1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.7
6 * The 'record instruction-history' command now starts counting instructions
7 at one. This also affects the instruction ranges reported by the
8 'record function-call-history' command when given the /i modifier.
10 * The command 'record function-call-history' supports a new modifier '/c' to
11 indent the function names based on their call stack depth.
12 The fields for the '/i' and '/l' modifier have been reordered.
13 The source line range is now prefixed with 'at'.
14 The instruction range is now prefixed with 'inst'.
15 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
16 "record instruction-history" and "list" commands.
18 * The ranges given as arguments to the 'record function-call-history' and
19 'record instruction-history' commands are now inclusive.
21 * The btrace record target now supports the 'record goto' command.
23 *** Changes in GDB 7.7
25 * Improved support for process record-replay and reverse debugging on
26 arm*-linux* targets. Support for thumb32 and syscall instruction
27 recording has been added.
29 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
31 * GDB now supports Fission DWP file format version 2.
32 http://gcc.gnu.org/wiki/DebugFission
34 * New convenience function "$_isvoid", to check whether an expression
35 is void. A void expression is an expression where the type of the
36 result is "void". For example, some convenience variables may be
37 "void" when evaluated (e.g., "$_exitcode" before the execution of
38 the program being debugged; or an undefined convenience variable).
39 Another example, when calling a function whose return type is
42 * The "maintenance print objfiles" command now takes an optional regexp.
44 * The "catch syscall" command now works on arm*-linux* targets.
46 * GDB now consistently shows "<not saved>" when printing values of
47 registers the debug info indicates have not been saved in the frame
48 and there's nowhere to retrieve them from
49 (callee-saved/call-clobbered registers):
54 (gdb) info registers rax
57 Before, the former would print "<optimized out>", and the latter
58 "*value not available*".
60 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
65 ** Frame filters and frame decorators have been added.
66 ** Temporary breakpoints are now supported.
67 ** Line tables representation has been added.
68 ** New attribute 'parent_type' for gdb.Field objects.
69 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
70 ** New attribute 'name' for gdb.Type objects.
74 Nios II ELF nios2*-*-elf
75 Nios II GNU/Linux nios2*-*-linux
76 Texas Instruments MSP430 msp430*-*-elf
78 * Removed native configurations
80 Support for these a.out NetBSD and OpenBSD obsolete configurations has
81 been removed. ELF variants of these configurations are kept supported.
83 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
84 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
85 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
86 i[34567]86-*-openbsd3.[0-3]
87 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
88 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
89 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
93 Like "catch throw", but catches a re-thrown exception.
95 Renamed from old "maint check-symtabs".
97 Perform consistency checks on symtabs.
99 Expand symtabs matching an optional regexp.
102 Display the details of GDB configure-time options.
104 maint set|show per-command
105 maint set|show per-command space
106 maint set|show per-command time
107 maint set|show per-command symtab
108 Enable display of per-command gdb resource usage.
110 remove-symbol-file FILENAME
111 remove-symbol-file -a ADDRESS
112 Remove a symbol file added via add-symbol-file. The file to remove
113 can be identified by its filename or by an address that lies within
114 the boundaries of this symbol file in memory.
117 info exceptions REGEXP
118 Display the list of Ada exceptions defined in the program being
119 debugged. If provided, only the exceptions whose names match REGEXP
124 set debug symfile off|on
126 Control display of debugging info regarding reading symbol files and
127 symbol tables within those files
129 set print raw frame-arguments
130 show print raw frame-arguments
131 Set/show whether to print frame arguments in raw mode,
132 disregarding any defined pretty-printers.
134 set remote trace-status-packet
135 show remote trace-status-packet
136 Set/show the use of remote protocol qTStatus packet.
140 Control display of debugging messages related to Nios II targets.
144 Control whether target-assisted range stepping is enabled.
146 set startup-with-shell
147 show startup-with-shell
148 Specifies whether Unix child processes are started via a shell or
153 Use the target memory cache for accesses to the code segment. This
154 improves performance of remote debugging (particularly disassembly).
156 * You can now use a literal value 'unlimited' for options that
157 interpret 0 or -1 as meaning "unlimited". E.g., "set
158 trace-buffer-size unlimited" is now an alias for "set
159 trace-buffer-size -1" and "set height unlimited" is now an alias for
162 * The "set debug symtab-create" debugging option of GDB has been changed to
163 accept a verbosity level. 0 means "off", 1 provides basic debugging
164 output, and values of 2 or greater provides more verbose output.
166 * New command-line options
168 Display the details of GDB configure-time options.
170 * The command 'tsave' can now support new option '-ctf' to save trace
171 buffer in Common Trace Format.
173 * Newly installed $prefix/bin/gcore acts as a shell interface for the
176 * GDB now implements the the C++ 'typeid' operator.
178 * The new convenience variable $_exception holds the exception being
179 thrown or caught at an exception-related catchpoint.
181 * The exception-related catchpoints, like "catch throw", now accept a
182 regular expression which can be used to filter exceptions by type.
184 * The new convenience variable $_exitsignal is automatically set to
185 the terminating signal number when the program being debugged dies
186 due to an uncaught signal.
190 ** All MI commands now accept an optional "--language" option.
191 Support for this feature can be verified by using the "-list-features"
192 command, which should contain "language-option".
194 ** The new command -info-gdb-mi-command allows the user to determine
195 whether a GDB/MI command is supported or not.
197 ** The "^error" result record returned when trying to execute an undefined
198 GDB/MI command now provides a variable named "code" whose content is the
199 "undefined-command" error code. Support for this feature can be verified
200 by using the "-list-features" command, which should contain
201 "undefined-command-error-code".
203 ** The -trace-save MI command can optionally save trace buffer in Common
206 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
208 ** The command -data-list-register-values now accepts an optional
209 "--skip-unavailable" option. When used, only the available registers
212 ** The new command -trace-frame-collected dumps collected variables,
213 computed expressions, tvars, memory and registers in a traceframe.
215 ** The commands -stack-list-locals, -stack-list-arguments and
216 -stack-list-variables now accept an option "--skip-unavailable".
217 When used, only the available locals or arguments are displayed.
219 ** The -exec-run command now accepts an optional "--start" option.
220 When used, the command follows the same semantics as the "start"
221 command, stopping the program's execution at the start of its
222 main subprogram. Support for this feature can be verified using
223 the "-list-features" command, which should contain
224 "exec-run-start-option".
226 ** The new commands -catch-assert and -catch-exceptions insert
227 catchpoints stopping the program when Ada exceptions are raised.
229 ** The new command -info-ada-exceptions provides the equivalent of
230 the new "info exceptions" command.
232 * New system-wide configuration scripts
233 A GDB installation now provides scripts suitable for use as system-wide
234 configuration scripts for the following systems:
238 * GDB now supports target-assigned range stepping with remote targets.
239 This improves the performance of stepping source lines by reducing
240 the number of control packets from/to GDB. See "New remote packets"
243 * GDB now understands the element 'tvar' in the XML traceframe info.
244 It has the id of the collected trace state variables.
246 * On S/390 targets that provide the transactional-execution feature,
247 the program interruption transaction diagnostic block (TDB) is now
248 represented as a number of additional "registers" in GDB.
254 The vCont packet supports a new 'r' action, that tells the remote
255 stub to step through an address range itself, without GDB
256 involvemement at each single-step.
258 qXfer:libraries-svr4:read's annex
259 The previously unused annex of the qXfer:libraries-svr4:read packet
260 is now used to support passing an argument list. The remote stub
261 reports support for this argument list to GDB's qSupported query.
262 The defined arguments are "start" and "prev", used to reduce work
263 necessary for library list updating, resulting in significant
266 * New features in the GDB remote stub, GDBserver
268 ** GDBserver now supports target-assisted range stepping. Currently
269 enabled on x86/x86_64 GNU/Linux targets.
271 ** GDBserver now adds element 'tvar' in the XML in the reply to
272 'qXfer:traceframe-info:read'. It has the id of the collected
273 trace state variables.
275 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
278 * New 'z' formatter for printing and examining memory, this displays the
279 value as hexadecimal zero padded on the left to the size of the type.
281 * GDB can now use Windows x64 unwinding data.
283 * The "set remotebaud" command has been replaced by "set serial baud".
284 Similarly, "show remotebaud" has been replaced by "show serial baud".
285 The "set remotebaud" and "show remotebaud" commands are still available
286 to provide backward compatibility with older versions of GDB.
288 *** Changes in GDB 7.6
290 * Target record has been renamed to record-full.
291 Record/replay is now enabled with the "record full" command.
292 This also affects settings that are associated with full record/replay
293 that have been moved from "set/show record" to "set/show record full":
295 set|show record full insn-number-max
296 set|show record full stop-at-limit
297 set|show record full memory-query
299 * A new record target "record-btrace" has been added. The new target
300 uses hardware support to record the control-flow of a process. It
301 does not support replaying the execution, but it implements the
302 below new commands for investigating the recorded execution log.
303 This new recording method can be enabled using:
307 The "record-btrace" target is only available on Intel Atom processors
308 and requires a Linux kernel 2.6.32 or later.
310 * Two new commands have been added for record/replay to give information
311 about the recorded execution without having to replay the execution.
312 The commands are only supported by "record btrace".
314 record instruction-history prints the execution history at
315 instruction granularity
317 record function-call-history prints the execution history at
320 * New native configurations
322 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
323 FreeBSD/powerpc powerpc*-*-freebsd
324 x86_64/Cygwin x86_64-*-cygwin*
325 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
329 ARM AArch64 aarch64*-*-elf
330 ARM AArch64 GNU/Linux aarch64*-*-linux
331 Lynx 178 PowerPC powerpc-*-lynx*178
332 x86_64/Cygwin x86_64-*-cygwin*
333 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
335 * If the configured location of system.gdbinit file (as given by the
336 --with-system-gdbinit option at configure time) is in the
337 data-directory (as specified by --with-gdb-datadir at configure
338 time) or in one of its subdirectories, then GDB will look for the
339 system-wide init file in the directory specified by the
340 --data-directory command-line option.
342 * New command line options:
344 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
345 other initialization files, unlike -nx which disables all of them.
347 * Removed command line options
349 -epoch This was used by the gdb mode in Epoch, an ancient fork of
352 * The 'ptype' and 'whatis' commands now accept an argument to control
355 * 'info proc' now works on some core files.
359 ** Vectors can be created with gdb.Type.vector.
361 ** Python's atexit.register now works in GDB.
363 ** Types can be pretty-printed via a Python API.
365 ** Python 3 is now supported (in addition to Python 2.4 or later)
367 ** New class gdb.Architecture exposes GDB's internal representation
368 of architecture in the Python API.
370 ** New method Frame.architecture returns the gdb.Architecture object
371 corresponding to the frame's architecture.
373 * New Python-based convenience functions:
375 ** $_memeq(buf1, buf2, length)
376 ** $_streq(str1, str2)
378 ** $_regex(str, regex)
380 * The 'cd' command now defaults to using '~' (the home directory) if not
383 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
384 default for GCC since November 2000.
386 * The command 'forward-search' can now be abbreviated as 'fo'.
388 * The command 'info tracepoints' can now display 'installed on target'
389 or 'not installed on target' for each non-pending location of tracepoint.
391 * New configure options
393 --enable-libmcheck/--disable-libmcheck
394 By default, development versions are built with -lmcheck on hosts
395 that support it, in order to help track memory corruption issues.
396 Release versions, on the other hand, are built without -lmcheck
397 by default. The --enable-libmcheck/--disable-libmcheck configure
398 options allow the user to override that default.
399 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
400 This configure option allows the user to build GDB with
401 libbabeltrace using which GDB can read Common Trace Format data.
403 * New commands (for set/show, see "New options" below)
406 Catch signals. This is similar to "handle", but allows commands and
407 conditions to be attached.
410 List the BFDs known to GDB.
412 python-interactive [command]
414 Start a Python interactive prompt, or evaluate the optional command
415 and print the result of expressions.
418 "py" is a new alias for "python".
420 enable type-printer [name]...
421 disable type-printer [name]...
422 Enable or disable type printers.
426 ** For the Renesas Super-H architecture, the "regs" command has been removed
427 (has been deprecated in GDB 7.5), and "info all-registers" should be used
432 set print type methods (on|off)
433 show print type methods
434 Control whether method declarations are displayed by "ptype".
435 The default is to show them.
437 set print type typedefs (on|off)
438 show print type typedefs
439 Control whether typedef definitions are displayed by "ptype".
440 The default is to show them.
442 set filename-display basename|relative|absolute
443 show filename-display
444 Control the way in which filenames is displayed.
445 The default is "relative", which preserves previous behavior.
447 set trace-buffer-size
448 show trace-buffer-size
449 Request target to change the size of trace buffer.
451 set remote trace-buffer-size-packet auto|on|off
452 show remote trace-buffer-size-packet
453 Control the use of the remote protocol `QTBuffer:size' packet.
457 Control display of debugging messages related to ARM AArch64.
460 set debug coff-pe-read
461 show debug coff-pe-read
462 Control display of debugging messages related to reading of COFF/PE
467 Control display of debugging messages related to Mach-O symbols
470 set debug notification
471 show debug notification
472 Control display of debugging info for async remote notification.
476 ** Command parameter changes are now notified using new async record
477 "=cmd-param-changed".
478 ** Trace frame changes caused by command "tfind" are now notified using
479 new async record "=traceframe-changed".
480 ** The creation, deletion and modification of trace state variables
481 are now notified using new async records "=tsv-created",
482 "=tsv-deleted" and "=tsv-modified".
483 ** The start and stop of process record are now notified using new
484 async record "=record-started" and "=record-stopped".
485 ** Memory changes are now notified using new async record
487 ** The data-disassemble command response will include a "fullname" field
488 containing the absolute file name when source has been requested.
489 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
490 command, to allow pattern filling of memory areas.
491 ** New commands "-catch-load"/"-catch-unload" added for intercepting
492 library load/unload events.
493 ** The response to breakpoint commands and breakpoint async records
494 includes an "installed" field containing a boolean state about each
495 non-pending tracepoint location is whether installed on target or not.
496 ** Output of the "-trace-status" command includes a "trace-file" field
497 containing the name of the trace file being examined. This field is
498 optional, and only present when examining a trace file.
499 ** The "fullname" field is now always present along with the "file" field,
500 even if the file cannot be found by GDB.
502 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
503 You must have the LZMA library available when configuring GDB for this
504 feature to be enabled. For more information, see:
505 http://fedoraproject.org/wiki/Features/MiniDebugInfo
510 Set the size of trace buffer. The remote stub reports support for this
511 packet to gdb's qSupported query.
514 Enable Branch Trace Store (BTS)-based branch tracing for the current
515 thread. The remote stub reports support for this packet to gdb's
519 Disable branch tracing for the current thread. The remote stub reports
520 support for this packet to gdb's qSupported query.
523 Read the traced branches for the current thread. The remote stub
524 reports support for this packet to gdb's qSupported query.
526 *** Changes in GDB 7.5
528 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
529 for more x32 ABI info.
531 * GDB now supports access to MIPS DSP registers on Linux targets.
533 * GDB now supports debugging microMIPS binaries.
535 * The "info os" command on GNU/Linux can now display information on
536 several new classes of objects managed by the operating system:
537 "info os procgroups" lists process groups
538 "info os files" lists file descriptors
539 "info os sockets" lists internet-domain sockets
540 "info os shm" lists shared-memory regions
541 "info os semaphores" lists semaphores
542 "info os msg" lists message queues
543 "info os modules" lists loaded kernel modules
545 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
546 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
547 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
548 options and inspect the probe arguments using the new $_probe_arg family
549 of convenience variables. You can obtain more information about SystemTap
550 in <http://sourceware.org/systemtap/>.
552 * GDB now supports reversible debugging on ARM, it allows you to
553 debug basic ARM and THUMB instructions, and provides
554 record/replay support.
556 * The option "symbol-reloading" has been deleted as it is no longer used.
560 ** GDB commands implemented in Python can now be put in command class
563 ** The "maint set python print-stack on|off" is now deleted.
565 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
566 apply "flag enum"-style pretty-printing to any enum.
568 ** gdb.lookup_symbol can now work when there is no current frame.
570 ** gdb.Symbol now has a 'line' attribute, holding the line number in
571 the source at which the symbol was defined.
573 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
574 method 'value'. The former indicates whether the symbol needs a
575 frame in order to compute its value, and the latter computes the
578 ** A new method 'referenced_value' on gdb.Value objects which can
579 dereference pointer as well as C++ reference values.
581 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
582 which return the global and static blocks (as gdb.Block objects),
583 of the underlying symbol table, respectively.
585 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
586 object associated with a PC value.
588 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
589 of the address range occupied by code for the current source line.
591 * Go language support.
592 GDB now supports debugging programs written in the Go programming
595 * GDBserver now supports stdio connections.
596 E.g. (gdb) target remote | ssh myhost gdbserver - hello
598 * The binary "gdbtui" can no longer be built or installed.
599 Use "gdb -tui" instead.
601 * GDB will now print "flag" enums specially. A flag enum is one where
602 all the enumerator values have no bits in common when pairwise
603 "and"ed. When printing a value whose type is a flag enum, GDB will
604 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
605 (gdb) print (enum E) 3
608 * The filename part of a linespec will now match trailing components
609 of a source file name. For example, "break gcc/expr.c:1000" will
610 now set a breakpoint in build/gcc/expr.c, but not
613 * The "info proc" and "generate-core-file" commands will now also
614 work on remote targets connected to GDBserver on Linux.
616 * The command "info catch" has been removed. It has been disabled
619 * The "catch exception" and "catch assert" commands now accept
620 a condition at the end of the command, much like the "break"
621 command does. For instance:
623 (gdb) catch exception Constraint_Error if Barrier = True
625 Previously, it was possible to add a condition to such catchpoints,
626 but it had to be done as a second step, after the catchpoint had been
627 created, using the "condition" command.
629 * The "info static-tracepoint-marker" command will now also work on
630 native Linux targets with in-process agent.
632 * GDB can now set breakpoints on inlined functions.
634 * The .gdb_index section has been updated to include symbols for
635 inlined functions. GDB will ignore older .gdb_index sections by
636 default, which could cause symbol files to be loaded more slowly
637 until their .gdb_index sections can be recreated. The new command
638 "set use-deprecated-index-sections on" will cause GDB to use any older
639 .gdb_index sections it finds. This will restore performance, but the
640 ability to set breakpoints on inlined functions will be lost in symbol
641 files with older .gdb_index sections.
643 The .gdb_index section has also been updated to record more information
644 about each symbol. This speeds up the "info variables", "info functions"
645 and "info types" commands when used with programs having the .gdb_index
646 section, as well as speeding up debugging with shared libraries using
647 the .gdb_index section.
649 * Ada support for GDB/MI Variable Objects has been added.
651 * GDB can now support 'breakpoint always-inserted mode' in 'record'
656 ** New command -info-os is the MI equivalent of "info os".
658 ** Output logs ("set logging" and related) now include MI output.
662 ** "set use-deprecated-index-sections on|off"
663 "show use-deprecated-index-sections on|off"
664 Controls the use of deprecated .gdb_index sections.
666 ** "catch load" and "catch unload" can be used to stop when a shared
667 library is loaded or unloaded, respectively.
669 ** "enable count" can be used to auto-disable a breakpoint after
672 ** "info vtbl" can be used to show the virtual method tables for
673 C++ and Java objects.
675 ** "explore" and its sub commands "explore value" and "explore type"
676 can be used to recursively explore values and types of
677 expressions. These commands are available only if GDB is
678 configured with '--with-python'.
680 ** "info auto-load" shows status of all kinds of auto-loaded files,
681 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
682 sequences of commands files, "info auto-load python-scripts"
683 shows status of auto-loading Python script files,
684 "info auto-load local-gdbinit" shows status of loading init file
685 (.gdbinit) from current directory and "info auto-load libthread-db" shows
686 status of inferior specific thread debugging shared library loading.
688 ** "info auto-load-scripts", "set auto-load-scripts on|off"
689 and "show auto-load-scripts" commands have been deprecated, use their
690 "info auto-load python-scripts", "set auto-load python-scripts on|off"
691 and "show auto-load python-scripts" counterparts instead.
693 ** "dprintf location,format,args..." creates a dynamic printf, which
694 is basically a breakpoint that does a printf and immediately
695 resumes your program's execution, so it is like a printf that you
696 can insert dynamically at runtime instead of at compiletime.
698 ** "set print symbol"
700 Controls whether GDB attempts to display the symbol, if any,
701 corresponding to addresses it prints. This defaults to "on", but
702 you can set it to "off" to restore GDB's previous behavior.
704 * Deprecated commands
706 ** For the Renesas Super-H architecture, the "regs" command has been
707 deprecated, and "info all-registers" should be used instead.
711 Renesas RL78 rl78-*-elf
712 HP OpenVMS ia64 ia64-hp-openvms*
714 * GDBserver supports evaluation of breakpoint conditions. When
715 support is advertised by GDBserver, GDB may be told to send the
716 breakpoint conditions in bytecode form to GDBserver. GDBserver
717 will only report the breakpoint trigger to GDB when its condition
723 show mips compression
724 Select the compressed ISA encoding used in functions that have no symbol
725 information available. The encoding can be set to either of:
728 and is updated automatically from ELF file flags if available.
