1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.10
6 * Support for tracepoints on aarch64-linux was added in GDBserver.
8 * The 'record instruction-history' command now indicates speculative execution
9 when using the Intel(R) Processor Trace recording format.
11 * GDB now allows users to specify explicit locations, bypassing
12 the linespec parser. This feature is also available to GDB/MI
17 maint set target-non-stop (on|off|auto)
18 maint show target-non-stop
19 Control whether GDB targets always operate in non-stop mode even if
20 "set non-stop" is "off". The default is "auto", meaning non-stop
21 mode is enabled if supported by the target.
24 maint show bfd-sharing
25 Control the reuse of bfd objects.
29 Control display of debugging info regarding bfd caching.
31 * The "disassemble" command accepts a new modifier: /s.
32 It prints mixed source+disassembly like /m with two differences:
33 - disassembled instructions are now printed in program order, and
34 - and source for all relevant files is now printed.
35 The "/m" option is now considered deprecated: its "source-centric"
36 output hasn't proved useful in practice.
38 *** Changes in GDB 7.10
40 * Support for process record-replay and reverse debugging on aarch64*-linux*
41 targets has been added. GDB now supports recording of A64 instruction set
42 including advance SIMD instructions.
44 * Support for Sun's version of the "stabs" debug file format has been removed.
46 * GDB now honors the content of the file /proc/PID/coredump_filter
47 (PID is the process ID) on GNU/Linux systems. This file can be used
48 to specify the types of memory mappings that will be included in a
49 corefile. For more information, please refer to the manual page of
50 "core(5)". GDB also has a new command: "set use-coredump-filter
51 on|off". It allows to set whether GDB will read the content of the
52 /proc/PID/coredump_filter file when generating a corefile.
54 * The "info os" command on GNU/Linux can now display information on
56 "info os cpus" Listing of all cpus/cores on the system
58 * GDB has two new commands: "set serial parity odd|even|none" and
59 "show serial parity". These allows to set or show parity for the
62 * The "info source" command now displays the producer string if it was
63 present in the debug info. This typically includes the compiler version
64 and may include things like its command line arguments.
66 * The "info dll", an alias of the "info sharedlibrary" command,
67 is now available on all platforms.
69 * Directory names supplied to the "set sysroot" commands may be
70 prefixed with "target:" to tell GDB to access shared libraries from
71 the target system, be it local or remote. This replaces the prefix
72 "remote:". The default sysroot has been changed from "" to
73 "target:". "remote:" is automatically converted to "target:" for
74 backward compatibility.
76 * The system root specified by "set sysroot" will be prepended to the
77 filename of the main executable (if reported to GDB as absolute by
78 the operating system) when starting processes remotely, and when
79 attaching to already-running local or remote processes.
81 * GDB now supports automatic location and retrieval of executable
82 files from remote targets. Remote debugging can now be initiated
83 using only a "target remote" or "target extended-remote" command
84 (no "set sysroot" or "file" commands are required). See "New remote
87 * The "dump" command now supports verilog hex format.
89 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
91 * On GNU/Linux, GDB and gdbserver are now able to access executable
92 and shared library files without a "set sysroot" command when
93 attaching to processes running in different mount namespaces from
94 the debugger. This makes it possible to attach to processes in
95 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
96 See "New remote packets" below.
98 * The "tui reg" command now provides completion for all of the
99 available register groups, including target specific groups.
101 * The HISTSIZE environment variable is no longer read when determining
102 the size of GDB's command history. GDB now instead reads the dedicated
103 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
104 disables truncation of command history. Non-numeric values of GDBHISTSIZE
109 ** Memory ports can now be unbuffered.
113 ** gdb.Objfile objects have a new attribute "username",
114 which is the name of the objfile as specified by the user,
115 without, for example, resolving symlinks.
116 ** You can now write frame unwinders in Python.
117 ** gdb.Type objects have a new method "optimized_out",
118 returning optimized out gdb.Value instance of this type.
119 ** gdb.Value objects have new methods "reference_value" and
120 "const_value" which return a reference to the value and a
121 "const" version of the value respectively.
125 maint print symbol-cache
126 Print the contents of the symbol cache.
128 maint print symbol-cache-statistics
129 Print statistics of symbol cache usage.
131 maint flush-symbol-cache
132 Flush the contents of the symbol cache.
134 maint set target-non-stop (on|off|auto)
135 maint show target-non-stop
136 Control whether GDB targets always operate in non-stop mode even if
137 "set non-stop" is "off". The default is "auto", meaning non-stop
138 mode is enabled if supported by the target.
142 Start branch trace recording using Branch Trace Store (BTS) format.
145 Evaluate expression by using the compiler and print result.
149 Explicit commands for enabling and disabling tui mode.
152 set mpx bound on i386 and amd64
153 Support for bound table investigation on Intel(R) MPX enabled applications.
157 Start branch trace recording using Intel(R) Processor Trace format.
160 Print information about branch tracing internals.
162 maint btrace packet-history
163 Print the raw branch tracing data.
165 maint btrace clear-packet-history
166 Discard the stored raw branch tracing data.
169 Discard all branch tracing data. It will be fetched and processed
170 anew by the next "record" command.
175 Renamed from "set debug dwarf2-die".
177 Renamed from "show debug dwarf2-die".
180 Renamed from "set debug dwarf2-read".
181 show debug dwarf-read
182 Renamed from "show debug dwarf2-read".
184 maint set dwarf always-disassemble
185 Renamed from "maint set dwarf2 always-disassemble".
186 maint show dwarf always-disassemble
187 Renamed from "maint show dwarf2 always-disassemble".
189 maint set dwarf max-cache-age
190 Renamed from "maint set dwarf2 max-cache-age".
191 maint show dwarf max-cache-age
192 Renamed from "maint show dwarf2 max-cache-age".
195 show debug dwarf-line
196 Control display of debugging info regarding DWARF line processing.
200 Set the maximum number of candidates to be considered during
201 completion. The default value is 200. This limit allows GDB
202 to avoid generating large completion lists, the computation of
203 which can cause the debugger to become temporarily unresponsive.
205 set history remove-duplicates
206 show history remove-duplicates
207 Control the removal of duplicate history entries.
209 maint set symbol-cache-size
210 maint show symbol-cache-size
211 Control the size of the symbol cache.
213 set|show record btrace bts buffer-size
214 Set and show the size of the ring buffer used for branch tracing in
216 The obtained size may differ from the requested size. Use "info
217 record" to see the obtained buffer size.
219 set debug linux-namespaces
220 show debug linux-namespaces
221 Control display of debugging info regarding Linux namespaces.
223 set|show record btrace pt buffer-size
224 Set and show the size of the ring buffer used for branch tracing in
225 Intel(R) Processor Trace format.
226 The obtained size may differ from the requested size. Use "info
227 record" to see the obtained buffer size.
229 maint set|show btrace pt skip-pad
230 Set and show whether PAD packets are skipped when computing the
233 * The command 'thread apply all' can now support new option '-ascending'
234 to call its specified command for all threads in ascending order.
236 * Python/Guile scripting
238 ** GDB now supports auto-loading of Python/Guile scripts contained in the
239 special section named `.debug_gdb_scripts'.
243 qXfer:btrace-conf:read
244 Return the branch trace configuration for the current thread.
246 Qbtrace-conf:bts:size
247 Set the requested ring buffer size for branch tracing in BTS format.
250 Enable Intel(R) Procesor Trace-based branch tracing for the current
251 process. The remote stub reports support for this packet to GDB's
255 Set the requested ring buffer size for branch tracing in Intel(R) Processor
259 Indicates a memory breakpoint instruction was executed, irrespective
260 of whether it was GDB that planted the breakpoint or the breakpoint
261 is hardcoded in the program. This is required for correct non-stop
265 Indicates the target stopped for a hardware breakpoint. This is
266 required for correct non-stop mode operation.
269 Return information about files on the remote system.
272 Return the full absolute name of the file that was executed to
273 create a process running on the remote system.
276 Select the filesystem on which vFile: operations with filename
277 arguments will operate. This is required for GDB to be able to
278 access files on remote targets where the remote stub does not
279 share a common filesystem with the inferior(s).
282 Indicates that a fork system call was executed.
285 Indicates that a vfork system call was executed.
287 vforkdone stop reason
288 Indicates that a vfork child of the specified process has executed
289 an exec or exit, allowing the vfork parent to resume execution.
291 fork-events and vfork-events features in qSupported
292 The qSupported packet allows GDB to request support for fork and
293 vfork events using new 'gdbfeatures' fork-events and vfork-events,
294 and the qSupported response can contain the corresponding
295 'stubfeatures'. Set and show commands can be used to display
296 whether these features are enabled.
298 * Extended-remote fork events
300 ** GDB now has support for fork events on extended-remote Linux
301 targets. For targets with Linux kernels 2.5.60 and later, this
302 enables follow-fork-mode and detach-on-fork for both fork and
303 vfork, as well as fork and vfork catchpoints.
305 * The info record command now shows the recording format and the
306 branch tracing configuration for the current thread when using
307 the btrace record target.
308 For the BTS format, it shows the ring buffer size.
310 * GDB now has support for DTrace USDT (Userland Static Defined
311 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
313 * GDB now supports access to vector registers on S/390 GNU/Linux
316 * Removed command line options
318 -xdb HP-UX XDB compatibility mode.
320 * Removed targets and native configurations
322 HP/PA running HP-UX hppa*-*-hpux*
323 Itanium running HP-UX ia64-*-hpux*
325 * New configure options
328 This configure option allows the user to build GDB with support for
329 Intel(R) Processor Trace (default: auto). This requires libipt.
331 --with-libipt-prefix=PATH
332 Specify the path to the version of libipt that GDB should use.
333 $PATH/include should contain the intel-pt.h header and
334 $PATH/lib should contain the libipt.so library.
336 *** Changes in GDB 7.9.1
340 ** Xmethods can now specify a result type.
342 *** Changes in GDB 7.9
344 * GDB now supports hardware watchpoints on x86 GNU Hurd.
348 ** You can now access frame registers from Python scripts.
349 ** New attribute 'producer' for gdb.Symtab objects.
350 ** gdb.Objfile objects have a new attribute "progspace",
351 which is the gdb.Progspace object of the containing program space.
352 ** gdb.Objfile objects have a new attribute "owner".
353 ** gdb.Objfile objects have a new attribute "build_id",
354 which is the build ID generated when the file was built.
355 ** gdb.Objfile objects have a new method "add_separate_debug_file".
356 ** A new event "gdb.clear_objfiles" has been added, triggered when
357 selecting a new file to debug.
358 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
359 ** New function gdb.lookup_objfile.
361 New events which are triggered when GDB modifies the state of the
364 ** gdb.events.inferior_call_pre: Function call is about to be made.
365 ** gdb.events.inferior_call_post: Function call has just been made.
366 ** gdb.events.memory_changed: A memory location has been altered.
367 ** gdb.events.register_changed: A register has been altered.
369 * New Python-based convenience functions:
371 ** $_caller_is(name [, number_of_frames])
372 ** $_caller_matches(regexp [, number_of_frames])
373 ** $_any_caller_is(name [, number_of_frames])
374 ** $_any_caller_matches(regexp [, number_of_frames])
376 * GDB now supports the compilation and injection of source code into
377 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
378 to compile the source code to object code, and if successful, inject
379 and execute that code within the current context of the inferior.
380 Currently the C language is supported. The commands used to
381 interface with this new feature are:
383 compile code [-raw|-r] [--] [source code]
384 compile file [-raw|-r] filename
388 demangle [-l language] [--] name
389 Demangle "name" in the specified language, or the current language
390 if elided. This command is renamed from the "maint demangle" command.
391 The latter is kept as a no-op to avoid "maint demangle" being interpreted
392 as "maint demangler-warning".
394 queue-signal signal-name-or-number
395 Queue a signal to be delivered to the thread when it is resumed.
397 add-auto-load-scripts-directory directory
398 Add entries to the list of directories from which to load auto-loaded
401 maint print user-registers
402 List all currently available "user" registers.
404 compile code [-r|-raw] [--] [source code]
405 Compile, inject, and execute in the inferior the executable object
406 code produced by compiling the provided source code.
408 compile file [-r|-raw] filename
409 Compile and inject into the inferior the executable object code
410 produced by compiling the source code stored in the filename
413 * On resume, GDB now always passes the signal the program had stopped
414 for to the thread the signal was sent to, even if the user changed
415 threads before resuming. Previously GDB would often (but not
416 always) deliver the signal to the thread that happens to be current
419 * Conversely, the "signal" command now consistently delivers the
420 requested signal to the current thread. GDB now asks for
421 confirmation if the program had stopped for a signal and the user
422 switched threads meanwhile.
424 * "breakpoint always-inserted" modes "off" and "auto" merged.
426 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
427 won't remove breakpoints from the target until all threads stop,
428 even in non-stop mode. The "auto" mode has been removed, and "off"
429 is now the default mode.
433 set debug symbol-lookup
434 show debug symbol-lookup
435 Control display of debugging info regarding symbol lookup.
439 ** The -list-thread-groups command outputs an exit-code field for
440 inferiors that have exited.
444 MIPS SDE mips*-sde*-elf*
448 Support for these obsolete configurations has been removed.
450 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
451 SGI Irix-5.x mips-*-irix5*
452 SGI Irix-6.x mips-*-irix6*
453 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
454 VAX running Ultrix vax-*-ultrix*
456 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
457 and "assf"), have been removed. Use the "sharedlibrary" command, or
458 its alias "share", instead.
460 *** Changes in GDB 7.8
462 * New command line options
465 This is an alias for the --data-directory option.
467 * GDB supports printing and modifying of variable length automatic arrays
468 as specified in ISO C99.
470 * The ARM simulator now supports instruction level tracing
471 with or without disassembly.
475 GDB now has support for scripting using Guile. Whether this is
476 available is determined at configure time.
477 Guile version 2.0 or greater is required.
478 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
480 * New commands (for set/show, see "New options" below)
484 Invoke CODE by passing it to the Guile interpreter.
488 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
490 info auto-load guile-scripts [regexp]
491 Print the list of automatically loaded Guile scripts.
493 * The source command is now capable of sourcing Guile scripts.
494 This feature is dependent on the debugger being built with Guile support.
498 set print symbol-loading (off|brief|full)
499 show print symbol-loading
500 Control whether to print informational messages when loading symbol
501 information for a file. The default is "full", but when debugging
502 programs with large numbers of shared libraries the amount of output
505 set guile print-stack (none|message|full)
506 show guile print-stack
507 Show a stack trace when an error is encountered in a Guile script.
509 set auto-load guile-scripts (on|off)
510 show auto-load guile-scripts
511 Control auto-loading of Guile script files.
513 maint ada set ignore-descriptive-types (on|off)
514 maint ada show ignore-descriptive-types
515 Control whether the debugger should ignore descriptive types in Ada
516 programs. The default is not to ignore the descriptive types. See
517 the user manual for more details on descriptive types and the intended
518 usage of this option.
520 set auto-connect-native-target
522 Control whether GDB is allowed to automatically connect to the
523 native target for the run, attach, etc. commands when not connected
524 to any target yet. See also "target native" below.
526 set record btrace replay-memory-access (read-only|read-write)
527 show record btrace replay-memory-access
528 Control what memory accesses are allowed during replay.
530 maint set target-async (on|off)
531 maint show target-async
532 This controls whether GDB targets operate in synchronous or
533 asynchronous mode. Normally the default is asynchronous, if it is
534 available; but this can be changed to more easily debug problems
535 occurring only in synchronous mode.
537 set mi-async (on|off)
539 Control whether MI asynchronous mode is preferred. This supersedes
540 "set target-async" of previous GDB versions.
542 * "set target-async" is deprecated as a CLI option and is now an alias
543 for "set mi-async" (only puts MI into async mode).
545 * Background execution commands (e.g., "c&", "s&", etc.) are now
546 possible ``out of the box'' if the target supports them. Previously
547 the user would need to explicitly enable the possibility with the
548 "set target-async on" command.
550 * New features in the GDB remote stub, GDBserver
552 ** New option --debug-format=option1[,option2,...] allows one to add
553 additional text to each output. At present only timestamps
554 are supported: --debug-format=timestamps.
555 Timestamps can also be turned on with the
556 "monitor set debug-format timestamps" command from GDB.
558 * The 'record instruction-history' command now starts counting instructions
559 at one. This also affects the instruction ranges reported by the
560 'record function-call-history' command when given the /i modifier.
562 * The command 'record function-call-history' supports a new modifier '/c' to
563 indent the function names based on their call stack depth.
564 The fields for the '/i' and '/l' modifier have been reordered.
565 The source line range is now prefixed with 'at'.
566 The instruction range is now prefixed with 'inst'.
567 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
568 "record instruction-history" and "list" commands.
570 * The ranges given as arguments to the 'record function-call-history' and
571 'record instruction-history' commands are now inclusive.
573 * The btrace record target now supports the 'record goto' command.
574 For locations inside the execution trace, the back trace is computed
575 based on the information stored in the execution trace.
577 * The btrace record target supports limited reverse execution and replay.
578 The target does not record data and therefore does not allow reading
581 * The "catch syscall" command now works on s390*-linux* targets.
583 * The "compare-sections" command is no longer specific to target
584 remote. It now works with all targets.
586 * All native targets are now consistently called "native".
587 Consequently, the "target child", "target GNU", "target djgpp",
588 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
589 commands have been replaced with "target native". The QNX/NTO port
590 leaves the "procfs" target in place and adds a "native" target for
591 consistency with other ports. The impact on users should be minimal
592 as these commands previously either throwed an error, or were
593 no-ops. The target's name is visible in the output of the following
594 commands: "help target", "info target", "info files", "maint print
597 * The "target native" command now connects to the native target. This
598 can be used to launch native programs even when "set
599 auto-connect-native-target" is set to off.
601 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.
603 * Support for Intel(R) AVX-512 registers on GNU/Linux.
604 Support displaying and modifying Intel(R) AVX-512 registers
605 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
609 qXfer:btrace:read's annex
610 The qXfer:btrace:read packet supports a new annex 'delta' to read
611 branch trace incrementally.
615 ** Valid Python operations on gdb.Value objects representing
616 structs/classes invoke the corresponding overloaded operators if
618 ** New `Xmethods' feature in the Python API. Xmethods are
619 additional methods or replacements for existing methods of a C++
620 class. This feature is useful for those cases where a method
621 defined in C++ source code could be inlined or optimized out by
622 the compiler, making it unavailable to GDB.
625 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
627 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
628 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
629 its alias "share", instead.
631 * The commands "set remotebaud" and "show remotebaud" are no longer
632 supported. Use "set serial baud" and "show serial baud" (respectively)
637 ** A new option "-gdb-set mi-async" replaces "-gdb-set
638 target-async". The latter is left as a deprecated alias of the
639 former for backward compatibility. If the target supports it,
640 CLI background execution commands are now always possible by
641 default, independently of whether the frontend stated a
642 preference for asynchronous execution with "-gdb-set mi-async".
643 Previously "-gdb-set target-async off" affected both MI execution
644 commands and CLI execution commands.
646 *** Changes in GDB 7.7
648 * Improved support for process record-replay and reverse debugging on
649 arm*-linux* targets. Support for thumb32 and syscall instruction
650 recording has been added.
652 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
654 * GDB now supports Fission DWP file format version 2.
655 http://gcc.gnu.org/wiki/DebugFission
657 * New convenience function "$_isvoid", to check whether an expression
658 is void. A void expression is an expression where the type of the
659 result is "void". For example, some convenience variables may be
660 "void" when evaluated (e.g., "$_exitcode" before the execution of
661 the program being debugged; or an undefined convenience variable).
662 Another example, when calling a function whose return type is
665 * The "maintenance print objfiles" command now takes an optional regexp.
667 * The "catch syscall" command now works on arm*-linux* targets.
669 * GDB now consistently shows "<not saved>" when printing values of
670 registers the debug info indicates have not been saved in the frame
671 and there's nowhere to retrieve them from
672 (callee-saved/call-clobbered registers):
677 (gdb) info registers rax
680 Before, the former would print "<optimized out>", and the latter
681 "*value not available*".
683 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
688 ** Frame filters and frame decorators have been added.
689 ** Temporary breakpoints are now supported.
690 ** Line tables representation has been added.
691 ** New attribute 'parent_type' for gdb.Field objects.
692 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
693 ** New attribute 'name' for gdb.Type objects.
697 Nios II ELF nios2*-*-elf
698 Nios II GNU/Linux nios2*-*-linux
699 Texas Instruments MSP430 msp430*-*-elf
701 * Removed native configurations
703 Support for these a.out NetBSD and OpenBSD obsolete configurations has
704 been removed. ELF variants of these configurations are kept supported.
706 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
707 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
708 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
709 i[34567]86-*-openbsd3.[0-3]
710 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
711 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
712 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
716 Like "catch throw", but catches a re-thrown exception.
718 Renamed from old "maint check-symtabs".
720 Perform consistency checks on symtabs.
722 Expand symtabs matching an optional regexp.
725 Display the details of GDB configure-time options.
727 maint set|show per-command
728 maint set|show per-command space
729 maint set|show per-command time
730 maint set|show per-command symtab
731 Enable display of per-command gdb resource usage.
733 remove-symbol-file FILENAME
734 remove-symbol-file -a ADDRESS
735 Remove a symbol file added via add-symbol-file. The file to remove
736 can be identified by its filename or by an address that lies within
737 the boundaries of this symbol file in memory.
740 info exceptions REGEXP
741 Display the list of Ada exceptions defined in the program being
742 debugged. If provided, only the exceptions whose names match REGEXP
747 set debug symfile off|on
749 Control display of debugging info regarding reading symbol files and
750 symbol tables within those files
752 set print raw frame-arguments
753 show print raw frame-arguments
754 Set/show whether to print frame arguments in raw mode,
755 disregarding any defined pretty-printers.
757 set remote trace-status-packet
758 show remote trace-status-packet
759 Set/show the use of remote protocol qTStatus packet.
763 Control display of debugging messages related to Nios II targets.
767 Control whether target-assisted range stepping is enabled.
769 set startup-with-shell
770 show startup-with-shell
771 Specifies whether Unix child processes are started via a shell or
776 Use the target memory cache for accesses to the code segment. This
777 improves performance of remote debugging (particularly disassembly).
779 * You can now use a literal value 'unlimited' for options that
780 interpret 0 or -1 as meaning "unlimited". E.g., "set
781 trace-buffer-size unlimited" is now an alias for "set
782 trace-buffer-size -1" and "set height unlimited" is now an alias for
785 * The "set debug symtab-create" debugging option of GDB has been changed to
786 accept a verbosity level. 0 means "off", 1 provides basic debugging
787 output, and values of 2 or greater provides more verbose output.
789 * New command-line options
791 Display the details of GDB configure-time options.
793 * The command 'tsave' can now support new option '-ctf' to save trace
794 buffer in Common Trace Format.
796 * Newly installed $prefix/bin/gcore acts as a shell interface for the
799 * GDB now implements the the C++ 'typeid' operator.
801 * The new convenience variable $_exception holds the exception being
802 thrown or caught at an exception-related catchpoint.
804 * The exception-related catchpoints, like "catch throw", now accept a
805 regular expression which can be used to filter exceptions by type.
807 * The new convenience variable $_exitsignal is automatically set to
808 the terminating signal number when the program being debugged dies
809 due to an uncaught signal.
813 ** All MI commands now accept an optional "--language" option.
814 Support for this feature can be verified by using the "-list-features"
815 command, which should contain "language-option".
