1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.7
8 maint ada set ignore-descriptive-types (on|off)
9 maint ada show ignore-descriptive-types
10 Control whether the debugger should ignore descriptive types in Ada
11 programs. The default is not to ignore the descriptive types. See
12 the user manual for more details on descriptive types and the intended
15 * New features in the GDB remote stub, GDBserver
17 ** New option --debug-format=option1[,option2,...] allows one to add
18 additional text to each output. At present only timestamps
19 are supported: --debug-format=timestamps.
20 Timestamps can also be turned on with the
21 "monitor set debug-format timestamps" command from GDB.
23 * The 'record instruction-history' command now starts counting instructions
24 at one. This also affects the instruction ranges reported by the
25 'record function-call-history' command when given the /i modifier.
27 * The command 'record function-call-history' supports a new modifier '/c' to
28 indent the function names based on their call stack depth.
29 The fields for the '/i' and '/l' modifier have been reordered.
30 The source line range is now prefixed with 'at'.
31 The instruction range is now prefixed with 'inst'.
32 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
33 "record instruction-history" and "list" commands.
35 * The ranges given as arguments to the 'record function-call-history' and
36 'record instruction-history' commands are now inclusive.
38 * The btrace record target now supports the 'record goto' command.
39 For locations inside the execution trace, the back trace is computed
40 based on the information stored in the execution trace.
42 * The btrace record target supports limited reverse execution and replay.
43 The target does not record data and therefore does not allow reading
46 * The "catch syscall" command now works on s390*-linux* targets.
50 qXfer:btrace:read's annex
51 The qXfer:btrace:read packet supports a new annex 'delta' to read
52 branch trace incrementally.
54 *** Changes in GDB 7.7
56 * Improved support for process record-replay and reverse debugging on
57 arm*-linux* targets. Support for thumb32 and syscall instruction
58 recording has been added.
60 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
62 * GDB now supports Fission DWP file format version 2.
63 http://gcc.gnu.org/wiki/DebugFission
65 * New convenience function "$_isvoid", to check whether an expression
66 is void. A void expression is an expression where the type of the
67 result is "void". For example, some convenience variables may be
68 "void" when evaluated (e.g., "$_exitcode" before the execution of
69 the program being debugged; or an undefined convenience variable).
70 Another example, when calling a function whose return type is
73 * The "maintenance print objfiles" command now takes an optional regexp.
75 * The "catch syscall" command now works on arm*-linux* targets.
77 * GDB now consistently shows "<not saved>" when printing values of
78 registers the debug info indicates have not been saved in the frame
79 and there's nowhere to retrieve them from
80 (callee-saved/call-clobbered registers):
85 (gdb) info registers rax
88 Before, the former would print "<optimized out>", and the latter
89 "*value not available*".
91 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
96 ** Frame filters and frame decorators have been added.
97 ** Temporary breakpoints are now supported.
98 ** Line tables representation has been added.
99 ** New attribute 'parent_type' for gdb.Field objects.
100 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
101 ** New attribute 'name' for gdb.Type objects.
105 Nios II ELF nios2*-*-elf
106 Nios II GNU/Linux nios2*-*-linux
107 Texas Instruments MSP430 msp430*-*-elf
109 * Removed native configurations
111 Support for these a.out NetBSD and OpenBSD obsolete configurations has
112 been removed. ELF variants of these configurations are kept supported.
114 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
115 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
116 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
117 i[34567]86-*-openbsd3.[0-3]
118 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
119 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
120 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
124 Like "catch throw", but catches a re-thrown exception.
126 Renamed from old "maint check-symtabs".
128 Perform consistency checks on symtabs.
130 Expand symtabs matching an optional regexp.
133 Display the details of GDB configure-time options.
135 maint set|show per-command
136 maint set|show per-command space
137 maint set|show per-command time
138 maint set|show per-command symtab
139 Enable display of per-command gdb resource usage.
141 remove-symbol-file FILENAME
142 remove-symbol-file -a ADDRESS
143 Remove a symbol file added via add-symbol-file. The file to remove
144 can be identified by its filename or by an address that lies within
145 the boundaries of this symbol file in memory.
148 info exceptions REGEXP
149 Display the list of Ada exceptions defined in the program being
150 debugged. If provided, only the exceptions whose names match REGEXP
155 set debug symfile off|on
157 Control display of debugging info regarding reading symbol files and
158 symbol tables within those files
160 set print raw frame-arguments
161 show print raw frame-arguments
162 Set/show whether to print frame arguments in raw mode,
163 disregarding any defined pretty-printers.
165 set remote trace-status-packet
166 show remote trace-status-packet
167 Set/show the use of remote protocol qTStatus packet.
171 Control display of debugging messages related to Nios II targets.
175 Control whether target-assisted range stepping is enabled.
177 set startup-with-shell
178 show startup-with-shell
179 Specifies whether Unix child processes are started via a shell or
184 Use the target memory cache for accesses to the code segment. This
185 improves performance of remote debugging (particularly disassembly).
187 * You can now use a literal value 'unlimited' for options that
188 interpret 0 or -1 as meaning "unlimited". E.g., "set
189 trace-buffer-size unlimited" is now an alias for "set
190 trace-buffer-size -1" and "set height unlimited" is now an alias for
193 * The "set debug symtab-create" debugging option of GDB has been changed to
194 accept a verbosity level. 0 means "off", 1 provides basic debugging
195 output, and values of 2 or greater provides more verbose output.
197 * New command-line options
199 Display the details of GDB configure-time options.
201 * The command 'tsave' can now support new option '-ctf' to save trace
202 buffer in Common Trace Format.
204 * Newly installed $prefix/bin/gcore acts as a shell interface for the
207 * GDB now implements the the C++ 'typeid' operator.
209 * The new convenience variable $_exception holds the exception being
210 thrown or caught at an exception-related catchpoint.
212 * The exception-related catchpoints, like "catch throw", now accept a
213 regular expression which can be used to filter exceptions by type.
215 * The new convenience variable $_exitsignal is automatically set to
216 the terminating signal number when the program being debugged dies
217 due to an uncaught signal.
221 ** All MI commands now accept an optional "--language" option.
222 Support for this feature can be verified by using the "-list-features"
223 command, which should contain "language-option".
225 ** The new command -info-gdb-mi-command allows the user to determine
226 whether a GDB/MI command is supported or not.
228 ** The "^error" result record returned when trying to execute an undefined
229 GDB/MI command now provides a variable named "code" whose content is the
230 "undefined-command" error code. Support for this feature can be verified
231 by using the "-list-features" command, which should contain
232 "undefined-command-error-code".
234 ** The -trace-save MI command can optionally save trace buffer in Common
237 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
239 ** The command -data-list-register-values now accepts an optional
240 "--skip-unavailable" option. When used, only the available registers
243 ** The new command -trace-frame-collected dumps collected variables,
244 computed expressions, tvars, memory and registers in a traceframe.
246 ** The commands -stack-list-locals, -stack-list-arguments and
247 -stack-list-variables now accept an option "--skip-unavailable".
248 When used, only the available locals or arguments are displayed.
250 ** The -exec-run command now accepts an optional "--start" option.
251 When used, the command follows the same semantics as the "start"
252 command, stopping the program's execution at the start of its
253 main subprogram. Support for this feature can be verified using
254 the "-list-features" command, which should contain
255 "exec-run-start-option".
257 ** The new commands -catch-assert and -catch-exceptions insert
258 catchpoints stopping the program when Ada exceptions are raised.
260 ** The new command -info-ada-exceptions provides the equivalent of
261 the new "info exceptions" command.
263 * New system-wide configuration scripts
264 A GDB installation now provides scripts suitable for use as system-wide
265 configuration scripts for the following systems:
269 * GDB now supports target-assigned range stepping with remote targets.
270 This improves the performance of stepping source lines by reducing
271 the number of control packets from/to GDB. See "New remote packets"
274 * GDB now understands the element 'tvar' in the XML traceframe info.
275 It has the id of the collected trace state variables.
277 * On S/390 targets that provide the transactional-execution feature,
278 the program interruption transaction diagnostic block (TDB) is now
279 represented as a number of additional "registers" in GDB.
285 The vCont packet supports a new 'r' action, that tells the remote
286 stub to step through an address range itself, without GDB
287 involvemement at each single-step.
289 qXfer:libraries-svr4:read's annex
290 The previously unused annex of the qXfer:libraries-svr4:read packet
291 is now used to support passing an argument list. The remote stub
292 reports support for this argument list to GDB's qSupported query.
293 The defined arguments are "start" and "prev", used to reduce work
294 necessary for library list updating, resulting in significant
297 * New features in the GDB remote stub, GDBserver
299 ** GDBserver now supports target-assisted range stepping. Currently
300 enabled on x86/x86_64 GNU/Linux targets.
302 ** GDBserver now adds element 'tvar' in the XML in the reply to
303 'qXfer:traceframe-info:read'. It has the id of the collected
304 trace state variables.
306 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
309 * New 'z' formatter for printing and examining memory, this displays the
310 value as hexadecimal zero padded on the left to the size of the type.
312 * GDB can now use Windows x64 unwinding data.
314 * The "set remotebaud" command has been replaced by "set serial baud".
315 Similarly, "show remotebaud" has been replaced by "show serial baud".
316 The "set remotebaud" and "show remotebaud" commands are still available
317 to provide backward compatibility with older versions of GDB.
319 *** Changes in GDB 7.6
321 * Target record has been renamed to record-full.
322 Record/replay is now enabled with the "record full" command.
323 This also affects settings that are associated with full record/replay
324 that have been moved from "set/show record" to "set/show record full":
326 set|show record full insn-number-max
327 set|show record full stop-at-limit
328 set|show record full memory-query
330 * A new record target "record-btrace" has been added. The new target
331 uses hardware support to record the control-flow of a process. It
332 does not support replaying the execution, but it implements the
333 below new commands for investigating the recorded execution log.
334 This new recording method can be enabled using:
338 The "record-btrace" target is only available on Intel Atom processors
339 and requires a Linux kernel 2.6.32 or later.
341 * Two new commands have been added for record/replay to give information
342 about the recorded execution without having to replay the execution.
343 The commands are only supported by "record btrace".
345 record instruction-history prints the execution history at
346 instruction granularity
348 record function-call-history prints the execution history at
351 * New native configurations
353 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
354 FreeBSD/powerpc powerpc*-*-freebsd
355 x86_64/Cygwin x86_64-*-cygwin*
356 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
360 ARM AArch64 aarch64*-*-elf
361 ARM AArch64 GNU/Linux aarch64*-*-linux
362 Lynx 178 PowerPC powerpc-*-lynx*178
363 x86_64/Cygwin x86_64-*-cygwin*
364 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
366 * If the configured location of system.gdbinit file (as given by the
367 --with-system-gdbinit option at configure time) is in the
368 data-directory (as specified by --with-gdb-datadir at configure
369 time) or in one of its subdirectories, then GDB will look for the
370 system-wide init file in the directory specified by the
371 --data-directory command-line option.
373 * New command line options:
375 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
376 other initialization files, unlike -nx which disables all of them.
378 * Removed command line options
380 -epoch This was used by the gdb mode in Epoch, an ancient fork of
383 * The 'ptype' and 'whatis' commands now accept an argument to control
386 * 'info proc' now works on some core files.
390 ** Vectors can be created with gdb.Type.vector.
392 ** Python's atexit.register now works in GDB.
394 ** Types can be pretty-printed via a Python API.
396 ** Python 3 is now supported (in addition to Python 2.4 or later)
398 ** New class gdb.Architecture exposes GDB's internal representation
399 of architecture in the Python API.
401 ** New method Frame.architecture returns the gdb.Architecture object
402 corresponding to the frame's architecture.
404 * New Python-based convenience functions:
406 ** $_memeq(buf1, buf2, length)
407 ** $_streq(str1, str2)
409 ** $_regex(str, regex)
411 * The 'cd' command now defaults to using '~' (the home directory) if not
414 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
415 default for GCC since November 2000.
417 * The command 'forward-search' can now be abbreviated as 'fo'.
419 * The command 'info tracepoints' can now display 'installed on target'
420 or 'not installed on target' for each non-pending location of tracepoint.
422 * New configure options
424 --enable-libmcheck/--disable-libmcheck
425 By default, development versions are built with -lmcheck on hosts
426 that support it, in order to help track memory corruption issues.
427 Release versions, on the other hand, are built without -lmcheck
428 by default. The --enable-libmcheck/--disable-libmcheck configure
429 options allow the user to override that default.
430 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
431 This configure option allows the user to build GDB with
432 libbabeltrace using which GDB can read Common Trace Format data.
434 * New commands (for set/show, see "New options" below)
437 Catch signals. This is similar to "handle", but allows commands and
438 conditions to be attached.
441 List the BFDs known to GDB.
443 python-interactive [command]
445 Start a Python interactive prompt, or evaluate the optional command
446 and print the result of expressions.
449 "py" is a new alias for "python".
451 enable type-printer [name]...
452 disable type-printer [name]...
453 Enable or disable type printers.
457 ** For the Renesas Super-H architecture, the "regs" command has been removed
458 (has been deprecated in GDB 7.5), and "info all-registers" should be used
463 set print type methods (on|off)
464 show print type methods
465 Control whether method declarations are displayed by "ptype".
466 The default is to show them.
468 set print type typedefs (on|off)
469 show print type typedefs
470 Control whether typedef definitions are displayed by "ptype".
471 The default is to show them.
473 set filename-display basename|relative|absolute
474 show filename-display
475 Control the way in which filenames is displayed.
476 The default is "relative", which preserves previous behavior.
478 set trace-buffer-size
479 show trace-buffer-size
480 Request target to change the size of trace buffer.
482 set remote trace-buffer-size-packet auto|on|off
483 show remote trace-buffer-size-packet
484 Control the use of the remote protocol `QTBuffer:size' packet.
488 Control display of debugging messages related to ARM AArch64.
491 set debug coff-pe-read
492 show debug coff-pe-read
493 Control display of debugging messages related to reading of COFF/PE
498 Control display of debugging messages related to Mach-O symbols
501 set debug notification
502 show debug notification
503 Control display of debugging info for async remote notification.
507 ** Command parameter changes are now notified using new async record
508 "=cmd-param-changed".
509 ** Trace frame changes caused by command "tfind" are now notified using
510 new async record "=traceframe-changed".
511 ** The creation, deletion and modification of trace state variables
512 are now notified using new async records "=tsv-created",
513 "=tsv-deleted" and "=tsv-modified".
514 ** The start and stop of process record are now notified using new
515 async record "=record-started" and "=record-stopped".
516 ** Memory changes are now notified using new async record
518 ** The data-disassemble command response will include a "fullname" field
519 containing the absolute file name when source has been requested.
520 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
521 command, to allow pattern filling of memory areas.
522 ** New commands "-catch-load"/"-catch-unload" added for intercepting
523 library load/unload events.
524 ** The response to breakpoint commands and breakpoint async records
525 includes an "installed" field containing a boolean state about each
526 non-pending tracepoint location is whether installed on target or not.
527 ** Output of the "-trace-status" command includes a "trace-file" field
528 containing the name of the trace file being examined. This field is
529 optional, and only present when examining a trace file.
530 ** The "fullname" field is now always present along with the "file" field,
531 even if the file cannot be found by GDB.
533 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
534 You must have the LZMA library available when configuring GDB for this
535 feature to be enabled. For more information, see:
536 http://fedoraproject.org/wiki/Features/MiniDebugInfo
541 Set the size of trace buffer. The remote stub reports support for this
542 packet to gdb's qSupported query.
545 Enable Branch Trace Store (BTS)-based branch tracing for the current
546 thread. The remote stub reports support for this packet to gdb's
550 Disable branch tracing for the current thread. The remote stub reports
551 support for this packet to gdb's qSupported query.
554 Read the traced branches for the current thread. The remote stub
555 reports support for this packet to gdb's qSupported query.
557 *** Changes in GDB 7.5
559 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
560 for more x32 ABI info.
562 * GDB now supports access to MIPS DSP registers on Linux targets.
564 * GDB now supports debugging microMIPS binaries.
566 * The "info os" command on GNU/Linux can now display information on
567 several new classes of objects managed by the operating system:
568 "info os procgroups" lists process groups
569 "info os files" lists file descriptors
570 "info os sockets" lists internet-domain sockets
571 "info os shm" lists shared-memory regions
572 "info os semaphores" lists semaphores
573 "info os msg" lists message queues
574 "info os modules" lists loaded kernel modules
576 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
577 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
578 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
579 options and inspect the probe arguments using the new $_probe_arg family
580 of convenience variables. You can obtain more information about SystemTap
581 in <http://sourceware.org/systemtap/>.
583 * GDB now supports reversible debugging on ARM, it allows you to
584 debug basic ARM and THUMB instructions, and provides
585 record/replay support.
587 * The option "symbol-reloading" has been deleted as it is no longer used.
591 ** GDB commands implemented in Python can now be put in command class
594 ** The "maint set python print-stack on|off" is now deleted.
596 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
597 apply "flag enum"-style pretty-printing to any enum.
599 ** gdb.lookup_symbol can now work when there is no current frame.
601 ** gdb.Symbol now has a 'line' attribute, holding the line number in
602 the source at which the symbol was defined.
604 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
605 method 'value'. The former indicates whether the symbol needs a
606 frame in order to compute its value, and the latter computes the
609 ** A new method 'referenced_value' on gdb.Value objects which can
610 dereference pointer as well as C++ reference values.
612 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
613 which return the global and static blocks (as gdb.Block objects),
614 of the underlying symbol table, respectively.
616 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
617 object associated with a PC value.
619 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
620 of the address range occupied by code for the current source line.
622 * Go language support.
623 GDB now supports debugging programs written in the Go programming
626 * GDBserver now supports stdio connections.
627 E.g. (gdb) target remote | ssh myhost gdbserver - hello
629 * The binary "gdbtui" can no longer be built or installed.
630 Use "gdb -tui" instead.
632 * GDB will now print "flag" enums specially. A flag enum is one where
633 all the enumerator values have no bits in common when pairwise
634 "and"ed. When printing a value whose type is a flag enum, GDB will
635 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
636 (gdb) print (enum E) 3
639 * The filename part of a linespec will now match trailing components
640 of a source file name. For example, "break gcc/expr.c:1000" will
641 now set a breakpoint in build/gcc/expr.c, but not
644 * The "info proc" and "generate-core-file" commands will now also
645 work on remote targets connected to GDBserver on Linux.
647 * The command "info catch" has been removed. It has been disabled
650 * The "catch exception" and "catch assert" commands now accept
651 a condition at the end of the command, much like the "break"
652 command does. For instance:
654 (gdb) catch exception Constraint_Error if Barrier = True
656 Previously, it was possible to add a condition to such catchpoints,
657 but it had to be done as a second step, after the catchpoint had been
658 created, using the "condition" command.
660 * The "info static-tracepoint-marker" command will now also work on
661 native Linux targets with in-process agent.
663 * GDB can now set breakpoints on inlined functions.
665 * The .gdb_index section has been updated to include symbols for
666 inlined functions. GDB will ignore older .gdb_index sections by
667 default, which could cause symbol files to be loaded more slowly
668 until their .gdb_index sections can be recreated. The new command
669 "set use-deprecated-index-sections on" will cause GDB to use any older
670 .gdb_index sections it finds. This will restore performance, but the
671 ability to set breakpoints on inlined functions will be lost in symbol
672 files with older .gdb_index sections.
674 The .gdb_index section has also been updated to record more information
675 about each symbol. This speeds up the "info variables", "info functions"
676 and "info types" commands when used with programs having the .gdb_index
677 section, as well as speeding up debugging with shared libraries using
678 the .gdb_index section.
680 * Ada support for GDB/MI Variable Objects has been added.
682 * GDB can now support 'breakpoint always-inserted mode' in 'record'
687 ** New command -info-os is the MI equivalent of "info os".
689 ** Output logs ("set logging" and related) now include MI output.
693 ** "set use-deprecated-index-sections on|off"
694 "show use-deprecated-index-sections on|off"
695 Controls the use of deprecated .gdb_index sections.
697 ** "catch load" and "catch unload" can be used to stop when a shared
698 library is loaded or unloaded, respectively.
700 ** "enable count" can be used to auto-disable a breakpoint after
703 ** "info vtbl" can be used to show the virtual method tables for
704 C++ and Java objects.
706 ** "explore" and its sub commands "explore value" and "explore type"
707 can be used to recursively explore values and types of
708 expressions. These commands are available only if GDB is
709 configured with '--with-python'.
711 ** "info auto-load" shows status of all kinds of auto-loaded files,
712 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
713 sequences of commands files, "info auto-load python-scripts"
714 shows status of auto-loading Python script files,
715 "info auto-load local-gdbinit" shows status of loading init file
716 (.gdbinit) from current directory and "info auto-load libthread-db" shows
717 status of inferior specific thread debugging shared library loading.
719 ** "info auto-load-scripts", "set auto-load-scripts on|off"
720 and "show auto-load-scripts" commands have been deprecated, use their
721 "info auto-load python-scripts", "set auto-load python-scripts on|off"
722 and "show auto-load python-scripts" counterparts instead.
724 ** "dprintf location,format,args..." creates a dynamic printf, which
725 is basically a breakpoint that does a printf and immediately
726 resumes your program's execution, so it is like a printf that you
727 can insert dynamically at runtime instead of at compiletime.
