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.
27 qXfer:btrace:read's annex
28 The qXfer:btrace:read packet supports a new annex 'delta' to read
29 branch trace incrementally.
31 *** Changes in GDB 7.7
33 * Improved support for process record-replay and reverse debugging on
34 arm*-linux* targets. Support for thumb32 and syscall instruction
35 recording has been added.
37 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
39 * GDB now supports Fission DWP file format version 2.
40 http://gcc.gnu.org/wiki/DebugFission
42 * New convenience function "$_isvoid", to check whether an expression
43 is void. A void expression is an expression where the type of the
44 result is "void". For example, some convenience variables may be
45 "void" when evaluated (e.g., "$_exitcode" before the execution of
46 the program being debugged; or an undefined convenience variable).
47 Another example, when calling a function whose return type is
50 * The "maintenance print objfiles" command now takes an optional regexp.
52 * The "catch syscall" command now works on arm*-linux* targets.
54 * GDB now consistently shows "<not saved>" when printing values of
55 registers the debug info indicates have not been saved in the frame
56 and there's nowhere to retrieve them from
57 (callee-saved/call-clobbered registers):
62 (gdb) info registers rax
65 Before, the former would print "<optimized out>", and the latter
66 "*value not available*".
68 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
73 ** Frame filters and frame decorators have been added.
74 ** Temporary breakpoints are now supported.
75 ** Line tables representation has been added.
76 ** New attribute 'parent_type' for gdb.Field objects.
77 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
78 ** New attribute 'name' for gdb.Type objects.
82 Nios II ELF nios2*-*-elf
83 Nios II GNU/Linux nios2*-*-linux
84 Texas Instruments MSP430 msp430*-*-elf
86 * Removed native configurations
88 Support for these a.out NetBSD and OpenBSD obsolete configurations has
89 been removed. ELF variants of these configurations are kept supported.
91 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
92 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
93 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
94 i[34567]86-*-openbsd3.[0-3]
95 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
96 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
97 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
101 Like "catch throw", but catches a re-thrown exception.
103 Renamed from old "maint check-symtabs".
105 Perform consistency checks on symtabs.
107 Expand symtabs matching an optional regexp.
110 Display the details of GDB configure-time options.
112 maint set|show per-command
113 maint set|show per-command space
114 maint set|show per-command time
115 maint set|show per-command symtab
116 Enable display of per-command gdb resource usage.
118 remove-symbol-file FILENAME
119 remove-symbol-file -a ADDRESS
120 Remove a symbol file added via add-symbol-file. The file to remove
121 can be identified by its filename or by an address that lies within
122 the boundaries of this symbol file in memory.
125 info exceptions REGEXP
126 Display the list of Ada exceptions defined in the program being
127 debugged. If provided, only the exceptions whose names match REGEXP
132 set debug symfile off|on
134 Control display of debugging info regarding reading symbol files and
135 symbol tables within those files
137 set print raw frame-arguments
138 show print raw frame-arguments
139 Set/show whether to print frame arguments in raw mode,
140 disregarding any defined pretty-printers.
142 set remote trace-status-packet
143 show remote trace-status-packet
144 Set/show the use of remote protocol qTStatus packet.
148 Control display of debugging messages related to Nios II targets.
152 Control whether target-assisted range stepping is enabled.
154 set startup-with-shell
155 show startup-with-shell
156 Specifies whether Unix child processes are started via a shell or
161 Use the target memory cache for accesses to the code segment. This
162 improves performance of remote debugging (particularly disassembly).
164 * You can now use a literal value 'unlimited' for options that
165 interpret 0 or -1 as meaning "unlimited". E.g., "set
166 trace-buffer-size unlimited" is now an alias for "set
167 trace-buffer-size -1" and "set height unlimited" is now an alias for
170 * The "set debug symtab-create" debugging option of GDB has been changed to
171 accept a verbosity level. 0 means "off", 1 provides basic debugging
172 output, and values of 2 or greater provides more verbose output.
174 * New command-line options
176 Display the details of GDB configure-time options.
178 * The command 'tsave' can now support new option '-ctf' to save trace
179 buffer in Common Trace Format.
181 * Newly installed $prefix/bin/gcore acts as a shell interface for the
184 * GDB now implements the the C++ 'typeid' operator.
186 * The new convenience variable $_exception holds the exception being
187 thrown or caught at an exception-related catchpoint.
189 * The exception-related catchpoints, like "catch throw", now accept a
190 regular expression which can be used to filter exceptions by type.
192 * The new convenience variable $_exitsignal is automatically set to
193 the terminating signal number when the program being debugged dies
194 due to an uncaught signal.
198 ** All MI commands now accept an optional "--language" option.
199 Support for this feature can be verified by using the "-list-features"
200 command, which should contain "language-option".
202 ** The new command -info-gdb-mi-command allows the user to determine
203 whether a GDB/MI command is supported or not.
205 ** The "^error" result record returned when trying to execute an undefined
206 GDB/MI command now provides a variable named "code" whose content is the
207 "undefined-command" error code. Support for this feature can be verified
208 by using the "-list-features" command, which should contain
209 "undefined-command-error-code".
211 ** The -trace-save MI command can optionally save trace buffer in Common
214 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
216 ** The command -data-list-register-values now accepts an optional
217 "--skip-unavailable" option. When used, only the available registers
220 ** The new command -trace-frame-collected dumps collected variables,
221 computed expressions, tvars, memory and registers in a traceframe.
223 ** The commands -stack-list-locals, -stack-list-arguments and
224 -stack-list-variables now accept an option "--skip-unavailable".
225 When used, only the available locals or arguments are displayed.
227 ** The -exec-run command now accepts an optional "--start" option.
228 When used, the command follows the same semantics as the "start"
229 command, stopping the program's execution at the start of its
230 main subprogram. Support for this feature can be verified using
231 the "-list-features" command, which should contain
232 "exec-run-start-option".
234 ** The new commands -catch-assert and -catch-exceptions insert
235 catchpoints stopping the program when Ada exceptions are raised.
237 ** The new command -info-ada-exceptions provides the equivalent of
238 the new "info exceptions" command.
240 * New system-wide configuration scripts
241 A GDB installation now provides scripts suitable for use as system-wide
242 configuration scripts for the following systems:
246 * GDB now supports target-assigned range stepping with remote targets.
247 This improves the performance of stepping source lines by reducing
248 the number of control packets from/to GDB. See "New remote packets"
251 * GDB now understands the element 'tvar' in the XML traceframe info.
252 It has the id of the collected trace state variables.
254 * On S/390 targets that provide the transactional-execution feature,
255 the program interruption transaction diagnostic block (TDB) is now
256 represented as a number of additional "registers" in GDB.
262 The vCont packet supports a new 'r' action, that tells the remote
263 stub to step through an address range itself, without GDB
264 involvemement at each single-step.
