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.
55 * On GNU/Linux, GDB and gdbserver are now able to access executable
56 and shared library files without a "set sysroot" command when
57 attaching to processes running in different mount namespaces from
58 the debugger. This makes it possible to attach to processes in
59 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
60 See "New remote packets" below.
62 * The "tui reg" command now provides completion for all of the
63 available register groups, including target specific groups.
67 ** Memory ports can now be unbuffered.
71 ** gdb.Objfile objects have a new attribute "username",
72 which is the name of the objfile as specified by the user,
73 without, for example, resolving symlinks.
74 ** You can now write frame unwinders in Python.
75 ** gdb.Type objects have a new method "optimized_out",
76 returning optimized out gdb.Value instance of this type.
77 ** gdb.Value objects have new methods "reference_value" and
78 "const_value" which return a reference to the value and a
79 "const" version of the value respectively.
83 maint print symbol-cache
84 Print the contents of the symbol cache.
86 maint print symbol-cache-statistics
87 Print statistics of symbol cache usage.
89 maint flush-symbol-cache
90 Flush the contents of the symbol cache.
94 Start branch trace recording using Branch Trace Store (BTS) format.
97 Evaluate expression by using the compiler and print result.
101 Explicit commands for enabling and disabling tui mode.
104 set mpx bound on i386 and amd64
105 Support for bound table investigation on Intel(R) MPX enabled applications.
110 Renamed from "set debug dwarf2-die".
112 Renamed from "show debug dwarf2-die".
115 Renamed from "set debug dwarf2-read".
116 show debug dwarf-read
117 Renamed from "show debug dwarf2-read".
119 maint set dwarf always-disassemble
120 Renamed from "maint set dwarf2 always-disassemble".
121 maint show dwarf always-disassemble
122 Renamed from "maint show dwarf2 always-disassemble".
124 maint set dwarf max-cache-age
125 Renamed from "maint set dwarf2 max-cache-age".
126 maint show dwarf max-cache-age
127 Renamed from "maint show dwarf2 max-cache-age".
130 show debug dwarf-line
131 Control display of debugging info regarding DWARF line processing.
135 Set the maximum number of candidates to be considered during
136 completion. The default value is 200. This limit allows GDB
137 to avoid generating large completion lists, the computation of
138 which can cause the debugger to become temporarily unresponsive.
140 maint set symbol-cache-size
141 maint show symbol-cache-size
142 Control the size of the symbol cache.
144 set|show record btrace bts buffer-size
145 Set and show the size of the ring buffer used for branch tracing in
147 The obtained size may differ from the requested size. Use "info
148 record" to see the obtained buffer size.
150 set debug linux-namespaces
151 show debug linux-namespaces
152 Control display of debugging info regarding Linux namespaces.
154 * The command 'thread apply all' can now support new option '-ascending'
155 to call its specified command for all threads in ascending order.
157 * Python/Guile scripting
159 ** GDB now supports auto-loading of Python/Guile scripts contained in the
160 special section named `.debug_gdb_scripts'.
164 qXfer:btrace-conf:read
165 Return the branch trace configuration for the current thread.
167 Qbtrace-conf:bts:size
168 Set the requested ring buffer size for branch tracing in BTS format.
171 Indicates a memory breakpoint instruction was executed, irrespective
172 of whether it was GDB that planted the breakpoint or the breakpoint
173 is hardcoded in the program. This is required for correct non-stop
177 Indicates the target stopped for a hardware breakpoint. This is
178 required for correct non-stop mode operation.
181 Return information about files on the remote system.
184 Return the full absolute name of the file that was executed to
185 create a process running on the remote system.
188 Select the filesystem on which vFile: operations with filename
189 arguments will operate. This is required for GDB to be able to
190 access files on remote targets where the remote stub does not
191 share a common filesystem with the inferior(s).
194 Indicates that a fork system call was executed.
197 Indicates that a vfork system call was executed.
199 vforkdone stop reason
200 Indicates that a vfork child of the specified process has executed
201 an exec or exit, allowing the vfork parent to resume execution.
203 fork-events and vfork-events features in qSupported
204 The qSupported packet allows GDB to request support for fork and
205 vfork events using new 'gdbfeatures' fork-events and vfork-events,
206 and the qSupported response can contain the corresponding
207 'stubfeatures'. Set and show commands can be used to display
208 whether these features are enabled.
210 * Extended-remote fork events
212 ** GDB now has support for fork events on extended-remote Linux
213 targets. For targets with Linux kernels 2.5.60 and later, this
214 enables follow-fork-mode and detach-on-fork for both fork and
215 vfork, as well as fork and vfork catchpoints.
217 * The info record command now shows the recording format and the
218 branch tracing configuration for the current thread when using
219 the btrace record target.
220 For the BTS format, it shows the ring buffer size.
222 * GDB now has support for DTrace USDT (Userland Static Defined
223 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
225 * GDB now supports access to vector registers on S/390 GNU/Linux
228 * Removed command line options
230 -xdb HP-UX XDB compatibility mode.
232 * Removed targets and native configurations
234 HP/PA running HP-UX hppa*-*-hpux*
235 Itanium running HP-UX ia64-*-hpux*
237 *** Changes in GDB 7.9.1
241 ** Xmethods can now specify a result type.
243 *** Changes in GDB 7.9
245 * GDB now supports hardware watchpoints on x86 GNU Hurd.
249 ** You can now access frame registers from Python scripts.
250 ** New attribute 'producer' for gdb.Symtab objects.
251 ** gdb.Objfile objects have a new attribute "progspace",
252 which is the gdb.Progspace object of the containing program space.
253 ** gdb.Objfile objects have a new attribute "owner".
254 ** gdb.Objfile objects have a new attribute "build_id",
255 which is the build ID generated when the file was built.
256 ** gdb.Objfile objects have a new method "add_separate_debug_file".
257 ** A new event "gdb.clear_objfiles" has been added, triggered when
258 selecting a new file to debug.
259 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
260 ** New function gdb.lookup_objfile.
262 New events which are triggered when GDB modifies the state of the
265 ** gdb.events.inferior_call_pre: Function call is about to be made.
266 ** gdb.events.inferior_call_post: Function call has just been made.
267 ** gdb.events.memory_changed: A memory location has been altered.
268 ** gdb.events.register_changed: A register has been altered.
270 * New Python-based convenience functions:
272 ** $_caller_is(name [, number_of_frames])
273 ** $_caller_matches(regexp [, number_of_frames])
274 ** $_any_caller_is(name [, number_of_frames])
275 ** $_any_caller_matches(regexp [, number_of_frames])
277 * GDB now supports the compilation and injection of source code into
278 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
279 to compile the source code to object code, and if successful, inject
280 and execute that code within the current context of the inferior.
281 Currently the C language is supported. The commands used to
282 interface with this new feature are:
284 compile code [-raw|-r] [--] [source code]
285 compile file [-raw|-r] filename
289 demangle [-l language] [--] name
290 Demangle "name" in the specified language, or the current language
291 if elided. This command is renamed from the "maint demangle" command.
292 The latter is kept as a no-op to avoid "maint demangle" being interpreted
293 as "maint demangler-warning".
295 queue-signal signal-name-or-number
296 Queue a signal to be delivered to the thread when it is resumed.
298 add-auto-load-scripts-directory directory
299 Add entries to the list of directories from which to load auto-loaded
302 maint print user-registers
303 List all currently available "user" registers.
305 compile code [-r|-raw] [--] [source code]
306 Compile, inject, and execute in the inferior the executable object
307 code produced by compiling the provided source code.
309 compile file [-r|-raw] filename
310 Compile and inject into the inferior the executable object code
311 produced by compiling the source code stored in the filename
314 * On resume, GDB now always passes the signal the program had stopped
315 for to the thread the signal was sent to, even if the user changed
316 threads before resuming. Previously GDB would often (but not
317 always) deliver the signal to the thread that happens to be current
320 * Conversely, the "signal" command now consistently delivers the
321 requested signal to the current thread. GDB now asks for
322 confirmation if the program had stopped for a signal and the user
323 switched threads meanwhile.
325 * "breakpoint always-inserted" modes "off" and "auto" merged.
327 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
328 won't remove breakpoints from the target until all threads stop,
329 even in non-stop mode. The "auto" mode has been removed, and "off"
330 is now the default mode.
334 set debug symbol-lookup
335 show debug symbol-lookup
336 Control display of debugging info regarding symbol lookup.
340 ** The -list-thread-groups command outputs an exit-code field for
341 inferiors that have exited.
345 MIPS SDE mips*-sde*-elf*
349 Support for these obsolete configurations has been removed.
351 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
352 SGI Irix-5.x mips-*-irix5*
353 SGI Irix-6.x mips-*-irix6*
354 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
355 VAX running Ultrix vax-*-ultrix*
357 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
358 and "assf"), have been removed. Use the "sharedlibrary" command, or
359 its alias "share", instead.
361 *** Changes in GDB 7.8
363 * New command line options
366 This is an alias for the --data-directory option.
368 * GDB supports printing and modifying of variable length automatic arrays
369 as specified in ISO C99.
371 * The ARM simulator now supports instruction level tracing
372 with or without disassembly.
376 GDB now has support for scripting using Guile. Whether this is
377 available is determined at configure time.
378 Guile version 2.0 or greater is required.
379 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
381 * New commands (for set/show, see "New options" below)
385 Invoke CODE by passing it to the Guile interpreter.
389 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
391 info auto-load guile-scripts [regexp]
392 Print the list of automatically loaded Guile scripts.
394 * The source command is now capable of sourcing Guile scripts.
395 This feature is dependent on the debugger being built with Guile support.
399 set print symbol-loading (off|brief|full)
400 show print symbol-loading
401 Control whether to print informational messages when loading symbol
402 information for a file. The default is "full", but when debugging
403 programs with large numbers of shared libraries the amount of output
406 set guile print-stack (none|message|full)
407 show guile print-stack
408 Show a stack trace when an error is encountered in a Guile script.
410 set auto-load guile-scripts (on|off)
411 show auto-load guile-scripts
412 Control auto-loading of Guile script files.
414 maint ada set ignore-descriptive-types (on|off)
415 maint ada show ignore-descriptive-types
416 Control whether the debugger should ignore descriptive types in Ada
417 programs. The default is not to ignore the descriptive types. See
418 the user manual for more details on descriptive types and the intended
419 usage of this option.
421 set auto-connect-native-target
423 Control whether GDB is allowed to automatically connect to the
424 native target for the run, attach, etc. commands when not connected
425 to any target yet. See also "target native" below.
427 set record btrace replay-memory-access (read-only|read-write)
428 show record btrace replay-memory-access
429 Control what memory accesses are allowed during replay.
431 maint set target-async (on|off)
432 maint show target-async
433 This controls whether GDB targets operate in synchronous or
434 asynchronous mode. Normally the default is asynchronous, if it is
435 available; but this can be changed to more easily debug problems
436 occurring only in synchronous mode.
438 set mi-async (on|off)
440 Control whether MI asynchronous mode is preferred. This supersedes
441 "set target-async" of previous GDB versions.
443 * "set target-async" is deprecated as a CLI option and is now an alias
444 for "set mi-async" (only puts MI into async mode).
446 * Background execution commands (e.g., "c&", "s&", etc.) are now
447 possible ``out of the box'' if the target supports them. Previously
448 the user would need to explicitly enable the possibility with the
449 "set target-async on" command.
451 * New features in the GDB remote stub, GDBserver
453 ** New option --debug-format=option1[,option2,...] allows one to add
454 additional text to each output. At present only timestamps
455 are supported: --debug-format=timestamps.
456 Timestamps can also be turned on with the
457 "monitor set debug-format timestamps" command from GDB.
459 * The 'record instruction-history' command now starts counting instructions
460 at one. This also affects the instruction ranges reported by the
461 'record function-call-history' command when given the /i modifier.
463 * The command 'record function-call-history' supports a new modifier '/c' to
464 indent the function names based on their call stack depth.
465 The fields for the '/i' and '/l' modifier have been reordered.
466 The source line range is now prefixed with 'at'.
467 The instruction range is now prefixed with 'inst'.
468 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
469 "record instruction-history" and "list" commands.
471 * The ranges given as arguments to the 'record function-call-history' and
472 'record instruction-history' commands are now inclusive.
474 * The btrace record target now supports the 'record goto' command.
475 For locations inside the execution trace, the back trace is computed
476 based on the information stored in the execution trace.
478 * The btrace record target supports limited reverse execution and replay.
479 The target does not record data and therefore does not allow reading
482 * The "catch syscall" command now works on s390*-linux* targets.
484 * The "compare-sections" command is no longer specific to target
485 remote. It now works with all targets.
487 * All native targets are now consistently called "native".
488 Consequently, the "target child", "target GNU", "target djgpp",
489 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
490 commands have been replaced with "target native". The QNX/NTO port
491 leaves the "procfs" target in place and adds a "native" target for
492 consistency with other ports. The impact on users should be minimal
493 as these commands previously either throwed an error, or were
494 no-ops. The target's name is visible in the output of the following
495 commands: "help target", "info target", "info files", "maint print
498 * The "target native" command now connects to the native target. This
499 can be used to launch native programs even when "set
500 auto-connect-native-target" is set to off.
502 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.
504 * Support for Intel(R) AVX-512 registers on GNU/Linux.
505 Support displaying and modifying Intel(R) AVX-512 registers
506 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
510 qXfer:btrace:read's annex
511 The qXfer:btrace:read packet supports a new annex 'delta' to read
512 branch trace incrementally.
516 ** Valid Python operations on gdb.Value objects representing
517 structs/classes invoke the corresponding overloaded operators if
519 ** New `Xmethods' feature in the Python API. Xmethods are
520 additional methods or replacements for existing methods of a C++
521 class. This feature is useful for those cases where a method
522 defined in C++ source code could be inlined or optimized out by
523 the compiler, making it unavailable to GDB.
526 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
528 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
529 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
530 its alias "share", instead.
532 * The commands "set remotebaud" and "show remotebaud" are no longer
533 supported. Use "set serial baud" and "show serial baud" (respectively)
538 ** A new option "-gdb-set mi-async" replaces "-gdb-set
539 target-async". The latter is left as a deprecated alias of the
540 former for backward compatibility. If the target supports it,
541 CLI background execution commands are now always possible by
542 default, independently of whether the frontend stated a
543 preference for asynchronous execution with "-gdb-set mi-async".
544 Previously "-gdb-set target-async off" affected both MI execution
545 commands and CLI execution commands.
547 *** Changes in GDB 7.7
549 * Improved support for process record-replay and reverse debugging on
550 arm*-linux* targets. Support for thumb32 and syscall instruction
551 recording has been added.
553 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
555 * GDB now supports Fission DWP file format version 2.
556 http://gcc.gnu.org/wiki/DebugFission
558 * New convenience function "$_isvoid", to check whether an expression
559 is void. A void expression is an expression where the type of the
560 result is "void". For example, some convenience variables may be
561 "void" when evaluated (e.g., "$_exitcode" before the execution of
562 the program being debugged; or an undefined convenience variable).
563 Another example, when calling a function whose return type is
566 * The "maintenance print objfiles" command now takes an optional regexp.
568 * The "catch syscall" command now works on arm*-linux* targets.
570 * GDB now consistently shows "<not saved>" when printing values of
571 registers the debug info indicates have not been saved in the frame
572 and there's nowhere to retrieve them from
573 (callee-saved/call-clobbered registers):
578 (gdb) info registers rax
581 Before, the former would print "<optimized out>", and the latter
582 "*value not available*".
584 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
589 ** Frame filters and frame decorators have been added.
590 ** Temporary breakpoints are now supported.
591 ** Line tables representation has been added.
592 ** New attribute 'parent_type' for gdb.Field objects.
593 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
594 ** New attribute 'name' for gdb.Type objects.
598 Nios II ELF nios2*-*-elf
599 Nios II GNU/Linux nios2*-*-linux
600 Texas Instruments MSP430 msp430*-*-elf
602 * Removed native configurations
604 Support for these a.out NetBSD and OpenBSD obsolete configurations has
605 been removed. ELF variants of these configurations are kept supported.
607 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
608 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
609 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
610 i[34567]86-*-openbsd3.[0-3]
611 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
612 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
613 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
617 Like "catch throw", but catches a re-thrown exception.
619 Renamed from old "maint check-symtabs".
621 Perform consistency checks on symtabs.
623 Expand symtabs matching an optional regexp.
626 Display the details of GDB configure-time options.
628 maint set|show per-command
629 maint set|show per-command space
630 maint set|show per-command time
631 maint set|show per-command symtab
632 Enable display of per-command gdb resource usage.
634 remove-symbol-file FILENAME
635 remove-symbol-file -a ADDRESS
636 Remove a symbol file added via add-symbol-file. The file to remove
637 can be identified by its filename or by an address that lies within
638 the boundaries of this symbol file in memory.
641 info exceptions REGEXP
642 Display the list of Ada exceptions defined in the program being
643 debugged. If provided, only the exceptions whose names match REGEXP
648 set debug symfile off|on
650 Control display of debugging info regarding reading symbol files and
651 symbol tables within those files
653 set print raw frame-arguments
654 show print raw frame-arguments
655 Set/show whether to print frame arguments in raw mode,
656 disregarding any defined pretty-printers.
658 set remote trace-status-packet
659 show remote trace-status-packet
660 Set/show the use of remote protocol qTStatus packet.
664 Control display of debugging messages related to Nios II targets.
668 Control whether target-assisted range stepping is enabled.
670 set startup-with-shell
671 show startup-with-shell
672 Specifies whether Unix child processes are started via a shell or
677 Use the target memory cache for accesses to the code segment. This
678 improves performance of remote debugging (particularly disassembly).
680 * You can now use a literal value 'unlimited' for options that
681 interpret 0 or -1 as meaning "unlimited". E.g., "set
682 trace-buffer-size unlimited" is now an alias for "set
683 trace-buffer-size -1" and "set height unlimited" is now an alias for
686 * The "set debug symtab-create" debugging option of GDB has been changed to
687 accept a verbosity level. 0 means "off", 1 provides basic debugging
688 output, and values of 2 or greater provides more verbose output.
690 * New command-line options
692 Display the details of GDB configure-time options.
694 * The command 'tsave' can now support new option '-ctf' to save trace
695 buffer in Common Trace Format.
697 * Newly installed $prefix/bin/gcore acts as a shell interface for the
700 * GDB now implements the the C++ 'typeid' operator.
702 * The new convenience variable $_exception holds the exception being
703 thrown or caught at an exception-related catchpoint.
705 * The exception-related catchpoints, like "catch throw", now accept a
706 regular expression which can be used to filter exceptions by type.
708 * The new convenience variable $_exitsignal is automatically set to
709 the terminating signal number when the program being debugged dies
710 due to an uncaught signal.
714 ** All MI commands now accept an optional "--language" option.
715 Support for this feature can be verified by using the "-list-features"
716 command, which should contain "language-option".
718 ** The new command -info-gdb-mi-command allows the user to determine
719 whether a GDB/MI command is supported or not.
721 ** The "^error" result record returned when trying to execute an undefined
722 GDB/MI command now provides a variable named "code" whose content is the
723 "undefined-command" error code. Support for this feature can be verified
724 by using the "-list-features" command, which should contain
725 "undefined-command-error-code".
727 ** The -trace-save MI command can optionally save trace buffer in Common
730 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
732 ** The command -data-list-register-values now accepts an optional
733 "--skip-unavailable" option. When used, only the available registers
736 ** The new command -trace-frame-collected dumps collected variables,
737 computed expressions, tvars, memory and registers in a traceframe.
739 ** The commands -stack-list-locals, -stack-list-arguments and
740 -stack-list-variables now accept an option "--skip-unavailable".
741 When used, only the available locals or arguments are displayed.
743 ** The -exec-run command now accepts an optional "--start" option.
744 When used, the command follows the same semantics as the "start"
745 command, stopping the program's execution at the start of its
746 main subprogram. Support for this feature can be verified using
747 the "-list-features" command, which should contain
748 "exec-run-start-option".
750 ** The new commands -catch-assert and -catch-exceptions insert
751 catchpoints stopping the program when Ada exceptions are raised.
753 ** The new command -info-ada-exceptions provides the equivalent of
754 the new "info exceptions" command.
756 * New system-wide configuration scripts
757 A GDB installation now provides scripts suitable for use as system-wide
758 configuration scripts for the following systems:
762 * GDB now supports target-assigned range stepping with remote targets.
763 This improves the performance of stepping source lines by reducing
764 the number of control packets from/to GDB. See "New remote packets"
767 * GDB now understands the element 'tvar' in the XML traceframe info.
768 It has the id of the collected trace state variables.
770 * On S/390 targets that provide the transactional-execution feature,
771 the program interruption transaction diagnostic block (TDB) is now
772 represented as a number of additional "registers" in GDB.
778 The vCont packet supports a new 'r' action, that tells the remote
779 stub to step through an address range itself, without GDB
780 involvemement at each single-step.
782 qXfer:libraries-svr4:read's annex
783 The previously unused annex of the qXfer:libraries-svr4:read packet
784 is now used to support passing an argument list. The remote stub
785 reports support for this argument list to GDB's qSupported query.
786 The defined arguments are "start" and "prev", used to reduce work
787 necessary for library list updating, resulting in significant
790 * New features in the GDB remote stub, GDBserver
792 ** GDBserver now supports target-assisted range stepping. Currently
793 enabled on x86/x86_64 GNU/Linux targets.
795 ** GDBserver now adds element 'tvar' in the XML in the reply to
796 'qXfer:traceframe-info:read'. It has the id of the collected
797 trace state variables.
799 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
802 * New 'z' formatter for printing and examining memory, this displays the
803 value as hexadecimal zero padded on the left to the size of the type.
805 * GDB can now use Windows x64 unwinding data.
807 * The "set remotebaud" command has been replaced by "set serial baud".
808 Similarly, "show remotebaud" has been replaced by "show serial baud".
809 The "set remotebaud" and "show remotebaud" commands are still available
810 to provide backward compatibility with older versions of GDB.
812 *** Changes in GDB 7.6
814 * Target record has been renamed to record-full.
815 Record/replay is now enabled with the "record full" command.
816 This also affects settings that are associated with full record/replay
817 that have been moved from "set/show record" to "set/show record full":
819 set|show record full insn-number-max
820 set|show record full stop-at-limit
821 set|show record full memory-query
823 * A new record target "record-btrace" has been added. The new target
824 uses hardware support to record the control-flow of a process. It
825 does not support replaying the execution, but it implements the
826 below new commands for investigating the recorded execution log.
827 This new recording method can be enabled using:
831 The "record-btrace" target is only available on Intel Atom processors
832 and requires a Linux kernel 2.6.32 or later.
834 * Two new commands have been added for record/replay to give information
835 about the recorded execution without having to replay the execution.
