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.
22 For locations inside the execution trace, the back trace is computed
23 based on the information stored in the execution trace.
25 *** Changes in GDB 7.7
27 * Improved support for process record-replay and reverse debugging on
28 arm*-linux* targets. Support for thumb32 and syscall instruction
29 recording has been added.
31 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
33 * GDB now supports Fission DWP file format version 2.
34 http://gcc.gnu.org/wiki/DebugFission
36 * New convenience function "$_isvoid", to check whether an expression
37 is void. A void expression is an expression where the type of the
38 result is "void". For example, some convenience variables may be
39 "void" when evaluated (e.g., "$_exitcode" before the execution of
40 the program being debugged; or an undefined convenience variable).
41 Another example, when calling a function whose return type is
44 * The "maintenance print objfiles" command now takes an optional regexp.
46 * The "catch syscall" command now works on arm*-linux* targets.
48 * GDB now consistently shows "<not saved>" when printing values of
49 registers the debug info indicates have not been saved in the frame
50 and there's nowhere to retrieve them from
51 (callee-saved/call-clobbered registers):
56 (gdb) info registers rax
59 Before, the former would print "<optimized out>", and the latter
60 "*value not available*".
62 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
67 ** Frame filters and frame decorators have been added.
68 ** Temporary breakpoints are now supported.
69 ** Line tables representation has been added.
70 ** New attribute 'parent_type' for gdb.Field objects.
71 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
72 ** New attribute 'name' for gdb.Type objects.
76 Nios II ELF nios2*-*-elf
77 Nios II GNU/Linux nios2*-*-linux
78 Texas Instruments MSP430 msp430*-*-elf
80 * Removed native configurations
82 Support for these a.out NetBSD and OpenBSD obsolete configurations has
83 been removed. ELF variants of these configurations are kept supported.
85 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
86 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
87 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
88 i[34567]86-*-openbsd3.[0-3]
89 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
90 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
91 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
95 Like "catch throw", but catches a re-thrown exception.
97 Renamed from old "maint check-symtabs".
99 Perform consistency checks on symtabs.
101 Expand symtabs matching an optional regexp.
104 Display the details of GDB configure-time options.
106 maint set|show per-command
107 maint set|show per-command space
108 maint set|show per-command time
109 maint set|show per-command symtab
110 Enable display of per-command gdb resource usage.
112 remove-symbol-file FILENAME
113 remove-symbol-file -a ADDRESS
114 Remove a symbol file added via add-symbol-file. The file to remove
115 can be identified by its filename or by an address that lies within
116 the boundaries of this symbol file in memory.
119 info exceptions REGEXP
120 Display the list of Ada exceptions defined in the program being
121 debugged. If provided, only the exceptions whose names match REGEXP
126 set debug symfile off|on
128 Control display of debugging info regarding reading symbol files and
129 symbol tables within those files
131 set print raw frame-arguments
132 show print raw frame-arguments
133 Set/show whether to print frame arguments in raw mode,
134 disregarding any defined pretty-printers.
136 set remote trace-status-packet
137 show remote trace-status-packet
138 Set/show the use of remote protocol qTStatus packet.
142 Control display of debugging messages related to Nios II targets.
146 Control whether target-assisted range stepping is enabled.
148 set startup-with-shell
149 show startup-with-shell
150 Specifies whether Unix child processes are started via a shell or
155 Use the target memory cache for accesses to the code segment. This
156 improves performance of remote debugging (particularly disassembly).
158 * You can now use a literal value 'unlimited' for options that
159 interpret 0 or -1 as meaning "unlimited". E.g., "set
160 trace-buffer-size unlimited" is now an alias for "set
161 trace-buffer-size -1" and "set height unlimited" is now an alias for
164 * The "set debug symtab-create" debugging option of GDB has been changed to
165 accept a verbosity level. 0 means "off", 1 provides basic debugging
166 output, and values of 2 or greater provides more verbose output.
168 * New command-line options
170 Display the details of GDB configure-time options.
172 * The command 'tsave' can now support new option '-ctf' to save trace
173 buffer in Common Trace Format.
175 * Newly installed $prefix/bin/gcore acts as a shell interface for the
178 * GDB now implements the the C++ 'typeid' operator.
180 * The new convenience variable $_exception holds the exception being
181 thrown or caught at an exception-related catchpoint.
183 * The exception-related catchpoints, like "catch throw", now accept a
184 regular expression which can be used to filter exceptions by type.
186 * The new convenience variable $_exitsignal is automatically set to
187 the terminating signal number when the program being debugged dies
188 due to an uncaught signal.
192 ** All MI commands now accept an optional "--language" option.
193 Support for this feature can be verified by using the "-list-features"
194 command, which should contain "language-option".
196 ** The new command -info-gdb-mi-command allows the user to determine
197 whether a GDB/MI command is supported or not.
199 ** The "^error" result record returned when trying to execute an undefined
200 GDB/MI command now provides a variable named "code" whose content is the
201 "undefined-command" error code. Support for this feature can be verified
202 by using the "-list-features" command, which should contain
203 "undefined-command-error-code".
205 ** The -trace-save MI command can optionally save trace buffer in Common
208 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
210 ** The command -data-list-register-values now accepts an optional
211 "--skip-unavailable" option. When used, only the available registers
214 ** The new command -trace-frame-collected dumps collected variables,
215 computed expressions, tvars, memory and registers in a traceframe.
217 ** The commands -stack-list-locals, -stack-list-arguments and
218 -stack-list-variables now accept an option "--skip-unavailable".
219 When used, only the available locals or arguments are displayed.
221 ** The -exec-run command now accepts an optional "--start" option.
222 When used, the command follows the same semantics as the "start"
223 command, stopping the program's execution at the start of its
224 main subprogram. Support for this feature can be verified using
225 the "-list-features" command, which should contain
226 "exec-run-start-option".
228 ** The new commands -catch-assert and -catch-exceptions insert
229 catchpoints stopping the program when Ada exceptions are raised.
231 ** The new command -info-ada-exceptions provides the equivalent of
232 the new "info exceptions" command.
234 * New system-wide configuration scripts
235 A GDB installation now provides scripts suitable for use as system-wide
236 configuration scripts for the following systems:
240 * GDB now supports target-assigned range stepping with remote targets.
241 This improves the performance of stepping source lines by reducing
242 the number of control packets from/to GDB. See "New remote packets"
245 * GDB now understands the element 'tvar' in the XML traceframe info.
246 It has the id of the collected trace state variables.
248 * On S/390 targets that provide the transactional-execution feature,
249 the program interruption transaction diagnostic block (TDB) is now
250 represented as a number of additional "registers" in GDB.
256 The vCont packet supports a new 'r' action, that tells the remote
257 stub to step through an address range itself, without GDB
258 involvemement at each single-step.
260 qXfer:libraries-svr4:read's annex
261 The previously unused annex of the qXfer:libraries-svr4:read packet
262 is now used to support passing an argument list. The remote stub
263 reports support for this argument list to GDB's qSupported query.
264 The defined arguments are "start" and "prev", used to reduce work
265 necessary for library list updating, resulting in significant
268 * New features in the GDB remote stub, GDBserver
270 ** GDBserver now supports target-assisted range stepping. Currently
271 enabled on x86/x86_64 GNU/Linux targets.
273 ** GDBserver now adds element 'tvar' in the XML in the reply to
274 'qXfer:traceframe-info:read'. It has the id of the collected
275 trace state variables.
277 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
280 * New 'z' formatter for printing and examining memory, this displays the
281 value as hexadecimal zero padded on the left to the size of the type.
283 * GDB can now use Windows x64 unwinding data.
285 * The "set remotebaud" command has been replaced by "set serial baud".
286 Similarly, "show remotebaud" has been replaced by "show serial baud".
287 The "set remotebaud" and "show remotebaud" commands are still available
288 to provide backward compatibility with older versions of GDB.
290 *** Changes in GDB 7.6
292 * Target record has been renamed to record-full.
293 Record/replay is now enabled with the "record full" command.
294 This also affects settings that are associated with full record/replay
295 that have been moved from "set/show record" to "set/show record full":
297 set|show record full insn-number-max
298 set|show record full stop-at-limit
299 set|show record full memory-query
301 * A new record target "record-btrace" has been added. The new target
302 uses hardware support to record the control-flow of a process. It
303 does not support replaying the execution, but it implements the
304 below new commands for investigating the recorded execution log.
305 This new recording method can be enabled using:
309 The "record-btrace" target is only available on Intel Atom processors
310 and requires a Linux kernel 2.6.32 or later.
312 * Two new commands have been added for record/replay to give information
313 about the recorded execution without having to replay the execution.
314 The commands are only supported by "record btrace".
316 record instruction-history prints the execution history at
317 instruction granularity
319 record function-call-history prints the execution history at
322 * New native configurations
324 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
325 FreeBSD/powerpc powerpc*-*-freebsd
326 x86_64/Cygwin x86_64-*-cygwin*
327 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
331 ARM AArch64 aarch64*-*-elf
332 ARM AArch64 GNU/Linux aarch64*-*-linux
333 Lynx 178 PowerPC powerpc-*-lynx*178
334 x86_64/Cygwin x86_64-*-cygwin*
335 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
337 * If the configured location of system.gdbinit file (as given by the
338 --with-system-gdbinit option at configure time) is in the
339 data-directory (as specified by --with-gdb-datadir at configure
340 time) or in one of its subdirectories, then GDB will look for the
341 system-wide init file in the directory specified by the
342 --data-directory command-line option.
344 * New command line options:
346 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
347 other initialization files, unlike -nx which disables all of them.
349 * Removed command line options
351 -epoch This was used by the gdb mode in Epoch, an ancient fork of
354 * The 'ptype' and 'whatis' commands now accept an argument to control
357 * 'info proc' now works on some core files.
361 ** Vectors can be created with gdb.Type.vector.
363 ** Python's atexit.register now works in GDB.
365 ** Types can be pretty-printed via a Python API.
367 ** Python 3 is now supported (in addition to Python 2.4 or later)
369 ** New class gdb.Architecture exposes GDB's internal representation
370 of architecture in the Python API.
372 ** New method Frame.architecture returns the gdb.Architecture object
373 corresponding to the frame's architecture.
375 * New Python-based convenience functions:
377 ** $_memeq(buf1, buf2, length)
378 ** $_streq(str1, str2)
380 ** $_regex(str, regex)
382 * The 'cd' command now defaults to using '~' (the home directory) if not
385 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
386 default for GCC since November 2000.
388 * The command 'forward-search' can now be abbreviated as 'fo'.
390 * The command 'info tracepoints' can now display 'installed on target'
391 or 'not installed on target' for each non-pending location of tracepoint.
393 * New configure options
395 --enable-libmcheck/--disable-libmcheck
396 By default, development versions are built with -lmcheck on hosts
397 that support it, in order to help track memory corruption issues.
398 Release versions, on the other hand, are built without -lmcheck
399 by default. The --enable-libmcheck/--disable-libmcheck configure
400 options allow the user to override that default.
401 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
402 This configure option allows the user to build GDB with
403 libbabeltrace using which GDB can read Common Trace Format data.
405 * New commands (for set/show, see "New options" below)
408 Catch signals. This is similar to "handle", but allows commands and
409 conditions to be attached.
412 List the BFDs known to GDB.
414 python-interactive [command]
416 Start a Python interactive prompt, or evaluate the optional command
417 and print the result of expressions.
420 "py" is a new alias for "python".
422 enable type-printer [name]...
423 disable type-printer [name]...
424 Enable or disable type printers.
428 ** For the Renesas Super-H architecture, the "regs" command has been removed
429 (has been deprecated in GDB 7.5), and "info all-registers" should be used
434 set print type methods (on|off)
435 show print type methods
436 Control whether method declarations are displayed by "ptype".
437 The default is to show them.
439 set print type typedefs (on|off)
440 show print type typedefs
441 Control whether typedef definitions are displayed by "ptype".
442 The default is to show them.
444 set filename-display basename|relative|absolute
445 show filename-display
446 Control the way in which filenames is displayed.
447 The default is "relative", which preserves previous behavior.
449 set trace-buffer-size
450 show trace-buffer-size
451 Request target to change the size of trace buffer.
453 set remote trace-buffer-size-packet auto|on|off
454 show remote trace-buffer-size-packet
455 Control the use of the remote protocol `QTBuffer:size' packet.
459 Control display of debugging messages related to ARM AArch64.
462 set debug coff-pe-read
463 show debug coff-pe-read
464 Control display of debugging messages related to reading of COFF/PE
469 Control display of debugging messages related to Mach-O symbols
472 set debug notification
473 show debug notification
474 Control display of debugging info for async remote notification.
478 ** Command parameter changes are now notified using new async record
479 "=cmd-param-changed".
480 ** Trace frame changes caused by command "tfind" are now notified using
481 new async record "=traceframe-changed".
482 ** The creation, deletion and modification of trace state variables
483 are now notified using new async records "=tsv-created",
484 "=tsv-deleted" and "=tsv-modified".
485 ** The start and stop of process record are now notified using new
486 async record "=record-started" and "=record-stopped".
487 ** Memory changes are now notified using new async record
489 ** The data-disassemble command response will include a "fullname" field
490 containing the absolute file name when source has been requested.
491 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
492 command, to allow pattern filling of memory areas.
493 ** New commands "-catch-load"/"-catch-unload" added for intercepting
494 library load/unload events.
495 ** The response to breakpoint commands and breakpoint async records
496 includes an "installed" field containing a boolean state about each
497 non-pending tracepoint location is whether installed on target or not.
498 ** Output of the "-trace-status" command includes a "trace-file" field
499 containing the name of the trace file being examined. This field is
500 optional, and only present when examining a trace file.
501 ** The "fullname" field is now always present along with the "file" field,
502 even if the file cannot be found by GDB.
504 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
505 You must have the LZMA library available when configuring GDB for this
506 feature to be enabled. For more information, see:
507 http://fedoraproject.org/wiki/Features/MiniDebugInfo
512 Set the size of trace buffer. The remote stub reports support for this
513 packet to gdb's qSupported query.
516 Enable Branch Trace Store (BTS)-based branch tracing for the current
517 thread. The remote stub reports support for this packet to gdb's
521 Disable branch tracing for the current thread. The remote stub reports
522 support for this packet to gdb's qSupported query.
525 Read the traced branches for the current thread. The remote stub
526 reports support for this packet to gdb's qSupported query.
528 *** Changes in GDB 7.5
530 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
531 for more x32 ABI info.
533 * GDB now supports access to MIPS DSP registers on Linux targets.
535 * GDB now supports debugging microMIPS binaries.
537 * The "info os" command on GNU/Linux can now display information on
538 several new classes of objects managed by the operating system:
539 "info os procgroups" lists process groups
540 "info os files" lists file descriptors
541 "info os sockets" lists internet-domain sockets
542 "info os shm" lists shared-memory regions
543 "info os semaphores" lists semaphores
544 "info os msg" lists message queues
545 "info os modules" lists loaded kernel modules
547 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
548 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
549 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
550 options and inspect the probe arguments using the new $_probe_arg family
551 of convenience variables. You can obtain more information about SystemTap
552 in <http://sourceware.org/systemtap/>.
554 * GDB now supports reversible debugging on ARM, it allows you to
555 debug basic ARM and THUMB instructions, and provides
556 record/replay support.
558 * The option "symbol-reloading" has been deleted as it is no longer used.
562 ** GDB commands implemented in Python can now be put in command class
565 ** The "maint set python print-stack on|off" is now deleted.
567 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
568 apply "flag enum"-style pretty-printing to any enum.
570 ** gdb.lookup_symbol can now work when there is no current frame.
572 ** gdb.Symbol now has a 'line' attribute, holding the line number in
573 the source at which the symbol was defined.
575 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
576 method 'value'. The former indicates whether the symbol needs a
577 frame in order to compute its value, and the latter computes the
580 ** A new method 'referenced_value' on gdb.Value objects which can
581 dereference pointer as well as C++ reference values.
583 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
584 which return the global and static blocks (as gdb.Block objects),
585 of the underlying symbol table, respectively.
587 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
588 object associated with a PC value.
590 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
591 of the address range occupied by code for the current source line.
593 * Go language support.
594 GDB now supports debugging programs written in the Go programming
597 * GDBserver now supports stdio connections.
598 E.g. (gdb) target remote | ssh myhost gdbserver - hello
600 * The binary "gdbtui" can no longer be built or installed.
601 Use "gdb -tui" instead.
603 * GDB will now print "flag" enums specially. A flag enum is one where
604 all the enumerator values have no bits in common when pairwise
605 "and"ed. When printing a value whose type is a flag enum, GDB will
606 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
607 (gdb) print (enum E) 3
610 * The filename part of a linespec will now match trailing components
611 of a source file name. For example, "break gcc/expr.c:1000" will
612 now set a breakpoint in build/gcc/expr.c, but not
615 * The "info proc" and "generate-core-file" commands will now also
616 work on remote targets connected to GDBserver on Linux.
618 * The command "info catch" has been removed. It has been disabled
621 * The "catch exception" and "catch assert" commands now accept
622 a condition at the end of the command, much like the "break"
623 command does. For instance:
625 (gdb) catch exception Constraint_Error if Barrier = True
627 Previously, it was possible to add a condition to such catchpoints,
628 but it had to be done as a second step, after the catchpoint had been
629 created, using the "condition" command.
631 * The "info static-tracepoint-marker" command will now also work on
632 native Linux targets with in-process agent.
634 * GDB can now set breakpoints on inlined functions.
636 * The .gdb_index section has been updated to include symbols for
637 inlined functions. GDB will ignore older .gdb_index sections by
638 default, which could cause symbol files to be loaded more slowly
639 until their .gdb_index sections can be recreated. The new command
640 "set use-deprecated-index-sections on" will cause GDB to use any older
641 .gdb_index sections it finds. This will restore performance, but the
642 ability to set breakpoints on inlined functions will be lost in symbol
643 files with older .gdb_index sections.
645 The .gdb_index section has also been updated to record more information
646 about each symbol. This speeds up the "info variables", "info functions"
647 and "info types" commands when used with programs having the .gdb_index
648 section, as well as speeding up debugging with shared libraries using
649 the .gdb_index section.
651 * Ada support for GDB/MI Variable Objects has been added.
653 * GDB can now support 'breakpoint always-inserted mode' in 'record'
658 ** New command -info-os is the MI equivalent of "info os".
660 ** Output logs ("set logging" and related) now include MI output.
664 ** "set use-deprecated-index-sections on|off"
665 "show use-deprecated-index-sections on|off"
666 Controls the use of deprecated .gdb_index sections.
668 ** "catch load" and "catch unload" can be used to stop when a shared
669 library is loaded or unloaded, respectively.
671 ** "enable count" can be used to auto-disable a breakpoint after
674 ** "info vtbl" can be used to show the virtual method tables for
675 C++ and Java objects.
677 ** "explore" and its sub commands "explore value" and "explore type"
678 can be used to recursively explore values and types of
679 expressions. These commands are available only if GDB is
680 configured with '--with-python'.
682 ** "info auto-load" shows status of all kinds of auto-loaded files,
683 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
684 sequences of commands files, "info auto-load python-scripts"
685 shows status of auto-loading Python script files,
686 "info auto-load local-gdbinit" shows status of loading init file
687 (.gdbinit) from current directory and "info auto-load libthread-db" shows
688 status of inferior specific thread debugging shared library loading.
690 ** "info auto-load-scripts", "set auto-load-scripts on|off"
691 and "show auto-load-scripts" commands have been deprecated, use their
692 "info auto-load python-scripts", "set auto-load python-scripts on|off"
693 and "show auto-load python-scripts" counterparts instead.
695 ** "dprintf location,format,args..." creates a dynamic printf, which
696 is basically a breakpoint that does a printf and immediately
697 resumes your program's execution, so it is like a printf that you
698 can insert dynamically at runtime instead of at compiletime.
700 ** "set print symbol"
702 Controls whether GDB attempts to display the symbol, if any,
703 corresponding to addresses it prints. This defaults to "on", but
704 you can set it to "off" to restore GDB's previous behavior.
706 * Deprecated commands
708 ** For the Renesas Super-H architecture, the "regs" command has been
709 deprecated, and "info all-registers" should be used instead.
713 Renesas RL78 rl78-*-elf
714 HP OpenVMS ia64 ia64-hp-openvms*
716 * GDBserver supports evaluation of breakpoint conditions. When
717 support is advertised by GDBserver, GDB may be told to send the
718 breakpoint conditions in bytecode form to GDBserver. GDBserver
719 will only report the breakpoint trigger to GDB when its condition
725 show mips compression
726 Select the compressed ISA encoding used in functions that have no symbol
727 information available. The encoding can be set to either of:
730 and is updated automatically from ELF file flags if available.