266 qXfer:libraries-svr4:read's annex
267 The previously unused annex of the qXfer:libraries-svr4:read packet
268 is now used to support passing an argument list. The remote stub
269 reports support for this argument list to GDB's qSupported query.
270 The defined arguments are "start" and "prev", used to reduce work
271 necessary for library list updating, resulting in significant
274 * New features in the GDB remote stub, GDBserver
276 ** GDBserver now supports target-assisted range stepping. Currently
277 enabled on x86/x86_64 GNU/Linux targets.
279 ** GDBserver now adds element 'tvar' in the XML in the reply to
280 'qXfer:traceframe-info:read'. It has the id of the collected
281 trace state variables.
283 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
286 * New 'z' formatter for printing and examining memory, this displays the
287 value as hexadecimal zero padded on the left to the size of the type.
289 * GDB can now use Windows x64 unwinding data.
291 * The "set remotebaud" command has been replaced by "set serial baud".
292 Similarly, "show remotebaud" has been replaced by "show serial baud".
293 The "set remotebaud" and "show remotebaud" commands are still available
294 to provide backward compatibility with older versions of GDB.
296 *** Changes in GDB 7.6
298 * Target record has been renamed to record-full.
299 Record/replay is now enabled with the "record full" command.
300 This also affects settings that are associated with full record/replay
301 that have been moved from "set/show record" to "set/show record full":
303 set|show record full insn-number-max
304 set|show record full stop-at-limit
305 set|show record full memory-query
307 * A new record target "record-btrace" has been added. The new target
308 uses hardware support to record the control-flow of a process. It
309 does not support replaying the execution, but it implements the
310 below new commands for investigating the recorded execution log.
311 This new recording method can be enabled using:
315 The "record-btrace" target is only available on Intel Atom processors
316 and requires a Linux kernel 2.6.32 or later.
318 * Two new commands have been added for record/replay to give information
319 about the recorded execution without having to replay the execution.
320 The commands are only supported by "record btrace".
322 record instruction-history prints the execution history at
323 instruction granularity
325 record function-call-history prints the execution history at
328 * New native configurations
330 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
331 FreeBSD/powerpc powerpc*-*-freebsd
332 x86_64/Cygwin x86_64-*-cygwin*
333 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
337 ARM AArch64 aarch64*-*-elf
338 ARM AArch64 GNU/Linux aarch64*-*-linux
339 Lynx 178 PowerPC powerpc-*-lynx*178
340 x86_64/Cygwin x86_64-*-cygwin*
341 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
343 * If the configured location of system.gdbinit file (as given by the
344 --with-system-gdbinit option at configure time) is in the
345 data-directory (as specified by --with-gdb-datadir at configure
346 time) or in one of its subdirectories, then GDB will look for the
347 system-wide init file in the directory specified by the
348 --data-directory command-line option.
350 * New command line options:
352 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
353 other initialization files, unlike -nx which disables all of them.
355 * Removed command line options
357 -epoch This was used by the gdb mode in Epoch, an ancient fork of
360 * The 'ptype' and 'whatis' commands now accept an argument to control
363 * 'info proc' now works on some core files.
367 ** Vectors can be created with gdb.Type.vector.
369 ** Python's atexit.register now works in GDB.
371 ** Types can be pretty-printed via a Python API.
373 ** Python 3 is now supported (in addition to Python 2.4 or later)
375 ** New class gdb.Architecture exposes GDB's internal representation
376 of architecture in the Python API.
378 ** New method Frame.architecture returns the gdb.Architecture object
379 corresponding to the frame's architecture.
381 * New Python-based convenience functions:
383 ** $_memeq(buf1, buf2, length)
384 ** $_streq(str1, str2)
386 ** $_regex(str, regex)
388 * The 'cd' command now defaults to using '~' (the home directory) if not
391 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
392 default for GCC since November 2000.
394 * The command 'forward-search' can now be abbreviated as 'fo'.
396 * The command 'info tracepoints' can now display 'installed on target'
397 or 'not installed on target' for each non-pending location of tracepoint.
399 * New configure options
401 --enable-libmcheck/--disable-libmcheck
402 By default, development versions are built with -lmcheck on hosts
403 that support it, in order to help track memory corruption issues.
404 Release versions, on the other hand, are built without -lmcheck
405 by default. The --enable-libmcheck/--disable-libmcheck configure
406 options allow the user to override that default.
407 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
408 This configure option allows the user to build GDB with
409 libbabeltrace using which GDB can read Common Trace Format data.
411 * New commands (for set/show, see "New options" below)
414 Catch signals. This is similar to "handle", but allows commands and
415 conditions to be attached.
418 List the BFDs known to GDB.
420 python-interactive [command]
422 Start a Python interactive prompt, or evaluate the optional command
423 and print the result of expressions.
426 "py" is a new alias for "python".
428 enable type-printer [name]...
429 disable type-printer [name]...
430 Enable or disable type printers.
434 ** For the Renesas Super-H architecture, the "regs" command has been removed
435 (has been deprecated in GDB 7.5), and "info all-registers" should be used
440 set print type methods (on|off)
441 show print type methods
442 Control whether method declarations are displayed by "ptype".
443 The default is to show them.
445 set print type typedefs (on|off)
446 show print type typedefs
447 Control whether typedef definitions are displayed by "ptype".
448 The default is to show them.
450 set filename-display basename|relative|absolute
451 show filename-display
452 Control the way in which filenames is displayed.
453 The default is "relative", which preserves previous behavior.
455 set trace-buffer-size
456 show trace-buffer-size
457 Request target to change the size of trace buffer.
459 set remote trace-buffer-size-packet auto|on|off
460 show remote trace-buffer-size-packet
461 Control the use of the remote protocol `QTBuffer:size' packet.
465 Control display of debugging messages related to ARM AArch64.
468 set debug coff-pe-read
469 show debug coff-pe-read
470 Control display of debugging messages related to reading of COFF/PE
475 Control display of debugging messages related to Mach-O symbols
478 set debug notification
479 show debug notification
480 Control display of debugging info for async remote notification.
484 ** Command parameter changes are now notified using new async record
485 "=cmd-param-changed".
486 ** Trace frame changes caused by command "tfind" are now notified using
487 new async record "=traceframe-changed".
488 ** The creation, deletion and modification of trace state variables
489 are now notified using new async records "=tsv-created",
490 "=tsv-deleted" and "=tsv-modified".
491 ** The start and stop of process record are now notified using new
492 async record "=record-started" and "=record-stopped".
493 ** Memory changes are now notified using new async record
495 ** The data-disassemble command response will include a "fullname" field
496 containing the absolute file name when source has been requested.
497 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
498 command, to allow pattern filling of memory areas.
499 ** New commands "-catch-load"/"-catch-unload" added for intercepting
500 library load/unload events.