836 The commands are only supported by "record btrace".
838 record instruction-history prints the execution history at
839 instruction granularity
841 record function-call-history prints the execution history at
844 * New native configurations
846 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
847 FreeBSD/powerpc powerpc*-*-freebsd
848 x86_64/Cygwin x86_64-*-cygwin*
849 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
853 ARM AArch64 aarch64*-*-elf
854 ARM AArch64 GNU/Linux aarch64*-*-linux
855 Lynx 178 PowerPC powerpc-*-lynx*178
856 x86_64/Cygwin x86_64-*-cygwin*
857 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
859 * If the configured location of system.gdbinit file (as given by the
860 --with-system-gdbinit option at configure time) is in the
861 data-directory (as specified by --with-gdb-datadir at configure
862 time) or in one of its subdirectories, then GDB will look for the
863 system-wide init file in the directory specified by the
864 --data-directory command-line option.
866 * New command line options:
868 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
869 other initialization files, unlike -nx which disables all of them.
871 * Removed command line options
873 -epoch This was used by the gdb mode in Epoch, an ancient fork of
876 * The 'ptype' and 'whatis' commands now accept an argument to control
879 * 'info proc' now works on some core files.
883 ** Vectors can be created with gdb.Type.vector.
885 ** Python's atexit.register now works in GDB.
887 ** Types can be pretty-printed via a Python API.
889 ** Python 3 is now supported (in addition to Python 2.4 or later)
891 ** New class gdb.Architecture exposes GDB's internal representation
892 of architecture in the Python API.
894 ** New method Frame.architecture returns the gdb.Architecture object
895 corresponding to the frame's architecture.
897 * New Python-based convenience functions:
899 ** $_memeq(buf1, buf2, length)
900 ** $_streq(str1, str2)
902 ** $_regex(str, regex)
904 * The 'cd' command now defaults to using '~' (the home directory) if not
907 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
908 default for GCC since November 2000.
910 * The command 'forward-search' can now be abbreviated as 'fo'.
912 * The command 'info tracepoints' can now display 'installed on target'
913 or 'not installed on target' for each non-pending location of tracepoint.
915 * New configure options
917 --enable-libmcheck/--disable-libmcheck
918 By default, development versions are built with -lmcheck on hosts
919 that support it, in order to help track memory corruption issues.
920 Release versions, on the other hand, are built without -lmcheck
921 by default. The --enable-libmcheck/--disable-libmcheck configure
922 options allow the user to override that default.
923 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
924 This configure option allows the user to build GDB with
925 libbabeltrace using which GDB can read Common Trace Format data.
927 * New commands (for set/show, see "New options" below)
930 Catch signals. This is similar to "handle", but allows commands and
931 conditions to be attached.
934 List the BFDs known to GDB.
936 python-interactive [command]
938 Start a Python interactive prompt, or evaluate the optional command
939 and print the result of expressions.
942 "py" is a new alias for "python".
944 enable type-printer [name]...
945 disable type-printer [name]...
946 Enable or disable type printers.
950 ** For the Renesas Super-H architecture, the "regs" command has been removed
951 (has been deprecated in GDB 7.5), and "info all-registers" should be used
956 set print type methods (on|off)
957 show print type methods
958 Control whether method declarations are displayed by "ptype".
959 The default is to show them.
961 set print type typedefs (on|off)
962 show print type typedefs
963 Control whether typedef definitions are displayed by "ptype".
964 The default is to show them.
966 set filename-display basename|relative|absolute
967 show filename-display
968 Control the way in which filenames is displayed.
969 The default is "relative", which preserves previous behavior.
971 set trace-buffer-size
972 show trace-buffer-size
973 Request target to change the size of trace buffer.
975 set remote trace-buffer-size-packet auto|on|off
976 show remote trace-buffer-size-packet
977 Control the use of the remote protocol `QTBuffer:size' packet.
981 Control display of debugging messages related to ARM AArch64.
984 set debug coff-pe-read
985 show debug coff-pe-read
986 Control display of debugging messages related to reading of COFF/PE
991 Control display of debugging messages related to Mach-O symbols
994 set debug notification
995 show debug notification
996 Control display of debugging info for async remote notification.
1000 ** Command parameter changes are now notified using new async record
1001 "=cmd-param-changed".
1002 ** Trace frame changes caused by command "tfind" are now notified using
1003 new async record "=traceframe-changed".
1004 ** The creation, deletion and modification of trace state variables
1005 are now notified using new async records "=tsv-created",
1006 "=tsv-deleted" and "=tsv-modified".
1007 ** The start and stop of process record are now notified using new
1008 async record "=record-started" and "=record-stopped".
1009 ** Memory changes are now notified using new async record
1011 ** The data-disassemble command response will include a "fullname" field
1012 containing the absolute file name when source has been requested.
1013 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1014 command, to allow pattern filling of memory areas.
1015 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1016 library load/unload events.
1017 ** The response to breakpoint commands and breakpoint async records
1018 includes an "installed" field containing a boolean state about each
1019 non-pending tracepoint location is whether installed on target or not.
1020 ** Output of the "-trace-status" command includes a "trace-file" field
1021 containing the name of the trace file being examined. This field is
1022 optional, and only present when examining a trace file.
1023 ** The "fullname" field is now always present along with the "file" field,
1024 even if the file cannot be found by GDB.
1026 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1027 You must have the LZMA library available when configuring GDB for this
1028 feature to be enabled. For more information, see:
1029 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1031 * New remote packets
1034 Set the size of trace buffer. The remote stub reports support for this
1035 packet to gdb's qSupported query.
1038 Enable Branch Trace Store (BTS)-based branch tracing for the current
1039 thread. The remote stub reports support for this packet to gdb's
1043 Disable branch tracing for the current thread. The remote stub reports
1044 support for this packet to gdb's qSupported query.
1047 Read the traced branches for the current thread. The remote stub
1048 reports support for this packet to gdb's qSupported query.
1050 *** Changes in GDB 7.5
1052 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1053 for more x32 ABI info.
1055 * GDB now supports access to MIPS DSP registers on Linux targets.
1057 * GDB now supports debugging microMIPS binaries.
1059 * The "info os" command on GNU/Linux can now display information on
1060 several new classes of objects managed by the operating system:
1061 "info os procgroups" lists process groups
1062 "info os files" lists file descriptors
1063 "info os sockets" lists internet-domain sockets
1064 "info os shm" lists shared-memory regions
1065 "info os semaphores" lists semaphores
1066 "info os msg" lists message queues
1067 "info os modules" lists loaded kernel modules
1069 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1070 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1071 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1072 options and inspect the probe arguments using the new $_probe_arg family
1073 of convenience variables. You can obtain more information about SystemTap
1074 in <http://sourceware.org/systemtap/>.
1076 * GDB now supports reversible debugging on ARM, it allows you to
1077 debug basic ARM and THUMB instructions, and provides
1078 record/replay support.
1080 * The option "symbol-reloading" has been deleted as it is no longer used.
1084 ** GDB commands implemented in Python can now be put in command class
1087 ** The "maint set python print-stack on|off" is now deleted.
1089 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1090 apply "flag enum"-style pretty-printing to any enum.
1092 ** gdb.lookup_symbol can now work when there is no current frame.
1094 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1095 the source at which the symbol was defined.
1097 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1098 method 'value'. The former indicates whether the symbol needs a
1099 frame in order to compute its value, and the latter computes the
1102 ** A new method 'referenced_value' on gdb.Value objects which can
1103 dereference pointer as well as C++ reference values.
1105 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1106 which return the global and static blocks (as gdb.Block objects),
1107 of the underlying symbol table, respectively.
1109 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1110 object associated with a PC value.
1112 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1113 of the address range occupied by code for the current source line.
1115 * Go language support.
1116 GDB now supports debugging programs written in the Go programming
1119 * GDBserver now supports stdio connections.
1120 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1122 * The binary "gdbtui" can no longer be built or installed.
1123 Use "gdb -tui" instead.
1125 * GDB will now print "flag" enums specially. A flag enum is one where
1126 all the enumerator values have no bits in common when pairwise
1127 "and"ed. When printing a value whose type is a flag enum, GDB will
1128 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1129 (gdb) print (enum E) 3
1132 * The filename part of a linespec will now match trailing components
1133 of a source file name. For example, "break gcc/expr.c:1000" will
1134 now set a breakpoint in build/gcc/expr.c, but not
1135 build/libcpp/expr.c.
1137 * The "info proc" and "generate-core-file" commands will now also
1138 work on remote targets connected to GDBserver on Linux.
1140 * The command "info catch" has been removed. It has been disabled
1141 since December 2007.
1143 * The "catch exception" and "catch assert" commands now accept
1144 a condition at the end of the command, much like the "break"
1145 command does. For instance:
1147 (gdb) catch exception Constraint_Error if Barrier = True
1149 Previously, it was possible to add a condition to such catchpoints,
1150 but it had to be done as a second step, after the catchpoint had been
1151 created, using the "condition" command.
1153 * The "info static-tracepoint-marker" command will now also work on
1154 native Linux targets with in-process agent.
1156 * GDB can now set breakpoints on inlined functions.
1158 * The .gdb_index section has been updated to include symbols for
1159 inlined functions. GDB will ignore older .gdb_index sections by
1160 default, which could cause symbol files to be loaded more slowly
1161 until their .gdb_index sections can be recreated. The new command
1162 "set use-deprecated-index-sections on" will cause GDB to use any older
1163 .gdb_index sections it finds. This will restore performance, but the
1164 ability to set breakpoints on inlined functions will be lost in symbol
1165 files with older .gdb_index sections.
1167 The .gdb_index section has also been updated to record more information
1168 about each symbol. This speeds up the "info variables", "info functions"
1169 and "info types" commands when used with programs having the .gdb_index
1170 section, as well as speeding up debugging with shared libraries using
1171 the .gdb_index section.
1173 * Ada support for GDB/MI Variable Objects has been added.
1175 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1180 ** New command -info-os is the MI equivalent of "info os".
1182 ** Output logs ("set logging" and related) now include MI output.
1186 ** "set use-deprecated-index-sections on|off"
1187 "show use-deprecated-index-sections on|off"
1188 Controls the use of deprecated .gdb_index sections.
1190 ** "catch load" and "catch unload" can be used to stop when a shared
1191 library is loaded or unloaded, respectively.
1193 ** "enable count" can be used to auto-disable a breakpoint after
1196 ** "info vtbl" can be used to show the virtual method tables for
1197 C++ and Java objects.
1199 ** "explore" and its sub commands "explore value" and "explore type"
1200 can be used to recursively explore values and types of
1201 expressions. These commands are available only if GDB is
1202 configured with '--with-python'.
1204 ** "info auto-load" shows status of all kinds of auto-loaded files,
1205 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1206 sequences of commands files, "info auto-load python-scripts"
1207 shows status of auto-loading Python script files,
1208 "info auto-load local-gdbinit" shows status of loading init file
1209 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1210 status of inferior specific thread debugging shared library loading.
1212 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1213 and "show auto-load-scripts" commands have been deprecated, use their
1214 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1215 and "show auto-load python-scripts" counterparts instead.
1217 ** "dprintf location,format,args..." creates a dynamic printf, which
1218 is basically a breakpoint that does a printf and immediately
1219 resumes your program's execution, so it is like a printf that you
1220 can insert dynamically at runtime instead of at compiletime.
1222 ** "set print symbol"
1224 Controls whether GDB attempts to display the symbol, if any,
1225 corresponding to addresses it prints. This defaults to "on", but
1226 you can set it to "off" to restore GDB's previous behavior.
1228 * Deprecated commands
1230 ** For the Renesas Super-H architecture, the "regs" command has been
1231 deprecated, and "info all-registers" should be used instead.
1235 Renesas RL78 rl78-*-elf
1236 HP OpenVMS ia64 ia64-hp-openvms*
1238 * GDBserver supports evaluation of breakpoint conditions. When
1239 support is advertised by GDBserver, GDB may be told to send the
1240 breakpoint conditions in bytecode form to GDBserver. GDBserver
1241 will only report the breakpoint trigger to GDB when its condition
1246 set mips compression
1247 show mips compression
1248 Select the compressed ISA encoding used in functions that have no symbol
1249 information available. The encoding can be set to either of:
1252 and is updated automatically from ELF file flags if available.
1254 set breakpoint condition-evaluation
1255 show breakpoint condition-evaluation
1256 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1257 GDBserver ("target"). Default option "auto" chooses the most efficient
1259 This option can improve debugger efficiency depending on the speed of the
1263 Disable auto-loading globally.
1266 Show auto-loading setting of all kinds of auto-loaded files.
1268 set auto-load gdb-scripts on|off
1269 show auto-load gdb-scripts
1270 Control auto-loading of GDB canned sequences of commands files.
1272 set auto-load python-scripts on|off
1273 show auto-load python-scripts
1274 Control auto-loading of Python script files.
1276 set auto-load local-gdbinit on|off
1277 show auto-load local-gdbinit
1278 Control loading of init file (.gdbinit) from current directory.
1280 set auto-load libthread-db on|off
1281 show auto-load libthread-db
1282 Control auto-loading of inferior specific thread debugging shared library.
1284 set auto-load scripts-directory <dir1>[:<dir2>...]
1285 show auto-load scripts-directory
1286 Set a list of directories from which to load auto-loaded scripts.
1287 Automatically loaded Python scripts and GDB scripts are located in one
1288 of the directories listed by this option.
1289 The delimiter (':' above) may differ according to the host platform.
1291 set auto-load safe-path <dir1>[:<dir2>...]
1292 show auto-load safe-path
1293 Set a list of directories from which it is safe to auto-load files.
1294 The delimiter (':' above) may differ according to the host platform.
1296 set debug auto-load on|off
1297 show debug auto-load
1298 Control display of debugging info for auto-loading the files above.
1300 set dprintf-style gdb|call|agent
1302 Control the way in which a dynamic printf is performed; "gdb"
1303 requests a GDB printf command, while "call" causes dprintf to call a
1304 function in the inferior. "agent" requests that the target agent
1305 (such as GDBserver) do the printing.
1307 set dprintf-function <expr>
1308 show dprintf-function
1309 set dprintf-channel <expr>
1310 show dprintf-channel
1311 Set the function and optional first argument to the call when using
1312 the "call" style of dynamic printf.
1314 set disconnected-dprintf on|off
1315 show disconnected-dprintf
1316 Control whether agent-style dynamic printfs continue to be in effect
1317 after GDB disconnects.
1319 * New configure options
1321 --with-auto-load-dir
1322 Configure default value for the 'set auto-load scripts-directory'
1323 setting above. It defaults to '$debugdir:$datadir/auto-load',
1324 $debugdir representing global debugging info directories (available
1325 via 'show debug-file-directory') and $datadir representing GDB's data
1326 directory (available via 'show data-directory').
1328 --with-auto-load-safe-path
1329 Configure default value for the 'set auto-load safe-path' setting
1330 above. It defaults to the --with-auto-load-dir setting.
1332 --without-auto-load-safe-path
1333 Set 'set auto-load safe-path' to '/', effectively disabling this
1336 * New remote packets
1338 z0/z1 conditional breakpoints extension
1340 The z0/z1 breakpoint insertion packets have been extended to carry
1341 a list of conditional expressions over to the remote stub depending on the
1342 condition evaluation mode. The use of this extension can be controlled
1343 via the "set remote conditional-breakpoints-packet" command.
1347 Specify the signals which the remote stub may pass to the debugged
1348 program without GDB involvement.
1350 * New command line options
1352 --init-command=FILE, -ix Like --command, -x but execute it
1353 before loading inferior.
1354 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1355 execute it before loading inferior.
1357 *** Changes in GDB 7.4
1359 * GDB now handles ambiguous linespecs more consistently; the existing
1360 FILE:LINE support has been expanded to other types of linespecs. A
1361 breakpoint will now be set on all matching locations in all
1362 inferiors, and locations will be added or removed according to
1365 * GDB now allows you to skip uninteresting functions and files when
1366 stepping with the "skip function" and "skip file" commands.
1368 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1369 and "show remote hardware-watchpoint-length-limit". These allows to
1370 set or show the maximum length limit (in bytes) of a remote
1371 target hardware watchpoint.
1373 This allows e.g. to use "unlimited" hardware watchpoints with the
1374 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1375 watchpoints are slower than real hardware watchpoints but are
1376 significantly faster than gdb software watchpoints.
1380 ** The register_pretty_printer function in module gdb.printing now takes
1381 an optional `replace' argument. If True, the new printer replaces any
1384 ** The "maint set python print-stack on|off" command has been
1385 deprecated and will be deleted in GDB 7.5.
1386 A new command: "set python print-stack none|full|message" has
1387 replaced it. Additionally, the default for "print-stack" is
1388 now "message", which just prints the error message without
1391 ** A prompt substitution hook (prompt_hook) is now available to the
1394 ** A new Python module, gdb.prompt has been added to the GDB Python
1395 modules library. This module provides functionality for
1396 escape sequences in prompts (used by set/show
1397 extended-prompt). These escape sequences are replaced by their
1398 corresponding value.
1400 ** Python commands and convenience-functions located in
1401 'data-directory'/python/gdb/command and
1402 'data-directory'/python/gdb/function are now automatically loaded
1405 ** Blocks now provide four new attributes. global_block and
1406 static_block will return the global and static blocks
1407 respectively. is_static and is_global are boolean attributes
1408 that indicate if the block is one of those two types.
1410 ** Symbols now provide the "type" attribute, the type of the symbol.
1412 ** The "gdb.breakpoint" function has been deprecated in favor of
1415 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1416 of a function. This class is based on the "finish" command
1417 available in the CLI.
1419 ** Type objects for struct and union types now allow access to
1420 the fields using standard Python dictionary (mapping) methods.
1421 For example, "some_type['myfield']" now works, as does
1422 "some_type.items()".
1424 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1427 ** A new function, "deep_items" has been added to the gdb.types
1428 module in the GDB Python modules library. This function returns
1429 an iterator over the fields of a struct or union type. Unlike
1430 the standard Python "iteritems" method, it will recursively traverse
1431 any anonymous fields.
1435 ** "*stopped" events can report several new "reason"s, such as
1438 ** Breakpoint changes are now notified using new async records, like
1439 "=breakpoint-modified".
1441 ** New command -ada-task-info.
1443 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1444 $sdir specifies the default system locations of shared libraries.
1445 $pdir specifies the directory where the libpthread used by the application
1448 GDB no longer looks in $sdir and $pdir after it has searched the directories
1449 mentioned in libthread-db-search-path. If you want to search those
1450 directories, they must be specified in libthread-db-search-path.
1451 The default value of libthread-db-search-path on GNU/Linux and Solaris
1452 systems is now "$sdir:$pdir".
1454 $pdir is not supported by gdbserver, it is currently ignored.
1455 $sdir is supported by gdbserver.
1457 * New configure option --with-iconv-bin.
1458 When using the internationalization support like the one in the GNU C
1459 library, GDB will invoke the "iconv" program to get a list of supported
1460 character sets. If this program lives in a non-standard location, one can
1461 use this option to specify where to find it.
1463 * When natively debugging programs on PowerPC BookE processors running
1464 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1465 watchpoints, which specify a mask in addition to an address to watch.
1466 The mask specifies that some bits of an address (the bits which are
1467 reset in the mask) should be ignored when matching the address accessed
1468 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1469 section in the user manual for more details.
1471 * The new option --once causes GDBserver to stop listening for connections once
1472 the first connection is made. The listening port used by GDBserver will
1473 become available after that.
1475 * New commands "info macros" and "alias" have been added.
1477 * New function parameters suffix @entry specifies value of function parameter
1478 at the time the function got called. Entry values are available only since
1484 "!" is now an alias of the "shell" command.
1485 Note that no space is needed between "!" and SHELL COMMAND.
1489 watch EXPRESSION mask MASK_VALUE
1490 The watch command now supports the mask argument which allows creation
1491 of masked watchpoints, if the current architecture supports this feature.
1493 info auto-load-scripts [REGEXP]
1494 This command was formerly named "maintenance print section-scripts".
1495 It is now generally useful and is no longer a maintenance-only command.
1497 info macro [-all] [--] MACRO
1498 The info macro command has new options `-all' and `--'. The first for
1499 printing all definitions of a macro. The second for explicitly specifying
1500 the end of arguments and the beginning of the macro name in case the macro
1501 name starts with a hyphen.
1503 collect[/s] EXPRESSIONS
1504 The tracepoint collect command now takes an optional modifier "/s"
1505 that directs it to dereference pointer-to-character types and
1506 collect the bytes of memory up to a zero byte. The behavior is
1507 similar to what you see when you use the regular print command on a
1508 string. An optional integer following the "/s" sets a bound on the
1509 number of bytes that will be collected.
1512 The trace start command now interprets any supplied arguments as a
1513 note to be recorded with the trace run, with an effect similar to
1514 setting the variable trace-notes.
1517 The trace stop command now interprets any arguments as a note to be
1518 mentioned along with the tstatus report that the trace was stopped
1519 with a command. The effect is similar to setting the variable
1522 * Tracepoints can now be enabled and disabled at any time after a trace
1523 experiment has been started using the standard "enable" and "disable"
1524 commands. It is now possible to start a trace experiment with no enabled
1525 tracepoints; GDB will display a warning, but will allow the experiment to
1526 begin, assuming that tracepoints will be enabled as needed while the trace
1529 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1530 locations with 4-byte instructions, when they were previously
1531 limited to locations with instructions of 5 bytes or longer.
1535 set debug dwarf2-read
1536 show debug dwarf2-read
1537 Turns on or off display of debugging messages related to reading
1538 DWARF debug info. The default is off.
1540 set debug symtab-create
1541 show debug symtab-create
1542 Turns on or off display of debugging messages related to symbol table
1543 creation. The default is off.
1546 show extended-prompt
1547 Set the GDB prompt, and allow escape sequences to be inserted to
1548 display miscellaneous information (see 'help set extended-prompt'
1549 for the list of sequences). This prompt (and any information
1550 accessed through the escape sequences) is updated every time the
1551 prompt is displayed.
1553 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1554 show print entry-values
1555 Set printing of frame argument values at function entry. In some cases
1556 GDB can determine the value of function argument which was passed by the
1557 function caller, even if the value was modified inside the called function.
1559 set debug entry-values
1560 show debug entry-values
1561 Control display of debugging info for determining frame argument values at
1562 function entry and virtual tail call frames.
1564 set basenames-may-differ
1565 show basenames-may-differ
1566 Set whether a source file may have multiple base names.
1567 (A "base name" is the name of a file with the directory part removed.
1568 Example: The base name of "/home/user/hello.c" is "hello.c".)
1569 If set, GDB will canonicalize file names (e.g., expand symlinks)
1570 before comparing them. Canonicalization is an expensive operation,
1571 but it allows the same file be known by more than one base name.
1572 If not set (the default), all source files are assumed to have just
1573 one base name, and gdb will do file name comparisons more efficiently.