730 set breakpoint condition-evaluation
731 show breakpoint condition-evaluation
732 Control whether breakpoint conditions are evaluated by GDB ("host") or by
733 GDBserver ("target"). Default option "auto" chooses the most efficient
735 This option can improve debugger efficiency depending on the speed of the
739 Disable auto-loading globally.
742 Show auto-loading setting of all kinds of auto-loaded files.
744 set auto-load gdb-scripts on|off
745 show auto-load gdb-scripts
746 Control auto-loading of GDB canned sequences of commands files.
748 set auto-load python-scripts on|off
749 show auto-load python-scripts
750 Control auto-loading of Python script files.
752 set auto-load local-gdbinit on|off
753 show auto-load local-gdbinit
754 Control loading of init file (.gdbinit) from current directory.
756 set auto-load libthread-db on|off
757 show auto-load libthread-db
758 Control auto-loading of inferior specific thread debugging shared library.
760 set auto-load scripts-directory <dir1>[:<dir2>...]
761 show auto-load scripts-directory
762 Set a list of directories from which to load auto-loaded scripts.
763 Automatically loaded Python scripts and GDB scripts are located in one
764 of the directories listed by this option.
765 The delimiter (':' above) may differ according to the host platform.
767 set auto-load safe-path <dir1>[:<dir2>...]
768 show auto-load safe-path
769 Set a list of directories from which it is safe to auto-load files.
770 The delimiter (':' above) may differ according to the host platform.
772 set debug auto-load on|off
774 Control display of debugging info for auto-loading the files above.
776 set dprintf-style gdb|call|agent
778 Control the way in which a dynamic printf is performed; "gdb"
779 requests a GDB printf command, while "call" causes dprintf to call a
780 function in the inferior. "agent" requests that the target agent
781 (such as GDBserver) do the printing.
783 set dprintf-function <expr>
784 show dprintf-function
785 set dprintf-channel <expr>
787 Set the function and optional first argument to the call when using
788 the "call" style of dynamic printf.
790 set disconnected-dprintf on|off
791 show disconnected-dprintf
792 Control whether agent-style dynamic printfs continue to be in effect
793 after GDB disconnects.
795 * New configure options
798 Configure default value for the 'set auto-load scripts-directory'
799 setting above. It defaults to '$debugdir:$datadir/auto-load',
800 $debugdir representing global debugging info directories (available
801 via 'show debug-file-directory') and $datadir representing GDB's data
802 directory (available via 'show data-directory').
804 --with-auto-load-safe-path
805 Configure default value for the 'set auto-load safe-path' setting
806 above. It defaults to the --with-auto-load-dir setting.
808 --without-auto-load-safe-path
809 Set 'set auto-load safe-path' to '/', effectively disabling this
814 z0/z1 conditional breakpoints extension
816 The z0/z1 breakpoint insertion packets have been extended to carry
817 a list of conditional expressions over to the remote stub depending on the
818 condition evaluation mode. The use of this extension can be controlled
819 via the "set remote conditional-breakpoints-packet" command.
823 Specify the signals which the remote stub may pass to the debugged
824 program without GDB involvement.
826 * New command line options
828 --init-command=FILE, -ix Like --command, -x but execute it
829 before loading inferior.
830 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
831 execute it before loading inferior.
833 *** Changes in GDB 7.4
835 * GDB now handles ambiguous linespecs more consistently; the existing
836 FILE:LINE support has been expanded to other types of linespecs. A
837 breakpoint will now be set on all matching locations in all
838 inferiors, and locations will be added or removed according to
841 * GDB now allows you to skip uninteresting functions and files when
842 stepping with the "skip function" and "skip file" commands.
844 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
845 and "show remote hardware-watchpoint-length-limit". These allows to
846 set or show the maximum length limit (in bytes) of a remote
847 target hardware watchpoint.
849 This allows e.g. to use "unlimited" hardware watchpoints with the
850 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
851 watchpoints are slower than real hardware watchpoints but are
852 significantly faster than gdb software watchpoints.
856 ** The register_pretty_printer function in module gdb.printing now takes
857 an optional `replace' argument. If True, the new printer replaces any
860 ** The "maint set python print-stack on|off" command has been
861 deprecated and will be deleted in GDB 7.5.
862 A new command: "set python print-stack none|full|message" has
863 replaced it. Additionally, the default for "print-stack" is
864 now "message", which just prints the error message without
867 ** A prompt substitution hook (prompt_hook) is now available to the
870 ** A new Python module, gdb.prompt has been added to the GDB Python
871 modules library. This module provides functionality for
872 escape sequences in prompts (used by set/show
873 extended-prompt). These escape sequences are replaced by their
876 ** Python commands and convenience-functions located in
877 'data-directory'/python/gdb/command and
878 'data-directory'/python/gdb/function are now automatically loaded
881 ** Blocks now provide four new attributes. global_block and
882 static_block will return the global and static blocks
883 respectively. is_static and is_global are boolean attributes
884 that indicate if the block is one of those two types.
886 ** Symbols now provide the "type" attribute, the type of the symbol.
888 ** The "gdb.breakpoint" function has been deprecated in favor of
891 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
892 of a function. This class is based on the "finish" command
893 available in the CLI.
895 ** Type objects for struct and union types now allow access to
896 the fields using standard Python dictionary (mapping) methods.
897 For example, "some_type['myfield']" now works, as does
900 ** A new event "gdb.new_objfile" has been added, triggered by loading a
903 ** A new function, "deep_items" has been added to the gdb.types
904 module in the GDB Python modules library. This function returns
905 an iterator over the fields of a struct or union type. Unlike
906 the standard Python "iteritems" method, it will recursively traverse
907 any anonymous fields.
911 ** "*stopped" events can report several new "reason"s, such as
914 ** Breakpoint changes are now notified using new async records, like
915 "=breakpoint-modified".
917 ** New command -ada-task-info.
919 * libthread-db-search-path now supports two special values: $sdir and $pdir.
920 $sdir specifies the default system locations of shared libraries.
921 $pdir specifies the directory where the libpthread used by the application
924 GDB no longer looks in $sdir and $pdir after it has searched the directories
925 mentioned in libthread-db-search-path. If you want to search those
926 directories, they must be specified in libthread-db-search-path.
927 The default value of libthread-db-search-path on GNU/Linux and Solaris
928 systems is now "$sdir:$pdir".
930 $pdir is not supported by gdbserver, it is currently ignored.
931 $sdir is supported by gdbserver.
933 * New configure option --with-iconv-bin.
934 When using the internationalization support like the one in the GNU C
935 library, GDB will invoke the "iconv" program to get a list of supported
936 character sets. If this program lives in a non-standard location, one can
937 use this option to specify where to find it.
939 * When natively debugging programs on PowerPC BookE processors running
940 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
941 watchpoints, which specify a mask in addition to an address to watch.
942 The mask specifies that some bits of an address (the bits which are
943 reset in the mask) should be ignored when matching the address accessed
944 by the inferior against the watchpoint address. See the "PowerPC Embedded"
945 section in the user manual for more details.
947 * The new option --once causes GDBserver to stop listening for connections once
948 the first connection is made. The listening port used by GDBserver will
949 become available after that.
951 * New commands "info macros" and "alias" have been added.
953 * New function parameters suffix @entry specifies value of function parameter
954 at the time the function got called. Entry values are available only since
960 "!" is now an alias of the "shell" command.
961 Note that no space is needed between "!" and SHELL COMMAND.
965 watch EXPRESSION mask MASK_VALUE
966 The watch command now supports the mask argument which allows creation
967 of masked watchpoints, if the current architecture supports this feature.
969 info auto-load-scripts [REGEXP]
970 This command was formerly named "maintenance print section-scripts".
971 It is now generally useful and is no longer a maintenance-only command.
973 info macro [-all] [--] MACRO
974 The info macro command has new options `-all' and `--'. The first for
975 printing all definitions of a macro. The second for explicitly specifying
976 the end of arguments and the beginning of the macro name in case the macro
977 name starts with a hyphen.
979 collect[/s] EXPRESSIONS
980 The tracepoint collect command now takes an optional modifier "/s"
981 that directs it to dereference pointer-to-character types and
982 collect the bytes of memory up to a zero byte. The behavior is
983 similar to what you see when you use the regular print command on a
984 string. An optional integer following the "/s" sets a bound on the
985 number of bytes that will be collected.
988 The trace start command now interprets any supplied arguments as a
989 note to be recorded with the trace run, with an effect similar to
990 setting the variable trace-notes.
993 The trace stop command now interprets any arguments as a note to be
994 mentioned along with the tstatus report that the trace was stopped
995 with a command. The effect is similar to setting the variable
998 * Tracepoints can now be enabled and disabled at any time after a trace
999 experiment has been started using the standard "enable" and "disable"
1000 commands. It is now possible to start a trace experiment with no enabled
1001 tracepoints; GDB will display a warning, but will allow the experiment to
1002 begin, assuming that tracepoints will be enabled as needed while the trace
1005 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1006 locations with 4-byte instructions, when they were previously
1007 limited to locations with instructions of 5 bytes or longer.
1011 set debug dwarf2-read
1012 show debug dwarf2-read
1013 Turns on or off display of debugging messages related to reading
1014 DWARF debug info. The default is off.
1016 set debug symtab-create
1017 show debug symtab-create
1018 Turns on or off display of debugging messages related to symbol table
1019 creation. The default is off.
1022 show extended-prompt
1023 Set the GDB prompt, and allow escape sequences to be inserted to
1024 display miscellaneous information (see 'help set extended-prompt'
1025 for the list of sequences). This prompt (and any information
1026 accessed through the escape sequences) is updated every time the
1027 prompt is displayed.
1029 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1030 show print entry-values
1031 Set printing of frame argument values at function entry. In some cases
1032 GDB can determine the value of function argument which was passed by the
1033 function caller, even if the value was modified inside the called function.
1035 set debug entry-values
1036 show debug entry-values
1037 Control display of debugging info for determining frame argument values at
1038 function entry and virtual tail call frames.
1040 set basenames-may-differ
1041 show basenames-may-differ
1042 Set whether a source file may have multiple base names.
1043 (A "base name" is the name of a file with the directory part removed.
1044 Example: The base name of "/home/user/hello.c" is "hello.c".)
1045 If set, GDB will canonicalize file names (e.g., expand symlinks)
1046 before comparing them. Canonicalization is an expensive operation,
1047 but it allows the same file be known by more than one base name.
1048 If not set (the default), all source files are assumed to have just
1049 one base name, and gdb will do file name comparisons more efficiently.
1055 Set a user name and notes for the current and any future trace runs.
1056 This is useful for long-running and/or disconnected traces, to
1057 inform others (or yourself) as to who is running the trace, supply
1058 contact information, or otherwise explain what is going on.
1060 set trace-stop-notes
1061 show trace-stop-notes
1062 Set a note attached to the trace run, that is displayed when the
1063 trace has been stopped by a tstop command. This is useful for
1064 instance as an explanation, if you are stopping a trace run that was
1065 started by someone else.
1067 * New remote packets
1071 Dynamically enable a tracepoint in a started trace experiment.
1075 Dynamically disable a tracepoint in a started trace experiment.
1079 Set the user and notes of the trace run.
1083 Query the current status of a tracepoint.
1087 Query the minimum length of instruction at which a fast tracepoint may
1090 * Dcache size (number of lines) and line-size are now runtime-configurable
1091 via "set dcache line" and "set dcache line-size" commands.
1095 Texas Instruments TMS320C6x tic6x-*-*
1099 Renesas RL78 rl78-*-elf
1101 *** Changes in GDB 7.3.1
1103 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1105 *** Changes in GDB 7.3
1107 * GDB has a new command: "thread find [REGEXP]".
1108 It finds the thread id whose name, target id, or thread extra info
1109 matches the given regular expression.
1111 * The "catch syscall" command now works on mips*-linux* targets.
1113 * The -data-disassemble MI command now supports modes 2 and 3 for
1114 dumping the instruction opcodes.
1116 * New command line options
1118 -data-directory DIR Specify DIR as the "data-directory".
1119 This is mostly for testing purposes.
1121 * The "maint set python auto-load on|off" command has been renamed to
1122 "set auto-load-scripts on|off".
1124 * GDB has a new command: "set directories".
1125 It is like the "dir" command except that it replaces the
1126 source path list instead of augmenting it.
1128 * GDB now understands thread names.
1130 On GNU/Linux, "info threads" will display the thread name as set by
1131 prctl or pthread_setname_np.
1133 There is also a new command, "thread name", which can be used to
1134 assign a name internally for GDB to display.
1137 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1138 has been integrated into GDB.
1142 ** The function gdb.Write now accepts an optional keyword 'stream'.
1143 This keyword, when provided, will direct the output to either
1144 stdout, stderr, or GDB's logging output.
1146 ** Parameters can now be be sub-classed in Python, and in particular
1147 you may implement the get_set_doc and get_show_doc functions.
1148 This improves how Parameter set/show documentation is processed
1149 and allows for more dynamic content.
1151 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1152 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1153 have an is_valid method.
1155 ** Breakpoints can now be sub-classed in Python, and in particular
1156 you may implement a 'stop' function that is executed each time
1157 the inferior reaches that breakpoint.
1159 ** New function gdb.lookup_global_symbol looks up a global symbol.
1161 ** GDB values in Python are now callable if the value represents a
1162 function. For example, if 'some_value' represents a function that
1163 takes two integer parameters and returns a value, you can call
1164 that function like so:
1166 result = some_value (10,20)
1168 ** Module gdb.types has been added.
1169 It contains a collection of utilities for working with gdb.Types objects:
1170 get_basic_type, has_field, make_enum_dict.
1172 ** Module gdb.printing has been added.
1173 It contains utilities for writing and registering pretty-printers.
1174 New classes: PrettyPrinter, SubPrettyPrinter,
1175 RegexpCollectionPrettyPrinter.
1176 New function: register_pretty_printer.
1178 ** New commands "info pretty-printers", "enable pretty-printer" and
1179 "disable pretty-printer" have been added.
1181 ** gdb.parameter("directories") is now available.
1183 ** New function gdb.newest_frame returns the newest frame in the
1186 ** The gdb.InferiorThread class has a new "name" attribute. This
1187 holds the thread's name.
1189 ** Python Support for Inferior events.
1190 Python scripts can add observers to be notified of events
1191 occurring in the process being debugged.
1192 The following events are currently supported:
1193 - gdb.events.cont Continue event.
1194 - gdb.events.exited Inferior exited event.
1195 - gdb.events.stop Signal received, and Breakpoint hit events.
1199 ** GDB now puts template parameters in scope when debugging in an
1200 instantiation. For example, if you have:
1202 template<int X> int func (void) { return X; }
1204 then if you step into func<5>, "print X" will show "5". This
1205 feature requires proper debuginfo support from the compiler; it
1206 was added to GCC 4.5.
1208 ** The motion commands "next", "finish", "until", and "advance" now
1209 work better when exceptions are thrown. In particular, GDB will
1210 no longer lose control of the inferior; instead, the GDB will
1211 stop the inferior at the point at which the exception is caught.
1212 This functionality requires a change in the exception handling
1213 code that was introduced in GCC 4.5.
1215 * GDB now follows GCC's rules on accessing volatile objects when
1216 reading or writing target state during expression evaluation.
1217 One notable difference to prior behavior is that "print x = 0"
1218 no longer generates a read of x; the value of the assignment is
1219 now always taken directly from the value being assigned.
1221 * GDB now has some support for using labels in the program's source in
1222 linespecs. For instance, you can use "advance label" to continue
1223 execution to a label.
1225 * GDB now has support for reading and writing a new .gdb_index
1226 section. This section holds a fast index of DWARF debugging
1227 information and can be used to greatly speed up GDB startup and
1228 operation. See the documentation for `save gdb-index' for details.
1230 * The "watch" command now accepts an optional "-location" argument.
1231 When used, this causes GDB to watch the memory referred to by the
1232 expression. Such a watchpoint is never deleted due to it going out
1235 * GDB now supports thread debugging of core dumps on GNU/Linux.
1237 GDB now activates thread debugging using the libthread_db library
1238 when debugging GNU/Linux core dumps, similarly to when debugging
1239 live processes. As a result, when debugging a core dump file, GDB
1240 is now able to display pthread_t ids of threads. For example, "info
1241 threads" shows the same output as when debugging the process when it
1242 was live. In earlier releases, you'd see something like this:
1245 * 1 LWP 6780 main () at main.c:10
1247 While now you see this:
1250 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1252 It is also now possible to inspect TLS variables when debugging core
1255 When debugging a core dump generated on a machine other than the one
1256 used to run GDB, you may need to point GDB at the correct
1257 libthread_db library with the "set libthread-db-search-path"
1258 command. See the user manual for more details on this command.
1260 * When natively debugging programs on PowerPC BookE processors running
1261 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1262 which stop execution of the inferior whenever it executes an instruction
1263 at any address within the specified range. See the "PowerPC Embedded"
1264 section in the user manual for more details.
1266 * New features in the GDB remote stub, GDBserver
1268 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1269 and i686 LynxOS (version 5.x).
1271 ** GDBserver is now supported on Blackfin Linux.
1273 * New native configurations
1275 ia64 HP-UX ia64-*-hpux*
1279 Analog Devices, Inc. Blackfin Processor bfin-*
1281 * Ada task switching is now supported on sparc-elf targets when
1282 debugging a program using the Ravenscar Profile. For more information,
1283 see the "Tasking Support when using the Ravenscar Profile" section
1284 in the GDB user manual.
1286 * Guile support was removed.
1288 * New features in the GNU simulator
1290 ** The --map-info flag lists all known core mappings.
1292 ** CFI flashes may be simulated via the "cfi" device.
1294 *** Changes in GDB 7.2
1296 * Shared library support for remote targets by default
1298 When GDB is configured for a generic, non-OS specific target, like
1299 for example, --target=arm-eabi or one of the many *-*-elf targets,
1300 GDB now queries remote stubs for loaded shared libraries using the
1301 `qXfer:libraries:read' packet. Previously, shared library support
1302 was always disabled for such configurations.
1306 ** Argument Dependent Lookup (ADL)
1308 In C++ ADL lookup directs function search to the namespaces of its
1309 arguments even if the namespace has not been imported.
1319 Here the compiler will search for `foo' in the namespace of 'b'
1320 and find A::foo. GDB now supports this. This construct is commonly
1321 used in the Standard Template Library for operators.
1323 ** Improved User Defined Operator Support
1325 In addition to member operators, GDB now supports lookup of operators
1326 defined in a namespace and imported with a `using' directive, operators
1327 defined in the global scope, operators imported implicitly from an
1328 anonymous namespace, and the ADL operators mentioned in the previous
1330 GDB now also supports proper overload resolution for all the previously
1331 mentioned flavors of operators.
1333 ** static const class members
1335 Printing of static const class members that are initialized in the
1336 class definition has been fixed.
1338 * Windows Thread Information Block access.
1340 On Windows targets, GDB now supports displaying the Windows Thread
1341 Information Block (TIB) structure. This structure is visible either
1342 by using the new command `info w32 thread-information-block' or, by
1343 dereferencing the new convenience variable named `$_tlb', a
1344 thread-specific pointer to the TIB. This feature is also supported
1345 when remote debugging using GDBserver.
1347 * Static tracepoints
1349 Static tracepoints are calls in the user program into a tracing
1350 library. One such library is a port of the LTTng kernel tracer to
1351 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1352 When debugging with GDBserver, GDB now supports combining the GDB
1353 tracepoint machinery with such libraries. For example: the user can
1354 use GDB to probe a static tracepoint marker (a call from the user
1355 program into the tracing library) with the new "strace" command (see
1356 "New commands" below). This creates a "static tracepoint" in the
1357 breakpoint list, that can be manipulated with the same feature set
1358 as fast and regular tracepoints. E.g., collect registers, local and
1359 global variables, collect trace state variables, and define
1360 tracepoint conditions. In addition, the user can collect extra
1361 static tracepoint marker specific data, by collecting the new
1362 $_sdata internal variable. When analyzing the trace buffer, you can
1363 inspect $_sdata like any other variable available to GDB. For more
1364 information, see the "Tracepoints" chapter in GDB user manual. New
1365 remote packets have been defined to support static tracepoints, see
1366 the "New remote packets" section below.
1368 * Better reconstruction of tracepoints after disconnected tracing
1370 GDB will attempt to download the original source form of tracepoint
1371 definitions when starting a trace run, and then will upload these
1372 upon reconnection to the target, resulting in a more accurate
1373 reconstruction of the tracepoints that are in use on the target.
1377 You can now exercise direct control over the ways that GDB can
1378 affect your program. For instance, you can disallow the setting of
1379 breakpoints, so that the program can run continuously (assuming
1380 non-stop mode). In addition, the "observer" variable is available
1381 to switch all of the different controls; in observer mode, GDB
1382 cannot affect the target's behavior at all, which is useful for
1383 tasks like diagnosing live systems in the field.
1385 * The new convenience variable $_thread holds the number of the
1388 * New remote packets
1392 Return the address of the Windows Thread Information Block of a given thread.
1396 In response to several of the tracepoint packets, the target may now
1397 also respond with a number of intermediate `qRelocInsn' request
1398 packets before the final result packet, to have GDB handle
1399 relocating an instruction to execute at a different address. This
1400 is particularly useful for stubs that support fast tracepoints. GDB
1401 reports support for this feature in the qSupported packet.