501 ** The response to breakpoint commands and breakpoint async records
502 includes an "installed" field containing a boolean state about each
503 non-pending tracepoint location is whether installed on target or not.
504 ** Output of the "-trace-status" command includes a "trace-file" field
505 containing the name of the trace file being examined. This field is
506 optional, and only present when examining a trace file.
507 ** The "fullname" field is now always present along with the "file" field,
508 even if the file cannot be found by GDB.
510 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
511 You must have the LZMA library available when configuring GDB for this
512 feature to be enabled. For more information, see:
513 http://fedoraproject.org/wiki/Features/MiniDebugInfo
518 Set the size of trace buffer. The remote stub reports support for this
519 packet to gdb's qSupported query.
522 Enable Branch Trace Store (BTS)-based branch tracing for the current
523 thread. The remote stub reports support for this packet to gdb's
527 Disable branch tracing for the current thread. The remote stub reports
528 support for this packet to gdb's qSupported query.
531 Read the traced branches for the current thread. The remote stub
532 reports support for this packet to gdb's qSupported query.
534 *** Changes in GDB 7.5
536 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
537 for more x32 ABI info.
539 * GDB now supports access to MIPS DSP registers on Linux targets.
541 * GDB now supports debugging microMIPS binaries.
543 * The "info os" command on GNU/Linux can now display information on
544 several new classes of objects managed by the operating system:
545 "info os procgroups" lists process groups
546 "info os files" lists file descriptors
547 "info os sockets" lists internet-domain sockets
548 "info os shm" lists shared-memory regions
549 "info os semaphores" lists semaphores
550 "info os msg" lists message queues
551 "info os modules" lists loaded kernel modules
553 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
554 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
555 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
556 options and inspect the probe arguments using the new $_probe_arg family
557 of convenience variables. You can obtain more information about SystemTap
558 in <http://sourceware.org/systemtap/>.
560 * GDB now supports reversible debugging on ARM, it allows you to
561 debug basic ARM and THUMB instructions, and provides
562 record/replay support.
564 * The option "symbol-reloading" has been deleted as it is no longer used.
568 ** GDB commands implemented in Python can now be put in command class
571 ** The "maint set python print-stack on|off" is now deleted.
573 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
574 apply "flag enum"-style pretty-printing to any enum.
576 ** gdb.lookup_symbol can now work when there is no current frame.
578 ** gdb.Symbol now has a 'line' attribute, holding the line number in
579 the source at which the symbol was defined.
581 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
582 method 'value'. The former indicates whether the symbol needs a
583 frame in order to compute its value, and the latter computes the
586 ** A new method 'referenced_value' on gdb.Value objects which can
587 dereference pointer as well as C++ reference values.
589 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
590 which return the global and static blocks (as gdb.Block objects),
591 of the underlying symbol table, respectively.
593 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
594 object associated with a PC value.
596 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
597 of the address range occupied by code for the current source line.
599 * Go language support.
600 GDB now supports debugging programs written in the Go programming
603 * GDBserver now supports stdio connections.
604 E.g. (gdb) target remote | ssh myhost gdbserver - hello
606 * The binary "gdbtui" can no longer be built or installed.
607 Use "gdb -tui" instead.
609 * GDB will now print "flag" enums specially. A flag enum is one where
610 all the enumerator values have no bits in common when pairwise
611 "and"ed. When printing a value whose type is a flag enum, GDB will
612 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
613 (gdb) print (enum E) 3
616 * The filename part of a linespec will now match trailing components
617 of a source file name. For example, "break gcc/expr.c:1000" will
618 now set a breakpoint in build/gcc/expr.c, but not
621 * The "info proc" and "generate-core-file" commands will now also
622 work on remote targets connected to GDBserver on Linux.
624 * The command "info catch" has been removed. It has been disabled
627 * The "catch exception" and "catch assert" commands now accept
628 a condition at the end of the command, much like the "break"
629 command does. For instance:
631 (gdb) catch exception Constraint_Error if Barrier = True
633 Previously, it was possible to add a condition to such catchpoints,
634 but it had to be done as a second step, after the catchpoint had been
635 created, using the "condition" command.
637 * The "info static-tracepoint-marker" command will now also work on
638 native Linux targets with in-process agent.
640 * GDB can now set breakpoints on inlined functions.
642 * The .gdb_index section has been updated to include symbols for
643 inlined functions. GDB will ignore older .gdb_index sections by
644 default, which could cause symbol files to be loaded more slowly
645 until their .gdb_index sections can be recreated. The new command
646 "set use-deprecated-index-sections on" will cause GDB to use any older
647 .gdb_index sections it finds. This will restore performance, but the
648 ability to set breakpoints on inlined functions will be lost in symbol
649 files with older .gdb_index sections.
651 The .gdb_index section has also been updated to record more information
652 about each symbol. This speeds up the "info variables", "info functions"
653 and "info types" commands when used with programs having the .gdb_index
654 section, as well as speeding up debugging with shared libraries using
655 the .gdb_index section.
657 * Ada support for GDB/MI Variable Objects has been added.
659 * GDB can now support 'breakpoint always-inserted mode' in 'record'
664 ** New command -info-os is the MI equivalent of "info os".
666 ** Output logs ("set logging" and related) now include MI output.
670 ** "set use-deprecated-index-sections on|off"
671 "show use-deprecated-index-sections on|off"
672 Controls the use of deprecated .gdb_index sections.
674 ** "catch load" and "catch unload" can be used to stop when a shared
675 library is loaded or unloaded, respectively.
677 ** "enable count" can be used to auto-disable a breakpoint after
680 ** "info vtbl" can be used to show the virtual method tables for
681 C++ and Java objects.
683 ** "explore" and its sub commands "explore value" and "explore type"
684 can be used to recursively explore values and types of
685 expressions. These commands are available only if GDB is
686 configured with '--with-python'.
688 ** "info auto-load" shows status of all kinds of auto-loaded files,
689 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
690 sequences of commands files, "info auto-load python-scripts"
691 shows status of auto-loading Python script files,
692 "info auto-load local-gdbinit" shows status of loading init file
693 (.gdbinit) from current directory and "info auto-load libthread-db" shows
694 status of inferior specific thread debugging shared library loading.
696 ** "info auto-load-scripts", "set auto-load-scripts on|off"
697 and "show auto-load-scripts" commands have been deprecated, use their
698 "info auto-load python-scripts", "set auto-load python-scripts on|off"
699 and "show auto-load python-scripts" counterparts instead.
701 ** "dprintf location,format,args..." creates a dynamic printf, which
702 is basically a breakpoint that does a printf and immediately
703 resumes your program's execution, so it is like a printf that you
704 can insert dynamically at runtime instead of at compiletime.
706 ** "set print symbol"
708 Controls whether GDB attempts to display the symbol, if any,
709 corresponding to addresses it prints. This defaults to "on", but
710 you can set it to "off" to restore GDB's previous behavior.
