1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.11
6 * Fortran: Support structures with fields of dynamic types and
7 arrays of dynamic types.
9 * GDB now supports multibit bitfields and enums in target register
12 * New Python-based convenience function $_as_string(val), which returns
13 the textual representation of a value. This function is especially
14 useful to obtain the text label of an enum value.
16 * Intel MPX bound violation handling.
18 Segmentation faults caused by a Intel MPX boundary violation
19 now display the kind of violation (upper or lower), the memory
20 address accessed and the memory bounds, along with the usual
21 signal received and code location.
25 Program received signal SIGSEGV, Segmentation fault
26 Upper bound violation while accessing address 0x7fffffffc3b3
27 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
28 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
30 * Rust language support.
31 GDB now supports debugging programs written in the Rust programming
32 language. See https://www.rust-lang.org/ for more information about
38 skip -gfile file-glob-pattern
39 skip -function function
40 skip -rfunction regular-expression
41 A generalized form of the skip command, with new support for
42 glob-style file names and regular expressions for function names.
43 Additionally, a file spec and a function spec may now be combined.
45 maint info line-table REGEXP
46 Display the contents of GDB's internal line table data struture.
49 Run any GDB unit tests that were compiled in.
51 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
52 was added in GDBserver, including JIT compiling fast tracepoint's
53 conditional expression bytecode into native code.
55 * Support for various remote target protocols and ROM monitors has
58 target m32rsdi Remote M32R debugging over SDI
59 target mips MIPS remote debugging protocol
60 target pmon PMON ROM monitor
61 target ddb NEC's DDB variant of PMON for Vr4300
62 target rockhopper NEC RockHopper variant of PMON
63 target lsi LSI variant of PMO
65 * Support for tracepoints and fast tracepoints on powerpc-linux,
66 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
67 including JIT compiling fast tracepoint's conditional expression
68 bytecode into native code.
70 *** Changes in GDB 7.11
72 * GDB now supports debugging kernel-based threads on FreeBSD.
74 * Per-inferior thread numbers
76 Thread numbers are now per inferior instead of global. If you're
77 debugging multiple inferiors, GDB displays thread IDs using a
78 qualified INF_NUM.THR_NUM form. For example:
82 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
83 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
84 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
85 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
87 As consequence, thread numbers as visible in the $_thread
88 convenience variable and in Python's InferiorThread.num attribute
89 are no longer unique between inferiors.
91 GDB now maintains a second thread ID per thread, referred to as the
92 global thread ID, which is the new equivalent of thread numbers in
93 previous releases. See also $_gthread below.
95 For backwards compatibility, MI's thread IDs always refer to global
98 * Commands that accept thread IDs now accept the qualified
99 INF_NUM.THR_NUM form as well. For example:
102 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
105 * In commands that accept a list of thread IDs, you can now refer to
106 all threads of an inferior using a star wildcard. GDB accepts
107 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
108 refer to all threads of the current inferior. For example, "info
111 * You can use "info threads -gid" to display the global thread ID of
114 * The new convenience variable $_gthread holds the global number of
117 * The new convenience variable $_inferior holds the number of the
120 * GDB now displays the ID and name of the thread that hit a breakpoint
121 or received a signal, if your program is multi-threaded. For
124 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
125 Thread 1 "main" received signal SIGINT, Interrupt.
127 * Record btrace now supports non-stop mode.
129 * Support for tracepoints on aarch64-linux was added in GDBserver.
131 * The 'record instruction-history' command now indicates speculative execution
132 when using the Intel Processor Trace recording format.
134 * GDB now allows users to specify explicit locations, bypassing
135 the linespec parser. This feature is also available to GDB/MI
138 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
139 GDB now is able to debug both AArch64 applications and ARM applications
142 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
143 including JIT compiling fast tracepoint's conditional expression bytecode
146 * GDB now supports displaced stepping on AArch64 GNU/Linux.
148 * "info threads", "info inferiors", "info display", "info checkpoints"
149 and "maint info program-spaces" now list the corresponding items in
150 ascending ID order, for consistency with all other "info" commands.
152 * In Ada, the overloads selection menu has been enhanced to display the
153 parameter types and the return types for the matching overloaded subprograms.
157 maint set target-non-stop (on|off|auto)
158 maint show target-non-stop
159 Control whether GDB targets always operate in non-stop mode even if
160 "set non-stop" is "off". The default is "auto", meaning non-stop
161 mode is enabled if supported by the target.
163 maint set bfd-sharing
164 maint show bfd-sharing
165 Control the reuse of bfd objects.
169 Control display of debugging info regarding bfd caching.
173 Control display of debugging info regarding FreeBSD threads.
175 set remote multiprocess-extensions-packet
176 show remote multiprocess-extensions-packet
177 Set/show the use of the remote protocol multiprocess extensions.
179 set remote thread-events
180 show remote thread-events
181 Set/show the use of thread create/exit events.
183 set ada print-signatures on|off
184 show ada print-signatures"
185 Control whether parameter types and return types are displayed in overloads
186 selection menus. It is activaled (@code{on}) by default.
190 Controls the maximum size of memory, in bytes, that GDB will
191 allocate for value contents. Prevents incorrect programs from
192 causing GDB to allocate overly large buffers. Default is 64k.
194 * The "disassemble" command accepts a new modifier: /s.
195 It prints mixed source+disassembly like /m with two differences:
196 - disassembled instructions are now printed in program order, and
197 - and source for all relevant files is now printed.
198 The "/m" option is now considered deprecated: its "source-centric"
199 output hasn't proved useful in practice.
201 * The "record instruction-history" command accepts a new modifier: /s.
202 It behaves exactly like /m and prints mixed source+disassembly.
204 * The "set scheduler-locking" command supports a new mode "replay".
205 It behaves like "off" in record mode and like "on" in replay mode.
207 * Support for various ROM monitors has been removed:
209 target dbug dBUG ROM monitor for Motorola ColdFire
210 target picobug Motorola picobug monitor
211 target dink32 DINK32 ROM monitor for PowerPC
212 target m32r Renesas M32R/D ROM monitor
213 target mon2000 mon2000 ROM monitor
214 target ppcbug PPCBUG ROM monitor for PowerPC
216 * Support for reading/writing memory and extracting values on architectures
217 whose memory is addressable in units of any integral multiple of 8 bits.
222 Indicates that an exec system call was executed.
224 exec-events feature in qSupported
225 The qSupported packet allows GDB to request support for exec
226 events using the new 'gdbfeature' exec-event, and the qSupported
227 response can contain the corresponding 'stubfeature'. Set and
228 show commands can be used to display whether these features are enabled.
231 Equivalent to interrupting with the ^C character, but works in
234 thread created stop reason (T05 create:...)
235 Indicates that the thread was just created and is stopped at entry.
237 thread exit stop reply (w exitcode;tid)
238 Indicates that the thread has terminated.
241 Enables/disables thread create and exit event reporting. For
242 example, this is used in non-stop mode when GDB stops a set of
243 threads and synchronously waits for the their corresponding stop
244 replies. Without exit events, if one of the threads exits, GDB
245 would hang forever not knowing that it should no longer expect a
246 stop for that same thread.
249 Indicates that there are no resumed threads left in the target (all
250 threads are stopped). The remote stub reports support for this stop
251 reply to GDB's qSupported query.
253 QCatchSyscalls:1 [;SYSNO]...
255 Enable ("QCatchSyscalls:1") or disable ("QCatchSyscalls:0")
256 catching syscalls from the inferior process.
258 syscall_entry stop reason
259 Indicates that a syscall was just called.
261 syscall_return stop reason
262 Indicates that a syscall just returned.
264 QCatchSyscalls:1 in qSupported
265 The qSupported packet may now include QCatchSyscalls:1 in the reply
266 to indicate support for catching syscalls.
268 * Extended-remote exec events
270 ** GDB now has support for exec events on extended-remote Linux targets.
271 For such targets with Linux kernels 2.5.46 and later, this enables
272 follow-exec-mode and exec catchpoints.
274 set remote exec-event-feature-packet
275 show remote exec-event-feature-packet
276 Set/show the use of the remote exec event feature.
278 * Thread names in remote protocol
280 The reply to qXfer:threads:read may now include a name attribute for each
283 * Target remote mode fork and exec events
285 ** GDB now has support for fork and exec events on target remote mode
286 Linux targets. For such targets with Linux kernels 2.5.46 and later,
287 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
288 fork and exec catchpoints.
290 * Remote syscall events
292 ** GDB now has support for catch syscall on remote Linux targets,
293 currently enabled on x86/x86_64 architectures.
295 set remote catch-syscall-packet
296 show remote catch-syscall-packet
297 Set/show the use of the remote catch syscall feature.
301 ** The -var-set-format command now accepts the zero-hexadecimal
302 format. It outputs data in hexadecimal format with zero-padding on the
307 ** gdb.InferiorThread objects have a new attribute "global_num",
308 which refers to the thread's global thread ID. The existing
309 "num" attribute now refers to the thread's per-inferior number.
310 See "Per-inferior thread numbers" above.
311 ** gdb.InferiorThread objects have a new attribute "inferior", which
312 is the Inferior object the thread belongs to.
314 *** Changes in GDB 7.10
316 * Support for process record-replay and reverse debugging on aarch64*-linux*
317 targets has been added. GDB now supports recording of A64 instruction set
318 including advance SIMD instructions.
320 * Support for Sun's version of the "stabs" debug file format has been removed.
322 * GDB now honors the content of the file /proc/PID/coredump_filter
323 (PID is the process ID) on GNU/Linux systems. This file can be used
324 to specify the types of memory mappings that will be included in a
325 corefile. For more information, please refer to the manual page of
326 "core(5)". GDB also has a new command: "set use-coredump-filter
327 on|off". It allows to set whether GDB will read the content of the
328 /proc/PID/coredump_filter file when generating a corefile.
330 * The "info os" command on GNU/Linux can now display information on
332 "info os cpus" Listing of all cpus/cores on the system
334 * GDB has two new commands: "set serial parity odd|even|none" and
335 "show serial parity". These allows to set or show parity for the
338 * The "info source" command now displays the producer string if it was
339 present in the debug info. This typically includes the compiler version
340 and may include things like its command line arguments.
342 * The "info dll", an alias of the "info sharedlibrary" command,
343 is now available on all platforms.
345 * Directory names supplied to the "set sysroot" commands may be
346 prefixed with "target:" to tell GDB to access shared libraries from
347 the target system, be it local or remote. This replaces the prefix
348 "remote:". The default sysroot has been changed from "" to
349 "target:". "remote:" is automatically converted to "target:" for
350 backward compatibility.
352 * The system root specified by "set sysroot" will be prepended to the
353 filename of the main executable (if reported to GDB as absolute by
354 the operating system) when starting processes remotely, and when
355 attaching to already-running local or remote processes.
357 * GDB now supports automatic location and retrieval of executable
358 files from remote targets. Remote debugging can now be initiated
359 using only a "target remote" or "target extended-remote" command
360 (no "set sysroot" or "file" commands are required). See "New remote
363 * The "dump" command now supports verilog hex format.
365 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
367 * On GNU/Linux, GDB and gdbserver are now able to access executable
368 and shared library files without a "set sysroot" command when
369 attaching to processes running in different mount namespaces from
370 the debugger. This makes it possible to attach to processes in
371 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
372 See "New remote packets" below.
374 * The "tui reg" command now provides completion for all of the
375 available register groups, including target specific groups.
377 * The HISTSIZE environment variable is no longer read when determining
378 the size of GDB's command history. GDB now instead reads the dedicated
379 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
380 disables truncation of command history. Non-numeric values of GDBHISTSIZE
385 ** Memory ports can now be unbuffered.
389 ** gdb.Objfile objects have a new attribute "username",
390 which is the name of the objfile as specified by the user,
391 without, for example, resolving symlinks.
392 ** You can now write frame unwinders in Python.
393 ** gdb.Type objects have a new method "optimized_out",
394 returning optimized out gdb.Value instance of this type.
395 ** gdb.Value objects have new methods "reference_value" and
396 "const_value" which return a reference to the value and a
397 "const" version of the value respectively.
401 maint print symbol-cache
402 Print the contents of the symbol cache.
404 maint print symbol-cache-statistics
405 Print statistics of symbol cache usage.
407 maint flush-symbol-cache
408 Flush the contents of the symbol cache.
412 Start branch trace recording using Branch Trace Store (BTS) format.
415 Evaluate expression by using the compiler and print result.
419 Explicit commands for enabling and disabling tui mode.
422 set mpx bound on i386 and amd64
423 Support for bound table investigation on Intel MPX enabled applications.
427 Start branch trace recording using Intel Processor Trace format.
430 Print information about branch tracing internals.
432 maint btrace packet-history
433 Print the raw branch tracing data.
435 maint btrace clear-packet-history
436 Discard the stored raw branch tracing data.
439 Discard all branch tracing data. It will be fetched and processed
440 anew by the next "record" command.
445 Renamed from "set debug dwarf2-die".
447 Renamed from "show debug dwarf2-die".
450 Renamed from "set debug dwarf2-read".
451 show debug dwarf-read
452 Renamed from "show debug dwarf2-read".
454 maint set dwarf always-disassemble
455 Renamed from "maint set dwarf2 always-disassemble".
456 maint show dwarf always-disassemble
457 Renamed from "maint show dwarf2 always-disassemble".
459 maint set dwarf max-cache-age
460 Renamed from "maint set dwarf2 max-cache-age".
461 maint show dwarf max-cache-age
462 Renamed from "maint show dwarf2 max-cache-age".
465 show debug dwarf-line
466 Control display of debugging info regarding DWARF line processing.
470 Set the maximum number of candidates to be considered during
471 completion. The default value is 200. This limit allows GDB
472 to avoid generating large completion lists, the computation of
473 which can cause the debugger to become temporarily unresponsive.
475 set history remove-duplicates
476 show history remove-duplicates
477 Control the removal of duplicate history entries.
479 maint set symbol-cache-size
480 maint show symbol-cache-size
481 Control the size of the symbol cache.
483 set|show record btrace bts buffer-size
484 Set and show the size of the ring buffer used for branch tracing in
486 The obtained size may differ from the requested size. Use "info
487 record" to see the obtained buffer size.
489 set debug linux-namespaces
490 show debug linux-namespaces
491 Control display of debugging info regarding Linux namespaces.
493 set|show record btrace pt buffer-size
494 Set and show the size of the ring buffer used for branch tracing in
495 Intel Processor Trace format.
496 The obtained size may differ from the requested size. Use "info
497 record" to see the obtained buffer size.
499 maint set|show btrace pt skip-pad
500 Set and show whether PAD packets are skipped when computing the
503 * The command 'thread apply all' can now support new option '-ascending'
504 to call its specified command for all threads in ascending order.
506 * Python/Guile scripting
508 ** GDB now supports auto-loading of Python/Guile scripts contained in the
509 special section named `.debug_gdb_scripts'.
513 qXfer:btrace-conf:read
514 Return the branch trace configuration for the current thread.
516 Qbtrace-conf:bts:size
517 Set the requested ring buffer size for branch tracing in BTS format.
520 Enable Intel Procesor Trace-based branch tracing for the current
521 process. The remote stub reports support for this packet to GDB's
525 Set the requested ring buffer size for branch tracing in Intel Processor
529 Indicates a memory breakpoint instruction was executed, irrespective
530 of whether it was GDB that planted the breakpoint or the breakpoint
531 is hardcoded in the program. This is required for correct non-stop
535 Indicates the target stopped for a hardware breakpoint. This is
536 required for correct non-stop mode operation.
539 Return information about files on the remote system.
542 Return the full absolute name of the file that was executed to
543 create a process running on the remote system.
546 Select the filesystem on which vFile: operations with filename
547 arguments will operate. This is required for GDB to be able to
548 access files on remote targets where the remote stub does not
549 share a common filesystem with the inferior(s).
552 Indicates that a fork system call was executed.
555 Indicates that a vfork system call was executed.
557 vforkdone stop reason
558 Indicates that a vfork child of the specified process has executed
559 an exec or exit, allowing the vfork parent to resume execution.
561 fork-events and vfork-events features in qSupported
562 The qSupported packet allows GDB to request support for fork and
563 vfork events using new 'gdbfeatures' fork-events and vfork-events,
564 and the qSupported response can contain the corresponding
565 'stubfeatures'. Set and show commands can be used to display
566 whether these features are enabled.
568 * Extended-remote fork events
570 ** GDB now has support for fork events on extended-remote Linux
571 targets. For targets with Linux kernels 2.5.60 and later, this
572 enables follow-fork-mode and detach-on-fork for both fork and
573 vfork, as well as fork and vfork catchpoints.
575 * The info record command now shows the recording format and the
576 branch tracing configuration for the current thread when using
577 the btrace record target.
578 For the BTS format, it shows the ring buffer size.
580 * GDB now has support for DTrace USDT (Userland Static Defined
581 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
583 * GDB now supports access to vector registers on S/390 GNU/Linux
586 * Removed command line options
588 -xdb HP-UX XDB compatibility mode.
590 * Removed targets and native configurations
592 HP/PA running HP-UX hppa*-*-hpux*
593 Itanium running HP-UX ia64-*-hpux*
595 * New configure options
598 This configure option allows the user to build GDB with support for
599 Intel Processor Trace (default: auto). This requires libipt.
601 --with-libipt-prefix=PATH
602 Specify the path to the version of libipt that GDB should use.
603 $PATH/include should contain the intel-pt.h header and
604 $PATH/lib should contain the libipt.so library.
606 *** Changes in GDB 7.9.1
610 ** Xmethods can now specify a result type.
612 *** Changes in GDB 7.9
614 * GDB now supports hardware watchpoints on x86 GNU Hurd.
618 ** You can now access frame registers from Python scripts.
619 ** New attribute 'producer' for gdb.Symtab objects.
620 ** gdb.Objfile objects have a new attribute "progspace",
621 which is the gdb.Progspace object of the containing program space.
622 ** gdb.Objfile objects have a new attribute "owner".
623 ** gdb.Objfile objects have a new attribute "build_id",
624 which is the build ID generated when the file was built.
625 ** gdb.Objfile objects have a new method "add_separate_debug_file".
626 ** A new event "gdb.clear_objfiles" has been added, triggered when
627 selecting a new file to debug.
628 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
629 ** New function gdb.lookup_objfile.
631 New events which are triggered when GDB modifies the state of the
634 ** gdb.events.inferior_call_pre: Function call is about to be made.
635 ** gdb.events.inferior_call_post: Function call has just been made.
636 ** gdb.events.memory_changed: A memory location has been altered.
637 ** gdb.events.register_changed: A register has been altered.
639 * New Python-based convenience functions:
641 ** $_caller_is(name [, number_of_frames])
642 ** $_caller_matches(regexp [, number_of_frames])
643 ** $_any_caller_is(name [, number_of_frames])
644 ** $_any_caller_matches(regexp [, number_of_frames])
646 * GDB now supports the compilation and injection of source code into
647 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
648 to compile the source code to object code, and if successful, inject
649 and execute that code within the current context of the inferior.
650 Currently the C language is supported. The commands used to
651 interface with this new feature are:
653 compile code [-raw|-r] [--] [source code]
654 compile file [-raw|-r] filename
658 demangle [-l language] [--] name
659 Demangle "name" in the specified language, or the current language
660 if elided. This command is renamed from the "maint demangle" command.
661 The latter is kept as a no-op to avoid "maint demangle" being interpreted
662 as "maint demangler-warning".
664 queue-signal signal-name-or-number
665 Queue a signal to be delivered to the thread when it is resumed.
667 add-auto-load-scripts-directory directory
668 Add entries to the list of directories from which to load auto-loaded
671 maint print user-registers
672 List all currently available "user" registers.
674 compile code [-r|-raw] [--] [source code]
675 Compile, inject, and execute in the inferior the executable object
676 code produced by compiling the provided source code.
678 compile file [-r|-raw] filename
679 Compile and inject into the inferior the executable object code
680 produced by compiling the source code stored in the filename
683 * On resume, GDB now always passes the signal the program had stopped
684 for to the thread the signal was sent to, even if the user changed
685 threads before resuming. Previously GDB would often (but not
686 always) deliver the signal to the thread that happens to be current
689 * Conversely, the "signal" command now consistently delivers the
690 requested signal to the current thread. GDB now asks for
691 confirmation if the program had stopped for a signal and the user
692 switched threads meanwhile.
694 * "breakpoint always-inserted" modes "off" and "auto" merged.
696 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
697 won't remove breakpoints from the target until all threads stop,
698 even in non-stop mode. The "auto" mode has been removed, and "off"
699 is now the default mode.
703 set debug symbol-lookup
704 show debug symbol-lookup
705 Control display of debugging info regarding symbol lookup.
709 ** The -list-thread-groups command outputs an exit-code field for
710 inferiors that have exited.
714 MIPS SDE mips*-sde*-elf*
718 Support for these obsolete configurations has been removed.
720 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
721 SGI Irix-5.x mips-*-irix5*
722 SGI Irix-6.x mips-*-irix6*
723 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
724 VAX running Ultrix vax-*-ultrix*
726 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
727 and "assf"), have been removed. Use the "sharedlibrary" command, or
728 its alias "share", instead.
730 *** Changes in GDB 7.8
732 * New command line options
735 This is an alias for the --data-directory option.
737 * GDB supports printing and modifying of variable length automatic arrays
738 as specified in ISO C99.
740 * The ARM simulator now supports instruction level tracing
741 with or without disassembly.
745 GDB now has support for scripting using Guile. Whether this is
746 available is determined at configure time.
747 Guile version 2.0 or greater is required.
748 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
750 * New commands (for set/show, see "New options" below)
754 Invoke CODE by passing it to the Guile interpreter.
758 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
760 info auto-load guile-scripts [regexp]
761 Print the list of automatically loaded Guile scripts.
763 * The source command is now capable of sourcing Guile scripts.
764 This feature is dependent on the debugger being built with Guile support.
768 set print symbol-loading (off|brief|full)
769 show print symbol-loading
770 Control whether to print informational messages when loading symbol
771 information for a file. The default is "full", but when debugging
772 programs with large numbers of shared libraries the amount of output
775 set guile print-stack (none|message|full)
776 show guile print-stack
777 Show a stack trace when an error is encountered in a Guile script.
779 set auto-load guile-scripts (on|off)
780 show auto-load guile-scripts
781 Control auto-loading of Guile script files.
783 maint ada set ignore-descriptive-types (on|off)
784 maint ada show ignore-descriptive-types
785 Control whether the debugger should ignore descriptive types in Ada
786 programs. The default is not to ignore the descriptive types. See
787 the user manual for more details on descriptive types and the intended
788 usage of this option.
790 set auto-connect-native-target
792 Control whether GDB is allowed to automatically connect to the
793 native target for the run, attach, etc. commands when not connected
794 to any target yet. See also "target native" below.
796 set record btrace replay-memory-access (read-only|read-write)
797 show record btrace replay-memory-access
798 Control what memory accesses are allowed during replay.
800 maint set target-async (on|off)
801 maint show target-async
802 This controls whether GDB targets operate in synchronous or
803 asynchronous mode. Normally the default is asynchronous, if it is
804 available; but this can be changed to more easily debug problems
805 occurring only in synchronous mode.
807 set mi-async (on|off)
809 Control whether MI asynchronous mode is preferred. This supersedes
810 "set target-async" of previous GDB versions.
812 * "set target-async" is deprecated as a CLI option and is now an alias
813 for "set mi-async" (only puts MI into async mode).
815 * Background execution commands (e.g., "c&", "s&", etc.) are now
816 possible ``out of the box'' if the target supports them. Previously
817 the user would need to explicitly enable the possibility with the
818 "set target-async on" command.
820 * New features in the GDB remote stub, GDBserver
822 ** New option --debug-format=option1[,option2,...] allows one to add
823 additional text to each output. At present only timestamps
824 are supported: --debug-format=timestamps.
825 Timestamps can also be turned on with the
826 "monitor set debug-format timestamps" command from GDB.
828 * The 'record instruction-history' command now starts counting instructions
829 at one. This also affects the instruction ranges reported by the
830 'record function-call-history' command when given the /i modifier.
832 * The command 'record function-call-history' supports a new modifier '/c' to
833 indent the function names based on their call stack depth.
834 The fields for the '/i' and '/l' modifier have been reordered.
835 The source line range is now prefixed with 'at'.
836 The instruction range is now prefixed with 'inst'.
837 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
838 "record instruction-history" and "list" commands.