1405 List static tracepoint markers in the target program.
1409 List static tracepoint markers at a given address in the target
1412 qXfer:statictrace:read
1414 Read the static trace data collected (by a `collect $_sdata'
1415 tracepoint action). The remote stub reports support for this packet
1416 to gdb's qSupported query.
1420 Send the current settings of GDB's permission flags.
1424 Send part of the source (textual) form of a tracepoint definition,
1425 which includes location, conditional, and action list.
1427 * The source command now accepts a -s option to force searching for the
1428 script in the source search path even if the script name specifies
1431 * New features in the GDB remote stub, GDBserver
1433 - GDBserver now support tracepoints (including fast tracepoints, and
1434 static tracepoints). The feature is currently supported by the
1435 i386-linux and amd64-linux builds. See the "Tracepoints support
1436 in gdbserver" section in the manual for more information.
1438 GDBserver JIT compiles the tracepoint's conditional agent
1439 expression bytecode into native code whenever possible for low
1440 overhead dynamic tracepoints conditionals. For such tracepoints,
1441 an expression that examines program state is evaluated when the
1442 tracepoint is reached, in order to determine whether to capture
1443 trace data. If the condition is simple and false, processing the
1444 tracepoint finishes very quickly and no data is gathered.
1446 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1447 for static tracepoints support.
1449 - GDBserver now supports x86_64 Windows 64-bit debugging.
1451 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1452 it understands register description.
1454 * The --batch flag now disables pagination and queries.
1456 * X86 general purpose registers
1458 GDB now supports reading/writing byte, word and double-word x86
1459 general purpose registers directly. This means you can use, say,
1460 $ah or $ax to refer, respectively, to the byte register AH and
1461 16-bit word register AX that are actually portions of the 32-bit
1462 register EAX or 64-bit register RAX.
1464 * The `commands' command now accepts a range of breakpoints to modify.
1465 A plain `commands' following a command that creates multiple
1466 breakpoints affects all the breakpoints set by that command. This
1467 applies to breakpoints set by `rbreak', and also applies when a
1468 single `break' command creates multiple breakpoints (e.g.,
1469 breakpoints on overloaded c++ functions).
1471 * The `rbreak' command now accepts a filename specification as part of
1472 its argument, limiting the functions selected by the regex to those
1473 in the specified file.
1475 * Support for remote debugging Windows and SymbianOS shared libraries
1476 from Unix hosts has been improved. Non Windows GDB builds now can
1477 understand target reported file names that follow MS-DOS based file
1478 system semantics, such as file names that include drive letters and
1479 use the backslash character as directory separator. This makes it
1480 possible to transparently use the "set sysroot" and "set
1481 solib-search-path" on Unix hosts to point as host copies of the
1482 target's shared libraries. See the new command "set
1483 target-file-system-kind" described below, and the "Commands to
1484 specify files" section in the user manual for more information.
1488 eval template, expressions...
1489 Convert the values of one or more expressions under the control
1490 of the string template to a command line, and call it.
1492 set target-file-system-kind unix|dos-based|auto
1493 show target-file-system-kind
1494 Set or show the assumed file system kind for target reported file
1497 save breakpoints <filename>
1498 Save all current breakpoint definitions to a file suitable for use
1499 in a later debugging session. To read the saved breakpoint
1500 definitions, use the `source' command.
1502 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1505 info static-tracepoint-markers
1506 Display information about static tracepoint markers in the target.
1508 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1509 Define a static tracepoint by probing a marker at the given
1510 function, line, address, or marker ID.
1514 Enable and disable observer mode.
1516 set may-write-registers on|off
1517 set may-write-memory on|off
1518 set may-insert-breakpoints on|off
1519 set may-insert-tracepoints on|off
1520 set may-insert-fast-tracepoints on|off
1521 set may-interrupt on|off
1522 Set individual permissions for GDB effects on the target. Note that
1523 some of these settings can have undesirable or surprising
1524 consequences, particularly when changed in the middle of a session.
1525 For instance, disabling the writing of memory can prevent
1526 breakpoints from being inserted, cause single-stepping to fail, or
1527 even crash your program, if you disable after breakpoints have been
1528 inserted. However, GDB should not crash.
1530 set record memory-query on|off
1531 show record memory-query
1532 Control whether to stop the inferior if memory changes caused
1533 by an instruction cannot be recorded.
1538 The disassemble command now supports "start,+length" form of two arguments.
1542 ** GDB now provides a new directory location, called the python directory,
1543 where Python scripts written for GDB can be installed. The location
1544 of that directory is <data-directory>/python, where <data-directory>
1545 is the GDB data directory. For more details, see section `Scripting
1546 GDB using Python' in the manual.
1548 ** The GDB Python API now has access to breakpoints, symbols, symbol
1549 tables, program spaces, inferiors, threads and frame's code blocks.
1550 Additionally, GDB Parameters can now be created from the API, and
1551 manipulated via set/show in the CLI.
1553 ** New functions gdb.target_charset, gdb.target_wide_charset,
1554 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1556 ** New exception gdb.GdbError.
1558 ** Pretty-printers are now also looked up in the current program space.
1560 ** Pretty-printers can now be individually enabled and disabled.
1562 ** GDB now looks for names of Python scripts to auto-load in a
1563 special section named `.debug_gdb_scripts', in addition to looking
1564 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1566 * Tracepoint actions were unified with breakpoint commands. In particular,
1567 there are no longer differences in "info break" output for breakpoints and
1568 tracepoints and the "commands" command can be used for both tracepoints and
1569 regular breakpoints.
1573 ARM Symbian arm*-*-symbianelf*
1575 * D language support.
1576 GDB now supports debugging programs written in the D programming
1579 * GDB now supports the extended ptrace interface for PowerPC which is
1580 available since Linux kernel version 2.6.34. This automatically enables
1581 any hardware breakpoints and additional hardware watchpoints available in
1582 the processor. The old ptrace interface exposes just one hardware
1583 watchpoint and no hardware breakpoints.
1585 * GDB is now able to use the Data Value Compare (DVC) register available on
1586 embedded PowerPC processors to implement in hardware simple watchpoint
1587 conditions of the form:
1589 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1591 This works in native GDB running on Linux kernels with the extended ptrace
1592 interface mentioned above.
1594 *** Changes in GDB 7.1
1598 ** Namespace Support
1600 GDB now supports importing of namespaces in C++. This enables the
1601 user to inspect variables from imported namespaces. Support for
1602 namepace aliasing has also been added. So, if a namespace is
1603 aliased in the current scope (e.g. namepace C=A; ) the user can
1604 print variables using the alias (e.g. (gdb) print C::x).
1608 All known bugs relating to the printing of virtual base class were
1609 fixed. It is now possible to call overloaded static methods using a
1614 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1615 and reinterpret_cast<> are now handled by the C++ expression parser.
1619 Xilinx MicroBlaze microblaze-*-*
1624 Xilinx MicroBlaze microblaze
1627 * Multi-program debugging.
1629 GDB now has support for multi-program (a.k.a. multi-executable or
1630 multi-exec) debugging. This allows for debugging multiple inferiors
1631 simultaneously each running a different program under the same GDB
1632 session. See "Debugging Multiple Inferiors and Programs" in the
1633 manual for more information. This implied some user visible changes
1634 in the multi-inferior support. For example, "info inferiors" now
1635 lists inferiors that are not running yet or that have exited
1636 already. See also "New commands" and "New options" below.
1638 * New tracing features
1640 GDB's tracepoint facility now includes several new features:
1642 ** Trace state variables
1644 GDB tracepoints now include support for trace state variables, which
1645 are variables managed by the target agent during a tracing
1646 experiment. They are useful for tracepoints that trigger each
1647 other, so for instance one tracepoint can count hits in a variable,
1648 and then a second tracepoint has a condition that is true when the
1649 count reaches a particular value. Trace state variables share the
1650 $-syntax of GDB convenience variables, and can appear in both
1651 tracepoint actions and condition expressions. Use the "tvariable"
1652 command to create, and "info tvariables" to view; see "Trace State
1653 Variables" in the manual for more detail.
1657 GDB now includes an option for defining fast tracepoints, which
1658 targets may implement more efficiently, such as by installing a jump
1659 into the target agent rather than a trap instruction. The resulting
1660 speedup can be by two orders of magnitude or more, although the
1661 tradeoff is that some program locations on some target architectures
1662 might not allow fast tracepoint installation, for instance if the
1663 instruction to be replaced is shorter than the jump. To request a
1664 fast tracepoint, use the "ftrace" command, with syntax identical to
1665 the regular trace command.
1667 ** Disconnected tracing
1669 It is now possible to detach GDB from the target while it is running
1670 a trace experiment, then reconnect later to see how the experiment
1671 is going. In addition, a new variable disconnected-tracing lets you
1672 tell the target agent whether to continue running a trace if the
1673 connection is lost unexpectedly.
1677 GDB now has the ability to save the trace buffer into a file, and
1678 then use that file as a target, similarly to you can do with
1679 corefiles. You can select trace frames, print data that was
1680 collected in them, and use tstatus to display the state of the
1681 tracing run at the moment that it was saved. To create a trace
1682 file, use "tsave <filename>", and to use it, do "target tfile
1685 ** Circular trace buffer
1687 You can ask the target agent to handle the trace buffer as a
1688 circular buffer, discarding the oldest trace frames to make room for
1689 newer ones, by setting circular-trace-buffer to on. This feature may
1690 not be available for all target agents.
1695 The disassemble command, when invoked with two arguments, now requires
1696 the arguments to be comma-separated.
1699 The info variables command now displays variable definitions. Files
1700 which only declare a variable are not shown.
1703 The source command is now capable of sourcing Python scripts.
1704 This feature is dependent on the debugger being build with Python
1707 Related to this enhancement is also the introduction of a new command
1708 "set script-extension" (see below).
1710 * New commands (for set/show, see "New options" below)
1712 record save [<FILENAME>]
1713 Save a file (in core file format) containing the process record
1714 execution log for replay debugging at a later time.
1716 record restore <FILENAME>
1717 Restore the process record execution log that was saved at an
1718 earlier time, for replay debugging.
1720 add-inferior [-copies <N>] [-exec <FILENAME>]
1723 clone-inferior [-copies <N>] [ID]
1724 Make a new inferior ready to execute the same program another
1725 inferior has loaded.
1730 maint info program-spaces
1731 List the program spaces loaded into GDB.
1733 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1734 show remote interrupt-sequence
1735 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1736 as the sequence to the remote target in order to interrupt the execution.
1737 Ctrl-C is a default. Some system prefers BREAK which is high level of
1738 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1739 Magic SysRq g. It is BREAK signal and character 'g'.
1741 set remote interrupt-on-connect [on | off]
1742 show remote interrupt-on-connect
1743 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1744 remote target when gdb connects to it. This is needed when you debug
1747 set remotebreak [on | off]
1749 Deprecated. Use "set/show remote interrupt-sequence" instead.
1751 tvariable $NAME [ = EXP ]
1752 Create or modify a trace state variable.
1755 List trace state variables and their values.
1757 delete tvariable $NAME ...
1758 Delete one or more trace state variables.
1761 Evaluate the given expressions without collecting anything into the
1762 trace buffer. (Valid in tracepoint actions only.)
1764 ftrace FN / FILE:LINE / *ADDR
1765 Define a fast tracepoint at the given function, line, or address.
1767 * New expression syntax
1769 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1770 GDB now parses 0b101010 identically with 42.
1774 set follow-exec-mode new|same
1775 show follow-exec-mode
1776 Control whether GDB reuses the same inferior across an exec call or
1777 creates a new one. This is useful to be able to restart the old
1778 executable after the inferior having done an exec call.
1780 set default-collect EXPR, ...
1781 show default-collect
1782 Define a list of expressions to be collected at each tracepoint.
1783 This is a useful way to ensure essential items are not overlooked,
1784 such as registers or a critical global variable.
1786 set disconnected-tracing
1787 show disconnected-tracing
1788 If set to 1, the target is instructed to continue tracing if it
1789 loses its connection to GDB. If 0, the target is to stop tracing
1792 set circular-trace-buffer
1793 show circular-trace-buffer
1794 If set to on, the target is instructed to use a circular trace buffer
1795 and discard the oldest trace frames instead of stopping the trace due
1796 to a full trace buffer. If set to off, the trace stops when the buffer
1797 fills up. Some targets may not support this.
1799 set script-extension off|soft|strict
1800 show script-extension
1801 If set to "off", the debugger does not perform any script language
1802 recognition, and all sourced files are assumed to be GDB scripts.
1803 If set to "soft" (the default), files are sourced according to
1804 filename extension, falling back to GDB scripts if the first
1806 If set to "strict", files are sourced according to filename extension.
1808 set ada trust-PAD-over-XVS on|off
1809 show ada trust-PAD-over-XVS
1810 If off, activate a workaround against a bug in the debugging information
1811 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1812 the GCC sources for more information about the GNAT encoding and
1813 PAD types in particular). It is always safe to set this option to
1814 off, but this introduces a slight performance penalty. The default
1817 * Python API Improvements
1819 ** GDB provides the new class gdb.LazyString. This is useful in
1820 some pretty-printing cases. The new method gdb.Value.lazy_string
1821 provides a simple way to create objects of this type.
1823 ** The fields returned by gdb.Type.fields now have an
1824 `is_base_class' attribute.
1826 ** The new method gdb.Type.range returns the range of an array type.
1828 ** The new method gdb.parse_and_eval can be used to parse and
1829 evaluate an expression.
1831 * New remote packets
1834 Define a trace state variable.
1837 Get the current value of a trace state variable.
1840 Set desired tracing behavior upon disconnection.
1843 Set the trace buffer to be linear or circular.
1846 Get data about the tracepoints currently in use.
1850 Process record now works correctly with hardware watchpoints.
1852 Multiple bug fixes have been made to the mips-irix port, making it
1853 much more reliable. In particular:
1854 - Debugging threaded applications is now possible again. Previously,
1855 GDB would hang while starting the program, or while waiting for
1856 the program to stop at a breakpoint.
1857 - Attaching to a running process no longer hangs.
1858 - An error occurring while loading a core file has been fixed.
1859 - Changing the value of the PC register now works again. This fixes
1860 problems observed when using the "jump" command, or when calling
1861 a function from GDB, or even when assigning a new value to $pc.
1862 - With the "finish" and "return" commands, the return value for functions
1863 returning a small array is now correctly printed.
1864 - It is now possible to break on shared library code which gets executed
1865 during a shared library init phase (code executed while executing
1866 their .init section). Previously, the breakpoint would have no effect.
1867 - GDB is now able to backtrace through the signal handler for
1868 non-threaded programs.
1870 PIE (Position Independent Executable) programs debugging is now supported.
1871 This includes debugging execution of PIC (Position Independent Code) shared
1872 libraries although for that, it should be possible to run such libraries as an
1875 *** Changes in GDB 7.0
1877 * GDB now has an interface for JIT compilation. Applications that
1878 dynamically generate code can create symbol files in memory and register
1879 them with GDB. For users, the feature should work transparently, and
1880 for JIT developers, the interface is documented in the GDB manual in the
1881 "JIT Compilation Interface" chapter.
1883 * Tracepoints may now be conditional. The syntax is as for
1884 breakpoints; either an "if" clause appended to the "trace" command,
1885 or the "condition" command is available. GDB sends the condition to
1886 the target for evaluation using the same bytecode format as is used
1887 for tracepoint actions.
1889 * The disassemble command now supports: an optional /r modifier, print the
1890 raw instructions in hex as well as in symbolic form, and an optional /m
1891 modifier to print mixed source+assembly.
1893 * Process record and replay
1895 In a architecture environment that supports ``process record and
1896 replay'', ``process record and replay'' target can record a log of
1897 the process execution, and replay it with both forward and reverse
1900 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
1901 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
1902 set execution-direction {forward|reverse}, for targets that support
1905 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
1906 feature is available with a native GDB running on kernel version
1909 * GDB now has support for multi-byte and wide character sets on the
1910 target. Strings whose character type is wchar_t, char16_t, or
1911 char32_t are now correctly printed. GDB supports wide- and unicode-
1912 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
1913 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
1914 `printf'. This feature requires iconv to work properly; if your
1915 system does not have a working iconv, GDB can use GNU libiconv. See
1916 the installation instructions for more information.
1918 * GDB now supports automatic retrieval of shared library files from
1919 remote targets. To use this feature, specify a system root that begins
1920 with the `remote:' prefix, either via the `set sysroot' command or via
1921 the `--with-sysroot' configure-time option.
1923 * "info sharedlibrary" now takes an optional regex of libraries to show,
1924 and it now reports if a shared library has no debugging information.
1926 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
1927 now complete on file names.
1929 * When completing in expressions, gdb will attempt to limit
1930 completions to allowable structure or union fields, where appropriate.
1931 For instance, consider:
1933 # struct example { int f1; double f2; };
1934 # struct example variable;
1937 If the user types TAB at the end of this command line, the available
1938 completions will be "f1" and "f2".
1940 * Inlined functions are now supported. They show up in backtraces, and
1941 the "step", "next", and "finish" commands handle them automatically.
1943 * GDB now supports the token-splicing (##) and stringification (#)
1944 operators when expanding macros. It also supports variable-arity
1947 * GDB now supports inspecting extra signal information, exported by
1948 the new $_siginfo convenience variable. The feature is currently
1949 implemented on linux ARM, i386 and amd64.
1951 * GDB can now display the VFP floating point registers and NEON vector
1952 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
1953 can provide these registers (requires Linux 2.6.30 or later). Remote
1954 and simulator targets may also provide them.
1956 * New remote packets
1959 Search memory for a sequence of bytes.
1962 Turn off `+'/`-' protocol acknowledgments to permit more efficient
1963 operation over reliable transport links. Use of this packet is
1964 controlled by the `set remote noack-packet' command.
1967 Kill the process with the specified process ID. Use this in preference
1968 to `k' when multiprocess protocol extensions are supported.
1971 Obtains additional operating system information
1975 Read or write additional signal information.
1977 * Removed remote protocol undocumented extension
1979 An undocumented extension to the remote protocol's `S' stop reply
1980 packet that permited the stub to pass a process id was removed.
1981 Remote servers should use the `T' stop reply packet instead.
1983 * GDB now supports multiple function calling conventions according to the
1984 DWARF-2 DW_AT_calling_convention function attribute.
1986 * The SH target utilizes the aforementioned change to distinguish between gcc
1987 and Renesas calling convention. It also adds the new CLI commands
1988 `set/show sh calling-convention'.
1990 * GDB can now read compressed debug sections, as produced by GNU gold
1991 with the --compress-debug-sections=zlib flag.
1993 * 64-bit core files are now supported on AIX.
1995 * Thread switching is now supported on Tru64.
1997 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
1998 which will be allocated using malloc later in program execution.
2000 * The qXfer:libraries:read remote procotol packet now allows passing a
2001 list of section offsets.
2003 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2004 conditions handling signals delivered during attach or thread creation
2005 have also been fixed.
2007 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2008 From the user's standpoint, all unqualified instances of True and False
2009 are treated as the standard definitions, regardless of context.
2011 * GDB now parses C++ symbol and type names more flexibly. For
2014 template<typename T> class C { };
2017 GDB will now correctly handle all of:
2019 ptype C<char const *>
2020 ptype C<char const*>
2021 ptype C<const char *>
2022 ptype C<const char*>
2024 * New features in the GDB remote stub, gdbserver
2026 - The "--wrapper" command-line argument tells gdbserver to use a
2027 wrapper program to launch programs for debugging.
2029 - On PowerPC and S/390 targets, it is now possible to use a single
2030 gdbserver executable to debug both 32-bit and 64-bit programs.
2031 (This requires gdbserver itself to be built as a 64-bit executable.)
2033 - gdbserver uses the new noack protocol mode for TCP connections to
2034 reduce communications latency, if also supported and enabled in GDB.
2036 - Support for the sparc64-linux-gnu target is now included in
2039 - The amd64-linux build of gdbserver now supports debugging both
2040 32-bit and 64-bit programs.
2042 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2043 now support hardware watchpoints, and will use them automatically
2048 GDB now has support for scripting using Python. Whether this is
2049 available is determined at configure time.
2051 New GDB commands can now be written in Python.
2053 * Ada tasking support
2055 Ada tasks can now be inspected in GDB. The following commands have
2059 Print the list of Ada tasks.
2061 Print detailed information about task number N.
2063 Print the task number of the current task.
2065 Switch the context of debugging to task number N.
2067 * Support for user-defined prefixed commands. The "define" command can
2068 add new commands to existing prefixes, e.g. "target".
2070 * Multi-inferior, multi-process debugging.
2072 GDB now has generalized support for multi-inferior debugging. See
2073 "Debugging Multiple Inferiors" in the manual for more information.
2074 Although availability still depends on target support, the command
2075 set is more uniform now. The GNU/Linux specific multi-forks support
2076 has been migrated to this new framework. This implied some user
2077 visible changes; see "New commands" and also "Removed commands"
2080 * Target descriptions can now describe the target OS ABI. See the
2081 "Target Description Format" section in the user manual for more
2084 * Target descriptions can now describe "compatible" architectures
2085 to indicate that the target can execute applications for a different
2086 architecture in addition to those for the main target architecture.