712 * Deprecated commands
714 ** For the Renesas Super-H architecture, the "regs" command has been
715 deprecated, and "info all-registers" should be used instead.
719 Renesas RL78 rl78-*-elf
720 HP OpenVMS ia64 ia64-hp-openvms*
722 * GDBserver supports evaluation of breakpoint conditions. When
723 support is advertised by GDBserver, GDB may be told to send the
724 breakpoint conditions in bytecode form to GDBserver. GDBserver
725 will only report the breakpoint trigger to GDB when its condition
731 show mips compression
732 Select the compressed ISA encoding used in functions that have no symbol
733 information available. The encoding can be set to either of:
736 and is updated automatically from ELF file flags if available.
738 set breakpoint condition-evaluation
739 show breakpoint condition-evaluation
740 Control whether breakpoint conditions are evaluated by GDB ("host") or by
741 GDBserver ("target"). Default option "auto" chooses the most efficient
743 This option can improve debugger efficiency depending on the speed of the
747 Disable auto-loading globally.
750 Show auto-loading setting of all kinds of auto-loaded files.
752 set auto-load gdb-scripts on|off
753 show auto-load gdb-scripts
754 Control auto-loading of GDB canned sequences of commands files.
756 set auto-load python-scripts on|off
757 show auto-load python-scripts
758 Control auto-loading of Python script files.
760 set auto-load local-gdbinit on|off
761 show auto-load local-gdbinit
762 Control loading of init file (.gdbinit) from current directory.
764 set auto-load libthread-db on|off
765 show auto-load libthread-db
766 Control auto-loading of inferior specific thread debugging shared library.
768 set auto-load scripts-directory <dir1>[:<dir2>...]
769 show auto-load scripts-directory
770 Set a list of directories from which to load auto-loaded scripts.
771 Automatically loaded Python scripts and GDB scripts are located in one
772 of the directories listed by this option.
773 The delimiter (':' above) may differ according to the host platform.
775 set auto-load safe-path <dir1>[:<dir2>...]
776 show auto-load safe-path
777 Set a list of directories from which it is safe to auto-load files.
778 The delimiter (':' above) may differ according to the host platform.
780 set debug auto-load on|off
782 Control display of debugging info for auto-loading the files above.
784 set dprintf-style gdb|call|agent
786 Control the way in which a dynamic printf is performed; "gdb"
787 requests a GDB printf command, while "call" causes dprintf to call a
788 function in the inferior. "agent" requests that the target agent
789 (such as GDBserver) do the printing.
791 set dprintf-function <expr>
792 show dprintf-function
793 set dprintf-channel <expr>
795 Set the function and optional first argument to the call when using
796 the "call" style of dynamic printf.
798 set disconnected-dprintf on|off
799 show disconnected-dprintf
800 Control whether agent-style dynamic printfs continue to be in effect
801 after GDB disconnects.
803 * New configure options
806 Configure default value for the 'set auto-load scripts-directory'
807 setting above. It defaults to '$debugdir:$datadir/auto-load',
808 $debugdir representing global debugging info directories (available
809 via 'show debug-file-directory') and $datadir representing GDB's data
810 directory (available via 'show data-directory').
812 --with-auto-load-safe-path
813 Configure default value for the 'set auto-load safe-path' setting
814 above. It defaults to the --with-auto-load-dir setting.
816 --without-auto-load-safe-path
817 Set 'set auto-load safe-path' to '/', effectively disabling this
822 z0/z1 conditional breakpoints extension
824 The z0/z1 breakpoint insertion packets have been extended to carry
825 a list of conditional expressions over to the remote stub depending on the
826 condition evaluation mode. The use of this extension can be controlled
827 via the "set remote conditional-breakpoints-packet" command.
831 Specify the signals which the remote stub may pass to the debugged
832 program without GDB involvement.
834 * New command line options
836 --init-command=FILE, -ix Like --command, -x but execute it
837 before loading inferior.
838 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
839 execute it before loading inferior.
841 *** Changes in GDB 7.4
843 * GDB now handles ambiguous linespecs more consistently; the existing
844 FILE:LINE support has been expanded to other types of linespecs. A
845 breakpoint will now be set on all matching locations in all
846 inferiors, and locations will be added or removed according to
849 * GDB now allows you to skip uninteresting functions and files when
850 stepping with the "skip function" and "skip file" commands.
852 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
853 and "show remote hardware-watchpoint-length-limit". These allows to
854 set or show the maximum length limit (in bytes) of a remote
855 target hardware watchpoint.
857 This allows e.g. to use "unlimited" hardware watchpoints with the
858 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
859 watchpoints are slower than real hardware watchpoints but are
860 significantly faster than gdb software watchpoints.
864 ** The register_pretty_printer function in module gdb.printing now takes
865 an optional `replace' argument. If True, the new printer replaces any
868 ** The "maint set python print-stack on|off" command has been
869 deprecated and will be deleted in GDB 7.5.
870 A new command: "set python print-stack none|full|message" has
871 replaced it. Additionally, the default for "print-stack" is
872 now "message", which just prints the error message without
875 ** A prompt substitution hook (prompt_hook) is now available to the
878 ** A new Python module, gdb.prompt has been added to the GDB Python
879 modules library. This module provides functionality for
880 escape sequences in prompts (used by set/show
881 extended-prompt). These escape sequences are replaced by their
884 ** Python commands and convenience-functions located in
885 'data-directory'/python/gdb/command and
886 'data-directory'/python/gdb/function are now automatically loaded
889 ** Blocks now provide four new attributes. global_block and
890 static_block will return the global and static blocks
891 respectively. is_static and is_global are boolean attributes
892 that indicate if the block is one of those two types.
894 ** Symbols now provide the "type" attribute, the type of the symbol.
896 ** The "gdb.breakpoint" function has been deprecated in favor of
899 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
900 of a function. This class is based on the "finish" command
901 available in the CLI.
903 ** Type objects for struct and union types now allow access to
904 the fields using standard Python dictionary (mapping) methods.
905 For example, "some_type['myfield']" now works, as does
908 ** A new event "gdb.new_objfile" has been added, triggered by loading a
911 ** A new function, "deep_items" has been added to the gdb.types
912 module in the GDB Python modules library. This function returns
913 an iterator over the fields of a struct or union type. Unlike
914 the standard Python "iteritems" method, it will recursively traverse
915 any anonymous fields.
919 ** "*stopped" events can report several new "reason"s, such as
922 ** Breakpoint changes are now notified using new async records, like
923 "=breakpoint-modified".
925 ** New command -ada-task-info.
927 * libthread-db-search-path now supports two special values: $sdir and $pdir.
928 $sdir specifies the default system locations of shared libraries.
