1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.9
6 * Support for process record-replay and reverse debugging on aarch64*-linux*
7 targets has been added. GDB now supports recording of A64 instruction set
8 including advance SIMD instructions.
10 * GDB now honors the content of the file /proc/PID/coredump_filter
11 (PID is the process ID) on GNU/Linux systems. This file can be used
12 to specify the types of memory mappings that will be included in a
13 corefile. For more information, please refer to the manual page of
14 "core(5)". GDB also has a new command: "set use-coredump-filter
15 on|off". It allows to set whether GDB will read the content of the
16 /proc/PID/coredump_filter file when generating a corefile.
18 * The "info os" command on GNU/Linux can now display information on
20 "info os cpus" Listing of all cpus/cores on the system
22 * GDB has two new commands: "set serial parity odd|even|none" and
23 "show serial parity". These allows to set or show parity for the
26 * The "info source" command now displays the producer string if it was
27 present in the debug info. This typically includes the compiler version
28 and may include things like its command line arguments.
30 * The "info dll", an alias of the "info sharedlibrary" command,
31 is now available on all platforms.
33 * Directory names supplied to the "set sysroot" commands may be
34 prefixed with "target:" to tell GDB to access shared libraries from
35 the target system, be it local or remote. This replaces the prefix
36 "remote:". The default sysroot has been changed from "" to
37 "target:". "remote:" is automatically converted to "target:" for
38 backward compatibility.
40 * The system root specified by "set sysroot" will be prepended to the
41 filename of the main executable (if reported to GDB as absolute by
42 the operating system) when starting processes remotely, and when
43 attaching to already-running local or remote processes.
45 * GDB now supports automatic location and retrieval of executable
46 files from remote targets. Remote debugging can now be initiated
47 using only a "target remote" or "target extended-remote" command
48 (no "set sysroot" or "file" commands are required). See "New remote
51 * The "dump" command now supports verilog hex format.
53 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
57 ** Memory ports can now be unbuffered.
61 ** gdb.Objfile objects have a new attribute "username",
62 which is the name of the objfile as specified by the user,
63 without, for example, resolving symlinks.
64 ** You can now write frame unwinders in Python.
65 ** gdb.Type objects have a new method "optimized_out",
66 returning optimized out gdb.Value instance of this type.
67 ** gdb.Value objects have new methods "reference_value" and
68 "const_value" which return a reference to the value and a
69 "const" version of the value respectively.
73 maint print symbol-cache
74 Print the contents of the symbol cache.
76 maint print symbol-cache-statistics
77 Print statistics of symbol cache usage.
79 maint flush-symbol-cache
80 Flush the contents of the symbol cache.
84 Start branch trace recording using Branch Trace Store (BTS) format.
87 Evaluate expression by using the compiler and print result.
91 Explicit commands for enabling and disabling tui mode.
94 set mpx bound on i386 and amd64
95 Support for bound table investigation on Intel(R) MPX enabled applications.
100 Renamed from "set debug dwarf2-die".
102 Renamed from "show debug dwarf2-die".
105 Renamed from "set debug dwarf2-read".
106 show debug dwarf-read
107 Renamed from "show debug dwarf2-read".
109 maint set dwarf always-disassemble
110 Renamed from "maint set dwarf2 always-disassemble".
111 maint show dwarf always-disassemble
112 Renamed from "maint show dwarf2 always-disassemble".
114 maint set dwarf max-cache-age
115 Renamed from "maint set dwarf2 max-cache-age".
116 maint show dwarf max-cache-age
117 Renamed from "maint show dwarf2 max-cache-age".
120 show debug dwarf-line
121 Control display of debugging info regarding DWARF line processing.
125 Set the maximum number of candidates to be considered during
126 completion. The default value is 200. This limit allows GDB
127 to avoid generating large completion lists, the computation of
128 which can cause the debugger to become temporarily unresponsive.
130 maint set symbol-cache-size
131 maint show symbol-cache-size
132 Control the size of the symbol cache.
134 set|show record btrace bts buffer-size
135 Set and show the size of the ring buffer used for branch tracing in
137 The obtained size may differ from the requested size. Use "info
138 record" to see the obtained buffer size.
140 * The command 'thread apply all' can now support new option '-ascending'
141 to call its specified command for all threads in ascending order.
143 * Python/Guile scripting
145 ** GDB now supports auto-loading of Python/Guile scripts contained in the
146 special section named `.debug_gdb_scripts'.
150 qXfer:btrace-conf:read
151 Return the branch trace configuration for the current thread.
153 Qbtrace-conf:bts:size
154 Set the requested ring buffer size for branch tracing in BTS format.
157 Indicates a memory breakpoint instruction was executed, irrespective
158 of whether it was GDB that planted the breakpoint or the breakpoint
159 is hardcoded in the program. This is required for correct non-stop
163 Indicates the target stopped for a hardware breakpoint. This is
164 required for correct non-stop mode operation.
167 Return information about files on the remote system.
170 Return the full absolute name of the file that was executed to
171 create a process running on the remote system.
174 Indicates that a fork system call was executed.
177 Indicates that a vfork system call was executed.
179 vforkdone stop reason
180 Indicates that a vfork child of the specified process has executed
181 an exec or exit, allowing the vfork parent to resume execution.
183 fork-events and vfork-events features in qSupported
184 The qSupported packet allows GDB to request support for fork and
185 vfork events using new 'gdbfeatures' fork-events and vfork-events,
186 and the qSupported response can contain the corresponding
187 'stubfeatures'. Set and show commands can be used to display
188 whether these features are enabled.
190 * Extended-remote fork events
192 ** GDB now has support for fork events on extended-remote Linux
193 targets. For targets with Linux kernels 2.5.60 and later, this
194 enables follow-fork-mode and detach-on-fork for both fork and
195 vfork, as well as fork and vfork catchpoints.
197 * The info record command now shows the recording format and the
198 branch tracing configuration for the current thread when using
199 the btrace record target.
200 For the BTS format, it shows the ring buffer size.
202 * GDB now has support for DTrace USDT (Userland Static Defined
203 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
205 * GDB now supports access to vector registers on S/390 GNU/Linux
208 * Removed command line options
210 -xdb HP-UX XDB compatibility mode.
212 * Removed targets and native configurations
214 HP/PA running HP-UX hppa*-*-hpux*
215 Itanium running HP-UX ia64-*-hpux*
217 *** Changes in GDB 7.9.1
221 ** Xmethods can now specify a result type.
223 *** Changes in GDB 7.9
225 * GDB now supports hardware watchpoints on x86 GNU Hurd.
229 ** You can now access frame registers from Python scripts.
230 ** New attribute 'producer' for gdb.Symtab objects.
231 ** gdb.Objfile objects have a new attribute "progspace",
232 which is the gdb.Progspace object of the containing program space.
233 ** gdb.Objfile objects have a new attribute "owner".
234 ** gdb.Objfile objects have a new attribute "build_id",
235 which is the build ID generated when the file was built.
236 ** gdb.Objfile objects have a new method "add_separate_debug_file".
237 ** A new event "gdb.clear_objfiles" has been added, triggered when
238 selecting a new file to debug.
239 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
240 ** New function gdb.lookup_objfile.
242 New events which are triggered when GDB modifies the state of the
245 ** gdb.events.inferior_call_pre: Function call is about to be made.
246 ** gdb.events.inferior_call_post: Function call has just been made.
247 ** gdb.events.memory_changed: A memory location has been altered.
248 ** gdb.events.register_changed: A register has been altered.
250 * New Python-based convenience functions:
252 ** $_caller_is(name [, number_of_frames])
253 ** $_caller_matches(regexp [, number_of_frames])
254 ** $_any_caller_is(name [, number_of_frames])
255 ** $_any_caller_matches(regexp [, number_of_frames])
257 * GDB now supports the compilation and injection of source code into
258 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
259 to compile the source code to object code, and if successful, inject
260 and execute that code within the current context of the inferior.
261 Currently the C language is supported. The commands used to
262 interface with this new feature are:
264 compile code [-raw|-r] [--] [source code]
265 compile file [-raw|-r] filename
269 demangle [-l language] [--] name
270 Demangle "name" in the specified language, or the current language
271 if elided. This command is renamed from the "maint demangle" command.
272 The latter is kept as a no-op to avoid "maint demangle" being interpreted
273 as "maint demangler-warning".
275 queue-signal signal-name-or-number
276 Queue a signal to be delivered to the thread when it is resumed.
278 add-auto-load-scripts-directory directory
279 Add entries to the list of directories from which to load auto-loaded
282 maint print user-registers
283 List all currently available "user" registers.
285 compile code [-r|-raw] [--] [source code]
286 Compile, inject, and execute in the inferior the executable object
287 code produced by compiling the provided source code.
289 compile file [-r|-raw] filename
290 Compile and inject into the inferior the executable object code
291 produced by compiling the source code stored in the filename
294 * On resume, GDB now always passes the signal the program had stopped
295 for to the thread the signal was sent to, even if the user changed
296 threads before resuming. Previously GDB would often (but not
297 always) deliver the signal to the thread that happens to be current
300 * Conversely, the "signal" command now consistently delivers the
301 requested signal to the current thread. GDB now asks for
302 confirmation if the program had stopped for a signal and the user
303 switched threads meanwhile.
305 * "breakpoint always-inserted" modes "off" and "auto" merged.
307 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
308 won't remove breakpoints from the target until all threads stop,
309 even in non-stop mode. The "auto" mode has been removed, and "off"
310 is now the default mode.
314 set debug symbol-lookup
315 show debug symbol-lookup
316 Control display of debugging info regarding symbol lookup.
320 ** The -list-thread-groups command outputs an exit-code field for
321 inferiors that have exited.
325 MIPS SDE mips*-sde*-elf*
329 Support for these obsolete configurations has been removed.
331 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
332 SGI Irix-5.x mips-*-irix5*
333 SGI Irix-6.x mips-*-irix6*
334 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
335 VAX running Ultrix vax-*-ultrix*
337 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
338 and "assf"), have been removed. Use the "sharedlibrary" command, or
339 its alias "share", instead.
341 *** Changes in GDB 7.8
343 * New command line options
346 This is an alias for the --data-directory option.
348 * GDB supports printing and modifying of variable length automatic arrays
349 as specified in ISO C99.
351 * The ARM simulator now supports instruction level tracing
352 with or without disassembly.
356 GDB now has support for scripting using Guile. Whether this is
357 available is determined at configure time.
358 Guile version 2.0 or greater is required.
359 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
361 * New commands (for set/show, see "New options" below)
365 Invoke CODE by passing it to the Guile interpreter.
369 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
371 info auto-load guile-scripts [regexp]
372 Print the list of automatically loaded Guile scripts.
374 * The source command is now capable of sourcing Guile scripts.
375 This feature is dependent on the debugger being built with Guile support.
379 set print symbol-loading (off|brief|full)
380 show print symbol-loading
381 Control whether to print informational messages when loading symbol
382 information for a file. The default is "full", but when debugging
383 programs with large numbers of shared libraries the amount of output
386 set guile print-stack (none|message|full)
387 show guile print-stack
388 Show a stack trace when an error is encountered in a Guile script.
390 set auto-load guile-scripts (on|off)
391 show auto-load guile-scripts
392 Control auto-loading of Guile script files.
394 maint ada set ignore-descriptive-types (on|off)
395 maint ada show ignore-descriptive-types
396 Control whether the debugger should ignore descriptive types in Ada
397 programs. The default is not to ignore the descriptive types. See
398 the user manual for more details on descriptive types and the intended
399 usage of this option.
401 set auto-connect-native-target
403 Control whether GDB is allowed to automatically connect to the
404 native target for the run, attach, etc. commands when not connected
405 to any target yet. See also "target native" below.
407 set record btrace replay-memory-access (read-only|read-write)
408 show record btrace replay-memory-access
409 Control what memory accesses are allowed during replay.
411 maint set target-async (on|off)
412 maint show target-async
413 This controls whether GDB targets operate in synchronous or
414 asynchronous mode. Normally the default is asynchronous, if it is
415 available; but this can be changed to more easily debug problems
416 occurring only in synchronous mode.
418 set mi-async (on|off)
420 Control whether MI asynchronous mode is preferred. This supersedes
421 "set target-async" of previous GDB versions.
423 * "set target-async" is deprecated as a CLI option and is now an alias
424 for "set mi-async" (only puts MI into async mode).
426 * Background execution commands (e.g., "c&", "s&", etc.) are now
427 possible ``out of the box'' if the target supports them. Previously
428 the user would need to explicitly enable the possibility with the
429 "set target-async on" command.
431 * New features in the GDB remote stub, GDBserver
433 ** New option --debug-format=option1[,option2,...] allows one to add
434 additional text to each output. At present only timestamps
435 are supported: --debug-format=timestamps.
436 Timestamps can also be turned on with the
437 "monitor set debug-format timestamps" command from GDB.
439 * The 'record instruction-history' command now starts counting instructions
440 at one. This also affects the instruction ranges reported by the
441 'record function-call-history' command when given the /i modifier.
443 * The command 'record function-call-history' supports a new modifier '/c' to
444 indent the function names based on their call stack depth.
445 The fields for the '/i' and '/l' modifier have been reordered.
446 The source line range is now prefixed with 'at'.
447 The instruction range is now prefixed with 'inst'.
448 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
449 "record instruction-history" and "list" commands.
451 * The ranges given as arguments to the 'record function-call-history' and
452 'record instruction-history' commands are now inclusive.
454 * The btrace record target now supports the 'record goto' command.
455 For locations inside the execution trace, the back trace is computed
456 based on the information stored in the execution trace.
458 * The btrace record target supports limited reverse execution and replay.
459 The target does not record data and therefore does not allow reading
462 * The "catch syscall" command now works on s390*-linux* targets.
464 * The "compare-sections" command is no longer specific to target
465 remote. It now works with all targets.
467 * All native targets are now consistently called "native".
468 Consequently, the "target child", "target GNU", "target djgpp",
469 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
470 commands have been replaced with "target native". The QNX/NTO port
471 leaves the "procfs" target in place and adds a "native" target for
472 consistency with other ports. The impact on users should be minimal
473 as these commands previously either throwed an error, or were
474 no-ops. The target's name is visible in the output of the following
475 commands: "help target", "info target", "info files", "maint print
478 * The "target native" command now connects to the native target. This
479 can be used to launch native programs even when "set
480 auto-connect-native-target" is set to off.
482 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.
484 * Support for Intel(R) AVX-512 registers on GNU/Linux.
485 Support displaying and modifying Intel(R) AVX-512 registers
486 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
490 qXfer:btrace:read's annex
491 The qXfer:btrace:read packet supports a new annex 'delta' to read
492 branch trace incrementally.
496 ** Valid Python operations on gdb.Value objects representing
497 structs/classes invoke the corresponding overloaded operators if
499 ** New `Xmethods' feature in the Python API. Xmethods are
500 additional methods or replacements for existing methods of a C++
501 class. This feature is useful for those cases where a method
502 defined in C++ source code could be inlined or optimized out by
503 the compiler, making it unavailable to GDB.
506 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
508 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
509 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
510 its alias "share", instead.
512 * The commands "set remotebaud" and "show remotebaud" are no longer
513 supported. Use "set serial baud" and "show serial baud" (respectively)
518 ** A new option "-gdb-set mi-async" replaces "-gdb-set
519 target-async". The latter is left as a deprecated alias of the
520 former for backward compatibility. If the target supports it,
521 CLI background execution commands are now always possible by
522 default, independently of whether the frontend stated a
523 preference for asynchronous execution with "-gdb-set mi-async".
524 Previously "-gdb-set target-async off" affected both MI execution
525 commands and CLI execution commands.
527 *** Changes in GDB 7.7
529 * Improved support for process record-replay and reverse debugging on
530 arm*-linux* targets. Support for thumb32 and syscall instruction
531 recording has been added.
533 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
535 * GDB now supports Fission DWP file format version 2.
536 http://gcc.gnu.org/wiki/DebugFission
538 * New convenience function "$_isvoid", to check whether an expression
539 is void. A void expression is an expression where the type of the
540 result is "void". For example, some convenience variables may be
541 "void" when evaluated (e.g., "$_exitcode" before the execution of
542 the program being debugged; or an undefined convenience variable).
543 Another example, when calling a function whose return type is
546 * The "maintenance print objfiles" command now takes an optional regexp.
548 * The "catch syscall" command now works on arm*-linux* targets.
550 * GDB now consistently shows "<not saved>" when printing values of
551 registers the debug info indicates have not been saved in the frame
552 and there's nowhere to retrieve them from
553 (callee-saved/call-clobbered registers):
558 (gdb) info registers rax
561 Before, the former would print "<optimized out>", and the latter
562 "*value not available*".
564 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
569 ** Frame filters and frame decorators have been added.
570 ** Temporary breakpoints are now supported.
571 ** Line tables representation has been added.
572 ** New attribute 'parent_type' for gdb.Field objects.
573 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
574 ** New attribute 'name' for gdb.Type objects.
578 Nios II ELF nios2*-*-elf
579 Nios II GNU/Linux nios2*-*-linux
580 Texas Instruments MSP430 msp430*-*-elf
582 * Removed native configurations
584 Support for these a.out NetBSD and OpenBSD obsolete configurations has
585 been removed. ELF variants of these configurations are kept supported.
587 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
588 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
589 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
590 i[34567]86-*-openbsd3.[0-3]
591 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
592 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
593 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
597 Like "catch throw", but catches a re-thrown exception.
599 Renamed from old "maint check-symtabs".
601 Perform consistency checks on symtabs.
603 Expand symtabs matching an optional regexp.
606 Display the details of GDB configure-time options.
608 maint set|show per-command
609 maint set|show per-command space
610 maint set|show per-command time
611 maint set|show per-command symtab
612 Enable display of per-command gdb resource usage.
614 remove-symbol-file FILENAME
615 remove-symbol-file -a ADDRESS
616 Remove a symbol file added via add-symbol-file. The file to remove
617 can be identified by its filename or by an address that lies within
618 the boundaries of this symbol file in memory.
621 info exceptions REGEXP
622 Display the list of Ada exceptions defined in the program being
623 debugged. If provided, only the exceptions whose names match REGEXP
628 set debug symfile off|on
630 Control display of debugging info regarding reading symbol files and
631 symbol tables within those files
633 set print raw frame-arguments
634 show print raw frame-arguments
635 Set/show whether to print frame arguments in raw mode,
636 disregarding any defined pretty-printers.
638 set remote trace-status-packet
639 show remote trace-status-packet
640 Set/show the use of remote protocol qTStatus packet.
644 Control display of debugging messages related to Nios II targets.
648 Control whether target-assisted range stepping is enabled.
650 set startup-with-shell
651 show startup-with-shell
652 Specifies whether Unix child processes are started via a shell or
657 Use the target memory cache for accesses to the code segment. This
658 improves performance of remote debugging (particularly disassembly).
660 * You can now use a literal value 'unlimited' for options that
661 interpret 0 or -1 as meaning "unlimited". E.g., "set
662 trace-buffer-size unlimited" is now an alias for "set
663 trace-buffer-size -1" and "set height unlimited" is now an alias for
666 * The "set debug symtab-create" debugging option of GDB has been changed to
667 accept a verbosity level. 0 means "off", 1 provides basic debugging
668 output, and values of 2 or greater provides more verbose output.
670 * New command-line options
672 Display the details of GDB configure-time options.
674 * The command 'tsave' can now support new option '-ctf' to save trace
675 buffer in Common Trace Format.
677 * Newly installed $prefix/bin/gcore acts as a shell interface for the
680 * GDB now implements the the C++ 'typeid' operator.
682 * The new convenience variable $_exception holds the exception being
683 thrown or caught at an exception-related catchpoint.
685 * The exception-related catchpoints, like "catch throw", now accept a
686 regular expression which can be used to filter exceptions by type.
688 * The new convenience variable $_exitsignal is automatically set to
689 the terminating signal number when the program being debugged dies
690 due to an uncaught signal.
694 ** All MI commands now accept an optional "--language" option.
695 Support for this feature can be verified by using the "-list-features"
696 command, which should contain "language-option".
698 ** The new command -info-gdb-mi-command allows the user to determine
699 whether a GDB/MI command is supported or not.
701 ** The "^error" result record returned when trying to execute an undefined
702 GDB/MI command now provides a variable named "code" whose content is the
703 "undefined-command" error code. Support for this feature can be verified
704 by using the "-list-features" command, which should contain
705 "undefined-command-error-code".
707 ** The -trace-save MI command can optionally save trace buffer in Common
710 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
712 ** The command -data-list-register-values now accepts an optional
713 "--skip-unavailable" option. When used, only the available registers
716 ** The new command -trace-frame-collected dumps collected variables,
717 computed expressions, tvars, memory and registers in a traceframe.
719 ** The commands -stack-list-locals, -stack-list-arguments and
720 -stack-list-variables now accept an option "--skip-unavailable".
721 When used, only the available locals or arguments are displayed.
723 ** The -exec-run command now accepts an optional "--start" option.
724 When used, the command follows the same semantics as the "start"
725 command, stopping the program's execution at the start of its
726 main subprogram. Support for this feature can be verified using
727 the "-list-features" command, which should contain
728 "exec-run-start-option".
730 ** The new commands -catch-assert and -catch-exceptions insert
731 catchpoints stopping the program when Ada exceptions are raised.
733 ** The new command -info-ada-exceptions provides the equivalent of
734 the new "info exceptions" command.
736 * New system-wide configuration scripts
737 A GDB installation now provides scripts suitable for use as system-wide
738 configuration scripts for the following systems:
742 * GDB now supports target-assigned range stepping with remote targets.
743 This improves the performance of stepping source lines by reducing
744 the number of control packets from/to GDB. See "New remote packets"
747 * GDB now understands the element 'tvar' in the XML traceframe info.
748 It has the id of the collected trace state variables.
750 * On S/390 targets that provide the transactional-execution feature,
751 the program interruption transaction diagnostic block (TDB) is now
752 represented as a number of additional "registers" in GDB.
758 The vCont packet supports a new 'r' action, that tells the remote
759 stub to step through an address range itself, without GDB
760 involvemement at each single-step.
762 qXfer:libraries-svr4:read's annex
763 The previously unused annex of the qXfer:libraries-svr4:read packet
764 is now used to support passing an argument list. The remote stub
765 reports support for this argument list to GDB's qSupported query.
766 The defined arguments are "start" and "prev", used to reduce work
767 necessary for library list updating, resulting in significant
770 * New features in the GDB remote stub, GDBserver
772 ** GDBserver now supports target-assisted range stepping. Currently
773 enabled on x86/x86_64 GNU/Linux targets.
775 ** GDBserver now adds element 'tvar' in the XML in the reply to
776 'qXfer:traceframe-info:read'. It has the id of the collected
777 trace state variables.
779 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
782 * New 'z' formatter for printing and examining memory, this displays the
783 value as hexadecimal zero padded on the left to the size of the type.
785 * GDB can now use Windows x64 unwinding data.
787 * The "set remotebaud" command has been replaced by "set serial baud".