817 ** The new command -info-gdb-mi-command allows the user to determine
818 whether a GDB/MI command is supported or not.
820 ** The "^error" result record returned when trying to execute an undefined
821 GDB/MI command now provides a variable named "code" whose content is the
822 "undefined-command" error code. Support for this feature can be verified
823 by using the "-list-features" command, which should contain
824 "undefined-command-error-code".
826 ** The -trace-save MI command can optionally save trace buffer in Common
829 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
831 ** The command -data-list-register-values now accepts an optional
832 "--skip-unavailable" option. When used, only the available registers
835 ** The new command -trace-frame-collected dumps collected variables,
836 computed expressions, tvars, memory and registers in a traceframe.
838 ** The commands -stack-list-locals, -stack-list-arguments and
839 -stack-list-variables now accept an option "--skip-unavailable".
840 When used, only the available locals or arguments are displayed.
842 ** The -exec-run command now accepts an optional "--start" option.
843 When used, the command follows the same semantics as the "start"
844 command, stopping the program's execution at the start of its
845 main subprogram. Support for this feature can be verified using
846 the "-list-features" command, which should contain
847 "exec-run-start-option".
849 ** The new commands -catch-assert and -catch-exceptions insert
850 catchpoints stopping the program when Ada exceptions are raised.
852 ** The new command -info-ada-exceptions provides the equivalent of
853 the new "info exceptions" command.
855 * New system-wide configuration scripts
856 A GDB installation now provides scripts suitable for use as system-wide
857 configuration scripts for the following systems:
861 * GDB now supports target-assigned range stepping with remote targets.
862 This improves the performance of stepping source lines by reducing
863 the number of control packets from/to GDB. See "New remote packets"
866 * GDB now understands the element 'tvar' in the XML traceframe info.
867 It has the id of the collected trace state variables.
869 * On S/390 targets that provide the transactional-execution feature,
870 the program interruption transaction diagnostic block (TDB) is now
871 represented as a number of additional "registers" in GDB.
877 The vCont packet supports a new 'r' action, that tells the remote
878 stub to step through an address range itself, without GDB
879 involvemement at each single-step.
881 qXfer:libraries-svr4:read's annex
882 The previously unused annex of the qXfer:libraries-svr4:read packet
883 is now used to support passing an argument list. The remote stub
884 reports support for this argument list to GDB's qSupported query.
885 The defined arguments are "start" and "prev", used to reduce work
886 necessary for library list updating, resulting in significant
889 * New features in the GDB remote stub, GDBserver
891 ** GDBserver now supports target-assisted range stepping. Currently
892 enabled on x86/x86_64 GNU/Linux targets.
894 ** GDBserver now adds element 'tvar' in the XML in the reply to
895 'qXfer:traceframe-info:read'. It has the id of the collected
896 trace state variables.
898 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
901 * New 'z' formatter for printing and examining memory, this displays the
902 value as hexadecimal zero padded on the left to the size of the type.
904 * GDB can now use Windows x64 unwinding data.
906 * The "set remotebaud" command has been replaced by "set serial baud".
907 Similarly, "show remotebaud" has been replaced by "show serial baud".
908 The "set remotebaud" and "show remotebaud" commands are still available
909 to provide backward compatibility with older versions of GDB.
911 *** Changes in GDB 7.6
913 * Target record has been renamed to record-full.
914 Record/replay is now enabled with the "record full" command.
915 This also affects settings that are associated with full record/replay
916 that have been moved from "set/show record" to "set/show record full":
918 set|show record full insn-number-max
919 set|show record full stop-at-limit
920 set|show record full memory-query
922 * A new record target "record-btrace" has been added. The new target
923 uses hardware support to record the control-flow of a process. It
924 does not support replaying the execution, but it implements the
925 below new commands for investigating the recorded execution log.
926 This new recording method can be enabled using:
930 The "record-btrace" target is only available on Intel Atom processors
931 and requires a Linux kernel 2.6.32 or later.
933 * Two new commands have been added for record/replay to give information
934 about the recorded execution without having to replay the execution.
935 The commands are only supported by "record btrace".
937 record instruction-history prints the execution history at
938 instruction granularity
940 record function-call-history prints the execution history at
943 * New native configurations
945 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
946 FreeBSD/powerpc powerpc*-*-freebsd
947 x86_64/Cygwin x86_64-*-cygwin*
948 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
952 ARM AArch64 aarch64*-*-elf
953 ARM AArch64 GNU/Linux aarch64*-*-linux
954 Lynx 178 PowerPC powerpc-*-lynx*178
955 x86_64/Cygwin x86_64-*-cygwin*
956 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
958 * If the configured location of system.gdbinit file (as given by the
959 --with-system-gdbinit option at configure time) is in the
960 data-directory (as specified by --with-gdb-datadir at configure
961 time) or in one of its subdirectories, then GDB will look for the
962 system-wide init file in the directory specified by the
963 --data-directory command-line option.
965 * New command line options:
967 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
968 other initialization files, unlike -nx which disables all of them.
970 * Removed command line options
972 -epoch This was used by the gdb mode in Epoch, an ancient fork of
975 * The 'ptype' and 'whatis' commands now accept an argument to control
978 * 'info proc' now works on some core files.
982 ** Vectors can be created with gdb.Type.vector.
984 ** Python's atexit.register now works in GDB.
986 ** Types can be pretty-printed via a Python API.
988 ** Python 3 is now supported (in addition to Python 2.4 or later)
990 ** New class gdb.Architecture exposes GDB's internal representation
991 of architecture in the Python API.
993 ** New method Frame.architecture returns the gdb.Architecture object
994 corresponding to the frame's architecture.
996 * New Python-based convenience functions:
998 ** $_memeq(buf1, buf2, length)
999 ** $_streq(str1, str2)
1001 ** $_regex(str, regex)
1003 * The 'cd' command now defaults to using '~' (the home directory) if not
1006 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1007 default for GCC since November 2000.
1009 * The command 'forward-search' can now be abbreviated as 'fo'.
1011 * The command 'info tracepoints' can now display 'installed on target'
1012 or 'not installed on target' for each non-pending location of tracepoint.
1014 * New configure options
1016 --enable-libmcheck/--disable-libmcheck
1017 By default, development versions are built with -lmcheck on hosts
1018 that support it, in order to help track memory corruption issues.
1019 Release versions, on the other hand, are built without -lmcheck
1020 by default. The --enable-libmcheck/--disable-libmcheck configure
1021 options allow the user to override that default.
1022 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1023 This configure option allows the user to build GDB with
1024 libbabeltrace using which GDB can read Common Trace Format data.
1026 * New commands (for set/show, see "New options" below)
1029 Catch signals. This is similar to "handle", but allows commands and
1030 conditions to be attached.
1033 List the BFDs known to GDB.
1035 python-interactive [command]
1037 Start a Python interactive prompt, or evaluate the optional command
1038 and print the result of expressions.
1041 "py" is a new alias for "python".
1043 enable type-printer [name]...
1044 disable type-printer [name]...
1045 Enable or disable type printers.
1049 ** For the Renesas Super-H architecture, the "regs" command has been removed
1050 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1055 set print type methods (on|off)
1056 show print type methods
1057 Control whether method declarations are displayed by "ptype".
1058 The default is to show them.
1060 set print type typedefs (on|off)
1061 show print type typedefs
1062 Control whether typedef definitions are displayed by "ptype".
1063 The default is to show them.
1065 set filename-display basename|relative|absolute
1066 show filename-display
1067 Control the way in which filenames is displayed.
1068 The default is "relative", which preserves previous behavior.
1070 set trace-buffer-size
1071 show trace-buffer-size
1072 Request target to change the size of trace buffer.
1074 set remote trace-buffer-size-packet auto|on|off
1075 show remote trace-buffer-size-packet
1076 Control the use of the remote protocol `QTBuffer:size' packet.
1080 Control display of debugging messages related to ARM AArch64.
1083 set debug coff-pe-read
1084 show debug coff-pe-read
1085 Control display of debugging messages related to reading of COFF/PE
1090 Control display of debugging messages related to Mach-O symbols
1093 set debug notification
1094 show debug notification
1095 Control display of debugging info for async remote notification.
1099 ** Command parameter changes are now notified using new async record
1100 "=cmd-param-changed".
1101 ** Trace frame changes caused by command "tfind" are now notified using
1102 new async record "=traceframe-changed".
1103 ** The creation, deletion and modification of trace state variables
1104 are now notified using new async records "=tsv-created",
1105 "=tsv-deleted" and "=tsv-modified".
1106 ** The start and stop of process record are now notified using new
1107 async record "=record-started" and "=record-stopped".
1108 ** Memory changes are now notified using new async record
1110 ** The data-disassemble command response will include a "fullname" field
1111 containing the absolute file name when source has been requested.
1112 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1113 command, to allow pattern filling of memory areas.
1114 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1115 library load/unload events.
1116 ** The response to breakpoint commands and breakpoint async records
1117 includes an "installed" field containing a boolean state about each
1118 non-pending tracepoint location is whether installed on target or not.
1119 ** Output of the "-trace-status" command includes a "trace-file" field
1120 containing the name of the trace file being examined. This field is
1121 optional, and only present when examining a trace file.
1122 ** The "fullname" field is now always present along with the "file" field,
1123 even if the file cannot be found by GDB.
1125 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1126 You must have the LZMA library available when configuring GDB for this
1127 feature to be enabled. For more information, see:
1128 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1130 * New remote packets
1133 Set the size of trace buffer. The remote stub reports support for this
1134 packet to gdb's qSupported query.
1137 Enable Branch Trace Store (BTS)-based branch tracing for the current
1138 thread. The remote stub reports support for this packet to gdb's
1142 Disable branch tracing for the current thread. The remote stub reports
1143 support for this packet to gdb's qSupported query.
1146 Read the traced branches for the current thread. The remote stub
1147 reports support for this packet to gdb's qSupported query.
1149 *** Changes in GDB 7.5
1151 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1152 for more x32 ABI info.
1154 * GDB now supports access to MIPS DSP registers on Linux targets.
1156 * GDB now supports debugging microMIPS binaries.
1158 * The "info os" command on GNU/Linux can now display information on
1159 several new classes of objects managed by the operating system:
1160 "info os procgroups" lists process groups
1161 "info os files" lists file descriptors
1162 "info os sockets" lists internet-domain sockets
1163 "info os shm" lists shared-memory regions
1164 "info os semaphores" lists semaphores
1165 "info os msg" lists message queues
1166 "info os modules" lists loaded kernel modules
1168 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1169 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1170 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1171 options and inspect the probe arguments using the new $_probe_arg family
1172 of convenience variables. You can obtain more information about SystemTap
1173 in <http://sourceware.org/systemtap/>.
1175 * GDB now supports reversible debugging on ARM, it allows you to
1176 debug basic ARM and THUMB instructions, and provides
1177 record/replay support.
1179 * The option "symbol-reloading" has been deleted as it is no longer used.
1183 ** GDB commands implemented in Python can now be put in command class
1186 ** The "maint set python print-stack on|off" is now deleted.
1188 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1189 apply "flag enum"-style pretty-printing to any enum.
1191 ** gdb.lookup_symbol can now work when there is no current frame.
1193 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1194 the source at which the symbol was defined.
1196 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1197 method 'value'. The former indicates whether the symbol needs a
1198 frame in order to compute its value, and the latter computes the
1201 ** A new method 'referenced_value' on gdb.Value objects which can
1202 dereference pointer as well as C++ reference values.
1204 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1205 which return the global and static blocks (as gdb.Block objects),
1206 of the underlying symbol table, respectively.
1208 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1209 object associated with a PC value.
1211 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1212 of the address range occupied by code for the current source line.
1214 * Go language support.
1215 GDB now supports debugging programs written in the Go programming
1218 * GDBserver now supports stdio connections.
1219 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1221 * The binary "gdbtui" can no longer be built or installed.
1222 Use "gdb -tui" instead.
1224 * GDB will now print "flag" enums specially. A flag enum is one where
1225 all the enumerator values have no bits in common when pairwise
1226 "and"ed. When printing a value whose type is a flag enum, GDB will
1227 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1228 (gdb) print (enum E) 3
1231 * The filename part of a linespec will now match trailing components
1232 of a source file name. For example, "break gcc/expr.c:1000" will
1233 now set a breakpoint in build/gcc/expr.c, but not
1234 build/libcpp/expr.c.
1236 * The "info proc" and "generate-core-file" commands will now also
1237 work on remote targets connected to GDBserver on Linux.
1239 * The command "info catch" has been removed. It has been disabled
1240 since December 2007.
1242 * The "catch exception" and "catch assert" commands now accept
1243 a condition at the end of the command, much like the "break"
1244 command does. For instance:
1246 (gdb) catch exception Constraint_Error if Barrier = True
1248 Previously, it was possible to add a condition to such catchpoints,
1249 but it had to be done as a second step, after the catchpoint had been
1250 created, using the "condition" command.
1252 * The "info static-tracepoint-marker" command will now also work on
1253 native Linux targets with in-process agent.
1255 * GDB can now set breakpoints on inlined functions.
1257 * The .gdb_index section has been updated to include symbols for
1258 inlined functions. GDB will ignore older .gdb_index sections by
1259 default, which could cause symbol files to be loaded more slowly
1260 until their .gdb_index sections can be recreated. The new command
1261 "set use-deprecated-index-sections on" will cause GDB to use any older
1262 .gdb_index sections it finds. This will restore performance, but the
1263 ability to set breakpoints on inlined functions will be lost in symbol
1264 files with older .gdb_index sections.
1266 The .gdb_index section has also been updated to record more information
1267 about each symbol. This speeds up the "info variables", "info functions"
1268 and "info types" commands when used with programs having the .gdb_index
1269 section, as well as speeding up debugging with shared libraries using
1270 the .gdb_index section.
1272 * Ada support for GDB/MI Variable Objects has been added.
1274 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1279 ** New command -info-os is the MI equivalent of "info os".
1281 ** Output logs ("set logging" and related) now include MI output.
1285 ** "set use-deprecated-index-sections on|off"
1286 "show use-deprecated-index-sections on|off"
1287 Controls the use of deprecated .gdb_index sections.
1289 ** "catch load" and "catch unload" can be used to stop when a shared
1290 library is loaded or unloaded, respectively.
1292 ** "enable count" can be used to auto-disable a breakpoint after
1295 ** "info vtbl" can be used to show the virtual method tables for
1296 C++ and Java objects.
1298 ** "explore" and its sub commands "explore value" and "explore type"
1299 can be used to recursively explore values and types of
1300 expressions. These commands are available only if GDB is
1301 configured with '--with-python'.
1303 ** "info auto-load" shows status of all kinds of auto-loaded files,
1304 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1305 sequences of commands files, "info auto-load python-scripts"
1306 shows status of auto-loading Python script files,
1307 "info auto-load local-gdbinit" shows status of loading init file
1308 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1309 status of inferior specific thread debugging shared library loading.
1311 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1312 and "show auto-load-scripts" commands have been deprecated, use their
1313 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1314 and "show auto-load python-scripts" counterparts instead.
1316 ** "dprintf location,format,args..." creates a dynamic printf, which
1317 is basically a breakpoint that does a printf and immediately
1318 resumes your program's execution, so it is like a printf that you
1319 can insert dynamically at runtime instead of at compiletime.
1321 ** "set print symbol"
1323 Controls whether GDB attempts to display the symbol, if any,
1324 corresponding to addresses it prints. This defaults to "on", but
1325 you can set it to "off" to restore GDB's previous behavior.
1327 * Deprecated commands
1329 ** For the Renesas Super-H architecture, the "regs" command has been
1330 deprecated, and "info all-registers" should be used instead.
1334 Renesas RL78 rl78-*-elf
1335 HP OpenVMS ia64 ia64-hp-openvms*
1337 * GDBserver supports evaluation of breakpoint conditions. When
1338 support is advertised by GDBserver, GDB may be told to send the
1339 breakpoint conditions in bytecode form to GDBserver. GDBserver
1340 will only report the breakpoint trigger to GDB when its condition
1345 set mips compression
1346 show mips compression
1347 Select the compressed ISA encoding used in functions that have no symbol
1348 information available. The encoding can be set to either of:
1351 and is updated automatically from ELF file flags if available.
1353 set breakpoint condition-evaluation
1354 show breakpoint condition-evaluation
1355 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1356 GDBserver ("target"). Default option "auto" chooses the most efficient
1358 This option can improve debugger efficiency depending on the speed of the
1362 Disable auto-loading globally.
1365 Show auto-loading setting of all kinds of auto-loaded files.
1367 set auto-load gdb-scripts on|off
1368 show auto-load gdb-scripts
1369 Control auto-loading of GDB canned sequences of commands files.
1371 set auto-load python-scripts on|off
1372 show auto-load python-scripts
1373 Control auto-loading of Python script files.
1375 set auto-load local-gdbinit on|off
1376 show auto-load local-gdbinit
1377 Control loading of init file (.gdbinit) from current directory.
1379 set auto-load libthread-db on|off
1380 show auto-load libthread-db
1381 Control auto-loading of inferior specific thread debugging shared library.
1383 set auto-load scripts-directory <dir1>[:<dir2>...]
1384 show auto-load scripts-directory
1385 Set a list of directories from which to load auto-loaded scripts.
1386 Automatically loaded Python scripts and GDB scripts are located in one
1387 of the directories listed by this option.
1388 The delimiter (':' above) may differ according to the host platform.
1390 set auto-load safe-path <dir1>[:<dir2>...]
1391 show auto-load safe-path
1392 Set a list of directories from which it is safe to auto-load files.
1393 The delimiter (':' above) may differ according to the host platform.
1395 set debug auto-load on|off
1396 show debug auto-load
1397 Control display of debugging info for auto-loading the files above.
1399 set dprintf-style gdb|call|agent
1401 Control the way in which a dynamic printf is performed; "gdb"
1402 requests a GDB printf command, while "call" causes dprintf to call a
1403 function in the inferior. "agent" requests that the target agent
1404 (such as GDBserver) do the printing.
1406 set dprintf-function <expr>
1407 show dprintf-function
1408 set dprintf-channel <expr>
1409 show dprintf-channel
1410 Set the function and optional first argument to the call when using
1411 the "call" style of dynamic printf.
1413 set disconnected-dprintf on|off
1414 show disconnected-dprintf
1415 Control whether agent-style dynamic printfs continue to be in effect
1416 after GDB disconnects.
1418 * New configure options
1420 --with-auto-load-dir
1421 Configure default value for the 'set auto-load scripts-directory'
1422 setting above. It defaults to '$debugdir:$datadir/auto-load',
1423 $debugdir representing global debugging info directories (available
1424 via 'show debug-file-directory') and $datadir representing GDB's data
1425 directory (available via 'show data-directory').
1427 --with-auto-load-safe-path
1428 Configure default value for the 'set auto-load safe-path' setting
1429 above. It defaults to the --with-auto-load-dir setting.
1431 --without-auto-load-safe-path
1432 Set 'set auto-load safe-path' to '/', effectively disabling this
1435 * New remote packets
1437 z0/z1 conditional breakpoints extension
1439 The z0/z1 breakpoint insertion packets have been extended to carry
1440 a list of conditional expressions over to the remote stub depending on the
1441 condition evaluation mode. The use of this extension can be controlled
1442 via the "set remote conditional-breakpoints-packet" command.
1446 Specify the signals which the remote stub may pass to the debugged
1447 program without GDB involvement.
1449 * New command line options
1451 --init-command=FILE, -ix Like --command, -x but execute it
1452 before loading inferior.
1453 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1454 execute it before loading inferior.
1456 *** Changes in GDB 7.4
1458 * GDB now handles ambiguous linespecs more consistently; the existing
1459 FILE:LINE support has been expanded to other types of linespecs. A
1460 breakpoint will now be set on all matching locations in all
1461 inferiors, and locations will be added or removed according to
1464 * GDB now allows you to skip uninteresting functions and files when
1465 stepping with the "skip function" and "skip file" commands.
1467 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1468 and "show remote hardware-watchpoint-length-limit". These allows to
1469 set or show the maximum length limit (in bytes) of a remote
1470 target hardware watchpoint.
1472 This allows e.g. to use "unlimited" hardware watchpoints with the
1473 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1474 watchpoints are slower than real hardware watchpoints but are
1475 significantly faster than gdb software watchpoints.
1479 ** The register_pretty_printer function in module gdb.printing now takes
1480 an optional `replace' argument. If True, the new printer replaces any
1483 ** The "maint set python print-stack on|off" command has been
1484 deprecated and will be deleted in GDB 7.5.
1485 A new command: "set python print-stack none|full|message" has
1486 replaced it. Additionally, the default for "print-stack" is
1487 now "message", which just prints the error message without
1490 ** A prompt substitution hook (prompt_hook) is now available to the
1493 ** A new Python module, gdb.prompt has been added to the GDB Python
1494 modules library. This module provides functionality for
1495 escape sequences in prompts (used by set/show
1496 extended-prompt). These escape sequences are replaced by their
1497 corresponding value.
1499 ** Python commands and convenience-functions located in
1500 'data-directory'/python/gdb/command and
1501 'data-directory'/python/gdb/function are now automatically loaded
1504 ** Blocks now provide four new attributes. global_block and
1505 static_block will return the global and static blocks
1506 respectively. is_static and is_global are boolean attributes
1507 that indicate if the block is one of those two types.
1509 ** Symbols now provide the "type" attribute, the type of the symbol.
1511 ** The "gdb.breakpoint" function has been deprecated in favor of
1514 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1515 of a function. This class is based on the "finish" command
1516 available in the CLI.
1518 ** Type objects for struct and union types now allow access to
1519 the fields using standard Python dictionary (mapping) methods.
1520 For example, "some_type['myfield']" now works, as does
1521 "some_type.items()".
1523 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1526 ** A new function, "deep_items" has been added to the gdb.types
1527 module in the GDB Python modules library. This function returns
1528 an iterator over the fields of a struct or union type. Unlike
1529 the standard Python "iteritems" method, it will recursively traverse
1530 any anonymous fields.
1534 ** "*stopped" events can report several new "reason"s, such as
1537 ** Breakpoint changes are now notified using new async records, like
1538 "=breakpoint-modified".
1540 ** New command -ada-task-info.
1542 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1543 $sdir specifies the default system locations of shared libraries.
1544 $pdir specifies the directory where the libpthread used by the application
1547 GDB no longer looks in $sdir and $pdir after it has searched the directories
1548 mentioned in libthread-db-search-path. If you want to search those
1549 directories, they must be specified in libthread-db-search-path.
1550 The default value of libthread-db-search-path on GNU/Linux and Solaris
1551 systems is now "$sdir:$pdir".
1553 $pdir is not supported by gdbserver, it is currently ignored.
1554 $sdir is supported by gdbserver.
1556 * New configure option --with-iconv-bin.
1557 When using the internationalization support like the one in the GNU C
1558 library, GDB will invoke the "iconv" program to get a list of supported
1559 character sets. If this program lives in a non-standard location, one can
1560 use this option to specify where to find it.
1562 * When natively debugging programs on PowerPC BookE processors running
1563 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1564 watchpoints, which specify a mask in addition to an address to watch.
1565 The mask specifies that some bits of an address (the bits which are
1566 reset in the mask) should be ignored when matching the address accessed
1567 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1568 section in the user manual for more details.
1570 * The new option --once causes GDBserver to stop listening for connections once
1571 the first connection is made. The listening port used by GDBserver will
1572 become available after that.