929 $pdir specifies the directory where the libpthread used by the application
932 GDB no longer looks in $sdir and $pdir after it has searched the directories
933 mentioned in libthread-db-search-path. If you want to search those
934 directories, they must be specified in libthread-db-search-path.
935 The default value of libthread-db-search-path on GNU/Linux and Solaris
936 systems is now "$sdir:$pdir".
938 $pdir is not supported by gdbserver, it is currently ignored.
939 $sdir is supported by gdbserver.
941 * New configure option --with-iconv-bin.
942 When using the internationalization support like the one in the GNU C
943 library, GDB will invoke the "iconv" program to get a list of supported
944 character sets. If this program lives in a non-standard location, one can
945 use this option to specify where to find it.
947 * When natively debugging programs on PowerPC BookE processors running
948 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
949 watchpoints, which specify a mask in addition to an address to watch.
950 The mask specifies that some bits of an address (the bits which are
951 reset in the mask) should be ignored when matching the address accessed
952 by the inferior against the watchpoint address. See the "PowerPC Embedded"
953 section in the user manual for more details.
955 * The new option --once causes GDBserver to stop listening for connections once
956 the first connection is made. The listening port used by GDBserver will
957 become available after that.
959 * New commands "info macros" and "alias" have been added.
961 * New function parameters suffix @entry specifies value of function parameter
962 at the time the function got called. Entry values are available only since
968 "!" is now an alias of the "shell" command.
969 Note that no space is needed between "!" and SHELL COMMAND.
973 watch EXPRESSION mask MASK_VALUE
974 The watch command now supports the mask argument which allows creation
975 of masked watchpoints, if the current architecture supports this feature.
977 info auto-load-scripts [REGEXP]
978 This command was formerly named "maintenance print section-scripts".
979 It is now generally useful and is no longer a maintenance-only command.
981 info macro [-all] [--] MACRO
982 The info macro command has new options `-all' and `--'. The first for
983 printing all definitions of a macro. The second for explicitly specifying
984 the end of arguments and the beginning of the macro name in case the macro
985 name starts with a hyphen.
987 collect[/s] EXPRESSIONS
988 The tracepoint collect command now takes an optional modifier "/s"
989 that directs it to dereference pointer-to-character types and
990 collect the bytes of memory up to a zero byte. The behavior is
991 similar to what you see when you use the regular print command on a
992 string. An optional integer following the "/s" sets a bound on the
993 number of bytes that will be collected.
996 The trace start command now interprets any supplied arguments as a
997 note to be recorded with the trace run, with an effect similar to
998 setting the variable trace-notes.
1001 The trace stop command now interprets any arguments as a note to be
1002 mentioned along with the tstatus report that the trace was stopped
1003 with a command. The effect is similar to setting the variable
1006 * Tracepoints can now be enabled and disabled at any time after a trace
1007 experiment has been started using the standard "enable" and "disable"
1008 commands. It is now possible to start a trace experiment with no enabled
1009 tracepoints; GDB will display a warning, but will allow the experiment to
1010 begin, assuming that tracepoints will be enabled as needed while the trace
1013 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1014 locations with 4-byte instructions, when they were previously
1015 limited to locations with instructions of 5 bytes or longer.
1019 set debug dwarf2-read
1020 show debug dwarf2-read
1021 Turns on or off display of debugging messages related to reading
1022 DWARF debug info. The default is off.
1024 set debug symtab-create
1025 show debug symtab-create
1026 Turns on or off display of debugging messages related to symbol table
1027 creation. The default is off.
1030 show extended-prompt
1031 Set the GDB prompt, and allow escape sequences to be inserted to
1032 display miscellaneous information (see 'help set extended-prompt'
1033 for the list of sequences). This prompt (and any information
1034 accessed through the escape sequences) is updated every time the
1035 prompt is displayed.
1037 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1038 show print entry-values
1039 Set printing of frame argument values at function entry. In some cases
1040 GDB can determine the value of function argument which was passed by the
1041 function caller, even if the value was modified inside the called function.
1043 set debug entry-values
1044 show debug entry-values
1045 Control display of debugging info for determining frame argument values at
1046 function entry and virtual tail call frames.
1048 set basenames-may-differ
1049 show basenames-may-differ
1050 Set whether a source file may have multiple base names.
1051 (A "base name" is the name of a file with the directory part removed.
1052 Example: The base name of "/home/user/hello.c" is "hello.c".)
1053 If set, GDB will canonicalize file names (e.g., expand symlinks)
1054 before comparing them. Canonicalization is an expensive operation,
1055 but it allows the same file be known by more than one base name.
1056 If not set (the default), all source files are assumed to have just
1057 one base name, and gdb will do file name comparisons more efficiently.
1063 Set a user name and notes for the current and any future trace runs.
1064 This is useful for long-running and/or disconnected traces, to
1065 inform others (or yourself) as to who is running the trace, supply
1066 contact information, or otherwise explain what is going on.
1068 set trace-stop-notes
1069 show trace-stop-notes
1070 Set a note attached to the trace run, that is displayed when the
1071 trace has been stopped by a tstop command. This is useful for
1072 instance as an explanation, if you are stopping a trace run that was
1073 started by someone else.
1075 * New remote packets
1079 Dynamically enable a tracepoint in a started trace experiment.
1083 Dynamically disable a tracepoint in a started trace experiment.
1087 Set the user and notes of the trace run.
1091 Query the current status of a tracepoint.
1095 Query the minimum length of instruction at which a fast tracepoint may
1098 * Dcache size (number of lines) and line-size are now runtime-configurable
1099 via "set dcache line" and "set dcache line-size" commands.
1103 Texas Instruments TMS320C6x tic6x-*-*
1107 Renesas RL78 rl78-*-elf
1109 *** Changes in GDB 7.3.1
1111 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1113 *** Changes in GDB 7.3
1115 * GDB has a new command: "thread find [REGEXP]".
1116 It finds the thread id whose name, target id, or thread extra info
1117 matches the given regular expression.
1119 * The "catch syscall" command now works on mips*-linux* targets.
1121 * The -data-disassemble MI command now supports modes 2 and 3 for
1122 dumping the instruction opcodes.
1124 * New command line options
1126 -data-directory DIR Specify DIR as the "data-directory".
1127 This is mostly for testing purposes.
1129 * The "maint set python auto-load on|off" command has been renamed to
1130 "set auto-load-scripts on|off".
1132 * GDB has a new command: "set directories".
1133 It is like the "dir" command except that it replaces the
1134 source path list instead of augmenting it.
1136 * GDB now understands thread names.
1138 On GNU/Linux, "info threads" will display the thread name as set by
1139 prctl or pthread_setname_np.
1141 There is also a new command, "thread name", which can be used to
1142 assign a name internally for GDB to display.
1145 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1146 has been integrated into GDB.
1150 ** The function gdb.Write now accepts an optional keyword 'stream'.
1151 This keyword, when provided, will direct the output to either
1152 stdout, stderr, or GDB's logging output.