732 set breakpoint condition-evaluation
733 show breakpoint condition-evaluation
734 Control whether breakpoint conditions are evaluated by GDB ("host") or by
735 GDBserver ("target"). Default option "auto" chooses the most efficient
737 This option can improve debugger efficiency depending on the speed of the
741 Disable auto-loading globally.
744 Show auto-loading setting of all kinds of auto-loaded files.
746 set auto-load gdb-scripts on|off
747 show auto-load gdb-scripts
748 Control auto-loading of GDB canned sequences of commands files.
750 set auto-load python-scripts on|off
751 show auto-load python-scripts
752 Control auto-loading of Python script files.
754 set auto-load local-gdbinit on|off
755 show auto-load local-gdbinit
756 Control loading of init file (.gdbinit) from current directory.
758 set auto-load libthread-db on|off
759 show auto-load libthread-db
760 Control auto-loading of inferior specific thread debugging shared library.
762 set auto-load scripts-directory <dir1>[:<dir2>...]
763 show auto-load scripts-directory
764 Set a list of directories from which to load auto-loaded scripts.
765 Automatically loaded Python scripts and GDB scripts are located in one
766 of the directories listed by this option.
767 The delimiter (':' above) may differ according to the host platform.
769 set auto-load safe-path <dir1>[:<dir2>...]
770 show auto-load safe-path
771 Set a list of directories from which it is safe to auto-load files.
772 The delimiter (':' above) may differ according to the host platform.
774 set debug auto-load on|off
776 Control display of debugging info for auto-loading the files above.
778 set dprintf-style gdb|call|agent
780 Control the way in which a dynamic printf is performed; "gdb"
781 requests a GDB printf command, while "call" causes dprintf to call a
782 function in the inferior. "agent" requests that the target agent
783 (such as GDBserver) do the printing.
785 set dprintf-function <expr>
786 show dprintf-function
787 set dprintf-channel <expr>
789 Set the function and optional first argument to the call when using
790 the "call" style of dynamic printf.
792 set disconnected-dprintf on|off
793 show disconnected-dprintf
794 Control whether agent-style dynamic printfs continue to be in effect
795 after GDB disconnects.
797 * New configure options
800 Configure default value for the 'set auto-load scripts-directory'
801 setting above. It defaults to '$debugdir:$datadir/auto-load',
802 $debugdir representing global debugging info directories (available
803 via 'show debug-file-directory') and $datadir representing GDB's data
804 directory (available via 'show data-directory').
806 --with-auto-load-safe-path
807 Configure default value for the 'set auto-load safe-path' setting
808 above. It defaults to the --with-auto-load-dir setting.
810 --without-auto-load-safe-path
811 Set 'set auto-load safe-path' to '/', effectively disabling this
816 z0/z1 conditional breakpoints extension
818 The z0/z1 breakpoint insertion packets have been extended to carry
819 a list of conditional expressions over to the remote stub depending on the
820 condition evaluation mode. The use of this extension can be controlled
821 via the "set remote conditional-breakpoints-packet" command.
825 Specify the signals which the remote stub may pass to the debugged
826 program without GDB involvement.
828 * New command line options
830 --init-command=FILE, -ix Like --command, -x but execute it
831 before loading inferior.
832 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
833 execute it before loading inferior.
835 *** Changes in GDB 7.4
837 * GDB now handles ambiguous linespecs more consistently; the existing
838 FILE:LINE support has been expanded to other types of linespecs. A
839 breakpoint will now be set on all matching locations in all
840 inferiors, and locations will be added or removed according to
843 * GDB now allows you to skip uninteresting functions and files when
844 stepping with the "skip function" and "skip file" commands.
846 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
847 and "show remote hardware-watchpoint-length-limit". These allows to
848 set or show the maximum length limit (in bytes) of a remote
849 target hardware watchpoint.
851 This allows e.g. to use "unlimited" hardware watchpoints with the
852 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
853 watchpoints are slower than real hardware watchpoints but are
854 significantly faster than gdb software watchpoints.
858 ** The register_pretty_printer function in module gdb.printing now takes
859 an optional `replace' argument. If True, the new printer replaces any
862 ** The "maint set python print-stack on|off" command has been
863 deprecated and will be deleted in GDB 7.5.
864 A new command: "set python print-stack none|full|message" has
865 replaced it. Additionally, the default for "print-stack" is
866 now "message", which just prints the error message without
869 ** A prompt substitution hook (prompt_hook) is now available to the
872 ** A new Python module, gdb.prompt has been added to the GDB Python
873 modules library. This module provides functionality for
874 escape sequences in prompts (used by set/show
875 extended-prompt). These escape sequences are replaced by their
878 ** Python commands and convenience-functions located in
879 'data-directory'/python/gdb/command and
880 'data-directory'/python/gdb/function are now automatically loaded
883 ** Blocks now provide four new attributes. global_block and
884 static_block will return the global and static blocks
885 respectively. is_static and is_global are boolean attributes
886 that indicate if the block is one of those two types.
888 ** Symbols now provide the "type" attribute, the type of the symbol.
890 ** The "gdb.breakpoint" function has been deprecated in favor of
893 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
894 of a function. This class is based on the "finish" command
895 available in the CLI.
897 ** Type objects for struct and union types now allow access to
898 the fields using standard Python dictionary (mapping) methods.
899 For example, "some_type['myfield']" now works, as does
902 ** A new event "gdb.new_objfile" has been added, triggered by loading a
905 ** A new function, "deep_items" has been added to the gdb.types
906 module in the GDB Python modules library. This function returns
907 an iterator over the fields of a struct or union type. Unlike
908 the standard Python "iteritems" method, it will recursively traverse
909 any anonymous fields.
913 ** "*stopped" events can report several new "reason"s, such as
916 ** Breakpoint changes are now notified using new async records, like
917 "=breakpoint-modified".
919 ** New command -ada-task-info.
921 * libthread-db-search-path now supports two special values: $sdir and $pdir.
922 $sdir specifies the default system locations of shared libraries.
923 $pdir specifies the directory where the libpthread used by the application
926 GDB no longer looks in $sdir and $pdir after it has searched the directories
927 mentioned in libthread-db-search-path. If you want to search those
928 directories, they must be specified in libthread-db-search-path.
929 The default value of libthread-db-search-path on GNU/Linux and Solaris
930 systems is now "$sdir:$pdir".
932 $pdir is not supported by gdbserver, it is currently ignored.
933 $sdir is supported by gdbserver.
935 * New configure option --with-iconv-bin.
936 When using the internationalization support like the one in the GNU C
937 library, GDB will invoke the "iconv" program to get a list of supported
938 character sets. If this program lives in a non-standard location, one can
939 use this option to specify where to find it.
941 * When natively debugging programs on PowerPC BookE processors running
942 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
943 watchpoints, which specify a mask in addition to an address to watch.
944 The mask specifies that some bits of an address (the bits which are
945 reset in the mask) should be ignored when matching the address accessed
946 by the inferior against the watchpoint address. See the "PowerPC Embedded"
947 section in the user manual for more details.
949 * The new option --once causes GDBserver to stop listening for connections once
950 the first connection is made. The listening port used by GDBserver will
951 become available after that.
953 * New commands "info macros" and "alias" have been added.
955 * New function parameters suffix @entry specifies value of function parameter
956 at the time the function got called. Entry values are available only since
962 "!" is now an alias of the "shell" command.
963 Note that no space is needed between "!" and SHELL COMMAND.
967 watch EXPRESSION mask MASK_VALUE
968 The watch command now supports the mask argument which allows creation
969 of masked watchpoints, if the current architecture supports this feature.
971 info auto-load-scripts [REGEXP]
972 This command was formerly named "maintenance print section-scripts".
973 It is now generally useful and is no longer a maintenance-only command.
975 info macro [-all] [--] MACRO
976 The info macro command has new options `-all' and `--'. The first for
977 printing all definitions of a macro. The second for explicitly specifying
978 the end of arguments and the beginning of the macro name in case the macro
979 name starts with a hyphen.
981 collect[/s] EXPRESSIONS
982 The tracepoint collect command now takes an optional modifier "/s"
983 that directs it to dereference pointer-to-character types and
984 collect the bytes of memory up to a zero byte. The behavior is
985 similar to what you see when you use the regular print command on a
986 string. An optional integer following the "/s" sets a bound on the
987 number of bytes that will be collected.
990 The trace start command now interprets any supplied arguments as a
991 note to be recorded with the trace run, with an effect similar to
992 setting the variable trace-notes.
995 The trace stop command now interprets any arguments as a note to be
996 mentioned along with the tstatus report that the trace was stopped
997 with a command. The effect is similar to setting the variable
1000 * Tracepoints can now be enabled and disabled at any time after a trace
1001 experiment has been started using the standard "enable" and "disable"
1002 commands. It is now possible to start a trace experiment with no enabled
1003 tracepoints; GDB will display a warning, but will allow the experiment to
1004 begin, assuming that tracepoints will be enabled as needed while the trace
1007 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1008 locations with 4-byte instructions, when they were previously
1009 limited to locations with instructions of 5 bytes or longer.
1013 set debug dwarf2-read
1014 show debug dwarf2-read
1015 Turns on or off display of debugging messages related to reading
1016 DWARF debug info. The default is off.
1018 set debug symtab-create
1019 show debug symtab-create
1020 Turns on or off display of debugging messages related to symbol table
1021 creation. The default is off.
1024 show extended-prompt
1025 Set the GDB prompt, and allow escape sequences to be inserted to
1026 display miscellaneous information (see 'help set extended-prompt'
1027 for the list of sequences). This prompt (and any information
1028 accessed through the escape sequences) is updated every time the
1029 prompt is displayed.
1031 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1032 show print entry-values
1033 Set printing of frame argument values at function entry. In some cases
1034 GDB can determine the value of function argument which was passed by the
1035 function caller, even if the value was modified inside the called function.
1037 set debug entry-values
1038 show debug entry-values
1039 Control display of debugging info for determining frame argument values at
1040 function entry and virtual tail call frames.
1042 set basenames-may-differ
1043 show basenames-may-differ
1044 Set whether a source file may have multiple base names.
1045 (A "base name" is the name of a file with the directory part removed.
1046 Example: The base name of "/home/user/hello.c" is "hello.c".)
1047 If set, GDB will canonicalize file names (e.g., expand symlinks)
1048 before comparing them. Canonicalization is an expensive operation,
1049 but it allows the same file be known by more than one base name.
1050 If not set (the default), all source files are assumed to have just
1051 one base name, and gdb will do file name comparisons more efficiently.
1057 Set a user name and notes for the current and any future trace runs.
1058 This is useful for long-running and/or disconnected traces, to
1059 inform others (or yourself) as to who is running the trace, supply
1060 contact information, or otherwise explain what is going on.
1062 set trace-stop-notes
1063 show trace-stop-notes
1064 Set a note attached to the trace run, that is displayed when the
1065 trace has been stopped by a tstop command. This is useful for
1066 instance as an explanation, if you are stopping a trace run that was
1067 started by someone else.
1069 * New remote packets
1073 Dynamically enable a tracepoint in a started trace experiment.
1077 Dynamically disable a tracepoint in a started trace experiment.
1081 Set the user and notes of the trace run.
1085 Query the current status of a tracepoint.
1089 Query the minimum length of instruction at which a fast tracepoint may
1092 * Dcache size (number of lines) and line-size are now runtime-configurable
1093 via "set dcache line" and "set dcache line-size" commands.
1097 Texas Instruments TMS320C6x tic6x-*-*
1101 Renesas RL78 rl78-*-elf
1103 *** Changes in GDB 7.3.1
1105 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1107 *** Changes in GDB 7.3
1109 * GDB has a new command: "thread find [REGEXP]".
1110 It finds the thread id whose name, target id, or thread extra info
1111 matches the given regular expression.
1113 * The "catch syscall" command now works on mips*-linux* targets.
1115 * The -data-disassemble MI command now supports modes 2 and 3 for
1116 dumping the instruction opcodes.
1118 * New command line options
1120 -data-directory DIR Specify DIR as the "data-directory".
1121 This is mostly for testing purposes.
1123 * The "maint set python auto-load on|off" command has been renamed to
1124 "set auto-load-scripts on|off".
1126 * GDB has a new command: "set directories".
1127 It is like the "dir" command except that it replaces the
1128 source path list instead of augmenting it.
1130 * GDB now understands thread names.
1132 On GNU/Linux, "info threads" will display the thread name as set by
1133 prctl or pthread_setname_np.
1135 There is also a new command, "thread name", which can be used to
1136 assign a name internally for GDB to display.
1139 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1140 has been integrated into GDB.
1144 ** The function gdb.Write now accepts an optional keyword 'stream'.
1145 This keyword, when provided, will direct the output to either
1146 stdout, stderr, or GDB's logging output.
1148 ** Parameters can now be be sub-classed in Python, and in particular
1149 you may implement the get_set_doc and get_show_doc functions.
1150 This improves how Parameter set/show documentation is processed
1151 and allows for more dynamic content.
1153 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1154 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1155 have an is_valid method.
1157 ** Breakpoints can now be sub-classed in Python, and in particular
1158 you may implement a 'stop' function that is executed each time
1159 the inferior reaches that breakpoint.
1161 ** New function gdb.lookup_global_symbol looks up a global symbol.
1163 ** GDB values in Python are now callable if the value represents a
1164 function. For example, if 'some_value' represents a function that
1165 takes two integer parameters and returns a value, you can call
1166 that function like so:
1168 result = some_value (10,20)
1170 ** Module gdb.types has been added.
1171 It contains a collection of utilities for working with gdb.Types objects:
1172 get_basic_type, has_field, make_enum_dict.
1174 ** Module gdb.printing has been added.
1175 It contains utilities for writing and registering pretty-printers.
1176 New classes: PrettyPrinter, SubPrettyPrinter,
1177 RegexpCollectionPrettyPrinter.
1178 New function: register_pretty_printer.
1180 ** New commands "info pretty-printers", "enable pretty-printer" and
1181 "disable pretty-printer" have been added.
1183 ** gdb.parameter("directories") is now available.
1185 ** New function gdb.newest_frame returns the newest frame in the
1188 ** The gdb.InferiorThread class has a new "name" attribute. This
1189 holds the thread's name.
1191 ** Python Support for Inferior events.
1192 Python scripts can add observers to be notified of events
1193 occurring in the process being debugged.
1194 The following events are currently supported:
1195 - gdb.events.cont Continue event.
1196 - gdb.events.exited Inferior exited event.
1197 - gdb.events.stop Signal received, and Breakpoint hit events.
1201 ** GDB now puts template parameters in scope when debugging in an
1202 instantiation. For example, if you have:
1204 template<int X> int func (void) { return X; }
1206 then if you step into func<5>, "print X" will show "5". This
1207 feature requires proper debuginfo support from the compiler; it
1208 was added to GCC 4.5.
1210 ** The motion commands "next", "finish", "until", and "advance" now
1211 work better when exceptions are thrown. In particular, GDB will
1212 no longer lose control of the inferior; instead, the GDB will
1213 stop the inferior at the point at which the exception is caught.
1214 This functionality requires a change in the exception handling
1215 code that was introduced in GCC 4.5.
1217 * GDB now follows GCC's rules on accessing volatile objects when
1218 reading or writing target state during expression evaluation.
1219 One notable difference to prior behavior is that "print x = 0"
1220 no longer generates a read of x; the value of the assignment is
1221 now always taken directly from the value being assigned.
1223 * GDB now has some support for using labels in the program's source in
1224 linespecs. For instance, you can use "advance label" to continue
1225 execution to a label.
1227 * GDB now has support for reading and writing a new .gdb_index
1228 section. This section holds a fast index of DWARF debugging
1229 information and can be used to greatly speed up GDB startup and
1230 operation. See the documentation for `save gdb-index' for details.
1232 * The "watch" command now accepts an optional "-location" argument.
1233 When used, this causes GDB to watch the memory referred to by the
1234 expression. Such a watchpoint is never deleted due to it going out
1237 * GDB now supports thread debugging of core dumps on GNU/Linux.
1239 GDB now activates thread debugging using the libthread_db library
1240 when debugging GNU/Linux core dumps, similarly to when debugging
1241 live processes. As a result, when debugging a core dump file, GDB
1242 is now able to display pthread_t ids of threads. For example, "info
1243 threads" shows the same output as when debugging the process when it
1244 was live. In earlier releases, you'd see something like this:
1247 * 1 LWP 6780 main () at main.c:10
1249 While now you see this:
1252 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1254 It is also now possible to inspect TLS variables when debugging core
1257 When debugging a core dump generated on a machine other than the one
1258 used to run GDB, you may need to point GDB at the correct
1259 libthread_db library with the "set libthread-db-search-path"
1260 command. See the user manual for more details on this command.
1262 * When natively debugging programs on PowerPC BookE processors running
1263 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1264 which stop execution of the inferior whenever it executes an instruction
1265 at any address within the specified range. See the "PowerPC Embedded"
1266 section in the user manual for more details.
1268 * New features in the GDB remote stub, GDBserver
1270 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1271 and i686 LynxOS (version 5.x).
1273 ** GDBserver is now supported on Blackfin Linux.
1275 * New native configurations
1277 ia64 HP-UX ia64-*-hpux*
1281 Analog Devices, Inc. Blackfin Processor bfin-*
1283 * Ada task switching is now supported on sparc-elf targets when
1284 debugging a program using the Ravenscar Profile. For more information,
1285 see the "Tasking Support when using the Ravenscar Profile" section
1286 in the GDB user manual.
1288 * Guile support was removed.
1290 * New features in the GNU simulator
1292 ** The --map-info flag lists all known core mappings.
1294 ** CFI flashes may be simulated via the "cfi" device.
1296 *** Changes in GDB 7.2
1298 * Shared library support for remote targets by default
1300 When GDB is configured for a generic, non-OS specific target, like
1301 for example, --target=arm-eabi or one of the many *-*-elf targets,
1302 GDB now queries remote stubs for loaded shared libraries using the
1303 `qXfer:libraries:read' packet. Previously, shared library support
1304 was always disabled for such configurations.
1308 ** Argument Dependent Lookup (ADL)
1310 In C++ ADL lookup directs function search to the namespaces of its
1311 arguments even if the namespace has not been imported.
1321 Here the compiler will search for `foo' in the namespace of 'b'
1322 and find A::foo. GDB now supports this. This construct is commonly
1323 used in the Standard Template Library for operators.
1325 ** Improved User Defined Operator Support
1327 In addition to member operators, GDB now supports lookup of operators
1328 defined in a namespace and imported with a `using' directive, operators
1329 defined in the global scope, operators imported implicitly from an
1330 anonymous namespace, and the ADL operators mentioned in the previous
1332 GDB now also supports proper overload resolution for all the previously
1333 mentioned flavors of operators.
1335 ** static const class members
1337 Printing of static const class members that are initialized in the
1338 class definition has been fixed.
1340 * Windows Thread Information Block access.
1342 On Windows targets, GDB now supports displaying the Windows Thread
1343 Information Block (TIB) structure. This structure is visible either
1344 by using the new command `info w32 thread-information-block' or, by
1345 dereferencing the new convenience variable named `$_tlb', a
1346 thread-specific pointer to the TIB. This feature is also supported
1347 when remote debugging using GDBserver.
1349 * Static tracepoints
1351 Static tracepoints are calls in the user program into a tracing
1352 library. One such library is a port of the LTTng kernel tracer to
1353 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1354 When debugging with GDBserver, GDB now supports combining the GDB
1355 tracepoint machinery with such libraries. For example: the user can
1356 use GDB to probe a static tracepoint marker (a call from the user
1357 program into the tracing library) with the new "strace" command (see
1358 "New commands" below). This creates a "static tracepoint" in the
1359 breakpoint list, that can be manipulated with the same feature set
1360 as fast and regular tracepoints. E.g., collect registers, local and
1361 global variables, collect trace state variables, and define
1362 tracepoint conditions. In addition, the user can collect extra
1363 static tracepoint marker specific data, by collecting the new
1364 $_sdata internal variable. When analyzing the trace buffer, you can
1365 inspect $_sdata like any other variable available to GDB. For more
1366 information, see the "Tracepoints" chapter in GDB user manual. New
1367 remote packets have been defined to support static tracepoints, see
1368 the "New remote packets" section below.
1370 * Better reconstruction of tracepoints after disconnected tracing
1372 GDB will attempt to download the original source form of tracepoint
1373 definitions when starting a trace run, and then will upload these
1374 upon reconnection to the target, resulting in a more accurate
1375 reconstruction of the tracepoints that are in use on the target.
1379 You can now exercise direct control over the ways that GDB can
1380 affect your program. For instance, you can disallow the setting of
1381 breakpoints, so that the program can run continuously (assuming
1382 non-stop mode). In addition, the "observer" variable is available
1383 to switch all of the different controls; in observer mode, GDB
1384 cannot affect the target's behavior at all, which is useful for
1385 tasks like diagnosing live systems in the field.
1387 * The new convenience variable $_thread holds the number of the
1390 * New remote packets
1394 Return the address of the Windows Thread Information Block of a given thread.
1398 In response to several of the tracepoint packets, the target may now
1399 also respond with a number of intermediate `qRelocInsn' request
1400 packets before the final result packet, to have GDB handle
1401 relocating an instruction to execute at a different address. This
1402 is particularly useful for stubs that support fast tracepoints. GDB
1403 reports support for this feature in the qSupported packet.
1407 List static tracepoint markers in the target program.
1411 List static tracepoint markers at a given address in the target
1414 qXfer:statictrace:read
1416 Read the static trace data collected (by a `collect $_sdata'
1417 tracepoint action). The remote stub reports support for this packet
1418 to gdb's qSupported query.