1574 * New commands "info macros" and "alias" have been added.
1576 * New function parameters suffix @entry specifies value of function parameter
1577 at the time the function got called. Entry values are available only since
1583 "!" is now an alias of the "shell" command.
1584 Note that no space is needed between "!" and SHELL COMMAND.
1588 watch EXPRESSION mask MASK_VALUE
1589 The watch command now supports the mask argument which allows creation
1590 of masked watchpoints, if the current architecture supports this feature.
1592 info auto-load-scripts [REGEXP]
1593 This command was formerly named "maintenance print section-scripts".
1594 It is now generally useful and is no longer a maintenance-only command.
1596 info macro [-all] [--] MACRO
1597 The info macro command has new options `-all' and `--'. The first for
1598 printing all definitions of a macro. The second for explicitly specifying
1599 the end of arguments and the beginning of the macro name in case the macro
1600 name starts with a hyphen.
1602 collect[/s] EXPRESSIONS
1603 The tracepoint collect command now takes an optional modifier "/s"
1604 that directs it to dereference pointer-to-character types and
1605 collect the bytes of memory up to a zero byte. The behavior is
1606 similar to what you see when you use the regular print command on a
1607 string. An optional integer following the "/s" sets a bound on the
1608 number of bytes that will be collected.
1611 The trace start command now interprets any supplied arguments as a
1612 note to be recorded with the trace run, with an effect similar to
1613 setting the variable trace-notes.
1616 The trace stop command now interprets any arguments as a note to be
1617 mentioned along with the tstatus report that the trace was stopped
1618 with a command. The effect is similar to setting the variable
1621 * Tracepoints can now be enabled and disabled at any time after a trace
1622 experiment has been started using the standard "enable" and "disable"
1623 commands. It is now possible to start a trace experiment with no enabled
1624 tracepoints; GDB will display a warning, but will allow the experiment to
1625 begin, assuming that tracepoints will be enabled as needed while the trace
1628 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1629 locations with 4-byte instructions, when they were previously
1630 limited to locations with instructions of 5 bytes or longer.
1634 set debug dwarf2-read
1635 show debug dwarf2-read
1636 Turns on or off display of debugging messages related to reading
1637 DWARF debug info. The default is off.
1639 set debug symtab-create
1640 show debug symtab-create
1641 Turns on or off display of debugging messages related to symbol table
1642 creation. The default is off.
1645 show extended-prompt
1646 Set the GDB prompt, and allow escape sequences to be inserted to
1647 display miscellaneous information (see 'help set extended-prompt'
1648 for the list of sequences). This prompt (and any information
1649 accessed through the escape sequences) is updated every time the
1650 prompt is displayed.
1652 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1653 show print entry-values
1654 Set printing of frame argument values at function entry. In some cases
1655 GDB can determine the value of function argument which was passed by the
1656 function caller, even if the value was modified inside the called function.
1658 set debug entry-values
1659 show debug entry-values
1660 Control display of debugging info for determining frame argument values at
1661 function entry and virtual tail call frames.
1663 set basenames-may-differ
1664 show basenames-may-differ
1665 Set whether a source file may have multiple base names.
1666 (A "base name" is the name of a file with the directory part removed.
1667 Example: The base name of "/home/user/hello.c" is "hello.c".)
1668 If set, GDB will canonicalize file names (e.g., expand symlinks)
1669 before comparing them. Canonicalization is an expensive operation,
1670 but it allows the same file be known by more than one base name.
1671 If not set (the default), all source files are assumed to have just
1672 one base name, and gdb will do file name comparisons more efficiently.
1678 Set a user name and notes for the current and any future trace runs.
1679 This is useful for long-running and/or disconnected traces, to
1680 inform others (or yourself) as to who is running the trace, supply
1681 contact information, or otherwise explain what is going on.
1683 set trace-stop-notes
1684 show trace-stop-notes
1685 Set a note attached to the trace run, that is displayed when the
1686 trace has been stopped by a tstop command. This is useful for
1687 instance as an explanation, if you are stopping a trace run that was
1688 started by someone else.
1690 * New remote packets
1694 Dynamically enable a tracepoint in a started trace experiment.
1698 Dynamically disable a tracepoint in a started trace experiment.
1702 Set the user and notes of the trace run.
1706 Query the current status of a tracepoint.
1710 Query the minimum length of instruction at which a fast tracepoint may
1713 * Dcache size (number of lines) and line-size are now runtime-configurable
1714 via "set dcache line" and "set dcache line-size" commands.
1718 Texas Instruments TMS320C6x tic6x-*-*
1722 Renesas RL78 rl78-*-elf
1724 *** Changes in GDB 7.3.1
1726 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1728 *** Changes in GDB 7.3
1730 * GDB has a new command: "thread find [REGEXP]".
1731 It finds the thread id whose name, target id, or thread extra info
1732 matches the given regular expression.
1734 * The "catch syscall" command now works on mips*-linux* targets.
1736 * The -data-disassemble MI command now supports modes 2 and 3 for
1737 dumping the instruction opcodes.
1739 * New command line options
1741 -data-directory DIR Specify DIR as the "data-directory".
1742 This is mostly for testing purposes.
1744 * The "maint set python auto-load on|off" command has been renamed to
1745 "set auto-load-scripts on|off".
1747 * GDB has a new command: "set directories".
1748 It is like the "dir" command except that it replaces the
1749 source path list instead of augmenting it.
1751 * GDB now understands thread names.
1753 On GNU/Linux, "info threads" will display the thread name as set by
1754 prctl or pthread_setname_np.
1756 There is also a new command, "thread name", which can be used to
1757 assign a name internally for GDB to display.
1760 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1761 has been integrated into GDB.
1765 ** The function gdb.Write now accepts an optional keyword 'stream'.
1766 This keyword, when provided, will direct the output to either
1767 stdout, stderr, or GDB's logging output.
1769 ** Parameters can now be be sub-classed in Python, and in particular
1770 you may implement the get_set_doc and get_show_doc functions.
1771 This improves how Parameter set/show documentation is processed
1772 and allows for more dynamic content.
1774 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1775 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1776 have an is_valid method.
1778 ** Breakpoints can now be sub-classed in Python, and in particular
1779 you may implement a 'stop' function that is executed each time
1780 the inferior reaches that breakpoint.
1782 ** New function gdb.lookup_global_symbol looks up a global symbol.
1784 ** GDB values in Python are now callable if the value represents a
1785 function. For example, if 'some_value' represents a function that
1786 takes two integer parameters and returns a value, you can call
1787 that function like so:
1789 result = some_value (10,20)
1791 ** Module gdb.types has been added.
1792 It contains a collection of utilities for working with gdb.Types objects:
1793 get_basic_type, has_field, make_enum_dict.
1795 ** Module gdb.printing has been added.
1796 It contains utilities for writing and registering pretty-printers.
1797 New classes: PrettyPrinter, SubPrettyPrinter,
1798 RegexpCollectionPrettyPrinter.
1799 New function: register_pretty_printer.
1801 ** New commands "info pretty-printers", "enable pretty-printer" and
1802 "disable pretty-printer" have been added.
1804 ** gdb.parameter("directories") is now available.
1806 ** New function gdb.newest_frame returns the newest frame in the
1809 ** The gdb.InferiorThread class has a new "name" attribute. This
1810 holds the thread's name.
1812 ** Python Support for Inferior events.
1813 Python scripts can add observers to be notified of events
1814 occurring in the process being debugged.
1815 The following events are currently supported:
1816 - gdb.events.cont Continue event.
1817 - gdb.events.exited Inferior exited event.
1818 - gdb.events.stop Signal received, and Breakpoint hit events.
1822 ** GDB now puts template parameters in scope when debugging in an
1823 instantiation. For example, if you have:
1825 template<int X> int func (void) { return X; }
1827 then if you step into func<5>, "print X" will show "5". This
1828 feature requires proper debuginfo support from the compiler; it
1829 was added to GCC 4.5.
1831 ** The motion commands "next", "finish", "until", and "advance" now
1832 work better when exceptions are thrown. In particular, GDB will
1833 no longer lose control of the inferior; instead, the GDB will
1834 stop the inferior at the point at which the exception is caught.
1835 This functionality requires a change in the exception handling
1836 code that was introduced in GCC 4.5.
1838 * GDB now follows GCC's rules on accessing volatile objects when
1839 reading or writing target state during expression evaluation.
1840 One notable difference to prior behavior is that "print x = 0"
1841 no longer generates a read of x; the value of the assignment is
1842 now always taken directly from the value being assigned.
1844 * GDB now has some support for using labels in the program's source in
1845 linespecs. For instance, you can use "advance label" to continue
1846 execution to a label.
1848 * GDB now has support for reading and writing a new .gdb_index
1849 section. This section holds a fast index of DWARF debugging
1850 information and can be used to greatly speed up GDB startup and
1851 operation. See the documentation for `save gdb-index' for details.
1853 * The "watch" command now accepts an optional "-location" argument.
1854 When used, this causes GDB to watch the memory referred to by the
1855 expression. Such a watchpoint is never deleted due to it going out
1858 * GDB now supports thread debugging of core dumps on GNU/Linux.
1860 GDB now activates thread debugging using the libthread_db library
1861 when debugging GNU/Linux core dumps, similarly to when debugging
1862 live processes. As a result, when debugging a core dump file, GDB
1863 is now able to display pthread_t ids of threads. For example, "info
1864 threads" shows the same output as when debugging the process when it
1865 was live. In earlier releases, you'd see something like this:
1868 * 1 LWP 6780 main () at main.c:10
1870 While now you see this:
1873 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1875 It is also now possible to inspect TLS variables when debugging core
1878 When debugging a core dump generated on a machine other than the one
1879 used to run GDB, you may need to point GDB at the correct
1880 libthread_db library with the "set libthread-db-search-path"
1881 command. See the user manual for more details on this command.
1883 * When natively debugging programs on PowerPC BookE processors running
1884 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1885 which stop execution of the inferior whenever it executes an instruction
1886 at any address within the specified range. See the "PowerPC Embedded"
1887 section in the user manual for more details.
1889 * New features in the GDB remote stub, GDBserver
1891 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1892 and i686 LynxOS (version 5.x).
1894 ** GDBserver is now supported on Blackfin Linux.
1896 * New native configurations
1898 ia64 HP-UX ia64-*-hpux*
1902 Analog Devices, Inc. Blackfin Processor bfin-*
1904 * Ada task switching is now supported on sparc-elf targets when
1905 debugging a program using the Ravenscar Profile. For more information,
1906 see the "Tasking Support when using the Ravenscar Profile" section
1907 in the GDB user manual.
1909 * Guile support was removed.
1911 * New features in the GNU simulator
1913 ** The --map-info flag lists all known core mappings.
1915 ** CFI flashes may be simulated via the "cfi" device.
1917 *** Changes in GDB 7.2
1919 * Shared library support for remote targets by default
1921 When GDB is configured for a generic, non-OS specific target, like
1922 for example, --target=arm-eabi or one of the many *-*-elf targets,
1923 GDB now queries remote stubs for loaded shared libraries using the
1924 `qXfer:libraries:read' packet. Previously, shared library support
1925 was always disabled for such configurations.
1929 ** Argument Dependent Lookup (ADL)
1931 In C++ ADL lookup directs function search to the namespaces of its
1932 arguments even if the namespace has not been imported.
1942 Here the compiler will search for `foo' in the namespace of 'b'
1943 and find A::foo. GDB now supports this. This construct is commonly
1944 used in the Standard Template Library for operators.
1946 ** Improved User Defined Operator Support
1948 In addition to member operators, GDB now supports lookup of operators
1949 defined in a namespace and imported with a `using' directive, operators
1950 defined in the global scope, operators imported implicitly from an
1951 anonymous namespace, and the ADL operators mentioned in the previous
1953 GDB now also supports proper overload resolution for all the previously
1954 mentioned flavors of operators.
1956 ** static const class members
1958 Printing of static const class members that are initialized in the
1959 class definition has been fixed.
1961 * Windows Thread Information Block access.
1963 On Windows targets, GDB now supports displaying the Windows Thread
1964 Information Block (TIB) structure. This structure is visible either
1965 by using the new command `info w32 thread-information-block' or, by
1966 dereferencing the new convenience variable named `$_tlb', a
1967 thread-specific pointer to the TIB. This feature is also supported
1968 when remote debugging using GDBserver.
1970 * Static tracepoints
1972 Static tracepoints are calls in the user program into a tracing
1973 library. One such library is a port of the LTTng kernel tracer to
1974 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1975 When debugging with GDBserver, GDB now supports combining the GDB
1976 tracepoint machinery with such libraries. For example: the user can
1977 use GDB to probe a static tracepoint marker (a call from the user
1978 program into the tracing library) with the new "strace" command (see
1979 "New commands" below). This creates a "static tracepoint" in the
1980 breakpoint list, that can be manipulated with the same feature set
1981 as fast and regular tracepoints. E.g., collect registers, local and
1982 global variables, collect trace state variables, and define
1983 tracepoint conditions. In addition, the user can collect extra
1984 static tracepoint marker specific data, by collecting the new
1985 $_sdata internal variable. When analyzing the trace buffer, you can
1986 inspect $_sdata like any other variable available to GDB. For more
1987 information, see the "Tracepoints" chapter in GDB user manual. New
1988 remote packets have been defined to support static tracepoints, see
1989 the "New remote packets" section below.
1991 * Better reconstruction of tracepoints after disconnected tracing
1993 GDB will attempt to download the original source form of tracepoint
1994 definitions when starting a trace run, and then will upload these
1995 upon reconnection to the target, resulting in a more accurate
1996 reconstruction of the tracepoints that are in use on the target.
2000 You can now exercise direct control over the ways that GDB can
2001 affect your program. For instance, you can disallow the setting of
2002 breakpoints, so that the program can run continuously (assuming
2003 non-stop mode). In addition, the "observer" variable is available
2004 to switch all of the different controls; in observer mode, GDB
2005 cannot affect the target's behavior at all, which is useful for
2006 tasks like diagnosing live systems in the field.
2008 * The new convenience variable $_thread holds the number of the
2011 * New remote packets
2015 Return the address of the Windows Thread Information Block of a given thread.
2019 In response to several of the tracepoint packets, the target may now
2020 also respond with a number of intermediate `qRelocInsn' request
2021 packets before the final result packet, to have GDB handle
2022 relocating an instruction to execute at a different address. This
2023 is particularly useful for stubs that support fast tracepoints. GDB
2024 reports support for this feature in the qSupported packet.
2028 List static tracepoint markers in the target program.
2032 List static tracepoint markers at a given address in the target
2035 qXfer:statictrace:read
2037 Read the static trace data collected (by a `collect $_sdata'
2038 tracepoint action). The remote stub reports support for this packet
2039 to gdb's qSupported query.
2043 Send the current settings of GDB's permission flags.
2047 Send part of the source (textual) form of a tracepoint definition,
2048 which includes location, conditional, and action list.
2050 * The source command now accepts a -s option to force searching for the
2051 script in the source search path even if the script name specifies
2054 * New features in the GDB remote stub, GDBserver
2056 - GDBserver now support tracepoints (including fast tracepoints, and
2057 static tracepoints). The feature is currently supported by the
2058 i386-linux and amd64-linux builds. See the "Tracepoints support
2059 in gdbserver" section in the manual for more information.
2061 GDBserver JIT compiles the tracepoint's conditional agent
2062 expression bytecode into native code whenever possible for low
2063 overhead dynamic tracepoints conditionals. For such tracepoints,
2064 an expression that examines program state is evaluated when the
2065 tracepoint is reached, in order to determine whether to capture
2066 trace data. If the condition is simple and false, processing the
2067 tracepoint finishes very quickly and no data is gathered.
2069 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2070 for static tracepoints support.
2072 - GDBserver now supports x86_64 Windows 64-bit debugging.
2074 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2075 it understands register description.
2077 * The --batch flag now disables pagination and queries.
2079 * X86 general purpose registers
2081 GDB now supports reading/writing byte, word and double-word x86
2082 general purpose registers directly. This means you can use, say,
2083 $ah or $ax to refer, respectively, to the byte register AH and
2084 16-bit word register AX that are actually portions of the 32-bit
2085 register EAX or 64-bit register RAX.
2087 * The `commands' command now accepts a range of breakpoints to modify.
2088 A plain `commands' following a command that creates multiple
2089 breakpoints affects all the breakpoints set by that command. This
2090 applies to breakpoints set by `rbreak', and also applies when a
2091 single `break' command creates multiple breakpoints (e.g.,
2092 breakpoints on overloaded c++ functions).
2094 * The `rbreak' command now accepts a filename specification as part of
2095 its argument, limiting the functions selected by the regex to those
2096 in the specified file.
2098 * Support for remote debugging Windows and SymbianOS shared libraries
2099 from Unix hosts has been improved. Non Windows GDB builds now can
2100 understand target reported file names that follow MS-DOS based file
2101 system semantics, such as file names that include drive letters and
2102 use the backslash character as directory separator. This makes it
2103 possible to transparently use the "set sysroot" and "set
2104 solib-search-path" on Unix hosts to point as host copies of the
2105 target's shared libraries. See the new command "set
2106 target-file-system-kind" described below, and the "Commands to
2107 specify files" section in the user manual for more information.
2111 eval template, expressions...
2112 Convert the values of one or more expressions under the control
2113 of the string template to a command line, and call it.
2115 set target-file-system-kind unix|dos-based|auto
2116 show target-file-system-kind
2117 Set or show the assumed file system kind for target reported file
2120 save breakpoints <filename>
2121 Save all current breakpoint definitions to a file suitable for use
2122 in a later debugging session. To read the saved breakpoint
2123 definitions, use the `source' command.
2125 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2128 info static-tracepoint-markers
2129 Display information about static tracepoint markers in the target.
2131 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2132 Define a static tracepoint by probing a marker at the given
2133 function, line, address, or marker ID.
2137 Enable and disable observer mode.
2139 set may-write-registers on|off
2140 set may-write-memory on|off
2141 set may-insert-breakpoints on|off
2142 set may-insert-tracepoints on|off
2143 set may-insert-fast-tracepoints on|off
2144 set may-interrupt on|off
2145 Set individual permissions for GDB effects on the target. Note that
2146 some of these settings can have undesirable or surprising
2147 consequences, particularly when changed in the middle of a session.
2148 For instance, disabling the writing of memory can prevent
2149 breakpoints from being inserted, cause single-stepping to fail, or
2150 even crash your program, if you disable after breakpoints have been
2151 inserted. However, GDB should not crash.
2153 set record memory-query on|off
2154 show record memory-query
2155 Control whether to stop the inferior if memory changes caused
2156 by an instruction cannot be recorded.
2161 The disassemble command now supports "start,+length" form of two arguments.
2165 ** GDB now provides a new directory location, called the python directory,
2166 where Python scripts written for GDB can be installed. The location
2167 of that directory is <data-directory>/python, where <data-directory>
2168 is the GDB data directory. For more details, see section `Scripting
2169 GDB using Python' in the manual.
2171 ** The GDB Python API now has access to breakpoints, symbols, symbol
2172 tables, program spaces, inferiors, threads and frame's code blocks.
2173 Additionally, GDB Parameters can now be created from the API, and
2174 manipulated via set/show in the CLI.
2176 ** New functions gdb.target_charset, gdb.target_wide_charset,
2177 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2179 ** New exception gdb.GdbError.
2181 ** Pretty-printers are now also looked up in the current program space.
2183 ** Pretty-printers can now be individually enabled and disabled.
2185 ** GDB now looks for names of Python scripts to auto-load in a
2186 special section named `.debug_gdb_scripts', in addition to looking
2187 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2189 * Tracepoint actions were unified with breakpoint commands. In particular,
2190 there are no longer differences in "info break" output for breakpoints and
2191 tracepoints and the "commands" command can be used for both tracepoints and
2192 regular breakpoints.
2196 ARM Symbian arm*-*-symbianelf*
2198 * D language support.
2199 GDB now supports debugging programs written in the D programming
2202 * GDB now supports the extended ptrace interface for PowerPC which is
2203 available since Linux kernel version 2.6.34. This automatically enables
2204 any hardware breakpoints and additional hardware watchpoints available in
2205 the processor. The old ptrace interface exposes just one hardware
2206 watchpoint and no hardware breakpoints.
2208 * GDB is now able to use the Data Value Compare (DVC) register available on
2209 embedded PowerPC processors to implement in hardware simple watchpoint
2210 conditions of the form:
2212 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2214 This works in native GDB running on Linux kernels with the extended ptrace
2215 interface mentioned above.
2217 *** Changes in GDB 7.1
2221 ** Namespace Support
2223 GDB now supports importing of namespaces in C++. This enables the
2224 user to inspect variables from imported namespaces. Support for
2225 namepace aliasing has also been added. So, if a namespace is
2226 aliased in the current scope (e.g. namepace C=A; ) the user can
2227 print variables using the alias (e.g. (gdb) print C::x).
2231 All known bugs relating to the printing of virtual base class were
2232 fixed. It is now possible to call overloaded static methods using a
2237 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2238 and reinterpret_cast<> are now handled by the C++ expression parser.
2242 Xilinx MicroBlaze microblaze-*-*
2247 Xilinx MicroBlaze microblaze
2250 * Multi-program debugging.
2252 GDB now has support for multi-program (a.k.a. multi-executable or
2253 multi-exec) debugging. This allows for debugging multiple inferiors
2254 simultaneously each running a different program under the same GDB
2255 session. See "Debugging Multiple Inferiors and Programs" in the
2256 manual for more information. This implied some user visible changes
2257 in the multi-inferior support. For example, "info inferiors" now
2258 lists inferiors that are not running yet or that have exited
2259 already. See also "New commands" and "New options" below.
2261 * New tracing features
2263 GDB's tracepoint facility now includes several new features:
2265 ** Trace state variables
2267 GDB tracepoints now include support for trace state variables, which
2268 are variables managed by the target agent during a tracing
2269 experiment. They are useful for tracepoints that trigger each
2270 other, so for instance one tracepoint can count hits in a variable,
2271 and then a second tracepoint has a condition that is true when the
2272 count reaches a particular value. Trace state variables share the
2273 $-syntax of GDB convenience variables, and can appear in both
2274 tracepoint actions and condition expressions. Use the "tvariable"
2275 command to create, and "info tvariables" to view; see "Trace State
2276 Variables" in the manual for more detail.
2280 GDB now includes an option for defining fast tracepoints, which
2281 targets may implement more efficiently, such as by installing a jump
2282 into the target agent rather than a trap instruction. The resulting
2283 speedup can be by two orders of magnitude or more, although the
2284 tradeoff is that some program locations on some target architectures
2285 might not allow fast tracepoint installation, for instance if the
2286 instruction to be replaced is shorter than the jump. To request a
2287 fast tracepoint, use the "ftrace" command, with syntax identical to
2288 the regular trace command.
2290 ** Disconnected tracing
2292 It is now possible to detach GDB from the target while it is running
2293 a trace experiment, then reconnect later to see how the experiment
2294 is going. In addition, a new variable disconnected-tracing lets you
2295 tell the target agent whether to continue running a trace if the
2296 connection is lost unexpectedly.
2300 GDB now has the ability to save the trace buffer into a file, and
2301 then use that file as a target, similarly to you can do with
2302 corefiles. You can select trace frames, print data that was
2303 collected in them, and use tstatus to display the state of the
2304 tracing run at the moment that it was saved. To create a trace
2305 file, use "tsave <filename>", and to use it, do "target tfile
2308 ** Circular trace buffer
2310 You can ask the target agent to handle the trace buffer as a
2311 circular buffer, discarding the oldest trace frames to make room for
2312 newer ones, by setting circular-trace-buffer to on. This feature may
2313 not be available for all target agents.