1579 Set a user name and notes for the current and any future trace runs.
1580 This is useful for long-running and/or disconnected traces, to
1581 inform others (or yourself) as to who is running the trace, supply
1582 contact information, or otherwise explain what is going on.
1584 set trace-stop-notes
1585 show trace-stop-notes
1586 Set a note attached to the trace run, that is displayed when the
1587 trace has been stopped by a tstop command. This is useful for
1588 instance as an explanation, if you are stopping a trace run that was
1589 started by someone else.
1591 * New remote packets
1595 Dynamically enable a tracepoint in a started trace experiment.
1599 Dynamically disable a tracepoint in a started trace experiment.
1603 Set the user and notes of the trace run.
1607 Query the current status of a tracepoint.
1611 Query the minimum length of instruction at which a fast tracepoint may
1614 * Dcache size (number of lines) and line-size are now runtime-configurable
1615 via "set dcache line" and "set dcache line-size" commands.
1619 Texas Instruments TMS320C6x tic6x-*-*
1623 Renesas RL78 rl78-*-elf
1625 *** Changes in GDB 7.3.1
1627 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1629 *** Changes in GDB 7.3
1631 * GDB has a new command: "thread find [REGEXP]".
1632 It finds the thread id whose name, target id, or thread extra info
1633 matches the given regular expression.
1635 * The "catch syscall" command now works on mips*-linux* targets.
1637 * The -data-disassemble MI command now supports modes 2 and 3 for
1638 dumping the instruction opcodes.
1640 * New command line options
1642 -data-directory DIR Specify DIR as the "data-directory".
1643 This is mostly for testing purposes.
1645 * The "maint set python auto-load on|off" command has been renamed to
1646 "set auto-load-scripts on|off".
1648 * GDB has a new command: "set directories".
1649 It is like the "dir" command except that it replaces the
1650 source path list instead of augmenting it.
1652 * GDB now understands thread names.
1654 On GNU/Linux, "info threads" will display the thread name as set by
1655 prctl or pthread_setname_np.
1657 There is also a new command, "thread name", which can be used to
1658 assign a name internally for GDB to display.
1661 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1662 has been integrated into GDB.
1666 ** The function gdb.Write now accepts an optional keyword 'stream'.
1667 This keyword, when provided, will direct the output to either
1668 stdout, stderr, or GDB's logging output.
1670 ** Parameters can now be be sub-classed in Python, and in particular
1671 you may implement the get_set_doc and get_show_doc functions.
1672 This improves how Parameter set/show documentation is processed
1673 and allows for more dynamic content.
1675 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1676 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1677 have an is_valid method.
1679 ** Breakpoints can now be sub-classed in Python, and in particular
1680 you may implement a 'stop' function that is executed each time
1681 the inferior reaches that breakpoint.
1683 ** New function gdb.lookup_global_symbol looks up a global symbol.
1685 ** GDB values in Python are now callable if the value represents a
1686 function. For example, if 'some_value' represents a function that
1687 takes two integer parameters and returns a value, you can call
1688 that function like so:
1690 result = some_value (10,20)
1692 ** Module gdb.types has been added.
1693 It contains a collection of utilities for working with gdb.Types objects:
1694 get_basic_type, has_field, make_enum_dict.
1696 ** Module gdb.printing has been added.
1697 It contains utilities for writing and registering pretty-printers.
1698 New classes: PrettyPrinter, SubPrettyPrinter,
1699 RegexpCollectionPrettyPrinter.
1700 New function: register_pretty_printer.
1702 ** New commands "info pretty-printers", "enable pretty-printer" and
1703 "disable pretty-printer" have been added.
1705 ** gdb.parameter("directories") is now available.
1707 ** New function gdb.newest_frame returns the newest frame in the
1710 ** The gdb.InferiorThread class has a new "name" attribute. This
1711 holds the thread's name.
1713 ** Python Support for Inferior events.
1714 Python scripts can add observers to be notified of events
1715 occurring in the process being debugged.
1716 The following events are currently supported:
1717 - gdb.events.cont Continue event.
1718 - gdb.events.exited Inferior exited event.
1719 - gdb.events.stop Signal received, and Breakpoint hit events.
1723 ** GDB now puts template parameters in scope when debugging in an
1724 instantiation. For example, if you have:
1726 template<int X> int func (void) { return X; }
1728 then if you step into func<5>, "print X" will show "5". This
1729 feature requires proper debuginfo support from the compiler; it
1730 was added to GCC 4.5.
1732 ** The motion commands "next", "finish", "until", and "advance" now
1733 work better when exceptions are thrown. In particular, GDB will
1734 no longer lose control of the inferior; instead, the GDB will
1735 stop the inferior at the point at which the exception is caught.
1736 This functionality requires a change in the exception handling
1737 code that was introduced in GCC 4.5.
1739 * GDB now follows GCC's rules on accessing volatile objects when
1740 reading or writing target state during expression evaluation.
1741 One notable difference to prior behavior is that "print x = 0"
1742 no longer generates a read of x; the value of the assignment is
1743 now always taken directly from the value being assigned.
1745 * GDB now has some support for using labels in the program's source in
1746 linespecs. For instance, you can use "advance label" to continue
1747 execution to a label.
1749 * GDB now has support for reading and writing a new .gdb_index
1750 section. This section holds a fast index of DWARF debugging
1751 information and can be used to greatly speed up GDB startup and
1752 operation. See the documentation for `save gdb-index' for details.
1754 * The "watch" command now accepts an optional "-location" argument.
1755 When used, this causes GDB to watch the memory referred to by the
1756 expression. Such a watchpoint is never deleted due to it going out
1759 * GDB now supports thread debugging of core dumps on GNU/Linux.
1761 GDB now activates thread debugging using the libthread_db library
1762 when debugging GNU/Linux core dumps, similarly to when debugging
1763 live processes. As a result, when debugging a core dump file, GDB
1764 is now able to display pthread_t ids of threads. For example, "info
1765 threads" shows the same output as when debugging the process when it
1766 was live. In earlier releases, you'd see something like this:
1769 * 1 LWP 6780 main () at main.c:10
1771 While now you see this:
1774 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1776 It is also now possible to inspect TLS variables when debugging core
1779 When debugging a core dump generated on a machine other than the one
1780 used to run GDB, you may need to point GDB at the correct
1781 libthread_db library with the "set libthread-db-search-path"
1782 command. See the user manual for more details on this command.
1784 * When natively debugging programs on PowerPC BookE processors running
1785 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1786 which stop execution of the inferior whenever it executes an instruction
1787 at any address within the specified range. See the "PowerPC Embedded"
1788 section in the user manual for more details.
1790 * New features in the GDB remote stub, GDBserver
1792 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1793 and i686 LynxOS (version 5.x).
1795 ** GDBserver is now supported on Blackfin Linux.
1797 * New native configurations
1799 ia64 HP-UX ia64-*-hpux*
1803 Analog Devices, Inc. Blackfin Processor bfin-*
1805 * Ada task switching is now supported on sparc-elf targets when
1806 debugging a program using the Ravenscar Profile. For more information,
1807 see the "Tasking Support when using the Ravenscar Profile" section
1808 in the GDB user manual.
1810 * Guile support was removed.
1812 * New features in the GNU simulator
1814 ** The --map-info flag lists all known core mappings.
1816 ** CFI flashes may be simulated via the "cfi" device.
1818 *** Changes in GDB 7.2
1820 * Shared library support for remote targets by default
1822 When GDB is configured for a generic, non-OS specific target, like
1823 for example, --target=arm-eabi or one of the many *-*-elf targets,
1824 GDB now queries remote stubs for loaded shared libraries using the
1825 `qXfer:libraries:read' packet. Previously, shared library support
1826 was always disabled for such configurations.
1830 ** Argument Dependent Lookup (ADL)
1832 In C++ ADL lookup directs function search to the namespaces of its
1833 arguments even if the namespace has not been imported.
1843 Here the compiler will search for `foo' in the namespace of 'b'
1844 and find A::foo. GDB now supports this. This construct is commonly
1845 used in the Standard Template Library for operators.
1847 ** Improved User Defined Operator Support
1849 In addition to member operators, GDB now supports lookup of operators
1850 defined in a namespace and imported with a `using' directive, operators
1851 defined in the global scope, operators imported implicitly from an
1852 anonymous namespace, and the ADL operators mentioned in the previous
1854 GDB now also supports proper overload resolution for all the previously
1855 mentioned flavors of operators.
1857 ** static const class members
1859 Printing of static const class members that are initialized in the
1860 class definition has been fixed.
1862 * Windows Thread Information Block access.
1864 On Windows targets, GDB now supports displaying the Windows Thread
1865 Information Block (TIB) structure. This structure is visible either
1866 by using the new command `info w32 thread-information-block' or, by
1867 dereferencing the new convenience variable named `$_tlb', a
1868 thread-specific pointer to the TIB. This feature is also supported
1869 when remote debugging using GDBserver.
1871 * Static tracepoints
1873 Static tracepoints are calls in the user program into a tracing
1874 library. One such library is a port of the LTTng kernel tracer to
1875 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1876 When debugging with GDBserver, GDB now supports combining the GDB
1877 tracepoint machinery with such libraries. For example: the user can
1878 use GDB to probe a static tracepoint marker (a call from the user
1879 program into the tracing library) with the new "strace" command (see
1880 "New commands" below). This creates a "static tracepoint" in the
1881 breakpoint list, that can be manipulated with the same feature set
1882 as fast and regular tracepoints. E.g., collect registers, local and
1883 global variables, collect trace state variables, and define
1884 tracepoint conditions. In addition, the user can collect extra
1885 static tracepoint marker specific data, by collecting the new
1886 $_sdata internal variable. When analyzing the trace buffer, you can
1887 inspect $_sdata like any other variable available to GDB. For more
1888 information, see the "Tracepoints" chapter in GDB user manual. New
1889 remote packets have been defined to support static tracepoints, see
1890 the "New remote packets" section below.
1892 * Better reconstruction of tracepoints after disconnected tracing
1894 GDB will attempt to download the original source form of tracepoint
1895 definitions when starting a trace run, and then will upload these
1896 upon reconnection to the target, resulting in a more accurate
1897 reconstruction of the tracepoints that are in use on the target.
1901 You can now exercise direct control over the ways that GDB can
1902 affect your program. For instance, you can disallow the setting of
1903 breakpoints, so that the program can run continuously (assuming
1904 non-stop mode). In addition, the "observer" variable is available
1905 to switch all of the different controls; in observer mode, GDB
1906 cannot affect the target's behavior at all, which is useful for
1907 tasks like diagnosing live systems in the field.
1909 * The new convenience variable $_thread holds the number of the
1912 * New remote packets
1916 Return the address of the Windows Thread Information Block of a given thread.
1920 In response to several of the tracepoint packets, the target may now
1921 also respond with a number of intermediate `qRelocInsn' request
1922 packets before the final result packet, to have GDB handle
1923 relocating an instruction to execute at a different address. This
1924 is particularly useful for stubs that support fast tracepoints. GDB
1925 reports support for this feature in the qSupported packet.
1929 List static tracepoint markers in the target program.
1933 List static tracepoint markers at a given address in the target
1936 qXfer:statictrace:read
1938 Read the static trace data collected (by a `collect $_sdata'
1939 tracepoint action). The remote stub reports support for this packet
1940 to gdb's qSupported query.
1944 Send the current settings of GDB's permission flags.
1948 Send part of the source (textual) form of a tracepoint definition,
1949 which includes location, conditional, and action list.
1951 * The source command now accepts a -s option to force searching for the
1952 script in the source search path even if the script name specifies
1955 * New features in the GDB remote stub, GDBserver
1957 - GDBserver now support tracepoints (including fast tracepoints, and
1958 static tracepoints). The feature is currently supported by the
1959 i386-linux and amd64-linux builds. See the "Tracepoints support
1960 in gdbserver" section in the manual for more information.
1962 GDBserver JIT compiles the tracepoint's conditional agent
1963 expression bytecode into native code whenever possible for low
1964 overhead dynamic tracepoints conditionals. For such tracepoints,
1965 an expression that examines program state is evaluated when the
1966 tracepoint is reached, in order to determine whether to capture
1967 trace data. If the condition is simple and false, processing the
1968 tracepoint finishes very quickly and no data is gathered.
1970 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1971 for static tracepoints support.
1973 - GDBserver now supports x86_64 Windows 64-bit debugging.
1975 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1976 it understands register description.
1978 * The --batch flag now disables pagination and queries.
1980 * X86 general purpose registers
1982 GDB now supports reading/writing byte, word and double-word x86
1983 general purpose registers directly. This means you can use, say,
1984 $ah or $ax to refer, respectively, to the byte register AH and
1985 16-bit word register AX that are actually portions of the 32-bit
1986 register EAX or 64-bit register RAX.
1988 * The `commands' command now accepts a range of breakpoints to modify.
1989 A plain `commands' following a command that creates multiple
1990 breakpoints affects all the breakpoints set by that command. This
1991 applies to breakpoints set by `rbreak', and also applies when a
1992 single `break' command creates multiple breakpoints (e.g.,
1993 breakpoints on overloaded c++ functions).
1995 * The `rbreak' command now accepts a filename specification as part of
1996 its argument, limiting the functions selected by the regex to those
1997 in the specified file.
1999 * Support for remote debugging Windows and SymbianOS shared libraries
2000 from Unix hosts has been improved. Non Windows GDB builds now can
2001 understand target reported file names that follow MS-DOS based file
2002 system semantics, such as file names that include drive letters and
2003 use the backslash character as directory separator. This makes it
2004 possible to transparently use the "set sysroot" and "set
2005 solib-search-path" on Unix hosts to point as host copies of the
2006 target's shared libraries. See the new command "set
2007 target-file-system-kind" described below, and the "Commands to
2008 specify files" section in the user manual for more information.
2012 eval template, expressions...
2013 Convert the values of one or more expressions under the control
2014 of the string template to a command line, and call it.
2016 set target-file-system-kind unix|dos-based|auto
2017 show target-file-system-kind
2018 Set or show the assumed file system kind for target reported file
2021 save breakpoints <filename>
2022 Save all current breakpoint definitions to a file suitable for use
2023 in a later debugging session. To read the saved breakpoint
2024 definitions, use the `source' command.
2026 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2029 info static-tracepoint-markers
2030 Display information about static tracepoint markers in the target.
2032 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2033 Define a static tracepoint by probing a marker at the given
2034 function, line, address, or marker ID.
2038 Enable and disable observer mode.
2040 set may-write-registers on|off
2041 set may-write-memory on|off
2042 set may-insert-breakpoints on|off
2043 set may-insert-tracepoints on|off
2044 set may-insert-fast-tracepoints on|off
2045 set may-interrupt on|off
2046 Set individual permissions for GDB effects on the target. Note that
2047 some of these settings can have undesirable or surprising
2048 consequences, particularly when changed in the middle of a session.
2049 For instance, disabling the writing of memory can prevent
2050 breakpoints from being inserted, cause single-stepping to fail, or
2051 even crash your program, if you disable after breakpoints have been
2052 inserted. However, GDB should not crash.
2054 set record memory-query on|off
2055 show record memory-query
2056 Control whether to stop the inferior if memory changes caused
2057 by an instruction cannot be recorded.
2062 The disassemble command now supports "start,+length" form of two arguments.
2066 ** GDB now provides a new directory location, called the python directory,
2067 where Python scripts written for GDB can be installed. The location
2068 of that directory is <data-directory>/python, where <data-directory>
2069 is the GDB data directory. For more details, see section `Scripting
2070 GDB using Python' in the manual.
2072 ** The GDB Python API now has access to breakpoints, symbols, symbol
2073 tables, program spaces, inferiors, threads and frame's code blocks.
2074 Additionally, GDB Parameters can now be created from the API, and
2075 manipulated via set/show in the CLI.
2077 ** New functions gdb.target_charset, gdb.target_wide_charset,
2078 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2080 ** New exception gdb.GdbError.
2082 ** Pretty-printers are now also looked up in the current program space.
2084 ** Pretty-printers can now be individually enabled and disabled.
2086 ** GDB now looks for names of Python scripts to auto-load in a
2087 special section named `.debug_gdb_scripts', in addition to looking
2088 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2090 * Tracepoint actions were unified with breakpoint commands. In particular,
2091 there are no longer differences in "info break" output for breakpoints and
2092 tracepoints and the "commands" command can be used for both tracepoints and
2093 regular breakpoints.
2097 ARM Symbian arm*-*-symbianelf*
2099 * D language support.
2100 GDB now supports debugging programs written in the D programming
2103 * GDB now supports the extended ptrace interface for PowerPC which is
2104 available since Linux kernel version 2.6.34. This automatically enables
2105 any hardware breakpoints and additional hardware watchpoints available in
2106 the processor. The old ptrace interface exposes just one hardware
2107 watchpoint and no hardware breakpoints.
2109 * GDB is now able to use the Data Value Compare (DVC) register available on
2110 embedded PowerPC processors to implement in hardware simple watchpoint
2111 conditions of the form:
2113 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2115 This works in native GDB running on Linux kernels with the extended ptrace
2116 interface mentioned above.
2118 *** Changes in GDB 7.1
2122 ** Namespace Support
2124 GDB now supports importing of namespaces in C++. This enables the
2125 user to inspect variables from imported namespaces. Support for
2126 namepace aliasing has also been added. So, if a namespace is
2127 aliased in the current scope (e.g. namepace C=A; ) the user can
2128 print variables using the alias (e.g. (gdb) print C::x).
2132 All known bugs relating to the printing of virtual base class were
2133 fixed. It is now possible to call overloaded static methods using a
2138 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2139 and reinterpret_cast<> are now handled by the C++ expression parser.
2143 Xilinx MicroBlaze microblaze-*-*
2148 Xilinx MicroBlaze microblaze
2151 * Multi-program debugging.
2153 GDB now has support for multi-program (a.k.a. multi-executable or
2154 multi-exec) debugging. This allows for debugging multiple inferiors
2155 simultaneously each running a different program under the same GDB
2156 session. See "Debugging Multiple Inferiors and Programs" in the
2157 manual for more information. This implied some user visible changes
2158 in the multi-inferior support. For example, "info inferiors" now
2159 lists inferiors that are not running yet or that have exited
2160 already. See also "New commands" and "New options" below.
2162 * New tracing features
2164 GDB's tracepoint facility now includes several new features:
2166 ** Trace state variables
2168 GDB tracepoints now include support for trace state variables, which
2169 are variables managed by the target agent during a tracing
2170 experiment. They are useful for tracepoints that trigger each
2171 other, so for instance one tracepoint can count hits in a variable,
2172 and then a second tracepoint has a condition that is true when the
2173 count reaches a particular value. Trace state variables share the
2174 $-syntax of GDB convenience variables, and can appear in both
2175 tracepoint actions and condition expressions. Use the "tvariable"
2176 command to create, and "info tvariables" to view; see "Trace State
2177 Variables" in the manual for more detail.
2181 GDB now includes an option for defining fast tracepoints, which
2182 targets may implement more efficiently, such as by installing a jump
2183 into the target agent rather than a trap instruction. The resulting
2184 speedup can be by two orders of magnitude or more, although the
2185 tradeoff is that some program locations on some target architectures
2186 might not allow fast tracepoint installation, for instance if the
2187 instruction to be replaced is shorter than the jump. To request a
2188 fast tracepoint, use the "ftrace" command, with syntax identical to
2189 the regular trace command.
2191 ** Disconnected tracing
2193 It is now possible to detach GDB from the target while it is running
2194 a trace experiment, then reconnect later to see how the experiment
2195 is going. In addition, a new variable disconnected-tracing lets you
2196 tell the target agent whether to continue running a trace if the
2197 connection is lost unexpectedly.
2201 GDB now has the ability to save the trace buffer into a file, and
2202 then use that file as a target, similarly to you can do with
2203 corefiles. You can select trace frames, print data that was
2204 collected in them, and use tstatus to display the state of the
2205 tracing run at the moment that it was saved. To create a trace
2206 file, use "tsave <filename>", and to use it, do "target tfile
2209 ** Circular trace buffer
2211 You can ask the target agent to handle the trace buffer as a
2212 circular buffer, discarding the oldest trace frames to make room for
2213 newer ones, by setting circular-trace-buffer to on. This feature may
2214 not be available for all target agents.
2219 The disassemble command, when invoked with two arguments, now requires
2220 the arguments to be comma-separated.
2223 The info variables command now displays variable definitions. Files
2224 which only declare a variable are not shown.
2227 The source command is now capable of sourcing Python scripts.
2228 This feature is dependent on the debugger being build with Python
2231 Related to this enhancement is also the introduction of a new command
2232 "set script-extension" (see below).
2234 * New commands (for set/show, see "New options" below)
2236 record save [<FILENAME>]
2237 Save a file (in core file format) containing the process record
2238 execution log for replay debugging at a later time.
2240 record restore <FILENAME>
2241 Restore the process record execution log that was saved at an
2242 earlier time, for replay debugging.
2244 add-inferior [-copies <N>] [-exec <FILENAME>]
2247 clone-inferior [-copies <N>] [ID]
2248 Make a new inferior ready to execute the same program another
2249 inferior has loaded.
2254 maint info program-spaces
2255 List the program spaces loaded into GDB.
2257 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2258 show remote interrupt-sequence
2259 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2260 as the sequence to the remote target in order to interrupt the execution.
2261 Ctrl-C is a default. Some system prefers BREAK which is high level of
2262 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2263 Magic SysRq g. It is BREAK signal and character 'g'.
2265 set remote interrupt-on-connect [on | off]
2266 show remote interrupt-on-connect
2267 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2268 remote target when gdb connects to it. This is needed when you debug
2271 set remotebreak [on | off]
2273 Deprecated. Use "set/show remote interrupt-sequence" instead.
2275 tvariable $NAME [ = EXP ]
2276 Create or modify a trace state variable.
2279 List trace state variables and their values.
2281 delete tvariable $NAME ...
2282 Delete one or more trace state variables.
2285 Evaluate the given expressions without collecting anything into the
2286 trace buffer. (Valid in tracepoint actions only.)
2288 ftrace FN / FILE:LINE / *ADDR
2289 Define a fast tracepoint at the given function, line, or address.
2291 * New expression syntax
2293 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2294 GDB now parses 0b101010 identically with 42.
2298 set follow-exec-mode new|same
2299 show follow-exec-mode
2300 Control whether GDB reuses the same inferior across an exec call or
2301 creates a new one. This is useful to be able to restart the old
2302 executable after the inferior having done an exec call.
2304 set default-collect EXPR, ...
2305 show default-collect
2306 Define a list of expressions to be collected at each tracepoint.
2307 This is a useful way to ensure essential items are not overlooked,
2308 such as registers or a critical global variable.
2310 set disconnected-tracing
2311 show disconnected-tracing
2312 If set to 1, the target is instructed to continue tracing if it
2313 loses its connection to GDB. If 0, the target is to stop tracing
2316 set circular-trace-buffer
2317 show circular-trace-buffer
2318 If set to on, the target is instructed to use a circular trace buffer
2319 and discard the oldest trace frames instead of stopping the trace due
2320 to a full trace buffer. If set to off, the trace stops when the buffer
2321 fills up. Some targets may not support this.
