB can now effectively debug code for which GCC has performed live
5082 range splitting as part of its optimization. See gdb/doc/LRS for
5083 more details on the expected format of the stabs information.
5087 GDB's support for the GNU Hurd, including thread debugging, has been
5088 updated to work with current versions of the Hurd.
5092 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5093 instruction set. ARM GDB automatically detects when Thumb
5094 instructions are in use, and adjusts disassembly and backtracing
5099 GDB's MIPS target configurations now handle the MIP16 16-bit
5104 GDB now includes support for overlays; if an executable has been
5105 linked such that multiple sections are based at the same address, GDB
5106 will decide which section to use for symbolic info. You can choose to
5107 control the decision manually, using overlay commands, or implement
5108 additional target-side support and use "overlay load-target" to bring
5109 in the overlay mapping. Do "help overlay" for more detail.
5113 The command "info symbol <address>" displays information about
5114 the symbol at the specified address.
5118 The standard remote protocol now includes an extension that allows
5119 asynchronous collection and display of trace data. This requires
5120 extensive support in the target-side debugging stub. Tracing mode
5121 includes a new interaction mode in GDB and new commands: see the
5122 file tracepoint.c for more details.
5126 Configurations for embedded MIPS now include a simulator contributed
5127 by Cygnus Solutions. The simulator supports the instruction sets
5128 of most MIPS variants.
5132 Sparc configurations may now include the ERC32 simulator contributed
5133 by the European Space Agency. The simulator is not built into
5134 Sparc targets by default; configure with --enable-sim to include it.
5138 For target configurations that may include multiple variants of a
5139 basic architecture (such as MIPS and SH), you may now set the
5140 architecture explicitly. "set arch" sets, "info arch" lists
5141 the possible architectures.
5143 *** Changes in GDB-4.16:
5145 * New native configurations
5147 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5148 M68K NetBSD m68k-*-netbsd*
5149 PowerPC AIX 4.x powerpc-*-aix*
5150 PowerPC MacOS powerpc-*-macos*
5151 PowerPC Windows NT powerpcle-*-cygwin32
5152 RS/6000 AIX 4.x rs6000-*-aix4*
5156 ARM with RDP protocol arm-*-*
5157 I960 with MON960 i960-*-coff
5158 MIPS VxWorks mips*-*-vxworks*
5159 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5160 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5162 Matra Sparclet sparclet-*-*
5166 The powerpc-eabi configuration now includes the PSIM simulator,
5167 contributed by Andrew Cagney, with assistance from Mike Meissner.
5168 PSIM is a very elaborate model of the PowerPC, including not only
5169 basic instruction set execution, but also details of execution unit
5170 performance and I/O hardware. See sim/ppc/README for more details.
5174 GDB now works with Solaris 2.5.
5176 * Windows 95/NT native
5178 GDB will now work as a native debugger on Windows 95 and Windows NT.
5179 To build it from source, you must use the "gnu-win32" environment,
5180 which uses a DLL to emulate enough of Unix to run the GNU tools.
5181 Further information, binaries, and sources are available at
5182 ftp.cygnus.com, under pub/gnu-win32.
5184 * dont-repeat command
5186 If a user-defined command includes the command `dont-repeat', then the
5187 command will not be repeated if the user just types return. This is
5188 useful if the command is time-consuming to run, so that accidental
5189 extra keystrokes don't run the same command many times.
5191 * Send break instead of ^C
5193 The standard remote protocol now includes an option to send a break
5194 rather than a ^C to the target in order to interrupt it. By default,
5195 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5197 * Remote protocol timeout
5199 The standard remote protocol includes a new variable `remotetimeout'
5200 that allows you to set the number of seconds before GDB gives up trying
5201 to read from the target. The default value is 2.
5203 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5205 By default GDB will automatically keep track of objects as they are
5206 loaded and unloaded by the dynamic linker. By using the command `set
5207 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5208 when shared library events occur, thus allowing you to set breakpoints
5209 in shared libraries which are explicitly loaded by the inferior.
5211 Note this feature does not work on hpux8. On hpux9 you must link
5212 /usr/lib/end.o into your program. This feature should work
5213 automatically on hpux10.
5215 * Irix 5.x hardware watchpoint support
5217 Irix 5 configurations now support the use of hardware watchpoints.
5219 * Mips protocol "SYN garbage limit"
5221 When debugging a Mips target using the `target mips' protocol, you
5222 may set the number of characters that GDB will ignore by setting
5223 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5224 every character. The default value is 1050.
5226 * Recording and replaying remote debug sessions
5228 If you set `remotelogfile' to the name of a file, gdb will write to it
5229 a recording of a remote debug session. This recording may then be
5230 replayed back to gdb using "gdbreplay". See gdbserver/README for
5231 details. This is useful when you have a problem with GDB while doing
5232 remote debugging; you can make a recording of the session and send it
5233 to someone else, who can then recreate the problem.
5235 * Speedups for remote debugging
5237 GDB includes speedups for downloading and stepping MIPS systems using
5238 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5239 and more efficient S-record downloading.
5241 * Memory use reductions and statistics collection
5243 GDB now uses less memory and reports statistics about memory usage.
5244 Try the `maint print statistics' command, for example.
5246 *** Changes in GDB-4.15:
5248 * Psymtabs for XCOFF
5250 The symbol reader for AIX GDB now uses partial symbol tables. This
5251 can greatly improve startup time, especially for large executables.