788 Similarly, "show remotebaud" has been replaced by "show serial baud".
789 The "set remotebaud" and "show remotebaud" commands are still available
790 to provide backward compatibility with older versions of GDB.
792 *** Changes in GDB 7.6
794 * Target record has been renamed to record-full.
795 Record/replay is now enabled with the "record full" command.
796 This also affects settings that are associated with full record/replay
797 that have been moved from "set/show record" to "set/show record full":
799 set|show record full insn-number-max
800 set|show record full stop-at-limit
801 set|show record full memory-query
803 * A new record target "record-btrace" has been added. The new target
804 uses hardware support to record the control-flow of a process. It
805 does not support replaying the execution, but it implements the
806 below new commands for investigating the recorded execution log.
807 This new recording method can be enabled using:
811 The "record-btrace" target is only available on Intel Atom processors
812 and requires a Linux kernel 2.6.32 or later.
814 * Two new commands have been added for record/replay to give information
815 about the recorded execution without having to replay the execution.
816 The commands are only supported by "record btrace".
818 record instruction-history prints the execution history at
819 instruction granularity
821 record function-call-history prints the execution history at
824 * New native configurations
826 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
827 FreeBSD/powerpc powerpc*-*-freebsd
828 x86_64/Cygwin x86_64-*-cygwin*
829 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
833 ARM AArch64 aarch64*-*-elf
834 ARM AArch64 GNU/Linux aarch64*-*-linux
835 Lynx 178 PowerPC powerpc-*-lynx*178
836 x86_64/Cygwin x86_64-*-cygwin*
837 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
839 * If the configured location of system.gdbinit file (as given by the
840 --with-system-gdbinit option at configure time) is in the
841 data-directory (as specified by --with-gdb-datadir at configure
842 time) or in one of its subdirectories, then GDB will look for the
843 system-wide init file in the directory specified by the
844 --data-directory command-line option.
846 * New command line options:
848 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
849 other initialization files, unlike -nx which disables all of them.
851 * Removed command line options
853 -epoch This was used by the gdb mode in Epoch, an ancient fork of
856 * The 'ptype' and 'whatis' commands now accept an argument to control
859 * 'info proc' now works on some core files.
863 ** Vectors can be created with gdb.Type.vector.
865 ** Python's atexit.register now works in GDB.
867 ** Types can be pretty-printed via a Python API.
869 ** Python 3 is now supported (in addition to Python 2.4 or later)
871 ** New class gdb.Architecture exposes GDB's internal representation
872 of architecture in the Python API.
874 ** New method Frame.architecture returns the gdb.Architecture object
875 corresponding to the frame's architecture.
877 * New Python-based convenience functions:
879 ** $_memeq(buf1, buf2, length)
880 ** $_streq(str1, str2)
882 ** $_regex(str, regex)
884 * The 'cd' command now defaults to using '~' (the home directory) if not
887 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
888 default for GCC since November 2000.
890 * The command 'forward-search' can now be abbreviated as 'fo'.
892 * The command 'info tracepoints' can now display 'installed on target'
893 or 'not installed on target' for each non-pending location of tracepoint.
895 * New configure options
897 --enable-libmcheck/--disable-libmcheck
898 By default, development versions are built with -lmcheck on hosts
899 that support it, in order to help track memory corruption issues.
900 Release versions, on the other hand, are built without -lmcheck
901 by default. The --enable-libmcheck/--disable-libmcheck configure
902 options allow the user to override that default.
903 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
904 This configure option allows the user to build GDB with
905 libbabeltrace using which GDB can read Common Trace Format data.
907 * New commands (for set/show, see "New options" below)
910 Catch signals. This is similar to "handle", but allows commands and
911 conditions to be attached.
914 List the BFDs known to GDB.
916 python-interactive [command]
918 Start a Python interactive prompt, or evaluate the optional command
919 and print the result of expressions.
922 "py" is a new alias for "python".
924 enable type-printer [name]...
925 disable type-printer [name]...
926 Enable or disable type printers.
930 ** For the Renesas Super-H architecture, the "regs" command has been removed
931 (has been deprecated in GDB 7.5), and "info all-registers" should be used
936 set print type methods (on|off)
937 show print type methods
938 Control whether method declarations are displayed by "ptype".
939 The default is to show them.
941 set print type typedefs (on|off)
942 show print type typedefs
943 Control whether typedef definitions are displayed by "ptype".
944 The default is to show them.
946 set filename-display basename|relative|absolute
947 show filename-display
948 Control the way in which filenames is displayed.
949 The default is "relative", which preserves previous behavior.
951 set trace-buffer-size
952 show trace-buffer-size
953 Request target to change the size of trace buffer.
955 set remote trace-buffer-size-packet auto|on|off
956 show remote trace-buffer-size-packet
957 Control the use of the remote protocol `QTBuffer:size' packet.
961 Control display of debugging messages related to ARM AArch64.
964 set debug coff-pe-read
965 show debug coff-pe-read
966 Control display of debugging messages related to reading of COFF/PE
971 Control display of debugging messages related to Mach-O symbols
974 set debug notification
975 show debug notification
976 Control display of debugging info for async remote notification.
980 ** Command parameter changes are now notified using new async record
981 "=cmd-param-changed".
982 ** Trace frame changes caused by command "tfind" are now notified using
983 new async record "=traceframe-changed".
984 ** The creation, deletion and modification of trace state variables
985 are now notified using new async records "=tsv-created",
986 "=tsv-deleted" and "=tsv-modified".
987 ** The start and stop of process record are now notified using new
988 async record "=record-started" and "=record-stopped".
989 ** Memory changes are now notified using new async record
991 ** The data-disassemble command response will include a "fullname" field
992 containing the absolute file name when source has been requested.
993 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
994 command, to allow pattern filling of memory areas.
995 ** New commands "-catch-load"/"-catch-unload" added for intercepting
996 library load/unload events.
997 ** The response to breakpoint commands and breakpoint async records
998 includes an "installed" field containing a boolean state about each
999 non-pending tracepoint location is whether installed on target or not.
1000 ** Output of the "-trace-status" command includes a "trace-file" field
1001 containing the name of the trace file being examined. This field is
1002 optional, and only present when examining a trace file.
1003 ** The "fullname" field is now always present along with the "file" field,
1004 even if the file cannot be found by GDB.
1006 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1007 You must have the LZMA library available when configuring GDB for this
1008 feature to be enabled. For more information, see:
1009 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1011 * New remote packets
1014 Set the size of trace buffer. The remote stub reports support for this
1015 packet to gdb's qSupported query.
1018 Enable Branch Trace Store (BTS)-based branch tracing for the current
1019 thread. The remote stub reports support for this packet to gdb's
1023 Disable branch tracing for the current thread. The remote stub reports
1024 support for this packet to gdb's qSupported query.
1027 Read the traced branches for the current thread. The remote stub
1028 reports support for this packet to gdb's qSupported query.
1030 *** Changes in GDB 7.5
1032 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1033 for more x32 ABI info.
1035 * GDB now supports access to MIPS DSP registers on Linux targets.
1037 * GDB now supports debugging microMIPS binaries.
1039 * The "info os" command on GNU/Linux can now display information on
1040 several new classes of objects managed by the operating system:
1041 "info os procgroups" lists process groups
1042 "info os files" lists file descriptors
1043 "info os sockets" lists internet-domain sockets
1044 "info os shm" lists shared-memory regions
1045 "info os semaphores" lists semaphores
1046 "info os msg" lists message queues
1047 "info os modules" lists loaded kernel modules
1049 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1050 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1051 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1052 options and inspect the probe arguments using the new $_probe_arg family
1053 of convenience variables. You can obtain more information about SystemTap
1054 in <http://sourceware.org/systemtap/>.
1056 * GDB now supports reversible debugging on ARM, it allows you to
1057 debug basic ARM and THUMB instructions, and provides
1058 record/replay support.
1060 * The option "symbol-reloading" has been deleted as it is no longer used.
1064 ** GDB commands implemented in Python can now be put in command class
1067 ** The "maint set python print-stack on|off" is now deleted.
1069 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1070 apply "flag enum"-style pretty-printing to any enum.
1072 ** gdb.lookup_symbol can now work when there is no current frame.
1074 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1075 the source at which the symbol was defined.
1077 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1078 method 'value'. The former indicates whether the symbol needs a
1079 frame in order to compute its value, and the latter computes the
1082 ** A new method 'referenced_value' on gdb.Value objects which can
1083 dereference pointer as well as C++ reference values.
1085 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1086 which return the global and static blocks (as gdb.Block objects),
1087 of the underlying symbol table, respectively.
1089 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1090 object associated with a PC value.
1092 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1093 of the address range occupied by code for the current source line.
1095 * Go language support.
1096 GDB now supports debugging programs written in the Go programming
1099 * GDBserver now supports stdio connections.
1100 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1102 * The binary "gdbtui" can no longer be built or installed.
1103 Use "gdb -tui" instead.
1105 * GDB will now print "flag" enums specially. A flag enum is one where
1106 all the enumerator values have no bits in common when pairwise
1107 "and"ed. When printing a value whose type is a flag enum, GDB will
1108 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1109 (gdb) print (enum E) 3
1112 * The filename part of a linespec will now match trailing components
1113 of a source file name. For example, "break gcc/expr.c:1000" will
1114 now set a breakpoint in build/gcc/expr.c, but not
1115 build/libcpp/expr.c.
1117 * The "info proc" and "generate-core-file" commands will now also
1118 work on remote targets connected to GDBserver on Linux.
1120 * The command "info catch" has been removed. It has been disabled
1121 since December 2007.
1123 * The "catch exception" and "catch assert" commands now accept
1124 a condition at the end of the command, much like the "break"
1125 command does. For instance:
1127 (gdb) catch exception Constraint_Error if Barrier = True
1129 Previously, it was possible to add a condition to such catchpoints,
1130 but it had to be done as a second step, after the catchpoint had been
1131 created, using the "condition" command.
1133 * The "info static-tracepoint-marker" command will now also work on
1134 native Linux targets with in-process agent.
1136 * GDB can now set breakpoints on inlined functions.
1138 * The .gdb_index section has been updated to include symbols for
1139 inlined functions. GDB will ignore older .gdb_index sections by
1140 default, which could cause symbol files to be loaded more slowly
1141 until their .gdb_index sections can be recreated. The new command
1142 "set use-deprecated-index-sections on" will cause GDB to use any older
1143 .gdb_index sections it finds. This will restore performance, but the
1144 ability to set breakpoints on inlined functions will be lost in symbol
1145 files with older .gdb_index sections.
1147 The .gdb_index section has also been updated to record more information
1148 about each symbol. This speeds up the "info variables", "info functions"
1149 and "info types" commands when used with programs having the .gdb_index
1150 section, as well as speeding up debugging with shared libraries using
1151 the .gdb_index section.
1153 * Ada support for GDB/MI Variable Objects has been added.
1155 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1160 ** New command -info-os is the MI equivalent of "info os".
1162 ** Output logs ("set logging" and related) now include MI output.
1166 ** "set use-deprecated-index-sections on|off"
1167 "show use-deprecated-index-sections on|off"
1168 Controls the use of deprecated .gdb_index sections.
1170 ** "catch load" and "catch unload" can be used to stop when a shared
1171 library is loaded or unloaded, respectively.
1173 ** "enable count" can be used to auto-disable a breakpoint after
1176 ** "info vtbl" can be used to show the virtual method tables for
1177 C++ and Java objects.
1179 ** "explore" and its sub commands "explore value" and "explore type"
1180 can be used to recursively explore values and types of
1181 expressions. These commands are available only if GDB is
1182 configured with '--with-python'.
1184 ** "info auto-load" shows status of all kinds of auto-loaded files,
1185 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1186 sequences of commands files, "info auto-load python-scripts"
1187 shows status of auto-loading Python script files,
1188 "info auto-load local-gdbinit" shows status of loading init file
1189 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1190 status of inferior specific thread debugging shared library loading.
1192 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1193 and "show auto-load-scripts" commands have been deprecated, use their
1194 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1195 and "show auto-load python-scripts" counterparts instead.
1197 ** "dprintf location,format,args..." creates a dynamic printf, which
1198 is basically a breakpoint that does a printf and immediately
1199 resumes your program's execution, so it is like a printf that you
1200 can insert dynamically at runtime instead of at compiletime.
1202 ** "set print symbol"
1204 Controls whether GDB attempts to display the symbol, if any,
1205 corresponding to addresses it prints. This defaults to "on", but
1206 you can set it to "off" to restore GDB's previous behavior.
1208 * Deprecated commands
1210 ** For the Renesas Super-H architecture, the "regs" command has been
1211 deprecated, and "info all-registers" should be used instead.
1215 Renesas RL78 rl78-*-elf
1216 HP OpenVMS ia64 ia64-hp-openvms*
1218 * GDBserver supports evaluation of breakpoint conditions. When
1219 support is advertised by GDBserver, GDB may be told to send the
1220 breakpoint conditions in bytecode form to GDBserver. GDBserver
1221 will only report the breakpoint trigger to GDB when its condition
1226 set mips compression
1227 show mips compression
1228 Select the compressed ISA encoding used in functions that have no symbol
1229 information available. The encoding can be set to either of:
1232 and is updated automatically from ELF file flags if available.
1234 set breakpoint condition-evaluation
1235 show breakpoint condition-evaluation
1236 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1237 GDBserver ("target"). Default option "auto" chooses the most efficient
1239 This option can improve debugger efficiency depending on the speed of the
1243 Disable auto-loading globally.
1246 Show auto-loading setting of all kinds of auto-loaded files.
1248 set auto-load gdb-scripts on|off
1249 show auto-load gdb-scripts
1250 Control auto-loading of GDB canned sequences of commands files.
1252 set auto-load python-scripts on|off
1253 show auto-load python-scripts
1254 Control auto-loading of Python script files.
1256 set auto-load local-gdbinit on|off
1257 show auto-load local-gdbinit
1258 Control loading of init file (.gdbinit) from current directory.
1260 set auto-load libthread-db on|off
1261 show auto-load libthread-db
1262 Control auto-loading of inferior specific thread debugging shared library.
1264 set auto-load scripts-directory <dir1>[:<dir2>...]
1265 show auto-load scripts-directory
1266 Set a list of directories from which to load auto-loaded scripts.
1267 Automatically loaded Python scripts and GDB scripts are located in one
1268 of the directories listed by this option.
1269 The delimiter (':' above) may differ according to the host platform.
1271 set auto-load safe-path <dir1>[:<dir2>...]
1272 show auto-load safe-path
1273 Set a list of directories from which it is safe to auto-load files.
1274 The delimiter (':' above) may differ according to the host platform.
1276 set debug auto-load on|off
1277 show debug auto-load
1278 Control display of debugging info for auto-loading the files above.
1280 set dprintf-style gdb|call|agent
1282 Control the way in which a dynamic printf is performed; "gdb"
1283 requests a GDB printf command, while "call" causes dprintf to call a
1284 function in the inferior. "agent" requests that the target agent
1285 (such as GDBserver) do the printing.
1287 set dprintf-function <expr>
1288 show dprintf-function
1289 set dprintf-channel <expr>
1290 show dprintf-channel
1291 Set the function and optional first argument to the call when using
1292 the "call" style of dynamic printf.
1294 set disconnected-dprintf on|off
1295 show disconnected-dprintf
1296 Control whether agent-style dynamic printfs continue to be in effect
1297 after GDB disconnects.
1299 * New configure options
1301 --with-auto-load-dir
1302 Configure default value for the 'set auto-load scripts-directory'
1303 setting above. It defaults to '$debugdir:$datadir/auto-load',
1304 $debugdir representing global debugging info directories (available
1305 via 'show debug-file-directory') and $datadir representing GDB's data
1306 directory (available via 'show data-directory').
1308 --with-auto-load-safe-path
1309 Configure default value for the 'set auto-load safe-path' setting
1310 above. It defaults to the --with-auto-load-dir setting.
1312 --without-auto-load-safe-path
1313 Set 'set auto-load safe-path' to '/', effectively disabling this
1316 * New remote packets
1318 z0/z1 conditional breakpoints extension
1320 The z0/z1 breakpoint insertion packets have been extended to carry
1321 a list of conditional expressions over to the remote stub depending on the
1322 condition evaluation mode. The use of this extension can be controlled
1323 via the "set remote conditional-breakpoints-packet" command.
1327 Specify the signals which the remote stub may pass to the debugged
1328 program without GDB involvement.
1330 * New command line options
1332 --init-command=FILE, -ix Like --command, -x but execute it
1333 before loading inferior.
1334 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1335 execute it before loading inferior.
1337 *** Changes in GDB 7.4
1339 * GDB now handles ambiguous linespecs more consistently; the existing
1340 FILE:LINE support has been expanded to other types of linespecs. A
1341 breakpoint will now be set on all matching locations in all
1342 inferiors, and locations will be added or removed according to
1345 * GDB now allows you to skip uninteresting functions and files when
1346 stepping with the "skip function" and "skip file" commands.
1348 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1349 and "show remote hardware-watchpoint-length-limit". These allows to
1350 set or show the maximum length limit (in bytes) of a remote
1351 target hardware watchpoint.
1353 This allows e.g. to use "unlimited" hardware watchpoints with the
1354 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1355 watchpoints are slower than real hardware watchpoints but are
1356 significantly faster than gdb software watchpoints.
1360 ** The register_pretty_printer function in module gdb.printing now takes
1361 an optional `replace' argument. If True, the new printer replaces any
1364 ** The "maint set python print-stack on|off" command has been
1365 deprecated and will be deleted in GDB 7.5.
1366 A new command: "set python print-stack none|full|message" has
1367 replaced it. Additionally, the default for "print-stack" is
1368 now "message", which just prints the error message without
1371 ** A prompt substitution hook (prompt_hook) is now available to the
1374 ** A new Python module, gdb.prompt has been added to the GDB Python
1375 modules library. This module provides functionality for
1376 escape sequences in prompts (used by set/show
1377 extended-prompt). These escape sequences are replaced by their
1378 corresponding value.
1380 ** Python commands and convenience-functions located in
1381 'data-directory'/python/gdb/command and
1382 'data-directory'/python/gdb/function are now automatically loaded
1385 ** Blocks now provide four new attributes. global_block and
1386 static_block will return the global and static blocks
1387 respectively. is_static and is_global are boolean attributes
1388 that indicate if the block is one of those two types.
1390 ** Symbols now provide the "type" attribute, the type of the symbol.
1392 ** The "gdb.breakpoint" function has been deprecated in favor of
1395 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1396 of a function. This class is based on the "finish" command
1397 available in the CLI.
1399 ** Type objects for struct and union types now allow access to
1400 the fields using standard Python dictionary (mapping) methods.
1401 For example, "some_type['myfield']" now works, as does
1402 "some_type.items()".
1404 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1407 ** A new function, "deep_items" has been added to the gdb.types
1408 module in the GDB Python modules library. This function returns
1409 an iterator over the fields of a struct or union type. Unlike
1410 the standard Python "iteritems" method, it will recursively traverse
1411 any anonymous fields.
1415 ** "*stopped" events can report several new "reason"s, such as
1418 ** Breakpoint changes are now notified using new async records, like
1419 "=breakpoint-modified".
1421 ** New command -ada-task-info.
1423 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1424 $sdir specifies the default system locations of shared libraries.
1425 $pdir specifies the directory where the libpthread used by the application
1428 GDB no longer looks in $sdir and $pdir after it has searched the directories
1429 mentioned in libthread-db-search-path. If you want to search those
1430 directories, they must be specified in libthread-db-search-path.
1431 The default value of libthread-db-search-path on GNU/Linux and Solaris
1432 systems is now "$sdir:$pdir".
1434 $pdir is not supported by gdbserver, it is currently ignored.
1435 $sdir is supported by gdbserver.
1437 * New configure option --with-iconv-bin.
1438 When using the internationalization support like the one in the GNU C
1439 library, GDB will invoke the "iconv" program to get a list of supported
1440 character sets. If this program lives in a non-standard location, one can
1441 use this option to specify where to find it.
1443 * When natively debugging programs on PowerPC BookE processors running
1444 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1445 watchpoints, which specify a mask in addition to an address to watch.
1446 The mask specifies that some bits of an address (the bits which are
1447 reset in the mask) should be ignored when matching the address accessed
1448 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1449 section in the user manual for more details.
1451 * The new option --once causes GDBserver to stop listening for connections once
1452 the first connection is made. The listening port used by GDBserver will
1453 become available after that.
1455 * New commands "info macros" and "alias" have been added.
1457 * New function parameters suffix @entry specifies value of function parameter
1458 at the time the function got called. Entry values are available only since
1464 "!" is now an alias of the "shell" command.
1465 Note that no space is needed between "!" and SHELL COMMAND.
1469 watch EXPRESSION mask MASK_VALUE
1470 The watch command now supports the mask argument which allows creation
1471 of masked watchpoints, if the current architecture supports this feature.
1473 info auto-load-scripts [REGEXP]
1474 This command was formerly named "maintenance print section-scripts".
1475 It is now generally useful and is no longer a maintenance-only command.
1477 info macro [-all] [--] MACRO
1478 The info macro command has new options `-all' and `--'. The first for
1479 printing all definitions of a macro. The second for explicitly specifying
1480 the end of arguments and the beginning of the macro name in case the macro
1481 name starts with a hyphen.
1483 collect[/s] EXPRESSIONS
1484 The tracepoint collect command now takes an optional modifier "/s"
1485 that directs it to dereference pointer-to-character types and
1486 collect the bytes of memory up to a zero byte. The behavior is
1487 similar to what you see when you use the regular print command on a
1488 string. An optional integer following the "/s" sets a bound on the
1489 number of bytes that will be collected.
1492 The trace start command now interprets any supplied arguments as a
1493 note to be recorded with the trace run, with an effect similar to
1494 setting the variable trace-notes.
1497 The trace stop command now interprets any arguments as a note to be
1498 mentioned along with the tstatus report that the trace was stopped
1499 with a command. The effect is similar to setting the variable
1502 * Tracepoints can now be enabled and disabled at any time after a trace
1503 experiment has been started using the standard "enable" and "disable"
1504 commands. It is now possible to start a trace experiment with no enabled
1505 tracepoints; GDB will display a warning, but will allow the experiment to
1506 begin, assuming that tracepoints will be enabled as needed while the trace
1509 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1510 locations with 4-byte instructions, when they were previously
1511 limited to locations with instructions of 5 bytes or longer.
1515 set debug dwarf2-read
1516 show debug dwarf2-read
1517 Turns on or off display of debugging messages related to reading
1518 DWARF debug info. The default is off.
1520 set debug symtab-create
1521 show debug symtab-create
1522 Turns on or off display of debugging messages related to symbol table
1523 creation. The default is off.
1526 show extended-prompt
1527 Set the GDB prompt, and allow escape sequences to be inserted to
1528 display miscellaneous information (see 'help set extended-prompt'
1529 for the list of sequences). This prompt (and any information
1530 accessed through the escape sequences) is updated every time the
1531 prompt is displayed.