1422 Send the current settings of GDB's permission flags.
1426 Send part of the source (textual) form of a tracepoint definition,
1427 which includes location, conditional, and action list.
1429 * The source command now accepts a -s option to force searching for the
1430 script in the source search path even if the script name specifies
1433 * New features in the GDB remote stub, GDBserver
1435 - GDBserver now support tracepoints (including fast tracepoints, and
1436 static tracepoints). The feature is currently supported by the
1437 i386-linux and amd64-linux builds. See the "Tracepoints support
1438 in gdbserver" section in the manual for more information.
1440 GDBserver JIT compiles the tracepoint's conditional agent
1441 expression bytecode into native code whenever possible for low
1442 overhead dynamic tracepoints conditionals. For such tracepoints,
1443 an expression that examines program state is evaluated when the
1444 tracepoint is reached, in order to determine whether to capture
1445 trace data. If the condition is simple and false, processing the
1446 tracepoint finishes very quickly and no data is gathered.
1448 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1449 for static tracepoints support.
1451 - GDBserver now supports x86_64 Windows 64-bit debugging.
1453 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1454 it understands register description.
1456 * The --batch flag now disables pagination and queries.
1458 * X86 general purpose registers
1460 GDB now supports reading/writing byte, word and double-word x86
1461 general purpose registers directly. This means you can use, say,
1462 $ah or $ax to refer, respectively, to the byte register AH and
1463 16-bit word register AX that are actually portions of the 32-bit
1464 register EAX or 64-bit register RAX.
1466 * The `commands' command now accepts a range of breakpoints to modify.
1467 A plain `commands' following a command that creates multiple
1468 breakpoints affects all the breakpoints set by that command. This
1469 applies to breakpoints set by `rbreak', and also applies when a
1470 single `break' command creates multiple breakpoints (e.g.,
1471 breakpoints on overloaded c++ functions).
1473 * The `rbreak' command now accepts a filename specification as part of
1474 its argument, limiting the functions selected by the regex to those
1475 in the specified file.
1477 * Support for remote debugging Windows and SymbianOS shared libraries
1478 from Unix hosts has been improved. Non Windows GDB builds now can
1479 understand target reported file names that follow MS-DOS based file
1480 system semantics, such as file names that include drive letters and
1481 use the backslash character as directory separator. This makes it
1482 possible to transparently use the "set sysroot" and "set
1483 solib-search-path" on Unix hosts to point as host copies of the
1484 target's shared libraries. See the new command "set
1485 target-file-system-kind" described below, and the "Commands to
1486 specify files" section in the user manual for more information.
1490 eval template, expressions...
1491 Convert the values of one or more expressions under the control
1492 of the string template to a command line, and call it.
1494 set target-file-system-kind unix|dos-based|auto
1495 show target-file-system-kind
1496 Set or show the assumed file system kind for target reported file
1499 save breakpoints <filename>
1500 Save all current breakpoint definitions to a file suitable for use
1501 in a later debugging session. To read the saved breakpoint
1502 definitions, use the `source' command.
1504 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1507 info static-tracepoint-markers
1508 Display information about static tracepoint markers in the target.
1510 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1511 Define a static tracepoint by probing a marker at the given
1512 function, line, address, or marker ID.
1516 Enable and disable observer mode.
1518 set may-write-registers on|off
1519 set may-write-memory on|off
1520 set may-insert-breakpoints on|off
1521 set may-insert-tracepoints on|off
1522 set may-insert-fast-tracepoints on|off
1523 set may-interrupt on|off
1524 Set individual permissions for GDB effects on the target. Note that
1525 some of these settings can have undesirable or surprising
1526 consequences, particularly when changed in the middle of a session.
1527 For instance, disabling the writing of memory can prevent
1528 breakpoints from being inserted, cause single-stepping to fail, or
1529 even crash your program, if you disable after breakpoints have been
1530 inserted. However, GDB should not crash.
1532 set record memory-query on|off
1533 show record memory-query
1534 Control whether to stop the inferior if memory changes caused
1535 by an instruction cannot be recorded.
1540 The disassemble command now supports "start,+length" form of two arguments.
1544 ** GDB now provides a new directory location, called the python directory,
1545 where Python scripts written for GDB can be installed. The location
1546 of that directory is <data-directory>/python, where <data-directory>
1547 is the GDB data directory. For more details, see section `Scripting
1548 GDB using Python' in the manual.
1550 ** The GDB Python API now has access to breakpoints, symbols, symbol
1551 tables, program spaces, inferiors, threads and frame's code blocks.
1552 Additionally, GDB Parameters can now be created from the API, and
1553 manipulated via set/show in the CLI.
1555 ** New functions gdb.target_charset, gdb.target_wide_charset,
1556 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1558 ** New exception gdb.GdbError.
1560 ** Pretty-printers are now also looked up in the current program space.
1562 ** Pretty-printers can now be individually enabled and disabled.
1564 ** GDB now looks for names of Python scripts to auto-load in a
1565 special section named `.debug_gdb_scripts', in addition to looking
1566 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1568 * Tracepoint actions were unified with breakpoint commands. In particular,
1569 there are no longer differences in "info break" output for breakpoints and
1570 tracepoints and the "commands" command can be used for both tracepoints and
1571 regular breakpoints.
1575 ARM Symbian arm*-*-symbianelf*
1577 * D language support.
1578 GDB now supports debugging programs written in the D programming
1581 * GDB now supports the extended ptrace interface for PowerPC which is
1582 available since Linux kernel version 2.6.34. This automatically enables
1583 any hardware breakpoints and additional hardware watchpoints available in
1584 the processor. The old ptrace interface exposes just one hardware
1585 watchpoint and no hardware breakpoints.
1587 * GDB is now able to use the Data Value Compare (DVC) register available on
1588 embedded PowerPC processors to implement in hardware simple watchpoint
1589 conditions of the form:
1591 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1593 This works in native GDB running on Linux kernels with the extended ptrace
1594 interface mentioned above.
1596 *** Changes in GDB 7.1
1600 ** Namespace Support
1602 GDB now supports importing of namespaces in C++. This enables the
1603 user to inspect variables from imported namespaces. Support for
1604 namepace aliasing has also been added. So, if a namespace is
1605 aliased in the current scope (e.g. namepace C=A; ) the user can
1606 print variables using the alias (e.g. (gdb) print C::x).
1610 All known bugs relating to the printing of virtual base class were
1611 fixed. It is now possible to call overloaded static methods using a
1616 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1617 and reinterpret_cast<> are now handled by the C++ expression parser.
1621 Xilinx MicroBlaze microblaze-*-*
1626 Xilinx MicroBlaze microblaze
1629 * Multi-program debugging.
1631 GDB now has support for multi-program (a.k.a. multi-executable or
1632 multi-exec) debugging. This allows for debugging multiple inferiors
1633 simultaneously each running a different program under the same GDB
1634 session. See "Debugging Multiple Inferiors and Programs" in the
1635 manual for more information. This implied some user visible changes
1636 in the multi-inferior support. For example, "info inferiors" now
1637 lists inferiors that are not running yet or that have exited
1638 already. See also "New commands" and "New options" below.
1640 * New tracing features
1642 GDB's tracepoint facility now includes several new features:
1644 ** Trace state variables
1646 GDB tracepoints now include support for trace state variables, which
1647 are variables managed by the target agent during a tracing
1648 experiment. They are useful for tracepoints that trigger each
1649 other, so for instance one tracepoint can count hits in a variable,
1650 and then a second tracepoint has a condition that is true when the
1651 count reaches a particular value. Trace state variables share the
1652 $-syntax of GDB convenience variables, and can appear in both
1653 tracepoint actions and condition expressions. Use the "tvariable"
1654 command to create, and "info tvariables" to view; see "Trace State
1655 Variables" in the manual for more detail.
1659 GDB now includes an option for defining fast tracepoints, which
1660 targets may implement more efficiently, such as by installing a jump
1661 into the target agent rather than a trap instruction. The resulting
1662 speedup can be by two orders of magnitude or more, although the
1663 tradeoff is that some program locations on some target architectures
1664 might not allow fast tracepoint installation, for instance if the
1665 instruction to be replaced is shorter than the jump. To request a
1666 fast tracepoint, use the "ftrace" command, with syntax identical to
1667 the regular trace command.
1669 ** Disconnected tracing
1671 It is now possible to detach GDB from the target while it is running
1672 a trace experiment, then reconnect later to see how the experiment
1673 is going. In addition, a new variable disconnected-tracing lets you
1674 tell the target agent whether to continue running a trace if the
1675 connection is lost unexpectedly.
1679 GDB now has the ability to save the trace buffer into a file, and
1680 then use that file as a target, similarly to you can do with
1681 corefiles. You can select trace frames, print data that was
1682 collected in them, and use tstatus to display the state of the
1683 tracing run at the moment that it was saved. To create a trace
1684 file, use "tsave <filename>", and to use it, do "target tfile
1687 ** Circular trace buffer
1689 You can ask the target agent to handle the trace buffer as a
1690 circular buffer, discarding the oldest trace frames to make room for
1691 newer ones, by setting circular-trace-buffer to on. This feature may
1692 not be available for all target agents.
1697 The disassemble command, when invoked with two arguments, now requires
1698 the arguments to be comma-separated.
1701 The info variables command now displays variable definitions. Files
1702 which only declare a variable are not shown.
1705 The source command is now capable of sourcing Python scripts.
1706 This feature is dependent on the debugger being build with Python
1709 Related to this enhancement is also the introduction of a new command
1710 "set script-extension" (see below).
1712 * New commands (for set/show, see "New options" below)
1714 record save [<FILENAME>]
1715 Save a file (in core file format) containing the process record
1716 execution log for replay debugging at a later time.
1718 record restore <FILENAME>
1719 Restore the process record execution log that was saved at an
1720 earlier time, for replay debugging.
1722 add-inferior [-copies <N>] [-exec <FILENAME>]
1725 clone-inferior [-copies <N>] [ID]
1726 Make a new inferior ready to execute the same program another
1727 inferior has loaded.
1732 maint info program-spaces
1733 List the program spaces loaded into GDB.
1735 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1736 show remote interrupt-sequence
1737 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1738 as the sequence to the remote target in order to interrupt the execution.
1739 Ctrl-C is a default. Some system prefers BREAK which is high level of
1740 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1741 Magic SysRq g. It is BREAK signal and character 'g'.
1743 set remote interrupt-on-connect [on | off]
1744 show remote interrupt-on-connect
1745 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1746 remote target when gdb connects to it. This is needed when you debug
1749 set remotebreak [on | off]
1751 Deprecated. Use "set/show remote interrupt-sequence" instead.
1753 tvariable $NAME [ = EXP ]
1754 Create or modify a trace state variable.
1757 List trace state variables and their values.
1759 delete tvariable $NAME ...
1760 Delete one or more trace state variables.
1763 Evaluate the given expressions without collecting anything into the
1764 trace buffer. (Valid in tracepoint actions only.)
1766 ftrace FN / FILE:LINE / *ADDR
1767 Define a fast tracepoint at the given function, line, or address.
1769 * New expression syntax
1771 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1772 GDB now parses 0b101010 identically with 42.
1776 set follow-exec-mode new|same
1777 show follow-exec-mode
1778 Control whether GDB reuses the same inferior across an exec call or
1779 creates a new one. This is useful to be able to restart the old
1780 executable after the inferior having done an exec call.
1782 set default-collect EXPR, ...
1783 show default-collect
1784 Define a list of expressions to be collected at each tracepoint.
1785 This is a useful way to ensure essential items are not overlooked,
1786 such as registers or a critical global variable.
1788 set disconnected-tracing
1789 show disconnected-tracing
1790 If set to 1, the target is instructed to continue tracing if it
1791 loses its connection to GDB. If 0, the target is to stop tracing
1794 set circular-trace-buffer
1795 show circular-trace-buffer
1796 If set to on, the target is instructed to use a circular trace buffer
1797 and discard the oldest trace frames instead of stopping the trace due
1798 to a full trace buffer. If set to off, the trace stops when the buffer
1799 fills up. Some targets may not support this.
1801 set script-extension off|soft|strict
1802 show script-extension
1803 If set to "off", the debugger does not perform any script language
1804 recognition, and all sourced files are assumed to be GDB scripts.
1805 If set to "soft" (the default), files are sourced according to
1806 filename extension, falling back to GDB scripts if the first
1808 If set to "strict", files are sourced according to filename extension.
1810 set ada trust-PAD-over-XVS on|off
1811 show ada trust-PAD-over-XVS
1812 If off, activate a workaround against a bug in the debugging information
1813 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1814 the GCC sources for more information about the GNAT encoding and
1815 PAD types in particular). It is always safe to set this option to
1816 off, but this introduces a slight performance penalty. The default
1819 * Python API Improvements
1821 ** GDB provides the new class gdb.LazyString. This is useful in
1822 some pretty-printing cases. The new method gdb.Value.lazy_string
1823 provides a simple way to create objects of this type.
1825 ** The fields returned by gdb.Type.fields now have an
1826 `is_base_class' attribute.
1828 ** The new method gdb.Type.range returns the range of an array type.
1830 ** The new method gdb.parse_and_eval can be used to parse and
1831 evaluate an expression.
1833 * New remote packets
1836 Define a trace state variable.
1839 Get the current value of a trace state variable.
1842 Set desired tracing behavior upon disconnection.
1845 Set the trace buffer to be linear or circular.
1848 Get data about the tracepoints currently in use.
1852 Process record now works correctly with hardware watchpoints.
1854 Multiple bug fixes have been made to the mips-irix port, making it
1855 much more reliable. In particular:
1856 - Debugging threaded applications is now possible again. Previously,
1857 GDB would hang while starting the program, or while waiting for
1858 the program to stop at a breakpoint.
1859 - Attaching to a running process no longer hangs.
1860 - An error occurring while loading a core file has been fixed.
1861 - Changing the value of the PC register now works again. This fixes
1862 problems observed when using the "jump" command, or when calling
1863 a function from GDB, or even when assigning a new value to $pc.
1864 - With the "finish" and "return" commands, the return value for functions
1865 returning a small array is now correctly printed.
1866 - It is now possible to break on shared library code which gets executed
1867 during a shared library init phase (code executed while executing
1868 their .init section). Previously, the breakpoint would have no effect.
1869 - GDB is now able to backtrace through the signal handler for
1870 non-threaded programs.
1872 PIE (Position Independent Executable) programs debugging is now supported.
1873 This includes debugging execution of PIC (Position Independent Code) shared
1874 libraries although for that, it should be possible to run such libraries as an
1877 *** Changes in GDB 7.0
1879 * GDB now has an interface for JIT compilation. Applications that
1880 dynamically generate code can create symbol files in memory and register
1881 them with GDB. For users, the feature should work transparently, and
1882 for JIT developers, the interface is documented in the GDB manual in the
1883 "JIT Compilation Interface" chapter.
1885 * Tracepoints may now be conditional. The syntax is as for
1886 breakpoints; either an "if" clause appended to the "trace" command,
1887 or the "condition" command is available. GDB sends the condition to
1888 the target for evaluation using the same bytecode format as is used
1889 for tracepoint actions.
1891 * The disassemble command now supports: an optional /r modifier, print the
1892 raw instructions in hex as well as in symbolic form, and an optional /m
1893 modifier to print mixed source+assembly.
1895 * Process record and replay
1897 In a architecture environment that supports ``process record and
1898 replay'', ``process record and replay'' target can record a log of
1899 the process execution, and replay it with both forward and reverse
1902 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
1903 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
1904 set execution-direction {forward|reverse}, for targets that support
1907 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
1908 feature is available with a native GDB running on kernel version
1911 * GDB now has support for multi-byte and wide character sets on the
1912 target. Strings whose character type is wchar_t, char16_t, or
1913 char32_t are now correctly printed. GDB supports wide- and unicode-
1914 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
1915 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
1916 `printf'. This feature requires iconv to work properly; if your
1917 system does not have a working iconv, GDB can use GNU libiconv. See
1918 the installation instructions for more information.
1920 * GDB now supports automatic retrieval of shared library files from
1921 remote targets. To use this feature, specify a system root that begins
1922 with the `remote:' prefix, either via the `set sysroot' command or via
1923 the `--with-sysroot' configure-time option.
1925 * "info sharedlibrary" now takes an optional regex of libraries to show,
1926 and it now reports if a shared library has no debugging information.
1928 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
1929 now complete on file names.
1931 * When completing in expressions, gdb will attempt to limit
1932 completions to allowable structure or union fields, where appropriate.
1933 For instance, consider:
1935 # struct example { int f1; double f2; };
1936 # struct example variable;
1939 If the user types TAB at the end of this command line, the available
1940 completions will be "f1" and "f2".
1942 * Inlined functions are now supported. They show up in backtraces, and
1943 the "step", "next", and "finish" commands handle them automatically.
1945 * GDB now supports the token-splicing (##) and stringification (#)
1946 operators when expanding macros. It also supports variable-arity
1949 * GDB now supports inspecting extra signal information, exported by
1950 the new $_siginfo convenience variable. The feature is currently
1951 implemented on linux ARM, i386 and amd64.
1953 * GDB can now display the VFP floating point registers and NEON vector
1954 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
1955 can provide these registers (requires Linux 2.6.30 or later). Remote
1956 and simulator targets may also provide them.
1958 * New remote packets
1961 Search memory for a sequence of bytes.
1964 Turn off `+'/`-' protocol acknowledgments to permit more efficient
1965 operation over reliable transport links. Use of this packet is
1966 controlled by the `set remote noack-packet' command.
1969 Kill the process with the specified process ID. Use this in preference
1970 to `k' when multiprocess protocol extensions are supported.
1973 Obtains additional operating system information
1977 Read or write additional signal information.
1979 * Removed remote protocol undocumented extension
1981 An undocumented extension to the remote protocol's `S' stop reply
1982 packet that permited the stub to pass a process id was removed.
1983 Remote servers should use the `T' stop reply packet instead.
1985 * GDB now supports multiple function calling conventions according to the
1986 DWARF-2 DW_AT_calling_convention function attribute.
1988 * The SH target utilizes the aforementioned change to distinguish between gcc
1989 and Renesas calling convention. It also adds the new CLI commands
1990 `set/show sh calling-convention'.
1992 * GDB can now read compressed debug sections, as produced by GNU gold
1993 with the --compress-debug-sections=zlib flag.
1995 * 64-bit core files are now supported on AIX.
1997 * Thread switching is now supported on Tru64.
1999 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2000 which will be allocated using malloc later in program execution.
2002 * The qXfer:libraries:read remote procotol packet now allows passing a
2003 list of section offsets.
2005 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2006 conditions handling signals delivered during attach or thread creation
2007 have also been fixed.
2009 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2010 From the user's standpoint, all unqualified instances of True and False
2011 are treated as the standard definitions, regardless of context.
2013 * GDB now parses C++ symbol and type names more flexibly. For
2016 template<typename T> class C { };
2019 GDB will now correctly handle all of:
2021 ptype C<char const *>
2022 ptype C<char const*>
2023 ptype C<const char *>
2024 ptype C<const char*>
2026 * New features in the GDB remote stub, gdbserver
2028 - The "--wrapper" command-line argument tells gdbserver to use a
2029 wrapper program to launch programs for debugging.
2031 - On PowerPC and S/390 targets, it is now possible to use a single
2032 gdbserver executable to debug both 32-bit and 64-bit programs.
2033 (This requires gdbserver itself to be built as a 64-bit executable.)
2035 - gdbserver uses the new noack protocol mode for TCP connections to
2036 reduce communications latency, if also supported and enabled in GDB.
2038 - Support for the sparc64-linux-gnu target is now included in
2041 - The amd64-linux build of gdbserver now supports debugging both
2042 32-bit and 64-bit programs.
2044 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2045 now support hardware watchpoints, and will use them automatically
2050 GDB now has support for scripting using Python. Whether this is
2051 available is determined at configure time.
2053 New GDB commands can now be written in Python.
2055 * Ada tasking support
2057 Ada tasks can now be inspected in GDB. The following commands have
2061 Print the list of Ada tasks.
2063 Print detailed information about task number N.
2065 Print the task number of the current task.
2067 Switch the context of debugging to task number N.
2069 * Support for user-defined prefixed commands. The "define" command can
2070 add new commands to existing prefixes, e.g. "target".
2072 * Multi-inferior, multi-process debugging.
2074 GDB now has generalized support for multi-inferior debugging. See
2075 "Debugging Multiple Inferiors" in the manual for more information.
2076 Although availability still depends on target support, the command
2077 set is more uniform now. The GNU/Linux specific multi-forks support
2078 has been migrated to this new framework. This implied some user
2079 visible changes; see "New commands" and also "Removed commands"
2082 * Target descriptions can now describe the target OS ABI. See the
2083 "Target Description Format" section in the user manual for more
2086 * Target descriptions can now describe "compatible" architectures
2087 to indicate that the target can execute applications for a different
2088 architecture in addition to those for the main target architecture.
2089 See the "Target Description Format" section in the user manual for
2092 * Multi-architecture debugging.