1154 ** Parameters can now be be sub-classed in Python, and in particular
1155 you may implement the get_set_doc and get_show_doc functions.
1156 This improves how Parameter set/show documentation is processed
1157 and allows for more dynamic content.
1159 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1160 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1161 have an is_valid method.
1163 ** Breakpoints can now be sub-classed in Python, and in particular
1164 you may implement a 'stop' function that is executed each time
1165 the inferior reaches that breakpoint.
1167 ** New function gdb.lookup_global_symbol looks up a global symbol.
1169 ** GDB values in Python are now callable if the value represents a
1170 function. For example, if 'some_value' represents a function that
1171 takes two integer parameters and returns a value, you can call
1172 that function like so:
1174 result = some_value (10,20)
1176 ** Module gdb.types has been added.
1177 It contains a collection of utilities for working with gdb.Types objects:
1178 get_basic_type, has_field, make_enum_dict.
1180 ** Module gdb.printing has been added.
1181 It contains utilities for writing and registering pretty-printers.
1182 New classes: PrettyPrinter, SubPrettyPrinter,
1183 RegexpCollectionPrettyPrinter.
1184 New function: register_pretty_printer.
1186 ** New commands "info pretty-printers", "enable pretty-printer" and
1187 "disable pretty-printer" have been added.
1189 ** gdb.parameter("directories") is now available.
1191 ** New function gdb.newest_frame returns the newest frame in the
1194 ** The gdb.InferiorThread class has a new "name" attribute. This
1195 holds the thread's name.
1197 ** Python Support for Inferior events.
1198 Python scripts can add observers to be notified of events
1199 occurring in the process being debugged.
1200 The following events are currently supported:
1201 - gdb.events.cont Continue event.
1202 - gdb.events.exited Inferior exited event.
1203 - gdb.events.stop Signal received, and Breakpoint hit events.
1207 ** GDB now puts template parameters in scope when debugging in an
1208 instantiation. For example, if you have:
1210 template<int X> int func (void) { return X; }
1212 then if you step into func<5>, "print X" will show "5". This
1213 feature requires proper debuginfo support from the compiler; it
1214 was added to GCC 4.5.
1216 ** The motion commands "next", "finish", "until", and "advance" now
1217 work better when exceptions are thrown. In particular, GDB will
1218 no longer lose control of the inferior; instead, the GDB will
1219 stop the inferior at the point at which the exception is caught.
1220 This functionality requires a change in the exception handling
1221 code that was introduced in GCC 4.5.
1223 * GDB now follows GCC's rules on accessing volatile objects when
1224 reading or writing target state during expression evaluation.
1225 One notable difference to prior behavior is that "print x = 0"
1226 no longer generates a read of x; the value of the assignment is
1227 now always taken directly from the value being assigned.
1229 * GDB now has some support for using labels in the program's source in
1230 linespecs. For instance, you can use "advance label" to continue
1231 execution to a label.
1233 * GDB now has support for reading and writing a new .gdb_index
1234 section. This section holds a fast index of DWARF debugging
1235 information and can be used to greatly speed up GDB startup and
1236 operation. See the documentation for `save gdb-index' for details.
1238 * The "watch" command now accepts an optional "-location" argument.
1239 When used, this causes GDB to watch the memory referred to by the
1240 expression. Such a watchpoint is never deleted due to it going out
1243 * GDB now supports thread debugging of core dumps on GNU/Linux.
1245 GDB now activates thread debugging using the libthread_db library
1246 when debugging GNU/Linux core dumps, similarly to when debugging
1247 live processes. As a result, when debugging a core dump file, GDB
1248 is now able to display pthread_t ids of threads. For example, "info
1249 threads" shows the same output as when debugging the process when it
1250 was live. In earlier releases, you'd see something like this:
1253 * 1 LWP 6780 main () at main.c:10
1255 While now you see this:
1258 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1260 It is also now possible to inspect TLS variables when debugging core
1263 When debugging a core dump generated on a machine other than the one
1264 used to run GDB, you may need to point GDB at the correct
1265 libthread_db library with the "set libthread-db-search-path"
1266 command. See the user manual for more details on this command.
1268 * When natively debugging programs on PowerPC BookE processors running
1269 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1270 which stop execution of the inferior whenever it executes an instruction
1271 at any address within the specified range. See the "PowerPC Embedded"
1272 section in the user manual for more details.
1274 * New features in the GDB remote stub, GDBserver
1276 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1277 and i686 LynxOS (version 5.x).
1279 ** GDBserver is now supported on Blackfin Linux.
1281 * New native configurations
1283 ia64 HP-UX ia64-*-hpux*
1287 Analog Devices, Inc. Blackfin Processor bfin-*
1289 * Ada task switching is now supported on sparc-elf targets when
1290 debugging a program using the Ravenscar Profile. For more information,
1291 see the "Tasking Support when using the Ravenscar Profile" section
1292 in the GDB user manual.
1294 * Guile support was removed.
1296 * New features in the GNU simulator
1298 ** The --map-info flag lists all known core mappings.
1300 ** CFI flashes may be simulated via the "cfi" device.
1302 *** Changes in GDB 7.2
1304 * Shared library support for remote targets by default
1306 When GDB is configured for a generic, non-OS specific target, like
1307 for example, --target=arm-eabi or one of the many *-*-elf targets,
1308 GDB now queries remote stubs for loaded shared libraries using the
1309 `qXfer:libraries:read' packet. Previously, shared library support
1310 was always disabled for such configurations.
1314 ** Argument Dependent Lookup (ADL)
1316 In C++ ADL lookup directs function search to the namespaces of its
1317 arguments even if the namespace has not been imported.
1327 Here the compiler will search for `foo' in the namespace of 'b'
1328 and find A::foo. GDB now supports this. This construct is commonly
1329 used in the Standard Template Library for operators.
1331 ** Improved User Defined Operator Support
1333 In addition to member operators, GDB now supports lookup of operators
1334 defined in a namespace and imported with a `using' directive, operators
1335 defined in the global scope, operators imported implicitly from an
1336 anonymous namespace, and the ADL operators mentioned in the previous
1338 GDB now also supports proper overload resolution for all the previously
1339 mentioned flavors of operators.
1341 ** static const class members
1343 Printing of static const class members that are initialized in the
1344 class definition has been fixed.
1346 * Windows Thread Information Block access.
1348 On Windows targets, GDB now supports displaying the Windows Thread
1349 Information Block (TIB) structure. This structure is visible either
1350 by using the new command `info w32 thread-information-block' or, by
1351 dereferencing the new convenience variable named `$_tlb', a
1352 thread-specific pointer to the TIB. This feature is also supported
1353 when remote debugging using GDBserver.