5253 * Remote targets use caching
5255 Remote targets now use a data cache to speed up communication with the
5256 remote side. The data cache could lead to incorrect results because
5257 it doesn't know about volatile variables, thus making it impossible to
5258 debug targets which use memory mapped I/O devices. `set remotecache
5259 off' turns the the data cache off.
5261 * Remote targets may have threads
5263 The standard remote protocol now includes support for multiple threads
5264 in the target system, using new protocol commands 'H' and 'T'. See
5265 gdb/remote.c for details.
5269 If GDB is configured with `--enable-netrom', then it will include
5270 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5271 acts as though it is a bank of ROM on the target board, but you can
5272 write into it over the network. GDB's support consists only of
5273 support for fast loading into the emulated ROM; to debug, you must use
5274 another protocol, such as standard remote protocol. The usual
5275 sequence is something like
5277 target nrom <netrom-hostname>
5279 target remote <netrom-hostname>:1235
5283 GDB now includes support for the Apple Macintosh, as a host only. It
5284 may be run as either an MPW tool or as a standalone application, and
5285 it can debug through the serial port. All the usual GDB commands are
5286 available, but to the target command, you must supply "serial" as the
5287 device type instead of "/dev/ttyXX". See mpw-README in the main
5288 directory for more information on how to build. The MPW configuration
5289 scripts */mpw-config.in support only a few targets, and only the
5290 mips-idt-ecoff target has been tested.
5294 GDB configuration now uses autoconf. This is not user-visible,
5295 but does simplify configuration and building.
5299 GDB now supports hpux10.
5301 *** Changes in GDB-4.14:
5303 * New native configurations
5305 x86 FreeBSD i[345]86-*-freebsd
5306 x86 NetBSD i[345]86-*-netbsd
5307 NS32k NetBSD ns32k-*-netbsd
5308 Sparc NetBSD sparc-*-netbsd
5312 A29K VxWorks a29k-*-vxworks
5313 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5314 CPU32 EST-300 emulator m68*-*-est*
5315 PowerPC ELF powerpc-*-elf
5318 * Alpha OSF/1 support for procfs
5320 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5321 possible to attach to running processes. As the mounting of the /proc
5322 filesystem is optional on the Alpha, GDB automatically determines
5323 the availability of /proc during startup. This can lead to problems
5324 if /proc is unmounted after GDB has been started.
5326 * Arguments to user-defined commands
5328 User commands may accept up to 10 arguments separated by whitespace.
5329 Arguments are accessed within the user command via $arg0..$arg9. A
5332 print $arg0 + $arg1 + $arg2
5334 To execute the command use:
5337 Defines the command "adder" which prints the sum of its three arguments.
5338 Note the arguments are text substitutions, so they may reference variables,
5339 use complex expressions, or even perform inferior function calls.
5341 * New `if' and `while' commands
5343 This makes it possible to write more sophisticated user-defined
5344 commands. Both commands take a single argument, which is the
5345 expression to evaluate, and must be followed by the commands to
5346 execute, one per line, if the expression is nonzero, the list being
5347 terminated by the word `end'. The `if' command list may include an
5348 `else' word, which causes the following commands to be executed only
5349 if the expression is zero.
5351 * Fortran source language mode
5353 GDB now includes partial support for Fortran 77. It will recognize
5354 Fortran programs and can evaluate a subset of Fortran expressions, but
5355 variables and functions may not be handled correctly. GDB will work
5356 with G77, but does not yet know much about symbols emitted by other
5359 * Better HPUX support
5361 Most debugging facilities now work on dynamic executables for HPPAs
5362 running hpux9 or later. You can attach to running dynamically linked
5363 processes, but by default the dynamic libraries will be read-only, so
5364 for instance you won't be able to put breakpoints in them. To change
5365 that behavior do the following before running the program:
5371 This will cause the libraries to be mapped private and read-write.
5372 To revert to the normal behavior, do this:
5378 You cannot set breakpoints or examine data in the library until after
5379 the library is loaded if the function/data symbols do not have
5382 GDB can now also read debug symbols produced by the HP C compiler on
5383 HPPAs (sorry, no C++, Fortran or 68k support).
5385 * Target byte order now dynamically selectable
5387 You can choose which byte order to use with a target system, via the
5388 commands "set endian big" and "set endian little", and you can see the
5389 current setting by using "show endian". You can also give the command
5390 "set endian auto", in which case GDB will use the byte order
5391 associated with the executable. Currently, only embedded MIPS
5392 configurations support dynamic selection of target byte order.
5394 * New DOS host serial code
5396 This version uses DPMI interrupts to handle buffered I/O, so you
5397 no longer need to run asynctsr when debugging boards connected to
5400 *** Changes in GDB-4.13:
5402 * New "complete" command
5404 This lists all the possible completions for the rest of the line, if it
5405 were to be given as a command itself. This is intended for use by emacs.
5407 * Trailing space optional in prompt
5409 "set prompt" no longer adds a space for you after the prompt you set. This
5410 allows you to set a prompt which ends in a space or one that does not.
5412 * Breakpoint hit counts
5414 "info break" now displays a count of the number of times the breakpoint
5415 has been hit. This is especially useful in conjunction with "ignore"; you
5416 can ignore a large number of breakpoint hits, look at the breakpoint info
5417 to see how many times the breakpoint was hit, then run again, ignoring one
5418 less than that number, and this will get you quickly to the last hit of
5421 * Ability to stop printing at NULL character
5423 "set print null-stop" will cause GDB to stop printing the characters of
5424 an array when the first NULL is encountered. This is useful when large
5425 arrays actually contain only short strings.