2323 set script-extension off|soft|strict
2324 show script-extension
2325 If set to "off", the debugger does not perform any script language
2326 recognition, and all sourced files are assumed to be GDB scripts.
2327 If set to "soft" (the default), files are sourced according to
2328 filename extension, falling back to GDB scripts if the first
2330 If set to "strict", files are sourced according to filename extension.
2332 set ada trust-PAD-over-XVS on|off
2333 show ada trust-PAD-over-XVS
2334 If off, activate a workaround against a bug in the debugging information
2335 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2336 the GCC sources for more information about the GNAT encoding and
2337 PAD types in particular). It is always safe to set this option to
2338 off, but this introduces a slight performance penalty. The default
2341 * Python API Improvements
2343 ** GDB provides the new class gdb.LazyString. This is useful in
2344 some pretty-printing cases. The new method gdb.Value.lazy_string
2345 provides a simple way to create objects of this type.
2347 ** The fields returned by gdb.Type.fields now have an
2348 `is_base_class' attribute.
2350 ** The new method gdb.Type.range returns the range of an array type.
2352 ** The new method gdb.parse_and_eval can be used to parse and
2353 evaluate an expression.
2355 * New remote packets
2358 Define a trace state variable.
2361 Get the current value of a trace state variable.
2364 Set desired tracing behavior upon disconnection.
2367 Set the trace buffer to be linear or circular.
2370 Get data about the tracepoints currently in use.
2374 Process record now works correctly with hardware watchpoints.
2376 Multiple bug fixes have been made to the mips-irix port, making it
2377 much more reliable. In particular:
2378 - Debugging threaded applications is now possible again. Previously,
2379 GDB would hang while starting the program, or while waiting for
2380 the program to stop at a breakpoint.
2381 - Attaching to a running process no longer hangs.
2382 - An error occurring while loading a core file has been fixed.
2383 - Changing the value of the PC register now works again. This fixes
2384 problems observed when using the "jump" command, or when calling
2385 a function from GDB, or even when assigning a new value to $pc.
2386 - With the "finish" and "return" commands, the return value for functions
2387 returning a small array is now correctly printed.
2388 - It is now possible to break on shared library code which gets executed
2389 during a shared library init phase (code executed while executing
2390 their .init section). Previously, the breakpoint would have no effect.
2391 - GDB is now able to backtrace through the signal handler for
2392 non-threaded programs.
2394 PIE (Position Independent Executable) programs debugging is now supported.
2395 This includes debugging execution of PIC (Position Independent Code) shared
2396 libraries although for that, it should be possible to run such libraries as an
2399 *** Changes in GDB 7.0
2401 * GDB now has an interface for JIT compilation. Applications that
2402 dynamically generate code can create symbol files in memory and register
2403 them with GDB. For users, the feature should work transparently, and
2404 for JIT developers, the interface is documented in the GDB manual in the
2405 "JIT Compilation Interface" chapter.
2407 * Tracepoints may now be conditional. The syntax is as for
2408 breakpoints; either an "if" clause appended to the "trace" command,
2409 or the "condition" command is available. GDB sends the condition to
2410 the target for evaluation using the same bytecode format as is used
2411 for tracepoint actions.
2413 * The disassemble command now supports: an optional /r modifier, print the
2414 raw instructions in hex as well as in symbolic form, and an optional /m
2415 modifier to print mixed source+assembly.
2417 * Process record and replay
2419 In a architecture environment that supports ``process record and
2420 replay'', ``process record and replay'' target can record a log of
2421 the process execution, and replay it with both forward and reverse
2424 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2425 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2426 set execution-direction {forward|reverse}, for targets that support
2429 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2430 feature is available with a native GDB running on kernel version
2433 * GDB now has support for multi-byte and wide character sets on the
2434 target. Strings whose character type is wchar_t, char16_t, or
2435 char32_t are now correctly printed. GDB supports wide- and unicode-
2436 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2437 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2438 `printf'. This feature requires iconv to work properly; if your
2439 system does not have a working iconv, GDB can use GNU libiconv. See
2440 the installation instructions for more information.
2442 * GDB now supports automatic retrieval of shared library files from
2443 remote targets. To use this feature, specify a system root that begins
2444 with the `remote:' prefix, either via the `set sysroot' command or via
2445 the `--with-sysroot' configure-time option.
2447 * "info sharedlibrary" now takes an optional regex of libraries to show,
2448 and it now reports if a shared library has no debugging information.
2450 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2451 now complete on file names.
2453 * When completing in expressions, gdb will attempt to limit
2454 completions to allowable structure or union fields, where appropriate.
2455 For instance, consider:
2457 # struct example { int f1; double f2; };
2458 # struct example variable;
2461 If the user types TAB at the end of this command line, the available
2462 completions will be "f1" and "f2".
2464 * Inlined functions are now supported. They show up in backtraces, and
2465 the "step", "next", and "finish" commands handle them automatically.
2467 * GDB now supports the token-splicing (##) and stringification (#)
2468 operators when expanding macros. It also supports variable-arity
2471 * GDB now supports inspecting extra signal information, exported by
2472 the new $_siginfo convenience variable. The feature is currently
2473 implemented on linux ARM, i386 and amd64.
2475 * GDB can now display the VFP floating point registers and NEON vector
2476 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2477 can provide these registers (requires Linux 2.6.30 or later). Remote
2478 and simulator targets may also provide them.
2480 * New remote packets
2483 Search memory for a sequence of bytes.
2486 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2487 operation over reliable transport links. Use of this packet is
2488 controlled by the `set remote noack-packet' command.
2491 Kill the process with the specified process ID. Use this in preference
2492 to `k' when multiprocess protocol extensions are supported.
2495 Obtains additional operating system information
2499 Read or write additional signal information.
2501 * Removed remote protocol undocumented extension
2503 An undocumented extension to the remote protocol's `S' stop reply
2504 packet that permited the stub to pass a process id was removed.
2505 Remote servers should use the `T' stop reply packet instead.
2507 * GDB now supports multiple function calling conventions according to the
2508 DWARF-2 DW_AT_calling_convention function attribute.
2510 * The SH target utilizes the aforementioned change to distinguish between gcc
2511 and Renesas calling convention. It also adds the new CLI commands
2512 `set/show sh calling-convention'.
2514 * GDB can now read compressed debug sections, as produced by GNU gold
2515 with the --compress-debug-sections=zlib flag.
2517 * 64-bit core files are now supported on AIX.
2519 * Thread switching is now supported on Tru64.
2521 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2522 which will be allocated using malloc later in program execution.
2524 * The qXfer:libraries:read remote procotol packet now allows passing a
2525 list of section offsets.
2527 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2528 conditions handling signals delivered during attach or thread creation
2529 have also been fixed.
2531 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2532 From the user's standpoint, all unqualified instances of True and False
2533 are treated as the standard definitions, regardless of context.
2535 * GDB now parses C++ symbol and type names more flexibly. For
2538 template<typename T> class C { };
2541 GDB will now correctly handle all of:
2543 ptype C<char const *>
2544 ptype C<char const*>
2545 ptype C<const char *>
2546 ptype C<const char*>
2548 * New features in the GDB remote stub, gdbserver
2550 - The "--wrapper" command-line argument tells gdbserver to use a
2551 wrapper program to launch programs for debugging.
2553 - On PowerPC and S/390 targets, it is now possible to use a single
2554 gdbserver executable to debug both 32-bit and 64-bit programs.
2555 (This requires gdbserver itself to be built as a 64-bit executable.)
2557 - gdbserver uses the new noack protocol mode for TCP connections to
2558 reduce communications latency, if also supported and enabled in GDB.
2560 - Support for the sparc64-linux-gnu target is now included in
2563 - The amd64-linux build of gdbserver now supports debugging both
2564 32-bit and 64-bit programs.
2566 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2567 now support hardware watchpoints, and will use them automatically
2572 GDB now has support for scripting using Python. Whether this is
2573 available is determined at configure time.
2575 New GDB commands can now be written in Python.
2577 * Ada tasking support
2579 Ada tasks can now be inspected in GDB. The following commands have
2583 Print the list of Ada tasks.
2585 Print detailed information about task number N.
2587 Print the task number of the current task.
2589 Switch the context of debugging to task number N.
2591 * Support for user-defined prefixed commands. The "define" command can
2592 add new commands to existing prefixes, e.g. "target".
2594 * Multi-inferior, multi-process debugging.
2596 GDB now has generalized support for multi-inferior debugging. See
2597 "Debugging Multiple Inferiors" in the manual for more information.
2598 Although availability still depends on target support, the command
2599 set is more uniform now. The GNU/Linux specific multi-forks support
2600 has been migrated to this new framework. This implied some user
2601 visible changes; see "New commands" and also "Removed commands"
2604 * Target descriptions can now describe the target OS ABI. See the
2605 "Target Description Format" section in the user manual for more
2608 * Target descriptions can now describe "compatible" architectures
2609 to indicate that the target can execute applications for a different
2610 architecture in addition to those for the main target architecture.
2611 See the "Target Description Format" section in the user manual for
2614 * Multi-architecture debugging.
2616 GDB now includes general supports for debugging applications on
2617 hybrid systems that use more than one single processor architecture
2618 at the same time. Each such hybrid architecture still requires
2619 specific support to be added. The only hybrid architecture supported
2620 in this version of GDB is the Cell Broadband Engine.
2622 * GDB now supports integrated debugging of Cell/B.E. applications that
2623 use both the PPU and SPU architectures. To enable support for hybrid
2624 Cell/B.E. debugging, you need to configure GDB to support both the
2625 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2626 --enable-targets configure option.
2628 * Non-stop mode debugging.
2630 For some targets, GDB now supports an optional mode of operation in
2631 which you can examine stopped threads while other threads continue
2632 to execute freely. This is referred to as non-stop mode, with the
2633 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2634 section in the user manual for more information.
2636 To be able to support remote non-stop debugging, a remote stub needs
2637 to implement the non-stop mode remote protocol extensions, as
2638 described in the "Remote Non-Stop" section of the user manual. The
2639 GDB remote stub, gdbserver, has been adjusted to support these
2640 extensions on linux targets.
2642 * New commands (for set/show, see "New options" below)
2644 catch syscall [NAME(S) | NUMBER(S)]
2645 Catch system calls. Arguments, which should be names of system
2646 calls or their numbers, mean catch only those syscalls. Without
2647 arguments, every syscall will be caught. When the inferior issues
2648 any of the specified syscalls, GDB will stop and announce the system
2649 call, both when it is called and when its call returns. This
2650 feature is currently available with a native GDB running on the
2651 Linux Kernel, under the following architectures: x86, x86_64,
2652 PowerPC and PowerPC64.
2654 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2656 Search memory for a sequence of bytes.
2658 maint set python print-stack
2659 maint show python print-stack
2660 Show a stack trace when an error is encountered in a Python script.
2663 Invoke CODE by passing it to the Python interpreter.
2668 These allow macros to be defined, undefined, and listed
2672 Show operating system information about processes.
2675 List the inferiors currently under GDB's control.
2678 Switch focus to inferior number NUM.
2681 Detach from inferior number NUM.
2684 Kill inferior number NUM.
2688 set spu stop-on-load
2689 show spu stop-on-load
2690 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2692 set spu auto-flush-cache
2693 show spu auto-flush-cache
2694 Control whether to automatically flush the software-managed cache
2695 during Cell/B.E. debugging.
2697 set sh calling-convention
2698 show sh calling-convention
2699 Control the calling convention used when calling SH target functions.
2702 show debug timestamp
2703 Control display of timestamps with GDB debugging output.
2705 set disassemble-next-line
2706 show disassemble-next-line
2707 Control display of disassembled source lines or instructions when
2710 set remote noack-packet
2711 show remote noack-packet
2712 Set/show the use of remote protocol QStartNoAckMode packet. See above
2713 under "New remote packets."
2715 set remote query-attached-packet
2716 show remote query-attached-packet
2717 Control use of remote protocol `qAttached' (query-attached) packet.
2719 set remote read-siginfo-object
2720 show remote read-siginfo-object
2721 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2724 set remote write-siginfo-object
2725 show remote write-siginfo-object
2726 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2729 set remote reverse-continue
2730 show remote reverse-continue
2731 Control use of remote protocol 'bc' (reverse-continue) packet.
2733 set remote reverse-step
2734 show remote reverse-step
2735 Control use of remote protocol 'bs' (reverse-step) packet.
2737 set displaced-stepping
2738 show displaced-stepping
2739 Control displaced stepping mode. Displaced stepping is a way to
2740 single-step over breakpoints without removing them from the debuggee.
2741 Also known as "out-of-line single-stepping".
2744 show debug displaced
2745 Control display of debugging info for displaced stepping.
2747 maint set internal-error
2748 maint show internal-error
2749 Control what GDB does when an internal error is detected.
2751 maint set internal-warning
2752 maint show internal-warning
2753 Control what GDB does when an internal warning is detected.
2758 Use a wrapper program to launch programs for debugging.
2760 set multiple-symbols (all|ask|cancel)
2761 show multiple-symbols
2762 The value of this variable can be changed to adjust the debugger behavior
2763 when an expression or a breakpoint location contains an ambiguous symbol
2764 name (an overloaded function name, for instance).
2766 set breakpoint always-inserted
2767 show breakpoint always-inserted
2768 Keep breakpoints always inserted in the target, as opposed to inserting
2769 them when resuming the target, and removing them when the target stops.
2770 This option can improve debugger performance on slow remote targets.
2772 set arm fallback-mode (arm|thumb|auto)
2773 show arm fallback-mode
2774 set arm force-mode (arm|thumb|auto)
2776 These commands control how ARM GDB determines whether instructions
2777 are ARM or Thumb. The default for both settings is auto, which uses
2778 the current CPSR value for instructions without symbols; previous
2779 versions of GDB behaved as if "set arm fallback-mode arm".
2781 set disable-randomization
2782 show disable-randomization
2783 Standalone programs run with the virtual address space randomization enabled
2784 by default on some platforms. This option keeps the addresses stable across
2785 multiple debugging sessions.
2789 Control whether other threads are stopped or not when some thread hits
2794 Requests that asynchronous execution is enabled in the target, if available.
2795 In this case, it's possible to resume target in the background, and interact
2796 with GDB while the target is running. "show target-async" displays the
2797 current state of asynchronous execution of the target.
2799 set target-wide-charset
2800 show target-wide-charset
2801 The target-wide-charset is the name of the character set that GDB
2802 uses when printing characters whose type is wchar_t.
2804 set tcp auto-retry (on|off)
2806 set tcp connect-timeout
2807 show tcp connect-timeout
2808 These commands allow GDB to retry failed TCP connections to a remote stub
2809 with a specified timeout period; this is useful if the stub is launched
2810 in parallel with GDB but may not be ready to accept connections immediately.
2812 set libthread-db-search-path
2813 show libthread-db-search-path
2814 Control list of directories which GDB will search for appropriate
2817 set schedule-multiple (on|off)
2818 show schedule-multiple
2819 Allow GDB to resume all threads of all processes or only threads of
2820 the current process.
2824 Use more aggressive caching for accesses to the stack. This improves
2825 performance of remote debugging (particularly backtraces) without
2826 affecting correctness.
2828 set interactive-mode (on|off|auto)
2829 show interactive-mode
2830 Control whether GDB runs in interactive mode (on) or not (off).
2831 When in interactive mode, GDB waits for the user to answer all
2832 queries. Otherwise, GDB does not wait and assumes the default
2833 answer. When set to auto (the default), GDB determines which
2834 mode to use based on the stdin settings.
2839 For program forks, this is replaced by the new more generic `info
2840 inferiors' command. To list checkpoints, you can still use the
2841 `info checkpoints' command, which was an alias for the `info forks'
2845 Replaced by the new `inferior' command. To switch between
2846 checkpoints, you can still use the `restart' command, which was an
2847 alias for the `fork' command.
2850 This is removed, since some targets don't have a notion of
2851 processes. To switch between processes, you can still use the
2852 `inferior' command using GDB's own inferior number.
2855 For program forks, this is replaced by the new more generic `kill
2856 inferior' command. To delete a checkpoint, you can still use the
2857 `delete checkpoint' command, which was an alias for the `delete
2861 For program forks, this is replaced by the new more generic `detach
2862 inferior' command. To detach a checkpoint, you can still use the
2863 `detach checkpoint' command, which was an alias for the `detach
2866 * New native configurations
2868 x86/x86_64 Darwin i[34567]86-*-darwin*
2870 x86_64 MinGW x86_64-*-mingw*
2874 Lattice Mico32 lm32-*
2875 x86 DICOS i[34567]86-*-dicos*
2876 x86_64 DICOS x86_64-*-dicos*
2879 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2880 (mingw32ce) debugging.
2886 These commands were actually not implemented on any target.
2888 *** Changes in GDB 6.8
2890 * New native configurations
2892 NetBSD/hppa hppa*-*netbsd*
2893 Xtensa GNU/Linux xtensa*-*-linux*
2897 NetBSD/hppa hppa*-*-netbsd*
2898 Xtensa GNU/Lunux xtensa*-*-linux*
2900 * Change in command line behavior -- corefiles vs. process ids.
2902 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2903 attaching to process NUMBER fails, GDB no longer attempts to open a
2904 core file named NUMBER. Attaching to a program using the -c option
2905 is no longer supported. Instead, use the '-p' or '--pid' options.
2907 * GDB can now be built as a native debugger for debugging Windows x86
2908 (mingw32) Portable Executable (PE) programs.
2910 * Pending breakpoints no longer change their number when their address
2913 * GDB now supports breakpoints with multiple locations,
2914 including breakpoints on C++ constructors, inside C++ templates,
2915 and in inlined functions.
2917 * GDB's ability to debug optimized code has been improved. GDB more
2918 accurately identifies function bodies and lexical blocks that occupy
2919 more than one contiguous range of addresses.
2921 * Target descriptions can now describe registers for PowerPC.
2923 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2924 registers on PowerPC targets.
2926 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2927 targets even when the libthread_db library is not available.
2929 * The GDB remote stub, gdbserver, now supports the new file transfer
2930 commands (remote put, remote get, and remote delete).
2932 * The GDB remote stub, gdbserver, now supports run and attach in
2933 extended-remote mode.
2935 * hppa*64*-*-hpux11* target broken
2936 The debugger is unable to start a program and fails with the following
2937 error: "Error trying to get information about dynamic linker".
2938 The gdb-6.7 release is also affected.
2940 * GDB now supports the --enable-targets= configure option to allow
2941 building a single GDB executable that supports multiple remote
2942 target architectures.
2944 * GDB now supports debugging C and C++ programs which use the
2945 Decimal Floating Point extension. In addition, the PowerPC target
2946 now has a set of pseudo-registers to inspect decimal float values
2947 stored in two consecutive float registers.
2949 * The -break-insert MI command can optionally create pending
2952 * Improved support for debugging Ada
2953 Many improvements to the Ada language support have been made. These
2955 - Better support for Ada2005 interface types
2956 - Improved handling of arrays and slices in general
2957 - Better support for Taft-amendment types
2958 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2960 - Improved command completion in Ada
2963 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2968 set print frame-arguments (all|scalars|none)
2969 show print frame-arguments
2970 The value of this variable can be changed to control which argument
2971 values should be printed by the debugger when displaying a frame.
2976 Transfer files to and from a remote target, and delete remote files.
2983 Transfer files to and from a remote target, and delete remote files.
2985 * New remote packets
2992 Open, close, read, write, and delete files on the remote system.
2995 Attach to an existing process on the remote system, in extended-remote
2999 Run a new process on the remote system, in extended-remote mode.
3001 *** Changes in GDB 6.7
3003 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3004 bfd, libiberty and opcodes, as revealed by static analysis donated by
3005 Coverity, Inc. (http://scan.coverity.com).
3007 * When looking up multiply-defined global symbols, GDB will now prefer the
3008 symbol definition in the current shared library if it was built using the
3009 -Bsymbolic linker option.
3011 * When the Text User Interface (TUI) is not configured, GDB will now
3012 recognize the -tui command-line option and print a message that the TUI
3015 * The GDB remote stub, gdbserver, now has lower overhead for high
3016 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3018 * GDB for MIPS targets now autodetects whether a remote target provides
3019 32-bit or 64-bit register values.
3021 * Support for C++ member pointers has been improved.
3023 * GDB now understands XML target descriptions, which specify the
3024 target's overall architecture. GDB can read a description from
3025 a local file or over the remote serial protocol.
3027 * Vectors of single-byte data use a new integer type which is not
3028 automatically displayed as character or string data.
3030 * The /s format now works with the print command. It displays
3031 arrays of single-byte integers and pointers to single-byte integers
3034 * Target descriptions can now describe target-specific registers,
3035 for architectures which have implemented the support (currently
3036 only ARM, M68K, and MIPS).
3038 * GDB and the GDB remote stub, gdbserver, now support the XScale
3041 * The GDB remote stub, gdbserver, has been updated to support
3042 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3043 has been rewritten to use the standard GDB remote protocol.
3045 * GDB can now step into C++ functions which are called through thunks.
3047 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3049 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3050 layout. It also supports a TextSeg= and DataSeg= response when only
3051 segment base addresses (rather than offsets) are available.
3053 * The /i format now outputs any trailing branch delay slot instructions
3054 immediately following the last instruction within the count specified.
3056 * The GDB remote protocol "T" stop reply packet now supports a
3057 "library" response. Combined with the new "qXfer:libraries:read"
3058 packet, this response allows GDB to debug shared libraries on targets
3059 where the operating system manages the list of loaded libraries (e.g.
3060 Windows and SymbianOS).
3062 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3063 (DLLs) on Windows and Windows CE targets.
3065 * GDB now supports a faster verification that a .debug file matches its binary
3066 according to its build-id signature, if the signature is present.
3072 Enable or disable hardware flow control (RTS/CTS) on the serial port
3073 when debugging using remote targets.
3075 set mem inaccessible-by-default
3076 show mem inaccessible-by-default
3077 If the target supplies a memory map, for instance via the remote
3078 protocol's "qXfer:memory-map:read" packet, setting this variable
3079 prevents GDB from accessing memory outside the memory map. This
3080 is useful for targets with memory mapped registers or which react
3081 badly to accesses of unmapped address space.
3083 set breakpoint auto-hw
3084 show breakpoint auto-hw
3085 If the target supplies a memory map, for instance via the remote
3086 protocol's "qXfer:memory-map:read" packet, setting this variable
3087 lets GDB use hardware breakpoints automatically for memory regions
3088 where it can not use software breakpoints. This covers both the
3089 "break" command and internal breakpoints used for other commands
3090 including "next" and "finish".