729 ** "set print symbol"
731 Controls whether GDB attempts to display the symbol, if any,
732 corresponding to addresses it prints. This defaults to "on", but
733 you can set it to "off" to restore GDB's previous behavior.
735 * Deprecated commands
737 ** For the Renesas Super-H architecture, the "regs" command has been
738 deprecated, and "info all-registers" should be used instead.
742 Renesas RL78 rl78-*-elf
743 HP OpenVMS ia64 ia64-hp-openvms*
745 * GDBserver supports evaluation of breakpoint conditions. When
746 support is advertised by GDBserver, GDB may be told to send the
747 breakpoint conditions in bytecode form to GDBserver. GDBserver
748 will only report the breakpoint trigger to GDB when its condition
754 show mips compression
755 Select the compressed ISA encoding used in functions that have no symbol
756 information available. The encoding can be set to either of:
759 and is updated automatically from ELF file flags if available.
761 set breakpoint condition-evaluation
762 show breakpoint condition-evaluation
763 Control whether breakpoint conditions are evaluated by GDB ("host") or by
764 GDBserver ("target"). Default option "auto" chooses the most efficient
766 This option can improve debugger efficiency depending on the speed of the
770 Disable auto-loading globally.
773 Show auto-loading setting of all kinds of auto-loaded files.
775 set auto-load gdb-scripts on|off
776 show auto-load gdb-scripts
777 Control auto-loading of GDB canned sequences of commands files.
779 set auto-load python-scripts on|off
780 show auto-load python-scripts
781 Control auto-loading of Python script files.
783 set auto-load local-gdbinit on|off
784 show auto-load local-gdbinit
785 Control loading of init file (.gdbinit) from current directory.
787 set auto-load libthread-db on|off
788 show auto-load libthread-db
789 Control auto-loading of inferior specific thread debugging shared library.
791 set auto-load scripts-directory <dir1>[:<dir2>...]
792 show auto-load scripts-directory
793 Set a list of directories from which to load auto-loaded scripts.
794 Automatically loaded Python scripts and GDB scripts are located in one
795 of the directories listed by this option.
796 The delimiter (':' above) may differ according to the host platform.
798 set auto-load safe-path <dir1>[:<dir2>...]
799 show auto-load safe-path
800 Set a list of directories from which it is safe to auto-load files.
801 The delimiter (':' above) may differ according to the host platform.
803 set debug auto-load on|off
805 Control display of debugging info for auto-loading the files above.
807 set dprintf-style gdb|call|agent
809 Control the way in which a dynamic printf is performed; "gdb"
810 requests a GDB printf command, while "call" causes dprintf to call a
811 function in the inferior. "agent" requests that the target agent
812 (such as GDBserver) do the printing.
814 set dprintf-function <expr>
815 show dprintf-function
816 set dprintf-channel <expr>
818 Set the function and optional first argument to the call when using
819 the "call" style of dynamic printf.
821 set disconnected-dprintf on|off
822 show disconnected-dprintf
823 Control whether agent-style dynamic printfs continue to be in effect
824 after GDB disconnects.
826 * New configure options
829 Configure default value for the 'set auto-load scripts-directory'
830 setting above. It defaults to '$debugdir:$datadir/auto-load',
831 $debugdir representing global debugging info directories (available
832 via 'show debug-file-directory') and $datadir representing GDB's data
833 directory (available via 'show data-directory').
835 --with-auto-load-safe-path
836 Configure default value for the 'set auto-load safe-path' setting
837 above. It defaults to the --with-auto-load-dir setting.
839 --without-auto-load-safe-path
840 Set 'set auto-load safe-path' to '/', effectively disabling this
845 z0/z1 conditional breakpoints extension
847 The z0/z1 breakpoint insertion packets have been extended to carry
848 a list of conditional expressions over to the remote stub depending on the
849 condition evaluation mode. The use of this extension can be controlled
850 via the "set remote conditional-breakpoints-packet" command.
854 Specify the signals which the remote stub may pass to the debugged
855 program without GDB involvement.
857 * New command line options
859 --init-command=FILE, -ix Like --command, -x but execute it
860 before loading inferior.
861 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
862 execute it before loading inferior.
864 *** Changes in GDB 7.4
866 * GDB now handles ambiguous linespecs more consistently; the existing
867 FILE:LINE support has been expanded to other types of linespecs. A
868 breakpoint will now be set on all matching locations in all
869 inferiors, and locations will be added or removed according to
872 * GDB now allows you to skip uninteresting functions and files when
873 stepping with the "skip function" and "skip file" commands.
875 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
876 and "show remote hardware-watchpoint-length-limit". These allows to
877 set or show the maximum length limit (in bytes) of a remote
878 target hardware watchpoint.
880 This allows e.g. to use "unlimited" hardware watchpoints with the
881 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
882 watchpoints are slower than real hardware watchpoints but are
883 significantly faster than gdb software watchpoints.
887 ** The register_pretty_printer function in module gdb.printing now takes
888 an optional `replace' argument. If True, the new printer replaces any
891 ** The "maint set python print-stack on|off" command has been
892 deprecated and will be deleted in GDB 7.5.
893 A new command: "set python print-stack none|full|message" has
894 replaced it. Additionally, the default for "print-stack" is
895 now "message", which just prints the error message without
898 ** A prompt substitution hook (prompt_hook) is now available to the
901 ** A new Python module, gdb.prompt has been added to the GDB Python
902 modules library. This module provides functionality for
903 escape sequences in prompts (used by set/show
904 extended-prompt). These escape sequences are replaced by their
907 ** Python commands and convenience-functions located in
908 'data-directory'/python/gdb/command and
909 'data-directory'/python/gdb/function are now automatically loaded
912 ** Blocks now provide four new attributes. global_block and
913 static_block will return the global and static blocks
914 respectively. is_static and is_global are boolean attributes
915 that indicate if the block is one of those two types.
917 ** Symbols now provide the "type" attribute, the type of the symbol.
919 ** The "gdb.breakpoint" function has been deprecated in favor of
922 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
923 of a function. This class is based on the "finish" command
924 available in the CLI.
926 ** Type objects for struct and union types now allow access to
927 the fields using standard Python dictionary (mapping) methods.
928 For example, "some_type['myfield']" now works, as does
931 ** A new event "gdb.new_objfile" has been added, triggered by loading a
934 ** A new function, "deep_items" has been added to the gdb.types
935 module in the GDB Python modules library. This function returns
936 an iterator over the fields of a struct or union type. Unlike
937 the standard Python "iteritems" method, it will recursively traverse
938 any anonymous fields.
942 ** "*stopped" events can report several new "reason"s, such as
945 ** Breakpoint changes are now notified using new async records, like
946 "=breakpoint-modified".
948 ** New command -ada-task-info.
950 * libthread-db-search-path now supports two special values: $sdir and $pdir.
951 $sdir specifies the default system locations of shared libraries.
952 $pdir specifies the directory where the libpthread used by the application
955 GDB no longer looks in $sdir and $pdir after it has searched the directories
956 mentioned in libthread-db-search-path. If you want to search those
957 directories, they must be specified in libthread-db-search-path.
958 The default value of libthread-db-search-path on GNU/Linux and Solaris
959 systems is now "$sdir:$pdir".
961 $pdir is not supported by gdbserver, it is currently ignored.
962 $sdir is supported by gdbserver.
964 * New configure option --with-iconv-bin.
965 When using the internationalization support like the one in the GNU C
966 library, GDB will invoke the "iconv" program to get a list of supported
967 character sets. If this program lives in a non-standard location, one can
968 use this option to specify where to find it.
970 * When natively debugging programs on PowerPC BookE processors running
971 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
972 watchpoints, which specify a mask in addition to an address to watch.
973 The mask specifies that some bits of an address (the bits which are
974 reset in the mask) should be ignored when matching the address accessed
975 by the inferior against the watchpoint address. See the "PowerPC Embedded"
976 section in the user manual for more details.
978 * The new option --once causes GDBserver to stop listening for connections once
979 the first connection is made. The listening port used by GDBserver will
980 become available after that.
982 * New commands "info macros" and "alias" have been added.
984 * New function parameters suffix @entry specifies value of function parameter
985 at the time the function got called. Entry values are available only since
991 "!" is now an alias of the "shell" command.
992 Note that no space is needed between "!" and SHELL COMMAND.
996 watch EXPRESSION mask MASK_VALUE
997 The watch command now supports the mask argument which allows creation
998 of masked watchpoints, if the current architecture supports this feature.
1000 info auto-load-scripts [REGEXP]
1001 This command was formerly named "maintenance print section-scripts".
1002 It is now generally useful and is no longer a maintenance-only command.
1004 info macro [-all] [--] MACRO
1005 The info macro command has new options `-all' and `--'. The first for
1006 printing all definitions of a macro. The second for explicitly specifying
1007 the end of arguments and the beginning of the macro name in case the macro
1008 name starts with a hyphen.
1010 collect[/s] EXPRESSIONS
1011 The tracepoint collect command now takes an optional modifier "/s"
1012 that directs it to dereference pointer-to-character types and
1013 collect the bytes of memory up to a zero byte. The behavior is
1014 similar to what you see when you use the regular print command on a
1015 string. An optional integer following the "/s" sets a bound on the
1016 number of bytes that will be collected.
1019 The trace start command now interprets any supplied arguments as a
1020 note to be recorded with the trace run, with an effect similar to
1021 setting the variable trace-notes.
1024 The trace stop command now interprets any arguments as a note to be
1025 mentioned along with the tstatus report that the trace was stopped
1026 with a command. The effect is similar to setting the variable
1029 * Tracepoints can now be enabled and disabled at any time after a trace
1030 experiment has been started using the standard "enable" and "disable"
1031 commands. It is now possible to start a trace experiment with no enabled
1032 tracepoints; GDB will display a warning, but will allow the experiment to
1033 begin, assuming that tracepoints will be enabled as needed while the trace
1036 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1037 locations with 4-byte instructions, when they were previously
1038 limited to locations with instructions of 5 bytes or longer.
1042 set debug dwarf2-read
1043 show debug dwarf2-read
1044 Turns on or off display of debugging messages related to reading
1045 DWARF debug info. The default is off.
1047 set debug symtab-create
1048 show debug symtab-create
1049 Turns on or off display of debugging messages related to symbol table
1050 creation. The default is off.
1053 show extended-prompt
1054 Set the GDB prompt, and allow escape sequences to be inserted to
1055 display miscellaneous information (see 'help set extended-prompt'
1056 for the list of sequences). This prompt (and any information
1057 accessed through the escape sequences) is updated every time the
1058 prompt is displayed.
1060 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1061 show print entry-values
1062 Set printing of frame argument values at function entry. In some cases
1063 GDB can determine the value of function argument which was passed by the
1064 function caller, even if the value was modified inside the called function.
1066 set debug entry-values
1067 show debug entry-values
1068 Control display of debugging info for determining frame argument values at
1069 function entry and virtual tail call frames.
1071 set basenames-may-differ
1072 show basenames-may-differ
1073 Set whether a source file may have multiple base names.
1074 (A "base name" is the name of a file with the directory part removed.
1075 Example: The base name of "/home/user/hello.c" is "hello.c".)
1076 If set, GDB will canonicalize file names (e.g., expand symlinks)
1077 before comparing them. Canonicalization is an expensive operation,
1078 but it allows the same file be known by more than one base name.
1079 If not set (the default), all source files are assumed to have just
1080 one base name, and gdb will do file name comparisons more efficiently.
1086 Set a user name and notes for the current and any future trace runs.
1087 This is useful for long-running and/or disconnected traces, to
1088 inform others (or yourself) as to who is running the trace, supply
1089 contact information, or otherwise explain what is going on.
1091 set trace-stop-notes
1092 show trace-stop-notes
1093 Set a note attached to the trace run, that is displayed when the
1094 trace has been stopped by a tstop command. This is useful for
1095 instance as an explanation, if you are stopping a trace run that was
1096 started by someone else.
1098 * New remote packets
1102 Dynamically enable a tracepoint in a started trace experiment.
1106 Dynamically disable a tracepoint in a started trace experiment.
1110 Set the user and notes of the trace run.
1114 Query the current status of a tracepoint.
1118 Query the minimum length of instruction at which a fast tracepoint may
1121 * Dcache size (number of lines) and line-size are now runtime-configurable
1122 via "set dcache line" and "set dcache line-size" commands.
1126 Texas Instruments TMS320C6x tic6x-*-*
1130 Renesas RL78 rl78-*-elf
1132 *** Changes in GDB 7.3.1
1134 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1136 *** Changes in GDB 7.3
1138 * GDB has a new command: "thread find [REGEXP]".
1139 It finds the thread id whose name, target id, or thread extra info
1140 matches the given regular expression.
1142 * The "catch syscall" command now works on mips*-linux* targets.
1144 * The -data-disassemble MI command now supports modes 2 and 3 for
1145 dumping the instruction opcodes.
1147 * New command line options
1149 -data-directory DIR Specify DIR as the "data-directory".
1150 This is mostly for testing purposes.
1152 * The "maint set python auto-load on|off" command has been renamed to
1153 "set auto-load-scripts on|off".
1155 * GDB has a new command: "set directories".
1156 It is like the "dir" command except that it replaces the
1157 source path list instead of augmenting it.
1159 * GDB now understands thread names.
1161 On GNU/Linux, "info threads" will display the thread name as set by
1162 prctl or pthread_setname_np.
1164 There is also a new command, "thread name", which can be used to
1165 assign a name internally for GDB to display.
1168 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1169 has been integrated into GDB.
1173 ** The function gdb.Write now accepts an optional keyword 'stream'.
1174 This keyword, when provided, will direct the output to either
1175 stdout, stderr, or GDB's logging output.
1177 ** Parameters can now be be sub-classed in Python, and in particular
1178 you may implement the get_set_doc and get_show_doc functions.
1179 This improves how Parameter set/show documentation is processed
1180 and allows for more dynamic content.
1182 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1183 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1184 have an is_valid method.
1186 ** Breakpoints can now be sub-classed in Python, and in particular
1187 you may implement a 'stop' function that is executed each time
1188 the inferior reaches that breakpoint.
1190 ** New function gdb.lookup_global_symbol looks up a global symbol.
1192 ** GDB values in Python are now callable if the value represents a
1193 function. For example, if 'some_value' represents a function that
1194 takes two integer parameters and returns a value, you can call
1195 that function like so:
1197 result = some_value (10,20)
1199 ** Module gdb.types has been added.
1200 It contains a collection of utilities for working with gdb.Types objects:
1201 get_basic_type, has_field, make_enum_dict.
1203 ** Module gdb.printing has been added.
1204 It contains utilities for writing and registering pretty-printers.
1205 New classes: PrettyPrinter, SubPrettyPrinter,
1206 RegexpCollectionPrettyPrinter.
1207 New function: register_pretty_printer.
1209 ** New commands "info pretty-printers", "enable pretty-printer" and
1210 "disable pretty-printer" have been added.
1212 ** gdb.parameter("directories") is now available.
1214 ** New function gdb.newest_frame returns the newest frame in the
1217 ** The gdb.InferiorThread class has a new "name" attribute. This
1218 holds the thread's name.
1220 ** Python Support for Inferior events.
1221 Python scripts can add observers to be notified of events
1222 occurring in the process being debugged.
1223 The following events are currently supported:
1224 - gdb.events.cont Continue event.
1225 - gdb.events.exited Inferior exited event.
1226 - gdb.events.stop Signal received, and Breakpoint hit events.
1230 ** GDB now puts template parameters in scope when debugging in an
1231 instantiation. For example, if you have:
1233 template<int X> int func (void) { return X; }
1235 then if you step into func<5>, "print X" will show "5". This
1236 feature requires proper debuginfo support from the compiler; it
1237 was added to GCC 4.5.
1239 ** The motion commands "next", "finish", "until", and "advance" now
1240 work better when exceptions are thrown. In particular, GDB will
1241 no longer lose control of the inferior; instead, the GDB will
1242 stop the inferior at the point at which the exception is caught.
1243 This functionality requires a change in the exception handling
1244 code that was introduced in GCC 4.5.
1246 * GDB now follows GCC's rules on accessing volatile objects when
1247 reading or writing target state during expression evaluation.
1248 One notable difference to prior behavior is that "print x = 0"
1249 no longer generates a read of x; the value of the assignment is
1250 now always taken directly from the value being assigned.
1252 * GDB now has some support for using labels in the program's source in
1253 linespecs. For instance, you can use "advance label" to continue
1254 execution to a label.
1256 * GDB now has support for reading and writing a new .gdb_index
1257 section. This section holds a fast index of DWARF debugging
1258 information and can be used to greatly speed up GDB startup and
1259 operation. See the documentation for `save gdb-index' for details.
1261 * The "watch" command now accepts an optional "-location" argument.
1262 When used, this causes GDB to watch the memory referred to by the
1263 expression. Such a watchpoint is never deleted due to it going out
1266 * GDB now supports thread debugging of core dumps on GNU/Linux.
1268 GDB now activates thread debugging using the libthread_db library
1269 when debugging GNU/Linux core dumps, similarly to when debugging
1270 live processes. As a result, when debugging a core dump file, GDB
1271 is now able to display pthread_t ids of threads. For example, "info
1272 threads" shows the same output as when debugging the process when it
1273 was live. In earlier releases, you'd see something like this:
1276 * 1 LWP 6780 main () at main.c:10
1278 While now you see this:
1281 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1283 It is also now possible to inspect TLS variables when debugging core
1286 When debugging a core dump generated on a machine other than the one
1287 used to run GDB, you may need to point GDB at the correct
1288 libthread_db library with the "set libthread-db-search-path"
1289 command. See the user manual for more details on this command.
1291 * When natively debugging programs on PowerPC BookE processors running
1292 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1293 which stop execution of the inferior whenever it executes an instruction
1294 at any address within the specified range. See the "PowerPC Embedded"
1295 section in the user manual for more details.
1297 * New features in the GDB remote stub, GDBserver
1299 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1300 and i686 LynxOS (version 5.x).
1302 ** GDBserver is now supported on Blackfin Linux.
1304 * New native configurations
1306 ia64 HP-UX ia64-*-hpux*
1310 Analog Devices, Inc. Blackfin Processor bfin-*
1312 * Ada task switching is now supported on sparc-elf targets when
1313 debugging a program using the Ravenscar Profile. For more information,
1314 see the "Tasking Support when using the Ravenscar Profile" section
1315 in the GDB user manual.
1317 * Guile support was removed.
1319 * New features in the GNU simulator
1321 ** The --map-info flag lists all known core mappings.
1323 ** CFI flashes may be simulated via the "cfi" device.
1325 *** Changes in GDB 7.2
1327 * Shared library support for remote targets by default
1329 When GDB is configured for a generic, non-OS specific target, like
1330 for example, --target=arm-eabi or one of the many *-*-elf targets,
1331 GDB now queries remote stubs for loaded shared libraries using the
1332 `qXfer:libraries:read' packet. Previously, shared library support
1333 was always disabled for such configurations.
1337 ** Argument Dependent Lookup (ADL)
1339 In C++ ADL lookup directs function search to the namespaces of its
1340 arguments even if the namespace has not been imported.
1350 Here the compiler will search for `foo' in the namespace of 'b'
1351 and find A::foo. GDB now supports this. This construct is commonly
1352 used in the Standard Template Library for operators.
1354 ** Improved User Defined Operator Support
1356 In addition to member operators, GDB now supports lookup of operators
1357 defined in a namespace and imported with a `using' directive, operators
1358 defined in the global scope, operators imported implicitly from an
1359 anonymous namespace, and the ADL operators mentioned in the previous
1361 GDB now also supports proper overload resolution for all the previously
1362 mentioned flavors of operators.
1364 ** static const class members
1366 Printing of static const class members that are initialized in the
1367 class definition has been fixed.
1369 * Windows Thread Information Block access.
1371 On Windows targets, GDB now supports displaying the Windows Thread
1372 Information Block (TIB) structure. This structure is visible either
1373 by using the new command `info w32 thread-information-block' or, by
1374 dereferencing the new convenience variable named `$_tlb', a
1375 thread-specific pointer to the TIB. This feature is also supported
1376 when remote debugging using GDBserver.
1378 * Static tracepoints
1380 Static tracepoints are calls in the user program into a tracing
1381 library. One such library is a port of the LTTng kernel tracer to
1382 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1383 When debugging with GDBserver, GDB now supports combining the GDB
1384 tracepoint machinery with such libraries. For example: the user can
1385 use GDB to probe a static tracepoint marker (a call from the user
1386 program into the tracing library) with the new "strace" command (see
1387 "New commands" below). This creates a "static tracepoint" in the
1388 breakpoint list, that can be manipulated with the same feature set
1389 as fast and regular tracepoints. E.g., collect registers, local and
1390 global variables, collect trace state variables, and define
1391 tracepoint conditions. In addition, the user can collect extra
1392 static tracepoint marker specific data, by collecting the new
1393 $_sdata internal variable. When analyzing the trace buffer, you can
1394 inspect $_sdata like any other variable available to GDB. For more
1395 information, see the "Tracepoints" chapter in GDB user manual. New
1396 remote packets have been defined to support static tracepoints, see
1397 the "New remote packets" section below.