2318 The disassemble command, when invoked with two arguments, now requires
2319 the arguments to be comma-separated.
2322 The info variables command now displays variable definitions. Files
2323 which only declare a variable are not shown.
2326 The source command is now capable of sourcing Python scripts.
2327 This feature is dependent on the debugger being build with Python
2330 Related to this enhancement is also the introduction of a new command
2331 "set script-extension" (see below).
2333 * New commands (for set/show, see "New options" below)
2335 record save [<FILENAME>]
2336 Save a file (in core file format) containing the process record
2337 execution log for replay debugging at a later time.
2339 record restore <FILENAME>
2340 Restore the process record execution log that was saved at an
2341 earlier time, for replay debugging.
2343 add-inferior [-copies <N>] [-exec <FILENAME>]
2346 clone-inferior [-copies <N>] [ID]
2347 Make a new inferior ready to execute the same program another
2348 inferior has loaded.
2353 maint info program-spaces
2354 List the program spaces loaded into GDB.
2356 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2357 show remote interrupt-sequence
2358 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2359 as the sequence to the remote target in order to interrupt the execution.
2360 Ctrl-C is a default. Some system prefers BREAK which is high level of
2361 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2362 Magic SysRq g. It is BREAK signal and character 'g'.
2364 set remote interrupt-on-connect [on | off]
2365 show remote interrupt-on-connect
2366 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2367 remote target when gdb connects to it. This is needed when you debug
2370 set remotebreak [on | off]
2372 Deprecated. Use "set/show remote interrupt-sequence" instead.
2374 tvariable $NAME [ = EXP ]
2375 Create or modify a trace state variable.
2378 List trace state variables and their values.
2380 delete tvariable $NAME ...
2381 Delete one or more trace state variables.
2384 Evaluate the given expressions without collecting anything into the
2385 trace buffer. (Valid in tracepoint actions only.)
2387 ftrace FN / FILE:LINE / *ADDR
2388 Define a fast tracepoint at the given function, line, or address.
2390 * New expression syntax
2392 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2393 GDB now parses 0b101010 identically with 42.
2397 set follow-exec-mode new|same
2398 show follow-exec-mode
2399 Control whether GDB reuses the same inferior across an exec call or
2400 creates a new one. This is useful to be able to restart the old
2401 executable after the inferior having done an exec call.
2403 set default-collect EXPR, ...
2404 show default-collect
2405 Define a list of expressions to be collected at each tracepoint.
2406 This is a useful way to ensure essential items are not overlooked,
2407 such as registers or a critical global variable.
2409 set disconnected-tracing
2410 show disconnected-tracing
2411 If set to 1, the target is instructed to continue tracing if it
2412 loses its connection to GDB. If 0, the target is to stop tracing
2415 set circular-trace-buffer
2416 show circular-trace-buffer
2417 If set to on, the target is instructed to use a circular trace buffer
2418 and discard the oldest trace frames instead of stopping the trace due
2419 to a full trace buffer. If set to off, the trace stops when the buffer
2420 fills up. Some targets may not support this.
2422 set script-extension off|soft|strict
2423 show script-extension
2424 If set to "off", the debugger does not perform any script language
2425 recognition, and all sourced files are assumed to be GDB scripts.
2426 If set to "soft" (the default), files are sourced according to
2427 filename extension, falling back to GDB scripts if the first
2429 If set to "strict", files are sourced according to filename extension.
2431 set ada trust-PAD-over-XVS on|off
2432 show ada trust-PAD-over-XVS
2433 If off, activate a workaround against a bug in the debugging information
2434 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2435 the GCC sources for more information about the GNAT encoding and
2436 PAD types in particular). It is always safe to set this option to
2437 off, but this introduces a slight performance penalty. The default
2440 * Python API Improvements
2442 ** GDB provides the new class gdb.LazyString. This is useful in
2443 some pretty-printing cases. The new method gdb.Value.lazy_string
2444 provides a simple way to create objects of this type.
2446 ** The fields returned by gdb.Type.fields now have an
2447 `is_base_class' attribute.
2449 ** The new method gdb.Type.range returns the range of an array type.
2451 ** The new method gdb.parse_and_eval can be used to parse and
2452 evaluate an expression.
2454 * New remote packets
2457 Define a trace state variable.
2460 Get the current value of a trace state variable.
2463 Set desired tracing behavior upon disconnection.
2466 Set the trace buffer to be linear or circular.
2469 Get data about the tracepoints currently in use.
2473 Process record now works correctly with hardware watchpoints.
2475 Multiple bug fixes have been made to the mips-irix port, making it
2476 much more reliable. In particular:
2477 - Debugging threaded applications is now possible again. Previously,
2478 GDB would hang while starting the program, or while waiting for
2479 the program to stop at a breakpoint.
2480 - Attaching to a running process no longer hangs.
2481 - An error occurring while loading a core file has been fixed.
2482 - Changing the value of the PC register now works again. This fixes
2483 problems observed when using the "jump" command, or when calling
2484 a function from GDB, or even when assigning a new value to $pc.
2485 - With the "finish" and "return" commands, the return value for functions
2486 returning a small array is now correctly printed.
2487 - It is now possible to break on shared library code which gets executed
2488 during a shared library init phase (code executed while executing
2489 their .init section). Previously, the breakpoint would have no effect.
2490 - GDB is now able to backtrace through the signal handler for
2491 non-threaded programs.
2493 PIE (Position Independent Executable) programs debugging is now supported.
2494 This includes debugging execution of PIC (Position Independent Code) shared
2495 libraries although for that, it should be possible to run such libraries as an
2498 *** Changes in GDB 7.0
2500 * GDB now has an interface for JIT compilation. Applications that
2501 dynamically generate code can create symbol files in memory and register
2502 them with GDB. For users, the feature should work transparently, and
2503 for JIT developers, the interface is documented in the GDB manual in the
2504 "JIT Compilation Interface" chapter.
2506 * Tracepoints may now be conditional. The syntax is as for
2507 breakpoints; either an "if" clause appended to the "trace" command,
2508 or the "condition" command is available. GDB sends the condition to
2509 the target for evaluation using the same bytecode format as is used
2510 for tracepoint actions.
2512 * The disassemble command now supports: an optional /r modifier, print the
2513 raw instructions in hex as well as in symbolic form, and an optional /m
2514 modifier to print mixed source+assembly.
2516 * Process record and replay
2518 In a architecture environment that supports ``process record and
2519 replay'', ``process record and replay'' target can record a log of
2520 the process execution, and replay it with both forward and reverse
2523 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2524 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2525 set execution-direction {forward|reverse}, for targets that support
2528 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2529 feature is available with a native GDB running on kernel version
2532 * GDB now has support for multi-byte and wide character sets on the
2533 target. Strings whose character type is wchar_t, char16_t, or
2534 char32_t are now correctly printed. GDB supports wide- and unicode-
2535 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2536 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2537 `printf'. This feature requires iconv to work properly; if your
2538 system does not have a working iconv, GDB can use GNU libiconv. See
2539 the installation instructions for more information.
2541 * GDB now supports automatic retrieval of shared library files from
2542 remote targets. To use this feature, specify a system root that begins
2543 with the `remote:' prefix, either via the `set sysroot' command or via
2544 the `--with-sysroot' configure-time option.
2546 * "info sharedlibrary" now takes an optional regex of libraries to show,
2547 and it now reports if a shared library has no debugging information.
2549 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2550 now complete on file names.
2552 * When completing in expressions, gdb will attempt to limit
2553 completions to allowable structure or union fields, where appropriate.
2554 For instance, consider:
2556 # struct example { int f1; double f2; };
2557 # struct example variable;
2560 If the user types TAB at the end of this command line, the available
2561 completions will be "f1" and "f2".
2563 * Inlined functions are now supported. They show up in backtraces, and
2564 the "step", "next", and "finish" commands handle them automatically.
2566 * GDB now supports the token-splicing (##) and stringification (#)
2567 operators when expanding macros. It also supports variable-arity
2570 * GDB now supports inspecting extra signal information, exported by
2571 the new $_siginfo convenience variable. The feature is currently
2572 implemented on linux ARM, i386 and amd64.
2574 * GDB can now display the VFP floating point registers and NEON vector
2575 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2576 can provide these registers (requires Linux 2.6.30 or later). Remote
2577 and simulator targets may also provide them.
2579 * New remote packets
2582 Search memory for a sequence of bytes.
2585 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2586 operation over reliable transport links. Use of this packet is
2587 controlled by the `set remote noack-packet' command.
2590 Kill the process with the specified process ID. Use this in preference
2591 to `k' when multiprocess protocol extensions are supported.
2594 Obtains additional operating system information
2598 Read or write additional signal information.
2600 * Removed remote protocol undocumented extension
2602 An undocumented extension to the remote protocol's `S' stop reply
2603 packet that permited the stub to pass a process id was removed.
2604 Remote servers should use the `T' stop reply packet instead.
2606 * GDB now supports multiple function calling conventions according to the
2607 DWARF-2 DW_AT_calling_convention function attribute.
2609 * The SH target utilizes the aforementioned change to distinguish between gcc
2610 and Renesas calling convention. It also adds the new CLI commands
2611 `set/show sh calling-convention'.
2613 * GDB can now read compressed debug sections, as produced by GNU gold
2614 with the --compress-debug-sections=zlib flag.
2616 * 64-bit core files are now supported on AIX.
2618 * Thread switching is now supported on Tru64.
2620 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2621 which will be allocated using malloc later in program execution.
2623 * The qXfer:libraries:read remote procotol packet now allows passing a
2624 list of section offsets.
2626 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2627 conditions handling signals delivered during attach or thread creation
2628 have also been fixed.
2630 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2631 From the user's standpoint, all unqualified instances of True and False
2632 are treated as the standard definitions, regardless of context.
2634 * GDB now parses C++ symbol and type names more flexibly. For
2637 template<typename T> class C { };
2640 GDB will now correctly handle all of:
2642 ptype C<char const *>
2643 ptype C<char const*>
2644 ptype C<const char *>
2645 ptype C<const char*>
2647 * New features in the GDB remote stub, gdbserver
2649 - The "--wrapper" command-line argument tells gdbserver to use a
2650 wrapper program to launch programs for debugging.
2652 - On PowerPC and S/390 targets, it is now possible to use a single
2653 gdbserver executable to debug both 32-bit and 64-bit programs.
2654 (This requires gdbserver itself to be built as a 64-bit executable.)
2656 - gdbserver uses the new noack protocol mode for TCP connections to
2657 reduce communications latency, if also supported and enabled in GDB.
2659 - Support for the sparc64-linux-gnu target is now included in
2662 - The amd64-linux build of gdbserver now supports debugging both
2663 32-bit and 64-bit programs.
2665 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2666 now support hardware watchpoints, and will use them automatically
2671 GDB now has support for scripting using Python. Whether this is
2672 available is determined at configure time.
2674 New GDB commands can now be written in Python.
2676 * Ada tasking support
2678 Ada tasks can now be inspected in GDB. The following commands have
2682 Print the list of Ada tasks.
2684 Print detailed information about task number N.
2686 Print the task number of the current task.
2688 Switch the context of debugging to task number N.
2690 * Support for user-defined prefixed commands. The "define" command can
2691 add new commands to existing prefixes, e.g. "target".
2693 * Multi-inferior, multi-process debugging.
2695 GDB now has generalized support for multi-inferior debugging. See
2696 "Debugging Multiple Inferiors" in the manual for more information.
2697 Although availability still depends on target support, the command
2698 set is more uniform now. The GNU/Linux specific multi-forks support
2699 has been migrated to this new framework. This implied some user
2700 visible changes; see "New commands" and also "Removed commands"
2703 * Target descriptions can now describe the target OS ABI. See the
2704 "Target Description Format" section in the user manual for more
2707 * Target descriptions can now describe "compatible" architectures
2708 to indicate that the target can execute applications for a different
2709 architecture in addition to those for the main target architecture.
2710 See the "Target Description Format" section in the user manual for
2713 * Multi-architecture debugging.
2715 GDB now includes general supports for debugging applications on
2716 hybrid systems that use more than one single processor architecture
2717 at the same time. Each such hybrid architecture still requires
2718 specific support to be added. The only hybrid architecture supported
2719 in this version of GDB is the Cell Broadband Engine.
2721 * GDB now supports integrated debugging of Cell/B.E. applications that
2722 use both the PPU and SPU architectures. To enable support for hybrid
2723 Cell/B.E. debugging, you need to configure GDB to support both the
2724 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2725 --enable-targets configure option.
2727 * Non-stop mode debugging.
2729 For some targets, GDB now supports an optional mode of operation in
2730 which you can examine stopped threads while other threads continue
2731 to execute freely. This is referred to as non-stop mode, with the
2732 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2733 section in the user manual for more information.
2735 To be able to support remote non-stop debugging, a remote stub needs
2736 to implement the non-stop mode remote protocol extensions, as
2737 described in the "Remote Non-Stop" section of the user manual. The
2738 GDB remote stub, gdbserver, has been adjusted to support these
2739 extensions on linux targets.
2741 * New commands (for set/show, see "New options" below)
2743 catch syscall [NAME(S) | NUMBER(S)]
2744 Catch system calls. Arguments, which should be names of system
2745 calls or their numbers, mean catch only those syscalls. Without
2746 arguments, every syscall will be caught. When the inferior issues
2747 any of the specified syscalls, GDB will stop and announce the system
2748 call, both when it is called and when its call returns. This
2749 feature is currently available with a native GDB running on the
2750 Linux Kernel, under the following architectures: x86, x86_64,
2751 PowerPC and PowerPC64.
2753 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2755 Search memory for a sequence of bytes.
2757 maint set python print-stack
2758 maint show python print-stack
2759 Show a stack trace when an error is encountered in a Python script.
2762 Invoke CODE by passing it to the Python interpreter.
2767 These allow macros to be defined, undefined, and listed
2771 Show operating system information about processes.
2774 List the inferiors currently under GDB's control.
2777 Switch focus to inferior number NUM.
2780 Detach from inferior number NUM.
2783 Kill inferior number NUM.
2787 set spu stop-on-load
2788 show spu stop-on-load
2789 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2791 set spu auto-flush-cache
2792 show spu auto-flush-cache
2793 Control whether to automatically flush the software-managed cache
2794 during Cell/B.E. debugging.
2796 set sh calling-convention
2797 show sh calling-convention
2798 Control the calling convention used when calling SH target functions.
2801 show debug timestamp
2802 Control display of timestamps with GDB debugging output.
2804 set disassemble-next-line
2805 show disassemble-next-line
2806 Control display of disassembled source lines or instructions when
2809 set remote noack-packet
2810 show remote noack-packet
2811 Set/show the use of remote protocol QStartNoAckMode packet. See above
2812 under "New remote packets."
2814 set remote query-attached-packet
2815 show remote query-attached-packet
2816 Control use of remote protocol `qAttached' (query-attached) packet.
2818 set remote read-siginfo-object
2819 show remote read-siginfo-object
2820 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2823 set remote write-siginfo-object
2824 show remote write-siginfo-object
2825 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2828 set remote reverse-continue
2829 show remote reverse-continue
2830 Control use of remote protocol 'bc' (reverse-continue) packet.
2832 set remote reverse-step
2833 show remote reverse-step
2834 Control use of remote protocol 'bs' (reverse-step) packet.
2836 set displaced-stepping
2837 show displaced-stepping
2838 Control displaced stepping mode. Displaced stepping is a way to
2839 single-step over breakpoints without removing them from the debuggee.
2840 Also known as "out-of-line single-stepping".
2843 show debug displaced
2844 Control display of debugging info for displaced stepping.
2846 maint set internal-error
2847 maint show internal-error
2848 Control what GDB does when an internal error is detected.
2850 maint set internal-warning
2851 maint show internal-warning
2852 Control what GDB does when an internal warning is detected.
2857 Use a wrapper program to launch programs for debugging.
2859 set multiple-symbols (all|ask|cancel)
2860 show multiple-symbols
2861 The value of this variable can be changed to adjust the debugger behavior
2862 when an expression or a breakpoint location contains an ambiguous symbol
2863 name (an overloaded function name, for instance).
2865 set breakpoint always-inserted
2866 show breakpoint always-inserted
2867 Keep breakpoints always inserted in the target, as opposed to inserting
2868 them when resuming the target, and removing them when the target stops.
2869 This option can improve debugger performance on slow remote targets.
2871 set arm fallback-mode (arm|thumb|auto)
2872 show arm fallback-mode
2873 set arm force-mode (arm|thumb|auto)
2875 These commands control how ARM GDB determines whether instructions
2876 are ARM or Thumb. The default for both settings is auto, which uses
2877 the current CPSR value for instructions without symbols; previous
2878 versions of GDB behaved as if "set arm fallback-mode arm".
2880 set disable-randomization
2881 show disable-randomization
2882 Standalone programs run with the virtual address space randomization enabled
2883 by default on some platforms. This option keeps the addresses stable across
2884 multiple debugging sessions.
2888 Control whether other threads are stopped or not when some thread hits
2893 Requests that asynchronous execution is enabled in the target, if available.
2894 In this case, it's possible to resume target in the background, and interact
2895 with GDB while the target is running. "show target-async" displays the
2896 current state of asynchronous execution of the target.
2898 set target-wide-charset
2899 show target-wide-charset
2900 The target-wide-charset is the name of the character set that GDB
2901 uses when printing characters whose type is wchar_t.
2903 set tcp auto-retry (on|off)
2905 set tcp connect-timeout
2906 show tcp connect-timeout
2907 These commands allow GDB to retry failed TCP connections to a remote stub
2908 with a specified timeout period; this is useful if the stub is launched
2909 in parallel with GDB but may not be ready to accept connections immediately.
2911 set libthread-db-search-path
2912 show libthread-db-search-path
2913 Control list of directories which GDB will search for appropriate
2916 set schedule-multiple (on|off)
2917 show schedule-multiple
2918 Allow GDB to resume all threads of all processes or only threads of
2919 the current process.
2923 Use more aggressive caching for accesses to the stack. This improves
2924 performance of remote debugging (particularly backtraces) without
2925 affecting correctness.
2927 set interactive-mode (on|off|auto)
2928 show interactive-mode
2929 Control whether GDB runs in interactive mode (on) or not (off).
2930 When in interactive mode, GDB waits for the user to answer all
2931 queries. Otherwise, GDB does not wait and assumes the default
2932 answer. When set to auto (the default), GDB determines which
2933 mode to use based on the stdin settings.
2938 For program forks, this is replaced by the new more generic `info
2939 inferiors' command. To list checkpoints, you can still use the
2940 `info checkpoints' command, which was an alias for the `info forks'
2944 Replaced by the new `inferior' command. To switch between
2945 checkpoints, you can still use the `restart' command, which was an
2946 alias for the `fork' command.
2949 This is removed, since some targets don't have a notion of
2950 processes. To switch between processes, you can still use the
2951 `inferior' command using GDB's own inferior number.
2954 For program forks, this is replaced by the new more generic `kill
2955 inferior' command. To delete a checkpoint, you can still use the
2956 `delete checkpoint' command, which was an alias for the `delete
2960 For program forks, this is replaced by the new more generic `detach
2961 inferior' command. To detach a checkpoint, you can still use the
2962 `detach checkpoint' command, which was an alias for the `detach
2965 * New native configurations
2967 x86/x86_64 Darwin i[34567]86-*-darwin*
2969 x86_64 MinGW x86_64-*-mingw*
2973 Lattice Mico32 lm32-*
2974 x86 DICOS i[34567]86-*-dicos*
2975 x86_64 DICOS x86_64-*-dicos*
2978 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2979 (mingw32ce) debugging.
2985 These commands were actually not implemented on any target.
2987 *** Changes in GDB 6.8
2989 * New native configurations
2991 NetBSD/hppa hppa*-*netbsd*
2992 Xtensa GNU/Linux xtensa*-*-linux*
2996 NetBSD/hppa hppa*-*-netbsd*
2997 Xtensa GNU/Lunux xtensa*-*-linux*
2999 * Change in command line behavior -- corefiles vs. process ids.
3001 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3002 attaching to process NUMBER fails, GDB no longer attempts to open a
3003 core file named NUMBER. Attaching to a program using the -c option
3004 is no longer supported. Instead, use the '-p' or '--pid' options.
3006 * GDB can now be built as a native debugger for debugging Windows x86
3007 (mingw32) Portable Executable (PE) programs.
3009 * Pending breakpoints no longer change their number when their address
3012 * GDB now supports breakpoints with multiple locations,
3013 including breakpoints on C++ constructors, inside C++ templates,
3014 and in inlined functions.
3016 * GDB's ability to debug optimized code has been improved. GDB more
3017 accurately identifies function bodies and lexical blocks that occupy
3018 more than one contiguous range of addresses.
3020 * Target descriptions can now describe registers for PowerPC.
3022 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3023 registers on PowerPC targets.
3025 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3026 targets even when the libthread_db library is not available.
3028 * The GDB remote stub, gdbserver, now supports the new file transfer
3029 commands (remote put, remote get, and remote delete).
3031 * The GDB remote stub, gdbserver, now supports run and attach in
3032 extended-remote mode.
3034 * hppa*64*-*-hpux11* target broken
3035 The debugger is unable to start a program and fails with the following
3036 error: "Error trying to get information about dynamic linker".
3037 The gdb-6.7 release is also affected.
3039 * GDB now supports the --enable-targets= configure option to allow
3040 building a single GDB executable that supports multiple remote
3041 target architectures.
3043 * GDB now supports debugging C and C++ programs which use the
3044 Decimal Floating Point extension. In addition, the PowerPC target
3045 now has a set of pseudo-registers to inspect decimal float values
3046 stored in two consecutive float registers.
3048 * The -break-insert MI command can optionally create pending
3051 * Improved support for debugging Ada
3052 Many improvements to the Ada language support have been made. These
3054 - Better support for Ada2005 interface types
3055 - Improved handling of arrays and slices in general
3056 - Better support for Taft-amendment types
3057 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3059 - Improved command completion in Ada
3062 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3067 set print frame-arguments (all|scalars|none)
3068 show print frame-arguments
3069 The value of this variable can be changed to control which argument
3070 values should be printed by the debugger when displaying a frame.
3075 Transfer files to and from a remote target, and delete remote files.
3082 Transfer files to and from a remote target, and delete remote files.
3084 * New remote packets
3091 Open, close, read, write, and delete files on the remote system.
3094 Attach to an existing process on the remote system, in extended-remote
3098 Run a new process on the remote system, in extended-remote mode.
3100 *** Changes in GDB 6.7
3102 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3103 bfd, libiberty and opcodes, as revealed by static analysis donated by
3104 Coverity, Inc. (http://scan.coverity.com).
3106 * When looking up multiply-defined global symbols, GDB will now prefer the
3107 symbol definition in the current shared library if it was built using the
3108 -Bsymbolic linker option.
3110 * When the Text User Interface (TUI) is not configured, GDB will now
3111 recognize the -tui command-line option and print a message that the TUI
3114 * The GDB remote stub, gdbserver, now has lower overhead for high
3115 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3117 * GDB for MIPS targets now autodetects whether a remote target provides
3118 32-bit or 64-bit register values.
3120 * Support for C++ member pointers has been improved.
