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.
55 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
57 *** Changes in GDB 7.7
59 * Improved support for process record-replay and reverse debugging on
60 arm*-linux* targets. Support for thumb32 and syscall instruction
61 recording has been added.
63 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
65 * GDB now supports Fission DWP file format version 2.
66 http://gcc.gnu.org/wiki/DebugFission
68 * New convenience function "$_isvoid", to check whether an expression
69 is void. A void expression is an expression where the type of the
70 result is "void". For example, some convenience variables may be
71 "void" when evaluated (e.g., "$_exitcode" before the execution of
72 the program being debugged; or an undefined convenience variable).
73 Another example, when calling a function whose return type is
76 * The "maintenance print objfiles" command now takes an optional regexp.
78 * The "catch syscall" command now works on arm*-linux* targets.
80 * GDB now consistently shows "<not saved>" when printing values of
81 registers the debug info indicates have not been saved in the frame
82 and there's nowhere to retrieve them from
83 (callee-saved/call-clobbered registers):
88 (gdb) info registers rax
91 Before, the former would print "<optimized out>", and the latter
92 "*value not available*".
94 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
99 ** Frame filters and frame decorators have been added.
100 ** Temporary breakpoints are now supported.
101 ** Line tables representation has been added.
102 ** New attribute 'parent_type' for gdb.Field objects.
103 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
104 ** New attribute 'name' for gdb.Type objects.
108 Nios II ELF nios2*-*-elf
109 Nios II GNU/Linux nios2*-*-linux
110 Texas Instruments MSP430 msp430*-*-elf
112 * Removed native configurations
114 Support for these a.out NetBSD and OpenBSD obsolete configurations has
115 been removed. ELF variants of these configurations are kept supported.
117 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
118 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
119 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
120 i[34567]86-*-openbsd3.[0-3]
121 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
122 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
123 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
127 Like "catch throw", but catches a re-thrown exception.
129 Renamed from old "maint check-symtabs".
131 Perform consistency checks on symtabs.
133 Expand symtabs matching an optional regexp.
136 Display the details of GDB configure-time options.
138 maint set|show per-command
139 maint set|show per-command space
140 maint set|show per-command time
141 maint set|show per-command symtab
142 Enable display of per-command gdb resource usage.
144 remove-symbol-file FILENAME
145 remove-symbol-file -a ADDRESS
146 Remove a symbol file added via add-symbol-file. The file to remove
147 can be identified by its filename or by an address that lies within
148 the boundaries of this symbol file in memory.
151 info exceptions REGEXP
152 Display the list of Ada exceptions defined in the program being
153 debugged. If provided, only the exceptions whose names match REGEXP
158 set debug symfile off|on
160 Control display of debugging info regarding reading symbol files and
161 symbol tables within those files
163 set print raw frame-arguments
164 show print raw frame-arguments
165 Set/show whether to print frame arguments in raw mode,
166 disregarding any defined pretty-printers.
168 set remote trace-status-packet
169 show remote trace-status-packet
170 Set/show the use of remote protocol qTStatus packet.
174 Control display of debugging messages related to Nios II targets.
178 Control whether target-assisted range stepping is enabled.
180 set startup-with-shell
181 show startup-with-shell
182 Specifies whether Unix child processes are started via a shell or
187 Use the target memory cache for accesses to the code segment. This
188 improves performance of remote debugging (particularly disassembly).
190 * You can now use a literal value 'unlimited' for options that
191 interpret 0 or -1 as meaning "unlimited". E.g., "set
192 trace-buffer-size unlimited" is now an alias for "set
193 trace-buffer-size -1" and "set height unlimited" is now an alias for
196 * The "set debug symtab-create" debugging option of GDB has been changed to
197 accept a verbosity level. 0 means "off", 1 provides basic debugging
198 output, and values of 2 or greater provides more verbose output.
200 * New command-line options
202 Display the details of GDB configure-time options.
204 * The command 'tsave' can now support new option '-ctf' to save trace
205 buffer in Common Trace Format.
207 * Newly installed $prefix/bin/gcore acts as a shell interface for the
210 * GDB now implements the the C++ 'typeid' operator.
212 * The new convenience variable $_exception holds the exception being
213 thrown or caught at an exception-related catchpoint.
215 * The exception-related catchpoints, like "catch throw", now accept a
216 regular expression which can be used to filter exceptions by type.
218 * The new convenience variable $_exitsignal is automatically set to
219 the terminating signal number when the program being debugged dies
220 due to an uncaught signal.
224 ** All MI commands now accept an optional "--language" option.
225 Support for this feature can be verified by using the "-list-features"
226 command, which should contain "language-option".
228 ** The new command -info-gdb-mi-command allows the user to determine
229 whether a GDB/MI command is supported or not.
231 ** The "^error" result record returned when trying to execute an undefined
232 GDB/MI command now provides a variable named "code" whose content is the
233 "undefined-command" error code. Support for this feature can be verified
234 by using the "-list-features" command, which should contain
235 "undefined-command-error-code".
237 ** The -trace-save MI command can optionally save trace buffer in Common
240 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
242 ** The command -data-list-register-values now accepts an optional
243 "--skip-unavailable" option. When used, only the available registers
246 ** The new command -trace-frame-collected dumps collected variables,
247 computed expressions, tvars, memory and registers in a traceframe.
249 ** The commands -stack-list-locals, -stack-list-arguments and
250 -stack-list-variables now accept an option "--skip-unavailable".
251 When used, only the available locals or arguments are displayed.
253 ** The -exec-run command now accepts an optional "--start" option.
254 When used, the command follows the same semantics as the "start"
255 command, stopping the program's execution at the start of its
256 main subprogram. Support for this feature can be verified using
257 the "-list-features" command, which should contain
258 "exec-run-start-option".
260 ** The new commands -catch-assert and -catch-exceptions insert
261 catchpoints stopping the program when Ada exceptions are raised.
263 ** The new command -info-ada-exceptions provides the equivalent of
264 the new "info exceptions" command.
266 * New system-wide configuration scripts
267 A GDB installation now provides scripts suitable for use as system-wide
268 configuration scripts for the following systems:
272 * GDB now supports target-assigned range stepping with remote targets.
273 This improves the performance of stepping source lines by reducing
274 the number of control packets from/to GDB. See "New remote packets"
277 * GDB now understands the element 'tvar' in the XML traceframe info.
278 It has the id of the collected trace state variables.
280 * On S/390 targets that provide the transactional-execution feature,
281 the program interruption transaction diagnostic block (TDB) is now
282 represented as a number of additional "registers" in GDB.
288 The vCont packet supports a new 'r' action, that tells the remote
289 stub to step through an address range itself, without GDB
290 involvemement at each single-step.
292 qXfer:libraries-svr4:read's annex
293 The previously unused annex of the qXfer:libraries-svr4:read packet
294 is now used to support passing an argument list. The remote stub
295 reports support for this argument list to GDB's qSupported query.
296 The defined arguments are "start" and "prev", used to reduce work
297 necessary for library list updating, resulting in significant
300 * New features in the GDB remote stub, GDBserver
302 ** GDBserver now supports target-assisted range stepping. Currently
303 enabled on x86/x86_64 GNU/Linux targets.
305 ** GDBserver now adds element 'tvar' in the XML in the reply to
306 'qXfer:traceframe-info:read'. It has the id of the collected
307 trace state variables.
309 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
312 * New 'z' formatter for printing and examining memory, this displays the
313 value as hexadecimal zero padded on the left to the size of the type.
315 * GDB can now use Windows x64 unwinding data.
317 * The "set remotebaud" command has been replaced by "set serial baud".
318 Similarly, "show remotebaud" has been replaced by "show serial baud".
319 The "set remotebaud" and "show remotebaud" commands are still available
320 to provide backward compatibility with older versions of GDB.
322 *** Changes in GDB 7.6
324 * Target record has been renamed to record-full.
325 Record/replay is now enabled with the "record full" command.
326 This also affects settings that are associated with full record/replay
327 that have been moved from "set/show record" to "set/show record full":
329 set|show record full insn-number-max
330 set|show record full stop-at-limit
331 set|show record full memory-query
333 * A new record target "record-btrace" has been added. The new target
334 uses hardware support to record the control-flow of a process. It
335 does not support replaying the execution, but it implements the
336 below new commands for investigating the recorded execution log.
337 This new recording method can be enabled using:
341 The "record-btrace" target is only available on Intel Atom processors
342 and requires a Linux kernel 2.6.32 or later.
344 * Two new commands have been added for record/replay to give information
345 about the recorded execution without having to replay the execution.
346 The commands are only supported by "record btrace".
348 record instruction-history prints the execution history at
349 instruction granularity
351 record function-call-history prints the execution history at
354 * New native configurations
356 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
357 FreeBSD/powerpc powerpc*-*-freebsd
358 x86_64/Cygwin x86_64-*-cygwin*
359 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
363 ARM AArch64 aarch64*-*-elf
364 ARM AArch64 GNU/Linux aarch64*-*-linux
365 Lynx 178 PowerPC powerpc-*-lynx*178
366 x86_64/Cygwin x86_64-*-cygwin*
367 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
369 * If the configured location of system.gdbinit file (as given by the
370 --with-system-gdbinit option at configure time) is in the
371 data-directory (as specified by --with-gdb-datadir at configure
372 time) or in one of its subdirectories, then GDB will look for the
373 system-wide init file in the directory specified by the
374 --data-directory command-line option.
376 * New command line options:
378 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
379 other initialization files, unlike -nx which disables all of them.
381 * Removed command line options
383 -epoch This was used by the gdb mode in Epoch, an ancient fork of
386 * The 'ptype' and 'whatis' commands now accept an argument to control
389 * 'info proc' now works on some core files.
393 ** Vectors can be created with gdb.Type.vector.
395 ** Python's atexit.register now works in GDB.
397 ** Types can be pretty-printed via a Python API.
399 ** Python 3 is now supported (in addition to Python 2.4 or later)
401 ** New class gdb.Architecture exposes GDB's internal representation
402 of architecture in the Python API.
404 ** New method Frame.architecture returns the gdb.Architecture object
405 corresponding to the frame's architecture.
407 * New Python-based convenience functions:
409 ** $_memeq(buf1, buf2, length)
410 ** $_streq(str1, str2)
412 ** $_regex(str, regex)
414 * The 'cd' command now defaults to using '~' (the home directory) if not
417 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
418 default for GCC since November 2000.
420 * The command 'forward-search' can now be abbreviated as 'fo'.
422 * The command 'info tracepoints' can now display 'installed on target'
423 or 'not installed on target' for each non-pending location of tracepoint.
425 * New configure options
427 --enable-libmcheck/--disable-libmcheck
428 By default, development versions are built with -lmcheck on hosts
429 that support it, in order to help track memory corruption issues.
430 Release versions, on the other hand, are built without -lmcheck
431 by default. The --enable-libmcheck/--disable-libmcheck configure
432 options allow the user to override that default.
433 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
434 This configure option allows the user to build GDB with
435 libbabeltrace using which GDB can read Common Trace Format data.
437 * New commands (for set/show, see "New options" below)
440 Catch signals. This is similar to "handle", but allows commands and
441 conditions to be attached.
444 List the BFDs known to GDB.
446 python-interactive [command]
448 Start a Python interactive prompt, or evaluate the optional command
449 and print the result of expressions.
452 "py" is a new alias for "python".
454 enable type-printer [name]...
455 disable type-printer [name]...
456 Enable or disable type printers.
460 ** For the Renesas Super-H architecture, the "regs" command has been removed
461 (has been deprecated in GDB 7.5), and "info all-registers" should be used
466 set print type methods (on|off)
467 show print type methods
468 Control whether method declarations are displayed by "ptype".
469 The default is to show them.
471 set print type typedefs (on|off)
472 show print type typedefs
473 Control whether typedef definitions are displayed by "ptype".
474 The default is to show them.
476 set filename-display basename|relative|absolute
477 show filename-display
478 Control the way in which filenames is displayed.
479 The default is "relative", which preserves previous behavior.
481 set trace-buffer-size
482 show trace-buffer-size
483 Request target to change the size of trace buffer.
485 set remote trace-buffer-size-packet auto|on|off
486 show remote trace-buffer-size-packet
487 Control the use of the remote protocol `QTBuffer:size' packet.
491 Control display of debugging messages related to ARM AArch64.
494 set debug coff-pe-read
495 show debug coff-pe-read
496 Control display of debugging messages related to reading of COFF/PE
501 Control display of debugging messages related to Mach-O symbols
504 set debug notification
505 show debug notification
506 Control display of debugging info for async remote notification.
510 ** Command parameter changes are now notified using new async record
511 "=cmd-param-changed".
512 ** Trace frame changes caused by command "tfind" are now notified using
513 new async record "=traceframe-changed".
514 ** The creation, deletion and modification of trace state variables
515 are now notified using new async records "=tsv-created",
516 "=tsv-deleted" and "=tsv-modified".
517 ** The start and stop of process record are now notified using new
518 async record "=record-started" and "=record-stopped".
519 ** Memory changes are now notified using new async record
521 ** The data-disassemble command response will include a "fullname" field
522 containing the absolute file name when source has been requested.
523 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
524 command, to allow pattern filling of memory areas.
525 ** New commands "-catch-load"/"-catch-unload" added for intercepting
526 library load/unload events.
527 ** The response to breakpoint commands and breakpoint async records
528 includes an "installed" field containing a boolean state about each
529 non-pending tracepoint location is whether installed on target or not.
530 ** Output of the "-trace-status" command includes a "trace-file" field
531 containing the name of the trace file being examined. This field is
532 optional, and only present when examining a trace file.
533 ** The "fullname" field is now always present along with the "file" field,
534 even if the file cannot be found by GDB.
536 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
537 You must have the LZMA library available when configuring GDB for this
538 feature to be enabled. For more information, see:
539 http://fedoraproject.org/wiki/Features/MiniDebugInfo
544 Set the size of trace buffer. The remote stub reports support for this
545 packet to gdb's qSupported query.
548 Enable Branch Trace Store (BTS)-based branch tracing for the current
549 thread. The remote stub reports support for this packet to gdb's
553 Disable branch tracing for the current thread. The remote stub reports
554 support for this packet to gdb's qSupported query.
557 Read the traced branches for the current thread. The remote stub
558 reports support for this packet to gdb's qSupported query.
560 *** Changes in GDB 7.5
562 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
563 for more x32 ABI info.
565 * GDB now supports access to MIPS DSP registers on Linux targets.
567 * GDB now supports debugging microMIPS binaries.
569 * The "info os" command on GNU/Linux can now display information on
570 several new classes of objects managed by the operating system:
571 "info os procgroups" lists process groups
572 "info os files" lists file descriptors
573 "info os sockets" lists internet-domain sockets
574 "info os shm" lists shared-memory regions
575 "info os semaphores" lists semaphores
576 "info os msg" lists message queues
577 "info os modules" lists loaded kernel modules
579 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
580 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
581 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
582 options and inspect the probe arguments using the new $_probe_arg family
583 of convenience variables. You can obtain more information about SystemTap
584 in <http://sourceware.org/systemtap/>.
586 * GDB now supports reversible debugging on ARM, it allows you to
587 debug basic ARM and THUMB instructions, and provides
588 record/replay support.
590 * The option "symbol-reloading" has been deleted as it is no longer used.
594 ** GDB commands implemented in Python can now be put in command class
597 ** The "maint set python print-stack on|off" is now deleted.
599 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
600 apply "flag enum"-style pretty-printing to any enum.
602 ** gdb.lookup_symbol can now work when there is no current frame.
604 ** gdb.Symbol now has a 'line' attribute, holding the line number in
605 the source at which the symbol was defined.
607 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
608 method 'value'. The former indicates whether the symbol needs a
609 frame in order to compute its value, and the latter computes the
612 ** A new method 'referenced_value' on gdb.Value objects which can
613 dereference pointer as well as C++ reference values.
615 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
616 which return the global and static blocks (as gdb.Block objects),
617 of the underlying symbol table, respectively.
619 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
620 object associated with a PC value.
622 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
623 of the address range occupied by code for the current source line.
625 * Go language support.
626 GDB now supports debugging programs written in the Go programming
629 * GDBserver now supports stdio connections.
630 E.g. (gdb) target remote | ssh myhost gdbserver - hello
632 * The binary "gdbtui" can no longer be built or installed.
633 Use "gdb -tui" instead.
635 * GDB will now print "flag" enums specially. A flag enum is one where
636 all the enumerator values have no bits in common when pairwise
637 "and"ed. When printing a value whose type is a flag enum, GDB will
638 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
639 (gdb) print (enum E) 3
642 * The filename part of a linespec will now match trailing components
643 of a source file name. For example, "break gcc/expr.c:1000" will
644 now set a breakpoint in build/gcc/expr.c, but not
647 * The "info proc" and "generate-core-file" commands will now also
648 work on remote targets connected to GDBserver on Linux.
650 * The command "info catch" has been removed. It has been disabled
653 * The "catch exception" and "catch assert" commands now accept
654 a condition at the end of the command, much like the "break"
655 command does. For instance:
657 (gdb) catch exception Constraint_Error if Barrier = True
659 Previously, it was possible to add a condition to such catchpoints,
660 but it had to be done as a second step, after the catchpoint had been
661 created, using the "condition" command.
663 * The "info static-tracepoint-marker" command will now also work on
664 native Linux targets with in-process agent.
666 * GDB can now set breakpoints on inlined functions.
668 * The .gdb_index section has been updated to include symbols for
669 inlined functions. GDB will ignore older .gdb_index sections by
670 default, which could cause symbol files to be loaded more slowly
671 until their .gdb_index sections can be recreated. The new command
672 "set use-deprecated-index-sections on" will cause GDB to use any older
673 .gdb_index sections it finds. This will restore performance, but the
674 ability to set breakpoints on inlined functions will be lost in symbol
675 files with older .gdb_index sections.
677 The .gdb_index section has also been updated to record more information
678 about each symbol. This speeds up the "info variables", "info functions"
679 and "info types" commands when used with programs having the .gdb_index
680 section, as well as speeding up debugging with shared libraries using
681 the .gdb_index section.
683 * Ada support for GDB/MI Variable Objects has been added.
685 * GDB can now support 'breakpoint always-inserted mode' in 'record'
690 ** New command -info-os is the MI equivalent of "info os".
692 ** Output logs ("set logging" and related) now include MI output.
696 ** "set use-deprecated-index-sections on|off"
697 "show use-deprecated-index-sections on|off"
698 Controls the use of deprecated .gdb_index sections.
700 ** "catch load" and "catch unload" can be used to stop when a shared
701 library is loaded or unloaded, respectively.
703 ** "enable count" can be used to auto-disable a breakpoint after
706 ** "info vtbl" can be used to show the virtual method tables for
707 C++ and Java objects.
709 ** "explore" and its sub commands "explore value" and "explore type"
710 can be used to recursively explore values and types of
711 expressions. These commands are available only if GDB is
712 configured with '--with-python'.
714 ** "info auto-load" shows status of all kinds of auto-loaded files,
715 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
716 sequences of commands files, "info auto-load python-scripts"
717 shows status of auto-loading Python script files,
718 "info auto-load local-gdbinit" shows status of loading init file
719 (.gdbinit) from current directory and "info auto-load libthread-db" shows
720 status of inferior specific thread debugging shared library loading.
722 ** "info auto-load-scripts", "set auto-load-scripts on|off"
723 and "show auto-load-scripts" commands have been deprecated, use their
724 "info auto-load python-scripts", "set auto-load python-scripts on|off"
725 and "show auto-load python-scripts" counterparts instead.
727 ** "dprintf location,format,args..." creates a dynamic printf, which
728 is basically a breakpoint that does a printf and immediately
729 resumes your program's execution, so it is like a printf that you
730 can insert dynamically at runtime instead of at compiletime.
732 ** "set print symbol"
734 Controls whether GDB attempts to display the symbol, if any,
735 corresponding to addresses it prints. This defaults to "on", but
736 you can set it to "off" to restore GDB's previous behavior.
738 * Deprecated commands
740 ** For the Renesas Super-H architecture, the "regs" command has been
741 deprecated, and "info all-registers" should be used instead.
745 Renesas RL78 rl78-*-elf
746 HP OpenVMS ia64 ia64-hp-openvms*
748 * GDBserver supports evaluation of breakpoint conditions. When
749 support is advertised by GDBserver, GDB may be told to send the
750 breakpoint conditions in bytecode form to GDBserver. GDBserver
751 will only report the breakpoint trigger to GDB when its condition
757 show mips compression
758 Select the compressed ISA encoding used in functions that have no symbol
759 information available. The encoding can be set to either of:
762 and is updated automatically from ELF file flags if available.
764 set breakpoint condition-evaluation
765 show breakpoint condition-evaluation
766 Control whether breakpoint conditions are evaluated by GDB ("host") or by
767 GDBserver ("target"). Default option "auto" chooses the most efficient
769 This option can improve debugger efficiency depending on the speed of the
773 Disable auto-loading globally.
776 Show auto-loading setting of all kinds of auto-loaded files.
778 set auto-load gdb-scripts on|off
779 show auto-load gdb-scripts
780 Control auto-loading of GDB canned sequences of commands files.
782 set auto-load python-scripts on|off
783 show auto-load python-scripts
784 Control auto-loading of Python script files.
786 set auto-load local-gdbinit on|off
787 show auto-load local-gdbinit
788 Control loading of init file (.gdbinit) from current directory.
790 set auto-load libthread-db on|off
791 show auto-load libthread-db
792 Control auto-loading of inferior specific thread debugging shared library.
794 set auto-load scripts-directory <dir1>[:<dir2>...]