1399 * Better reconstruction of tracepoints after disconnected tracing
1401 GDB will attempt to download the original source form of tracepoint
1402 definitions when starting a trace run, and then will upload these
1403 upon reconnection to the target, resulting in a more accurate
1404 reconstruction of the tracepoints that are in use on the target.
1408 You can now exercise direct control over the ways that GDB can
1409 affect your program. For instance, you can disallow the setting of
1410 breakpoints, so that the program can run continuously (assuming
1411 non-stop mode). In addition, the "observer" variable is available
1412 to switch all of the different controls; in observer mode, GDB
1413 cannot affect the target's behavior at all, which is useful for
1414 tasks like diagnosing live systems in the field.
1416 * The new convenience variable $_thread holds the number of the
1419 * New remote packets
1423 Return the address of the Windows Thread Information Block of a given thread.
1427 In response to several of the tracepoint packets, the target may now
1428 also respond with a number of intermediate `qRelocInsn' request
1429 packets before the final result packet, to have GDB handle
1430 relocating an instruction to execute at a different address. This
1431 is particularly useful for stubs that support fast tracepoints. GDB
1432 reports support for this feature in the qSupported packet.
1436 List static tracepoint markers in the target program.
1440 List static tracepoint markers at a given address in the target
1443 qXfer:statictrace:read
1445 Read the static trace data collected (by a `collect $_sdata'
1446 tracepoint action). The remote stub reports support for this packet
1447 to gdb's qSupported query.
1451 Send the current settings of GDB's permission flags.
1455 Send part of the source (textual) form of a tracepoint definition,
1456 which includes location, conditional, and action list.
1458 * The source command now accepts a -s option to force searching for the
1459 script in the source search path even if the script name specifies
1462 * New features in the GDB remote stub, GDBserver
1464 - GDBserver now support tracepoints (including fast tracepoints, and
1465 static tracepoints). The feature is currently supported by the
1466 i386-linux and amd64-linux builds. See the "Tracepoints support
1467 in gdbserver" section in the manual for more information.
1469 GDBserver JIT compiles the tracepoint's conditional agent
1470 expression bytecode into native code whenever possible for low
1471 overhead dynamic tracepoints conditionals. For such tracepoints,
1472 an expression that examines program state is evaluated when the
1473 tracepoint is reached, in order to determine whether to capture
1474 trace data. If the condition is simple and false, processing the
1475 tracepoint finishes very quickly and no data is gathered.
1477 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1478 for static tracepoints support.
1480 - GDBserver now supports x86_64 Windows 64-bit debugging.
1482 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1483 it understands register description.
1485 * The --batch flag now disables pagination and queries.
1487 * X86 general purpose registers
1489 GDB now supports reading/writing byte, word and double-word x86
1490 general purpose registers directly. This means you can use, say,
1491 $ah or $ax to refer, respectively, to the byte register AH and
1492 16-bit word register AX that are actually portions of the 32-bit
1493 register EAX or 64-bit register RAX.
1495 * The `commands' command now accepts a range of breakpoints to modify.
1496 A plain `commands' following a command that creates multiple
1497 breakpoints affects all the breakpoints set by that command. This
1498 applies to breakpoints set by `rbreak', and also applies when a
1499 single `break' command creates multiple breakpoints (e.g.,
1500 breakpoints on overloaded c++ functions).
1502 * The `rbreak' command now accepts a filename specification as part of
1503 its argument, limiting the functions selected by the regex to those
1504 in the specified file.
1506 * Support for remote debugging Windows and SymbianOS shared libraries
1507 from Unix hosts has been improved. Non Windows GDB builds now can
1508 understand target reported file names that follow MS-DOS based file
1509 system semantics, such as file names that include drive letters and
1510 use the backslash character as directory separator. This makes it
1511 possible to transparently use the "set sysroot" and "set
1512 solib-search-path" on Unix hosts to point as host copies of the
1513 target's shared libraries. See the new command "set
1514 target-file-system-kind" described below, and the "Commands to
1515 specify files" section in the user manual for more information.
1519 eval template, expressions...
1520 Convert the values of one or more expressions under the control
1521 of the string template to a command line, and call it.
1523 set target-file-system-kind unix|dos-based|auto
1524 show target-file-system-kind
1525 Set or show the assumed file system kind for target reported file
1528 save breakpoints <filename>
1529 Save all current breakpoint definitions to a file suitable for use
1530 in a later debugging session. To read the saved breakpoint
1531 definitions, use the `source' command.
1533 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1536 info static-tracepoint-markers
1537 Display information about static tracepoint markers in the target.
1539 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1540 Define a static tracepoint by probing a marker at the given
1541 function, line, address, or marker ID.
1545 Enable and disable observer mode.
1547 set may-write-registers on|off
1548 set may-write-memory on|off
1549 set may-insert-breakpoints on|off
1550 set may-insert-tracepoints on|off
1551 set may-insert-fast-tracepoints on|off
1552 set may-interrupt on|off
1553 Set individual permissions for GDB effects on the target. Note that
1554 some of these settings can have undesirable or surprising
1555 consequences, particularly when changed in the middle of a session.
1556 For instance, disabling the writing of memory can prevent
1557 breakpoints from being inserted, cause single-stepping to fail, or
1558 even crash your program, if you disable after breakpoints have been
1559 inserted. However, GDB should not crash.
1561 set record memory-query on|off
1562 show record memory-query
1563 Control whether to stop the inferior if memory changes caused
1564 by an instruction cannot be recorded.
1569 The disassemble command now supports "start,+length" form of two arguments.
1573 ** GDB now provides a new directory location, called the python directory,
1574 where Python scripts written for GDB can be installed. The location
1575 of that directory is <data-directory>/python, where <data-directory>
1576 is the GDB data directory. For more details, see section `Scripting
1577 GDB using Python' in the manual.
1579 ** The GDB Python API now has access to breakpoints, symbols, symbol
1580 tables, program spaces, inferiors, threads and frame's code blocks.
1581 Additionally, GDB Parameters can now be created from the API, and
1582 manipulated via set/show in the CLI.
1584 ** New functions gdb.target_charset, gdb.target_wide_charset,
1585 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1587 ** New exception gdb.GdbError.
1589 ** Pretty-printers are now also looked up in the current program space.
1591 ** Pretty-printers can now be individually enabled and disabled.
1593 ** GDB now looks for names of Python scripts to auto-load in a
1594 special section named `.debug_gdb_scripts', in addition to looking
1595 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1597 * Tracepoint actions were unified with breakpoint commands. In particular,
1598 there are no longer differences in "info break" output for breakpoints and
1599 tracepoints and the "commands" command can be used for both tracepoints and
1600 regular breakpoints.
1604 ARM Symbian arm*-*-symbianelf*
1606 * D language support.
1607 GDB now supports debugging programs written in the D programming
1610 * GDB now supports the extended ptrace interface for PowerPC which is
1611 available since Linux kernel version 2.6.34. This automatically enables
1612 any hardware breakpoints and additional hardware watchpoints available in
1613 the processor. The old ptrace interface exposes just one hardware
1614 watchpoint and no hardware breakpoints.
1616 * GDB is now able to use the Data Value Compare (DVC) register available on
1617 embedded PowerPC processors to implement in hardware simple watchpoint
1618 conditions of the form:
1620 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1622 This works in native GDB running on Linux kernels with the extended ptrace
1623 interface mentioned above.
1625 *** Changes in GDB 7.1
1629 ** Namespace Support
1631 GDB now supports importing of namespaces in C++. This enables the
1632 user to inspect variables from imported namespaces. Support for
1633 namepace aliasing has also been added. So, if a namespace is
1634 aliased in the current scope (e.g. namepace C=A; ) the user can
1635 print variables using the alias (e.g. (gdb) print C::x).
1639 All known bugs relating to the printing of virtual base class were
1640 fixed. It is now possible to call overloaded static methods using a
1645 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1646 and reinterpret_cast<> are now handled by the C++ expression parser.
1650 Xilinx MicroBlaze microblaze-*-*
1655 Xilinx MicroBlaze microblaze
1658 * Multi-program debugging.
1660 GDB now has support for multi-program (a.k.a. multi-executable or
1661 multi-exec) debugging. This allows for debugging multiple inferiors
1662 simultaneously each running a different program under the same GDB
1663 session. See "Debugging Multiple Inferiors and Programs" in the
1664 manual for more information. This implied some user visible changes
1665 in the multi-inferior support. For example, "info inferiors" now
1666 lists inferiors that are not running yet or that have exited
1667 already. See also "New commands" and "New options" below.
1669 * New tracing features
1671 GDB's tracepoint facility now includes several new features:
1673 ** Trace state variables
1675 GDB tracepoints now include support for trace state variables, which
1676 are variables managed by the target agent during a tracing
1677 experiment. They are useful for tracepoints that trigger each
1678 other, so for instance one tracepoint can count hits in a variable,
1679 and then a second tracepoint has a condition that is true when the
1680 count reaches a particular value. Trace state variables share the
1681 $-syntax of GDB convenience variables, and can appear in both
1682 tracepoint actions and condition expressions. Use the "tvariable"
1683 command to create, and "info tvariables" to view; see "Trace State
1684 Variables" in the manual for more detail.
1688 GDB now includes an option for defining fast tracepoints, which
1689 targets may implement more efficiently, such as by installing a jump
1690 into the target agent rather than a trap instruction. The resulting
1691 speedup can be by two orders of magnitude or more, although the
1692 tradeoff is that some program locations on some target architectures
1693 might not allow fast tracepoint installation, for instance if the
1694 instruction to be replaced is shorter than the jump. To request a
1695 fast tracepoint, use the "ftrace" command, with syntax identical to
1696 the regular trace command.
1698 ** Disconnected tracing
1700 It is now possible to detach GDB from the target while it is running
1701 a trace experiment, then reconnect later to see how the experiment
1702 is going. In addition, a new variable disconnected-tracing lets you
1703 tell the target agent whether to continue running a trace if the
1704 connection is lost unexpectedly.
1708 GDB now has the ability to save the trace buffer into a file, and
1709 then use that file as a target, similarly to you can do with
1710 corefiles. You can select trace frames, print data that was
1711 collected in them, and use tstatus to display the state of the
1712 tracing run at the moment that it was saved. To create a trace
1713 file, use "tsave <filename>", and to use it, do "target tfile
1716 ** Circular trace buffer
1718 You can ask the target agent to handle the trace buffer as a
1719 circular buffer, discarding the oldest trace frames to make room for
1720 newer ones, by setting circular-trace-buffer to on. This feature may
1721 not be available for all target agents.
1726 The disassemble command, when invoked with two arguments, now requires
1727 the arguments to be comma-separated.
1730 The info variables command now displays variable definitions. Files
1731 which only declare a variable are not shown.
1734 The source command is now capable of sourcing Python scripts.
1735 This feature is dependent on the debugger being build with Python
1738 Related to this enhancement is also the introduction of a new command
1739 "set script-extension" (see below).
1741 * New commands (for set/show, see "New options" below)
1743 record save [<FILENAME>]
1744 Save a file (in core file format) containing the process record
1745 execution log for replay debugging at a later time.
1747 record restore <FILENAME>
1748 Restore the process record execution log that was saved at an
1749 earlier time, for replay debugging.
1751 add-inferior [-copies <N>] [-exec <FILENAME>]
1754 clone-inferior [-copies <N>] [ID]
1755 Make a new inferior ready to execute the same program another
1756 inferior has loaded.
1761 maint info program-spaces
1762 List the program spaces loaded into GDB.
1764 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1765 show remote interrupt-sequence
1766 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1767 as the sequence to the remote target in order to interrupt the execution.
1768 Ctrl-C is a default. Some system prefers BREAK which is high level of
1769 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1770 Magic SysRq g. It is BREAK signal and character 'g'.
1772 set remote interrupt-on-connect [on | off]
1773 show remote interrupt-on-connect
1774 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1775 remote target when gdb connects to it. This is needed when you debug
1778 set remotebreak [on | off]
1780 Deprecated. Use "set/show remote interrupt-sequence" instead.
1782 tvariable $NAME [ = EXP ]
1783 Create or modify a trace state variable.
1786 List trace state variables and their values.
1788 delete tvariable $NAME ...
1789 Delete one or more trace state variables.
1792 Evaluate the given expressions without collecting anything into the
1793 trace buffer. (Valid in tracepoint actions only.)
1795 ftrace FN / FILE:LINE / *ADDR
1796 Define a fast tracepoint at the given function, line, or address.
1798 * New expression syntax
1800 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1801 GDB now parses 0b101010 identically with 42.
1805 set follow-exec-mode new|same
1806 show follow-exec-mode
1807 Control whether GDB reuses the same inferior across an exec call or
1808 creates a new one. This is useful to be able to restart the old
1809 executable after the inferior having done an exec call.
1811 set default-collect EXPR, ...
1812 show default-collect
1813 Define a list of expressions to be collected at each tracepoint.
1814 This is a useful way to ensure essential items are not overlooked,
1815 such as registers or a critical global variable.
1817 set disconnected-tracing
1818 show disconnected-tracing
1819 If set to 1, the target is instructed to continue tracing if it
1820 loses its connection to GDB. If 0, the target is to stop tracing
1823 set circular-trace-buffer
1824 show circular-trace-buffer
1825 If set to on, the target is instructed to use a circular trace buffer
1826 and discard the oldest trace frames instead of stopping the trace due
1827 to a full trace buffer. If set to off, the trace stops when the buffer
1828 fills up. Some targets may not support this.
1830 set script-extension off|soft|strict
1831 show script-extension
1832 If set to "off", the debugger does not perform any script language
1833 recognition, and all sourced files are assumed to be GDB scripts.
1834 If set to "soft" (the default), files are sourced according to
1835 filename extension, falling back to GDB scripts if the first
1837 If set to "strict", files are sourced according to filename extension.
1839 set ada trust-PAD-over-XVS on|off
1840 show ada trust-PAD-over-XVS
1841 If off, activate a workaround against a bug in the debugging information
1842 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1843 the GCC sources for more information about the GNAT encoding and
1844 PAD types in particular). It is always safe to set this option to
1845 off, but this introduces a slight performance penalty. The default
1848 * Python API Improvements
1850 ** GDB provides the new class gdb.LazyString. This is useful in
1851 some pretty-printing cases. The new method gdb.Value.lazy_string
1852 provides a simple way to create objects of this type.
1854 ** The fields returned by gdb.Type.fields now have an
1855 `is_base_class' attribute.
1857 ** The new method gdb.Type.range returns the range of an array type.
1859 ** The new method gdb.parse_and_eval can be used to parse and
1860 evaluate an expression.
1862 * New remote packets
1865 Define a trace state variable.
1868 Get the current value of a trace state variable.
1871 Set desired tracing behavior upon disconnection.
1874 Set the trace buffer to be linear or circular.
1877 Get data about the tracepoints currently in use.
1881 Process record now works correctly with hardware watchpoints.
1883 Multiple bug fixes have been made to the mips-irix port, making it
1884 much more reliable. In particular:
1885 - Debugging threaded applications is now possible again. Previously,
1886 GDB would hang while starting the program, or while waiting for
1887 the program to stop at a breakpoint.
1888 - Attaching to a running process no longer hangs.
1889 - An error occurring while loading a core file has been fixed.
1890 - Changing the value of the PC register now works again. This fixes
1891 problems observed when using the "jump" command, or when calling
1892 a function from GDB, or even when assigning a new value to $pc.
1893 - With the "finish" and "return" commands, the return value for functions
1894 returning a small array is now correctly printed.
1895 - It is now possible to break on shared library code which gets executed
1896 during a shared library init phase (code executed while executing
1897 their .init section). Previously, the breakpoint would have no effect.
1898 - GDB is now able to backtrace through the signal handler for
1899 non-threaded programs.
1901 PIE (Position Independent Executable) programs debugging is now supported.
1902 This includes debugging execution of PIC (Position Independent Code) shared
1903 libraries although for that, it should be possible to run such libraries as an
1906 *** Changes in GDB 7.0
1908 * GDB now has an interface for JIT compilation. Applications that
1909 dynamically generate code can create symbol files in memory and register
1910 them with GDB. For users, the feature should work transparently, and
1911 for JIT developers, the interface is documented in the GDB manual in the
1912 "JIT Compilation Interface" chapter.
1914 * Tracepoints may now be conditional. The syntax is as for
1915 breakpoints; either an "if" clause appended to the "trace" command,
1916 or the "condition" command is available. GDB sends the condition to
1917 the target for evaluation using the same bytecode format as is used
1918 for tracepoint actions.
1920 * The disassemble command now supports: an optional /r modifier, print the
1921 raw instructions in hex as well as in symbolic form, and an optional /m
1922 modifier to print mixed source+assembly.
1924 * Process record and replay
1926 In a architecture environment that supports ``process record and
1927 replay'', ``process record and replay'' target can record a log of
1928 the process execution, and replay it with both forward and reverse
1931 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
1932 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
1933 set execution-direction {forward|reverse}, for targets that support
1936 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
1937 feature is available with a native GDB running on kernel version
1940 * GDB now has support for multi-byte and wide character sets on the
1941 target. Strings whose character type is wchar_t, char16_t, or
1942 char32_t are now correctly printed. GDB supports wide- and unicode-
1943 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
1944 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
1945 `printf'. This feature requires iconv to work properly; if your
1946 system does not have a working iconv, GDB can use GNU libiconv. See
1947 the installation instructions for more information.
1949 * GDB now supports automatic retrieval of shared library files from
1950 remote targets. To use this feature, specify a system root that begins
1951 with the `remote:' prefix, either via the `set sysroot' command or via
1952 the `--with-sysroot' configure-time option.
1954 * "info sharedlibrary" now takes an optional regex of libraries to show,
1955 and it now reports if a shared library has no debugging information.
1957 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
1958 now complete on file names.
1960 * When completing in expressions, gdb will attempt to limit
1961 completions to allowable structure or union fields, where appropriate.
1962 For instance, consider:
1964 # struct example { int f1; double f2; };
1965 # struct example variable;
1968 If the user types TAB at the end of this command line, the available
1969 completions will be "f1" and "f2".
1971 * Inlined functions are now supported. They show up in backtraces, and
1972 the "step", "next", and "finish" commands handle them automatically.
1974 * GDB now supports the token-splicing (##) and stringification (#)
1975 operators when expanding macros. It also supports variable-arity
1978 * GDB now supports inspecting extra signal information, exported by
1979 the new $_siginfo convenience variable. The feature is currently
1980 implemented on linux ARM, i386 and amd64.
1982 * GDB can now display the VFP floating point registers and NEON vector
1983 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
1984 can provide these registers (requires Linux 2.6.30 or later). Remote
1985 and simulator targets may also provide them.
1987 * New remote packets
1990 Search memory for a sequence of bytes.
1993 Turn off `+'/`-' protocol acknowledgments to permit more efficient
1994 operation over reliable transport links. Use of this packet is
1995 controlled by the `set remote noack-packet' command.
1998 Kill the process with the specified process ID. Use this in preference
1999 to `k' when multiprocess protocol extensions are supported.
2002 Obtains additional operating system information
2006 Read or write additional signal information.
2008 * Removed remote protocol undocumented extension
2010 An undocumented extension to the remote protocol's `S' stop reply
2011 packet that permited the stub to pass a process id was removed.
2012 Remote servers should use the `T' stop reply packet instead.
2014 * GDB now supports multiple function calling conventions according to the
2015 DWARF-2 DW_AT_calling_convention function attribute.
2017 * The SH target utilizes the aforementioned change to distinguish between gcc
2018 and Renesas calling convention. It also adds the new CLI commands
2019 `set/show sh calling-convention'.
2021 * GDB can now read compressed debug sections, as produced by GNU gold
2022 with the --compress-debug-sections=zlib flag.
2024 * 64-bit core files are now supported on AIX.
2026 * Thread switching is now supported on Tru64.
2028 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2029 which will be allocated using malloc later in program execution.
2031 * The qXfer:libraries:read remote procotol packet now allows passing a
2032 list of section offsets.
2034 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2035 conditions handling signals delivered during attach or thread creation
2036 have also been fixed.
2038 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2039 From the user's standpoint, all unqualified instances of True and False
2040 are treated as the standard definitions, regardless of context.
2042 * GDB now parses C++ symbol and type names more flexibly. For
2045 template<typename T> class C { };
2048 GDB will now correctly handle all of:
2050 ptype C<char const *>
2051 ptype C<char const*>
2052 ptype C<const char *>
2053 ptype C<const char*>
2055 * New features in the GDB remote stub, gdbserver
2057 - The "--wrapper" command-line argument tells gdbserver to use a
2058 wrapper program to launch programs for debugging.
2060 - On PowerPC and S/390 targets, it is now possible to use a single
2061 gdbserver executable to debug both 32-bit and 64-bit programs.
2062 (This requires gdbserver itself to be built as a 64-bit executable.)
2064 - gdbserver uses the new noack protocol mode for TCP connections to
2065 reduce communications latency, if also supported and enabled in GDB.
2067 - Support for the sparc64-linux-gnu target is now included in
2070 - The amd64-linux build of gdbserver now supports debugging both
2071 32-bit and 64-bit programs.
2073 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2074 now support hardware watchpoints, and will use them automatically
2079 GDB now has support for scripting using Python. Whether this is
2080 available is determined at configure time.