1355 * Static tracepoints
1357 Static tracepoints are calls in the user program into a tracing
1358 library. One such library is a port of the LTTng kernel tracer to
1359 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1360 When debugging with GDBserver, GDB now supports combining the GDB
1361 tracepoint machinery with such libraries. For example: the user can
1362 use GDB to probe a static tracepoint marker (a call from the user
1363 program into the tracing library) with the new "strace" command (see
1364 "New commands" below). This creates a "static tracepoint" in the
1365 breakpoint list, that can be manipulated with the same feature set
1366 as fast and regular tracepoints. E.g., collect registers, local and
1367 global variables, collect trace state variables, and define
1368 tracepoint conditions. In addition, the user can collect extra
1369 static tracepoint marker specific data, by collecting the new
1370 $_sdata internal variable. When analyzing the trace buffer, you can
1371 inspect $_sdata like any other variable available to GDB. For more
1372 information, see the "Tracepoints" chapter in GDB user manual. New
1373 remote packets have been defined to support static tracepoints, see
1374 the "New remote packets" section below.
1376 * Better reconstruction of tracepoints after disconnected tracing
1378 GDB will attempt to download the original source form of tracepoint
1379 definitions when starting a trace run, and then will upload these
1380 upon reconnection to the target, resulting in a more accurate
1381 reconstruction of the tracepoints that are in use on the target.
1385 You can now exercise direct control over the ways that GDB can
1386 affect your program. For instance, you can disallow the setting of
1387 breakpoints, so that the program can run continuously (assuming
1388 non-stop mode). In addition, the "observer" variable is available
1389 to switch all of the different controls; in observer mode, GDB
1390 cannot affect the target's behavior at all, which is useful for
1391 tasks like diagnosing live systems in the field.
1393 * The new convenience variable $_thread holds the number of the
1396 * New remote packets
1400 Return the address of the Windows Thread Information Block of a given thread.
1404 In response to several of the tracepoint packets, the target may now
1405 also respond with a number of intermediate `qRelocInsn' request
1406 packets before the final result packet, to have GDB handle
1407 relocating an instruction to execute at a different address. This
1408 is particularly useful for stubs that support fast tracepoints. GDB
1409 reports support for this feature in the qSupported packet.
1413 List static tracepoint markers in the target program.
1417 List static tracepoint markers at a given address in the target
1420 qXfer:statictrace:read
1422 Read the static trace data collected (by a `collect $_sdata'
1423 tracepoint action). The remote stub reports support for this packet
1424 to gdb's qSupported query.
1428 Send the current settings of GDB's permission flags.
1432 Send part of the source (textual) form of a tracepoint definition,
1433 which includes location, conditional, and action list.
1435 * The source command now accepts a -s option to force searching for the
1436 script in the source search path even if the script name specifies
1439 * New features in the GDB remote stub, GDBserver
1441 - GDBserver now support tracepoints (including fast tracepoints, and
1442 static tracepoints). The feature is currently supported by the
1443 i386-linux and amd64-linux builds. See the "Tracepoints support
1444 in gdbserver" section in the manual for more information.
1446 GDBserver JIT compiles the tracepoint's conditional agent
1447 expression bytecode into native code whenever possible for low
1448 overhead dynamic tracepoints conditionals. For such tracepoints,
1449 an expression that examines program state is evaluated when the
1450 tracepoint is reached, in order to determine whether to capture
1451 trace data. If the condition is simple and false, processing the
1452 tracepoint finishes very quickly and no data is gathered.
1454 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1455 for static tracepoints support.
1457 - GDBserver now supports x86_64 Windows 64-bit debugging.
1459 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1460 it understands register description.
1462 * The --batch flag now disables pagination and queries.
1464 * X86 general purpose registers
1466 GDB now supports reading/writing byte, word and double-word x86
1467 general purpose registers directly. This means you can use, say,
1468 $ah or $ax to refer, respectively, to the byte register AH and
1469 16-bit word register AX that are actually portions of the 32-bit
1470 register EAX or 64-bit register RAX.
1472 * The `commands' command now accepts a range of breakpoints to modify.
1473 A plain `commands' following a command that creates multiple
1474 breakpoints affects all the breakpoints set by that command. This
1475 applies to breakpoints set by `rbreak', and also applies when a
1476 single `break' command creates multiple breakpoints (e.g.,
1477 breakpoints on overloaded c++ functions).
1479 * The `rbreak' command now accepts a filename specification as part of
1480 its argument, limiting the functions selected by the regex to those
1481 in the specified file.
1483 * Support for remote debugging Windows and SymbianOS shared libraries
1484 from Unix hosts has been improved. Non Windows GDB builds now can
1485 understand target reported file names that follow MS-DOS based file
1486 system semantics, such as file names that include drive letters and
1487 use the backslash character as directory separator. This makes it
1488 possible to transparently use the "set sysroot" and "set
1489 solib-search-path" on Unix hosts to point as host copies of the
1490 target's shared libraries. See the new command "set
1491 target-file-system-kind" described below, and the "Commands to
1492 specify files" section in the user manual for more information.
1496 eval template, expressions...
1497 Convert the values of one or more expressions under the control
1498 of the string template to a command line, and call it.
1500 set target-file-system-kind unix|dos-based|auto
1501 show target-file-system-kind
1502 Set or show the assumed file system kind for target reported file
1505 save breakpoints <filename>
1506 Save all current breakpoint definitions to a file suitable for use
1507 in a later debugging session. To read the saved breakpoint
1508 definitions, use the `source' command.
1510 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1513 info static-tracepoint-markers
1514 Display information about static tracepoint markers in the target.
1516 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1517 Define a static tracepoint by probing a marker at the given
1518 function, line, address, or marker ID.
1522 Enable and disable observer mode.
1524 set may-write-registers on|off
1525 set may-write-memory on|off
1526 set may-insert-breakpoints on|off
1527 set may-insert-tracepoints on|off
1528 set may-insert-fast-tracepoints on|off
1529 set may-interrupt on|off
1530 Set individual permissions for GDB effects on the target. Note that
1531 some of these settings can have undesirable or surprising
1532 consequences, particularly when changed in the middle of a session.
1533 For instance, disabling the writing of memory can prevent
1534 breakpoints from being inserted, cause single-stepping to fail, or
1535 even crash your program, if you disable after breakpoints have been
1536 inserted. However, GDB should not crash.
1538 set record memory-query on|off
1539 show record memory-query
1540 Control whether to stop the inferior if memory changes caused
1541 by an instruction cannot be recorded.
1546 The disassemble command now supports "start,+length" form of two arguments.
1550 ** GDB now provides a new directory location, called the python directory,
1551 where Python scripts written for GDB can be installed. The location
1552 of that directory is <data-directory>/python, where <data-directory>
1553 is the GDB data directory. For more details, see section `Scripting
1554 GDB using Python' in the manual.
1556 ** The GDB Python API now has access to breakpoints, symbols, symbol
1557 tables, program spaces, inferiors, threads and frame's code blocks.