2087 See the "Target Description Format" section in the user manual for
2090 * Multi-architecture debugging.
2092 GDB now includes general supports for debugging applications on
2093 hybrid systems that use more than one single processor architecture
2094 at the same time. Each such hybrid architecture still requires
2095 specific support to be added. The only hybrid architecture supported
2096 in this version of GDB is the Cell Broadband Engine.
2098 * GDB now supports integrated debugging of Cell/B.E. applications that
2099 use both the PPU and SPU architectures. To enable support for hybrid
2100 Cell/B.E. debugging, you need to configure GDB to support both the
2101 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2102 --enable-targets configure option.
2104 * Non-stop mode debugging.
2106 For some targets, GDB now supports an optional mode of operation in
2107 which you can examine stopped threads while other threads continue
2108 to execute freely. This is referred to as non-stop mode, with the
2109 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2110 section in the user manual for more information.
2112 To be able to support remote non-stop debugging, a remote stub needs
2113 to implement the non-stop mode remote protocol extensions, as
2114 described in the "Remote Non-Stop" section of the user manual. The
2115 GDB remote stub, gdbserver, has been adjusted to support these
2116 extensions on linux targets.
2118 * New commands (for set/show, see "New options" below)
2120 catch syscall [NAME(S) | NUMBER(S)]
2121 Catch system calls. Arguments, which should be names of system
2122 calls or their numbers, mean catch only those syscalls. Without
2123 arguments, every syscall will be caught. When the inferior issues
2124 any of the specified syscalls, GDB will stop and announce the system
2125 call, both when it is called and when its call returns. This
2126 feature is currently available with a native GDB running on the
2127 Linux Kernel, under the following architectures: x86, x86_64,
2128 PowerPC and PowerPC64.
2130 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2132 Search memory for a sequence of bytes.
2134 maint set python print-stack
2135 maint show python print-stack
2136 Show a stack trace when an error is encountered in a Python script.
2139 Invoke CODE by passing it to the Python interpreter.
2144 These allow macros to be defined, undefined, and listed
2148 Show operating system information about processes.
2151 List the inferiors currently under GDB's control.
2154 Switch focus to inferior number NUM.
2157 Detach from inferior number NUM.
2160 Kill inferior number NUM.
2164 set spu stop-on-load
2165 show spu stop-on-load
2166 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2168 set spu auto-flush-cache
2169 show spu auto-flush-cache
2170 Control whether to automatically flush the software-managed cache
2171 during Cell/B.E. debugging.
2173 set sh calling-convention
2174 show sh calling-convention
2175 Control the calling convention used when calling SH target functions.
2178 show debug timestamp
2179 Control display of timestamps with GDB debugging output.
2181 set disassemble-next-line
2182 show disassemble-next-line
2183 Control display of disassembled source lines or instructions when
2186 set remote noack-packet
2187 show remote noack-packet
2188 Set/show the use of remote protocol QStartNoAckMode packet. See above
2189 under "New remote packets."
2191 set remote query-attached-packet
2192 show remote query-attached-packet
2193 Control use of remote protocol `qAttached' (query-attached) packet.
2195 set remote read-siginfo-object
2196 show remote read-siginfo-object
2197 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2200 set remote write-siginfo-object
2201 show remote write-siginfo-object
2202 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2205 set remote reverse-continue
2206 show remote reverse-continue
2207 Control use of remote protocol 'bc' (reverse-continue) packet.
2209 set remote reverse-step
2210 show remote reverse-step
2211 Control use of remote protocol 'bs' (reverse-step) packet.
2213 set displaced-stepping
2214 show displaced-stepping
2215 Control displaced stepping mode. Displaced stepping is a way to
2216 single-step over breakpoints without removing them from the debuggee.
2217 Also known as "out-of-line single-stepping".
2220 show debug displaced
2221 Control display of debugging info for displaced stepping.
2223 maint set internal-error
2224 maint show internal-error
2225 Control what GDB does when an internal error is detected.
2227 maint set internal-warning
2228 maint show internal-warning
2229 Control what GDB does when an internal warning is detected.
2234 Use a wrapper program to launch programs for debugging.
2236 set multiple-symbols (all|ask|cancel)
2237 show multiple-symbols
2238 The value of this variable can be changed to adjust the debugger behavior
2239 when an expression or a breakpoint location contains an ambiguous symbol
2240 name (an overloaded function name, for instance).
2242 set breakpoint always-inserted
2243 show breakpoint always-inserted
2244 Keep breakpoints always inserted in the target, as opposed to inserting
2245 them when resuming the target, and removing them when the target stops.
2246 This option can improve debugger performance on slow remote targets.
2248 set arm fallback-mode (arm|thumb|auto)
2249 show arm fallback-mode
2250 set arm force-mode (arm|thumb|auto)
2252 These commands control how ARM GDB determines whether instructions
2253 are ARM or Thumb. The default for both settings is auto, which uses
2254 the current CPSR value for instructions without symbols; previous
2255 versions of GDB behaved as if "set arm fallback-mode arm".
2257 set disable-randomization
2258 show disable-randomization
2259 Standalone programs run with the virtual address space randomization enabled
2260 by default on some platforms. This option keeps the addresses stable across
2261 multiple debugging sessions.
2265 Control whether other threads are stopped or not when some thread hits
2270 Requests that asynchronous execution is enabled in the target, if available.
2271 In this case, it's possible to resume target in the background, and interact
2272 with GDB while the target is running. "show target-async" displays the
2273 current state of asynchronous execution of the target.
2275 set target-wide-charset
2276 show target-wide-charset
2277 The target-wide-charset is the name of the character set that GDB
2278 uses when printing characters whose type is wchar_t.
2280 set tcp auto-retry (on|off)
2282 set tcp connect-timeout
2283 show tcp connect-timeout
2284 These commands allow GDB to retry failed TCP connections to a remote stub
2285 with a specified timeout period; this is useful if the stub is launched
2286 in parallel with GDB but may not be ready to accept connections immediately.
2288 set libthread-db-search-path
2289 show libthread-db-search-path
2290 Control list of directories which GDB will search for appropriate
2293 set schedule-multiple (on|off)
2294 show schedule-multiple
2295 Allow GDB to resume all threads of all processes or only threads of
2296 the current process.
2300 Use more aggressive caching for accesses to the stack. This improves
2301 performance of remote debugging (particularly backtraces) without
2302 affecting correctness.
2304 set interactive-mode (on|off|auto)
2305 show interactive-mode
2306 Control whether GDB runs in interactive mode (on) or not (off).
2307 When in interactive mode, GDB waits for the user to answer all
2308 queries. Otherwise, GDB does not wait and assumes the default
2309 answer. When set to auto (the default), GDB determines which
2310 mode to use based on the stdin settings.
2315 For program forks, this is replaced by the new more generic `info
2316 inferiors' command. To list checkpoints, you can still use the
2317 `info checkpoints' command, which was an alias for the `info forks'
2321 Replaced by the new `inferior' command. To switch between
2322 checkpoints, you can still use the `restart' command, which was an
2323 alias for the `fork' command.
2326 This is removed, since some targets don't have a notion of
2327 processes. To switch between processes, you can still use the
2328 `inferior' command using GDB's own inferior number.
2331 For program forks, this is replaced by the new more generic `kill
2332 inferior' command. To delete a checkpoint, you can still use the
2333 `delete checkpoint' command, which was an alias for the `delete
2337 For program forks, this is replaced by the new more generic `detach
2338 inferior' command. To detach a checkpoint, you can still use the
2339 `detach checkpoint' command, which was an alias for the `detach
2342 * New native configurations
2344 x86/x86_64 Darwin i[34567]86-*-darwin*
2346 x86_64 MinGW x86_64-*-mingw*
2350 Lattice Mico32 lm32-*
2351 x86 DICOS i[34567]86-*-dicos*
2352 x86_64 DICOS x86_64-*-dicos*
2355 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2356 (mingw32ce) debugging.
2362 These commands were actually not implemented on any target.
2364 *** Changes in GDB 6.8
2366 * New native configurations
2368 NetBSD/hppa hppa*-*netbsd*
2369 Xtensa GNU/Linux xtensa*-*-linux*
2373 NetBSD/hppa hppa*-*-netbsd*
2374 Xtensa GNU/Lunux xtensa*-*-linux*
2376 * Change in command line behavior -- corefiles vs. process ids.
2378 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2379 attaching to process NUMBER fails, GDB no longer attempts to open a
2380 core file named NUMBER. Attaching to a program using the -c option
2381 is no longer supported. Instead, use the '-p' or '--pid' options.
2383 * GDB can now be built as a native debugger for debugging Windows x86
2384 (mingw32) Portable Executable (PE) programs.
2386 * Pending breakpoints no longer change their number when their address
2389 * GDB now supports breakpoints with multiple locations,
2390 including breakpoints on C++ constructors, inside C++ templates,
2391 and in inlined functions.
2393 * GDB's ability to debug optimized code has been improved. GDB more
2394 accurately identifies function bodies and lexical blocks that occupy
2395 more than one contiguous range of addresses.
2397 * Target descriptions can now describe registers for PowerPC.
2399 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2400 registers on PowerPC targets.
2402 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2403 targets even when the libthread_db library is not available.
2405 * The GDB remote stub, gdbserver, now supports the new file transfer
2406 commands (remote put, remote get, and remote delete).
2408 * The GDB remote stub, gdbserver, now supports run and attach in
2409 extended-remote mode.
2411 * hppa*64*-*-hpux11* target broken
2412 The debugger is unable to start a program and fails with the following
2413 error: "Error trying to get information about dynamic linker".
2414 The gdb-6.7 release is also affected.
2416 * GDB now supports the --enable-targets= configure option to allow
2417 building a single GDB executable that supports multiple remote
2418 target architectures.
2420 * GDB now supports debugging C and C++ programs which use the
2421 Decimal Floating Point extension. In addition, the PowerPC target
2422 now has a set of pseudo-registers to inspect decimal float values
2423 stored in two consecutive float registers.
2425 * The -break-insert MI command can optionally create pending
2428 * Improved support for debugging Ada
2429 Many improvements to the Ada language support have been made. These
2431 - Better support for Ada2005 interface types
2432 - Improved handling of arrays and slices in general
2433 - Better support for Taft-amendment types
2434 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2436 - Improved command completion in Ada
2439 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2444 set print frame-arguments (all|scalars|none)
2445 show print frame-arguments
2446 The value of this variable can be changed to control which argument
2447 values should be printed by the debugger when displaying a frame.
2452 Transfer files to and from a remote target, and delete remote files.
2459 Transfer files to and from a remote target, and delete remote files.
2461 * New remote packets
2468 Open, close, read, write, and delete files on the remote system.
2471 Attach to an existing process on the remote system, in extended-remote
2475 Run a new process on the remote system, in extended-remote mode.
2477 *** Changes in GDB 6.7
2479 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2480 bfd, libiberty and opcodes, as revealed by static analysis donated by
2481 Coverity, Inc. (http://scan.coverity.com).
2483 * When looking up multiply-defined global symbols, GDB will now prefer the
2484 symbol definition in the current shared library if it was built using the
2485 -Bsymbolic linker option.
2487 * When the Text User Interface (TUI) is not configured, GDB will now
2488 recognize the -tui command-line option and print a message that the TUI
2491 * The GDB remote stub, gdbserver, now has lower overhead for high
2492 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2494 * GDB for MIPS targets now autodetects whether a remote target provides
2495 32-bit or 64-bit register values.
2497 * Support for C++ member pointers has been improved.
2499 * GDB now understands XML target descriptions, which specify the
2500 target's overall architecture. GDB can read a description from
2501 a local file or over the remote serial protocol.
2503 * Vectors of single-byte data use a new integer type which is not
2504 automatically displayed as character or string data.
2506 * The /s format now works with the print command. It displays
2507 arrays of single-byte integers and pointers to single-byte integers
2510 * Target descriptions can now describe target-specific registers,
2511 for architectures which have implemented the support (currently
2512 only ARM, M68K, and MIPS).
2514 * GDB and the GDB remote stub, gdbserver, now support the XScale
2517 * The GDB remote stub, gdbserver, has been updated to support
2518 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2519 has been rewritten to use the standard GDB remote protocol.
2521 * GDB can now step into C++ functions which are called through thunks.
2523 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2525 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2526 layout. It also supports a TextSeg= and DataSeg= response when only
2527 segment base addresses (rather than offsets) are available.
2529 * The /i format now outputs any trailing branch delay slot instructions
2530 immediately following the last instruction within the count specified.
2532 * The GDB remote protocol "T" stop reply packet now supports a
2533 "library" response. Combined with the new "qXfer:libraries:read"
2534 packet, this response allows GDB to debug shared libraries on targets
2535 where the operating system manages the list of loaded libraries (e.g.
2536 Windows and SymbianOS).
2538 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2539 (DLLs) on Windows and Windows CE targets.
2541 * GDB now supports a faster verification that a .debug file matches its binary
2542 according to its build-id signature, if the signature is present.
2548 Enable or disable hardware flow control (RTS/CTS) on the serial port
2549 when debugging using remote targets.
2551 set mem inaccessible-by-default
2552 show mem inaccessible-by-default
2553 If the target supplies a memory map, for instance via the remote
2554 protocol's "qXfer:memory-map:read" packet, setting this variable
2555 prevents GDB from accessing memory outside the memory map. This
2556 is useful for targets with memory mapped registers or which react
2557 badly to accesses of unmapped address space.
2559 set breakpoint auto-hw
2560 show breakpoint auto-hw
2561 If the target supplies a memory map, for instance via the remote
2562 protocol's "qXfer:memory-map:read" packet, setting this variable
2563 lets GDB use hardware breakpoints automatically for memory regions
2564 where it can not use software breakpoints. This covers both the
2565 "break" command and internal breakpoints used for other commands
2566 including "next" and "finish".
2569 catch exception unhandled
2570 Stop the program execution when Ada exceptions are raised.
2573 Stop the program execution when an Ada assertion failed.
2577 Set an alternate system root for target files. This is a more
2578 general version of "set solib-absolute-prefix", which is now
2579 an alias to "set sysroot".
2582 Provide extended SPU facility status information. This set of
2583 commands is available only when debugging the Cell/B.E. SPU
2586 * New native configurations
2588 OpenBSD/sh sh*-*openbsd*
2591 unset tdesc filename
2593 Use the specified local file as an XML target description, and do
2594 not query the target for its built-in description.
2598 OpenBSD/sh sh*-*-openbsd*
2599 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2600 Toshiba Media Processor mep-elf
2602 * New remote packets
2605 Ignore the specified signals; pass them directly to the debugged program
2606 without stopping other threads or reporting them to GDB.
2608 qXfer:features:read:
2609 Read an XML target description from the target, which describes its
2614 Read or write contents of an spufs file on the target system. These
2615 packets are available only on the Cell/B.E. SPU architecture.
2617 qXfer:libraries:read:
2618 Report the loaded shared libraries. Combined with new "T" packet
2619 response, this packet allows GDB to debug shared libraries on
2620 targets where the operating system manages the list of loaded
2621 libraries (e.g. Windows and SymbianOS).
2625 Support for these obsolete configurations has been removed.
2633 i[34567]86-*-lynxos*
2634 i[34567]86-*-netware*
2635 i[34567]86-*-sco3.2v5*
2636 i[34567]86-*-sco3.2v4*
2638 i[34567]86-*-sysv4.2*
2641 i[34567]86-*-unixware2*
2642 i[34567]86-*-unixware*
2651 * Other removed features
2658 Various m68k-only ROM monitors.
2665 Various Renesas ROM monitors and debugging interfaces for SH and
2670 Support for a Macraigor serial interface to on-chip debugging.
2671 GDB does not directly support the newer parallel or USB
2676 A debug information format. The predecessor to DWARF 2 and
2677 DWARF 3, which are still supported.
2679 Support for the HP aCC compiler on HP-UX/PA-RISC
2681 SOM-encapsulated symbolic debugging information, automatic
2682 invocation of pxdb, and the aCC custom C++ ABI. This does not
2683 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2684 with aCC can still be debugged on an assembly level.
2686 MIPS ".pdr" sections
2688 A MIPS-specific format used to describe stack frame layout
2689 in debugging information.
2693 GDB could work with an older version of Guile to debug
2694 the interpreter and Scheme programs running in it.
2696 set mips stack-arg-size
2697 set mips saved-gpreg-size
2699 Use "set mips abi" to control parameter passing for MIPS.
2701 *** Changes in GDB 6.6
2706 Cell Broadband Engine SPU spu-elf
2708 * GDB can now be configured as a cross-debugger targeting native Windows
2709 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2710 running on a Windows system over TCP/IP to debug Windows programs.
2712 * The GDB remote stub, gdbserver, has been updated to support Windows and
2713 Cygwin debugging. Both single-threaded and multi-threaded programs are
2716 * The "set trust-readonly-sections" command works again. This command was
2717 broken in GDB 6.3, 6.4, and 6.5.
2719 * The "load" command now supports writing to flash memory, if the remote
2720 stub provides the required support.
2722 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2723 longer requires symbolic debug information (e.g. DWARF-2).
2728 unset substitute-path
2729 show substitute-path
2730 Manage a list of substitution rules that GDB uses to rewrite the name
2731 of the directories where the sources are located. This can be useful
2732 for instance when the sources were moved to a different location
2733 between compilation and debugging.
2737 Print each CLI command as it is executed. Each command is prefixed with
2738 a number of `+' symbols representing the nesting depth.
2739 The source command now has a `-v' option to enable the same feature.
2743 The ARM Demon monitor support (RDP protocol, "target rdp").
2745 Kernel Object Display, an embedded debugging feature which only worked with
2746 an obsolete version of Cisco IOS.
2748 The 'set download-write-size' and 'show download-write-size' commands.
2750 * New remote packets
2753 Tell a stub about GDB client features, and request remote target features.
2754 The first feature implemented is PacketSize, which allows the target to
2755 specify the size of packets it can handle - to minimize the number of
2756 packets required and improve performance when connected to a remote
2760 Fetch an OS auxilliary vector from the remote stub. This packet is a
2761 more efficient replacement for qPart:auxv:read.
2763 qXfer:memory-map:read:
2764 Fetch a memory map from the remote stub, including information about
2765 RAM, ROM, and flash memory devices.
2770 Erase and program a flash memory device.
2772 * Removed remote packets
2775 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2776 used it, and only gdbserver implemented it.
2778 *** Changes in GDB 6.5
2782 Renesas M32C/M16C m32c-elf
2784 Morpho Technologies ms1 ms1-elf
2788 init-if-undefined Initialize a convenience variable, but
2789 only if it doesn't already have a value.
2791 The following commands are presently only implemented for native GNU/Linux:
2793 checkpoint Save a snapshot of the program state.
2795 restart <n> Return the program state to a
2796 previously saved state.
2798 info checkpoints List currently saved checkpoints.
2800 delete-checkpoint <n> Delete a previously saved checkpoint.
2802 set|show detach-on-fork Tell gdb whether to detach from a newly
2803 forked process, or to keep debugging it.
2805 info forks List forks of the user program that
2806 are available to be debugged.
2808 fork <n> Switch to debugging one of several
2809 forks of the user program that are
2810 available to be debugged.
2812 delete-fork <n> Delete a fork from the list of forks
2813 that are available to be debugged (and
2814 kill the forked process).
2816 detach-fork <n> Delete a fork from the list of forks
2817 that are available to be debugged (and
2818 allow the process to continue).
2822 Morpho Technologies ms2 ms1-elf
2824 * Improved Windows host support
2826 GDB now builds as a cross debugger hosted on i686-mingw32, including
2827 native console support, and remote communications using either
2828 network sockets or serial ports.
2830 * Improved Modula-2 language support
2832 GDB can now print most types in the Modula-2 syntax. This includes:
2833 basic types, set types, record types, enumerated types, range types,
2834 pointer types and ARRAY types. Procedure var parameters are correctly
2835 printed and hexadecimal addresses and character constants are also
2836 written in the Modula-2 syntax. Best results can be obtained by using
2837 GNU Modula-2 together with the -gdwarf-2 command line option.
2841 The ARM rdi-share module.
2843 The Netware NLM debug server.
2845 *** Changes in GDB 6.4
2847 * New native configurations
2849 OpenBSD/arm arm*-*-openbsd*
2850 OpenBSD/mips64 mips64-*-openbsd*
2854 Morpho Technologies ms1 ms1-elf
2856 * New command line options
2858 --batch-silent As for --batch, but totally silent.
2859 --return-child-result The debugger will exist with the same value
2860 the child (debugged) program exited with.
2861 --eval-command COMMAND, -ex COMMAND
2862 Execute a single GDB CLI command. This may be
2863 specified multiple times and in conjunction
2864 with the --command (-x) option.