2094 GDB now includes general supports for debugging applications on
2095 hybrid systems that use more than one single processor architecture
2096 at the same time. Each such hybrid architecture still requires
2097 specific support to be added. The only hybrid architecture supported
2098 in this version of GDB is the Cell Broadband Engine.
2100 * GDB now supports integrated debugging of Cell/B.E. applications that
2101 use both the PPU and SPU architectures. To enable support for hybrid
2102 Cell/B.E. debugging, you need to configure GDB to support both the
2103 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2104 --enable-targets configure option.
2106 * Non-stop mode debugging.
2108 For some targets, GDB now supports an optional mode of operation in
2109 which you can examine stopped threads while other threads continue
2110 to execute freely. This is referred to as non-stop mode, with the
2111 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2112 section in the user manual for more information.
2114 To be able to support remote non-stop debugging, a remote stub needs
2115 to implement the non-stop mode remote protocol extensions, as
2116 described in the "Remote Non-Stop" section of the user manual. The
2117 GDB remote stub, gdbserver, has been adjusted to support these
2118 extensions on linux targets.
2120 * New commands (for set/show, see "New options" below)
2122 catch syscall [NAME(S) | NUMBER(S)]
2123 Catch system calls. Arguments, which should be names of system
2124 calls or their numbers, mean catch only those syscalls. Without
2125 arguments, every syscall will be caught. When the inferior issues
2126 any of the specified syscalls, GDB will stop and announce the system
2127 call, both when it is called and when its call returns. This
2128 feature is currently available with a native GDB running on the
2129 Linux Kernel, under the following architectures: x86, x86_64,
2130 PowerPC and PowerPC64.
2132 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2134 Search memory for a sequence of bytes.
2136 maint set python print-stack
2137 maint show python print-stack
2138 Show a stack trace when an error is encountered in a Python script.
2141 Invoke CODE by passing it to the Python interpreter.
2146 These allow macros to be defined, undefined, and listed
2150 Show operating system information about processes.
2153 List the inferiors currently under GDB's control.
2156 Switch focus to inferior number NUM.
2159 Detach from inferior number NUM.
2162 Kill inferior number NUM.
2166 set spu stop-on-load
2167 show spu stop-on-load
2168 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2170 set spu auto-flush-cache
2171 show spu auto-flush-cache
2172 Control whether to automatically flush the software-managed cache
2173 during Cell/B.E. debugging.
2175 set sh calling-convention
2176 show sh calling-convention
2177 Control the calling convention used when calling SH target functions.
2180 show debug timestamp
2181 Control display of timestamps with GDB debugging output.
2183 set disassemble-next-line
2184 show disassemble-next-line
2185 Control display of disassembled source lines or instructions when
2188 set remote noack-packet
2189 show remote noack-packet
2190 Set/show the use of remote protocol QStartNoAckMode packet. See above
2191 under "New remote packets."
2193 set remote query-attached-packet
2194 show remote query-attached-packet
2195 Control use of remote protocol `qAttached' (query-attached) packet.
2197 set remote read-siginfo-object
2198 show remote read-siginfo-object
2199 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2202 set remote write-siginfo-object
2203 show remote write-siginfo-object
2204 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2207 set remote reverse-continue
2208 show remote reverse-continue
2209 Control use of remote protocol 'bc' (reverse-continue) packet.
2211 set remote reverse-step
2212 show remote reverse-step
2213 Control use of remote protocol 'bs' (reverse-step) packet.
2215 set displaced-stepping
2216 show displaced-stepping
2217 Control displaced stepping mode. Displaced stepping is a way to
2218 single-step over breakpoints without removing them from the debuggee.
2219 Also known as "out-of-line single-stepping".
2222 show debug displaced
2223 Control display of debugging info for displaced stepping.
2225 maint set internal-error
2226 maint show internal-error
2227 Control what GDB does when an internal error is detected.
2229 maint set internal-warning
2230 maint show internal-warning
2231 Control what GDB does when an internal warning is detected.
2236 Use a wrapper program to launch programs for debugging.
2238 set multiple-symbols (all|ask|cancel)
2239 show multiple-symbols
2240 The value of this variable can be changed to adjust the debugger behavior
2241 when an expression or a breakpoint location contains an ambiguous symbol
2242 name (an overloaded function name, for instance).
2244 set breakpoint always-inserted
2245 show breakpoint always-inserted
2246 Keep breakpoints always inserted in the target, as opposed to inserting
2247 them when resuming the target, and removing them when the target stops.
2248 This option can improve debugger performance on slow remote targets.
2250 set arm fallback-mode (arm|thumb|auto)
2251 show arm fallback-mode
2252 set arm force-mode (arm|thumb|auto)
2254 These commands control how ARM GDB determines whether instructions
2255 are ARM or Thumb. The default for both settings is auto, which uses
2256 the current CPSR value for instructions without symbols; previous
2257 versions of GDB behaved as if "set arm fallback-mode arm".
2259 set disable-randomization
2260 show disable-randomization
2261 Standalone programs run with the virtual address space randomization enabled
2262 by default on some platforms. This option keeps the addresses stable across
2263 multiple debugging sessions.
2267 Control whether other threads are stopped or not when some thread hits
2272 Requests that asynchronous execution is enabled in the target, if available.
2273 In this case, it's possible to resume target in the background, and interact
2274 with GDB while the target is running. "show target-async" displays the
2275 current state of asynchronous execution of the target.
2277 set target-wide-charset
2278 show target-wide-charset
2279 The target-wide-charset is the name of the character set that GDB
2280 uses when printing characters whose type is wchar_t.
2282 set tcp auto-retry (on|off)
2284 set tcp connect-timeout
2285 show tcp connect-timeout
2286 These commands allow GDB to retry failed TCP connections to a remote stub
2287 with a specified timeout period; this is useful if the stub is launched
2288 in parallel with GDB but may not be ready to accept connections immediately.
2290 set libthread-db-search-path
2291 show libthread-db-search-path
2292 Control list of directories which GDB will search for appropriate
2295 set schedule-multiple (on|off)
2296 show schedule-multiple
2297 Allow GDB to resume all threads of all processes or only threads of
2298 the current process.
2302 Use more aggressive caching for accesses to the stack. This improves
2303 performance of remote debugging (particularly backtraces) without
2304 affecting correctness.
2306 set interactive-mode (on|off|auto)
2307 show interactive-mode
2308 Control whether GDB runs in interactive mode (on) or not (off).
2309 When in interactive mode, GDB waits for the user to answer all
2310 queries. Otherwise, GDB does not wait and assumes the default
2311 answer. When set to auto (the default), GDB determines which
2312 mode to use based on the stdin settings.
2317 For program forks, this is replaced by the new more generic `info
2318 inferiors' command. To list checkpoints, you can still use the
2319 `info checkpoints' command, which was an alias for the `info forks'
2323 Replaced by the new `inferior' command. To switch between
2324 checkpoints, you can still use the `restart' command, which was an
2325 alias for the `fork' command.
2328 This is removed, since some targets don't have a notion of
2329 processes. To switch between processes, you can still use the
2330 `inferior' command using GDB's own inferior number.
2333 For program forks, this is replaced by the new more generic `kill
2334 inferior' command. To delete a checkpoint, you can still use the
2335 `delete checkpoint' command, which was an alias for the `delete
2339 For program forks, this is replaced by the new more generic `detach
2340 inferior' command. To detach a checkpoint, you can still use the
2341 `detach checkpoint' command, which was an alias for the `detach
2344 * New native configurations
2346 x86/x86_64 Darwin i[34567]86-*-darwin*
2348 x86_64 MinGW x86_64-*-mingw*
2352 Lattice Mico32 lm32-*
2353 x86 DICOS i[34567]86-*-dicos*
2354 x86_64 DICOS x86_64-*-dicos*
2357 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2358 (mingw32ce) debugging.
2364 These commands were actually not implemented on any target.
2366 *** Changes in GDB 6.8
2368 * New native configurations
2370 NetBSD/hppa hppa*-*netbsd*
2371 Xtensa GNU/Linux xtensa*-*-linux*
2375 NetBSD/hppa hppa*-*-netbsd*
2376 Xtensa GNU/Lunux xtensa*-*-linux*
2378 * Change in command line behavior -- corefiles vs. process ids.
2380 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2381 attaching to process NUMBER fails, GDB no longer attempts to open a
2382 core file named NUMBER. Attaching to a program using the -c option
2383 is no longer supported. Instead, use the '-p' or '--pid' options.
2385 * GDB can now be built as a native debugger for debugging Windows x86
2386 (mingw32) Portable Executable (PE) programs.
2388 * Pending breakpoints no longer change their number when their address
2391 * GDB now supports breakpoints with multiple locations,
2392 including breakpoints on C++ constructors, inside C++ templates,
2393 and in inlined functions.
2395 * GDB's ability to debug optimized code has been improved. GDB more
2396 accurately identifies function bodies and lexical blocks that occupy
2397 more than one contiguous range of addresses.
2399 * Target descriptions can now describe registers for PowerPC.
2401 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2402 registers on PowerPC targets.
2404 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2405 targets even when the libthread_db library is not available.
2407 * The GDB remote stub, gdbserver, now supports the new file transfer
2408 commands (remote put, remote get, and remote delete).
2410 * The GDB remote stub, gdbserver, now supports run and attach in
2411 extended-remote mode.
2413 * hppa*64*-*-hpux11* target broken
2414 The debugger is unable to start a program and fails with the following
2415 error: "Error trying to get information about dynamic linker".
2416 The gdb-6.7 release is also affected.
2418 * GDB now supports the --enable-targets= configure option to allow
2419 building a single GDB executable that supports multiple remote
2420 target architectures.
2422 * GDB now supports debugging C and C++ programs which use the
2423 Decimal Floating Point extension. In addition, the PowerPC target
2424 now has a set of pseudo-registers to inspect decimal float values
2425 stored in two consecutive float registers.
2427 * The -break-insert MI command can optionally create pending
2430 * Improved support for debugging Ada
2431 Many improvements to the Ada language support have been made. These
2433 - Better support for Ada2005 interface types
2434 - Improved handling of arrays and slices in general
2435 - Better support for Taft-amendment types
2436 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2438 - Improved command completion in Ada
2441 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2446 set print frame-arguments (all|scalars|none)
2447 show print frame-arguments
2448 The value of this variable can be changed to control which argument
2449 values should be printed by the debugger when displaying a frame.
2454 Transfer files to and from a remote target, and delete remote files.
2461 Transfer files to and from a remote target, and delete remote files.
2463 * New remote packets
2470 Open, close, read, write, and delete files on the remote system.
2473 Attach to an existing process on the remote system, in extended-remote
2477 Run a new process on the remote system, in extended-remote mode.
2479 *** Changes in GDB 6.7
2481 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2482 bfd, libiberty and opcodes, as revealed by static analysis donated by
2483 Coverity, Inc. (http://scan.coverity.com).
2485 * When looking up multiply-defined global symbols, GDB will now prefer the
2486 symbol definition in the current shared library if it was built using the
2487 -Bsymbolic linker option.
2489 * When the Text User Interface (TUI) is not configured, GDB will now
2490 recognize the -tui command-line option and print a message that the TUI
2493 * The GDB remote stub, gdbserver, now has lower overhead for high
2494 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2496 * GDB for MIPS targets now autodetects whether a remote target provides
2497 32-bit or 64-bit register values.
2499 * Support for C++ member pointers has been improved.
2501 * GDB now understands XML target descriptions, which specify the
2502 target's overall architecture. GDB can read a description from
2503 a local file or over the remote serial protocol.
2505 * Vectors of single-byte data use a new integer type which is not
2506 automatically displayed as character or string data.
2508 * The /s format now works with the print command. It displays
2509 arrays of single-byte integers and pointers to single-byte integers
2512 * Target descriptions can now describe target-specific registers,
2513 for architectures which have implemented the support (currently
2514 only ARM, M68K, and MIPS).
2516 * GDB and the GDB remote stub, gdbserver, now support the XScale
2519 * The GDB remote stub, gdbserver, has been updated to support
2520 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2521 has been rewritten to use the standard GDB remote protocol.
2523 * GDB can now step into C++ functions which are called through thunks.
2525 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2527 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2528 layout. It also supports a TextSeg= and DataSeg= response when only
2529 segment base addresses (rather than offsets) are available.
2531 * The /i format now outputs any trailing branch delay slot instructions
2532 immediately following the last instruction within the count specified.
2534 * The GDB remote protocol "T" stop reply packet now supports a
2535 "library" response. Combined with the new "qXfer:libraries:read"
2536 packet, this response allows GDB to debug shared libraries on targets
2537 where the operating system manages the list of loaded libraries (e.g.
2538 Windows and SymbianOS).
2540 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2541 (DLLs) on Windows and Windows CE targets.
2543 * GDB now supports a faster verification that a .debug file matches its binary
2544 according to its build-id signature, if the signature is present.
2550 Enable or disable hardware flow control (RTS/CTS) on the serial port
2551 when debugging using remote targets.
2553 set mem inaccessible-by-default
2554 show mem inaccessible-by-default
2555 If the target supplies a memory map, for instance via the remote
2556 protocol's "qXfer:memory-map:read" packet, setting this variable
2557 prevents GDB from accessing memory outside the memory map. This
2558 is useful for targets with memory mapped registers or which react
2559 badly to accesses of unmapped address space.
2561 set breakpoint auto-hw
2562 show breakpoint auto-hw
2563 If the target supplies a memory map, for instance via the remote
2564 protocol's "qXfer:memory-map:read" packet, setting this variable
2565 lets GDB use hardware breakpoints automatically for memory regions
2566 where it can not use software breakpoints. This covers both the
2567 "break" command and internal breakpoints used for other commands
2568 including "next" and "finish".
2571 catch exception unhandled
2572 Stop the program execution when Ada exceptions are raised.
2575 Stop the program execution when an Ada assertion failed.
2579 Set an alternate system root for target files. This is a more
2580 general version of "set solib-absolute-prefix", which is now
2581 an alias to "set sysroot".
2584 Provide extended SPU facility status information. This set of
2585 commands is available only when debugging the Cell/B.E. SPU
2588 * New native configurations
2590 OpenBSD/sh sh*-*openbsd*
2593 unset tdesc filename
2595 Use the specified local file as an XML target description, and do
2596 not query the target for its built-in description.
2600 OpenBSD/sh sh*-*-openbsd*
2601 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2602 Toshiba Media Processor mep-elf
2604 * New remote packets
2607 Ignore the specified signals; pass them directly to the debugged program
2608 without stopping other threads or reporting them to GDB.
2610 qXfer:features:read:
2611 Read an XML target description from the target, which describes its
2616 Read or write contents of an spufs file on the target system. These
2617 packets are available only on the Cell/B.E. SPU architecture.
2619 qXfer:libraries:read:
2620 Report the loaded shared libraries. Combined with new "T" packet
2621 response, this packet allows GDB to debug shared libraries on
2622 targets where the operating system manages the list of loaded
2623 libraries (e.g. Windows and SymbianOS).
2627 Support for these obsolete configurations has been removed.
2635 i[34567]86-*-lynxos*
2636 i[34567]86-*-netware*
2637 i[34567]86-*-sco3.2v5*
2638 i[34567]86-*-sco3.2v4*
2640 i[34567]86-*-sysv4.2*
2643 i[34567]86-*-unixware2*
2644 i[34567]86-*-unixware*
2653 * Other removed features
2660 Various m68k-only ROM monitors.
2667 Various Renesas ROM monitors and debugging interfaces for SH and
2672 Support for a Macraigor serial interface to on-chip debugging.
2673 GDB does not directly support the newer parallel or USB
2678 A debug information format. The predecessor to DWARF 2 and
2679 DWARF 3, which are still supported.
2681 Support for the HP aCC compiler on HP-UX/PA-RISC
2683 SOM-encapsulated symbolic debugging information, automatic
2684 invocation of pxdb, and the aCC custom C++ ABI. This does not
2685 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2686 with aCC can still be debugged on an assembly level.
2688 MIPS ".pdr" sections
2690 A MIPS-specific format used to describe stack frame layout
2691 in debugging information.
2695 GDB could work with an older version of Guile to debug
2696 the interpreter and Scheme programs running in it.
2698 set mips stack-arg-size
2699 set mips saved-gpreg-size
2701 Use "set mips abi" to control parameter passing for MIPS.
2703 *** Changes in GDB 6.6
2708 Cell Broadband Engine SPU spu-elf
2710 * GDB can now be configured as a cross-debugger targeting native Windows
2711 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2712 running on a Windows system over TCP/IP to debug Windows programs.
2714 * The GDB remote stub, gdbserver, has been updated to support Windows and
2715 Cygwin debugging. Both single-threaded and multi-threaded programs are
2718 * The "set trust-readonly-sections" command works again. This command was
2719 broken in GDB 6.3, 6.4, and 6.5.
2721 * The "load" command now supports writing to flash memory, if the remote
2722 stub provides the required support.
2724 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2725 longer requires symbolic debug information (e.g. DWARF-2).
2730 unset substitute-path
2731 show substitute-path
2732 Manage a list of substitution rules that GDB uses to rewrite the name
2733 of the directories where the sources are located. This can be useful
2734 for instance when the sources were moved to a different location
2735 between compilation and debugging.
2739 Print each CLI command as it is executed. Each command is prefixed with
2740 a number of `+' symbols representing the nesting depth.
2741 The source command now has a `-v' option to enable the same feature.
2745 The ARM Demon monitor support (RDP protocol, "target rdp").
2747 Kernel Object Display, an embedded debugging feature which only worked with
2748 an obsolete version of Cisco IOS.
2750 The 'set download-write-size' and 'show download-write-size' commands.
2752 * New remote packets
2755 Tell a stub about GDB client features, and request remote target features.
2756 The first feature implemented is PacketSize, which allows the target to
2757 specify the size of packets it can handle - to minimize the number of
2758 packets required and improve performance when connected to a remote
2762 Fetch an OS auxilliary vector from the remote stub. This packet is a
2763 more efficient replacement for qPart:auxv:read.
2765 qXfer:memory-map:read:
2766 Fetch a memory map from the remote stub, including information about
2767 RAM, ROM, and flash memory devices.
2772 Erase and program a flash memory device.
2774 * Removed remote packets
2777 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2778 used it, and only gdbserver implemented it.
2780 *** Changes in GDB 6.5
2784 Renesas M32C/M16C m32c-elf
2786 Morpho Technologies ms1 ms1-elf
2790 init-if-undefined Initialize a convenience variable, but
2791 only if it doesn't already have a value.
2793 The following commands are presently only implemented for native GNU/Linux:
2795 checkpoint Save a snapshot of the program state.
2797 restart <n> Return the program state to a
2798 previously saved state.
2800 info checkpoints List currently saved checkpoints.
2802 delete-checkpoint <n> Delete a previously saved checkpoint.
2804 set|show detach-on-fork Tell gdb whether to detach from a newly
2805 forked process, or to keep debugging it.
2807 info forks List forks of the user program that
2808 are available to be debugged.
2810 fork <n> Switch to debugging one of several
2811 forks of the user program that are
2812 available to be debugged.
2814 delete-fork <n> Delete a fork from the list of forks
2815 that are available to be debugged (and
2816 kill the forked process).
2818 detach-fork <n> Delete a fork from the list of forks
2819 that are available to be debugged (and
2820 allow the process to continue).
2824 Morpho Technologies ms2 ms1-elf
2826 * Improved Windows host support
2828 GDB now builds as a cross debugger hosted on i686-mingw32, including
2829 native console support, and remote communications using either
2830 network sockets or serial ports.
2832 * Improved Modula-2 language support
2834 GDB can now print most types in the Modula-2 syntax. This includes:
2835 basic types, set types, record types, enumerated types, range types,
2836 pointer types and ARRAY types. Procedure var parameters are correctly
2837 printed and hexadecimal addresses and character constants are also
2838 written in the Modula-2 syntax. Best results can be obtained by using
2839 GNU Modula-2 together with the -gdwarf-2 command line option.
2843 The ARM rdi-share module.
2845 The Netware NLM debug server.
2847 *** Changes in GDB 6.4
2849 * New native configurations
2851 OpenBSD/arm arm*-*-openbsd*
2852 OpenBSD/mips64 mips64-*-openbsd*
2856 Morpho Technologies ms1 ms1-elf
2858 * New command line options
2860 --batch-silent As for --batch, but totally silent.
2861 --return-child-result The debugger will exist with the same value
2862 the child (debugged) program exited with.
2863 --eval-command COMMAND, -ex COMMAND
2864 Execute a single GDB CLI command. This may be
2865 specified multiple times and in conjunction
2866 with the --command (-x) option.
2868 * Deprecated commands removed
2870 The following commands, that were deprecated in 2000, have been
2874 set|show arm disassembly-flavor set|show arm disassembler
2875 othernames set arm disassembler
2876 set|show remotedebug set|show debug remote
2877 set|show archdebug set|show debug arch
2878 set|show eventdebug set|show debug event
2881 * New BSD user-level threads support
2883 It is now possible to debug programs using the user-level threads
2884 library on OpenBSD and FreeBSD. Currently supported (target)
2887 FreeBSD/amd64 x86_64-*-freebsd*
2888 FreeBSD/i386 i386-*-freebsd*
2889 OpenBSD/i386 i386-*-openbsd*
2891 Note that the new kernel threads libraries introduced in FreeBSD 5.x
2892 are not yet supported.