795 show auto-load scripts-directory
796 Set a list of directories from which to load auto-loaded scripts.
797 Automatically loaded Python scripts and GDB scripts are located in one
798 of the directories listed by this option.
799 The delimiter (':' above) may differ according to the host platform.
801 set auto-load safe-path <dir1>[:<dir2>...]
802 show auto-load safe-path
803 Set a list of directories from which it is safe to auto-load files.
804 The delimiter (':' above) may differ according to the host platform.
806 set debug auto-load on|off
808 Control display of debugging info for auto-loading the files above.
810 set dprintf-style gdb|call|agent
812 Control the way in which a dynamic printf is performed; "gdb"
813 requests a GDB printf command, while "call" causes dprintf to call a
814 function in the inferior. "agent" requests that the target agent
815 (such as GDBserver) do the printing.
817 set dprintf-function <expr>
818 show dprintf-function
819 set dprintf-channel <expr>
821 Set the function and optional first argument to the call when using
822 the "call" style of dynamic printf.
824 set disconnected-dprintf on|off
825 show disconnected-dprintf
826 Control whether agent-style dynamic printfs continue to be in effect
827 after GDB disconnects.
829 * New configure options
832 Configure default value for the 'set auto-load scripts-directory'
833 setting above. It defaults to '$debugdir:$datadir/auto-load',
834 $debugdir representing global debugging info directories (available
835 via 'show debug-file-directory') and $datadir representing GDB's data
836 directory (available via 'show data-directory').
838 --with-auto-load-safe-path
839 Configure default value for the 'set auto-load safe-path' setting
840 above. It defaults to the --with-auto-load-dir setting.
842 --without-auto-load-safe-path
843 Set 'set auto-load safe-path' to '/', effectively disabling this
848 z0/z1 conditional breakpoints extension
850 The z0/z1 breakpoint insertion packets have been extended to carry
851 a list of conditional expressions over to the remote stub depending on the
852 condition evaluation mode. The use of this extension can be controlled
853 via the "set remote conditional-breakpoints-packet" command.
857 Specify the signals which the remote stub may pass to the debugged
858 program without GDB involvement.
860 * New command line options
862 --init-command=FILE, -ix Like --command, -x but execute it
863 before loading inferior.
864 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
865 execute it before loading inferior.
867 *** Changes in GDB 7.4
869 * GDB now handles ambiguous linespecs more consistently; the existing
870 FILE:LINE support has been expanded to other types of linespecs. A
871 breakpoint will now be set on all matching locations in all
872 inferiors, and locations will be added or removed according to
875 * GDB now allows you to skip uninteresting functions and files when
876 stepping with the "skip function" and "skip file" commands.
878 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
879 and "show remote hardware-watchpoint-length-limit". These allows to
880 set or show the maximum length limit (in bytes) of a remote
881 target hardware watchpoint.
883 This allows e.g. to use "unlimited" hardware watchpoints with the
884 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
885 watchpoints are slower than real hardware watchpoints but are
886 significantly faster than gdb software watchpoints.
890 ** The register_pretty_printer function in module gdb.printing now takes
891 an optional `replace' argument. If True, the new printer replaces any
894 ** The "maint set python print-stack on|off" command has been
895 deprecated and will be deleted in GDB 7.5.
896 A new command: "set python print-stack none|full|message" has
897 replaced it. Additionally, the default for "print-stack" is
898 now "message", which just prints the error message without
901 ** A prompt substitution hook (prompt_hook) is now available to the
904 ** A new Python module, gdb.prompt has been added to the GDB Python
905 modules library. This module provides functionality for
906 escape sequences in prompts (used by set/show
907 extended-prompt). These escape sequences are replaced by their
910 ** Python commands and convenience-functions located in
911 'data-directory'/python/gdb/command and
912 'data-directory'/python/gdb/function are now automatically loaded
915 ** Blocks now provide four new attributes. global_block and
916 static_block will return the global and static blocks
917 respectively. is_static and is_global are boolean attributes
918 that indicate if the block is one of those two types.
920 ** Symbols now provide the "type" attribute, the type of the symbol.
922 ** The "gdb.breakpoint" function has been deprecated in favor of
925 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
926 of a function. This class is based on the "finish" command
927 available in the CLI.
929 ** Type objects for struct and union types now allow access to
930 the fields using standard Python dictionary (mapping) methods.
931 For example, "some_type['myfield']" now works, as does
934 ** A new event "gdb.new_objfile" has been added, triggered by loading a
937 ** A new function, "deep_items" has been added to the gdb.types
938 module in the GDB Python modules library. This function returns
939 an iterator over the fields of a struct or union type. Unlike
940 the standard Python "iteritems" method, it will recursively traverse
941 any anonymous fields.
945 ** "*stopped" events can report several new "reason"s, such as
948 ** Breakpoint changes are now notified using new async records, like
949 "=breakpoint-modified".
951 ** New command -ada-task-info.
953 * libthread-db-search-path now supports two special values: $sdir and $pdir.
954 $sdir specifies the default system locations of shared libraries.
955 $pdir specifies the directory where the libpthread used by the application
958 GDB no longer looks in $sdir and $pdir after it has searched the directories
959 mentioned in libthread-db-search-path. If you want to search those
960 directories, they must be specified in libthread-db-search-path.
961 The default value of libthread-db-search-path on GNU/Linux and Solaris
962 systems is now "$sdir:$pdir".
964 $pdir is not supported by gdbserver, it is currently ignored.
965 $sdir is supported by gdbserver.
967 * New configure option --with-iconv-bin.
968 When using the internationalization support like the one in the GNU C
969 library, GDB will invoke the "iconv" program to get a list of supported
970 character sets. If this program lives in a non-standard location, one can
971 use this option to specify where to find it.
973 * When natively debugging programs on PowerPC BookE processors running
974 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
975 watchpoints, which specify a mask in addition to an address to watch.
976 The mask specifies that some bits of an address (the bits which are
977 reset in the mask) should be ignored when matching the address accessed
978 by the inferior against the watchpoint address. See the "PowerPC Embedded"
979 section in the user manual for more details.
981 * The new option --once causes GDBserver to stop listening for connections once
982 the first connection is made. The listening port used by GDBserver will
983 become available after that.
985 * New commands "info macros" and "alias" have been added.
987 * New function parameters suffix @entry specifies value of function parameter
988 at the time the function got called. Entry values are available only since
994 "!" is now an alias of the "shell" command.
995 Note that no space is needed between "!" and SHELL COMMAND.
999 watch EXPRESSION mask MASK_VALUE
1000 The watch command now supports the mask argument which allows creation
1001 of masked watchpoints, if the current architecture supports this feature.
1003 info auto-load-scripts [REGEXP]
1004 This command was formerly named "maintenance print section-scripts".
1005 It is now generally useful and is no longer a maintenance-only command.
1007 info macro [-all] [--] MACRO
1008 The info macro command has new options `-all' and `--'. The first for
1009 printing all definitions of a macro. The second for explicitly specifying
1010 the end of arguments and the beginning of the macro name in case the macro
1011 name starts with a hyphen.
1013 collect[/s] EXPRESSIONS
1014 The tracepoint collect command now takes an optional modifier "/s"
1015 that directs it to dereference pointer-to-character types and
1016 collect the bytes of memory up to a zero byte. The behavior is
1017 similar to what you see when you use the regular print command on a
1018 string. An optional integer following the "/s" sets a bound on the
1019 number of bytes that will be collected.
1022 The trace start command now interprets any supplied arguments as a
1023 note to be recorded with the trace run, with an effect similar to
1024 setting the variable trace-notes.
1027 The trace stop command now interprets any arguments as a note to be
1028 mentioned along with the tstatus report that the trace was stopped
1029 with a command. The effect is similar to setting the variable
1032 * Tracepoints can now be enabled and disabled at any time after a trace
1033 experiment has been started using the standard "enable" and "disable"
1034 commands. It is now possible to start a trace experiment with no enabled
1035 tracepoints; GDB will display a warning, but will allow the experiment to
1036 begin, assuming that tracepoints will be enabled as needed while the trace
1039 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1040 locations with 4-byte instructions, when they were previously
1041 limited to locations with instructions of 5 bytes or longer.
1045 set debug dwarf2-read
1046 show debug dwarf2-read
1047 Turns on or off display of debugging messages related to reading
1048 DWARF debug info. The default is off.
1050 set debug symtab-create
1051 show debug symtab-create
1052 Turns on or off display of debugging messages related to symbol table
1053 creation. The default is off.
1056 show extended-prompt
1057 Set the GDB prompt, and allow escape sequences to be inserted to
1058 display miscellaneous information (see 'help set extended-prompt'
1059 for the list of sequences). This prompt (and any information
1060 accessed through the escape sequences) is updated every time the
1061 prompt is displayed.
1063 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1064 show print entry-values
1065 Set printing of frame argument values at function entry. In some cases
1066 GDB can determine the value of function argument which was passed by the
1067 function caller, even if the value was modified inside the called function.
1069 set debug entry-values
1070 show debug entry-values
1071 Control display of debugging info for determining frame argument values at
1072 function entry and virtual tail call frames.
1074 set basenames-may-differ
1075 show basenames-may-differ
1076 Set whether a source file may have multiple base names.
1077 (A "base name" is the name of a file with the directory part removed.
1078 Example: The base name of "/home/user/hello.c" is "hello.c".)
1079 If set, GDB will canonicalize file names (e.g., expand symlinks)
1080 before comparing them. Canonicalization is an expensive operation,
1081 but it allows the same file be known by more than one base name.
1082 If not set (the default), all source files are assumed to have just
1083 one base name, and gdb will do file name comparisons more efficiently.
1089 Set a user name and notes for the current and any future trace runs.
1090 This is useful for long-running and/or disconnected traces, to
1091 inform others (or yourself) as to who is running the trace, supply
1092 contact information, or otherwise explain what is going on.
1094 set trace-stop-notes
1095 show trace-stop-notes
1096 Set a note attached to the trace run, that is displayed when the
1097 trace has been stopped by a tstop command. This is useful for
1098 instance as an explanation, if you are stopping a trace run that was
1099 started by someone else.
1101 * New remote packets
1105 Dynamically enable a tracepoint in a started trace experiment.
1109 Dynamically disable a tracepoint in a started trace experiment.
1113 Set the user and notes of the trace run.
1117 Query the current status of a tracepoint.
1121 Query the minimum length of instruction at which a fast tracepoint may
1124 * Dcache size (number of lines) and line-size are now runtime-configurable
1125 via "set dcache line" and "set dcache line-size" commands.
1129 Texas Instruments TMS320C6x tic6x-*-*
1133 Renesas RL78 rl78-*-elf
1135 *** Changes in GDB 7.3.1
1137 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1139 *** Changes in GDB 7.3
1141 * GDB has a new command: "thread find [REGEXP]".
1142 It finds the thread id whose name, target id, or thread extra info
1143 matches the given regular expression.
1145 * The "catch syscall" command now works on mips*-linux* targets.
1147 * The -data-disassemble MI command now supports modes 2 and 3 for
1148 dumping the instruction opcodes.
1150 * New command line options
1152 -data-directory DIR Specify DIR as the "data-directory".
1153 This is mostly for testing purposes.
1155 * The "maint set python auto-load on|off" command has been renamed to
1156 "set auto-load-scripts on|off".
1158 * GDB has a new command: "set directories".
1159 It is like the "dir" command except that it replaces the
1160 source path list instead of augmenting it.
1162 * GDB now understands thread names.
1164 On GNU/Linux, "info threads" will display the thread name as set by
1165 prctl or pthread_setname_np.
1167 There is also a new command, "thread name", which can be used to
1168 assign a name internally for GDB to display.
1171 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1172 has been integrated into GDB.
1176 ** The function gdb.Write now accepts an optional keyword 'stream'.
1177 This keyword, when provided, will direct the output to either
1178 stdout, stderr, or GDB's logging output.
1180 ** Parameters can now be be sub-classed in Python, and in particular
1181 you may implement the get_set_doc and get_show_doc functions.
1182 This improves how Parameter set/show documentation is processed
1183 and allows for more dynamic content.
1185 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1186 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1187 have an is_valid method.
1189 ** Breakpoints can now be sub-classed in Python, and in particular
1190 you may implement a 'stop' function that is executed each time
1191 the inferior reaches that breakpoint.
1193 ** New function gdb.lookup_global_symbol looks up a global symbol.
1195 ** GDB values in Python are now callable if the value represents a
1196 function. For example, if 'some_value' represents a function that
1197 takes two integer parameters and returns a value, you can call
1198 that function like so:
1200 result = some_value (10,20)
1202 ** Module gdb.types has been added.
1203 It contains a collection of utilities for working with gdb.Types objects:
1204 get_basic_type, has_field, make_enum_dict.
1206 ** Module gdb.printing has been added.
1207 It contains utilities for writing and registering pretty-printers.
1208 New classes: PrettyPrinter, SubPrettyPrinter,
1209 RegexpCollectionPrettyPrinter.
1210 New function: register_pretty_printer.
1212 ** New commands "info pretty-printers", "enable pretty-printer" and
1213 "disable pretty-printer" have been added.
1215 ** gdb.parameter("directories") is now available.
1217 ** New function gdb.newest_frame returns the newest frame in the
1220 ** The gdb.InferiorThread class has a new "name" attribute. This
1221 holds the thread's name.
1223 ** Python Support for Inferior events.
1224 Python scripts can add observers to be notified of events
1225 occurring in the process being debugged.
1226 The following events are currently supported:
1227 - gdb.events.cont Continue event.
1228 - gdb.events.exited Inferior exited event.
1229 - gdb.events.stop Signal received, and Breakpoint hit events.
1233 ** GDB now puts template parameters in scope when debugging in an
1234 instantiation. For example, if you have:
1236 template<int X> int func (void) { return X; }
1238 then if you step into func<5>, "print X" will show "5". This
1239 feature requires proper debuginfo support from the compiler; it
1240 was added to GCC 4.5.
1242 ** The motion commands "next", "finish", "until", and "advance" now
1243 work better when exceptions are thrown. In particular, GDB will
1244 no longer lose control of the inferior; instead, the GDB will
1245 stop the inferior at the point at which the exception is caught.
1246 This functionality requires a change in the exception handling
1247 code that was introduced in GCC 4.5.
1249 * GDB now follows GCC's rules on accessing volatile objects when
1250 reading or writing target state during expression evaluation.
1251 One notable difference to prior behavior is that "print x = 0"
1252 no longer generates a read of x; the value of the assignment is
1253 now always taken directly from the value being assigned.
1255 * GDB now has some support for using labels in the program's source in
1256 linespecs. For instance, you can use "advance label" to continue
1257 execution to a label.
1259 * GDB now has support for reading and writing a new .gdb_index
1260 section. This section holds a fast index of DWARF debugging
1261 information and can be used to greatly speed up GDB startup and
1262 operation. See the documentation for `save gdb-index' for details.
1264 * The "watch" command now accepts an optional "-location" argument.
1265 When used, this causes GDB to watch the memory referred to by the
1266 expression. Such a watchpoint is never deleted due to it going out
1269 * GDB now supports thread debugging of core dumps on GNU/Linux.
1271 GDB now activates thread debugging using the libthread_db library
1272 when debugging GNU/Linux core dumps, similarly to when debugging
1273 live processes. As a result, when debugging a core dump file, GDB
1274 is now able to display pthread_t ids of threads. For example, "info
1275 threads" shows the same output as when debugging the process when it
1276 was live. In earlier releases, you'd see something like this:
1279 * 1 LWP 6780 main () at main.c:10
1281 While now you see this:
1284 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1286 It is also now possible to inspect TLS variables when debugging core
1289 When debugging a core dump generated on a machine other than the one
1290 used to run GDB, you may need to point GDB at the correct
1291 libthread_db library with the "set libthread-db-search-path"
1292 command. See the user manual for more details on this command.
1294 * When natively debugging programs on PowerPC BookE processors running
1295 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1296 which stop execution of the inferior whenever it executes an instruction
1297 at any address within the specified range. See the "PowerPC Embedded"
1298 section in the user manual for more details.
1300 * New features in the GDB remote stub, GDBserver
1302 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1303 and i686 LynxOS (version 5.x).
1305 ** GDBserver is now supported on Blackfin Linux.
1307 * New native configurations
1309 ia64 HP-UX ia64-*-hpux*
1313 Analog Devices, Inc. Blackfin Processor bfin-*
1315 * Ada task switching is now supported on sparc-elf targets when
1316 debugging a program using the Ravenscar Profile. For more information,
1317 see the "Tasking Support when using the Ravenscar Profile" section
1318 in the GDB user manual.
1320 * Guile support was removed.
1322 * New features in the GNU simulator
1324 ** The --map-info flag lists all known core mappings.
1326 ** CFI flashes may be simulated via the "cfi" device.
1328 *** Changes in GDB 7.2
1330 * Shared library support for remote targets by default
1332 When GDB is configured for a generic, non-OS specific target, like
1333 for example, --target=arm-eabi or one of the many *-*-elf targets,
1334 GDB now queries remote stubs for loaded shared libraries using the
1335 `qXfer:libraries:read' packet. Previously, shared library support
1336 was always disabled for such configurations.
1340 ** Argument Dependent Lookup (ADL)
1342 In C++ ADL lookup directs function search to the namespaces of its
1343 arguments even if the namespace has not been imported.
1353 Here the compiler will search for `foo' in the namespace of 'b'
1354 and find A::foo. GDB now supports this. This construct is commonly
1355 used in the Standard Template Library for operators.
1357 ** Improved User Defined Operator Support
1359 In addition to member operators, GDB now supports lookup of operators
1360 defined in a namespace and imported with a `using' directive, operators
1361 defined in the global scope, operators imported implicitly from an
1362 anonymous namespace, and the ADL operators mentioned in the previous
1364 GDB now also supports proper overload resolution for all the previously
1365 mentioned flavors of operators.
1367 ** static const class members
1369 Printing of static const class members that are initialized in the
1370 class definition has been fixed.
1372 * Windows Thread Information Block access.
1374 On Windows targets, GDB now supports displaying the Windows Thread
1375 Information Block (TIB) structure. This structure is visible either
1376 by using the new command `info w32 thread-information-block' or, by
1377 dereferencing the new convenience variable named `$_tlb', a
1378 thread-specific pointer to the TIB. This feature is also supported
1379 when remote debugging using GDBserver.
1381 * Static tracepoints
1383 Static tracepoints are calls in the user program into a tracing
1384 library. One such library is a port of the LTTng kernel tracer to
1385 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1386 When debugging with GDBserver, GDB now supports combining the GDB
1387 tracepoint machinery with such libraries. For example: the user can
1388 use GDB to probe a static tracepoint marker (a call from the user
1389 program into the tracing library) with the new "strace" command (see
1390 "New commands" below). This creates a "static tracepoint" in the
1391 breakpoint list, that can be manipulated with the same feature set
1392 as fast and regular tracepoints. E.g., collect registers, local and
1393 global variables, collect trace state variables, and define
1394 tracepoint conditions. In addition, the user can collect extra
1395 static tracepoint marker specific data, by collecting the new
1396 $_sdata internal variable. When analyzing the trace buffer, you can
1397 inspect $_sdata like any other variable available to GDB. For more
1398 information, see the "Tracepoints" chapter in GDB user manual. New
1399 remote packets have been defined to support static tracepoints, see
1400 the "New remote packets" section below.
1402 * Better reconstruction of tracepoints after disconnected tracing
1404 GDB will attempt to download the original source form of tracepoint
1405 definitions when starting a trace run, and then will upload these
1406 upon reconnection to the target, resulting in a more accurate
1407 reconstruction of the tracepoints that are in use on the target.
1411 You can now exercise direct control over the ways that GDB can
1412 affect your program. For instance, you can disallow the setting of
1413 breakpoints, so that the program can run continuously (assuming
1414 non-stop mode). In addition, the "observer" variable is available
1415 to switch all of the different controls; in observer mode, GDB
1416 cannot affect the target's behavior at all, which is useful for
1417 tasks like diagnosing live systems in the field.
1419 * The new convenience variable $_thread holds the number of the
1422 * New remote packets
1426 Return the address of the Windows Thread Information Block of a given thread.
1430 In response to several of the tracepoint packets, the target may now
1431 also respond with a number of intermediate `qRelocInsn' request
1432 packets before the final result packet, to have GDB handle
1433 relocating an instruction to execute at a different address. This
1434 is particularly useful for stubs that support fast tracepoints. GDB
1435 reports support for this feature in the qSupported packet.
1439 List static tracepoint markers in the target program.
1443 List static tracepoint markers at a given address in the target
1446 qXfer:statictrace:read
1448 Read the static trace data collected (by a `collect $_sdata'
1449 tracepoint action). The remote stub reports support for this packet
1450 to gdb's qSupported query.