3093 catch exception unhandled
3094 Stop the program execution when Ada exceptions are raised.
3097 Stop the program execution when an Ada assertion failed.
3101 Set an alternate system root for target files. This is a more
3102 general version of "set solib-absolute-prefix", which is now
3103 an alias to "set sysroot".
3106 Provide extended SPU facility status information. This set of
3107 commands is available only when debugging the Cell/B.E. SPU
3110 * New native configurations
3112 OpenBSD/sh sh*-*openbsd*
3115 unset tdesc filename
3117 Use the specified local file as an XML target description, and do
3118 not query the target for its built-in description.
3122 OpenBSD/sh sh*-*-openbsd*
3123 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3124 Toshiba Media Processor mep-elf
3126 * New remote packets
3129 Ignore the specified signals; pass them directly to the debugged program
3130 without stopping other threads or reporting them to GDB.
3132 qXfer:features:read:
3133 Read an XML target description from the target, which describes its
3138 Read or write contents of an spufs file on the target system. These
3139 packets are available only on the Cell/B.E. SPU architecture.
3141 qXfer:libraries:read:
3142 Report the loaded shared libraries. Combined with new "T" packet
3143 response, this packet allows GDB to debug shared libraries on
3144 targets where the operating system manages the list of loaded
3145 libraries (e.g. Windows and SymbianOS).
3149 Support for these obsolete configurations has been removed.
3157 i[34567]86-*-lynxos*
3158 i[34567]86-*-netware*
3159 i[34567]86-*-sco3.2v5*
3160 i[34567]86-*-sco3.2v4*
3162 i[34567]86-*-sysv4.2*
3165 i[34567]86-*-unixware2*
3166 i[34567]86-*-unixware*
3175 * Other removed features
3182 Various m68k-only ROM monitors.
3189 Various Renesas ROM monitors and debugging interfaces for SH and
3194 Support for a Macraigor serial interface to on-chip debugging.
3195 GDB does not directly support the newer parallel or USB
3200 A debug information format. The predecessor to DWARF 2 and
3201 DWARF 3, which are still supported.
3203 Support for the HP aCC compiler on HP-UX/PA-RISC
3205 SOM-encapsulated symbolic debugging information, automatic
3206 invocation of pxdb, and the aCC custom C++ ABI. This does not
3207 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3208 with aCC can still be debugged on an assembly level.
3210 MIPS ".pdr" sections
3212 A MIPS-specific format used to describe stack frame layout
3213 in debugging information.
3217 GDB could work with an older version of Guile to debug
3218 the interpreter and Scheme programs running in it.
3220 set mips stack-arg-size
3221 set mips saved-gpreg-size
3223 Use "set mips abi" to control parameter passing for MIPS.
3225 *** Changes in GDB 6.6
3230 Cell Broadband Engine SPU spu-elf
3232 * GDB can now be configured as a cross-debugger targeting native Windows
3233 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3234 running on a Windows system over TCP/IP to debug Windows programs.
3236 * The GDB remote stub, gdbserver, has been updated to support Windows and
3237 Cygwin debugging. Both single-threaded and multi-threaded programs are
3240 * The "set trust-readonly-sections" command works again. This command was
3241 broken in GDB 6.3, 6.4, and 6.5.
3243 * The "load" command now supports writing to flash memory, if the remote
3244 stub provides the required support.
3246 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3247 longer requires symbolic debug information (e.g. DWARF-2).
3252 unset substitute-path
3253 show substitute-path
3254 Manage a list of substitution rules that GDB uses to rewrite the name
3255 of the directories where the sources are located. This can be useful
3256 for instance when the sources were moved to a different location
3257 between compilation and debugging.
3261 Print each CLI command as it is executed. Each command is prefixed with
3262 a number of `+' symbols representing the nesting depth.
3263 The source command now has a `-v' option to enable the same feature.
3267 The ARM Demon monitor support (RDP protocol, "target rdp").
3269 Kernel Object Display, an embedded debugging feature which only worked with
3270 an obsolete version of Cisco IOS.
3272 The 'set download-write-size' and 'show download-write-size' commands.
3274 * New remote packets
3277 Tell a stub about GDB client features, and request remote target features.
3278 The first feature implemented is PacketSize, which allows the target to
3279 specify the size of packets it can handle - to minimize the number of
3280 packets required and improve performance when connected to a remote
3284 Fetch an OS auxilliary vector from the remote stub. This packet is a
3285 more efficient replacement for qPart:auxv:read.
3287 qXfer:memory-map:read:
3288 Fetch a memory map from the remote stub, including information about
3289 RAM, ROM, and flash memory devices.
3294 Erase and program a flash memory device.
3296 * Removed remote packets
3299 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3300 used it, and only gdbserver implemented it.
3302 *** Changes in GDB 6.5
3306 Renesas M32C/M16C m32c-elf
3308 Morpho Technologies ms1 ms1-elf
3312 init-if-undefined Initialize a convenience variable, but
3313 only if it doesn't already have a value.
3315 The following commands are presently only implemented for native GNU/Linux:
3317 checkpoint Save a snapshot of the program state.
3319 restart <n> Return the program state to a
3320 previously saved state.
3322 info checkpoints List currently saved checkpoints.
3324 delete-checkpoint <n> Delete a previously saved checkpoint.
3326 set|show detach-on-fork Tell gdb whether to detach from a newly
3327 forked process, or to keep debugging it.
3329 info forks List forks of the user program that
3330 are available to be debugged.
3332 fork <n> Switch to debugging one of several
3333 forks of the user program that are
3334 available to be debugged.
3336 delete-fork <n> Delete a fork from the list of forks
3337 that are available to be debugged (and
3338 kill the forked process).
3340 detach-fork <n> Delete a fork from the list of forks
3341 that are available to be debugged (and
3342 allow the process to continue).
3346 Morpho Technologies ms2 ms1-elf
3348 * Improved Windows host support
3350 GDB now builds as a cross debugger hosted on i686-mingw32, including
3351 native console support, and remote communications using either
3352 network sockets or serial ports.
3354 * Improved Modula-2 language support
3356 GDB can now print most types in the Modula-2 syntax. This includes:
3357 basic types, set types, record types, enumerated types, range types,
3358 pointer types and ARRAY types. Procedure var parameters are correctly
3359 printed and hexadecimal addresses and character constants are also
3360 written in the Modula-2 syntax. Best results can be obtained by using
3361 GNU Modula-2 together with the -gdwarf-2 command line option.
3365 The ARM rdi-share module.
3367 The Netware NLM debug server.
3369 *** Changes in GDB 6.4
3371 * New native configurations
3373 OpenBSD/arm arm*-*-openbsd*
3374 OpenBSD/mips64 mips64-*-openbsd*
3378 Morpho Technologies ms1 ms1-elf
3380 * New command line options
3382 --batch-silent As for --batch, but totally silent.
3383 --return-child-result The debugger will exist with the same value
3384 the child (debugged) program exited with.
3385 --eval-command COMMAND, -ex COMMAND
3386 Execute a single GDB CLI command. This may be
3387 specified multiple times and in conjunction
3388 with the --command (-x) option.
3390 * Deprecated commands removed
3392 The following commands, that were deprecated in 2000, have been
3396 set|show arm disassembly-flavor set|show arm disassembler
3397 othernames set arm disassembler
3398 set|show remotedebug set|show debug remote
3399 set|show archdebug set|show debug arch
3400 set|show eventdebug set|show debug event
3403 * New BSD user-level threads support
3405 It is now possible to debug programs using the user-level threads
3406 library on OpenBSD and FreeBSD. Currently supported (target)
3409 FreeBSD/amd64 x86_64-*-freebsd*
3410 FreeBSD/i386 i386-*-freebsd*
3411 OpenBSD/i386 i386-*-openbsd*
3413 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3414 are not yet supported.
3416 * New support for Matsushita MN10300 w/sim added
3417 (Work in progress). mn10300-elf.
3419 * REMOVED configurations and files
3421 VxWorks and the XDR protocol *-*-vxworks
3422 Motorola MCORE mcore-*-*
3423 National Semiconductor NS32000 ns32k-*-*
3425 * New "set print array-indexes" command
3427 After turning this setting "on", GDB prints the index of each element
3428 when displaying arrays. The default is "off" to preserve the previous
3431 * VAX floating point support
3433 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3435 * User-defined command support
3437 In addition to using $arg0..$arg9 for argument passing, it is now possible
3438 to use $argc to determine now many arguments have been passed. See the
3439 section on user-defined commands in the user manual for more information.
3441 *** Changes in GDB 6.3:
3443 * New command line option
3445 GDB now accepts -l followed by a number to set the timeout for remote
3448 * GDB works with GCC -feliminate-dwarf2-dups
3450 GDB now supports a more compact representation of DWARF-2 debug
3451 information using DW_FORM_ref_addr references. These are produced
3452 by GCC with the option -feliminate-dwarf2-dups and also by some
3453 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3454 to use -feliminate-dwarf2-dups.
3456 * Internationalization
3458 When supported by the host system, GDB will be built with
3459 internationalization (libintl). The task of marking up the sources is
3460 continued, we're looking forward to our first translation.
3464 Initial support for debugging programs compiled with the GNAT
3465 implementation of the Ada programming language has been integrated
3466 into GDB. In this release, support is limited to expression evaluation.
3468 * New native configurations
3470 GNU/Linux/m32r m32r-*-linux-gnu
3474 GDB's remote protocol now includes support for the 'p' packet. This
3475 packet is used to fetch individual registers from a remote inferior.
3477 * END-OF-LIFE registers[] compatibility module
3479 GDB's internal register infrastructure has been completely rewritten.
3480 The new infrastructure making possible the implementation of key new
3481 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3484 GDB 6.3 will be the last release to include the the registers[]
3485 compatibility module that allowed out-of-date configurations to
3486 continue to work. This change directly impacts the following
3496 powerpc bdm protocol
3498 Unless there is activity to revive these configurations, they will be
3499 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3501 * OBSOLETE configurations and files
3503 Configurations that have been declared obsolete in this release have
3504 been commented out. Unless there is activity to revive these
3505 configurations, the next release of GDB will have their sources
3506 permanently REMOVED.
3515 *** Changes in GDB 6.2.1:
3517 * MIPS `break main; run' gave an heuristic-fence-post warning
3519 When attempting to run even a simple program, a warning about
3520 heuristic-fence-post being hit would be reported. This problem has
3523 * MIPS IRIX 'long double' crashed GDB
3525 When examining a long double variable, GDB would get a segmentation
3526 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3527 IRIX long double values).
3531 A bug in the VAX stack code was causing problems with the "next"
3532 command. This problem has been fixed.
3534 *** Changes in GDB 6.2:
3536 * Fix for ``many threads''
3538 On GNU/Linux systems that use the NPTL threads library, a program
3539 rapidly creating and deleting threads would confuse GDB leading to the
3542 ptrace: No such process.
3543 thread_db_get_info: cannot get thread info: generic error
3545 This problem has been fixed.
3547 * "-async" and "-noasync" options removed.
3549 Support for the broken "-noasync" option has been removed (it caused
3552 * New ``start'' command.
3554 This command runs the program until the begining of the main procedure.
3556 * New BSD Kernel Data Access Library (libkvm) interface
3558 Using ``target kvm'' it is now possible to debug kernel core dumps and
3559 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3560 platforms. Currently supported (native-only) configurations are:
3562 FreeBSD/amd64 x86_64-*-freebsd*
3563 FreeBSD/i386 i?86-*-freebsd*
3564 NetBSD/i386 i?86-*-netbsd*
3565 NetBSD/m68k m68*-*-netbsd*
3566 NetBSD/sparc sparc-*-netbsd*
3567 OpenBSD/amd64 x86_64-*-openbsd*
3568 OpenBSD/i386 i?86-*-openbsd*
3569 OpenBSD/m68k m68*-openbsd*
3570 OpenBSD/sparc sparc-*-openbsd*
3572 * Signal trampoline code overhauled
3574 Many generic problems with GDB's signal handling code have been fixed.
3575 These include: backtraces through non-contiguous stacks; recognition
3576 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3577 call; backtrace through a signal trampoline; step into and out of
3578 signal handlers; and single-stepping in the signal trampoline.
3580 Please note that kernel bugs are a limiting factor here. These
3581 features have been shown to work on an s390 GNU/Linux system that
3582 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3584 * Cygwin support for DWARF 2 added.
3586 * New native configurations
3588 GNU/Linux/hppa hppa*-*-linux*
3589 OpenBSD/hppa hppa*-*-openbsd*
3590 OpenBSD/m68k m68*-*-openbsd*
3591 OpenBSD/m88k m88*-*-openbsd*
3592 OpenBSD/powerpc powerpc-*-openbsd*
3593 NetBSD/vax vax-*-netbsd*
3594 OpenBSD/vax vax-*-openbsd*
3596 * END-OF-LIFE frame compatibility module
3598 GDB's internal frame infrastructure has been completely rewritten.
3599 The new infrastructure making it possible to support key new features
3600 including DWARF 2 Call Frame Information. To aid in the task of
3601 migrating old configurations to this new infrastructure, a
3602 compatibility module, that allowed old configurations to continue to
3603 work, was also included.
3605 GDB 6.2 will be the last release to include this frame compatibility
3606 module. This change directly impacts the following configurations:
3616 Unless there is activity to revive these configurations, they will be
3617 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3619 * REMOVED configurations and files
3621 Sun 3, running SunOS 3 m68*-*-sunos3*
3622 Sun 3, running SunOS 4 m68*-*-sunos4*
3623 Sun 2, running SunOS 3 m68000-*-sunos3*
3624 Sun 2, running SunOS 4 m68000-*-sunos4*
3625 Motorola 680x0 running LynxOS m68*-*-lynxos*
3626 AT&T 3b1/Unix pc m68*-att-*
3627 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3628 decstation mips-dec-* mips-little-*
3629 riscos mips-*-riscos* mips-*-sysv*
3630 sonymips mips-sony-*
3631 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3633 *** Changes in GDB 6.1.1:
3635 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3637 The TUI (Text-mode User Interface) is now built as part of a default
3638 GDB configuration. It is enabled by either selecting the TUI with the
3639 command line option "-i=tui" or by running the separate "gdbtui"
3640 program. For more information on the TUI, see the manual "Debugging
3643 * Pending breakpoint support (also included in GDB 6.1)
3645 Support has been added to allow you to specify breakpoints in shared
3646 libraries that have not yet been loaded. If a breakpoint location
3647 cannot be found, and the "breakpoint pending" option is set to auto,
3648 GDB queries you if you wish to make the breakpoint pending on a future
3649 shared-library load. If and when GDB resolves the breakpoint symbol,
3650 the pending breakpoint is removed as one or more regular breakpoints
3653 Pending breakpoints are very useful for GCJ Java debugging.
3655 * Fixed ISO-C build problems
3657 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3658 non ISO-C code that stopped them being built using a more strict ISO-C
3659 compiler (e.g., IBM's C compiler).
3661 * Fixed build problem on IRIX 5
3663 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3664 wasn't able to compile compile on an IRIX 5 system.
3666 * Added execute permission to gdb/gdbserver/configure
3668 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3669 permission. This bug would cause configure to fail on a number of
3670 systems (Solaris, IRIX). Ref: server/519.
3672 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3674 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3675 has been updated to use constant array sizes.
3677 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3679 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3680 its generated DWARF Call Frame Info. This encoding was causing GDB to
3681 panic, that panic has been fixed. Ref: gdb/1628.
3683 * Fixed a problem when examining parameters in shared library code.
3685 When examining parameters in optimized shared library code generated
3686 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3687 not available''. GDB now correctly displays the variable's value.
3689 *** Changes in GDB 6.1:
3691 * Removed --with-mmalloc
3693 Support for the mmalloc memory manager has been removed, as it
3694 conflicted with the internal gdb byte cache.
3696 * Changes in AMD64 configurations
3698 The AMD64 target now includes the %cs and %ss registers. As a result
3699 the AMD64 remote protocol has changed; this affects the floating-point
3700 and SSE registers. If you rely on those registers for your debugging,
3701 you should upgrade gdbserver on the remote side.
3703 * Revised SPARC target
3705 The SPARC target has been completely revised, incorporating the
3706 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3707 support for LynxOS and SunOS 4 has been dropped. Calling functions
3708 from within GDB on operating systems with a non-executable stack
3709 (Solaris, OpenBSD) now works.
3713 GDB has a new C++ demangler which does a better job on the mangled
3714 names generated by current versions of g++. It also runs faster, so
3715 with this and other changes gdb should now start faster on large C++
3718 * DWARF 2 Location Expressions
3720 GDB support for location expressions has been extended to support function
3721 arguments and frame bases. Older versions of GDB could crash when they
3724 * C++ nested types and namespaces
3726 GDB's support for nested types and namespaces in C++ has been
3727 improved, especially if you use the DWARF 2 debugging format. (This
3728 is the default for recent versions of GCC on most platforms.)
3729 Specifically, if you have a class "Inner" defined within a class or
3730 namespace "Outer", then GDB realizes that the class's name is
3731 "Outer::Inner", not simply "Inner". This should greatly reduce the
3732 frequency of complaints about not finding RTTI symbols. In addition,
3733 if you are stopped at inside of a function defined within a namespace,
3734 GDB modifies its name lookup accordingly.
3736 * New native configurations
3738 NetBSD/amd64 x86_64-*-netbsd*
3739 OpenBSD/amd64 x86_64-*-openbsd*
3740 OpenBSD/alpha alpha*-*-openbsd*
3741 OpenBSD/sparc sparc-*-openbsd*
3742 OpenBSD/sparc64 sparc64-*-openbsd*
3744 * New debugging protocols
3746 M32R with SDI protocol m32r-*-elf*
3748 * "set prompt-escape-char" command deleted.
3750 The command "set prompt-escape-char" has been deleted. This command,
3751 and its very obscure effet on GDB's prompt, was never documented,
3752 tested, nor mentioned in the NEWS file.
3754 * OBSOLETE configurations and files
3756 Configurations that have been declared obsolete in this release have
3757 been commented out. Unless there is activity to revive these
3758 configurations, the next release of GDB will have their sources
3759 permanently REMOVED.
3761 Sun 3, running SunOS 3 m68*-*-sunos3*
3762 Sun 3, running SunOS 4 m68*-*-sunos4*
3763 Sun 2, running SunOS 3 m68000-*-sunos3*
3764 Sun 2, running SunOS 4 m68000-*-sunos4*
3765 Motorola 680x0 running LynxOS m68*-*-lynxos*
3766 AT&T 3b1/Unix pc m68*-att-*
3767 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3768 decstation mips-dec-* mips-little-*
3769 riscos mips-*-riscos* mips-*-sysv*
3770 sonymips mips-sony-*
3771 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3773 * REMOVED configurations and files
3775 SGI Irix-4.x mips-sgi-irix4 or iris4
3776 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3777 Z8000 simulator z8k-zilog-none or z8ksim
3778 Matsushita MN10200 w/simulator mn10200-*-*
3779 H8/500 simulator h8500-hitachi-hms or h8500hms
3780 HP/PA running BSD hppa*-*-bsd*
3781 HP/PA running OSF/1 hppa*-*-osf*
3782 HP/PA Pro target hppa*-*-pro*
3783 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3784 386BSD i[3456]86-*-bsd*
3785 Sequent family i[3456]86-sequent-sysv4*
3786 i[3456]86-sequent-sysv*
3787 i[3456]86-sequent-bsd*
3788 SPARC running LynxOS sparc-*-lynxos*
3789 SPARC running SunOS 4 sparc-*-sunos4*
3790 Tsqware Sparclet sparclet-*-*
3791 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3793 *** Changes in GDB 6.0:
3797 Support for debugging the Objective-C programming language has been
3798 integrated into GDB.
3800 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3802 DWARF 2's Call Frame Information makes available compiler generated
3803 information that more exactly describes the program's run-time stack.
3804 By using this information, GDB is able to provide more robust stack
3807 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3808 have been updated to use a new backtrace mechanism which includes
3809 DWARF 2 CFI support.
3813 GDB's remote protocol has been extended to include support for hosted
3814 file I/O (where the remote target uses GDB's file system). See GDB's
3815 remote protocol documentation for details.
3817 * All targets using the new architecture framework.
3819 All of GDB's targets have been updated to use the new internal
3820 architecture framework. The way is now open for future GDB releases
3821 to include cross-architecture native debugging support (i386 on amd64,
3824 * GNU/Linux's Thread Local Storage (TLS)
3826 GDB now includes support for for the GNU/Linux implementation of
3827 per-thread variables.
3829 * GNU/Linux's Native POSIX Thread Library (NPTL)
3831 GDB's thread code has been updated to work with either the new
3832 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3834 * Separate debug info.
3836 GDB, in conjunction with BINUTILS, now supports a mechanism for
3837 automatically loading debug information from a separate file. Instead
3838 of shipping full debug and non-debug versions of system libraries,
3839 system integrators can now instead ship just the stripped libraries
3840 and optional debug files.
3842 * DWARF 2 Location Expressions
3844 DWARF 2 Location Expressions allow the compiler to more completely
3845 describe the location of variables (even in optimized code) to the
3848 GDB now includes preliminary support for location expressions (support
3849 for DW_OP_piece is still missing).
3853 A number of long standing bugs that caused GDB to die while starting a
3854 Java application have been fixed. GDB's Java support is now
3855 considered "useable".
3857 * GNU/Linux support for fork, vfork, and exec.
3859 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3860 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3863 * GDB supports logging output to a file
3865 There are two new commands, "set logging" and "show logging", which can be
3866 used to capture GDB's output to a file.
3868 * The meaning of "detach" has changed for gdbserver
3870 The "detach" command will now resume the application, as documented. To
3871 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3874 * d10v, m68hc11 `regs' command deprecated
3876 The `info registers' command has been updated so that it displays the
3877 registers using a format identical to the old `regs' command.
3881 A new command, "maint set profile on/off", has been added. This command can
3882 be used to enable or disable profiling while running GDB, to profile a
3883 session or a set of commands. In addition there is a new configure switch,
3884 "--enable-profiling", which will cause GDB to be compiled with profiling
3885 data, for more informative profiling results.
3887 * Default MI syntax changed to "mi2".
3889 The default MI (machine interface) syntax, enabled by the command line
3890 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3891 "mi1", can be enabled by specifying the option "-i=mi1".
3893 Support for the original "mi0" syntax (included in GDB 5.0) has been
3896 Fix for gdb/192: removed extraneous space when displaying frame level.
3897 Fix for gdb/672: update changelist is now output in mi list format.
3898 Fix for gdb/702: a -var-assign that updates the value now shows up
3899 in a subsequent -var-update.
3901 * New native configurations.
3903 FreeBSD/amd64 x86_64-*-freebsd*
3905 * Multi-arched targets.
3907 HP/PA HPUX11 hppa*-*-hpux*
3908 Renesas M32R/D w/simulator m32r-*-elf*
3910 * OBSOLETE configurations and files
3912 Configurations that have been declared obsolete in this release have
3913 been commented out. Unless there is activity to revive these
3914 configurations, the next release of GDB will have their sources
3915 permanently REMOVED.