2894 * New support for Matsushita MN10300 w/sim added
2895 (Work in progress). mn10300-elf.
2897 * REMOVED configurations and files
2899 VxWorks and the XDR protocol *-*-vxworks
2900 Motorola MCORE mcore-*-*
2901 National Semiconductor NS32000 ns32k-*-*
2903 * New "set print array-indexes" command
2905 After turning this setting "on", GDB prints the index of each element
2906 when displaying arrays. The default is "off" to preserve the previous
2909 * VAX floating point support
2911 GDB now supports the not-quite-ieee VAX F and D floating point formats.
2913 * User-defined command support
2915 In addition to using $arg0..$arg9 for argument passing, it is now possible
2916 to use $argc to determine now many arguments have been passed. See the
2917 section on user-defined commands in the user manual for more information.
2919 *** Changes in GDB 6.3:
2921 * New command line option
2923 GDB now accepts -l followed by a number to set the timeout for remote
2926 * GDB works with GCC -feliminate-dwarf2-dups
2928 GDB now supports a more compact representation of DWARF-2 debug
2929 information using DW_FORM_ref_addr references. These are produced
2930 by GCC with the option -feliminate-dwarf2-dups and also by some
2931 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
2932 to use -feliminate-dwarf2-dups.
2934 * Internationalization
2936 When supported by the host system, GDB will be built with
2937 internationalization (libintl). The task of marking up the sources is
2938 continued, we're looking forward to our first translation.
2942 Initial support for debugging programs compiled with the GNAT
2943 implementation of the Ada programming language has been integrated
2944 into GDB. In this release, support is limited to expression evaluation.
2946 * New native configurations
2948 GNU/Linux/m32r m32r-*-linux-gnu
2952 GDB's remote protocol now includes support for the 'p' packet. This
2953 packet is used to fetch individual registers from a remote inferior.
2955 * END-OF-LIFE registers[] compatibility module
2957 GDB's internal register infrastructure has been completely rewritten.
2958 The new infrastructure making possible the implementation of key new
2959 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
2962 GDB 6.3 will be the last release to include the the registers[]
2963 compatibility module that allowed out-of-date configurations to
2964 continue to work. This change directly impacts the following
2974 powerpc bdm protocol
2976 Unless there is activity to revive these configurations, they will be
2977 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
2979 * OBSOLETE configurations and files
2981 Configurations that have been declared obsolete in this release have
2982 been commented out. Unless there is activity to revive these
2983 configurations, the next release of GDB will have their sources
2984 permanently REMOVED.
2993 *** Changes in GDB 6.2.1:
2995 * MIPS `break main; run' gave an heuristic-fence-post warning
2997 When attempting to run even a simple program, a warning about
2998 heuristic-fence-post being hit would be reported. This problem has
3001 * MIPS IRIX 'long double' crashed GDB
3003 When examining a long double variable, GDB would get a segmentation
3004 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3005 IRIX long double values).
3009 A bug in the VAX stack code was causing problems with the "next"
3010 command. This problem has been fixed.
3012 *** Changes in GDB 6.2:
3014 * Fix for ``many threads''
3016 On GNU/Linux systems that use the NPTL threads library, a program
3017 rapidly creating and deleting threads would confuse GDB leading to the
3020 ptrace: No such process.
3021 thread_db_get_info: cannot get thread info: generic error
3023 This problem has been fixed.
3025 * "-async" and "-noasync" options removed.
3027 Support for the broken "-noasync" option has been removed (it caused
3030 * New ``start'' command.
3032 This command runs the program until the begining of the main procedure.
3034 * New BSD Kernel Data Access Library (libkvm) interface
3036 Using ``target kvm'' it is now possible to debug kernel core dumps and
3037 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3038 platforms. Currently supported (native-only) configurations are:
3040 FreeBSD/amd64 x86_64-*-freebsd*
3041 FreeBSD/i386 i?86-*-freebsd*
3042 NetBSD/i386 i?86-*-netbsd*
3043 NetBSD/m68k m68*-*-netbsd*
3044 NetBSD/sparc sparc-*-netbsd*
3045 OpenBSD/amd64 x86_64-*-openbsd*
3046 OpenBSD/i386 i?86-*-openbsd*
3047 OpenBSD/m68k m68*-openbsd*
3048 OpenBSD/sparc sparc-*-openbsd*
3050 * Signal trampoline code overhauled
3052 Many generic problems with GDB's signal handling code have been fixed.
3053 These include: backtraces through non-contiguous stacks; recognition
3054 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3055 call; backtrace through a signal trampoline; step into and out of
3056 signal handlers; and single-stepping in the signal trampoline.
3058 Please note that kernel bugs are a limiting factor here. These
3059 features have been shown to work on an s390 GNU/Linux system that
3060 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3062 * Cygwin support for DWARF 2 added.
3064 * New native configurations
3066 GNU/Linux/hppa hppa*-*-linux*
3067 OpenBSD/hppa hppa*-*-openbsd*
3068 OpenBSD/m68k m68*-*-openbsd*
3069 OpenBSD/m88k m88*-*-openbsd*
3070 OpenBSD/powerpc powerpc-*-openbsd*
3071 NetBSD/vax vax-*-netbsd*
3072 OpenBSD/vax vax-*-openbsd*
3074 * END-OF-LIFE frame compatibility module
3076 GDB's internal frame infrastructure has been completely rewritten.
3077 The new infrastructure making it possible to support key new features
3078 including DWARF 2 Call Frame Information. To aid in the task of
3079 migrating old configurations to this new infrastructure, a
3080 compatibility module, that allowed old configurations to continue to
3081 work, was also included.
3083 GDB 6.2 will be the last release to include this frame compatibility
3084 module. This change directly impacts the following configurations:
3094 Unless there is activity to revive these configurations, they will be
3095 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3097 * REMOVED configurations and files
3099 Sun 3, running SunOS 3 m68*-*-sunos3*
3100 Sun 3, running SunOS 4 m68*-*-sunos4*
3101 Sun 2, running SunOS 3 m68000-*-sunos3*
3102 Sun 2, running SunOS 4 m68000-*-sunos4*
3103 Motorola 680x0 running LynxOS m68*-*-lynxos*
3104 AT&T 3b1/Unix pc m68*-att-*
3105 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3106 decstation mips-dec-* mips-little-*
3107 riscos mips-*-riscos* mips-*-sysv*
3108 sonymips mips-sony-*
3109 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3111 *** Changes in GDB 6.1.1:
3113 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3115 The TUI (Text-mode User Interface) is now built as part of a default
3116 GDB configuration. It is enabled by either selecting the TUI with the
3117 command line option "-i=tui" or by running the separate "gdbtui"
3118 program. For more information on the TUI, see the manual "Debugging
3121 * Pending breakpoint support (also included in GDB 6.1)
3123 Support has been added to allow you to specify breakpoints in shared
3124 libraries that have not yet been loaded. If a breakpoint location
3125 cannot be found, and the "breakpoint pending" option is set to auto,
3126 GDB queries you if you wish to make the breakpoint pending on a future
3127 shared-library load. If and when GDB resolves the breakpoint symbol,
3128 the pending breakpoint is removed as one or more regular breakpoints
3131 Pending breakpoints are very useful for GCJ Java debugging.
3133 * Fixed ISO-C build problems
3135 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3136 non ISO-C code that stopped them being built using a more strict ISO-C
3137 compiler (e.g., IBM's C compiler).
3139 * Fixed build problem on IRIX 5
3141 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3142 wasn't able to compile compile on an IRIX 5 system.
3144 * Added execute permission to gdb/gdbserver/configure
3146 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3147 permission. This bug would cause configure to fail on a number of
3148 systems (Solaris, IRIX). Ref: server/519.
3150 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3152 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3153 has been updated to use constant array sizes.
3155 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3157 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3158 its generated DWARF Call Frame Info. This encoding was causing GDB to
3159 panic, that panic has been fixed. Ref: gdb/1628.
3161 * Fixed a problem when examining parameters in shared library code.
3163 When examining parameters in optimized shared library code generated
3164 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3165 not available''. GDB now correctly displays the variable's value.
3167 *** Changes in GDB 6.1:
3169 * Removed --with-mmalloc
3171 Support for the mmalloc memory manager has been removed, as it
3172 conflicted with the internal gdb byte cache.
3174 * Changes in AMD64 configurations
3176 The AMD64 target now includes the %cs and %ss registers. As a result
3177 the AMD64 remote protocol has changed; this affects the floating-point
3178 and SSE registers. If you rely on those registers for your debugging,
3179 you should upgrade gdbserver on the remote side.
3181 * Revised SPARC target
3183 The SPARC target has been completely revised, incorporating the
3184 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3185 support for LynxOS and SunOS 4 has been dropped. Calling functions
3186 from within GDB on operating systems with a non-executable stack
3187 (Solaris, OpenBSD) now works.
3191 GDB has a new C++ demangler which does a better job on the mangled
3192 names generated by current versions of g++. It also runs faster, so
3193 with this and other changes gdb should now start faster on large C++
3196 * DWARF 2 Location Expressions
3198 GDB support for location expressions has been extended to support function
3199 arguments and frame bases. Older versions of GDB could crash when they
3202 * C++ nested types and namespaces
3204 GDB's support for nested types and namespaces in C++ has been
3205 improved, especially if you use the DWARF 2 debugging format. (This
3206 is the default for recent versions of GCC on most platforms.)
3207 Specifically, if you have a class "Inner" defined within a class or
3208 namespace "Outer", then GDB realizes that the class's name is
3209 "Outer::Inner", not simply "Inner". This should greatly reduce the
3210 frequency of complaints about not finding RTTI symbols. In addition,
3211 if you are stopped at inside of a function defined within a namespace,
3212 GDB modifies its name lookup accordingly.
3214 * New native configurations
3216 NetBSD/amd64 x86_64-*-netbsd*
3217 OpenBSD/amd64 x86_64-*-openbsd*
3218 OpenBSD/alpha alpha*-*-openbsd*
3219 OpenBSD/sparc sparc-*-openbsd*
3220 OpenBSD/sparc64 sparc64-*-openbsd*
3222 * New debugging protocols
3224 M32R with SDI protocol m32r-*-elf*
3226 * "set prompt-escape-char" command deleted.
3228 The command "set prompt-escape-char" has been deleted. This command,
3229 and its very obscure effet on GDB's prompt, was never documented,
3230 tested, nor mentioned in the NEWS file.
3232 * OBSOLETE configurations and files
3234 Configurations that have been declared obsolete in this release have
3235 been commented out. Unless there is activity to revive these
3236 configurations, the next release of GDB will have their sources
3237 permanently REMOVED.
3239 Sun 3, running SunOS 3 m68*-*-sunos3*
3240 Sun 3, running SunOS 4 m68*-*-sunos4*
3241 Sun 2, running SunOS 3 m68000-*-sunos3*
3242 Sun 2, running SunOS 4 m68000-*-sunos4*
3243 Motorola 680x0 running LynxOS m68*-*-lynxos*
3244 AT&T 3b1/Unix pc m68*-att-*
3245 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3246 decstation mips-dec-* mips-little-*
3247 riscos mips-*-riscos* mips-*-sysv*
3248 sonymips mips-sony-*
3249 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3251 * REMOVED configurations and files
3253 SGI Irix-4.x mips-sgi-irix4 or iris4
3254 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3255 Z8000 simulator z8k-zilog-none or z8ksim
3256 Matsushita MN10200 w/simulator mn10200-*-*
3257 H8/500 simulator h8500-hitachi-hms or h8500hms
3258 HP/PA running BSD hppa*-*-bsd*
3259 HP/PA running OSF/1 hppa*-*-osf*
3260 HP/PA Pro target hppa*-*-pro*
3261 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3262 386BSD i[3456]86-*-bsd*
3263 Sequent family i[3456]86-sequent-sysv4*
3264 i[3456]86-sequent-sysv*
3265 i[3456]86-sequent-bsd*
3266 SPARC running LynxOS sparc-*-lynxos*
3267 SPARC running SunOS 4 sparc-*-sunos4*
3268 Tsqware Sparclet sparclet-*-*
3269 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3271 *** Changes in GDB 6.0:
3275 Support for debugging the Objective-C programming language has been
3276 integrated into GDB.
3278 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3280 DWARF 2's Call Frame Information makes available compiler generated
3281 information that more exactly describes the program's run-time stack.
3282 By using this information, GDB is able to provide more robust stack
3285 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3286 have been updated to use a new backtrace mechanism which includes
3287 DWARF 2 CFI support.
3291 GDB's remote protocol has been extended to include support for hosted
3292 file I/O (where the remote target uses GDB's file system). See GDB's
3293 remote protocol documentation for details.
3295 * All targets using the new architecture framework.
3297 All of GDB's targets have been updated to use the new internal
3298 architecture framework. The way is now open for future GDB releases
3299 to include cross-architecture native debugging support (i386 on amd64,
3302 * GNU/Linux's Thread Local Storage (TLS)
3304 GDB now includes support for for the GNU/Linux implementation of
3305 per-thread variables.
3307 * GNU/Linux's Native POSIX Thread Library (NPTL)
3309 GDB's thread code has been updated to work with either the new
3310 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3312 * Separate debug info.
3314 GDB, in conjunction with BINUTILS, now supports a mechanism for
3315 automatically loading debug information from a separate file. Instead
3316 of shipping full debug and non-debug versions of system libraries,
3317 system integrators can now instead ship just the stripped libraries
3318 and optional debug files.
3320 * DWARF 2 Location Expressions
3322 DWARF 2 Location Expressions allow the compiler to more completely
3323 describe the location of variables (even in optimized code) to the
3326 GDB now includes preliminary support for location expressions (support
3327 for DW_OP_piece is still missing).
3331 A number of long standing bugs that caused GDB to die while starting a
3332 Java application have been fixed. GDB's Java support is now
3333 considered "useable".
3335 * GNU/Linux support for fork, vfork, and exec.
3337 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3338 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3341 * GDB supports logging output to a file
3343 There are two new commands, "set logging" and "show logging", which can be
3344 used to capture GDB's output to a file.
3346 * The meaning of "detach" has changed for gdbserver
3348 The "detach" command will now resume the application, as documented. To
3349 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3352 * d10v, m68hc11 `regs' command deprecated
3354 The `info registers' command has been updated so that it displays the
3355 registers using a format identical to the old `regs' command.
3359 A new command, "maint set profile on/off", has been added. This command can
3360 be used to enable or disable profiling while running GDB, to profile a
3361 session or a set of commands. In addition there is a new configure switch,
3362 "--enable-profiling", which will cause GDB to be compiled with profiling
3363 data, for more informative profiling results.
3365 * Default MI syntax changed to "mi2".
3367 The default MI (machine interface) syntax, enabled by the command line
3368 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3369 "mi1", can be enabled by specifying the option "-i=mi1".
3371 Support for the original "mi0" syntax (included in GDB 5.0) has been
3374 Fix for gdb/192: removed extraneous space when displaying frame level.
3375 Fix for gdb/672: update changelist is now output in mi list format.
3376 Fix for gdb/702: a -var-assign that updates the value now shows up
3377 in a subsequent -var-update.
3379 * New native configurations.
3381 FreeBSD/amd64 x86_64-*-freebsd*
3383 * Multi-arched targets.
3385 HP/PA HPUX11 hppa*-*-hpux*
3386 Renesas M32R/D w/simulator m32r-*-elf*
3388 * OBSOLETE configurations and files
3390 Configurations that have been declared obsolete in this release have
3391 been commented out. Unless there is activity to revive these
3392 configurations, the next release of GDB will have their sources
3393 permanently REMOVED.
3395 Z8000 simulator z8k-zilog-none or z8ksim
3396 Matsushita MN10200 w/simulator mn10200-*-*
3397 H8/500 simulator h8500-hitachi-hms or h8500hms
3398 HP/PA running BSD hppa*-*-bsd*
3399 HP/PA running OSF/1 hppa*-*-osf*
3400 HP/PA Pro target hppa*-*-pro*
3401 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3402 Sequent family i[3456]86-sequent-sysv4*
3403 i[3456]86-sequent-sysv*
3404 i[3456]86-sequent-bsd*
3405 Tsqware Sparclet sparclet-*-*
3406 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3408 * REMOVED configurations and files
3411 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3412 IBM AIX PS/2 i[3456]86-*-aix
3413 i386 running Mach 3.0 i[3456]86-*-mach3*
3414 i386 running Mach i[3456]86-*-mach*
3415 i386 running OSF/1 i[3456]86-*osf1mk*
3416 HP/Apollo 68k Family m68*-apollo*-sysv*,
3418 m68*-hp-bsd*, m68*-hp-hpux*
3419 Argonaut Risc Chip (ARC) arc-*-*
3420 Mitsubishi D30V d30v-*-*
3421 Fujitsu FR30 fr30-*-elf*
3422 OS/9000 i[34]86-*-os9k
3423 I960 with MON960 i960-*-coff
3425 * MIPS $fp behavior changed
3427 The convenience variable $fp, for the MIPS, now consistently returns
3428 the address of the current frame's base. Previously, depending on the
3429 context, $fp could refer to either $sp or the current frame's base
3430 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3431 The GNU Source-Level Debugger''.
3433 *** Changes in GDB 5.3:
3435 * GNU/Linux shared library multi-threaded performance improved.
3437 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3438 `/proc', in preference to `ptrace' for memory reads. This may result
3439 in an improvement in the start-up time of multi-threaded, shared
3440 library applications when run under GDB. One GDB user writes: ``loads
3441 shared libs like mad''.
3443 * ``gdbserver'' now supports multi-threaded applications on some targets
3445 Support for debugging multi-threaded applications which use
3446 the GNU/Linux LinuxThreads package has been added for
3447 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3448 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3450 * GDB now supports C/C++ preprocessor macros.
3452 GDB now expands preprocessor macro invocations in C/C++ expressions,
3453 and provides various commands for showing macro definitions and how
3456 The new command `macro expand EXPRESSION' expands any macro
3457 invocations in expression, and shows the result.
3459 The new command `show macro MACRO-NAME' shows the definition of the
3460 macro named MACRO-NAME, and where it was defined.
3462 Most compilers don't include information about macros in the debugging
3463 information by default. In GCC 3.1, for example, you need to compile
3464 your program with the options `-gdwarf-2 -g3'. If the macro
3465 information is present in the executable, GDB will read it.
3467 * Multi-arched targets.
3469 DEC Alpha (partial) alpha*-*-*
3470 DEC VAX (partial) vax-*-*
3472 National Semiconductor NS32000 (partial) ns32k-*-*
3473 Motorola 68000 (partial) m68k-*-*
3474 Motorola MCORE mcore-*-*
3478 Fujitsu FRV architecture added by Red Hat frv*-*-*
3481 * New native configurations
3483 Alpha NetBSD alpha*-*-netbsd*
3484 SH NetBSD sh*-*-netbsdelf*
3485 MIPS NetBSD mips*-*-netbsd*
3486 UltraSPARC NetBSD sparc64-*-netbsd*
3488 * OBSOLETE configurations and files
3490 Configurations that have been declared obsolete in this release have
3491 been commented out. Unless there is activity to revive these
3492 configurations, the next release of GDB will have their sources
3493 permanently REMOVED.
3495 Mitsubishi D30V d30v-*-*
3496 OS/9000 i[34]86-*-os9k
3497 IBM AIX PS/2 i[3456]86-*-aix
3498 Fujitsu FR30 fr30-*-elf*
3499 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3500 Argonaut Risc Chip (ARC) arc-*-*
3501 i386 running Mach 3.0 i[3456]86-*-mach3*
3502 i386 running Mach i[3456]86-*-mach*
3503 i386 running OSF/1 i[3456]86-*osf1mk*
3504 HP/Apollo 68k Family m68*-apollo*-sysv*,
3506 m68*-hp-bsd*, m68*-hp-hpux*
3507 I960 with MON960 i960-*-coff
3509 * OBSOLETE languages
3511 CHILL, a Pascal like language used by telecommunications companies.
3513 * REMOVED configurations and files
3515 AMD 29k family via UDI a29k-amd-udi, udi29k
3516 A29K VxWorks a29k-*-vxworks
3517 AMD 29000 embedded, using EBMON a29k-none-none
3518 AMD 29000 embedded with COFF a29k-none-coff
3519 AMD 29000 embedded with a.out a29k-none-aout
3521 testsuite/gdb.hp/gdb.threads-hp/ directory
3523 * New command "set max-user-call-depth <nnn>"
3525 This command allows the user to limit the call depth of user-defined
3526 commands. The default is 1024.
3528 * Changes in FreeBSD/i386 native debugging.
3530 Support for the "generate-core-file" has been added.
3532 * New commands "dump", "append", and "restore".
3534 These commands allow data to be copied from target memory
3535 to a bfd-format or binary file (dump and append), and back
3536 from a file into memory (restore).
3538 * Improved "next/step" support on multi-processor Alpha Tru64.
3540 The previous single-step mechanism could cause unpredictable problems,
3541 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3542 of a software single-step mechanism prevents this.