1454 Send the current settings of GDB's permission flags.
1458 Send part of the source (textual) form of a tracepoint definition,
1459 which includes location, conditional, and action list.
1461 * The source command now accepts a -s option to force searching for the
1462 script in the source search path even if the script name specifies
1465 * New features in the GDB remote stub, GDBserver
1467 - GDBserver now support tracepoints (including fast tracepoints, and
1468 static tracepoints). The feature is currently supported by the
1469 i386-linux and amd64-linux builds. See the "Tracepoints support
1470 in gdbserver" section in the manual for more information.
1472 GDBserver JIT compiles the tracepoint's conditional agent
1473 expression bytecode into native code whenever possible for low
1474 overhead dynamic tracepoints conditionals. For such tracepoints,
1475 an expression that examines program state is evaluated when the
1476 tracepoint is reached, in order to determine whether to capture
1477 trace data. If the condition is simple and false, processing the
1478 tracepoint finishes very quickly and no data is gathered.
1480 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1481 for static tracepoints support.
1483 - GDBserver now supports x86_64 Windows 64-bit debugging.
1485 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1486 it understands register description.
1488 * The --batch flag now disables pagination and queries.
1490 * X86 general purpose registers
1492 GDB now supports reading/writing byte, word and double-word x86
1493 general purpose registers directly. This means you can use, say,
1494 $ah or $ax to refer, respectively, to the byte register AH and
1495 16-bit word register AX that are actually portions of the 32-bit
1496 register EAX or 64-bit register RAX.
1498 * The `commands' command now accepts a range of breakpoints to modify.
1499 A plain `commands' following a command that creates multiple
1500 breakpoints affects all the breakpoints set by that command. This
1501 applies to breakpoints set by `rbreak', and also applies when a
1502 single `break' command creates multiple breakpoints (e.g.,
1503 breakpoints on overloaded c++ functions).
1505 * The `rbreak' command now accepts a filename specification as part of
1506 its argument, limiting the functions selected by the regex to those
1507 in the specified file.
1509 * Support for remote debugging Windows and SymbianOS shared libraries
1510 from Unix hosts has been improved. Non Windows GDB builds now can
1511 understand target reported file names that follow MS-DOS based file
1512 system semantics, such as file names that include drive letters and
1513 use the backslash character as directory separator. This makes it
1514 possible to transparently use the "set sysroot" and "set
1515 solib-search-path" on Unix hosts to point as host copies of the
1516 target's shared libraries. See the new command "set
1517 target-file-system-kind" described below, and the "Commands to
1518 specify files" section in the user manual for more information.
1522 eval template, expressions...
1523 Convert the values of one or more expressions under the control
1524 of the string template to a command line, and call it.
1526 set target-file-system-kind unix|dos-based|auto
1527 show target-file-system-kind
1528 Set or show the assumed file system kind for target reported file
1531 save breakpoints <filename>
1532 Save all current breakpoint definitions to a file suitable for use
1533 in a later debugging session. To read the saved breakpoint
1534 definitions, use the `source' command.
1536 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1539 info static-tracepoint-markers
1540 Display information about static tracepoint markers in the target.
1542 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1543 Define a static tracepoint by probing a marker at the given
1544 function, line, address, or marker ID.
1548 Enable and disable observer mode.
1550 set may-write-registers on|off
1551 set may-write-memory on|off
1552 set may-insert-breakpoints on|off
1553 set may-insert-tracepoints on|off
1554 set may-insert-fast-tracepoints on|off
1555 set may-interrupt on|off
1556 Set individual permissions for GDB effects on the target. Note that
1557 some of these settings can have undesirable or surprising
1558 consequences, particularly when changed in the middle of a session.
1559 For instance, disabling the writing of memory can prevent
1560 breakpoints from being inserted, cause single-stepping to fail, or
1561 even crash your program, if you disable after breakpoints have been
1562 inserted. However, GDB should not crash.
1564 set record memory-query on|off
1565 show record memory-query
1566 Control whether to stop the inferior if memory changes caused
1567 by an instruction cannot be recorded.
1572 The disassemble command now supports "start,+length" form of two arguments.
1576 ** GDB now provides a new directory location, called the python directory,
1577 where Python scripts written for GDB can be installed. The location
1578 of that directory is <data-directory>/python, where <data-directory>
1579 is the GDB data directory. For more details, see section `Scripting
1580 GDB using Python' in the manual.
1582 ** The GDB Python API now has access to breakpoints, symbols, symbol
1583 tables, program spaces, inferiors, threads and frame's code blocks.
1584 Additionally, GDB Parameters can now be created from the API, and
1585 manipulated via set/show in the CLI.
1587 ** New functions gdb.target_charset, gdb.target_wide_charset,
1588 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1590 ** New exception gdb.GdbError.
1592 ** Pretty-printers are now also looked up in the current program space.
1594 ** Pretty-printers can now be individually enabled and disabled.
1596 ** GDB now looks for names of Python scripts to auto-load in a
1597 special section named `.debug_gdb_scripts', in addition to looking
1598 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1600 * Tracepoint actions were unified with breakpoint commands. In particular,
1601 there are no longer differences in "info break" output for breakpoints and
1602 tracepoints and the "commands" command can be used for both tracepoints and
1603 regular breakpoints.
1607 ARM Symbian arm*-*-symbianelf*
1609 * D language support.
1610 GDB now supports debugging programs written in the D programming
1613 * GDB now supports the extended ptrace interface for PowerPC which is
1614 available since Linux kernel version 2.6.34. This automatically enables
1615 any hardware breakpoints and additional hardware watchpoints available in
1616 the processor. The old ptrace interface exposes just one hardware
1617 watchpoint and no hardware breakpoints.
1619 * GDB is now able to use the Data Value Compare (DVC) register available on
1620 embedded PowerPC processors to implement in hardware simple watchpoint
1621 conditions of the form:
1623 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1625 This works in native GDB running on Linux kernels with the extended ptrace
1626 interface mentioned above.
1628 *** Changes in GDB 7.1
1632 ** Namespace Support
1634 GDB now supports importing of namespaces in C++. This enables the
1635 user to inspect variables from imported namespaces. Support for
1636 namepace aliasing has also been added. So, if a namespace is
1637 aliased in the current scope (e.g. namepace C=A; ) the user can
1638 print variables using the alias (e.g. (gdb) print C::x).
1642 All known bugs relating to the printing of virtual base class were
1643 fixed. It is now possible to call overloaded static methods using a
1648 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1649 and reinterpret_cast<> are now handled by the C++ expression parser.
1653 Xilinx MicroBlaze microblaze-*-*
1658 Xilinx MicroBlaze microblaze
1661 * Multi-program debugging.
1663 GDB now has support for multi-program (a.k.a. multi-executable or
1664 multi-exec) debugging. This allows for debugging multiple inferiors
1665 simultaneously each running a different program under the same GDB
1666 session. See "Debugging Multiple Inferiors and Programs" in the
1667 manual for more information. This implied some user visible changes
1668 in the multi-inferior support. For example, "info inferiors" now
1669 lists inferiors that are not running yet or that have exited
1670 already. See also "New commands" and "New options" below.
1672 * New tracing features
1674 GDB's tracepoint facility now includes several new features:
1676 ** Trace state variables
1678 GDB tracepoints now include support for trace state variables, which
1679 are variables managed by the target agent during a tracing
1680 experiment. They are useful for tracepoints that trigger each
1681 other, so for instance one tracepoint can count hits in a variable,
1682 and then a second tracepoint has a condition that is true when the
1683 count reaches a particular value. Trace state variables share the
1684 $-syntax of GDB convenience variables, and can appear in both
1685 tracepoint actions and condition expressions. Use the "tvariable"
1686 command to create, and "info tvariables" to view; see "Trace State
1687 Variables" in the manual for more detail.
1691 GDB now includes an option for defining fast tracepoints, which
1692 targets may implement more efficiently, such as by installing a jump
1693 into the target agent rather than a trap instruction. The resulting
1694 speedup can be by two orders of magnitude or more, although the
1695 tradeoff is that some program locations on some target architectures
1696 might not allow fast tracepoint installation, for instance if the
1697 instruction to be replaced is shorter than the jump. To request a
1698 fast tracepoint, use the "ftrace" command, with syntax identical to
1699 the regular trace command.
1701 ** Disconnected tracing
1703 It is now possible to detach GDB from the target while it is running
1704 a trace experiment, then reconnect later to see how the experiment
1705 is going. In addition, a new variable disconnected-tracing lets you
1706 tell the target agent whether to continue running a trace if the
1707 connection is lost unexpectedly.
1711 GDB now has the ability to save the trace buffer into a file, and
1712 then use that file as a target, similarly to you can do with
1713 corefiles. You can select trace frames, print data that was
1714 collected in them, and use tstatus to display the state of the
1715 tracing run at the moment that it was saved. To create a trace
1716 file, use "tsave <filename>", and to use it, do "target tfile
1719 ** Circular trace buffer
1721 You can ask the target agent to handle the trace buffer as a
1722 circular buffer, discarding the oldest trace frames to make room for
1723 newer ones, by setting circular-trace-buffer to on. This feature may
1724 not be available for all target agents.
1729 The disassemble command, when invoked with two arguments, now requires
1730 the arguments to be comma-separated.
1733 The info variables command now displays variable definitions. Files
1734 which only declare a variable are not shown.
1737 The source command is now capable of sourcing Python scripts.
1738 This feature is dependent on the debugger being build with Python
1741 Related to this enhancement is also the introduction of a new command
1742 "set script-extension" (see below).
1744 * New commands (for set/show, see "New options" below)
1746 record save [<FILENAME>]
1747 Save a file (in core file format) containing the process record
1748 execution log for replay debugging at a later time.
1750 record restore <FILENAME>
1751 Restore the process record execution log that was saved at an
1752 earlier time, for replay debugging.
1754 add-inferior [-copies <N>] [-exec <FILENAME>]
1757 clone-inferior [-copies <N>] [ID]
1758 Make a new inferior ready to execute the same program another
1759 inferior has loaded.
1764 maint info program-spaces
1765 List the program spaces loaded into GDB.
1767 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1768 show remote interrupt-sequence
1769 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1770 as the sequence to the remote target in order to interrupt the execution.
1771 Ctrl-C is a default. Some system prefers BREAK which is high level of
1772 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1773 Magic SysRq g. It is BREAK signal and character 'g'.
1775 set remote interrupt-on-connect [on | off]
1776 show remote interrupt-on-connect
1777 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1778 remote target when gdb connects to it. This is needed when you debug
1781 set remotebreak [on | off]
1783 Deprecated. Use "set/show remote interrupt-sequence" instead.
1785 tvariable $NAME [ = EXP ]
1786 Create or modify a trace state variable.
1789 List trace state variables and their values.
1791 delete tvariable $NAME ...
1792 Delete one or more trace state variables.
1795 Evaluate the given expressions without collecting anything into the
1796 trace buffer. (Valid in tracepoint actions only.)
1798 ftrace FN / FILE:LINE / *ADDR
1799 Define a fast tracepoint at the given function, line, or address.
1801 * New expression syntax
1803 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1804 GDB now parses 0b101010 identically with 42.
1808 set follow-exec-mode new|same
1809 show follow-exec-mode
1810 Control whether GDB reuses the same inferior across an exec call or
1811 creates a new one. This is useful to be able to restart the old
1812 executable after the inferior having done an exec call.
1814 set default-collect EXPR, ...
1815 show default-collect
1816 Define a list of expressions to be collected at each tracepoint.
1817 This is a useful way to ensure essential items are not overlooked,
1818 such as registers or a critical global variable.
1820 set disconnected-tracing
1821 show disconnected-tracing
1822 If set to 1, the target is instructed to continue tracing if it
1823 loses its connection to GDB. If 0, the target is to stop tracing
1826 set circular-trace-buffer
1827 show circular-trace-buffer
1828 If set to on, the target is instructed to use a circular trace buffer
1829 and discard the oldest trace frames instead of stopping the trace due
1830 to a full trace buffer. If set to off, the trace stops when the buffer
1831 fills up. Some targets may not support this.
1833 set script-extension off|soft|strict
1834 show script-extension
1835 If set to "off", the debugger does not perform any script language
1836 recognition, and all sourced files are assumed to be GDB scripts.
1837 If set to "soft" (the default), files are sourced according to
1838 filename extension, falling back to GDB scripts if the first
1840 If set to "strict", files are sourced according to filename extension.
1842 set ada trust-PAD-over-XVS on|off
1843 show ada trust-PAD-over-XVS
1844 If off, activate a workaround against a bug in the debugging information
1845 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1846 the GCC sources for more information about the GNAT encoding and
1847 PAD types in particular). It is always safe to set this option to
1848 off, but this introduces a slight performance penalty. The default
1851 * Python API Improvements
1853 ** GDB provides the new class gdb.LazyString. This is useful in
1854 some pretty-printing cases. The new method gdb.Value.lazy_string
1855 provides a simple way to create objects of this type.
1857 ** The fields returned by gdb.Type.fields now have an
1858 `is_base_class' attribute.
1860 ** The new method gdb.Type.range returns the range of an array type.
1862 ** The new method gdb.parse_and_eval can be used to parse and
1863 evaluate an expression.
1865 * New remote packets
1868 Define a trace state variable.
1871 Get the current value of a trace state variable.
1874 Set desired tracing behavior upon disconnection.
1877 Set the trace buffer to be linear or circular.
1880 Get data about the tracepoints currently in use.
1884 Process record now works correctly with hardware watchpoints.
1886 Multiple bug fixes have been made to the mips-irix port, making it
1887 much more reliable. In particular:
1888 - Debugging threaded applications is now possible again. Previously,
1889 GDB would hang while starting the program, or while waiting for
1890 the program to stop at a breakpoint.
1891 - Attaching to a running process no longer hangs.
1892 - An error occurring while loading a core file has been fixed.
1893 - Changing the value of the PC register now works again. This fixes
1894 problems observed when using the "jump" command, or when calling
1895 a function from GDB, or even when assigning a new value to $pc.
1896 - With the "finish" and "return" commands, the return value for functions
1897 returning a small array is now correctly printed.
1898 - It is now possible to break on shared library code which gets executed
1899 during a shared library init phase (code executed while executing
1900 their .init section). Previously, the breakpoint would have no effect.
1901 - GDB is now able to backtrace through the signal handler for
1902 non-threaded programs.
1904 PIE (Position Independent Executable) programs debugging is now supported.
1905 This includes debugging execution of PIC (Position Independent Code) shared
1906 libraries although for that, it should be possible to run such libraries as an
1909 *** Changes in GDB 7.0
1911 * GDB now has an interface for JIT compilation. Applications that
1912 dynamically generate code can create symbol files in memory and register
1913 them with GDB. For users, the feature should work transparently, and
1914 for JIT developers, the interface is documented in the GDB manual in the
1915 "JIT Compilation Interface" chapter.
1917 * Tracepoints may now be conditional. The syntax is as for
1918 breakpoints; either an "if" clause appended to the "trace" command,
1919 or the "condition" command is available. GDB sends the condition to
1920 the target for evaluation using the same bytecode format as is used
1921 for tracepoint actions.
1923 * The disassemble command now supports: an optional /r modifier, print the
1924 raw instructions in hex as well as in symbolic form, and an optional /m
1925 modifier to print mixed source+assembly.
1927 * Process record and replay
1929 In a architecture environment that supports ``process record and
1930 replay'', ``process record and replay'' target can record a log of
1931 the process execution, and replay it with both forward and reverse
1934 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
1935 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
1936 set execution-direction {forward|reverse}, for targets that support
1939 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
1940 feature is available with a native GDB running on kernel version
1943 * GDB now has support for multi-byte and wide character sets on the
1944 target. Strings whose character type is wchar_t, char16_t, or
1945 char32_t are now correctly printed. GDB supports wide- and unicode-
1946 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
1947 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
1948 `printf'. This feature requires iconv to work properly; if your
1949 system does not have a working iconv, GDB can use GNU libiconv. See
1950 the installation instructions for more information.
1952 * GDB now supports automatic retrieval of shared library files from
1953 remote targets. To use this feature, specify a system root that begins
1954 with the `remote:' prefix, either via the `set sysroot' command or via
1955 the `--with-sysroot' configure-time option.
1957 * "info sharedlibrary" now takes an optional regex of libraries to show,
1958 and it now reports if a shared library has no debugging information.
1960 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
1961 now complete on file names.
1963 * When completing in expressions, gdb will attempt to limit
1964 completions to allowable structure or union fields, where appropriate.
1965 For instance, consider:
1967 # struct example { int f1; double f2; };
1968 # struct example variable;
1971 If the user types TAB at the end of this command line, the available
1972 completions will be "f1" and "f2".
1974 * Inlined functions are now supported. They show up in backtraces, and
1975 the "step", "next", and "finish" commands handle them automatically.
1977 * GDB now supports the token-splicing (##) and stringification (#)
1978 operators when expanding macros. It also supports variable-arity
1981 * GDB now supports inspecting extra signal information, exported by
1982 the new $_siginfo convenience variable. The feature is currently
1983 implemented on linux ARM, i386 and amd64.
1985 * GDB can now display the VFP floating point registers and NEON vector
1986 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
1987 can provide these registers (requires Linux 2.6.30 or later). Remote
1988 and simulator targets may also provide them.
1990 * New remote packets
1993 Search memory for a sequence of bytes.
1996 Turn off `+'/`-' protocol acknowledgments to permit more efficient
1997 operation over reliable transport links. Use of this packet is
1998 controlled by the `set remote noack-packet' command.
2001 Kill the process with the specified process ID. Use this in preference
2002 to `k' when multiprocess protocol extensions are supported.
2005 Obtains additional operating system information
2009 Read or write additional signal information.
2011 * Removed remote protocol undocumented extension
2013 An undocumented extension to the remote protocol's `S' stop reply
2014 packet that permited the stub to pass a process id was removed.
2015 Remote servers should use the `T' stop reply packet instead.
2017 * GDB now supports multiple function calling conventions according to the
2018 DWARF-2 DW_AT_calling_convention function attribute.
2020 * The SH target utilizes the aforementioned change to distinguish between gcc
2021 and Renesas calling convention. It also adds the new CLI commands
2022 `set/show sh calling-convention'.
2024 * GDB can now read compressed debug sections, as produced by GNU gold
2025 with the --compress-debug-sections=zlib flag.
2027 * 64-bit core files are now supported on AIX.
2029 * Thread switching is now supported on Tru64.
2031 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2032 which will be allocated using malloc later in program execution.
2034 * The qXfer:libraries:read remote procotol packet now allows passing a
2035 list of section offsets.
2037 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2038 conditions handling signals delivered during attach or thread creation
2039 have also been fixed.
2041 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2042 From the user's standpoint, all unqualified instances of True and False
2043 are treated as the standard definitions, regardless of context.
2045 * GDB now parses C++ symbol and type names more flexibly. For
2048 template<typename T> class C { };
2051 GDB will now correctly handle all of:
2053 ptype C<char const *>
2054 ptype C<char const*>
2055 ptype C<const char *>
2056 ptype C<const char*>
2058 * New features in the GDB remote stub, gdbserver
2060 - The "--wrapper" command-line argument tells gdbserver to use a
2061 wrapper program to launch programs for debugging.
2063 - On PowerPC and S/390 targets, it is now possible to use a single
2064 gdbserver executable to debug both 32-bit and 64-bit programs.
2065 (This requires gdbserver itself to be built as a 64-bit executable.)
2067 - gdbserver uses the new noack protocol mode for TCP connections to
2068 reduce communications latency, if also supported and enabled in GDB.
2070 - Support for the sparc64-linux-gnu target is now included in
2073 - The amd64-linux build of gdbserver now supports debugging both
2074 32-bit and 64-bit programs.
2076 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2077 now support hardware watchpoints, and will use them automatically
2082 GDB now has support for scripting using Python. Whether this is
2083 available is determined at configure time.
2085 New GDB commands can now be written in Python.
2087 * Ada tasking support
2089 Ada tasks can now be inspected in GDB. The following commands have
2093 Print the list of Ada tasks.
2095 Print detailed information about task number N.
2097 Print the task number of the current task.
2099 Switch the context of debugging to task number N.
2101 * Support for user-defined prefixed commands. The "define" command can
2102 add new commands to existing prefixes, e.g. "target".
2104 * Multi-inferior, multi-process debugging.
2106 GDB now has generalized support for multi-inferior debugging. See
2107 "Debugging Multiple Inferiors" in the manual for more information.
2108 Although availability still depends on target support, the command
2109 set is more uniform now. The GNU/Linux specific multi-forks support
2110 has been migrated to this new framework. This implied some user
2111 visible changes; see "New commands" and also "Removed commands"
2114 * Target descriptions can now describe the target OS ABI. See the
2115 "Target Description Format" section in the user manual for more
2118 * Target descriptions can now describe "compatible" architectures
2119 to indicate that the target can execute applications for a different
2120 architecture in addition to those for the main target architecture.
2121 See the "Target Description Format" section in the user manual for
2124 * Multi-architecture debugging.