3917 Z8000 simulator z8k-zilog-none or z8ksim
3918 Matsushita MN10200 w/simulator mn10200-*-*
3919 H8/500 simulator h8500-hitachi-hms or h8500hms
3920 HP/PA running BSD hppa*-*-bsd*
3921 HP/PA running OSF/1 hppa*-*-osf*
3922 HP/PA Pro target hppa*-*-pro*
3923 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3924 Sequent family i[3456]86-sequent-sysv4*
3925 i[3456]86-sequent-sysv*
3926 i[3456]86-sequent-bsd*
3927 Tsqware Sparclet sparclet-*-*
3928 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3930 * REMOVED configurations and files
3933 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3934 IBM AIX PS/2 i[3456]86-*-aix
3935 i386 running Mach 3.0 i[3456]86-*-mach3*
3936 i386 running Mach i[3456]86-*-mach*
3937 i386 running OSF/1 i[3456]86-*osf1mk*
3938 HP/Apollo 68k Family m68*-apollo*-sysv*,
3940 m68*-hp-bsd*, m68*-hp-hpux*
3941 Argonaut Risc Chip (ARC) arc-*-*
3942 Mitsubishi D30V d30v-*-*
3943 Fujitsu FR30 fr30-*-elf*
3944 OS/9000 i[34]86-*-os9k
3945 I960 with MON960 i960-*-coff
3947 * MIPS $fp behavior changed
3949 The convenience variable $fp, for the MIPS, now consistently returns
3950 the address of the current frame's base. Previously, depending on the
3951 context, $fp could refer to either $sp or the current frame's base
3952 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3953 The GNU Source-Level Debugger''.
3955 *** Changes in GDB 5.3:
3957 * GNU/Linux shared library multi-threaded performance improved.
3959 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3960 `/proc', in preference to `ptrace' for memory reads. This may result
3961 in an improvement in the start-up time of multi-threaded, shared
3962 library applications when run under GDB. One GDB user writes: ``loads
3963 shared libs like mad''.
3965 * ``gdbserver'' now supports multi-threaded applications on some targets
3967 Support for debugging multi-threaded applications which use
3968 the GNU/Linux LinuxThreads package has been added for
3969 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3970 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3972 * GDB now supports C/C++ preprocessor macros.
3974 GDB now expands preprocessor macro invocations in C/C++ expressions,
3975 and provides various commands for showing macro definitions and how
3978 The new command `macro expand EXPRESSION' expands any macro
3979 invocations in expression, and shows the result.
3981 The new command `show macro MACRO-NAME' shows the definition of the
3982 macro named MACRO-NAME, and where it was defined.
3984 Most compilers don't include information about macros in the debugging
3985 information by default. In GCC 3.1, for example, you need to compile
3986 your program with the options `-gdwarf-2 -g3'. If the macro
3987 information is present in the executable, GDB will read it.
3989 * Multi-arched targets.
3991 DEC Alpha (partial) alpha*-*-*
3992 DEC VAX (partial) vax-*-*
3994 National Semiconductor NS32000 (partial) ns32k-*-*
3995 Motorola 68000 (partial) m68k-*-*
3996 Motorola MCORE mcore-*-*
4000 Fujitsu FRV architecture added by Red Hat frv*-*-*
4003 * New native configurations
4005 Alpha NetBSD alpha*-*-netbsd*
4006 SH NetBSD sh*-*-netbsdelf*
4007 MIPS NetBSD mips*-*-netbsd*
4008 UltraSPARC NetBSD sparc64-*-netbsd*
4010 * OBSOLETE configurations and files
4012 Configurations that have been declared obsolete in this release have
4013 been commented out. Unless there is activity to revive these
4014 configurations, the next release of GDB will have their sources
4015 permanently REMOVED.
4017 Mitsubishi D30V d30v-*-*
4018 OS/9000 i[34]86-*-os9k
4019 IBM AIX PS/2 i[3456]86-*-aix
4020 Fujitsu FR30 fr30-*-elf*
4021 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4022 Argonaut Risc Chip (ARC) arc-*-*
4023 i386 running Mach 3.0 i[3456]86-*-mach3*
4024 i386 running Mach i[3456]86-*-mach*
4025 i386 running OSF/1 i[3456]86-*osf1mk*
4026 HP/Apollo 68k Family m68*-apollo*-sysv*,
4028 m68*-hp-bsd*, m68*-hp-hpux*
4029 I960 with MON960 i960-*-coff
4031 * OBSOLETE languages
4033 CHILL, a Pascal like language used by telecommunications companies.
4035 * REMOVED configurations and files
4037 AMD 29k family via UDI a29k-amd-udi, udi29k
4038 A29K VxWorks a29k-*-vxworks
4039 AMD 29000 embedded, using EBMON a29k-none-none
4040 AMD 29000 embedded with COFF a29k-none-coff
4041 AMD 29000 embedded with a.out a29k-none-aout
4043 testsuite/gdb.hp/gdb.threads-hp/ directory
4045 * New command "set max-user-call-depth <nnn>"
4047 This command allows the user to limit the call depth of user-defined
4048 commands. The default is 1024.
4050 * Changes in FreeBSD/i386 native debugging.
4052 Support for the "generate-core-file" has been added.
4054 * New commands "dump", "append", and "restore".
4056 These commands allow data to be copied from target memory
4057 to a bfd-format or binary file (dump and append), and back
4058 from a file into memory (restore).
4060 * Improved "next/step" support on multi-processor Alpha Tru64.
4062 The previous single-step mechanism could cause unpredictable problems,
4063 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4064 of a software single-step mechanism prevents this.
4066 *** Changes in GDB 5.2.1:
4074 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4075 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4076 Fix, by Joel Brobecker imported from mainline.
4078 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4079 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4080 Fix, by Fred Fish, imported from mainline.
4082 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4083 Surprisingly enough, it works now.
4084 By Michal Ludvig, imported from mainline.
4086 i386 hardware watchpoint support:
4087 avoid misses on second run for some targets.
4088 By Pierre Muller, imported from mainline.
4090 *** Changes in GDB 5.2:
4092 * New command "set trust-readonly-sections on[off]".
4094 This command is a hint that tells gdb that read-only sections
4095 really are read-only (ie. that their contents will not change).
4096 In this mode, gdb will go to the object file rather than the
4097 target to read memory from read-only sections (such as ".text").
4098 This can be a significant performance improvement on some
4099 (notably embedded) targets.
4101 * New command "generate-core-file" (or "gcore").
4103 This new gdb command allows the user to drop a core file of the child
4104 process state at any time. So far it's been implemented only for
4105 GNU/Linux and Solaris, but should be relatively easily ported to other
4106 hosts. Argument is core file name (defaults to core.<pid>).
4108 * New command line option
4110 GDB now accepts --pid or -p followed by a process id.
4112 * Change in command line behavior -- corefiles vs. process ids.
4114 There is a subtle behavior in the way in which GDB handles
4115 command line arguments. The first non-flag argument is always
4116 a program to debug, but the second non-flag argument may either
4117 be a corefile or a process id. Previously, GDB would attempt to
4118 open the second argument as a corefile, and if that failed, would
4119 issue a superfluous error message and then attempt to attach it as
4120 a process. Now, if the second argument begins with a non-digit,
4121 it will be treated as a corefile. If it begins with a digit,
4122 GDB will attempt to attach it as a process, and if no such process
4123 is found, will then attempt to open it as a corefile.
4125 * Changes in ARM configurations.
4127 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4128 configuration is fully multi-arch.
4130 * New native configurations
4132 ARM NetBSD arm*-*-netbsd*
4133 x86 OpenBSD i[3456]86-*-openbsd*
4134 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4135 Sparc64 running FreeBSD sparc64-*-freebsd*
4139 Sanyo XStormy16 xstormy16-elf
4141 * OBSOLETE configurations and files
4143 Configurations that have been declared obsolete in this release have
4144 been commented out. Unless there is activity to revive these
4145 configurations, the next release of GDB will have their sources
4146 permanently REMOVED.
4148 AMD 29k family via UDI a29k-amd-udi, udi29k
4149 A29K VxWorks a29k-*-vxworks
4150 AMD 29000 embedded, using EBMON a29k-none-none
4151 AMD 29000 embedded with COFF a29k-none-coff
4152 AMD 29000 embedded with a.out a29k-none-aout
4154 testsuite/gdb.hp/gdb.threads-hp/ directory
4156 * REMOVED configurations and files
4158 TI TMS320C80 tic80-*-*
4160 PowerPC Solaris powerpcle-*-solaris*
4161 PowerPC Windows NT powerpcle-*-cygwin32
4162 PowerPC Netware powerpc-*-netware*
4163 Harris/CXUX m88k m88*-harris-cxux*
4164 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4165 ns32k-utek-sysv* ns32k-utek-*
4166 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4167 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4168 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4169 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4170 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4172 * Changes to command line processing
4174 The new `--args' feature can be used to specify command-line arguments
4175 for the inferior from gdb's command line.
4177 * Changes to key bindings
4179 There is a new `operate-and-get-next' function bound to `C-o'.
4181 *** Changes in GDB 5.1.1
4183 Fix compile problem on DJGPP.
4185 Fix a problem with floating-point registers on the i386 being
4188 Fix to stop GDB crashing on .debug_str debug info.
4190 Numerous documentation fixes.
4192 Numerous testsuite fixes.
4194 *** Changes in GDB 5.1:
4196 * New native configurations
4198 Alpha FreeBSD alpha*-*-freebsd*
4199 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4200 MIPS GNU/Linux mips*-*-linux*
4201 MIPS SGI Irix 6.x mips*-sgi-irix6*
4202 ia64 AIX ia64-*-aix*
4203 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4207 Motorola 68HC11 and 68HC12 m68hc11-elf
4209 UltraSparc running GNU/Linux sparc64-*-linux*
4211 * OBSOLETE configurations and files
4213 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4214 Harris/CXUX m88k m88*-harris-cxux*
4215 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4216 ns32k-utek-sysv* ns32k-utek-*
4217 TI TMS320C80 tic80-*-*
4219 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4220 PowerPC Solaris powerpcle-*-solaris*
4221 PowerPC Windows NT powerpcle-*-cygwin32
4222 PowerPC Netware powerpc-*-netware*
4223 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4224 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4225 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4226 Apple Macintosh (MPW) host N/A
4228 stuff.c (Program to stuff files into a specially prepared space in kdb)
4229 kdb-start.c (Main loop for the standalone kernel debugger)
4231 Configurations that have been declared obsolete in this release have
4232 been commented out. Unless there is activity to revive these
4233 configurations, the next release of GDB will have their sources
4234 permanently REMOVED.
4236 * REMOVED configurations and files
4238 Altos 3068 m68*-altos-*
4239 Convex c1-*-*, c2-*-*
4241 ARM RISCix arm-*-* (as host)
4245 * GDB has been converted to ISO C.
4247 GDB's source code has been converted to ISO C. In particular, the
4248 sources are fully protoized, and rely on standard headers being
4253 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4255 * The MI enabled by default.
4257 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4258 revised and enabled by default. Packages which use GDB as a debugging
4259 engine behind a UI or another front end are encouraged to switch to
4260 using the GDB/MI interface, instead of the old annotations interface
4261 which is now deprecated.
4263 * Support for debugging Pascal programs.
4265 GDB now includes support for debugging Pascal programs. The following
4266 main features are supported:
4268 - Pascal-specific data types such as sets;
4270 - automatic recognition of Pascal sources based on file-name
4273 - Pascal-style display of data types, variables, and functions;
4275 - a Pascal expression parser.
4277 However, some important features are not yet supported.
4279 - Pascal string operations are not supported at all;
4281 - there are some problems with boolean types;
4283 - Pascal type hexadecimal constants are not supported
4284 because they conflict with the internal variables format;
4286 - support for Pascal objects and classes is not full yet;
4288 - unlike Pascal, GDB is case-sensitive for symbol names.
4290 * Changes in completion.
4292 Commands such as `shell', `run' and `set args', which pass arguments
4293 to inferior programs, now complete on file names, similar to what
4294 users expect at the shell prompt.
4296 Commands which accept locations, such as `disassemble', `print',
4297 `breakpoint', `until', etc. now complete on filenames as well as
4298 program symbols. Thus, if you type "break foob TAB", and the source
4299 files linked into the programs include `foobar.c', that file name will
4300 be one of the candidates for completion. However, file names are not
4301 considered for completion after you typed a colon that delimits a file
4302 name from a name of a function in that file, as in "break foo.c:bar".
4304 `set demangle-style' completes on available demangling styles.
4306 * New platform-independent commands:
4308 It is now possible to define a post-hook for a command as well as a
4309 hook that runs before the command. For more details, see the
4310 documentation of `hookpost' in the GDB manual.
4312 * Changes in GNU/Linux native debugging.
4314 Support for debugging multi-threaded programs has been completely
4315 revised for all platforms except m68k and sparc. You can now debug as
4316 many threads as your system allows you to have.
4318 Attach/detach is supported for multi-threaded programs.
4320 Support for SSE registers was added for x86. This doesn't work for
4321 multi-threaded programs though.
4323 * Changes in MIPS configurations.
4325 Multi-arch support is enabled for all MIPS configurations.
4327 GDB can now be built as native debugger on SGI Irix 6.x systems for
4328 debugging n32 executables. (Debugging 64-bit executables is not yet
4331 * Unified support for hardware watchpoints in all x86 configurations.
4333 Most (if not all) native x86 configurations support hardware-assisted
4334 breakpoints and watchpoints in a unified manner. This support
4335 implements debug register sharing between watchpoints, which allows to
4336 put a virtually infinite number of watchpoints on the same address,
4337 and also supports watching regions up to 16 bytes with several debug
4340 The new maintenance command `maintenance show-debug-regs' toggles
4341 debugging print-outs in functions that insert, remove, and test
4342 watchpoints and hardware breakpoints.
4344 * Changes in the DJGPP native configuration.
4346 New command ``info dos sysinfo'' displays assorted information about
4347 the CPU, OS, memory, and DPMI server.
4349 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4350 display information about segment descriptors stored in GDT, LDT, and
4353 New commands ``info dos pde'' and ``info dos pte'' display entries
4354 from Page Directory and Page Tables (for now works with CWSDPMI only).
4355 New command ``info dos address-pte'' displays the Page Table entry for
4356 a given linear address.
4358 GDB can now pass command lines longer than 126 characters to the
4359 program being debugged (requires an update to the libdbg.a library
4360 which is part of the DJGPP development kit).
4362 DWARF2 debug info is now supported.
4364 It is now possible to `step' and `next' through calls to `longjmp'.
4366 * Changes in documentation.
4368 All GDB documentation was converted to GFDL, the GNU Free
4369 Documentation License.
4371 Tracepoints-related commands are now fully documented in the GDB
4374 TUI, the Text-mode User Interface, is now documented in the manual.
4376 Tracepoints-related commands are now fully documented in the GDB
4379 The "GDB Internals" manual now has an index. It also includes
4380 documentation of `ui_out' functions, GDB coding standards, x86
4381 hardware watchpoints, and memory region attributes.
4383 * GDB's version number moved to ``version.in''
4385 The Makefile variable VERSION has been replaced by the file
4386 ``version.in''. People creating GDB distributions should update the
4387 contents of this file.
4391 GUD support is now a standard part of the EMACS distribution.
4393 *** Changes in GDB 5.0:
4395 * Improved support for debugging FP programs on x86 targets
4397 Unified and much-improved support for debugging floating-point
4398 programs on all x86 targets. In particular, ``info float'' now
4399 displays the FP registers in the same format on all x86 targets, with
4400 greater level of detail.
4402 * Improvements and bugfixes in hardware-assisted watchpoints
4404 It is now possible to watch array elements, struct members, and
4405 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4406 on x86 targets no longer erroneously trigger when the address is
4409 * Improvements in the native DJGPP version of GDB
4411 The distribution now includes all the scripts and auxiliary files
4412 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4413 machines ``out of the box''.
4415 The DJGPP version can now debug programs that use signals. It is
4416 possible to catch signals that happened in the debuggee, deliver
4417 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4418 would kill the program being debugged.) Programs that hook hardware
4419 interrupts (keyboard, timer, etc.) can also be debugged.
4421 It is now possible to debug DJGPP programs that redirect their
4422 standard handles or switch them to raw (as opposed to cooked) mode, or
4423 even close them. The command ``run < foo > bar'' works as expected,
4424 and ``info terminal'' reports useful information about the debuggee's
4425 terminal, including raw/cooked mode, redirection, etc.
4427 The DJGPP version now uses termios functions for console I/O, which
4428 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4431 DOS-style file names with drive letters are now fully supported by
4434 It is now possible to debug DJGPP programs that switch their working
4435 directory. It is also possible to rerun the debuggee any number of
4436 times without restarting GDB; thus, you can use the same setup,
4437 breakpoints, etc. for many debugging sessions.
4439 * New native configurations
4441 ARM GNU/Linux arm*-*-linux*
4442 PowerPC GNU/Linux powerpc-*-linux*
4446 Motorola MCore mcore-*-*
4447 x86 VxWorks i[3456]86-*-vxworks*
4448 PowerPC VxWorks powerpc-*-vxworks*
4449 TI TMS320C80 tic80-*-*
4451 * OBSOLETE configurations
4453 Altos 3068 m68*-altos-*
4454 Convex c1-*-*, c2-*-*
4456 ARM RISCix arm-*-* (as host)
4459 Configurations that have been declared obsolete will be commented out,
4460 but the code will be left in place. If there is no activity to revive
4461 these configurations before the next release of GDB, the sources will
4462 be permanently REMOVED.
4464 * Gould support removed
4466 Support for the Gould PowerNode and NP1 has been removed.
4468 * New features for SVR4
4470 On SVR4 native platforms (such as Solaris), if you attach to a process
4471 without first loading a symbol file, GDB will now attempt to locate and
4472 load symbols from the running process's executable file.
4474 * Many C++ enhancements
4476 C++ support has been greatly improved. Overload resolution now works properly
4477 in almost all cases. RTTI support is on the way.
4479 * Remote targets can connect to a sub-program
4481 A popen(3) style serial-device has been added. This device starts a
4482 sub-process (such as a stand-alone simulator) and then communicates
4483 with that. The sub-program to run is specified using the syntax
4484 ``|<program> <args>'' vis:
4486 (gdb) set remotedebug 1
4487 (gdb) target extended-remote |mn10300-elf-sim program-args
4489 * MIPS 64 remote protocol
4491 A long standing bug in the mips64 remote protocol where by GDB
4492 expected certain 32 bit registers (ex SR) to be transfered as 32
4493 instead of 64 bits has been fixed.
4495 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4496 added to provide backward compatibility with older versions of GDB.
4498 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4500 The command ``set remotebinarydownload'' command has been replaced by
4501 ``set remote X-packet''. Other commands in ``set remote'' family
4502 include ``set remote P-packet''.
4504 * Breakpoint commands accept ranges.
4506 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4507 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4508 ``tracepoint passcount'' also accepts a range of tracepoints.
4510 * ``apropos'' command added.
4512 The ``apropos'' command searches through command names and
4513 documentation strings, printing out matches, making it much easier to
4514 try to find a command that does what you are looking for.
4518 A new machine oriented interface (MI) has been added to GDB. This
4519 interface is designed for debug environments running GDB as a separate
4520 process. This is part of the long term libGDB project. See the
4521 "GDB/MI" chapter of the GDB manual for further information. It can be
4522 enabled by configuring with:
4524 .../configure --enable-gdbmi
4526 *** Changes in GDB-4.18:
4528 * New native configurations
4530 HP-UX 10.20 hppa*-*-hpux10.20
4531 HP-UX 11.x hppa*-*-hpux11.0*
4532 M68K GNU/Linux m68*-*-linux*
4536 Fujitsu FR30 fr30-*-elf*
4537 Intel StrongARM strongarm-*-*
4538 Mitsubishi D30V d30v-*-*
4540 * OBSOLETE configurations
4542 Gould PowerNode, NP1 np1-*-*, pn-*-*
4544 Configurations that have been declared obsolete will be commented out,
4545 but the code will be left in place. If there is no activity to revive
4546 these configurations before the next release of GDB, the sources will
4547 be permanently REMOVED.
4551 As a compatibility experiment, GDB's source files buildsym.h and
4552 buildsym.c have been converted to pure standard C, no longer
4553 containing any K&R compatibility code. We believe that all systems in
4554 use today either come with a standard C compiler, or have a GCC port
4555 available. If this is not true, please report the affected
4556 configuration to bug-gdb@gnu.org immediately. See the README file for
4557 information about getting a standard C compiler if you don't have one
4562 GDB now uses readline 2.2.
4564 * set extension-language
4566 You can now control the mapping between filename extensions and source
4567 languages by using the `set extension-language' command. For instance,
4568 you can ask GDB to treat .c files as C++ by saying
4569 set extension-language .c c++
4570 The command `info extensions' lists all of the recognized extensions
4571 and their associated languages.
4573 * Setting processor type for PowerPC and RS/6000
4575 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4576 you can use the `set processor' command to specify what variant of the
4577 PowerPC family you are debugging. The command
4581 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4582 following PowerPC and RS6000 variants:
4584 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4585 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4587 403GC IBM PowerPC 403GC
4588 505 Motorola PowerPC 505
4589 860 Motorola PowerPC 860 or 850
4590 601 Motorola PowerPC 601
4591 602 Motorola PowerPC 602
4592 603 Motorola/IBM PowerPC 603 or 603e
4593 604 Motorola PowerPC 604 or 604e
4594 750 Motorola/IBM PowerPC 750 or 750
4596 At the moment, this command just tells GDB what to name the
4597 special-purpose processor registers. Since almost all the affected
4598 registers are inaccessible to user-level programs, this command is
4599 only useful for remote debugging in its present form.
4603 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4604 more extensive support for HP-UX. Added features include shared
4605 library support, kernel threads and hardware watchpoints for 11.00,
4606 support for HP's ANSI C and C++ compilers, and a compatibility mode
4607 for xdb and dbx commands.
4611 HP's donation includes the new concept of catchpoints, which is a
4612 generalization of the old catch command. On HP-UX, it is now possible
4613 to catch exec, fork, and vfork, as well as library loading.
4615 This means that the existing catch command has changed; its first
4616 argument now specifies the type of catch to be set up. See the
4617 output of "help catch" for a list of catchpoint types.
4619 * Debugging across forks
4621 On HP-UX, you can choose which process to debug when a fork() happens
4626 HP has donated a curses-based terminal user interface (TUI). To get
4627 it, build with --enable-tui. Although this can be enabled for any
4628 configuration, at present it only works for native HP debugging.
4630 * GDB remote protocol additions
4632 A new protocol packet 'X' that writes binary data is now available.
4633 Default behavior is to try 'X', then drop back to 'M' if the stub
4634 fails to respond. The settable variable `remotebinarydownload'
4635 allows explicit control over the use of 'X'.