3544 *** Changes in GDB 5.2.1:
3552 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3553 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3554 Fix, by Joel Brobecker imported from mainline.
3556 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3557 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3558 Fix, by Fred Fish, imported from mainline.
3560 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3561 Surprisingly enough, it works now.
3562 By Michal Ludvig, imported from mainline.
3564 i386 hardware watchpoint support:
3565 avoid misses on second run for some targets.
3566 By Pierre Muller, imported from mainline.
3568 *** Changes in GDB 5.2:
3570 * New command "set trust-readonly-sections on[off]".
3572 This command is a hint that tells gdb that read-only sections
3573 really are read-only (ie. that their contents will not change).
3574 In this mode, gdb will go to the object file rather than the
3575 target to read memory from read-only sections (such as ".text").
3576 This can be a significant performance improvement on some
3577 (notably embedded) targets.
3579 * New command "generate-core-file" (or "gcore").
3581 This new gdb command allows the user to drop a core file of the child
3582 process state at any time. So far it's been implemented only for
3583 GNU/Linux and Solaris, but should be relatively easily ported to other
3584 hosts. Argument is core file name (defaults to core.<pid>).
3586 * New command line option
3588 GDB now accepts --pid or -p followed by a process id.
3590 * Change in command line behavior -- corefiles vs. process ids.
3592 There is a subtle behavior in the way in which GDB handles
3593 command line arguments. The first non-flag argument is always
3594 a program to debug, but the second non-flag argument may either
3595 be a corefile or a process id. Previously, GDB would attempt to
3596 open the second argument as a corefile, and if that failed, would
3597 issue a superfluous error message and then attempt to attach it as
3598 a process. Now, if the second argument begins with a non-digit,
3599 it will be treated as a corefile. If it begins with a digit,
3600 GDB will attempt to attach it as a process, and if no such process
3601 is found, will then attempt to open it as a corefile.
3603 * Changes in ARM configurations.
3605 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3606 configuration is fully multi-arch.
3608 * New native configurations
3610 ARM NetBSD arm*-*-netbsd*
3611 x86 OpenBSD i[3456]86-*-openbsd*
3612 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3613 Sparc64 running FreeBSD sparc64-*-freebsd*
3617 Sanyo XStormy16 xstormy16-elf
3619 * OBSOLETE configurations and files
3621 Configurations that have been declared obsolete in this release have
3622 been commented out. Unless there is activity to revive these
3623 configurations, the next release of GDB will have their sources
3624 permanently REMOVED.
3626 AMD 29k family via UDI a29k-amd-udi, udi29k
3627 A29K VxWorks a29k-*-vxworks
3628 AMD 29000 embedded, using EBMON a29k-none-none
3629 AMD 29000 embedded with COFF a29k-none-coff
3630 AMD 29000 embedded with a.out a29k-none-aout
3632 testsuite/gdb.hp/gdb.threads-hp/ directory
3634 * REMOVED configurations and files
3636 TI TMS320C80 tic80-*-*
3638 PowerPC Solaris powerpcle-*-solaris*
3639 PowerPC Windows NT powerpcle-*-cygwin32
3640 PowerPC Netware powerpc-*-netware*
3641 Harris/CXUX m88k m88*-harris-cxux*
3642 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3643 ns32k-utek-sysv* ns32k-utek-*
3644 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3645 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3646 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3647 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3648 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3650 * Changes to command line processing
3652 The new `--args' feature can be used to specify command-line arguments
3653 for the inferior from gdb's command line.
3655 * Changes to key bindings
3657 There is a new `operate-and-get-next' function bound to `C-o'.
3659 *** Changes in GDB 5.1.1
3661 Fix compile problem on DJGPP.
3663 Fix a problem with floating-point registers on the i386 being
3666 Fix to stop GDB crashing on .debug_str debug info.
3668 Numerous documentation fixes.
3670 Numerous testsuite fixes.
3672 *** Changes in GDB 5.1:
3674 * New native configurations
3676 Alpha FreeBSD alpha*-*-freebsd*
3677 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3678 MIPS GNU/Linux mips*-*-linux*
3679 MIPS SGI Irix 6.x mips*-sgi-irix6*
3680 ia64 AIX ia64-*-aix*
3681 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3685 Motorola 68HC11 and 68HC12 m68hc11-elf
3687 UltraSparc running GNU/Linux sparc64-*-linux*
3689 * OBSOLETE configurations and files
3691 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3692 Harris/CXUX m88k m88*-harris-cxux*
3693 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3694 ns32k-utek-sysv* ns32k-utek-*
3695 TI TMS320C80 tic80-*-*
3697 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3698 PowerPC Solaris powerpcle-*-solaris*
3699 PowerPC Windows NT powerpcle-*-cygwin32
3700 PowerPC Netware powerpc-*-netware*
3701 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3702 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3703 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3704 Apple Macintosh (MPW) host N/A
3706 stuff.c (Program to stuff files into a specially prepared space in kdb)
3707 kdb-start.c (Main loop for the standalone kernel debugger)
3709 Configurations that have been declared obsolete in this release have
3710 been commented out. Unless there is activity to revive these
3711 configurations, the next release of GDB will have their sources
3712 permanently REMOVED.
3714 * REMOVED configurations and files
3716 Altos 3068 m68*-altos-*
3717 Convex c1-*-*, c2-*-*
3719 ARM RISCix arm-*-* (as host)
3723 * GDB has been converted to ISO C.
3725 GDB's source code has been converted to ISO C. In particular, the
3726 sources are fully protoized, and rely on standard headers being
3731 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3733 * The MI enabled by default.
3735 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3736 revised and enabled by default. Packages which use GDB as a debugging
3737 engine behind a UI or another front end are encouraged to switch to
3738 using the GDB/MI interface, instead of the old annotations interface
3739 which is now deprecated.
3741 * Support for debugging Pascal programs.
3743 GDB now includes support for debugging Pascal programs. The following
3744 main features are supported:
3746 - Pascal-specific data types such as sets;
3748 - automatic recognition of Pascal sources based on file-name
3751 - Pascal-style display of data types, variables, and functions;
3753 - a Pascal expression parser.
3755 However, some important features are not yet supported.
3757 - Pascal string operations are not supported at all;
3759 - there are some problems with boolean types;
3761 - Pascal type hexadecimal constants are not supported
3762 because they conflict with the internal variables format;
3764 - support for Pascal objects and classes is not full yet;
3766 - unlike Pascal, GDB is case-sensitive for symbol names.
3768 * Changes in completion.
3770 Commands such as `shell', `run' and `set args', which pass arguments
3771 to inferior programs, now complete on file names, similar to what
3772 users expect at the shell prompt.
3774 Commands which accept locations, such as `disassemble', `print',
3775 `breakpoint', `until', etc. now complete on filenames as well as
3776 program symbols. Thus, if you type "break foob TAB", and the source
3777 files linked into the programs include `foobar.c', that file name will
3778 be one of the candidates for completion. However, file names are not
3779 considered for completion after you typed a colon that delimits a file
3780 name from a name of a function in that file, as in "break foo.c:bar".
3782 `set demangle-style' completes on available demangling styles.
3784 * New platform-independent commands:
3786 It is now possible to define a post-hook for a command as well as a
3787 hook that runs before the command. For more details, see the
3788 documentation of `hookpost' in the GDB manual.
3790 * Changes in GNU/Linux native debugging.
3792 Support for debugging multi-threaded programs has been completely
3793 revised for all platforms except m68k and sparc. You can now debug as
3794 many threads as your system allows you to have.
3796 Attach/detach is supported for multi-threaded programs.
3798 Support for SSE registers was added for x86. This doesn't work for
3799 multi-threaded programs though.
3801 * Changes in MIPS configurations.
3803 Multi-arch support is enabled for all MIPS configurations.
3805 GDB can now be built as native debugger on SGI Irix 6.x systems for
3806 debugging n32 executables. (Debugging 64-bit executables is not yet
3809 * Unified support for hardware watchpoints in all x86 configurations.
3811 Most (if not all) native x86 configurations support hardware-assisted
3812 breakpoints and watchpoints in a unified manner. This support
3813 implements debug register sharing between watchpoints, which allows to
3814 put a virtually infinite number of watchpoints on the same address,
3815 and also supports watching regions up to 16 bytes with several debug
3818 The new maintenance command `maintenance show-debug-regs' toggles
3819 debugging print-outs in functions that insert, remove, and test
3820 watchpoints and hardware breakpoints.
3822 * Changes in the DJGPP native configuration.
3824 New command ``info dos sysinfo'' displays assorted information about
3825 the CPU, OS, memory, and DPMI server.
3827 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3828 display information about segment descriptors stored in GDT, LDT, and
3831 New commands ``info dos pde'' and ``info dos pte'' display entries
3832 from Page Directory and Page Tables (for now works with CWSDPMI only).
3833 New command ``info dos address-pte'' displays the Page Table entry for
3834 a given linear address.
3836 GDB can now pass command lines longer than 126 characters to the
3837 program being debugged (requires an update to the libdbg.a library
3838 which is part of the DJGPP development kit).
3840 DWARF2 debug info is now supported.
3842 It is now possible to `step' and `next' through calls to `longjmp'.
3844 * Changes in documentation.
3846 All GDB documentation was converted to GFDL, the GNU Free
3847 Documentation License.
3849 Tracepoints-related commands are now fully documented in the GDB
3852 TUI, the Text-mode User Interface, is now documented in the manual.
3854 Tracepoints-related commands are now fully documented in the GDB
3857 The "GDB Internals" manual now has an index. It also includes
3858 documentation of `ui_out' functions, GDB coding standards, x86
3859 hardware watchpoints, and memory region attributes.
3861 * GDB's version number moved to ``version.in''
3863 The Makefile variable VERSION has been replaced by the file
3864 ``version.in''. People creating GDB distributions should update the
3865 contents of this file.
3869 GUD support is now a standard part of the EMACS distribution.
3871 *** Changes in GDB 5.0:
3873 * Improved support for debugging FP programs on x86 targets
3875 Unified and much-improved support for debugging floating-point
3876 programs on all x86 targets. In particular, ``info float'' now
3877 displays the FP registers in the same format on all x86 targets, with
3878 greater level of detail.
3880 * Improvements and bugfixes in hardware-assisted watchpoints
3882 It is now possible to watch array elements, struct members, and
3883 bitfields with hardware-assisted watchpoints. Data-read watchpoints
3884 on x86 targets no longer erroneously trigger when the address is
3887 * Improvements in the native DJGPP version of GDB
3889 The distribution now includes all the scripts and auxiliary files
3890 necessary to build the native DJGPP version on MS-DOS/MS-Windows
3891 machines ``out of the box''.
3893 The DJGPP version can now debug programs that use signals. It is
3894 possible to catch signals that happened in the debuggee, deliver
3895 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
3896 would kill the program being debugged.) Programs that hook hardware
3897 interrupts (keyboard, timer, etc.) can also be debugged.
3899 It is now possible to debug DJGPP programs that redirect their
3900 standard handles or switch them to raw (as opposed to cooked) mode, or
3901 even close them. The command ``run < foo > bar'' works as expected,
3902 and ``info terminal'' reports useful information about the debuggee's
3903 terminal, including raw/cooked mode, redirection, etc.
3905 The DJGPP version now uses termios functions for console I/O, which
3906 enables debugging graphics programs. Interrupting GDB with Ctrl-C
3909 DOS-style file names with drive letters are now fully supported by
3912 It is now possible to debug DJGPP programs that switch their working
3913 directory. It is also possible to rerun the debuggee any number of
3914 times without restarting GDB; thus, you can use the same setup,
3915 breakpoints, etc. for many debugging sessions.
3917 * New native configurations
3919 ARM GNU/Linux arm*-*-linux*
3920 PowerPC GNU/Linux powerpc-*-linux*
3924 Motorola MCore mcore-*-*
3925 x86 VxWorks i[3456]86-*-vxworks*
3926 PowerPC VxWorks powerpc-*-vxworks*
3927 TI TMS320C80 tic80-*-*
3929 * OBSOLETE configurations
3931 Altos 3068 m68*-altos-*
3932 Convex c1-*-*, c2-*-*
3934 ARM RISCix arm-*-* (as host)
3937 Configurations that have been declared obsolete will be commented out,
3938 but the code will be left in place. If there is no activity to revive
3939 these configurations before the next release of GDB, the sources will
3940 be permanently REMOVED.
3942 * Gould support removed
3944 Support for the Gould PowerNode and NP1 has been removed.
3946 * New features for SVR4
3948 On SVR4 native platforms (such as Solaris), if you attach to a process
3949 without first loading a symbol file, GDB will now attempt to locate and
3950 load symbols from the running process's executable file.
3952 * Many C++ enhancements
3954 C++ support has been greatly improved. Overload resolution now works properly
3955 in almost all cases. RTTI support is on the way.
3957 * Remote targets can connect to a sub-program
3959 A popen(3) style serial-device has been added. This device starts a
3960 sub-process (such as a stand-alone simulator) and then communicates
3961 with that. The sub-program to run is specified using the syntax
3962 ``|<program> <args>'' vis:
3964 (gdb) set remotedebug 1
3965 (gdb) target extended-remote |mn10300-elf-sim program-args
3967 * MIPS 64 remote protocol
3969 A long standing bug in the mips64 remote protocol where by GDB
3970 expected certain 32 bit registers (ex SR) to be transfered as 32
3971 instead of 64 bits has been fixed.
3973 The command ``set remote-mips64-transfers-32bit-regs on'' has been
3974 added to provide backward compatibility with older versions of GDB.
3976 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
3978 The command ``set remotebinarydownload'' command has been replaced by
3979 ``set remote X-packet''. Other commands in ``set remote'' family
3980 include ``set remote P-packet''.
3982 * Breakpoint commands accept ranges.
3984 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
3985 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
3986 ``tracepoint passcount'' also accepts a range of tracepoints.
3988 * ``apropos'' command added.
3990 The ``apropos'' command searches through command names and
3991 documentation strings, printing out matches, making it much easier to
3992 try to find a command that does what you are looking for.
3996 A new machine oriented interface (MI) has been added to GDB. This
3997 interface is designed for debug environments running GDB as a separate
3998 process. This is part of the long term libGDB project. See the
3999 "GDB/MI" chapter of the GDB manual for further information. It can be
4000 enabled by configuring with:
4002 .../configure --enable-gdbmi
4004 *** Changes in GDB-4.18:
4006 * New native configurations
4008 HP-UX 10.20 hppa*-*-hpux10.20
4009 HP-UX 11.x hppa*-*-hpux11.0*
4010 M68K GNU/Linux m68*-*-linux*
4014 Fujitsu FR30 fr30-*-elf*
4015 Intel StrongARM strongarm-*-*
4016 Mitsubishi D30V d30v-*-*
4018 * OBSOLETE configurations
4020 Gould PowerNode, NP1 np1-*-*, pn-*-*
4022 Configurations that have been declared obsolete will be commented out,
4023 but the code will be left in place. If there is no activity to revive
4024 these configurations before the next release of GDB, the sources will
4025 be permanently REMOVED.
4029 As a compatibility experiment, GDB's source files buildsym.h and
4030 buildsym.c have been converted to pure standard C, no longer
4031 containing any K&R compatibility code. We believe that all systems in
4032 use today either come with a standard C compiler, or have a GCC port
4033 available. If this is not true, please report the affected
4034 configuration to bug-gdb@gnu.org immediately. See the README file for
4035 information about getting a standard C compiler if you don't have one
4040 GDB now uses readline 2.2.
4042 * set extension-language
4044 You can now control the mapping between filename extensions and source
4045 languages by using the `set extension-language' command. For instance,
4046 you can ask GDB to treat .c files as C++ by saying
4047 set extension-language .c c++
4048 The command `info extensions' lists all of the recognized extensions
4049 and their associated languages.
4051 * Setting processor type for PowerPC and RS/6000
4053 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4054 you can use the `set processor' command to specify what variant of the
4055 PowerPC family you are debugging. The command
4059 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4060 following PowerPC and RS6000 variants:
4062 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4063 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4065 403GC IBM PowerPC 403GC
4066 505 Motorola PowerPC 505
4067 860 Motorola PowerPC 860 or 850
4068 601 Motorola PowerPC 601
4069 602 Motorola PowerPC 602
4070 603 Motorola/IBM PowerPC 603 or 603e
4071 604 Motorola PowerPC 604 or 604e
4072 750 Motorola/IBM PowerPC 750 or 750
4074 At the moment, this command just tells GDB what to name the
4075 special-purpose processor registers. Since almost all the affected
4076 registers are inaccessible to user-level programs, this command is
4077 only useful for remote debugging in its present form.
4081 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4082 more extensive support for HP-UX. Added features include shared
4083 library support, kernel threads and hardware watchpoints for 11.00,
4084 support for HP's ANSI C and C++ compilers, and a compatibility mode
4085 for xdb and dbx commands.
4089 HP's donation includes the new concept of catchpoints, which is a
4090 generalization of the old catch command. On HP-UX, it is now possible
4091 to catch exec, fork, and vfork, as well as library loading.
4093 This means that the existing catch command has changed; its first
4094 argument now specifies the type of catch to be set up. See the
4095 output of "help catch" for a list of catchpoint types.
4097 * Debugging across forks
4099 On HP-UX, you can choose which process to debug when a fork() happens
4104 HP has donated a curses-based terminal user interface (TUI). To get
4105 it, build with --enable-tui. Although this can be enabled for any
4106 configuration, at present it only works for native HP debugging.
4108 * GDB remote protocol additions
4110 A new protocol packet 'X' that writes binary data is now available.
4111 Default behavior is to try 'X', then drop back to 'M' if the stub
4112 fails to respond. The settable variable `remotebinarydownload'
4113 allows explicit control over the use of 'X'.
4115 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4116 full 64-bit address. The command
4118 set remoteaddresssize 32
4120 can be used to revert to the old behaviour. For existing remote stubs
4121 the change should not be noticed, as the additional address information
4124 In order to assist in debugging stubs, you may use the maintenance
4125 command `packet' to send any text string to the stub. For instance,
4127 maint packet heythere
4129 sends the packet "$heythere#<checksum>". Note that it is very easy to
4130 disrupt a debugging session by sending the wrong packet at the wrong
4133 The compare-sections command allows you to compare section data on the
4134 target to what is in the executable file without uploading or
4135 downloading, by comparing CRC checksums.
4137 * Tracing can collect general expressions
4139 You may now collect general expressions at tracepoints. This requires
4140 further additions to the target-side stub; see tracepoint.c and
4141 doc/agentexpr.texi for further details.
4143 * mask-address variable for Mips
4145 For Mips targets, you may control the zeroing of the upper 32 bits of
4146 a 64-bit address by entering `set mask-address on'. This is mainly
4147 of interest to users of embedded R4xxx and R5xxx processors.
4149 * Higher serial baud rates
4151 GDB's serial code now allows you to specify baud rates 57600, 115200,
4152 230400, and 460800 baud. (Note that your host system may not be able
4153 to achieve all of these rates.)
4157 The i960 configuration now includes an initial implementation of a
4158 builtin simulator, contributed by Jim Wilson.
4161 *** Changes in GDB-4.17:
4163 * New native configurations
4165 Alpha GNU/Linux alpha*-*-linux*
4166 Unixware 2.x i[3456]86-unixware2*
4167 Irix 6.x mips*-sgi-irix6*
4168 PowerPC GNU/Linux powerpc-*-linux*
4169 PowerPC Solaris powerpcle-*-solaris*
4170 Sparc GNU/Linux sparc-*-linux*
4171 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4175 Argonaut Risc Chip (ARC) arc-*-*
4176 Hitachi H8/300S h8300*-*-*
4177 Matsushita MN10200 w/simulator mn10200-*-*
4178 Matsushita MN10300 w/simulator mn10300-*-*
4179 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4180 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4181 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4182 Mitsubishi D10V w/simulator d10v-*-*
4183 Mitsubishi M32R/D w/simulator m32r-*-elf*
4184 Tsqware Sparclet sparclet-*-*
4185 NEC V850 w/simulator v850-*-*
4187 * New debugging protocols
4189 ARM with RDI protocol arm*-*-*
4190 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4191 DDB and LSI variants of PMON protocol mips*-*-*
4192 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4193 PowerPC with SDS protocol powerpc{,le}-*-eabi
4194 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4198 All configurations can now understand and use the DWARF 2 debugging
4199 format. The choice is automatic, if the symbol file contains DWARF 2
4204 GDB now includes basic Java language support. This support is
4205 only useful with Java compilers that produce native machine code.
4207 * solib-absolute-prefix and solib-search-path
4209 For SunOS and SVR4 shared libraries, you may now set the prefix for
4210 loading absolute shared library symbol files, and the search path for
4211 locating non-absolute shared library symbol files.
4213 * Live range splitting
4215 GDB can now effectively debug code for which GCC has performed live
4216 range splitting as part of its optimization. See gdb/doc/LRS for
4217 more details on the expected format of the stabs information.
4221 GDB's support for the GNU Hurd, including thread debugging, has been
4222 updated to work with current versions of the Hurd.