2126 GDB now includes general supports for debugging applications on
2127 hybrid systems that use more than one single processor architecture
2128 at the same time. Each such hybrid architecture still requires
2129 specific support to be added. The only hybrid architecture supported
2130 in this version of GDB is the Cell Broadband Engine.
2132 * GDB now supports integrated debugging of Cell/B.E. applications that
2133 use both the PPU and SPU architectures. To enable support for hybrid
2134 Cell/B.E. debugging, you need to configure GDB to support both the
2135 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2136 --enable-targets configure option.
2138 * Non-stop mode debugging.
2140 For some targets, GDB now supports an optional mode of operation in
2141 which you can examine stopped threads while other threads continue
2142 to execute freely. This is referred to as non-stop mode, with the
2143 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2144 section in the user manual for more information.
2146 To be able to support remote non-stop debugging, a remote stub needs
2147 to implement the non-stop mode remote protocol extensions, as
2148 described in the "Remote Non-Stop" section of the user manual. The
2149 GDB remote stub, gdbserver, has been adjusted to support these
2150 extensions on linux targets.
2152 * New commands (for set/show, see "New options" below)
2154 catch syscall [NAME(S) | NUMBER(S)]
2155 Catch system calls. Arguments, which should be names of system
2156 calls or their numbers, mean catch only those syscalls. Without
2157 arguments, every syscall will be caught. When the inferior issues
2158 any of the specified syscalls, GDB will stop and announce the system
2159 call, both when it is called and when its call returns. This
2160 feature is currently available with a native GDB running on the
2161 Linux Kernel, under the following architectures: x86, x86_64,
2162 PowerPC and PowerPC64.
2164 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2166 Search memory for a sequence of bytes.
2168 maint set python print-stack
2169 maint show python print-stack
2170 Show a stack trace when an error is encountered in a Python script.
2173 Invoke CODE by passing it to the Python interpreter.
2178 These allow macros to be defined, undefined, and listed
2182 Show operating system information about processes.
2185 List the inferiors currently under GDB's control.
2188 Switch focus to inferior number NUM.
2191 Detach from inferior number NUM.
2194 Kill inferior number NUM.
2198 set spu stop-on-load
2199 show spu stop-on-load
2200 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2202 set spu auto-flush-cache
2203 show spu auto-flush-cache
2204 Control whether to automatically flush the software-managed cache
2205 during Cell/B.E. debugging.
2207 set sh calling-convention
2208 show sh calling-convention
2209 Control the calling convention used when calling SH target functions.
2212 show debug timestamp
2213 Control display of timestamps with GDB debugging output.
2215 set disassemble-next-line
2216 show disassemble-next-line
2217 Control display of disassembled source lines or instructions when
2220 set remote noack-packet
2221 show remote noack-packet
2222 Set/show the use of remote protocol QStartNoAckMode packet. See above
2223 under "New remote packets."
2225 set remote query-attached-packet
2226 show remote query-attached-packet
2227 Control use of remote protocol `qAttached' (query-attached) packet.
2229 set remote read-siginfo-object
2230 show remote read-siginfo-object
2231 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2234 set remote write-siginfo-object
2235 show remote write-siginfo-object
2236 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2239 set remote reverse-continue
2240 show remote reverse-continue
2241 Control use of remote protocol 'bc' (reverse-continue) packet.
2243 set remote reverse-step
2244 show remote reverse-step
2245 Control use of remote protocol 'bs' (reverse-step) packet.
2247 set displaced-stepping
2248 show displaced-stepping
2249 Control displaced stepping mode. Displaced stepping is a way to
2250 single-step over breakpoints without removing them from the debuggee.
2251 Also known as "out-of-line single-stepping".
2254 show debug displaced
2255 Control display of debugging info for displaced stepping.
2257 maint set internal-error
2258 maint show internal-error
2259 Control what GDB does when an internal error is detected.
2261 maint set internal-warning
2262 maint show internal-warning
2263 Control what GDB does when an internal warning is detected.
2268 Use a wrapper program to launch programs for debugging.
2270 set multiple-symbols (all|ask|cancel)
2271 show multiple-symbols
2272 The value of this variable can be changed to adjust the debugger behavior
2273 when an expression or a breakpoint location contains an ambiguous symbol
2274 name (an overloaded function name, for instance).
2276 set breakpoint always-inserted
2277 show breakpoint always-inserted
2278 Keep breakpoints always inserted in the target, as opposed to inserting
2279 them when resuming the target, and removing them when the target stops.
2280 This option can improve debugger performance on slow remote targets.
2282 set arm fallback-mode (arm|thumb|auto)
2283 show arm fallback-mode
2284 set arm force-mode (arm|thumb|auto)
2286 These commands control how ARM GDB determines whether instructions
2287 are ARM or Thumb. The default for both settings is auto, which uses
2288 the current CPSR value for instructions without symbols; previous
2289 versions of GDB behaved as if "set arm fallback-mode arm".
2291 set disable-randomization
2292 show disable-randomization
2293 Standalone programs run with the virtual address space randomization enabled
2294 by default on some platforms. This option keeps the addresses stable across
2295 multiple debugging sessions.
2299 Control whether other threads are stopped or not when some thread hits
2304 Requests that asynchronous execution is enabled in the target, if available.
2305 In this case, it's possible to resume target in the background, and interact
2306 with GDB while the target is running. "show target-async" displays the
2307 current state of asynchronous execution of the target.
2309 set target-wide-charset
2310 show target-wide-charset
2311 The target-wide-charset is the name of the character set that GDB
2312 uses when printing characters whose type is wchar_t.
2314 set tcp auto-retry (on|off)
2316 set tcp connect-timeout
2317 show tcp connect-timeout
2318 These commands allow GDB to retry failed TCP connections to a remote stub
2319 with a specified timeout period; this is useful if the stub is launched
2320 in parallel with GDB but may not be ready to accept connections immediately.
2322 set libthread-db-search-path
2323 show libthread-db-search-path
2324 Control list of directories which GDB will search for appropriate
2327 set schedule-multiple (on|off)
2328 show schedule-multiple
2329 Allow GDB to resume all threads of all processes or only threads of
2330 the current process.
2334 Use more aggressive caching for accesses to the stack. This improves
2335 performance of remote debugging (particularly backtraces) without
2336 affecting correctness.
2338 set interactive-mode (on|off|auto)
2339 show interactive-mode
2340 Control whether GDB runs in interactive mode (on) or not (off).
2341 When in interactive mode, GDB waits for the user to answer all
2342 queries. Otherwise, GDB does not wait and assumes the default
2343 answer. When set to auto (the default), GDB determines which
2344 mode to use based on the stdin settings.
2349 For program forks, this is replaced by the new more generic `info
2350 inferiors' command. To list checkpoints, you can still use the
2351 `info checkpoints' command, which was an alias for the `info forks'
2355 Replaced by the new `inferior' command. To switch between
2356 checkpoints, you can still use the `restart' command, which was an
2357 alias for the `fork' command.
2360 This is removed, since some targets don't have a notion of
2361 processes. To switch between processes, you can still use the
2362 `inferior' command using GDB's own inferior number.
2365 For program forks, this is replaced by the new more generic `kill
2366 inferior' command. To delete a checkpoint, you can still use the
2367 `delete checkpoint' command, which was an alias for the `delete
2371 For program forks, this is replaced by the new more generic `detach
2372 inferior' command. To detach a checkpoint, you can still use the
2373 `detach checkpoint' command, which was an alias for the `detach
2376 * New native configurations
2378 x86/x86_64 Darwin i[34567]86-*-darwin*
2380 x86_64 MinGW x86_64-*-mingw*
2384 Lattice Mico32 lm32-*
2385 x86 DICOS i[34567]86-*-dicos*
2386 x86_64 DICOS x86_64-*-dicos*
2389 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2390 (mingw32ce) debugging.
2396 These commands were actually not implemented on any target.
2398 *** Changes in GDB 6.8
2400 * New native configurations
2402 NetBSD/hppa hppa*-*netbsd*
2403 Xtensa GNU/Linux xtensa*-*-linux*
2407 NetBSD/hppa hppa*-*-netbsd*
2408 Xtensa GNU/Lunux xtensa*-*-linux*
2410 * Change in command line behavior -- corefiles vs. process ids.
2412 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2413 attaching to process NUMBER fails, GDB no longer attempts to open a
2414 core file named NUMBER. Attaching to a program using the -c option
2415 is no longer supported. Instead, use the '-p' or '--pid' options.
2417 * GDB can now be built as a native debugger for debugging Windows x86
2418 (mingw32) Portable Executable (PE) programs.
2420 * Pending breakpoints no longer change their number when their address
2423 * GDB now supports breakpoints with multiple locations,
2424 including breakpoints on C++ constructors, inside C++ templates,
2425 and in inlined functions.
2427 * GDB's ability to debug optimized code has been improved. GDB more
2428 accurately identifies function bodies and lexical blocks that occupy
2429 more than one contiguous range of addresses.
2431 * Target descriptions can now describe registers for PowerPC.
2433 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2434 registers on PowerPC targets.
2436 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2437 targets even when the libthread_db library is not available.
2439 * The GDB remote stub, gdbserver, now supports the new file transfer
2440 commands (remote put, remote get, and remote delete).
2442 * The GDB remote stub, gdbserver, now supports run and attach in
2443 extended-remote mode.
2445 * hppa*64*-*-hpux11* target broken
2446 The debugger is unable to start a program and fails with the following
2447 error: "Error trying to get information about dynamic linker".
2448 The gdb-6.7 release is also affected.
2450 * GDB now supports the --enable-targets= configure option to allow
2451 building a single GDB executable that supports multiple remote
2452 target architectures.
2454 * GDB now supports debugging C and C++ programs which use the
2455 Decimal Floating Point extension. In addition, the PowerPC target
2456 now has a set of pseudo-registers to inspect decimal float values
2457 stored in two consecutive float registers.
2459 * The -break-insert MI command can optionally create pending
2462 * Improved support for debugging Ada
2463 Many improvements to the Ada language support have been made. These
2465 - Better support for Ada2005 interface types
2466 - Improved handling of arrays and slices in general
2467 - Better support for Taft-amendment types
2468 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2470 - Improved command completion in Ada
2473 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2478 set print frame-arguments (all|scalars|none)
2479 show print frame-arguments
2480 The value of this variable can be changed to control which argument
2481 values should be printed by the debugger when displaying a frame.
2486 Transfer files to and from a remote target, and delete remote files.
2493 Transfer files to and from a remote target, and delete remote files.
2495 * New remote packets
2502 Open, close, read, write, and delete files on the remote system.
2505 Attach to an existing process on the remote system, in extended-remote
2509 Run a new process on the remote system, in extended-remote mode.
2511 *** Changes in GDB 6.7
2513 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2514 bfd, libiberty and opcodes, as revealed by static analysis donated by
2515 Coverity, Inc. (http://scan.coverity.com).
2517 * When looking up multiply-defined global symbols, GDB will now prefer the
2518 symbol definition in the current shared library if it was built using the
2519 -Bsymbolic linker option.
2521 * When the Text User Interface (TUI) is not configured, GDB will now
2522 recognize the -tui command-line option and print a message that the TUI
2525 * The GDB remote stub, gdbserver, now has lower overhead for high
2526 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2528 * GDB for MIPS targets now autodetects whether a remote target provides
2529 32-bit or 64-bit register values.
2531 * Support for C++ member pointers has been improved.
2533 * GDB now understands XML target descriptions, which specify the
2534 target's overall architecture. GDB can read a description from
2535 a local file or over the remote serial protocol.
2537 * Vectors of single-byte data use a new integer type which is not
2538 automatically displayed as character or string data.
2540 * The /s format now works with the print command. It displays
2541 arrays of single-byte integers and pointers to single-byte integers
2544 * Target descriptions can now describe target-specific registers,
2545 for architectures which have implemented the support (currently
2546 only ARM, M68K, and MIPS).
2548 * GDB and the GDB remote stub, gdbserver, now support the XScale
2551 * The GDB remote stub, gdbserver, has been updated to support
2552 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2553 has been rewritten to use the standard GDB remote protocol.
2555 * GDB can now step into C++ functions which are called through thunks.
2557 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2559 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2560 layout. It also supports a TextSeg= and DataSeg= response when only
2561 segment base addresses (rather than offsets) are available.
2563 * The /i format now outputs any trailing branch delay slot instructions
2564 immediately following the last instruction within the count specified.
2566 * The GDB remote protocol "T" stop reply packet now supports a
2567 "library" response. Combined with the new "qXfer:libraries:read"
2568 packet, this response allows GDB to debug shared libraries on targets
2569 where the operating system manages the list of loaded libraries (e.g.
2570 Windows and SymbianOS).
2572 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2573 (DLLs) on Windows and Windows CE targets.
2575 * GDB now supports a faster verification that a .debug file matches its binary
2576 according to its build-id signature, if the signature is present.
2582 Enable or disable hardware flow control (RTS/CTS) on the serial port
2583 when debugging using remote targets.
2585 set mem inaccessible-by-default
2586 show mem inaccessible-by-default
2587 If the target supplies a memory map, for instance via the remote
2588 protocol's "qXfer:memory-map:read" packet, setting this variable
2589 prevents GDB from accessing memory outside the memory map. This
2590 is useful for targets with memory mapped registers or which react
2591 badly to accesses of unmapped address space.
2593 set breakpoint auto-hw
2594 show breakpoint auto-hw
2595 If the target supplies a memory map, for instance via the remote
2596 protocol's "qXfer:memory-map:read" packet, setting this variable
2597 lets GDB use hardware breakpoints automatically for memory regions
2598 where it can not use software breakpoints. This covers both the
2599 "break" command and internal breakpoints used for other commands
2600 including "next" and "finish".
2603 catch exception unhandled
2604 Stop the program execution when Ada exceptions are raised.
2607 Stop the program execution when an Ada assertion failed.
2611 Set an alternate system root for target files. This is a more
2612 general version of "set solib-absolute-prefix", which is now
2613 an alias to "set sysroot".
2616 Provide extended SPU facility status information. This set of
2617 commands is available only when debugging the Cell/B.E. SPU
2620 * New native configurations
2622 OpenBSD/sh sh*-*openbsd*
2625 unset tdesc filename
2627 Use the specified local file as an XML target description, and do
2628 not query the target for its built-in description.
2632 OpenBSD/sh sh*-*-openbsd*
2633 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2634 Toshiba Media Processor mep-elf
2636 * New remote packets
2639 Ignore the specified signals; pass them directly to the debugged program
2640 without stopping other threads or reporting them to GDB.
2642 qXfer:features:read:
2643 Read an XML target description from the target, which describes its
2648 Read or write contents of an spufs file on the target system. These
2649 packets are available only on the Cell/B.E. SPU architecture.
2651 qXfer:libraries:read:
2652 Report the loaded shared libraries. Combined with new "T" packet
2653 response, this packet allows GDB to debug shared libraries on
2654 targets where the operating system manages the list of loaded
2655 libraries (e.g. Windows and SymbianOS).
2659 Support for these obsolete configurations has been removed.
2667 i[34567]86-*-lynxos*
2668 i[34567]86-*-netware*
2669 i[34567]86-*-sco3.2v5*
2670 i[34567]86-*-sco3.2v4*
2672 i[34567]86-*-sysv4.2*
2675 i[34567]86-*-unixware2*
2676 i[34567]86-*-unixware*
2685 * Other removed features
2692 Various m68k-only ROM monitors.
2699 Various Renesas ROM monitors and debugging interfaces for SH and
2704 Support for a Macraigor serial interface to on-chip debugging.
2705 GDB does not directly support the newer parallel or USB
2710 A debug information format. The predecessor to DWARF 2 and
2711 DWARF 3, which are still supported.
2713 Support for the HP aCC compiler on HP-UX/PA-RISC
2715 SOM-encapsulated symbolic debugging information, automatic
2716 invocation of pxdb, and the aCC custom C++ ABI. This does not
2717 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2718 with aCC can still be debugged on an assembly level.
2720 MIPS ".pdr" sections
2722 A MIPS-specific format used to describe stack frame layout
2723 in debugging information.
2727 GDB could work with an older version of Guile to debug
2728 the interpreter and Scheme programs running in it.
2730 set mips stack-arg-size
2731 set mips saved-gpreg-size
2733 Use "set mips abi" to control parameter passing for MIPS.
2735 *** Changes in GDB 6.6
2740 Cell Broadband Engine SPU spu-elf
2742 * GDB can now be configured as a cross-debugger targeting native Windows
2743 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2744 running on a Windows system over TCP/IP to debug Windows programs.
2746 * The GDB remote stub, gdbserver, has been updated to support Windows and
2747 Cygwin debugging. Both single-threaded and multi-threaded programs are
2750 * The "set trust-readonly-sections" command works again. This command was
2751 broken in GDB 6.3, 6.4, and 6.5.
2753 * The "load" command now supports writing to flash memory, if the remote
2754 stub provides the required support.
2756 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2757 longer requires symbolic debug information (e.g. DWARF-2).
2762 unset substitute-path
2763 show substitute-path
2764 Manage a list of substitution rules that GDB uses to rewrite the name
2765 of the directories where the sources are located. This can be useful
2766 for instance when the sources were moved to a different location
2767 between compilation and debugging.
2771 Print each CLI command as it is executed. Each command is prefixed with
2772 a number of `+' symbols representing the nesting depth.
2773 The source command now has a `-v' option to enable the same feature.
2777 The ARM Demon monitor support (RDP protocol, "target rdp").
2779 Kernel Object Display, an embedded debugging feature which only worked with
2780 an obsolete version of Cisco IOS.
2782 The 'set download-write-size' and 'show download-write-size' commands.
2784 * New remote packets
2787 Tell a stub about GDB client features, and request remote target features.
2788 The first feature implemented is PacketSize, which allows the target to
2789 specify the size of packets it can handle - to minimize the number of
2790 packets required and improve performance when connected to a remote
2794 Fetch an OS auxilliary vector from the remote stub. This packet is a
2795 more efficient replacement for qPart:auxv:read.
2797 qXfer:memory-map:read:
2798 Fetch a memory map from the remote stub, including information about
2799 RAM, ROM, and flash memory devices.
2804 Erase and program a flash memory device.
2806 * Removed remote packets
2809 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2810 used it, and only gdbserver implemented it.
2812 *** Changes in GDB 6.5
2816 Renesas M32C/M16C m32c-elf
2818 Morpho Technologies ms1 ms1-elf
2822 init-if-undefined Initialize a convenience variable, but
2823 only if it doesn't already have a value.
2825 The following commands are presently only implemented for native GNU/Linux:
2827 checkpoint Save a snapshot of the program state.
2829 restart <n> Return the program state to a
2830 previously saved state.
2832 info checkpoints List currently saved checkpoints.
2834 delete-checkpoint <n> Delete a previously saved checkpoint.
2836 set|show detach-on-fork Tell gdb whether to detach from a newly
2837 forked process, or to keep debugging it.
2839 info forks List forks of the user program that
2840 are available to be debugged.
2842 fork <n> Switch to debugging one of several
2843 forks of the user program that are
2844 available to be debugged.
2846 delete-fork <n> Delete a fork from the list of forks
2847 that are available to be debugged (and
2848 kill the forked process).
2850 detach-fork <n> Delete a fork from the list of forks
2851 that are available to be debugged (and
2852 allow the process to continue).
2856 Morpho Technologies ms2 ms1-elf
2858 * Improved Windows host support
2860 GDB now builds as a cross debugger hosted on i686-mingw32, including
2861 native console support, and remote communications using either
2862 network sockets or serial ports.
2864 * Improved Modula-2 language support
2866 GDB can now print most types in the Modula-2 syntax. This includes:
2867 basic types, set types, record types, enumerated types, range types,
2868 pointer types and ARRAY types. Procedure var parameters are correctly
2869 printed and hexadecimal addresses and character constants are also
2870 written in the Modula-2 syntax. Best results can be obtained by using
2871 GNU Modula-2 together with the -gdwarf-2 command line option.
2875 The ARM rdi-share module.
2877 The Netware NLM debug server.
2879 *** Changes in GDB 6.4
2881 * New native configurations
2883 OpenBSD/arm arm*-*-openbsd*
2884 OpenBSD/mips64 mips64-*-openbsd*
2888 Morpho Technologies ms1 ms1-elf
2890 * New command line options
2892 --batch-silent As for --batch, but totally silent.
2893 --return-child-result The debugger will exist with the same value
2894 the child (debugged) program exited with.
2895 --eval-command COMMAND, -ex COMMAND
2896 Execute a single GDB CLI command. This may be
2897 specified multiple times and in conjunction
2898 with the --command (-x) option.
2900 * Deprecated commands removed
2902 The following commands, that were deprecated in 2000, have been
2906 set|show arm disassembly-flavor set|show arm disassembler
2907 othernames set arm disassembler
2908 set|show remotedebug set|show debug remote
2909 set|show archdebug set|show debug arch
2910 set|show eventdebug set|show debug event
2913 * New BSD user-level threads support
2915 It is now possible to debug programs using the user-level threads
2916 library on OpenBSD and FreeBSD. Currently supported (target)
2919 FreeBSD/amd64 x86_64-*-freebsd*
2920 FreeBSD/i386 i386-*-freebsd*
2921 OpenBSD/i386 i386-*-openbsd*
2923 Note that the new kernel threads libraries introduced in FreeBSD 5.x
2924 are not yet supported.