2866 * Deprecated commands removed
2868 The following commands, that were deprecated in 2000, have been
2872 set|show arm disassembly-flavor set|show arm disassembler
2873 othernames set arm disassembler
2874 set|show remotedebug set|show debug remote
2875 set|show archdebug set|show debug arch
2876 set|show eventdebug set|show debug event
2879 * New BSD user-level threads support
2881 It is now possible to debug programs using the user-level threads
2882 library on OpenBSD and FreeBSD. Currently supported (target)
2885 FreeBSD/amd64 x86_64-*-freebsd*
2886 FreeBSD/i386 i386-*-freebsd*
2887 OpenBSD/i386 i386-*-openbsd*
2889 Note that the new kernel threads libraries introduced in FreeBSD 5.x
2890 are not yet supported.
2892 * New support for Matsushita MN10300 w/sim added
2893 (Work in progress). mn10300-elf.
2895 * REMOVED configurations and files
2897 VxWorks and the XDR protocol *-*-vxworks
2898 Motorola MCORE mcore-*-*
2899 National Semiconductor NS32000 ns32k-*-*
2901 * New "set print array-indexes" command
2903 After turning this setting "on", GDB prints the index of each element
2904 when displaying arrays. The default is "off" to preserve the previous
2907 * VAX floating point support
2909 GDB now supports the not-quite-ieee VAX F and D floating point formats.
2911 * User-defined command support
2913 In addition to using $arg0..$arg9 for argument passing, it is now possible
2914 to use $argc to determine now many arguments have been passed. See the
2915 section on user-defined commands in the user manual for more information.
2917 *** Changes in GDB 6.3:
2919 * New command line option
2921 GDB now accepts -l followed by a number to set the timeout for remote
2924 * GDB works with GCC -feliminate-dwarf2-dups
2926 GDB now supports a more compact representation of DWARF-2 debug
2927 information using DW_FORM_ref_addr references. These are produced
2928 by GCC with the option -feliminate-dwarf2-dups and also by some
2929 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
2930 to use -feliminate-dwarf2-dups.
2932 * Internationalization
2934 When supported by the host system, GDB will be built with
2935 internationalization (libintl). The task of marking up the sources is
2936 continued, we're looking forward to our first translation.
2940 Initial support for debugging programs compiled with the GNAT
2941 implementation of the Ada programming language has been integrated
2942 into GDB. In this release, support is limited to expression evaluation.
2944 * New native configurations
2946 GNU/Linux/m32r m32r-*-linux-gnu
2950 GDB's remote protocol now includes support for the 'p' packet. This
2951 packet is used to fetch individual registers from a remote inferior.
2953 * END-OF-LIFE registers[] compatibility module
2955 GDB's internal register infrastructure has been completely rewritten.
2956 The new infrastructure making possible the implementation of key new
2957 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
2960 GDB 6.3 will be the last release to include the the registers[]
2961 compatibility module that allowed out-of-date configurations to
2962 continue to work. This change directly impacts the following
2972 powerpc bdm protocol
2974 Unless there is activity to revive these configurations, they will be
2975 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
2977 * OBSOLETE configurations and files
2979 Configurations that have been declared obsolete in this release have
2980 been commented out. Unless there is activity to revive these
2981 configurations, the next release of GDB will have their sources
2982 permanently REMOVED.
2991 *** Changes in GDB 6.2.1:
2993 * MIPS `break main; run' gave an heuristic-fence-post warning
2995 When attempting to run even a simple program, a warning about
2996 heuristic-fence-post being hit would be reported. This problem has
2999 * MIPS IRIX 'long double' crashed GDB
3001 When examining a long double variable, GDB would get a segmentation
3002 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3003 IRIX long double values).
3007 A bug in the VAX stack code was causing problems with the "next"
3008 command. This problem has been fixed.
3010 *** Changes in GDB 6.2:
3012 * Fix for ``many threads''
3014 On GNU/Linux systems that use the NPTL threads library, a program
3015 rapidly creating and deleting threads would confuse GDB leading to the
3018 ptrace: No such process.
3019 thread_db_get_info: cannot get thread info: generic error
3021 This problem has been fixed.
3023 * "-async" and "-noasync" options removed.
3025 Support for the broken "-noasync" option has been removed (it caused
3028 * New ``start'' command.
3030 This command runs the program until the begining of the main procedure.
3032 * New BSD Kernel Data Access Library (libkvm) interface
3034 Using ``target kvm'' it is now possible to debug kernel core dumps and
3035 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3036 platforms. Currently supported (native-only) configurations are:
3038 FreeBSD/amd64 x86_64-*-freebsd*
3039 FreeBSD/i386 i?86-*-freebsd*
3040 NetBSD/i386 i?86-*-netbsd*
3041 NetBSD/m68k m68*-*-netbsd*
3042 NetBSD/sparc sparc-*-netbsd*
3043 OpenBSD/amd64 x86_64-*-openbsd*
3044 OpenBSD/i386 i?86-*-openbsd*
3045 OpenBSD/m68k m68*-openbsd*
3046 OpenBSD/sparc sparc-*-openbsd*
3048 * Signal trampoline code overhauled
3050 Many generic problems with GDB's signal handling code have been fixed.
3051 These include: backtraces through non-contiguous stacks; recognition
3052 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3053 call; backtrace through a signal trampoline; step into and out of
3054 signal handlers; and single-stepping in the signal trampoline.
3056 Please note that kernel bugs are a limiting factor here. These
3057 features have been shown to work on an s390 GNU/Linux system that
3058 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3060 * Cygwin support for DWARF 2 added.
3062 * New native configurations
3064 GNU/Linux/hppa hppa*-*-linux*
3065 OpenBSD/hppa hppa*-*-openbsd*
3066 OpenBSD/m68k m68*-*-openbsd*
3067 OpenBSD/m88k m88*-*-openbsd*
3068 OpenBSD/powerpc powerpc-*-openbsd*
3069 NetBSD/vax vax-*-netbsd*
3070 OpenBSD/vax vax-*-openbsd*
3072 * END-OF-LIFE frame compatibility module
3074 GDB's internal frame infrastructure has been completely rewritten.
3075 The new infrastructure making it possible to support key new features
3076 including DWARF 2 Call Frame Information. To aid in the task of
3077 migrating old configurations to this new infrastructure, a
3078 compatibility module, that allowed old configurations to continue to
3079 work, was also included.
3081 GDB 6.2 will be the last release to include this frame compatibility
3082 module. This change directly impacts the following configurations:
3092 Unless there is activity to revive these configurations, they will be
3093 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3095 * REMOVED configurations and files
3097 Sun 3, running SunOS 3 m68*-*-sunos3*
3098 Sun 3, running SunOS 4 m68*-*-sunos4*
3099 Sun 2, running SunOS 3 m68000-*-sunos3*
3100 Sun 2, running SunOS 4 m68000-*-sunos4*
3101 Motorola 680x0 running LynxOS m68*-*-lynxos*
3102 AT&T 3b1/Unix pc m68*-att-*
3103 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3104 decstation mips-dec-* mips-little-*
3105 riscos mips-*-riscos* mips-*-sysv*
3106 sonymips mips-sony-*
3107 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3109 *** Changes in GDB 6.1.1:
3111 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3113 The TUI (Text-mode User Interface) is now built as part of a default
3114 GDB configuration. It is enabled by either selecting the TUI with the
3115 command line option "-i=tui" or by running the separate "gdbtui"
3116 program. For more information on the TUI, see the manual "Debugging
3119 * Pending breakpoint support (also included in GDB 6.1)
3121 Support has been added to allow you to specify breakpoints in shared
3122 libraries that have not yet been loaded. If a breakpoint location
3123 cannot be found, and the "breakpoint pending" option is set to auto,
3124 GDB queries you if you wish to make the breakpoint pending on a future
3125 shared-library load. If and when GDB resolves the breakpoint symbol,
3126 the pending breakpoint is removed as one or more regular breakpoints
3129 Pending breakpoints are very useful for GCJ Java debugging.
3131 * Fixed ISO-C build problems
3133 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3134 non ISO-C code that stopped them being built using a more strict ISO-C
3135 compiler (e.g., IBM's C compiler).
3137 * Fixed build problem on IRIX 5
3139 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3140 wasn't able to compile compile on an IRIX 5 system.
3142 * Added execute permission to gdb/gdbserver/configure
3144 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3145 permission. This bug would cause configure to fail on a number of
3146 systems (Solaris, IRIX). Ref: server/519.
3148 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3150 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3151 has been updated to use constant array sizes.
3153 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3155 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3156 its generated DWARF Call Frame Info. This encoding was causing GDB to
3157 panic, that panic has been fixed. Ref: gdb/1628.
3159 * Fixed a problem when examining parameters in shared library code.
3161 When examining parameters in optimized shared library code generated
3162 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3163 not available''. GDB now correctly displays the variable's value.
3165 *** Changes in GDB 6.1:
3167 * Removed --with-mmalloc
3169 Support for the mmalloc memory manager has been removed, as it
3170 conflicted with the internal gdb byte cache.
3172 * Changes in AMD64 configurations
3174 The AMD64 target now includes the %cs and %ss registers. As a result
3175 the AMD64 remote protocol has changed; this affects the floating-point
3176 and SSE registers. If you rely on those registers for your debugging,
3177 you should upgrade gdbserver on the remote side.
3179 * Revised SPARC target
3181 The SPARC target has been completely revised, incorporating the
3182 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3183 support for LynxOS and SunOS 4 has been dropped. Calling functions
3184 from within GDB on operating systems with a non-executable stack
3185 (Solaris, OpenBSD) now works.
3189 GDB has a new C++ demangler which does a better job on the mangled
3190 names generated by current versions of g++. It also runs faster, so
3191 with this and other changes gdb should now start faster on large C++
3194 * DWARF 2 Location Expressions
3196 GDB support for location expressions has been extended to support function
3197 arguments and frame bases. Older versions of GDB could crash when they
3200 * C++ nested types and namespaces
3202 GDB's support for nested types and namespaces in C++ has been
3203 improved, especially if you use the DWARF 2 debugging format. (This
3204 is the default for recent versions of GCC on most platforms.)
3205 Specifically, if you have a class "Inner" defined within a class or
3206 namespace "Outer", then GDB realizes that the class's name is
3207 "Outer::Inner", not simply "Inner". This should greatly reduce the
3208 frequency of complaints about not finding RTTI symbols. In addition,
3209 if you are stopped at inside of a function defined within a namespace,
3210 GDB modifies its name lookup accordingly.
3212 * New native configurations
3214 NetBSD/amd64 x86_64-*-netbsd*
3215 OpenBSD/amd64 x86_64-*-openbsd*
3216 OpenBSD/alpha alpha*-*-openbsd*
3217 OpenBSD/sparc sparc-*-openbsd*
3218 OpenBSD/sparc64 sparc64-*-openbsd*
3220 * New debugging protocols
3222 M32R with SDI protocol m32r-*-elf*
3224 * "set prompt-escape-char" command deleted.
3226 The command "set prompt-escape-char" has been deleted. This command,
3227 and its very obscure effet on GDB's prompt, was never documented,
3228 tested, nor mentioned in the NEWS file.
3230 * OBSOLETE configurations and files
3232 Configurations that have been declared obsolete in this release have
3233 been commented out. Unless there is activity to revive these
3234 configurations, the next release of GDB will have their sources
3235 permanently REMOVED.
3237 Sun 3, running SunOS 3 m68*-*-sunos3*
3238 Sun 3, running SunOS 4 m68*-*-sunos4*
3239 Sun 2, running SunOS 3 m68000-*-sunos3*
3240 Sun 2, running SunOS 4 m68000-*-sunos4*
3241 Motorola 680x0 running LynxOS m68*-*-lynxos*
3242 AT&T 3b1/Unix pc m68*-att-*
3243 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3244 decstation mips-dec-* mips-little-*
3245 riscos mips-*-riscos* mips-*-sysv*
3246 sonymips mips-sony-*
3247 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3249 * REMOVED configurations and files
3251 SGI Irix-4.x mips-sgi-irix4 or iris4
3252 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3253 Z8000 simulator z8k-zilog-none or z8ksim
3254 Matsushita MN10200 w/simulator mn10200-*-*
3255 H8/500 simulator h8500-hitachi-hms or h8500hms
3256 HP/PA running BSD hppa*-*-bsd*
3257 HP/PA running OSF/1 hppa*-*-osf*
3258 HP/PA Pro target hppa*-*-pro*
3259 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3260 386BSD i[3456]86-*-bsd*
3261 Sequent family i[3456]86-sequent-sysv4*
3262 i[3456]86-sequent-sysv*
3263 i[3456]86-sequent-bsd*
3264 SPARC running LynxOS sparc-*-lynxos*
3265 SPARC running SunOS 4 sparc-*-sunos4*
3266 Tsqware Sparclet sparclet-*-*
3267 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3269 *** Changes in GDB 6.0:
3273 Support for debugging the Objective-C programming language has been
3274 integrated into GDB.
3276 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3278 DWARF 2's Call Frame Information makes available compiler generated
3279 information that more exactly describes the program's run-time stack.
3280 By using this information, GDB is able to provide more robust stack
3283 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3284 have been updated to use a new backtrace mechanism which includes
3285 DWARF 2 CFI support.
3289 GDB's remote protocol has been extended to include support for hosted
3290 file I/O (where the remote target uses GDB's file system). See GDB's
3291 remote protocol documentation for details.
3293 * All targets using the new architecture framework.
3295 All of GDB's targets have been updated to use the new internal
3296 architecture framework. The way is now open for future GDB releases
3297 to include cross-architecture native debugging support (i386 on amd64,
3300 * GNU/Linux's Thread Local Storage (TLS)
3302 GDB now includes support for for the GNU/Linux implementation of
3303 per-thread variables.
3305 * GNU/Linux's Native POSIX Thread Library (NPTL)
3307 GDB's thread code has been updated to work with either the new
3308 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3310 * Separate debug info.
3312 GDB, in conjunction with BINUTILS, now supports a mechanism for
3313 automatically loading debug information from a separate file. Instead
3314 of shipping full debug and non-debug versions of system libraries,
3315 system integrators can now instead ship just the stripped libraries
3316 and optional debug files.
3318 * DWARF 2 Location Expressions
3320 DWARF 2 Location Expressions allow the compiler to more completely
3321 describe the location of variables (even in optimized code) to the
3324 GDB now includes preliminary support for location expressions (support
3325 for DW_OP_piece is still missing).
3329 A number of long standing bugs that caused GDB to die while starting a
3330 Java application have been fixed. GDB's Java support is now
3331 considered "useable".
3333 * GNU/Linux support for fork, vfork, and exec.
3335 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3336 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3339 * GDB supports logging output to a file
3341 There are two new commands, "set logging" and "show logging", which can be
3342 used to capture GDB's output to a file.
3344 * The meaning of "detach" has changed for gdbserver
3346 The "detach" command will now resume the application, as documented. To
3347 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3350 * d10v, m68hc11 `regs' command deprecated
3352 The `info registers' command has been updated so that it displays the
3353 registers using a format identical to the old `regs' command.
3357 A new command, "maint set profile on/off", has been added. This command can
3358 be used to enable or disable profiling while running GDB, to profile a
3359 session or a set of commands. In addition there is a new configure switch,
3360 "--enable-profiling", which will cause GDB to be compiled with profiling
3361 data, for more informative profiling results.
3363 * Default MI syntax changed to "mi2".
3365 The default MI (machine interface) syntax, enabled by the command line
3366 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3367 "mi1", can be enabled by specifying the option "-i=mi1".
3369 Support for the original "mi0" syntax (included in GDB 5.0) has been
3372 Fix for gdb/192: removed extraneous space when displaying frame level.
3373 Fix for gdb/672: update changelist is now output in mi list format.
3374 Fix for gdb/702: a -var-assign that updates the value now shows up
3375 in a subsequent -var-update.
3377 * New native configurations.
3379 FreeBSD/amd64 x86_64-*-freebsd*
3381 * Multi-arched targets.
3383 HP/PA HPUX11 hppa*-*-hpux*
3384 Renesas M32R/D w/simulator m32r-*-elf*
3386 * OBSOLETE configurations and files
3388 Configurations that have been declared obsolete in this release have
3389 been commented out. Unless there is activity to revive these
3390 configurations, the next release of GDB will have their sources
3391 permanently REMOVED.
3393 Z8000 simulator z8k-zilog-none or z8ksim
3394 Matsushita MN10200 w/simulator mn10200-*-*
3395 H8/500 simulator h8500-hitachi-hms or h8500hms
3396 HP/PA running BSD hppa*-*-bsd*
3397 HP/PA running OSF/1 hppa*-*-osf*
3398 HP/PA Pro target hppa*-*-pro*
3399 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3400 Sequent family i[3456]86-sequent-sysv4*
3401 i[3456]86-sequent-sysv*
3402 i[3456]86-sequent-bsd*
3403 Tsqware Sparclet sparclet-*-*
3404 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3406 * REMOVED configurations and files
3409 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3410 IBM AIX PS/2 i[3456]86-*-aix
3411 i386 running Mach 3.0 i[3456]86-*-mach3*
3412 i386 running Mach i[3456]86-*-mach*
3413 i386 running OSF/1 i[3456]86-*osf1mk*
3414 HP/Apollo 68k Family m68*-apollo*-sysv*,
3416 m68*-hp-bsd*, m68*-hp-hpux*
3417 Argonaut Risc Chip (ARC) arc-*-*
3418 Mitsubishi D30V d30v-*-*
3419 Fujitsu FR30 fr30-*-elf*
3420 OS/9000 i[34]86-*-os9k
3421 I960 with MON960 i960-*-coff
3423 * MIPS $fp behavior changed
3425 The convenience variable $fp, for the MIPS, now consistently returns
3426 the address of the current frame's base. Previously, depending on the
3427 context, $fp could refer to either $sp or the current frame's base
3428 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3429 The GNU Source-Level Debugger''.
3431 *** Changes in GDB 5.3:
3433 * GNU/Linux shared library multi-threaded performance improved.
3435 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3436 `/proc', in preference to `ptrace' for memory reads. This may result
3437 in an improvement in the start-up time of multi-threaded, shared
3438 library applications when run under GDB. One GDB user writes: ``loads
3439 shared libs like mad''.
3441 * ``gdbserver'' now supports multi-threaded applications on some targets
3443 Support for debugging multi-threaded applications which use
3444 the GNU/Linux LinuxThreads package has been added for
3445 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3446 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3448 * GDB now supports C/C++ preprocessor macros.
3450 GDB now expands preprocessor macro invocations in C/C++ expressions,
3451 and provides various commands for showing macro definitions and how
3454 The new command `macro expand EXPRESSION' expands any macro
3455 invocations in expression, and shows the result.
3457 The new command `show macro MACRO-NAME' shows the definition of the
3458 macro named MACRO-NAME, and where it was defined.
3460 Most compilers don't include information about macros in the debugging
3461 information by default. In GCC 3.1, for example, you need to compile
3462 your program with the options `-gdwarf-2 -g3'. If the macro
3463 information is present in the executable, GDB will read it.
3465 * Multi-arched targets.
3467 DEC Alpha (partial) alpha*-*-*
3468 DEC VAX (partial) vax-*-*
3470 National Semiconductor NS32000 (partial) ns32k-*-*
3471 Motorola 68000 (partial) m68k-*-*
3472 Motorola MCORE mcore-*-*
3476 Fujitsu FRV architecture added by Red Hat frv*-*-*
3479 * New native configurations
3481 Alpha NetBSD alpha*-*-netbsd*
3482 SH NetBSD sh*-*-netbsdelf*
3483 MIPS NetBSD mips*-*-netbsd*
3484 UltraSPARC NetBSD sparc64-*-netbsd*
3486 * OBSOLETE configurations and files
3488 Configurations that have been declared obsolete in this release have
3489 been commented out. Unless there is activity to revive these
3490 configurations, the next release of GDB will have their sources
3491 permanently REMOVED.
3493 Mitsubishi D30V d30v-*-*
3494 OS/9000 i[34]86-*-os9k
3495 IBM AIX PS/2 i[3456]86-*-aix
3496 Fujitsu FR30 fr30-*-elf*
3497 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3498 Argonaut Risc Chip (ARC) arc-*-*
3499 i386 running Mach 3.0 i[3456]86-*-mach3*
3500 i386 running Mach i[3456]86-*-mach*
3501 i386 running OSF/1 i[3456]86-*osf1mk*
3502 HP/Apollo 68k Family m68*-apollo*-sysv*,
3504 m68*-hp-bsd*, m68*-hp-hpux*
3505 I960 with MON960 i960-*-coff
3507 * OBSOLETE languages
3509 CHILL, a Pascal like language used by telecommunications companies.
3511 * REMOVED configurations and files
3513 AMD 29k family via UDI a29k-amd-udi, udi29k
3514 A29K VxWorks a29k-*-vxworks
3515 AMD 29000 embedded, using EBMON a29k-none-none
3516 AMD 29000 embedded with COFF a29k-none-coff
3517 AMD 29000 embedded with a.out a29k-none-aout
3519 testsuite/gdb.hp/gdb.threads-hp/ directory
3521 * New command "set max-user-call-depth <nnn>"
3523 This command allows the user to limit the call depth of user-defined
3524 commands. The default is 1024.
3526 * Changes in FreeBSD/i386 native debugging.
3528 Support for the "generate-core-file" has been added.
3530 * New commands "dump", "append", and "restore".
3532 These commands allow data to be copied from target memory
3533 to a bfd-format or binary file (dump and append), and back
3534 from a file into memory (restore).