840 * The ranges given as arguments to the 'record function-call-history' and
841 'record instruction-history' commands are now inclusive.
843 * The btrace record target now supports the 'record goto' command.
844 For locations inside the execution trace, the back trace is computed
845 based on the information stored in the execution trace.
847 * The btrace record target supports limited reverse execution and replay.
848 The target does not record data and therefore does not allow reading
851 * The "catch syscall" command now works on s390*-linux* targets.
853 * The "compare-sections" command is no longer specific to target
854 remote. It now works with all targets.
856 * All native targets are now consistently called "native".
857 Consequently, the "target child", "target GNU", "target djgpp",
858 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
859 commands have been replaced with "target native". The QNX/NTO port
860 leaves the "procfs" target in place and adds a "native" target for
861 consistency with other ports. The impact on users should be minimal
862 as these commands previously either throwed an error, or were
863 no-ops. The target's name is visible in the output of the following
864 commands: "help target", "info target", "info files", "maint print
867 * The "target native" command now connects to the native target. This
868 can be used to launch native programs even when "set
869 auto-connect-native-target" is set to off.
871 * GDB now supports access to Intel MPX registers on GNU/Linux.
873 * Support for Intel AVX-512 registers on GNU/Linux.
874 Support displaying and modifying Intel AVX-512 registers
875 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
879 qXfer:btrace:read's annex
880 The qXfer:btrace:read packet supports a new annex 'delta' to read
881 branch trace incrementally.
885 ** Valid Python operations on gdb.Value objects representing
886 structs/classes invoke the corresponding overloaded operators if
888 ** New `Xmethods' feature in the Python API. Xmethods are
889 additional methods or replacements for existing methods of a C++
890 class. This feature is useful for those cases where a method
891 defined in C++ source code could be inlined or optimized out by
892 the compiler, making it unavailable to GDB.
895 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
897 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
898 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
899 its alias "share", instead.
901 * The commands "set remotebaud" and "show remotebaud" are no longer
902 supported. Use "set serial baud" and "show serial baud" (respectively)
907 ** A new option "-gdb-set mi-async" replaces "-gdb-set
908 target-async". The latter is left as a deprecated alias of the
909 former for backward compatibility. If the target supports it,
910 CLI background execution commands are now always possible by
911 default, independently of whether the frontend stated a
912 preference for asynchronous execution with "-gdb-set mi-async".
913 Previously "-gdb-set target-async off" affected both MI execution
914 commands and CLI execution commands.
916 *** Changes in GDB 7.7
918 * Improved support for process record-replay and reverse debugging on
919 arm*-linux* targets. Support for thumb32 and syscall instruction
920 recording has been added.
922 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
924 * GDB now supports Fission DWP file format version 2.
925 http://gcc.gnu.org/wiki/DebugFission
927 * New convenience function "$_isvoid", to check whether an expression
928 is void. A void expression is an expression where the type of the
929 result is "void". For example, some convenience variables may be
930 "void" when evaluated (e.g., "$_exitcode" before the execution of
931 the program being debugged; or an undefined convenience variable).
932 Another example, when calling a function whose return type is
935 * The "maintenance print objfiles" command now takes an optional regexp.
937 * The "catch syscall" command now works on arm*-linux* targets.
939 * GDB now consistently shows "<not saved>" when printing values of
940 registers the debug info indicates have not been saved in the frame
941 and there's nowhere to retrieve them from
942 (callee-saved/call-clobbered registers):
947 (gdb) info registers rax
950 Before, the former would print "<optimized out>", and the latter
951 "*value not available*".
953 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
958 ** Frame filters and frame decorators have been added.
959 ** Temporary breakpoints are now supported.
960 ** Line tables representation has been added.
961 ** New attribute 'parent_type' for gdb.Field objects.
962 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
963 ** New attribute 'name' for gdb.Type objects.
967 Nios II ELF nios2*-*-elf
968 Nios II GNU/Linux nios2*-*-linux
969 Texas Instruments MSP430 msp430*-*-elf
971 * Removed native configurations
973 Support for these a.out NetBSD and OpenBSD obsolete configurations has
974 been removed. ELF variants of these configurations are kept supported.
976 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
977 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
978 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
979 i[34567]86-*-openbsd3.[0-3]
980 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
981 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
982 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
986 Like "catch throw", but catches a re-thrown exception.
988 Renamed from old "maint check-symtabs".
990 Perform consistency checks on symtabs.
992 Expand symtabs matching an optional regexp.
995 Display the details of GDB configure-time options.
997 maint set|show per-command
998 maint set|show per-command space
999 maint set|show per-command time
1000 maint set|show per-command symtab
1001 Enable display of per-command gdb resource usage.
1003 remove-symbol-file FILENAME
1004 remove-symbol-file -a ADDRESS
1005 Remove a symbol file added via add-symbol-file. The file to remove
1006 can be identified by its filename or by an address that lies within
1007 the boundaries of this symbol file in memory.
1010 info exceptions REGEXP
1011 Display the list of Ada exceptions defined in the program being
1012 debugged. If provided, only the exceptions whose names match REGEXP
1017 set debug symfile off|on
1019 Control display of debugging info regarding reading symbol files and
1020 symbol tables within those files
1022 set print raw frame-arguments
1023 show print raw frame-arguments
1024 Set/show whether to print frame arguments in raw mode,
1025 disregarding any defined pretty-printers.
1027 set remote trace-status-packet
1028 show remote trace-status-packet
1029 Set/show the use of remote protocol qTStatus packet.
1033 Control display of debugging messages related to Nios II targets.
1037 Control whether target-assisted range stepping is enabled.
1039 set startup-with-shell
1040 show startup-with-shell
1041 Specifies whether Unix child processes are started via a shell or
1046 Use the target memory cache for accesses to the code segment. This
1047 improves performance of remote debugging (particularly disassembly).
1049 * You can now use a literal value 'unlimited' for options that
1050 interpret 0 or -1 as meaning "unlimited". E.g., "set
1051 trace-buffer-size unlimited" is now an alias for "set
1052 trace-buffer-size -1" and "set height unlimited" is now an alias for
1055 * The "set debug symtab-create" debugging option of GDB has been changed to
1056 accept a verbosity level. 0 means "off", 1 provides basic debugging
1057 output, and values of 2 or greater provides more verbose output.
1059 * New command-line options
1061 Display the details of GDB configure-time options.
1063 * The command 'tsave' can now support new option '-ctf' to save trace
1064 buffer in Common Trace Format.
1066 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1069 * GDB now implements the the C++ 'typeid' operator.
1071 * The new convenience variable $_exception holds the exception being
1072 thrown or caught at an exception-related catchpoint.
1074 * The exception-related catchpoints, like "catch throw", now accept a
1075 regular expression which can be used to filter exceptions by type.
1077 * The new convenience variable $_exitsignal is automatically set to
1078 the terminating signal number when the program being debugged dies
1079 due to an uncaught signal.
1083 ** All MI commands now accept an optional "--language" option.
1084 Support for this feature can be verified by using the "-list-features"
1085 command, which should contain "language-option".
1087 ** The new command -info-gdb-mi-command allows the user to determine
1088 whether a GDB/MI command is supported or not.
1090 ** The "^error" result record returned when trying to execute an undefined
1091 GDB/MI command now provides a variable named "code" whose content is the
1092 "undefined-command" error code. Support for this feature can be verified
1093 by using the "-list-features" command, which should contain
1094 "undefined-command-error-code".
1096 ** The -trace-save MI command can optionally save trace buffer in Common
1099 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1101 ** The command -data-list-register-values now accepts an optional
1102 "--skip-unavailable" option. When used, only the available registers
1105 ** The new command -trace-frame-collected dumps collected variables,
1106 computed expressions, tvars, memory and registers in a traceframe.
1108 ** The commands -stack-list-locals, -stack-list-arguments and
1109 -stack-list-variables now accept an option "--skip-unavailable".
1110 When used, only the available locals or arguments are displayed.
1112 ** The -exec-run command now accepts an optional "--start" option.
1113 When used, the command follows the same semantics as the "start"
1114 command, stopping the program's execution at the start of its
1115 main subprogram. Support for this feature can be verified using
1116 the "-list-features" command, which should contain
1117 "exec-run-start-option".
1119 ** The new commands -catch-assert and -catch-exceptions insert
1120 catchpoints stopping the program when Ada exceptions are raised.
1122 ** The new command -info-ada-exceptions provides the equivalent of
1123 the new "info exceptions" command.
1125 * New system-wide configuration scripts
1126 A GDB installation now provides scripts suitable for use as system-wide
1127 configuration scripts for the following systems:
1131 * GDB now supports target-assigned range stepping with remote targets.
1132 This improves the performance of stepping source lines by reducing
1133 the number of control packets from/to GDB. See "New remote packets"
1136 * GDB now understands the element 'tvar' in the XML traceframe info.
1137 It has the id of the collected trace state variables.
1139 * On S/390 targets that provide the transactional-execution feature,
1140 the program interruption transaction diagnostic block (TDB) is now
1141 represented as a number of additional "registers" in GDB.
1143 * New remote packets
1147 The vCont packet supports a new 'r' action, that tells the remote
1148 stub to step through an address range itself, without GDB
1149 involvemement at each single-step.
1151 qXfer:libraries-svr4:read's annex
1152 The previously unused annex of the qXfer:libraries-svr4:read packet
1153 is now used to support passing an argument list. The remote stub
1154 reports support for this argument list to GDB's qSupported query.
1155 The defined arguments are "start" and "prev", used to reduce work
1156 necessary for library list updating, resulting in significant
1159 * New features in the GDB remote stub, GDBserver
1161 ** GDBserver now supports target-assisted range stepping. Currently
1162 enabled on x86/x86_64 GNU/Linux targets.
1164 ** GDBserver now adds element 'tvar' in the XML in the reply to
1165 'qXfer:traceframe-info:read'. It has the id of the collected
1166 trace state variables.
1168 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1171 * New 'z' formatter for printing and examining memory, this displays the
1172 value as hexadecimal zero padded on the left to the size of the type.
1174 * GDB can now use Windows x64 unwinding data.
1176 * The "set remotebaud" command has been replaced by "set serial baud".
1177 Similarly, "show remotebaud" has been replaced by "show serial baud".
1178 The "set remotebaud" and "show remotebaud" commands are still available
1179 to provide backward compatibility with older versions of GDB.
1181 *** Changes in GDB 7.6
1183 * Target record has been renamed to record-full.
1184 Record/replay is now enabled with the "record full" command.
1185 This also affects settings that are associated with full record/replay
1186 that have been moved from "set/show record" to "set/show record full":
1188 set|show record full insn-number-max
1189 set|show record full stop-at-limit
1190 set|show record full memory-query
1192 * A new record target "record-btrace" has been added. The new target
1193 uses hardware support to record the control-flow of a process. It
1194 does not support replaying the execution, but it implements the
1195 below new commands for investigating the recorded execution log.
1196 This new recording method can be enabled using:
1200 The "record-btrace" target is only available on Intel Atom processors
1201 and requires a Linux kernel 2.6.32 or later.
1203 * Two new commands have been added for record/replay to give information
1204 about the recorded execution without having to replay the execution.
1205 The commands are only supported by "record btrace".
1207 record instruction-history prints the execution history at
1208 instruction granularity
1210 record function-call-history prints the execution history at
1211 function granularity
1213 * New native configurations
1215 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1216 FreeBSD/powerpc powerpc*-*-freebsd
1217 x86_64/Cygwin x86_64-*-cygwin*
1218 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1222 ARM AArch64 aarch64*-*-elf
1223 ARM AArch64 GNU/Linux aarch64*-*-linux
1224 Lynx 178 PowerPC powerpc-*-lynx*178
1225 x86_64/Cygwin x86_64-*-cygwin*
1226 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1228 * If the configured location of system.gdbinit file (as given by the
1229 --with-system-gdbinit option at configure time) is in the
1230 data-directory (as specified by --with-gdb-datadir at configure
1231 time) or in one of its subdirectories, then GDB will look for the
1232 system-wide init file in the directory specified by the
1233 --data-directory command-line option.
1235 * New command line options:
1237 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1238 other initialization files, unlike -nx which disables all of them.
1240 * Removed command line options
1242 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1245 * The 'ptype' and 'whatis' commands now accept an argument to control
1248 * 'info proc' now works on some core files.
1252 ** Vectors can be created with gdb.Type.vector.
1254 ** Python's atexit.register now works in GDB.
1256 ** Types can be pretty-printed via a Python API.
1258 ** Python 3 is now supported (in addition to Python 2.4 or later)
1260 ** New class gdb.Architecture exposes GDB's internal representation
1261 of architecture in the Python API.
1263 ** New method Frame.architecture returns the gdb.Architecture object
1264 corresponding to the frame's architecture.
1266 * New Python-based convenience functions:
1268 ** $_memeq(buf1, buf2, length)
1269 ** $_streq(str1, str2)
1271 ** $_regex(str, regex)
1273 * The 'cd' command now defaults to using '~' (the home directory) if not
1276 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1277 default for GCC since November 2000.
1279 * The command 'forward-search' can now be abbreviated as 'fo'.
1281 * The command 'info tracepoints' can now display 'installed on target'
1282 or 'not installed on target' for each non-pending location of tracepoint.
1284 * New configure options
1286 --enable-libmcheck/--disable-libmcheck
1287 By default, development versions are built with -lmcheck on hosts
1288 that support it, in order to help track memory corruption issues.
1289 Release versions, on the other hand, are built without -lmcheck
1290 by default. The --enable-libmcheck/--disable-libmcheck configure
1291 options allow the user to override that default.
1292 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1293 This configure option allows the user to build GDB with
1294 libbabeltrace using which GDB can read Common Trace Format data.
1296 * New commands (for set/show, see "New options" below)
1299 Catch signals. This is similar to "handle", but allows commands and
1300 conditions to be attached.
1303 List the BFDs known to GDB.
1305 python-interactive [command]
1307 Start a Python interactive prompt, or evaluate the optional command
1308 and print the result of expressions.
1311 "py" is a new alias for "python".
1313 enable type-printer [name]...
1314 disable type-printer [name]...
1315 Enable or disable type printers.
1319 ** For the Renesas Super-H architecture, the "regs" command has been removed
1320 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1325 set print type methods (on|off)
1326 show print type methods
1327 Control whether method declarations are displayed by "ptype".
1328 The default is to show them.
1330 set print type typedefs (on|off)
1331 show print type typedefs
1332 Control whether typedef definitions are displayed by "ptype".
1333 The default is to show them.
1335 set filename-display basename|relative|absolute
1336 show filename-display
1337 Control the way in which filenames is displayed.
1338 The default is "relative", which preserves previous behavior.
1340 set trace-buffer-size
1341 show trace-buffer-size
1342 Request target to change the size of trace buffer.
1344 set remote trace-buffer-size-packet auto|on|off
1345 show remote trace-buffer-size-packet
1346 Control the use of the remote protocol `QTBuffer:size' packet.
1350 Control display of debugging messages related to ARM AArch64.
1353 set debug coff-pe-read
1354 show debug coff-pe-read
1355 Control display of debugging messages related to reading of COFF/PE
1360 Control display of debugging messages related to Mach-O symbols
1363 set debug notification
1364 show debug notification
1365 Control display of debugging info for async remote notification.
1369 ** Command parameter changes are now notified using new async record
1370 "=cmd-param-changed".
1371 ** Trace frame changes caused by command "tfind" are now notified using
1372 new async record "=traceframe-changed".
1373 ** The creation, deletion and modification of trace state variables
1374 are now notified using new async records "=tsv-created",
1375 "=tsv-deleted" and "=tsv-modified".
1376 ** The start and stop of process record are now notified using new
1377 async record "=record-started" and "=record-stopped".
1378 ** Memory changes are now notified using new async record
1380 ** The data-disassemble command response will include a "fullname" field
1381 containing the absolute file name when source has been requested.
1382 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1383 command, to allow pattern filling of memory areas.
1384 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1385 library load/unload events.
1386 ** The response to breakpoint commands and breakpoint async records
1387 includes an "installed" field containing a boolean state about each
1388 non-pending tracepoint location is whether installed on target or not.
1389 ** Output of the "-trace-status" command includes a "trace-file" field
1390 containing the name of the trace file being examined. This field is
1391 optional, and only present when examining a trace file.
1392 ** The "fullname" field is now always present along with the "file" field,
1393 even if the file cannot be found by GDB.
1395 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1396 You must have the LZMA library available when configuring GDB for this
1397 feature to be enabled. For more information, see:
1398 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1400 * New remote packets
1403 Set the size of trace buffer. The remote stub reports support for this
1404 packet to gdb's qSupported query.
1407 Enable Branch Trace Store (BTS)-based branch tracing for the current
1408 thread. The remote stub reports support for this packet to gdb's
1412 Disable branch tracing for the current thread. The remote stub reports
1413 support for this packet to gdb's qSupported query.
1416 Read the traced branches for the current thread. The remote stub
1417 reports support for this packet to gdb's qSupported query.
1419 *** Changes in GDB 7.5
1421 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1422 for more x32 ABI info.
1424 * GDB now supports access to MIPS DSP registers on Linux targets.
1426 * GDB now supports debugging microMIPS binaries.
1428 * The "info os" command on GNU/Linux can now display information on
1429 several new classes of objects managed by the operating system:
1430 "info os procgroups" lists process groups
1431 "info os files" lists file descriptors
1432 "info os sockets" lists internet-domain sockets
1433 "info os shm" lists shared-memory regions
1434 "info os semaphores" lists semaphores
1435 "info os msg" lists message queues
1436 "info os modules" lists loaded kernel modules
1438 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1439 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1440 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1441 options and inspect the probe arguments using the new $_probe_arg family
1442 of convenience variables. You can obtain more information about SystemTap
1443 in <http://sourceware.org/systemtap/>.
1445 * GDB now supports reversible debugging on ARM, it allows you to
1446 debug basic ARM and THUMB instructions, and provides
1447 record/replay support.
1449 * The option "symbol-reloading" has been deleted as it is no longer used.
1453 ** GDB commands implemented in Python can now be put in command class
1456 ** The "maint set python print-stack on|off" is now deleted.
1458 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1459 apply "flag enum"-style pretty-printing to any enum.
1461 ** gdb.lookup_symbol can now work when there is no current frame.
1463 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1464 the source at which the symbol was defined.
1466 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1467 method 'value'. The former indicates whether the symbol needs a
1468 frame in order to compute its value, and the latter computes the
1471 ** A new method 'referenced_value' on gdb.Value objects which can
1472 dereference pointer as well as C++ reference values.
1474 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1475 which return the global and static blocks (as gdb.Block objects),
1476 of the underlying symbol table, respectively.
1478 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1479 object associated with a PC value.
1481 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1482 of the address range occupied by code for the current source line.
1484 * Go language support.
1485 GDB now supports debugging programs written in the Go programming
1488 * GDBserver now supports stdio connections.
1489 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1491 * The binary "gdbtui" can no longer be built or installed.
1492 Use "gdb -tui" instead.
1494 * GDB will now print "flag" enums specially. A flag enum is one where
1495 all the enumerator values have no bits in common when pairwise
1496 "and"ed. When printing a value whose type is a flag enum, GDB will
1497 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1498 (gdb) print (enum E) 3
1501 * The filename part of a linespec will now match trailing components
1502 of a source file name. For example, "break gcc/expr.c:1000" will
1503 now set a breakpoint in build/gcc/expr.c, but not
1504 build/libcpp/expr.c.
1506 * The "info proc" and "generate-core-file" commands will now also
1507 work on remote targets connected to GDBserver on Linux.
1509 * The command "info catch" has been removed. It has been disabled
1510 since December 2007.
1512 * The "catch exception" and "catch assert" commands now accept
1513 a condition at the end of the command, much like the "break"
1514 command does. For instance:
1516 (gdb) catch exception Constraint_Error if Barrier = True
1518 Previously, it was possible to add a condition to such catchpoints,
1519 but it had to be done as a second step, after the catchpoint had been
1520 created, using the "condition" command.
1522 * The "info static-tracepoint-marker" command will now also work on
1523 native Linux targets with in-process agent.
1525 * GDB can now set breakpoints on inlined functions.
1527 * The .gdb_index section has been updated to include symbols for
1528 inlined functions. GDB will ignore older .gdb_index sections by
1529 default, which could cause symbol files to be loaded more slowly
1530 until their .gdb_index sections can be recreated. The new command
1531 "set use-deprecated-index-sections on" will cause GDB to use any older
1532 .gdb_index sections it finds. This will restore performance, but the
1533 ability to set breakpoints on inlined functions will be lost in symbol
1534 files with older .gdb_index sections.
1536 The .gdb_index section has also been updated to record more information
1537 about each symbol. This speeds up the "info variables", "info functions"
1538 and "info types" commands when used with programs having the .gdb_index
1539 section, as well as speeding up debugging with shared libraries using
1540 the .gdb_index section.
1542 * Ada support for GDB/MI Variable Objects has been added.
1544 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1549 ** New command -info-os is the MI equivalent of "info os".
1551 ** Output logs ("set logging" and related) now include MI output.
1555 ** "set use-deprecated-index-sections on|off"
1556 "show use-deprecated-index-sections on|off"
1557 Controls the use of deprecated .gdb_index sections.
1559 ** "catch load" and "catch unload" can be used to stop when a shared
1560 library is loaded or unloaded, respectively.
1562 ** "enable count" can be used to auto-disable a breakpoint after
1565 ** "info vtbl" can be used to show the virtual method tables for
1566 C++ and Java objects.
1568 ** "explore" and its sub commands "explore value" and "explore type"
1569 can be used to recursively explore values and types of
1570 expressions. These commands are available only if GDB is
1571 configured with '--with-python'.
1573 ** "info auto-load" shows status of all kinds of auto-loaded files,
1574 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1575 sequences of commands files, "info auto-load python-scripts"
1576 shows status of auto-loading Python script files,
1577 "info auto-load local-gdbinit" shows status of loading init file
1578 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1579 status of inferior specific thread debugging shared library loading.
1581 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1582 and "show auto-load-scripts" commands have been deprecated, use their
1583 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1584 and "show auto-load python-scripts" counterparts instead.
1586 ** "dprintf location,format,args..." creates a dynamic printf, which
1587 is basically a breakpoint that does a printf and immediately
1588 resumes your program's execution, so it is like a printf that you
1589 can insert dynamically at runtime instead of at compiletime.
1591 ** "set print symbol"
1593 Controls whether GDB attempts to display the symbol, if any,
1594 corresponding to addresses it prints. This defaults to "on", but
1595 you can set it to "off" to restore GDB's previous behavior.
1597 * Deprecated commands
1599 ** For the Renesas Super-H architecture, the "regs" command has been
1600 deprecated, and "info all-registers" should be used instead.
1604 Renesas RL78 rl78-*-elf
1605 HP OpenVMS ia64 ia64-hp-openvms*
1607 * GDBserver supports evaluation of breakpoint conditions. When
1608 support is advertised by GDBserver, GDB may be told to send the
1609 breakpoint conditions in bytecode form to GDBserver. GDBserver
1610 will only report the breakpoint trigger to GDB when its condition
1615 set mips compression
1616 show mips compression
1617 Select the compressed ISA encoding used in functions that have no symbol
1618 information available. The encoding can be set to either of:
1621 and is updated automatically from ELF file flags if available.
1623 set breakpoint condition-evaluation
1624 show breakpoint condition-evaluation
1625 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1626 GDBserver ("target"). Default option "auto" chooses the most efficient
1628 This option can improve debugger efficiency depending on the speed of the
1632 Disable auto-loading globally.
1635 Show auto-loading setting of all kinds of auto-loaded files.
1637 set auto-load gdb-scripts on|off
1638 show auto-load gdb-scripts
1639 Control auto-loading of GDB canned sequences of commands files.
1641 set auto-load python-scripts on|off
1642 show auto-load python-scripts
1643 Control auto-loading of Python script files.
1645 set auto-load local-gdbinit on|off
1646 show auto-load local-gdbinit
1647 Control loading of init file (.gdbinit) from current directory.
1649 set auto-load libthread-db on|off
1650 show auto-load libthread-db
1651 Control auto-loading of inferior specific thread debugging shared library.
1653 set auto-load scripts-directory <dir1>[:<dir2>...]
1654 show auto-load scripts-directory
1655 Set a list of directories from which to load auto-loaded scripts.
1656 Automatically loaded Python scripts and GDB scripts are located in one
1657 of the directories listed by this option.
1658 The delimiter (':' above) may differ according to the host platform.
1660 set auto-load safe-path <dir1>[:<dir2>...]