4226 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4227 instruction set. ARM GDB automatically detects when Thumb
4228 instructions are in use, and adjusts disassembly and backtracing
4233 GDB's MIPS target configurations now handle the MIP16 16-bit
4238 GDB now includes support for overlays; if an executable has been
4239 linked such that multiple sections are based at the same address, GDB
4240 will decide which section to use for symbolic info. You can choose to
4241 control the decision manually, using overlay commands, or implement
4242 additional target-side support and use "overlay load-target" to bring
4243 in the overlay mapping. Do "help overlay" for more detail.
4247 The command "info symbol <address>" displays information about
4248 the symbol at the specified address.
4252 The standard remote protocol now includes an extension that allows
4253 asynchronous collection and display of trace data. This requires
4254 extensive support in the target-side debugging stub. Tracing mode
4255 includes a new interaction mode in GDB and new commands: see the
4256 file tracepoint.c for more details.
4260 Configurations for embedded MIPS now include a simulator contributed
4261 by Cygnus Solutions. The simulator supports the instruction sets
4262 of most MIPS variants.
4266 Sparc configurations may now include the ERC32 simulator contributed
4267 by the European Space Agency. The simulator is not built into
4268 Sparc targets by default; configure with --enable-sim to include it.
4272 For target configurations that may include multiple variants of a
4273 basic architecture (such as MIPS and SH), you may now set the
4274 architecture explicitly. "set arch" sets, "info arch" lists
4275 the possible architectures.
4277 *** Changes in GDB-4.16:
4279 * New native configurations
4281 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4282 M68K NetBSD m68k-*-netbsd*
4283 PowerPC AIX 4.x powerpc-*-aix*
4284 PowerPC MacOS powerpc-*-macos*
4285 PowerPC Windows NT powerpcle-*-cygwin32
4286 RS/6000 AIX 4.x rs6000-*-aix4*
4290 ARM with RDP protocol arm-*-*
4291 I960 with MON960 i960-*-coff
4292 MIPS VxWorks mips*-*-vxworks*
4293 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4294 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4296 Matra Sparclet sparclet-*-*
4300 The powerpc-eabi configuration now includes the PSIM simulator,
4301 contributed by Andrew Cagney, with assistance from Mike Meissner.
4302 PSIM is a very elaborate model of the PowerPC, including not only
4303 basic instruction set execution, but also details of execution unit
4304 performance and I/O hardware. See sim/ppc/README for more details.
4308 GDB now works with Solaris 2.5.
4310 * Windows 95/NT native
4312 GDB will now work as a native debugger on Windows 95 and Windows NT.
4313 To build it from source, you must use the "gnu-win32" environment,
4314 which uses a DLL to emulate enough of Unix to run the GNU tools.
4315 Further information, binaries, and sources are available at
4316 ftp.cygnus.com, under pub/gnu-win32.
4318 * dont-repeat command
4320 If a user-defined command includes the command `dont-repeat', then the
4321 command will not be repeated if the user just types return. This is
4322 useful if the command is time-consuming to run, so that accidental
4323 extra keystrokes don't run the same command many times.
4325 * Send break instead of ^C
4327 The standard remote protocol now includes an option to send a break
4328 rather than a ^C to the target in order to interrupt it. By default,
4329 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4331 * Remote protocol timeout
4333 The standard remote protocol includes a new variable `remotetimeout'
4334 that allows you to set the number of seconds before GDB gives up trying
4335 to read from the target. The default value is 2.
4337 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4339 By default GDB will automatically keep track of objects as they are
4340 loaded and unloaded by the dynamic linker. By using the command `set
4341 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4342 when shared library events occur, thus allowing you to set breakpoints
4343 in shared libraries which are explicitly loaded by the inferior.
4345 Note this feature does not work on hpux8. On hpux9 you must link
4346 /usr/lib/end.o into your program. This feature should work
4347 automatically on hpux10.
4349 * Irix 5.x hardware watchpoint support
4351 Irix 5 configurations now support the use of hardware watchpoints.
4353 * Mips protocol "SYN garbage limit"
4355 When debugging a Mips target using the `target mips' protocol, you
4356 may set the number of characters that GDB will ignore by setting
4357 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4358 every character. The default value is 1050.
4360 * Recording and replaying remote debug sessions
4362 If you set `remotelogfile' to the name of a file, gdb will write to it
4363 a recording of a remote debug session. This recording may then be
4364 replayed back to gdb using "gdbreplay". See gdbserver/README for
4365 details. This is useful when you have a problem with GDB while doing
4366 remote debugging; you can make a recording of the session and send it
4367 to someone else, who can then recreate the problem.
4369 * Speedups for remote debugging
4371 GDB includes speedups for downloading and stepping MIPS systems using
4372 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4373 and more efficient S-record downloading.
4375 * Memory use reductions and statistics collection
4377 GDB now uses less memory and reports statistics about memory usage.
4378 Try the `maint print statistics' command, for example.
4380 *** Changes in GDB-4.15:
4382 * Psymtabs for XCOFF
4384 The symbol reader for AIX GDB now uses partial symbol tables. This
4385 can greatly improve startup time, especially for large executables.
4387 * Remote targets use caching
4389 Remote targets now use a data cache to speed up communication with the
4390 remote side. The data cache could lead to incorrect results because
4391 it doesn't know about volatile variables, thus making it impossible to
4392 debug targets which use memory mapped I/O devices. `set remotecache
4393 off' turns the the data cache off.
4395 * Remote targets may have threads
4397 The standard remote protocol now includes support for multiple threads
4398 in the target system, using new protocol commands 'H' and 'T'. See
4399 gdb/remote.c for details.
4403 If GDB is configured with `--enable-netrom', then it will include
4404 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4405 acts as though it is a bank of ROM on the target board, but you can
4406 write into it over the network. GDB's support consists only of
4407 support for fast loading into the emulated ROM; to debug, you must use
4408 another protocol, such as standard remote protocol. The usual
4409 sequence is something like
4411 target nrom <netrom-hostname>
4413 target remote <netrom-hostname>:1235
4417 GDB now includes support for the Apple Macintosh, as a host only. It
4418 may be run as either an MPW tool or as a standalone application, and
4419 it can debug through the serial port. All the usual GDB commands are
4420 available, but to the target command, you must supply "serial" as the
4421 device type instead of "/dev/ttyXX". See mpw-README in the main
4422 directory for more information on how to build. The MPW configuration
4423 scripts */mpw-config.in support only a few targets, and only the
4424 mips-idt-ecoff target has been tested.
4428 GDB configuration now uses autoconf. This is not user-visible,
4429 but does simplify configuration and building.
4433 GDB now supports hpux10.
4435 *** Changes in GDB-4.14:
4437 * New native configurations
4439 x86 FreeBSD i[345]86-*-freebsd
4440 x86 NetBSD i[345]86-*-netbsd
4441 NS32k NetBSD ns32k-*-netbsd
4442 Sparc NetBSD sparc-*-netbsd
4446 A29K VxWorks a29k-*-vxworks
4447 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4448 CPU32 EST-300 emulator m68*-*-est*
4449 PowerPC ELF powerpc-*-elf
4452 * Alpha OSF/1 support for procfs
4454 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4455 possible to attach to running processes. As the mounting of the /proc
4456 filesystem is optional on the Alpha, GDB automatically determines
4457 the availability of /proc during startup. This can lead to problems
4458 if /proc is unmounted after GDB has been started.
4460 * Arguments to user-defined commands
4462 User commands may accept up to 10 arguments separated by whitespace.
4463 Arguments are accessed within the user command via $arg0..$arg9. A
4466 print $arg0 + $arg1 + $arg2
4468 To execute the command use:
4471 Defines the command "adder" which prints the sum of its three arguments.
4472 Note the arguments are text substitutions, so they may reference variables,
4473 use complex expressions, or even perform inferior function calls.
4475 * New `if' and `while' commands
4477 This makes it possible to write more sophisticated user-defined
4478 commands. Both commands take a single argument, which is the
4479 expression to evaluate, and must be followed by the commands to
4480 execute, one per line, if the expression is nonzero, the list being
4481 terminated by the word `end'. The `if' command list may include an
4482 `else' word, which causes the following commands to be executed only
4483 if the expression is zero.
4485 * Fortran source language mode
4487 GDB now includes partial support for Fortran 77. It will recognize
4488 Fortran programs and can evaluate a subset of Fortran expressions, but
4489 variables and functions may not be handled correctly. GDB will work
4490 with G77, but does not yet know much about symbols emitted by other
4493 * Better HPUX support
4495 Most debugging facilities now work on dynamic executables for HPPAs
4496 running hpux9 or later. You can attach to running dynamically linked
4497 processes, but by default the dynamic libraries will be read-only, so
4498 for instance you won't be able to put breakpoints in them. To change
4499 that behavior do the following before running the program:
4505 This will cause the libraries to be mapped private and read-write.
4506 To revert to the normal behavior, do this:
4512 You cannot set breakpoints or examine data in the library until after
4513 the library is loaded if the function/data symbols do not have
4516 GDB can now also read debug symbols produced by the HP C compiler on
4517 HPPAs (sorry, no C++, Fortran or 68k support).
4519 * Target byte order now dynamically selectable
4521 You can choose which byte order to use with a target system, via the
4522 commands "set endian big" and "set endian little", and you can see the
4523 current setting by using "show endian". You can also give the command
4524 "set endian auto", in which case GDB will use the byte order
4525 associated with the executable. Currently, only embedded MIPS
4526 configurations support dynamic selection of target byte order.
4528 * New DOS host serial code
4530 This version uses DPMI interrupts to handle buffered I/O, so you
4531 no longer need to run asynctsr when debugging boards connected to
4534 *** Changes in GDB-4.13:
4536 * New "complete" command
4538 This lists all the possible completions for the rest of the line, if it
4539 were to be given as a command itself. This is intended for use by emacs.
4541 * Trailing space optional in prompt
4543 "set prompt" no longer adds a space for you after the prompt you set. This
4544 allows you to set a prompt which ends in a space or one that does not.
4546 * Breakpoint hit counts
4548 "info break" now displays a count of the number of times the breakpoint
4549 has been hit. This is especially useful in conjunction with "ignore"; you
4550 can ignore a large number of breakpoint hits, look at the breakpoint info
4551 to see how many times the breakpoint was hit, then run again, ignoring one
4552 less than that number, and this will get you quickly to the last hit of
4555 * Ability to stop printing at NULL character
4557 "set print null-stop" will cause GDB to stop printing the characters of
4558 an array when the first NULL is encountered. This is useful when large
4559 arrays actually contain only short strings.
4561 * Shared library breakpoints
4563 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4564 breakpoints in shared libraries before the executable is run.
4566 * Hardware watchpoints
4568 There is a new hardware breakpoint for the watch command for sparclite
4569 targets. See gdb/sparclite/hw_breakpoint.note.
4571 Hardware watchpoints are also now supported under GNU/Linux.
4575 Annotations have been added. These are for use with graphical interfaces,
4576 and are still experimental. Currently only gdba.el uses these.
4578 * Improved Irix 5 support
4580 GDB now works properly with Irix 5.2.
4582 * Improved HPPA support
4584 GDB now works properly with the latest GCC and GAS.
4586 * New native configurations
4588 Sequent PTX4 i[34]86-sequent-ptx4
4589 HPPA running OSF/1 hppa*-*-osf*
4590 Atari TT running SVR4 m68*-*-sysv4*
4591 RS/6000 LynxOS rs6000-*-lynxos*
4595 OS/9000 i[34]86-*-os9k
4596 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4599 * Hitachi SH7000 and E7000-PC ICE support
4601 There is now support for communicating with the Hitachi E7000-PC ICE.
4602 This is available automatically when GDB is configured for the SH.
4606 As usual, a variety of small fixes and improvements, both generic
4607 and configuration-specific. See the ChangeLog for more detail.
4609 *** Changes in GDB-4.12:
4611 * Irix 5 is now supported
4615 GDB-4.12 on the HPPA has a number of changes which make it unable
4616 to debug the output from the currently released versions of GCC and
4617 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4618 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4619 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4622 *** Changes in GDB-4.11:
4624 * User visible changes:
4628 The "set remotedebug" option is now consistent between the mips remote
4629 target, remote targets using the gdb-specific protocol, UDI (AMD's
4630 debug protocol for the 29k) and the 88k bug monitor. It is now an
4631 integer specifying a debug level (normally 0 or 1, but 2 means more
4632 debugging info for the mips target).
4634 * DEC Alpha native support
4636 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4637 debug info, but GDB works fairly well with the DEC compiler and should
4638 work with a future GCC release. See the README file for a few
4639 Alpha-specific notes.
4641 * Preliminary thread implementation
4643 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4645 * LynxOS native and target support for 386
4647 This release has been hosted on LynxOS 2.2, and also can be configured
4648 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4651 * Improvements in C++ mangling/demangling.
4653 This release has much better g++ debugging, specifically in name
4654 mangling/demangling, virtual function calls, print virtual table,
4655 call methods, ...etc.
4657 *** Changes in GDB-4.10:
4659 * User visible changes:
4661 Remote debugging using the GDB-specific (`target remote') protocol now
4662 supports the `load' command. This is only useful if you have some
4663 other way of getting the stub to the target system, and you can put it
4664 somewhere in memory where it won't get clobbered by the download.
4666 Filename completion now works.
4668 When run under emacs mode, the "info line" command now causes the
4669 arrow to point to the line specified. Also, "info line" prints
4670 addresses in symbolic form (as well as hex).
4672 All vxworks based targets now support a user settable option, called
4673 vxworks-timeout. This option represents the number of seconds gdb
4674 should wait for responses to rpc's. You might want to use this if
4675 your vxworks target is, perhaps, a slow software simulator or happens
4676 to be on the far side of a thin network line.
4680 This release contains support for using a DEC alpha as a GDB host for
4681 cross debugging. Native alpha debugging is not supported yet.
4684 *** Changes in GDB-4.9:
4688 This is the first GDB release which is accompanied by a matching testsuite.
4689 The testsuite requires installation of dejagnu, which should be available
4690 via ftp from most sites that carry GNU software.
4694 'Cfront' style demangling has had its name changed to 'ARM' style, to
4695 emphasize that it was written from the specifications in the C++ Annotated
4696 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4697 disclaimers, it still generated too much confusion with users attempting to
4698 use gdb with AT&T cfront.
4702 GDB now uses a standard remote interface to a simulator library.
4703 So far, the library contains simulators for the Zilog Z8001/2, the
4704 Hitachi H8/300, H8/500 and Super-H.
4706 * New targets supported
4708 H8/300 simulator h8300-hitachi-hms or h8300hms
4709 H8/500 simulator h8500-hitachi-hms or h8500hms
4710 SH simulator sh-hitachi-hms or sh
4711 Z8000 simulator z8k-zilog-none or z8ksim
4712 IDT MIPS board over serial line mips-idt-ecoff
4714 Cross-debugging to GO32 targets is supported. It requires a custom
4715 version of the i386-stub.c module which is integrated with the
4716 GO32 memory extender.
4718 * New remote protocols
4720 MIPS remote debugging protocol.
4722 * New source languages supported
4724 This version includes preliminary support for Chill, a Pascal like language
4725 used by telecommunications companies. Chill support is also being integrated
4726 into the GNU compiler, but we don't know when it will be publically available.
4729 *** Changes in GDB-4.8:
4731 * HP Precision Architecture supported
4733 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4734 version of this support was available as a set of patches from the
4735 University of Utah. GDB does not support debugging of programs
4736 compiled with the HP compiler, because HP will not document their file
4737 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4738 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4740 Many problems in the preliminary version have been fixed.
4742 * Faster and better demangling
4744 We have improved template demangling and fixed numerous bugs in the GNU style
4745 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4746 character types (wchar_t) are now supported. Demangling of each symbol is now
4747 only done once, and is cached when the symbol table for a file is read in.
4748 This results in a small increase in memory usage for C programs, a moderate
4749 increase in memory usage for C++ programs, and a fantastic speedup in
4752 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4753 from the specifications in the Annotated Reference Manual, which AT&T's
4754 compiler does not actually implement.
4756 * G++ multiple inheritance compiler problem
4758 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4759 inheritance lattices was reworked to properly discover ambiguities. We
4760 recently found an example which causes this new algorithm to fail in a
4761 very subtle way, producing bad debug information for those classes.
4762 The file 'gcc.patch' (in this directory) can be applied to gcc to
4763 circumvent the problem. A future GCC release will contain a complete
4766 The previous G++ debug info problem (mentioned below for the gdb-4.7
4767 release) is fixed in gcc version 2.3.2.
4769 * Improved configure script
4771 The `configure' script will now attempt to guess your system type if
4772 you don't supply a host system type. The old scheme of supplying a
4773 host system triplet is preferable over using this. All the magic is
4774 done in the new `config.guess' script. Examine it for details.
4776 We have also brought our configure script much more in line with the FSF's
4777 version. It now supports the --with-xxx options. In particular,
4778 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4779 The resulting GDB will not be able to read arbitrary object file formats --
4780 only the format ``expected'' to be used on the configured target system.
4781 We hope to make this the default in a future release.
4783 * Documentation improvements
4785 There's new internal documentation on how to modify GDB, and how to
4786 produce clean changes to the code. We implore people to read it
4787 before submitting changes.
4789 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4790 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4791 `info' files are also provided. To build `info' files from scratch,
4792 you will need the latest `makeinfo' release, which will be available in
4793 a future texinfo-X.Y release.
4795 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4796 We're not sure exactly which versions have this problem, but it has
4797 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4798 or better. If that isn't possible, there is a patch in
4799 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4800 around this problem.
4804 GDB now supports array constants that can be used in expressions typed in by
4805 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4806 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4809 The new directory `gdb/sparclite' contains a program that demonstrates
4810 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4812 * New native hosts supported
4814 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4815 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4817 * New targets supported
4819 AMD 29k family via UDI a29k-amd-udi or udi29k
4821 * New file formats supported
4823 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4824 HPUX core files, and SCO 3.2v2 core files.
4828 Attaching to processes now works again; thanks for the many bug reports.
4830 We have also stomped on a bunch of core dumps caused by
4831 printf_filtered("%s") problems.
4833 We eliminated a copyright problem on the rpc and ptrace header files
4834 for VxWorks, which was discovered at the last minute during the 4.7
4835 release. You should now be able to build a VxWorks GDB.
4837 You can now interrupt gdb while an attached process is running. This
4838 will cause the attached process to stop, and give control back to GDB.
4840 We fixed problems caused by using too many file descriptors
4841 for reading symbols from object files and libraries. This was
4842 especially a problem for programs that used many (~100) shared
4845 The `step' command now only enters a subroutine if there is line number
4846 information for the subroutine. Otherwise it acts like the `next'
4847 command. Previously, `step' would enter subroutines if there was
4848 any debugging information about the routine. This avoids problems
4849 when using `cc -g1' on MIPS machines.
4851 * Internal improvements
4853 GDB's internal interfaces have been improved to make it easier to support
4854 debugging of multiple languages in the future.
4856 GDB now uses a common structure for symbol information internally.
4857 Minimal symbols (derived from linkage symbols in object files), partial
4858 symbols (from a quick scan of debug information), and full symbols
4859 contain a common subset of information, making it easier to write
4860 shared code that handles any of them.
4862 * New command line options
4864 We now accept --silent as an alias for --quiet.
4868 The memory-mapped-malloc library is now licensed under the GNU Library
4869 General Public License.
4871 *** Changes in GDB-4.7:
4873 * Host/native/target split
4875 GDB has had some major internal surgery to untangle the support for
4876 hosts and remote targets. Now, when you configure GDB for a remote
4877 target, it will no longer load in all of the support for debugging
4878 local programs on the host. When fully completed and tested, this will
4879 ensure that arbitrary host/target combinations are possible.
4881 The primary conceptual shift is to separate the non-portable code in
4882 GDB into three categories. Host specific code is required any time GDB
4883 is compiled on that host, regardless of the target. Target specific
4884 code relates to the peculiarities of the target, but can be compiled on
4885 any host. Native specific code is everything else: it can only be
4886 built when the host and target are the same system. Child process
4887 handling and core file support are two common `native' examples.
4889 GDB's use of /proc for controlling Unix child processes is now cleaner.
4890 It has been split out into a single module under the `target_ops' vector,
4891 plus two native-dependent functions for each system that uses /proc.
4893 * New hosts supported
4895 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
4896 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4897 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
4899 * New targets supported
4901 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4902 68030 and CPU32 m68030-*-*, m68332-*-*
4904 * New native hosts supported
4906 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4907 (386bsd is not well tested yet)
4908 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
4910 * New file formats supported
4912 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
4913 supports reading of `a.out.adobe' object files, which are an a.out
4914 format extended with minimal information about multiple sections.
4918 `show copying' is the same as the old `info copying'.
4919 `show warranty' is the same as `info warrantee'.
4920 These were renamed for consistency. The old commands continue to work.
4922 `info handle' is a new alias for `info signals'.
4924 You can now define pre-command hooks, which attach arbitrary command
4925 scripts to any command. The commands in the hook will be executed
4926 prior to the user's command. You can also create a hook which will be
4927 executed whenever the program stops. See gdb.texinfo.
4931 We now deal with Cfront style name mangling, and can even extract type
4932 info from mangled symbols. GDB can automatically figure out which
4933 symbol mangling style your C++ compiler uses.