1533 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1534 show print entry-values
1535 Set printing of frame argument values at function entry. In some cases
1536 GDB can determine the value of function argument which was passed by the
1537 function caller, even if the value was modified inside the called function.
1539 set debug entry-values
1540 show debug entry-values
1541 Control display of debugging info for determining frame argument values at
1542 function entry and virtual tail call frames.
1544 set basenames-may-differ
1545 show basenames-may-differ
1546 Set whether a source file may have multiple base names.
1547 (A "base name" is the name of a file with the directory part removed.
1548 Example: The base name of "/home/user/hello.c" is "hello.c".)
1549 If set, GDB will canonicalize file names (e.g., expand symlinks)
1550 before comparing them. Canonicalization is an expensive operation,
1551 but it allows the same file be known by more than one base name.
1552 If not set (the default), all source files are assumed to have just
1553 one base name, and gdb will do file name comparisons more efficiently.
1559 Set a user name and notes for the current and any future trace runs.
1560 This is useful for long-running and/or disconnected traces, to
1561 inform others (or yourself) as to who is running the trace, supply
1562 contact information, or otherwise explain what is going on.
1564 set trace-stop-notes
1565 show trace-stop-notes
1566 Set a note attached to the trace run, that is displayed when the
1567 trace has been stopped by a tstop command. This is useful for
1568 instance as an explanation, if you are stopping a trace run that was
1569 started by someone else.
1571 * New remote packets
1575 Dynamically enable a tracepoint in a started trace experiment.
1579 Dynamically disable a tracepoint in a started trace experiment.
1583 Set the user and notes of the trace run.
1587 Query the current status of a tracepoint.
1591 Query the minimum length of instruction at which a fast tracepoint may
1594 * Dcache size (number of lines) and line-size are now runtime-configurable
1595 via "set dcache line" and "set dcache line-size" commands.
1599 Texas Instruments TMS320C6x tic6x-*-*
1603 Renesas RL78 rl78-*-elf
1605 *** Changes in GDB 7.3.1
1607 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1609 *** Changes in GDB 7.3
1611 * GDB has a new command: "thread find [REGEXP]".
1612 It finds the thread id whose name, target id, or thread extra info
1613 matches the given regular expression.
1615 * The "catch syscall" command now works on mips*-linux* targets.
1617 * The -data-disassemble MI command now supports modes 2 and 3 for
1618 dumping the instruction opcodes.
1620 * New command line options
1622 -data-directory DIR Specify DIR as the "data-directory".
1623 This is mostly for testing purposes.
1625 * The "maint set python auto-load on|off" command has been renamed to
1626 "set auto-load-scripts on|off".
1628 * GDB has a new command: "set directories".
1629 It is like the "dir" command except that it replaces the
1630 source path list instead of augmenting it.
1632 * GDB now understands thread names.
1634 On GNU/Linux, "info threads" will display the thread name as set by
1635 prctl or pthread_setname_np.
1637 There is also a new command, "thread name", which can be used to
1638 assign a name internally for GDB to display.
1641 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1642 has been integrated into GDB.
1646 ** The function gdb.Write now accepts an optional keyword 'stream'.
1647 This keyword, when provided, will direct the output to either
1648 stdout, stderr, or GDB's logging output.
1650 ** Parameters can now be be sub-classed in Python, and in particular
1651 you may implement the get_set_doc and get_show_doc functions.
1652 This improves how Parameter set/show documentation is processed
1653 and allows for more dynamic content.
1655 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1656 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1657 have an is_valid method.
1659 ** Breakpoints can now be sub-classed in Python, and in particular
1660 you may implement a 'stop' function that is executed each time
1661 the inferior reaches that breakpoint.
1663 ** New function gdb.lookup_global_symbol looks up a global symbol.
1665 ** GDB values in Python are now callable if the value represents a
1666 function. For example, if 'some_value' represents a function that
1667 takes two integer parameters and returns a value, you can call
1668 that function like so:
1670 result = some_value (10,20)
1672 ** Module gdb.types has been added.
1673 It contains a collection of utilities for working with gdb.Types objects:
1674 get_basic_type, has_field, make_enum_dict.
1676 ** Module gdb.printing has been added.
1677 It contains utilities for writing and registering pretty-printers.
1678 New classes: PrettyPrinter, SubPrettyPrinter,
1679 RegexpCollectionPrettyPrinter.
1680 New function: register_pretty_printer.
1682 ** New commands "info pretty-printers", "enable pretty-printer" and
1683 "disable pretty-printer" have been added.
1685 ** gdb.parameter("directories") is now available.
1687 ** New function gdb.newest_frame returns the newest frame in the
1690 ** The gdb.InferiorThread class has a new "name" attribute. This
1691 holds the thread's name.
1693 ** Python Support for Inferior events.
1694 Python scripts can add observers to be notified of events
1695 occurring in the process being debugged.
1696 The following events are currently supported:
1697 - gdb.events.cont Continue event.
1698 - gdb.events.exited Inferior exited event.
1699 - gdb.events.stop Signal received, and Breakpoint hit events.
1703 ** GDB now puts template parameters in scope when debugging in an
1704 instantiation. For example, if you have:
1706 template<int X> int func (void) { return X; }
1708 then if you step into func<5>, "print X" will show "5". This
1709 feature requires proper debuginfo support from the compiler; it
1710 was added to GCC 4.5.
1712 ** The motion commands "next", "finish", "until", and "advance" now
1713 work better when exceptions are thrown. In particular, GDB will
1714 no longer lose control of the inferior; instead, the GDB will
1715 stop the inferior at the point at which the exception is caught.
1716 This functionality requires a change in the exception handling
1717 code that was introduced in GCC 4.5.
1719 * GDB now follows GCC's rules on accessing volatile objects when
1720 reading or writing target state during expression evaluation.
1721 One notable difference to prior behavior is that "print x = 0"
1722 no longer generates a read of x; the value of the assignment is
1723 now always taken directly from the value being assigned.
1725 * GDB now has some support for using labels in the program's source in
1726 linespecs. For instance, you can use "advance label" to continue
1727 execution to a label.
1729 * GDB now has support for reading and writing a new .gdb_index
1730 section. This section holds a fast index of DWARF debugging
1731 information and can be used to greatly speed up GDB startup and
1732 operation. See the documentation for `save gdb-index' for details.
1734 * The "watch" command now accepts an optional "-location" argument.
1735 When used, this causes GDB to watch the memory referred to by the
1736 expression. Such a watchpoint is never deleted due to it going out
1739 * GDB now supports thread debugging of core dumps on GNU/Linux.
1741 GDB now activates thread debugging using the libthread_db library
1742 when debugging GNU/Linux core dumps, similarly to when debugging
1743 live processes. As a result, when debugging a core dump file, GDB
1744 is now able to display pthread_t ids of threads. For example, "info
1745 threads" shows the same output as when debugging the process when it
1746 was live. In earlier releases, you'd see something like this:
1749 * 1 LWP 6780 main () at main.c:10
1751 While now you see this:
1754 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1756 It is also now possible to inspect TLS variables when debugging core
1759 When debugging a core dump generated on a machine other than the one
1760 used to run GDB, you may need to point GDB at the correct
1761 libthread_db library with the "set libthread-db-search-path"
1762 command. See the user manual for more details on this command.
1764 * When natively debugging programs on PowerPC BookE processors running
1765 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1766 which stop execution of the inferior whenever it executes an instruction
1767 at any address within the specified range. See the "PowerPC Embedded"
1768 section in the user manual for more details.
1770 * New features in the GDB remote stub, GDBserver
1772 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1773 and i686 LynxOS (version 5.x).
1775 ** GDBserver is now supported on Blackfin Linux.
1777 * New native configurations
1779 ia64 HP-UX ia64-*-hpux*
1783 Analog Devices, Inc. Blackfin Processor bfin-*
1785 * Ada task switching is now supported on sparc-elf targets when
1786 debugging a program using the Ravenscar Profile. For more information,
1787 see the "Tasking Support when using the Ravenscar Profile" section
1788 in the GDB user manual.
1790 * Guile support was removed.
1792 * New features in the GNU simulator
1794 ** The --map-info flag lists all known core mappings.
1796 ** CFI flashes may be simulated via the "cfi" device.
1798 *** Changes in GDB 7.2
1800 * Shared library support for remote targets by default
1802 When GDB is configured for a generic, non-OS specific target, like
1803 for example, --target=arm-eabi or one of the many *-*-elf targets,
1804 GDB now queries remote stubs for loaded shared libraries using the
1805 `qXfer:libraries:read' packet. Previously, shared library support
1806 was always disabled for such configurations.
1810 ** Argument Dependent Lookup (ADL)
1812 In C++ ADL lookup directs function search to the namespaces of its
1813 arguments even if the namespace has not been imported.
1823 Here the compiler will search for `foo' in the namespace of 'b'
1824 and find A::foo. GDB now supports this. This construct is commonly
1825 used in the Standard Template Library for operators.
1827 ** Improved User Defined Operator Support
1829 In addition to member operators, GDB now supports lookup of operators
1830 defined in a namespace and imported with a `using' directive, operators
1831 defined in the global scope, operators imported implicitly from an
1832 anonymous namespace, and the ADL operators mentioned in the previous
1834 GDB now also supports proper overload resolution for all the previously
1835 mentioned flavors of operators.
1837 ** static const class members
1839 Printing of static const class members that are initialized in the
1840 class definition has been fixed.
1842 * Windows Thread Information Block access.
1844 On Windows targets, GDB now supports displaying the Windows Thread
1845 Information Block (TIB) structure. This structure is visible either
1846 by using the new command `info w32 thread-information-block' or, by
1847 dereferencing the new convenience variable named `$_tlb', a
1848 thread-specific pointer to the TIB. This feature is also supported
1849 when remote debugging using GDBserver.
1851 * Static tracepoints
1853 Static tracepoints are calls in the user program into a tracing
1854 library. One such library is a port of the LTTng kernel tracer to
1855 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1856 When debugging with GDBserver, GDB now supports combining the GDB
1857 tracepoint machinery with such libraries. For example: the user can
1858 use GDB to probe a static tracepoint marker (a call from the user
1859 program into the tracing library) with the new "strace" command (see
1860 "New commands" below). This creates a "static tracepoint" in the
1861 breakpoint list, that can be manipulated with the same feature set
1862 as fast and regular tracepoints. E.g., collect registers, local and
1863 global variables, collect trace state variables, and define
1864 tracepoint conditions. In addition, the user can collect extra
1865 static tracepoint marker specific data, by collecting the new
1866 $_sdata internal variable. When analyzing the trace buffer, you can
1867 inspect $_sdata like any other variable available to GDB. For more
1868 information, see the "Tracepoints" chapter in GDB user manual. New
1869 remote packets have been defined to support static tracepoints, see
1870 the "New remote packets" section below.
1872 * Better reconstruction of tracepoints after disconnected tracing
1874 GDB will attempt to download the original source form of tracepoint
1875 definitions when starting a trace run, and then will upload these
1876 upon reconnection to the target, resulting in a more accurate
1877 reconstruction of the tracepoints that are in use on the target.
1881 You can now exercise direct control over the ways that GDB can
1882 affect your program. For instance, you can disallow the setting of
1883 breakpoints, so that the program can run continuously (assuming
1884 non-stop mode). In addition, the "observer" variable is available
1885 to switch all of the different controls; in observer mode, GDB
1886 cannot affect the target's behavior at all, which is useful for
1887 tasks like diagnosing live systems in the field.
1889 * The new convenience variable $_thread holds the number of the
1892 * New remote packets
1896 Return the address of the Windows Thread Information Block of a given thread.
1900 In response to several of the tracepoint packets, the target may now
1901 also respond with a number of intermediate `qRelocInsn' request
1902 packets before the final result packet, to have GDB handle
1903 relocating an instruction to execute at a different address. This
1904 is particularly useful for stubs that support fast tracepoints. GDB
1905 reports support for this feature in the qSupported packet.
1909 List static tracepoint markers in the target program.
1913 List static tracepoint markers at a given address in the target
1916 qXfer:statictrace:read
1918 Read the static trace data collected (by a `collect $_sdata'
1919 tracepoint action). The remote stub reports support for this packet
1920 to gdb's qSupported query.
1924 Send the current settings of GDB's permission flags.
1928 Send part of the source (textual) form of a tracepoint definition,
1929 which includes location, conditional, and action list.
1931 * The source command now accepts a -s option to force searching for the
1932 script in the source search path even if the script name specifies
1935 * New features in the GDB remote stub, GDBserver
1937 - GDBserver now support tracepoints (including fast tracepoints, and
1938 static tracepoints). The feature is currently supported by the
1939 i386-linux and amd64-linux builds. See the "Tracepoints support
1940 in gdbserver" section in the manual for more information.
1942 GDBserver JIT compiles the tracepoint's conditional agent
1943 expression bytecode into native code whenever possible for low
1944 overhead dynamic tracepoints conditionals. For such tracepoints,
1945 an expression that examines program state is evaluated when the
1946 tracepoint is reached, in order to determine whether to capture
1947 trace data. If the condition is simple and false, processing the
1948 tracepoint finishes very quickly and no data is gathered.
1950 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1951 for static tracepoints support.
1953 - GDBserver now supports x86_64 Windows 64-bit debugging.
1955 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1956 it understands register description.
1958 * The --batch flag now disables pagination and queries.
1960 * X86 general purpose registers
1962 GDB now supports reading/writing byte, word and double-word x86
1963 general purpose registers directly. This means you can use, say,
1964 $ah or $ax to refer, respectively, to the byte register AH and
1965 16-bit word register AX that are actually portions of the 32-bit
1966 register EAX or 64-bit register RAX.
1968 * The `commands' command now accepts a range of breakpoints to modify.
1969 A plain `commands' following a command that creates multiple
1970 breakpoints affects all the breakpoints set by that command. This
1971 applies to breakpoints set by `rbreak', and also applies when a
1972 single `break' command creates multiple breakpoints (e.g.,
1973 breakpoints on overloaded c++ functions).
1975 * The `rbreak' command now accepts a filename specification as part of
1976 its argument, limiting the functions selected by the regex to those
1977 in the specified file.
1979 * Support for remote debugging Windows and SymbianOS shared libraries
1980 from Unix hosts has been improved. Non Windows GDB builds now can
1981 understand target reported file names that follow MS-DOS based file
1982 system semantics, such as file names that include drive letters and
1983 use the backslash character as directory separator. This makes it
1984 possible to transparently use the "set sysroot" and "set
1985 solib-search-path" on Unix hosts to point as host copies of the
1986 target's shared libraries. See the new command "set
1987 target-file-system-kind" described below, and the "Commands to
1988 specify files" section in the user manual for more information.
1992 eval template, expressions...
1993 Convert the values of one or more expressions under the control
1994 of the string template to a command line, and call it.
1996 set target-file-system-kind unix|dos-based|auto
1997 show target-file-system-kind
1998 Set or show the assumed file system kind for target reported file
2001 save breakpoints <filename>
2002 Save all current breakpoint definitions to a file suitable for use
2003 in a later debugging session. To read the saved breakpoint
2004 definitions, use the `source' command.
2006 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2009 info static-tracepoint-markers
2010 Display information about static tracepoint markers in the target.
2012 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2013 Define a static tracepoint by probing a marker at the given
2014 function, line, address, or marker ID.
2018 Enable and disable observer mode.
2020 set may-write-registers on|off
2021 set may-write-memory on|off
2022 set may-insert-breakpoints on|off
2023 set may-insert-tracepoints on|off
2024 set may-insert-fast-tracepoints on|off
2025 set may-interrupt on|off
2026 Set individual permissions for GDB effects on the target. Note that
2027 some of these settings can have undesirable or surprising
2028 consequences, particularly when changed in the middle of a session.
2029 For instance, disabling the writing of memory can prevent
2030 breakpoints from being inserted, cause single-stepping to fail, or
2031 even crash your program, if you disable after breakpoints have been
2032 inserted. However, GDB should not crash.
2034 set record memory-query on|off
2035 show record memory-query
2036 Control whether to stop the inferior if memory changes caused
2037 by an instruction cannot be recorded.
2042 The disassemble command now supports "start,+length" form of two arguments.
2046 ** GDB now provides a new directory location, called the python directory,
2047 where Python scripts written for GDB can be installed. The location
2048 of that directory is <data-directory>/python, where <data-directory>
2049 is the GDB data directory. For more details, see section `Scripting
2050 GDB using Python' in the manual.
2052 ** The GDB Python API now has access to breakpoints, symbols, symbol
2053 tables, program spaces, inferiors, threads and frame's code blocks.
2054 Additionally, GDB Parameters can now be created from the API, and
2055 manipulated via set/show in the CLI.
2057 ** New functions gdb.target_charset, gdb.target_wide_charset,
2058 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2060 ** New exception gdb.GdbError.
2062 ** Pretty-printers are now also looked up in the current program space.
2064 ** Pretty-printers can now be individually enabled and disabled.
2066 ** GDB now looks for names of Python scripts to auto-load in a
2067 special section named `.debug_gdb_scripts', in addition to looking
2068 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2070 * Tracepoint actions were unified with breakpoint commands. In particular,
2071 there are no longer differences in "info break" output for breakpoints and
2072 tracepoints and the "commands" command can be used for both tracepoints and
2073 regular breakpoints.
2077 ARM Symbian arm*-*-symbianelf*
2079 * D language support.
2080 GDB now supports debugging programs written in the D programming
2083 * GDB now supports the extended ptrace interface for PowerPC which is
2084 available since Linux kernel version 2.6.34. This automatically enables
2085 any hardware breakpoints and additional hardware watchpoints available in
2086 the processor. The old ptrace interface exposes just one hardware
2087 watchpoint and no hardware breakpoints.
2089 * GDB is now able to use the Data Value Compare (DVC) register available on
2090 embedded PowerPC processors to implement in hardware simple watchpoint
2091 conditions of the form:
2093 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2095 This works in native GDB running on Linux kernels with the extended ptrace
2096 interface mentioned above.
2098 *** Changes in GDB 7.1
2102 ** Namespace Support
2104 GDB now supports importing of namespaces in C++. This enables the
2105 user to inspect variables from imported namespaces. Support for
2106 namepace aliasing has also been added. So, if a namespace is
2107 aliased in the current scope (e.g. namepace C=A; ) the user can
2108 print variables using the alias (e.g. (gdb) print C::x).
2112 All known bugs relating to the printing of virtual base class were
2113 fixed. It is now possible to call overloaded static methods using a
2118 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2119 and reinterpret_cast<> are now handled by the C++ expression parser.
2123 Xilinx MicroBlaze microblaze-*-*
2128 Xilinx MicroBlaze microblaze
2131 * Multi-program debugging.
2133 GDB now has support for multi-program (a.k.a. multi-executable or
2134 multi-exec) debugging. This allows for debugging multiple inferiors
2135 simultaneously each running a different program under the same GDB
2136 session. See "Debugging Multiple Inferiors and Programs" in the
2137 manual for more information. This implied some user visible changes
2138 in the multi-inferior support. For example, "info inferiors" now
2139 lists inferiors that are not running yet or that have exited
2140 already. See also "New commands" and "New options" below.
2142 * New tracing features
2144 GDB's tracepoint facility now includes several new features:
2146 ** Trace state variables
2148 GDB tracepoints now include support for trace state variables, which
2149 are variables managed by the target agent during a tracing
2150 experiment. They are useful for tracepoints that trigger each
2151 other, so for instance one tracepoint can count hits in a variable,
2152 and then a second tracepoint has a condition that is true when the
2153 count reaches a particular value. Trace state variables share the
2154 $-syntax of GDB convenience variables, and can appear in both
2155 tracepoint actions and condition expressions. Use the "tvariable"
2156 command to create, and "info tvariables" to view; see "Trace State
2157 Variables" in the manual for more detail.
2161 GDB now includes an option for defining fast tracepoints, which
2162 targets may implement more efficiently, such as by installing a jump
2163 into the target agent rather than a trap instruction. The resulting
2164 speedup can be by two orders of magnitude or more, although the
2165 tradeoff is that some program locations on some target architectures
2166 might not allow fast tracepoint installation, for instance if the
2167 instruction to be replaced is shorter than the jump. To request a
2168 fast tracepoint, use the "ftrace" command, with syntax identical to
2169 the regular trace command.
2171 ** Disconnected tracing
2173 It is now possible to detach GDB from the target while it is running
2174 a trace experiment, then reconnect later to see how the experiment
2175 is going. In addition, a new variable disconnected-tracing lets you
2176 tell the target agent whether to continue running a trace if the
2177 connection is lost unexpectedly.
2181 GDB now has the ability to save the trace buffer into a file, and
2182 then use that file as a target, similarly to you can do with
2183 corefiles. You can select trace frames, print data that was
2184 collected in them, and use tstatus to display the state of the
2185 tracing run at the moment that it was saved. To create a trace
2186 file, use "tsave <filename>", and to use it, do "target tfile
2189 ** Circular trace buffer
2191 You can ask the target agent to handle the trace buffer as a
2192 circular buffer, discarding the oldest trace frames to make room for
2193 newer ones, by setting circular-trace-buffer to on. This feature may
2194 not be available for all target agents.
2199 The disassemble command, when invoked with two arguments, now requires
2200 the arguments to be comma-separated.
2203 The info variables command now displays variable definitions. Files
2204 which only declare a variable are not shown.
2207 The source command is now capable of sourcing Python scripts.
2208 This feature is dependent on the debugger being build with Python
2211 Related to this enhancement is also the introduction of a new command
2212 "set script-extension" (see below).
2214 * New commands (for set/show, see "New options" below)
2216 record save [<FILENAME>]
2217 Save a file (in core file format) containing the process record
2218 execution log for replay debugging at a later time.
2220 record restore <FILENAME>
2221 Restore the process record execution log that was saved at an
2222 earlier time, for replay debugging.
2224 add-inferior [-copies <N>] [-exec <FILENAME>]
2227 clone-inferior [-copies <N>] [ID]
2228 Make a new inferior ready to execute the same program another
2229 inferior has loaded.
2234 maint info program-spaces
2235 List the program spaces loaded into GDB.
2237 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2238 show remote interrupt-sequence
2239 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2240 as the sequence to the remote target in order to interrupt the execution.
2241 Ctrl-C is a default. Some system prefers BREAK which is high level of
2242 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2243 Magic SysRq g. It is BREAK signal and character 'g'.
2245 set remote interrupt-on-connect [on | off]
2246 show remote interrupt-on-connect
2247 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2248 remote target when gdb connects to it. This is needed when you debug
2251 set remotebreak [on | off]
2253 Deprecated. Use "set/show remote interrupt-sequence" instead.
2255 tvariable $NAME [ = EXP ]
2256 Create or modify a trace state variable.
2259 List trace state variables and their values.
2261 delete tvariable $NAME ...
2262 Delete one or more trace state variables.
2265 Evaluate the given expressions without collecting anything into the
2266 trace buffer. (Valid in tracepoint actions only.)
2268 ftrace FN / FILE:LINE / *ADDR
2269 Define a fast tracepoint at the given function, line, or address.
2271 * New expression syntax
2273 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2274 GDB now parses 0b101010 identically with 42.