1661 show auto-load safe-path
1662 Set a list of directories from which it is safe to auto-load files.
1663 The delimiter (':' above) may differ according to the host platform.
1665 set debug auto-load on|off
1666 show debug auto-load
1667 Control display of debugging info for auto-loading the files above.
1669 set dprintf-style gdb|call|agent
1671 Control the way in which a dynamic printf is performed; "gdb"
1672 requests a GDB printf command, while "call" causes dprintf to call a
1673 function in the inferior. "agent" requests that the target agent
1674 (such as GDBserver) do the printing.
1676 set dprintf-function <expr>
1677 show dprintf-function
1678 set dprintf-channel <expr>
1679 show dprintf-channel
1680 Set the function and optional first argument to the call when using
1681 the "call" style of dynamic printf.
1683 set disconnected-dprintf on|off
1684 show disconnected-dprintf
1685 Control whether agent-style dynamic printfs continue to be in effect
1686 after GDB disconnects.
1688 * New configure options
1690 --with-auto-load-dir
1691 Configure default value for the 'set auto-load scripts-directory'
1692 setting above. It defaults to '$debugdir:$datadir/auto-load',
1693 $debugdir representing global debugging info directories (available
1694 via 'show debug-file-directory') and $datadir representing GDB's data
1695 directory (available via 'show data-directory').
1697 --with-auto-load-safe-path
1698 Configure default value for the 'set auto-load safe-path' setting
1699 above. It defaults to the --with-auto-load-dir setting.
1701 --without-auto-load-safe-path
1702 Set 'set auto-load safe-path' to '/', effectively disabling this
1705 * New remote packets
1707 z0/z1 conditional breakpoints extension
1709 The z0/z1 breakpoint insertion packets have been extended to carry
1710 a list of conditional expressions over to the remote stub depending on the
1711 condition evaluation mode. The use of this extension can be controlled
1712 via the "set remote conditional-breakpoints-packet" command.
1716 Specify the signals which the remote stub may pass to the debugged
1717 program without GDB involvement.
1719 * New command line options
1721 --init-command=FILE, -ix Like --command, -x but execute it
1722 before loading inferior.
1723 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1724 execute it before loading inferior.
1726 *** Changes in GDB 7.4
1728 * GDB now handles ambiguous linespecs more consistently; the existing
1729 FILE:LINE support has been expanded to other types of linespecs. A
1730 breakpoint will now be set on all matching locations in all
1731 inferiors, and locations will be added or removed according to
1734 * GDB now allows you to skip uninteresting functions and files when
1735 stepping with the "skip function" and "skip file" commands.
1737 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1738 and "show remote hardware-watchpoint-length-limit". These allows to
1739 set or show the maximum length limit (in bytes) of a remote
1740 target hardware watchpoint.
1742 This allows e.g. to use "unlimited" hardware watchpoints with the
1743 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1744 watchpoints are slower than real hardware watchpoints but are
1745 significantly faster than gdb software watchpoints.
1749 ** The register_pretty_printer function in module gdb.printing now takes
1750 an optional `replace' argument. If True, the new printer replaces any
1753 ** The "maint set python print-stack on|off" command has been
1754 deprecated and will be deleted in GDB 7.5.
1755 A new command: "set python print-stack none|full|message" has
1756 replaced it. Additionally, the default for "print-stack" is
1757 now "message", which just prints the error message without
1760 ** A prompt substitution hook (prompt_hook) is now available to the
1763 ** A new Python module, gdb.prompt has been added to the GDB Python
1764 modules library. This module provides functionality for
1765 escape sequences in prompts (used by set/show
1766 extended-prompt). These escape sequences are replaced by their
1767 corresponding value.
1769 ** Python commands and convenience-functions located in
1770 'data-directory'/python/gdb/command and
1771 'data-directory'/python/gdb/function are now automatically loaded
1774 ** Blocks now provide four new attributes. global_block and
1775 static_block will return the global and static blocks
1776 respectively. is_static and is_global are boolean attributes
1777 that indicate if the block is one of those two types.
1779 ** Symbols now provide the "type" attribute, the type of the symbol.
1781 ** The "gdb.breakpoint" function has been deprecated in favor of
1784 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1785 of a function. This class is based on the "finish" command
1786 available in the CLI.
1788 ** Type objects for struct and union types now allow access to
1789 the fields using standard Python dictionary (mapping) methods.
1790 For example, "some_type['myfield']" now works, as does
1791 "some_type.items()".
1793 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1796 ** A new function, "deep_items" has been added to the gdb.types
1797 module in the GDB Python modules library. This function returns
1798 an iterator over the fields of a struct or union type. Unlike
1799 the standard Python "iteritems" method, it will recursively traverse
1800 any anonymous fields.
1804 ** "*stopped" events can report several new "reason"s, such as
1807 ** Breakpoint changes are now notified using new async records, like
1808 "=breakpoint-modified".
1810 ** New command -ada-task-info.
1812 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1813 $sdir specifies the default system locations of shared libraries.
1814 $pdir specifies the directory where the libpthread used by the application
1817 GDB no longer looks in $sdir and $pdir after it has searched the directories
1818 mentioned in libthread-db-search-path. If you want to search those
1819 directories, they must be specified in libthread-db-search-path.
1820 The default value of libthread-db-search-path on GNU/Linux and Solaris
1821 systems is now "$sdir:$pdir".
1823 $pdir is not supported by gdbserver, it is currently ignored.
1824 $sdir is supported by gdbserver.
1826 * New configure option --with-iconv-bin.
1827 When using the internationalization support like the one in the GNU C
1828 library, GDB will invoke the "iconv" program to get a list of supported
1829 character sets. If this program lives in a non-standard location, one can
1830 use this option to specify where to find it.
1832 * When natively debugging programs on PowerPC BookE processors running
1833 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1834 watchpoints, which specify a mask in addition to an address to watch.
1835 The mask specifies that some bits of an address (the bits which are
1836 reset in the mask) should be ignored when matching the address accessed
1837 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1838 section in the user manual for more details.
1840 * The new option --once causes GDBserver to stop listening for connections once
1841 the first connection is made. The listening port used by GDBserver will
1842 become available after that.
1844 * New commands "info macros" and "alias" have been added.
1846 * New function parameters suffix @entry specifies value of function parameter
1847 at the time the function got called. Entry values are available only since
1853 "!" is now an alias of the "shell" command.
1854 Note that no space is needed between "!" and SHELL COMMAND.
1858 watch EXPRESSION mask MASK_VALUE
1859 The watch command now supports the mask argument which allows creation
1860 of masked watchpoints, if the current architecture supports this feature.
1862 info auto-load-scripts [REGEXP]
1863 This command was formerly named "maintenance print section-scripts".
1864 It is now generally useful and is no longer a maintenance-only command.
1866 info macro [-all] [--] MACRO
1867 The info macro command has new options `-all' and `--'. The first for
1868 printing all definitions of a macro. The second for explicitly specifying
1869 the end of arguments and the beginning of the macro name in case the macro
1870 name starts with a hyphen.
1872 collect[/s] EXPRESSIONS
1873 The tracepoint collect command now takes an optional modifier "/s"
1874 that directs it to dereference pointer-to-character types and
1875 collect the bytes of memory up to a zero byte. The behavior is
1876 similar to what you see when you use the regular print command on a
1877 string. An optional integer following the "/s" sets a bound on the
1878 number of bytes that will be collected.
1881 The trace start command now interprets any supplied arguments as a
1882 note to be recorded with the trace run, with an effect similar to
1883 setting the variable trace-notes.
1886 The trace stop command now interprets any arguments as a note to be
1887 mentioned along with the tstatus report that the trace was stopped
1888 with a command. The effect is similar to setting the variable
1891 * Tracepoints can now be enabled and disabled at any time after a trace
1892 experiment has been started using the standard "enable" and "disable"
1893 commands. It is now possible to start a trace experiment with no enabled
1894 tracepoints; GDB will display a warning, but will allow the experiment to
1895 begin, assuming that tracepoints will be enabled as needed while the trace
1898 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1899 locations with 4-byte instructions, when they were previously
1900 limited to locations with instructions of 5 bytes or longer.
1904 set debug dwarf2-read
1905 show debug dwarf2-read
1906 Turns on or off display of debugging messages related to reading
1907 DWARF debug info. The default is off.
1909 set debug symtab-create
1910 show debug symtab-create
1911 Turns on or off display of debugging messages related to symbol table
1912 creation. The default is off.
1915 show extended-prompt
1916 Set the GDB prompt, and allow escape sequences to be inserted to
1917 display miscellaneous information (see 'help set extended-prompt'
1918 for the list of sequences). This prompt (and any information
1919 accessed through the escape sequences) is updated every time the
1920 prompt is displayed.
1922 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1923 show print entry-values
1924 Set printing of frame argument values at function entry. In some cases
1925 GDB can determine the value of function argument which was passed by the
1926 function caller, even if the value was modified inside the called function.
1928 set debug entry-values
1929 show debug entry-values
1930 Control display of debugging info for determining frame argument values at
1931 function entry and virtual tail call frames.
1933 set basenames-may-differ
1934 show basenames-may-differ
1935 Set whether a source file may have multiple base names.
1936 (A "base name" is the name of a file with the directory part removed.
1937 Example: The base name of "/home/user/hello.c" is "hello.c".)
1938 If set, GDB will canonicalize file names (e.g., expand symlinks)
1939 before comparing them. Canonicalization is an expensive operation,
1940 but it allows the same file be known by more than one base name.
1941 If not set (the default), all source files are assumed to have just
1942 one base name, and gdb will do file name comparisons more efficiently.
1948 Set a user name and notes for the current and any future trace runs.
1949 This is useful for long-running and/or disconnected traces, to
1950 inform others (or yourself) as to who is running the trace, supply
1951 contact information, or otherwise explain what is going on.
1953 set trace-stop-notes
1954 show trace-stop-notes
1955 Set a note attached to the trace run, that is displayed when the
1956 trace has been stopped by a tstop command. This is useful for
1957 instance as an explanation, if you are stopping a trace run that was
1958 started by someone else.
1960 * New remote packets
1964 Dynamically enable a tracepoint in a started trace experiment.
1968 Dynamically disable a tracepoint in a started trace experiment.
1972 Set the user and notes of the trace run.
1976 Query the current status of a tracepoint.
1980 Query the minimum length of instruction at which a fast tracepoint may
1983 * Dcache size (number of lines) and line-size are now runtime-configurable
1984 via "set dcache line" and "set dcache line-size" commands.
1988 Texas Instruments TMS320C6x tic6x-*-*
1992 Renesas RL78 rl78-*-elf
1994 *** Changes in GDB 7.3.1
1996 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1998 *** Changes in GDB 7.3
2000 * GDB has a new command: "thread find [REGEXP]".
2001 It finds the thread id whose name, target id, or thread extra info
2002 matches the given regular expression.
2004 * The "catch syscall" command now works on mips*-linux* targets.
2006 * The -data-disassemble MI command now supports modes 2 and 3 for
2007 dumping the instruction opcodes.
2009 * New command line options
2011 -data-directory DIR Specify DIR as the "data-directory".
2012 This is mostly for testing purposes.
2014 * The "maint set python auto-load on|off" command has been renamed to
2015 "set auto-load-scripts on|off".
2017 * GDB has a new command: "set directories".
2018 It is like the "dir" command except that it replaces the
2019 source path list instead of augmenting it.
2021 * GDB now understands thread names.
2023 On GNU/Linux, "info threads" will display the thread name as set by
2024 prctl or pthread_setname_np.
2026 There is also a new command, "thread name", which can be used to
2027 assign a name internally for GDB to display.
2030 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2031 has been integrated into GDB.
2035 ** The function gdb.Write now accepts an optional keyword 'stream'.
2036 This keyword, when provided, will direct the output to either
2037 stdout, stderr, or GDB's logging output.
2039 ** Parameters can now be be sub-classed in Python, and in particular
2040 you may implement the get_set_doc and get_show_doc functions.
2041 This improves how Parameter set/show documentation is processed
2042 and allows for more dynamic content.
2044 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2045 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2046 have an is_valid method.
2048 ** Breakpoints can now be sub-classed in Python, and in particular
2049 you may implement a 'stop' function that is executed each time
2050 the inferior reaches that breakpoint.
2052 ** New function gdb.lookup_global_symbol looks up a global symbol.
2054 ** GDB values in Python are now callable if the value represents a
2055 function. For example, if 'some_value' represents a function that
2056 takes two integer parameters and returns a value, you can call
2057 that function like so:
2059 result = some_value (10,20)
2061 ** Module gdb.types has been added.
2062 It contains a collection of utilities for working with gdb.Types objects:
2063 get_basic_type, has_field, make_enum_dict.
2065 ** Module gdb.printing has been added.
2066 It contains utilities for writing and registering pretty-printers.
2067 New classes: PrettyPrinter, SubPrettyPrinter,
2068 RegexpCollectionPrettyPrinter.
2069 New function: register_pretty_printer.
2071 ** New commands "info pretty-printers", "enable pretty-printer" and
2072 "disable pretty-printer" have been added.
2074 ** gdb.parameter("directories") is now available.
2076 ** New function gdb.newest_frame returns the newest frame in the
2079 ** The gdb.InferiorThread class has a new "name" attribute. This
2080 holds the thread's name.
2082 ** Python Support for Inferior events.
2083 Python scripts can add observers to be notified of events
2084 occurring in the process being debugged.
2085 The following events are currently supported:
2086 - gdb.events.cont Continue event.
2087 - gdb.events.exited Inferior exited event.
2088 - gdb.events.stop Signal received, and Breakpoint hit events.
2092 ** GDB now puts template parameters in scope when debugging in an
2093 instantiation. For example, if you have:
2095 template<int X> int func (void) { return X; }
2097 then if you step into func<5>, "print X" will show "5". This
2098 feature requires proper debuginfo support from the compiler; it
2099 was added to GCC 4.5.
2101 ** The motion commands "next", "finish", "until", and "advance" now
2102 work better when exceptions are thrown. In particular, GDB will
2103 no longer lose control of the inferior; instead, the GDB will
2104 stop the inferior at the point at which the exception is caught.
2105 This functionality requires a change in the exception handling
2106 code that was introduced in GCC 4.5.
2108 * GDB now follows GCC's rules on accessing volatile objects when
2109 reading or writing target state during expression evaluation.
2110 One notable difference to prior behavior is that "print x = 0"
2111 no longer generates a read of x; the value of the assignment is
2112 now always taken directly from the value being assigned.
2114 * GDB now has some support for using labels in the program's source in
2115 linespecs. For instance, you can use "advance label" to continue
2116 execution to a label.
2118 * GDB now has support for reading and writing a new .gdb_index
2119 section. This section holds a fast index of DWARF debugging
2120 information and can be used to greatly speed up GDB startup and
2121 operation. See the documentation for `save gdb-index' for details.
2123 * The "watch" command now accepts an optional "-location" argument.
2124 When used, this causes GDB to watch the memory referred to by the
2125 expression. Such a watchpoint is never deleted due to it going out
2128 * GDB now supports thread debugging of core dumps on GNU/Linux.
2130 GDB now activates thread debugging using the libthread_db library
2131 when debugging GNU/Linux core dumps, similarly to when debugging
2132 live processes. As a result, when debugging a core dump file, GDB
2133 is now able to display pthread_t ids of threads. For example, "info
2134 threads" shows the same output as when debugging the process when it
2135 was live. In earlier releases, you'd see something like this:
2138 * 1 LWP 6780 main () at main.c:10
2140 While now you see this:
2143 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2145 It is also now possible to inspect TLS variables when debugging core
2148 When debugging a core dump generated on a machine other than the one
2149 used to run GDB, you may need to point GDB at the correct
2150 libthread_db library with the "set libthread-db-search-path"
2151 command. See the user manual for more details on this command.
2153 * When natively debugging programs on PowerPC BookE processors running
2154 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2155 which stop execution of the inferior whenever it executes an instruction
2156 at any address within the specified range. See the "PowerPC Embedded"
2157 section in the user manual for more details.
2159 * New features in the GDB remote stub, GDBserver
2161 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2162 and i686 LynxOS (version 5.x).
2164 ** GDBserver is now supported on Blackfin Linux.
2166 * New native configurations
2168 ia64 HP-UX ia64-*-hpux*
2172 Analog Devices, Inc. Blackfin Processor bfin-*
2174 * Ada task switching is now supported on sparc-elf targets when
2175 debugging a program using the Ravenscar Profile. For more information,
2176 see the "Tasking Support when using the Ravenscar Profile" section
2177 in the GDB user manual.
2179 * Guile support was removed.
2181 * New features in the GNU simulator
2183 ** The --map-info flag lists all known core mappings.
2185 ** CFI flashes may be simulated via the "cfi" device.
2187 *** Changes in GDB 7.2
2189 * Shared library support for remote targets by default
2191 When GDB is configured for a generic, non-OS specific target, like
2192 for example, --target=arm-eabi or one of the many *-*-elf targets,
2193 GDB now queries remote stubs for loaded shared libraries using the
2194 `qXfer:libraries:read' packet. Previously, shared library support
2195 was always disabled for such configurations.
2199 ** Argument Dependent Lookup (ADL)
2201 In C++ ADL lookup directs function search to the namespaces of its
2202 arguments even if the namespace has not been imported.
2212 Here the compiler will search for `foo' in the namespace of 'b'
2213 and find A::foo. GDB now supports this. This construct is commonly
2214 used in the Standard Template Library for operators.
2216 ** Improved User Defined Operator Support
2218 In addition to member operators, GDB now supports lookup of operators
2219 defined in a namespace and imported with a `using' directive, operators
2220 defined in the global scope, operators imported implicitly from an
2221 anonymous namespace, and the ADL operators mentioned in the previous
2223 GDB now also supports proper overload resolution for all the previously
2224 mentioned flavors of operators.
2226 ** static const class members
2228 Printing of static const class members that are initialized in the
2229 class definition has been fixed.
2231 * Windows Thread Information Block access.
2233 On Windows targets, GDB now supports displaying the Windows Thread
2234 Information Block (TIB) structure. This structure is visible either
2235 by using the new command `info w32 thread-information-block' or, by
2236 dereferencing the new convenience variable named `$_tlb', a
2237 thread-specific pointer to the TIB. This feature is also supported
2238 when remote debugging using GDBserver.
2240 * Static tracepoints
2242 Static tracepoints are calls in the user program into a tracing
2243 library. One such library is a port of the LTTng kernel tracer to
2244 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2245 When debugging with GDBserver, GDB now supports combining the GDB
2246 tracepoint machinery with such libraries. For example: the user can
2247 use GDB to probe a static tracepoint marker (a call from the user
2248 program into the tracing library) with the new "strace" command (see
2249 "New commands" below). This creates a "static tracepoint" in the
2250 breakpoint list, that can be manipulated with the same feature set
2251 as fast and regular tracepoints. E.g., collect registers, local and
2252 global variables, collect trace state variables, and define
2253 tracepoint conditions. In addition, the user can collect extra
2254 static tracepoint marker specific data, by collecting the new
2255 $_sdata internal variable. When analyzing the trace buffer, you can
2256 inspect $_sdata like any other variable available to GDB. For more
2257 information, see the "Tracepoints" chapter in GDB user manual. New
2258 remote packets have been defined to support static tracepoints, see
2259 the "New remote packets" section below.
2261 * Better reconstruction of tracepoints after disconnected tracing
2263 GDB will attempt to download the original source form of tracepoint
2264 definitions when starting a trace run, and then will upload these
2265 upon reconnection to the target, resulting in a more accurate
2266 reconstruction of the tracepoints that are in use on the target.
2270 You can now exercise direct control over the ways that GDB can
2271 affect your program. For instance, you can disallow the setting of
2272 breakpoints, so that the program can run continuously (assuming
2273 non-stop mode). In addition, the "observer" variable is available
2274 to switch all of the different controls; in observer mode, GDB
2275 cannot affect the target's behavior at all, which is useful for
2276 tasks like diagnosing live systems in the field.
2278 * The new convenience variable $_thread holds the number of the
2281 * New remote packets
2285 Return the address of the Windows Thread Information Block of a given thread.
2289 In response to several of the tracepoint packets, the target may now
2290 also respond with a number of intermediate `qRelocInsn' request
2291 packets before the final result packet, to have GDB handle
2292 relocating an instruction to execute at a different address. This
2293 is particularly useful for stubs that support fast tracepoints. GDB
2294 reports support for this feature in the qSupported packet.
2298 List static tracepoint markers in the target program.
2302 List static tracepoint markers at a given address in the target
2305 qXfer:statictrace:read
2307 Read the static trace data collected (by a `collect $_sdata'
2308 tracepoint action). The remote stub reports support for this packet
2309 to gdb's qSupported query.
2313 Send the current settings of GDB's permission flags.
2317 Send part of the source (textual) form of a tracepoint definition,
2318 which includes location, conditional, and action list.
2320 * The source command now accepts a -s option to force searching for the
2321 script in the source search path even if the script name specifies
2324 * New features in the GDB remote stub, GDBserver
2326 - GDBserver now support tracepoints (including fast tracepoints, and
2327 static tracepoints). The feature is currently supported by the
2328 i386-linux and amd64-linux builds. See the "Tracepoints support
2329 in gdbserver" section in the manual for more information.
2331 GDBserver JIT compiles the tracepoint's conditional agent
2332 expression bytecode into native code whenever possible for low
2333 overhead dynamic tracepoints conditionals. For such tracepoints,
2334 an expression that examines program state is evaluated when the
2335 tracepoint is reached, in order to determine whether to capture
2336 trace data. If the condition is simple and false, processing the
2337 tracepoint finishes very quickly and no data is gathered.
2339 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2340 for static tracepoints support.
2342 - GDBserver now supports x86_64 Windows 64-bit debugging.
2344 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2345 it understands register description.
2347 * The --batch flag now disables pagination and queries.
2349 * X86 general purpose registers
2351 GDB now supports reading/writing byte, word and double-word x86
2352 general purpose registers directly. This means you can use, say,
2353 $ah or $ax to refer, respectively, to the byte register AH and
2354 16-bit word register AX that are actually portions of the 32-bit
2355 register EAX or 64-bit register RAX.
2357 * The `commands' command now accepts a range of breakpoints to modify.
2358 A plain `commands' following a command that creates multiple
2359 breakpoints affects all the breakpoints set by that command. This
2360 applies to breakpoints set by `rbreak', and also applies when a
2361 single `break' command creates multiple breakpoints (e.g.,
2362 breakpoints on overloaded c++ functions).
2364 * The `rbreak' command now accepts a filename specification as part of
2365 its argument, limiting the functions selected by the regex to those
2366 in the specified file.
2368 * Support for remote debugging Windows and SymbianOS shared libraries
2369 from Unix hosts has been improved. Non Windows GDB builds now can
2370 understand target reported file names that follow MS-DOS based file
2371 system semantics, such as file names that include drive letters and
2372 use the backslash character as directory separator. This makes it
2373 possible to transparently use the "set sysroot" and "set
2374 solib-search-path" on Unix hosts to point as host copies of the
2375 target's shared libraries. See the new command "set
2376 target-file-system-kind" described below, and the "Commands to
2377 specify files" section in the user manual for more information.
2381 eval template, expressions...
2382 Convert the values of one or more expressions under the control
2383 of the string template to a command line, and call it.
2385 set target-file-system-kind unix|dos-based|auto
2386 show target-file-system-kind
2387 Set or show the assumed file system kind for target reported file
2390 save breakpoints <filename>
2391 Save all current breakpoint definitions to a file suitable for use
2392 in a later debugging session. To read the saved breakpoint
2393 definitions, use the `source' command.
2395 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2398 info static-tracepoint-markers
2399 Display information about static tracepoint markers in the target.
2401 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2402 Define a static tracepoint by probing a marker at the given
2403 function, line, address, or marker ID.
2407 Enable and disable observer mode.
2409 set may-write-registers on|off
2410 set may-write-memory on|off
2411 set may-insert-breakpoints on|off
2412 set may-insert-tracepoints on|off
2413 set may-insert-fast-tracepoints on|off
2414 set may-interrupt on|off
2415 Set individual permissions for GDB effects on the target. Note that
2416 some of these settings can have undesirable or surprising
2417 consequences, particularly when changed in the middle of a session.
2418 For instance, disabling the writing of memory can prevent
2419 breakpoints from being inserted, cause single-stepping to fail, or
2420 even crash your program, if you disable after breakpoints have been
2421 inserted. However, GDB should not crash.