2926 * New support for Matsushita MN10300 w/sim added
2927 (Work in progress). mn10300-elf.
2929 * REMOVED configurations and files
2931 VxWorks and the XDR protocol *-*-vxworks
2932 Motorola MCORE mcore-*-*
2933 National Semiconductor NS32000 ns32k-*-*
2935 * New "set print array-indexes" command
2937 After turning this setting "on", GDB prints the index of each element
2938 when displaying arrays. The default is "off" to preserve the previous
2941 * VAX floating point support
2943 GDB now supports the not-quite-ieee VAX F and D floating point formats.
2945 * User-defined command support
2947 In addition to using $arg0..$arg9 for argument passing, it is now possible
2948 to use $argc to determine now many arguments have been passed. See the
2949 section on user-defined commands in the user manual for more information.
2951 *** Changes in GDB 6.3:
2953 * New command line option
2955 GDB now accepts -l followed by a number to set the timeout for remote
2958 * GDB works with GCC -feliminate-dwarf2-dups
2960 GDB now supports a more compact representation of DWARF-2 debug
2961 information using DW_FORM_ref_addr references. These are produced
2962 by GCC with the option -feliminate-dwarf2-dups and also by some
2963 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
2964 to use -feliminate-dwarf2-dups.
2966 * Internationalization
2968 When supported by the host system, GDB will be built with
2969 internationalization (libintl). The task of marking up the sources is
2970 continued, we're looking forward to our first translation.
2974 Initial support for debugging programs compiled with the GNAT
2975 implementation of the Ada programming language has been integrated
2976 into GDB. In this release, support is limited to expression evaluation.
2978 * New native configurations
2980 GNU/Linux/m32r m32r-*-linux-gnu
2984 GDB's remote protocol now includes support for the 'p' packet. This
2985 packet is used to fetch individual registers from a remote inferior.
2987 * END-OF-LIFE registers[] compatibility module
2989 GDB's internal register infrastructure has been completely rewritten.
2990 The new infrastructure making possible the implementation of key new
2991 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
2994 GDB 6.3 will be the last release to include the the registers[]
2995 compatibility module that allowed out-of-date configurations to
2996 continue to work. This change directly impacts the following
3006 powerpc bdm protocol
3008 Unless there is activity to revive these configurations, they will be
3009 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3011 * OBSOLETE configurations and files
3013 Configurations that have been declared obsolete in this release have
3014 been commented out. Unless there is activity to revive these
3015 configurations, the next release of GDB will have their sources
3016 permanently REMOVED.
3025 *** Changes in GDB 6.2.1:
3027 * MIPS `break main; run' gave an heuristic-fence-post warning
3029 When attempting to run even a simple program, a warning about
3030 heuristic-fence-post being hit would be reported. This problem has
3033 * MIPS IRIX 'long double' crashed GDB
3035 When examining a long double variable, GDB would get a segmentation
3036 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3037 IRIX long double values).
3041 A bug in the VAX stack code was causing problems with the "next"
3042 command. This problem has been fixed.
3044 *** Changes in GDB 6.2:
3046 * Fix for ``many threads''
3048 On GNU/Linux systems that use the NPTL threads library, a program
3049 rapidly creating and deleting threads would confuse GDB leading to the
3052 ptrace: No such process.
3053 thread_db_get_info: cannot get thread info: generic error
3055 This problem has been fixed.
3057 * "-async" and "-noasync" options removed.
3059 Support for the broken "-noasync" option has been removed (it caused
3062 * New ``start'' command.
3064 This command runs the program until the begining of the main procedure.
3066 * New BSD Kernel Data Access Library (libkvm) interface
3068 Using ``target kvm'' it is now possible to debug kernel core dumps and
3069 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3070 platforms. Currently supported (native-only) configurations are:
3072 FreeBSD/amd64 x86_64-*-freebsd*
3073 FreeBSD/i386 i?86-*-freebsd*
3074 NetBSD/i386 i?86-*-netbsd*
3075 NetBSD/m68k m68*-*-netbsd*
3076 NetBSD/sparc sparc-*-netbsd*
3077 OpenBSD/amd64 x86_64-*-openbsd*
3078 OpenBSD/i386 i?86-*-openbsd*
3079 OpenBSD/m68k m68*-openbsd*
3080 OpenBSD/sparc sparc-*-openbsd*
3082 * Signal trampoline code overhauled
3084 Many generic problems with GDB's signal handling code have been fixed.
3085 These include: backtraces through non-contiguous stacks; recognition
3086 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3087 call; backtrace through a signal trampoline; step into and out of
3088 signal handlers; and single-stepping in the signal trampoline.
3090 Please note that kernel bugs are a limiting factor here. These
3091 features have been shown to work on an s390 GNU/Linux system that
3092 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3094 * Cygwin support for DWARF 2 added.
3096 * New native configurations
3098 GNU/Linux/hppa hppa*-*-linux*
3099 OpenBSD/hppa hppa*-*-openbsd*
3100 OpenBSD/m68k m68*-*-openbsd*
3101 OpenBSD/m88k m88*-*-openbsd*
3102 OpenBSD/powerpc powerpc-*-openbsd*
3103 NetBSD/vax vax-*-netbsd*
3104 OpenBSD/vax vax-*-openbsd*
3106 * END-OF-LIFE frame compatibility module
3108 GDB's internal frame infrastructure has been completely rewritten.
3109 The new infrastructure making it possible to support key new features
3110 including DWARF 2 Call Frame Information. To aid in the task of
3111 migrating old configurations to this new infrastructure, a
3112 compatibility module, that allowed old configurations to continue to
3113 work, was also included.
3115 GDB 6.2 will be the last release to include this frame compatibility
3116 module. This change directly impacts the following configurations:
3126 Unless there is activity to revive these configurations, they will be
3127 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3129 * REMOVED configurations and files
3131 Sun 3, running SunOS 3 m68*-*-sunos3*
3132 Sun 3, running SunOS 4 m68*-*-sunos4*
3133 Sun 2, running SunOS 3 m68000-*-sunos3*
3134 Sun 2, running SunOS 4 m68000-*-sunos4*
3135 Motorola 680x0 running LynxOS m68*-*-lynxos*
3136 AT&T 3b1/Unix pc m68*-att-*
3137 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3138 decstation mips-dec-* mips-little-*
3139 riscos mips-*-riscos* mips-*-sysv*
3140 sonymips mips-sony-*
3141 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3143 *** Changes in GDB 6.1.1:
3145 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3147 The TUI (Text-mode User Interface) is now built as part of a default
3148 GDB configuration. It is enabled by either selecting the TUI with the
3149 command line option "-i=tui" or by running the separate "gdbtui"
3150 program. For more information on the TUI, see the manual "Debugging
3153 * Pending breakpoint support (also included in GDB 6.1)
3155 Support has been added to allow you to specify breakpoints in shared
3156 libraries that have not yet been loaded. If a breakpoint location
3157 cannot be found, and the "breakpoint pending" option is set to auto,
3158 GDB queries you if you wish to make the breakpoint pending on a future
3159 shared-library load. If and when GDB resolves the breakpoint symbol,
3160 the pending breakpoint is removed as one or more regular breakpoints
3163 Pending breakpoints are very useful for GCJ Java debugging.
3165 * Fixed ISO-C build problems
3167 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3168 non ISO-C code that stopped them being built using a more strict ISO-C
3169 compiler (e.g., IBM's C compiler).
3171 * Fixed build problem on IRIX 5
3173 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3174 wasn't able to compile compile on an IRIX 5 system.
3176 * Added execute permission to gdb/gdbserver/configure
3178 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3179 permission. This bug would cause configure to fail on a number of
3180 systems (Solaris, IRIX). Ref: server/519.
3182 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3184 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3185 has been updated to use constant array sizes.
3187 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3189 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3190 its generated DWARF Call Frame Info. This encoding was causing GDB to
3191 panic, that panic has been fixed. Ref: gdb/1628.
3193 * Fixed a problem when examining parameters in shared library code.
3195 When examining parameters in optimized shared library code generated
3196 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3197 not available''. GDB now correctly displays the variable's value.
3199 *** Changes in GDB 6.1:
3201 * Removed --with-mmalloc
3203 Support for the mmalloc memory manager has been removed, as it
3204 conflicted with the internal gdb byte cache.
3206 * Changes in AMD64 configurations
3208 The AMD64 target now includes the %cs and %ss registers. As a result
3209 the AMD64 remote protocol has changed; this affects the floating-point
3210 and SSE registers. If you rely on those registers for your debugging,
3211 you should upgrade gdbserver on the remote side.
3213 * Revised SPARC target
3215 The SPARC target has been completely revised, incorporating the
3216 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3217 support for LynxOS and SunOS 4 has been dropped. Calling functions
3218 from within GDB on operating systems with a non-executable stack
3219 (Solaris, OpenBSD) now works.
3223 GDB has a new C++ demangler which does a better job on the mangled
3224 names generated by current versions of g++. It also runs faster, so
3225 with this and other changes gdb should now start faster on large C++
3228 * DWARF 2 Location Expressions
3230 GDB support for location expressions has been extended to support function
3231 arguments and frame bases. Older versions of GDB could crash when they
3234 * C++ nested types and namespaces
3236 GDB's support for nested types and namespaces in C++ has been
3237 improved, especially if you use the DWARF 2 debugging format. (This
3238 is the default for recent versions of GCC on most platforms.)
3239 Specifically, if you have a class "Inner" defined within a class or
3240 namespace "Outer", then GDB realizes that the class's name is
3241 "Outer::Inner", not simply "Inner". This should greatly reduce the
3242 frequency of complaints about not finding RTTI symbols. In addition,
3243 if you are stopped at inside of a function defined within a namespace,
3244 GDB modifies its name lookup accordingly.
3246 * New native configurations
3248 NetBSD/amd64 x86_64-*-netbsd*
3249 OpenBSD/amd64 x86_64-*-openbsd*
3250 OpenBSD/alpha alpha*-*-openbsd*
3251 OpenBSD/sparc sparc-*-openbsd*
3252 OpenBSD/sparc64 sparc64-*-openbsd*
3254 * New debugging protocols
3256 M32R with SDI protocol m32r-*-elf*
3258 * "set prompt-escape-char" command deleted.
3260 The command "set prompt-escape-char" has been deleted. This command,
3261 and its very obscure effet on GDB's prompt, was never documented,
3262 tested, nor mentioned in the NEWS file.
3264 * OBSOLETE configurations and files
3266 Configurations that have been declared obsolete in this release have
3267 been commented out. Unless there is activity to revive these
3268 configurations, the next release of GDB will have their sources
3269 permanently REMOVED.
3271 Sun 3, running SunOS 3 m68*-*-sunos3*
3272 Sun 3, running SunOS 4 m68*-*-sunos4*
3273 Sun 2, running SunOS 3 m68000-*-sunos3*
3274 Sun 2, running SunOS 4 m68000-*-sunos4*
3275 Motorola 680x0 running LynxOS m68*-*-lynxos*
3276 AT&T 3b1/Unix pc m68*-att-*
3277 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3278 decstation mips-dec-* mips-little-*
3279 riscos mips-*-riscos* mips-*-sysv*
3280 sonymips mips-sony-*
3281 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3283 * REMOVED configurations and files
3285 SGI Irix-4.x mips-sgi-irix4 or iris4
3286 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3287 Z8000 simulator z8k-zilog-none or z8ksim
3288 Matsushita MN10200 w/simulator mn10200-*-*
3289 H8/500 simulator h8500-hitachi-hms or h8500hms
3290 HP/PA running BSD hppa*-*-bsd*
3291 HP/PA running OSF/1 hppa*-*-osf*
3292 HP/PA Pro target hppa*-*-pro*
3293 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3294 386BSD i[3456]86-*-bsd*
3295 Sequent family i[3456]86-sequent-sysv4*
3296 i[3456]86-sequent-sysv*
3297 i[3456]86-sequent-bsd*
3298 SPARC running LynxOS sparc-*-lynxos*
3299 SPARC running SunOS 4 sparc-*-sunos4*
3300 Tsqware Sparclet sparclet-*-*
3301 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3303 *** Changes in GDB 6.0:
3307 Support for debugging the Objective-C programming language has been
3308 integrated into GDB.
3310 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3312 DWARF 2's Call Frame Information makes available compiler generated
3313 information that more exactly describes the program's run-time stack.
3314 By using this information, GDB is able to provide more robust stack
3317 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3318 have been updated to use a new backtrace mechanism which includes
3319 DWARF 2 CFI support.
3323 GDB's remote protocol has been extended to include support for hosted
3324 file I/O (where the remote target uses GDB's file system). See GDB's
3325 remote protocol documentation for details.
3327 * All targets using the new architecture framework.
3329 All of GDB's targets have been updated to use the new internal
3330 architecture framework. The way is now open for future GDB releases
3331 to include cross-architecture native debugging support (i386 on amd64,
3334 * GNU/Linux's Thread Local Storage (TLS)
3336 GDB now includes support for for the GNU/Linux implementation of
3337 per-thread variables.
3339 * GNU/Linux's Native POSIX Thread Library (NPTL)
3341 GDB's thread code has been updated to work with either the new
3342 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3344 * Separate debug info.
3346 GDB, in conjunction with BINUTILS, now supports a mechanism for
3347 automatically loading debug information from a separate file. Instead
3348 of shipping full debug and non-debug versions of system libraries,
3349 system integrators can now instead ship just the stripped libraries
3350 and optional debug files.
3352 * DWARF 2 Location Expressions
3354 DWARF 2 Location Expressions allow the compiler to more completely
3355 describe the location of variables (even in optimized code) to the
3358 GDB now includes preliminary support for location expressions (support
3359 for DW_OP_piece is still missing).
3363 A number of long standing bugs that caused GDB to die while starting a
3364 Java application have been fixed. GDB's Java support is now
3365 considered "useable".
3367 * GNU/Linux support for fork, vfork, and exec.
3369 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3370 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3373 * GDB supports logging output to a file
3375 There are two new commands, "set logging" and "show logging", which can be
3376 used to capture GDB's output to a file.
3378 * The meaning of "detach" has changed for gdbserver
3380 The "detach" command will now resume the application, as documented. To
3381 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3384 * d10v, m68hc11 `regs' command deprecated
3386 The `info registers' command has been updated so that it displays the
3387 registers using a format identical to the old `regs' command.
3391 A new command, "maint set profile on/off", has been added. This command can
3392 be used to enable or disable profiling while running GDB, to profile a
3393 session or a set of commands. In addition there is a new configure switch,
3394 "--enable-profiling", which will cause GDB to be compiled with profiling
3395 data, for more informative profiling results.
3397 * Default MI syntax changed to "mi2".
3399 The default MI (machine interface) syntax, enabled by the command line
3400 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3401 "mi1", can be enabled by specifying the option "-i=mi1".
3403 Support for the original "mi0" syntax (included in GDB 5.0) has been
3406 Fix for gdb/192: removed extraneous space when displaying frame level.
3407 Fix for gdb/672: update changelist is now output in mi list format.
3408 Fix for gdb/702: a -var-assign that updates the value now shows up
3409 in a subsequent -var-update.
3411 * New native configurations.
3413 FreeBSD/amd64 x86_64-*-freebsd*
3415 * Multi-arched targets.
3417 HP/PA HPUX11 hppa*-*-hpux*
3418 Renesas M32R/D w/simulator m32r-*-elf*
3420 * OBSOLETE configurations and files
3422 Configurations that have been declared obsolete in this release have
3423 been commented out. Unless there is activity to revive these
3424 configurations, the next release of GDB will have their sources
3425 permanently REMOVED.
3427 Z8000 simulator z8k-zilog-none or z8ksim
3428 Matsushita MN10200 w/simulator mn10200-*-*
3429 H8/500 simulator h8500-hitachi-hms or h8500hms
3430 HP/PA running BSD hppa*-*-bsd*
3431 HP/PA running OSF/1 hppa*-*-osf*
3432 HP/PA Pro target hppa*-*-pro*
3433 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3434 Sequent family i[3456]86-sequent-sysv4*
3435 i[3456]86-sequent-sysv*
3436 i[3456]86-sequent-bsd*
3437 Tsqware Sparclet sparclet-*-*
3438 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3440 * REMOVED configurations and files
3443 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3444 IBM AIX PS/2 i[3456]86-*-aix
3445 i386 running Mach 3.0 i[3456]86-*-mach3*
3446 i386 running Mach i[3456]86-*-mach*
3447 i386 running OSF/1 i[3456]86-*osf1mk*
3448 HP/Apollo 68k Family m68*-apollo*-sysv*,
3450 m68*-hp-bsd*, m68*-hp-hpux*
3451 Argonaut Risc Chip (ARC) arc-*-*
3452 Mitsubishi D30V d30v-*-*
3453 Fujitsu FR30 fr30-*-elf*
3454 OS/9000 i[34]86-*-os9k
3455 I960 with MON960 i960-*-coff
3457 * MIPS $fp behavior changed
3459 The convenience variable $fp, for the MIPS, now consistently returns
3460 the address of the current frame's base. Previously, depending on the
3461 context, $fp could refer to either $sp or the current frame's base
3462 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3463 The GNU Source-Level Debugger''.
3465 *** Changes in GDB 5.3:
3467 * GNU/Linux shared library multi-threaded performance improved.
3469 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3470 `/proc', in preference to `ptrace' for memory reads. This may result
3471 in an improvement in the start-up time of multi-threaded, shared
3472 library applications when run under GDB. One GDB user writes: ``loads
3473 shared libs like mad''.
3475 * ``gdbserver'' now supports multi-threaded applications on some targets
3477 Support for debugging multi-threaded applications which use
3478 the GNU/Linux LinuxThreads package has been added for
3479 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3480 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3482 * GDB now supports C/C++ preprocessor macros.
3484 GDB now expands preprocessor macro invocations in C/C++ expressions,
3485 and provides various commands for showing macro definitions and how
3488 The new command `macro expand EXPRESSION' expands any macro
3489 invocations in expression, and shows the result.
3491 The new command `show macro MACRO-NAME' shows the definition of the
3492 macro named MACRO-NAME, and where it was defined.
3494 Most compilers don't include information about macros in the debugging
3495 information by default. In GCC 3.1, for example, you need to compile
3496 your program with the options `-gdwarf-2 -g3'. If the macro
3497 information is present in the executable, GDB will read it.
3499 * Multi-arched targets.
3501 DEC Alpha (partial) alpha*-*-*
3502 DEC VAX (partial) vax-*-*
3504 National Semiconductor NS32000 (partial) ns32k-*-*
3505 Motorola 68000 (partial) m68k-*-*
3506 Motorola MCORE mcore-*-*
3510 Fujitsu FRV architecture added by Red Hat frv*-*-*
3513 * New native configurations
3515 Alpha NetBSD alpha*-*-netbsd*
3516 SH NetBSD sh*-*-netbsdelf*
3517 MIPS NetBSD mips*-*-netbsd*
3518 UltraSPARC NetBSD sparc64-*-netbsd*
3520 * OBSOLETE configurations and files
3522 Configurations that have been declared obsolete in this release have
3523 been commented out. Unless there is activity to revive these
3524 configurations, the next release of GDB will have their sources
3525 permanently REMOVED.
3527 Mitsubishi D30V d30v-*-*
3528 OS/9000 i[34]86-*-os9k
3529 IBM AIX PS/2 i[3456]86-*-aix
3530 Fujitsu FR30 fr30-*-elf*
3531 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3532 Argonaut Risc Chip (ARC) arc-*-*
3533 i386 running Mach 3.0 i[3456]86-*-mach3*
3534 i386 running Mach i[3456]86-*-mach*
3535 i386 running OSF/1 i[3456]86-*osf1mk*
3536 HP/Apollo 68k Family m68*-apollo*-sysv*,
3538 m68*-hp-bsd*, m68*-hp-hpux*
3539 I960 with MON960 i960-*-coff
3541 * OBSOLETE languages
3543 CHILL, a Pascal like language used by telecommunications companies.
3545 * REMOVED configurations and files
3547 AMD 29k family via UDI a29k-amd-udi, udi29k
3548 A29K VxWorks a29k-*-vxworks
3549 AMD 29000 embedded, using EBMON a29k-none-none
3550 AMD 29000 embedded with COFF a29k-none-coff
3551 AMD 29000 embedded with a.out a29k-none-aout
3553 testsuite/gdb.hp/gdb.threads-hp/ directory
3555 * New command "set max-user-call-depth <nnn>"
3557 This command allows the user to limit the call depth of user-defined
3558 commands. The default is 1024.
3560 * Changes in FreeBSD/i386 native debugging.
3562 Support for the "generate-core-file" has been added.
3564 * New commands "dump", "append", and "restore".
3566 These commands allow data to be copied from target memory
3567 to a bfd-format or binary file (dump and append), and back
3568 from a file into memory (restore).
3570 * Improved "next/step" support on multi-processor Alpha Tru64.
3572 The previous single-step mechanism could cause unpredictable problems,
3573 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3574 of a software single-step mechanism prevents this.