3536 * Improved "next/step" support on multi-processor Alpha Tru64.
3538 The previous single-step mechanism could cause unpredictable problems,
3539 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3540 of a software single-step mechanism prevents this.
3542 *** Changes in GDB 5.2.1:
3550 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3551 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3552 Fix, by Joel Brobecker imported from mainline.
3554 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3555 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3556 Fix, by Fred Fish, imported from mainline.
3558 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3559 Surprisingly enough, it works now.
3560 By Michal Ludvig, imported from mainline.
3562 i386 hardware watchpoint support:
3563 avoid misses on second run for some targets.
3564 By Pierre Muller, imported from mainline.
3566 *** Changes in GDB 5.2:
3568 * New command "set trust-readonly-sections on[off]".
3570 This command is a hint that tells gdb that read-only sections
3571 really are read-only (ie. that their contents will not change).
3572 In this mode, gdb will go to the object file rather than the
3573 target to read memory from read-only sections (such as ".text").
3574 This can be a significant performance improvement on some
3575 (notably embedded) targets.
3577 * New command "generate-core-file" (or "gcore").
3579 This new gdb command allows the user to drop a core file of the child
3580 process state at any time. So far it's been implemented only for
3581 GNU/Linux and Solaris, but should be relatively easily ported to other
3582 hosts. Argument is core file name (defaults to core.<pid>).
3584 * New command line option
3586 GDB now accepts --pid or -p followed by a process id.
3588 * Change in command line behavior -- corefiles vs. process ids.
3590 There is a subtle behavior in the way in which GDB handles
3591 command line arguments. The first non-flag argument is always
3592 a program to debug, but the second non-flag argument may either
3593 be a corefile or a process id. Previously, GDB would attempt to
3594 open the second argument as a corefile, and if that failed, would
3595 issue a superfluous error message and then attempt to attach it as
3596 a process. Now, if the second argument begins with a non-digit,
3597 it will be treated as a corefile. If it begins with a digit,
3598 GDB will attempt to attach it as a process, and if no such process
3599 is found, will then attempt to open it as a corefile.
3601 * Changes in ARM configurations.
3603 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3604 configuration is fully multi-arch.
3606 * New native configurations
3608 ARM NetBSD arm*-*-netbsd*
3609 x86 OpenBSD i[3456]86-*-openbsd*
3610 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3611 Sparc64 running FreeBSD sparc64-*-freebsd*
3615 Sanyo XStormy16 xstormy16-elf
3617 * OBSOLETE configurations and files
3619 Configurations that have been declared obsolete in this release have
3620 been commented out. Unless there is activity to revive these
3621 configurations, the next release of GDB will have their sources
3622 permanently REMOVED.
3624 AMD 29k family via UDI a29k-amd-udi, udi29k
3625 A29K VxWorks a29k-*-vxworks
3626 AMD 29000 embedded, using EBMON a29k-none-none
3627 AMD 29000 embedded with COFF a29k-none-coff
3628 AMD 29000 embedded with a.out a29k-none-aout
3630 testsuite/gdb.hp/gdb.threads-hp/ directory
3632 * REMOVED configurations and files
3634 TI TMS320C80 tic80-*-*
3636 PowerPC Solaris powerpcle-*-solaris*
3637 PowerPC Windows NT powerpcle-*-cygwin32
3638 PowerPC Netware powerpc-*-netware*
3639 Harris/CXUX m88k m88*-harris-cxux*
3640 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3641 ns32k-utek-sysv* ns32k-utek-*
3642 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3643 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3644 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3645 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3646 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3648 * Changes to command line processing
3650 The new `--args' feature can be used to specify command-line arguments
3651 for the inferior from gdb's command line.
3653 * Changes to key bindings
3655 There is a new `operate-and-get-next' function bound to `C-o'.
3657 *** Changes in GDB 5.1.1
3659 Fix compile problem on DJGPP.
3661 Fix a problem with floating-point registers on the i386 being
3664 Fix to stop GDB crashing on .debug_str debug info.
3666 Numerous documentation fixes.
3668 Numerous testsuite fixes.
3670 *** Changes in GDB 5.1:
3672 * New native configurations
3674 Alpha FreeBSD alpha*-*-freebsd*
3675 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3676 MIPS GNU/Linux mips*-*-linux*
3677 MIPS SGI Irix 6.x mips*-sgi-irix6*
3678 ia64 AIX ia64-*-aix*
3679 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3683 Motorola 68HC11 and 68HC12 m68hc11-elf
3685 UltraSparc running GNU/Linux sparc64-*-linux*
3687 * OBSOLETE configurations and files
3689 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3690 Harris/CXUX m88k m88*-harris-cxux*
3691 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3692 ns32k-utek-sysv* ns32k-utek-*
3693 TI TMS320C80 tic80-*-*
3695 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3696 PowerPC Solaris powerpcle-*-solaris*
3697 PowerPC Windows NT powerpcle-*-cygwin32
3698 PowerPC Netware powerpc-*-netware*
3699 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3700 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3701 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3702 Apple Macintosh (MPW) host N/A
3704 stuff.c (Program to stuff files into a specially prepared space in kdb)
3705 kdb-start.c (Main loop for the standalone kernel debugger)
3707 Configurations that have been declared obsolete in this release have
3708 been commented out. Unless there is activity to revive these
3709 configurations, the next release of GDB will have their sources
3710 permanently REMOVED.
3712 * REMOVED configurations and files
3714 Altos 3068 m68*-altos-*
3715 Convex c1-*-*, c2-*-*
3717 ARM RISCix arm-*-* (as host)
3721 * GDB has been converted to ISO C.
3723 GDB's source code has been converted to ISO C. In particular, the
3724 sources are fully protoized, and rely on standard headers being
3729 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3731 * The MI enabled by default.
3733 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3734 revised and enabled by default. Packages which use GDB as a debugging
3735 engine behind a UI or another front end are encouraged to switch to
3736 using the GDB/MI interface, instead of the old annotations interface
3737 which is now deprecated.
3739 * Support for debugging Pascal programs.
3741 GDB now includes support for debugging Pascal programs. The following
3742 main features are supported:
3744 - Pascal-specific data types such as sets;
3746 - automatic recognition of Pascal sources based on file-name
3749 - Pascal-style display of data types, variables, and functions;
3751 - a Pascal expression parser.
3753 However, some important features are not yet supported.
3755 - Pascal string operations are not supported at all;
3757 - there are some problems with boolean types;
3759 - Pascal type hexadecimal constants are not supported
3760 because they conflict with the internal variables format;
3762 - support for Pascal objects and classes is not full yet;
3764 - unlike Pascal, GDB is case-sensitive for symbol names.
3766 * Changes in completion.
3768 Commands such as `shell', `run' and `set args', which pass arguments
3769 to inferior programs, now complete on file names, similar to what
3770 users expect at the shell prompt.
3772 Commands which accept locations, such as `disassemble', `print',
3773 `breakpoint', `until', etc. now complete on filenames as well as
3774 program symbols. Thus, if you type "break foob TAB", and the source
3775 files linked into the programs include `foobar.c', that file name will
3776 be one of the candidates for completion. However, file names are not
3777 considered for completion after you typed a colon that delimits a file
3778 name from a name of a function in that file, as in "break foo.c:bar".
3780 `set demangle-style' completes on available demangling styles.
3782 * New platform-independent commands:
3784 It is now possible to define a post-hook for a command as well as a
3785 hook that runs before the command. For more details, see the
3786 documentation of `hookpost' in the GDB manual.
3788 * Changes in GNU/Linux native debugging.
3790 Support for debugging multi-threaded programs has been completely
3791 revised for all platforms except m68k and sparc. You can now debug as
3792 many threads as your system allows you to have.
3794 Attach/detach is supported for multi-threaded programs.
3796 Support for SSE registers was added for x86. This doesn't work for
3797 multi-threaded programs though.
3799 * Changes in MIPS configurations.
3801 Multi-arch support is enabled for all MIPS configurations.
3803 GDB can now be built as native debugger on SGI Irix 6.x systems for
3804 debugging n32 executables. (Debugging 64-bit executables is not yet
3807 * Unified support for hardware watchpoints in all x86 configurations.
3809 Most (if not all) native x86 configurations support hardware-assisted
3810 breakpoints and watchpoints in a unified manner. This support
3811 implements debug register sharing between watchpoints, which allows to
3812 put a virtually infinite number of watchpoints on the same address,
3813 and also supports watching regions up to 16 bytes with several debug
3816 The new maintenance command `maintenance show-debug-regs' toggles
3817 debugging print-outs in functions that insert, remove, and test
3818 watchpoints and hardware breakpoints.
3820 * Changes in the DJGPP native configuration.
3822 New command ``info dos sysinfo'' displays assorted information about
3823 the CPU, OS, memory, and DPMI server.
3825 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3826 display information about segment descriptors stored in GDT, LDT, and
3829 New commands ``info dos pde'' and ``info dos pte'' display entries
3830 from Page Directory and Page Tables (for now works with CWSDPMI only).
3831 New command ``info dos address-pte'' displays the Page Table entry for
3832 a given linear address.
3834 GDB can now pass command lines longer than 126 characters to the
3835 program being debugged (requires an update to the libdbg.a library
3836 which is part of the DJGPP development kit).
3838 DWARF2 debug info is now supported.
3840 It is now possible to `step' and `next' through calls to `longjmp'.
3842 * Changes in documentation.
3844 All GDB documentation was converted to GFDL, the GNU Free
3845 Documentation License.
3847 Tracepoints-related commands are now fully documented in the GDB
3850 TUI, the Text-mode User Interface, is now documented in the manual.
3852 Tracepoints-related commands are now fully documented in the GDB
3855 The "GDB Internals" manual now has an index. It also includes
3856 documentation of `ui_out' functions, GDB coding standards, x86
3857 hardware watchpoints, and memory region attributes.
3859 * GDB's version number moved to ``version.in''
3861 The Makefile variable VERSION has been replaced by the file
3862 ``version.in''. People creating GDB distributions should update the
3863 contents of this file.
3867 GUD support is now a standard part of the EMACS distribution.
3869 *** Changes in GDB 5.0:
3871 * Improved support for debugging FP programs on x86 targets
3873 Unified and much-improved support for debugging floating-point
3874 programs on all x86 targets. In particular, ``info float'' now
3875 displays the FP registers in the same format on all x86 targets, with
3876 greater level of detail.
3878 * Improvements and bugfixes in hardware-assisted watchpoints
3880 It is now possible to watch array elements, struct members, and
3881 bitfields with hardware-assisted watchpoints. Data-read watchpoints
3882 on x86 targets no longer erroneously trigger when the address is
3885 * Improvements in the native DJGPP version of GDB
3887 The distribution now includes all the scripts and auxiliary files
3888 necessary to build the native DJGPP version on MS-DOS/MS-Windows
3889 machines ``out of the box''.
3891 The DJGPP version can now debug programs that use signals. It is
3892 possible to catch signals that happened in the debuggee, deliver
3893 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
3894 would kill the program being debugged.) Programs that hook hardware
3895 interrupts (keyboard, timer, etc.) can also be debugged.
3897 It is now possible to debug DJGPP programs that redirect their
3898 standard handles or switch them to raw (as opposed to cooked) mode, or
3899 even close them. The command ``run < foo > bar'' works as expected,
3900 and ``info terminal'' reports useful information about the debuggee's
3901 terminal, including raw/cooked mode, redirection, etc.
3903 The DJGPP version now uses termios functions for console I/O, which
3904 enables debugging graphics programs. Interrupting GDB with Ctrl-C
3907 DOS-style file names with drive letters are now fully supported by
3910 It is now possible to debug DJGPP programs that switch their working
3911 directory. It is also possible to rerun the debuggee any number of
3912 times without restarting GDB; thus, you can use the same setup,
3913 breakpoints, etc. for many debugging sessions.
3915 * New native configurations
3917 ARM GNU/Linux arm*-*-linux*
3918 PowerPC GNU/Linux powerpc-*-linux*
3922 Motorola MCore mcore-*-*
3923 x86 VxWorks i[3456]86-*-vxworks*
3924 PowerPC VxWorks powerpc-*-vxworks*
3925 TI TMS320C80 tic80-*-*
3927 * OBSOLETE configurations
3929 Altos 3068 m68*-altos-*
3930 Convex c1-*-*, c2-*-*
3932 ARM RISCix arm-*-* (as host)
3935 Configurations that have been declared obsolete will be commented out,
3936 but the code will be left in place. If there is no activity to revive
3937 these configurations before the next release of GDB, the sources will
3938 be permanently REMOVED.
3940 * Gould support removed
3942 Support for the Gould PowerNode and NP1 has been removed.
3944 * New features for SVR4
3946 On SVR4 native platforms (such as Solaris), if you attach to a process
3947 without first loading a symbol file, GDB will now attempt to locate and
3948 load symbols from the running process's executable file.
3950 * Many C++ enhancements
3952 C++ support has been greatly improved. Overload resolution now works properly
3953 in almost all cases. RTTI support is on the way.
3955 * Remote targets can connect to a sub-program
3957 A popen(3) style serial-device has been added. This device starts a
3958 sub-process (such as a stand-alone simulator) and then communicates
3959 with that. The sub-program to run is specified using the syntax
3960 ``|<program> <args>'' vis:
3962 (gdb) set remotedebug 1
3963 (gdb) target extended-remote |mn10300-elf-sim program-args
3965 * MIPS 64 remote protocol
3967 A long standing bug in the mips64 remote protocol where by GDB
3968 expected certain 32 bit registers (ex SR) to be transfered as 32
3969 instead of 64 bits has been fixed.
3971 The command ``set remote-mips64-transfers-32bit-regs on'' has been
3972 added to provide backward compatibility with older versions of GDB.
3974 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
3976 The command ``set remotebinarydownload'' command has been replaced by
3977 ``set remote X-packet''. Other commands in ``set remote'' family
3978 include ``set remote P-packet''.
3980 * Breakpoint commands accept ranges.
3982 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
3983 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
3984 ``tracepoint passcount'' also accepts a range of tracepoints.
3986 * ``apropos'' command added.
3988 The ``apropos'' command searches through command names and
3989 documentation strings, printing out matches, making it much easier to
3990 try to find a command that does what you are looking for.
3994 A new machine oriented interface (MI) has been added to GDB. This
3995 interface is designed for debug environments running GDB as a separate
3996 process. This is part of the long term libGDB project. See the
3997 "GDB/MI" chapter of the GDB manual for further information. It can be
3998 enabled by configuring with:
4000 .../configure --enable-gdbmi
4002 *** Changes in GDB-4.18:
4004 * New native configurations
4006 HP-UX 10.20 hppa*-*-hpux10.20
4007 HP-UX 11.x hppa*-*-hpux11.0*
4008 M68K GNU/Linux m68*-*-linux*
4012 Fujitsu FR30 fr30-*-elf*
4013 Intel StrongARM strongarm-*-*
4014 Mitsubishi D30V d30v-*-*
4016 * OBSOLETE configurations
4018 Gould PowerNode, NP1 np1-*-*, pn-*-*
4020 Configurations that have been declared obsolete will be commented out,
4021 but the code will be left in place. If there is no activity to revive
4022 these configurations before the next release of GDB, the sources will
4023 be permanently REMOVED.
4027 As a compatibility experiment, GDB's source files buildsym.h and
4028 buildsym.c have been converted to pure standard C, no longer
4029 containing any K&R compatibility code. We believe that all systems in
4030 use today either come with a standard C compiler, or have a GCC port
4031 available. If this is not true, please report the affected
4032 configuration to bug-gdb@gnu.org immediately. See the README file for
4033 information about getting a standard C compiler if you don't have one
4038 GDB now uses readline 2.2.
4040 * set extension-language
4042 You can now control the mapping between filename extensions and source
4043 languages by using the `set extension-language' command. For instance,
4044 you can ask GDB to treat .c files as C++ by saying
4045 set extension-language .c c++
4046 The command `info extensions' lists all of the recognized extensions
4047 and their associated languages.
4049 * Setting processor type for PowerPC and RS/6000
4051 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4052 you can use the `set processor' command to specify what variant of the
4053 PowerPC family you are debugging. The command
4057 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4058 following PowerPC and RS6000 variants:
4060 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4061 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4063 403GC IBM PowerPC 403GC
4064 505 Motorola PowerPC 505
4065 860 Motorola PowerPC 860 or 850
4066 601 Motorola PowerPC 601
4067 602 Motorola PowerPC 602
4068 603 Motorola/IBM PowerPC 603 or 603e
4069 604 Motorola PowerPC 604 or 604e
4070 750 Motorola/IBM PowerPC 750 or 750
4072 At the moment, this command just tells GDB what to name the
4073 special-purpose processor registers. Since almost all the affected
4074 registers are inaccessible to user-level programs, this command is
4075 only useful for remote debugging in its present form.
4079 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4080 more extensive support for HP-UX. Added features include shared
4081 library support, kernel threads and hardware watchpoints for 11.00,
4082 support for HP's ANSI C and C++ compilers, and a compatibility mode
4083 for xdb and dbx commands.
4087 HP's donation includes the new concept of catchpoints, which is a
4088 generalization of the old catch command. On HP-UX, it is now possible
4089 to catch exec, fork, and vfork, as well as library loading.
4091 This means that the existing catch command has changed; its first
4092 argument now specifies the type of catch to be set up. See the
4093 output of "help catch" for a list of catchpoint types.
4095 * Debugging across forks
4097 On HP-UX, you can choose which process to debug when a fork() happens
4102 HP has donated a curses-based terminal user interface (TUI). To get
4103 it, build with --enable-tui. Although this can be enabled for any
4104 configuration, at present it only works for native HP debugging.
4106 * GDB remote protocol additions
4108 A new protocol packet 'X' that writes binary data is now available.
4109 Default behavior is to try 'X', then drop back to 'M' if the stub
4110 fails to respond. The settable variable `remotebinarydownload'
4111 allows explicit control over the use of 'X'.
4113 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4114 full 64-bit address. The command
4116 set remoteaddresssize 32
4118 can be used to revert to the old behaviour. For existing remote stubs
4119 the change should not be noticed, as the additional address information
4122 In order to assist in debugging stubs, you may use the maintenance
4123 command `packet' to send any text string to the stub. For instance,
4125 maint packet heythere
4127 sends the packet "$heythere#<checksum>". Note that it is very easy to
4128 disrupt a debugging session by sending the wrong packet at the wrong
4131 The compare-sections command allows you to compare section data on the
4132 target to what is in the executable file without uploading or
4133 downloading, by comparing CRC checksums.
4135 * Tracing can collect general expressions
4137 You may now collect general expressions at tracepoints. This requires
4138 further additions to the target-side stub; see tracepoint.c and
4139 doc/agentexpr.texi for further details.
4141 * mask-address variable for Mips
4143 For Mips targets, you may control the zeroing of the upper 32 bits of
4144 a 64-bit address by entering `set mask-address on'. This is mainly
4145 of interest to users of embedded R4xxx and R5xxx processors.
4147 * Higher serial baud rates
4149 GDB's serial code now allows you to specify baud rates 57600, 115200,
4150 230400, and 460800 baud. (Note that your host system may not be able
4151 to achieve all of these rates.)
4155 The i960 configuration now includes an initial implementation of a
4156 builtin simulator, contributed by Jim Wilson.
4159 *** Changes in GDB-4.17:
4161 * New native configurations
4163 Alpha GNU/Linux alpha*-*-linux*
4164 Unixware 2.x i[3456]86-unixware2*
4165 Irix 6.x mips*-sgi-irix6*
4166 PowerPC GNU/Linux powerpc-*-linux*
4167 PowerPC Solaris powerpcle-*-solaris*
4168 Sparc GNU/Linux sparc-*-linux*
4169 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4173 Argonaut Risc Chip (ARC) arc-*-*
4174 Hitachi H8/300S h8300*-*-*
4175 Matsushita MN10200 w/simulator mn10200-*-*
4176 Matsushita MN10300 w/simulator mn10300-*-*
4177 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4178 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4179 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4180 Mitsubishi D10V w/simulator d10v-*-*
4181 Mitsubishi M32R/D w/simulator m32r-*-elf*
4182 Tsqware Sparclet sparclet-*-*
4183 NEC V850 w/simulator v850-*-*
4185 * New debugging protocols
4187 ARM with RDI protocol arm*-*-*
4188 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4189 DDB and LSI variants of PMON protocol mips*-*-*
4190 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4191 PowerPC with SDS protocol powerpc{,le}-*-eabi
4192 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4196 All configurations can now understand and use the DWARF 2 debugging
4197 format. The choice is automatic, if the symbol file contains DWARF 2
4202 GDB now includes basic Java language support. This support is
4203 only useful with Java compilers that produce native machine code.
4205 * solib-absolute-prefix and solib-search-path
4207 For SunOS and SVR4 shared libraries, you may now set the prefix for
4208 loading absolute shared library symbol files, and the search path for
4209 locating non-absolute shared library symbol files.
4211 * Live range splitting
4213 GDB can now effectively debug code for which GCC has performed live
4214 range splitting as part of its optimization. See gdb/doc/LRS for
4215 more details on the expected format of the stabs information.
4219 GDB's support for the GNU Hurd, including thread debugging, has been
4220 updated to work with current versions of the Hurd.