2278 set follow-exec-mode new|same
2279 show follow-exec-mode
2280 Control whether GDB reuses the same inferior across an exec call or
2281 creates a new one. This is useful to be able to restart the old
2282 executable after the inferior having done an exec call.
2284 set default-collect EXPR, ...
2285 show default-collect
2286 Define a list of expressions to be collected at each tracepoint.
2287 This is a useful way to ensure essential items are not overlooked,
2288 such as registers or a critical global variable.
2290 set disconnected-tracing
2291 show disconnected-tracing
2292 If set to 1, the target is instructed to continue tracing if it
2293 loses its connection to GDB. If 0, the target is to stop tracing
2296 set circular-trace-buffer
2297 show circular-trace-buffer
2298 If set to on, the target is instructed to use a circular trace buffer
2299 and discard the oldest trace frames instead of stopping the trace due
2300 to a full trace buffer. If set to off, the trace stops when the buffer
2301 fills up. Some targets may not support this.
2303 set script-extension off|soft|strict
2304 show script-extension
2305 If set to "off", the debugger does not perform any script language
2306 recognition, and all sourced files are assumed to be GDB scripts.
2307 If set to "soft" (the default), files are sourced according to
2308 filename extension, falling back to GDB scripts if the first
2310 If set to "strict", files are sourced according to filename extension.
2312 set ada trust-PAD-over-XVS on|off
2313 show ada trust-PAD-over-XVS
2314 If off, activate a workaround against a bug in the debugging information
2315 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2316 the GCC sources for more information about the GNAT encoding and
2317 PAD types in particular). It is always safe to set this option to
2318 off, but this introduces a slight performance penalty. The default
2321 * Python API Improvements
2323 ** GDB provides the new class gdb.LazyString. This is useful in
2324 some pretty-printing cases. The new method gdb.Value.lazy_string
2325 provides a simple way to create objects of this type.
2327 ** The fields returned by gdb.Type.fields now have an
2328 `is_base_class' attribute.
2330 ** The new method gdb.Type.range returns the range of an array type.
2332 ** The new method gdb.parse_and_eval can be used to parse and
2333 evaluate an expression.
2335 * New remote packets
2338 Define a trace state variable.
2341 Get the current value of a trace state variable.
2344 Set desired tracing behavior upon disconnection.
2347 Set the trace buffer to be linear or circular.
2350 Get data about the tracepoints currently in use.
2354 Process record now works correctly with hardware watchpoints.
2356 Multiple bug fixes have been made to the mips-irix port, making it
2357 much more reliable. In particular:
2358 - Debugging threaded applications is now possible again. Previously,
2359 GDB would hang while starting the program, or while waiting for
2360 the program to stop at a breakpoint.
2361 - Attaching to a running process no longer hangs.
2362 - An error occurring while loading a core file has been fixed.
2363 - Changing the value of the PC register now works again. This fixes
2364 problems observed when using the "jump" command, or when calling
2365 a function from GDB, or even when assigning a new value to $pc.
2366 - With the "finish" and "return" commands, the return value for functions
2367 returning a small array is now correctly printed.
2368 - It is now possible to break on shared library code which gets executed
2369 during a shared library init phase (code executed while executing
2370 their .init section). Previously, the breakpoint would have no effect.
2371 - GDB is now able to backtrace through the signal handler for
2372 non-threaded programs.
2374 PIE (Position Independent Executable) programs debugging is now supported.
2375 This includes debugging execution of PIC (Position Independent Code) shared
2376 libraries although for that, it should be possible to run such libraries as an
2379 *** Changes in GDB 7.0
2381 * GDB now has an interface for JIT compilation. Applications that
2382 dynamically generate code can create symbol files in memory and register
2383 them with GDB. For users, the feature should work transparently, and
2384 for JIT developers, the interface is documented in the GDB manual in the
2385 "JIT Compilation Interface" chapter.
2387 * Tracepoints may now be conditional. The syntax is as for
2388 breakpoints; either an "if" clause appended to the "trace" command,
2389 or the "condition" command is available. GDB sends the condition to
2390 the target for evaluation using the same bytecode format as is used
2391 for tracepoint actions.
2393 * The disassemble command now supports: an optional /r modifier, print the
2394 raw instructions in hex as well as in symbolic form, and an optional /m
2395 modifier to print mixed source+assembly.
2397 * Process record and replay
2399 In a architecture environment that supports ``process record and
2400 replay'', ``process record and replay'' target can record a log of
2401 the process execution, and replay it with both forward and reverse
2404 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2405 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2406 set execution-direction {forward|reverse}, for targets that support
2409 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2410 feature is available with a native GDB running on kernel version
2413 * GDB now has support for multi-byte and wide character sets on the
2414 target. Strings whose character type is wchar_t, char16_t, or
2415 char32_t are now correctly printed. GDB supports wide- and unicode-
2416 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2417 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2418 `printf'. This feature requires iconv to work properly; if your
2419 system does not have a working iconv, GDB can use GNU libiconv. See
2420 the installation instructions for more information.
2422 * GDB now supports automatic retrieval of shared library files from
2423 remote targets. To use this feature, specify a system root that begins
2424 with the `remote:' prefix, either via the `set sysroot' command or via
2425 the `--with-sysroot' configure-time option.
2427 * "info sharedlibrary" now takes an optional regex of libraries to show,
2428 and it now reports if a shared library has no debugging information.
2430 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2431 now complete on file names.
2433 * When completing in expressions, gdb will attempt to limit
2434 completions to allowable structure or union fields, where appropriate.
2435 For instance, consider:
2437 # struct example { int f1; double f2; };
2438 # struct example variable;
2441 If the user types TAB at the end of this command line, the available
2442 completions will be "f1" and "f2".
2444 * Inlined functions are now supported. They show up in backtraces, and
2445 the "step", "next", and "finish" commands handle them automatically.
2447 * GDB now supports the token-splicing (##) and stringification (#)
2448 operators when expanding macros. It also supports variable-arity
2451 * GDB now supports inspecting extra signal information, exported by
2452 the new $_siginfo convenience variable. The feature is currently
2453 implemented on linux ARM, i386 and amd64.
2455 * GDB can now display the VFP floating point registers and NEON vector
2456 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2457 can provide these registers (requires Linux 2.6.30 or later). Remote
2458 and simulator targets may also provide them.
2460 * New remote packets
2463 Search memory for a sequence of bytes.
2466 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2467 operation over reliable transport links. Use of this packet is
2468 controlled by the `set remote noack-packet' command.
2471 Kill the process with the specified process ID. Use this in preference
2472 to `k' when multiprocess protocol extensions are supported.
2475 Obtains additional operating system information
2479 Read or write additional signal information.
2481 * Removed remote protocol undocumented extension
2483 An undocumented extension to the remote protocol's `S' stop reply
2484 packet that permited the stub to pass a process id was removed.
2485 Remote servers should use the `T' stop reply packet instead.
2487 * GDB now supports multiple function calling conventions according to the
2488 DWARF-2 DW_AT_calling_convention function attribute.
2490 * The SH target utilizes the aforementioned change to distinguish between gcc
2491 and Renesas calling convention. It also adds the new CLI commands
2492 `set/show sh calling-convention'.
2494 * GDB can now read compressed debug sections, as produced by GNU gold
2495 with the --compress-debug-sections=zlib flag.
2497 * 64-bit core files are now supported on AIX.
2499 * Thread switching is now supported on Tru64.
2501 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2502 which will be allocated using malloc later in program execution.
2504 * The qXfer:libraries:read remote procotol packet now allows passing a
2505 list of section offsets.
2507 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2508 conditions handling signals delivered during attach or thread creation
2509 have also been fixed.
2511 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2512 From the user's standpoint, all unqualified instances of True and False
2513 are treated as the standard definitions, regardless of context.
2515 * GDB now parses C++ symbol and type names more flexibly. For
2518 template<typename T> class C { };
2521 GDB will now correctly handle all of:
2523 ptype C<char const *>
2524 ptype C<char const*>
2525 ptype C<const char *>
2526 ptype C<const char*>
2528 * New features in the GDB remote stub, gdbserver
2530 - The "--wrapper" command-line argument tells gdbserver to use a
2531 wrapper program to launch programs for debugging.
2533 - On PowerPC and S/390 targets, it is now possible to use a single
2534 gdbserver executable to debug both 32-bit and 64-bit programs.
2535 (This requires gdbserver itself to be built as a 64-bit executable.)
2537 - gdbserver uses the new noack protocol mode for TCP connections to
2538 reduce communications latency, if also supported and enabled in GDB.
2540 - Support for the sparc64-linux-gnu target is now included in
2543 - The amd64-linux build of gdbserver now supports debugging both
2544 32-bit and 64-bit programs.
2546 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2547 now support hardware watchpoints, and will use them automatically
2552 GDB now has support for scripting using Python. Whether this is
2553 available is determined at configure time.
2555 New GDB commands can now be written in Python.
2557 * Ada tasking support
2559 Ada tasks can now be inspected in GDB. The following commands have
2563 Print the list of Ada tasks.
2565 Print detailed information about task number N.
2567 Print the task number of the current task.
2569 Switch the context of debugging to task number N.
2571 * Support for user-defined prefixed commands. The "define" command can
2572 add new commands to existing prefixes, e.g. "target".
2574 * Multi-inferior, multi-process debugging.
2576 GDB now has generalized support for multi-inferior debugging. See
2577 "Debugging Multiple Inferiors" in the manual for more information.
2578 Although availability still depends on target support, the command
2579 set is more uniform now. The GNU/Linux specific multi-forks support
2580 has been migrated to this new framework. This implied some user
2581 visible changes; see "New commands" and also "Removed commands"
2584 * Target descriptions can now describe the target OS ABI. See the
2585 "Target Description Format" section in the user manual for more
2588 * Target descriptions can now describe "compatible" architectures
2589 to indicate that the target can execute applications for a different
2590 architecture in addition to those for the main target architecture.
2591 See the "Target Description Format" section in the user manual for
2594 * Multi-architecture debugging.
2596 GDB now includes general supports for debugging applications on
2597 hybrid systems that use more than one single processor architecture
2598 at the same time. Each such hybrid architecture still requires
2599 specific support to be added. The only hybrid architecture supported
2600 in this version of GDB is the Cell Broadband Engine.
2602 * GDB now supports integrated debugging of Cell/B.E. applications that
2603 use both the PPU and SPU architectures. To enable support for hybrid
2604 Cell/B.E. debugging, you need to configure GDB to support both the
2605 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2606 --enable-targets configure option.
2608 * Non-stop mode debugging.
2610 For some targets, GDB now supports an optional mode of operation in
2611 which you can examine stopped threads while other threads continue
2612 to execute freely. This is referred to as non-stop mode, with the
2613 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2614 section in the user manual for more information.
2616 To be able to support remote non-stop debugging, a remote stub needs
2617 to implement the non-stop mode remote protocol extensions, as
2618 described in the "Remote Non-Stop" section of the user manual. The
2619 GDB remote stub, gdbserver, has been adjusted to support these
2620 extensions on linux targets.
2622 * New commands (for set/show, see "New options" below)
2624 catch syscall [NAME(S) | NUMBER(S)]
2625 Catch system calls. Arguments, which should be names of system
2626 calls or their numbers, mean catch only those syscalls. Without
2627 arguments, every syscall will be caught. When the inferior issues
2628 any of the specified syscalls, GDB will stop and announce the system
2629 call, both when it is called and when its call returns. This
2630 feature is currently available with a native GDB running on the
2631 Linux Kernel, under the following architectures: x86, x86_64,
2632 PowerPC and PowerPC64.
2634 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2636 Search memory for a sequence of bytes.
2638 maint set python print-stack
2639 maint show python print-stack
2640 Show a stack trace when an error is encountered in a Python script.
2643 Invoke CODE by passing it to the Python interpreter.
2648 These allow macros to be defined, undefined, and listed
2652 Show operating system information about processes.
2655 List the inferiors currently under GDB's control.
2658 Switch focus to inferior number NUM.
2661 Detach from inferior number NUM.
2664 Kill inferior number NUM.
2668 set spu stop-on-load
2669 show spu stop-on-load
2670 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2672 set spu auto-flush-cache
2673 show spu auto-flush-cache
2674 Control whether to automatically flush the software-managed cache
2675 during Cell/B.E. debugging.
2677 set sh calling-convention
2678 show sh calling-convention
2679 Control the calling convention used when calling SH target functions.
2682 show debug timestamp
2683 Control display of timestamps with GDB debugging output.
2685 set disassemble-next-line
2686 show disassemble-next-line
2687 Control display of disassembled source lines or instructions when
2690 set remote noack-packet
2691 show remote noack-packet
2692 Set/show the use of remote protocol QStartNoAckMode packet. See above
2693 under "New remote packets."
2695 set remote query-attached-packet
2696 show remote query-attached-packet
2697 Control use of remote protocol `qAttached' (query-attached) packet.
2699 set remote read-siginfo-object
2700 show remote read-siginfo-object
2701 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2704 set remote write-siginfo-object
2705 show remote write-siginfo-object
2706 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2709 set remote reverse-continue
2710 show remote reverse-continue
2711 Control use of remote protocol 'bc' (reverse-continue) packet.
2713 set remote reverse-step
2714 show remote reverse-step
2715 Control use of remote protocol 'bs' (reverse-step) packet.
2717 set displaced-stepping
2718 show displaced-stepping
2719 Control displaced stepping mode. Displaced stepping is a way to
2720 single-step over breakpoints without removing them from the debuggee.
2721 Also known as "out-of-line single-stepping".
2724 show debug displaced
2725 Control display of debugging info for displaced stepping.
2727 maint set internal-error
2728 maint show internal-error
2729 Control what GDB does when an internal error is detected.
2731 maint set internal-warning
2732 maint show internal-warning
2733 Control what GDB does when an internal warning is detected.
2738 Use a wrapper program to launch programs for debugging.
2740 set multiple-symbols (all|ask|cancel)
2741 show multiple-symbols
2742 The value of this variable can be changed to adjust the debugger behavior
2743 when an expression or a breakpoint location contains an ambiguous symbol
2744 name (an overloaded function name, for instance).
2746 set breakpoint always-inserted
2747 show breakpoint always-inserted
2748 Keep breakpoints always inserted in the target, as opposed to inserting
2749 them when resuming the target, and removing them when the target stops.
2750 This option can improve debugger performance on slow remote targets.
2752 set arm fallback-mode (arm|thumb|auto)
2753 show arm fallback-mode
2754 set arm force-mode (arm|thumb|auto)
2756 These commands control how ARM GDB determines whether instructions
2757 are ARM or Thumb. The default for both settings is auto, which uses
2758 the current CPSR value for instructions without symbols; previous
2759 versions of GDB behaved as if "set arm fallback-mode arm".
2761 set disable-randomization
2762 show disable-randomization
2763 Standalone programs run with the virtual address space randomization enabled
2764 by default on some platforms. This option keeps the addresses stable across
2765 multiple debugging sessions.
2769 Control whether other threads are stopped or not when some thread hits
2774 Requests that asynchronous execution is enabled in the target, if available.
2775 In this case, it's possible to resume target in the background, and interact
2776 with GDB while the target is running. "show target-async" displays the
2777 current state of asynchronous execution of the target.
2779 set target-wide-charset
2780 show target-wide-charset
2781 The target-wide-charset is the name of the character set that GDB
2782 uses when printing characters whose type is wchar_t.
2784 set tcp auto-retry (on|off)
2786 set tcp connect-timeout
2787 show tcp connect-timeout
2788 These commands allow GDB to retry failed TCP connections to a remote stub
2789 with a specified timeout period; this is useful if the stub is launched
2790 in parallel with GDB but may not be ready to accept connections immediately.
2792 set libthread-db-search-path
2793 show libthread-db-search-path
2794 Control list of directories which GDB will search for appropriate
2797 set schedule-multiple (on|off)
2798 show schedule-multiple
2799 Allow GDB to resume all threads of all processes or only threads of
2800 the current process.
2804 Use more aggressive caching for accesses to the stack. This improves
2805 performance of remote debugging (particularly backtraces) without
2806 affecting correctness.
2808 set interactive-mode (on|off|auto)
2809 show interactive-mode
2810 Control whether GDB runs in interactive mode (on) or not (off).
2811 When in interactive mode, GDB waits for the user to answer all
2812 queries. Otherwise, GDB does not wait and assumes the default
2813 answer. When set to auto (the default), GDB determines which
2814 mode to use based on the stdin settings.
2819 For program forks, this is replaced by the new more generic `info
2820 inferiors' command. To list checkpoints, you can still use the
2821 `info checkpoints' command, which was an alias for the `info forks'
2825 Replaced by the new `inferior' command. To switch between
2826 checkpoints, you can still use the `restart' command, which was an
2827 alias for the `fork' command.
2830 This is removed, since some targets don't have a notion of
2831 processes. To switch between processes, you can still use the
2832 `inferior' command using GDB's own inferior number.
2835 For program forks, this is replaced by the new more generic `kill
2836 inferior' command. To delete a checkpoint, you can still use the
2837 `delete checkpoint' command, which was an alias for the `delete
2841 For program forks, this is replaced by the new more generic `detach
2842 inferior' command. To detach a checkpoint, you can still use the
2843 `detach checkpoint' command, which was an alias for the `detach
2846 * New native configurations
2848 x86/x86_64 Darwin i[34567]86-*-darwin*
2850 x86_64 MinGW x86_64-*-mingw*
2854 Lattice Mico32 lm32-*
2855 x86 DICOS i[34567]86-*-dicos*
2856 x86_64 DICOS x86_64-*-dicos*
2859 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2860 (mingw32ce) debugging.
2866 These commands were actually not implemented on any target.
2868 *** Changes in GDB 6.8
2870 * New native configurations
2872 NetBSD/hppa hppa*-*netbsd*
2873 Xtensa GNU/Linux xtensa*-*-linux*
2877 NetBSD/hppa hppa*-*-netbsd*
2878 Xtensa GNU/Lunux xtensa*-*-linux*
2880 * Change in command line behavior -- corefiles vs. process ids.
2882 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2883 attaching to process NUMBER fails, GDB no longer attempts to open a
2884 core file named NUMBER. Attaching to a program using the -c option
2885 is no longer supported. Instead, use the '-p' or '--pid' options.
2887 * GDB can now be built as a native debugger for debugging Windows x86
2888 (mingw32) Portable Executable (PE) programs.
2890 * Pending breakpoints no longer change their number when their address
2893 * GDB now supports breakpoints with multiple locations,
2894 including breakpoints on C++ constructors, inside C++ templates,
2895 and in inlined functions.
2897 * GDB's ability to debug optimized code has been improved. GDB more
2898 accurately identifies function bodies and lexical blocks that occupy
2899 more than one contiguous range of addresses.
2901 * Target descriptions can now describe registers for PowerPC.
2903 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2904 registers on PowerPC targets.
2906 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2907 targets even when the libthread_db library is not available.
2909 * The GDB remote stub, gdbserver, now supports the new file transfer
2910 commands (remote put, remote get, and remote delete).
2912 * The GDB remote stub, gdbserver, now supports run and attach in
2913 extended-remote mode.
2915 * hppa*64*-*-hpux11* target broken
2916 The debugger is unable to start a program and fails with the following
2917 error: "Error trying to get information about dynamic linker".
2918 The gdb-6.7 release is also affected.
2920 * GDB now supports the --enable-targets= configure option to allow
2921 building a single GDB executable that supports multiple remote
2922 target architectures.
2924 * GDB now supports debugging C and C++ programs which use the
2925 Decimal Floating Point extension. In addition, the PowerPC target
2926 now has a set of pseudo-registers to inspect decimal float values
2927 stored in two consecutive float registers.
2929 * The -break-insert MI command can optionally create pending
2932 * Improved support for debugging Ada
2933 Many improvements to the Ada language support have been made. These
2935 - Better support for Ada2005 interface types
2936 - Improved handling of arrays and slices in general
2937 - Better support for Taft-amendment types
2938 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2940 - Improved command completion in Ada
2943 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2948 set print frame-arguments (all|scalars|none)
2949 show print frame-arguments
2950 The value of this variable can be changed to control which argument
2951 values should be printed by the debugger when displaying a frame.
2956 Transfer files to and from a remote target, and delete remote files.
2963 Transfer files to and from a remote target, and delete remote files.
2965 * New remote packets
2972 Open, close, read, write, and delete files on the remote system.
2975 Attach to an existing process on the remote system, in extended-remote
2979 Run a new process on the remote system, in extended-remote mode.
2981 *** Changes in GDB 6.7
2983 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2984 bfd, libiberty and opcodes, as revealed by static analysis donated by
2985 Coverity, Inc. (http://scan.coverity.com).
2987 * When looking up multiply-defined global symbols, GDB will now prefer the
2988 symbol definition in the current shared library if it was built using the
2989 -Bsymbolic linker option.
2991 * When the Text User Interface (TUI) is not configured, GDB will now
2992 recognize the -tui command-line option and print a message that the TUI
2995 * The GDB remote stub, gdbserver, now has lower overhead for high
2996 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2998 * GDB for MIPS targets now autodetects whether a remote target provides
2999 32-bit or 64-bit register values.
3001 * Support for C++ member pointers has been improved.
3003 * GDB now understands XML target descriptions, which specify the
3004 target's overall architecture. GDB can read a description from
3005 a local file or over the remote serial protocol.
3007 * Vectors of single-byte data use a new integer type which is not
3008 automatically displayed as character or string data.
3010 * The /s format now works with the print command. It displays
3011 arrays of single-byte integers and pointers to single-byte integers
3014 * Target descriptions can now describe target-specific registers,
3015 for architectures which have implemented the support (currently
3016 only ARM, M68K, and MIPS).
3018 * GDB and the GDB remote stub, gdbserver, now support the XScale
3021 * The GDB remote stub, gdbserver, has been updated to support
3022 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3023 has been rewritten to use the standard GDB remote protocol.
3025 * GDB can now step into C++ functions which are called through thunks.
3027 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3029 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3030 layout. It also supports a TextSeg= and DataSeg= response when only
3031 segment base addresses (rather than offsets) are available.
3033 * The /i format now outputs any trailing branch delay slot instructions
3034 immediately following the last instruction within the count specified.
3036 * The GDB remote protocol "T" stop reply packet now supports a
3037 "library" response. Combined with the new "qXfer:libraries:read"
3038 packet, this response allows GDB to debug shared libraries on targets
3039 where the operating system manages the list of loaded libraries (e.g.
3040 Windows and SymbianOS).
3042 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3043 (DLLs) on Windows and Windows CE targets.
3045 * GDB now supports a faster verification that a .debug file matches its binary
3046 according to its build-id signature, if the signature is present.
3052 Enable or disable hardware flow control (RTS/CTS) on the serial port
3053 when debugging using remote targets.
3055 set mem inaccessible-by-default
3056 show mem inaccessible-by-default
3057 If the target supplies a memory map, for instance via the remote
3058 protocol's "qXfer:memory-map:read" packet, setting this variable
3059 prevents GDB from accessing memory outside the memory map. This
3060 is useful for targets with memory mapped registers or which react
3061 badly to accesses of unmapped address space.