2423 set record memory-query on|off
2424 show record memory-query
2425 Control whether to stop the inferior if memory changes caused
2426 by an instruction cannot be recorded.
2431 The disassemble command now supports "start,+length" form of two arguments.
2435 ** GDB now provides a new directory location, called the python directory,
2436 where Python scripts written for GDB can be installed. The location
2437 of that directory is <data-directory>/python, where <data-directory>
2438 is the GDB data directory. For more details, see section `Scripting
2439 GDB using Python' in the manual.
2441 ** The GDB Python API now has access to breakpoints, symbols, symbol
2442 tables, program spaces, inferiors, threads and frame's code blocks.
2443 Additionally, GDB Parameters can now be created from the API, and
2444 manipulated via set/show in the CLI.
2446 ** New functions gdb.target_charset, gdb.target_wide_charset,
2447 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2449 ** New exception gdb.GdbError.
2451 ** Pretty-printers are now also looked up in the current program space.
2453 ** Pretty-printers can now be individually enabled and disabled.
2455 ** GDB now looks for names of Python scripts to auto-load in a
2456 special section named `.debug_gdb_scripts', in addition to looking
2457 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2459 * Tracepoint actions were unified with breakpoint commands. In particular,
2460 there are no longer differences in "info break" output for breakpoints and
2461 tracepoints and the "commands" command can be used for both tracepoints and
2462 regular breakpoints.
2466 ARM Symbian arm*-*-symbianelf*
2468 * D language support.
2469 GDB now supports debugging programs written in the D programming
2472 * GDB now supports the extended ptrace interface for PowerPC which is
2473 available since Linux kernel version 2.6.34. This automatically enables
2474 any hardware breakpoints and additional hardware watchpoints available in
2475 the processor. The old ptrace interface exposes just one hardware
2476 watchpoint and no hardware breakpoints.
2478 * GDB is now able to use the Data Value Compare (DVC) register available on
2479 embedded PowerPC processors to implement in hardware simple watchpoint
2480 conditions of the form:
2482 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2484 This works in native GDB running on Linux kernels with the extended ptrace
2485 interface mentioned above.
2487 *** Changes in GDB 7.1
2491 ** Namespace Support
2493 GDB now supports importing of namespaces in C++. This enables the
2494 user to inspect variables from imported namespaces. Support for
2495 namepace aliasing has also been added. So, if a namespace is
2496 aliased in the current scope (e.g. namepace C=A; ) the user can
2497 print variables using the alias (e.g. (gdb) print C::x).
2501 All known bugs relating to the printing of virtual base class were
2502 fixed. It is now possible to call overloaded static methods using a
2507 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2508 and reinterpret_cast<> are now handled by the C++ expression parser.
2512 Xilinx MicroBlaze microblaze-*-*
2517 Xilinx MicroBlaze microblaze
2520 * Multi-program debugging.
2522 GDB now has support for multi-program (a.k.a. multi-executable or
2523 multi-exec) debugging. This allows for debugging multiple inferiors
2524 simultaneously each running a different program under the same GDB
2525 session. See "Debugging Multiple Inferiors and Programs" in the
2526 manual for more information. This implied some user visible changes
2527 in the multi-inferior support. For example, "info inferiors" now
2528 lists inferiors that are not running yet or that have exited
2529 already. See also "New commands" and "New options" below.
2531 * New tracing features
2533 GDB's tracepoint facility now includes several new features:
2535 ** Trace state variables
2537 GDB tracepoints now include support for trace state variables, which
2538 are variables managed by the target agent during a tracing
2539 experiment. They are useful for tracepoints that trigger each
2540 other, so for instance one tracepoint can count hits in a variable,
2541 and then a second tracepoint has a condition that is true when the
2542 count reaches a particular value. Trace state variables share the
2543 $-syntax of GDB convenience variables, and can appear in both
2544 tracepoint actions and condition expressions. Use the "tvariable"
2545 command to create, and "info tvariables" to view; see "Trace State
2546 Variables" in the manual for more detail.
2550 GDB now includes an option for defining fast tracepoints, which
2551 targets may implement more efficiently, such as by installing a jump
2552 into the target agent rather than a trap instruction. The resulting
2553 speedup can be by two orders of magnitude or more, although the
2554 tradeoff is that some program locations on some target architectures
2555 might not allow fast tracepoint installation, for instance if the
2556 instruction to be replaced is shorter than the jump. To request a
2557 fast tracepoint, use the "ftrace" command, with syntax identical to
2558 the regular trace command.
2560 ** Disconnected tracing
2562 It is now possible to detach GDB from the target while it is running
2563 a trace experiment, then reconnect later to see how the experiment
2564 is going. In addition, a new variable disconnected-tracing lets you
2565 tell the target agent whether to continue running a trace if the
2566 connection is lost unexpectedly.
2570 GDB now has the ability to save the trace buffer into a file, and
2571 then use that file as a target, similarly to you can do with
2572 corefiles. You can select trace frames, print data that was
2573 collected in them, and use tstatus to display the state of the
2574 tracing run at the moment that it was saved. To create a trace
2575 file, use "tsave <filename>", and to use it, do "target tfile
2578 ** Circular trace buffer
2580 You can ask the target agent to handle the trace buffer as a
2581 circular buffer, discarding the oldest trace frames to make room for
2582 newer ones, by setting circular-trace-buffer to on. This feature may
2583 not be available for all target agents.
2588 The disassemble command, when invoked with two arguments, now requires
2589 the arguments to be comma-separated.
2592 The info variables command now displays variable definitions. Files
2593 which only declare a variable are not shown.
2596 The source command is now capable of sourcing Python scripts.
2597 This feature is dependent on the debugger being build with Python
2600 Related to this enhancement is also the introduction of a new command
2601 "set script-extension" (see below).
2603 * New commands (for set/show, see "New options" below)
2605 record save [<FILENAME>]
2606 Save a file (in core file format) containing the process record
2607 execution log for replay debugging at a later time.
2609 record restore <FILENAME>
2610 Restore the process record execution log that was saved at an
2611 earlier time, for replay debugging.
2613 add-inferior [-copies <N>] [-exec <FILENAME>]
2616 clone-inferior [-copies <N>] [ID]
2617 Make a new inferior ready to execute the same program another
2618 inferior has loaded.
2623 maint info program-spaces
2624 List the program spaces loaded into GDB.
2626 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2627 show remote interrupt-sequence
2628 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2629 as the sequence to the remote target in order to interrupt the execution.
2630 Ctrl-C is a default. Some system prefers BREAK which is high level of
2631 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2632 Magic SysRq g. It is BREAK signal and character 'g'.
2634 set remote interrupt-on-connect [on | off]
2635 show remote interrupt-on-connect
2636 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2637 remote target when gdb connects to it. This is needed when you debug
2640 set remotebreak [on | off]
2642 Deprecated. Use "set/show remote interrupt-sequence" instead.
2644 tvariable $NAME [ = EXP ]
2645 Create or modify a trace state variable.
2648 List trace state variables and their values.
2650 delete tvariable $NAME ...
2651 Delete one or more trace state variables.
2654 Evaluate the given expressions without collecting anything into the
2655 trace buffer. (Valid in tracepoint actions only.)
2657 ftrace FN / FILE:LINE / *ADDR
2658 Define a fast tracepoint at the given function, line, or address.
2660 * New expression syntax
2662 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2663 GDB now parses 0b101010 identically with 42.
2667 set follow-exec-mode new|same
2668 show follow-exec-mode
2669 Control whether GDB reuses the same inferior across an exec call or
2670 creates a new one. This is useful to be able to restart the old
2671 executable after the inferior having done an exec call.
2673 set default-collect EXPR, ...
2674 show default-collect
2675 Define a list of expressions to be collected at each tracepoint.
2676 This is a useful way to ensure essential items are not overlooked,
2677 such as registers or a critical global variable.
2679 set disconnected-tracing
2680 show disconnected-tracing
2681 If set to 1, the target is instructed to continue tracing if it
2682 loses its connection to GDB. If 0, the target is to stop tracing
2685 set circular-trace-buffer
2686 show circular-trace-buffer
2687 If set to on, the target is instructed to use a circular trace buffer
2688 and discard the oldest trace frames instead of stopping the trace due
2689 to a full trace buffer. If set to off, the trace stops when the buffer
2690 fills up. Some targets may not support this.
2692 set script-extension off|soft|strict
2693 show script-extension
2694 If set to "off", the debugger does not perform any script language
2695 recognition, and all sourced files are assumed to be GDB scripts.
2696 If set to "soft" (the default), files are sourced according to
2697 filename extension, falling back to GDB scripts if the first
2699 If set to "strict", files are sourced according to filename extension.
2701 set ada trust-PAD-over-XVS on|off
2702 show ada trust-PAD-over-XVS
2703 If off, activate a workaround against a bug in the debugging information
2704 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2705 the GCC sources for more information about the GNAT encoding and
2706 PAD types in particular). It is always safe to set this option to
2707 off, but this introduces a slight performance penalty. The default
2710 * Python API Improvements
2712 ** GDB provides the new class gdb.LazyString. This is useful in
2713 some pretty-printing cases. The new method gdb.Value.lazy_string
2714 provides a simple way to create objects of this type.
2716 ** The fields returned by gdb.Type.fields now have an
2717 `is_base_class' attribute.
2719 ** The new method gdb.Type.range returns the range of an array type.
2721 ** The new method gdb.parse_and_eval can be used to parse and
2722 evaluate an expression.
2724 * New remote packets
2727 Define a trace state variable.
2730 Get the current value of a trace state variable.
2733 Set desired tracing behavior upon disconnection.
2736 Set the trace buffer to be linear or circular.
2739 Get data about the tracepoints currently in use.
2743 Process record now works correctly with hardware watchpoints.
2745 Multiple bug fixes have been made to the mips-irix port, making it
2746 much more reliable. In particular:
2747 - Debugging threaded applications is now possible again. Previously,
2748 GDB would hang while starting the program, or while waiting for
2749 the program to stop at a breakpoint.
2750 - Attaching to a running process no longer hangs.
2751 - An error occurring while loading a core file has been fixed.
2752 - Changing the value of the PC register now works again. This fixes
2753 problems observed when using the "jump" command, or when calling
2754 a function from GDB, or even when assigning a new value to $pc.
2755 - With the "finish" and "return" commands, the return value for functions
2756 returning a small array is now correctly printed.
2757 - It is now possible to break on shared library code which gets executed
2758 during a shared library init phase (code executed while executing
2759 their .init section). Previously, the breakpoint would have no effect.
2760 - GDB is now able to backtrace through the signal handler for
2761 non-threaded programs.
2763 PIE (Position Independent Executable) programs debugging is now supported.
2764 This includes debugging execution of PIC (Position Independent Code) shared
2765 libraries although for that, it should be possible to run such libraries as an
2768 *** Changes in GDB 7.0
2770 * GDB now has an interface for JIT compilation. Applications that
2771 dynamically generate code can create symbol files in memory and register
2772 them with GDB. For users, the feature should work transparently, and
2773 for JIT developers, the interface is documented in the GDB manual in the
2774 "JIT Compilation Interface" chapter.
2776 * Tracepoints may now be conditional. The syntax is as for
2777 breakpoints; either an "if" clause appended to the "trace" command,
2778 or the "condition" command is available. GDB sends the condition to
2779 the target for evaluation using the same bytecode format as is used
2780 for tracepoint actions.
2782 * The disassemble command now supports: an optional /r modifier, print the
2783 raw instructions in hex as well as in symbolic form, and an optional /m
2784 modifier to print mixed source+assembly.
2786 * Process record and replay
2788 In a architecture environment that supports ``process record and
2789 replay'', ``process record and replay'' target can record a log of
2790 the process execution, and replay it with both forward and reverse
2793 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2794 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2795 set execution-direction {forward|reverse}, for targets that support
2798 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2799 feature is available with a native GDB running on kernel version
2802 * GDB now has support for multi-byte and wide character sets on the
2803 target. Strings whose character type is wchar_t, char16_t, or
2804 char32_t are now correctly printed. GDB supports wide- and unicode-
2805 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2806 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2807 `printf'. This feature requires iconv to work properly; if your
2808 system does not have a working iconv, GDB can use GNU libiconv. See
2809 the installation instructions for more information.
2811 * GDB now supports automatic retrieval of shared library files from
2812 remote targets. To use this feature, specify a system root that begins
2813 with the `remote:' prefix, either via the `set sysroot' command or via
2814 the `--with-sysroot' configure-time option.
2816 * "info sharedlibrary" now takes an optional regex of libraries to show,
2817 and it now reports if a shared library has no debugging information.
2819 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2820 now complete on file names.
2822 * When completing in expressions, gdb will attempt to limit
2823 completions to allowable structure or union fields, where appropriate.
2824 For instance, consider:
2826 # struct example { int f1; double f2; };
2827 # struct example variable;
2830 If the user types TAB at the end of this command line, the available
2831 completions will be "f1" and "f2".
2833 * Inlined functions are now supported. They show up in backtraces, and
2834 the "step", "next", and "finish" commands handle them automatically.
2836 * GDB now supports the token-splicing (##) and stringification (#)
2837 operators when expanding macros. It also supports variable-arity
2840 * GDB now supports inspecting extra signal information, exported by
2841 the new $_siginfo convenience variable. The feature is currently
2842 implemented on linux ARM, i386 and amd64.
2844 * GDB can now display the VFP floating point registers and NEON vector
2845 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2846 can provide these registers (requires Linux 2.6.30 or later). Remote
2847 and simulator targets may also provide them.
2849 * New remote packets
2852 Search memory for a sequence of bytes.
2855 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2856 operation over reliable transport links. Use of this packet is
2857 controlled by the `set remote noack-packet' command.
2860 Kill the process with the specified process ID. Use this in preference
2861 to `k' when multiprocess protocol extensions are supported.
2864 Obtains additional operating system information
2868 Read or write additional signal information.
2870 * Removed remote protocol undocumented extension
2872 An undocumented extension to the remote protocol's `S' stop reply
2873 packet that permited the stub to pass a process id was removed.
2874 Remote servers should use the `T' stop reply packet instead.
2876 * GDB now supports multiple function calling conventions according to the
2877 DWARF-2 DW_AT_calling_convention function attribute.
2879 * The SH target utilizes the aforementioned change to distinguish between gcc
2880 and Renesas calling convention. It also adds the new CLI commands
2881 `set/show sh calling-convention'.
2883 * GDB can now read compressed debug sections, as produced by GNU gold
2884 with the --compress-debug-sections=zlib flag.
2886 * 64-bit core files are now supported on AIX.
2888 * Thread switching is now supported on Tru64.
2890 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2891 which will be allocated using malloc later in program execution.
2893 * The qXfer:libraries:read remote procotol packet now allows passing a
2894 list of section offsets.
2896 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2897 conditions handling signals delivered during attach or thread creation
2898 have also been fixed.
2900 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2901 From the user's standpoint, all unqualified instances of True and False
2902 are treated as the standard definitions, regardless of context.
2904 * GDB now parses C++ symbol and type names more flexibly. For
2907 template<typename T> class C { };
2910 GDB will now correctly handle all of:
2912 ptype C<char const *>
2913 ptype C<char const*>
2914 ptype C<const char *>
2915 ptype C<const char*>
2917 * New features in the GDB remote stub, gdbserver
2919 - The "--wrapper" command-line argument tells gdbserver to use a
2920 wrapper program to launch programs for debugging.
2922 - On PowerPC and S/390 targets, it is now possible to use a single
2923 gdbserver executable to debug both 32-bit and 64-bit programs.
2924 (This requires gdbserver itself to be built as a 64-bit executable.)
2926 - gdbserver uses the new noack protocol mode for TCP connections to
2927 reduce communications latency, if also supported and enabled in GDB.
2929 - Support for the sparc64-linux-gnu target is now included in
2932 - The amd64-linux build of gdbserver now supports debugging both
2933 32-bit and 64-bit programs.
2935 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2936 now support hardware watchpoints, and will use them automatically
2941 GDB now has support for scripting using Python. Whether this is
2942 available is determined at configure time.
2944 New GDB commands can now be written in Python.
2946 * Ada tasking support
2948 Ada tasks can now be inspected in GDB. The following commands have
2952 Print the list of Ada tasks.
2954 Print detailed information about task number N.
2956 Print the task number of the current task.
2958 Switch the context of debugging to task number N.
2960 * Support for user-defined prefixed commands. The "define" command can
2961 add new commands to existing prefixes, e.g. "target".
2963 * Multi-inferior, multi-process debugging.
2965 GDB now has generalized support for multi-inferior debugging. See
2966 "Debugging Multiple Inferiors" in the manual for more information.
2967 Although availability still depends on target support, the command
2968 set is more uniform now. The GNU/Linux specific multi-forks support
2969 has been migrated to this new framework. This implied some user
2970 visible changes; see "New commands" and also "Removed commands"
2973 * Target descriptions can now describe the target OS ABI. See the
2974 "Target Description Format" section in the user manual for more
2977 * Target descriptions can now describe "compatible" architectures
2978 to indicate that the target can execute applications for a different
2979 architecture in addition to those for the main target architecture.
2980 See the "Target Description Format" section in the user manual for
2983 * Multi-architecture debugging.
2985 GDB now includes general supports for debugging applications on
2986 hybrid systems that use more than one single processor architecture
2987 at the same time. Each such hybrid architecture still requires
2988 specific support to be added. The only hybrid architecture supported
2989 in this version of GDB is the Cell Broadband Engine.
2991 * GDB now supports integrated debugging of Cell/B.E. applications that
2992 use both the PPU and SPU architectures. To enable support for hybrid
2993 Cell/B.E. debugging, you need to configure GDB to support both the
2994 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2995 --enable-targets configure option.
2997 * Non-stop mode debugging.
2999 For some targets, GDB now supports an optional mode of operation in
3000 which you can examine stopped threads while other threads continue
3001 to execute freely. This is referred to as non-stop mode, with the
3002 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3003 section in the user manual for more information.
3005 To be able to support remote non-stop debugging, a remote stub needs
3006 to implement the non-stop mode remote protocol extensions, as
3007 described in the "Remote Non-Stop" section of the user manual. The
3008 GDB remote stub, gdbserver, has been adjusted to support these
3009 extensions on linux targets.
3011 * New commands (for set/show, see "New options" below)
3013 catch syscall [NAME(S) | NUMBER(S)]
3014 Catch system calls. Arguments, which should be names of system
3015 calls or their numbers, mean catch only those syscalls. Without
3016 arguments, every syscall will be caught. When the inferior issues
3017 any of the specified syscalls, GDB will stop and announce the system
3018 call, both when it is called and when its call returns. This
3019 feature is currently available with a native GDB running on the
3020 Linux Kernel, under the following architectures: x86, x86_64,
3021 PowerPC and PowerPC64.
3023 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3025 Search memory for a sequence of bytes.
3027 maint set python print-stack
3028 maint show python print-stack
3029 Show a stack trace when an error is encountered in a Python script.
3032 Invoke CODE by passing it to the Python interpreter.
3037 These allow macros to be defined, undefined, and listed
3041 Show operating system information about processes.
3044 List the inferiors currently under GDB's control.
3047 Switch focus to inferior number NUM.
3050 Detach from inferior number NUM.
3053 Kill inferior number NUM.
3057 set spu stop-on-load
3058 show spu stop-on-load
3059 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3061 set spu auto-flush-cache
3062 show spu auto-flush-cache
3063 Control whether to automatically flush the software-managed cache
3064 during Cell/B.E. debugging.
3066 set sh calling-convention
3067 show sh calling-convention
3068 Control the calling convention used when calling SH target functions.
3071 show debug timestamp
3072 Control display of timestamps with GDB debugging output.
3074 set disassemble-next-line
3075 show disassemble-next-line
3076 Control display of disassembled source lines or instructions when
3079 set remote noack-packet
3080 show remote noack-packet
3081 Set/show the use of remote protocol QStartNoAckMode packet. See above
3082 under "New remote packets."
3084 set remote query-attached-packet
3085 show remote query-attached-packet
3086 Control use of remote protocol `qAttached' (query-attached) packet.
3088 set remote read-siginfo-object
3089 show remote read-siginfo-object
3090 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3093 set remote write-siginfo-object
3094 show remote write-siginfo-object
3095 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3098 set remote reverse-continue
3099 show remote reverse-continue
3100 Control use of remote protocol 'bc' (reverse-continue) packet.
3102 set remote reverse-step
3103 show remote reverse-step
3104 Control use of remote protocol 'bs' (reverse-step) packet.
3106 set displaced-stepping
3107 show displaced-stepping
3108 Control displaced stepping mode. Displaced stepping is a way to
3109 single-step over breakpoints without removing them from the debuggee.
3110 Also known as "out-of-line single-stepping".
3113 show debug displaced
3114 Control display of debugging info for displaced stepping.
3116 maint set internal-error
3117 maint show internal-error
3118 Control what GDB does when an internal error is detected.
3120 maint set internal-warning
3121 maint show internal-warning
3122 Control what GDB does when an internal warning is detected.
3127 Use a wrapper program to launch programs for debugging.
3129 set multiple-symbols (all|ask|cancel)
3130 show multiple-symbols
3131 The value of this variable can be changed to adjust the debugger behavior
3132 when an expression or a breakpoint location contains an ambiguous symbol
3133 name (an overloaded function name, for instance).
3135 set breakpoint always-inserted
3136 show breakpoint always-inserted
3137 Keep breakpoints always inserted in the target, as opposed to inserting
3138 them when resuming the target, and removing them when the target stops.
3139 This option can improve debugger performance on slow remote targets.
3141 set arm fallback-mode (arm|thumb|auto)
3142 show arm fallback-mode
3143 set arm force-mode (arm|thumb|auto)
3145 These commands control how ARM GDB determines whether instructions
3146 are ARM or Thumb. The default for both settings is auto, which uses
3147 the current CPSR value for instructions without symbols; previous
3148 versions of GDB behaved as if "set arm fallback-mode arm".
3150 set disable-randomization
3151 show disable-randomization
3152 Standalone programs run with the virtual address space randomization enabled
3153 by default on some platforms. This option keeps the addresses stable across
3154 multiple debugging sessions.
3158 Control whether other threads are stopped or not when some thread hits
3163 Requests that asynchronous execution is enabled in the target, if available.
3164 In this case, it's possible to resume target in the background, and interact
3165 with GDB while the target is running. "show target-async" displays the
3166 current state of asynchronous execution of the target.
3168 set target-wide-charset
3169 show target-wide-charset
3170 The target-wide-charset is the name of the character set that GDB
3171 uses when printing characters whose type is wchar_t.
3173 set tcp auto-retry (on|off)
3175 set tcp connect-timeout
3176 show tcp connect-timeout
3177 These commands allow GDB to retry failed TCP connections to a remote stub
3178 with a specified timeout period; this is useful if the stub is launched
3179 in parallel with GDB but may not be ready to accept connections immediately.
3181 set libthread-db-search-path
3182 show libthread-db-search-path
3183 Control list of directories which GDB will search for appropriate
3186 set schedule-multiple (on|off)
3187 show schedule-multiple
3188 Allow GDB to resume all threads of all processes or only threads of
3189 the current process.
3193 Use more aggressive caching for accesses to the stack. This improves
3194 performance of remote debugging (particularly backtraces) without
3195 affecting correctness.
3197 set interactive-mode (on|off|auto)
3198 show interactive-mode
3199 Control whether GDB runs in interactive mode (on) or not (off).
3200 When in interactive mode, GDB waits for the user to answer all
3201 queries. Otherwise, GDB does not wait and assumes the default
3202 answer. When set to auto (the default), GDB determines which
3203 mode to use based on the stdin settings.
3208 For program forks, this is replaced by the new more generic `info
3209 inferiors' command. To list checkpoints, you can still use the
3210 `info checkpoints' command, which was an alias for the `info forks'
3214 Replaced by the new `inferior' command. To switch between
3215 checkpoints, you can still use the `restart' command, which was an
3216 alias for the `fork' command.
3219 This is removed, since some targets don't have a notion of
3220 processes. To switch between processes, you can still use the
3221 `inferior' command using GDB's own inferior number.