5427 * Shared library breakpoints
5429 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5430 breakpoints in shared libraries before the executable is run.
5432 * Hardware watchpoints
5434 There is a new hardware breakpoint for the watch command for sparclite
5435 targets. See gdb/sparclite/hw_breakpoint.note.
5437 Hardware watchpoints are also now supported under GNU/Linux.
5441 Annotations have been added. These are for use with graphical interfaces,
5442 and are still experimental. Currently only gdba.el uses these.
5444 * Improved Irix 5 support
5446 GDB now works properly with Irix 5.2.
5448 * Improved HPPA support
5450 GDB now works properly with the latest GCC and GAS.
5452 * New native configurations
5454 Sequent PTX4 i[34]86-sequent-ptx4
5455 HPPA running OSF/1 hppa*-*-osf*
5456 Atari TT running SVR4 m68*-*-sysv4*
5457 RS/6000 LynxOS rs6000-*-lynxos*
5461 OS/9000 i[34]86-*-os9k
5462 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5465 * Hitachi SH7000 and E7000-PC ICE support
5467 There is now support for communicating with the Hitachi E7000-PC ICE.
5468 This is available automatically when GDB is configured for the SH.
5472 As usual, a variety of small fixes and improvements, both generic
5473 and configuration-specific. See the ChangeLog for more detail.
5475 *** Changes in GDB-4.12:
5477 * Irix 5 is now supported
5481 GDB-4.12 on the HPPA has a number of changes which make it unable
5482 to debug the output from the currently released versions of GCC and
5483 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5484 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5485 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5488 *** Changes in GDB-4.11:
5490 * User visible changes:
5494 The "set remotedebug" option is now consistent between the mips remote
5495 target, remote targets using the gdb-specific protocol, UDI (AMD's
5496 debug protocol for the 29k) and the 88k bug monitor. It is now an
5497 integer specifying a debug level (normally 0 or 1, but 2 means more
5498 debugging info for the mips target).
5500 * DEC Alpha native support
5502 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5503 debug info, but GDB works fairly well with the DEC compiler and should
5504 work with a future GCC release. See the README file for a few
5505 Alpha-specific notes.
5507 * Preliminary thread implementation
5509 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5511 * LynxOS native and target support for 386
5513 This release has been hosted on LynxOS 2.2, and also can be configured
5514 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5517 * Improvements in C++ mangling/demangling.
5519 This release has much better g++ debugging, specifically in name
5520 mangling/demangling, virtual function calls, print virtual table,
5521 call methods, ...etc.
5523 *** Changes in GDB-4.10:
5525 * User visible changes:
5527 Remote debugging using the GDB-specific (`target remote') protocol now
5528 supports the `load' command. This is only useful if you have some
5529 other way of getting the stub to the target system, and you can put it
5530 somewhere in memory where it won't get clobbered by the download.
5532 Filename completion now works.
5534 When run under emacs mode, the "info line" command now causes the
5535 arrow to point to the line specified. Also, "info line" prints
5536 addresses in symbolic form (as well as hex).
5538 All vxworks based targets now support a user settable option, called
5539 vxworks-timeout. This option represents the number of seconds gdb
5540 should wait for responses to rpc's. You might want to use this if
5541 your vxworks target is, perhaps, a slow software simulator or happens
5542 to be on the far side of a thin network line.
5546 This release contains support for using a DEC alpha as a GDB host for
5547 cross debugging. Native alpha debugging is not supported yet.
5550 *** Changes in GDB-4.9:
5554 This is the first GDB release which is accompanied by a matching testsuite.
5555 The testsuite requires installation of dejagnu, which should be available
5556 via ftp from most sites that carry GNU software.
5560 'Cfront' style demangling has had its name changed to 'ARM' style, to
5561 emphasize that it was written from the specifications in the C++ Annotated
5562 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5563 disclaimers, it still generated too much confusion with users attempting to
5564 use gdb with AT&T cfront.
5568 GDB now uses a standard remote interface to a simulator library.
5569 So far, the library contains simulators for the Zilog Z8001/2, the
5570 Hitachi H8/300, H8/500 and Super-H.
5572 * New targets supported
5574 H8/300 simulator h8300-hitachi-hms or h8300hms
5575 H8/500 simulator h8500-hitachi-hms or h8500hms
5576 SH simulator sh-hitachi-hms or sh
5577 Z8000 simulator z8k-zilog-none or z8ksim
5578 IDT MIPS board over serial line mips-idt-ecoff
5580 Cross-debugging to GO32 targets is supported. It requires a custom
5581 version of the i386-stub.c module which is integrated with the
5582 GO32 memory extender.
5584 * New remote protocols
5586 MIPS remote debugging protocol.
5588 * New source languages supported
5590 This version includes preliminary support for Chill, a Pascal like language
5591 used by telecommunications companies. Chill support is also being integrated
5592 into the GNU compiler, but we don't know when it will be publically available.
5595 *** Changes in GDB-4.8:
5597 * HP Precision Architecture supported
5599 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5600 version of this support was available as a set of patches from the
5601 University of Utah. GDB does not support debugging of programs
5602 compiled with the HP compiler, because HP will not document their file
5603 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5604 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5606 Many problems in the preliminary version have been fixed.
5608 * Faster and better demangling
5610 We have improved template demangling and fixed numerous bugs in the GNU style
5611 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5612 character types (wchar_t) are now supported. Demangling of each symbol is now
5613 only done once, and is cached when the symbol table for a file is read in.