3063 set breakpoint auto-hw
3064 show breakpoint auto-hw
3065 If the target supplies a memory map, for instance via the remote
3066 protocol's "qXfer:memory-map:read" packet, setting this variable
3067 lets GDB use hardware breakpoints automatically for memory regions
3068 where it can not use software breakpoints. This covers both the
3069 "break" command and internal breakpoints used for other commands
3070 including "next" and "finish".
3073 catch exception unhandled
3074 Stop the program execution when Ada exceptions are raised.
3077 Stop the program execution when an Ada assertion failed.
3081 Set an alternate system root for target files. This is a more
3082 general version of "set solib-absolute-prefix", which is now
3083 an alias to "set sysroot".
3086 Provide extended SPU facility status information. This set of
3087 commands is available only when debugging the Cell/B.E. SPU
3090 * New native configurations
3092 OpenBSD/sh sh*-*openbsd*
3095 unset tdesc filename
3097 Use the specified local file as an XML target description, and do
3098 not query the target for its built-in description.
3102 OpenBSD/sh sh*-*-openbsd*
3103 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3104 Toshiba Media Processor mep-elf
3106 * New remote packets
3109 Ignore the specified signals; pass them directly to the debugged program
3110 without stopping other threads or reporting them to GDB.
3112 qXfer:features:read:
3113 Read an XML target description from the target, which describes its
3118 Read or write contents of an spufs file on the target system. These
3119 packets are available only on the Cell/B.E. SPU architecture.
3121 qXfer:libraries:read:
3122 Report the loaded shared libraries. Combined with new "T" packet
3123 response, this packet allows GDB to debug shared libraries on
3124 targets where the operating system manages the list of loaded
3125 libraries (e.g. Windows and SymbianOS).
3129 Support for these obsolete configurations has been removed.
3137 i[34567]86-*-lynxos*
3138 i[34567]86-*-netware*
3139 i[34567]86-*-sco3.2v5*
3140 i[34567]86-*-sco3.2v4*
3142 i[34567]86-*-sysv4.2*
3145 i[34567]86-*-unixware2*
3146 i[34567]86-*-unixware*
3155 * Other removed features
3162 Various m68k-only ROM monitors.
3169 Various Renesas ROM monitors and debugging interfaces for SH and
3174 Support for a Macraigor serial interface to on-chip debugging.
3175 GDB does not directly support the newer parallel or USB
3180 A debug information format. The predecessor to DWARF 2 and
3181 DWARF 3, which are still supported.
3183 Support for the HP aCC compiler on HP-UX/PA-RISC
3185 SOM-encapsulated symbolic debugging information, automatic
3186 invocation of pxdb, and the aCC custom C++ ABI. This does not
3187 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3188 with aCC can still be debugged on an assembly level.
3190 MIPS ".pdr" sections
3192 A MIPS-specific format used to describe stack frame layout
3193 in debugging information.
3197 GDB could work with an older version of Guile to debug
3198 the interpreter and Scheme programs running in it.
3200 set mips stack-arg-size
3201 set mips saved-gpreg-size
3203 Use "set mips abi" to control parameter passing for MIPS.
3205 *** Changes in GDB 6.6
3210 Cell Broadband Engine SPU spu-elf
3212 * GDB can now be configured as a cross-debugger targeting native Windows
3213 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3214 running on a Windows system over TCP/IP to debug Windows programs.
3216 * The GDB remote stub, gdbserver, has been updated to support Windows and
3217 Cygwin debugging. Both single-threaded and multi-threaded programs are
3220 * The "set trust-readonly-sections" command works again. This command was
3221 broken in GDB 6.3, 6.4, and 6.5.
3223 * The "load" command now supports writing to flash memory, if the remote
3224 stub provides the required support.
3226 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3227 longer requires symbolic debug information (e.g. DWARF-2).
3232 unset substitute-path
3233 show substitute-path
3234 Manage a list of substitution rules that GDB uses to rewrite the name
3235 of the directories where the sources are located. This can be useful
3236 for instance when the sources were moved to a different location
3237 between compilation and debugging.
3241 Print each CLI command as it is executed. Each command is prefixed with
3242 a number of `+' symbols representing the nesting depth.
3243 The source command now has a `-v' option to enable the same feature.
3247 The ARM Demon monitor support (RDP protocol, "target rdp").
3249 Kernel Object Display, an embedded debugging feature which only worked with
3250 an obsolete version of Cisco IOS.
3252 The 'set download-write-size' and 'show download-write-size' commands.
3254 * New remote packets
3257 Tell a stub about GDB client features, and request remote target features.
3258 The first feature implemented is PacketSize, which allows the target to
3259 specify the size of packets it can handle - to minimize the number of
3260 packets required and improve performance when connected to a remote
3264 Fetch an OS auxilliary vector from the remote stub. This packet is a
3265 more efficient replacement for qPart:auxv:read.
3267 qXfer:memory-map:read:
3268 Fetch a memory map from the remote stub, including information about
3269 RAM, ROM, and flash memory devices.
3274 Erase and program a flash memory device.
3276 * Removed remote packets
3279 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3280 used it, and only gdbserver implemented it.
3282 *** Changes in GDB 6.5
3286 Renesas M32C/M16C m32c-elf
3288 Morpho Technologies ms1 ms1-elf
3292 init-if-undefined Initialize a convenience variable, but
3293 only if it doesn't already have a value.
3295 The following commands are presently only implemented for native GNU/Linux:
3297 checkpoint Save a snapshot of the program state.
3299 restart <n> Return the program state to a
3300 previously saved state.
3302 info checkpoints List currently saved checkpoints.
3304 delete-checkpoint <n> Delete a previously saved checkpoint.
3306 set|show detach-on-fork Tell gdb whether to detach from a newly
3307 forked process, or to keep debugging it.
3309 info forks List forks of the user program that
3310 are available to be debugged.
3312 fork <n> Switch to debugging one of several
3313 forks of the user program that are
3314 available to be debugged.
3316 delete-fork <n> Delete a fork from the list of forks
3317 that are available to be debugged (and
3318 kill the forked process).
3320 detach-fork <n> Delete a fork from the list of forks
3321 that are available to be debugged (and
3322 allow the process to continue).
3326 Morpho Technologies ms2 ms1-elf
3328 * Improved Windows host support
3330 GDB now builds as a cross debugger hosted on i686-mingw32, including
3331 native console support, and remote communications using either
3332 network sockets or serial ports.
3334 * Improved Modula-2 language support
3336 GDB can now print most types in the Modula-2 syntax. This includes:
3337 basic types, set types, record types, enumerated types, range types,
3338 pointer types and ARRAY types. Procedure var parameters are correctly
3339 printed and hexadecimal addresses and character constants are also
3340 written in the Modula-2 syntax. Best results can be obtained by using
3341 GNU Modula-2 together with the -gdwarf-2 command line option.
3345 The ARM rdi-share module.
3347 The Netware NLM debug server.
3349 *** Changes in GDB 6.4
3351 * New native configurations
3353 OpenBSD/arm arm*-*-openbsd*
3354 OpenBSD/mips64 mips64-*-openbsd*
3358 Morpho Technologies ms1 ms1-elf
3360 * New command line options
3362 --batch-silent As for --batch, but totally silent.
3363 --return-child-result The debugger will exist with the same value
3364 the child (debugged) program exited with.
3365 --eval-command COMMAND, -ex COMMAND
3366 Execute a single GDB CLI command. This may be
3367 specified multiple times and in conjunction
3368 with the --command (-x) option.
3370 * Deprecated commands removed
3372 The following commands, that were deprecated in 2000, have been
3376 set|show arm disassembly-flavor set|show arm disassembler
3377 othernames set arm disassembler
3378 set|show remotedebug set|show debug remote
3379 set|show archdebug set|show debug arch
3380 set|show eventdebug set|show debug event
3383 * New BSD user-level threads support
3385 It is now possible to debug programs using the user-level threads
3386 library on OpenBSD and FreeBSD. Currently supported (target)
3389 FreeBSD/amd64 x86_64-*-freebsd*
3390 FreeBSD/i386 i386-*-freebsd*
3391 OpenBSD/i386 i386-*-openbsd*
3393 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3394 are not yet supported.
3396 * New support for Matsushita MN10300 w/sim added
3397 (Work in progress). mn10300-elf.
3399 * REMOVED configurations and files
3401 VxWorks and the XDR protocol *-*-vxworks
3402 Motorola MCORE mcore-*-*
3403 National Semiconductor NS32000 ns32k-*-*
3405 * New "set print array-indexes" command
3407 After turning this setting "on", GDB prints the index of each element
3408 when displaying arrays. The default is "off" to preserve the previous
3411 * VAX floating point support
3413 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3415 * User-defined command support
3417 In addition to using $arg0..$arg9 for argument passing, it is now possible
3418 to use $argc to determine now many arguments have been passed. See the
3419 section on user-defined commands in the user manual for more information.
3421 *** Changes in GDB 6.3:
3423 * New command line option
3425 GDB now accepts -l followed by a number to set the timeout for remote
3428 * GDB works with GCC -feliminate-dwarf2-dups
3430 GDB now supports a more compact representation of DWARF-2 debug
3431 information using DW_FORM_ref_addr references. These are produced
3432 by GCC with the option -feliminate-dwarf2-dups and also by some
3433 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3434 to use -feliminate-dwarf2-dups.
3436 * Internationalization
3438 When supported by the host system, GDB will be built with
3439 internationalization (libintl). The task of marking up the sources is
3440 continued, we're looking forward to our first translation.
3444 Initial support for debugging programs compiled with the GNAT
3445 implementation of the Ada programming language has been integrated
3446 into GDB. In this release, support is limited to expression evaluation.
3448 * New native configurations
3450 GNU/Linux/m32r m32r-*-linux-gnu
3454 GDB's remote protocol now includes support for the 'p' packet. This
3455 packet is used to fetch individual registers from a remote inferior.
3457 * END-OF-LIFE registers[] compatibility module
3459 GDB's internal register infrastructure has been completely rewritten.
3460 The new infrastructure making possible the implementation of key new
3461 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3464 GDB 6.3 will be the last release to include the the registers[]
3465 compatibility module that allowed out-of-date configurations to
3466 continue to work. This change directly impacts the following
3476 powerpc bdm protocol
3478 Unless there is activity to revive these configurations, they will be
3479 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3481 * OBSOLETE configurations and files
3483 Configurations that have been declared obsolete in this release have
3484 been commented out. Unless there is activity to revive these
3485 configurations, the next release of GDB will have their sources
3486 permanently REMOVED.
3495 *** Changes in GDB 6.2.1:
3497 * MIPS `break main; run' gave an heuristic-fence-post warning
3499 When attempting to run even a simple program, a warning about
3500 heuristic-fence-post being hit would be reported. This problem has
3503 * MIPS IRIX 'long double' crashed GDB
3505 When examining a long double variable, GDB would get a segmentation
3506 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3507 IRIX long double values).
3511 A bug in the VAX stack code was causing problems with the "next"
3512 command. This problem has been fixed.
3514 *** Changes in GDB 6.2:
3516 * Fix for ``many threads''
3518 On GNU/Linux systems that use the NPTL threads library, a program
3519 rapidly creating and deleting threads would confuse GDB leading to the
3522 ptrace: No such process.
3523 thread_db_get_info: cannot get thread info: generic error
3525 This problem has been fixed.
3527 * "-async" and "-noasync" options removed.
3529 Support for the broken "-noasync" option has been removed (it caused
3532 * New ``start'' command.
3534 This command runs the program until the begining of the main procedure.
3536 * New BSD Kernel Data Access Library (libkvm) interface
3538 Using ``target kvm'' it is now possible to debug kernel core dumps and
3539 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3540 platforms. Currently supported (native-only) configurations are:
3542 FreeBSD/amd64 x86_64-*-freebsd*
3543 FreeBSD/i386 i?86-*-freebsd*
3544 NetBSD/i386 i?86-*-netbsd*
3545 NetBSD/m68k m68*-*-netbsd*
3546 NetBSD/sparc sparc-*-netbsd*
3547 OpenBSD/amd64 x86_64-*-openbsd*
3548 OpenBSD/i386 i?86-*-openbsd*
3549 OpenBSD/m68k m68*-openbsd*
3550 OpenBSD/sparc sparc-*-openbsd*
3552 * Signal trampoline code overhauled
3554 Many generic problems with GDB's signal handling code have been fixed.
3555 These include: backtraces through non-contiguous stacks; recognition
3556 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3557 call; backtrace through a signal trampoline; step into and out of
3558 signal handlers; and single-stepping in the signal trampoline.
3560 Please note that kernel bugs are a limiting factor here. These
3561 features have been shown to work on an s390 GNU/Linux system that
3562 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3564 * Cygwin support for DWARF 2 added.
3566 * New native configurations
3568 GNU/Linux/hppa hppa*-*-linux*
3569 OpenBSD/hppa hppa*-*-openbsd*
3570 OpenBSD/m68k m68*-*-openbsd*
3571 OpenBSD/m88k m88*-*-openbsd*
3572 OpenBSD/powerpc powerpc-*-openbsd*
3573 NetBSD/vax vax-*-netbsd*
3574 OpenBSD/vax vax-*-openbsd*
3576 * END-OF-LIFE frame compatibility module
3578 GDB's internal frame infrastructure has been completely rewritten.
3579 The new infrastructure making it possible to support key new features
3580 including DWARF 2 Call Frame Information. To aid in the task of
3581 migrating old configurations to this new infrastructure, a
3582 compatibility module, that allowed old configurations to continue to
3583 work, was also included.
3585 GDB 6.2 will be the last release to include this frame compatibility
3586 module. This change directly impacts the following configurations:
3596 Unless there is activity to revive these configurations, they will be
3597 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3599 * REMOVED configurations and files
3601 Sun 3, running SunOS 3 m68*-*-sunos3*
3602 Sun 3, running SunOS 4 m68*-*-sunos4*
3603 Sun 2, running SunOS 3 m68000-*-sunos3*
3604 Sun 2, running SunOS 4 m68000-*-sunos4*
3605 Motorola 680x0 running LynxOS m68*-*-lynxos*
3606 AT&T 3b1/Unix pc m68*-att-*
3607 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3608 decstation mips-dec-* mips-little-*
3609 riscos mips-*-riscos* mips-*-sysv*
3610 sonymips mips-sony-*
3611 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3613 *** Changes in GDB 6.1.1:
3615 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3617 The TUI (Text-mode User Interface) is now built as part of a default
3618 GDB configuration. It is enabled by either selecting the TUI with the
3619 command line option "-i=tui" or by running the separate "gdbtui"
3620 program. For more information on the TUI, see the manual "Debugging
3623 * Pending breakpoint support (also included in GDB 6.1)
3625 Support has been added to allow you to specify breakpoints in shared
3626 libraries that have not yet been loaded. If a breakpoint location
3627 cannot be found, and the "breakpoint pending" option is set to auto,
3628 GDB queries you if you wish to make the breakpoint pending on a future
3629 shared-library load. If and when GDB resolves the breakpoint symbol,
3630 the pending breakpoint is removed as one or more regular breakpoints
3633 Pending breakpoints are very useful for GCJ Java debugging.
3635 * Fixed ISO-C build problems
3637 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3638 non ISO-C code that stopped them being built using a more strict ISO-C
3639 compiler (e.g., IBM's C compiler).
3641 * Fixed build problem on IRIX 5
3643 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3644 wasn't able to compile compile on an IRIX 5 system.
3646 * Added execute permission to gdb/gdbserver/configure
3648 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3649 permission. This bug would cause configure to fail on a number of
3650 systems (Solaris, IRIX). Ref: server/519.
3652 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3654 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3655 has been updated to use constant array sizes.
3657 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3659 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3660 its generated DWARF Call Frame Info. This encoding was causing GDB to
3661 panic, that panic has been fixed. Ref: gdb/1628.
3663 * Fixed a problem when examining parameters in shared library code.
3665 When examining parameters in optimized shared library code generated
3666 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3667 not available''. GDB now correctly displays the variable's value.
3669 *** Changes in GDB 6.1:
3671 * Removed --with-mmalloc
3673 Support for the mmalloc memory manager has been removed, as it
3674 conflicted with the internal gdb byte cache.
3676 * Changes in AMD64 configurations
3678 The AMD64 target now includes the %cs and %ss registers. As a result
3679 the AMD64 remote protocol has changed; this affects the floating-point
3680 and SSE registers. If you rely on those registers for your debugging,
3681 you should upgrade gdbserver on the remote side.
3683 * Revised SPARC target
3685 The SPARC target has been completely revised, incorporating the
3686 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3687 support for LynxOS and SunOS 4 has been dropped. Calling functions
3688 from within GDB on operating systems with a non-executable stack
3689 (Solaris, OpenBSD) now works.
3693 GDB has a new C++ demangler which does a better job on the mangled
3694 names generated by current versions of g++. It also runs faster, so
3695 with this and other changes gdb should now start faster on large C++
3698 * DWARF 2 Location Expressions
3700 GDB support for location expressions has been extended to support function
3701 arguments and frame bases. Older versions of GDB could crash when they
3704 * C++ nested types and namespaces
3706 GDB's support for nested types and namespaces in C++ has been
3707 improved, especially if you use the DWARF 2 debugging format. (This
3708 is the default for recent versions of GCC on most platforms.)
3709 Specifically, if you have a class "Inner" defined within a class or
3710 namespace "Outer", then GDB realizes that the class's name is
3711 "Outer::Inner", not simply "Inner". This should greatly reduce the
3712 frequency of complaints about not finding RTTI symbols. In addition,
3713 if you are stopped at inside of a function defined within a namespace,
3714 GDB modifies its name lookup accordingly.
3716 * New native configurations
3718 NetBSD/amd64 x86_64-*-netbsd*
3719 OpenBSD/amd64 x86_64-*-openbsd*
3720 OpenBSD/alpha alpha*-*-openbsd*
3721 OpenBSD/sparc sparc-*-openbsd*
3722 OpenBSD/sparc64 sparc64-*-openbsd*
3724 * New debugging protocols
3726 M32R with SDI protocol m32r-*-elf*
3728 * "set prompt-escape-char" command deleted.
3730 The command "set prompt-escape-char" has been deleted. This command,
3731 and its very obscure effet on GDB's prompt, was never documented,
3732 tested, nor mentioned in the NEWS file.
3734 * OBSOLETE configurations and files
3736 Configurations that have been declared obsolete in this release have
3737 been commented out. Unless there is activity to revive these
3738 configurations, the next release of GDB will have their sources
3739 permanently REMOVED.
3741 Sun 3, running SunOS 3 m68*-*-sunos3*
3742 Sun 3, running SunOS 4 m68*-*-sunos4*
3743 Sun 2, running SunOS 3 m68000-*-sunos3*
3744 Sun 2, running SunOS 4 m68000-*-sunos4*
3745 Motorola 680x0 running LynxOS m68*-*-lynxos*
3746 AT&T 3b1/Unix pc m68*-att-*
3747 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3748 decstation mips-dec-* mips-little-*
3749 riscos mips-*-riscos* mips-*-sysv*
3750 sonymips mips-sony-*
3751 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3753 * REMOVED configurations and files
3755 SGI Irix-4.x mips-sgi-irix4 or iris4
3756 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3757 Z8000 simulator z8k-zilog-none or z8ksim
3758 Matsushita MN10200 w/simulator mn10200-*-*
3759 H8/500 simulator h8500-hitachi-hms or h8500hms
3760 HP/PA running BSD hppa*-*-bsd*
3761 HP/PA running OSF/1 hppa*-*-osf*
3762 HP/PA Pro target hppa*-*-pro*
3763 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3764 386BSD i[3456]86-*-bsd*
3765 Sequent family i[3456]86-sequent-sysv4*
3766 i[3456]86-sequent-sysv*
3767 i[3456]86-sequent-bsd*
3768 SPARC running LynxOS sparc-*-lynxos*
3769 SPARC running SunOS 4 sparc-*-sunos4*
3770 Tsqware Sparclet sparclet-*-*
3771 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3773 *** Changes in GDB 6.0:
3777 Support for debugging the Objective-C programming language has been
3778 integrated into GDB.
3780 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3782 DWARF 2's Call Frame Information makes available compiler generated
3783 information that more exactly describes the program's run-time stack.
3784 By using this information, GDB is able to provide more robust stack
3787 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3788 have been updated to use a new backtrace mechanism which includes
3789 DWARF 2 CFI support.
3793 GDB's remote protocol has been extended to include support for hosted
3794 file I/O (where the remote target uses GDB's file system). See GDB's
3795 remote protocol documentation for details.
3797 * All targets using the new architecture framework.
3799 All of GDB's targets have been updated to use the new internal
3800 architecture framework. The way is now open for future GDB releases
3801 to include cross-architecture native debugging support (i386 on amd64,
3804 * GNU/Linux's Thread Local Storage (TLS)
3806 GDB now includes support for for the GNU/Linux implementation of
3807 per-thread variables.
3809 * GNU/Linux's Native POSIX Thread Library (NPTL)
3811 GDB's thread code has been updated to work with either the new
3812 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3814 * Separate debug info.
3816 GDB, in conjunction with BINUTILS, now supports a mechanism for
3817 automatically loading debug information from a separate file. Instead
3818 of shipping full debug and non-debug versions of system libraries,
3819 system integrators can now instead ship just the stripped libraries
3820 and optional debug files.
3822 * DWARF 2 Location Expressions
3824 DWARF 2 Location Expressions allow the compiler to more completely
3825 describe the location of variables (even in optimized code) to the
3828 GDB now includes preliminary support for location expressions (support
3829 for DW_OP_piece is still missing).
3833 A number of long standing bugs that caused GDB to die while starting a
3834 Java application have been fixed. GDB's Java support is now
3835 considered "useable".
3837 * GNU/Linux support for fork, vfork, and exec.
3839 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3840 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3843 * GDB supports logging output to a file
3845 There are two new commands, "set logging" and "show logging", which can be
3846 used to capture GDB's output to a file.
3848 * The meaning of "detach" has changed for gdbserver
3850 The "detach" command will now resume the application, as documented. To
3851 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3854 * d10v, m68hc11 `regs' command deprecated
3856 The `info registers' command has been updated so that it displays the
3857 registers using a format identical to the old `regs' command.
3861 A new command, "maint set profile on/off", has been added. This command can
3862 be used to enable or disable profiling while running GDB, to profile a
3863 session or a set of commands. In addition there is a new configure switch,
3864 "--enable-profiling", which will cause GDB to be compiled with profiling
3865 data, for more informative profiling results.
3867 * Default MI syntax changed to "mi2".
3869 The default MI (machine interface) syntax, enabled by the command line
3870 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3871 "mi1", can be enabled by specifying the option "-i=mi1".
3873 Support for the original "mi0" syntax (included in GDB 5.0) has been
3876 Fix for gdb/192: removed extraneous space when displaying frame level.
3877 Fix for gdb/672: update changelist is now output in mi list format.
3878 Fix for gdb/702: a -var-assign that updates the value now shows up
3879 in a subsequent -var-update.