3576 *** Changes in GDB 5.2.1:
3584 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3585 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3586 Fix, by Joel Brobecker imported from mainline.
3588 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3589 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3590 Fix, by Fred Fish, imported from mainline.
3592 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3593 Surprisingly enough, it works now.
3594 By Michal Ludvig, imported from mainline.
3596 i386 hardware watchpoint support:
3597 avoid misses on second run for some targets.
3598 By Pierre Muller, imported from mainline.
3600 *** Changes in GDB 5.2:
3602 * New command "set trust-readonly-sections on[off]".
3604 This command is a hint that tells gdb that read-only sections
3605 really are read-only (ie. that their contents will not change).
3606 In this mode, gdb will go to the object file rather than the
3607 target to read memory from read-only sections (such as ".text").
3608 This can be a significant performance improvement on some
3609 (notably embedded) targets.
3611 * New command "generate-core-file" (or "gcore").
3613 This new gdb command allows the user to drop a core file of the child
3614 process state at any time. So far it's been implemented only for
3615 GNU/Linux and Solaris, but should be relatively easily ported to other
3616 hosts. Argument is core file name (defaults to core.<pid>).
3618 * New command line option
3620 GDB now accepts --pid or -p followed by a process id.
3622 * Change in command line behavior -- corefiles vs. process ids.
3624 There is a subtle behavior in the way in which GDB handles
3625 command line arguments. The first non-flag argument is always
3626 a program to debug, but the second non-flag argument may either
3627 be a corefile or a process id. Previously, GDB would attempt to
3628 open the second argument as a corefile, and if that failed, would
3629 issue a superfluous error message and then attempt to attach it as
3630 a process. Now, if the second argument begins with a non-digit,
3631 it will be treated as a corefile. If it begins with a digit,
3632 GDB will attempt to attach it as a process, and if no such process
3633 is found, will then attempt to open it as a corefile.
3635 * Changes in ARM configurations.
3637 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3638 configuration is fully multi-arch.
3640 * New native configurations
3642 ARM NetBSD arm*-*-netbsd*
3643 x86 OpenBSD i[3456]86-*-openbsd*
3644 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3645 Sparc64 running FreeBSD sparc64-*-freebsd*
3649 Sanyo XStormy16 xstormy16-elf
3651 * OBSOLETE configurations and files
3653 Configurations that have been declared obsolete in this release have
3654 been commented out. Unless there is activity to revive these
3655 configurations, the next release of GDB will have their sources
3656 permanently REMOVED.
3658 AMD 29k family via UDI a29k-amd-udi, udi29k
3659 A29K VxWorks a29k-*-vxworks
3660 AMD 29000 embedded, using EBMON a29k-none-none
3661 AMD 29000 embedded with COFF a29k-none-coff
3662 AMD 29000 embedded with a.out a29k-none-aout
3664 testsuite/gdb.hp/gdb.threads-hp/ directory
3666 * REMOVED configurations and files
3668 TI TMS320C80 tic80-*-*
3670 PowerPC Solaris powerpcle-*-solaris*
3671 PowerPC Windows NT powerpcle-*-cygwin32
3672 PowerPC Netware powerpc-*-netware*
3673 Harris/CXUX m88k m88*-harris-cxux*
3674 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3675 ns32k-utek-sysv* ns32k-utek-*
3676 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3677 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3678 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3679 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3680 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3682 * Changes to command line processing
3684 The new `--args' feature can be used to specify command-line arguments
3685 for the inferior from gdb's command line.
3687 * Changes to key bindings
3689 There is a new `operate-and-get-next' function bound to `C-o'.
3691 *** Changes in GDB 5.1.1
3693 Fix compile problem on DJGPP.
3695 Fix a problem with floating-point registers on the i386 being
3698 Fix to stop GDB crashing on .debug_str debug info.
3700 Numerous documentation fixes.
3702 Numerous testsuite fixes.
3704 *** Changes in GDB 5.1:
3706 * New native configurations
3708 Alpha FreeBSD alpha*-*-freebsd*
3709 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3710 MIPS GNU/Linux mips*-*-linux*
3711 MIPS SGI Irix 6.x mips*-sgi-irix6*
3712 ia64 AIX ia64-*-aix*
3713 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3717 Motorola 68HC11 and 68HC12 m68hc11-elf
3719 UltraSparc running GNU/Linux sparc64-*-linux*
3721 * OBSOLETE configurations and files
3723 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3724 Harris/CXUX m88k m88*-harris-cxux*
3725 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3726 ns32k-utek-sysv* ns32k-utek-*
3727 TI TMS320C80 tic80-*-*
3729 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3730 PowerPC Solaris powerpcle-*-solaris*
3731 PowerPC Windows NT powerpcle-*-cygwin32
3732 PowerPC Netware powerpc-*-netware*
3733 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3734 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3735 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3736 Apple Macintosh (MPW) host N/A
3738 stuff.c (Program to stuff files into a specially prepared space in kdb)
3739 kdb-start.c (Main loop for the standalone kernel debugger)
3741 Configurations that have been declared obsolete in this release have
3742 been commented out. Unless there is activity to revive these
3743 configurations, the next release of GDB will have their sources
3744 permanently REMOVED.
3746 * REMOVED configurations and files
3748 Altos 3068 m68*-altos-*
3749 Convex c1-*-*, c2-*-*
3751 ARM RISCix arm-*-* (as host)
3755 * GDB has been converted to ISO C.
3757 GDB's source code has been converted to ISO C. In particular, the
3758 sources are fully protoized, and rely on standard headers being
3763 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3765 * The MI enabled by default.
3767 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3768 revised and enabled by default. Packages which use GDB as a debugging
3769 engine behind a UI or another front end are encouraged to switch to
3770 using the GDB/MI interface, instead of the old annotations interface
3771 which is now deprecated.
3773 * Support for debugging Pascal programs.
3775 GDB now includes support for debugging Pascal programs. The following
3776 main features are supported:
3778 - Pascal-specific data types such as sets;
3780 - automatic recognition of Pascal sources based on file-name
3783 - Pascal-style display of data types, variables, and functions;
3785 - a Pascal expression parser.
3787 However, some important features are not yet supported.
3789 - Pascal string operations are not supported at all;
3791 - there are some problems with boolean types;
3793 - Pascal type hexadecimal constants are not supported
3794 because they conflict with the internal variables format;
3796 - support for Pascal objects and classes is not full yet;
3798 - unlike Pascal, GDB is case-sensitive for symbol names.
3800 * Changes in completion.
3802 Commands such as `shell', `run' and `set args', which pass arguments
3803 to inferior programs, now complete on file names, similar to what
3804 users expect at the shell prompt.
3806 Commands which accept locations, such as `disassemble', `print',
3807 `breakpoint', `until', etc. now complete on filenames as well as
3808 program symbols. Thus, if you type "break foob TAB", and the source
3809 files linked into the programs include `foobar.c', that file name will
3810 be one of the candidates for completion. However, file names are not
3811 considered for completion after you typed a colon that delimits a file
3812 name from a name of a function in that file, as in "break foo.c:bar".
3814 `set demangle-style' completes on available demangling styles.
3816 * New platform-independent commands:
3818 It is now possible to define a post-hook for a command as well as a
3819 hook that runs before the command. For more details, see the
3820 documentation of `hookpost' in the GDB manual.
3822 * Changes in GNU/Linux native debugging.
3824 Support for debugging multi-threaded programs has been completely
3825 revised for all platforms except m68k and sparc. You can now debug as
3826 many threads as your system allows you to have.
3828 Attach/detach is supported for multi-threaded programs.
3830 Support for SSE registers was added for x86. This doesn't work for
3831 multi-threaded programs though.
3833 * Changes in MIPS configurations.
3835 Multi-arch support is enabled for all MIPS configurations.
3837 GDB can now be built as native debugger on SGI Irix 6.x systems for
3838 debugging n32 executables. (Debugging 64-bit executables is not yet
3841 * Unified support for hardware watchpoints in all x86 configurations.
3843 Most (if not all) native x86 configurations support hardware-assisted
3844 breakpoints and watchpoints in a unified manner. This support
3845 implements debug register sharing between watchpoints, which allows to
3846 put a virtually infinite number of watchpoints on the same address,
3847 and also supports watching regions up to 16 bytes with several debug
3850 The new maintenance command `maintenance show-debug-regs' toggles
3851 debugging print-outs in functions that insert, remove, and test
3852 watchpoints and hardware breakpoints.
3854 * Changes in the DJGPP native configuration.
3856 New command ``info dos sysinfo'' displays assorted information about
3857 the CPU, OS, memory, and DPMI server.
3859 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3860 display information about segment descriptors stored in GDT, LDT, and
3863 New commands ``info dos pde'' and ``info dos pte'' display entries
3864 from Page Directory and Page Tables (for now works with CWSDPMI only).
3865 New command ``info dos address-pte'' displays the Page Table entry for
3866 a given linear address.
3868 GDB can now pass command lines longer than 126 characters to the
3869 program being debugged (requires an update to the libdbg.a library
3870 which is part of the DJGPP development kit).
3872 DWARF2 debug info is now supported.
3874 It is now possible to `step' and `next' through calls to `longjmp'.
3876 * Changes in documentation.
3878 All GDB documentation was converted to GFDL, the GNU Free
3879 Documentation License.
3881 Tracepoints-related commands are now fully documented in the GDB
3884 TUI, the Text-mode User Interface, is now documented in the manual.
3886 Tracepoints-related commands are now fully documented in the GDB
3889 The "GDB Internals" manual now has an index. It also includes
3890 documentation of `ui_out' functions, GDB coding standards, x86
3891 hardware watchpoints, and memory region attributes.
3893 * GDB's version number moved to ``version.in''
3895 The Makefile variable VERSION has been replaced by the file
3896 ``version.in''. People creating GDB distributions should update the
3897 contents of this file.
3901 GUD support is now a standard part of the EMACS distribution.
3903 *** Changes in GDB 5.0:
3905 * Improved support for debugging FP programs on x86 targets
3907 Unified and much-improved support for debugging floating-point
3908 programs on all x86 targets. In particular, ``info float'' now
3909 displays the FP registers in the same format on all x86 targets, with
3910 greater level of detail.
3912 * Improvements and bugfixes in hardware-assisted watchpoints
3914 It is now possible to watch array elements, struct members, and
3915 bitfields with hardware-assisted watchpoints. Data-read watchpoints
3916 on x86 targets no longer erroneously trigger when the address is
3919 * Improvements in the native DJGPP version of GDB
3921 The distribution now includes all the scripts and auxiliary files
3922 necessary to build the native DJGPP version on MS-DOS/MS-Windows
3923 machines ``out of the box''.
3925 The DJGPP version can now debug programs that use signals. It is
3926 possible to catch signals that happened in the debuggee, deliver
3927 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
3928 would kill the program being debugged.) Programs that hook hardware
3929 interrupts (keyboard, timer, etc.) can also be debugged.
3931 It is now possible to debug DJGPP programs that redirect their
3932 standard handles or switch them to raw (as opposed to cooked) mode, or
3933 even close them. The command ``run < foo > bar'' works as expected,
3934 and ``info terminal'' reports useful information about the debuggee's
3935 terminal, including raw/cooked mode, redirection, etc.
3937 The DJGPP version now uses termios functions for console I/O, which
3938 enables debugging graphics programs. Interrupting GDB with Ctrl-C
3941 DOS-style file names with drive letters are now fully supported by
3944 It is now possible to debug DJGPP programs that switch their working
3945 directory. It is also possible to rerun the debuggee any number of
3946 times without restarting GDB; thus, you can use the same setup,
3947 breakpoints, etc. for many debugging sessions.
3949 * New native configurations
3951 ARM GNU/Linux arm*-*-linux*
3952 PowerPC GNU/Linux powerpc-*-linux*
3956 Motorola MCore mcore-*-*
3957 x86 VxWorks i[3456]86-*-vxworks*
3958 PowerPC VxWorks powerpc-*-vxworks*
3959 TI TMS320C80 tic80-*-*
3961 * OBSOLETE configurations
3963 Altos 3068 m68*-altos-*
3964 Convex c1-*-*, c2-*-*
3966 ARM RISCix arm-*-* (as host)
3969 Configurations that have been declared obsolete will be commented out,
3970 but the code will be left in place. If there is no activity to revive
3971 these configurations before the next release of GDB, the sources will
3972 be permanently REMOVED.
3974 * Gould support removed
3976 Support for the Gould PowerNode and NP1 has been removed.
3978 * New features for SVR4
3980 On SVR4 native platforms (such as Solaris), if you attach to a process
3981 without first loading a symbol file, GDB will now attempt to locate and
3982 load symbols from the running process's executable file.
3984 * Many C++ enhancements
3986 C++ support has been greatly improved. Overload resolution now works properly
3987 in almost all cases. RTTI support is on the way.
3989 * Remote targets can connect to a sub-program
3991 A popen(3) style serial-device has been added. This device starts a
3992 sub-process (such as a stand-alone simulator) and then communicates
3993 with that. The sub-program to run is specified using the syntax
3994 ``|<program> <args>'' vis:
3996 (gdb) set remotedebug 1
3997 (gdb) target extended-remote |mn10300-elf-sim program-args
3999 * MIPS 64 remote protocol
4001 A long standing bug in the mips64 remote protocol where by GDB
4002 expected certain 32 bit registers (ex SR) to be transfered as 32
4003 instead of 64 bits has been fixed.
4005 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4006 added to provide backward compatibility with older versions of GDB.
4008 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4010 The command ``set remotebinarydownload'' command has been replaced by
4011 ``set remote X-packet''. Other commands in ``set remote'' family
4012 include ``set remote P-packet''.
4014 * Breakpoint commands accept ranges.
4016 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4017 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4018 ``tracepoint passcount'' also accepts a range of tracepoints.
4020 * ``apropos'' command added.
4022 The ``apropos'' command searches through command names and
4023 documentation strings, printing out matches, making it much easier to
4024 try to find a command that does what you are looking for.
4028 A new machine oriented interface (MI) has been added to GDB. This
4029 interface is designed for debug environments running GDB as a separate
4030 process. This is part of the long term libGDB project. See the
4031 "GDB/MI" chapter of the GDB manual for further information. It can be
4032 enabled by configuring with:
4034 .../configure --enable-gdbmi
4036 *** Changes in GDB-4.18:
4038 * New native configurations
4040 HP-UX 10.20 hppa*-*-hpux10.20
4041 HP-UX 11.x hppa*-*-hpux11.0*
4042 M68K GNU/Linux m68*-*-linux*
4046 Fujitsu FR30 fr30-*-elf*
4047 Intel StrongARM strongarm-*-*
4048 Mitsubishi D30V d30v-*-*
4050 * OBSOLETE configurations
4052 Gould PowerNode, NP1 np1-*-*, pn-*-*
4054 Configurations that have been declared obsolete will be commented out,
4055 but the code will be left in place. If there is no activity to revive
4056 these configurations before the next release of GDB, the sources will
4057 be permanently REMOVED.
4061 As a compatibility experiment, GDB's source files buildsym.h and
4062 buildsym.c have been converted to pure standard C, no longer
4063 containing any K&R compatibility code. We believe that all systems in
4064 use today either come with a standard C compiler, or have a GCC port
4065 available. If this is not true, please report the affected
4066 configuration to bug-gdb@gnu.org immediately. See the README file for
4067 information about getting a standard C compiler if you don't have one
4072 GDB now uses readline 2.2.
4074 * set extension-language
4076 You can now control the mapping between filename extensions and source
4077 languages by using the `set extension-language' command. For instance,
4078 you can ask GDB to treat .c files as C++ by saying
4079 set extension-language .c c++
4080 The command `info extensions' lists all of the recognized extensions
4081 and their associated languages.
4083 * Setting processor type for PowerPC and RS/6000
4085 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4086 you can use the `set processor' command to specify what variant of the
4087 PowerPC family you are debugging. The command
4091 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4092 following PowerPC and RS6000 variants:
4094 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4095 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4097 403GC IBM PowerPC 403GC
4098 505 Motorola PowerPC 505
4099 860 Motorola PowerPC 860 or 850
4100 601 Motorola PowerPC 601
4101 602 Motorola PowerPC 602
4102 603 Motorola/IBM PowerPC 603 or 603e
4103 604 Motorola PowerPC 604 or 604e
4104 750 Motorola/IBM PowerPC 750 or 750
4106 At the moment, this command just tells GDB what to name the
4107 special-purpose processor registers. Since almost all the affected
4108 registers are inaccessible to user-level programs, this command is
4109 only useful for remote debugging in its present form.
4113 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4114 more extensive support for HP-UX. Added features include shared
4115 library support, kernel threads and hardware watchpoints for 11.00,
4116 support for HP's ANSI C and C++ compilers, and a compatibility mode
4117 for xdb and dbx commands.
4121 HP's donation includes the new concept of catchpoints, which is a
4122 generalization of the old catch command. On HP-UX, it is now possible
4123 to catch exec, fork, and vfork, as well as library loading.
4125 This means that the existing catch command has changed; its first
4126 argument now specifies the type of catch to be set up. See the
4127 output of "help catch" for a list of catchpoint types.
4129 * Debugging across forks
4131 On HP-UX, you can choose which process to debug when a fork() happens
4136 HP has donated a curses-based terminal user interface (TUI). To get
4137 it, build with --enable-tui. Although this can be enabled for any
4138 configuration, at present it only works for native HP debugging.
4140 * GDB remote protocol additions
4142 A new protocol packet 'X' that writes binary data is now available.
4143 Default behavior is to try 'X', then drop back to 'M' if the stub
4144 fails to respond. The settable variable `remotebinarydownload'
4145 allows explicit control over the use of 'X'.
4147 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4148 full 64-bit address. The command
4150 set remoteaddresssize 32
4152 can be used to revert to the old behaviour. For existing remote stubs
4153 the change should not be noticed, as the additional address information
4156 In order to assist in debugging stubs, you may use the maintenance
4157 command `packet' to send any text string to the stub. For instance,
4159 maint packet heythere
4161 sends the packet "$heythere#<checksum>". Note that it is very easy to
4162 disrupt a debugging session by sending the wrong packet at the wrong
4165 The compare-sections command allows you to compare section data on the
4166 target to what is in the executable file without uploading or
4167 downloading, by comparing CRC checksums.
4169 * Tracing can collect general expressions
4171 You may now collect general expressions at tracepoints. This requires
4172 further additions to the target-side stub; see tracepoint.c and
4173 doc/agentexpr.texi for further details.
4175 * mask-address variable for Mips
4177 For Mips targets, you may control the zeroing of the upper 32 bits of
4178 a 64-bit address by entering `set mask-address on'. This is mainly
4179 of interest to users of embedded R4xxx and R5xxx processors.
4181 * Higher serial baud rates
4183 GDB's serial code now allows you to specify baud rates 57600, 115200,
4184 230400, and 460800 baud. (Note that your host system may not be able
4185 to achieve all of these rates.)
4189 The i960 configuration now includes an initial implementation of a
4190 builtin simulator, contributed by Jim Wilson.
4193 *** Changes in GDB-4.17:
4195 * New native configurations
4197 Alpha GNU/Linux alpha*-*-linux*
4198 Unixware 2.x i[3456]86-unixware2*
4199 Irix 6.x mips*-sgi-irix6*
4200 PowerPC GNU/Linux powerpc-*-linux*
4201 PowerPC Solaris powerpcle-*-solaris*
4202 Sparc GNU/Linux sparc-*-linux*
4203 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4207 Argonaut Risc Chip (ARC) arc-*-*
4208 Hitachi H8/300S h8300*-*-*
4209 Matsushita MN10200 w/simulator mn10200-*-*
4210 Matsushita MN10300 w/simulator mn10300-*-*
4211 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4212 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4213 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4214 Mitsubishi D10V w/simulator d10v-*-*
4215 Mitsubishi M32R/D w/simulator m32r-*-elf*
4216 Tsqware Sparclet sparclet-*-*
4217 NEC V850 w/simulator v850-*-*
4219 * New debugging protocols
4221 ARM with RDI protocol arm*-*-*
4222 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4223 DDB and LSI variants of PMON protocol mips*-*-*
4224 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4225 PowerPC with SDS protocol powerpc{,le}-*-eabi
4226 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4230 All configurations can now understand and use the DWARF 2 debugging
4231 format. The choice is automatic, if the symbol file contains DWARF 2
4236 GDB now includes basic Java language support. This support is
4237 only useful with Java compilers that produce native machine code.
4239 * solib-absolute-prefix and solib-search-path
4241 For SunOS and SVR4 shared libraries, you may now set the prefix for
4242 loading absolute shared library symbol files, and the search path for
4243 locating non-absolute shared library symbol files.
4245 * Live range splitting
4247 GDB can now effectively debug code for which GCC has performed live
4248 range splitting as part of its optimization. See gdb/doc/LRS for
4249 more details on the expected format of the stabs information.
4253 GDB's support for the GNU Hurd, including thread debugging, has been
4254 updated to work with current versions of the Hurd.