5614 This results in a small increase in memory usage for C programs, a moderate
5615 increase in memory usage for C++ programs, and a fantastic speedup in
5618 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5619 from the specifications in the Annotated Reference Manual, which AT&T's
5620 compiler does not actually implement.
5622 * G++ multiple inheritance compiler problem
5624 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5625 inheritance lattices was reworked to properly discover ambiguities. We
5626 recently found an example which causes this new algorithm to fail in a
5627 very subtle way, producing bad debug information for those classes.
5628 The file 'gcc.patch' (in this directory) can be applied to gcc to
5629 circumvent the problem. A future GCC release will contain a complete
5632 The previous G++ debug info problem (mentioned below for the gdb-4.7
5633 release) is fixed in gcc version 2.3.2.
5635 * Improved configure script
5637 The `configure' script will now attempt to guess your system type if
5638 you don't supply a host system type. The old scheme of supplying a
5639 host system triplet is preferable over using this. All the magic is
5640 done in the new `config.guess' script. Examine it for details.
5642 We have also brought our configure script much more in line with the FSF's
5643 version. It now supports the --with-xxx options. In particular,
5644 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5645 The resulting GDB will not be able to read arbitrary object file formats --
5646 only the format ``expected'' to be used on the configured target system.
5647 We hope to make this the default in a future release.
5649 * Documentation improvements
5651 There's new internal documentation on how to modify GDB, and how to
5652 produce clean changes to the code. We implore people to read it
5653 before submitting changes.
5655 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5656 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5657 `info' files are also provided. To build `info' files from scratch,
5658 you will need the latest `makeinfo' release, which will be available in
5659 a future texinfo-X.Y release.
5661 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5662 We're not sure exactly which versions have this problem, but it has
5663 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5664 or better. If that isn't possible, there is a patch in
5665 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5666 around this problem.
5670 GDB now supports array constants that can be used in expressions typed in by
5671 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5672 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5675 The new directory `gdb/sparclite' contains a program that demonstrates
5676 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5678 * New native hosts supported
5680 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5681 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5683 * New targets supported
5685 AMD 29k family via UDI a29k-amd-udi or udi29k
5687 * New file formats supported
5689 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5690 HPUX core files, and SCO 3.2v2 core files.
5694 Attaching to processes now works again; thanks for the many bug reports.
5696 We have also stomped on a bunch of core dumps caused by
5697 printf_filtered("%s") problems.
5699 We eliminated a copyright problem on the rpc and ptrace header files
5700 for VxWorks, which was discovered at the last minute during the 4.7
5701 release. You should now be able to build a VxWorks GDB.
5703 You can now interrupt gdb while an attached process is running. This
5704 will cause the attached process to stop, and give control back to GDB.
5706 We fixed problems caused by using too many file descriptors
5707 for reading symbols from object files and libraries. This was
5708 especially a problem for programs that used many (~100) shared
5711 The `step' command now only enters a subroutine if there is line number
5712 information for the subroutine. Otherwise it acts like the `next'
5713 command. Previously, `step' would enter subroutines if there was
5714 any debugging information about the routine. This avoids problems
5715 when using `cc -g1' on MIPS machines.
5717 * Internal improvements
5719 GDB's internal interfaces have been improved to make it easier to support
5720 debugging of multiple languages in the future.
5722 GDB now uses a common structure for symbol information internally.
5723 Minimal symbols (derived from linkage symbols in object files), partial
5724 symbols (from a quick scan of debug information), and full symbols
5725 contain a common subset of information, making it easier to write
5726 shared code that handles any of them.
5728 * New command line options
5730 We now accept --silent as an alias for --quiet.
5734 The memory-mapped-malloc library is now licensed under the GNU Library
5735 General Public License.
5737 *** Changes in GDB-4.7:
5739 * Host/native/target split
5741 GDB has had some major internal surgery to untangle the support for
5742 hosts and remote targets. Now, when you configure GDB for a remote
5743 target, it will no longer load in all of the support for debugging
5744 local programs on the host. When fully completed and tested, this will
5745 ensure that arbitrary host/target combinations are possible.
5747 The primary conceptual shift is to separate the non-portable code in
5748 GDB into three categories. Host specific code is required any time GDB
5749 is compiled on that host, regardless of the target. Target specific
5750 code relates to the peculiarities of the target, but can be compiled on
5751 any host. Native specific code is everything else: it can only be
5752 built when the host and target are the same system. Child process
5753 handling and core file support are two common `native' examples.
5755 GDB's use of /proc for controlling Unix child processes is now cleaner.
5756 It has been split out into a single module under the `target_ops' vector,
5757 plus two native-dependent functions for each system that uses /proc.
5759 * New hosts supported
5761 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5762 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5763 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5765 * New targets supported
5767 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5768 68030 and CPU32 m68030-*-*, m68332-*-*
5770 * New native hosts supported
5772 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5773 (386bsd is not well tested yet)
5774 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5776 * New file formats supported
5778 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5779 supports reading of `a.out.adobe' object files, which are an a.out
5780 format extended with minimal information about multiple sections.
5784 `show copying' is the same as the old `info copying'.
5785 `show warranty' is the same as `info warrantee'.
5786 These were renamed for consistency. The old commands continue to work.
5788 `info handle' is a new alias for `info signals'.
5790 You can now define pre-command hooks, which attach arbitrary command
5791 scripts to any command. The commands in the hook will be executed
5792 prior to the user's command. You can also create a hook which will be
5793 executed whenever the program stops. See gdb.texinfo.