3122 * GDB now understands XML target descriptions, which specify the
3123 target's overall architecture. GDB can read a description from
3124 a local file or over the remote serial protocol.
3126 * Vectors of single-byte data use a new integer type which is not
3127 automatically displayed as character or string data.
3129 * The /s format now works with the print command. It displays
3130 arrays of single-byte integers and pointers to single-byte integers
3133 * Target descriptions can now describe target-specific registers,
3134 for architectures which have implemented the support (currently
3135 only ARM, M68K, and MIPS).
3137 * GDB and the GDB remote stub, gdbserver, now support the XScale
3140 * The GDB remote stub, gdbserver, has been updated to support
3141 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3142 has been rewritten to use the standard GDB remote protocol.
3144 * GDB can now step into C++ functions which are called through thunks.
3146 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3148 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3149 layout. It also supports a TextSeg= and DataSeg= response when only
3150 segment base addresses (rather than offsets) are available.
3152 * The /i format now outputs any trailing branch delay slot instructions
3153 immediately following the last instruction within the count specified.
3155 * The GDB remote protocol "T" stop reply packet now supports a
3156 "library" response. Combined with the new "qXfer:libraries:read"
3157 packet, this response allows GDB to debug shared libraries on targets
3158 where the operating system manages the list of loaded libraries (e.g.
3159 Windows and SymbianOS).
3161 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3162 (DLLs) on Windows and Windows CE targets.
3164 * GDB now supports a faster verification that a .debug file matches its binary
3165 according to its build-id signature, if the signature is present.
3171 Enable or disable hardware flow control (RTS/CTS) on the serial port
3172 when debugging using remote targets.
3174 set mem inaccessible-by-default
3175 show mem inaccessible-by-default
3176 If the target supplies a memory map, for instance via the remote
3177 protocol's "qXfer:memory-map:read" packet, setting this variable
3178 prevents GDB from accessing memory outside the memory map. This
3179 is useful for targets with memory mapped registers or which react
3180 badly to accesses of unmapped address space.
3182 set breakpoint auto-hw
3183 show breakpoint auto-hw
3184 If the target supplies a memory map, for instance via the remote
3185 protocol's "qXfer:memory-map:read" packet, setting this variable
3186 lets GDB use hardware breakpoints automatically for memory regions
3187 where it can not use software breakpoints. This covers both the
3188 "break" command and internal breakpoints used for other commands
3189 including "next" and "finish".
3192 catch exception unhandled
3193 Stop the program execution when Ada exceptions are raised.
3196 Stop the program execution when an Ada assertion failed.
3200 Set an alternate system root for target files. This is a more
3201 general version of "set solib-absolute-prefix", which is now
3202 an alias to "set sysroot".
3205 Provide extended SPU facility status information. This set of
3206 commands is available only when debugging the Cell/B.E. SPU
3209 * New native configurations
3211 OpenBSD/sh sh*-*openbsd*
3214 unset tdesc filename
3216 Use the specified local file as an XML target description, and do
3217 not query the target for its built-in description.
3221 OpenBSD/sh sh*-*-openbsd*
3222 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3223 Toshiba Media Processor mep-elf
3225 * New remote packets
3228 Ignore the specified signals; pass them directly to the debugged program
3229 without stopping other threads or reporting them to GDB.
3231 qXfer:features:read:
3232 Read an XML target description from the target, which describes its
3237 Read or write contents of an spufs file on the target system. These
3238 packets are available only on the Cell/B.E. SPU architecture.
3240 qXfer:libraries:read:
3241 Report the loaded shared libraries. Combined with new "T" packet
3242 response, this packet allows GDB to debug shared libraries on
3243 targets where the operating system manages the list of loaded
3244 libraries (e.g. Windows and SymbianOS).
3248 Support for these obsolete configurations has been removed.
3256 i[34567]86-*-lynxos*
3257 i[34567]86-*-netware*
3258 i[34567]86-*-sco3.2v5*
3259 i[34567]86-*-sco3.2v4*
3261 i[34567]86-*-sysv4.2*
3264 i[34567]86-*-unixware2*
3265 i[34567]86-*-unixware*
3274 * Other removed features
3281 Various m68k-only ROM monitors.
3288 Various Renesas ROM monitors and debugging interfaces for SH and
3293 Support for a Macraigor serial interface to on-chip debugging.
3294 GDB does not directly support the newer parallel or USB
3299 A debug information format. The predecessor to DWARF 2 and
3300 DWARF 3, which are still supported.
3302 Support for the HP aCC compiler on HP-UX/PA-RISC
3304 SOM-encapsulated symbolic debugging information, automatic
3305 invocation of pxdb, and the aCC custom C++ ABI. This does not
3306 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3307 with aCC can still be debugged on an assembly level.
3309 MIPS ".pdr" sections
3311 A MIPS-specific format used to describe stack frame layout
3312 in debugging information.
3316 GDB could work with an older version of Guile to debug
3317 the interpreter and Scheme programs running in it.
3319 set mips stack-arg-size
3320 set mips saved-gpreg-size
3322 Use "set mips abi" to control parameter passing for MIPS.
3324 *** Changes in GDB 6.6
3329 Cell Broadband Engine SPU spu-elf
3331 * GDB can now be configured as a cross-debugger targeting native Windows
3332 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3333 running on a Windows system over TCP/IP to debug Windows programs.
3335 * The GDB remote stub, gdbserver, has been updated to support Windows and
3336 Cygwin debugging. Both single-threaded and multi-threaded programs are
3339 * The "set trust-readonly-sections" command works again. This command was
3340 broken in GDB 6.3, 6.4, and 6.5.
3342 * The "load" command now supports writing to flash memory, if the remote
3343 stub provides the required support.
3345 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3346 longer requires symbolic debug information (e.g. DWARF-2).
3351 unset substitute-path
3352 show substitute-path
3353 Manage a list of substitution rules that GDB uses to rewrite the name
3354 of the directories where the sources are located. This can be useful
3355 for instance when the sources were moved to a different location
3356 between compilation and debugging.
3360 Print each CLI command as it is executed. Each command is prefixed with
3361 a number of `+' symbols representing the nesting depth.
3362 The source command now has a `-v' option to enable the same feature.
3366 The ARM Demon monitor support (RDP protocol, "target rdp").
3368 Kernel Object Display, an embedded debugging feature which only worked with
3369 an obsolete version of Cisco IOS.
3371 The 'set download-write-size' and 'show download-write-size' commands.
3373 * New remote packets
3376 Tell a stub about GDB client features, and request remote target features.
3377 The first feature implemented is PacketSize, which allows the target to
3378 specify the size of packets it can handle - to minimize the number of
3379 packets required and improve performance when connected to a remote
3383 Fetch an OS auxilliary vector from the remote stub. This packet is a
3384 more efficient replacement for qPart:auxv:read.
3386 qXfer:memory-map:read:
3387 Fetch a memory map from the remote stub, including information about
3388 RAM, ROM, and flash memory devices.
3393 Erase and program a flash memory device.
3395 * Removed remote packets
3398 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3399 used it, and only gdbserver implemented it.
3401 *** Changes in GDB 6.5
3405 Renesas M32C/M16C m32c-elf
3407 Morpho Technologies ms1 ms1-elf
3411 init-if-undefined Initialize a convenience variable, but
3412 only if it doesn't already have a value.
3414 The following commands are presently only implemented for native GNU/Linux:
3416 checkpoint Save a snapshot of the program state.
3418 restart <n> Return the program state to a
3419 previously saved state.
3421 info checkpoints List currently saved checkpoints.
3423 delete-checkpoint <n> Delete a previously saved checkpoint.
3425 set|show detach-on-fork Tell gdb whether to detach from a newly
3426 forked process, or to keep debugging it.
3428 info forks List forks of the user program that
3429 are available to be debugged.
3431 fork <n> Switch to debugging one of several
3432 forks of the user program that are
3433 available to be debugged.
3435 delete-fork <n> Delete a fork from the list of forks
3436 that are available to be debugged (and
3437 kill the forked process).
3439 detach-fork <n> Delete a fork from the list of forks
3440 that are available to be debugged (and
3441 allow the process to continue).
3445 Morpho Technologies ms2 ms1-elf
3447 * Improved Windows host support
3449 GDB now builds as a cross debugger hosted on i686-mingw32, including
3450 native console support, and remote communications using either
3451 network sockets or serial ports.
3453 * Improved Modula-2 language support
3455 GDB can now print most types in the Modula-2 syntax. This includes:
3456 basic types, set types, record types, enumerated types, range types,
3457 pointer types and ARRAY types. Procedure var parameters are correctly
3458 printed and hexadecimal addresses and character constants are also
3459 written in the Modula-2 syntax. Best results can be obtained by using
3460 GNU Modula-2 together with the -gdwarf-2 command line option.
3464 The ARM rdi-share module.
3466 The Netware NLM debug server.
3468 *** Changes in GDB 6.4
3470 * New native configurations
3472 OpenBSD/arm arm*-*-openbsd*
3473 OpenBSD/mips64 mips64-*-openbsd*
3477 Morpho Technologies ms1 ms1-elf
3479 * New command line options
3481 --batch-silent As for --batch, but totally silent.
3482 --return-child-result The debugger will exist with the same value
3483 the child (debugged) program exited with.
3484 --eval-command COMMAND, -ex COMMAND
3485 Execute a single GDB CLI command. This may be
3486 specified multiple times and in conjunction
3487 with the --command (-x) option.
3489 * Deprecated commands removed
3491 The following commands, that were deprecated in 2000, have been
3495 set|show arm disassembly-flavor set|show arm disassembler
3496 othernames set arm disassembler
3497 set|show remotedebug set|show debug remote
3498 set|show archdebug set|show debug arch
3499 set|show eventdebug set|show debug event
3502 * New BSD user-level threads support
3504 It is now possible to debug programs using the user-level threads
3505 library on OpenBSD and FreeBSD. Currently supported (target)
3508 FreeBSD/amd64 x86_64-*-freebsd*
3509 FreeBSD/i386 i386-*-freebsd*
3510 OpenBSD/i386 i386-*-openbsd*
3512 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3513 are not yet supported.
3515 * New support for Matsushita MN10300 w/sim added
3516 (Work in progress). mn10300-elf.
3518 * REMOVED configurations and files
3520 VxWorks and the XDR protocol *-*-vxworks
3521 Motorola MCORE mcore-*-*
3522 National Semiconductor NS32000 ns32k-*-*
3524 * New "set print array-indexes" command
3526 After turning this setting "on", GDB prints the index of each element
3527 when displaying arrays. The default is "off" to preserve the previous
3530 * VAX floating point support
3532 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3534 * User-defined command support
3536 In addition to using $arg0..$arg9 for argument passing, it is now possible
3537 to use $argc to determine now many arguments have been passed. See the
3538 section on user-defined commands in the user manual for more information.
3540 *** Changes in GDB 6.3:
3542 * New command line option
3544 GDB now accepts -l followed by a number to set the timeout for remote
3547 * GDB works with GCC -feliminate-dwarf2-dups
3549 GDB now supports a more compact representation of DWARF-2 debug
3550 information using DW_FORM_ref_addr references. These are produced
3551 by GCC with the option -feliminate-dwarf2-dups and also by some
3552 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3553 to use -feliminate-dwarf2-dups.
3555 * Internationalization
3557 When supported by the host system, GDB will be built with
3558 internationalization (libintl). The task of marking up the sources is
3559 continued, we're looking forward to our first translation.
3563 Initial support for debugging programs compiled with the GNAT
3564 implementation of the Ada programming language has been integrated
3565 into GDB. In this release, support is limited to expression evaluation.
3567 * New native configurations
3569 GNU/Linux/m32r m32r-*-linux-gnu
3573 GDB's remote protocol now includes support for the 'p' packet. This
3574 packet is used to fetch individual registers from a remote inferior.
3576 * END-OF-LIFE registers[] compatibility module
3578 GDB's internal register infrastructure has been completely rewritten.
3579 The new infrastructure making possible the implementation of key new
3580 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3583 GDB 6.3 will be the last release to include the the registers[]
3584 compatibility module that allowed out-of-date configurations to
3585 continue to work. This change directly impacts the following
3595 powerpc bdm protocol
3597 Unless there is activity to revive these configurations, they will be
3598 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3600 * OBSOLETE configurations and files
3602 Configurations that have been declared obsolete in this release have
3603 been commented out. Unless there is activity to revive these
3604 configurations, the next release of GDB will have their sources
3605 permanently REMOVED.
3614 *** Changes in GDB 6.2.1:
3616 * MIPS `break main; run' gave an heuristic-fence-post warning
3618 When attempting to run even a simple program, a warning about
3619 heuristic-fence-post being hit would be reported. This problem has
3622 * MIPS IRIX 'long double' crashed GDB
3624 When examining a long double variable, GDB would get a segmentation
3625 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3626 IRIX long double values).
3630 A bug in the VAX stack code was causing problems with the "next"
3631 command. This problem has been fixed.
3633 *** Changes in GDB 6.2:
3635 * Fix for ``many threads''
3637 On GNU/Linux systems that use the NPTL threads library, a program
3638 rapidly creating and deleting threads would confuse GDB leading to the
3641 ptrace: No such process.
3642 thread_db_get_info: cannot get thread info: generic error
3644 This problem has been fixed.
3646 * "-async" and "-noasync" options removed.
3648 Support for the broken "-noasync" option has been removed (it caused
3651 * New ``start'' command.
3653 This command runs the program until the begining of the main procedure.
3655 * New BSD Kernel Data Access Library (libkvm) interface
3657 Using ``target kvm'' it is now possible to debug kernel core dumps and
3658 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3659 platforms. Currently supported (native-only) configurations are:
3661 FreeBSD/amd64 x86_64-*-freebsd*
3662 FreeBSD/i386 i?86-*-freebsd*
3663 NetBSD/i386 i?86-*-netbsd*
3664 NetBSD/m68k m68*-*-netbsd*
3665 NetBSD/sparc sparc-*-netbsd*
3666 OpenBSD/amd64 x86_64-*-openbsd*
3667 OpenBSD/i386 i?86-*-openbsd*
3668 OpenBSD/m68k m68*-openbsd*
3669 OpenBSD/sparc sparc-*-openbsd*
3671 * Signal trampoline code overhauled
3673 Many generic problems with GDB's signal handling code have been fixed.
3674 These include: backtraces through non-contiguous stacks; recognition
3675 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3676 call; backtrace through a signal trampoline; step into and out of
3677 signal handlers; and single-stepping in the signal trampoline.
3679 Please note that kernel bugs are a limiting factor here. These
3680 features have been shown to work on an s390 GNU/Linux system that
3681 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3683 * Cygwin support for DWARF 2 added.
3685 * New native configurations
3687 GNU/Linux/hppa hppa*-*-linux*
3688 OpenBSD/hppa hppa*-*-openbsd*
3689 OpenBSD/m68k m68*-*-openbsd*
3690 OpenBSD/m88k m88*-*-openbsd*
3691 OpenBSD/powerpc powerpc-*-openbsd*
3692 NetBSD/vax vax-*-netbsd*
3693 OpenBSD/vax vax-*-openbsd*
3695 * END-OF-LIFE frame compatibility module
3697 GDB's internal frame infrastructure has been completely rewritten.
3698 The new infrastructure making it possible to support key new features
3699 including DWARF 2 Call Frame Information. To aid in the task of
3700 migrating old configurations to this new infrastructure, a
3701 compatibility module, that allowed old configurations to continue to
3702 work, was also included.
3704 GDB 6.2 will be the last release to include this frame compatibility
3705 module. This change directly impacts the following configurations:
3715 Unless there is activity to revive these configurations, they will be
3716 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3718 * REMOVED configurations and files
3720 Sun 3, running SunOS 3 m68*-*-sunos3*
3721 Sun 3, running SunOS 4 m68*-*-sunos4*
3722 Sun 2, running SunOS 3 m68000-*-sunos3*
3723 Sun 2, running SunOS 4 m68000-*-sunos4*
3724 Motorola 680x0 running LynxOS m68*-*-lynxos*
3725 AT&T 3b1/Unix pc m68*-att-*
3726 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3727 decstation mips-dec-* mips-little-*
3728 riscos mips-*-riscos* mips-*-sysv*
3729 sonymips mips-sony-*
3730 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3732 *** Changes in GDB 6.1.1:
3734 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3736 The TUI (Text-mode User Interface) is now built as part of a default
3737 GDB configuration. It is enabled by either selecting the TUI with the
3738 command line option "-i=tui" or by running the separate "gdbtui"
3739 program. For more information on the TUI, see the manual "Debugging
3742 * Pending breakpoint support (also included in GDB 6.1)
3744 Support has been added to allow you to specify breakpoints in shared
3745 libraries that have not yet been loaded. If a breakpoint location
3746 cannot be found, and the "breakpoint pending" option is set to auto,
3747 GDB queries you if you wish to make the breakpoint pending on a future
3748 shared-library load. If and when GDB resolves the breakpoint symbol,
3749 the pending breakpoint is removed as one or more regular breakpoints
3752 Pending breakpoints are very useful for GCJ Java debugging.
3754 * Fixed ISO-C build problems
3756 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3757 non ISO-C code that stopped them being built using a more strict ISO-C
3758 compiler (e.g., IBM's C compiler).
3760 * Fixed build problem on IRIX 5
3762 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3763 wasn't able to compile compile on an IRIX 5 system.
3765 * Added execute permission to gdb/gdbserver/configure
3767 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3768 permission. This bug would cause configure to fail on a number of
3769 systems (Solaris, IRIX). Ref: server/519.
3771 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3773 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3774 has been updated to use constant array sizes.
3776 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3778 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3779 its generated DWARF Call Frame Info. This encoding was causing GDB to
3780 panic, that panic has been fixed. Ref: gdb/1628.
3782 * Fixed a problem when examining parameters in shared library code.
3784 When examining parameters in optimized shared library code generated
3785 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3786 not available''. GDB now correctly displays the variable's value.
3788 *** Changes in GDB 6.1:
3790 * Removed --with-mmalloc
3792 Support for the mmalloc memory manager has been removed, as it
3793 conflicted with the internal gdb byte cache.
3795 * Changes in AMD64 configurations
3797 The AMD64 target now includes the %cs and %ss registers. As a result
3798 the AMD64 remote protocol has changed; this affects the floating-point
3799 and SSE registers. If you rely on those registers for your debugging,
3800 you should upgrade gdbserver on the remote side.
3802 * Revised SPARC target
3804 The SPARC target has been completely revised, incorporating the
3805 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3806 support for LynxOS and SunOS 4 has been dropped. Calling functions
3807 from within GDB on operating systems with a non-executable stack
3808 (Solaris, OpenBSD) now works.
3812 GDB has a new C++ demangler which does a better job on the mangled
3813 names generated by current versions of g++. It also runs faster, so
3814 with this and other changes gdb should now start faster on large C++
3817 * DWARF 2 Location Expressions
3819 GDB support for location expressions has been extended to support function
3820 arguments and frame bases. Older versions of GDB could crash when they
3823 * C++ nested types and namespaces
3825 GDB's support for nested types and namespaces in C++ has been
3826 improved, especially if you use the DWARF 2 debugging format. (This
3827 is the default for recent versions of GCC on most platforms.)
3828 Specifically, if you have a class "Inner" defined within a class or
3829 namespace "Outer", then GDB realizes that the class's name is
3830 "Outer::Inner", not simply "Inner". This should greatly reduce the
3831 frequency of complaints about not finding RTTI symbols. In addition,
3832 if you are stopped at inside of a function defined within a namespace,
3833 GDB modifies its name lookup accordingly.
3835 * New native configurations
3837 NetBSD/amd64 x86_64-*-netbsd*
3838 OpenBSD/amd64 x86_64-*-openbsd*
3839 OpenBSD/alpha alpha*-*-openbsd*
3840 OpenBSD/sparc sparc-*-openbsd*
3841 OpenBSD/sparc64 sparc64-*-openbsd*
3843 * New debugging protocols
3845 M32R with SDI protocol m32r-*-elf*
3847 * "set prompt-escape-char" command deleted.
3849 The command "set prompt-escape-char" has been deleted. This command,
3850 and its very obscure effet on GDB's prompt, was never documented,
3851 tested, nor mentioned in the NEWS file.
3853 * OBSOLETE configurations and files
3855 Configurations that have been declared obsolete in this release have
3856 been commented out. Unless there is activity to revive these
3857 configurations, the next release of GDB will have their sources
3858 permanently REMOVED.
3860 Sun 3, running SunOS 3 m68*-*-sunos3*
3861 Sun 3, running SunOS 4 m68*-*-sunos4*
3862 Sun 2, running SunOS 3 m68000-*-sunos3*
3863 Sun 2, running SunOS 4 m68000-*-sunos4*
3864 Motorola 680x0 running LynxOS m68*-*-lynxos*
3865 AT&T 3b1/Unix pc m68*-att-*
3866 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3867 decstation mips-dec-* mips-little-*
3868 riscos mips-*-riscos* mips-*-sysv*
3869 sonymips mips-sony-*
3870 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3872 * REMOVED configurations and files
3874 SGI Irix-4.x mips-sgi-irix4 or iris4
3875 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3876 Z8000 simulator z8k-zilog-none or z8ksim
3877 Matsushita MN10200 w/simulator mn10200-*-*
3878 H8/500 simulator h8500-hitachi-hms or h8500hms
3879 HP/PA running BSD hppa*-*-bsd*
3880 HP/PA running OSF/1 hppa*-*-osf*
3881 HP/PA Pro target hppa*-*-pro*
3882 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3883 386BSD i[3456]86-*-bsd*
3884 Sequent family i[3456]86-sequent-sysv4*
3885 i[3456]86-sequent-sysv*
3886 i[3456]86-sequent-bsd*
3887 SPARC running LynxOS sparc-*-lynxos*
3888 SPARC running SunOS 4 sparc-*-sunos4*
3889 Tsqware Sparclet sparclet-*-*
3890 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3892 *** Changes in GDB 6.0:
3896 Support for debugging the Objective-C programming language has been
3897 integrated into GDB.
3899 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3901 DWARF 2's Call Frame Information makes available compiler generated
3902 information that more exactly describes the program's run-time stack.
3903 By using this information, GDB is able to provide more robust stack
3906 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3907 have been updated to use a new backtrace mechanism which includes
3908 DWARF 2 CFI support.
3912 GDB's remote protocol has been extended to include support for hosted
3913 file I/O (where the remote target uses GDB's file system). See GDB's
3914 remote protocol documentation for details.
3916 * All targets using the new architecture framework.
3918 All of GDB's targets have been updated to use the new internal
3919 architecture framework. The way is now open for future GDB releases
3920 to include cross-architecture native debugging support (i386 on amd64,
3923 * GNU/Linux's Thread Local Storage (TLS)
3925 GDB now includes support for for the GNU/Linux implementation of
3926 per-thread variables.
3928 * GNU/Linux's Native POSIX Thread Library (NPTL)
3930 GDB's thread code has been updated to work with either the new
3931 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3933 * Separate debug info.
3935 GDB, in conjunction with BINUTILS, now supports a mechanism for
3936 automatically loading debug information from a separate file. Instead
3937 of shipping full debug and non-debug versions of system libraries,
3938 system integrators can now instead ship just the stripped libraries
3939 and optional debug files.
3941 * DWARF 2 Location Expressions
3943 DWARF 2 Location Expressions allow the compiler to more completely
3944 describe the location of variables (even in optimized code) to the
3947 GDB now includes preliminary support for location expressions (support
3948 for DW_OP_piece is still missing).