2082 New GDB commands can now be written in Python.
2084 * Ada tasking support
2086 Ada tasks can now be inspected in GDB. The following commands have
2090 Print the list of Ada tasks.
2092 Print detailed information about task number N.
2094 Print the task number of the current task.
2096 Switch the context of debugging to task number N.
2098 * Support for user-defined prefixed commands. The "define" command can
2099 add new commands to existing prefixes, e.g. "target".
2101 * Multi-inferior, multi-process debugging.
2103 GDB now has generalized support for multi-inferior debugging. See
2104 "Debugging Multiple Inferiors" in the manual for more information.
2105 Although availability still depends on target support, the command
2106 set is more uniform now. The GNU/Linux specific multi-forks support
2107 has been migrated to this new framework. This implied some user
2108 visible changes; see "New commands" and also "Removed commands"
2111 * Target descriptions can now describe the target OS ABI. See the
2112 "Target Description Format" section in the user manual for more
2115 * Target descriptions can now describe "compatible" architectures
2116 to indicate that the target can execute applications for a different
2117 architecture in addition to those for the main target architecture.
2118 See the "Target Description Format" section in the user manual for
2121 * Multi-architecture debugging.
2123 GDB now includes general supports for debugging applications on
2124 hybrid systems that use more than one single processor architecture
2125 at the same time. Each such hybrid architecture still requires
2126 specific support to be added. The only hybrid architecture supported
2127 in this version of GDB is the Cell Broadband Engine.
2129 * GDB now supports integrated debugging of Cell/B.E. applications that
2130 use both the PPU and SPU architectures. To enable support for hybrid
2131 Cell/B.E. debugging, you need to configure GDB to support both the
2132 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2133 --enable-targets configure option.
2135 * Non-stop mode debugging.
2137 For some targets, GDB now supports an optional mode of operation in
2138 which you can examine stopped threads while other threads continue
2139 to execute freely. This is referred to as non-stop mode, with the
2140 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2141 section in the user manual for more information.
2143 To be able to support remote non-stop debugging, a remote stub needs
2144 to implement the non-stop mode remote protocol extensions, as
2145 described in the "Remote Non-Stop" section of the user manual. The
2146 GDB remote stub, gdbserver, has been adjusted to support these
2147 extensions on linux targets.
2149 * New commands (for set/show, see "New options" below)
2151 catch syscall [NAME(S) | NUMBER(S)]
2152 Catch system calls. Arguments, which should be names of system
2153 calls or their numbers, mean catch only those syscalls. Without
2154 arguments, every syscall will be caught. When the inferior issues
2155 any of the specified syscalls, GDB will stop and announce the system
2156 call, both when it is called and when its call returns. This
2157 feature is currently available with a native GDB running on the
2158 Linux Kernel, under the following architectures: x86, x86_64,
2159 PowerPC and PowerPC64.
2161 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2163 Search memory for a sequence of bytes.
2165 maint set python print-stack
2166 maint show python print-stack
2167 Show a stack trace when an error is encountered in a Python script.
2170 Invoke CODE by passing it to the Python interpreter.
2175 These allow macros to be defined, undefined, and listed
2179 Show operating system information about processes.
2182 List the inferiors currently under GDB's control.
2185 Switch focus to inferior number NUM.
2188 Detach from inferior number NUM.
2191 Kill inferior number NUM.
2195 set spu stop-on-load
2196 show spu stop-on-load
2197 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2199 set spu auto-flush-cache
2200 show spu auto-flush-cache
2201 Control whether to automatically flush the software-managed cache
2202 during Cell/B.E. debugging.
2204 set sh calling-convention
2205 show sh calling-convention
2206 Control the calling convention used when calling SH target functions.
2209 show debug timestamp
2210 Control display of timestamps with GDB debugging output.
2212 set disassemble-next-line
2213 show disassemble-next-line
2214 Control display of disassembled source lines or instructions when
2217 set remote noack-packet
2218 show remote noack-packet
2219 Set/show the use of remote protocol QStartNoAckMode packet. See above
2220 under "New remote packets."
2222 set remote query-attached-packet
2223 show remote query-attached-packet
2224 Control use of remote protocol `qAttached' (query-attached) packet.
2226 set remote read-siginfo-object
2227 show remote read-siginfo-object
2228 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2231 set remote write-siginfo-object
2232 show remote write-siginfo-object
2233 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2236 set remote reverse-continue
2237 show remote reverse-continue
2238 Control use of remote protocol 'bc' (reverse-continue) packet.
2240 set remote reverse-step
2241 show remote reverse-step
2242 Control use of remote protocol 'bs' (reverse-step) packet.
2244 set displaced-stepping
2245 show displaced-stepping
2246 Control displaced stepping mode. Displaced stepping is a way to
2247 single-step over breakpoints without removing them from the debuggee.
2248 Also known as "out-of-line single-stepping".
2251 show debug displaced
2252 Control display of debugging info for displaced stepping.
2254 maint set internal-error
2255 maint show internal-error
2256 Control what GDB does when an internal error is detected.
2258 maint set internal-warning
2259 maint show internal-warning
2260 Control what GDB does when an internal warning is detected.
2265 Use a wrapper program to launch programs for debugging.
2267 set multiple-symbols (all|ask|cancel)
2268 show multiple-symbols
2269 The value of this variable can be changed to adjust the debugger behavior
2270 when an expression or a breakpoint location contains an ambiguous symbol
2271 name (an overloaded function name, for instance).
2273 set breakpoint always-inserted
2274 show breakpoint always-inserted
2275 Keep breakpoints always inserted in the target, as opposed to inserting
2276 them when resuming the target, and removing them when the target stops.
2277 This option can improve debugger performance on slow remote targets.
2279 set arm fallback-mode (arm|thumb|auto)
2280 show arm fallback-mode
2281 set arm force-mode (arm|thumb|auto)
2283 These commands control how ARM GDB determines whether instructions
2284 are ARM or Thumb. The default for both settings is auto, which uses
2285 the current CPSR value for instructions without symbols; previous
2286 versions of GDB behaved as if "set arm fallback-mode arm".
2288 set disable-randomization
2289 show disable-randomization
2290 Standalone programs run with the virtual address space randomization enabled
2291 by default on some platforms. This option keeps the addresses stable across
2292 multiple debugging sessions.
2296 Control whether other threads are stopped or not when some thread hits
2301 Requests that asynchronous execution is enabled in the target, if available.
2302 In this case, it's possible to resume target in the background, and interact
2303 with GDB while the target is running. "show target-async" displays the
2304 current state of asynchronous execution of the target.
2306 set target-wide-charset
2307 show target-wide-charset
2308 The target-wide-charset is the name of the character set that GDB
2309 uses when printing characters whose type is wchar_t.
2311 set tcp auto-retry (on|off)
2313 set tcp connect-timeout
2314 show tcp connect-timeout
2315 These commands allow GDB to retry failed TCP connections to a remote stub
2316 with a specified timeout period; this is useful if the stub is launched
2317 in parallel with GDB but may not be ready to accept connections immediately.
2319 set libthread-db-search-path
2320 show libthread-db-search-path
2321 Control list of directories which GDB will search for appropriate
2324 set schedule-multiple (on|off)
2325 show schedule-multiple
2326 Allow GDB to resume all threads of all processes or only threads of
2327 the current process.
2331 Use more aggressive caching for accesses to the stack. This improves
2332 performance of remote debugging (particularly backtraces) without
2333 affecting correctness.
2335 set interactive-mode (on|off|auto)
2336 show interactive-mode
2337 Control whether GDB runs in interactive mode (on) or not (off).
2338 When in interactive mode, GDB waits for the user to answer all
2339 queries. Otherwise, GDB does not wait and assumes the default
2340 answer. When set to auto (the default), GDB determines which
2341 mode to use based on the stdin settings.
2346 For program forks, this is replaced by the new more generic `info
2347 inferiors' command. To list checkpoints, you can still use the
2348 `info checkpoints' command, which was an alias for the `info forks'
2352 Replaced by the new `inferior' command. To switch between
2353 checkpoints, you can still use the `restart' command, which was an
2354 alias for the `fork' command.
2357 This is removed, since some targets don't have a notion of
2358 processes. To switch between processes, you can still use the
2359 `inferior' command using GDB's own inferior number.
2362 For program forks, this is replaced by the new more generic `kill
2363 inferior' command. To delete a checkpoint, you can still use the
2364 `delete checkpoint' command, which was an alias for the `delete
2368 For program forks, this is replaced by the new more generic `detach
2369 inferior' command. To detach a checkpoint, you can still use the
2370 `detach checkpoint' command, which was an alias for the `detach
2373 * New native configurations
2375 x86/x86_64 Darwin i[34567]86-*-darwin*
2377 x86_64 MinGW x86_64-*-mingw*
2381 Lattice Mico32 lm32-*
2382 x86 DICOS i[34567]86-*-dicos*
2383 x86_64 DICOS x86_64-*-dicos*
2386 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2387 (mingw32ce) debugging.
2393 These commands were actually not implemented on any target.
2395 *** Changes in GDB 6.8
2397 * New native configurations
2399 NetBSD/hppa hppa*-*netbsd*
2400 Xtensa GNU/Linux xtensa*-*-linux*
2404 NetBSD/hppa hppa*-*-netbsd*
2405 Xtensa GNU/Lunux xtensa*-*-linux*
2407 * Change in command line behavior -- corefiles vs. process ids.
2409 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2410 attaching to process NUMBER fails, GDB no longer attempts to open a
2411 core file named NUMBER. Attaching to a program using the -c option
2412 is no longer supported. Instead, use the '-p' or '--pid' options.
2414 * GDB can now be built as a native debugger for debugging Windows x86
2415 (mingw32) Portable Executable (PE) programs.
2417 * Pending breakpoints no longer change their number when their address
2420 * GDB now supports breakpoints with multiple locations,
2421 including breakpoints on C++ constructors, inside C++ templates,
2422 and in inlined functions.
2424 * GDB's ability to debug optimized code has been improved. GDB more
2425 accurately identifies function bodies and lexical blocks that occupy
2426 more than one contiguous range of addresses.
2428 * Target descriptions can now describe registers for PowerPC.
2430 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2431 registers on PowerPC targets.
2433 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2434 targets even when the libthread_db library is not available.
2436 * The GDB remote stub, gdbserver, now supports the new file transfer
2437 commands (remote put, remote get, and remote delete).
2439 * The GDB remote stub, gdbserver, now supports run and attach in
2440 extended-remote mode.
2442 * hppa*64*-*-hpux11* target broken
2443 The debugger is unable to start a program and fails with the following
2444 error: "Error trying to get information about dynamic linker".
2445 The gdb-6.7 release is also affected.
2447 * GDB now supports the --enable-targets= configure option to allow
2448 building a single GDB executable that supports multiple remote
2449 target architectures.
2451 * GDB now supports debugging C and C++ programs which use the
2452 Decimal Floating Point extension. In addition, the PowerPC target
2453 now has a set of pseudo-registers to inspect decimal float values
2454 stored in two consecutive float registers.
2456 * The -break-insert MI command can optionally create pending
2459 * Improved support for debugging Ada
2460 Many improvements to the Ada language support have been made. These
2462 - Better support for Ada2005 interface types
2463 - Improved handling of arrays and slices in general
2464 - Better support for Taft-amendment types
2465 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2467 - Improved command completion in Ada
2470 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2475 set print frame-arguments (all|scalars|none)
2476 show print frame-arguments
2477 The value of this variable can be changed to control which argument
2478 values should be printed by the debugger when displaying a frame.
2483 Transfer files to and from a remote target, and delete remote files.
2490 Transfer files to and from a remote target, and delete remote files.
2492 * New remote packets
2499 Open, close, read, write, and delete files on the remote system.
2502 Attach to an existing process on the remote system, in extended-remote
2506 Run a new process on the remote system, in extended-remote mode.
2508 *** Changes in GDB 6.7
2510 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2511 bfd, libiberty and opcodes, as revealed by static analysis donated by
2512 Coverity, Inc. (http://scan.coverity.com).
2514 * When looking up multiply-defined global symbols, GDB will now prefer the
2515 symbol definition in the current shared library if it was built using the
2516 -Bsymbolic linker option.
2518 * When the Text User Interface (TUI) is not configured, GDB will now
2519 recognize the -tui command-line option and print a message that the TUI
2522 * The GDB remote stub, gdbserver, now has lower overhead for high
2523 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2525 * GDB for MIPS targets now autodetects whether a remote target provides
2526 32-bit or 64-bit register values.
2528 * Support for C++ member pointers has been improved.
2530 * GDB now understands XML target descriptions, which specify the
2531 target's overall architecture. GDB can read a description from
2532 a local file or over the remote serial protocol.
2534 * Vectors of single-byte data use a new integer type which is not
2535 automatically displayed as character or string data.
2537 * The /s format now works with the print command. It displays
2538 arrays of single-byte integers and pointers to single-byte integers
2541 * Target descriptions can now describe target-specific registers,
2542 for architectures which have implemented the support (currently
2543 only ARM, M68K, and MIPS).
2545 * GDB and the GDB remote stub, gdbserver, now support the XScale
2548 * The GDB remote stub, gdbserver, has been updated to support
2549 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2550 has been rewritten to use the standard GDB remote protocol.
2552 * GDB can now step into C++ functions which are called through thunks.
2554 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2556 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2557 layout. It also supports a TextSeg= and DataSeg= response when only
2558 segment base addresses (rather than offsets) are available.
2560 * The /i format now outputs any trailing branch delay slot instructions
2561 immediately following the last instruction within the count specified.
2563 * The GDB remote protocol "T" stop reply packet now supports a
2564 "library" response. Combined with the new "qXfer:libraries:read"
2565 packet, this response allows GDB to debug shared libraries on targets
2566 where the operating system manages the list of loaded libraries (e.g.
2567 Windows and SymbianOS).
2569 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2570 (DLLs) on Windows and Windows CE targets.
2572 * GDB now supports a faster verification that a .debug file matches its binary
2573 according to its build-id signature, if the signature is present.
2579 Enable or disable hardware flow control (RTS/CTS) on the serial port
2580 when debugging using remote targets.
2582 set mem inaccessible-by-default
2583 show mem inaccessible-by-default
2584 If the target supplies a memory map, for instance via the remote
2585 protocol's "qXfer:memory-map:read" packet, setting this variable
2586 prevents GDB from accessing memory outside the memory map. This
2587 is useful for targets with memory mapped registers or which react
2588 badly to accesses of unmapped address space.
2590 set breakpoint auto-hw
2591 show breakpoint auto-hw
2592 If the target supplies a memory map, for instance via the remote
2593 protocol's "qXfer:memory-map:read" packet, setting this variable
2594 lets GDB use hardware breakpoints automatically for memory regions
2595 where it can not use software breakpoints. This covers both the
2596 "break" command and internal breakpoints used for other commands
2597 including "next" and "finish".
2600 catch exception unhandled
2601 Stop the program execution when Ada exceptions are raised.
2604 Stop the program execution when an Ada assertion failed.
2608 Set an alternate system root for target files. This is a more
2609 general version of "set solib-absolute-prefix", which is now
2610 an alias to "set sysroot".
2613 Provide extended SPU facility status information. This set of
2614 commands is available only when debugging the Cell/B.E. SPU
2617 * New native configurations
2619 OpenBSD/sh sh*-*openbsd*
2622 unset tdesc filename
2624 Use the specified local file as an XML target description, and do
2625 not query the target for its built-in description.
2629 OpenBSD/sh sh*-*-openbsd*
2630 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2631 Toshiba Media Processor mep-elf
2633 * New remote packets
2636 Ignore the specified signals; pass them directly to the debugged program
2637 without stopping other threads or reporting them to GDB.
2639 qXfer:features:read:
2640 Read an XML target description from the target, which describes its
2645 Read or write contents of an spufs file on the target system. These
2646 packets are available only on the Cell/B.E. SPU architecture.
2648 qXfer:libraries:read:
2649 Report the loaded shared libraries. Combined with new "T" packet
2650 response, this packet allows GDB to debug shared libraries on
2651 targets where the operating system manages the list of loaded
2652 libraries (e.g. Windows and SymbianOS).
2656 Support for these obsolete configurations has been removed.
2664 i[34567]86-*-lynxos*
2665 i[34567]86-*-netware*
2666 i[34567]86-*-sco3.2v5*
2667 i[34567]86-*-sco3.2v4*
2669 i[34567]86-*-sysv4.2*
2672 i[34567]86-*-unixware2*
2673 i[34567]86-*-unixware*
2682 * Other removed features
2689 Various m68k-only ROM monitors.
2696 Various Renesas ROM monitors and debugging interfaces for SH and
2701 Support for a Macraigor serial interface to on-chip debugging.
2702 GDB does not directly support the newer parallel or USB
2707 A debug information format. The predecessor to DWARF 2 and
2708 DWARF 3, which are still supported.
2710 Support for the HP aCC compiler on HP-UX/PA-RISC
2712 SOM-encapsulated symbolic debugging information, automatic
2713 invocation of pxdb, and the aCC custom C++ ABI. This does not
2714 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2715 with aCC can still be debugged on an assembly level.
2717 MIPS ".pdr" sections
2719 A MIPS-specific format used to describe stack frame layout
2720 in debugging information.
2724 GDB could work with an older version of Guile to debug
2725 the interpreter and Scheme programs running in it.
2727 set mips stack-arg-size
2728 set mips saved-gpreg-size
2730 Use "set mips abi" to control parameter passing for MIPS.
2732 *** Changes in GDB 6.6
2737 Cell Broadband Engine SPU spu-elf
2739 * GDB can now be configured as a cross-debugger targeting native Windows
2740 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2741 running on a Windows system over TCP/IP to debug Windows programs.
2743 * The GDB remote stub, gdbserver, has been updated to support Windows and
2744 Cygwin debugging. Both single-threaded and multi-threaded programs are
2747 * The "set trust-readonly-sections" command works again. This command was
2748 broken in GDB 6.3, 6.4, and 6.5.
2750 * The "load" command now supports writing to flash memory, if the remote
2751 stub provides the required support.
2753 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2754 longer requires symbolic debug information (e.g. DWARF-2).
2759 unset substitute-path
2760 show substitute-path
2761 Manage a list of substitution rules that GDB uses to rewrite the name
2762 of the directories where the sources are located. This can be useful
2763 for instance when the sources were moved to a different location
2764 between compilation and debugging.
2768 Print each CLI command as it is executed. Each command is prefixed with
2769 a number of `+' symbols representing the nesting depth.
2770 The source command now has a `-v' option to enable the same feature.
2774 The ARM Demon monitor support (RDP protocol, "target rdp").
2776 Kernel Object Display, an embedded debugging feature which only worked with
2777 an obsolete version of Cisco IOS.
2779 The 'set download-write-size' and 'show download-write-size' commands.
2781 * New remote packets
2784 Tell a stub about GDB client features, and request remote target features.
2785 The first feature implemented is PacketSize, which allows the target to
2786 specify the size of packets it can handle - to minimize the number of
2787 packets required and improve performance when connected to a remote
2791 Fetch an OS auxilliary vector from the remote stub. This packet is a
2792 more efficient replacement for qPart:auxv:read.
2794 qXfer:memory-map:read:
2795 Fetch a memory map from the remote stub, including information about
2796 RAM, ROM, and flash memory devices.
2801 Erase and program a flash memory device.
2803 * Removed remote packets
2806 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2807 used it, and only gdbserver implemented it.
2809 *** Changes in GDB 6.5
2813 Renesas M32C/M16C m32c-elf
2815 Morpho Technologies ms1 ms1-elf
2819 init-if-undefined Initialize a convenience variable, but
2820 only if it doesn't already have a value.
2822 The following commands are presently only implemented for native GNU/Linux:
2824 checkpoint Save a snapshot of the program state.
2826 restart <n> Return the program state to a
2827 previously saved state.
2829 info checkpoints List currently saved checkpoints.
2831 delete-checkpoint <n> Delete a previously saved checkpoint.
2833 set|show detach-on-fork Tell gdb whether to detach from a newly
2834 forked process, or to keep debugging it.
2836 info forks List forks of the user program that
2837 are available to be debugged.
2839 fork <n> Switch to debugging one of several
2840 forks of the user program that are
2841 available to be debugged.
2843 delete-fork <n> Delete a fork from the list of forks
2844 that are available to be debugged (and
2845 kill the forked process).
2847 detach-fork <n> Delete a fork from the list of forks
2848 that are available to be debugged (and
2849 allow the process to continue).
2853 Morpho Technologies ms2 ms1-elf
2855 * Improved Windows host support
2857 GDB now builds as a cross debugger hosted on i686-mingw32, including
2858 native console support, and remote communications using either
2859 network sockets or serial ports.
2861 * Improved Modula-2 language support
2863 GDB can now print most types in the Modula-2 syntax. This includes:
2864 basic types, set types, record types, enumerated types, range types,
2865 pointer types and ARRAY types. Procedure var parameters are correctly
2866 printed and hexadecimal addresses and character constants are also
2867 written in the Modula-2 syntax. Best results can be obtained by using
2868 GNU Modula-2 together with the -gdwarf-2 command line option.
2872 The ARM rdi-share module.
2874 The Netware NLM debug server.
2876 *** Changes in GDB 6.4
2878 * New native configurations
2880 OpenBSD/arm arm*-*-openbsd*
2881 OpenBSD/mips64 mips64-*-openbsd*
2885 Morpho Technologies ms1 ms1-elf
2887 * New command line options
2889 --batch-silent As for --batch, but totally silent.