3881 * New native configurations.
3883 FreeBSD/amd64 x86_64-*-freebsd*
3885 * Multi-arched targets.
3887 HP/PA HPUX11 hppa*-*-hpux*
3888 Renesas M32R/D w/simulator m32r-*-elf*
3890 * OBSOLETE configurations and files
3892 Configurations that have been declared obsolete in this release have
3893 been commented out. Unless there is activity to revive these
3894 configurations, the next release of GDB will have their sources
3895 permanently REMOVED.
3897 Z8000 simulator z8k-zilog-none or z8ksim
3898 Matsushita MN10200 w/simulator mn10200-*-*
3899 H8/500 simulator h8500-hitachi-hms or h8500hms
3900 HP/PA running BSD hppa*-*-bsd*
3901 HP/PA running OSF/1 hppa*-*-osf*
3902 HP/PA Pro target hppa*-*-pro*
3903 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3904 Sequent family i[3456]86-sequent-sysv4*
3905 i[3456]86-sequent-sysv*
3906 i[3456]86-sequent-bsd*
3907 Tsqware Sparclet sparclet-*-*
3908 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3910 * REMOVED configurations and files
3913 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3914 IBM AIX PS/2 i[3456]86-*-aix
3915 i386 running Mach 3.0 i[3456]86-*-mach3*
3916 i386 running Mach i[3456]86-*-mach*
3917 i386 running OSF/1 i[3456]86-*osf1mk*
3918 HP/Apollo 68k Family m68*-apollo*-sysv*,
3920 m68*-hp-bsd*, m68*-hp-hpux*
3921 Argonaut Risc Chip (ARC) arc-*-*
3922 Mitsubishi D30V d30v-*-*
3923 Fujitsu FR30 fr30-*-elf*
3924 OS/9000 i[34]86-*-os9k
3925 I960 with MON960 i960-*-coff
3927 * MIPS $fp behavior changed
3929 The convenience variable $fp, for the MIPS, now consistently returns
3930 the address of the current frame's base. Previously, depending on the
3931 context, $fp could refer to either $sp or the current frame's base
3932 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3933 The GNU Source-Level Debugger''.
3935 *** Changes in GDB 5.3:
3937 * GNU/Linux shared library multi-threaded performance improved.
3939 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3940 `/proc', in preference to `ptrace' for memory reads. This may result
3941 in an improvement in the start-up time of multi-threaded, shared
3942 library applications when run under GDB. One GDB user writes: ``loads
3943 shared libs like mad''.
3945 * ``gdbserver'' now supports multi-threaded applications on some targets
3947 Support for debugging multi-threaded applications which use
3948 the GNU/Linux LinuxThreads package has been added for
3949 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3950 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3952 * GDB now supports C/C++ preprocessor macros.
3954 GDB now expands preprocessor macro invocations in C/C++ expressions,
3955 and provides various commands for showing macro definitions and how
3958 The new command `macro expand EXPRESSION' expands any macro
3959 invocations in expression, and shows the result.
3961 The new command `show macro MACRO-NAME' shows the definition of the
3962 macro named MACRO-NAME, and where it was defined.
3964 Most compilers don't include information about macros in the debugging
3965 information by default. In GCC 3.1, for example, you need to compile
3966 your program with the options `-gdwarf-2 -g3'. If the macro
3967 information is present in the executable, GDB will read it.
3969 * Multi-arched targets.
3971 DEC Alpha (partial) alpha*-*-*
3972 DEC VAX (partial) vax-*-*
3974 National Semiconductor NS32000 (partial) ns32k-*-*
3975 Motorola 68000 (partial) m68k-*-*
3976 Motorola MCORE mcore-*-*
3980 Fujitsu FRV architecture added by Red Hat frv*-*-*
3983 * New native configurations
3985 Alpha NetBSD alpha*-*-netbsd*
3986 SH NetBSD sh*-*-netbsdelf*
3987 MIPS NetBSD mips*-*-netbsd*
3988 UltraSPARC NetBSD sparc64-*-netbsd*
3990 * OBSOLETE configurations and files
3992 Configurations that have been declared obsolete in this release have
3993 been commented out. Unless there is activity to revive these
3994 configurations, the next release of GDB will have their sources
3995 permanently REMOVED.
3997 Mitsubishi D30V d30v-*-*
3998 OS/9000 i[34]86-*-os9k
3999 IBM AIX PS/2 i[3456]86-*-aix
4000 Fujitsu FR30 fr30-*-elf*
4001 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4002 Argonaut Risc Chip (ARC) arc-*-*
4003 i386 running Mach 3.0 i[3456]86-*-mach3*
4004 i386 running Mach i[3456]86-*-mach*
4005 i386 running OSF/1 i[3456]86-*osf1mk*
4006 HP/Apollo 68k Family m68*-apollo*-sysv*,
4008 m68*-hp-bsd*, m68*-hp-hpux*
4009 I960 with MON960 i960-*-coff
4011 * OBSOLETE languages
4013 CHILL, a Pascal like language used by telecommunications companies.
4015 * REMOVED configurations and files
4017 AMD 29k family via UDI a29k-amd-udi, udi29k
4018 A29K VxWorks a29k-*-vxworks
4019 AMD 29000 embedded, using EBMON a29k-none-none
4020 AMD 29000 embedded with COFF a29k-none-coff
4021 AMD 29000 embedded with a.out a29k-none-aout
4023 testsuite/gdb.hp/gdb.threads-hp/ directory
4025 * New command "set max-user-call-depth <nnn>"
4027 This command allows the user to limit the call depth of user-defined
4028 commands. The default is 1024.
4030 * Changes in FreeBSD/i386 native debugging.
4032 Support for the "generate-core-file" has been added.
4034 * New commands "dump", "append", and "restore".
4036 These commands allow data to be copied from target memory
4037 to a bfd-format or binary file (dump and append), and back
4038 from a file into memory (restore).
4040 * Improved "next/step" support on multi-processor Alpha Tru64.
4042 The previous single-step mechanism could cause unpredictable problems,
4043 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4044 of a software single-step mechanism prevents this.
4046 *** Changes in GDB 5.2.1:
4054 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4055 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4056 Fix, by Joel Brobecker imported from mainline.
4058 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4059 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4060 Fix, by Fred Fish, imported from mainline.
4062 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4063 Surprisingly enough, it works now.
4064 By Michal Ludvig, imported from mainline.
4066 i386 hardware watchpoint support:
4067 avoid misses on second run for some targets.
4068 By Pierre Muller, imported from mainline.
4070 *** Changes in GDB 5.2:
4072 * New command "set trust-readonly-sections on[off]".
4074 This command is a hint that tells gdb that read-only sections
4075 really are read-only (ie. that their contents will not change).
4076 In this mode, gdb will go to the object file rather than the
4077 target to read memory from read-only sections (such as ".text").
4078 This can be a significant performance improvement on some
4079 (notably embedded) targets.
4081 * New command "generate-core-file" (or "gcore").
4083 This new gdb command allows the user to drop a core file of the child
4084 process state at any time. So far it's been implemented only for
4085 GNU/Linux and Solaris, but should be relatively easily ported to other
4086 hosts. Argument is core file name (defaults to core.<pid>).
4088 * New command line option
4090 GDB now accepts --pid or -p followed by a process id.
4092 * Change in command line behavior -- corefiles vs. process ids.
4094 There is a subtle behavior in the way in which GDB handles
4095 command line arguments. The first non-flag argument is always
4096 a program to debug, but the second non-flag argument may either
4097 be a corefile or a process id. Previously, GDB would attempt to
4098 open the second argument as a corefile, and if that failed, would
4099 issue a superfluous error message and then attempt to attach it as
4100 a process. Now, if the second argument begins with a non-digit,
4101 it will be treated as a corefile. If it begins with a digit,
4102 GDB will attempt to attach it as a process, and if no such process
4103 is found, will then attempt to open it as a corefile.
4105 * Changes in ARM configurations.
4107 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4108 configuration is fully multi-arch.
4110 * New native configurations
4112 ARM NetBSD arm*-*-netbsd*
4113 x86 OpenBSD i[3456]86-*-openbsd*
4114 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4115 Sparc64 running FreeBSD sparc64-*-freebsd*
4119 Sanyo XStormy16 xstormy16-elf
4121 * OBSOLETE configurations and files
4123 Configurations that have been declared obsolete in this release have
4124 been commented out. Unless there is activity to revive these
4125 configurations, the next release of GDB will have their sources
4126 permanently REMOVED.
4128 AMD 29k family via UDI a29k-amd-udi, udi29k
4129 A29K VxWorks a29k-*-vxworks
4130 AMD 29000 embedded, using EBMON a29k-none-none
4131 AMD 29000 embedded with COFF a29k-none-coff
4132 AMD 29000 embedded with a.out a29k-none-aout
4134 testsuite/gdb.hp/gdb.threads-hp/ directory
4136 * REMOVED configurations and files
4138 TI TMS320C80 tic80-*-*
4140 PowerPC Solaris powerpcle-*-solaris*
4141 PowerPC Windows NT powerpcle-*-cygwin32
4142 PowerPC Netware powerpc-*-netware*
4143 Harris/CXUX m88k m88*-harris-cxux*
4144 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4145 ns32k-utek-sysv* ns32k-utek-*
4146 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4147 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4148 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4149 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4150 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4152 * Changes to command line processing
4154 The new `--args' feature can be used to specify command-line arguments
4155 for the inferior from gdb's command line.
4157 * Changes to key bindings
4159 There is a new `operate-and-get-next' function bound to `C-o'.
4161 *** Changes in GDB 5.1.1
4163 Fix compile problem on DJGPP.
4165 Fix a problem with floating-point registers on the i386 being
4168 Fix to stop GDB crashing on .debug_str debug info.
4170 Numerous documentation fixes.
4172 Numerous testsuite fixes.
4174 *** Changes in GDB 5.1:
4176 * New native configurations
4178 Alpha FreeBSD alpha*-*-freebsd*
4179 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4180 MIPS GNU/Linux mips*-*-linux*
4181 MIPS SGI Irix 6.x mips*-sgi-irix6*
4182 ia64 AIX ia64-*-aix*
4183 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4187 Motorola 68HC11 and 68HC12 m68hc11-elf
4189 UltraSparc running GNU/Linux sparc64-*-linux*
4191 * OBSOLETE configurations and files
4193 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4194 Harris/CXUX m88k m88*-harris-cxux*
4195 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4196 ns32k-utek-sysv* ns32k-utek-*
4197 TI TMS320C80 tic80-*-*
4199 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4200 PowerPC Solaris powerpcle-*-solaris*
4201 PowerPC Windows NT powerpcle-*-cygwin32
4202 PowerPC Netware powerpc-*-netware*
4203 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4204 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4205 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4206 Apple Macintosh (MPW) host N/A
4208 stuff.c (Program to stuff files into a specially prepared space in kdb)
4209 kdb-start.c (Main loop for the standalone kernel debugger)
4211 Configurations that have been declared obsolete in this release have
4212 been commented out. Unless there is activity to revive these
4213 configurations, the next release of GDB will have their sources
4214 permanently REMOVED.
4216 * REMOVED configurations and files
4218 Altos 3068 m68*-altos-*
4219 Convex c1-*-*, c2-*-*
4221 ARM RISCix arm-*-* (as host)
4225 * GDB has been converted to ISO C.
4227 GDB's source code has been converted to ISO C. In particular, the
4228 sources are fully protoized, and rely on standard headers being
4233 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4235 * The MI enabled by default.
4237 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4238 revised and enabled by default. Packages which use GDB as a debugging
4239 engine behind a UI or another front end are encouraged to switch to
4240 using the GDB/MI interface, instead of the old annotations interface
4241 which is now deprecated.
4243 * Support for debugging Pascal programs.
4245 GDB now includes support for debugging Pascal programs. The following
4246 main features are supported:
4248 - Pascal-specific data types such as sets;
4250 - automatic recognition of Pascal sources based on file-name
4253 - Pascal-style display of data types, variables, and functions;
4255 - a Pascal expression parser.
4257 However, some important features are not yet supported.
4259 - Pascal string operations are not supported at all;
4261 - there are some problems with boolean types;
4263 - Pascal type hexadecimal constants are not supported
4264 because they conflict with the internal variables format;
4266 - support for Pascal objects and classes is not full yet;
4268 - unlike Pascal, GDB is case-sensitive for symbol names.
4270 * Changes in completion.
4272 Commands such as `shell', `run' and `set args', which pass arguments
4273 to inferior programs, now complete on file names, similar to what
4274 users expect at the shell prompt.
4276 Commands which accept locations, such as `disassemble', `print',
4277 `breakpoint', `until', etc. now complete on filenames as well as
4278 program symbols. Thus, if you type "break foob TAB", and the source
4279 files linked into the programs include `foobar.c', that file name will
4280 be one of the candidates for completion. However, file names are not
4281 considered for completion after you typed a colon that delimits a file
4282 name from a name of a function in that file, as in "break foo.c:bar".
4284 `set demangle-style' completes on available demangling styles.
4286 * New platform-independent commands:
4288 It is now possible to define a post-hook for a command as well as a
4289 hook that runs before the command. For more details, see the
4290 documentation of `hookpost' in the GDB manual.
4292 * Changes in GNU/Linux native debugging.
4294 Support for debugging multi-threaded programs has been completely
4295 revised for all platforms except m68k and sparc. You can now debug as
4296 many threads as your system allows you to have.
4298 Attach/detach is supported for multi-threaded programs.
4300 Support for SSE registers was added for x86. This doesn't work for
4301 multi-threaded programs though.
4303 * Changes in MIPS configurations.
4305 Multi-arch support is enabled for all MIPS configurations.
4307 GDB can now be built as native debugger on SGI Irix 6.x systems for
4308 debugging n32 executables. (Debugging 64-bit executables is not yet
4311 * Unified support for hardware watchpoints in all x86 configurations.
4313 Most (if not all) native x86 configurations support hardware-assisted
4314 breakpoints and watchpoints in a unified manner. This support
4315 implements debug register sharing between watchpoints, which allows to
4316 put a virtually infinite number of watchpoints on the same address,
4317 and also supports watching regions up to 16 bytes with several debug
4320 The new maintenance command `maintenance show-debug-regs' toggles
4321 debugging print-outs in functions that insert, remove, and test
4322 watchpoints and hardware breakpoints.
4324 * Changes in the DJGPP native configuration.
4326 New command ``info dos sysinfo'' displays assorted information about
4327 the CPU, OS, memory, and DPMI server.
4329 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4330 display information about segment descriptors stored in GDT, LDT, and
4333 New commands ``info dos pde'' and ``info dos pte'' display entries
4334 from Page Directory and Page Tables (for now works with CWSDPMI only).
4335 New command ``info dos address-pte'' displays the Page Table entry for
4336 a given linear address.
4338 GDB can now pass command lines longer than 126 characters to the
4339 program being debugged (requires an update to the libdbg.a library
4340 which is part of the DJGPP development kit).
4342 DWARF2 debug info is now supported.
4344 It is now possible to `step' and `next' through calls to `longjmp'.
4346 * Changes in documentation.
4348 All GDB documentation was converted to GFDL, the GNU Free
4349 Documentation License.
4351 Tracepoints-related commands are now fully documented in the GDB
4354 TUI, the Text-mode User Interface, is now documented in the manual.
4356 Tracepoints-related commands are now fully documented in the GDB
4359 The "GDB Internals" manual now has an index. It also includes
4360 documentation of `ui_out' functions, GDB coding standards, x86
4361 hardware watchpoints, and memory region attributes.
4363 * GDB's version number moved to ``version.in''
4365 The Makefile variable VERSION has been replaced by the file
4366 ``version.in''. People creating GDB distributions should update the
4367 contents of this file.
4371 GUD support is now a standard part of the EMACS distribution.
4373 *** Changes in GDB 5.0:
4375 * Improved support for debugging FP programs on x86 targets
4377 Unified and much-improved support for debugging floating-point
4378 programs on all x86 targets. In particular, ``info float'' now
4379 displays the FP registers in the same format on all x86 targets, with
4380 greater level of detail.
4382 * Improvements and bugfixes in hardware-assisted watchpoints
4384 It is now possible to watch array elements, struct members, and
4385 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4386 on x86 targets no longer erroneously trigger when the address is
4389 * Improvements in the native DJGPP version of GDB
4391 The distribution now includes all the scripts and auxiliary files
4392 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4393 machines ``out of the box''.
4395 The DJGPP version can now debug programs that use signals. It is
4396 possible to catch signals that happened in the debuggee, deliver
4397 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4398 would kill the program being debugged.) Programs that hook hardware
4399 interrupts (keyboard, timer, etc.) can also be debugged.
4401 It is now possible to debug DJGPP programs that redirect their
4402 standard handles or switch them to raw (as opposed to cooked) mode, or
4403 even close them. The command ``run < foo > bar'' works as expected,
4404 and ``info terminal'' reports useful information about the debuggee's
4405 terminal, including raw/cooked mode, redirection, etc.
4407 The DJGPP version now uses termios functions for console I/O, which
4408 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4411 DOS-style file names with drive letters are now fully supported by
4414 It is now possible to debug DJGPP programs that switch their working
4415 directory. It is also possible to rerun the debuggee any number of
4416 times without restarting GDB; thus, you can use the same setup,
4417 breakpoints, etc. for many debugging sessions.
4419 * New native configurations
4421 ARM GNU/Linux arm*-*-linux*
4422 PowerPC GNU/Linux powerpc-*-linux*
4426 Motorola MCore mcore-*-*
4427 x86 VxWorks i[3456]86-*-vxworks*
4428 PowerPC VxWorks powerpc-*-vxworks*
4429 TI TMS320C80 tic80-*-*
4431 * OBSOLETE configurations
4433 Altos 3068 m68*-altos-*
4434 Convex c1-*-*, c2-*-*
4436 ARM RISCix arm-*-* (as host)
4439 Configurations that have been declared obsolete will be commented out,
4440 but the code will be left in place. If there is no activity to revive
4441 these configurations before the next release of GDB, the sources will
4442 be permanently REMOVED.
4444 * Gould support removed
4446 Support for the Gould PowerNode and NP1 has been removed.
4448 * New features for SVR4
4450 On SVR4 native platforms (such as Solaris), if you attach to a process
4451 without first loading a symbol file, GDB will now attempt to locate and
4452 load symbols from the running process's executable file.
4454 * Many C++ enhancements
4456 C++ support has been greatly improved. Overload resolution now works properly
4457 in almost all cases. RTTI support is on the way.
4459 * Remote targets can connect to a sub-program
4461 A popen(3) style serial-device has been added. This device starts a
4462 sub-process (such as a stand-alone simulator) and then communicates
4463 with that. The sub-program to run is specified using the syntax
4464 ``|<program> <args>'' vis:
4466 (gdb) set remotedebug 1
4467 (gdb) target extended-remote |mn10300-elf-sim program-args
4469 * MIPS 64 remote protocol
4471 A long standing bug in the mips64 remote protocol where by GDB
4472 expected certain 32 bit registers (ex SR) to be transfered as 32
4473 instead of 64 bits has been fixed.
4475 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4476 added to provide backward compatibility with older versions of GDB.
4478 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4480 The command ``set remotebinarydownload'' command has been replaced by
4481 ``set remote X-packet''. Other commands in ``set remote'' family
4482 include ``set remote P-packet''.
4484 * Breakpoint commands accept ranges.
4486 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4487 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4488 ``tracepoint passcount'' also accepts a range of tracepoints.
4490 * ``apropos'' command added.
4492 The ``apropos'' command searches through command names and
4493 documentation strings, printing out matches, making it much easier to
4494 try to find a command that does what you are looking for.
4498 A new machine oriented interface (MI) has been added to GDB. This
4499 interface is designed for debug environments running GDB as a separate
4500 process. This is part of the long term libGDB project. See the
4501 "GDB/MI" chapter of the GDB manual for further information. It can be
4502 enabled by configuring with:
4504 .../configure --enable-gdbmi
4506 *** Changes in GDB-4.18:
4508 * New native configurations
4510 HP-UX 10.20 hppa*-*-hpux10.20
4511 HP-UX 11.x hppa*-*-hpux11.0*
4512 M68K GNU/Linux m68*-*-linux*
4516 Fujitsu FR30 fr30-*-elf*
4517 Intel StrongARM strongarm-*-*
4518 Mitsubishi D30V d30v-*-*
4520 * OBSOLETE configurations
4522 Gould PowerNode, NP1 np1-*-*, pn-*-*
4524 Configurations that have been declared obsolete will be commented out,
4525 but the code will be left in place. If there is no activity to revive
4526 these configurations before the next release of GDB, the sources will
4527 be permanently REMOVED.
4531 As a compatibility experiment, GDB's source files buildsym.h and
4532 buildsym.c have been converted to pure standard C, no longer
4533 containing any K&R compatibility code. We believe that all systems in
4534 use today either come with a standard C compiler, or have a GCC port
4535 available. If this is not true, please report the affected
4536 configuration to bug-gdb@gnu.org immediately. See the README file for
4537 information about getting a standard C compiler if you don't have one
4542 GDB now uses readline 2.2.
4544 * set extension-language
4546 You can now control the mapping between filename extensions and source
4547 languages by using the `set extension-language' command. For instance,
4548 you can ask GDB to treat .c files as C++ by saying
4549 set extension-language .c c++
4550 The command `info extensions' lists all of the recognized extensions
4551 and their associated languages.
4553 * Setting processor type for PowerPC and RS/6000
4555 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4556 you can use the `set processor' command to specify what variant of the
4557 PowerPC family you are debugging. The command
4561 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4562 following PowerPC and RS6000 variants:
4564 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4565 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4567 403GC IBM PowerPC 403GC
4568 505 Motorola PowerPC 505
4569 860 Motorola PowerPC 860 or 850
4570 601 Motorola PowerPC 601
4571 602 Motorola PowerPC 602
4572 603 Motorola/IBM PowerPC 603 or 603e
4573 604 Motorola PowerPC 604 or 604e
4574 750 Motorola/IBM PowerPC 750 or 750
4576 At the moment, this command just tells GDB what to name the
4577 special-purpose processor registers. Since almost all the affected
4578 registers are inaccessible to user-level programs, this command is
4579 only useful for remote debugging in its present form.
4583 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4584 more extensive support for HP-UX. Added features include shared
4585 library support, kernel threads and hardware watchpoints for 11.00,
4586 support for HP's ANSI C and C++ compilers, and a compatibility mode
4587 for xdb and dbx commands.
4591 HP's donation includes the new concept of catchpoints, which is a
4592 generalization of the old catch command. On HP-UX, it is now possible
4593 to catch exec, fork, and vfork, as well as library loading.
4595 This means that the existing catch command has changed; its first
4596 argument now specifies the type of catch to be set up. See the
4597 output of "help catch" for a list of catchpoint types.
4599 * Debugging across forks
4601 On HP-UX, you can choose which process to debug when a fork() happens
4606 HP has donated a curses-based terminal user interface (TUI). To get
4607 it, build with --enable-tui. Although this can be enabled for any
4608 configuration, at present it only works for native HP debugging.