3224 For program forks, this is replaced by the new more generic `kill
3225 inferior' command. To delete a checkpoint, you can still use the
3226 `delete checkpoint' command, which was an alias for the `delete
3230 For program forks, this is replaced by the new more generic `detach
3231 inferior' command. To detach a checkpoint, you can still use the
3232 `detach checkpoint' command, which was an alias for the `detach
3235 * New native configurations
3237 x86/x86_64 Darwin i[34567]86-*-darwin*
3239 x86_64 MinGW x86_64-*-mingw*
3243 Lattice Mico32 lm32-*
3244 x86 DICOS i[34567]86-*-dicos*
3245 x86_64 DICOS x86_64-*-dicos*
3248 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3249 (mingw32ce) debugging.
3255 These commands were actually not implemented on any target.
3257 *** Changes in GDB 6.8
3259 * New native configurations
3261 NetBSD/hppa hppa*-*netbsd*
3262 Xtensa GNU/Linux xtensa*-*-linux*
3266 NetBSD/hppa hppa*-*-netbsd*
3267 Xtensa GNU/Lunux xtensa*-*-linux*
3269 * Change in command line behavior -- corefiles vs. process ids.
3271 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3272 attaching to process NUMBER fails, GDB no longer attempts to open a
3273 core file named NUMBER. Attaching to a program using the -c option
3274 is no longer supported. Instead, use the '-p' or '--pid' options.
3276 * GDB can now be built as a native debugger for debugging Windows x86
3277 (mingw32) Portable Executable (PE) programs.
3279 * Pending breakpoints no longer change their number when their address
3282 * GDB now supports breakpoints with multiple locations,
3283 including breakpoints on C++ constructors, inside C++ templates,
3284 and in inlined functions.
3286 * GDB's ability to debug optimized code has been improved. GDB more
3287 accurately identifies function bodies and lexical blocks that occupy
3288 more than one contiguous range of addresses.
3290 * Target descriptions can now describe registers for PowerPC.
3292 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3293 registers on PowerPC targets.
3295 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3296 targets even when the libthread_db library is not available.
3298 * The GDB remote stub, gdbserver, now supports the new file transfer
3299 commands (remote put, remote get, and remote delete).
3301 * The GDB remote stub, gdbserver, now supports run and attach in
3302 extended-remote mode.
3304 * hppa*64*-*-hpux11* target broken
3305 The debugger is unable to start a program and fails with the following
3306 error: "Error trying to get information about dynamic linker".
3307 The gdb-6.7 release is also affected.
3309 * GDB now supports the --enable-targets= configure option to allow
3310 building a single GDB executable that supports multiple remote
3311 target architectures.
3313 * GDB now supports debugging C and C++ programs which use the
3314 Decimal Floating Point extension. In addition, the PowerPC target
3315 now has a set of pseudo-registers to inspect decimal float values
3316 stored in two consecutive float registers.
3318 * The -break-insert MI command can optionally create pending
3321 * Improved support for debugging Ada
3322 Many improvements to the Ada language support have been made. These
3324 - Better support for Ada2005 interface types
3325 - Improved handling of arrays and slices in general
3326 - Better support for Taft-amendment types
3327 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3329 - Improved command completion in Ada
3332 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3337 set print frame-arguments (all|scalars|none)
3338 show print frame-arguments
3339 The value of this variable can be changed to control which argument
3340 values should be printed by the debugger when displaying a frame.
3345 Transfer files to and from a remote target, and delete remote files.
3352 Transfer files to and from a remote target, and delete remote files.
3354 * New remote packets
3361 Open, close, read, write, and delete files on the remote system.
3364 Attach to an existing process on the remote system, in extended-remote
3368 Run a new process on the remote system, in extended-remote mode.
3370 *** Changes in GDB 6.7
3372 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3373 bfd, libiberty and opcodes, as revealed by static analysis donated by
3374 Coverity, Inc. (http://scan.coverity.com).
3376 * When looking up multiply-defined global symbols, GDB will now prefer the
3377 symbol definition in the current shared library if it was built using the
3378 -Bsymbolic linker option.
3380 * When the Text User Interface (TUI) is not configured, GDB will now
3381 recognize the -tui command-line option and print a message that the TUI
3384 * The GDB remote stub, gdbserver, now has lower overhead for high
3385 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3387 * GDB for MIPS targets now autodetects whether a remote target provides
3388 32-bit or 64-bit register values.
3390 * Support for C++ member pointers has been improved.
3392 * GDB now understands XML target descriptions, which specify the
3393 target's overall architecture. GDB can read a description from
3394 a local file or over the remote serial protocol.
3396 * Vectors of single-byte data use a new integer type which is not
3397 automatically displayed as character or string data.
3399 * The /s format now works with the print command. It displays
3400 arrays of single-byte integers and pointers to single-byte integers
3403 * Target descriptions can now describe target-specific registers,
3404 for architectures which have implemented the support (currently
3405 only ARM, M68K, and MIPS).
3407 * GDB and the GDB remote stub, gdbserver, now support the XScale
3410 * The GDB remote stub, gdbserver, has been updated to support
3411 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3412 has been rewritten to use the standard GDB remote protocol.
3414 * GDB can now step into C++ functions which are called through thunks.
3416 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3418 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3419 layout. It also supports a TextSeg= and DataSeg= response when only
3420 segment base addresses (rather than offsets) are available.
3422 * The /i format now outputs any trailing branch delay slot instructions
3423 immediately following the last instruction within the count specified.
3425 * The GDB remote protocol "T" stop reply packet now supports a
3426 "library" response. Combined with the new "qXfer:libraries:read"
3427 packet, this response allows GDB to debug shared libraries on targets
3428 where the operating system manages the list of loaded libraries (e.g.
3429 Windows and SymbianOS).
3431 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3432 (DLLs) on Windows and Windows CE targets.
3434 * GDB now supports a faster verification that a .debug file matches its binary
3435 according to its build-id signature, if the signature is present.
3441 Enable or disable hardware flow control (RTS/CTS) on the serial port
3442 when debugging using remote targets.
3444 set mem inaccessible-by-default
3445 show mem inaccessible-by-default
3446 If the target supplies a memory map, for instance via the remote
3447 protocol's "qXfer:memory-map:read" packet, setting this variable
3448 prevents GDB from accessing memory outside the memory map. This
3449 is useful for targets with memory mapped registers or which react
3450 badly to accesses of unmapped address space.
3452 set breakpoint auto-hw
3453 show breakpoint auto-hw
3454 If the target supplies a memory map, for instance via the remote
3455 protocol's "qXfer:memory-map:read" packet, setting this variable
3456 lets GDB use hardware breakpoints automatically for memory regions
3457 where it can not use software breakpoints. This covers both the
3458 "break" command and internal breakpoints used for other commands
3459 including "next" and "finish".
3462 catch exception unhandled
3463 Stop the program execution when Ada exceptions are raised.
3466 Stop the program execution when an Ada assertion failed.
3470 Set an alternate system root for target files. This is a more
3471 general version of "set solib-absolute-prefix", which is now
3472 an alias to "set sysroot".
3475 Provide extended SPU facility status information. This set of
3476 commands is available only when debugging the Cell/B.E. SPU
3479 * New native configurations
3481 OpenBSD/sh sh*-*openbsd*
3484 unset tdesc filename
3486 Use the specified local file as an XML target description, and do
3487 not query the target for its built-in description.
3491 OpenBSD/sh sh*-*-openbsd*
3492 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3493 Toshiba Media Processor mep-elf
3495 * New remote packets
3498 Ignore the specified signals; pass them directly to the debugged program
3499 without stopping other threads or reporting them to GDB.
3501 qXfer:features:read:
3502 Read an XML target description from the target, which describes its
3507 Read or write contents of an spufs file on the target system. These
3508 packets are available only on the Cell/B.E. SPU architecture.
3510 qXfer:libraries:read:
3511 Report the loaded shared libraries. Combined with new "T" packet
3512 response, this packet allows GDB to debug shared libraries on
3513 targets where the operating system manages the list of loaded
3514 libraries (e.g. Windows and SymbianOS).
3518 Support for these obsolete configurations has been removed.
3526 i[34567]86-*-lynxos*
3527 i[34567]86-*-netware*
3528 i[34567]86-*-sco3.2v5*
3529 i[34567]86-*-sco3.2v4*
3531 i[34567]86-*-sysv4.2*
3534 i[34567]86-*-unixware2*
3535 i[34567]86-*-unixware*
3544 * Other removed features
3551 Various m68k-only ROM monitors.
3558 Various Renesas ROM monitors and debugging interfaces for SH and
3563 Support for a Macraigor serial interface to on-chip debugging.
3564 GDB does not directly support the newer parallel or USB
3569 A debug information format. The predecessor to DWARF 2 and
3570 DWARF 3, which are still supported.
3572 Support for the HP aCC compiler on HP-UX/PA-RISC
3574 SOM-encapsulated symbolic debugging information, automatic
3575 invocation of pxdb, and the aCC custom C++ ABI. This does not
3576 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3577 with aCC can still be debugged on an assembly level.
3579 MIPS ".pdr" sections
3581 A MIPS-specific format used to describe stack frame layout
3582 in debugging information.
3586 GDB could work with an older version of Guile to debug
3587 the interpreter and Scheme programs running in it.
3589 set mips stack-arg-size
3590 set mips saved-gpreg-size
3592 Use "set mips abi" to control parameter passing for MIPS.
3594 *** Changes in GDB 6.6
3599 Cell Broadband Engine SPU spu-elf
3601 * GDB can now be configured as a cross-debugger targeting native Windows
3602 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3603 running on a Windows system over TCP/IP to debug Windows programs.
3605 * The GDB remote stub, gdbserver, has been updated to support Windows and
3606 Cygwin debugging. Both single-threaded and multi-threaded programs are
3609 * The "set trust-readonly-sections" command works again. This command was
3610 broken in GDB 6.3, 6.4, and 6.5.
3612 * The "load" command now supports writing to flash memory, if the remote
3613 stub provides the required support.
3615 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3616 longer requires symbolic debug information (e.g. DWARF-2).
3621 unset substitute-path
3622 show substitute-path
3623 Manage a list of substitution rules that GDB uses to rewrite the name
3624 of the directories where the sources are located. This can be useful
3625 for instance when the sources were moved to a different location
3626 between compilation and debugging.
3630 Print each CLI command as it is executed. Each command is prefixed with
3631 a number of `+' symbols representing the nesting depth.
3632 The source command now has a `-v' option to enable the same feature.
3636 The ARM Demon monitor support (RDP protocol, "target rdp").
3638 Kernel Object Display, an embedded debugging feature which only worked with
3639 an obsolete version of Cisco IOS.
3641 The 'set download-write-size' and 'show download-write-size' commands.
3643 * New remote packets
3646 Tell a stub about GDB client features, and request remote target features.
3647 The first feature implemented is PacketSize, which allows the target to
3648 specify the size of packets it can handle - to minimize the number of
3649 packets required and improve performance when connected to a remote
3653 Fetch an OS auxilliary vector from the remote stub. This packet is a
3654 more efficient replacement for qPart:auxv:read.
3656 qXfer:memory-map:read:
3657 Fetch a memory map from the remote stub, including information about
3658 RAM, ROM, and flash memory devices.
3663 Erase and program a flash memory device.
3665 * Removed remote packets
3668 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3669 used it, and only gdbserver implemented it.
3671 *** Changes in GDB 6.5
3675 Renesas M32C/M16C m32c-elf
3677 Morpho Technologies ms1 ms1-elf
3681 init-if-undefined Initialize a convenience variable, but
3682 only if it doesn't already have a value.
3684 The following commands are presently only implemented for native GNU/Linux:
3686 checkpoint Save a snapshot of the program state.
3688 restart <n> Return the program state to a
3689 previously saved state.
3691 info checkpoints List currently saved checkpoints.
3693 delete-checkpoint <n> Delete a previously saved checkpoint.
3695 set|show detach-on-fork Tell gdb whether to detach from a newly
3696 forked process, or to keep debugging it.
3698 info forks List forks of the user program that
3699 are available to be debugged.
3701 fork <n> Switch to debugging one of several
3702 forks of the user program that are
3703 available to be debugged.
3705 delete-fork <n> Delete a fork from the list of forks
3706 that are available to be debugged (and
3707 kill the forked process).
3709 detach-fork <n> Delete a fork from the list of forks
3710 that are available to be debugged (and
3711 allow the process to continue).
3715 Morpho Technologies ms2 ms1-elf
3717 * Improved Windows host support
3719 GDB now builds as a cross debugger hosted on i686-mingw32, including
3720 native console support, and remote communications using either
3721 network sockets or serial ports.
3723 * Improved Modula-2 language support
3725 GDB can now print most types in the Modula-2 syntax. This includes:
3726 basic types, set types, record types, enumerated types, range types,
3727 pointer types and ARRAY types. Procedure var parameters are correctly
3728 printed and hexadecimal addresses and character constants are also
3729 written in the Modula-2 syntax. Best results can be obtained by using
3730 GNU Modula-2 together with the -gdwarf-2 command line option.
3734 The ARM rdi-share module.
3736 The Netware NLM debug server.
3738 *** Changes in GDB 6.4
3740 * New native configurations
3742 OpenBSD/arm arm*-*-openbsd*
3743 OpenBSD/mips64 mips64-*-openbsd*
3747 Morpho Technologies ms1 ms1-elf
3749 * New command line options
3751 --batch-silent As for --batch, but totally silent.
3752 --return-child-result The debugger will exist with the same value
3753 the child (debugged) program exited with.
3754 --eval-command COMMAND, -ex COMMAND
3755 Execute a single GDB CLI command. This may be
3756 specified multiple times and in conjunction
3757 with the --command (-x) option.
3759 * Deprecated commands removed
3761 The following commands, that were deprecated in 2000, have been
3765 set|show arm disassembly-flavor set|show arm disassembler
3766 othernames set arm disassembler
3767 set|show remotedebug set|show debug remote
3768 set|show archdebug set|show debug arch
3769 set|show eventdebug set|show debug event
3772 * New BSD user-level threads support
3774 It is now possible to debug programs using the user-level threads
3775 library on OpenBSD and FreeBSD. Currently supported (target)
3778 FreeBSD/amd64 x86_64-*-freebsd*
3779 FreeBSD/i386 i386-*-freebsd*
3780 OpenBSD/i386 i386-*-openbsd*
3782 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3783 are not yet supported.
3785 * New support for Matsushita MN10300 w/sim added
3786 (Work in progress). mn10300-elf.
3788 * REMOVED configurations and files
3790 VxWorks and the XDR protocol *-*-vxworks
3791 Motorola MCORE mcore-*-*
3792 National Semiconductor NS32000 ns32k-*-*
3794 * New "set print array-indexes" command
3796 After turning this setting "on", GDB prints the index of each element
3797 when displaying arrays. The default is "off" to preserve the previous
3800 * VAX floating point support
3802 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3804 * User-defined command support
3806 In addition to using $arg0..$arg9 for argument passing, it is now possible
3807 to use $argc to determine now many arguments have been passed. See the
3808 section on user-defined commands in the user manual for more information.
3810 *** Changes in GDB 6.3:
3812 * New command line option
3814 GDB now accepts -l followed by a number to set the timeout for remote
3817 * GDB works with GCC -feliminate-dwarf2-dups
3819 GDB now supports a more compact representation of DWARF-2 debug
3820 information using DW_FORM_ref_addr references. These are produced
3821 by GCC with the option -feliminate-dwarf2-dups and also by some
3822 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3823 to use -feliminate-dwarf2-dups.
3825 * Internationalization
3827 When supported by the host system, GDB will be built with
3828 internationalization (libintl). The task of marking up the sources is
3829 continued, we're looking forward to our first translation.
3833 Initial support for debugging programs compiled with the GNAT
3834 implementation of the Ada programming language has been integrated
3835 into GDB. In this release, support is limited to expression evaluation.
3837 * New native configurations
3839 GNU/Linux/m32r m32r-*-linux-gnu
3843 GDB's remote protocol now includes support for the 'p' packet. This
3844 packet is used to fetch individual registers from a remote inferior.
3846 * END-OF-LIFE registers[] compatibility module
3848 GDB's internal register infrastructure has been completely rewritten.
3849 The new infrastructure making possible the implementation of key new
3850 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3853 GDB 6.3 will be the last release to include the the registers[]
3854 compatibility module that allowed out-of-date configurations to
3855 continue to work. This change directly impacts the following
3865 powerpc bdm protocol
3867 Unless there is activity to revive these configurations, they will be
3868 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3870 * OBSOLETE configurations and files
3872 Configurations that have been declared obsolete in this release have
3873 been commented out. Unless there is activity to revive these
3874 configurations, the next release of GDB will have their sources
3875 permanently REMOVED.
3884 *** Changes in GDB 6.2.1:
3886 * MIPS `break main; run' gave an heuristic-fence-post warning
3888 When attempting to run even a simple program, a warning about
3889 heuristic-fence-post being hit would be reported. This problem has
3892 * MIPS IRIX 'long double' crashed GDB
3894 When examining a long double variable, GDB would get a segmentation
3895 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3896 IRIX long double values).
3900 A bug in the VAX stack code was causing problems with the "next"
3901 command. This problem has been fixed.
3903 *** Changes in GDB 6.2:
3905 * Fix for ``many threads''
3907 On GNU/Linux systems that use the NPTL threads library, a program
3908 rapidly creating and deleting threads would confuse GDB leading to the
3911 ptrace: No such process.
3912 thread_db_get_info: cannot get thread info: generic error
3914 This problem has been fixed.
3916 * "-async" and "-noasync" options removed.
3918 Support for the broken "-noasync" option has been removed (it caused
3921 * New ``start'' command.
3923 This command runs the program until the begining of the main procedure.
3925 * New BSD Kernel Data Access Library (libkvm) interface
3927 Using ``target kvm'' it is now possible to debug kernel core dumps and
3928 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3929 platforms. Currently supported (native-only) configurations are:
3931 FreeBSD/amd64 x86_64-*-freebsd*
3932 FreeBSD/i386 i?86-*-freebsd*
3933 NetBSD/i386 i?86-*-netbsd*
3934 NetBSD/m68k m68*-*-netbsd*
3935 NetBSD/sparc sparc-*-netbsd*
3936 OpenBSD/amd64 x86_64-*-openbsd*
3937 OpenBSD/i386 i?86-*-openbsd*
3938 OpenBSD/m68k m68*-openbsd*
3939 OpenBSD/sparc sparc-*-openbsd*
3941 * Signal trampoline code overhauled
3943 Many generic problems with GDB's signal handling code have been fixed.
3944 These include: backtraces through non-contiguous stacks; recognition
3945 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3946 call; backtrace through a signal trampoline; step into and out of
3947 signal handlers; and single-stepping in the signal trampoline.
3949 Please note that kernel bugs are a limiting factor here. These
3950 features have been shown to work on an s390 GNU/Linux system that
3951 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3953 * Cygwin support for DWARF 2 added.
3955 * New native configurations
3957 GNU/Linux/hppa hppa*-*-linux*
3958 OpenBSD/hppa hppa*-*-openbsd*
3959 OpenBSD/m68k m68*-*-openbsd*
3960 OpenBSD/m88k m88*-*-openbsd*
3961 OpenBSD/powerpc powerpc-*-openbsd*
3962 NetBSD/vax vax-*-netbsd*
3963 OpenBSD/vax vax-*-openbsd*
3965 * END-OF-LIFE frame compatibility module
3967 GDB's internal frame infrastructure has been completely rewritten.
3968 The new infrastructure making it possible to support key new features
3969 including DWARF 2 Call Frame Information. To aid in the task of
3970 migrating old configurations to this new infrastructure, a
3971 compatibility module, that allowed old configurations to continue to
3972 work, was also included.
3974 GDB 6.2 will be the last release to include this frame compatibility
3975 module. This change directly impacts the following configurations:
3985 Unless there is activity to revive these configurations, they will be
3986 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3988 * REMOVED configurations and files
3990 Sun 3, running SunOS 3 m68*-*-sunos3*
3991 Sun 3, running SunOS 4 m68*-*-sunos4*
3992 Sun 2, running SunOS 3 m68000-*-sunos3*
3993 Sun 2, running SunOS 4 m68000-*-sunos4*
3994 Motorola 680x0 running LynxOS m68*-*-lynxos*
3995 AT&T 3b1/Unix pc m68*-att-*
3996 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3997 decstation mips-dec-* mips-little-*
3998 riscos mips-*-riscos* mips-*-sysv*
3999 sonymips mips-sony-*
4000 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4002 *** Changes in GDB 6.1.1:
4004 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4006 The TUI (Text-mode User Interface) is now built as part of a default
4007 GDB configuration. It is enabled by either selecting the TUI with the
4008 command line option "-i=tui" or by running the separate "gdbtui"
4009 program. For more information on the TUI, see the manual "Debugging
4012 * Pending breakpoint support (also included in GDB 6.1)
4014 Support has been added to allow you to specify breakpoints in shared
4015 libraries that have not yet been loaded. If a breakpoint location
4016 cannot be found, and the "breakpoint pending" option is set to auto,
4017 GDB queries you if you wish to make the breakpoint pending on a future
4018 shared-library load. If and when GDB resolves the breakpoint symbol,
4019 the pending breakpoint is removed as one or more regular breakpoints
4022 Pending breakpoints are very useful for GCJ Java debugging.
4024 * Fixed ISO-C build problems
4026 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4027 non ISO-C code that stopped them being built using a more strict ISO-C
4028 compiler (e.g., IBM's C compiler).
4030 * Fixed build problem on IRIX 5
4032 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4033 wasn't able to compile compile on an IRIX 5 system.
4035 * Added execute permission to gdb/gdbserver/configure
4037 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4038 permission. This bug would cause configure to fail on a number of
4039 systems (Solaris, IRIX). Ref: server/519.
4041 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4043 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4044 has been updated to use constant array sizes.
4046 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4048 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4049 its generated DWARF Call Frame Info. This encoding was causing GDB to
4050 panic, that panic has been fixed. Ref: gdb/1628.
4052 * Fixed a problem when examining parameters in shared library code.
4054 When examining parameters in optimized shared library code generated
4055 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4056 not available''. GDB now correctly displays the variable's value.
4058 *** Changes in GDB 6.1:
4060 * Removed --with-mmalloc
4062 Support for the mmalloc memory manager has been removed, as it
4063 conflicted with the internal gdb byte cache.
4065 * Changes in AMD64 configurations
4067 The AMD64 target now includes the %cs and %ss registers. As a result
4068 the AMD64 remote protocol has changed; this affects the floating-point
4069 and SSE registers. If you rely on those registers for your debugging,
4070 you should upgrade gdbserver on the remote side.
4072 * Revised SPARC target
4074 The SPARC target has been completely revised, incorporating the
4075 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4076 support for LynxOS and SunOS 4 has been dropped. Calling functions
4077 from within GDB on operating systems with a non-executable stack
4078 (Solaris, OpenBSD) now works.
4082 GDB has a new C++ demangler which does a better job on the mangled
4083 names generated by current versions of g++. It also runs faster, so
4084 with this and other changes gdb should now start faster on large C++
4087 * DWARF 2 Location Expressions
4089 GDB support for location expressions has been extended to support function
4090 arguments and frame bases. Older versions of GDB could crash when they
4093 * C++ nested types and namespaces
4095 GDB's support for nested types and namespaces in C++ has been
4096 improved, especially if you use the DWARF 2 debugging format. (This
4097 is the default for recent versions of GCC on most platforms.)
4098 Specifically, if you have a class "Inner" defined within a class or
4099 namespace "Outer", then GDB realizes that the class's name is
4100 "Outer::Inner", not simply "Inner". This should greatly reduce the
4101 frequency of complaints about not finding RTTI symbols. In addition,
4102 if you are stopped at inside of a function defined within a namespace,
4103 GDB modifies its name lookup accordingly.
4105 * New native configurations
4107 NetBSD/amd64 x86_64-*-netbsd*
4108 OpenBSD/amd64 x86_64-*-openbsd*
4109 OpenBSD/alpha alpha*-*-openbsd*
4110 OpenBSD/sparc sparc-*-openbsd*
4111 OpenBSD/sparc64 sparc64-*-openbsd*
4113 * New debugging protocols
4115 M32R with SDI protocol m32r-*-elf*
4117 * "set prompt-escape-char" command deleted.
4119 The command "set prompt-escape-char" has been deleted. This command,
4120 and its very obscure effet on GDB's prompt, was never documented,
4121 tested, nor mentioned in the NEWS file.
4123 * OBSOLETE configurations and files
4125 Configurations that have been declared obsolete in this release have
4126 been commented out. Unless there is activity to revive these
4127 configurations, the next release of GDB will have their sources
4128 permanently REMOVED.