2890 --return-child-result The debugger will exist with the same value
2891 the child (debugged) program exited with.
2892 --eval-command COMMAND, -ex COMMAND
2893 Execute a single GDB CLI command. This may be
2894 specified multiple times and in conjunction
2895 with the --command (-x) option.
2897 * Deprecated commands removed
2899 The following commands, that were deprecated in 2000, have been
2903 set|show arm disassembly-flavor set|show arm disassembler
2904 othernames set arm disassembler
2905 set|show remotedebug set|show debug remote
2906 set|show archdebug set|show debug arch
2907 set|show eventdebug set|show debug event
2910 * New BSD user-level threads support
2912 It is now possible to debug programs using the user-level threads
2913 library on OpenBSD and FreeBSD. Currently supported (target)
2916 FreeBSD/amd64 x86_64-*-freebsd*
2917 FreeBSD/i386 i386-*-freebsd*
2918 OpenBSD/i386 i386-*-openbsd*
2920 Note that the new kernel threads libraries introduced in FreeBSD 5.x
2921 are not yet supported.
2923 * New support for Matsushita MN10300 w/sim added
2924 (Work in progress). mn10300-elf.
2926 * REMOVED configurations and files
2928 VxWorks and the XDR protocol *-*-vxworks
2929 Motorola MCORE mcore-*-*
2930 National Semiconductor NS32000 ns32k-*-*
2932 * New "set print array-indexes" command
2934 After turning this setting "on", GDB prints the index of each element
2935 when displaying arrays. The default is "off" to preserve the previous
2938 * VAX floating point support
2940 GDB now supports the not-quite-ieee VAX F and D floating point formats.
2942 * User-defined command support
2944 In addition to using $arg0..$arg9 for argument passing, it is now possible
2945 to use $argc to determine now many arguments have been passed. See the
2946 section on user-defined commands in the user manual for more information.
2948 *** Changes in GDB 6.3:
2950 * New command line option
2952 GDB now accepts -l followed by a number to set the timeout for remote
2955 * GDB works with GCC -feliminate-dwarf2-dups
2957 GDB now supports a more compact representation of DWARF-2 debug
2958 information using DW_FORM_ref_addr references. These are produced
2959 by GCC with the option -feliminate-dwarf2-dups and also by some
2960 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
2961 to use -feliminate-dwarf2-dups.
2963 * Internationalization
2965 When supported by the host system, GDB will be built with
2966 internationalization (libintl). The task of marking up the sources is
2967 continued, we're looking forward to our first translation.
2971 Initial support for debugging programs compiled with the GNAT
2972 implementation of the Ada programming language has been integrated
2973 into GDB. In this release, support is limited to expression evaluation.
2975 * New native configurations
2977 GNU/Linux/m32r m32r-*-linux-gnu
2981 GDB's remote protocol now includes support for the 'p' packet. This
2982 packet is used to fetch individual registers from a remote inferior.
2984 * END-OF-LIFE registers[] compatibility module
2986 GDB's internal register infrastructure has been completely rewritten.
2987 The new infrastructure making possible the implementation of key new
2988 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
2991 GDB 6.3 will be the last release to include the the registers[]
2992 compatibility module that allowed out-of-date configurations to
2993 continue to work. This change directly impacts the following
3003 powerpc bdm protocol
3005 Unless there is activity to revive these configurations, they will be
3006 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3008 * OBSOLETE configurations and files
3010 Configurations that have been declared obsolete in this release have
3011 been commented out. Unless there is activity to revive these
3012 configurations, the next release of GDB will have their sources
3013 permanently REMOVED.
3022 *** Changes in GDB 6.2.1:
3024 * MIPS `break main; run' gave an heuristic-fence-post warning
3026 When attempting to run even a simple program, a warning about
3027 heuristic-fence-post being hit would be reported. This problem has
3030 * MIPS IRIX 'long double' crashed GDB
3032 When examining a long double variable, GDB would get a segmentation
3033 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3034 IRIX long double values).
3038 A bug in the VAX stack code was causing problems with the "next"
3039 command. This problem has been fixed.
3041 *** Changes in GDB 6.2:
3043 * Fix for ``many threads''
3045 On GNU/Linux systems that use the NPTL threads library, a program
3046 rapidly creating and deleting threads would confuse GDB leading to the
3049 ptrace: No such process.
3050 thread_db_get_info: cannot get thread info: generic error
3052 This problem has been fixed.
3054 * "-async" and "-noasync" options removed.
3056 Support for the broken "-noasync" option has been removed (it caused
3059 * New ``start'' command.
3061 This command runs the program until the begining of the main procedure.
3063 * New BSD Kernel Data Access Library (libkvm) interface
3065 Using ``target kvm'' it is now possible to debug kernel core dumps and
3066 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3067 platforms. Currently supported (native-only) configurations are:
3069 FreeBSD/amd64 x86_64-*-freebsd*
3070 FreeBSD/i386 i?86-*-freebsd*
3071 NetBSD/i386 i?86-*-netbsd*
3072 NetBSD/m68k m68*-*-netbsd*
3073 NetBSD/sparc sparc-*-netbsd*
3074 OpenBSD/amd64 x86_64-*-openbsd*
3075 OpenBSD/i386 i?86-*-openbsd*
3076 OpenBSD/m68k m68*-openbsd*
3077 OpenBSD/sparc sparc-*-openbsd*
3079 * Signal trampoline code overhauled
3081 Many generic problems with GDB's signal handling code have been fixed.
3082 These include: backtraces through non-contiguous stacks; recognition
3083 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3084 call; backtrace through a signal trampoline; step into and out of
3085 signal handlers; and single-stepping in the signal trampoline.
3087 Please note that kernel bugs are a limiting factor here. These
3088 features have been shown to work on an s390 GNU/Linux system that
3089 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3091 * Cygwin support for DWARF 2 added.
3093 * New native configurations
3095 GNU/Linux/hppa hppa*-*-linux*
3096 OpenBSD/hppa hppa*-*-openbsd*
3097 OpenBSD/m68k m68*-*-openbsd*
3098 OpenBSD/m88k m88*-*-openbsd*
3099 OpenBSD/powerpc powerpc-*-openbsd*
3100 NetBSD/vax vax-*-netbsd*
3101 OpenBSD/vax vax-*-openbsd*
3103 * END-OF-LIFE frame compatibility module
3105 GDB's internal frame infrastructure has been completely rewritten.
3106 The new infrastructure making it possible to support key new features
3107 including DWARF 2 Call Frame Information. To aid in the task of
3108 migrating old configurations to this new infrastructure, a
3109 compatibility module, that allowed old configurations to continue to
3110 work, was also included.
3112 GDB 6.2 will be the last release to include this frame compatibility
3113 module. This change directly impacts the following configurations:
3123 Unless there is activity to revive these configurations, they will be
3124 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3126 * REMOVED configurations and files
3128 Sun 3, running SunOS 3 m68*-*-sunos3*
3129 Sun 3, running SunOS 4 m68*-*-sunos4*
3130 Sun 2, running SunOS 3 m68000-*-sunos3*
3131 Sun 2, running SunOS 4 m68000-*-sunos4*
3132 Motorola 680x0 running LynxOS m68*-*-lynxos*
3133 AT&T 3b1/Unix pc m68*-att-*
3134 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3135 decstation mips-dec-* mips-little-*
3136 riscos mips-*-riscos* mips-*-sysv*
3137 sonymips mips-sony-*
3138 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3140 *** Changes in GDB 6.1.1:
3142 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3144 The TUI (Text-mode User Interface) is now built as part of a default
3145 GDB configuration. It is enabled by either selecting the TUI with the
3146 command line option "-i=tui" or by running the separate "gdbtui"
3147 program. For more information on the TUI, see the manual "Debugging
3150 * Pending breakpoint support (also included in GDB 6.1)
3152 Support has been added to allow you to specify breakpoints in shared
3153 libraries that have not yet been loaded. If a breakpoint location
3154 cannot be found, and the "breakpoint pending" option is set to auto,
3155 GDB queries you if you wish to make the breakpoint pending on a future
3156 shared-library load. If and when GDB resolves the breakpoint symbol,
3157 the pending breakpoint is removed as one or more regular breakpoints
3160 Pending breakpoints are very useful for GCJ Java debugging.
3162 * Fixed ISO-C build problems
3164 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3165 non ISO-C code that stopped them being built using a more strict ISO-C
3166 compiler (e.g., IBM's C compiler).
3168 * Fixed build problem on IRIX 5
3170 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3171 wasn't able to compile compile on an IRIX 5 system.
3173 * Added execute permission to gdb/gdbserver/configure
3175 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3176 permission. This bug would cause configure to fail on a number of
3177 systems (Solaris, IRIX). Ref: server/519.
3179 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3181 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3182 has been updated to use constant array sizes.
3184 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3186 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3187 its generated DWARF Call Frame Info. This encoding was causing GDB to
3188 panic, that panic has been fixed. Ref: gdb/1628.
3190 * Fixed a problem when examining parameters in shared library code.
3192 When examining parameters in optimized shared library code generated
3193 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3194 not available''. GDB now correctly displays the variable's value.
3196 *** Changes in GDB 6.1:
3198 * Removed --with-mmalloc
3200 Support for the mmalloc memory manager has been removed, as it
3201 conflicted with the internal gdb byte cache.
3203 * Changes in AMD64 configurations
3205 The AMD64 target now includes the %cs and %ss registers. As a result
3206 the AMD64 remote protocol has changed; this affects the floating-point
3207 and SSE registers. If you rely on those registers for your debugging,
3208 you should upgrade gdbserver on the remote side.
3210 * Revised SPARC target
3212 The SPARC target has been completely revised, incorporating the
3213 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3214 support for LynxOS and SunOS 4 has been dropped. Calling functions
3215 from within GDB on operating systems with a non-executable stack
3216 (Solaris, OpenBSD) now works.
3220 GDB has a new C++ demangler which does a better job on the mangled
3221 names generated by current versions of g++. It also runs faster, so
3222 with this and other changes gdb should now start faster on large C++
3225 * DWARF 2 Location Expressions
3227 GDB support for location expressions has been extended to support function
3228 arguments and frame bases. Older versions of GDB could crash when they
3231 * C++ nested types and namespaces
3233 GDB's support for nested types and namespaces in C++ has been
3234 improved, especially if you use the DWARF 2 debugging format. (This
3235 is the default for recent versions of GCC on most platforms.)
3236 Specifically, if you have a class "Inner" defined within a class or
3237 namespace "Outer", then GDB realizes that the class's name is
3238 "Outer::Inner", not simply "Inner". This should greatly reduce the
3239 frequency of complaints about not finding RTTI symbols. In addition,
3240 if you are stopped at inside of a function defined within a namespace,
3241 GDB modifies its name lookup accordingly.
3243 * New native configurations
3245 NetBSD/amd64 x86_64-*-netbsd*
3246 OpenBSD/amd64 x86_64-*-openbsd*
3247 OpenBSD/alpha alpha*-*-openbsd*
3248 OpenBSD/sparc sparc-*-openbsd*
3249 OpenBSD/sparc64 sparc64-*-openbsd*
3251 * New debugging protocols
3253 M32R with SDI protocol m32r-*-elf*
3255 * "set prompt-escape-char" command deleted.
3257 The command "set prompt-escape-char" has been deleted. This command,
3258 and its very obscure effet on GDB's prompt, was never documented,
3259 tested, nor mentioned in the NEWS file.
3261 * OBSOLETE configurations and files
3263 Configurations that have been declared obsolete in this release have
3264 been commented out. Unless there is activity to revive these
3265 configurations, the next release of GDB will have their sources
3266 permanently REMOVED.
3268 Sun 3, running SunOS 3 m68*-*-sunos3*
3269 Sun 3, running SunOS 4 m68*-*-sunos4*
3270 Sun 2, running SunOS 3 m68000-*-sunos3*
3271 Sun 2, running SunOS 4 m68000-*-sunos4*
3272 Motorola 680x0 running LynxOS m68*-*-lynxos*
3273 AT&T 3b1/Unix pc m68*-att-*
3274 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3275 decstation mips-dec-* mips-little-*
3276 riscos mips-*-riscos* mips-*-sysv*
3277 sonymips mips-sony-*
3278 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3280 * REMOVED configurations and files
3282 SGI Irix-4.x mips-sgi-irix4 or iris4
3283 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3284 Z8000 simulator z8k-zilog-none or z8ksim
3285 Matsushita MN10200 w/simulator mn10200-*-*
3286 H8/500 simulator h8500-hitachi-hms or h8500hms
3287 HP/PA running BSD hppa*-*-bsd*
3288 HP/PA running OSF/1 hppa*-*-osf*
3289 HP/PA Pro target hppa*-*-pro*
3290 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3291 386BSD i[3456]86-*-bsd*
3292 Sequent family i[3456]86-sequent-sysv4*
3293 i[3456]86-sequent-sysv*
3294 i[3456]86-sequent-bsd*
3295 SPARC running LynxOS sparc-*-lynxos*
3296 SPARC running SunOS 4 sparc-*-sunos4*
3297 Tsqware Sparclet sparclet-*-*
3298 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3300 *** Changes in GDB 6.0:
3304 Support for debugging the Objective-C programming language has been
3305 integrated into GDB.
3307 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3309 DWARF 2's Call Frame Information makes available compiler generated
3310 information that more exactly describes the program's run-time stack.
3311 By using this information, GDB is able to provide more robust stack
3314 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3315 have been updated to use a new backtrace mechanism which includes
3316 DWARF 2 CFI support.
3320 GDB's remote protocol has been extended to include support for hosted
3321 file I/O (where the remote target uses GDB's file system). See GDB's
3322 remote protocol documentation for details.
3324 * All targets using the new architecture framework.
3326 All of GDB's targets have been updated to use the new internal
3327 architecture framework. The way is now open for future GDB releases
3328 to include cross-architecture native debugging support (i386 on amd64,
3331 * GNU/Linux's Thread Local Storage (TLS)
3333 GDB now includes support for for the GNU/Linux implementation of
3334 per-thread variables.
3336 * GNU/Linux's Native POSIX Thread Library (NPTL)
3338 GDB's thread code has been updated to work with either the new
3339 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3341 * Separate debug info.
3343 GDB, in conjunction with BINUTILS, now supports a mechanism for
3344 automatically loading debug information from a separate file. Instead
3345 of shipping full debug and non-debug versions of system libraries,
3346 system integrators can now instead ship just the stripped libraries
3347 and optional debug files.
3349 * DWARF 2 Location Expressions
3351 DWARF 2 Location Expressions allow the compiler to more completely
3352 describe the location of variables (even in optimized code) to the
3355 GDB now includes preliminary support for location expressions (support
3356 for DW_OP_piece is still missing).
3360 A number of long standing bugs that caused GDB to die while starting a
3361 Java application have been fixed. GDB's Java support is now
3362 considered "useable".
3364 * GNU/Linux support for fork, vfork, and exec.
3366 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3367 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3370 * GDB supports logging output to a file
3372 There are two new commands, "set logging" and "show logging", which can be
3373 used to capture GDB's output to a file.
3375 * The meaning of "detach" has changed for gdbserver
3377 The "detach" command will now resume the application, as documented. To
3378 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3381 * d10v, m68hc11 `regs' command deprecated
3383 The `info registers' command has been updated so that it displays the
3384 registers using a format identical to the old `regs' command.
3388 A new command, "maint set profile on/off", has been added. This command can
3389 be used to enable or disable profiling while running GDB, to profile a
3390 session or a set of commands. In addition there is a new configure switch,
3391 "--enable-profiling", which will cause GDB to be compiled with profiling
3392 data, for more informative profiling results.
3394 * Default MI syntax changed to "mi2".
3396 The default MI (machine interface) syntax, enabled by the command line
3397 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3398 "mi1", can be enabled by specifying the option "-i=mi1".
3400 Support for the original "mi0" syntax (included in GDB 5.0) has been
3403 Fix for gdb/192: removed extraneous space when displaying frame level.
3404 Fix for gdb/672: update changelist is now output in mi list format.
3405 Fix for gdb/702: a -var-assign that updates the value now shows up
3406 in a subsequent -var-update.
3408 * New native configurations.
3410 FreeBSD/amd64 x86_64-*-freebsd*
3412 * Multi-arched targets.
3414 HP/PA HPUX11 hppa*-*-hpux*
3415 Renesas M32R/D w/simulator m32r-*-elf*
3417 * OBSOLETE configurations and files
3419 Configurations that have been declared obsolete in this release have
3420 been commented out. Unless there is activity to revive these
3421 configurations, the next release of GDB will have their sources
3422 permanently REMOVED.
3424 Z8000 simulator z8k-zilog-none or z8ksim
3425 Matsushita MN10200 w/simulator mn10200-*-*
3426 H8/500 simulator h8500-hitachi-hms or h8500hms
3427 HP/PA running BSD hppa*-*-bsd*
3428 HP/PA running OSF/1 hppa*-*-osf*
3429 HP/PA Pro target hppa*-*-pro*
3430 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3431 Sequent family i[3456]86-sequent-sysv4*
3432 i[3456]86-sequent-sysv*
3433 i[3456]86-sequent-bsd*
3434 Tsqware Sparclet sparclet-*-*
3435 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3437 * REMOVED configurations and files
3440 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3441 IBM AIX PS/2 i[3456]86-*-aix
3442 i386 running Mach 3.0 i[3456]86-*-mach3*
3443 i386 running Mach i[3456]86-*-mach*
3444 i386 running OSF/1 i[3456]86-*osf1mk*
3445 HP/Apollo 68k Family m68*-apollo*-sysv*,
3447 m68*-hp-bsd*, m68*-hp-hpux*
3448 Argonaut Risc Chip (ARC) arc-*-*
3449 Mitsubishi D30V d30v-*-*
3450 Fujitsu FR30 fr30-*-elf*
3451 OS/9000 i[34]86-*-os9k
3452 I960 with MON960 i960-*-coff
3454 * MIPS $fp behavior changed
3456 The convenience variable $fp, for the MIPS, now consistently returns
3457 the address of the current frame's base. Previously, depending on the
3458 context, $fp could refer to either $sp or the current frame's base
3459 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3460 The GNU Source-Level Debugger''.
3462 *** Changes in GDB 5.3:
3464 * GNU/Linux shared library multi-threaded performance improved.
3466 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3467 `/proc', in preference to `ptrace' for memory reads. This may result
3468 in an improvement in the start-up time of multi-threaded, shared
3469 library applications when run under GDB. One GDB user writes: ``loads
3470 shared libs like mad''.
3472 * ``gdbserver'' now supports multi-threaded applications on some targets
3474 Support for debugging multi-threaded applications which use
3475 the GNU/Linux LinuxThreads package has been added for
3476 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3477 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3479 * GDB now supports C/C++ preprocessor macros.
3481 GDB now expands preprocessor macro invocations in C/C++ expressions,
3482 and provides various commands for showing macro definitions and how
3485 The new command `macro expand EXPRESSION' expands any macro
3486 invocations in expression, and shows the result.
3488 The new command `show macro MACRO-NAME' shows the definition of the
3489 macro named MACRO-NAME, and where it was defined.
3491 Most compilers don't include information about macros in the debugging
3492 information by default. In GCC 3.1, for example, you need to compile
3493 your program with the options `-gdwarf-2 -g3'. If the macro
3494 information is present in the executable, GDB will read it.
3496 * Multi-arched targets.
3498 DEC Alpha (partial) alpha*-*-*
3499 DEC VAX (partial) vax-*-*
3501 National Semiconductor NS32000 (partial) ns32k-*-*
3502 Motorola 68000 (partial) m68k-*-*
3503 Motorola MCORE mcore-*-*
3507 Fujitsu FRV architecture added by Red Hat frv*-*-*
3510 * New native configurations
3512 Alpha NetBSD alpha*-*-netbsd*
3513 SH NetBSD sh*-*-netbsdelf*
3514 MIPS NetBSD mips*-*-netbsd*
3515 UltraSPARC NetBSD sparc64-*-netbsd*
3517 * OBSOLETE configurations and files
3519 Configurations that have been declared obsolete in this release have
3520 been commented out. Unless there is activity to revive these
3521 configurations, the next release of GDB will have their sources
3522 permanently REMOVED.
3524 Mitsubishi D30V d30v-*-*
3525 OS/9000 i[34]86-*-os9k
3526 IBM AIX PS/2 i[3456]86-*-aix
3527 Fujitsu FR30 fr30-*-elf*
3528 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3529 Argonaut Risc Chip (ARC) arc-*-*
3530 i386 running Mach 3.0 i[3456]86-*-mach3*
3531 i386 running Mach i[3456]86-*-mach*
3532 i386 running OSF/1 i[3456]86-*osf1mk*
3533 HP/Apollo 68k Family m68*-apollo*-sysv*,
3535 m68*-hp-bsd*, m68*-hp-hpux*
3536 I960 with MON960 i960-*-coff
3538 * OBSOLETE languages
3540 CHILL, a Pascal like language used by telecommunications companies.
3542 * REMOVED configurations and files
3544 AMD 29k family via UDI a29k-amd-udi, udi29k
3545 A29K VxWorks a29k-*-vxworks
3546 AMD 29000 embedded, using EBMON a29k-none-none
3547 AMD 29000 embedded with COFF a29k-none-coff
3548 AMD 29000 embedded with a.out a29k-none-aout
3550 testsuite/gdb.hp/gdb.threads-hp/ directory
3552 * New command "set max-user-call-depth <nnn>"
3554 This command allows the user to limit the call depth of user-defined
3555 commands. The default is 1024.