4224 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4225 instruction set. ARM GDB automatically detects when Thumb
4226 instructions are in use, and adjusts disassembly and backtracing
4231 GDB's MIPS target configurations now handle the MIP16 16-bit
4236 GDB now includes support for overlays; if an executable has been
4237 linked such that multiple sections are based at the same address, GDB
4238 will decide which section to use for symbolic info. You can choose to
4239 control the decision manually, using overlay commands, or implement
4240 additional target-side support and use "overlay load-target" to bring
4241 in the overlay mapping. Do "help overlay" for more detail.
4245 The command "info symbol <address>" displays information about
4246 the symbol at the specified address.
4250 The standard remote protocol now includes an extension that allows
4251 asynchronous collection and display of trace data. This requires
4252 extensive support in the target-side debugging stub. Tracing mode
4253 includes a new interaction mode in GDB and new commands: see the
4254 file tracepoint.c for more details.
4258 Configurations for embedded MIPS now include a simulator contributed
4259 by Cygnus Solutions. The simulator supports the instruction sets
4260 of most MIPS variants.
4264 Sparc configurations may now include the ERC32 simulator contributed
4265 by the European Space Agency. The simulator is not built into
4266 Sparc targets by default; configure with --enable-sim to include it.
4270 For target configurations that may include multiple variants of a
4271 basic architecture (such as MIPS and SH), you may now set the
4272 architecture explicitly. "set arch" sets, "info arch" lists
4273 the possible architectures.
4275 *** Changes in GDB-4.16:
4277 * New native configurations
4279 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4280 M68K NetBSD m68k-*-netbsd*
4281 PowerPC AIX 4.x powerpc-*-aix*
4282 PowerPC MacOS powerpc-*-macos*
4283 PowerPC Windows NT powerpcle-*-cygwin32
4284 RS/6000 AIX 4.x rs6000-*-aix4*
4288 ARM with RDP protocol arm-*-*
4289 I960 with MON960 i960-*-coff
4290 MIPS VxWorks mips*-*-vxworks*
4291 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4292 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4294 Matra Sparclet sparclet-*-*
4298 The powerpc-eabi configuration now includes the PSIM simulator,
4299 contributed by Andrew Cagney, with assistance from Mike Meissner.
4300 PSIM is a very elaborate model of the PowerPC, including not only
4301 basic instruction set execution, but also details of execution unit
4302 performance and I/O hardware. See sim/ppc/README for more details.
4306 GDB now works with Solaris 2.5.
4308 * Windows 95/NT native
4310 GDB will now work as a native debugger on Windows 95 and Windows NT.
4311 To build it from source, you must use the "gnu-win32" environment,
4312 which uses a DLL to emulate enough of Unix to run the GNU tools.
4313 Further information, binaries, and sources are available at
4314 ftp.cygnus.com, under pub/gnu-win32.
4316 * dont-repeat command
4318 If a user-defined command includes the command `dont-repeat', then the
4319 command will not be repeated if the user just types return. This is
4320 useful if the command is time-consuming to run, so that accidental
4321 extra keystrokes don't run the same command many times.
4323 * Send break instead of ^C
4325 The standard remote protocol now includes an option to send a break
4326 rather than a ^C to the target in order to interrupt it. By default,
4327 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4329 * Remote protocol timeout
4331 The standard remote protocol includes a new variable `remotetimeout'
4332 that allows you to set the number of seconds before GDB gives up trying
4333 to read from the target. The default value is 2.
4335 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4337 By default GDB will automatically keep track of objects as they are
4338 loaded and unloaded by the dynamic linker. By using the command `set
4339 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4340 when shared library events occur, thus allowing you to set breakpoints
4341 in shared libraries which are explicitly loaded by the inferior.
4343 Note this feature does not work on hpux8. On hpux9 you must link
4344 /usr/lib/end.o into your program. This feature should work
4345 automatically on hpux10.
4347 * Irix 5.x hardware watchpoint support
4349 Irix 5 configurations now support the use of hardware watchpoints.
4351 * Mips protocol "SYN garbage limit"
4353 When debugging a Mips target using the `target mips' protocol, you
4354 may set the number of characters that GDB will ignore by setting
4355 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4356 every character. The default value is 1050.
4358 * Recording and replaying remote debug sessions
4360 If you set `remotelogfile' to the name of a file, gdb will write to it
4361 a recording of a remote debug session. This recording may then be
4362 replayed back to gdb using "gdbreplay". See gdbserver/README for
4363 details. This is useful when you have a problem with GDB while doing
4364 remote debugging; you can make a recording of the session and send it
4365 to someone else, who can then recreate the problem.
4367 * Speedups for remote debugging
4369 GDB includes speedups for downloading and stepping MIPS systems using
4370 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4371 and more efficient S-record downloading.
4373 * Memory use reductions and statistics collection
4375 GDB now uses less memory and reports statistics about memory usage.
4376 Try the `maint print statistics' command, for example.
4378 *** Changes in GDB-4.15:
4380 * Psymtabs for XCOFF
4382 The symbol reader for AIX GDB now uses partial symbol tables. This
4383 can greatly improve startup time, especially for large executables.
4385 * Remote targets use caching
4387 Remote targets now use a data cache to speed up communication with the
4388 remote side. The data cache could lead to incorrect results because
4389 it doesn't know about volatile variables, thus making it impossible to
4390 debug targets which use memory mapped I/O devices. `set remotecache
4391 off' turns the the data cache off.
4393 * Remote targets may have threads
4395 The standard remote protocol now includes support for multiple threads
4396 in the target system, using new protocol commands 'H' and 'T'. See
4397 gdb/remote.c for details.
4401 If GDB is configured with `--enable-netrom', then it will include
4402 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4403 acts as though it is a bank of ROM on the target board, but you can
4404 write into it over the network. GDB's support consists only of
4405 support for fast loading into the emulated ROM; to debug, you must use
4406 another protocol, such as standard remote protocol. The usual
4407 sequence is something like
4409 target nrom <netrom-hostname>
4411 target remote <netrom-hostname>:1235
4415 GDB now includes support for the Apple Macintosh, as a host only. It
4416 may be run as either an MPW tool or as a standalone application, and
4417 it can debug through the serial port. All the usual GDB commands are
4418 available, but to the target command, you must supply "serial" as the
4419 device type instead of "/dev/ttyXX". See mpw-README in the main
4420 directory for more information on how to build. The MPW configuration
4421 scripts */mpw-config.in support only a few targets, and only the
4422 mips-idt-ecoff target has been tested.
4426 GDB configuration now uses autoconf. This is not user-visible,
4427 but does simplify configuration and building.
4431 GDB now supports hpux10.
4433 *** Changes in GDB-4.14:
4435 * New native configurations
4437 x86 FreeBSD i[345]86-*-freebsd
4438 x86 NetBSD i[345]86-*-netbsd
4439 NS32k NetBSD ns32k-*-netbsd
4440 Sparc NetBSD sparc-*-netbsd
4444 A29K VxWorks a29k-*-vxworks
4445 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4446 CPU32 EST-300 emulator m68*-*-est*
4447 PowerPC ELF powerpc-*-elf
4450 * Alpha OSF/1 support for procfs
4452 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4453 possible to attach to running processes. As the mounting of the /proc
4454 filesystem is optional on the Alpha, GDB automatically determines
4455 the availability of /proc during startup. This can lead to problems
4456 if /proc is unmounted after GDB has been started.
4458 * Arguments to user-defined commands
4460 User commands may accept up to 10 arguments separated by whitespace.
4461 Arguments are accessed within the user command via $arg0..$arg9. A
4464 print $arg0 + $arg1 + $arg2
4466 To execute the command use:
4469 Defines the command "adder" which prints the sum of its three arguments.
4470 Note the arguments are text substitutions, so they may reference variables,
4471 use complex expressions, or even perform inferior function calls.
4473 * New `if' and `while' commands
4475 This makes it possible to write more sophisticated user-defined
4476 commands. Both commands take a single argument, which is the
4477 expression to evaluate, and must be followed by the commands to
4478 execute, one per line, if the expression is nonzero, the list being
4479 terminated by the word `end'. The `if' command list may include an
4480 `else' word, which causes the following commands to be executed only
4481 if the expression is zero.
4483 * Fortran source language mode
4485 GDB now includes partial support for Fortran 77. It will recognize
4486 Fortran programs and can evaluate a subset of Fortran expressions, but
4487 variables and functions may not be handled correctly. GDB will work
4488 with G77, but does not yet know much about symbols emitted by other
4491 * Better HPUX support
4493 Most debugging facilities now work on dynamic executables for HPPAs
4494 running hpux9 or later. You can attach to running dynamically linked
4495 processes, but by default the dynamic libraries will be read-only, so
4496 for instance you won't be able to put breakpoints in them. To change
4497 that behavior do the following before running the program:
4503 This will cause the libraries to be mapped private and read-write.
4504 To revert to the normal behavior, do this:
4510 You cannot set breakpoints or examine data in the library until after
4511 the library is loaded if the function/data symbols do not have
4514 GDB can now also read debug symbols produced by the HP C compiler on
4515 HPPAs (sorry, no C++, Fortran or 68k support).
4517 * Target byte order now dynamically selectable
4519 You can choose which byte order to use with a target system, via the
4520 commands "set endian big" and "set endian little", and you can see the
4521 current setting by using "show endian". You can also give the command
4522 "set endian auto", in which case GDB will use the byte order
4523 associated with the executable. Currently, only embedded MIPS
4524 configurations support dynamic selection of target byte order.
4526 * New DOS host serial code
4528 This version uses DPMI interrupts to handle buffered I/O, so you
4529 no longer need to run asynctsr when debugging boards connected to
4532 *** Changes in GDB-4.13:
4534 * New "complete" command
4536 This lists all the possible completions for the rest of the line, if it
4537 were to be given as a command itself. This is intended for use by emacs.
4539 * Trailing space optional in prompt
4541 "set prompt" no longer adds a space for you after the prompt you set. This
4542 allows you to set a prompt which ends in a space or one that does not.
4544 * Breakpoint hit counts
4546 "info break" now displays a count of the number of times the breakpoint
4547 has been hit. This is especially useful in conjunction with "ignore"; you
4548 can ignore a large number of breakpoint hits, look at the breakpoint info
4549 to see how many times the breakpoint was hit, then run again, ignoring one
4550 less than that number, and this will get you quickly to the last hit of
4553 * Ability to stop printing at NULL character
4555 "set print null-stop" will cause GDB to stop printing the characters of
4556 an array when the first NULL is encountered. This is useful when large
4557 arrays actually contain only short strings.
4559 * Shared library breakpoints
4561 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4562 breakpoints in shared libraries before the executable is run.
4564 * Hardware watchpoints
4566 There is a new hardware breakpoint for the watch command for sparclite
4567 targets. See gdb/sparclite/hw_breakpoint.note.
4569 Hardware watchpoints are also now supported under GNU/Linux.
4573 Annotations have been added. These are for use with graphical interfaces,
4574 and are still experimental. Currently only gdba.el uses these.
4576 * Improved Irix 5 support
4578 GDB now works properly with Irix 5.2.
4580 * Improved HPPA support
4582 GDB now works properly with the latest GCC and GAS.
4584 * New native configurations
4586 Sequent PTX4 i[34]86-sequent-ptx4
4587 HPPA running OSF/1 hppa*-*-osf*
4588 Atari TT running SVR4 m68*-*-sysv4*
4589 RS/6000 LynxOS rs6000-*-lynxos*
4593 OS/9000 i[34]86-*-os9k
4594 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4597 * Hitachi SH7000 and E7000-PC ICE support
4599 There is now support for communicating with the Hitachi E7000-PC ICE.
4600 This is available automatically when GDB is configured for the SH.
4604 As usual, a variety of small fixes and improvements, both generic
4605 and configuration-specific. See the ChangeLog for more detail.
4607 *** Changes in GDB-4.12:
4609 * Irix 5 is now supported
4613 GDB-4.12 on the HPPA has a number of changes which make it unable
4614 to debug the output from the currently released versions of GCC and
4615 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4616 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4617 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4620 *** Changes in GDB-4.11:
4622 * User visible changes:
4626 The "set remotedebug" option is now consistent between the mips remote
4627 target, remote targets using the gdb-specific protocol, UDI (AMD's
4628 debug protocol for the 29k) and the 88k bug monitor. It is now an
4629 integer specifying a debug level (normally 0 or 1, but 2 means more
4630 debugging info for the mips target).
4632 * DEC Alpha native support
4634 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4635 debug info, but GDB works fairly well with the DEC compiler and should
4636 work with a future GCC release. See the README file for a few
4637 Alpha-specific notes.
4639 * Preliminary thread implementation
4641 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4643 * LynxOS native and target support for 386
4645 This release has been hosted on LynxOS 2.2, and also can be configured
4646 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4649 * Improvements in C++ mangling/demangling.
4651 This release has much better g++ debugging, specifically in name
4652 mangling/demangling, virtual function calls, print virtual table,
4653 call methods, ...etc.
4655 *** Changes in GDB-4.10:
4657 * User visible changes:
4659 Remote debugging using the GDB-specific (`target remote') protocol now
4660 supports the `load' command. This is only useful if you have some
4661 other way of getting the stub to the target system, and you can put it
4662 somewhere in memory where it won't get clobbered by the download.
4664 Filename completion now works.
4666 When run under emacs mode, the "info line" command now causes the
4667 arrow to point to the line specified. Also, "info line" prints
4668 addresses in symbolic form (as well as hex).
4670 All vxworks based targets now support a user settable option, called
4671 vxworks-timeout. This option represents the number of seconds gdb
4672 should wait for responses to rpc's. You might want to use this if
4673 your vxworks target is, perhaps, a slow software simulator or happens
4674 to be on the far side of a thin network line.
4678 This release contains support for using a DEC alpha as a GDB host for
4679 cross debugging. Native alpha debugging is not supported yet.
4682 *** Changes in GDB-4.9:
4686 This is the first GDB release which is accompanied by a matching testsuite.
4687 The testsuite requires installation of dejagnu, which should be available
4688 via ftp from most sites that carry GNU software.
4692 'Cfront' style demangling has had its name changed to 'ARM' style, to
4693 emphasize that it was written from the specifications in the C++ Annotated
4694 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4695 disclaimers, it still generated too much confusion with users attempting to
4696 use gdb with AT&T cfront.
4700 GDB now uses a standard remote interface to a simulator library.
4701 So far, the library contains simulators for the Zilog Z8001/2, the
4702 Hitachi H8/300, H8/500 and Super-H.
4704 * New targets supported
4706 H8/300 simulator h8300-hitachi-hms or h8300hms
4707 H8/500 simulator h8500-hitachi-hms or h8500hms
4708 SH simulator sh-hitachi-hms or sh
4709 Z8000 simulator z8k-zilog-none or z8ksim
4710 IDT MIPS board over serial line mips-idt-ecoff
4712 Cross-debugging to GO32 targets is supported. It requires a custom
4713 version of the i386-stub.c module which is integrated with the
4714 GO32 memory extender.
4716 * New remote protocols
4718 MIPS remote debugging protocol.
4720 * New source languages supported
4722 This version includes preliminary support for Chill, a Pascal like language
4723 used by telecommunications companies. Chill support is also being integrated
4724 into the GNU compiler, but we don't know when it will be publically available.
4727 *** Changes in GDB-4.8:
4729 * HP Precision Architecture supported
4731 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4732 version of this support was available as a set of patches from the
4733 University of Utah. GDB does not support debugging of programs
4734 compiled with the HP compiler, because HP will not document their file
4735 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4736 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4738 Many problems in the preliminary version have been fixed.
4740 * Faster and better demangling
4742 We have improved template demangling and fixed numerous bugs in the GNU style
4743 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4744 character types (wchar_t) are now supported. Demangling of each symbol is now
4745 only done once, and is cached when the symbol table for a file is read in.
4746 This results in a small increase in memory usage for C programs, a moderate
4747 increase in memory usage for C++ programs, and a fantastic speedup in
4750 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4751 from the specifications in the Annotated Reference Manual, which AT&T's
4752 compiler does not actually implement.
4754 * G++ multiple inheritance compiler problem
4756 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4757 inheritance lattices was reworked to properly discover ambiguities. We
4758 recently found an example which causes this new algorithm to fail in a
4759 very subtle way, producing bad debug information for those classes.
4760 The file 'gcc.patch' (in this directory) can be applied to gcc to
4761 circumvent the problem. A future GCC release will contain a complete
4764 The previous G++ debug info problem (mentioned below for the gdb-4.7
4765 release) is fixed in gcc version 2.3.2.
4767 * Improved configure script
4769 The `configure' script will now attempt to guess your system type if
4770 you don't supply a host system type. The old scheme of supplying a
4771 host system triplet is preferable over using this. All the magic is
4772 done in the new `config.guess' script. Examine it for details.
4774 We have also brought our configure script much more in line with the FSF's
4775 version. It now supports the --with-xxx options. In particular,
4776 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4777 The resulting GDB will not be able to read arbitrary object file formats --
4778 only the format ``expected'' to be used on the configured target system.
4779 We hope to make this the default in a future release.
4781 * Documentation improvements
4783 There's new internal documentation on how to modify GDB, and how to
4784 produce clean changes to the code. We implore people to read it
4785 before submitting changes.
4787 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4788 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4789 `info' files are also provided. To build `info' files from scratch,
4790 you will need the latest `makeinfo' release, which will be available in
4791 a future texinfo-X.Y release.
4793 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4794 We're not sure exactly which versions have this problem, but it has
4795 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4796 or better. If that isn't possible, there is a patch in
4797 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4798 around this problem.
4802 GDB now supports array constants that can be used in expressions typed in by
4803 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4804 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4807 The new directory `gdb/sparclite' contains a program that demonstrates
4808 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4810 * New native hosts supported
4812 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4813 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4815 * New targets supported
4817 AMD 29k family via UDI a29k-amd-udi or udi29k
4819 * New file formats supported
4821 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4822 HPUX core files, and SCO 3.2v2 core files.
4826 Attaching to processes now works again; thanks for the many bug reports.
4828 We have also stomped on a bunch of core dumps caused by
4829 printf_filtered("%s") problems.
4831 We eliminated a copyright problem on the rpc and ptrace header files
4832 for VxWorks, which was discovered at the last minute during the 4.7
4833 release. You should now be able to build a VxWorks GDB.
4835 You can now interrupt gdb while an attached process is running. This
4836 will cause the attached process to stop, and give control back to GDB.
4838 We fixed problems caused by using too many file descriptors
4839 for reading symbols from object files and libraries. This was
4840 especially a problem for programs that used many (~100) shared
4843 The `step' command now only enters a subroutine if there is line number
4844 information for the subroutine. Otherwise it acts like the `next'
4845 command. Previously, `step' would enter subroutines if there was
4846 any debugging information about the routine. This avoids problems
4847 when using `cc -g1' on MIPS machines.
4849 * Internal improvements
4851 GDB's internal interfaces have been improved to make it easier to support
4852 debugging of multiple languages in the future.
4854 GDB now uses a common structure for symbol information internally.
4855 Minimal symbols (derived from linkage symbols in object files), partial
4856 symbols (from a quick scan of debug information), and full symbols
4857 contain a common subset of information, making it easier to write
4858 shared code that handles any of them.
4860 * New command line options
4862 We now accept --silent as an alias for --quiet.
4866 The memory-mapped-malloc library is now licensed under the GNU Library
4867 General Public License.
4869 *** Changes in GDB-4.7:
4871 * Host/native/target split
4873 GDB has had some major internal surgery to untangle the support for
4874 hosts and remote targets. Now, when you configure GDB for a remote
4875 target, it will no longer load in all of the support for debugging
4876 local programs on the host. When fully completed and tested, this will
4877 ensure that arbitrary host/target combinations are possible.
4879 The primary conceptual shift is to separate the non-portable code in
4880 GDB into three categories. Host specific code is required any time GDB
4881 is compiled on that host, regardless of the target. Target specific
4882 code relates to the peculiarities of the target, but can be compiled on
4883 any host. Native specific code is everything else: it can only be
4884 built when the host and target are the same system. Child process
4885 handling and core file support are two common `native' examples.
4887 GDB's use of /proc for controlling Unix child processes is now cleaner.
4888 It has been split out into a single module under the `target_ops' vector,
4889 plus two native-dependent functions for each system that uses /proc.
4891 * New hosts supported
4893 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
4894 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4895 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
4897 * New targets supported
4899 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4900 68030 and CPU32 m68030-*-*, m68332-*-*
4902 * New native hosts supported
4904 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4905 (386bsd is not well tested yet)
4906 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
4908 * New file formats supported
4910 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
4911 supports reading of `a.out.adobe' object files, which are an a.out
4912 format extended with minimal information about multiple sections.
4916 `show copying' is the same as the old `info copying'.
4917 `show warranty' is the same as `info warrantee'.
4918 These were renamed for consistency. The old commands continue to work.
4920 `info handle' is a new alias for `info signals'.
4922 You can now define pre-command hooks, which attach arbitrary command
4923 scripts to any command. The commands in the hook will be executed
4924 prior to the user's command. You can also create a hook which will be
4925 executed whenever the program stops. See gdb.texinfo.