3952 A number of long standing bugs that caused GDB to die while starting a
3953 Java application have been fixed. GDB's Java support is now
3954 considered "useable".
3956 * GNU/Linux support for fork, vfork, and exec.
3958 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3959 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3962 * GDB supports logging output to a file
3964 There are two new commands, "set logging" and "show logging", which can be
3965 used to capture GDB's output to a file.
3967 * The meaning of "detach" has changed for gdbserver
3969 The "detach" command will now resume the application, as documented. To
3970 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3973 * d10v, m68hc11 `regs' command deprecated
3975 The `info registers' command has been updated so that it displays the
3976 registers using a format identical to the old `regs' command.
3980 A new command, "maint set profile on/off", has been added. This command can
3981 be used to enable or disable profiling while running GDB, to profile a
3982 session or a set of commands. In addition there is a new configure switch,
3983 "--enable-profiling", which will cause GDB to be compiled with profiling
3984 data, for more informative profiling results.
3986 * Default MI syntax changed to "mi2".
3988 The default MI (machine interface) syntax, enabled by the command line
3989 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3990 "mi1", can be enabled by specifying the option "-i=mi1".
3992 Support for the original "mi0" syntax (included in GDB 5.0) has been
3995 Fix for gdb/192: removed extraneous space when displaying frame level.
3996 Fix for gdb/672: update changelist is now output in mi list format.
3997 Fix for gdb/702: a -var-assign that updates the value now shows up
3998 in a subsequent -var-update.
4000 * New native configurations.
4002 FreeBSD/amd64 x86_64-*-freebsd*
4004 * Multi-arched targets.
4006 HP/PA HPUX11 hppa*-*-hpux*
4007 Renesas M32R/D w/simulator m32r-*-elf*
4009 * OBSOLETE configurations and files
4011 Configurations that have been declared obsolete in this release have
4012 been commented out. Unless there is activity to revive these
4013 configurations, the next release of GDB will have their sources
4014 permanently REMOVED.
4016 Z8000 simulator z8k-zilog-none or z8ksim
4017 Matsushita MN10200 w/simulator mn10200-*-*
4018 H8/500 simulator h8500-hitachi-hms or h8500hms
4019 HP/PA running BSD hppa*-*-bsd*
4020 HP/PA running OSF/1 hppa*-*-osf*
4021 HP/PA Pro target hppa*-*-pro*
4022 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4023 Sequent family i[3456]86-sequent-sysv4*
4024 i[3456]86-sequent-sysv*
4025 i[3456]86-sequent-bsd*
4026 Tsqware Sparclet sparclet-*-*
4027 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4029 * REMOVED configurations and files
4032 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4033 IBM AIX PS/2 i[3456]86-*-aix
4034 i386 running Mach 3.0 i[3456]86-*-mach3*
4035 i386 running Mach i[3456]86-*-mach*
4036 i386 running OSF/1 i[3456]86-*osf1mk*
4037 HP/Apollo 68k Family m68*-apollo*-sysv*,
4039 m68*-hp-bsd*, m68*-hp-hpux*
4040 Argonaut Risc Chip (ARC) arc-*-*
4041 Mitsubishi D30V d30v-*-*
4042 Fujitsu FR30 fr30-*-elf*
4043 OS/9000 i[34]86-*-os9k
4044 I960 with MON960 i960-*-coff
4046 * MIPS $fp behavior changed
4048 The convenience variable $fp, for the MIPS, now consistently returns
4049 the address of the current frame's base. Previously, depending on the
4050 context, $fp could refer to either $sp or the current frame's base
4051 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4052 The GNU Source-Level Debugger''.
4054 *** Changes in GDB 5.3:
4056 * GNU/Linux shared library multi-threaded performance improved.
4058 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4059 `/proc', in preference to `ptrace' for memory reads. This may result
4060 in an improvement in the start-up time of multi-threaded, shared
4061 library applications when run under GDB. One GDB user writes: ``loads
4062 shared libs like mad''.
4064 * ``gdbserver'' now supports multi-threaded applications on some targets
4066 Support for debugging multi-threaded applications which use
4067 the GNU/Linux LinuxThreads package has been added for
4068 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4069 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4071 * GDB now supports C/C++ preprocessor macros.
4073 GDB now expands preprocessor macro invocations in C/C++ expressions,
4074 and provides various commands for showing macro definitions and how
4077 The new command `macro expand EXPRESSION' expands any macro
4078 invocations in expression, and shows the result.
4080 The new command `show macro MACRO-NAME' shows the definition of the
4081 macro named MACRO-NAME, and where it was defined.
4083 Most compilers don't include information about macros in the debugging
4084 information by default. In GCC 3.1, for example, you need to compile
4085 your program with the options `-gdwarf-2 -g3'. If the macro
4086 information is present in the executable, GDB will read it.
4088 * Multi-arched targets.
4090 DEC Alpha (partial) alpha*-*-*
4091 DEC VAX (partial) vax-*-*
4093 National Semiconductor NS32000 (partial) ns32k-*-*
4094 Motorola 68000 (partial) m68k-*-*
4095 Motorola MCORE mcore-*-*
4099 Fujitsu FRV architecture added by Red Hat frv*-*-*
4102 * New native configurations
4104 Alpha NetBSD alpha*-*-netbsd*
4105 SH NetBSD sh*-*-netbsdelf*
4106 MIPS NetBSD mips*-*-netbsd*
4107 UltraSPARC NetBSD sparc64-*-netbsd*
4109 * OBSOLETE configurations and files
4111 Configurations that have been declared obsolete in this release have
4112 been commented out. Unless there is activity to revive these
4113 configurations, the next release of GDB will have their sources
4114 permanently REMOVED.
4116 Mitsubishi D30V d30v-*-*
4117 OS/9000 i[34]86-*-os9k
4118 IBM AIX PS/2 i[3456]86-*-aix
4119 Fujitsu FR30 fr30-*-elf*
4120 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4121 Argonaut Risc Chip (ARC) arc-*-*
4122 i386 running Mach 3.0 i[3456]86-*-mach3*
4123 i386 running Mach i[3456]86-*-mach*
4124 i386 running OSF/1 i[3456]86-*osf1mk*
4125 HP/Apollo 68k Family m68*-apollo*-sysv*,
4127 m68*-hp-bsd*, m68*-hp-hpux*
4128 I960 with MON960 i960-*-coff
4130 * OBSOLETE languages
4132 CHILL, a Pascal like language used by telecommunications companies.
4134 * REMOVED configurations and files
4136 AMD 29k family via UDI a29k-amd-udi, udi29k
4137 A29K VxWorks a29k-*-vxworks
4138 AMD 29000 embedded, using EBMON a29k-none-none
4139 AMD 29000 embedded with COFF a29k-none-coff
4140 AMD 29000 embedded with a.out a29k-none-aout
4142 testsuite/gdb.hp/gdb.threads-hp/ directory
4144 * New command "set max-user-call-depth <nnn>"
4146 This command allows the user to limit the call depth of user-defined
4147 commands. The default is 1024.
4149 * Changes in FreeBSD/i386 native debugging.
4151 Support for the "generate-core-file" has been added.
4153 * New commands "dump", "append", and "restore".
4155 These commands allow data to be copied from target memory
4156 to a bfd-format or binary file (dump and append), and back
4157 from a file into memory (restore).
4159 * Improved "next/step" support on multi-processor Alpha Tru64.
4161 The previous single-step mechanism could cause unpredictable problems,
4162 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4163 of a software single-step mechanism prevents this.
4165 *** Changes in GDB 5.2.1:
4173 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4174 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4175 Fix, by Joel Brobecker imported from mainline.
4177 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4178 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4179 Fix, by Fred Fish, imported from mainline.
4181 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4182 Surprisingly enough, it works now.
4183 By Michal Ludvig, imported from mainline.
4185 i386 hardware watchpoint support:
4186 avoid misses on second run for some targets.
4187 By Pierre Muller, imported from mainline.
4189 *** Changes in GDB 5.2:
4191 * New command "set trust-readonly-sections on[off]".
4193 This command is a hint that tells gdb that read-only sections
4194 really are read-only (ie. that their contents will not change).
4195 In this mode, gdb will go to the object file rather than the
4196 target to read memory from read-only sections (such as ".text").
4197 This can be a significant performance improvement on some
4198 (notably embedded) targets.
4200 * New command "generate-core-file" (or "gcore").
4202 This new gdb command allows the user to drop a core file of the child
4203 process state at any time. So far it's been implemented only for
4204 GNU/Linux and Solaris, but should be relatively easily ported to other
4205 hosts. Argument is core file name (defaults to core.<pid>).
4207 * New command line option
4209 GDB now accepts --pid or -p followed by a process id.
4211 * Change in command line behavior -- corefiles vs. process ids.
4213 There is a subtle behavior in the way in which GDB handles
4214 command line arguments. The first non-flag argument is always
4215 a program to debug, but the second non-flag argument may either
4216 be a corefile or a process id. Previously, GDB would attempt to
4217 open the second argument as a corefile, and if that failed, would
4218 issue a superfluous error message and then attempt to attach it as
4219 a process. Now, if the second argument begins with a non-digit,
4220 it will be treated as a corefile. If it begins with a digit,
4221 GDB will attempt to attach it as a process, and if no such process
4222 is found, will then attempt to open it as a corefile.
4224 * Changes in ARM configurations.
4226 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4227 configuration is fully multi-arch.
4229 * New native configurations
4231 ARM NetBSD arm*-*-netbsd*
4232 x86 OpenBSD i[3456]86-*-openbsd*
4233 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4234 Sparc64 running FreeBSD sparc64-*-freebsd*
4238 Sanyo XStormy16 xstormy16-elf
4240 * OBSOLETE configurations and files
4242 Configurations that have been declared obsolete in this release have
4243 been commented out. Unless there is activity to revive these
4244 configurations, the next release of GDB will have their sources
4245 permanently REMOVED.
4247 AMD 29k family via UDI a29k-amd-udi, udi29k
4248 A29K VxWorks a29k-*-vxworks
4249 AMD 29000 embedded, using EBMON a29k-none-none
4250 AMD 29000 embedded with COFF a29k-none-coff
4251 AMD 29000 embedded with a.out a29k-none-aout
4253 testsuite/gdb.hp/gdb.threads-hp/ directory
4255 * REMOVED configurations and files
4257 TI TMS320C80 tic80-*-*
4259 PowerPC Solaris powerpcle-*-solaris*
4260 PowerPC Windows NT powerpcle-*-cygwin32
4261 PowerPC Netware powerpc-*-netware*
4262 Harris/CXUX m88k m88*-harris-cxux*
4263 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4264 ns32k-utek-sysv* ns32k-utek-*
4265 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4266 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4267 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4268 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4269 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4271 * Changes to command line processing
4273 The new `--args' feature can be used to specify command-line arguments
4274 for the inferior from gdb's command line.
4276 * Changes to key bindings
4278 There is a new `operate-and-get-next' function bound to `C-o'.
4280 *** Changes in GDB 5.1.1
4282 Fix compile problem on DJGPP.
4284 Fix a problem with floating-point registers on the i386 being
4287 Fix to stop GDB crashing on .debug_str debug info.
4289 Numerous documentation fixes.
4291 Numerous testsuite fixes.
4293 *** Changes in GDB 5.1:
4295 * New native configurations
4297 Alpha FreeBSD alpha*-*-freebsd*
4298 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4299 MIPS GNU/Linux mips*-*-linux*
4300 MIPS SGI Irix 6.x mips*-sgi-irix6*
4301 ia64 AIX ia64-*-aix*
4302 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4306 Motorola 68HC11 and 68HC12 m68hc11-elf
4308 UltraSparc running GNU/Linux sparc64-*-linux*
4310 * OBSOLETE configurations and files
4312 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4313 Harris/CXUX m88k m88*-harris-cxux*
4314 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4315 ns32k-utek-sysv* ns32k-utek-*
4316 TI TMS320C80 tic80-*-*
4318 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4319 PowerPC Solaris powerpcle-*-solaris*
4320 PowerPC Windows NT powerpcle-*-cygwin32
4321 PowerPC Netware powerpc-*-netware*
4322 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4323 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4324 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4325 Apple Macintosh (MPW) host N/A
4327 stuff.c (Program to stuff files into a specially prepared space in kdb)
4328 kdb-start.c (Main loop for the standalone kernel debugger)
4330 Configurations that have been declared obsolete in this release have
4331 been commented out. Unless there is activity to revive these
4332 configurations, the next release of GDB will have their sources
4333 permanently REMOVED.
4335 * REMOVED configurations and files
4337 Altos 3068 m68*-altos-*
4338 Convex c1-*-*, c2-*-*
4340 ARM RISCix arm-*-* (as host)
4344 * GDB has been converted to ISO C.
4346 GDB's source code has been converted to ISO C. In particular, the
4347 sources are fully protoized, and rely on standard headers being
4352 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4354 * The MI enabled by default.
4356 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4357 revised and enabled by default. Packages which use GDB as a debugging
4358 engine behind a UI or another front end are encouraged to switch to
4359 using the GDB/MI interface, instead of the old annotations interface
4360 which is now deprecated.
4362 * Support for debugging Pascal programs.
4364 GDB now includes support for debugging Pascal programs. The following
4365 main features are supported:
4367 - Pascal-specific data types such as sets;
4369 - automatic recognition of Pascal sources based on file-name
4372 - Pascal-style display of data types, variables, and functions;
4374 - a Pascal expression parser.
4376 However, some important features are not yet supported.
4378 - Pascal string operations are not supported at all;
4380 - there are some problems with boolean types;
4382 - Pascal type hexadecimal constants are not supported
4383 because they conflict with the internal variables format;
4385 - support for Pascal objects and classes is not full yet;
4387 - unlike Pascal, GDB is case-sensitive for symbol names.
4389 * Changes in completion.
4391 Commands such as `shell', `run' and `set args', which pass arguments
4392 to inferior programs, now complete on file names, similar to what
4393 users expect at the shell prompt.
4395 Commands which accept locations, such as `disassemble', `print',
4396 `breakpoint', `until', etc. now complete on filenames as well as
4397 program symbols. Thus, if you type "break foob TAB", and the source
4398 files linked into the programs include `foobar.c', that file name will
4399 be one of the candidates for completion. However, file names are not
4400 considered for completion after you typed a colon that delimits a file
4401 name from a name of a function in that file, as in "break foo.c:bar".
4403 `set demangle-style' completes on available demangling styles.
4405 * New platform-independent commands:
4407 It is now possible to define a post-hook for a command as well as a
4408 hook that runs before the command. For more details, see the
4409 documentation of `hookpost' in the GDB manual.
4411 * Changes in GNU/Linux native debugging.
4413 Support for debugging multi-threaded programs has been completely
4414 revised for all platforms except m68k and sparc. You can now debug as
4415 many threads as your system allows you to have.
4417 Attach/detach is supported for multi-threaded programs.
4419 Support for SSE registers was added for x86. This doesn't work for
4420 multi-threaded programs though.
4422 * Changes in MIPS configurations.
4424 Multi-arch support is enabled for all MIPS configurations.
4426 GDB can now be built as native debugger on SGI Irix 6.x systems for
4427 debugging n32 executables. (Debugging 64-bit executables is not yet
4430 * Unified support for hardware watchpoints in all x86 configurations.
4432 Most (if not all) native x86 configurations support hardware-assisted
4433 breakpoints and watchpoints in a unified manner. This support
4434 implements debug register sharing between watchpoints, which allows to
4435 put a virtually infinite number of watchpoints on the same address,
4436 and also supports watching regions up to 16 bytes with several debug
4439 The new maintenance command `maintenance show-debug-regs' toggles
4440 debugging print-outs in functions that insert, remove, and test
4441 watchpoints and hardware breakpoints.
4443 * Changes in the DJGPP native configuration.
4445 New command ``info dos sysinfo'' displays assorted information about
4446 the CPU, OS, memory, and DPMI server.
4448 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4449 display information about segment descriptors stored in GDT, LDT, and
4452 New commands ``info dos pde'' and ``info dos pte'' display entries
4453 from Page Directory and Page Tables (for now works with CWSDPMI only).
4454 New command ``info dos address-pte'' displays the Page Table entry for
4455 a given linear address.
4457 GDB can now pass command lines longer than 126 characters to the
4458 program being debugged (requires an update to the libdbg.a library
4459 which is part of the DJGPP development kit).
4461 DWARF2 debug info is now supported.
4463 It is now possible to `step' and `next' through calls to `longjmp'.
4465 * Changes in documentation.
4467 All GDB documentation was converted to GFDL, the GNU Free
4468 Documentation License.
4470 Tracepoints-related commands are now fully documented in the GDB
4473 TUI, the Text-mode User Interface, is now documented in the manual.
4475 Tracepoints-related commands are now fully documented in the GDB
4478 The "GDB Internals" manual now has an index. It also includes
4479 documentation of `ui_out' functions, GDB coding standards, x86
4480 hardware watchpoints, and memory region attributes.
4482 * GDB's version number moved to ``version.in''
4484 The Makefile variable VERSION has been replaced by the file
4485 ``version.in''. People creating GDB distributions should update the
4486 contents of this file.
4490 GUD support is now a standard part of the EMACS distribution.
4492 *** Changes in GDB 5.0:
4494 * Improved support for debugging FP programs on x86 targets
4496 Unified and much-improved support for debugging floating-point
4497 programs on all x86 targets. In particular, ``info float'' now
4498 displays the FP registers in the same format on all x86 targets, with
4499 greater level of detail.
4501 * Improvements and bugfixes in hardware-assisted watchpoints
4503 It is now possible to watch array elements, struct members, and
4504 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4505 on x86 targets no longer erroneously trigger when the address is
4508 * Improvements in the native DJGPP version of GDB
4510 The distribution now includes all the scripts and auxiliary files
4511 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4512 machines ``out of the box''.
4514 The DJGPP version can now debug programs that use signals. It is
4515 possible to catch signals that happened in the debuggee, deliver
4516 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4517 would kill the program being debugged.) Programs that hook hardware
4518 interrupts (keyboard, timer, etc.) can also be debugged.
4520 It is now possible to debug DJGPP programs that redirect their
4521 standard handles or switch them to raw (as opposed to cooked) mode, or
4522 even close them. The command ``run < foo > bar'' works as expected,
4523 and ``info terminal'' reports useful information about the debuggee's
4524 terminal, including raw/cooked mode, redirection, etc.
4526 The DJGPP version now uses termios functions for console I/O, which
4527 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4530 DOS-style file names with drive letters are now fully supported by
4533 It is now possible to debug DJGPP programs that switch their working
4534 directory. It is also possible to rerun the debuggee any number of
4535 times without restarting GDB; thus, you can use the same setup,
4536 breakpoints, etc. for many debugging sessions.
4538 * New native configurations
4540 ARM GNU/Linux arm*-*-linux*
4541 PowerPC GNU/Linux powerpc-*-linux*
4545 Motorola MCore mcore-*-*
4546 x86 VxWorks i[3456]86-*-vxworks*
4547 PowerPC VxWorks powerpc-*-vxworks*
4548 TI TMS320C80 tic80-*-*
4550 * OBSOLETE configurations
4552 Altos 3068 m68*-altos-*
4553 Convex c1-*-*, c2-*-*
4555 ARM RISCix arm-*-* (as host)
4558 Configurations that have been declared obsolete will be commented out,
4559 but the code will be left in place. If there is no activity to revive
4560 these configurations before the next release of GDB, the sources will
4561 be permanently REMOVED.
4563 * Gould support removed
4565 Support for the Gould PowerNode and NP1 has been removed.
4567 * New features for SVR4
4569 On SVR4 native platforms (such as Solaris), if you attach to a process
4570 without first loading a symbol file, GDB will now attempt to locate and
4571 load symbols from the running process's executable file.
4573 * Many C++ enhancements
4575 C++ support has been greatly improved. Overload resolution now works properly
4576 in almost all cases. RTTI support is on the way.
4578 * Remote targets can connect to a sub-program
4580 A popen(3) style serial-device has been added. This device starts a
4581 sub-process (such as a stand-alone simulator) and then communicates
4582 with that. The sub-program to run is specified using the syntax
4583 ``|<program> <args>'' vis:
4585 (gdb) set remotedebug 1
4586 (gdb) target extended-remote |mn10300-elf-sim program-args
4588 * MIPS 64 remote protocol
4590 A long standing bug in the mips64 remote protocol where by GDB
4591 expected certain 32 bit registers (ex SR) to be transfered as 32
4592 instead of 64 bits has been fixed.
4594 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4595 added to provide backward compatibility with older versions of GDB.
4597 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4599 The command ``set remotebinarydownload'' command has been replaced by
4600 ``set remote X-packet''. Other commands in ``set remote'' family
4601 include ``set remote P-packet''.
4603 * Breakpoint commands accept ranges.
4605 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4606 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4607 ``tracepoint passcount'' also accepts a range of tracepoints.
4609 * ``apropos'' command added.
4611 The ``apropos'' command searches through command names and
4612 documentation strings, printing out matches, making it much easier to
4613 try to find a command that does what you are looking for.
4617 A new machine oriented interface (MI) has been added to GDB. This
4618 interface is designed for debug environments running GDB as a separate
4619 process. This is part of the long term libGDB project. See the
4620 "GDB/MI" chapter of the GDB manual for further information. It can be
4621 enabled by configuring with:
4623 .../configure --enable-gdbmi
4625 *** Changes in GDB-4.18:
4627 * New native configurations
4629 HP-UX 10.20 hppa*-*-hpux10.20
4630 HP-UX 11.x hppa*-*-hpux11.0*
4631 M68K GNU/Linux m68*-*-linux*
4635 Fujitsu FR30 fr30-*-elf*
4636 Intel StrongARM strongarm-*-*
4637 Mitsubishi D30V d30v-*-*
4639 * OBSOLETE configurations
4641 Gould PowerNode, NP1 np1-*-*, pn-*-*
4643 Configurations that have been declared obsolete will be commented out,
4644 but the code will be left in place. If there is no activity to revive
4645 these configurations before the next release of GDB, the sources will
4646 be permanently REMOVED.
4650 As a compatibility experiment, GDB's source files buildsym.h and
4651 buildsym.c have been converted to pure standard C, no longer
4652 containing any K&R compatibility code. We believe that all systems in
4653 use today either come with a standard C compiler, or have a GCC port
4654 available. If this is not true, please report the affected
4655 configuration to bug-gdb@gnu.org immediately. See the README file for
4656 information about getting a standard C compiler if you don't have one
4661 GDB now uses readline 2.2.
4663 * set extension-language
4665 You can now control the mapping between filename extensions and source
4666 languages by using the `set extension-language' command. For instance,
4667 you can ask GDB to treat .c files as C++ by saying
4668 set extension-language .c c++
4669 The command `info extensions' lists all of the recognized extensions
4670 and their associated languages.
4672 * Setting processor type for PowerPC and RS/6000
4674 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4675 you can use the `set processor' command to specify what variant of the
4676 PowerPC family you are debugging. The command
4680 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4681 following PowerPC and RS6000 variants:
4683 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4684 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4686 403GC IBM PowerPC 403GC
4687 505 Motorola PowerPC 505
4688 860 Motorola PowerPC 860 or 850
4689 601 Motorola PowerPC 601
4690 602 Motorola PowerPC 602
4691 603 Motorola/IBM PowerPC 603 or 603e
4692 604 Motorola PowerPC 604 or 604e
4693 750 Motorola/IBM PowerPC 750 or 750
4695 At the moment, this command just tells GDB what to name the
4696 special-purpose processor registers. Since almost all the affected
4697 registers are inaccessible to user-level programs, this command is
4698 only useful for remote debugging in its present form.