3557 * Changes in FreeBSD/i386 native debugging.
3559 Support for the "generate-core-file" has been added.
3561 * New commands "dump", "append", and "restore".
3563 These commands allow data to be copied from target memory
3564 to a bfd-format or binary file (dump and append), and back
3565 from a file into memory (restore).
3567 * Improved "next/step" support on multi-processor Alpha Tru64.
3569 The previous single-step mechanism could cause unpredictable problems,
3570 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3571 of a software single-step mechanism prevents this.
3573 *** Changes in GDB 5.2.1:
3581 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3582 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3583 Fix, by Joel Brobecker imported from mainline.
3585 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3586 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3587 Fix, by Fred Fish, imported from mainline.
3589 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3590 Surprisingly enough, it works now.
3591 By Michal Ludvig, imported from mainline.
3593 i386 hardware watchpoint support:
3594 avoid misses on second run for some targets.
3595 By Pierre Muller, imported from mainline.
3597 *** Changes in GDB 5.2:
3599 * New command "set trust-readonly-sections on[off]".
3601 This command is a hint that tells gdb that read-only sections
3602 really are read-only (ie. that their contents will not change).
3603 In this mode, gdb will go to the object file rather than the
3604 target to read memory from read-only sections (such as ".text").
3605 This can be a significant performance improvement on some
3606 (notably embedded) targets.
3608 * New command "generate-core-file" (or "gcore").
3610 This new gdb command allows the user to drop a core file of the child
3611 process state at any time. So far it's been implemented only for
3612 GNU/Linux and Solaris, but should be relatively easily ported to other
3613 hosts. Argument is core file name (defaults to core.<pid>).
3615 * New command line option
3617 GDB now accepts --pid or -p followed by a process id.
3619 * Change in command line behavior -- corefiles vs. process ids.
3621 There is a subtle behavior in the way in which GDB handles
3622 command line arguments. The first non-flag argument is always
3623 a program to debug, but the second non-flag argument may either
3624 be a corefile or a process id. Previously, GDB would attempt to
3625 open the second argument as a corefile, and if that failed, would
3626 issue a superfluous error message and then attempt to attach it as
3627 a process. Now, if the second argument begins with a non-digit,
3628 it will be treated as a corefile. If it begins with a digit,
3629 GDB will attempt to attach it as a process, and if no such process
3630 is found, will then attempt to open it as a corefile.
3632 * Changes in ARM configurations.
3634 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3635 configuration is fully multi-arch.
3637 * New native configurations
3639 ARM NetBSD arm*-*-netbsd*
3640 x86 OpenBSD i[3456]86-*-openbsd*
3641 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3642 Sparc64 running FreeBSD sparc64-*-freebsd*
3646 Sanyo XStormy16 xstormy16-elf
3648 * OBSOLETE configurations and files
3650 Configurations that have been declared obsolete in this release have
3651 been commented out. Unless there is activity to revive these
3652 configurations, the next release of GDB will have their sources
3653 permanently REMOVED.
3655 AMD 29k family via UDI a29k-amd-udi, udi29k
3656 A29K VxWorks a29k-*-vxworks
3657 AMD 29000 embedded, using EBMON a29k-none-none
3658 AMD 29000 embedded with COFF a29k-none-coff
3659 AMD 29000 embedded with a.out a29k-none-aout
3661 testsuite/gdb.hp/gdb.threads-hp/ directory
3663 * REMOVED configurations and files
3665 TI TMS320C80 tic80-*-*
3667 PowerPC Solaris powerpcle-*-solaris*
3668 PowerPC Windows NT powerpcle-*-cygwin32
3669 PowerPC Netware powerpc-*-netware*
3670 Harris/CXUX m88k m88*-harris-cxux*
3671 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3672 ns32k-utek-sysv* ns32k-utek-*
3673 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3674 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3675 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3676 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3677 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3679 * Changes to command line processing
3681 The new `--args' feature can be used to specify command-line arguments
3682 for the inferior from gdb's command line.
3684 * Changes to key bindings
3686 There is a new `operate-and-get-next' function bound to `C-o'.
3688 *** Changes in GDB 5.1.1
3690 Fix compile problem on DJGPP.
3692 Fix a problem with floating-point registers on the i386 being
3695 Fix to stop GDB crashing on .debug_str debug info.
3697 Numerous documentation fixes.
3699 Numerous testsuite fixes.
3701 *** Changes in GDB 5.1:
3703 * New native configurations
3705 Alpha FreeBSD alpha*-*-freebsd*
3706 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3707 MIPS GNU/Linux mips*-*-linux*
3708 MIPS SGI Irix 6.x mips*-sgi-irix6*
3709 ia64 AIX ia64-*-aix*
3710 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3714 Motorola 68HC11 and 68HC12 m68hc11-elf
3716 UltraSparc running GNU/Linux sparc64-*-linux*
3718 * OBSOLETE configurations and files
3720 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3721 Harris/CXUX m88k m88*-harris-cxux*
3722 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3723 ns32k-utek-sysv* ns32k-utek-*
3724 TI TMS320C80 tic80-*-*
3726 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3727 PowerPC Solaris powerpcle-*-solaris*
3728 PowerPC Windows NT powerpcle-*-cygwin32
3729 PowerPC Netware powerpc-*-netware*
3730 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3731 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3732 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3733 Apple Macintosh (MPW) host N/A
3735 stuff.c (Program to stuff files into a specially prepared space in kdb)
3736 kdb-start.c (Main loop for the standalone kernel debugger)
3738 Configurations that have been declared obsolete in this release have
3739 been commented out. Unless there is activity to revive these
3740 configurations, the next release of GDB will have their sources
3741 permanently REMOVED.
3743 * REMOVED configurations and files
3745 Altos 3068 m68*-altos-*
3746 Convex c1-*-*, c2-*-*
3748 ARM RISCix arm-*-* (as host)
3752 * GDB has been converted to ISO C.
3754 GDB's source code has been converted to ISO C. In particular, the
3755 sources are fully protoized, and rely on standard headers being
3760 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3762 * The MI enabled by default.
3764 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3765 revised and enabled by default. Packages which use GDB as a debugging
3766 engine behind a UI or another front end are encouraged to switch to
3767 using the GDB/MI interface, instead of the old annotations interface
3768 which is now deprecated.
3770 * Support for debugging Pascal programs.
3772 GDB now includes support for debugging Pascal programs. The following
3773 main features are supported:
3775 - Pascal-specific data types such as sets;
3777 - automatic recognition of Pascal sources based on file-name
3780 - Pascal-style display of data types, variables, and functions;
3782 - a Pascal expression parser.
3784 However, some important features are not yet supported.
3786 - Pascal string operations are not supported at all;
3788 - there are some problems with boolean types;
3790 - Pascal type hexadecimal constants are not supported
3791 because they conflict with the internal variables format;
3793 - support for Pascal objects and classes is not full yet;
3795 - unlike Pascal, GDB is case-sensitive for symbol names.
3797 * Changes in completion.
3799 Commands such as `shell', `run' and `set args', which pass arguments
3800 to inferior programs, now complete on file names, similar to what
3801 users expect at the shell prompt.
3803 Commands which accept locations, such as `disassemble', `print',
3804 `breakpoint', `until', etc. now complete on filenames as well as
3805 program symbols. Thus, if you type "break foob TAB", and the source
3806 files linked into the programs include `foobar.c', that file name will
3807 be one of the candidates for completion. However, file names are not
3808 considered for completion after you typed a colon that delimits a file
3809 name from a name of a function in that file, as in "break foo.c:bar".
3811 `set demangle-style' completes on available demangling styles.
3813 * New platform-independent commands:
3815 It is now possible to define a post-hook for a command as well as a
3816 hook that runs before the command. For more details, see the
3817 documentation of `hookpost' in the GDB manual.
3819 * Changes in GNU/Linux native debugging.
3821 Support for debugging multi-threaded programs has been completely
3822 revised for all platforms except m68k and sparc. You can now debug as
3823 many threads as your system allows you to have.
3825 Attach/detach is supported for multi-threaded programs.
3827 Support for SSE registers was added for x86. This doesn't work for
3828 multi-threaded programs though.
3830 * Changes in MIPS configurations.
3832 Multi-arch support is enabled for all MIPS configurations.
3834 GDB can now be built as native debugger on SGI Irix 6.x systems for
3835 debugging n32 executables. (Debugging 64-bit executables is not yet
3838 * Unified support for hardware watchpoints in all x86 configurations.
3840 Most (if not all) native x86 configurations support hardware-assisted
3841 breakpoints and watchpoints in a unified manner. This support
3842 implements debug register sharing between watchpoints, which allows to
3843 put a virtually infinite number of watchpoints on the same address,
3844 and also supports watching regions up to 16 bytes with several debug
3847 The new maintenance command `maintenance show-debug-regs' toggles
3848 debugging print-outs in functions that insert, remove, and test
3849 watchpoints and hardware breakpoints.
3851 * Changes in the DJGPP native configuration.
3853 New command ``info dos sysinfo'' displays assorted information about
3854 the CPU, OS, memory, and DPMI server.
3856 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3857 display information about segment descriptors stored in GDT, LDT, and
3860 New commands ``info dos pde'' and ``info dos pte'' display entries
3861 from Page Directory and Page Tables (for now works with CWSDPMI only).
3862 New command ``info dos address-pte'' displays the Page Table entry for
3863 a given linear address.
3865 GDB can now pass command lines longer than 126 characters to the
3866 program being debugged (requires an update to the libdbg.a library
3867 which is part of the DJGPP development kit).
3869 DWARF2 debug info is now supported.
3871 It is now possible to `step' and `next' through calls to `longjmp'.
3873 * Changes in documentation.
3875 All GDB documentation was converted to GFDL, the GNU Free
3876 Documentation License.
3878 Tracepoints-related commands are now fully documented in the GDB
3881 TUI, the Text-mode User Interface, is now documented in the manual.
3883 Tracepoints-related commands are now fully documented in the GDB
3886 The "GDB Internals" manual now has an index. It also includes
3887 documentation of `ui_out' functions, GDB coding standards, x86
3888 hardware watchpoints, and memory region attributes.
3890 * GDB's version number moved to ``version.in''
3892 The Makefile variable VERSION has been replaced by the file
3893 ``version.in''. People creating GDB distributions should update the
3894 contents of this file.
3898 GUD support is now a standard part of the EMACS distribution.
3900 *** Changes in GDB 5.0:
3902 * Improved support for debugging FP programs on x86 targets
3904 Unified and much-improved support for debugging floating-point
3905 programs on all x86 targets. In particular, ``info float'' now
3906 displays the FP registers in the same format on all x86 targets, with
3907 greater level of detail.
3909 * Improvements and bugfixes in hardware-assisted watchpoints
3911 It is now possible to watch array elements, struct members, and
3912 bitfields with hardware-assisted watchpoints. Data-read watchpoints
3913 on x86 targets no longer erroneously trigger when the address is
3916 * Improvements in the native DJGPP version of GDB
3918 The distribution now includes all the scripts and auxiliary files
3919 necessary to build the native DJGPP version on MS-DOS/MS-Windows
3920 machines ``out of the box''.
3922 The DJGPP version can now debug programs that use signals. It is
3923 possible to catch signals that happened in the debuggee, deliver
3924 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
3925 would kill the program being debugged.) Programs that hook hardware
3926 interrupts (keyboard, timer, etc.) can also be debugged.
3928 It is now possible to debug DJGPP programs that redirect their
3929 standard handles or switch them to raw (as opposed to cooked) mode, or
3930 even close them. The command ``run < foo > bar'' works as expected,
3931 and ``info terminal'' reports useful information about the debuggee's
3932 terminal, including raw/cooked mode, redirection, etc.
3934 The DJGPP version now uses termios functions for console I/O, which
3935 enables debugging graphics programs. Interrupting GDB with Ctrl-C
3938 DOS-style file names with drive letters are now fully supported by
3941 It is now possible to debug DJGPP programs that switch their working
3942 directory. It is also possible to rerun the debuggee any number of
3943 times without restarting GDB; thus, you can use the same setup,
3944 breakpoints, etc. for many debugging sessions.
3946 * New native configurations
3948 ARM GNU/Linux arm*-*-linux*
3949 PowerPC GNU/Linux powerpc-*-linux*
3953 Motorola MCore mcore-*-*
3954 x86 VxWorks i[3456]86-*-vxworks*
3955 PowerPC VxWorks powerpc-*-vxworks*
3956 TI TMS320C80 tic80-*-*
3958 * OBSOLETE configurations
3960 Altos 3068 m68*-altos-*
3961 Convex c1-*-*, c2-*-*
3963 ARM RISCix arm-*-* (as host)
3966 Configurations that have been declared obsolete will be commented out,
3967 but the code will be left in place. If there is no activity to revive
3968 these configurations before the next release of GDB, the sources will
3969 be permanently REMOVED.
3971 * Gould support removed
3973 Support for the Gould PowerNode and NP1 has been removed.
3975 * New features for SVR4
3977 On SVR4 native platforms (such as Solaris), if you attach to a process
3978 without first loading a symbol file, GDB will now attempt to locate and
3979 load symbols from the running process's executable file.
3981 * Many C++ enhancements
3983 C++ support has been greatly improved. Overload resolution now works properly
3984 in almost all cases. RTTI support is on the way.
3986 * Remote targets can connect to a sub-program
3988 A popen(3) style serial-device has been added. This device starts a
3989 sub-process (such as a stand-alone simulator) and then communicates
3990 with that. The sub-program to run is specified using the syntax
3991 ``|<program> <args>'' vis:
3993 (gdb) set remotedebug 1
3994 (gdb) target extended-remote |mn10300-elf-sim program-args
3996 * MIPS 64 remote protocol
3998 A long standing bug in the mips64 remote protocol where by GDB
3999 expected certain 32 bit registers (ex SR) to be transfered as 32
4000 instead of 64 bits has been fixed.
4002 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4003 added to provide backward compatibility with older versions of GDB.
4005 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4007 The command ``set remotebinarydownload'' command has been replaced by
4008 ``set remote X-packet''. Other commands in ``set remote'' family
4009 include ``set remote P-packet''.
4011 * Breakpoint commands accept ranges.
4013 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4014 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4015 ``tracepoint passcount'' also accepts a range of tracepoints.
4017 * ``apropos'' command added.
4019 The ``apropos'' command searches through command names and
4020 documentation strings, printing out matches, making it much easier to
4021 try to find a command that does what you are looking for.
4025 A new machine oriented interface (MI) has been added to GDB. This
4026 interface is designed for debug environments running GDB as a separate
4027 process. This is part of the long term libGDB project. See the
4028 "GDB/MI" chapter of the GDB manual for further information. It can be
4029 enabled by configuring with:
4031 .../configure --enable-gdbmi
4033 *** Changes in GDB-4.18:
4035 * New native configurations
4037 HP-UX 10.20 hppa*-*-hpux10.20
4038 HP-UX 11.x hppa*-*-hpux11.0*
4039 M68K GNU/Linux m68*-*-linux*
4043 Fujitsu FR30 fr30-*-elf*
4044 Intel StrongARM strongarm-*-*
4045 Mitsubishi D30V d30v-*-*
4047 * OBSOLETE configurations
4049 Gould PowerNode, NP1 np1-*-*, pn-*-*
4051 Configurations that have been declared obsolete will be commented out,
4052 but the code will be left in place. If there is no activity to revive
4053 these configurations before the next release of GDB, the sources will
4054 be permanently REMOVED.
4058 As a compatibility experiment, GDB's source files buildsym.h and
4059 buildsym.c have been converted to pure standard C, no longer
4060 containing any K&R compatibility code. We believe that all systems in
4061 use today either come with a standard C compiler, or have a GCC port
4062 available. If this is not true, please report the affected
4063 configuration to bug-gdb@gnu.org immediately. See the README file for
4064 information about getting a standard C compiler if you don't have one
4069 GDB now uses readline 2.2.
4071 * set extension-language
4073 You can now control the mapping between filename extensions and source
4074 languages by using the `set extension-language' command. For instance,
4075 you can ask GDB to treat .c files as C++ by saying
4076 set extension-language .c c++
4077 The command `info extensions' lists all of the recognized extensions
4078 and their associated languages.
4080 * Setting processor type for PowerPC and RS/6000
4082 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4083 you can use the `set processor' command to specify what variant of the
4084 PowerPC family you are debugging. The command
4088 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4089 following PowerPC and RS6000 variants:
4091 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4092 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4094 403GC IBM PowerPC 403GC
4095 505 Motorola PowerPC 505
4096 860 Motorola PowerPC 860 or 850
4097 601 Motorola PowerPC 601
4098 602 Motorola PowerPC 602
4099 603 Motorola/IBM PowerPC 603 or 603e
4100 604 Motorola PowerPC 604 or 604e
4101 750 Motorola/IBM PowerPC 750 or 750
4103 At the moment, this command just tells GDB what to name the
4104 special-purpose processor registers. Since almost all the affected
4105 registers are inaccessible to user-level programs, this command is
4106 only useful for remote debugging in its present form.
4110 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4111 more extensive support for HP-UX. Added features include shared
4112 library support, kernel threads and hardware watchpoints for 11.00,
4113 support for HP's ANSI C and C++ compilers, and a compatibility mode
4114 for xdb and dbx commands.
4118 HP's donation includes the new concept of catchpoints, which is a
4119 generalization of the old catch command. On HP-UX, it is now possible
4120 to catch exec, fork, and vfork, as well as library loading.
4122 This means that the existing catch command has changed; its first
4123 argument now specifies the type of catch to be set up. See the
4124 output of "help catch" for a list of catchpoint types.
4126 * Debugging across forks
4128 On HP-UX, you can choose which process to debug when a fork() happens
4133 HP has donated a curses-based terminal user interface (TUI). To get
4134 it, build with --enable-tui. Although this can be enabled for any
4135 configuration, at present it only works for native HP debugging.
4137 * GDB remote protocol additions
4139 A new protocol packet 'X' that writes binary data is now available.
4140 Default behavior is to try 'X', then drop back to 'M' if the stub
4141 fails to respond. The settable variable `remotebinarydownload'
4142 allows explicit control over the use of 'X'.
4144 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4145 full 64-bit address. The command
4147 set remoteaddresssize 32
4149 can be used to revert to the old behaviour. For existing remote stubs
4150 the change should not be noticed, as the additional address information
4153 In order to assist in debugging stubs, you may use the maintenance
4154 command `packet' to send any text string to the stub. For instance,
4156 maint packet heythere
4158 sends the packet "$heythere#<checksum>". Note that it is very easy to
4159 disrupt a debugging session by sending the wrong packet at the wrong
4162 The compare-sections command allows you to compare section data on the
4163 target to what is in the executable file without uploading or
4164 downloading, by comparing CRC checksums.
4166 * Tracing can collect general expressions
4168 You may now collect general expressions at tracepoints. This requires
4169 further additions to the target-side stub; see tracepoint.c and
4170 doc/agentexpr.texi for further details.
4172 * mask-address variable for Mips
4174 For Mips targets, you may control the zeroing of the upper 32 bits of
4175 a 64-bit address by entering `set mask-address on'. This is mainly
4176 of interest to users of embedded R4xxx and R5xxx processors.
4178 * Higher serial baud rates
4180 GDB's serial code now allows you to specify baud rates 57600, 115200,
4181 230400, and 460800 baud. (Note that your host system may not be able
4182 to achieve all of these rates.)
4186 The i960 configuration now includes an initial implementation of a
4187 builtin simulator, contributed by Jim Wilson.
4190 *** Changes in GDB-4.17:
4192 * New native configurations
4194 Alpha GNU/Linux alpha*-*-linux*
4195 Unixware 2.x i[3456]86-unixware2*
4196 Irix 6.x mips*-sgi-irix6*
4197 PowerPC GNU/Linux powerpc-*-linux*
4198 PowerPC Solaris powerpcle-*-solaris*
4199 Sparc GNU/Linux sparc-*-linux*
4200 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4204 Argonaut Risc Chip (ARC) arc-*-*
4205 Hitachi H8/300S h8300*-*-*
4206 Matsushita MN10200 w/simulator mn10200-*-*
4207 Matsushita MN10300 w/simulator mn10300-*-*
4208 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4209 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4210 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4211 Mitsubishi D10V w/simulator d10v-*-*
4212 Mitsubishi M32R/D w/simulator m32r-*-elf*
4213 Tsqware Sparclet sparclet-*-*
4214 NEC V850 w/simulator v850-*-*
4216 * New debugging protocols
4218 ARM with RDI protocol arm*-*-*
4219 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4220 DDB and LSI variants of PMON protocol mips*-*-*
4221 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4222 PowerPC with SDS protocol powerpc{,le}-*-eabi
4223 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4227 All configurations can now understand and use the DWARF 2 debugging
4228 format. The choice is automatic, if the symbol file contains DWARF 2
4233 GDB now includes basic Java language support. This support is
4234 only useful with Java compilers that produce native machine code.
4236 * solib-absolute-prefix and solib-search-path
4238 For SunOS and SVR4 shared libraries, you may now set the prefix for
4239 loading absolute shared library symbol files, and the search path for
4240 locating non-absolute shared library symbol files.