4935 Calling of methods and virtual functions has been improved as well.
4939 The crash that occured when debugging Sun Ansi-C compiled binaries is
4940 fixed. This was due to mishandling of the extra N_SO stabs output
4943 We also finally got Ultrix 4.2 running in house, and fixed core file
4944 support, with help from a dozen people on the net.
4946 John M. Farrell discovered that the reason that single-stepping was so
4947 slow on all of the Mips based platforms (primarily SGI and DEC) was
4948 that we were trying to demangle and lookup a symbol used for internal
4949 purposes on every instruction that was being stepped through. Changing
4950 the name of that symbol so that it couldn't be mistaken for a C++
4951 mangled symbol sped things up a great deal.
4953 Rich Pixley sped up symbol lookups in general by getting much smarter
4954 about when C++ symbol mangling is necessary. This should make symbol
4955 completion (TAB on the command line) much faster. It's not as fast as
4956 we'd like, but it's significantly faster than gdb-4.6.
4960 A new user controllable variable 'call_scratch_address' can
4961 specify the location of a scratch area to be used when GDB
4962 calls a function in the target. This is necessary because the
4963 usual method of putting the scratch area on the stack does not work
4964 in systems that have separate instruction and data spaces.
4966 We integrated changes to support the 29k UDI (Universal Debugger
4967 Interface), but discovered at the last minute that we didn't have all
4968 of the appropriate copyright paperwork. We are working with AMD to
4969 resolve this, and hope to have it available soon.
4973 We have sped up the remote serial line protocol, especially for targets
4974 with lots of registers. It now supports a new `expedited status' ('T')
4975 message which can be used in place of the existing 'S' status message.
4976 This allows the remote stub to send only the registers that GDB
4977 needs to make a quick decision about single-stepping or conditional
4978 breakpoints, eliminating the need to fetch the entire register set for
4979 each instruction being stepped through.
4981 The GDB remote serial protocol now implements a write-through cache for
4982 registers, only re-reading the registers if the target has run.
4984 There is also a new remote serial stub for SPARC processors. You can
4985 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
4986 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
4987 processor with a serial port.
4991 Configure.in files have become much easier to read and modify. A new
4992 `table driven' format makes it more obvious what configurations are
4993 supported, and what files each one uses.
4997 There is a new opcodes library which will eventually contain all of the
4998 disassembly routines and opcode tables. At present, it only contains
4999 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5000 disassembler (binutils/objdump) to share these routines.
5002 The libiberty library is now copylefted under the GNU Library General
5003 Public License. This allows more liberal use, and was done so libg++
5004 can use it. This makes no difference to GDB, since the Library License
5005 grants all the rights from the General Public License.
5009 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5010 reference to the stabs symbol info used by the debugger. It is (as far
5011 as we know) the only published document on this fascinating topic. We
5012 encourage you to read it, compare it to the stabs information on your
5013 system, and send improvements on the document in general (to
5014 bug-gdb@prep.ai.mit.edu).
5016 And, of course, many bugs have been fixed.
5019 *** Changes in GDB-4.6:
5021 * Better support for C++ function names
5023 GDB now accepts as input the "demangled form" of C++ overloaded function
5024 names and member function names, and can do command completion on such names
5025 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5026 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5027 Make use of command completion, it is your friend.
5029 GDB also now accepts a variety of C++ mangled symbol formats. They are
5030 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5031 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5032 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5033 for the list of formats.
5035 * G++ symbol mangling problem
5037 Recent versions of gcc have a bug in how they emit debugging information for
5038 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5039 directory) can be applied to gcc to fix the problem. Alternatively, if you
5040 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5041 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5042 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5045 * New 'maintenance' command
5047 All of the commands related to hacking GDB internals have been moved out of
5048 the main command set, and now live behind the 'maintenance' command. This
5049 can also be abbreviated as 'mt'. The following changes were made:
5051 dump-me -> maintenance dump-me
5052 info all-breakpoints -> maintenance info breakpoints
5053 printmsyms -> maintenance print msyms
5054 printobjfiles -> maintenance print objfiles
5055 printpsyms -> maintenance print psymbols
5056 printsyms -> maintenance print symbols
5058 The following commands are new:
5060 maintenance demangle Call internal GDB demangler routine to
5061 demangle a C++ link name and prints the result.
5062 maintenance print type Print a type chain for a given symbol
5064 * Change to .gdbinit file processing
5066 We now read the $HOME/.gdbinit file before processing the argv arguments
5067 (e.g. reading symbol files or core files). This allows global parameters to
5068 be set, which will apply during the symbol reading. The ./.gdbinit is still
5069 read after argv processing.
5071 * New hosts supported
5073 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5075 GNU/Linux support i386-unknown-linux or linux
5077 We are also including code to support the HP/PA running BSD and HPUX. This
5078 is almost guaranteed not to work, as we didn't have time to test or build it
5079 for this release. We are including it so that the more adventurous (or
5080 masochistic) of you can play with it. We also had major problems with the
5081 fact that the compiler that we got from HP doesn't support the -g option.
5084 * New targets supported
5086 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5088 * More smarts about finding #include files
5090 GDB now remembers the compilation directory for all include files, and for
5091 all files from which C is generated (like yacc and lex sources). This
5092 greatly improves GDB's ability to find yacc/lex sources, and include files,
5093 especially if you are debugging your program from a directory different from
5094 the one that contains your sources.
5096 We also fixed a bug which caused difficulty with listing and setting
5097 breakpoints in include files which contain C code. (In the past, you had to
5098 try twice in order to list an include file that you hadn't looked at before.)
5100 * Interesting infernals change
5102 GDB now deals with arbitrary numbers of sections, where the symbols for each
5103 section must be relocated relative to that section's landing place in the
5104 target's address space. This work was needed to support ELF with embedded
5105 stabs used by Solaris-2.0.
5107 * Bug fixes (of course!)
5109 There have been loads of fixes for the following things:
5110 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5111 i960, stabs, DOS(GO32), procfs, etc...
5113 See the ChangeLog for details.
5115 *** Changes in GDB-4.5:
5117 * New machines supported (host and target)
5119 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5121 SGI Irix-4.x mips-sgi-irix4 or iris4
5123 * New malloc package
5125 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5126 Mmalloc is capable of handling mutiple heaps of memory. It is also
5127 capable of saving a heap to a file, and then mapping it back in later.
5128 This can be used to greatly speedup the startup of GDB by using a
5129 pre-parsed symbol table which lives in a mmalloc managed heap. For
5130 more details, please read mmalloc/mmalloc.texi.
5134 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5135 'help info proc' for details.
5137 * MIPS ecoff symbol table format
5139 The code that reads MIPS symbol table format is now supported on all hosts.
5140 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5143 * File name changes for MS-DOS
5145 Many files in the config directories have been renamed to make it easier to
5146 support GDB on MS-DOSe systems (which have very restrictive file name
5147 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5148 environment) is close to working but has some remaining problems. Note
5149 that debugging of DOS programs is not supported, due to limitations
5150 in the ``operating system'', but it can be used to host cross-debugging.
5152 * Cross byte order fixes
5154 Many fixes have been made to support cross debugging of Sparc and MIPS
5155 targets from hosts whose byte order differs.
5157 * New -mapped and -readnow options
5159 If memory-mapped files are available on your system through the 'mmap'
5160 system call, you can use the -mapped option on the `file' or
5161 `symbol-file' commands to cause GDB to write the symbols from your
5162 program into a reusable file. If the program you are debugging is
5163 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5164 Future GDB debugging sessions will notice the presence of this file,
5165 and will quickly map in symbol information from it, rather than reading
5166 the symbol table from the executable program. Using the '-mapped'
5167 option in a GDB `file' or `symbol-file' command has the same effect as
5168 starting GDB with the '-mapped' command-line option.
5170 You can cause GDB to read the entire symbol table immediately by using
5171 the '-readnow' option with any of the commands that load symbol table
5172 information (or on the GDB command line). This makes the command
5173 slower, but makes future operations faster.
5175 The -mapped and -readnow options are typically combined in order to
5176 build a `fred.syms' file that contains complete symbol information.
5177 A simple GDB invocation to do nothing but build a `.syms' file for future
5180 gdb -batch -nx -mapped -readnow programname
5182 The `.syms' file is specific to the host machine on which GDB is run.
5183 It holds an exact image of GDB's internal symbol table. It cannot be
5184 shared across multiple host platforms.
5186 * longjmp() handling
5188 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5189 siglongjmp() without losing control. This feature has not yet been ported to
5190 all systems. It currently works on many 386 platforms, all MIPS-based
5191 platforms (SGI, DECstation, etc), and Sun3/4.
5195 Preliminary work has been put in to support the new Solaris OS from Sun. At
5196 this time, it can control and debug processes, but it is not capable of
5201 As always, many many bug fixes. The major areas were with g++, and mipsread.
5202 People using the MIPS-based platforms should experience fewer mysterious
5203 crashes and trashed symbol tables.
5205 *** Changes in GDB-4.4:
5207 * New machines supported (host and target)
5209 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5211 BSD Reno on Vax vax-dec-bsd
5212 Ultrix on Vax vax-dec-ultrix
5214 * New machines supported (target)
5216 AMD 29000 embedded, using EBMON a29k-none-none
5220 GDB continues to improve its handling of C++. `References' work better.
5221 The demangler has also been improved, and now deals with symbols mangled as
5222 per the Annotated C++ Reference Guide.
5224 GDB also now handles `stabs' symbol information embedded in MIPS
5225 `ecoff' symbol tables. Since the ecoff format was not easily
5226 extensible to handle new languages such as C++, this appeared to be a
5227 good way to put C++ debugging info into MIPS binaries. This option
5228 will be supported in the GNU C compiler, version 2, when it is
5231 * New features for SVR4
5233 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5234 shared libraries. Debugging dynamically linked programs should present
5235 only minor differences from debugging statically linked programs.
5237 The `info proc' command will print out information about any process
5238 on an SVR4 system (including the one you are debugging). At the moment,
5239 it prints the address mappings of the process.
5241 If you bring up GDB on another SVR4 system, please send mail to
5242 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5244 * Better dynamic linking support in SunOS
5246 Reading symbols from shared libraries which contain debugging symbols
5247 now works properly. However, there remain issues such as automatic
5248 skipping of `transfer vector' code during function calls, which
5249 make it harder to debug code in a shared library, than to debug the
5250 same code linked statically.
5254 GDB is now using the latest `getopt' routines from the FSF. This
5255 version accepts the -- prefix for options with long names. GDB will
5256 continue to accept the old forms (-option and +option) as well.
5257 Various single letter abbreviations for options have been explicity
5258 added to the option table so that they won't get overshadowed in the
5259 future by other options that begin with the same letter.
5263 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5264 Many assorted bugs have been handled. Many more remain to be handled.
5265 See the various ChangeLog files (primarily in gdb and bfd) for details.
5268 *** Changes in GDB-4.3:
5270 * New machines supported (host and target)
5272 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5273 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5274 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5276 * Almost SCO Unix support
5278 We had hoped to support:
5279 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5280 (except for core file support), but we discovered very late in the release
5281 that it has problems with process groups that render gdb unusable. Sorry
5282 about that. I encourage people to fix it and post the fixes.
5284 * Preliminary ELF and DWARF support
5286 GDB can read ELF object files on System V Release 4, and can handle
5287 debugging records for C, in DWARF format, in ELF files. This support
5288 is preliminary. If you bring up GDB on another SVR4 system, please
5289 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5294 GDB now uses the latest `readline' library. One user-visible change
5295 is that two tabs will list possible command completions, which previously
5296 required typing M-? (meta-question mark, or ESC ?).
5300 The `stepi' bug that many of you noticed has been squashed.
5301 Many bugs in C++ have been handled. Many more remain to be handled.
5302 See the various ChangeLog files (primarily in gdb and bfd) for details.
5304 * State of the MIPS world (in case you wondered):
5306 GDB can understand the symbol tables emitted by the compilers
5307 supplied by most vendors of MIPS-based machines, including DEC. These
5308 symbol tables are in a format that essentially nobody else uses.
5310 Some versions of gcc come with an assembler post-processor called
5311 mips-tfile. This program is required if you want to do source-level
5312 debugging of gcc-compiled programs. I believe FSF does not ship
5313 mips-tfile with gcc version 1, but it will eventually come with gcc
5316 Debugging of g++ output remains a problem. g++ version 1.xx does not
5317 really support it at all. (If you're lucky, you should be able to get
5318 line numbers and stack traces to work, but no parameters or local
5319 variables.) With some work it should be possible to improve the
5322 When gcc version 2 is released, you will have somewhat better luck.
5323 However, even then you will get confusing results for inheritance and
5326 We will eventually provide full debugging of g++ output on
5327 DECstations. This will probably involve some kind of stabs-in-ecoff
5328 encapulation, but the details have not been worked out yet.
5331 *** Changes in GDB-4.2:
5333 * Improved configuration
5335 Only one copy of `configure' exists now, and it is not self-modifying.
5336 Porting BFD is simpler.
5340 The `step' and `next' commands now only stop at the first instruction
5341 of a source line. This prevents the multiple stops that used to occur
5342 in switch statements, for-loops, etc. `Step' continues to stop if a
5343 function that has debugging information is called within the line.
5347 Lots of small bugs fixed. More remain.
5349 * New host supported (not target)
5351 Intel 386 PC clone running Mach i386-none-mach
5354 *** Changes in GDB-4.1:
5356 * Multiple source language support
5358 GDB now has internal scaffolding to handle several source languages.
5359 It determines the type of each source file from its filename extension,
5360 and will switch expression parsing and number formatting to match the
5361 language of the function in the currently selected stack frame.
5362 You can also specifically set the language to be used, with
5363 `set language c' or `set language modula-2'.
5367 GDB now has preliminary support for the GNU Modula-2 compiler,
5368 currently under development at the State University of New York at
5369 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5370 continue through the fall of 1991 and into 1992.
5372 Other Modula-2 compilers are currently not supported, and attempting to
5373 debug programs compiled with them will likely result in an error as the
5374 symbol table is read. Feel free to work on it, though!
5376 There are hooks in GDB for strict type checking and range checking,
5377 in the `Modula-2 philosophy', but they do not currently work.
5381 GDB can now write to executable and core files (e.g. patch
5382 a variable's value). You must turn this switch on, specify
5383 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5384 by assigning a new value to a variable. Modifications take
5387 * Automatic SunOS shared library reading
5389 When you run your program, GDB automatically determines where its
5390 shared libraries (if any) have been loaded, and reads their symbols.
5391 The `share' command is no longer needed. This also works when
5392 examining core files.
5396 You can specify the number of lines that the `list' command shows.
5399 * New machines supported (host and target)
5401 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5402 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5403 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5405 * New hosts supported (not targets)
5407 IBM RT/PC: romp-ibm-aix or rtpc
5409 * New targets supported (not hosts)
5411 AMD 29000 embedded with COFF a29k-none-coff
5412 AMD 29000 embedded with a.out a29k-none-aout
5413 Ultracomputer remote kernel debug a29k-nyu-kern
5415 * New remote interfaces
5421 *** Changes in GDB-4.0:
5425 Wide output is wrapped at good places to make the output more readable.
5427 Gdb now supports cross-debugging from a host machine of one type to a
5428 target machine of another type. Communication with the target system
5429 is over serial lines. The ``target'' command handles connecting to the
5430 remote system; the ``load'' command will download a program into the
5431 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5432 also supports debugging of realtime processes running under VxWorks,
5433 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5434 stub on the target system.
5436 New CPUs supported include the AMD 29000 and Intel 960.
5438 GDB now reads object files and symbol tables via a ``binary file''
5439 library, which allows a single copy of GDB to debug programs of multiple
5440 object file types such as a.out and coff.
5442 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5443 refcard.dvi and refcard.ps are available to format it).
5446 * Control-Variable user interface simplified
5448 All variables that control the operation of the debugger can be set
5449 by the ``set'' command, and displayed by the ``show'' command.
5451 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5452 ``Show prompt'' produces the response:
5453 Gdb's prompt is new-gdb=>.
5455 What follows are the NEW set commands. The command ``help set'' will
5456 print a complete list of old and new set commands. ``help set FOO''
5457 will give a longer description of the variable FOO. ``show'' will show
5458 all of the variable descriptions and their current settings.
5460 confirm on/off: Enables warning questions for operations that are
5461 hard to recover from, e.g. rerunning the program while
5462 it is already running. Default is ON.
5464 editing on/off: Enables EMACS style command line editing
5465 of input. Previous lines can be recalled with
5466 control-P, the current line can be edited with control-B,
5467 you can search for commands with control-R, etc.
5470 history filename NAME: NAME is where the gdb command history
5471 will be stored. The default is .gdb_history,
5472 or the value of the environment variable
5475 history size N: The size, in commands, of the command history. The
5476 default is 256, or the value of the environment variable
5479 history save on/off: If this value is set to ON, the history file will
5480 be saved after exiting gdb. If set to OFF, the
5481 file will not be saved. The default is OFF.
5483 history expansion on/off: If this value is set to ON, then csh-like
5484 history expansion will be performed on
5485 command line input. The default is OFF.
5487 radix N: Sets the default radix for input and output. It can be set
5488 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5489 in the current radix, so "set radix 10" is always a no-op.
5491 height N: This integer value is the number of lines on a page. Default
5492 is 24, the current `stty rows'' setting, or the ``li#''
5493 setting from the termcap entry matching the environment
5496 width N: This integer value is the number of characters on a line.
5497 Default is 80, the current `stty cols'' setting, or the ``co#''
5498 setting from the termcap entry matching the environment
5501 Note: ``set screensize'' is obsolete. Use ``set height'' and
5502 ``set width'' instead.
5504 print address on/off: Print memory addresses in various command displays,
5505 such as stack traces and structure values. Gdb looks
5506 more ``symbolic'' if you turn this off; it looks more
5507 ``machine level'' with it on. Default is ON.
5509 print array on/off: Prettyprint arrays. New convenient format! Default
5512 print demangle on/off: Print C++ symbols in "source" form if on,
5515 print asm-demangle on/off: Same, for assembler level printouts
5518 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5521 * Support for Epoch Environment.
5523 The epoch environment is a version of Emacs v18 with windowing. One
5524 new command, ``inspect'', is identical to ``print'', except that if you
5525 are running in the epoch environment, the value is printed in its own
5529 * Support for Shared Libraries
5531 GDB can now debug programs and core files that use SunOS shared libraries.
5532 Symbols from a shared library cannot be referenced
5533 before the shared library has been linked with the program (this
5534 happens after you type ``run'' and before the function main() is entered).
5535 At any time after this linking (including when examining core files
5536 from dynamically linked programs), gdb reads the symbols from each
5537 shared library when you type the ``sharedlibrary'' command.
5538 It can be abbreviated ``share''.
5540 sharedlibrary REGEXP: Load shared object library symbols for files
5541 matching a unix regular expression. No argument
5542 indicates to load symbols for all shared libraries.
5544 info sharedlibrary: Status of loaded shared libraries.
5549 A watchpoint stops execution of a program whenever the value of an
5550 expression changes. Checking for this slows down execution
5551 tremendously whenever you are in the scope of the expression, but is
5552 quite useful for catching tough ``bit-spreader'' or pointer misuse
5553 problems. Some machines such as the 386 have hardware for doing this
5554 more quickly, and future versions of gdb will use this hardware.
5556 watch EXP: Set a watchpoint (breakpoint) for an expression.
5558 info watchpoints: Information about your watchpoints.
5560 delete N: Deletes watchpoint number N (same as breakpoints).
5561 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5562 enable N: Re-enables watchpoint number N (same as breakpoints).
5565 * C++ multiple inheritance
5567 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5570 * C++ exception handling
5572 Gdb now supports limited C++ exception handling. Besides the existing
5573 ability to breakpoint on an exception handler, gdb can breakpoint on
5574 the raising of an exception (before the stack is peeled back to the
5577 catch FOO: If there is a FOO exception handler in the dynamic scope,
5578 set a breakpoint to catch exceptions which may be raised there.
5579 Multiple exceptions (``catch foo bar baz'') may be caught.
5581 info catch: Lists all exceptions which may be caught in the
5582 current stack frame.
5585 * Minor command changes
5587 The command ``call func (arg, arg, ...)'' now acts like the print
5588 command, except it does not print or save a value if the function's result
5589 is void. This is similar to dbx usage.
5591 The ``up'' and ``down'' commands now always print the frame they end up
5592 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5593 frames without printing.
5595 * New directory command
5597 'dir' now adds directories to the FRONT of the source search path.
5598 The path starts off empty. Source files that contain debug information
5599 about the directory in which they were compiled can be found even
5600 with an empty path; Sun CC and GCC include this information. If GDB can't
5601 find your source file in the current directory, type "dir .".
5603 * Configuring GDB for compilation
5605 For normal use, type ``./configure host''. See README or gdb.texinfo
5608 GDB now handles cross debugging. If you are remotely debugging between
5609 two different machines, type ``./configure host -target=targ''.
5610 Host is the machine where GDB will run; targ is the machine
5611 where the program that you are debugging will run.
5613 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.