4702 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4703 more extensive support for HP-UX. Added features include shared
4704 library support, kernel threads and hardware watchpoints for 11.00,
4705 support for HP's ANSI C and C++ compilers, and a compatibility mode
4706 for xdb and dbx commands.
4710 HP's donation includes the new concept of catchpoints, which is a
4711 generalization of the old catch command. On HP-UX, it is now possible
4712 to catch exec, fork, and vfork, as well as library loading.
4714 This means that the existing catch command has changed; its first
4715 argument now specifies the type of catch to be set up. See the
4716 output of "help catch" for a list of catchpoint types.
4718 * Debugging across forks
4720 On HP-UX, you can choose which process to debug when a fork() happens
4725 HP has donated a curses-based terminal user interface (TUI). To get
4726 it, build with --enable-tui. Although this can be enabled for any
4727 configuration, at present it only works for native HP debugging.
4729 * GDB remote protocol additions
4731 A new protocol packet 'X' that writes binary data is now available.
4732 Default behavior is to try 'X', then drop back to 'M' if the stub
4733 fails to respond. The settable variable `remotebinarydownload'
4734 allows explicit control over the use of 'X'.
4736 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4737 full 64-bit address. The command
4739 set remoteaddresssize 32
4741 can be used to revert to the old behaviour. For existing remote stubs
4742 the change should not be noticed, as the additional address information
4745 In order to assist in debugging stubs, you may use the maintenance
4746 command `packet' to send any text string to the stub. For instance,
4748 maint packet heythere
4750 sends the packet "$heythere#<checksum>". Note that it is very easy to
4751 disrupt a debugging session by sending the wrong packet at the wrong
4754 The compare-sections command allows you to compare section data on the
4755 target to what is in the executable file without uploading or
4756 downloading, by comparing CRC checksums.
4758 * Tracing can collect general expressions
4760 You may now collect general expressions at tracepoints. This requires
4761 further additions to the target-side stub; see tracepoint.c and
4762 doc/agentexpr.texi for further details.
4764 * mask-address variable for Mips
4766 For Mips targets, you may control the zeroing of the upper 32 bits of
4767 a 64-bit address by entering `set mask-address on'. This is mainly
4768 of interest to users of embedded R4xxx and R5xxx processors.
4770 * Higher serial baud rates
4772 GDB's serial code now allows you to specify baud rates 57600, 115200,
4773 230400, and 460800 baud. (Note that your host system may not be able
4774 to achieve all of these rates.)
4778 The i960 configuration now includes an initial implementation of a
4779 builtin simulator, contributed by Jim Wilson.
4782 *** Changes in GDB-4.17:
4784 * New native configurations
4786 Alpha GNU/Linux alpha*-*-linux*
4787 Unixware 2.x i[3456]86-unixware2*
4788 Irix 6.x mips*-sgi-irix6*
4789 PowerPC GNU/Linux powerpc-*-linux*
4790 PowerPC Solaris powerpcle-*-solaris*
4791 Sparc GNU/Linux sparc-*-linux*
4792 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4796 Argonaut Risc Chip (ARC) arc-*-*
4797 Hitachi H8/300S h8300*-*-*
4798 Matsushita MN10200 w/simulator mn10200-*-*
4799 Matsushita MN10300 w/simulator mn10300-*-*
4800 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4801 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4802 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4803 Mitsubishi D10V w/simulator d10v-*-*
4804 Mitsubishi M32R/D w/simulator m32r-*-elf*
4805 Tsqware Sparclet sparclet-*-*
4806 NEC V850 w/simulator v850-*-*
4808 * New debugging protocols
4810 ARM with RDI protocol arm*-*-*
4811 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4812 DDB and LSI variants of PMON protocol mips*-*-*
4813 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4814 PowerPC with SDS protocol powerpc{,le}-*-eabi
4815 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4819 All configurations can now understand and use the DWARF 2 debugging
4820 format. The choice is automatic, if the symbol file contains DWARF 2
4825 GDB now includes basic Java language support. This support is
4826 only useful with Java compilers that produce native machine code.
4828 * solib-absolute-prefix and solib-search-path
4830 For SunOS and SVR4 shared libraries, you may now set the prefix for
4831 loading absolute shared library symbol files, and the search path for
4832 locating non-absolute shared library symbol files.
4834 * Live range splitting
4836 GDB can now effectively debug code for which GCC has performed live
4837 range splitting as part of its optimization. See gdb/doc/LRS for
4838 more details on the expected format of the stabs information.
4842 GDB's support for the GNU Hurd, including thread debugging, has been
4843 updated to work with current versions of the Hurd.
4847 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4848 instruction set. ARM GDB automatically detects when Thumb
4849 instructions are in use, and adjusts disassembly and backtracing
4854 GDB's MIPS target configurations now handle the MIP16 16-bit
4859 GDB now includes support for overlays; if an executable has been
4860 linked such that multiple sections are based at the same address, GDB
4861 will decide which section to use for symbolic info. You can choose to
4862 control the decision manually, using overlay commands, or implement
4863 additional target-side support and use "overlay load-target" to bring
4864 in the overlay mapping. Do "help overlay" for more detail.
4868 The command "info symbol <address>" displays information about
4869 the symbol at the specified address.
4873 The standard remote protocol now includes an extension that allows
4874 asynchronous collection and display of trace data. This requires
4875 extensive support in the target-side debugging stub. Tracing mode
4876 includes a new interaction mode in GDB and new commands: see the
4877 file tracepoint.c for more details.
4881 Configurations for embedded MIPS now include a simulator contributed
4882 by Cygnus Solutions. The simulator supports the instruction sets
4883 of most MIPS variants.
4887 Sparc configurations may now include the ERC32 simulator contributed
4888 by the European Space Agency. The simulator is not built into
4889 Sparc targets by default; configure with --enable-sim to include it.
4893 For target configurations that may include multiple variants of a
4894 basic architecture (such as MIPS and SH), you may now set the
4895 architecture explicitly. "set arch" sets, "info arch" lists
4896 the possible architectures.
4898 *** Changes in GDB-4.16:
4900 * New native configurations
4902 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4903 M68K NetBSD m68k-*-netbsd*
4904 PowerPC AIX 4.x powerpc-*-aix*
4905 PowerPC MacOS powerpc-*-macos*
4906 PowerPC Windows NT powerpcle-*-cygwin32
4907 RS/6000 AIX 4.x rs6000-*-aix4*
4911 ARM with RDP protocol arm-*-*
4912 I960 with MON960 i960-*-coff
4913 MIPS VxWorks mips*-*-vxworks*
4914 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4915 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4917 Matra Sparclet sparclet-*-*
4921 The powerpc-eabi configuration now includes the PSIM simulator,
4922 contributed by Andrew Cagney, with assistance from Mike Meissner.
4923 PSIM is a very elaborate model of the PowerPC, including not only
4924 basic instruction set execution, but also details of execution unit
4925 performance and I/O hardware. See sim/ppc/README for more details.
4929 GDB now works with Solaris 2.5.
4931 * Windows 95/NT native
4933 GDB will now work as a native debugger on Windows 95 and Windows NT.
4934 To build it from source, you must use the "gnu-win32" environment,
4935 which uses a DLL to emulate enough of Unix to run the GNU tools.
4936 Further information, binaries, and sources are available at
4937 ftp.cygnus.com, under pub/gnu-win32.
4939 * dont-repeat command
4941 If a user-defined command includes the command `dont-repeat', then the
4942 command will not be repeated if the user just types return. This is
4943 useful if the command is time-consuming to run, so that accidental
4944 extra keystrokes don't run the same command many times.
4946 * Send break instead of ^C
4948 The standard remote protocol now includes an option to send a break
4949 rather than a ^C to the target in order to interrupt it. By default,
4950 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4952 * Remote protocol timeout
4954 The standard remote protocol includes a new variable `remotetimeout'
4955 that allows you to set the number of seconds before GDB gives up trying
4956 to read from the target. The default value is 2.
4958 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4960 By default GDB will automatically keep track of objects as they are
4961 loaded and unloaded by the dynamic linker. By using the command `set
4962 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4963 when shared library events occur, thus allowing you to set breakpoints
4964 in shared libraries which are explicitly loaded by the inferior.
4966 Note this feature does not work on hpux8. On hpux9 you must link
4967 /usr/lib/end.o into your program. This feature should work
4968 automatically on hpux10.
4970 * Irix 5.x hardware watchpoint support
4972 Irix 5 configurations now support the use of hardware watchpoints.
4974 * Mips protocol "SYN garbage limit"
4976 When debugging a Mips target using the `target mips' protocol, you
4977 may set the number of characters that GDB will ignore by setting
4978 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4979 every character. The default value is 1050.
4981 * Recording and replaying remote debug sessions
4983 If you set `remotelogfile' to the name of a file, gdb will write to it
4984 a recording of a remote debug session. This recording may then be
4985 replayed back to gdb using "gdbreplay". See gdbserver/README for
4986 details. This is useful when you have a problem with GDB while doing
4987 remote debugging; you can make a recording of the session and send it
4988 to someone else, who can then recreate the problem.
4990 * Speedups for remote debugging
4992 GDB includes speedups for downloading and stepping MIPS systems using
4993 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4994 and more efficient S-record downloading.
4996 * Memory use reductions and statistics collection
4998 GDB now uses less memory and reports statistics about memory usage.
4999 Try the `maint print statistics' command, for example.
5001 *** Changes in GDB-4.15:
5003 * Psymtabs for XCOFF
5005 The symbol reader for AIX GDB now uses partial symbol tables. This
5006 can greatly improve startup time, especially for large executables.
5008 * Remote targets use caching
5010 Remote targets now use a data cache to speed up communication with the
5011 remote side. The data cache could lead to incorrect results because
5012 it doesn't know about volatile variables, thus making it impossible to
5013 debug targets which use memory mapped I/O devices. `set remotecache
5014 off' turns the the data cache off.
5016 * Remote targets may have threads
5018 The standard remote protocol now includes support for multiple threads
5019 in the target system, using new protocol commands 'H' and 'T'. See
5020 gdb/remote.c for details.
5024 If GDB is configured with `--enable-netrom', then it will include
5025 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5026 acts as though it is a bank of ROM on the target board, but you can
5027 write into it over the network. GDB's support consists only of
5028 support for fast loading into the emulated ROM; to debug, you must use
5029 another protocol, such as standard remote protocol. The usual
5030 sequence is something like
5032 target nrom <netrom-hostname>
5034 target remote <netrom-hostname>:1235
5038 GDB now includes support for the Apple Macintosh, as a host only. It
5039 may be run as either an MPW tool or as a standalone application, and
5040 it can debug through the serial port. All the usual GDB commands are
5041 available, but to the target command, you must supply "serial" as the
5042 device type instead of "/dev/ttyXX". See mpw-README in the main
5043 directory for more information on how to build. The MPW configuration
5044 scripts */mpw-config.in support only a few targets, and only the
5045 mips-idt-ecoff target has been tested.
5049 GDB configuration now uses autoconf. This is not user-visible,
5050 but does simplify configuration and building.
5054 GDB now supports hpux10.
5056 *** Changes in GDB-4.14:
5058 * New native configurations
5060 x86 FreeBSD i[345]86-*-freebsd
5061 x86 NetBSD i[345]86-*-netbsd
5062 NS32k NetBSD ns32k-*-netbsd
5063 Sparc NetBSD sparc-*-netbsd
5067 A29K VxWorks a29k-*-vxworks
5068 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5069 CPU32 EST-300 emulator m68*-*-est*
5070 PowerPC ELF powerpc-*-elf
5073 * Alpha OSF/1 support for procfs
5075 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5076 possible to attach to running processes. As the mounting of the /proc
5077 filesystem is optional on the Alpha, GDB automatically determines
5078 the availability of /proc during startup. This can lead to problems
5079 if /proc is unmounted after GDB has been started.
5081 * Arguments to user-defined commands
5083 User commands may accept up to 10 arguments separated by whitespace.
5084 Arguments are accessed within the user command via $arg0..$arg9. A
5087 print $arg0 + $arg1 + $arg2
5089 To execute the command use:
5092 Defines the command "adder" which prints the sum of its three arguments.
5093 Note the arguments are text substitutions, so they may reference variables,
5094 use complex expressions, or even perform inferior function calls.
5096 * New `if' and `while' commands
5098 This makes it possible to write more sophisticated user-defined
5099 commands. Both commands take a single argument, which is the
5100 expression to evaluate, and must be followed by the commands to
5101 execute, one per line, if the expression is nonzero, the list being
5102 terminated by the word `end'. The `if' command list may include an
5103 `else' word, which causes the following commands to be executed only
5104 if the expression is zero.
5106 * Fortran source language mode
5108 GDB now includes partial support for Fortran 77. It will recognize
5109 Fortran programs and can evaluate a subset of Fortran expressions, but
5110 variables and functions may not be handled correctly. GDB will work
5111 with G77, but does not yet know much about symbols emitted by other
5114 * Better HPUX support
5116 Most debugging facilities now work on dynamic executables for HPPAs
5117 running hpux9 or later. You can attach to running dynamically linked
5118 processes, but by default the dynamic libraries will be read-only, so
5119 for instance you won't be able to put breakpoints in them. To change
5120 that behavior do the following before running the program:
5126 This will cause the libraries to be mapped private and read-write.
5127 To revert to the normal behavior, do this:
5133 You cannot set breakpoints or examine data in the library until after
5134 the library is loaded if the function/data symbols do not have
5137 GDB can now also read debug symbols produced by the HP C compiler on
5138 HPPAs (sorry, no C++, Fortran or 68k support).
5140 * Target byte order now dynamically selectable
5142 You can choose which byte order to use with a target system, via the
5143 commands "set endian big" and "set endian little", and you can see the
5144 current setting by using "show endian". You can also give the command
5145 "set endian auto", in which case GDB will use the byte order
5146 associated with the executable. Currently, only embedded MIPS
5147 configurations support dynamic selection of target byte order.
5149 * New DOS host serial code
5151 This version uses DPMI interrupts to handle buffered I/O, so you
5152 no longer need to run asynctsr when debugging boards connected to
5155 *** Changes in GDB-4.13:
5157 * New "complete" command
5159 This lists all the possible completions for the rest of the line, if it
5160 were to be given as a command itself. This is intended for use by emacs.
5162 * Trailing space optional in prompt
5164 "set prompt" no longer adds a space for you after the prompt you set. This
5165 allows you to set a prompt which ends in a space or one that does not.
5167 * Breakpoint hit counts
5169 "info break" now displays a count of the number of times the breakpoint
5170 has been hit. This is especially useful in conjunction with "ignore"; you
5171 can ignore a large number of breakpoint hits, look at the breakpoint info
5172 to see how many times the breakpoint was hit, then run again, ignoring one
5173 less than that number, and this will get you quickly to the last hit of
5176 * Ability to stop printing at NULL character
5178 "set print null-stop" will cause GDB to stop printing the characters of
5179 an array when the first NULL is encountered. This is useful when large
5180 arrays actually contain only short strings.
5182 * Shared library breakpoints
5184 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5185 breakpoints in shared libraries before the executable is run.
5187 * Hardware watchpoints
5189 There is a new hardware breakpoint for the watch command for sparclite
5190 targets. See gdb/sparclite/hw_breakpoint.note.
5192 Hardware watchpoints are also now supported under GNU/Linux.
5196 Annotations have been added. These are for use with graphical interfaces,
5197 and are still experimental. Currently only gdba.el uses these.
5199 * Improved Irix 5 support
5201 GDB now works properly with Irix 5.2.
5203 * Improved HPPA support
5205 GDB now works properly with the latest GCC and GAS.
5207 * New native configurations
5209 Sequent PTX4 i[34]86-sequent-ptx4
5210 HPPA running OSF/1 hppa*-*-osf*
5211 Atari TT running SVR4 m68*-*-sysv4*
5212 RS/6000 LynxOS rs6000-*-lynxos*
5216 OS/9000 i[34]86-*-os9k
5217 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5220 * Hitachi SH7000 and E7000-PC ICE support
5222 There is now support for communicating with the Hitachi E7000-PC ICE.
5223 This is available automatically when GDB is configured for the SH.
5227 As usual, a variety of small fixes and improvements, both generic
5228 and configuration-specific. See the ChangeLog for more detail.
5230 *** Changes in GDB-4.12:
5232 * Irix 5 is now supported
5236 GDB-4.12 on the HPPA has a number of changes which make it unable
5237 to debug the output from the currently released versions of GCC and
5238 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5239 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5240 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5243 *** Changes in GDB-4.11:
5245 * User visible changes:
5249 The "set remotedebug" option is now consistent between the mips remote
5250 target, remote targets using the gdb-specific protocol, UDI (AMD's
5251 debug protocol for the 29k) and the 88k bug monitor. It is now an
5252 integer specifying a debug level (normally 0 or 1, but 2 means more
5253 debugging info for the mips target).
5255 * DEC Alpha native support
5257 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5258 debug info, but GDB works fairly well with the DEC compiler and should
5259 work with a future GCC release. See the README file for a few
5260 Alpha-specific notes.
5262 * Preliminary thread implementation
5264 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5266 * LynxOS native and target support for 386
5268 This release has been hosted on LynxOS 2.2, and also can be configured
5269 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5272 * Improvements in C++ mangling/demangling.
5274 This release has much better g++ debugging, specifically in name
5275 mangling/demangling, virtual function calls, print virtual table,
5276 call methods, ...etc.
5278 *** Changes in GDB-4.10:
5280 * User visible changes:
5282 Remote debugging using the GDB-specific (`target remote') protocol now
5283 supports the `load' command. This is only useful if you have some
5284 other way of getting the stub to the target system, and you can put it
5285 somewhere in memory where it won't get clobbered by the download.
5287 Filename completion now works.
5289 When run under emacs mode, the "info line" command now causes the
5290 arrow to point to the line specified. Also, "info line" prints
5291 addresses in symbolic form (as well as hex).
5293 All vxworks based targets now support a user settable option, called
5294 vxworks-timeout. This option represents the number of seconds gdb
5295 should wait for responses to rpc's. You might want to use this if
5296 your vxworks target is, perhaps, a slow software simulator or happens
5297 to be on the far side of a thin network line.
5301 This release contains support for using a DEC alpha as a GDB host for
5302 cross debugging. Native alpha debugging is not supported yet.
5305 *** Changes in GDB-4.9:
5309 This is the first GDB release which is accompanied by a matching testsuite.
5310 The testsuite requires installation of dejagnu, which should be available
5311 via ftp from most sites that carry GNU software.
5315 'Cfront' style demangling has had its name changed to 'ARM' style, to
5316 emphasize that it was written from the specifications in the C++ Annotated
5317 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5318 disclaimers, it still generated too much confusion with users attempting to
5319 use gdb with AT&T cfront.
5323 GDB now uses a standard remote interface to a simulator library.
5324 So far, the library contains simulators for the Zilog Z8001/2, the
5325 Hitachi H8/300, H8/500 and Super-H.
5327 * New targets supported
5329 H8/300 simulator h8300-hitachi-hms or h8300hms
5330 H8/500 simulator h8500-hitachi-hms or h8500hms
5331 SH simulator sh-hitachi-hms or sh
5332 Z8000 simulator z8k-zilog-none or z8ksim
5333 IDT MIPS board over serial line mips-idt-ecoff
5335 Cross-debugging to GO32 targets is supported. It requires a custom
5336 version of the i386-stub.c module which is integrated with the
5337 GO32 memory extender.
5339 * New remote protocols
5341 MIPS remote debugging protocol.
5343 * New source languages supported
5345 This version includes preliminary support for Chill, a Pascal like language
5346 used by telecommunications companies. Chill support is also being integrated
5347 into the GNU compiler, but we don't know when it will be publically available.
5350 *** Changes in GDB-4.8:
5352 * HP Precision Architecture supported
5354 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5355 version of this support was available as a set of patches from the
5356 University of Utah. GDB does not support debugging of programs
5357 compiled with the HP compiler, because HP will not document their file
5358 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5359 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5361 Many problems in the preliminary version have been fixed.
5363 * Faster and better demangling
5365 We have improved template demangling and fixed numerous bugs in the GNU style
5366 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5367 character types (wchar_t) are now supported. Demangling of each symbol is now
5368 only done once, and is cached when the symbol table for a file is read in.
5369 This results in a small increase in memory usage for C programs, a moderate
5370 increase in memory usage for C++ programs, and a fantastic speedup in
5373 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5374 from the specifications in the Annotated Reference Manual, which AT&T's
5375 compiler does not actually implement.
5377 * G++ multiple inheritance compiler problem
5379 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5380 inheritance lattices was reworked to properly discover ambiguities. We
5381 recently found an example which causes this new algorithm to fail in a
5382 very subtle way, producing bad debug information for those classes.
5383 The file 'gcc.patch' (in this directory) can be applied to gcc to
5384 circumvent the problem. A future GCC release will contain a complete
5387 The previous G++ debug info problem (mentioned below for the gdb-4.7
5388 release) is fixed in gcc version 2.3.2.
5390 * Improved configure script
5392 The `configure' script will now attempt to guess your system type if
5393 you don't supply a host system type. The old scheme of supplying a
5394 host system triplet is preferable over using this. All the magic is
5395 done in the new `config.guess' script. Examine it for details.
5397 We have also brought our configure script much more in line with the FSF's
5398 version. It now supports the --with-xxx options. In particular,
5399 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5400 The resulting GDB will not be able to read arbitrary object file formats --
5401 only the format ``expected'' to be used on the configured target system.
5402 We hope to make this the default in a future release.
5404 * Documentation improvements
5406 There's new internal documentation on how to modify GDB, and how to
5407 produce clean changes to the code. We implore people to read it
5408 before submitting changes.
5410 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5411 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5412 `info' files are also provided. To build `info' files from scratch,
5413 you will need the latest `makeinfo' release, which will be available in
5414 a future texinfo-X.Y release.
5416 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5417 We're not sure exactly which versions have this problem, but it has
5418 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5419 or better. If that isn't possible, there is a patch in
5420 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5421 around this problem.
5425 GDB now supports array constants that can be used in expressions typed in by
5426 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5427 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5430 The new directory `gdb/sparclite' contains a program that demonstrates
5431 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5433 * New native hosts supported
5435 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5436 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5438 * New targets supported
5440 AMD 29k family via UDI a29k-amd-udi or udi29k
5442 * New file formats supported
5444 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5445 HPUX core files, and SCO 3.2v2 core files.
5449 Attaching to processes now works again; thanks for the many bug reports.
5451 We have also stomped on a bunch of core dumps caused by
5452 printf_filtered("%s") problems.
5454 We eliminated a copyright problem on the rpc and ptrace header files
5455 for VxWorks, which was discovered at the last minute during the 4.7
5456 release. You should now be able to build a VxWorks GDB.
5458 You can now interrupt gdb while an attached process is running. This
5459 will cause the attached process to stop, and give control back to GDB.
5461 We fixed problems caused by using too many file descriptors
5462 for reading symbols from object files and libraries. This was
5463 especially a problem for programs that used many (~100) shared
5466 The `step' command now only enters a subroutine if there is line number
5467 information for the subroutine. Otherwise it acts like the `next'
5468 command. Previously, `step' would enter subroutines if there was
5469 any debugging information about the routine. This avoids problems
5470 when using `cc -g1' on MIPS machines.