4242 * Live range splitting
4244 GDB can now effectively debug code for which GCC has performed live
4245 range splitting as part of its optimization. See gdb/doc/LRS for
4246 more details on the expected format of the stabs information.
4250 GDB's support for the GNU Hurd, including thread debugging, has been
4251 updated to work with current versions of the Hurd.
4255 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4256 instruction set. ARM GDB automatically detects when Thumb
4257 instructions are in use, and adjusts disassembly and backtracing
4262 GDB's MIPS target configurations now handle the MIP16 16-bit
4267 GDB now includes support for overlays; if an executable has been
4268 linked such that multiple sections are based at the same address, GDB
4269 will decide which section to use for symbolic info. You can choose to
4270 control the decision manually, using overlay commands, or implement
4271 additional target-side support and use "overlay load-target" to bring
4272 in the overlay mapping. Do "help overlay" for more detail.
4276 The command "info symbol <address>" displays information about
4277 the symbol at the specified address.
4281 The standard remote protocol now includes an extension that allows
4282 asynchronous collection and display of trace data. This requires
4283 extensive support in the target-side debugging stub. Tracing mode
4284 includes a new interaction mode in GDB and new commands: see the
4285 file tracepoint.c for more details.
4289 Configurations for embedded MIPS now include a simulator contributed
4290 by Cygnus Solutions. The simulator supports the instruction sets
4291 of most MIPS variants.
4295 Sparc configurations may now include the ERC32 simulator contributed
4296 by the European Space Agency. The simulator is not built into
4297 Sparc targets by default; configure with --enable-sim to include it.
4301 For target configurations that may include multiple variants of a
4302 basic architecture (such as MIPS and SH), you may now set the
4303 architecture explicitly. "set arch" sets, "info arch" lists
4304 the possible architectures.
4306 *** Changes in GDB-4.16:
4308 * New native configurations
4310 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4311 M68K NetBSD m68k-*-netbsd*
4312 PowerPC AIX 4.x powerpc-*-aix*
4313 PowerPC MacOS powerpc-*-macos*
4314 PowerPC Windows NT powerpcle-*-cygwin32
4315 RS/6000 AIX 4.x rs6000-*-aix4*
4319 ARM with RDP protocol arm-*-*
4320 I960 with MON960 i960-*-coff
4321 MIPS VxWorks mips*-*-vxworks*
4322 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4323 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4325 Matra Sparclet sparclet-*-*
4329 The powerpc-eabi configuration now includes the PSIM simulator,
4330 contributed by Andrew Cagney, with assistance from Mike Meissner.
4331 PSIM is a very elaborate model of the PowerPC, including not only
4332 basic instruction set execution, but also details of execution unit
4333 performance and I/O hardware. See sim/ppc/README for more details.
4337 GDB now works with Solaris 2.5.
4339 * Windows 95/NT native
4341 GDB will now work as a native debugger on Windows 95 and Windows NT.
4342 To build it from source, you must use the "gnu-win32" environment,
4343 which uses a DLL to emulate enough of Unix to run the GNU tools.
4344 Further information, binaries, and sources are available at
4345 ftp.cygnus.com, under pub/gnu-win32.
4347 * dont-repeat command
4349 If a user-defined command includes the command `dont-repeat', then the
4350 command will not be repeated if the user just types return. This is
4351 useful if the command is time-consuming to run, so that accidental
4352 extra keystrokes don't run the same command many times.
4354 * Send break instead of ^C
4356 The standard remote protocol now includes an option to send a break
4357 rather than a ^C to the target in order to interrupt it. By default,
4358 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4360 * Remote protocol timeout
4362 The standard remote protocol includes a new variable `remotetimeout'
4363 that allows you to set the number of seconds before GDB gives up trying
4364 to read from the target. The default value is 2.
4366 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4368 By default GDB will automatically keep track of objects as they are
4369 loaded and unloaded by the dynamic linker. By using the command `set
4370 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4371 when shared library events occur, thus allowing you to set breakpoints
4372 in shared libraries which are explicitly loaded by the inferior.
4374 Note this feature does not work on hpux8. On hpux9 you must link
4375 /usr/lib/end.o into your program. This feature should work
4376 automatically on hpux10.
4378 * Irix 5.x hardware watchpoint support
4380 Irix 5 configurations now support the use of hardware watchpoints.
4382 * Mips protocol "SYN garbage limit"
4384 When debugging a Mips target using the `target mips' protocol, you
4385 may set the number of characters that GDB will ignore by setting
4386 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4387 every character. The default value is 1050.
4389 * Recording and replaying remote debug sessions
4391 If you set `remotelogfile' to the name of a file, gdb will write to it
4392 a recording of a remote debug session. This recording may then be
4393 replayed back to gdb using "gdbreplay". See gdbserver/README for
4394 details. This is useful when you have a problem with GDB while doing
4395 remote debugging; you can make a recording of the session and send it
4396 to someone else, who can then recreate the problem.
4398 * Speedups for remote debugging
4400 GDB includes speedups for downloading and stepping MIPS systems using
4401 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4402 and more efficient S-record downloading.
4404 * Memory use reductions and statistics collection
4406 GDB now uses less memory and reports statistics about memory usage.
4407 Try the `maint print statistics' command, for example.
4409 *** Changes in GDB-4.15:
4411 * Psymtabs for XCOFF
4413 The symbol reader for AIX GDB now uses partial symbol tables. This
4414 can greatly improve startup time, especially for large executables.
4416 * Remote targets use caching
4418 Remote targets now use a data cache to speed up communication with the
4419 remote side. The data cache could lead to incorrect results because
4420 it doesn't know about volatile variables, thus making it impossible to
4421 debug targets which use memory mapped I/O devices. `set remotecache
4422 off' turns the the data cache off.
4424 * Remote targets may have threads
4426 The standard remote protocol now includes support for multiple threads
4427 in the target system, using new protocol commands 'H' and 'T'. See
4428 gdb/remote.c for details.
4432 If GDB is configured with `--enable-netrom', then it will include
4433 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4434 acts as though it is a bank of ROM on the target board, but you can
4435 write into it over the network. GDB's support consists only of
4436 support for fast loading into the emulated ROM; to debug, you must use
4437 another protocol, such as standard remote protocol. The usual
4438 sequence is something like
4440 target nrom <netrom-hostname>
4442 target remote <netrom-hostname>:1235
4446 GDB now includes support for the Apple Macintosh, as a host only. It
4447 may be run as either an MPW tool or as a standalone application, and
4448 it can debug through the serial port. All the usual GDB commands are
4449 available, but to the target command, you must supply "serial" as the
4450 device type instead of "/dev/ttyXX". See mpw-README in the main
4451 directory for more information on how to build. The MPW configuration
4452 scripts */mpw-config.in support only a few targets, and only the
4453 mips-idt-ecoff target has been tested.
4457 GDB configuration now uses autoconf. This is not user-visible,
4458 but does simplify configuration and building.
4462 GDB now supports hpux10.
4464 *** Changes in GDB-4.14:
4466 * New native configurations
4468 x86 FreeBSD i[345]86-*-freebsd
4469 x86 NetBSD i[345]86-*-netbsd
4470 NS32k NetBSD ns32k-*-netbsd
4471 Sparc NetBSD sparc-*-netbsd
4475 A29K VxWorks a29k-*-vxworks
4476 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4477 CPU32 EST-300 emulator m68*-*-est*
4478 PowerPC ELF powerpc-*-elf
4481 * Alpha OSF/1 support for procfs
4483 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4484 possible to attach to running processes. As the mounting of the /proc
4485 filesystem is optional on the Alpha, GDB automatically determines
4486 the availability of /proc during startup. This can lead to problems
4487 if /proc is unmounted after GDB has been started.
4489 * Arguments to user-defined commands
4491 User commands may accept up to 10 arguments separated by whitespace.
4492 Arguments are accessed within the user command via $arg0..$arg9. A
4495 print $arg0 + $arg1 + $arg2
4497 To execute the command use:
4500 Defines the command "adder" which prints the sum of its three arguments.
4501 Note the arguments are text substitutions, so they may reference variables,
4502 use complex expressions, or even perform inferior function calls.
4504 * New `if' and `while' commands
4506 This makes it possible to write more sophisticated user-defined
4507 commands. Both commands take a single argument, which is the
4508 expression to evaluate, and must be followed by the commands to
4509 execute, one per line, if the expression is nonzero, the list being
4510 terminated by the word `end'. The `if' command list may include an
4511 `else' word, which causes the following commands to be executed only
4512 if the expression is zero.
4514 * Fortran source language mode
4516 GDB now includes partial support for Fortran 77. It will recognize
4517 Fortran programs and can evaluate a subset of Fortran expressions, but
4518 variables and functions may not be handled correctly. GDB will work
4519 with G77, but does not yet know much about symbols emitted by other
4522 * Better HPUX support
4524 Most debugging facilities now work on dynamic executables for HPPAs
4525 running hpux9 or later. You can attach to running dynamically linked
4526 processes, but by default the dynamic libraries will be read-only, so
4527 for instance you won't be able to put breakpoints in them. To change
4528 that behavior do the following before running the program:
4534 This will cause the libraries to be mapped private and read-write.
4535 To revert to the normal behavior, do this:
4541 You cannot set breakpoints or examine data in the library until after
4542 the library is loaded if the function/data symbols do not have
4545 GDB can now also read debug symbols produced by the HP C compiler on
4546 HPPAs (sorry, no C++, Fortran or 68k support).
4548 * Target byte order now dynamically selectable
4550 You can choose which byte order to use with a target system, via the
4551 commands "set endian big" and "set endian little", and you can see the
4552 current setting by using "show endian". You can also give the command
4553 "set endian auto", in which case GDB will use the byte order
4554 associated with the executable. Currently, only embedded MIPS
4555 configurations support dynamic selection of target byte order.
4557 * New DOS host serial code
4559 This version uses DPMI interrupts to handle buffered I/O, so you
4560 no longer need to run asynctsr when debugging boards connected to
4563 *** Changes in GDB-4.13:
4565 * New "complete" command
4567 This lists all the possible completions for the rest of the line, if it
4568 were to be given as a command itself. This is intended for use by emacs.
4570 * Trailing space optional in prompt
4572 "set prompt" no longer adds a space for you after the prompt you set. This
4573 allows you to set a prompt which ends in a space or one that does not.
4575 * Breakpoint hit counts
4577 "info break" now displays a count of the number of times the breakpoint
4578 has been hit. This is especially useful in conjunction with "ignore"; you
4579 can ignore a large number of breakpoint hits, look at the breakpoint info
4580 to see how many times the breakpoint was hit, then run again, ignoring one
4581 less than that number, and this will get you quickly to the last hit of
4584 * Ability to stop printing at NULL character
4586 "set print null-stop" will cause GDB to stop printing the characters of
4587 an array when the first NULL is encountered. This is useful when large
4588 arrays actually contain only short strings.
4590 * Shared library breakpoints
4592 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4593 breakpoints in shared libraries before the executable is run.
4595 * Hardware watchpoints
4597 There is a new hardware breakpoint for the watch command for sparclite
4598 targets. See gdb/sparclite/hw_breakpoint.note.
4600 Hardware watchpoints are also now supported under GNU/Linux.
4604 Annotations have been added. These are for use with graphical interfaces,
4605 and are still experimental. Currently only gdba.el uses these.
4607 * Improved Irix 5 support
4609 GDB now works properly with Irix 5.2.
4611 * Improved HPPA support
4613 GDB now works properly with the latest GCC and GAS.
4615 * New native configurations
4617 Sequent PTX4 i[34]86-sequent-ptx4
4618 HPPA running OSF/1 hppa*-*-osf*
4619 Atari TT running SVR4 m68*-*-sysv4*
4620 RS/6000 LynxOS rs6000-*-lynxos*
4624 OS/9000 i[34]86-*-os9k
4625 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4628 * Hitachi SH7000 and E7000-PC ICE support
4630 There is now support for communicating with the Hitachi E7000-PC ICE.
4631 This is available automatically when GDB is configured for the SH.
4635 As usual, a variety of small fixes and improvements, both generic
4636 and configuration-specific. See the ChangeLog for more detail.
4638 *** Changes in GDB-4.12:
4640 * Irix 5 is now supported
4644 GDB-4.12 on the HPPA has a number of changes which make it unable
4645 to debug the output from the currently released versions of GCC and
4646 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4647 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4648 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4651 *** Changes in GDB-4.11:
4653 * User visible changes:
4657 The "set remotedebug" option is now consistent between the mips remote
4658 target, remote targets using the gdb-specific protocol, UDI (AMD's
4659 debug protocol for the 29k) and the 88k bug monitor. It is now an
4660 integer specifying a debug level (normally 0 or 1, but 2 means more
4661 debugging info for the mips target).
4663 * DEC Alpha native support
4665 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4666 debug info, but GDB works fairly well with the DEC compiler and should
4667 work with a future GCC release. See the README file for a few
4668 Alpha-specific notes.
4670 * Preliminary thread implementation
4672 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4674 * LynxOS native and target support for 386
4676 This release has been hosted on LynxOS 2.2, and also can be configured
4677 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4680 * Improvements in C++ mangling/demangling.
4682 This release has much better g++ debugging, specifically in name
4683 mangling/demangling, virtual function calls, print virtual table,
4684 call methods, ...etc.
4686 *** Changes in GDB-4.10:
4688 * User visible changes:
4690 Remote debugging using the GDB-specific (`target remote') protocol now
4691 supports the `load' command. This is only useful if you have some
4692 other way of getting the stub to the target system, and you can put it
4693 somewhere in memory where it won't get clobbered by the download.
4695 Filename completion now works.
4697 When run under emacs mode, the "info line" command now causes the
4698 arrow to point to the line specified. Also, "info line" prints
4699 addresses in symbolic form (as well as hex).
4701 All vxworks based targets now support a user settable option, called
4702 vxworks-timeout. This option represents the number of seconds gdb
4703 should wait for responses to rpc's. You might want to use this if
4704 your vxworks target is, perhaps, a slow software simulator or happens
4705 to be on the far side of a thin network line.
4709 This release contains support for using a DEC alpha as a GDB host for
4710 cross debugging. Native alpha debugging is not supported yet.
4713 *** Changes in GDB-4.9:
4717 This is the first GDB release which is accompanied by a matching testsuite.
4718 The testsuite requires installation of dejagnu, which should be available
4719 via ftp from most sites that carry GNU software.
4723 'Cfront' style demangling has had its name changed to 'ARM' style, to
4724 emphasize that it was written from the specifications in the C++ Annotated
4725 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4726 disclaimers, it still generated too much confusion with users attempting to
4727 use gdb with AT&T cfront.
4731 GDB now uses a standard remote interface to a simulator library.
4732 So far, the library contains simulators for the Zilog Z8001/2, the
4733 Hitachi H8/300, H8/500 and Super-H.
4735 * New targets supported
4737 H8/300 simulator h8300-hitachi-hms or h8300hms
4738 H8/500 simulator h8500-hitachi-hms or h8500hms
4739 SH simulator sh-hitachi-hms or sh
4740 Z8000 simulator z8k-zilog-none or z8ksim
4741 IDT MIPS board over serial line mips-idt-ecoff
4743 Cross-debugging to GO32 targets is supported. It requires a custom
4744 version of the i386-stub.c module which is integrated with the
4745 GO32 memory extender.
4747 * New remote protocols
4749 MIPS remote debugging protocol.
4751 * New source languages supported
4753 This version includes preliminary support for Chill, a Pascal like language
4754 used by telecommunications companies. Chill support is also being integrated
4755 into the GNU compiler, but we don't know when it will be publically available.
4758 *** Changes in GDB-4.8:
4760 * HP Precision Architecture supported
4762 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4763 version of this support was available as a set of patches from the
4764 University of Utah. GDB does not support debugging of programs
4765 compiled with the HP compiler, because HP will not document their file
4766 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4767 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4769 Many problems in the preliminary version have been fixed.
4771 * Faster and better demangling
4773 We have improved template demangling and fixed numerous bugs in the GNU style
4774 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4775 character types (wchar_t) are now supported. Demangling of each symbol is now
4776 only done once, and is cached when the symbol table for a file is read in.
4777 This results in a small increase in memory usage for C programs, a moderate
4778 increase in memory usage for C++ programs, and a fantastic speedup in
4781 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4782 from the specifications in the Annotated Reference Manual, which AT&T's
4783 compiler does not actually implement.
4785 * G++ multiple inheritance compiler problem
4787 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4788 inheritance lattices was reworked to properly discover ambiguities. We
4789 recently found an example which causes this new algorithm to fail in a
4790 very subtle way, producing bad debug information for those classes.
4791 The file 'gcc.patch' (in this directory) can be applied to gcc to
4792 circumvent the problem. A future GCC release will contain a complete
4795 The previous G++ debug info problem (mentioned below for the gdb-4.7
4796 release) is fixed in gcc version 2.3.2.
4798 * Improved configure script
4800 The `configure' script will now attempt to guess your system type if
4801 you don't supply a host system type. The old scheme of supplying a
4802 host system triplet is preferable over using this. All the magic is
4803 done in the new `config.guess' script. Examine it for details.
4805 We have also brought our configure script much more in line with the FSF's
4806 version. It now supports the --with-xxx options. In particular,
4807 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4808 The resulting GDB will not be able to read arbitrary object file formats --
4809 only the format ``expected'' to be used on the configured target system.
4810 We hope to make this the default in a future release.
4812 * Documentation improvements
4814 There's new internal documentation on how to modify GDB, and how to
4815 produce clean changes to the code. We implore people to read it
4816 before submitting changes.
4818 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4819 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4820 `info' files are also provided. To build `info' files from scratch,
4821 you will need the latest `makeinfo' release, which will be available in
4822 a future texinfo-X.Y release.
4824 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4825 We're not sure exactly which versions have this problem, but it has
4826 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4827 or better. If that isn't possible, there is a patch in
4828 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4829 around this problem.
4833 GDB now supports array constants that can be used in expressions typed in by
4834 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4835 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4838 The new directory `gdb/sparclite' contains a program that demonstrates
4839 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4841 * New native hosts supported
4843 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4844 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4846 * New targets supported
4848 AMD 29k family via UDI a29k-amd-udi or udi29k
4850 * New file formats supported
4852 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4853 HPUX core files, and SCO 3.2v2 core files.
4857 Attaching to processes now works again; thanks for the many bug reports.
4859 We have also stomped on a bunch of core dumps caused by
4860 printf_filtered("%s") problems.
4862 We eliminated a copyright problem on the rpc and ptrace header files
4863 for VxWorks, which was discovered at the last minute during the 4.7
4864 release. You should now be able to build a VxWorks GDB.
4866 You can now interrupt gdb while an attached process is running. This
4867 will cause the attached process to stop, and give control back to GDB.
4869 We fixed problems caused by using too many file descriptors
4870 for reading symbols from object files and libraries. This was
4871 especially a problem for programs that used many (~100) shared
4874 The `step' command now only enters a subroutine if there is line number
4875 information for the subroutine. Otherwise it acts like the `next'
4876 command. Previously, `step' would enter subroutines if there was
4877 any debugging information about the routine. This avoids problems
4878 when using `cc -g1' on MIPS machines.
4880 * Internal improvements
4882 GDB's internal interfaces have been improved to make it easier to support
4883 debugging of multiple languages in the future.
4885 GDB now uses a common structure for symbol information internally.
4886 Minimal symbols (derived from linkage symbols in object files), partial
4887 symbols (from a quick scan of debug information), and full symbols
4888 contain a common subset of information, making it easier to write
4889 shared code that handles any of them.
4891 * New command line options
4893 We now accept --silent as an alias for --quiet.
4897 The memory-mapped-malloc library is now licensed under the GNU Library
4898 General Public License.
4900 *** Changes in GDB-4.7:
4902 * Host/native/target split
4904 GDB has had some major internal surgery to untangle the support for
4905 hosts and remote targets. Now, when you configure GDB for a remote
4906 target, it will no longer load in all of the support for debugging
4907 local programs on the host. When fully completed and tested, this will
4908 ensure that arbitrary host/target combinations are possible.
4910 The primary conceptual shift is to separate the non-portable code in
4911 GDB into three categories. Host specific code is required any time GDB
4912 is compiled on that host, regardless of the target. Target specific
4913 code relates to the peculiarities of the target, but can be compiled on
4914 any host. Native specific code is everything else: it can only be
4915 built when the host and target are the same system. Child process
4916 handling and core file support are two common `native' examples.
4918 GDB's use of /proc for controlling Unix child processes is now cleaner.
4919 It has been split out into a single module under the `target_ops' vector,
4920 plus two native-dependent functions for each system that uses /proc.
4922 * New hosts supported
4924 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
4925 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4926 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
4928 * New targets supported
4930 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4931 68030 and CPU32 m68030-*-*, m68332-*-*
4933 * New native hosts supported
4935 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4936 (386bsd is not well tested yet)
4937 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
4939 * New file formats supported
4941 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
4942 supports reading of `a.out.adobe' object files, which are an a.out
4943 format extended with minimal information about multiple sections.
4947 `show copying' is the same as the old `info copying'.
4948 `show warranty' is the same as `info warrantee'.
4949 These were renamed for consistency. The old commands continue to work.
4951 `info handle' is a new alias for `info signals'.
4953 You can now define pre-command hooks, which attach arbitrary command
4954 scripts to any command. The commands in the hook will be executed
4955 prior to the user's command. You can also create a hook which will be
4956 executed whenever the program stops. See gdb.texinfo.