4130 Sun 3, running SunOS 3 m68*-*-sunos3*
4131 Sun 3, running SunOS 4 m68*-*-sunos4*
4132 Sun 2, running SunOS 3 m68000-*-sunos3*
4133 Sun 2, running SunOS 4 m68000-*-sunos4*
4134 Motorola 680x0 running LynxOS m68*-*-lynxos*
4135 AT&T 3b1/Unix pc m68*-att-*
4136 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4137 decstation mips-dec-* mips-little-*
4138 riscos mips-*-riscos* mips-*-sysv*
4139 sonymips mips-sony-*
4140 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4142 * REMOVED configurations and files
4144 SGI Irix-4.x mips-sgi-irix4 or iris4
4145 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4146 Z8000 simulator z8k-zilog-none or z8ksim
4147 Matsushita MN10200 w/simulator mn10200-*-*
4148 H8/500 simulator h8500-hitachi-hms or h8500hms
4149 HP/PA running BSD hppa*-*-bsd*
4150 HP/PA running OSF/1 hppa*-*-osf*
4151 HP/PA Pro target hppa*-*-pro*
4152 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4153 386BSD i[3456]86-*-bsd*
4154 Sequent family i[3456]86-sequent-sysv4*
4155 i[3456]86-sequent-sysv*
4156 i[3456]86-sequent-bsd*
4157 SPARC running LynxOS sparc-*-lynxos*
4158 SPARC running SunOS 4 sparc-*-sunos4*
4159 Tsqware Sparclet sparclet-*-*
4160 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4162 *** Changes in GDB 6.0:
4166 Support for debugging the Objective-C programming language has been
4167 integrated into GDB.
4169 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4171 DWARF 2's Call Frame Information makes available compiler generated
4172 information that more exactly describes the program's run-time stack.
4173 By using this information, GDB is able to provide more robust stack
4176 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4177 have been updated to use a new backtrace mechanism which includes
4178 DWARF 2 CFI support.
4182 GDB's remote protocol has been extended to include support for hosted
4183 file I/O (where the remote target uses GDB's file system). See GDB's
4184 remote protocol documentation for details.
4186 * All targets using the new architecture framework.
4188 All of GDB's targets have been updated to use the new internal
4189 architecture framework. The way is now open for future GDB releases
4190 to include cross-architecture native debugging support (i386 on amd64,
4193 * GNU/Linux's Thread Local Storage (TLS)
4195 GDB now includes support for for the GNU/Linux implementation of
4196 per-thread variables.
4198 * GNU/Linux's Native POSIX Thread Library (NPTL)
4200 GDB's thread code has been updated to work with either the new
4201 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4203 * Separate debug info.
4205 GDB, in conjunction with BINUTILS, now supports a mechanism for
4206 automatically loading debug information from a separate file. Instead
4207 of shipping full debug and non-debug versions of system libraries,
4208 system integrators can now instead ship just the stripped libraries
4209 and optional debug files.
4211 * DWARF 2 Location Expressions
4213 DWARF 2 Location Expressions allow the compiler to more completely
4214 describe the location of variables (even in optimized code) to the
4217 GDB now includes preliminary support for location expressions (support
4218 for DW_OP_piece is still missing).
4222 A number of long standing bugs that caused GDB to die while starting a
4223 Java application have been fixed. GDB's Java support is now
4224 considered "useable".
4226 * GNU/Linux support for fork, vfork, and exec.
4228 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4229 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4232 * GDB supports logging output to a file
4234 There are two new commands, "set logging" and "show logging", which can be
4235 used to capture GDB's output to a file.
4237 * The meaning of "detach" has changed for gdbserver
4239 The "detach" command will now resume the application, as documented. To
4240 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4243 * d10v, m68hc11 `regs' command deprecated
4245 The `info registers' command has been updated so that it displays the
4246 registers using a format identical to the old `regs' command.
4250 A new command, "maint set profile on/off", has been added. This command can
4251 be used to enable or disable profiling while running GDB, to profile a
4252 session or a set of commands. In addition there is a new configure switch,
4253 "--enable-profiling", which will cause GDB to be compiled with profiling
4254 data, for more informative profiling results.
4256 * Default MI syntax changed to "mi2".
4258 The default MI (machine interface) syntax, enabled by the command line
4259 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4260 "mi1", can be enabled by specifying the option "-i=mi1".
4262 Support for the original "mi0" syntax (included in GDB 5.0) has been
4265 Fix for gdb/192: removed extraneous space when displaying frame level.
4266 Fix for gdb/672: update changelist is now output in mi list format.
4267 Fix for gdb/702: a -var-assign that updates the value now shows up
4268 in a subsequent -var-update.
4270 * New native configurations.
4272 FreeBSD/amd64 x86_64-*-freebsd*
4274 * Multi-arched targets.
4276 HP/PA HPUX11 hppa*-*-hpux*
4277 Renesas M32R/D w/simulator m32r-*-elf*
4279 * OBSOLETE configurations and files
4281 Configurations that have been declared obsolete in this release have
4282 been commented out. Unless there is activity to revive these
4283 configurations, the next release of GDB will have their sources
4284 permanently REMOVED.
4286 Z8000 simulator z8k-zilog-none or z8ksim
4287 Matsushita MN10200 w/simulator mn10200-*-*
4288 H8/500 simulator h8500-hitachi-hms or h8500hms
4289 HP/PA running BSD hppa*-*-bsd*
4290 HP/PA running OSF/1 hppa*-*-osf*
4291 HP/PA Pro target hppa*-*-pro*
4292 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4293 Sequent family i[3456]86-sequent-sysv4*
4294 i[3456]86-sequent-sysv*
4295 i[3456]86-sequent-bsd*
4296 Tsqware Sparclet sparclet-*-*
4297 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4299 * REMOVED configurations and files
4302 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4303 IBM AIX PS/2 i[3456]86-*-aix
4304 i386 running Mach 3.0 i[3456]86-*-mach3*
4305 i386 running Mach i[3456]86-*-mach*
4306 i386 running OSF/1 i[3456]86-*osf1mk*
4307 HP/Apollo 68k Family m68*-apollo*-sysv*,
4309 m68*-hp-bsd*, m68*-hp-hpux*
4310 Argonaut Risc Chip (ARC) arc-*-*
4311 Mitsubishi D30V d30v-*-*
4312 Fujitsu FR30 fr30-*-elf*
4313 OS/9000 i[34]86-*-os9k
4314 I960 with MON960 i960-*-coff
4316 * MIPS $fp behavior changed
4318 The convenience variable $fp, for the MIPS, now consistently returns
4319 the address of the current frame's base. Previously, depending on the
4320 context, $fp could refer to either $sp or the current frame's base
4321 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4322 The GNU Source-Level Debugger''.
4324 *** Changes in GDB 5.3:
4326 * GNU/Linux shared library multi-threaded performance improved.
4328 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4329 `/proc', in preference to `ptrace' for memory reads. This may result
4330 in an improvement in the start-up time of multi-threaded, shared
4331 library applications when run under GDB. One GDB user writes: ``loads
4332 shared libs like mad''.
4334 * ``gdbserver'' now supports multi-threaded applications on some targets
4336 Support for debugging multi-threaded applications which use
4337 the GNU/Linux LinuxThreads package has been added for
4338 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4339 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4341 * GDB now supports C/C++ preprocessor macros.
4343 GDB now expands preprocessor macro invocations in C/C++ expressions,
4344 and provides various commands for showing macro definitions and how
4347 The new command `macro expand EXPRESSION' expands any macro
4348 invocations in expression, and shows the result.
4350 The new command `show macro MACRO-NAME' shows the definition of the
4351 macro named MACRO-NAME, and where it was defined.
4353 Most compilers don't include information about macros in the debugging
4354 information by default. In GCC 3.1, for example, you need to compile
4355 your program with the options `-gdwarf-2 -g3'. If the macro
4356 information is present in the executable, GDB will read it.
4358 * Multi-arched targets.
4360 DEC Alpha (partial) alpha*-*-*
4361 DEC VAX (partial) vax-*-*
4363 National Semiconductor NS32000 (partial) ns32k-*-*
4364 Motorola 68000 (partial) m68k-*-*
4365 Motorola MCORE mcore-*-*
4369 Fujitsu FRV architecture added by Red Hat frv*-*-*
4372 * New native configurations
4374 Alpha NetBSD alpha*-*-netbsd*
4375 SH NetBSD sh*-*-netbsdelf*
4376 MIPS NetBSD mips*-*-netbsd*
4377 UltraSPARC NetBSD sparc64-*-netbsd*
4379 * OBSOLETE configurations and files
4381 Configurations that have been declared obsolete in this release have
4382 been commented out. Unless there is activity to revive these
4383 configurations, the next release of GDB will have their sources
4384 permanently REMOVED.
4386 Mitsubishi D30V d30v-*-*
4387 OS/9000 i[34]86-*-os9k
4388 IBM AIX PS/2 i[3456]86-*-aix
4389 Fujitsu FR30 fr30-*-elf*
4390 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4391 Argonaut Risc Chip (ARC) arc-*-*
4392 i386 running Mach 3.0 i[3456]86-*-mach3*
4393 i386 running Mach i[3456]86-*-mach*
4394 i386 running OSF/1 i[3456]86-*osf1mk*
4395 HP/Apollo 68k Family m68*-apollo*-sysv*,
4397 m68*-hp-bsd*, m68*-hp-hpux*
4398 I960 with MON960 i960-*-coff
4400 * OBSOLETE languages
4402 CHILL, a Pascal like language used by telecommunications companies.
4404 * REMOVED configurations and files
4406 AMD 29k family via UDI a29k-amd-udi, udi29k
4407 A29K VxWorks a29k-*-vxworks
4408 AMD 29000 embedded, using EBMON a29k-none-none
4409 AMD 29000 embedded with COFF a29k-none-coff
4410 AMD 29000 embedded with a.out a29k-none-aout
4412 testsuite/gdb.hp/gdb.threads-hp/ directory
4414 * New command "set max-user-call-depth <nnn>"
4416 This command allows the user to limit the call depth of user-defined
4417 commands. The default is 1024.
4419 * Changes in FreeBSD/i386 native debugging.
4421 Support for the "generate-core-file" has been added.
4423 * New commands "dump", "append", and "restore".
4425 These commands allow data to be copied from target memory
4426 to a bfd-format or binary file (dump and append), and back
4427 from a file into memory (restore).
4429 * Improved "next/step" support on multi-processor Alpha Tru64.
4431 The previous single-step mechanism could cause unpredictable problems,
4432 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4433 of a software single-step mechanism prevents this.
4435 *** Changes in GDB 5.2.1:
4443 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4444 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4445 Fix, by Joel Brobecker imported from mainline.
4447 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4448 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4449 Fix, by Fred Fish, imported from mainline.
4451 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4452 Surprisingly enough, it works now.
4453 By Michal Ludvig, imported from mainline.
4455 i386 hardware watchpoint support:
4456 avoid misses on second run for some targets.
4457 By Pierre Muller, imported from mainline.
4459 *** Changes in GDB 5.2:
4461 * New command "set trust-readonly-sections on[off]".
4463 This command is a hint that tells gdb that read-only sections
4464 really are read-only (ie. that their contents will not change).
4465 In this mode, gdb will go to the object file rather than the
4466 target to read memory from read-only sections (such as ".text").
4467 This can be a significant performance improvement on some
4468 (notably embedded) targets.
4470 * New command "generate-core-file" (or "gcore").
4472 This new gdb command allows the user to drop a core file of the child
4473 process state at any time. So far it's been implemented only for
4474 GNU/Linux and Solaris, but should be relatively easily ported to other
4475 hosts. Argument is core file name (defaults to core.<pid>).
4477 * New command line option
4479 GDB now accepts --pid or -p followed by a process id.
4481 * Change in command line behavior -- corefiles vs. process ids.
4483 There is a subtle behavior in the way in which GDB handles
4484 command line arguments. The first non-flag argument is always
4485 a program to debug, but the second non-flag argument may either
4486 be a corefile or a process id. Previously, GDB would attempt to
4487 open the second argument as a corefile, and if that failed, would
4488 issue a superfluous error message and then attempt to attach it as
4489 a process. Now, if the second argument begins with a non-digit,
4490 it will be treated as a corefile. If it begins with a digit,
4491 GDB will attempt to attach it as a process, and if no such process
4492 is found, will then attempt to open it as a corefile.
4494 * Changes in ARM configurations.
4496 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4497 configuration is fully multi-arch.
4499 * New native configurations
4501 ARM NetBSD arm*-*-netbsd*
4502 x86 OpenBSD i[3456]86-*-openbsd*
4503 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4504 Sparc64 running FreeBSD sparc64-*-freebsd*
4508 Sanyo XStormy16 xstormy16-elf
4510 * OBSOLETE configurations and files
4512 Configurations that have been declared obsolete in this release have
4513 been commented out. Unless there is activity to revive these
4514 configurations, the next release of GDB will have their sources
4515 permanently REMOVED.
4517 AMD 29k family via UDI a29k-amd-udi, udi29k
4518 A29K VxWorks a29k-*-vxworks
4519 AMD 29000 embedded, using EBMON a29k-none-none
4520 AMD 29000 embedded with COFF a29k-none-coff
4521 AMD 29000 embedded with a.out a29k-none-aout
4523 testsuite/gdb.hp/gdb.threads-hp/ directory
4525 * REMOVED configurations and files
4527 TI TMS320C80 tic80-*-*
4529 PowerPC Solaris powerpcle-*-solaris*
4530 PowerPC Windows NT powerpcle-*-cygwin32
4531 PowerPC Netware powerpc-*-netware*
4532 Harris/CXUX m88k m88*-harris-cxux*
4533 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4534 ns32k-utek-sysv* ns32k-utek-*
4535 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4536 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4537 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4538 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4539 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4541 * Changes to command line processing
4543 The new `--args' feature can be used to specify command-line arguments
4544 for the inferior from gdb's command line.
4546 * Changes to key bindings
4548 There is a new `operate-and-get-next' function bound to `C-o'.
4550 *** Changes in GDB 5.1.1
4552 Fix compile problem on DJGPP.
4554 Fix a problem with floating-point registers on the i386 being
4557 Fix to stop GDB crashing on .debug_str debug info.
4559 Numerous documentation fixes.
4561 Numerous testsuite fixes.
4563 *** Changes in GDB 5.1:
4565 * New native configurations
4567 Alpha FreeBSD alpha*-*-freebsd*
4568 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4569 MIPS GNU/Linux mips*-*-linux*
4570 MIPS SGI Irix 6.x mips*-sgi-irix6*
4571 ia64 AIX ia64-*-aix*
4572 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4576 Motorola 68HC11 and 68HC12 m68hc11-elf
4578 UltraSparc running GNU/Linux sparc64-*-linux*
4580 * OBSOLETE configurations and files
4582 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4583 Harris/CXUX m88k m88*-harris-cxux*
4584 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4585 ns32k-utek-sysv* ns32k-utek-*
4586 TI TMS320C80 tic80-*-*
4588 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4589 PowerPC Solaris powerpcle-*-solaris*
4590 PowerPC Windows NT powerpcle-*-cygwin32
4591 PowerPC Netware powerpc-*-netware*
4592 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4593 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4594 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4595 Apple Macintosh (MPW) host N/A
4597 stuff.c (Program to stuff files into a specially prepared space in kdb)
4598 kdb-start.c (Main loop for the standalone kernel debugger)
4600 Configurations that have been declared obsolete in this release have
4601 been commented out. Unless there is activity to revive these
4602 configurations, the next release of GDB will have their sources
4603 permanently REMOVED.
4605 * REMOVED configurations and files
4607 Altos 3068 m68*-altos-*
4608 Convex c1-*-*, c2-*-*
4610 ARM RISCix arm-*-* (as host)
4614 * GDB has been converted to ISO C.
4616 GDB's source code has been converted to ISO C. In particular, the
4617 sources are fully protoized, and rely on standard headers being
4622 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4624 * The MI enabled by default.
4626 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4627 revised and enabled by default. Packages which use GDB as a debugging
4628 engine behind a UI or another front end are encouraged to switch to
4629 using the GDB/MI interface, instead of the old annotations interface
4630 which is now deprecated.
4632 * Support for debugging Pascal programs.
4634 GDB now includes support for debugging Pascal programs. The following
4635 main features are supported:
4637 - Pascal-specific data types such as sets;
4639 - automatic recognition of Pascal sources based on file-name
4642 - Pascal-style display of data types, variables, and functions;
4644 - a Pascal expression parser.
4646 However, some important features are not yet supported.
4648 - Pascal string operations are not supported at all;
4650 - there are some problems with boolean types;
4652 - Pascal type hexadecimal constants are not supported
4653 because they conflict with the internal variables format;
4655 - support for Pascal objects and classes is not full yet;
4657 - unlike Pascal, GDB is case-sensitive for symbol names.
4659 * Changes in completion.
4661 Commands such as `shell', `run' and `set args', which pass arguments
4662 to inferior programs, now complete on file names, similar to what
4663 users expect at the shell prompt.
4665 Commands which accept locations, such as `disassemble', `print',
4666 `breakpoint', `until', etc. now complete on filenames as well as
4667 program symbols. Thus, if you type "break foob TAB", and the source
4668 files linked into the programs include `foobar.c', that file name will
4669 be one of the candidates for completion. However, file names are not
4670 considered for completion after you typed a colon that delimits a file
4671 name from a name of a function in that file, as in "break foo.c:bar".
4673 `set demangle-style' completes on available demangling styles.
4675 * New platform-independent commands:
4677 It is now possible to define a post-hook for a command as well as a
4678 hook that runs before the command. For more details, see the
4679 documentation of `hookpost' in the GDB manual.
4681 * Changes in GNU/Linux native debugging.
4683 Support for debugging multi-threaded programs has been completely
4684 revised for all platforms except m68k and sparc. You can now debug as
4685 many threads as your system allows you to have.
4687 Attach/detach is supported for multi-threaded programs.
4689 Support for SSE registers was added for x86. This doesn't work for
4690 multi-threaded programs though.
4692 * Changes in MIPS configurations.
4694 Multi-arch support is enabled for all MIPS configurations.
4696 GDB can now be built as native debugger on SGI Irix 6.x systems for
4697 debugging n32 executables. (Debugging 64-bit executables is not yet
4700 * Unified support for hardware watchpoints in all x86 configurations.
4702 Most (if not all) native x86 configurations support hardware-assisted
4703 breakpoints and watchpoints in a unified manner. This support
4704 implements debug register sharing between watchpoints, which allows to
4705 put a virtually infinite number of watchpoints on the same address,
4706 and also supports watching regions up to 16 bytes with several debug
4709 The new maintenance command `maintenance show-debug-regs' toggles
4710 debugging print-outs in functions that insert, remove, and test
4711 watchpoints and hardware breakpoints.
4713 * Changes in the DJGPP native configuration.
4715 New command ``info dos sysinfo'' displays assorted information about
4716 the CPU, OS, memory, and DPMI server.
4718 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4719 display information about segment descriptors stored in GDT, LDT, and
4722 New commands ``info dos pde'' and ``info dos pte'' display entries
4723 from Page Directory and Page Tables (for now works with CWSDPMI only).
4724 New command ``info dos address-pte'' displays the Page Table entry for
4725 a given linear address.
4727 GDB can now pass command lines longer than 126 characters to the
4728 program being debugged (requires an update to the libdbg.a library
4729 which is part of the DJGPP development kit).
4731 DWARF2 debug info is now supported.
4733 It is now possible to `step' and `next' through calls to `longjmp'.
4735 * Changes in documentation.
4737 All GDB documentation was converted to GFDL, the GNU Free
4738 Documentation License.
4740 Tracepoints-related commands are now fully documented in the GDB
4743 TUI, the Text-mode User Interface, is now documented in the manual.
4745 Tracepoints-related commands are now fully documented in the GDB
4748 The "GDB Internals" manual now has an index. It also includes
4749 documentation of `ui_out' functions, GDB coding standards, x86
4750 hardware watchpoints, and memory region attributes.
4752 * GDB's version number moved to ``version.in''
4754 The Makefile variable VERSION has been replaced by the file
4755 ``version.in''. People creating GDB distributions should update the
4756 contents of this file.
4760 GUD support is now a standard part of the EMACS distribution.
4762 *** Changes in GDB 5.0:
4764 * Improved support for debugging FP programs on x86 targets
4766 Unified and much-improved support for debugging floating-point
4767 programs on all x86 targets. In particular, ``info float'' now
4768 displays the FP registers in the same format on all x86 targets, with
4769 greater level of detail.
4771 * Improvements and bugfixes in hardware-assisted watchpoints
4773 It is now possible to watch array elements, struct members, and
4774 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4775 on x86 targets no longer erroneously trigger when the address is
4778 * Improvements in the native DJGPP version of GDB
4780 The distribution now includes all the scripts and auxiliary files
4781 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4782 machines ``out of the box''.
4784 The DJGPP version can now debug programs that use signals. It is
4785 possible to catch signals that happened in the debuggee, deliver
4786 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4787 would kill the program being debugged.) Programs that hook hardware
4788 interrupts (keyboard, timer, etc.) can also be debugged.
4790 It is now possible to debug DJGPP programs that redirect their
4791 standard handles or switch them to raw (as opposed to cooked) mode, or
4792 even close them. The command ``run < foo > bar'' works as expected,
4793 and ``info terminal'' reports useful information about the debuggee's
4794 terminal, including raw/cooked mode, redirection, etc.
4796 The DJGPP version now uses termios functions for console I/O, which
4797 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4800 DOS-style file names with drive letters are now fully supported by
4803 It is now possible to debug DJGPP programs that switch their working
4804 directory. It is also possible to rerun the debuggee any number of
4805 times without restarting GDB; thus, you can use the same setup,
4806 breakpoints, etc. for many debugging sessions.
4808 * New native configurations
4810 ARM GNU/Linux arm*-*-linux*
4811 PowerPC GNU/Linux powerpc-*-linux*
4815 Motorola MCore mcore-*-*
4816 x86 VxWorks i[3456]86-*-vxworks*
4817 PowerPC VxWorks powerpc-*-vxworks*
4818 TI TMS320C80 tic80-*-*
4820 * OBSOLETE configurations
4822 Altos 3068 m68*-altos-*
4823 Convex c1-*-*, c2-*-*
4825 ARM RISCix arm-*-* (as host)
4828 Configurations that have been declared obsolete will be commented out,
4829 but the code will be left in place. If there is no activity to revive
4830 these configurations before the next release of GDB, the sources will
4831 be permanently REMOVED.
4833 * Gould support removed
4835 Support for the Gould PowerNode and NP1 has been removed.
4837 * New features for SVR4
4839 On SVR4 native platforms (such as Solaris), if you attach to a process
4840 without first loading a symbol file, GDB will now attempt to locate and
4841 load symbols from the running process's executable file.
4843 * Many C++ enhancements
4845 C++ support has been greatly improved. Overload resolution now works properly
4846 in almost all cases. RTTI support is on the way.
4848 * Remote targets can connect to a sub-program
4850 A popen(3) style serial-device has been added. This device starts a
4851 sub-process (such as a stand-alone simulator) and then communicates
4852 with that. The sub-program to run is specified using the syntax
4853 ``|<program> <args>'' vis:
4855 (gdb) set remotedebug 1
4856 (gdb) target extended-remote |mn10300-elf-sim program-args
4858 * MIPS 64 remote protocol
4860 A long standing bug in the mips64 remote protocol where by GDB
4861 expected certain 32 bit registers (ex SR) to be transfered as 32
4862 instead of 64 bits has been fixed.
4864 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4865 added to provide backward compatibility with older versions of GDB.
4867 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4869 The command ``set remotebinarydownload'' command has been replaced by
4870 ``set remote X-packet''. Other commands in ``set remote'' family
4871 include ``set remote P-packet''.
4873 * Breakpoint commands accept ranges.
4875 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4876 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4877 ``tracepoint passcount'' also accepts a range of tracepoints.
4879 * ``apropos'' command added.
4881 The ``apropos'' command searches through command names and
4882 documentation strings, printing out matches, making it much easier to
4883 try to find a command that does what you are looking for.