5797 We now deal with Cfront style name mangling, and can even extract type
5798 info from mangled symbols. GDB can automatically figure out which
5799 symbol mangling style your C++ compiler uses.
5801 Calling of methods and virtual functions has been improved as well.
5805 The crash that occured when debugging Sun Ansi-C compiled binaries is
5806 fixed. This was due to mishandling of the extra N_SO stabs output
5809 We also finally got Ultrix 4.2 running in house, and fixed core file
5810 support, with help from a dozen people on the net.
5812 John M. Farrell discovered that the reason that single-stepping was so
5813 slow on all of the Mips based platforms (primarily SGI and DEC) was
5814 that we were trying to demangle and lookup a symbol used for internal
5815 purposes on every instruction that was being stepped through. Changing
5816 the name of that symbol so that it couldn't be mistaken for a C++
5817 mangled symbol sped things up a great deal.
5819 Rich Pixley sped up symbol lookups in general by getting much smarter
5820 about when C++ symbol mangling is necessary. This should make symbol
5821 completion (TAB on the command line) much faster. It's not as fast as
5822 we'd like, but it's significantly faster than gdb-4.6.
5826 A new user controllable variable 'call_scratch_address' can
5827 specify the location of a scratch area to be used when GDB
5828 calls a function in the target. This is necessary because the
5829 usual method of putting the scratch area on the stack does not work
5830 in systems that have separate instruction and data spaces.
5832 We integrated changes to support the 29k UDI (Universal Debugger
5833 Interface), but discovered at the last minute that we didn't have all
5834 of the appropriate copyright paperwork. We are working with AMD to
5835 resolve this, and hope to have it available soon.
5839 We have sped up the remote serial line protocol, especially for targets
5840 with lots of registers. It now supports a new `expedited status' ('T')
5841 message which can be used in place of the existing 'S' status message.
5842 This allows the remote stub to send only the registers that GDB
5843 needs to make a quick decision about single-stepping or conditional
5844 breakpoints, eliminating the need to fetch the entire register set for
5845 each instruction being stepped through.
5847 The GDB remote serial protocol now implements a write-through cache for
5848 registers, only re-reading the registers if the target has run.
5850 There is also a new remote serial stub for SPARC processors. You can
5851 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5852 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5853 processor with a serial port.
5857 Configure.in files have become much easier to read and modify. A new
5858 `table driven' format makes it more obvious what configurations are
5859 supported, and what files each one uses.
5863 There is a new opcodes library which will eventually contain all of the
5864 disassembly routines and opcode tables. At present, it only contains
5865 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5866 disassembler (binutils/objdump) to share these routines.
5868 The libiberty library is now copylefted under the GNU Library General
5869 Public License. This allows more liberal use, and was done so libg++
5870 can use it. This makes no difference to GDB, since the Library License
5871 grants all the rights from the General Public License.
5875 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5876 reference to the stabs symbol info used by the debugger. It is (as far
5877 as we know) the only published document on this fascinating topic. We
5878 encourage you to read it, compare it to the stabs information on your
5879 system, and send improvements on the document in general (to
5880 bug-gdb@prep.ai.mit.edu).
5882 And, of course, many bugs have been fixed.
5885 *** Changes in GDB-4.6:
5887 * Better support for C++ function names
5889 GDB now accepts as input the "demangled form" of C++ overloaded function
5890 names and member function names, and can do command completion on such names
5891 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5892 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5893 Make use of command completion, it is your friend.
5895 GDB also now accepts a variety of C++ mangled symbol formats. They are
5896 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5897 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5898 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5899 for the list of formats.
5901 * G++ symbol mangling problem
5903 Recent versions of gcc have a bug in how they emit debugging information for
5904 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5905 directory) can be applied to gcc to fix the problem. Alternatively, if you
5906 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5907 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5908 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5911 * New 'maintenance' command
5913 All of the commands related to hacking GDB internals have been moved out of
5914 the main command set, and now live behind the 'maintenance' command. This
5915 can also be abbreviated as 'mt'. The following changes were made:
5917 dump-me -> maintenance dump-me
5918 info all-breakpoints -> maintenance info breakpoints
5919 printmsyms -> maintenance print msyms
5920 printobjfiles -> maintenance print objfiles
5921 printpsyms -> maintenance print psymbols
5922 printsyms -> maintenance print symbols
5924 The following commands are new:
5926 maintenance demangle Call internal GDB demangler routine to
5927 demangle a C++ link name and prints the result.
5928 maintenance print type Print a type chain for a given symbol
5930 * Change to .gdbinit file processing
5932 We now read the $HOME/.gdbinit file before processing the argv arguments
5933 (e.g. reading symbol files or core files). This allows global parameters to
5934 be set, which will apply during the symbol reading. The ./.gdbinit is still
5935 read after argv processing.
5937 * New hosts supported
5939 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5941 GNU/Linux support i386-unknown-linux or linux
5943 We are also including code to support the HP/PA running BSD and HPUX. This
5944 is almost guaranteed not to work, as we didn't have time to test or build it
5945 for this release. We are including it so that the more adventurous (or
5946 masochistic) of you can play with it. We also had major problems with the
5947 fact that the compiler that we got from HP doesn't support the -g option.
5950 * New targets supported
5952 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5954 * More smarts about finding #include files
5956 GDB now remembers the compilation directory for all include files, and for
5957 all files from which C is generated (like yacc and lex sources). This
5958 greatly improves GDB's ability to find yacc/lex sources, and include files,
5959 especially if you are debugging your program from a directory different from
5960 the one that contains your sources.