4258 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4259 instruction set. ARM GDB automatically detects when Thumb
4260 instructions are in use, and adjusts disassembly and backtracing
4265 GDB's MIPS target configurations now handle the MIP16 16-bit
4270 GDB now includes support for overlays; if an executable has been
4271 linked such that multiple sections are based at the same address, GDB
4272 will decide which section to use for symbolic info. You can choose to
4273 control the decision manually, using overlay commands, or implement
4274 additional target-side support and use "overlay load-target" to bring
4275 in the overlay mapping. Do "help overlay" for more detail.
4279 The command "info symbol <address>" displays information about
4280 the symbol at the specified address.
4284 The standard remote protocol now includes an extension that allows
4285 asynchronous collection and display of trace data. This requires
4286 extensive support in the target-side debugging stub. Tracing mode
4287 includes a new interaction mode in GDB and new commands: see the
4288 file tracepoint.c for more details.
4292 Configurations for embedded MIPS now include a simulator contributed
4293 by Cygnus Solutions. The simulator supports the instruction sets
4294 of most MIPS variants.
4298 Sparc configurations may now include the ERC32 simulator contributed
4299 by the European Space Agency. The simulator is not built into
4300 Sparc targets by default; configure with --enable-sim to include it.
4304 For target configurations that may include multiple variants of a
4305 basic architecture (such as MIPS and SH), you may now set the
4306 architecture explicitly. "set arch" sets, "info arch" lists
4307 the possible architectures.
4309 *** Changes in GDB-4.16:
4311 * New native configurations
4313 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4314 M68K NetBSD m68k-*-netbsd*
4315 PowerPC AIX 4.x powerpc-*-aix*
4316 PowerPC MacOS powerpc-*-macos*
4317 PowerPC Windows NT powerpcle-*-cygwin32
4318 RS/6000 AIX 4.x rs6000-*-aix4*
4322 ARM with RDP protocol arm-*-*
4323 I960 with MON960 i960-*-coff
4324 MIPS VxWorks mips*-*-vxworks*
4325 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4326 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4328 Matra Sparclet sparclet-*-*
4332 The powerpc-eabi configuration now includes the PSIM simulator,
4333 contributed by Andrew Cagney, with assistance from Mike Meissner.
4334 PSIM is a very elaborate model of the PowerPC, including not only
4335 basic instruction set execution, but also details of execution unit
4336 performance and I/O hardware. See sim/ppc/README for more details.
4340 GDB now works with Solaris 2.5.
4342 * Windows 95/NT native
4344 GDB will now work as a native debugger on Windows 95 and Windows NT.
4345 To build it from source, you must use the "gnu-win32" environment,
4346 which uses a DLL to emulate enough of Unix to run the GNU tools.
4347 Further information, binaries, and sources are available at
4348 ftp.cygnus.com, under pub/gnu-win32.
4350 * dont-repeat command
4352 If a user-defined command includes the command `dont-repeat', then the
4353 command will not be repeated if the user just types return. This is
4354 useful if the command is time-consuming to run, so that accidental
4355 extra keystrokes don't run the same command many times.
4357 * Send break instead of ^C
4359 The standard remote protocol now includes an option to send a break
4360 rather than a ^C to the target in order to interrupt it. By default,
4361 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4363 * Remote protocol timeout
4365 The standard remote protocol includes a new variable `remotetimeout'
4366 that allows you to set the number of seconds before GDB gives up trying
4367 to read from the target. The default value is 2.
4369 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4371 By default GDB will automatically keep track of objects as they are
4372 loaded and unloaded by the dynamic linker. By using the command `set
4373 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4374 when shared library events occur, thus allowing you to set breakpoints
4375 in shared libraries which are explicitly loaded by the inferior.
4377 Note this feature does not work on hpux8. On hpux9 you must link
4378 /usr/lib/end.o into your program. This feature should work
4379 automatically on hpux10.
4381 * Irix 5.x hardware watchpoint support
4383 Irix 5 configurations now support the use of hardware watchpoints.
4385 * Mips protocol "SYN garbage limit"
4387 When debugging a Mips target using the `target mips' protocol, you
4388 may set the number of characters that GDB will ignore by setting
4389 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4390 every character. The default value is 1050.
4392 * Recording and replaying remote debug sessions
4394 If you set `remotelogfile' to the name of a file, gdb will write to it
4395 a recording of a remote debug session. This recording may then be
4396 replayed back to gdb using "gdbreplay". See gdbserver/README for
4397 details. This is useful when you have a problem with GDB while doing
4398 remote debugging; you can make a recording of the session and send it
4399 to someone else, who can then recreate the problem.
4401 * Speedups for remote debugging
4403 GDB includes speedups for downloading and stepping MIPS systems using
4404 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4405 and more efficient S-record downloading.
4407 * Memory use reductions and statistics collection
4409 GDB now uses less memory and reports statistics about memory usage.
4410 Try the `maint print statistics' command, for example.
4412 *** Changes in GDB-4.15:
4414 * Psymtabs for XCOFF
4416 The symbol reader for AIX GDB now uses partial symbol tables. This
4417 can greatly improve startup time, especially for large executables.
4419 * Remote targets use caching
4421 Remote targets now use a data cache to speed up communication with the
4422 remote side. The data cache could lead to incorrect results because
4423 it doesn't know about volatile variables, thus making it impossible to
4424 debug targets which use memory mapped I/O devices. `set remotecache
4425 off' turns the the data cache off.
4427 * Remote targets may have threads
4429 The standard remote protocol now includes support for multiple threads
4430 in the target system, using new protocol commands 'H' and 'T'. See
4431 gdb/remote.c for details.
4435 If GDB is configured with `--enable-netrom', then it will include
4436 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4437 acts as though it is a bank of ROM on the target board, but you can
4438 write into it over the network. GDB's support consists only of
4439 support for fast loading into the emulated ROM; to debug, you must use
4440 another protocol, such as standard remote protocol. The usual
4441 sequence is something like
4443 target nrom <netrom-hostname>
4445 target remote <netrom-hostname>:1235
4449 GDB now includes support for the Apple Macintosh, as a host only. It
4450 may be run as either an MPW tool or as a standalone application, and
4451 it can debug through the serial port. All the usual GDB commands are
4452 available, but to the target command, you must supply "serial" as the
4453 device type instead of "/dev/ttyXX". See mpw-README in the main
4454 directory for more information on how to build. The MPW configuration
4455 scripts */mpw-config.in support only a few targets, and only the
4456 mips-idt-ecoff target has been tested.
4460 GDB configuration now uses autoconf. This is not user-visible,
4461 but does simplify configuration and building.
4465 GDB now supports hpux10.
4467 *** Changes in GDB-4.14:
4469 * New native configurations
4471 x86 FreeBSD i[345]86-*-freebsd
4472 x86 NetBSD i[345]86-*-netbsd
4473 NS32k NetBSD ns32k-*-netbsd
4474 Sparc NetBSD sparc-*-netbsd
4478 A29K VxWorks a29k-*-vxworks
4479 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4480 CPU32 EST-300 emulator m68*-*-est*
4481 PowerPC ELF powerpc-*-elf
4484 * Alpha OSF/1 support for procfs
4486 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4487 possible to attach to running processes. As the mounting of the /proc
4488 filesystem is optional on the Alpha, GDB automatically determines
4489 the availability of /proc during startup. This can lead to problems
4490 if /proc is unmounted after GDB has been started.
4492 * Arguments to user-defined commands
4494 User commands may accept up to 10 arguments separated by whitespace.
4495 Arguments are accessed within the user command via $arg0..$arg9. A
4498 print $arg0 + $arg1 + $arg2
4500 To execute the command use:
4503 Defines the command "adder" which prints the sum of its three arguments.
4504 Note the arguments are text substitutions, so they may reference variables,
4505 use complex expressions, or even perform inferior function calls.
4507 * New `if' and `while' commands
4509 This makes it possible to write more sophisticated user-defined
4510 commands. Both commands take a single argument, which is the
4511 expression to evaluate, and must be followed by the commands to
4512 execute, one per line, if the expression is nonzero, the list being
4513 terminated by the word `end'. The `if' command list may include an
4514 `else' word, which causes the following commands to be executed only
4515 if the expression is zero.
4517 * Fortran source language mode
4519 GDB now includes partial support for Fortran 77. It will recognize
4520 Fortran programs and can evaluate a subset of Fortran expressions, but
4521 variables and functions may not be handled correctly. GDB will work
4522 with G77, but does not yet know much about symbols emitted by other
4525 * Better HPUX support
4527 Most debugging facilities now work on dynamic executables for HPPAs
4528 running hpux9 or later. You can attach to running dynamically linked
4529 processes, but by default the dynamic libraries will be read-only, so
4530 for instance you won't be able to put breakpoints in them. To change
4531 that behavior do the following before running the program:
4537 This will cause the libraries to be mapped private and read-write.
4538 To revert to the normal behavior, do this:
4544 You cannot set breakpoints or examine data in the library until after
4545 the library is loaded if the function/data symbols do not have
4548 GDB can now also read debug symbols produced by the HP C compiler on
4549 HPPAs (sorry, no C++, Fortran or 68k support).
4551 * Target byte order now dynamically selectable
4553 You can choose which byte order to use with a target system, via the
4554 commands "set endian big" and "set endian little", and you can see the
4555 current setting by using "show endian". You can also give the command
4556 "set endian auto", in which case GDB will use the byte order
4557 associated with the executable. Currently, only embedded MIPS
4558 configurations support dynamic selection of target byte order.
4560 * New DOS host serial code
4562 This version uses DPMI interrupts to handle buffered I/O, so you
4563 no longer need to run asynctsr when debugging boards connected to
4566 *** Changes in GDB-4.13:
4568 * New "complete" command
4570 This lists all the possible completions for the rest of the line, if it
4571 were to be given as a command itself. This is intended for use by emacs.
4573 * Trailing space optional in prompt
4575 "set prompt" no longer adds a space for you after the prompt you set. This
4576 allows you to set a prompt which ends in a space or one that does not.
4578 * Breakpoint hit counts
4580 "info break" now displays a count of the number of times the breakpoint
4581 has been hit. This is especially useful in conjunction with "ignore"; you
4582 can ignore a large number of breakpoint hits, look at the breakpoint info
4583 to see how many times the breakpoint was hit, then run again, ignoring one
4584 less than that number, and this will get you quickly to the last hit of
4587 * Ability to stop printing at NULL character
4589 "set print null-stop" will cause GDB to stop printing the characters of
4590 an array when the first NULL is encountered. This is useful when large
4591 arrays actually contain only short strings.
4593 * Shared library breakpoints
4595 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4596 breakpoints in shared libraries before the executable is run.
4598 * Hardware watchpoints
4600 There is a new hardware breakpoint for the watch command for sparclite
4601 targets. See gdb/sparclite/hw_breakpoint.note.
4603 Hardware watchpoints are also now supported under GNU/Linux.
4607 Annotations have been added. These are for use with graphical interfaces,
4608 and are still experimental. Currently only gdba.el uses these.
4610 * Improved Irix 5 support
4612 GDB now works properly with Irix 5.2.
4614 * Improved HPPA support
4616 GDB now works properly with the latest GCC and GAS.
4618 * New native configurations
4620 Sequent PTX4 i[34]86-sequent-ptx4
4621 HPPA running OSF/1 hppa*-*-osf*
4622 Atari TT running SVR4 m68*-*-sysv4*
4623 RS/6000 LynxOS rs6000-*-lynxos*
4627 OS/9000 i[34]86-*-os9k
4628 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4631 * Hitachi SH7000 and E7000-PC ICE support
4633 There is now support for communicating with the Hitachi E7000-PC ICE.
4634 This is available automatically when GDB is configured for the SH.
4638 As usual, a variety of small fixes and improvements, both generic
4639 and configuration-specific. See the ChangeLog for more detail.
4641 *** Changes in GDB-4.12:
4643 * Irix 5 is now supported
4647 GDB-4.12 on the HPPA has a number of changes which make it unable
4648 to debug the output from the currently released versions of GCC and
4649 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4650 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4651 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4654 *** Changes in GDB-4.11:
4656 * User visible changes:
4660 The "set remotedebug" option is now consistent between the mips remote
4661 target, remote targets using the gdb-specific protocol, UDI (AMD's
4662 debug protocol for the 29k) and the 88k bug monitor. It is now an
4663 integer specifying a debug level (normally 0 or 1, but 2 means more
4664 debugging info for the mips target).
4666 * DEC Alpha native support
4668 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4669 debug info, but GDB works fairly well with the DEC compiler and should
4670 work with a future GCC release. See the README file for a few
4671 Alpha-specific notes.
4673 * Preliminary thread implementation
4675 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4677 * LynxOS native and target support for 386
4679 This release has been hosted on LynxOS 2.2, and also can be configured
4680 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4683 * Improvements in C++ mangling/demangling.
4685 This release has much better g++ debugging, specifically in name
4686 mangling/demangling, virtual function calls, print virtual table,
4687 call methods, ...etc.
4689 *** Changes in GDB-4.10:
4691 * User visible changes:
4693 Remote debugging using the GDB-specific (`target remote') protocol now
4694 supports the `load' command. This is only useful if you have some
4695 other way of getting the stub to the target system, and you can put it
4696 somewhere in memory where it won't get clobbered by the download.
4698 Filename completion now works.
4700 When run under emacs mode, the "info line" command now causes the
4701 arrow to point to the line specified. Also, "info line" prints
4702 addresses in symbolic form (as well as hex).
4704 All vxworks based targets now support a user settable option, called
4705 vxworks-timeout. This option represents the number of seconds gdb
4706 should wait for responses to rpc's. You might want to use this if
4707 your vxworks target is, perhaps, a slow software simulator or happens
4708 to be on the far side of a thin network line.
4712 This release contains support for using a DEC alpha as a GDB host for
4713 cross debugging. Native alpha debugging is not supported yet.
4716 *** Changes in GDB-4.9:
4720 This is the first GDB release which is accompanied by a matching testsuite.
4721 The testsuite requires installation of dejagnu, which should be available
4722 via ftp from most sites that carry GNU software.
4726 'Cfront' style demangling has had its name changed to 'ARM' style, to
4727 emphasize that it was written from the specifications in the C++ Annotated
4728 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4729 disclaimers, it still generated too much confusion with users attempting to
4730 use gdb with AT&T cfront.
4734 GDB now uses a standard remote interface to a simulator library.
4735 So far, the library contains simulators for the Zilog Z8001/2, the
4736 Hitachi H8/300, H8/500 and Super-H.
4738 * New targets supported
4740 H8/300 simulator h8300-hitachi-hms or h8300hms
4741 H8/500 simulator h8500-hitachi-hms or h8500hms
4742 SH simulator sh-hitachi-hms or sh
4743 Z8000 simulator z8k-zilog-none or z8ksim
4744 IDT MIPS board over serial line mips-idt-ecoff
4746 Cross-debugging to GO32 targets is supported. It requires a custom
4747 version of the i386-stub.c module which is integrated with the
4748 GO32 memory extender.
4750 * New remote protocols
4752 MIPS remote debugging protocol.
4754 * New source languages supported
4756 This version includes preliminary support for Chill, a Pascal like language
4757 used by telecommunications companies. Chill support is also being integrated
4758 into the GNU compiler, but we don't know when it will be publically available.
4761 *** Changes in GDB-4.8:
4763 * HP Precision Architecture supported
4765 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4766 version of this support was available as a set of patches from the
4767 University of Utah. GDB does not support debugging of programs
4768 compiled with the HP compiler, because HP will not document their file
4769 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4770 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4772 Many problems in the preliminary version have been fixed.
4774 * Faster and better demangling
4776 We have improved template demangling and fixed numerous bugs in the GNU style
4777 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4778 character types (wchar_t) are now supported. Demangling of each symbol is now
4779 only done once, and is cached when the symbol table for a file is read in.
4780 This results in a small increase in memory usage for C programs, a moderate
4781 increase in memory usage for C++ programs, and a fantastic speedup in
4784 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4785 from the specifications in the Annotated Reference Manual, which AT&T's
4786 compiler does not actually implement.
4788 * G++ multiple inheritance compiler problem
4790 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4791 inheritance lattices was reworked to properly discover ambiguities. We
4792 recently found an example which causes this new algorithm to fail in a
4793 very subtle way, producing bad debug information for those classes.
4794 The file 'gcc.patch' (in this directory) can be applied to gcc to
4795 circumvent the problem. A future GCC release will contain a complete
4798 The previous G++ debug info problem (mentioned below for the gdb-4.7
4799 release) is fixed in gcc version 2.3.2.
4801 * Improved configure script
4803 The `configure' script will now attempt to guess your system type if
4804 you don't supply a host system type. The old scheme of supplying a
4805 host system triplet is preferable over using this. All the magic is
4806 done in the new `config.guess' script. Examine it for details.
4808 We have also brought our configure script much more in line with the FSF's
4809 version. It now supports the --with-xxx options. In particular,
4810 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4811 The resulting GDB will not be able to read arbitrary object file formats --
4812 only the format ``expected'' to be used on the configured target system.
4813 We hope to make this the default in a future release.
4815 * Documentation improvements
4817 There's new internal documentation on how to modify GDB, and how to
4818 produce clean changes to the code. We implore people to read it
4819 before submitting changes.
4821 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4822 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4823 `info' files are also provided. To build `info' files from scratch,
4824 you will need the latest `makeinfo' release, which will be available in
4825 a future texinfo-X.Y release.
4827 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4828 We're not sure exactly which versions have this problem, but it has
4829 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4830 or better. If that isn't possible, there is a patch in
4831 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4832 around this problem.
4836 GDB now supports array constants that can be used in expressions typed in by
4837 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4838 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4841 The new directory `gdb/sparclite' contains a program that demonstrates
4842 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4844 * New native hosts supported
4846 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4847 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4849 * New targets supported
4851 AMD 29k family via UDI a29k-amd-udi or udi29k
4853 * New file formats supported
4855 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4856 HPUX core files, and SCO 3.2v2 core files.
4860 Attaching to processes now works again; thanks for the many bug reports.
4862 We have also stomped on a bunch of core dumps caused by
4863 printf_filtered("%s") problems.
4865 We eliminated a copyright problem on the rpc and ptrace header files
4866 for VxWorks, which was discovered at the last minute during the 4.7
4867 release. You should now be able to build a VxWorks GDB.
4869 You can now interrupt gdb while an attached process is running. This
4870 will cause the attached process to stop, and give control back to GDB.
4872 We fixed problems caused by using too many file descriptors
4873 for reading symbols from object files and libraries. This was
4874 especially a problem for programs that used many (~100) shared
4877 The `step' command now only enters a subroutine if there is line number
4878 information for the subroutine. Otherwise it acts like the `next'
4879 command. Previously, `step' would enter subroutines if there was
4880 any debugging information about the routine. This avoids problems
4881 when using `cc -g1' on MIPS machines.
4883 * Internal improvements
4885 GDB's internal interfaces have been improved to make it easier to support
4886 debugging of multiple languages in the future.
4888 GDB now uses a common structure for symbol information internally.
4889 Minimal symbols (derived from linkage symbols in object files), partial
4890 symbols (from a quick scan of debug information), and full symbols
4891 contain a common subset of information, making it easier to write
4892 shared code that handles any of them.
4894 * New command line options
4896 We now accept --silent as an alias for --quiet.
4900 The memory-mapped-malloc library is now licensed under the GNU Library
4901 General Public License.
4903 *** Changes in GDB-4.7:
4905 * Host/native/target split
4907 GDB has had some major internal surgery to untangle the support for
4908 hosts and remote targets. Now, when you configure GDB for a remote
4909 target, it will no longer load in all of the support for debugging
4910 local programs on the host. When fully completed and tested, this will
4911 ensure that arbitrary host/target combinations are possible.
4913 The primary conceptual shift is to separate the non-portable code in
4914 GDB into three categories. Host specific code is required any time GDB
4915 is compiled on that host, regardless of the target. Target specific
4916 code relates to the peculiarities of the target, but can be compiled on
4917 any host. Native specific code is everything else: it can only be
4918 built when the host and target are the same system. Child process
4919 handling and core file support are two common `native' examples.
4921 GDB's use of /proc for controlling Unix child processes is now cleaner.
4922 It has been split out into a single module under the `target_ops' vector,
4923 plus two native-dependent functions for each system that uses /proc.
4925 * New hosts supported
4927 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
4928 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4929 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
4931 * New targets supported
4933 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4934 68030 and CPU32 m68030-*-*, m68332-*-*
4936 * New native hosts supported
4938 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4939 (386bsd is not well tested yet)
4940 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
4942 * New file formats supported
4944 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
4945 supports reading of `a.out.adobe' object files, which are an a.out
4946 format extended with minimal information about multiple sections.
4950 `show copying' is the same as the old `info copying'.
4951 `show warranty' is the same as `info warrantee'.
4952 These were renamed for consistency. The old commands continue to work.
4954 `info handle' is a new alias for `info signals'.
4956 You can now define pre-command hooks, which attach arbitrary command
4957 scripts to any command. The commands in the hook will be executed
4958 prior to the user's command. You can also create a hook which will be
4959 executed whenever the program stops. See gdb.texinfo.
4963 We now deal with Cfront style name mangling, and can even extract type
4964 info from mangled symbols. GDB can automatically figure out which
4965 symbol mangling style your C++ compiler uses.