4887 A new machine oriented interface (MI) has been added to GDB. This
4888 interface is designed for debug environments running GDB as a separate
4889 process. This is part of the long term libGDB project. See the
4890 "GDB/MI" chapter of the GDB manual for further information. It can be
4891 enabled by configuring with:
4893 .../configure --enable-gdbmi
4895 *** Changes in GDB-4.18:
4897 * New native configurations
4899 HP-UX 10.20 hppa*-*-hpux10.20
4900 HP-UX 11.x hppa*-*-hpux11.0*
4901 M68K GNU/Linux m68*-*-linux*
4905 Fujitsu FR30 fr30-*-elf*
4906 Intel StrongARM strongarm-*-*
4907 Mitsubishi D30V d30v-*-*
4909 * OBSOLETE configurations
4911 Gould PowerNode, NP1 np1-*-*, pn-*-*
4913 Configurations that have been declared obsolete will be commented out,
4914 but the code will be left in place. If there is no activity to revive
4915 these configurations before the next release of GDB, the sources will
4916 be permanently REMOVED.
4920 As a compatibility experiment, GDB's source files buildsym.h and
4921 buildsym.c have been converted to pure standard C, no longer
4922 containing any K&R compatibility code. We believe that all systems in
4923 use today either come with a standard C compiler, or have a GCC port
4924 available. If this is not true, please report the affected
4925 configuration to bug-gdb@gnu.org immediately. See the README file for
4926 information about getting a standard C compiler if you don't have one
4931 GDB now uses readline 2.2.
4933 * set extension-language
4935 You can now control the mapping between filename extensions and source
4936 languages by using the `set extension-language' command. For instance,
4937 you can ask GDB to treat .c files as C++ by saying
4938 set extension-language .c c++
4939 The command `info extensions' lists all of the recognized extensions
4940 and their associated languages.
4942 * Setting processor type for PowerPC and RS/6000
4944 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4945 you can use the `set processor' command to specify what variant of the
4946 PowerPC family you are debugging. The command
4950 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4951 following PowerPC and RS6000 variants:
4953 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4954 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4956 403GC IBM PowerPC 403GC
4957 505 Motorola PowerPC 505
4958 860 Motorola PowerPC 860 or 850
4959 601 Motorola PowerPC 601
4960 602 Motorola PowerPC 602
4961 603 Motorola/IBM PowerPC 603 or 603e
4962 604 Motorola PowerPC 604 or 604e
4963 750 Motorola/IBM PowerPC 750 or 750
4965 At the moment, this command just tells GDB what to name the
4966 special-purpose processor registers. Since almost all the affected
4967 registers are inaccessible to user-level programs, this command is
4968 only useful for remote debugging in its present form.
4972 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4973 more extensive support for HP-UX. Added features include shared
4974 library support, kernel threads and hardware watchpoints for 11.00,
4975 support for HP's ANSI C and C++ compilers, and a compatibility mode
4976 for xdb and dbx commands.
4980 HP's donation includes the new concept of catchpoints, which is a
4981 generalization of the old catch command. On HP-UX, it is now possible
4982 to catch exec, fork, and vfork, as well as library loading.
4984 This means that the existing catch command has changed; its first
4985 argument now specifies the type of catch to be set up. See the
4986 output of "help catch" for a list of catchpoint types.
4988 * Debugging across forks
4990 On HP-UX, you can choose which process to debug when a fork() happens
4995 HP has donated a curses-based terminal user interface (TUI). To get
4996 it, build with --enable-tui. Although this can be enabled for any
4997 configuration, at present it only works for native HP debugging.
4999 * GDB remote protocol additions
5001 A new protocol packet 'X' that writes binary data is now available.
5002 Default behavior is to try 'X', then drop back to 'M' if the stub
5003 fails to respond. The settable variable `remotebinarydownload'
5004 allows explicit control over the use of 'X'.
5006 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5007 full 64-bit address. The command
5009 set remoteaddresssize 32
5011 can be used to revert to the old behaviour. For existing remote stubs
5012 the change should not be noticed, as the additional address information
5015 In order to assist in debugging stubs, you may use the maintenance
5016 command `packet' to send any text string to the stub. For instance,
5018 maint packet heythere
5020 sends the packet "$heythere#<checksum>". Note that it is very easy to
5021 disrupt a debugging session by sending the wrong packet at the wrong
5024 The compare-sections command allows you to compare section data on the
5025 target to what is in the executable file without uploading or
5026 downloading, by comparing CRC checksums.
5028 * Tracing can collect general expressions
5030 You may now collect general expressions at tracepoints. This requires
5031 further additions to the target-side stub; see tracepoint.c and
5032 doc/agentexpr.texi for further details.
5034 * mask-address variable for Mips
5036 For Mips targets, you may control the zeroing of the upper 32 bits of
5037 a 64-bit address by entering `set mask-address on'. This is mainly
5038 of interest to users of embedded R4xxx and R5xxx processors.
5040 * Higher serial baud rates
5042 GDB's serial code now allows you to specify baud rates 57600, 115200,
5043 230400, and 460800 baud. (Note that your host system may not be able
5044 to achieve all of these rates.)
5048 The i960 configuration now includes an initial implementation of a
5049 builtin simulator, contributed by Jim Wilson.
5052 *** Changes in GDB-4.17:
5054 * New native configurations
5056 Alpha GNU/Linux alpha*-*-linux*
5057 Unixware 2.x i[3456]86-unixware2*
5058 Irix 6.x mips*-sgi-irix6*
5059 PowerPC GNU/Linux powerpc-*-linux*
5060 PowerPC Solaris powerpcle-*-solaris*
5061 Sparc GNU/Linux sparc-*-linux*
5062 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5066 Argonaut Risc Chip (ARC) arc-*-*
5067 Hitachi H8/300S h8300*-*-*
5068 Matsushita MN10200 w/simulator mn10200-*-*
5069 Matsushita MN10300 w/simulator mn10300-*-*
5070 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5071 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5072 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5073 Mitsubishi D10V w/simulator d10v-*-*
5074 Mitsubishi M32R/D w/simulator m32r-*-elf*
5075 Tsqware Sparclet sparclet-*-*
5076 NEC V850 w/simulator v850-*-*
5078 * New debugging protocols
5080 ARM with RDI protocol arm*-*-*
5081 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5082 DDB and LSI variants of PMON protocol mips*-*-*
5083 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5084 PowerPC with SDS protocol powerpc{,le}-*-eabi
5085 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5089 All configurations can now understand and use the DWARF 2 debugging
5090 format. The choice is automatic, if the symbol file contains DWARF 2
5095 GDB now includes basic Java language support. This support is
5096 only useful with Java compilers that produce native machine code.
5098 * solib-absolute-prefix and solib-search-path
5100 For SunOS and SVR4 shared libraries, you may now set the prefix for
5101 loading absolute shared library symbol files, and the search path for
5102 locating non-absolute shared library symbol files.
5104 * Live range splitting
5106 GDB can now effectively debug code for which GCC has performed live
5107 range splitting as part of its optimization. See gdb/doc/LRS for
5108 more details on the expected format of the stabs information.
5112 GDB's support for the GNU Hurd, including thread debugging, has been
5113 updated to work with current versions of the Hurd.
5117 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5118 instruction set. ARM GDB automatically detects when Thumb
5119 instructions are in use, and adjusts disassembly and backtracing
5124 GDB's MIPS target configurations now handle the MIP16 16-bit
5129 GDB now includes support for overlays; if an executable has been
5130 linked such that multiple sections are based at the same address, GDB
5131 will decide which section to use for symbolic info. You can choose to
5132 control the decision manually, using overlay commands, or implement
5133 additional target-side support and use "overlay load-target" to bring
5134 in the overlay mapping. Do "help overlay" for more detail.
5138 The command "info symbol <address>" displays information about
5139 the symbol at the specified address.
5143 The standard remote protocol now includes an extension that allows
5144 asynchronous collection and display of trace data. This requires
5145 extensive support in the target-side debugging stub. Tracing mode
5146 includes a new interaction mode in GDB and new commands: see the
5147 file tracepoint.c for more details.
5151 Configurations for embedded MIPS now include a simulator contributed
5152 by Cygnus Solutions. The simulator supports the instruction sets
5153 of most MIPS variants.
5157 Sparc configurations may now include the ERC32 simulator contributed
5158 by the European Space Agency. The simulator is not built into
5159 Sparc targets by default; configure with --enable-sim to include it.
5163 For target configurations that may include multiple variants of a
5164 basic architecture (such as MIPS and SH), you may now set the
5165 architecture explicitly. "set arch" sets, "info arch" lists
5166 the possible architectures.
5168 *** Changes in GDB-4.16:
5170 * New native configurations
5172 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5173 M68K NetBSD m68k-*-netbsd*
5174 PowerPC AIX 4.x powerpc-*-aix*
5175 PowerPC MacOS powerpc-*-macos*
5176 PowerPC Windows NT powerpcle-*-cygwin32
5177 RS/6000 AIX 4.x rs6000-*-aix4*
5181 ARM with RDP protocol arm-*-*
5182 I960 with MON960 i960-*-coff
5183 MIPS VxWorks mips*-*-vxworks*
5184 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5185 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5187 Matra Sparclet sparclet-*-*
5191 The powerpc-eabi configuration now includes the PSIM simulator,
5192 contributed by Andrew Cagney, with assistance from Mike Meissner.
5193 PSIM is a very elaborate model of the PowerPC, including not only
5194 basic instruction set execution, but also details of execution unit
5195 performance and I/O hardware. See sim/ppc/README for more details.
5199 GDB now works with Solaris 2.5.
5201 * Windows 95/NT native
5203 GDB will now work as a native debugger on Windows 95 and Windows NT.
5204 To build it from source, you must use the "gnu-win32" environment,
5205 which uses a DLL to emulate enough of Unix to run the GNU tools.
5206 Further information, binaries, and sources are available at
5207 ftp.cygnus.com, under pub/gnu-win32.
5209 * dont-repeat command
5211 If a user-defined command includes the command `dont-repeat', then the
5212 command will not be repeated if the user just types return. This is
5213 useful if the command is time-consuming to run, so that accidental
5214 extra keystrokes don't run the same command many times.
5216 * Send break instead of ^C
5218 The standard remote protocol now includes an option to send a break
5219 rather than a ^C to the target in order to interrupt it. By default,
5220 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5222 * Remote protocol timeout
5224 The standard remote protocol includes a new variable `remotetimeout'
5225 that allows you to set the number of seconds before GDB gives up trying
5226 to read from the target. The default value is 2.
5228 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5230 By default GDB will automatically keep track of objects as they are
5231 loaded and unloaded by the dynamic linker. By using the command `set
5232 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5233 when shared library events occur, thus allowing you to set breakpoints
5234 in shared libraries which are explicitly loaded by the inferior.
5236 Note this feature does not work on hpux8. On hpux9 you must link
5237 /usr/lib/end.o into your program. This feature should work
5238 automatically on hpux10.
5240 * Irix 5.x hardware watchpoint support
5242 Irix 5 configurations now support the use of hardware watchpoints.
5244 * Mips protocol "SYN garbage limit"
5246 When debugging a Mips target using the `target mips' protocol, you
5247 may set the number of characters that GDB will ignore by setting
5248 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5249 every character. The default value is 1050.
5251 * Recording and replaying remote debug sessions
5253 If you set `remotelogfile' to the name of a file, gdb will write to it
5254 a recording of a remote debug session. This recording may then be
5255 replayed back to gdb using "gdbreplay". See gdbserver/README for
5256 details. This is useful when you have a problem with GDB while doing
5257 remote debugging; you can make a recording of the session and send it
5258 to someone else, who can then recreate the problem.
5260 * Speedups for remote debugging
5262 GDB includes speedups for downloading and stepping MIPS systems using
5263 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5264 and more efficient S-record downloading.
5266 * Memory use reductions and statistics collection
5268 GDB now uses less memory and reports statistics about memory usage.
5269 Try the `maint print statistics' command, for example.
5271 *** Changes in GDB-4.15:
5273 * Psymtabs for XCOFF
5275 The symbol reader for AIX GDB now uses partial symbol tables. This
5276 can greatly improve startup time, especially for large executables.
5278 * Remote targets use caching
5280 Remote targets now use a data cache to speed up communication with the
5281 remote side. The data cache could lead to incorrect results because
5282 it doesn't know about volatile variables, thus making it impossible to
5283 debug targets which use memory mapped I/O devices. `set remotecache
5284 off' turns the the data cache off.
5286 * Remote targets may have threads
5288 The standard remote protocol now includes support for multiple threads
5289 in the target system, using new protocol commands 'H' and 'T'. See
5290 gdb/remote.c for details.
5294 If GDB is configured with `--enable-netrom', then it will include
5295 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5296 acts as though it is a bank of ROM on the target board, but you can
5297 write into it over the network. GDB's support consists only of
5298 support for fast loading into the emulated ROM; to debug, you must use
5299 another protocol, such as standard remote protocol. The usual
5300 sequence is something like
5302 target nrom <netrom-hostname>
5304 target remote <netrom-hostname>:1235
5308 GDB now includes support for the Apple Macintosh, as a host only. It
5309 may be run as either an MPW tool or as a standalone application, and
5310 it can debug through the serial port. All the usual GDB commands are
5311 available, but to the target command, you must supply "serial" as the
5312 device type instead of "/dev/ttyXX". See mpw-README in the main
5313 directory for more information on how to build. The MPW configuration
5314 scripts */mpw-config.in support only a few targets, and only the
5315 mips-idt-ecoff target has been tested.
5319 GDB configuration now uses autoconf. This is not user-visible,
5320 but does simplify configuration and building.
5324 GDB now supports hpux10.
5326 *** Changes in GDB-4.14:
5328 * New native configurations
5330 x86 FreeBSD i[345]86-*-freebsd
5331 x86 NetBSD i[345]86-*-netbsd
5332 NS32k NetBSD ns32k-*-netbsd
5333 Sparc NetBSD sparc-*-netbsd
5337 A29K VxWorks a29k-*-vxworks
5338 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5339 CPU32 EST-300 emulator m68*-*-est*
5340 PowerPC ELF powerpc-*-elf
5343 * Alpha OSF/1 support for procfs
5345 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5346 possible to attach to running processes. As the mounting of the /proc
5347 filesystem is optional on the Alpha, GDB automatically determines
5348 the availability of /proc during startup. This can lead to problems
5349 if /proc is unmounted after GDB has been started.
5351 * Arguments to user-defined commands
5353 User commands may accept up to 10 arguments separated by whitespace.
5354 Arguments are accessed within the user command via $arg0..$arg9. A
5357 print $arg0 + $arg1 + $arg2
5359 To execute the command use:
5362 Defines the command "adder" which prints the sum of its three arguments.
5363 Note the arguments are text substitutions, so they may reference variables,
5364 use complex expressions, or even perform inferior function calls.
5366 * New `if' and `while' commands
5368 This makes it possible to write more sophisticated user-defined
5369 commands. Both commands take a single argument, which is the
5370 expression to evaluate, and must be followed by the commands to
5371 execute, one per line, if the expression is nonzero, the list being
5372 terminated by the word `end'. The `if' command list may include an
5373 `else' word, which causes the following commands to be executed only
5374 if the expression is zero.
5376 * Fortran source language mode
5378 GDB now includes partial support for Fortran 77. It will recognize
5379 Fortran programs and can evaluate a subset of Fortran expressions, but
5380 variables and functions may not be handled correctly. GDB will work
5381 with G77, but does not yet know much about symbols emitted by other
5384 * Better HPUX support
5386 Most debugging facilities now work on dynamic executables for HPPAs
5387 running hpux9 or later. You can attach to running dynamically linked
5388 processes, but by default the dynamic libraries will be read-only, so
5389 for instance you won't be able to put breakpoints in them. To change
5390 that behavior do the following before running the program:
5396 This will cause the libraries to be mapped private and read-write.
5397 To revert to the normal behavior, do this:
5403 You cannot set breakpoints or examine data in the library until after
5404 the library is loaded if the function/data symbols do not have
5407 GDB can now also read debug symbols produced by the HP C compiler on
5408 HPPAs (sorry, no C++, Fortran or 68k support).
5410 * Target byte order now dynamically selectable
5412 You can choose which byte order to use with a target system, via the
5413 commands "set endian big" and "set endian little", and you can see the
5414 current setting by using "show endian". You can also give the command
5415 "set endian auto", in which case GDB will use the byte order
5416 associated with the executable. Currently, only embedded MIPS
5417 configurations support dynamic selection of target byte order.
5419 * New DOS host serial code
5421 This version uses DPMI interrupts to handle buffered I/O, so you
5422 no longer need to run asynctsr when debugging boards connected to
5425 *** Changes in GDB-4.13:
5427 * New "complete" command
5429 This lists all the possible completions for the rest of the line, if it
5430 were to be given as a command itself. This is intended for use by emacs.
5432 * Trailing space optional in prompt
5434 "set prompt" no longer adds a space for you after the prompt you set. This
5435 allows you to set a prompt which ends in a space or one that does not.
5437 * Breakpoint hit counts
5439 "info break" now displays a count of the number of times the breakpoint
5440 has been hit. This is especially useful in conjunction with "ignore"; you
5441 can ignore a large number of breakpoint hits, look at the breakpoint info
5442 to see how many times the breakpoint was hit, then run again, ignoring one
5443 less than that number, and this will get you quickly to the last hit of
5446 * Ability to stop printing at NULL character
5448 "set print null-stop" will cause GDB to stop printing the characters of
5449 an array when the first NULL is encountered. This is useful when large
5450 arrays actually contain only short strings.
5452 * Shared library breakpoints
5454 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5455 breakpoints in shared libraries before the executable is run.
5457 * Hardware watchpoints
5459 There is a new hardware breakpoint for the watch command for sparclite
5460 targets. See gdb/sparclite/hw_breakpoint.note.
5462 Hardware watchpoints are also now supported under GNU/Linux.
5466 Annotations have been added. These are for use with graphical interfaces,
5467 and are still experimental. Currently only gdba.el uses these.
5469 * Improved Irix 5 support
5471 GDB now works properly with Irix 5.2.
5473 * Improved HPPA support
5475 GDB now works properly with the latest GCC and GAS.
5477 * New native configurations
5479 Sequent PTX4 i[34]86-sequent-ptx4
5480 HPPA running OSF/1 hppa*-*-osf*
5481 Atari TT running SVR4 m68*-*-sysv4*
5482 RS/6000 LynxOS rs6000-*-lynxos*
5486 OS/9000 i[34]86-*-os9k
5487 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5490 * Hitachi SH7000 and E7000-PC ICE support
5492 There is now support for communicating with the Hitachi E7000-PC ICE.
5493 This is available automatically when GDB is configured for the SH.
5497 As usual, a variety of small fixes and improvements, both generic
5498 and configuration-specific. See the ChangeLog for more detail.
5500 *** Changes in GDB-4.12:
5502 * Irix 5 is now supported
5506 GDB-4.12 on the HPPA has a number of changes which make it unable
5507 to debug the output from the currently released versions of GCC and
5508 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5509 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5510 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5513 *** Changes in GDB-4.11:
5515 * User visible changes:
5519 The "set remotedebug" option is now consistent between the mips remote
5520 target, remote targets using the gdb-specific protocol, UDI (AMD's
5521 debug protocol for the 29k) and the 88k bug monitor. It is now an
5522 integer specifying a debug level (normally 0 or 1, but 2 means more
5523 debugging info for the mips target).
5525 * DEC Alpha native support
5527 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5528 debug info, but GDB works fairly well with the DEC compiler and should
5529 work with a future GCC release. See the README file for a few
5530 Alpha-specific notes.
5532 * Preliminary thread implementation
5534 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5536 * LynxOS native and target support for 386
5538 This release has been hosted on LynxOS 2.2, and also can be configured
5539 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5542 * Improvements in C++ mangling/demangling.
5544 This release has much better g++ debugging, specifically in name
5545 mangling/demangling, virtual function calls, print virtual table,
5546 call methods, ...etc.
5548 *** Changes in GDB-4.10:
5550 * User visible changes:
5552 Remote debugging using the GDB-specific (`target remote') protocol now
5553 supports the `load' command. This is only useful if you have some
5554 other way of getting the stub to the target system, and you can put it
5555 somewhere in memory where it won't get clobbered by the download.
5557 Filename completion now works.
5559 When run under emacs mode, the "info line" command now causes the
5560 arrow to point to the line specified. Also, "info line" prints
5561 addresses in symbolic form (as well as hex).
5563 All vxworks based targets now support a user settable option, called
5564 vxworks-timeout. This option represents the number of seconds gdb
5565 should wait for responses to rpc's. You might want to use this if
5566 your vxworks target is, perhaps, a slow software simulator or happens
5567 to be on the far side of a thin network line.
5571 This release contains support for using a DEC alpha as a GDB host for
5572 cross debugging. Native alpha debugging is not supported yet.
5575 *** Changes in GDB-4.9:
5579 This is the first GDB release which is accompanied by a matching testsuite.
5580 The testsuite requires installation of dejagnu, which should be available
5581 via ftp from most sites that carry GNU software.
5585 'Cfront' style demangling has had its name changed to 'ARM' style, to
5586 emphasize that it was written from the specifications in the C++ Annotated
5587 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5588 disclaimers, it still generated too much confusion with users attempting to
5589 use gdb with AT&T cfront.
5593 GDB now uses a standard remote interface to a simulator library.
5594 So far, the library contains simulators for the Zilog Z8001/2, the
5595 Hitachi H8/300, H8/500 and Super-H.
5597 * New targets supported
5599 H8/300 simulator h8300-hitachi-hms or h8300hms
5600 H8/500 simulator h8500-hitachi-hms or h8500hms
5601 SH simulator sh-hitachi-hms or sh
5602 Z8000 simulator z8k-zilog-none or z8ksim
5603 IDT MIPS board over serial line mips-idt-ecoff
5605 Cross-debugging to GO32 targets is supported. It requires a custom
5606 version of the i386-stub.c module which is integrated with the
5607 GO32 memory extender.
5609 * New remote protocols
5611 MIPS remote debugging protocol.
5613 * New source languages supported
5615 This version includes preliminary support for Chill, a Pascal like language
5616 used by telecommunications companies. Chill support is also being integrated
5617 into the GNU compiler, but we don't know when it will be publically available.
5620 *** Changes in GDB-4.8:
5622 * HP Precision Architecture supported
5624 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5625 version of this support was available as a set of patches from the
5626 University of Utah. GDB does not support debugging of programs
5627 compiled with the HP compiler, because HP will not document their file
5628 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5629 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5631 Many problems in the preliminary version have been fixed.
5633 * Faster and better demangling
5635 We have improved template demangling and fixed numerous bugs in the GNU style
5636 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5637 character types (wchar_t) are now supported. Demangling of each symbol is now
5638 only done once, and is cached when the symbol table for a file is read in.
5639 This results in a small increase in memory usage for C programs, a moderate
5640 increase in memory usage for C++ programs, and a fantastic speedup in
5643 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5644 from the specifications in the Annotated Reference Manual, which AT&T's
5645 compiler does not actually implement.
5647 * G++ multiple inheritance compiler problem
5649 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5650 inheritance lattices was reworked to properly discover ambiguities. We
5651 recently found an example which causes this new algorithm to fail in a
5652 very subtle way, producing bad debug information for those classes.
5653 The file 'gcc.patch' (in this directory) can be applied to gcc to
5654 circumvent the problem. A future GCC release will contain a complete
5657 The previous G++ debug info problem (mentioned below for the gdb-4.7
5658 release) is fixed in gcc version 2.3.2.
5660 * Improved configure script
5662 The `configure' script will now attempt to guess your system type if
5663 you don't supply a host system type. The old scheme of supplying a
5664 host system triplet is preferable over using this. All the magic is
5665 done in the new `config.guess' script. Examine it for details.
5667 We have also brought our configure script much more in line with the FSF's
5668 version. It now supports the --with-xxx options. In particular,
5669 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5670 The resulting GDB will not be able to read arbitrary object file formats --
5671 only the format ``expected'' to be used on the configured target system.
5672 We hope to make this the default in a future release.
5674 * Documentation improvements
5676 There's new internal documentation on how to modify GDB, and how to
5677 produce clean changes to the code. We implore people to read it
5678 before submitting changes.
5680 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5681 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5682 `info' files are also provided. To build `info' files from scratch,
5683 you will need the latest `makeinfo' release, which will be available in
5684 a future texinfo-X.Y release.
5686 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5687 We're not sure exactly which versions have this problem, but it has
5688 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5689 or better. If that isn't possible, there is a patch in
5690 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5691 around this problem.
5695 GDB now supports array constants that can be used in expressions typed in by
5696 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5697 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5700 The new directory `gdb/sparclite' contains a program that demonstrates
5701 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5703 * New native hosts supported
5705 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5706 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5708 * New targets supported
5710 AMD 29k family via UDI a29k-amd-udi or udi29k
5712 * New file formats supported
5714 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5715 HPUX core files, and SCO 3.2v2 core files.