5962 We also fixed a bug which caused difficulty with listing and setting
5963 breakpoints in include files which contain C code. (In the past, you had to
5964 try twice in order to list an include file that you hadn't looked at before.)
5966 * Interesting infernals change
5968 GDB now deals with arbitrary numbers of sections, where the symbols for each
5969 section must be relocated relative to that section's landing place in the
5970 target's address space. This work was needed to support ELF with embedded
5971 stabs used by Solaris-2.0.
5973 * Bug fixes (of course!)
5975 There have been loads of fixes for the following things:
5976 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5977 i960, stabs, DOS(GO32), procfs, etc...
5979 See the ChangeLog for details.
5981 *** Changes in GDB-4.5:
5983 * New machines supported (host and target)
5985 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5987 SGI Irix-4.x mips-sgi-irix4 or iris4
5989 * New malloc package
5991 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5992 Mmalloc is capable of handling mutiple heaps of memory. It is also
5993 capable of saving a heap to a file, and then mapping it back in later.
5994 This can be used to greatly speedup the startup of GDB by using a
5995 pre-parsed symbol table which lives in a mmalloc managed heap. For
5996 more details, please read mmalloc/mmalloc.texi.
6000 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6001 'help info proc' for details.
6003 * MIPS ecoff symbol table format
6005 The code that reads MIPS symbol table format is now supported on all hosts.
6006 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6009 * File name changes for MS-DOS
6011 Many files in the config directories have been renamed to make it easier to
6012 support GDB on MS-DOSe systems (which have very restrictive file name
6013 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6014 environment) is close to working but has some remaining problems. Note
6015 that debugging of DOS programs is not supported, due to limitations
6016 in the ``operating system'', but it can be used to host cross-debugging.
6018 * Cross byte order fixes
6020 Many fixes have been made to support cross debugging of Sparc and MIPS
6021 targets from hosts whose byte order differs.
6023 * New -mapped and -readnow options
6025 If memory-mapped files are available on your system through the 'mmap'
6026 system call, you can use the -mapped option on the `file' or
6027 `symbol-file' commands to cause GDB to write the symbols from your
6028 program into a reusable file. If the program you are debugging is
6029 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6030 Future GDB debugging sessions will notice the presence of this file,
6031 and will quickly map in symbol information from it, rather than reading
6032 the symbol table from the executable program. Using the '-mapped'
6033 option in a GDB `file' or `symbol-file' command has the same effect as
6034 starting GDB with the '-mapped' command-line option.
6036 You can cause GDB to read the entire symbol table immediately by using
6037 the '-readnow' option with any of the commands that load symbol table
6038 information (or on the GDB command line). This makes the command
6039 slower, but makes future operations faster.
6041 The -mapped and -readnow options are typically combined in order to
6042 build a `fred.syms' file that contains complete symbol information.
6043 A simple GDB invocation to do nothing but build a `.syms' file for future
6046 gdb -batch -nx -mapped -readnow programname
6048 The `.syms' file is specific to the host machine on which GDB is run.
6049 It holds an exact image of GDB's internal symbol table. It cannot be
6050 shared across multiple host platforms.
6052 * longjmp() handling
6054 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6055 siglongjmp() without losing control. This feature has not yet been ported to
6056 all systems. It currently works on many 386 platforms, all MIPS-based
6057 platforms (SGI, DECstation, etc), and Sun3/4.
6061 Preliminary work has been put in to support the new Solaris OS from Sun. At
6062 this time, it can control and debug processes, but it is not capable of
6067 As always, many many bug fixes. The major areas were with g++, and mipsread.
6068 People using the MIPS-based platforms should experience fewer mysterious
6069 crashes and trashed symbol tables.
6071 *** Changes in GDB-4.4:
6073 * New machines supported (host and target)
6075 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6077 BSD Reno on Vax vax-dec-bsd
6078 Ultrix on Vax vax-dec-ultrix
6080 * New machines supported (target)
6082 AMD 29000 embedded, using EBMON a29k-none-none
6086 GDB continues to improve its handling of C++. `References' work better.
6087 The demangler has also been improved, and now deals with symbols mangled as
6088 per the Annotated C++ Reference Guide.
6090 GDB also now handles `stabs' symbol information embedded in MIPS
6091 `ecoff' symbol tables. Since the ecoff format was not easily
6092 extensible to handle new languages such as C++, this appeared to be a
6093 good way to put C++ debugging info into MIPS binaries. This option
6094 will be supported in the GNU C compiler, version 2, when it is
6097 * New features for SVR4
6099 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6100 shared libraries. Debugging dynamically linked programs should present
6101 only minor differences from debugging statically linked programs.
6103 The `info proc' command will print out information about any process
6104 on an SVR4 system (including the one you are debugging). At the moment,
6105 it prints the address mappings of the process.
6107 If you bring up GDB on another SVR4 system, please send mail to
6108 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6110 * Better dynamic linking support in SunOS
6112 Reading symbols from shared libraries which contain debugging symbols
6113 now works properly. However, there remain issues such as automatic
6114 skipping of `transfer vector' code during function calls, which
6115 make it harder to debug code in a shared library, than to debug the
6116 same code linked statically.
6120 GDB is now using the latest `getopt' routines from the FSF. This
6121 version accepts the -- prefix for options with long names. GDB will
6122 continue to accept the old forms (-option and +option) as well.