4610 * GDB remote protocol additions
4612 A new protocol packet 'X' that writes binary data is now available.
4613 Default behavior is to try 'X', then drop back to 'M' if the stub
4614 fails to respond. The settable variable `remotebinarydownload'
4615 allows explicit control over the use of 'X'.
4617 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4618 full 64-bit address. The command
4620 set remoteaddresssize 32
4622 can be used to revert to the old behaviour. For existing remote stubs
4623 the change should not be noticed, as the additional address information
4626 In order to assist in debugging stubs, you may use the maintenance
4627 command `packet' to send any text string to the stub. For instance,
4629 maint packet heythere
4631 sends the packet "$heythere#<checksum>". Note that it is very easy to
4632 disrupt a debugging session by sending the wrong packet at the wrong
4635 The compare-sections command allows you to compare section data on the
4636 target to what is in the executable file without uploading or
4637 downloading, by comparing CRC checksums.
4639 * Tracing can collect general expressions
4641 You may now collect general expressions at tracepoints. This requires
4642 further additions to the target-side stub; see tracepoint.c and
4643 doc/agentexpr.texi for further details.
4645 * mask-address variable for Mips
4647 For Mips targets, you may control the zeroing of the upper 32 bits of
4648 a 64-bit address by entering `set mask-address on'. This is mainly
4649 of interest to users of embedded R4xxx and R5xxx processors.
4651 * Higher serial baud rates
4653 GDB's serial code now allows you to specify baud rates 57600, 115200,
4654 230400, and 460800 baud. (Note that your host system may not be able
4655 to achieve all of these rates.)
4659 The i960 configuration now includes an initial implementation of a
4660 builtin simulator, contributed by Jim Wilson.
4663 *** Changes in GDB-4.17:
4665 * New native configurations
4667 Alpha GNU/Linux alpha*-*-linux*
4668 Unixware 2.x i[3456]86-unixware2*
4669 Irix 6.x mips*-sgi-irix6*
4670 PowerPC GNU/Linux powerpc-*-linux*
4671 PowerPC Solaris powerpcle-*-solaris*
4672 Sparc GNU/Linux sparc-*-linux*
4673 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4677 Argonaut Risc Chip (ARC) arc-*-*
4678 Hitachi H8/300S h8300*-*-*
4679 Matsushita MN10200 w/simulator mn10200-*-*
4680 Matsushita MN10300 w/simulator mn10300-*-*
4681 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4682 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4683 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4684 Mitsubishi D10V w/simulator d10v-*-*
4685 Mitsubishi M32R/D w/simulator m32r-*-elf*
4686 Tsqware Sparclet sparclet-*-*
4687 NEC V850 w/simulator v850-*-*
4689 * New debugging protocols
4691 ARM with RDI protocol arm*-*-*
4692 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4693 DDB and LSI variants of PMON protocol mips*-*-*
4694 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4695 PowerPC with SDS protocol powerpc{,le}-*-eabi
4696 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4700 All configurations can now understand and use the DWARF 2 debugging
4701 format. The choice is automatic, if the symbol file contains DWARF 2
4706 GDB now includes basic Java language support. This support is
4707 only useful with Java compilers that produce native machine code.
4709 * solib-absolute-prefix and solib-search-path
4711 For SunOS and SVR4 shared libraries, you may now set the prefix for
4712 loading absolute shared library symbol files, and the search path for
4713 locating non-absolute shared library symbol files.
4715 * Live range splitting
4717 GDB can now effectively debug code for which GCC has performed live
4718 range splitting as part of its optimization. See gdb/doc/LRS for
4719 more details on the expected format of the stabs information.
4723 GDB's support for the GNU Hurd, including thread debugging, has been
4724 updated to work with current versions of the Hurd.
4728 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4729 instruction set. ARM GDB automatically detects when Thumb
4730 instructions are in use, and adjusts disassembly and backtracing
4735 GDB's MIPS target configurations now handle the MIP16 16-bit
4740 GDB now includes support for overlays; if an executable has been
4741 linked such that multiple sections are based at the same address, GDB
4742 will decide which section to use for symbolic info. You can choose to
4743 control the decision manually, using overlay commands, or implement
4744 additional target-side support and use "overlay load-target" to bring
4745 in the overlay mapping. Do "help overlay" for more detail.
4749 The command "info symbol <address>" displays information about
4750 the symbol at the specified address.
4754 The standard remote protocol now includes an extension that allows
4755 asynchronous collection and display of trace data. This requires
4756 extensive support in the target-side debugging stub. Tracing mode
4757 includes a new interaction mode in GDB and new commands: see the
4758 file tracepoint.c for more details.
4762 Configurations for embedded MIPS now include a simulator contributed
4763 by Cygnus Solutions. The simulator supports the instruction sets
4764 of most MIPS variants.
4768 Sparc configurations may now include the ERC32 simulator contributed
4769 by the European Space Agency. The simulator is not built into
4770 Sparc targets by default; configure with --enable-sim to include it.
4774 For target configurations that may include multiple variants of a
4775 basic architecture (such as MIPS and SH), you may now set the
4776 architecture explicitly. "set arch" sets, "info arch" lists
4777 the possible architectures.
4779 *** Changes in GDB-4.16:
4781 * New native configurations
4783 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4784 M68K NetBSD m68k-*-netbsd*
4785 PowerPC AIX 4.x powerpc-*-aix*
4786 PowerPC MacOS powerpc-*-macos*
4787 PowerPC Windows NT powerpcle-*-cygwin32
4788 RS/6000 AIX 4.x rs6000-*-aix4*
4792 ARM with RDP protocol arm-*-*
4793 I960 with MON960 i960-*-coff
4794 MIPS VxWorks mips*-*-vxworks*
4795 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4796 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4798 Matra Sparclet sparclet-*-*
4802 The powerpc-eabi configuration now includes the PSIM simulator,
4803 contributed by Andrew Cagney, with assistance from Mike Meissner.
4804 PSIM is a very elaborate model of the PowerPC, including not only
4805 basic instruction set execution, but also details of execution unit
4806 performance and I/O hardware. See sim/ppc/README for more details.
4810 GDB now works with Solaris 2.5.
4812 * Windows 95/NT native
4814 GDB will now work as a native debugger on Windows 95 and Windows NT.
4815 To build it from source, you must use the "gnu-win32" environment,
4816 which uses a DLL to emulate enough of Unix to run the GNU tools.
4817 Further information, binaries, and sources are available at
4818 ftp.cygnus.com, under pub/gnu-win32.
4820 * dont-repeat command
4822 If a user-defined command includes the command `dont-repeat', then the
4823 command will not be repeated if the user just types return. This is
4824 useful if the command is time-consuming to run, so that accidental
4825 extra keystrokes don't run the same command many times.
4827 * Send break instead of ^C
4829 The standard remote protocol now includes an option to send a break
4830 rather than a ^C to the target in order to interrupt it. By default,
4831 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4833 * Remote protocol timeout
4835 The standard remote protocol includes a new variable `remotetimeout'
4836 that allows you to set the number of seconds before GDB gives up trying
4837 to read from the target. The default value is 2.
4839 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4841 By default GDB will automatically keep track of objects as they are
4842 loaded and unloaded by the dynamic linker. By using the command `set
4843 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4844 when shared library events occur, thus allowing you to set breakpoints
4845 in shared libraries which are explicitly loaded by the inferior.
4847 Note this feature does not work on hpux8. On hpux9 you must link
4848 /usr/lib/end.o into your program. This feature should work
4849 automatically on hpux10.
4851 * Irix 5.x hardware watchpoint support
4853 Irix 5 configurations now support the use of hardware watchpoints.
4855 * Mips protocol "SYN garbage limit"
4857 When debugging a Mips target using the `target mips' protocol, you
4858 may set the number of characters that GDB will ignore by setting
4859 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4860 every character. The default value is 1050.
4862 * Recording and replaying remote debug sessions
4864 If you set `remotelogfile' to the name of a file, gdb will write to it
4865 a recording of a remote debug session. This recording may then be
4866 replayed back to gdb using "gdbreplay". See gdbserver/README for
4867 details. This is useful when you have a problem with GDB while doing
4868 remote debugging; you can make a recording of the session and send it
4869 to someone else, who can then recreate the problem.
4871 * Speedups for remote debugging
4873 GDB includes speedups for downloading and stepping MIPS systems using
4874 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4875 and more efficient S-record downloading.
4877 * Memory use reductions and statistics collection
4879 GDB now uses less memory and reports statistics about memory usage.
4880 Try the `maint print statistics' command, for example.
4882 *** Changes in GDB-4.15:
4884 * Psymtabs for XCOFF
4886 The symbol reader for AIX GDB now uses partial symbol tables. This
4887 can greatly improve startup time, especially for large executables.
4889 * Remote targets use caching
4891 Remote targets now use a data cache to speed up communication with the
4892 remote side. The data cache could lead to incorrect results because
4893 it doesn't know about volatile variables, thus making it impossible to
4894 debug targets which use memory mapped I/O devices. `set remotecache
4895 off' turns the the data cache off.
4897 * Remote targets may have threads
4899 The standard remote protocol now includes support for multiple threads
4900 in the target system, using new protocol commands 'H' and 'T'. See
4901 gdb/remote.c for details.
4905 If GDB is configured with `--enable-netrom', then it will include
4906 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4907 acts as though it is a bank of ROM on the target board, but you can
4908 write into it over the network. GDB's support consists only of
4909 support for fast loading into the emulated ROM; to debug, you must use
4910 another protocol, such as standard remote protocol. The usual
4911 sequence is something like
4913 target nrom <netrom-hostname>
4915 target remote <netrom-hostname>:1235
4919 GDB now includes support for the Apple Macintosh, as a host only. It
4920 may be run as either an MPW tool or as a standalone application, and
4921 it can debug through the serial port. All the usual GDB commands are
4922 available, but to the target command, you must supply "serial" as the
4923 device type instead of "/dev/ttyXX". See mpw-README in the main
4924 directory for more information on how to build. The MPW configuration
4925 scripts */mpw-config.in support only a few targets, and only the
4926 mips-idt-ecoff target has been tested.
4930 GDB configuration now uses autoconf. This is not user-visible,
4931 but does simplify configuration and building.
4935 GDB now supports hpux10.
4937 *** Changes in GDB-4.14:
4939 * New native configurations
4941 x86 FreeBSD i[345]86-*-freebsd
4942 x86 NetBSD i[345]86-*-netbsd
4943 NS32k NetBSD ns32k-*-netbsd
4944 Sparc NetBSD sparc-*-netbsd
4948 A29K VxWorks a29k-*-vxworks
4949 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4950 CPU32 EST-300 emulator m68*-*-est*
4951 PowerPC ELF powerpc-*-elf
4954 * Alpha OSF/1 support for procfs
4956 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4957 possible to attach to running processes. As the mounting of the /proc
4958 filesystem is optional on the Alpha, GDB automatically determines
4959 the availability of /proc during startup. This can lead to problems
4960 if /proc is unmounted after GDB has been started.
4962 * Arguments to user-defined commands
4964 User commands may accept up to 10 arguments separated by whitespace.
4965 Arguments are accessed within the user command via $arg0..$arg9. A
4968 print $arg0 + $arg1 + $arg2
4970 To execute the command use:
4973 Defines the command "adder" which prints the sum of its three arguments.
4974 Note the arguments are text substitutions, so they may reference variables,
4975 use complex expressions, or even perform inferior function calls.
4977 * New `if' and `while' commands
4979 This makes it possible to write more sophisticated user-defined
4980 commands. Both commands take a single argument, which is the
4981 expression to evaluate, and must be followed by the commands to
4982 execute, one per line, if the expression is nonzero, the list being
4983 terminated by the word `end'. The `if' command list may include an
4984 `else' word, which causes the following commands to be executed only
4985 if the expression is zero.
4987 * Fortran source language mode
4989 GDB now includes partial support for Fortran 77. It will recognize
4990 Fortran programs and can evaluate a subset of Fortran expressions, but
4991 variables and functions may not be handled correctly. GDB will work
4992 with G77, but does not yet know much about symbols emitted by other
4995 * Better HPUX support
4997 Most debugging facilities now work on dynamic executables for HPPAs
4998 running hpux9 or later. You can attach to running dynamically linked
4999 processes, but by default the dynamic libraries will be read-only, so
5000 for instance you won't be able to put breakpoints in them. To change
5001 that behavior do the following before running the program:
5007 This will cause the libraries to be mapped private and read-write.
5008 To revert to the normal behavior, do this:
5014 You cannot set breakpoints or examine data in the library until after
5015 the library is loaded if the function/data symbols do not have
5018 GDB can now also read debug symbols produced by the HP C compiler on
5019 HPPAs (sorry, no C++, Fortran or 68k support).
5021 * Target byte order now dynamically selectable
5023 You can choose which byte order to use with a target system, via the
5024 commands "set endian big" and "set endian little", and you can see the
5025 current setting by using "show endian". You can also give the command
5026 "set endian auto", in which case GDB will use the byte order
5027 associated with the executable. Currently, only embedded MIPS
5028 configurations support dynamic selection of target byte order.
5030 * New DOS host serial code
5032 This version uses DPMI interrupts to handle buffered I/O, so you
5033 no longer need to run asynctsr when debugging boards connected to
5036 *** Changes in GDB-4.13:
5038 * New "complete" command
5040 This lists all the possible completions for the rest of the line, if it
5041 were to be given as a command itself. This is intended for use by emacs.
5043 * Trailing space optional in prompt
5045 "set prompt" no longer adds a space for you after the prompt you set. This
5046 allows you to set a prompt which ends in a space or one that does not.
5048 * Breakpoint hit counts
5050 "info break" now displays a count of the number of times the breakpoint
5051 has been hit. This is especially useful in conjunction with "ignore"; you
5052 can ignore a large number of breakpoint hits, look at the breakpoint info
5053 to see how many times the breakpoint was hit, then run again, ignoring one
5054 less than that number, and this will get you quickly to the last hit of
5057 * Ability to stop printing at NULL character
5059 "set print null-stop" will cause GDB to stop printing the characters of
5060 an array when the first NULL is encountered. This is useful when large
5061 arrays actually contain only short strings.
5063 * Shared library breakpoints
5065 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5066 breakpoints in shared libraries before the executable is run.
5068 * Hardware watchpoints
5070 There is a new hardware breakpoint for the watch command for sparclite
5071 targets. See gdb/sparclite/hw_breakpoint.note.
5073 Hardware watchpoints are also now supported under GNU/Linux.
5077 Annotations have been added. These are for use with graphical interfaces,
5078 and are still experimental. Currently only gdba.el uses these.
5080 * Improved Irix 5 support
5082 GDB now works properly with Irix 5.2.
5084 * Improved HPPA support
5086 GDB now works properly with the latest GCC and GAS.
5088 * New native configurations
5090 Sequent PTX4 i[34]86-sequent-ptx4
5091 HPPA running OSF/1 hppa*-*-osf*
5092 Atari TT running SVR4 m68*-*-sysv4*
5093 RS/6000 LynxOS rs6000-*-lynxos*
5097 OS/9000 i[34]86-*-os9k
5098 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5101 * Hitachi SH7000 and E7000-PC ICE support
5103 There is now support for communicating with the Hitachi E7000-PC ICE.
5104 This is available automatically when GDB is configured for the SH.
5108 As usual, a variety of small fixes and improvements, both generic
5109 and configuration-specific. See the ChangeLog for more detail.
5111 *** Changes in GDB-4.12:
5113 * Irix 5 is now supported
5117 GDB-4.12 on the HPPA has a number of changes which make it unable
5118 to debug the output from the currently released versions of GCC and
5119 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5120 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5121 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5124 *** Changes in GDB-4.11:
5126 * User visible changes:
5130 The "set remotedebug" option is now consistent between the mips remote
5131 target, remote targets using the gdb-specific protocol, UDI (AMD's
5132 debug protocol for the 29k) and the 88k bug monitor. It is now an
5133 integer specifying a debug level (normally 0 or 1, but 2 means more
5134 debugging info for the mips target).
5136 * DEC Alpha native support
5138 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5139 debug info, but GDB works fairly well with the DEC compiler and should
5140 work with a future GCC release. See the README file for a few
5141 Alpha-specific notes.
5143 * Preliminary thread implementation
5145 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5147 * LynxOS native and target support for 386
5149 This release has been hosted on LynxOS 2.2, and also can be configured
5150 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5153 * Improvements in C++ mangling/demangling.
5155 This release has much better g++ debugging, specifically in name
5156 mangling/demangling, virtual function calls, print virtual table,
5157 call methods, ...etc.
5159 *** Changes in GDB-4.10:
5161 * User visible changes:
5163 Remote debugging using the GDB-specific (`target remote') protocol now
5164 supports the `load' command. This is only useful if you have some
5165 other way of getting the stub to the target system, and you can put it
5166 somewhere in memory where it won't get clobbered by the download.
5168 Filename completion now works.
5170 When run under emacs mode, the "info line" command now causes the
5171 arrow to point to the line specified. Also, "info line" prints
5172 addresses in symbolic form (as well as hex).
5174 All vxworks based targets now support a user settable option, called
5175 vxworks-timeout. This option represents the number of seconds gdb
5176 should wait for responses to rpc's. You might want to use this if
5177 your vxworks target is, perhaps, a slow software simulator or happens
5178 to be on the far side of a thin network line.
5182 This release contains support for using a DEC alpha as a GDB host for
5183 cross debugging. Native alpha debugging is not supported yet.
5186 *** Changes in GDB-4.9:
5190 This is the first GDB release which is accompanied by a matching testsuite.
5191 The testsuite requires installation of dejagnu, which should be available
5192 via ftp from most sites that carry GNU software.
5196 'Cfront' style demangling has had its name changed to 'ARM' style, to
5197 emphasize that it was written from the specifications in the C++ Annotated
5198 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5199 disclaimers, it still generated too much confusion with users attempting to
5200 use gdb with AT&T cfront.
5204 GDB now uses a standard remote interface to a simulator library.
5205 So far, the library contains simulators for the Zilog Z8001/2, the
5206 Hitachi H8/300, H8/500 and Super-H.
5208 * New targets supported
5210 H8/300 simulator h8300-hitachi-hms or h8300hms
5211 H8/500 simulator h8500-hitachi-hms or h8500hms
5212 SH simulator sh-hitachi-hms or sh
5213 Z8000 simulator z8k-zilog-none or z8ksim
5214 IDT MIPS board over serial line mips-idt-ecoff
5216 Cross-debugging to GO32 targets is supported. It requires a custom
5217 version of the i386-stub.c module which is integrated with the
5218 GO32 memory extender.
5220 * New remote protocols
5222 MIPS remote debugging protocol.
5224 * New source languages supported
5226 This version includes preliminary support for Chill, a Pascal like language
5227 used by telecommunications companies. Chill support is also being integrated
5228 into the GNU compiler, but we don't know when it will be publically available.
5231 *** Changes in GDB-4.8:
5233 * HP Precision Architecture supported
5235 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5236 version of this support was available as a set of patches from the
5237 University of Utah. GDB does not support debugging of programs
5238 compiled with the HP compiler, because HP will not document their file
5239 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5240 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5242 Many problems in the preliminary version have been fixed.
5244 * Faster and better demangling
5246 We have improved template demangling and fixed numerous bugs in the GNU style
5247 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5248 character types (wchar_t) are now supported. Demangling of each symbol is now
5249 only done once, and is cached when the symbol table for a file is read in.
5250 This results in a small increase in memory usage for C programs, a moderate
5251 increase in memory usage for C++ programs, and a fantastic speedup in
5254 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5255 from the specifications in the Annotated Reference Manual, which AT&T's
5256 compiler does not actually implement.
5258 * G++ multiple inheritance compiler problem
5260 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5261 inheritance lattices was reworked to properly discover ambiguities. We
5262 recently found an example which causes this new algorithm to fail in a
5263 very subtle way, producing bad debug information for those classes.
5264 The file 'gcc.patch' (in this directory) can be applied to gcc to
5265 circumvent the problem. A future GCC release will contain a complete
5268 The previous G++ debug info problem (mentioned below for the gdb-4.7
5269 release) is fixed in gcc version 2.3.2.
5271 * Improved configure script
5273 The `configure' script will now attempt to guess your system type if
5274 you don't supply a host system type. The old scheme of supplying a
5275 host system triplet is preferable over using this. All the magic is
5276 done in the new `config.guess' script. Examine it for details.
5278 We have also brought our configure script much more in line with the FSF's
5279 version. It now supports the --with-xxx options. In particular,
5280 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5281 The resulting GDB will not be able to read arbitrary object file formats --
5282 only the format ``expected'' to be used on the configured target system.
5283 We hope to make this the default in a future release.
5285 * Documentation improvements
5287 There's new internal documentation on how to modify GDB, and how to
5288 produce clean changes to the code. We implore people to read it
5289 before submitting changes.
5291 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5292 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5293 `info' files are also provided. To build `info' files from scratch,
5294 you will need the latest `makeinfo' release, which will be available in
5295 a future texinfo-X.Y release.
5297 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5298 We're not sure exactly which versions have this problem, but it has
5299 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5300 or better. If that isn't possible, there is a patch in
5301 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5302 around this problem.
5306 GDB now supports array constants that can be used in expressions typed in by
5307 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5308 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5311 The new directory `gdb/sparclite' contains a program that demonstrates
5312 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5314 * New native hosts supported
5316 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5317 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5319 * New targets supported
5321 AMD 29k family via UDI a29k-amd-udi or udi29k
5323 * New file formats supported
5325 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5326 HPUX core files, and SCO 3.2v2 core files.
5330 Attaching to processes now works again; thanks for the many bug reports.
5332 We have also stomped on a bunch of core dumps caused by
5333 printf_filtered("%s") problems.
5335 We eliminated a copyright problem on the rpc and ptrace header files
5336 for VxWorks, which was discovered at the last minute during the 4.7
5337 release. You should now be able to build a VxWorks GDB.
5339 You can now interrupt gdb while an attached process is running. This
5340 will cause the attached process to stop, and give control back to GDB.
5342 We fixed problems caused by using too many file descriptors
5343 for reading symbols from object files and libraries. This was
5344 especially a problem for programs that used many (~100) shared
5347 The `step' command now only enters a subroutine if there is line number
5348 information for the subroutine. Otherwise it acts like the `next'
5349 command. Previously, `step' would enter subroutines if there was
5350 any debugging information about the routine. This avoids problems
5351 when using `cc -g1' on MIPS machines.
5353 * Internal improvements
5355 GDB's internal interfaces have been improved to make it easier to support
5356 debugging of multiple languages in the future.
5358 GDB now uses a common structure for symbol information internally.
5359 Minimal symbols (derived from linkage symbols in object files), partial
5360 symbols (from a quick scan of debug information), and full symbols
5361 contain a common subset of information, making it easier to write
5362 shared code that handles any of them.