4929 We now deal with Cfront style name mangling, and can even extract type
4930 info from mangled symbols. GDB can automatically figure out which
4931 symbol mangling style your C++ compiler uses.
4933 Calling of methods and virtual functions has been improved as well.
4937 The crash that occured when debugging Sun Ansi-C compiled binaries is
4938 fixed. This was due to mishandling of the extra N_SO stabs output
4941 We also finally got Ultrix 4.2 running in house, and fixed core file
4942 support, with help from a dozen people on the net.
4944 John M. Farrell discovered that the reason that single-stepping was so
4945 slow on all of the Mips based platforms (primarily SGI and DEC) was
4946 that we were trying to demangle and lookup a symbol used for internal
4947 purposes on every instruction that was being stepped through. Changing
4948 the name of that symbol so that it couldn't be mistaken for a C++
4949 mangled symbol sped things up a great deal.
4951 Rich Pixley sped up symbol lookups in general by getting much smarter
4952 about when C++ symbol mangling is necessary. This should make symbol
4953 completion (TAB on the command line) much faster. It's not as fast as
4954 we'd like, but it's significantly faster than gdb-4.6.
4958 A new user controllable variable 'call_scratch_address' can
4959 specify the location of a scratch area to be used when GDB
4960 calls a function in the target. This is necessary because the
4961 usual method of putting the scratch area on the stack does not work
4962 in systems that have separate instruction and data spaces.
4964 We integrated changes to support the 29k UDI (Universal Debugger
4965 Interface), but discovered at the last minute that we didn't have all
4966 of the appropriate copyright paperwork. We are working with AMD to
4967 resolve this, and hope to have it available soon.
4971 We have sped up the remote serial line protocol, especially for targets
4972 with lots of registers. It now supports a new `expedited status' ('T')
4973 message which can be used in place of the existing 'S' status message.
4974 This allows the remote stub to send only the registers that GDB
4975 needs to make a quick decision about single-stepping or conditional
4976 breakpoints, eliminating the need to fetch the entire register set for
4977 each instruction being stepped through.
4979 The GDB remote serial protocol now implements a write-through cache for
4980 registers, only re-reading the registers if the target has run.
4982 There is also a new remote serial stub for SPARC processors. You can
4983 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
4984 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
4985 processor with a serial port.
4989 Configure.in files have become much easier to read and modify. A new
4990 `table driven' format makes it more obvious what configurations are
4991 supported, and what files each one uses.
4995 There is a new opcodes library which will eventually contain all of the
4996 disassembly routines and opcode tables. At present, it only contains
4997 Sparc and Z8000 routines. This will allow the assembler, debugger, and
4998 disassembler (binutils/objdump) to share these routines.
5000 The libiberty library is now copylefted under the GNU Library General
5001 Public License. This allows more liberal use, and was done so libg++
5002 can use it. This makes no difference to GDB, since the Library License
5003 grants all the rights from the General Public License.
5007 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5008 reference to the stabs symbol info used by the debugger. It is (as far
5009 as we know) the only published document on this fascinating topic. We
5010 encourage you to read it, compare it to the stabs information on your
5011 system, and send improvements on the document in general (to
5012 bug-gdb@prep.ai.mit.edu).
5014 And, of course, many bugs have been fixed.
5017 *** Changes in GDB-4.6:
5019 * Better support for C++ function names
5021 GDB now accepts as input the "demangled form" of C++ overloaded function
5022 names and member function names, and can do command completion on such names
5023 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5024 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5025 Make use of command completion, it is your friend.
5027 GDB also now accepts a variety of C++ mangled symbol formats. They are
5028 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5029 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5030 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5031 for the list of formats.
5033 * G++ symbol mangling problem
5035 Recent versions of gcc have a bug in how they emit debugging information for
5036 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5037 directory) can be applied to gcc to fix the problem. Alternatively, if you
5038 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5039 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5040 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5043 * New 'maintenance' command
5045 All of the commands related to hacking GDB internals have been moved out of
5046 the main command set, and now live behind the 'maintenance' command. This
5047 can also be abbreviated as 'mt'. The following changes were made:
5049 dump-me -> maintenance dump-me
5050 info all-breakpoints -> maintenance info breakpoints
5051 printmsyms -> maintenance print msyms
5052 printobjfiles -> maintenance print objfiles
5053 printpsyms -> maintenance print psymbols
5054 printsyms -> maintenance print symbols
5056 The following commands are new:
5058 maintenance demangle Call internal GDB demangler routine to
5059 demangle a C++ link name and prints the result.
5060 maintenance print type Print a type chain for a given symbol
5062 * Change to .gdbinit file processing
5064 We now read the $HOME/.gdbinit file before processing the argv arguments
5065 (e.g. reading symbol files or core files). This allows global parameters to
5066 be set, which will apply during the symbol reading. The ./.gdbinit is still
5067 read after argv processing.
5069 * New hosts supported
5071 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5073 GNU/Linux support i386-unknown-linux or linux
5075 We are also including code to support the HP/PA running BSD and HPUX. This
5076 is almost guaranteed not to work, as we didn't have time to test or build it
5077 for this release. We are including it so that the more adventurous (or
5078 masochistic) of you can play with it. We also had major problems with the
5079 fact that the compiler that we got from HP doesn't support the -g option.
5082 * New targets supported
5084 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5086 * More smarts about finding #include files
5088 GDB now remembers the compilation directory for all include files, and for
5089 all files from which C is generated (like yacc and lex sources). This
5090 greatly improves GDB's ability to find yacc/lex sources, and include files,
5091 especially if you are debugging your program from a directory different from
5092 the one that contains your sources.
5094 We also fixed a bug which caused difficulty with listing and setting
5095 breakpoints in include files which contain C code. (In the past, you had to
5096 try twice in order to list an include file that you hadn't looked at before.)
5098 * Interesting infernals change
5100 GDB now deals with arbitrary numbers of sections, where the symbols for each
5101 section must be relocated relative to that section's landing place in the
5102 target's address space. This work was needed to support ELF with embedded
5103 stabs used by Solaris-2.0.
5105 * Bug fixes (of course!)
5107 There have been loads of fixes for the following things:
5108 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5109 i960, stabs, DOS(GO32), procfs, etc...
5111 See the ChangeLog for details.
5113 *** Changes in GDB-4.5:
5115 * New machines supported (host and target)
5117 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5119 SGI Irix-4.x mips-sgi-irix4 or iris4
5121 * New malloc package
5123 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5124 Mmalloc is capable of handling mutiple heaps of memory. It is also
5125 capable of saving a heap to a file, and then mapping it back in later.
5126 This can be used to greatly speedup the startup of GDB by using a
5127 pre-parsed symbol table which lives in a mmalloc managed heap. For
5128 more details, please read mmalloc/mmalloc.texi.
5132 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5133 'help info proc' for details.
5135 * MIPS ecoff symbol table format
5137 The code that reads MIPS symbol table format is now supported on all hosts.
5138 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5141 * File name changes for MS-DOS
5143 Many files in the config directories have been renamed to make it easier to
5144 support GDB on MS-DOSe systems (which have very restrictive file name
5145 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5146 environment) is close to working but has some remaining problems. Note
5147 that debugging of DOS programs is not supported, due to limitations
5148 in the ``operating system'', but it can be used to host cross-debugging.
5150 * Cross byte order fixes
5152 Many fixes have been made to support cross debugging of Sparc and MIPS
5153 targets from hosts whose byte order differs.
5155 * New -mapped and -readnow options
5157 If memory-mapped files are available on your system through the 'mmap'
5158 system call, you can use the -mapped option on the `file' or
5159 `symbol-file' commands to cause GDB to write the symbols from your
5160 program into a reusable file. If the program you are debugging is
5161 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5162 Future GDB debugging sessions will notice the presence of this file,
5163 and will quickly map in symbol information from it, rather than reading
5164 the symbol table from the executable program. Using the '-mapped'
5165 option in a GDB `file' or `symbol-file' command has the same effect as
5166 starting GDB with the '-mapped' command-line option.
5168 You can cause GDB to read the entire symbol table immediately by using
5169 the '-readnow' option with any of the commands that load symbol table
5170 information (or on the GDB command line). This makes the command
5171 slower, but makes future operations faster.
5173 The -mapped and -readnow options are typically combined in order to
5174 build a `fred.syms' file that contains complete symbol information.
5175 A simple GDB invocation to do nothing but build a `.syms' file for future
5178 gdb -batch -nx -mapped -readnow programname
5180 The `.syms' file is specific to the host machine on which GDB is run.
5181 It holds an exact image of GDB's internal symbol table. It cannot be
5182 shared across multiple host platforms.
5184 * longjmp() handling
5186 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5187 siglongjmp() without losing control. This feature has not yet been ported to
5188 all systems. It currently works on many 386 platforms, all MIPS-based
5189 platforms (SGI, DECstation, etc), and Sun3/4.
5193 Preliminary work has been put in to support the new Solaris OS from Sun. At
5194 this time, it can control and debug processes, but it is not capable of
5199 As always, many many bug fixes. The major areas were with g++, and mipsread.
5200 People using the MIPS-based platforms should experience fewer mysterious
5201 crashes and trashed symbol tables.
5203 *** Changes in GDB-4.4:
5205 * New machines supported (host and target)
5207 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5209 BSD Reno on Vax vax-dec-bsd
5210 Ultrix on Vax vax-dec-ultrix
5212 * New machines supported (target)
5214 AMD 29000 embedded, using EBMON a29k-none-none
5218 GDB continues to improve its handling of C++. `References' work better.
5219 The demangler has also been improved, and now deals with symbols mangled as
5220 per the Annotated C++ Reference Guide.
5222 GDB also now handles `stabs' symbol information embedded in MIPS
5223 `ecoff' symbol tables. Since the ecoff format was not easily
5224 extensible to handle new languages such as C++, this appeared to be a
5225 good way to put C++ debugging info into MIPS binaries. This option
5226 will be supported in the GNU C compiler, version 2, when it is
5229 * New features for SVR4
5231 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5232 shared libraries. Debugging dynamically linked programs should present
5233 only minor differences from debugging statically linked programs.
5235 The `info proc' command will print out information about any process
5236 on an SVR4 system (including the one you are debugging). At the moment,
5237 it prints the address mappings of the process.
5239 If you bring up GDB on another SVR4 system, please send mail to
5240 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5242 * Better dynamic linking support in SunOS
5244 Reading symbols from shared libraries which contain debugging symbols
5245 now works properly. However, there remain issues such as automatic
5246 skipping of `transfer vector' code during function calls, which
5247 make it harder to debug code in a shared library, than to debug the
5248 same code linked statically.
5252 GDB is now using the latest `getopt' routines from the FSF. This
5253 version accepts the -- prefix for options with long names. GDB will
5254 continue to accept the old forms (-option and +option) as well.
5255 Various single letter abbreviations for options have been explicity
5256 added to the option table so that they won't get overshadowed in the
5257 future by other options that begin with the same letter.
5261 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5262 Many assorted bugs have been handled. Many more remain to be handled.
5263 See the various ChangeLog files (primarily in gdb and bfd) for details.
5266 *** Changes in GDB-4.3:
5268 * New machines supported (host and target)
5270 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5271 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5272 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5274 * Almost SCO Unix support
5276 We had hoped to support:
5277 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5278 (except for core file support), but we discovered very late in the release
5279 that it has problems with process groups that render gdb unusable. Sorry
5280 about that. I encourage people to fix it and post the fixes.
5282 * Preliminary ELF and DWARF support
5284 GDB can read ELF object files on System V Release 4, and can handle
5285 debugging records for C, in DWARF format, in ELF files. This support
5286 is preliminary. If you bring up GDB on another SVR4 system, please
5287 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5292 GDB now uses the latest `readline' library. One user-visible change
5293 is that two tabs will list possible command completions, which previously
5294 required typing M-? (meta-question mark, or ESC ?).
5298 The `stepi' bug that many of you noticed has been squashed.
5299 Many bugs in C++ have been handled. Many more remain to be handled.
5300 See the various ChangeLog files (primarily in gdb and bfd) for details.
5302 * State of the MIPS world (in case you wondered):
5304 GDB can understand the symbol tables emitted by the compilers
5305 supplied by most vendors of MIPS-based machines, including DEC. These
5306 symbol tables are in a format that essentially nobody else uses.
5308 Some versions of gcc come with an assembler post-processor called
5309 mips-tfile. This program is required if you want to do source-level
5310 debugging of gcc-compiled programs. I believe FSF does not ship
5311 mips-tfile with gcc version 1, but it will eventually come with gcc
5314 Debugging of g++ output remains a problem. g++ version 1.xx does not
5315 really support it at all. (If you're lucky, you should be able to get
5316 line numbers and stack traces to work, but no parameters or local
5317 variables.) With some work it should be possible to improve the
5320 When gcc version 2 is released, you will have somewhat better luck.
5321 However, even then you will get confusing results for inheritance and
5324 We will eventually provide full debugging of g++ output on
5325 DECstations. This will probably involve some kind of stabs-in-ecoff
5326 encapulation, but the details have not been worked out yet.
5329 *** Changes in GDB-4.2:
5331 * Improved configuration
5333 Only one copy of `configure' exists now, and it is not self-modifying.
5334 Porting BFD is simpler.
5338 The `step' and `next' commands now only stop at the first instruction
5339 of a source line. This prevents the multiple stops that used to occur
5340 in switch statements, for-loops, etc. `Step' continues to stop if a
5341 function that has debugging information is called within the line.
5345 Lots of small bugs fixed. More remain.
5347 * New host supported (not target)
5349 Intel 386 PC clone running Mach i386-none-mach
5352 *** Changes in GDB-4.1:
5354 * Multiple source language support
5356 GDB now has internal scaffolding to handle several source languages.
5357 It determines the type of each source file from its filename extension,
5358 and will switch expression parsing and number formatting to match the
5359 language of the function in the currently selected stack frame.
5360 You can also specifically set the language to be used, with
5361 `set language c' or `set language modula-2'.
5365 GDB now has preliminary support for the GNU Modula-2 compiler,
5366 currently under development at the State University of New York at
5367 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5368 continue through the fall of 1991 and into 1992.
5370 Other Modula-2 compilers are currently not supported, and attempting to
5371 debug programs compiled with them will likely result in an error as the
5372 symbol table is read. Feel free to work on it, though!
5374 There are hooks in GDB for strict type checking and range checking,
5375 in the `Modula-2 philosophy', but they do not currently work.
5379 GDB can now write to executable and core files (e.g. patch
5380 a variable's value). You must turn this switch on, specify
5381 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5382 by assigning a new value to a variable. Modifications take
5385 * Automatic SunOS shared library reading
5387 When you run your program, GDB automatically determines where its
5388 shared libraries (if any) have been loaded, and reads their symbols.
5389 The `share' command is no longer needed. This also works when
5390 examining core files.
5394 You can specify the number of lines that the `list' command shows.
5397 * New machines supported (host and target)
5399 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5400 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5401 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5403 * New hosts supported (not targets)
5405 IBM RT/PC: romp-ibm-aix or rtpc
5407 * New targets supported (not hosts)
5409 AMD 29000 embedded with COFF a29k-none-coff
5410 AMD 29000 embedded with a.out a29k-none-aout
5411 Ultracomputer remote kernel debug a29k-nyu-kern
5413 * New remote interfaces
5419 *** Changes in GDB-4.0:
5423 Wide output is wrapped at good places to make the output more readable.
5425 Gdb now supports cross-debugging from a host machine of one type to a
5426 target machine of another type. Communication with the target system
5427 is over serial lines. The ``target'' command handles connecting to the
5428 remote system; the ``load'' command will download a program into the
5429 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5430 also supports debugging of realtime processes running under VxWorks,
5431 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5432 stub on the target system.
5434 New CPUs supported include the AMD 29000 and Intel 960.
5436 GDB now reads object files and symbol tables via a ``binary file''
5437 library, which allows a single copy of GDB to debug programs of multiple
5438 object file types such as a.out and coff.
5440 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5441 refcard.dvi and refcard.ps are available to format it).
5444 * Control-Variable user interface simplified
5446 All variables that control the operation of the debugger can be set
5447 by the ``set'' command, and displayed by the ``show'' command.
5449 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5450 ``Show prompt'' produces the response:
5451 Gdb's prompt is new-gdb=>.
5453 What follows are the NEW set commands. The command ``help set'' will
5454 print a complete list of old and new set commands. ``help set FOO''
5455 will give a longer description of the variable FOO. ``show'' will show
5456 all of the variable descriptions and their current settings.
5458 confirm on/off: Enables warning questions for operations that are
5459 hard to recover from, e.g. rerunning the program while
5460 it is already running. Default is ON.
5462 editing on/off: Enables EMACS style command line editing
5463 of input. Previous lines can be recalled with
5464 control-P, the current line can be edited with control-B,
5465 you can search for commands with control-R, etc.
5468 history filename NAME: NAME is where the gdb command history
5469 will be stored. The default is .gdb_history,
5470 or the value of the environment variable
5473 history size N: The size, in commands, of the command history. The
5474 default is 256, or the value of the environment variable
5477 history save on/off: If this value is set to ON, the history file will
5478 be saved after exiting gdb. If set to OFF, the
5479 file will not be saved. The default is OFF.
5481 history expansion on/off: If this value is set to ON, then csh-like
5482 history expansion will be performed on
5483 command line input. The default is OFF.
5485 radix N: Sets the default radix for input and output. It can be set
5486 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5487 in the current radix, so "set radix 10" is always a no-op.
5489 height N: This integer value is the number of lines on a page. Default
5490 is 24, the current `stty rows'' setting, or the ``li#''
5491 setting from the termcap entry matching the environment
5494 width N: This integer value is the number of characters on a line.
5495 Default is 80, the current `stty cols'' setting, or the ``co#''
5496 setting from the termcap entry matching the environment
5499 Note: ``set screensize'' is obsolete. Use ``set height'' and
5500 ``set width'' instead.
5502 print address on/off: Print memory addresses in various command displays,
5503 such as stack traces and structure values. Gdb looks
5504 more ``symbolic'' if you turn this off; it looks more
5505 ``machine level'' with it on. Default is ON.
5507 print array on/off: Prettyprint arrays. New convenient format! Default
5510 print demangle on/off: Print C++ symbols in "source" form if on,
5513 print asm-demangle on/off: Same, for assembler level printouts
5516 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5519 * Support for Epoch Environment.
5521 The epoch environment is a version of Emacs v18 with windowing. One
5522 new command, ``inspect'', is identical to ``print'', except that if you
5523 are running in the epoch environment, the value is printed in its own
5527 * Support for Shared Libraries
5529 GDB can now debug programs and core files that use SunOS shared libraries.
5530 Symbols from a shared library cannot be referenced
5531 before the shared library has been linked with the program (this
5532 happens after you type ``run'' and before the function main() is entered).
5533 At any time after this linking (including when examining core files
5534 from dynamically linked programs), gdb reads the symbols from each
5535 shared library when you type the ``sharedlibrary'' command.
5536 It can be abbreviated ``share''.
5538 sharedlibrary REGEXP: Load shared object library symbols for files
5539 matching a unix regular expression. No argument
5540 indicates to load symbols for all shared libraries.
5542 info sharedlibrary: Status of loaded shared libraries.
5547 A watchpoint stops execution of a program whenever the value of an
5548 expression changes. Checking for this slows down execution
5549 tremendously whenever you are in the scope of the expression, but is
5550 quite useful for catching tough ``bit-spreader'' or pointer misuse
5551 problems. Some machines such as the 386 have hardware for doing this
5552 more quickly, and future versions of gdb will use this hardware.
5554 watch EXP: Set a watchpoint (breakpoint) for an expression.
5556 info watchpoints: Information about your watchpoints.
5558 delete N: Deletes watchpoint number N (same as breakpoints).
5559 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5560 enable N: Re-enables watchpoint number N (same as breakpoints).
5563 * C++ multiple inheritance
5565 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5568 * C++ exception handling
5570 Gdb now supports limited C++ exception handling. Besides the existing
5571 ability to breakpoint on an exception handler, gdb can breakpoint on
5572 the raising of an exception (before the stack is peeled back to the
5575 catch FOO: If there is a FOO exception handler in the dynamic scope,
5576 set a breakpoint to catch exceptions which may be raised there.
5577 Multiple exceptions (``catch foo bar baz'') may be caught.
5579 info catch: Lists all exceptions which may be caught in the
5580 current stack frame.
5583 * Minor command changes
5585 The command ``call func (arg, arg, ...)'' now acts like the print
5586 command, except it does not print or save a value if the function's result
5587 is void. This is similar to dbx usage.
5589 The ``up'' and ``down'' commands now always print the frame they end up
5590 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5591 frames without printing.
5593 * New directory command
5595 'dir' now adds directories to the FRONT of the source search path.
5596 The path starts off empty. Source files that contain debug information
5597 about the directory in which they were compiled can be found even
5598 with an empty path; Sun CC and GCC include this information. If GDB can't
5599 find your source file in the current directory, type "dir .".
5601 * Configuring GDB for compilation
5603 For normal use, type ``./configure host''. See README or gdb.texinfo
5606 GDB now handles cross debugging. If you are remotely debugging between
5607 two different machines, type ``./configure host -target=targ''.
5608 Host is the machine where GDB will run; targ is the machine
5609 where the program that you are debugging will run.
5611 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.