6123 Various single letter abbreviations for options have been explicity
6124 added to the option table so that they won't get overshadowed in the
6125 future by other options that begin with the same letter.
6129 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6130 Many assorted bugs have been handled. Many more remain to be handled.
6131 See the various ChangeLog files (primarily in gdb and bfd) for details.
6134 *** Changes in GDB-4.3:
6136 * New machines supported (host and target)
6138 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6139 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6140 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6142 * Almost SCO Unix support
6144 We had hoped to support:
6145 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6146 (except for core file support), but we discovered very late in the release
6147 that it has problems with process groups that render gdb unusable. Sorry
6148 about that. I encourage people to fix it and post the fixes.
6150 * Preliminary ELF and DWARF support
6152 GDB can read ELF object files on System V Release 4, and can handle
6153 debugging records for C, in DWARF format, in ELF files. This support
6154 is preliminary. If you bring up GDB on another SVR4 system, please
6155 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6160 GDB now uses the latest `readline' library. One user-visible change
6161 is that two tabs will list possible command completions, which previously
6162 required typing M-? (meta-question mark, or ESC ?).
6166 The `stepi' bug that many of you noticed has been squashed.
6167 Many bugs in C++ have been handled. Many more remain to be handled.
6168 See the various ChangeLog files (primarily in gdb and bfd) for details.
6170 * State of the MIPS world (in case you wondered):
6172 GDB can understand the symbol tables emitted by the compilers
6173 supplied by most vendors of MIPS-based machines, including DEC. These
6174 symbol tables are in a format that essentially nobody else uses.
6176 Some versions of gcc come with an assembler post-processor called
6177 mips-tfile. This program is required if you want to do source-level
6178 debugging of gcc-compiled programs. I believe FSF does not ship
6179 mips-tfile with gcc version 1, but it will eventually come with gcc
6182 Debugging of g++ output remains a problem. g++ version 1.xx does not
6183 really support it at all. (If you're lucky, you should be able to get
6184 line numbers and stack traces to work, but no parameters or local
6185 variables.) With some work it should be possible to improve the
6188 When gcc version 2 is released, you will have somewhat better luck.
6189 However, even then you will get confusing results for inheritance and
6192 We will eventually provide full debugging of g++ output on
6193 DECstations. This will probably involve some kind of stabs-in-ecoff
6194 encapulation, but the details have not been worked out yet.
6197 *** Changes in GDB-4.2:
6199 * Improved configuration
6201 Only one copy of `configure' exists now, and it is not self-modifying.
6202 Porting BFD is simpler.
6206 The `step' and `next' commands now only stop at the first instruction
6207 of a source line. This prevents the multiple stops that used to occur
6208 in switch statements, for-loops, etc. `Step' continues to stop if a
6209 function that has debugging information is called within the line.
6213 Lots of small bugs fixed. More remain.
6215 * New host supported (not target)
6217 Intel 386 PC clone running Mach i386-none-mach
6220 *** Changes in GDB-4.1:
6222 * Multiple source language support
6224 GDB now has internal scaffolding to handle several source languages.
6225 It determines the type of each source file from its filename extension,
6226 and will switch expression parsing and number formatting to match the
6227 language of the function in the currently selected stack frame.
6228 You can also specifically set the language to be used, with
6229 `set language c' or `set language modula-2'.
6233 GDB now has preliminary support for the GNU Modula-2 compiler,
6234 currently under development at the State University of New York at
6235 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6236 continue through the fall of 1991 and into 1992.
6238 Other Modula-2 compilers are currently not supported, and attempting to
6239 debug programs compiled with them will likely result in an error as the
6240 symbol table is read. Feel free to work on it, though!
6242 There are hooks in GDB for strict type checking and range checking,
6243 in the `Modula-2 philosophy', but they do not currently work.
6247 GDB can now write to executable and core files (e.g. patch
6248 a variable's value). You must turn this switch on, specify
6249 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6250 by assigning a new value to a variable. Modifications take
6253 * Automatic SunOS shared library reading
6255 When you run your program, GDB automatically determines where its
6256 shared libraries (if any) have been loaded, and reads their symbols.
6257 The `share' command is no longer needed. This also works when
6258 examining core files.
6262 You can specify the number of lines that the `list' command shows.
6265 * New machines supported (host and target)
6267 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6268 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6269 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6271 * New hosts supported (not targets)
6273 IBM RT/PC: romp-ibm-aix or rtpc
6275 * New targets supported (not hosts)
6277 AMD 29000 embedded with COFF a29k-none-coff
6278 AMD 29000 embedded with a.out a29k-none-aout
6279 Ultracomputer remote kernel debug a29k-nyu-kern
6281 * New remote interfaces
6287 *** Changes in GDB-4.0:
6291 Wide output is wrapped at good places to make the output more readable.
6293 Gdb now supports cross-debugging from a host machine of one type to a
6294 target machine of another type. Communication with the target system
6295 is over serial lines. The ``target'' command handles connecting to the
6296 remote system; the ``load'' command will download a program into the
6297 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6298 also supports debugging of realtime processes running under VxWorks,
6299 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6300 stub on the target system.
6302 New CPUs supported include the AMD 29000 and Intel 960.
6304 GDB now reads object files and symbol tables via a ``binary file''
6305 library, which allows a single copy of GDB to debug programs of multiple
6306 object file types such as a.out and coff.
6308 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6309 refcard.dvi and refcard.ps are available to format it).