4637 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4638 full 64-bit address. The command
4640 set remoteaddresssize 32
4642 can be used to revert to the old behaviour. For existing remote stubs
4643 the change should not be noticed, as the additional address information
4646 In order to assist in debugging stubs, you may use the maintenance
4647 command `packet' to send any text string to the stub. For instance,
4649 maint packet heythere
4651 sends the packet "$heythere#<checksum>". Note that it is very easy to
4652 disrupt a debugging session by sending the wrong packet at the wrong
4655 The compare-sections command allows you to compare section data on the
4656 target to what is in the executable file without uploading or
4657 downloading, by comparing CRC checksums.
4659 * Tracing can collect general expressions
4661 You may now collect general expressions at tracepoints. This requires
4662 further additions to the target-side stub; see tracepoint.c and
4663 doc/agentexpr.texi for further details.
4665 * mask-address variable for Mips
4667 For Mips targets, you may control the zeroing of the upper 32 bits of
4668 a 64-bit address by entering `set mask-address on'. This is mainly
4669 of interest to users of embedded R4xxx and R5xxx processors.
4671 * Higher serial baud rates
4673 GDB's serial code now allows you to specify baud rates 57600, 115200,
4674 230400, and 460800 baud. (Note that your host system may not be able
4675 to achieve all of these rates.)
4679 The i960 configuration now includes an initial implementation of a
4680 builtin simulator, contributed by Jim Wilson.
4683 *** Changes in GDB-4.17:
4685 * New native configurations
4687 Alpha GNU/Linux alpha*-*-linux*
4688 Unixware 2.x i[3456]86-unixware2*
4689 Irix 6.x mips*-sgi-irix6*
4690 PowerPC GNU/Linux powerpc-*-linux*
4691 PowerPC Solaris powerpcle-*-solaris*
4692 Sparc GNU/Linux sparc-*-linux*
4693 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4697 Argonaut Risc Chip (ARC) arc-*-*
4698 Hitachi H8/300S h8300*-*-*
4699 Matsushita MN10200 w/simulator mn10200-*-*
4700 Matsushita MN10300 w/simulator mn10300-*-*
4701 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4702 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4703 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4704 Mitsubishi D10V w/simulator d10v-*-*
4705 Mitsubishi M32R/D w/simulator m32r-*-elf*
4706 Tsqware Sparclet sparclet-*-*
4707 NEC V850 w/simulator v850-*-*
4709 * New debugging protocols
4711 ARM with RDI protocol arm*-*-*
4712 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4713 DDB and LSI variants of PMON protocol mips*-*-*
4714 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4715 PowerPC with SDS protocol powerpc{,le}-*-eabi
4716 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4720 All configurations can now understand and use the DWARF 2 debugging
4721 format. The choice is automatic, if the symbol file contains DWARF 2
4726 GDB now includes basic Java language support. This support is
4727 only useful with Java compilers that produce native machine code.
4729 * solib-absolute-prefix and solib-search-path
4731 For SunOS and SVR4 shared libraries, you may now set the prefix for
4732 loading absolute shared library symbol files, and the search path for
4733 locating non-absolute shared library symbol files.
4735 * Live range splitting
4737 GDB can now effectively debug code for which GCC has performed live
4738 range splitting as part of its optimization. See gdb/doc/LRS for
4739 more details on the expected format of the stabs information.
4743 GDB's support for the GNU Hurd, including thread debugging, has been
4744 updated to work with current versions of the Hurd.
4748 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4749 instruction set. ARM GDB automatically detects when Thumb
4750 instructions are in use, and adjusts disassembly and backtracing
4755 GDB's MIPS target configurations now handle the MIP16 16-bit
4760 GDB now includes support for overlays; if an executable has been
4761 linked such that multiple sections are based at the same address, GDB
4762 will decide which section to use for symbolic info. You can choose to
4763 control the decision manually, using overlay commands, or implement
4764 additional target-side support and use "overlay load-target" to bring
4765 in the overlay mapping. Do "help overlay" for more detail.
4769 The command "info symbol <address>" displays information about
4770 the symbol at the specified address.
4774 The standard remote protocol now includes an extension that allows
4775 asynchronous collection and display of trace data. This requires
4776 extensive support in the target-side debugging stub. Tracing mode
4777 includes a new interaction mode in GDB and new commands: see the
4778 file tracepoint.c for more details.
4782 Configurations for embedded MIPS now include a simulator contributed
4783 by Cygnus Solutions. The simulator supports the instruction sets
4784 of most MIPS variants.
4788 Sparc configurations may now include the ERC32 simulator contributed
4789 by the European Space Agency. The simulator is not built into
4790 Sparc targets by default; configure with --enable-sim to include it.
4794 For target configurations that may include multiple variants of a
4795 basic architecture (such as MIPS and SH), you may now set the
4796 architecture explicitly. "set arch" sets, "info arch" lists
4797 the possible architectures.
4799 *** Changes in GDB-4.16:
4801 * New native configurations
4803 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4804 M68K NetBSD m68k-*-netbsd*
4805 PowerPC AIX 4.x powerpc-*-aix*
4806 PowerPC MacOS powerpc-*-macos*
4807 PowerPC Windows NT powerpcle-*-cygwin32
4808 RS/6000 AIX 4.x rs6000-*-aix4*
4812 ARM with RDP protocol arm-*-*
4813 I960 with MON960 i960-*-coff
4814 MIPS VxWorks mips*-*-vxworks*
4815 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4816 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4818 Matra Sparclet sparclet-*-*
4822 The powerpc-eabi configuration now includes the PSIM simulator,
4823 contributed by Andrew Cagney, with assistance from Mike Meissner.
4824 PSIM is a very elaborate model of the PowerPC, including not only
4825 basic instruction set execution, but also details of execution unit
4826 performance and I/O hardware. See sim/ppc/README for more details.
4830 GDB now works with Solaris 2.5.
4832 * Windows 95/NT native
4834 GDB will now work as a native debugger on Windows 95 and Windows NT.
4835 To build it from source, you must use the "gnu-win32" environment,
4836 which uses a DLL to emulate enough of Unix to run the GNU tools.
4837 Further information, binaries, and sources are available at
4838 ftp.cygnus.com, under pub/gnu-win32.
4840 * dont-repeat command
4842 If a user-defined command includes the command `dont-repeat', then the
4843 command will not be repeated if the user just types return. This is
4844 useful if the command is time-consuming to run, so that accidental
4845 extra keystrokes don't run the same command many times.
4847 * Send break instead of ^C
4849 The standard remote protocol now includes an option to send a break
4850 rather than a ^C to the target in order to interrupt it. By default,
4851 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4853 * Remote protocol timeout
4855 The standard remote protocol includes a new variable `remotetimeout'
4856 that allows you to set the number of seconds before GDB gives up trying
4857 to read from the target. The default value is 2.
4859 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4861 By default GDB will automatically keep track of objects as they are
4862 loaded and unloaded by the dynamic linker. By using the command `set
4863 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4864 when shared library events occur, thus allowing you to set breakpoints
4865 in shared libraries which are explicitly loaded by the inferior.
4867 Note this feature does not work on hpux8. On hpux9 you must link
4868 /usr/lib/end.o into your program. This feature should work
4869 automatically on hpux10.
4871 * Irix 5.x hardware watchpoint support
4873 Irix 5 configurations now support the use of hardware watchpoints.
4875 * Mips protocol "SYN garbage limit"
4877 When debugging a Mips target using the `target mips' protocol, you
4878 may set the number of characters that GDB will ignore by setting
4879 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4880 every character. The default value is 1050.
4882 * Recording and replaying remote debug sessions
4884 If you set `remotelogfile' to the name of a file, gdb will write to it
4885 a recording of a remote debug session. This recording may then be
4886 replayed back to gdb using "gdbreplay". See gdbserver/README for
4887 details. This is useful when you have a problem with GDB while doing
4888 remote debugging; you can make a recording of the session and send it
4889 to someone else, who can then recreate the problem.
4891 * Speedups for remote debugging
4893 GDB includes speedups for downloading and stepping MIPS systems using
4894 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4895 and more efficient S-record downloading.
4897 * Memory use reductions and statistics collection
4899 GDB now uses less memory and reports statistics about memory usage.
4900 Try the `maint print statistics' command, for example.
4902 *** Changes in GDB-4.15:
4904 * Psymtabs for XCOFF
4906 The symbol reader for AIX GDB now uses partial symbol tables. This
4907 can greatly improve startup time, especially for large executables.
4909 * Remote targets use caching
4911 Remote targets now use a data cache to speed up communication with the
4912 remote side. The data cache could lead to incorrect results because
4913 it doesn't know about volatile variables, thus making it impossible to
4914 debug targets which use memory mapped I/O devices. `set remotecache
4915 off' turns the the data cache off.
4917 * Remote targets may have threads
4919 The standard remote protocol now includes support for multiple threads
4920 in the target system, using new protocol commands 'H' and 'T'. See
4921 gdb/remote.c for details.
4925 If GDB is configured with `--enable-netrom', then it will include
4926 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4927 acts as though it is a bank of ROM on the target board, but you can
4928 write into it over the network. GDB's support consists only of
4929 support for fast loading into the emulated ROM; to debug, you must use
4930 another protocol, such as standard remote protocol. The usual
4931 sequence is something like
4933 target nrom <netrom-hostname>
4935 target remote <netrom-hostname>:1235
4939 GDB now includes support for the Apple Macintosh, as a host only. It
4940 may be run as either an MPW tool or as a standalone application, and
4941 it can debug through the serial port. All the usual GDB commands are
4942 available, but to the target command, you must supply "serial" as the
4943 device type instead of "/dev/ttyXX". See mpw-README in the main
4944 directory for more information on how to build. The MPW configuration
4945 scripts */mpw-config.in support only a few targets, and only the
4946 mips-idt-ecoff target has been tested.
4950 GDB configuration now uses autoconf. This is not user-visible,
4951 but does simplify configuration and building.
4955 GDB now supports hpux10.
4957 *** Changes in GDB-4.14:
4959 * New native configurations
4961 x86 FreeBSD i[345]86-*-freebsd
4962 x86 NetBSD i[345]86-*-netbsd
4963 NS32k NetBSD ns32k-*-netbsd
4964 Sparc NetBSD sparc-*-netbsd
4968 A29K VxWorks a29k-*-vxworks
4969 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4970 CPU32 EST-300 emulator m68*-*-est*
4971 PowerPC ELF powerpc-*-elf
4974 * Alpha OSF/1 support for procfs
4976 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4977 possible to attach to running processes. As the mounting of the /proc
4978 filesystem is optional on the Alpha, GDB automatically determines
4979 the availability of /proc during startup. This can lead to problems
4980 if /proc is unmounted after GDB has been started.
4982 * Arguments to user-defined commands
4984 User commands may accept up to 10 arguments separated by whitespace.
4985 Arguments are accessed within the user command via $arg0..$arg9. A
4988 print $arg0 + $arg1 + $arg2
4990 To execute the command use:
4993 Defines the command "adder" which prints the sum of its three arguments.
4994 Note the arguments are text substitutions, so they may reference variables,
4995 use complex expressions, or even perform inferior function calls.
4997 * New `if' and `while' commands
4999 This makes it possible to write more sophisticated user-defined
5000 commands. Both commands take a single argument, which is the
5001 expression to evaluate, and must be followed by the commands to
5002 execute, one per line, if the expression is nonzero, the list being
5003 terminated by the word `end'. The `if' command list may include an
5004 `else' word, which causes the following commands to be executed only
5005 if the expression is zero.
5007 * Fortran source language mode
5009 GDB now includes partial support for Fortran 77. It will recognize
5010 Fortran programs and can evaluate a subset of Fortran expressions, but
5011 variables and functions may not be handled correctly. GDB will work
5012 with G77, but does not yet know much about symbols emitted by other
5015 * Better HPUX support
5017 Most debugging facilities now work on dynamic executables for HPPAs
5018 running hpux9 or later. You can attach to running dynamically linked
5019 processes, but by default the dynamic libraries will be read-only, so
5020 for instance you won't be able to put breakpoints in them. To change
5021 that behavior do the following before running the program:
5027 This will cause the libraries to be mapped private and read-write.
5028 To revert to the normal behavior, do this:
5034 You cannot set breakpoints or examine data in the library until after
5035 the library is loaded if the function/data symbols do not have
5038 GDB can now also read debug symbols produced by the HP C compiler on
5039 HPPAs (sorry, no C++, Fortran or 68k support).
5041 * Target byte order now dynamically selectable
5043 You can choose which byte order to use with a target system, via the
5044 commands "set endian big" and "set endian little", and you can see the
5045 current setting by using "show endian". You can also give the command
5046 "set endian auto", in which case GDB will use the byte order
5047 associated with the executable. Currently, only embedded MIPS
5048 configurations support dynamic selection of target byte order.
5050 * New DOS host serial code
5052 This version uses DPMI interrupts to handle buffered I/O, so you
5053 no longer need to run asynctsr when debugging boards connected to
5056 *** Changes in GDB-4.13:
5058 * New "complete" command
5060 This lists all the possible completions for the rest of the line, if it
5061 were to be given as a command itself. This is intended for use by emacs.
5063 * Trailing space optional in prompt
5065 "set prompt" no longer adds a space for you after the prompt you set. This
5066 allows you to set a prompt which ends in a space or one that does not.
5068 * Breakpoint hit counts
5070 "info break" now displays a count of the number of times the breakpoint
5071 has been hit. This is especially useful in conjunction with "ignore"; you
5072 can ignore a large number of breakpoint hits, look at the breakpoint info
5073 to see how many times the breakpoint was hit, then run again, ignoring one
5074 less than that number, and this will get you quickly to the last hit of
5077 * Ability to stop printing at NULL character
5079 "set print null-stop" will cause GDB to stop printing the characters of
5080 an array when the first NULL is encountered. This is useful when large
5081 arrays actually contain only short strings.
5083 * Shared library breakpoints
5085 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5086 breakpoints in shared libraries before the executable is run.
5088 * Hardware watchpoints
5090 There is a new hardware breakpoint for the watch command for sparclite
5091 targets. See gdb/sparclite/hw_breakpoint.note.
5093 Hardware watchpoints are also now supported under GNU/Linux.
5097 Annotations have been added. These are for use with graphical interfaces,
5098 and are still experimental. Currently only gdba.el uses these.
5100 * Improved Irix 5 support
5102 GDB now works properly with Irix 5.2.
5104 * Improved HPPA support
5106 GDB now works properly with the latest GCC and GAS.
5108 * New native configurations
5110 Sequent PTX4 i[34]86-sequent-ptx4
5111 HPPA running OSF/1 hppa*-*-osf*
5112 Atari TT running SVR4 m68*-*-sysv4*
5113 RS/6000 LynxOS rs6000-*-lynxos*
5117 OS/9000 i[34]86-*-os9k
5118 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5121 * Hitachi SH7000 and E7000-PC ICE support
5123 There is now support for communicating with the Hitachi E7000-PC ICE.
5124 This is available automatically when GDB is configured for the SH.
5128 As usual, a variety of small fixes and improvements, both generic
5129 and configuration-specific. See the ChangeLog for more detail.
5131 *** Changes in GDB-4.12:
5133 * Irix 5 is now supported
5137 GDB-4.12 on the HPPA has a number of changes which make it unable
5138 to debug the output from the currently released versions of GCC and
5139 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5140 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5141 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5144 *** Changes in GDB-4.11:
5146 * User visible changes:
5150 The "set remotedebug" option is now consistent between the mips remote
5151 target, remote targets using the gdb-specific protocol, UDI (AMD's
5152 debug protocol for the 29k) and the 88k bug monitor. It is now an
5153 integer specifying a debug level (normally 0 or 1, but 2 means more
5154 debugging info for the mips target).
5156 * DEC Alpha native support
5158 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5159 debug info, but GDB works fairly well with the DEC compiler and should
5160 work with a future GCC release. See the README file for a few
5161 Alpha-specific notes.
5163 * Preliminary thread implementation
5165 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5167 * LynxOS native and target support for 386
5169 This release has been hosted on LynxOS 2.2, and also can be configured
5170 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5173 * Improvements in C++ mangling/demangling.
5175 This release has much better g++ debugging, specifically in name
5176 mangling/demangling, virtual function calls, print virtual table,
5177 call methods, ...etc.
5179 *** Changes in GDB-4.10:
5181 * User visible changes:
5183 Remote debugging using the GDB-specific (`target remote') protocol now
5184 supports the `load' command. This is only useful if you have some
5185 other way of getting the stub to the target system, and you can put it
5186 somewhere in memory where it won't get clobbered by the download.
5188 Filename completion now works.
5190 When run under emacs mode, the "info line" command now causes the
5191 arrow to point to the line specified. Also, "info line" prints
5192 addresses in symbolic form (as well as hex).
5194 All vxworks based targets now support a user settable option, called
5195 vxworks-timeout. This option represents the number of seconds gdb
5196 should wait for responses to rpc's. You might want to use this if
5197 your vxworks target is, perhaps, a slow software simulator or happens
5198 to be on the far side of a thin network line.
5202 This release contains support for using a DEC alpha as a GDB host for
5203 cross debugging. Native alpha debugging is not supported yet.
5206 *** Changes in GDB-4.9:
5210 This is the first GDB release which is accompanied by a matching testsuite.
5211 The testsuite requires installation of dejagnu, which should be available
5212 via ftp from most sites that carry GNU software.
5216 'Cfront' style demangling has had its name changed to 'ARM' style, to
5217 emphasize that it was written from the specifications in the C++ Annotated
5218 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5219 disclaimers, it still generated too much confusion with users attempting to
5220 use gdb with AT&T cfront.
5224 GDB now uses a standard remote interface to a simulator library.
5225 So far, the library contains simulators for the Zilog Z8001/2, the
5226 Hitachi H8/300, H8/500 and Super-H.
5228 * New targets supported
5230 H8/300 simulator h8300-hitachi-hms or h8300hms
5231 H8/500 simulator h8500-hitachi-hms or h8500hms
5232 SH simulator sh-hitachi-hms or sh
5233 Z8000 simulator z8k-zilog-none or z8ksim
5234 IDT MIPS board over serial line mips-idt-ecoff
5236 Cross-debugging to GO32 targets is supported. It requires a custom
5237 version of the i386-stub.c module which is integrated with the
5238 GO32 memory extender.
5240 * New remote protocols
5242 MIPS remote debugging protocol.
5244 * New source languages supported
5246 This version includes preliminary support for Chill, a Pascal like language
5247 used by telecommunications companies. Chill support is also being integrated
5248 into the GNU compiler, but we don't know when it will be publically available.
5251 *** Changes in GDB-4.8:
5253 * HP Precision Architecture supported
5255 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5256 version of this support was available as a set of patches from the
5257 University of Utah. GDB does not support debugging of programs
5258 compiled with the HP compiler, because HP will not document their file
5259 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5260 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5262 Many problems in the preliminary version have been fixed.
5264 * Faster and better demangling
5266 We have improved template demangling and fixed numerous bugs in the GNU style
5267 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5268 character types (wchar_t) are now supported. Demangling of each symbol is now
5269 only done once, and is cached when the symbol table for a file is read in.
5270 This results in a small increase in memory usage for C programs, a moderate
5271 increase in memory usage for C++ programs, and a fantastic speedup in
5274 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5275 from the specifications in the Annotated Reference Manual, which AT&T's
5276 compiler does not actually implement.
5278 * G++ multiple inheritance compiler problem
5280 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5281 inheritance lattices was reworked to properly discover ambiguities. We
5282 recently found an example which causes this new algorithm to fail in a
5283 very subtle way, producing bad debug information for those classes.
5284 The file 'gcc.patch' (in this directory) can be applied to gcc to
5285 circumvent the problem. A future GCC release will contain a complete
5288 The previous G++ debug info problem (mentioned below for the gdb-4.7
5289 release) is fixed in gcc version 2.3.2.
5291 * Improved configure script
5293 The `configure' script will now attempt to guess your system type if
5294 you don't supply a host system type. The old scheme of supplying a
5295 host system triplet is preferable over using this. All the magic is
5296 done in the new `config.guess' script. Examine it for details.
5298 We have also brought our configure script much more in line with the FSF's
5299 version. It now supports the --with-xxx options. In particular,
5300 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5301 The resulting GDB will not be able to read arbitrary object file formats --
5302 only the format ``expected'' to be used on the configured target system.
5303 We hope to make this the default in a future release.
5305 * Documentation improvements
5307 There's new internal documentation on how to modify GDB, and how to
5308 produce clean changes to the code. We implore people to read it
5309 before submitting changes.
5311 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5312 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5313 `info' files are also provided. To build `info' files from scratch,
5314 you will need the latest `makeinfo' release, which will be available in
5315 a future texinfo-X.Y release.
5317 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5318 We're not sure exactly which versions have this problem, but it has
5319 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5320 or better. If that isn't possible, there is a patch in
5321 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5322 around this problem.
5326 GDB now supports array constants that can be used in expressions typed in by
5327 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5328 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5331 The new directory `gdb/sparclite' contains a program that demonstrates
5332 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5334 * New native hosts supported
5336 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5337 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5339 * New targets supported
5341 AMD 29k family via UDI a29k-amd-udi or udi29k
5343 * New file formats supported
5345 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5346 HPUX core files, and SCO 3.2v2 core files.
5350 Attaching to processes now works again; thanks for the many bug reports.
5352 We have also stomped on a bunch of core dumps caused by
5353 printf_filtered("%s") problems.
5355 We eliminated a copyright problem on the rpc and ptrace header files
5356 for VxWorks, which was discovered at the last minute during the 4.7
5357 release. You should now be able to build a VxWorks GDB.
5359 You can now interrupt gdb while an attached process is running. This
5360 will cause the attached process to stop, and give control back to GDB.
5362 We fixed problems caused by using too many file descriptors
5363 for reading symbols from object files and libraries. This was
5364 especially a problem for programs that used many (~100) shared
5367 The `step' command now only enters a subroutine if there is line number
5368 information for the subroutine. Otherwise it acts like the `next'
5369 command. Previously, `step' would enter subroutines if there was
5370 any debugging information about the routine. This avoids problems
5371 when using `cc -g1' on MIPS machines.
5373 * Internal improvements
5375 GDB's internal interfaces have been improved to make it easier to support
5376 debugging of multiple languages in the future.
5378 GDB now uses a common structure for symbol information internally.
5379 Minimal symbols (derived from linkage symbols in object files), partial
5380 symbols (from a quick scan of debug information), and full symbols
5381 contain a common subset of information, making it easier to write
5382 shared code that handles any of them.