4960 We now deal with Cfront style name mangling, and can even extract type
4961 info from mangled symbols. GDB can automatically figure out which
4962 symbol mangling style your C++ compiler uses.
4964 Calling of methods and virtual functions has been improved as well.
4968 The crash that occured when debugging Sun Ansi-C compiled binaries is
4969 fixed. This was due to mishandling of the extra N_SO stabs output
4972 We also finally got Ultrix 4.2 running in house, and fixed core file
4973 support, with help from a dozen people on the net.
4975 John M. Farrell discovered that the reason that single-stepping was so
4976 slow on all of the Mips based platforms (primarily SGI and DEC) was
4977 that we were trying to demangle and lookup a symbol used for internal
4978 purposes on every instruction that was being stepped through. Changing
4979 the name of that symbol so that it couldn't be mistaken for a C++
4980 mangled symbol sped things up a great deal.
4982 Rich Pixley sped up symbol lookups in general by getting much smarter
4983 about when C++ symbol mangling is necessary. This should make symbol
4984 completion (TAB on the command line) much faster. It's not as fast as
4985 we'd like, but it's significantly faster than gdb-4.6.
4989 A new user controllable variable 'call_scratch_address' can
4990 specify the location of a scratch area to be used when GDB
4991 calls a function in the target. This is necessary because the
4992 usual method of putting the scratch area on the stack does not work
4993 in systems that have separate instruction and data spaces.
4995 We integrated changes to support the 29k UDI (Universal Debugger
4996 Interface), but discovered at the last minute that we didn't have all
4997 of the appropriate copyright paperwork. We are working with AMD to
4998 resolve this, and hope to have it available soon.
5002 We have sped up the remote serial line protocol, especially for targets
5003 with lots of registers. It now supports a new `expedited status' ('T')
5004 message which can be used in place of the existing 'S' status message.
5005 This allows the remote stub to send only the registers that GDB
5006 needs to make a quick decision about single-stepping or conditional
5007 breakpoints, eliminating the need to fetch the entire register set for
5008 each instruction being stepped through.
5010 The GDB remote serial protocol now implements a write-through cache for
5011 registers, only re-reading the registers if the target has run.
5013 There is also a new remote serial stub for SPARC processors. You can
5014 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5015 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5016 processor with a serial port.
5020 Configure.in files have become much easier to read and modify. A new
5021 `table driven' format makes it more obvious what configurations are
5022 supported, and what files each one uses.
5026 There is a new opcodes library which will eventually contain all of the
5027 disassembly routines and opcode tables. At present, it only contains
5028 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5029 disassembler (binutils/objdump) to share these routines.
5031 The libiberty library is now copylefted under the GNU Library General
5032 Public License. This allows more liberal use, and was done so libg++
5033 can use it. This makes no difference to GDB, since the Library License
5034 grants all the rights from the General Public License.
5038 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5039 reference to the stabs symbol info used by the debugger. It is (as far
5040 as we know) the only published document on this fascinating topic. We
5041 encourage you to read it, compare it to the stabs information on your
5042 system, and send improvements on the document in general (to
5043 bug-gdb@prep.ai.mit.edu).
5045 And, of course, many bugs have been fixed.
5048 *** Changes in GDB-4.6:
5050 * Better support for C++ function names
5052 GDB now accepts as input the "demangled form" of C++ overloaded function
5053 names and member function names, and can do command completion on such names
5054 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5055 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5056 Make use of command completion, it is your friend.
5058 GDB also now accepts a variety of C++ mangled symbol formats. They are
5059 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5060 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5061 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5062 for the list of formats.
5064 * G++ symbol mangling problem
5066 Recent versions of gcc have a bug in how they emit debugging information for
5067 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5068 directory) can be applied to gcc to fix the problem. Alternatively, if you
5069 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5070 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5071 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5074 * New 'maintenance' command
5076 All of the commands related to hacking GDB internals have been moved out of
5077 the main command set, and now live behind the 'maintenance' command. This
5078 can also be abbreviated as 'mt'. The following changes were made:
5080 dump-me -> maintenance dump-me
5081 info all-breakpoints -> maintenance info breakpoints
5082 printmsyms -> maintenance print msyms
5083 printobjfiles -> maintenance print objfiles
5084 printpsyms -> maintenance print psymbols
5085 printsyms -> maintenance print symbols
5087 The following commands are new:
5089 maintenance demangle Call internal GDB demangler routine to
5090 demangle a C++ link name and prints the result.
5091 maintenance print type Print a type chain for a given symbol
5093 * Change to .gdbinit file processing
5095 We now read the $HOME/.gdbinit file before processing the argv arguments
5096 (e.g. reading symbol files or core files). This allows global parameters to
5097 be set, which will apply during the symbol reading. The ./.gdbinit is still
5098 read after argv processing.
5100 * New hosts supported
5102 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5104 GNU/Linux support i386-unknown-linux or linux
5106 We are also including code to support the HP/PA running BSD and HPUX. This
5107 is almost guaranteed not to work, as we didn't have time to test or build it
5108 for this release. We are including it so that the more adventurous (or
5109 masochistic) of you can play with it. We also had major problems with the
5110 fact that the compiler that we got from HP doesn't support the -g option.
5113 * New targets supported
5115 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5117 * More smarts about finding #include files
5119 GDB now remembers the compilation directory for all include files, and for
5120 all files from which C is generated (like yacc and lex sources). This
5121 greatly improves GDB's ability to find yacc/lex sources, and include files,
5122 especially if you are debugging your program from a directory different from
5123 the one that contains your sources.
5125 We also fixed a bug which caused difficulty with listing and setting
5126 breakpoints in include files which contain C code. (In the past, you had to
5127 try twice in order to list an include file that you hadn't looked at before.)
5129 * Interesting infernals change
5131 GDB now deals with arbitrary numbers of sections, where the symbols for each
5132 section must be relocated relative to that section's landing place in the
5133 target's address space. This work was needed to support ELF with embedded
5134 stabs used by Solaris-2.0.
5136 * Bug fixes (of course!)
5138 There have been loads of fixes for the following things:
5139 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5140 i960, stabs, DOS(GO32), procfs, etc...
5142 See the ChangeLog for details.
5144 *** Changes in GDB-4.5:
5146 * New machines supported (host and target)
5148 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5150 SGI Irix-4.x mips-sgi-irix4 or iris4
5152 * New malloc package
5154 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5155 Mmalloc is capable of handling mutiple heaps of memory. It is also
5156 capable of saving a heap to a file, and then mapping it back in later.
5157 This can be used to greatly speedup the startup of GDB by using a
5158 pre-parsed symbol table which lives in a mmalloc managed heap. For
5159 more details, please read mmalloc/mmalloc.texi.
5163 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5164 'help info proc' for details.
5166 * MIPS ecoff symbol table format
5168 The code that reads MIPS symbol table format is now supported on all hosts.
5169 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5172 * File name changes for MS-DOS
5174 Many files in the config directories have been renamed to make it easier to
5175 support GDB on MS-DOSe systems (which have very restrictive file name
5176 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5177 environment) is close to working but has some remaining problems. Note
5178 that debugging of DOS programs is not supported, due to limitations
5179 in the ``operating system'', but it can be used to host cross-debugging.
5181 * Cross byte order fixes
5183 Many fixes have been made to support cross debugging of Sparc and MIPS
5184 targets from hosts whose byte order differs.
5186 * New -mapped and -readnow options
5188 If memory-mapped files are available on your system through the 'mmap'
5189 system call, you can use the -mapped option on the `file' or
5190 `symbol-file' commands to cause GDB to write the symbols from your
5191 program into a reusable file. If the program you are debugging is
5192 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5193 Future GDB debugging sessions will notice the presence of this file,
5194 and will quickly map in symbol information from it, rather than reading
5195 the symbol table from the executable program. Using the '-mapped'
5196 option in a GDB `file' or `symbol-file' command has the same effect as
5197 starting GDB with the '-mapped' command-line option.
5199 You can cause GDB to read the entire symbol table immediately by using
5200 the '-readnow' option with any of the commands that load symbol table
5201 information (or on the GDB command line). This makes the command
5202 slower, but makes future operations faster.
5204 The -mapped and -readnow options are typically combined in order to
5205 build a `fred.syms' file that contains complete symbol information.
5206 A simple GDB invocation to do nothing but build a `.syms' file for future
5209 gdb -batch -nx -mapped -readnow programname
5211 The `.syms' file is specific to the host machine on which GDB is run.
5212 It holds an exact image of GDB's internal symbol table. It cannot be
5213 shared across multiple host platforms.
5215 * longjmp() handling
5217 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5218 siglongjmp() without losing control. This feature has not yet been ported to
5219 all systems. It currently works on many 386 platforms, all MIPS-based
5220 platforms (SGI, DECstation, etc), and Sun3/4.
5224 Preliminary work has been put in to support the new Solaris OS from Sun. At
5225 this time, it can control and debug processes, but it is not capable of
5230 As always, many many bug fixes. The major areas were with g++, and mipsread.
5231 People using the MIPS-based platforms should experience fewer mysterious
5232 crashes and trashed symbol tables.
5234 *** Changes in GDB-4.4:
5236 * New machines supported (host and target)
5238 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5240 BSD Reno on Vax vax-dec-bsd
5241 Ultrix on Vax vax-dec-ultrix
5243 * New machines supported (target)
5245 AMD 29000 embedded, using EBMON a29k-none-none
5249 GDB continues to improve its handling of C++. `References' work better.
5250 The demangler has also been improved, and now deals with symbols mangled as
5251 per the Annotated C++ Reference Guide.
5253 GDB also now handles `stabs' symbol information embedded in MIPS
5254 `ecoff' symbol tables. Since the ecoff format was not easily
5255 extensible to handle new languages such as C++, this appeared to be a
5256 good way to put C++ debugging info into MIPS binaries. This option
5257 will be supported in the GNU C compiler, version 2, when it is
5260 * New features for SVR4
5262 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5263 shared libraries. Debugging dynamically linked programs should present
5264 only minor differences from debugging statically linked programs.
5266 The `info proc' command will print out information about any process
5267 on an SVR4 system (including the one you are debugging). At the moment,
5268 it prints the address mappings of the process.
5270 If you bring up GDB on another SVR4 system, please send mail to
5271 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5273 * Better dynamic linking support in SunOS
5275 Reading symbols from shared libraries which contain debugging symbols
5276 now works properly. However, there remain issues such as automatic
5277 skipping of `transfer vector' code during function calls, which
5278 make it harder to debug code in a shared library, than to debug the
5279 same code linked statically.
5283 GDB is now using the latest `getopt' routines from the FSF. This
5284 version accepts the -- prefix for options with long names. GDB will
5285 continue to accept the old forms (-option and +option) as well.
5286 Various single letter abbreviations for options have been explicity
5287 added to the option table so that they won't get overshadowed in the
5288 future by other options that begin with the same letter.
5292 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5293 Many assorted bugs have been handled. Many more remain to be handled.
5294 See the various ChangeLog files (primarily in gdb and bfd) for details.
5297 *** Changes in GDB-4.3:
5299 * New machines supported (host and target)
5301 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5302 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5303 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5305 * Almost SCO Unix support
5307 We had hoped to support:
5308 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5309 (except for core file support), but we discovered very late in the release
5310 that it has problems with process groups that render gdb unusable. Sorry
5311 about that. I encourage people to fix it and post the fixes.
5313 * Preliminary ELF and DWARF support
5315 GDB can read ELF object files on System V Release 4, and can handle
5316 debugging records for C, in DWARF format, in ELF files. This support
5317 is preliminary. If you bring up GDB on another SVR4 system, please
5318 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5323 GDB now uses the latest `readline' library. One user-visible change
5324 is that two tabs will list possible command completions, which previously
5325 required typing M-? (meta-question mark, or ESC ?).
5329 The `stepi' bug that many of you noticed has been squashed.
5330 Many bugs in C++ have been handled. Many more remain to be handled.
5331 See the various ChangeLog files (primarily in gdb and bfd) for details.
5333 * State of the MIPS world (in case you wondered):
5335 GDB can understand the symbol tables emitted by the compilers
5336 supplied by most vendors of MIPS-based machines, including DEC. These
5337 symbol tables are in a format that essentially nobody else uses.
5339 Some versions of gcc come with an assembler post-processor called
5340 mips-tfile. This program is required if you want to do source-level
5341 debugging of gcc-compiled programs. I believe FSF does not ship
5342 mips-tfile with gcc version 1, but it will eventually come with gcc
5345 Debugging of g++ output remains a problem. g++ version 1.xx does not
5346 really support it at all. (If you're lucky, you should be able to get
5347 line numbers and stack traces to work, but no parameters or local
5348 variables.) With some work it should be possible to improve the
5351 When gcc version 2 is released, you will have somewhat better luck.
5352 However, even then you will get confusing results for inheritance and
5355 We will eventually provide full debugging of g++ output on
5356 DECstations. This will probably involve some kind of stabs-in-ecoff
5357 encapulation, but the details have not been worked out yet.
5360 *** Changes in GDB-4.2:
5362 * Improved configuration
5364 Only one copy of `configure' exists now, and it is not self-modifying.
5365 Porting BFD is simpler.
5369 The `step' and `next' commands now only stop at the first instruction
5370 of a source line. This prevents the multiple stops that used to occur
5371 in switch statements, for-loops, etc. `Step' continues to stop if a
5372 function that has debugging information is called within the line.
5376 Lots of small bugs fixed. More remain.
5378 * New host supported (not target)
5380 Intel 386 PC clone running Mach i386-none-mach
5383 *** Changes in GDB-4.1:
5385 * Multiple source language support
5387 GDB now has internal scaffolding to handle several source languages.
5388 It determines the type of each source file from its filename extension,
5389 and will switch expression parsing and number formatting to match the
5390 language of the function in the currently selected stack frame.
5391 You can also specifically set the language to be used, with
5392 `set language c' or `set language modula-2'.
5396 GDB now has preliminary support for the GNU Modula-2 compiler,
5397 currently under development at the State University of New York at
5398 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5399 continue through the fall of 1991 and into 1992.
5401 Other Modula-2 compilers are currently not supported, and attempting to
5402 debug programs compiled with them will likely result in an error as the
5403 symbol table is read. Feel free to work on it, though!
5405 There are hooks in GDB for strict type checking and range checking,
5406 in the `Modula-2 philosophy', but they do not currently work.
5410 GDB can now write to executable and core files (e.g. patch
5411 a variable's value). You must turn this switch on, specify
5412 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5413 by assigning a new value to a variable. Modifications take
5416 * Automatic SunOS shared library reading
5418 When you run your program, GDB automatically determines where its
5419 shared libraries (if any) have been loaded, and reads their symbols.
5420 The `share' command is no longer needed. This also works when
5421 examining core files.
5425 You can specify the number of lines that the `list' command shows.
5428 * New machines supported (host and target)
5430 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5431 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5432 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5434 * New hosts supported (not targets)
5436 IBM RT/PC: romp-ibm-aix or rtpc
5438 * New targets supported (not hosts)
5440 AMD 29000 embedded with COFF a29k-none-coff
5441 AMD 29000 embedded with a.out a29k-none-aout
5442 Ultracomputer remote kernel debug a29k-nyu-kern
5444 * New remote interfaces
5450 *** Changes in GDB-4.0:
5454 Wide output is wrapped at good places to make the output more readable.
5456 Gdb now supports cross-debugging from a host machine of one type to a
5457 target machine of another type. Communication with the target system
5458 is over serial lines. The ``target'' command handles connecting to the
5459 remote system; the ``load'' command will download a program into the
5460 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5461 also supports debugging of realtime processes running under VxWorks,
5462 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5463 stub on the target system.
5465 New CPUs supported include the AMD 29000 and Intel 960.
5467 GDB now reads object files and symbol tables via a ``binary file''
5468 library, which allows a single copy of GDB to debug programs of multiple
5469 object file types such as a.out and coff.
5471 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5472 refcard.dvi and refcard.ps are available to format it).
5475 * Control-Variable user interface simplified
5477 All variables that control the operation of the debugger can be set
5478 by the ``set'' command, and displayed by the ``show'' command.
5480 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5481 ``Show prompt'' produces the response:
5482 Gdb's prompt is new-gdb=>.
5484 What follows are the NEW set commands. The command ``help set'' will
5485 print a complete list of old and new set commands. ``help set FOO''
5486 will give a longer description of the variable FOO. ``show'' will show
5487 all of the variable descriptions and their current settings.
5489 confirm on/off: Enables warning questions for operations that are
5490 hard to recover from, e.g. rerunning the program while
5491 it is already running. Default is ON.
5493 editing on/off: Enables EMACS style command line editing
5494 of input. Previous lines can be recalled with
5495 control-P, the current line can be edited with control-B,
5496 you can search for commands with control-R, etc.
5499 history filename NAME: NAME is where the gdb command history
5500 will be stored. The default is .gdb_history,
5501 or the value of the environment variable
5504 history size N: The size, in commands, of the command history. The
5505 default is 256, or the value of the environment variable
5508 history save on/off: If this value is set to ON, the history file will
5509 be saved after exiting gdb. If set to OFF, the
5510 file will not be saved. The default is OFF.
5512 history expansion on/off: If this value is set to ON, then csh-like
5513 history expansion will be performed on
5514 command line input. The default is OFF.
5516 radix N: Sets the default radix for input and output. It can be set
5517 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5518 in the current radix, so "set radix 10" is always a no-op.
5520 height N: This integer value is the number of lines on a page. Default
5521 is 24, the current `stty rows'' setting, or the ``li#''
5522 setting from the termcap entry matching the environment
5525 width N: This integer value is the number of characters on a line.
5526 Default is 80, the current `stty cols'' setting, or the ``co#''
5527 setting from the termcap entry matching the environment
5530 Note: ``set screensize'' is obsolete. Use ``set height'' and
5531 ``set width'' instead.
5533 print address on/off: Print memory addresses in various command displays,
5534 such as stack traces and structure values. Gdb looks
5535 more ``symbolic'' if you turn this off; it looks more
5536 ``machine level'' with it on. Default is ON.
5538 print array on/off: Prettyprint arrays. New convenient format! Default
5541 print demangle on/off: Print C++ symbols in "source" form if on,
5544 print asm-demangle on/off: Same, for assembler level printouts
5547 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5550 * Support for Epoch Environment.
5552 The epoch environment is a version of Emacs v18 with windowing. One
5553 new command, ``inspect'', is identical to ``print'', except that if you
5554 are running in the epoch environment, the value is printed in its own
5558 * Support for Shared Libraries
5560 GDB can now debug programs and core files that use SunOS shared libraries.
5561 Symbols from a shared library cannot be referenced
5562 before the shared library has been linked with the program (this
5563 happens after you type ``run'' and before the function main() is entered).
5564 At any time after this linking (including when examining core files
5565 from dynamically linked programs), gdb reads the symbols from each
5566 shared library when you type the ``sharedlibrary'' command.
5567 It can be abbreviated ``share''.
5569 sharedlibrary REGEXP: Load shared object library symbols for files
5570 matching a unix regular expression. No argument
5571 indicates to load symbols for all shared libraries.
5573 info sharedlibrary: Status of loaded shared libraries.
5578 A watchpoint stops execution of a program whenever the value of an
5579 expression changes. Checking for this slows down execution
5580 tremendously whenever you are in the scope of the expression, but is
5581 quite useful for catching tough ``bit-spreader'' or pointer misuse
5582 problems. Some machines such as the 386 have hardware for doing this
5583 more quickly, and future versions of gdb will use this hardware.
5585 watch EXP: Set a watchpoint (breakpoint) for an expression.
5587 info watchpoints: Information about your watchpoints.
5589 delete N: Deletes watchpoint number N (same as breakpoints).
5590 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5591 enable N: Re-enables watchpoint number N (same as breakpoints).
5594 * C++ multiple inheritance
5596 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5599 * C++ exception handling
5601 Gdb now supports limited C++ exception handling. Besides the existing
5602 ability to breakpoint on an exception handler, gdb can breakpoint on
5603 the raising of an exception (before the stack is peeled back to the
5606 catch FOO: If there is a FOO exception handler in the dynamic scope,
5607 set a breakpoint to catch exceptions which may be raised there.
5608 Multiple exceptions (``catch foo bar baz'') may be caught.
5610 info catch: Lists all exceptions which may be caught in the
5611 current stack frame.
5614 * Minor command changes
5616 The command ``call func (arg, arg, ...)'' now acts like the print
5617 command, except it does not print or save a value if the function's result
5618 is void. This is similar to dbx usage.
5620 The ``up'' and ``down'' commands now always print the frame they end up
5621 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5622 frames without printing.
5624 * New directory command
5626 'dir' now adds directories to the FRONT of the source search path.
5627 The path starts off empty. Source files that contain debug information
5628 about the directory in which they were compiled can be found even
5629 with an empty path; Sun CC and GCC include this information. If GDB can't
5630 find your source file in the current directory, type "dir .".
5632 * Configuring GDB for compilation
5634 For normal use, type ``./configure host''. See README or gdb.texinfo
5637 GDB now handles cross debugging. If you are remotely debugging between
5638 two different machines, type ``./configure host -target=targ''.
5639 Host is the machine where GDB will run; targ is the machine
5640 where the program that you are debugging will run.
5642 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.