6312 * Control-Variable user interface simplified
6314 All variables that control the operation of the debugger can be set
6315 by the ``set'' command, and displayed by the ``show'' command.
6317 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6318 ``Show prompt'' produces the response:
6319 Gdb's prompt is new-gdb=>.
6321 What follows are the NEW set commands. The command ``help set'' will
6322 print a complete list of old and new set commands. ``help set FOO''
6323 will give a longer description of the variable FOO. ``show'' will show
6324 all of the variable descriptions and their current settings.
6326 confirm on/off: Enables warning questions for operations that are
6327 hard to recover from, e.g. rerunning the program while
6328 it is already running. Default is ON.
6330 editing on/off: Enables EMACS style command line editing
6331 of input. Previous lines can be recalled with
6332 control-P, the current line can be edited with control-B,
6333 you can search for commands with control-R, etc.
6336 history filename NAME: NAME is where the gdb command history
6337 will be stored. The default is .gdb_history,
6338 or the value of the environment variable
6341 history size N: The size, in commands, of the command history. The
6342 default is 256, or the value of the environment variable
6345 history save on/off: If this value is set to ON, the history file will
6346 be saved after exiting gdb. If set to OFF, the
6347 file will not be saved. The default is OFF.
6349 history expansion on/off: If this value is set to ON, then csh-like
6350 history expansion will be performed on
6351 command line input. The default is OFF.
6353 radix N: Sets the default radix for input and output. It can be set
6354 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6355 in the current radix, so "set radix 10" is always a no-op.
6357 height N: This integer value is the number of lines on a page. Default
6358 is 24, the current `stty rows'' setting, or the ``li#''
6359 setting from the termcap entry matching the environment
6362 width N: This integer value is the number of characters on a line.
6363 Default is 80, the current `stty cols'' setting, or the ``co#''
6364 setting from the termcap entry matching the environment
6367 Note: ``set screensize'' is obsolete. Use ``set height'' and
6368 ``set width'' instead.
6370 print address on/off: Print memory addresses in various command displays,
6371 such as stack traces and structure values. Gdb looks
6372 more ``symbolic'' if you turn this off; it looks more
6373 ``machine level'' with it on. Default is ON.
6375 print array on/off: Prettyprint arrays. New convenient format! Default
6378 print demangle on/off: Print C++ symbols in "source" form if on,
6381 print asm-demangle on/off: Same, for assembler level printouts
6384 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6387 * Support for Epoch Environment.
6389 The epoch environment is a version of Emacs v18 with windowing. One
6390 new command, ``inspect'', is identical to ``print'', except that if you
6391 are running in the epoch environment, the value is printed in its own
6395 * Support for Shared Libraries
6397 GDB can now debug programs and core files that use SunOS shared libraries.
6398 Symbols from a shared library cannot be referenced
6399 before the shared library has been linked with the program (this
6400 happens after you type ``run'' and before the function main() is entered).
6401 At any time after this linking (including when examining core files
6402 from dynamically linked programs), gdb reads the symbols from each
6403 shared library when you type the ``sharedlibrary'' command.
6404 It can be abbreviated ``share''.
6406 sharedlibrary REGEXP: Load shared object library symbols for files
6407 matching a unix regular expression. No argument
6408 indicates to load symbols for all shared libraries.
6410 info sharedlibrary: Status of loaded shared libraries.
6415 A watchpoint stops execution of a program whenever the value of an
6416 expression changes. Checking for this slows down execution
6417 tremendously whenever you are in the scope of the expression, but is
6418 quite useful for catching tough ``bit-spreader'' or pointer misuse
6419 problems. Some machines such as the 386 have hardware for doing this
6420 more quickly, and future versions of gdb will use this hardware.
6422 watch EXP: Set a watchpoint (breakpoint) for an expression.
6424 info watchpoints: Information about your watchpoints.
6426 delete N: Deletes watchpoint number N (same as breakpoints).
6427 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6428 enable N: Re-enables watchpoint number N (same as breakpoints).
6431 * C++ multiple inheritance
6433 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6436 * C++ exception handling
6438 Gdb now supports limited C++ exception handling. Besides the existing
6439 ability to breakpoint on an exception handler, gdb can breakpoint on
6440 the raising of an exception (before the stack is peeled back to the
6443 catch FOO: If there is a FOO exception handler in the dynamic scope,
6444 set a breakpoint to catch exceptions which may be raised there.
6445 Multiple exceptions (``catch foo bar baz'') may be caught.
6447 info catch: Lists all exceptions which may be caught in the
6448 current stack frame.
6451 * Minor command changes
6453 The command ``call func (arg, arg, ...)'' now acts like the print
6454 command, except it does not print or save a value if the function's result
6455 is void. This is similar to dbx usage.
6457 The ``up'' and ``down'' commands now always print the frame they end up
6458 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6459 frames without printing.
6461 * New directory command
6463 'dir' now adds directories to the FRONT of the source search path.
6464 The path starts off empty. Source files that contain debug information
6465 about the directory in which they were compiled can be found even
6466 with an empty path; Sun CC and GCC include this information. If GDB can't
6467 find your source file in the current directory, type "dir .".
6469 * Configuring GDB for compilation
6471 For normal use, type ``./configure host''. See README or gdb.texinfo
6474 GDB now handles cross debugging. If you are remotely debugging between
6475 two different machines, type ``./configure host -target=targ''.
6476 Host is the machine where GDB will run; targ is the machine
6477 where the program that you are debugging will run.
projects / external / binutils.git / blob