5384 * New command line options
5386 We now accept --silent as an alias for --quiet.
5390 The memory-mapped-malloc library is now licensed under the GNU Library
5391 General Public License.
5393 *** Changes in GDB-4.7:
5395 * Host/native/target split
5397 GDB has had some major internal surgery to untangle the support for
5398 hosts and remote targets. Now, when you configure GDB for a remote
5399 target, it will no longer load in all of the support for debugging
5400 local programs on the host. When fully completed and tested, this will
5401 ensure that arbitrary host/target combinations are possible.
5403 The primary conceptual shift is to separate the non-portable code in
5404 GDB into three categories. Host specific code is required any time GDB
5405 is compiled on that host, regardless of the target. Target specific
5406 code relates to the peculiarities of the target, but can be compiled on
5407 any host. Native specific code is everything else: it can only be
5408 built when the host and target are the same system. Child process
5409 handling and core file support are two common `native' examples.
5411 GDB's use of /proc for controlling Unix child processes is now cleaner.
5412 It has been split out into a single module under the `target_ops' vector,
5413 plus two native-dependent functions for each system that uses /proc.
5415 * New hosts supported
5417 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5418 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5419 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5421 * New targets supported
5423 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5424 68030 and CPU32 m68030-*-*, m68332-*-*
5426 * New native hosts supported
5428 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5429 (386bsd is not well tested yet)
5430 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5432 * New file formats supported
5434 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5435 supports reading of `a.out.adobe' object files, which are an a.out
5436 format extended with minimal information about multiple sections.
5440 `show copying' is the same as the old `info copying'.
5441 `show warranty' is the same as `info warrantee'.
5442 These were renamed for consistency. The old commands continue to work.
5444 `info handle' is a new alias for `info signals'.
5446 You can now define pre-command hooks, which attach arbitrary command
5447 scripts to any command. The commands in the hook will be executed
5448 prior to the user's command. You can also create a hook which will be
5449 executed whenever the program stops. See gdb.texinfo.
5453 We now deal with Cfront style name mangling, and can even extract type
5454 info from mangled symbols. GDB can automatically figure out which
5455 symbol mangling style your C++ compiler uses.
5457 Calling of methods and virtual functions has been improved as well.
5461 The crash that occured when debugging Sun Ansi-C compiled binaries is
5462 fixed. This was due to mishandling of the extra N_SO stabs output
5465 We also finally got Ultrix 4.2 running in house, and fixed core file
5466 support, with help from a dozen people on the net.
5468 John M. Farrell discovered that the reason that single-stepping was so
5469 slow on all of the Mips based platforms (primarily SGI and DEC) was
5470 that we were trying to demangle and lookup a symbol used for internal
5471 purposes on every instruction that was being stepped through. Changing
5472 the name of that symbol so that it couldn't be mistaken for a C++
5473 mangled symbol sped things up a great deal.
5475 Rich Pixley sped up symbol lookups in general by getting much smarter
5476 about when C++ symbol mangling is necessary. This should make symbol
5477 completion (TAB on the command line) much faster. It's not as fast as
5478 we'd like, but it's significantly faster than gdb-4.6.
5482 A new user controllable variable 'call_scratch_address' can
5483 specify the location of a scratch area to be used when GDB
5484 calls a function in the target. This is necessary because the
5485 usual method of putting the scratch area on the stack does not work
5486 in systems that have separate instruction and data spaces.
5488 We integrated changes to support the 29k UDI (Universal Debugger
5489 Interface), but discovered at the last minute that we didn't have all
5490 of the appropriate copyright paperwork. We are working with AMD to
5491 resolve this, and hope to have it available soon.
5495 We have sped up the remote serial line protocol, especially for targets
5496 with lots of registers. It now supports a new `expedited status' ('T')
5497 message which can be used in place of the existing 'S' status message.
5498 This allows the remote stub to send only the registers that GDB
5499 needs to make a quick decision about single-stepping or conditional
5500 breakpoints, eliminating the need to fetch the entire register set for
5501 each instruction being stepped through.
5503 The GDB remote serial protocol now implements a write-through cache for
5504 registers, only re-reading the registers if the target has run.
5506 There is also a new remote serial stub for SPARC processors. You can
5507 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5508 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5509 processor with a serial port.
5513 Configure.in files have become much easier to read and modify. A new
5514 `table driven' format makes it more obvious what configurations are
5515 supported, and what files each one uses.
5519 There is a new opcodes library which will eventually contain all of the
5520 disassembly routines and opcode tables. At present, it only contains
5521 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5522 disassembler (binutils/objdump) to share these routines.
5524 The libiberty library is now copylefted under the GNU Library General
5525 Public License. This allows more liberal use, and was done so libg++
5526 can use it. This makes no difference to GDB, since the Library License
5527 grants all the rights from the General Public License.
5531 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5532 reference to the stabs symbol info used by the debugger. It is (as far
5533 as we know) the only published document on this fascinating topic. We
5534 encourage you to read it, compare it to the stabs information on your
5535 system, and send improvements on the document in general (to
5536 bug-gdb@prep.ai.mit.edu).
5538 And, of course, many bugs have been fixed.
5541 *** Changes in GDB-4.6:
5543 * Better support for C++ function names
5545 GDB now accepts as input the "demangled form" of C++ overloaded function
5546 names and member function names, and can do command completion on such names
5547 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5548 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5549 Make use of command completion, it is your friend.
5551 GDB also now accepts a variety of C++ mangled symbol formats. They are
5552 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5553 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5554 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5555 for the list of formats.
5557 * G++ symbol mangling problem
5559 Recent versions of gcc have a bug in how they emit debugging information for
5560 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5561 directory) can be applied to gcc to fix the problem. Alternatively, if you
5562 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5563 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5564 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5567 * New 'maintenance' command
5569 All of the commands related to hacking GDB internals have been moved out of
5570 the main command set, and now live behind the 'maintenance' command. This
5571 can also be abbreviated as 'mt'. The following changes were made:
5573 dump-me -> maintenance dump-me
5574 info all-breakpoints -> maintenance info breakpoints
5575 printmsyms -> maintenance print msyms
5576 printobjfiles -> maintenance print objfiles
5577 printpsyms -> maintenance print psymbols
5578 printsyms -> maintenance print symbols
5580 The following commands are new:
5582 maintenance demangle Call internal GDB demangler routine to
5583 demangle a C++ link name and prints the result.
5584 maintenance print type Print a type chain for a given symbol
5586 * Change to .gdbinit file processing
5588 We now read the $HOME/.gdbinit file before processing the argv arguments
5589 (e.g. reading symbol files or core files). This allows global parameters to
5590 be set, which will apply during the symbol reading. The ./.gdbinit is still
5591 read after argv processing.
5593 * New hosts supported
5595 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5597 GNU/Linux support i386-unknown-linux or linux
5599 We are also including code to support the HP/PA running BSD and HPUX. This
5600 is almost guaranteed not to work, as we didn't have time to test or build it
5601 for this release. We are including it so that the more adventurous (or
5602 masochistic) of you can play with it. We also had major problems with the
5603 fact that the compiler that we got from HP doesn't support the -g option.
5606 * New targets supported
5608 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5610 * More smarts about finding #include files
5612 GDB now remembers the compilation directory for all include files, and for
5613 all files from which C is generated (like yacc and lex sources). This
5614 greatly improves GDB's ability to find yacc/lex sources, and include files,
5615 especially if you are debugging your program from a directory different from
5616 the one that contains your sources.
5618 We also fixed a bug which caused difficulty with listing and setting
5619 breakpoints in include files which contain C code. (In the past, you had to
5620 try twice in order to list an include file that you hadn't looked at before.)
5622 * Interesting infernals change
5624 GDB now deals with arbitrary numbers of sections, where the symbols for each
5625 section must be relocated relative to that section's landing place in the
5626 target's address space. This work was needed to support ELF with embedded
5627 stabs used by Solaris-2.0.
5629 * Bug fixes (of course!)
5631 There have been loads of fixes for the following things:
5632 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5633 i960, stabs, DOS(GO32), procfs, etc...
5635 See the ChangeLog for details.
5637 *** Changes in GDB-4.5:
5639 * New machines supported (host and target)
5641 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5643 SGI Irix-4.x mips-sgi-irix4 or iris4
5645 * New malloc package
5647 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5648 Mmalloc is capable of handling mutiple heaps of memory. It is also
5649 capable of saving a heap to a file, and then mapping it back in later.
5650 This can be used to greatly speedup the startup of GDB by using a
5651 pre-parsed symbol table which lives in a mmalloc managed heap. For
5652 more details, please read mmalloc/mmalloc.texi.
5656 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5657 'help info proc' for details.
5659 * MIPS ecoff symbol table format
5661 The code that reads MIPS symbol table format is now supported on all hosts.
5662 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5665 * File name changes for MS-DOS
5667 Many files in the config directories have been renamed to make it easier to
5668 support GDB on MS-DOSe systems (which have very restrictive file name
5669 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5670 environment) is close to working but has some remaining problems. Note
5671 that debugging of DOS programs is not supported, due to limitations
5672 in the ``operating system'', but it can be used to host cross-debugging.
5674 * Cross byte order fixes
5676 Many fixes have been made to support cross debugging of Sparc and MIPS
5677 targets from hosts whose byte order differs.
5679 * New -mapped and -readnow options
5681 If memory-mapped files are available on your system through the 'mmap'
5682 system call, you can use the -mapped option on the `file' or
5683 `symbol-file' commands to cause GDB to write the symbols from your
5684 program into a reusable file. If the program you are debugging is
5685 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5686 Future GDB debugging sessions will notice the presence of this file,
5687 and will quickly map in symbol information from it, rather than reading
5688 the symbol table from the executable program. Using the '-mapped'
5689 option in a GDB `file' or `symbol-file' command has the same effect as
5690 starting GDB with the '-mapped' command-line option.
5692 You can cause GDB to read the entire symbol table immediately by using
5693 the '-readnow' option with any of the commands that load symbol table
5694 information (or on the GDB command line). This makes the command
5695 slower, but makes future operations faster.
5697 The -mapped and -readnow options are typically combined in order to
5698 build a `fred.syms' file that contains complete symbol information.
5699 A simple GDB invocation to do nothing but build a `.syms' file for future
5702 gdb -batch -nx -mapped -readnow programname
5704 The `.syms' file is specific to the host machine on which GDB is run.
5705 It holds an exact image of GDB's internal symbol table. It cannot be
5706 shared across multiple host platforms.
5708 * longjmp() handling
5710 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5711 siglongjmp() without losing control. This feature has not yet been ported to
5712 all systems. It currently works on many 386 platforms, all MIPS-based
5713 platforms (SGI, DECstation, etc), and Sun3/4.
5717 Preliminary work has been put in to support the new Solaris OS from Sun. At
5718 this time, it can control and debug processes, but it is not capable of
5723 As always, many many bug fixes. The major areas were with g++, and mipsread.
5724 People using the MIPS-based platforms should experience fewer mysterious
5725 crashes and trashed symbol tables.
5727 *** Changes in GDB-4.4:
5729 * New machines supported (host and target)
5731 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5733 BSD Reno on Vax vax-dec-bsd
5734 Ultrix on Vax vax-dec-ultrix
5736 * New machines supported (target)
5738 AMD 29000 embedded, using EBMON a29k-none-none
5742 GDB continues to improve its handling of C++. `References' work better.
5743 The demangler has also been improved, and now deals with symbols mangled as
5744 per the Annotated C++ Reference Guide.
5746 GDB also now handles `stabs' symbol information embedded in MIPS
5747 `ecoff' symbol tables. Since the ecoff format was not easily
5748 extensible to handle new languages such as C++, this appeared to be a
5749 good way to put C++ debugging info into MIPS binaries. This option
5750 will be supported in the GNU C compiler, version 2, when it is
5753 * New features for SVR4
5755 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5756 shared libraries. Debugging dynamically linked programs should present
5757 only minor differences from debugging statically linked programs.
5759 The `info proc' command will print out information about any process
5760 on an SVR4 system (including the one you are debugging). At the moment,
5761 it prints the address mappings of the process.
5763 If you bring up GDB on another SVR4 system, please send mail to
5764 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5766 * Better dynamic linking support in SunOS
5768 Reading symbols from shared libraries which contain debugging symbols
5769 now works properly. However, there remain issues such as automatic
5770 skipping of `transfer vector' code during function calls, which
5771 make it harder to debug code in a shared library, than to debug the
5772 same code linked statically.
5776 GDB is now using the latest `getopt' routines from the FSF. This
5777 version accepts the -- prefix for options with long names. GDB will
5778 continue to accept the old forms (-option and +option) as well.
5779 Various single letter abbreviations for options have been explicity
5780 added to the option table so that they won't get overshadowed in the
5781 future by other options that begin with the same letter.
5785 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5786 Many assorted bugs have been handled. Many more remain to be handled.
5787 See the various ChangeLog files (primarily in gdb and bfd) for details.
5790 *** Changes in GDB-4.3:
5792 * New machines supported (host and target)
5794 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5795 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5796 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5798 * Almost SCO Unix support
5800 We had hoped to support:
5801 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5802 (except for core file support), but we discovered very late in the release
5803 that it has problems with process groups that render gdb unusable. Sorry
5804 about that. I encourage people to fix it and post the fixes.
5806 * Preliminary ELF and DWARF support
5808 GDB can read ELF object files on System V Release 4, and can handle
5809 debugging records for C, in DWARF format, in ELF files. This support
5810 is preliminary. If you bring up GDB on another SVR4 system, please
5811 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5816 GDB now uses the latest `readline' library. One user-visible change
5817 is that two tabs will list possible command completions, which previously
5818 required typing M-? (meta-question mark, or ESC ?).
5822 The `stepi' bug that many of you noticed has been squashed.
5823 Many bugs in C++ have been handled. Many more remain to be handled.
5824 See the various ChangeLog files (primarily in gdb and bfd) for details.
5826 * State of the MIPS world (in case you wondered):
5828 GDB can understand the symbol tables emitted by the compilers
5829 supplied by most vendors of MIPS-based machines, including DEC. These
5830 symbol tables are in a format that essentially nobody else uses.
5832 Some versions of gcc come with an assembler post-processor called
5833 mips-tfile. This program is required if you want to do source-level
5834 debugging of gcc-compiled programs. I believe FSF does not ship
5835 mips-tfile with gcc version 1, but it will eventually come with gcc
5838 Debugging of g++ output remains a problem. g++ version 1.xx does not
5839 really support it at all. (If you're lucky, you should be able to get
5840 line numbers and stack traces to work, but no parameters or local
5841 variables.) With some work it should be possible to improve the
5844 When gcc version 2 is released, you will have somewhat better luck.
5845 However, even then you will get confusing results for inheritance and
5848 We will eventually provide full debugging of g++ output on
5849 DECstations. This will probably involve some kind of stabs-in-ecoff
5850 encapulation, but the details have not been worked out yet.
5853 *** Changes in GDB-4.2:
5855 * Improved configuration
5857 Only one copy of `configure' exists now, and it is not self-modifying.
5858 Porting BFD is simpler.
5862 The `step' and `next' commands now only stop at the first instruction
5863 of a source line. This prevents the multiple stops that used to occur
5864 in switch statements, for-loops, etc. `Step' continues to stop if a
5865 function that has debugging information is called within the line.
5869 Lots of small bugs fixed. More remain.
5871 * New host supported (not target)
5873 Intel 386 PC clone running Mach i386-none-mach
5876 *** Changes in GDB-4.1:
5878 * Multiple source language support
5880 GDB now has internal scaffolding to handle several source languages.
5881 It determines the type of each source file from its filename extension,
5882 and will switch expression parsing and number formatting to match the
5883 language of the function in the currently selected stack frame.
5884 You can also specifically set the language to be used, with
5885 `set language c' or `set language modula-2'.
5889 GDB now has preliminary support for the GNU Modula-2 compiler,
5890 currently under development at the State University of New York at
5891 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5892 continue through the fall of 1991 and into 1992.
5894 Other Modula-2 compilers are currently not supported, and attempting to
5895 debug programs compiled with them will likely result in an error as the
5896 symbol table is read. Feel free to work on it, though!
5898 There are hooks in GDB for strict type checking and range checking,
5899 in the `Modula-2 philosophy', but they do not currently work.
5903 GDB can now write to executable and core files (e.g. patch
5904 a variable's value). You must turn this switch on, specify
5905 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5906 by assigning a new value to a variable. Modifications take
5909 * Automatic SunOS shared library reading
5911 When you run your program, GDB automatically determines where its
5912 shared libraries (if any) have been loaded, and reads their symbols.
5913 The `share' command is no longer needed. This also works when
5914 examining core files.
5918 You can specify the number of lines that the `list' command shows.
5921 * New machines supported (host and target)
5923 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5924 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5925 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5927 * New hosts supported (not targets)
5929 IBM RT/PC: romp-ibm-aix or rtpc
5931 * New targets supported (not hosts)
5933 AMD 29000 embedded with COFF a29k-none-coff
5934 AMD 29000 embedded with a.out a29k-none-aout
5935 Ultracomputer remote kernel debug a29k-nyu-kern
5937 * New remote interfaces
5943 *** Changes in GDB-4.0:
5947 Wide output is wrapped at good places to make the output more readable.
5949 Gdb now supports cross-debugging from a host machine of one type to a
5950 target machine of another type. Communication with the target system
5951 is over serial lines. The ``target'' command handles connecting to the
5952 remote system; the ``load'' command will download a program into the
5953 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5954 also supports debugging of realtime processes running under VxWorks,
5955 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5956 stub on the target system.
5958 New CPUs supported include the AMD 29000 and Intel 960.
5960 GDB now reads object files and symbol tables via a ``binary file''
5961 library, which allows a single copy of GDB to debug programs of multiple
5962 object file types such as a.out and coff.
5964 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5965 refcard.dvi and refcard.ps are available to format it).
5968 * Control-Variable user interface simplified
5970 All variables that control the operation of the debugger can be set
5971 by the ``set'' command, and displayed by the ``show'' command.
5973 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5974 ``Show prompt'' produces the response:
5975 Gdb's prompt is new-gdb=>.
5977 What follows are the NEW set commands. The command ``help set'' will
5978 print a complete list of old and new set commands. ``help set FOO''
5979 will give a longer description of the variable FOO. ``show'' will show
5980 all of the variable descriptions and their current settings.
5982 confirm on/off: Enables warning questions for operations that are
5983 hard to recover from, e.g. rerunning the program while
5984 it is already running. Default is ON.
5986 editing on/off: Enables EMACS style command line editing
5987 of input. Previous lines can be recalled with
5988 control-P, the current line can be edited with control-B,
5989 you can search for commands with control-R, etc.
5992 history filename NAME: NAME is where the gdb command history
5993 will be stored. The default is .gdb_history,
5994 or the value of the environment variable
5997 history size N: The size, in commands, of the command history. The
5998 default is 256, or the value of the environment variable
6001 history save on/off: If this value is set to ON, the history file will
6002 be saved after exiting gdb. If set to OFF, the
6003 file will not be saved. The default is OFF.
6005 history expansion on/off: If this value is set to ON, then csh-like
6006 history expansion will be performed on
6007 command line input. The default is OFF.
6009 radix N: Sets the default radix for input and output. It can be set
6010 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6011 in the current radix, so "set radix 10" is always a no-op.
6013 height N: This integer value is the number of lines on a page. Default
6014 is 24, the current `stty rows'' setting, or the ``li#''
6015 setting from the termcap entry matching the environment
6018 width N: This integer value is the number of characters on a line.
6019 Default is 80, the current `stty cols'' setting, or the ``co#''
6020 setting from the termcap entry matching the environment
6023 Note: ``set screensize'' is obsolete. Use ``set height'' and
6024 ``set width'' instead.
6026 print address on/off: Print memory addresses in various command displays,
6027 such as stack traces and structure values. Gdb looks
6028 more ``symbolic'' if you turn this off; it looks more
6029 ``machine level'' with it on. Default is ON.
6031 print array on/off: Prettyprint arrays. New convenient format! Default
6034 print demangle on/off: Print C++ symbols in "source" form if on,
6037 print asm-demangle on/off: Same, for assembler level printouts
6040 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6043 * Support for Epoch Environment.
6045 The epoch environment is a version of Emacs v18 with windowing. One
6046 new command, ``inspect'', is identical to ``print'', except that if you
6047 are running in the epoch environment, the value is printed in its own
6051 * Support for Shared Libraries
6053 GDB can now debug programs and core files that use SunOS shared libraries.
6054 Symbols from a shared library cannot be referenced
6055 before the shared library has been linked with the program (this
6056 happens after you type ``run'' and before the function main() is entered).
6057 At any time after this linking (including when examining core files
6058 from dynamically linked programs), gdb reads the symbols from each
6059 shared library when you type the ``sharedlibrary'' command.
6060 It can be abbreviated ``share''.
6062 sharedlibrary REGEXP: Load shared object library symbols for files
6063 matching a unix regular expression. No argument
6064 indicates to load symbols for all shared libraries.
6066 info sharedlibrary: Status of loaded shared libraries.
6071 A watchpoint stops execution of a program whenever the value of an
6072 expression changes. Checking for this slows down execution
6073 tremendously whenever you are in the scope of the expression, but is
6074 quite useful for catching tough ``bit-spreader'' or pointer misuse
6075 problems. Some machines such as the 386 have hardware for doing this
6076 more quickly, and future versions of gdb will use this hardware.
6078 watch EXP: Set a watchpoint (breakpoint) for an expression.
6080 info watchpoints: Information about your watchpoints.
6082 delete N: Deletes watchpoint number N (same as breakpoints).
6083 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6084 enable N: Re-enables watchpoint number N (same as breakpoints).
6087 * C++ multiple inheritance
6089 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6092 * C++ exception handling
6094 Gdb now supports limited C++ exception handling. Besides the existing
6095 ability to breakpoint on an exception handler, gdb can breakpoint on
6096 the raising of an exception (before the stack is peeled back to the
6099 catch FOO: If there is a FOO exception handler in the dynamic scope,
6100 set a breakpoint to catch exceptions which may be raised there.
6101 Multiple exceptions (``catch foo bar baz'') may be caught.
6103 info catch: Lists all exceptions which may be caught in the
6104 current stack frame.
6107 * Minor command changes
6109 The command ``call func (arg, arg, ...)'' now acts like the print
6110 command, except it does not print or save a value if the function's result
6111 is void. This is similar to dbx usage.
6113 The ``up'' and ``down'' commands now always print the frame they end up
6114 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6115 frames without printing.
6117 * New directory command
6119 'dir' now adds directories to the FRONT of the source search path.
6120 The path starts off empty. Source files that contain debug information
6121 about the directory in which they were compiled can be found even
6122 with an empty path; Sun CC and GCC include this information. If GDB can't
6123 find your source file in the current directory, type "dir .".
6125 * Configuring GDB for compilation
6127 For normal use, type ``./configure host''. See README or gdb.texinfo
6130 GDB now handles cross debugging. If you are remotely debugging between
6131 two different machines, type ``./configure host -target=targ''.
6132 Host is the machine where GDB will run; targ is the machine
6133 where the program that you are debugging will run.