5364 * New command line options
5366 We now accept --silent as an alias for --quiet.
5370 The memory-mapped-malloc library is now licensed under the GNU Library
5371 General Public License.
5373 *** Changes in GDB-4.7:
5375 * Host/native/target split
5377 GDB has had some major internal surgery to untangle the support for
5378 hosts and remote targets. Now, when you configure GDB for a remote
5379 target, it will no longer load in all of the support for debugging
5380 local programs on the host. When fully completed and tested, this will
5381 ensure that arbitrary host/target combinations are possible.
5383 The primary conceptual shift is to separate the non-portable code in
5384 GDB into three categories. Host specific code is required any time GDB
5385 is compiled on that host, regardless of the target. Target specific
5386 code relates to the peculiarities of the target, but can be compiled on
5387 any host. Native specific code is everything else: it can only be
5388 built when the host and target are the same system. Child process
5389 handling and core file support are two common `native' examples.
5391 GDB's use of /proc for controlling Unix child processes is now cleaner.
5392 It has been split out into a single module under the `target_ops' vector,
5393 plus two native-dependent functions for each system that uses /proc.
5395 * New hosts supported
5397 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5398 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5399 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5401 * New targets supported
5403 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5404 68030 and CPU32 m68030-*-*, m68332-*-*
5406 * New native hosts supported
5408 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5409 (386bsd is not well tested yet)
5410 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5412 * New file formats supported
5414 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5415 supports reading of `a.out.adobe' object files, which are an a.out
5416 format extended with minimal information about multiple sections.
5420 `show copying' is the same as the old `info copying'.
5421 `show warranty' is the same as `info warrantee'.
5422 These were renamed for consistency. The old commands continue to work.
5424 `info handle' is a new alias for `info signals'.
5426 You can now define pre-command hooks, which attach arbitrary command
5427 scripts to any command. The commands in the hook will be executed
5428 prior to the user's command. You can also create a hook which will be
5429 executed whenever the program stops. See gdb.texinfo.
5433 We now deal with Cfront style name mangling, and can even extract type
5434 info from mangled symbols. GDB can automatically figure out which
5435 symbol mangling style your C++ compiler uses.
5437 Calling of methods and virtual functions has been improved as well.
5441 The crash that occured when debugging Sun Ansi-C compiled binaries is
5442 fixed. This was due to mishandling of the extra N_SO stabs output
5445 We also finally got Ultrix 4.2 running in house, and fixed core file
5446 support, with help from a dozen people on the net.
5448 John M. Farrell discovered that the reason that single-stepping was so
5449 slow on all of the Mips based platforms (primarily SGI and DEC) was
5450 that we were trying to demangle and lookup a symbol used for internal
5451 purposes on every instruction that was being stepped through. Changing
5452 the name of that symbol so that it couldn't be mistaken for a C++
5453 mangled symbol sped things up a great deal.
5455 Rich Pixley sped up symbol lookups in general by getting much smarter
5456 about when C++ symbol mangling is necessary. This should make symbol
5457 completion (TAB on the command line) much faster. It's not as fast as
5458 we'd like, but it's significantly faster than gdb-4.6.
5462 A new user controllable variable 'call_scratch_address' can
5463 specify the location of a scratch area to be used when GDB
5464 calls a function in the target. This is necessary because the
5465 usual method of putting the scratch area on the stack does not work
5466 in systems that have separate instruction and data spaces.
5468 We integrated changes to support the 29k UDI (Universal Debugger
5469 Interface), but discovered at the last minute that we didn't have all
5470 of the appropriate copyright paperwork. We are working with AMD to
5471 resolve this, and hope to have it available soon.
5475 We have sped up the remote serial line protocol, especially for targets
5476 with lots of registers. It now supports a new `expedited status' ('T')
5477 message which can be used in place of the existing 'S' status message.
5478 This allows the remote stub to send only the registers that GDB
5479 needs to make a quick decision about single-stepping or conditional
5480 breakpoints, eliminating the need to fetch the entire register set for
5481 each instruction being stepped through.
5483 The GDB remote serial protocol now implements a write-through cache for
5484 registers, only re-reading the registers if the target has run.
5486 There is also a new remote serial stub for SPARC processors. You can
5487 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5488 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5489 processor with a serial port.
5493 Configure.in files have become much easier to read and modify. A new
5494 `table driven' format makes it more obvious what configurations are
5495 supported, and what files each one uses.
5499 There is a new opcodes library which will eventually contain all of the
5500 disassembly routines and opcode tables. At present, it only contains
5501 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5502 disassembler (binutils/objdump) to share these routines.
5504 The libiberty library is now copylefted under the GNU Library General
5505 Public License. This allows more liberal use, and was done so libg++
5506 can use it. This makes no difference to GDB, since the Library License
5507 grants all the rights from the General Public License.
5511 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5512 reference to the stabs symbol info used by the debugger. It is (as far
5513 as we know) the only published document on this fascinating topic. We
5514 encourage you to read it, compare it to the stabs information on your
5515 system, and send improvements on the document in general (to
5516 bug-gdb@prep.ai.mit.edu).
5518 And, of course, many bugs have been fixed.
5521 *** Changes in GDB-4.6:
5523 * Better support for C++ function names
5525 GDB now accepts as input the "demangled form" of C++ overloaded function
5526 names and member function names, and can do command completion on such names
5527 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5528 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5529 Make use of command completion, it is your friend.
5531 GDB also now accepts a variety of C++ mangled symbol formats. They are
5532 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5533 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5534 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5535 for the list of formats.
5537 * G++ symbol mangling problem
5539 Recent versions of gcc have a bug in how they emit debugging information for
5540 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5541 directory) can be applied to gcc to fix the problem. Alternatively, if you
5542 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5543 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5544 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5547 * New 'maintenance' command
5549 All of the commands related to hacking GDB internals have been moved out of
5550 the main command set, and now live behind the 'maintenance' command. This
5551 can also be abbreviated as 'mt'. The following changes were made:
5553 dump-me -> maintenance dump-me
5554 info all-breakpoints -> maintenance info breakpoints
5555 printmsyms -> maintenance print msyms
5556 printobjfiles -> maintenance print objfiles
5557 printpsyms -> maintenance print psymbols
5558 printsyms -> maintenance print symbols
5560 The following commands are new:
5562 maintenance demangle Call internal GDB demangler routine to
5563 demangle a C++ link name and prints the result.
5564 maintenance print type Print a type chain for a given symbol
5566 * Change to .gdbinit file processing
5568 We now read the $HOME/.gdbinit file before processing the argv arguments
5569 (e.g. reading symbol files or core files). This allows global parameters to
5570 be set, which will apply during the symbol reading. The ./.gdbinit is still
5571 read after argv processing.
5573 * New hosts supported
5575 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5577 GNU/Linux support i386-unknown-linux or linux
5579 We are also including code to support the HP/PA running BSD and HPUX. This
5580 is almost guaranteed not to work, as we didn't have time to test or build it
5581 for this release. We are including it so that the more adventurous (or
5582 masochistic) of you can play with it. We also had major problems with the
5583 fact that the compiler that we got from HP doesn't support the -g option.
5586 * New targets supported
5588 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5590 * More smarts about finding #include files
5592 GDB now remembers the compilation directory for all include files, and for
5593 all files from which C is generated (like yacc and lex sources). This
5594 greatly improves GDB's ability to find yacc/lex sources, and include files,
5595 especially if you are debugging your program from a directory different from
5596 the one that contains your sources.
5598 We also fixed a bug which caused difficulty with listing and setting
5599 breakpoints in include files which contain C code. (In the past, you had to
5600 try twice in order to list an include file that you hadn't looked at before.)
5602 * Interesting infernals change
5604 GDB now deals with arbitrary numbers of sections, where the symbols for each
5605 section must be relocated relative to that section's landing place in the
5606 target's address space. This work was needed to support ELF with embedded
5607 stabs used by Solaris-2.0.
5609 * Bug fixes (of course!)
5611 There have been loads of fixes for the following things:
5612 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5613 i960, stabs, DOS(GO32), procfs, etc...
5615 See the ChangeLog for details.
5617 *** Changes in GDB-4.5:
5619 * New machines supported (host and target)
5621 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5623 SGI Irix-4.x mips-sgi-irix4 or iris4
5625 * New malloc package
5627 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5628 Mmalloc is capable of handling mutiple heaps of memory. It is also
5629 capable of saving a heap to a file, and then mapping it back in later.
5630 This can be used to greatly speedup the startup of GDB by using a
5631 pre-parsed symbol table which lives in a mmalloc managed heap. For
5632 more details, please read mmalloc/mmalloc.texi.
5636 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5637 'help info proc' for details.
5639 * MIPS ecoff symbol table format
5641 The code that reads MIPS symbol table format is now supported on all hosts.
5642 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5645 * File name changes for MS-DOS
5647 Many files in the config directories have been renamed to make it easier to
5648 support GDB on MS-DOSe systems (which have very restrictive file name
5649 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5650 environment) is close to working but has some remaining problems. Note
5651 that debugging of DOS programs is not supported, due to limitations
5652 in the ``operating system'', but it can be used to host cross-debugging.
5654 * Cross byte order fixes
5656 Many fixes have been made to support cross debugging of Sparc and MIPS
5657 targets from hosts whose byte order differs.
5659 * New -mapped and -readnow options
5661 If memory-mapped files are available on your system through the 'mmap'
5662 system call, you can use the -mapped option on the `file' or
5663 `symbol-file' commands to cause GDB to write the symbols from your
5664 program into a reusable file. If the program you are debugging is
5665 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5666 Future GDB debugging sessions will notice the presence of this file,
5667 and will quickly map in symbol information from it, rather than reading
5668 the symbol table from the executable program. Using the '-mapped'
5669 option in a GDB `file' or `symbol-file' command has the same effect as
5670 starting GDB with the '-mapped' command-line option.
5672 You can cause GDB to read the entire symbol table immediately by using
5673 the '-readnow' option with any of the commands that load symbol table
5674 information (or on the GDB command line). This makes the command
5675 slower, but makes future operations faster.
5677 The -mapped and -readnow options are typically combined in order to
5678 build a `fred.syms' file that contains complete symbol information.
5679 A simple GDB invocation to do nothing but build a `.syms' file for future
5682 gdb -batch -nx -mapped -readnow programname
5684 The `.syms' file is specific to the host machine on which GDB is run.
5685 It holds an exact image of GDB's internal symbol table. It cannot be
5686 shared across multiple host platforms.
5688 * longjmp() handling
5690 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5691 siglongjmp() without losing control. This feature has not yet been ported to
5692 all systems. It currently works on many 386 platforms, all MIPS-based
5693 platforms (SGI, DECstation, etc), and Sun3/4.
5697 Preliminary work has been put in to support the new Solaris OS from Sun. At
5698 this time, it can control and debug processes, but it is not capable of
5703 As always, many many bug fixes. The major areas were with g++, and mipsread.
5704 People using the MIPS-based platforms should experience fewer mysterious
5705 crashes and trashed symbol tables.
5707 *** Changes in GDB-4.4:
5709 * New machines supported (host and target)
5711 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5713 BSD Reno on Vax vax-dec-bsd
5714 Ultrix on Vax vax-dec-ultrix
5716 * New machines supported (target)
5718 AMD 29000 embedded, using EBMON a29k-none-none
5722 GDB continues to improve its handling of C++. `References' work better.
5723 The demangler has also been improved, and now deals with symbols mangled as
5724 per the Annotated C++ Reference Guide.
5726 GDB also now handles `stabs' symbol information embedded in MIPS
5727 `ecoff' symbol tables. Since the ecoff format was not easily
5728 extensible to handle new languages such as C++, this appeared to be a
5729 good way to put C++ debugging info into MIPS binaries. This option
5730 will be supported in the GNU C compiler, version 2, when it is
5733 * New features for SVR4
5735 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5736 shared libraries. Debugging dynamically linked programs should present
5737 only minor differences from debugging statically linked programs.
5739 The `info proc' command will print out information about any process
5740 on an SVR4 system (including the one you are debugging). At the moment,
5741 it prints the address mappings of the process.
5743 If you bring up GDB on another SVR4 system, please send mail to
5744 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5746 * Better dynamic linking support in SunOS
5748 Reading symbols from shared libraries which contain debugging symbols
5749 now works properly. However, there remain issues such as automatic
5750 skipping of `transfer vector' code during function calls, which
5751 make it harder to debug code in a shared library, than to debug the
5752 same code linked statically.
5756 GDB is now using the latest `getopt' routines from the FSF. This
5757 version accepts the -- prefix for options with long names. GDB will
5758 continue to accept the old forms (-option and +option) as well.
5759 Various single letter abbreviations for options have been explicity
5760 added to the option table so that they won't get overshadowed in the
5761 future by other options that begin with the same letter.
5765 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5766 Many assorted bugs have been handled. Many more remain to be handled.
5767 See the various ChangeLog files (primarily in gdb and bfd) for details.
5770 *** Changes in GDB-4.3:
5772 * New machines supported (host and target)
5774 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5775 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5776 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5778 * Almost SCO Unix support
5780 We had hoped to support:
5781 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5782 (except for core file support), but we discovered very late in the release
5783 that it has problems with process groups that render gdb unusable. Sorry
5784 about that. I encourage people to fix it and post the fixes.
5786 * Preliminary ELF and DWARF support
5788 GDB can read ELF object files on System V Release 4, and can handle
5789 debugging records for C, in DWARF format, in ELF files. This support
5790 is preliminary. If you bring up GDB on another SVR4 system, please
5791 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5796 GDB now uses the latest `readline' library. One user-visible change
5797 is that two tabs will list possible command completions, which previously
5798 required typing M-? (meta-question mark, or ESC ?).
5802 The `stepi' bug that many of you noticed has been squashed.
5803 Many bugs in C++ have been handled. Many more remain to be handled.
5804 See the various ChangeLog files (primarily in gdb and bfd) for details.
5806 * State of the MIPS world (in case you wondered):
5808 GDB can understand the symbol tables emitted by the compilers
5809 supplied by most vendors of MIPS-based machines, including DEC. These
5810 symbol tables are in a format that essentially nobody else uses.
5812 Some versions of gcc come with an assembler post-processor called
5813 mips-tfile. This program is required if you want to do source-level
5814 debugging of gcc-compiled programs. I believe FSF does not ship
5815 mips-tfile with gcc version 1, but it will eventually come with gcc
5818 Debugging of g++ output remains a problem. g++ version 1.xx does not
5819 really support it at all. (If you're lucky, you should be able to get
5820 line numbers and stack traces to work, but no parameters or local
5821 variables.) With some work it should be possible to improve the
5824 When gcc version 2 is released, you will have somewhat better luck.
5825 However, even then you will get confusing results for inheritance and
5828 We will eventually provide full debugging of g++ output on
5829 DECstations. This will probably involve some kind of stabs-in-ecoff
5830 encapulation, but the details have not been worked out yet.
5833 *** Changes in GDB-4.2:
5835 * Improved configuration
5837 Only one copy of `configure' exists now, and it is not self-modifying.
5838 Porting BFD is simpler.
5842 The `step' and `next' commands now only stop at the first instruction
5843 of a source line. This prevents the multiple stops that used to occur
5844 in switch statements, for-loops, etc. `Step' continues to stop if a
5845 function that has debugging information is called within the line.
5849 Lots of small bugs fixed. More remain.
5851 * New host supported (not target)
5853 Intel 386 PC clone running Mach i386-none-mach
5856 *** Changes in GDB-4.1:
5858 * Multiple source language support
5860 GDB now has internal scaffolding to handle several source languages.
5861 It determines the type of each source file from its filename extension,
5862 and will switch expression parsing and number formatting to match the
5863 language of the function in the currently selected stack frame.
5864 You can also specifically set the language to be used, with
5865 `set language c' or `set language modula-2'.
5869 GDB now has preliminary support for the GNU Modula-2 compiler,
5870 currently under development at the State University of New York at
5871 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5872 continue through the fall of 1991 and into 1992.
5874 Other Modula-2 compilers are currently not supported, and attempting to
5875 debug programs compiled with them will likely result in an error as the
5876 symbol table is read. Feel free to work on it, though!
5878 There are hooks in GDB for strict type checking and range checking,
5879 in the `Modula-2 philosophy', but they do not currently work.
5883 GDB can now write to executable and core files (e.g. patch
5884 a variable's value). You must turn this switch on, specify
5885 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5886 by assigning a new value to a variable. Modifications take
5889 * Automatic SunOS shared library reading
5891 When you run your program, GDB automatically determines where its
5892 shared libraries (if any) have been loaded, and reads their symbols.
5893 The `share' command is no longer needed. This also works when
5894 examining core files.
5898 You can specify the number of lines that the `list' command shows.
5901 * New machines supported (host and target)
5903 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5904 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5905 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5907 * New hosts supported (not targets)
5909 IBM RT/PC: romp-ibm-aix or rtpc
5911 * New targets supported (not hosts)
5913 AMD 29000 embedded with COFF a29k-none-coff
5914 AMD 29000 embedded with a.out a29k-none-aout
5915 Ultracomputer remote kernel debug a29k-nyu-kern
5917 * New remote interfaces
5923 *** Changes in GDB-4.0:
5927 Wide output is wrapped at good places to make the output more readable.
5929 Gdb now supports cross-debugging from a host machine of one type to a
5930 target machine of another type. Communication with the target system
5931 is over serial lines. The ``target'' command handles connecting to the
5932 remote system; the ``load'' command will download a program into the
5933 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5934 also supports debugging of realtime processes running under VxWorks,
5935 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5936 stub on the target system.
5938 New CPUs supported include the AMD 29000 and Intel 960.
5940 GDB now reads object files and symbol tables via a ``binary file''
5941 library, which allows a single copy of GDB to debug programs of multiple
5942 object file types such as a.out and coff.
5944 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5945 refcard.dvi and refcard.ps are available to format it).
5948 * Control-Variable user interface simplified
5950 All variables that control the operation of the debugger can be set
5951 by the ``set'' command, and displayed by the ``show'' command.
5953 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5954 ``Show prompt'' produces the response:
5955 Gdb's prompt is new-gdb=>.
5957 What follows are the NEW set commands. The command ``help set'' will
5958 print a complete list of old and new set commands. ``help set FOO''
5959 will give a longer description of the variable FOO. ``show'' will show
5960 all of the variable descriptions and their current settings.
5962 confirm on/off: Enables warning questions for operations that are
5963 hard to recover from, e.g. rerunning the program while
5964 it is already running. Default is ON.
5966 editing on/off: Enables EMACS style command line editing
5967 of input. Previous lines can be recalled with
5968 control-P, the current line can be edited with control-B,
5969 you can search for commands with control-R, etc.
5972 history filename NAME: NAME is where the gdb command history
5973 will be stored. The default is .gdb_history,
5974 or the value of the environment variable
5977 history size N: The size, in commands, of the command history. The
5978 default is 256, or the value of the environment variable
5981 history save on/off: If this value is set to ON, the history file will
5982 be saved after exiting gdb. If set to OFF, the
5983 file will not be saved. The default is OFF.
5985 history expansion on/off: If this value is set to ON, then csh-like
5986 history expansion will be performed on
5987 command line input. The default is OFF.
5989 radix N: Sets the default radix for input and output. It can be set
5990 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5991 in the current radix, so "set radix 10" is always a no-op.
5993 height N: This integer value is the number of lines on a page. Default
5994 is 24, the current `stty rows'' setting, or the ``li#''
5995 setting from the termcap entry matching the environment
5998 width N: This integer value is the number of characters on a line.
5999 Default is 80, the current `stty cols'' setting, or the ``co#''
6000 setting from the termcap entry matching the environment
6003 Note: ``set screensize'' is obsolete. Use ``set height'' and
6004 ``set width'' instead.
6006 print address on/off: Print memory addresses in various command displays,
6007 such as stack traces and structure values. Gdb looks
6008 more ``symbolic'' if you turn this off; it looks more
6009 ``machine level'' with it on. Default is ON.
6011 print array on/off: Prettyprint arrays. New convenient format! Default
6014 print demangle on/off: Print C++ symbols in "source" form if on,
6017 print asm-demangle on/off: Same, for assembler level printouts
6020 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6023 * Support for Epoch Environment.
6025 The epoch environment is a version of Emacs v18 with windowing. One
6026 new command, ``inspect'', is identical to ``print'', except that if you
6027 are running in the epoch environment, the value is printed in its own
6031 * Support for Shared Libraries
6033 GDB can now debug programs and core files that use SunOS shared libraries.
6034 Symbols from a shared library cannot be referenced
6035 before the shared library has been linked with the program (this
6036 happens after you type ``run'' and before the function main() is entered).
6037 At any time after this linking (including when examining core files
6038 from dynamically linked programs), gdb reads the symbols from each
6039 shared library when you type the ``sharedlibrary'' command.
6040 It can be abbreviated ``share''.
6042 sharedlibrary REGEXP: Load shared object library symbols for files
6043 matching a unix regular expression. No argument
6044 indicates to load symbols for all shared libraries.
6046 info sharedlibrary: Status of loaded shared libraries.
6051 A watchpoint stops execution of a program whenever the value of an
6052 expression changes. Checking for this slows down execution
6053 tremendously whenever you are in the scope of the expression, but is
6054 quite useful for catching tough ``bit-spreader'' or pointer misuse
6055 problems. Some machines such as the 386 have hardware for doing this
6056 more quickly, and future versions of gdb will use this hardware.
6058 watch EXP: Set a watchpoint (breakpoint) for an expression.
6060 info watchpoints: Information about your watchpoints.
6062 delete N: Deletes watchpoint number N (same as breakpoints).
6063 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6064 enable N: Re-enables watchpoint number N (same as breakpoints).
6067 * C++ multiple inheritance
6069 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6072 * C++ exception handling
6074 Gdb now supports limited C++ exception handling. Besides the existing
6075 ability to breakpoint on an exception handler, gdb can breakpoint on
6076 the raising of an exception (before the stack is peeled back to the
6079 catch FOO: If there is a FOO exception handler in the dynamic scope,
6080 set a breakpoint to catch exceptions which may be raised there.
6081 Multiple exceptions (``catch foo bar baz'') may be caught.
6083 info catch: Lists all exceptions which may be caught in the
6084 current stack frame.
6087 * Minor command changes
6089 The command ``call func (arg, arg, ...)'' now acts like the print
6090 command, except it does not print or save a value if the function's result
6091 is void. This is similar to dbx usage.
6093 The ``up'' and ``down'' commands now always print the frame they end up
6094 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6095 frames without printing.
6097 * New directory command
6099 'dir' now adds directories to the FRONT of the source search path.
6100 The path starts off empty. Source files that contain debug information
6101 about the directory in which they were compiled can be found even
6102 with an empty path; Sun CC and GCC include this information. If GDB can't
6103 find your source file in the current directory, type "dir .".
6105 * Configuring GDB for compilation
6107 For normal use, type ``./configure host''. See README or gdb.texinfo
6110 GDB now handles cross debugging. If you are remotely debugging between
6111 two different machines, type ``./configure host -target=targ''.
6112 Host is the machine where GDB will run; targ is the machine
6113 where the program that you are debugging will run.