5719 Attaching to processes now works again; thanks for the many bug reports.
5721 We have also stomped on a bunch of core dumps caused by
5722 printf_filtered("%s") problems.
5724 We eliminated a copyright problem on the rpc and ptrace header files
5725 for VxWorks, which was discovered at the last minute during the 4.7
5726 release. You should now be able to build a VxWorks GDB.
5728 You can now interrupt gdb while an attached process is running. This
5729 will cause the attached process to stop, and give control back to GDB.
5731 We fixed problems caused by using too many file descriptors
5732 for reading symbols from object files and libraries. This was
5733 especially a problem for programs that used many (~100) shared
5736 The `step' command now only enters a subroutine if there is line number
5737 information for the subroutine. Otherwise it acts like the `next'
5738 command. Previously, `step' would enter subroutines if there was
5739 any debugging information about the routine. This avoids problems
5740 when using `cc -g1' on MIPS machines.
5742 * Internal improvements
5744 GDB's internal interfaces have been improved to make it easier to support
5745 debugging of multiple languages in the future.
5747 GDB now uses a common structure for symbol information internally.
5748 Minimal symbols (derived from linkage symbols in object files), partial
5749 symbols (from a quick scan of debug information), and full symbols
5750 contain a common subset of information, making it easier to write
5751 shared code that handles any of them.
5753 * New command line options
5755 We now accept --silent as an alias for --quiet.
5759 The memory-mapped-malloc library is now licensed under the GNU Library
5760 General Public License.
5762 *** Changes in GDB-4.7:
5764 * Host/native/target split
5766 GDB has had some major internal surgery to untangle the support for
5767 hosts and remote targets. Now, when you configure GDB for a remote
5768 target, it will no longer load in all of the support for debugging
5769 local programs on the host. When fully completed and tested, this will
5770 ensure that arbitrary host/target combinations are possible.
5772 The primary conceptual shift is to separate the non-portable code in
5773 GDB into three categories. Host specific code is required any time GDB
5774 is compiled on that host, regardless of the target. Target specific
5775 code relates to the peculiarities of the target, but can be compiled on
5776 any host. Native specific code is everything else: it can only be
5777 built when the host and target are the same system. Child process
5778 handling and core file support are two common `native' examples.
5780 GDB's use of /proc for controlling Unix child processes is now cleaner.
5781 It has been split out into a single module under the `target_ops' vector,
5782 plus two native-dependent functions for each system that uses /proc.
5784 * New hosts supported
5786 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5787 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5788 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5790 * New targets supported
5792 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5793 68030 and CPU32 m68030-*-*, m68332-*-*
5795 * New native hosts supported
5797 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5798 (386bsd is not well tested yet)
5799 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5801 * New file formats supported
5803 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5804 supports reading of `a.out.adobe' object files, which are an a.out
5805 format extended with minimal information about multiple sections.
5809 `show copying' is the same as the old `info copying'.
5810 `show warranty' is the same as `info warrantee'.
5811 These were renamed for consistency. The old commands continue to work.
5813 `info handle' is a new alias for `info signals'.
5815 You can now define pre-command hooks, which attach arbitrary command
5816 scripts to any command. The commands in the hook will be executed
5817 prior to the user's command. You can also create a hook which will be
5818 executed whenever the program stops. See gdb.texinfo.
5822 We now deal with Cfront style name mangling, and can even extract type
5823 info from mangled symbols. GDB can automatically figure out which
5824 symbol mangling style your C++ compiler uses.
5826 Calling of methods and virtual functions has been improved as well.
5830 The crash that occured when debugging Sun Ansi-C compiled binaries is
5831 fixed. This was due to mishandling of the extra N_SO stabs output
5834 We also finally got Ultrix 4.2 running in house, and fixed core file
5835 support, with help from a dozen people on the net.
5837 John M. Farrell discovered that the reason that single-stepping was so
5838 slow on all of the Mips based platforms (primarily SGI and DEC) was
5839 that we were trying to demangle and lookup a symbol used for internal
5840 purposes on every instruction that was being stepped through. Changing
5841 the name of that symbol so that it couldn't be mistaken for a C++
5842 mangled symbol sped things up a great deal.
5844 Rich Pixley sped up symbol lookups in general by getting much smarter
5845 about when C++ symbol mangling is necessary. This should make symbol
5846 completion (TAB on the command line) much faster. It's not as fast as
5847 we'd like, but it's significantly faster than gdb-4.6.
5851 A new user controllable variable 'call_scratch_address' can
5852 specify the location of a scratch area to be used when GDB
5853 calls a function in the target. This is necessary because the
5854 usual method of putting the scratch area on the stack does not work
5855 in systems that have separate instruction and data spaces.
5857 We integrated changes to support the 29k UDI (Universal Debugger
5858 Interface), but discovered at the last minute that we didn't have all
5859 of the appropriate copyright paperwork. We are working with AMD to
5860 resolve this, and hope to have it available soon.
5864 We have sped up the remote serial line protocol, especially for targets
5865 with lots of registers. It now supports a new `expedited status' ('T')
5866 message which can be used in place of the existing 'S' status message.
5867 This allows the remote stub to send only the registers that GDB
5868 needs to make a quick decision about single-stepping or conditional
5869 breakpoints, eliminating the need to fetch the entire register set for
5870 each instruction being stepped through.
5872 The GDB remote serial protocol now implements a write-through cache for
5873 registers, only re-reading the registers if the target has run.
5875 There is also a new remote serial stub for SPARC processors. You can
5876 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5877 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5878 processor with a serial port.
5882 Configure.in files have become much easier to read and modify. A new
5883 `table driven' format makes it more obvious what configurations are
5884 supported, and what files each one uses.
5888 There is a new opcodes library which will eventually contain all of the
5889 disassembly routines and opcode tables. At present, it only contains
5890 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5891 disassembler (binutils/objdump) to share these routines.
5893 The libiberty library is now copylefted under the GNU Library General
5894 Public License. This allows more liberal use, and was done so libg++
5895 can use it. This makes no difference to GDB, since the Library License
5896 grants all the rights from the General Public License.
5900 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5901 reference to the stabs symbol info used by the debugger. It is (as far
5902 as we know) the only published document on this fascinating topic. We
5903 encourage you to read it, compare it to the stabs information on your
5904 system, and send improvements on the document in general (to
5905 bug-gdb@prep.ai.mit.edu).
5907 And, of course, many bugs have been fixed.
5910 *** Changes in GDB-4.6:
5912 * Better support for C++ function names
5914 GDB now accepts as input the "demangled form" of C++ overloaded function
5915 names and member function names, and can do command completion on such names
5916 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5917 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5918 Make use of command completion, it is your friend.
5920 GDB also now accepts a variety of C++ mangled symbol formats. They are
5921 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5922 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5923 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5924 for the list of formats.
5926 * G++ symbol mangling problem
5928 Recent versions of gcc have a bug in how they emit debugging information for
5929 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5930 directory) can be applied to gcc to fix the problem. Alternatively, if you
5931 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5932 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5933 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5936 * New 'maintenance' command
5938 All of the commands related to hacking GDB internals have been moved out of
5939 the main command set, and now live behind the 'maintenance' command. This
5940 can also be abbreviated as 'mt'. The following changes were made:
5942 dump-me -> maintenance dump-me
5943 info all-breakpoints -> maintenance info breakpoints
5944 printmsyms -> maintenance print msyms
5945 printobjfiles -> maintenance print objfiles
5946 printpsyms -> maintenance print psymbols
5947 printsyms -> maintenance print symbols
5949 The following commands are new:
5951 maintenance demangle Call internal GDB demangler routine to
5952 demangle a C++ link name and prints the result.
5953 maintenance print type Print a type chain for a given symbol
5955 * Change to .gdbinit file processing
5957 We now read the $HOME/.gdbinit file before processing the argv arguments
5958 (e.g. reading symbol files or core files). This allows global parameters to
5959 be set, which will apply during the symbol reading. The ./.gdbinit is still
5960 read after argv processing.
5962 * New hosts supported
5964 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5966 GNU/Linux support i386-unknown-linux or linux
5968 We are also including code to support the HP/PA running BSD and HPUX. This
5969 is almost guaranteed not to work, as we didn't have time to test or build it
5970 for this release. We are including it so that the more adventurous (or
5971 masochistic) of you can play with it. We also had major problems with the
5972 fact that the compiler that we got from HP doesn't support the -g option.
5975 * New targets supported
5977 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5979 * More smarts about finding #include files
5981 GDB now remembers the compilation directory for all include files, and for
5982 all files from which C is generated (like yacc and lex sources). This
5983 greatly improves GDB's ability to find yacc/lex sources, and include files,
5984 especially if you are debugging your program from a directory different from
5985 the one that contains your sources.
5987 We also fixed a bug which caused difficulty with listing and setting
5988 breakpoints in include files which contain C code. (In the past, you had to
5989 try twice in order to list an include file that you hadn't looked at before.)
5991 * Interesting infernals change
5993 GDB now deals with arbitrary numbers of sections, where the symbols for each
5994 section must be relocated relative to that section's landing place in the
5995 target's address space. This work was needed to support ELF with embedded
5996 stabs used by Solaris-2.0.
5998 * Bug fixes (of course!)
6000 There have been loads of fixes for the following things:
6001 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6002 i960, stabs, DOS(GO32), procfs, etc...
6004 See the ChangeLog for details.
6006 *** Changes in GDB-4.5:
6008 * New machines supported (host and target)
6010 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6012 SGI Irix-4.x mips-sgi-irix4 or iris4
6014 * New malloc package
6016 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6017 Mmalloc is capable of handling mutiple heaps of memory. It is also
6018 capable of saving a heap to a file, and then mapping it back in later.
6019 This can be used to greatly speedup the startup of GDB by using a
6020 pre-parsed symbol table which lives in a mmalloc managed heap. For
6021 more details, please read mmalloc/mmalloc.texi.
6025 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6026 'help info proc' for details.
6028 * MIPS ecoff symbol table format
6030 The code that reads MIPS symbol table format is now supported on all hosts.
6031 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6034 * File name changes for MS-DOS
6036 Many files in the config directories have been renamed to make it easier to
6037 support GDB on MS-DOSe systems (which have very restrictive file name
6038 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6039 environment) is close to working but has some remaining problems. Note
6040 that debugging of DOS programs is not supported, due to limitations
6041 in the ``operating system'', but it can be used to host cross-debugging.
6043 * Cross byte order fixes
6045 Many fixes have been made to support cross debugging of Sparc and MIPS
6046 targets from hosts whose byte order differs.
6048 * New -mapped and -readnow options
6050 If memory-mapped files are available on your system through the 'mmap'
6051 system call, you can use the -mapped option on the `file' or
6052 `symbol-file' commands to cause GDB to write the symbols from your
6053 program into a reusable file. If the program you are debugging is
6054 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6055 Future GDB debugging sessions will notice the presence of this file,
6056 and will quickly map in symbol information from it, rather than reading
6057 the symbol table from the executable program. Using the '-mapped'
6058 option in a GDB `file' or `symbol-file' command has the same effect as
6059 starting GDB with the '-mapped' command-line option.
6061 You can cause GDB to read the entire symbol table immediately by using
6062 the '-readnow' option with any of the commands that load symbol table
6063 information (or on the GDB command line). This makes the command
6064 slower, but makes future operations faster.
6066 The -mapped and -readnow options are typically combined in order to
6067 build a `fred.syms' file that contains complete symbol information.
6068 A simple GDB invocation to do nothing but build a `.syms' file for future
6071 gdb -batch -nx -mapped -readnow programname
6073 The `.syms' file is specific to the host machine on which GDB is run.
6074 It holds an exact image of GDB's internal symbol table. It cannot be
6075 shared across multiple host platforms.
6077 * longjmp() handling
6079 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6080 siglongjmp() without losing control. This feature has not yet been ported to
6081 all systems. It currently works on many 386 platforms, all MIPS-based
6082 platforms (SGI, DECstation, etc), and Sun3/4.
6086 Preliminary work has been put in to support the new Solaris OS from Sun. At
6087 this time, it can control and debug processes, but it is not capable of
6092 As always, many many bug fixes. The major areas were with g++, and mipsread.
6093 People using the MIPS-based platforms should experience fewer mysterious
6094 crashes and trashed symbol tables.
6096 *** Changes in GDB-4.4:
6098 * New machines supported (host and target)
6100 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6102 BSD Reno on Vax vax-dec-bsd
6103 Ultrix on Vax vax-dec-ultrix
6105 * New machines supported (target)
6107 AMD 29000 embedded, using EBMON a29k-none-none
6111 GDB continues to improve its handling of C++. `References' work better.
6112 The demangler has also been improved, and now deals with symbols mangled as
6113 per the Annotated C++ Reference Guide.
6115 GDB also now handles `stabs' symbol information embedded in MIPS
6116 `ecoff' symbol tables. Since the ecoff format was not easily
6117 extensible to handle new languages such as C++, this appeared to be a
6118 good way to put C++ debugging info into MIPS binaries. This option
6119 will be supported in the GNU C compiler, version 2, when it is
6122 * New features for SVR4
6124 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6125 shared libraries. Debugging dynamically linked programs should present
6126 only minor differences from debugging statically linked programs.
6128 The `info proc' command will print out information about any process
6129 on an SVR4 system (including the one you are debugging). At the moment,
6130 it prints the address mappings of the process.
6132 If you bring up GDB on another SVR4 system, please send mail to
6133 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6135 * Better dynamic linking support in SunOS
6137 Reading symbols from shared libraries which contain debugging symbols
6138 now works properly. However, there remain issues such as automatic
6139 skipping of `transfer vector' code during function calls, which
6140 make it harder to debug code in a shared library, than to debug the
6141 same code linked statically.
6145 GDB is now using the latest `getopt' routines from the FSF. This
6146 version accepts the -- prefix for options with long names. GDB will
6147 continue to accept the old forms (-option and +option) as well.
6148 Various single letter abbreviations for options have been explicity
6149 added to the option table so that they won't get overshadowed in the
6150 future by other options that begin with the same letter.
6154 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6155 Many assorted bugs have been handled. Many more remain to be handled.
6156 See the various ChangeLog files (primarily in gdb and bfd) for details.
6159 *** Changes in GDB-4.3:
6161 * New machines supported (host and target)
6163 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6164 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6165 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6167 * Almost SCO Unix support
6169 We had hoped to support:
6170 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6171 (except for core file support), but we discovered very late in the release
6172 that it has problems with process groups that render gdb unusable. Sorry
6173 about that. I encourage people to fix it and post the fixes.
6175 * Preliminary ELF and DWARF support
6177 GDB can read ELF object files on System V Release 4, and can handle
6178 debugging records for C, in DWARF format, in ELF files. This support
6179 is preliminary. If you bring up GDB on another SVR4 system, please
6180 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6185 GDB now uses the latest `readline' library. One user-visible change
6186 is that two tabs will list possible command completions, which previously
6187 required typing M-? (meta-question mark, or ESC ?).
6191 The `stepi' bug that many of you noticed has been squashed.
6192 Many bugs in C++ have been handled. Many more remain to be handled.
6193 See the various ChangeLog files (primarily in gdb and bfd) for details.
6195 * State of the MIPS world (in case you wondered):
6197 GDB can understand the symbol tables emitted by the compilers
6198 supplied by most vendors of MIPS-based machines, including DEC. These
6199 symbol tables are in a format that essentially nobody else uses.
6201 Some versions of gcc come with an assembler post-processor called
6202 mips-tfile. This program is required if you want to do source-level
6203 debugging of gcc-compiled programs. I believe FSF does not ship
6204 mips-tfile with gcc version 1, but it will eventually come with gcc
6207 Debugging of g++ output remains a problem. g++ version 1.xx does not
6208 really support it at all. (If you're lucky, you should be able to get
6209 line numbers and stack traces to work, but no parameters or local
6210 variables.) With some work it should be possible to improve the
6213 When gcc version 2 is released, you will have somewhat better luck.
6214 However, even then you will get confusing results for inheritance and
6217 We will eventually provide full debugging of g++ output on
6218 DECstations. This will probably involve some kind of stabs-in-ecoff
6219 encapulation, but the details have not been worked out yet.
6222 *** Changes in GDB-4.2:
6224 * Improved configuration
6226 Only one copy of `configure' exists now, and it is not self-modifying.
6227 Porting BFD is simpler.
6231 The `step' and `next' commands now only stop at the first instruction
6232 of a source line. This prevents the multiple stops that used to occur
6233 in switch statements, for-loops, etc. `Step' continues to stop if a
6234 function that has debugging information is called within the line.
6238 Lots of small bugs fixed. More remain.
6240 * New host supported (not target)
6242 Intel 386 PC clone running Mach i386-none-mach
6245 *** Changes in GDB-4.1:
6247 * Multiple source language support
6249 GDB now has internal scaffolding to handle several source languages.
6250 It determines the type of each source file from its filename extension,
6251 and will switch expression parsing and number formatting to match the
6252 language of the function in the currently selected stack frame.
6253 You can also specifically set the language to be used, with
6254 `set language c' or `set language modula-2'.
6258 GDB now has preliminary support for the GNU Modula-2 compiler,
6259 currently under development at the State University of New York at
6260 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6261 continue through the fall of 1991 and into 1992.
6263 Other Modula-2 compilers are currently not supported, and attempting to
6264 debug programs compiled with them will likely result in an error as the
6265 symbol table is read. Feel free to work on it, though!
6267 There are hooks in GDB for strict type checking and range checking,
6268 in the `Modula-2 philosophy', but they do not currently work.
6272 GDB can now write to executable and core files (e.g. patch
6273 a variable's value). You must turn this switch on, specify
6274 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6275 by assigning a new value to a variable. Modifications take
6278 * Automatic SunOS shared library reading
6280 When you run your program, GDB automatically determines where its
6281 shared libraries (if any) have been loaded, and reads their symbols.
6282 The `share' command is no longer needed. This also works when
6283 examining core files.
6287 You can specify the number of lines that the `list' command shows.
6290 * New machines supported (host and target)
6292 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6293 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6294 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6296 * New hosts supported (not targets)
6298 IBM RT/PC: romp-ibm-aix or rtpc
6300 * New targets supported (not hosts)
6302 AMD 29000 embedded with COFF a29k-none-coff
6303 AMD 29000 embedded with a.out a29k-none-aout
6304 Ultracomputer remote kernel debug a29k-nyu-kern
6306 * New remote interfaces
6312 *** Changes in GDB-4.0:
6316 Wide output is wrapped at good places to make the output more readable.
6318 Gdb now supports cross-debugging from a host machine of one type to a
6319 target machine of another type. Communication with the target system
6320 is over serial lines. The ``target'' command handles connecting to the
6321 remote system; the ``load'' command will download a program into the
6322 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6323 also supports debugging of realtime processes running under VxWorks,
6324 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6325 stub on the target system.
6327 New CPUs supported include the AMD 29000 and Intel 960.
6329 GDB now reads object files and symbol tables via a ``binary file''
6330 library, which allows a single copy of GDB to debug programs of multiple
6331 object file types such as a.out and coff.
6333 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6334 refcard.dvi and refcard.ps are available to format it).
6337 * Control-Variable user interface simplified
6339 All variables that control the operation of the debugger can be set
6340 by the ``set'' command, and displayed by the ``show'' command.
6342 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6343 ``Show prompt'' produces the response:
6344 Gdb's prompt is new-gdb=>.
6346 What follows are the NEW set commands. The command ``help set'' will
6347 print a complete list of old and new set commands. ``help set FOO''
6348 will give a longer description of the variable FOO. ``show'' will show
6349 all of the variable descriptions and their current settings.
6351 confirm on/off: Enables warning questions for operations that are
6352 hard to recover from, e.g. rerunning the program while
6353 it is already running. Default is ON.
6355 editing on/off: Enables EMACS style command line editing
6356 of input. Previous lines can be recalled with
6357 control-P, the current line can be edited with control-B,
6358 you can search for commands with control-R, etc.
6361 history filename NAME: NAME is where the gdb command history
6362 will be stored. The default is .gdb_history,
6363 or the value of the environment variable
6366 history size N: The size, in commands, of the command history. The
6367 default is 256, or the value of the environment variable
6370 history save on/off: If this value is set to ON, the history file will
6371 be saved after exiting gdb. If set to OFF, the
6372 file will not be saved. The default is OFF.
6374 history expansion on/off: If this value is set to ON, then csh-like
6375 history expansion will be performed on
6376 command line input. The default is OFF.
6378 radix N: Sets the default radix for input and output. It can be set
6379 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6380 in the current radix, so "set radix 10" is always a no-op.
6382 height N: This integer value is the number of lines on a page. Default
6383 is 24, the current `stty rows'' setting, or the ``li#''
6384 setting from the termcap entry matching the environment
6387 width N: This integer value is the number of characters on a line.
6388 Default is 80, the current `stty cols'' setting, or the ``co#''
6389 setting from the termcap entry matching the environment
6392 Note: ``set screensize'' is obsolete. Use ``set height'' and
6393 ``set width'' instead.
6395 print address on/off: Print memory addresses in various command displays,
6396 such as stack traces and structure values. Gdb looks
6397 more ``symbolic'' if you turn this off; it looks more
6398 ``machine level'' with it on. Default is ON.
6400 print array on/off: Prettyprint arrays. New convenient format! Default
6403 print demangle on/off: Print C++ symbols in "source" form if on,
6406 print asm-demangle on/off: Same, for assembler level printouts
6409 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6412 * Support for Epoch Environment.
6414 The epoch environment is a version of Emacs v18 with windowing. One
6415 new command, ``inspect'', is identical to ``print'', except that if you
6416 are running in the epoch environment, the value is printed in its own
6420 * Support for Shared Libraries
6422 GDB can now debug programs and core files that use SunOS shared libraries.
6423 Symbols from a shared library cannot be referenced
6424 before the shared library has been linked with the program (this
6425 happens after you type ``run'' and before the function main() is entered).
6426 At any time after this linking (including when examining core files
6427 from dynamically linked programs), gdb reads the symbols from each
6428 shared library when you type the ``sharedlibrary'' command.
6429 It can be abbreviated ``share''.
6431 sharedlibrary REGEXP: Load shared object library symbols for files
6432 matching a unix regular expression. No argument
6433 indicates to load symbols for all shared libraries.
6435 info sharedlibrary: Status of loaded shared libraries.
6440 A watchpoint stops execution of a program whenever the value of an
6441 expression changes. Checking for this slows down execution
6442 tremendously whenever you are in the scope of the expression, but is
6443 quite useful for catching tough ``bit-spreader'' or pointer misuse
6444 problems. Some machines such as the 386 have hardware for doing this
6445 more quickly, and future versions of gdb will use this hardware.
6447 watch EXP: Set a watchpoint (breakpoint) for an expression.
6449 info watchpoints: Information about your watchpoints.
6451 delete N: Deletes watchpoint number N (same as breakpoints).
6452 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6453 enable N: Re-enables watchpoint number N (same as breakpoints).
6456 * C++ multiple inheritance
6458 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6461 * C++ exception handling
6463 Gdb now supports limited C++ exception handling. Besides the existing
6464 ability to breakpoint on an exception handler, gdb can breakpoint on
6465 the raising of an exception (before the stack is peeled back to the
6468 catch FOO: If there is a FOO exception handler in the dynamic scope,
6469 set a breakpoint to catch exceptions which may be raised there.
6470 Multiple exceptions (``catch foo bar baz'') may be caught.
6472 info catch: Lists all exceptions which may be caught in the
6473 current stack frame.
6476 * Minor command changes
6478 The command ``call func (arg, arg, ...)'' now acts like the print
6479 command, except it does not print or save a value if the function's result
6480 is void. This is similar to dbx usage.
6482 The ``up'' and ``down'' commands now always print the frame they end up
6483 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6484 frames without printing.
6486 * New directory command
6488 'dir' now adds directories to the FRONT of the source search path.
6489 The path starts off empty. Source files that contain debug information
6490 about the directory in which they were compiled can be found even
6491 with an empty path; Sun CC and GCC include this information. If GDB can't
6492 find your source file in the current directory, type "dir .".
6494 * Configuring GDB for compilation
6496 For normal use, type ``./configure host''. See README or gdb.texinfo
6499 GDB now handles cross debugging. If you are remotely debugging between
6500 two different machines, type ``./configure host -target=targ''.
6501 Host is the machine where GDB will run; targ is the machine
6502 where the program that you are debugging will run.
projects / external / binutils.git / blob