5472 * Internal improvements
5474 GDB's internal interfaces have been improved to make it easier to support
5475 debugging of multiple languages in the future.
5477 GDB now uses a common structure for symbol information internally.
5478 Minimal symbols (derived from linkage symbols in object files), partial
5479 symbols (from a quick scan of debug information), and full symbols
5480 contain a common subset of information, making it easier to write
5481 shared code that handles any of them.
5483 * New command line options
5485 We now accept --silent as an alias for --quiet.
5489 The memory-mapped-malloc library is now licensed under the GNU Library
5490 General Public License.
5492 *** Changes in GDB-4.7:
5494 * Host/native/target split
5496 GDB has had some major internal surgery to untangle the support for
5497 hosts and remote targets. Now, when you configure GDB for a remote
5498 target, it will no longer load in all of the support for debugging
5499 local programs on the host. When fully completed and tested, this will
5500 ensure that arbitrary host/target combinations are possible.
5502 The primary conceptual shift is to separate the non-portable code in
5503 GDB into three categories. Host specific code is required any time GDB
5504 is compiled on that host, regardless of the target. Target specific
5505 code relates to the peculiarities of the target, but can be compiled on
5506 any host. Native specific code is everything else: it can only be
5507 built when the host and target are the same system. Child process
5508 handling and core file support are two common `native' examples.
5510 GDB's use of /proc for controlling Unix child processes is now cleaner.
5511 It has been split out into a single module under the `target_ops' vector,
5512 plus two native-dependent functions for each system that uses /proc.
5514 * New hosts supported
5516 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5517 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5518 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5520 * New targets supported
5522 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5523 68030 and CPU32 m68030-*-*, m68332-*-*
5525 * New native hosts supported
5527 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5528 (386bsd is not well tested yet)
5529 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5531 * New file formats supported
5533 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5534 supports reading of `a.out.adobe' object files, which are an a.out
5535 format extended with minimal information about multiple sections.
5539 `show copying' is the same as the old `info copying'.
5540 `show warranty' is the same as `info warrantee'.
5541 These were renamed for consistency. The old commands continue to work.
5543 `info handle' is a new alias for `info signals'.
5545 You can now define pre-command hooks, which attach arbitrary command
5546 scripts to any command. The commands in the hook will be executed
5547 prior to the user's command. You can also create a hook which will be
5548 executed whenever the program stops. See gdb.texinfo.
5552 We now deal with Cfront style name mangling, and can even extract type
5553 info from mangled symbols. GDB can automatically figure out which
5554 symbol mangling style your C++ compiler uses.
5556 Calling of methods and virtual functions has been improved as well.
5560 The crash that occured when debugging Sun Ansi-C compiled binaries is
5561 fixed. This was due to mishandling of the extra N_SO stabs output
5564 We also finally got Ultrix 4.2 running in house, and fixed core file
5565 support, with help from a dozen people on the net.
5567 John M. Farrell discovered that the reason that single-stepping was so
5568 slow on all of the Mips based platforms (primarily SGI and DEC) was
5569 that we were trying to demangle and lookup a symbol used for internal
5570 purposes on every instruction that was being stepped through. Changing
5571 the name of that symbol so that it couldn't be mistaken for a C++
5572 mangled symbol sped things up a great deal.
5574 Rich Pixley sped up symbol lookups in general by getting much smarter
5575 about when C++ symbol mangling is necessary. This should make symbol
5576 completion (TAB on the command line) much faster. It's not as fast as
5577 we'd like, but it's significantly faster than gdb-4.6.
5581 A new user controllable variable 'call_scratch_address' can
5582 specify the location of a scratch area to be used when GDB
5583 calls a function in the target. This is necessary because the
5584 usual method of putting the scratch area on the stack does not work
5585 in systems that have separate instruction and data spaces.
5587 We integrated changes to support the 29k UDI (Universal Debugger
5588 Interface), but discovered at the last minute that we didn't have all
5589 of the appropriate copyright paperwork. We are working with AMD to
5590 resolve this, and hope to have it available soon.
5594 We have sped up the remote serial line protocol, especially for targets
5595 with lots of registers. It now supports a new `expedited status' ('T')
5596 message which can be used in place of the existing 'S' status message.
5597 This allows the remote stub to send only the registers that GDB
5598 needs to make a quick decision about single-stepping or conditional
5599 breakpoints, eliminating the need to fetch the entire register set for
5600 each instruction being stepped through.
5602 The GDB remote serial protocol now implements a write-through cache for
5603 registers, only re-reading the registers if the target has run.
5605 There is also a new remote serial stub for SPARC processors. You can
5606 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5607 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5608 processor with a serial port.
5612 Configure.in files have become much easier to read and modify. A new
5613 `table driven' format makes it more obvious what configurations are
5614 supported, and what files each one uses.
5618 There is a new opcodes library which will eventually contain all of the
5619 disassembly routines and opcode tables. At present, it only contains
5620 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5621 disassembler (binutils/objdump) to share these routines.
5623 The libiberty library is now copylefted under the GNU Library General
5624 Public License. This allows more liberal use, and was done so libg++
5625 can use it. This makes no difference to GDB, since the Library License
5626 grants all the rights from the General Public License.
5630 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5631 reference to the stabs symbol info used by the debugger. It is (as far
5632 as we know) the only published document on this fascinating topic. We
5633 encourage you to read it, compare it to the stabs information on your
5634 system, and send improvements on the document in general (to
5635 bug-gdb@prep.ai.mit.edu).
5637 And, of course, many bugs have been fixed.
5640 *** Changes in GDB-4.6:
5642 * Better support for C++ function names
5644 GDB now accepts as input the "demangled form" of C++ overloaded function
5645 names and member function names, and can do command completion on such names
5646 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5647 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5648 Make use of command completion, it is your friend.
5650 GDB also now accepts a variety of C++ mangled symbol formats. They are
5651 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5652 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5653 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5654 for the list of formats.
5656 * G++ symbol mangling problem
5658 Recent versions of gcc have a bug in how they emit debugging information for
5659 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5660 directory) can be applied to gcc to fix the problem. Alternatively, if you
5661 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5662 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5663 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5666 * New 'maintenance' command
5668 All of the commands related to hacking GDB internals have been moved out of
5669 the main command set, and now live behind the 'maintenance' command. This
5670 can also be abbreviated as 'mt'. The following changes were made:
5672 dump-me -> maintenance dump-me
5673 info all-breakpoints -> maintenance info breakpoints
5674 printmsyms -> maintenance print msyms
5675 printobjfiles -> maintenance print objfiles
5676 printpsyms -> maintenance print psymbols
5677 printsyms -> maintenance print symbols
5679 The following commands are new:
5681 maintenance demangle Call internal GDB demangler routine to
5682 demangle a C++ link name and prints the result.
5683 maintenance print type Print a type chain for a given symbol
5685 * Change to .gdbinit file processing
5687 We now read the $HOME/.gdbinit file before processing the argv arguments
5688 (e.g. reading symbol files or core files). This allows global parameters to
5689 be set, which will apply during the symbol reading. The ./.gdbinit is still
5690 read after argv processing.
5692 * New hosts supported
5694 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5696 GNU/Linux support i386-unknown-linux or linux
5698 We are also including code to support the HP/PA running BSD and HPUX. This
5699 is almost guaranteed not to work, as we didn't have time to test or build it
5700 for this release. We are including it so that the more adventurous (or
5701 masochistic) of you can play with it. We also had major problems with the
5702 fact that the compiler that we got from HP doesn't support the -g option.
5705 * New targets supported
5707 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5709 * More smarts about finding #include files
5711 GDB now remembers the compilation directory for all include files, and for
5712 all files from which C is generated (like yacc and lex sources). This
5713 greatly improves GDB's ability to find yacc/lex sources, and include files,
5714 especially if you are debugging your program from a directory different from
5715 the one that contains your sources.
5717 We also fixed a bug which caused difficulty with listing and setting
5718 breakpoints in include files which contain C code. (In the past, you had to
5719 try twice in order to list an include file that you hadn't looked at before.)
5721 * Interesting infernals change
5723 GDB now deals with arbitrary numbers of sections, where the symbols for each
5724 section must be relocated relative to that section's landing place in the
5725 target's address space. This work was needed to support ELF with embedded
5726 stabs used by Solaris-2.0.
5728 * Bug fixes (of course!)
5730 There have been loads of fixes for the following things:
5731 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5732 i960, stabs, DOS(GO32), procfs, etc...
5734 See the ChangeLog for details.
5736 *** Changes in GDB-4.5:
5738 * New machines supported (host and target)
5740 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5742 SGI Irix-4.x mips-sgi-irix4 or iris4
5744 * New malloc package
5746 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5747 Mmalloc is capable of handling mutiple heaps of memory. It is also
5748 capable of saving a heap to a file, and then mapping it back in later.
5749 This can be used to greatly speedup the startup of GDB by using a
5750 pre-parsed symbol table which lives in a mmalloc managed heap. For
5751 more details, please read mmalloc/mmalloc.texi.
5755 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5756 'help info proc' for details.
5758 * MIPS ecoff symbol table format
5760 The code that reads MIPS symbol table format is now supported on all hosts.
5761 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5764 * File name changes for MS-DOS
5766 Many files in the config directories have been renamed to make it easier to
5767 support GDB on MS-DOSe systems (which have very restrictive file name
5768 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5769 environment) is close to working but has some remaining problems. Note
5770 that debugging of DOS programs is not supported, due to limitations
5771 in the ``operating system'', but it can be used to host cross-debugging.
5773 * Cross byte order fixes
5775 Many fixes have been made to support cross debugging of Sparc and MIPS
5776 targets from hosts whose byte order differs.
5778 * New -mapped and -readnow options
5780 If memory-mapped files are available on your system through the 'mmap'
5781 system call, you can use the -mapped option on the `file' or
5782 `symbol-file' commands to cause GDB to write the symbols from your
5783 program into a reusable file. If the program you are debugging is
5784 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5785 Future GDB debugging sessions will notice the presence of this file,
5786 and will quickly map in symbol information from it, rather than reading
5787 the symbol table from the executable program. Using the '-mapped'
5788 option in a GDB `file' or `symbol-file' command has the same effect as
5789 starting GDB with the '-mapped' command-line option.
5791 You can cause GDB to read the entire symbol table immediately by using
5792 the '-readnow' option with any of the commands that load symbol table
5793 information (or on the GDB command line). This makes the command
5794 slower, but makes future operations faster.
5796 The -mapped and -readnow options are typically combined in order to
5797 build a `fred.syms' file that contains complete symbol information.
5798 A simple GDB invocation to do nothing but build a `.syms' file for future
5801 gdb -batch -nx -mapped -readnow programname
5803 The `.syms' file is specific to the host machine on which GDB is run.
5804 It holds an exact image of GDB's internal symbol table. It cannot be
5805 shared across multiple host platforms.
5807 * longjmp() handling
5809 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5810 siglongjmp() without losing control. This feature has not yet been ported to
5811 all systems. It currently works on many 386 platforms, all MIPS-based
5812 platforms (SGI, DECstation, etc), and Sun3/4.
5816 Preliminary work has been put in to support the new Solaris OS from Sun. At
5817 this time, it can control and debug processes, but it is not capable of
5822 As always, many many bug fixes. The major areas were with g++, and mipsread.
5823 People using the MIPS-based platforms should experience fewer mysterious
5824 crashes and trashed symbol tables.
5826 *** Changes in GDB-4.4:
5828 * New machines supported (host and target)
5830 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5832 BSD Reno on Vax vax-dec-bsd
5833 Ultrix on Vax vax-dec-ultrix
5835 * New machines supported (target)
5837 AMD 29000 embedded, using EBMON a29k-none-none
5841 GDB continues to improve its handling of C++. `References' work better.
5842 The demangler has also been improved, and now deals with symbols mangled as
5843 per the Annotated C++ Reference Guide.
5845 GDB also now handles `stabs' symbol information embedded in MIPS
5846 `ecoff' symbol tables. Since the ecoff format was not easily
5847 extensible to handle new languages such as C++, this appeared to be a
5848 good way to put C++ debugging info into MIPS binaries. This option
5849 will be supported in the GNU C compiler, version 2, when it is
5852 * New features for SVR4
5854 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5855 shared libraries. Debugging dynamically linked programs should present
5856 only minor differences from debugging statically linked programs.
5858 The `info proc' command will print out information about any process
5859 on an SVR4 system (including the one you are debugging). At the moment,
5860 it prints the address mappings of the process.
5862 If you bring up GDB on another SVR4 system, please send mail to
5863 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5865 * Better dynamic linking support in SunOS
5867 Reading symbols from shared libraries which contain debugging symbols
5868 now works properly. However, there remain issues such as automatic
5869 skipping of `transfer vector' code during function calls, which
5870 make it harder to debug code in a shared library, than to debug the
5871 same code linked statically.
5875 GDB is now using the latest `getopt' routines from the FSF. This
5876 version accepts the -- prefix for options with long names. GDB will
5877 continue to accept the old forms (-option and +option) as well.
5878 Various single letter abbreviations for options have been explicity
5879 added to the option table so that they won't get overshadowed in the
5880 future by other options that begin with the same letter.
5884 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5885 Many assorted bugs have been handled. Many more remain to be handled.
5886 See the various ChangeLog files (primarily in gdb and bfd) for details.
5889 *** Changes in GDB-4.3:
5891 * New machines supported (host and target)
5893 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5894 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5895 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5897 * Almost SCO Unix support
5899 We had hoped to support:
5900 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5901 (except for core file support), but we discovered very late in the release
5902 that it has problems with process groups that render gdb unusable. Sorry
5903 about that. I encourage people to fix it and post the fixes.
5905 * Preliminary ELF and DWARF support
5907 GDB can read ELF object files on System V Release 4, and can handle
5908 debugging records for C, in DWARF format, in ELF files. This support
5909 is preliminary. If you bring up GDB on another SVR4 system, please
5910 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5915 GDB now uses the latest `readline' library. One user-visible change
5916 is that two tabs will list possible command completions, which previously
5917 required typing M-? (meta-question mark, or ESC ?).
5921 The `stepi' bug that many of you noticed has been squashed.
5922 Many bugs in C++ have been handled. Many more remain to be handled.
5923 See the various ChangeLog files (primarily in gdb and bfd) for details.
5925 * State of the MIPS world (in case you wondered):
5927 GDB can understand the symbol tables emitted by the compilers
5928 supplied by most vendors of MIPS-based machines, including DEC. These
5929 symbol tables are in a format that essentially nobody else uses.
5931 Some versions of gcc come with an assembler post-processor called
5932 mips-tfile. This program is required if you want to do source-level
5933 debugging of gcc-compiled programs. I believe FSF does not ship
5934 mips-tfile with gcc version 1, but it will eventually come with gcc
5937 Debugging of g++ output remains a problem. g++ version 1.xx does not
5938 really support it at all. (If you're lucky, you should be able to get
5939 line numbers and stack traces to work, but no parameters or local
5940 variables.) With some work it should be possible to improve the
5943 When gcc version 2 is released, you will have somewhat better luck.
5944 However, even then you will get confusing results for inheritance and
5947 We will eventually provide full debugging of g++ output on
5948 DECstations. This will probably involve some kind of stabs-in-ecoff
5949 encapulation, but the details have not been worked out yet.
5952 *** Changes in GDB-4.2:
5954 * Improved configuration
5956 Only one copy of `configure' exists now, and it is not self-modifying.
5957 Porting BFD is simpler.
5961 The `step' and `next' commands now only stop at the first instruction
5962 of a source line. This prevents the multiple stops that used to occur
5963 in switch statements, for-loops, etc. `Step' continues to stop if a
5964 function that has debugging information is called within the line.
5968 Lots of small bugs fixed. More remain.
5970 * New host supported (not target)
5972 Intel 386 PC clone running Mach i386-none-mach
5975 *** Changes in GDB-4.1:
5977 * Multiple source language support
5979 GDB now has internal scaffolding to handle several source languages.
5980 It determines the type of each source file from its filename extension,
5981 and will switch expression parsing and number formatting to match the
5982 language of the function in the currently selected stack frame.
5983 You can also specifically set the language to be used, with
5984 `set language c' or `set language modula-2'.
5988 GDB now has preliminary support for the GNU Modula-2 compiler,
5989 currently under development at the State University of New York at
5990 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5991 continue through the fall of 1991 and into 1992.
5993 Other Modula-2 compilers are currently not supported, and attempting to
5994 debug programs compiled with them will likely result in an error as the
5995 symbol table is read. Feel free to work on it, though!
5997 There are hooks in GDB for strict type checking and range checking,
5998 in the `Modula-2 philosophy', but they do not currently work.
6002 GDB can now write to executable and core files (e.g. patch
6003 a variable's value). You must turn this switch on, specify
6004 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6005 by assigning a new value to a variable. Modifications take
6008 * Automatic SunOS shared library reading
6010 When you run your program, GDB automatically determines where its
6011 shared libraries (if any) have been loaded, and reads their symbols.
6012 The `share' command is no longer needed. This also works when
6013 examining core files.
6017 You can specify the number of lines that the `list' command shows.
6020 * New machines supported (host and target)
6022 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6023 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6024 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6026 * New hosts supported (not targets)
6028 IBM RT/PC: romp-ibm-aix or rtpc
6030 * New targets supported (not hosts)
6032 AMD 29000 embedded with COFF a29k-none-coff
6033 AMD 29000 embedded with a.out a29k-none-aout
6034 Ultracomputer remote kernel debug a29k-nyu-kern
6036 * New remote interfaces
6042 *** Changes in GDB-4.0:
6046 Wide output is wrapped at good places to make the output more readable.
6048 Gdb now supports cross-debugging from a host machine of one type to a
6049 target machine of another type. Communication with the target system
6050 is over serial lines. The ``target'' command handles connecting to the
6051 remote system; the ``load'' command will download a program into the
6052 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6053 also supports debugging of realtime processes running under VxWorks,
6054 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6055 stub on the target system.
6057 New CPUs supported include the AMD 29000 and Intel 960.
6059 GDB now reads object files and symbol tables via a ``binary file''
6060 library, which allows a single copy of GDB to debug programs of multiple
6061 object file types such as a.out and coff.
6063 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6064 refcard.dvi and refcard.ps are available to format it).
6067 * Control-Variable user interface simplified
6069 All variables that control the operation of the debugger can be set
6070 by the ``set'' command, and displayed by the ``show'' command.
6072 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6073 ``Show prompt'' produces the response:
6074 Gdb's prompt is new-gdb=>.
6076 What follows are the NEW set commands. The command ``help set'' will
6077 print a complete list of old and new set commands. ``help set FOO''
6078 will give a longer description of the variable FOO. ``show'' will show
6079 all of the variable descriptions and their current settings.
6081 confirm on/off: Enables warning questions for operations that are
6082 hard to recover from, e.g. rerunning the program while
6083 it is already running. Default is ON.
6085 editing on/off: Enables EMACS style command line editing
6086 of input. Previous lines can be recalled with
6087 control-P, the current line can be edited with control-B,
6088 you can search for commands with control-R, etc.
6091 history filename NAME: NAME is where the gdb command history
6092 will be stored. The default is .gdb_history,
6093 or the value of the environment variable
6096 history size N: The size, in commands, of the command history. The
6097 default is 256, or the value of the environment variable
6100 history save on/off: If this value is set to ON, the history file will
6101 be saved after exiting gdb. If set to OFF, the
6102 file will not be saved. The default is OFF.
6104 history expansion on/off: If this value is set to ON, then csh-like
6105 history expansion will be performed on
6106 command line input. The default is OFF.
6108 radix N: Sets the default radix for input and output. It can be set
6109 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6110 in the current radix, so "set radix 10" is always a no-op.
6112 height N: This integer value is the number of lines on a page. Default
6113 is 24, the current `stty rows'' setting, or the ``li#''
6114 setting from the termcap entry matching the environment
6117 width N: This integer value is the number of characters on a line.
6118 Default is 80, the current `stty cols'' setting, or the ``co#''
6119 setting from the termcap entry matching the environment
6122 Note: ``set screensize'' is obsolete. Use ``set height'' and
6123 ``set width'' instead.
6125 print address on/off: Print memory addresses in various command displays,
6126 such as stack traces and structure values. Gdb looks
6127 more ``symbolic'' if you turn this off; it looks more
6128 ``machine level'' with it on. Default is ON.
6130 print array on/off: Prettyprint arrays. New convenient format! Default
6133 print demangle on/off: Print C++ symbols in "source" form if on,
6136 print asm-demangle on/off: Same, for assembler level printouts
6139 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6142 * Support for Epoch Environment.
6144 The epoch environment is a version of Emacs v18 with windowing. One
6145 new command, ``inspect'', is identical to ``print'', except that if you
6146 are running in the epoch environment, the value is printed in its own
6150 * Support for Shared Libraries
6152 GDB can now debug programs and core files that use SunOS shared libraries.
6153 Symbols from a shared library cannot be referenced
6154 before the shared library has been linked with the program (this
6155 happens after you type ``run'' and before the function main() is entered).
6156 At any time after this linking (including when examining core files
6157 from dynamically linked programs), gdb reads the symbols from each
6158 shared library when you type the ``sharedlibrary'' command.
6159 It can be abbreviated ``share''.
6161 sharedlibrary REGEXP: Load shared object library symbols for files
6162 matching a unix regular expression. No argument
6163 indicates to load symbols for all shared libraries.
6165 info sharedlibrary: Status of loaded shared libraries.
6170 A watchpoint stops execution of a program whenever the value of an
6171 expression changes. Checking for this slows down execution
6172 tremendously whenever you are in the scope of the expression, but is
6173 quite useful for catching tough ``bit-spreader'' or pointer misuse
6174 problems. Some machines such as the 386 have hardware for doing this
6175 more quickly, and future versions of gdb will use this hardware.
6177 watch EXP: Set a watchpoint (breakpoint) for an expression.
6179 info watchpoints: Information about your watchpoints.
6181 delete N: Deletes watchpoint number N (same as breakpoints).
6182 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6183 enable N: Re-enables watchpoint number N (same as breakpoints).
6186 * C++ multiple inheritance
6188 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6191 * C++ exception handling
6193 Gdb now supports limited C++ exception handling. Besides the existing
6194 ability to breakpoint on an exception handler, gdb can breakpoint on
6195 the raising of an exception (before the stack is peeled back to the
6198 catch FOO: If there is a FOO exception handler in the dynamic scope,
6199 set a breakpoint to catch exceptions which may be raised there.
6200 Multiple exceptions (``catch foo bar baz'') may be caught.
6202 info catch: Lists all exceptions which may be caught in the
6203 current stack frame.
6206 * Minor command changes
6208 The command ``call func (arg, arg, ...)'' now acts like the print
6209 command, except it does not print or save a value if the function's result
6210 is void. This is similar to dbx usage.
6212 The ``up'' and ``down'' commands now always print the frame they end up
6213 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6214 frames without printing.
6216 * New directory command
6218 'dir' now adds directories to the FRONT of the source search path.
6219 The path starts off empty. Source files that contain debug information
6220 about the directory in which they were compiled can be found even
6221 with an empty path; Sun CC and GCC include this information. If GDB can't
6222 find your source file in the current directory, type "dir .".
6224 * Configuring GDB for compilation
6226 For normal use, type ``./configure host''. See README or gdb.texinfo
6229 GDB now handles cross debugging. If you are remotely debugging between
6230 two different machines, type ``./configure host -target=targ''.
6231 Host is the machine where GDB will run; targ is the machine
6232 where the program that you are debugging will run.