4967 Calling of methods and virtual functions has been improved as well.
4971 The crash that occured when debugging Sun Ansi-C compiled binaries is
4972 fixed. This was due to mishandling of the extra N_SO stabs output
4975 We also finally got Ultrix 4.2 running in house, and fixed core file
4976 support, with help from a dozen people on the net.
4978 John M. Farrell discovered that the reason that single-stepping was so
4979 slow on all of the Mips based platforms (primarily SGI and DEC) was
4980 that we were trying to demangle and lookup a symbol used for internal
4981 purposes on every instruction that was being stepped through. Changing
4982 the name of that symbol so that it couldn't be mistaken for a C++
4983 mangled symbol sped things up a great deal.
4985 Rich Pixley sped up symbol lookups in general by getting much smarter
4986 about when C++ symbol mangling is necessary. This should make symbol
4987 completion (TAB on the command line) much faster. It's not as fast as
4988 we'd like, but it's significantly faster than gdb-4.6.
4992 A new user controllable variable 'call_scratch_address' can
4993 specify the location of a scratch area to be used when GDB
4994 calls a function in the target. This is necessary because the
4995 usual method of putting the scratch area on the stack does not work
4996 in systems that have separate instruction and data spaces.
4998 We integrated changes to support the 29k UDI (Universal Debugger
4999 Interface), but discovered at the last minute that we didn't have all
5000 of the appropriate copyright paperwork. We are working with AMD to
5001 resolve this, and hope to have it available soon.
5005 We have sped up the remote serial line protocol, especially for targets
5006 with lots of registers. It now supports a new `expedited status' ('T')
5007 message which can be used in place of the existing 'S' status message.
5008 This allows the remote stub to send only the registers that GDB
5009 needs to make a quick decision about single-stepping or conditional
5010 breakpoints, eliminating the need to fetch the entire register set for
5011 each instruction being stepped through.
5013 The GDB remote serial protocol now implements a write-through cache for
5014 registers, only re-reading the registers if the target has run.
5016 There is also a new remote serial stub for SPARC processors. You can
5017 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5018 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5019 processor with a serial port.
5023 Configure.in files have become much easier to read and modify. A new
5024 `table driven' format makes it more obvious what configurations are
5025 supported, and what files each one uses.
5029 There is a new opcodes library which will eventually contain all of the
5030 disassembly routines and opcode tables. At present, it only contains
5031 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5032 disassembler (binutils/objdump) to share these routines.
5034 The libiberty library is now copylefted under the GNU Library General
5035 Public License. This allows more liberal use, and was done so libg++
5036 can use it. This makes no difference to GDB, since the Library License
5037 grants all the rights from the General Public License.
5041 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5042 reference to the stabs symbol info used by the debugger. It is (as far
5043 as we know) the only published document on this fascinating topic. We
5044 encourage you to read it, compare it to the stabs information on your
5045 system, and send improvements on the document in general (to
5046 bug-gdb@prep.ai.mit.edu).
5048 And, of course, many bugs have been fixed.
5051 *** Changes in GDB-4.6:
5053 * Better support for C++ function names
5055 GDB now accepts as input the "demangled form" of C++ overloaded function
5056 names and member function names, and can do command completion on such names
5057 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5058 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5059 Make use of command completion, it is your friend.
5061 GDB also now accepts a variety of C++ mangled symbol formats. They are
5062 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5063 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5064 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5065 for the list of formats.
5067 * G++ symbol mangling problem
5069 Recent versions of gcc have a bug in how they emit debugging information for
5070 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5071 directory) can be applied to gcc to fix the problem. Alternatively, if you
5072 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5073 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5074 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5077 * New 'maintenance' command
5079 All of the commands related to hacking GDB internals have been moved out of
5080 the main command set, and now live behind the 'maintenance' command. This
5081 can also be abbreviated as 'mt'. The following changes were made:
5083 dump-me -> maintenance dump-me
5084 info all-breakpoints -> maintenance info breakpoints
5085 printmsyms -> maintenance print msyms
5086 printobjfiles -> maintenance print objfiles
5087 printpsyms -> maintenance print psymbols
5088 printsyms -> maintenance print symbols
5090 The following commands are new:
5092 maintenance demangle Call internal GDB demangler routine to
5093 demangle a C++ link name and prints the result.
5094 maintenance print type Print a type chain for a given symbol
5096 * Change to .gdbinit file processing
5098 We now read the $HOME/.gdbinit file before processing the argv arguments
5099 (e.g. reading symbol files or core files). This allows global parameters to
5100 be set, which will apply during the symbol reading. The ./.gdbinit is still
5101 read after argv processing.
5103 * New hosts supported
5105 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5107 GNU/Linux support i386-unknown-linux or linux
5109 We are also including code to support the HP/PA running BSD and HPUX. This
5110 is almost guaranteed not to work, as we didn't have time to test or build it
5111 for this release. We are including it so that the more adventurous (or
5112 masochistic) of you can play with it. We also had major problems with the
5113 fact that the compiler that we got from HP doesn't support the -g option.
5116 * New targets supported
5118 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5120 * More smarts about finding #include files
5122 GDB now remembers the compilation directory for all include files, and for
5123 all files from which C is generated (like yacc and lex sources). This
5124 greatly improves GDB's ability to find yacc/lex sources, and include files,
5125 especially if you are debugging your program from a directory different from
5126 the one that contains your sources.
5128 We also fixed a bug which caused difficulty with listing and setting
5129 breakpoints in include files which contain C code. (In the past, you had to
5130 try twice in order to list an include file that you hadn't looked at before.)
5132 * Interesting infernals change
5134 GDB now deals with arbitrary numbers of sections, where the symbols for each
5135 section must be relocated relative to that section's landing place in the
5136 target's address space. This work was needed to support ELF with embedded
5137 stabs used by Solaris-2.0.
5139 * Bug fixes (of course!)
5141 There have been loads of fixes for the following things:
5142 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5143 i960, stabs, DOS(GO32), procfs, etc...
5145 See the ChangeLog for details.
5147 *** Changes in GDB-4.5:
5149 * New machines supported (host and target)
5151 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5153 SGI Irix-4.x mips-sgi-irix4 or iris4
5155 * New malloc package
5157 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5158 Mmalloc is capable of handling mutiple heaps of memory. It is also
5159 capable of saving a heap to a file, and then mapping it back in later.
5160 This can be used to greatly speedup the startup of GDB by using a
5161 pre-parsed symbol table which lives in a mmalloc managed heap. For
5162 more details, please read mmalloc/mmalloc.texi.
5166 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5167 'help info proc' for details.
5169 * MIPS ecoff symbol table format
5171 The code that reads MIPS symbol table format is now supported on all hosts.
5172 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5175 * File name changes for MS-DOS
5177 Many files in the config directories have been renamed to make it easier to
5178 support GDB on MS-DOSe systems (which have very restrictive file name
5179 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5180 environment) is close to working but has some remaining problems. Note
5181 that debugging of DOS programs is not supported, due to limitations
5182 in the ``operating system'', but it can be used to host cross-debugging.
5184 * Cross byte order fixes
5186 Many fixes have been made to support cross debugging of Sparc and MIPS
5187 targets from hosts whose byte order differs.
5189 * New -mapped and -readnow options
5191 If memory-mapped files are available on your system through the 'mmap'
5192 system call, you can use the -mapped option on the `file' or
5193 `symbol-file' commands to cause GDB to write the symbols from your
5194 program into a reusable file. If the program you are debugging is
5195 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5196 Future GDB debugging sessions will notice the presence of this file,
5197 and will quickly map in symbol information from it, rather than reading
5198 the symbol table from the executable program. Using the '-mapped'
5199 option in a GDB `file' or `symbol-file' command has the same effect as
5200 starting GDB with the '-mapped' command-line option.
5202 You can cause GDB to read the entire symbol table immediately by using
5203 the '-readnow' option with any of the commands that load symbol table
5204 information (or on the GDB command line). This makes the command
5205 slower, but makes future operations faster.
5207 The -mapped and -readnow options are typically combined in order to
5208 build a `fred.syms' file that contains complete symbol information.
5209 A simple GDB invocation to do nothing but build a `.syms' file for future
5212 gdb -batch -nx -mapped -readnow programname
5214 The `.syms' file is specific to the host machine on which GDB is run.
5215 It holds an exact image of GDB's internal symbol table. It cannot be
5216 shared across multiple host platforms.
5218 * longjmp() handling
5220 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5221 siglongjmp() without losing control. This feature has not yet been ported to
5222 all systems. It currently works on many 386 platforms, all MIPS-based
5223 platforms (SGI, DECstation, etc), and Sun3/4.
5227 Preliminary work has been put in to support the new Solaris OS from Sun. At
5228 this time, it can control and debug processes, but it is not capable of
5233 As always, many many bug fixes. The major areas were with g++, and mipsread.
5234 People using the MIPS-based platforms should experience fewer mysterious
5235 crashes and trashed symbol tables.
5237 *** Changes in GDB-4.4:
5239 * New machines supported (host and target)
5241 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5243 BSD Reno on Vax vax-dec-bsd
5244 Ultrix on Vax vax-dec-ultrix
5246 * New machines supported (target)
5248 AMD 29000 embedded, using EBMON a29k-none-none
5252 GDB continues to improve its handling of C++. `References' work better.
5253 The demangler has also been improved, and now deals with symbols mangled as
5254 per the Annotated C++ Reference Guide.
5256 GDB also now handles `stabs' symbol information embedded in MIPS
5257 `ecoff' symbol tables. Since the ecoff format was not easily
5258 extensible to handle new languages such as C++, this appeared to be a
5259 good way to put C++ debugging info into MIPS binaries. This option
5260 will be supported in the GNU C compiler, version 2, when it is
5263 * New features for SVR4
5265 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5266 shared libraries. Debugging dynamically linked programs should present
5267 only minor differences from debugging statically linked programs.
5269 The `info proc' command will print out information about any process
5270 on an SVR4 system (including the one you are debugging). At the moment,
5271 it prints the address mappings of the process.
5273 If you bring up GDB on another SVR4 system, please send mail to
5274 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5276 * Better dynamic linking support in SunOS
5278 Reading symbols from shared libraries which contain debugging symbols
5279 now works properly. However, there remain issues such as automatic
5280 skipping of `transfer vector' code during function calls, which
5281 make it harder to debug code in a shared library, than to debug the
5282 same code linked statically.
5286 GDB is now using the latest `getopt' routines from the FSF. This
5287 version accepts the -- prefix for options with long names. GDB will
5288 continue to accept the old forms (-option and +option) as well.
5289 Various single letter abbreviations for options have been explicity
5290 added to the option table so that they won't get overshadowed in the
5291 future by other options that begin with the same letter.
5295 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5296 Many assorted bugs have been handled. Many more remain to be handled.
5297 See the various ChangeLog files (primarily in gdb and bfd) for details.
5300 *** Changes in GDB-4.3:
5302 * New machines supported (host and target)
5304 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5305 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5306 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5308 * Almost SCO Unix support
5310 We had hoped to support:
5311 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5312 (except for core file support), but we discovered very late in the release
5313 that it has problems with process groups that render gdb unusable. Sorry
5314 about that. I encourage people to fix it and post the fixes.
5316 * Preliminary ELF and DWARF support
5318 GDB can read ELF object files on System V Release 4, and can handle
5319 debugging records for C, in DWARF format, in ELF files. This support
5320 is preliminary. If you bring up GDB on another SVR4 system, please
5321 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5326 GDB now uses the latest `readline' library. One user-visible change
5327 is that two tabs will list possible command completions, which previously
5328 required typing M-? (meta-question mark, or ESC ?).
5332 The `stepi' bug that many of you noticed has been squashed.
5333 Many bugs in C++ have been handled. Many more remain to be handled.
5334 See the various ChangeLog files (primarily in gdb and bfd) for details.
5336 * State of the MIPS world (in case you wondered):
5338 GDB can understand the symbol tables emitted by the compilers
5339 supplied by most vendors of MIPS-based machines, including DEC. These
5340 symbol tables are in a format that essentially nobody else uses.
5342 Some versions of gcc come with an assembler post-processor called
5343 mips-tfile. This program is required if you want to do source-level
5344 debugging of gcc-compiled programs. I believe FSF does not ship
5345 mips-tfile with gcc version 1, but it will eventually come with gcc
5348 Debugging of g++ output remains a problem. g++ version 1.xx does not
5349 really support it at all. (If you're lucky, you should be able to get
5350 line numbers and stack traces to work, but no parameters or local
5351 variables.) With some work it should be possible to improve the
5354 When gcc version 2 is released, you will have somewhat better luck.
5355 However, even then you will get confusing results for inheritance and
5358 We will eventually provide full debugging of g++ output on
5359 DECstations. This will probably involve some kind of stabs-in-ecoff
5360 encapulation, but the details have not been worked out yet.
5363 *** Changes in GDB-4.2:
5365 * Improved configuration
5367 Only one copy of `configure' exists now, and it is not self-modifying.
5368 Porting BFD is simpler.
5372 The `step' and `next' commands now only stop at the first instruction
5373 of a source line. This prevents the multiple stops that used to occur
5374 in switch statements, for-loops, etc. `Step' continues to stop if a
5375 function that has debugging information is called within the line.
5379 Lots of small bugs fixed. More remain.
5381 * New host supported (not target)
5383 Intel 386 PC clone running Mach i386-none-mach
5386 *** Changes in GDB-4.1:
5388 * Multiple source language support
5390 GDB now has internal scaffolding to handle several source languages.
5391 It determines the type of each source file from its filename extension,
5392 and will switch expression parsing and number formatting to match the
5393 language of the function in the currently selected stack frame.
5394 You can also specifically set the language to be used, with
5395 `set language c' or `set language modula-2'.
5399 GDB now has preliminary support for the GNU Modula-2 compiler,
5400 currently under development at the State University of New York at
5401 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5402 continue through the fall of 1991 and into 1992.
5404 Other Modula-2 compilers are currently not supported, and attempting to
5405 debug programs compiled with them will likely result in an error as the
5406 symbol table is read. Feel free to work on it, though!
5408 There are hooks in GDB for strict type checking and range checking,
5409 in the `Modula-2 philosophy', but they do not currently work.
5413 GDB can now write to executable and core files (e.g. patch
5414 a variable's value). You must turn this switch on, specify
5415 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5416 by assigning a new value to a variable. Modifications take
5419 * Automatic SunOS shared library reading
5421 When you run your program, GDB automatically determines where its
5422 shared libraries (if any) have been loaded, and reads their symbols.
5423 The `share' command is no longer needed. This also works when
5424 examining core files.
5428 You can specify the number of lines that the `list' command shows.
5431 * New machines supported (host and target)
5433 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5434 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5435 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5437 * New hosts supported (not targets)
5439 IBM RT/PC: romp-ibm-aix or rtpc
5441 * New targets supported (not hosts)
5443 AMD 29000 embedded with COFF a29k-none-coff
5444 AMD 29000 embedded with a.out a29k-none-aout
5445 Ultracomputer remote kernel debug a29k-nyu-kern
5447 * New remote interfaces
5453 *** Changes in GDB-4.0:
5457 Wide output is wrapped at good places to make the output more readable.
5459 Gdb now supports cross-debugging from a host machine of one type to a
5460 target machine of another type. Communication with the target system
5461 is over serial lines. The ``target'' command handles connecting to the
5462 remote system; the ``load'' command will download a program into the
5463 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5464 also supports debugging of realtime processes running under VxWorks,
5465 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5466 stub on the target system.
5468 New CPUs supported include the AMD 29000 and Intel 960.
5470 GDB now reads object files and symbol tables via a ``binary file''
5471 library, which allows a single copy of GDB to debug programs of multiple
5472 object file types such as a.out and coff.
5474 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5475 refcard.dvi and refcard.ps are available to format it).
5478 * Control-Variable user interface simplified
5480 All variables that control the operation of the debugger can be set
5481 by the ``set'' command, and displayed by the ``show'' command.
5483 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5484 ``Show prompt'' produces the response:
5485 Gdb's prompt is new-gdb=>.
5487 What follows are the NEW set commands. The command ``help set'' will
5488 print a complete list of old and new set commands. ``help set FOO''
5489 will give a longer description of the variable FOO. ``show'' will show
5490 all of the variable descriptions and their current settings.
5492 confirm on/off: Enables warning questions for operations that are
5493 hard to recover from, e.g. rerunning the program while
5494 it is already running. Default is ON.
5496 editing on/off: Enables EMACS style command line editing
5497 of input. Previous lines can be recalled with
5498 control-P, the current line can be edited with control-B,
5499 you can search for commands with control-R, etc.
5502 history filename NAME: NAME is where the gdb command history
5503 will be stored. The default is .gdb_history,
5504 or the value of the environment variable
5507 history size N: The size, in commands, of the command history. The
5508 default is 256, or the value of the environment variable
5511 history save on/off: If this value is set to ON, the history file will
5512 be saved after exiting gdb. If set to OFF, the
5513 file will not be saved. The default is OFF.
5515 history expansion on/off: If this value is set to ON, then csh-like
5516 history expansion will be performed on
5517 command line input. The default is OFF.
5519 radix N: Sets the default radix for input and output. It can be set
5520 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5521 in the current radix, so "set radix 10" is always a no-op.
5523 height N: This integer value is the number of lines on a page. Default
5524 is 24, the current `stty rows'' setting, or the ``li#''
5525 setting from the termcap entry matching the environment
5528 width N: This integer value is the number of characters on a line.
5529 Default is 80, the current `stty cols'' setting, or the ``co#''
5530 setting from the termcap entry matching the environment
5533 Note: ``set screensize'' is obsolete. Use ``set height'' and
5534 ``set width'' instead.
5536 print address on/off: Print memory addresses in various command displays,
5537 such as stack traces and structure values. Gdb looks
5538 more ``symbolic'' if you turn this off; it looks more
5539 ``machine level'' with it on. Default is ON.
5541 print array on/off: Prettyprint arrays. New convenient format! Default
5544 print demangle on/off: Print C++ symbols in "source" form if on,
5547 print asm-demangle on/off: Same, for assembler level printouts
5550 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5553 * Support for Epoch Environment.
5555 The epoch environment is a version of Emacs v18 with windowing. One
5556 new command, ``inspect'', is identical to ``print'', except that if you
5557 are running in the epoch environment, the value is printed in its own
5561 * Support for Shared Libraries
5563 GDB can now debug programs and core files that use SunOS shared libraries.
5564 Symbols from a shared library cannot be referenced
5565 before the shared library has been linked with the program (this
5566 happens after you type ``run'' and before the function main() is entered).
5567 At any time after this linking (including when examining core files
5568 from dynamically linked programs), gdb reads the symbols from each
5569 shared library when you type the ``sharedlibrary'' command.
5570 It can be abbreviated ``share''.
5572 sharedlibrary REGEXP: Load shared object library symbols for files
5573 matching a unix regular expression. No argument
5574 indicates to load symbols for all shared libraries.
5576 info sharedlibrary: Status of loaded shared libraries.
5581 A watchpoint stops execution of a program whenever the value of an
5582 expression changes. Checking for this slows down execution
5583 tremendously whenever you are in the scope of the expression, but is
5584 quite useful for catching tough ``bit-spreader'' or pointer misuse
5585 problems. Some machines such as the 386 have hardware for doing this
5586 more quickly, and future versions of gdb will use this hardware.
5588 watch EXP: Set a watchpoint (breakpoint) for an expression.
5590 info watchpoints: Information about your watchpoints.
5592 delete N: Deletes watchpoint number N (same as breakpoints).
5593 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5594 enable N: Re-enables watchpoint number N (same as breakpoints).
5597 * C++ multiple inheritance
5599 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5602 * C++ exception handling
5604 Gdb now supports limited C++ exception handling. Besides the existing
5605 ability to breakpoint on an exception handler, gdb can breakpoint on
5606 the raising of an exception (before the stack is peeled back to the
5609 catch FOO: If there is a FOO exception handler in the dynamic scope,
5610 set a breakpoint to catch exceptions which may be raised there.
5611 Multiple exceptions (``catch foo bar baz'') may be caught.
5613 info catch: Lists all exceptions which may be caught in the
5614 current stack frame.
5617 * Minor command changes
5619 The command ``call func (arg, arg, ...)'' now acts like the print
5620 command, except it does not print or save a value if the function's result
5621 is void. This is similar to dbx usage.
5623 The ``up'' and ``down'' commands now always print the frame they end up
5624 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5625 frames without printing.
5627 * New directory command
5629 'dir' now adds directories to the FRONT of the source search path.
5630 The path starts off empty. Source files that contain debug information
5631 about the directory in which they were compiled can be found even
5632 with an empty path; Sun CC and GCC include this information. If GDB can't
5633 find your source file in the current directory, type "dir .".
5635 * Configuring GDB for compilation
5637 For normal use, type ``./configure host''. See README or gdb.texinfo
5640 GDB now handles cross debugging. If you are remotely debugging between
5641 two different machines, type ``./configure host -target=targ''.
5642 Host is the machine where GDB will run; targ is the machine
5643 where the program that you are debugging will run.
5645 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.