1558 Additionally, GDB Parameters can now be created from the API, and
1559 manipulated via set/show in the CLI.
1561 ** New functions gdb.target_charset, gdb.target_wide_charset,
1562 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1564 ** New exception gdb.GdbError.
1566 ** Pretty-printers are now also looked up in the current program space.
1568 ** Pretty-printers can now be individually enabled and disabled.
1570 ** GDB now looks for names of Python scripts to auto-load in a
1571 special section named `.debug_gdb_scripts', in addition to looking
1572 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1574 * Tracepoint actions were unified with breakpoint commands. In particular,
1575 there are no longer differences in "info break" output for breakpoints and
1576 tracepoints and the "commands" command can be used for both tracepoints and
1577 regular breakpoints.
1581 ARM Symbian arm*-*-symbianelf*
1583 * D language support.
1584 GDB now supports debugging programs written in the D programming
1587 * GDB now supports the extended ptrace interface for PowerPC which is
1588 available since Linux kernel version 2.6.34. This automatically enables
1589 any hardware breakpoints and additional hardware watchpoints available in
1590 the processor. The old ptrace interface exposes just one hardware
1591 watchpoint and no hardware breakpoints.
1593 * GDB is now able to use the Data Value Compare (DVC) register available on
1594 embedded PowerPC processors to implement in hardware simple watchpoint
1595 conditions of the form:
1597 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1599 This works in native GDB running on Linux kernels with the extended ptrace
1600 interface mentioned above.
1602 *** Changes in GDB 7.1
1606 ** Namespace Support
1608 GDB now supports importing of namespaces in C++. This enables the
1609 user to inspect variables from imported namespaces. Support for
1610 namepace aliasing has also been added. So, if a namespace is
1611 aliased in the current scope (e.g. namepace C=A; ) the user can
1612 print variables using the alias (e.g. (gdb) print C::x).
1616 All known bugs relating to the printing of virtual base class were
1617 fixed. It is now possible to call overloaded static methods using a
1622 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1623 and reinterpret_cast<> are now handled by the C++ expression parser.
1627 Xilinx MicroBlaze microblaze-*-*
1632 Xilinx MicroBlaze microblaze
1635 * Multi-program debugging.
1637 GDB now has support for multi-program (a.k.a. multi-executable or
1638 multi-exec) debugging. This allows for debugging multiple inferiors
1639 simultaneously each running a different program under the same GDB
1640 session. See "Debugging Multiple Inferiors and Programs" in the
1641 manual for more information. This implied some user visible changes
1642 in the multi-inferior support. For example, "info inferiors" now
1643 lists inferiors that are not running yet or that have exited
1644 already. See also "New commands" and "New options" below.
1646 * New tracing features
1648 GDB's tracepoint facility now includes several new features:
1650 ** Trace state variables
1652 GDB tracepoints now include support for trace state variables, which
1653 are variables managed by the target agent during a tracing
1654 experiment. They are useful for tracepoints that trigger each
1655 other, so for instance one tracepoint can count hits in a variable,
1656 and then a second tracepoint has a condition that is true when the
1657 count reaches a particular value. Trace state variables share the
1658 $-syntax of GDB convenience variables, and can appear in both
1659 tracepoint actions and condition expressions. Use the "tvariable"
1660 command to create, and "info tvariables" to view; see "Trace State
1661 Variables" in the manual for more detail.
1665 GDB now includes an option for defining fast tracepoints, which
1666 targets may implement more efficiently, such as by installing a jump
1667 into the target agent rather than a trap instruction. The resulting
1668 speedup can be by two orders of magnitude or more, although the
1669 tradeoff is that some program locations on some target architectures
1670 might not allow fast tracepoint installation, for instance if the
1671 instruction to be replaced is shorter than the jump. To request a
1672 fast tracepoint, use the "ftrace" command, with syntax identical to
1673 the regular trace command.
1675 ** Disconnected tracing
1677 It is now possible to detach GDB from the target while it is running
1678 a trace experiment, then reconnect later to see how the experiment
1679 is going. In addition, a new variable disconnected-tracing lets you
1680 tell the target agent whether to continue running a trace if the
1681 connection is lost unexpectedly.
1685 GDB now has the ability to save the trace buffer into a file, and
1686 then use that file as a target, similarly to you can do with
1687 corefiles. You can select trace frames, print data that was
1688 collected in them, and use tstatus to display the state of the
1689 tracing run at the moment that it was saved. To create a trace
1690 file, use "tsave <filename>", and to use it, do "target tfile
1693 ** Circular trace buffer
1695 You can ask the target agent to handle the trace buffer as a
1696 circular buffer, discarding the oldest trace frames to make room for
1697 newer ones, by setting circular-trace-buffer to on. This feature may
1698 not be available for all target agents.
1703 The disassemble command, when invoked with two arguments, now requires
1704 the arguments to be comma-separated.
1707 The info variables command now displays variable definitions. Files
1708 which only declare a variable are not shown.
1711 The source command is now capable of sourcing Python scripts.
1712 This feature is dependent on the debugger being build with Python
1715 Related to this enhancement is also the introduction of a new command
1716 "set script-extension" (see below).
1718 * New commands (for set/show, see "New options" below)
1720 record save [<FILENAME>]
1721 Save a file (in core file format) containing the process record
1722 execution log for replay debugging at a later time.
1724 record restore <FILENAME>
1725 Restore the process record execution log that was saved at an
1726 earlier time, for replay debugging.
1728 add-inferior [-copies <N>] [-exec <FILENAME>]
1731 clone-inferior [-copies <N>] [ID]
1732 Make a new inferior ready to execute the same program another
1733 inferior has loaded.
1738 maint info program-spaces
1739 List the program spaces loaded into GDB.
1741 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1742 show remote interrupt-sequence
1743 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1744 as the sequence to the remote target in order to interrupt the execution.
1745 Ctrl-C is a default. Some system prefers BREAK which is high level of
1746 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1747 Magic SysRq g. It is BREAK signal and character 'g'.
1749 set remote interrupt-on-connect [on | off]
1750 show remote interrupt-on-connect
1751 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1752 remote target when gdb connects to it. This is needed when you debug
1755 set remotebreak [on | off]
1757 Deprecated. Use "set/show remote interrupt-sequence" instead.
1759 tvariable $NAME [ = EXP ]
1760 Create or modify a trace state variable.
1763 List trace state variables and their values.
1765 delete tvariable $NAME ...
1766 Delete one or more trace state variables.
1769 Evaluate the given expressions without collecting anything into the
1770 trace buffer. (Valid in tracepoint actions only.)
1772 ftrace FN / FILE:LINE / *ADDR
1773 Define a fast tracepoint at the given function, line, or address.
1775 * New expression syntax
1777 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1778 GDB now parses 0b101010 identically with 42.
1782 set follow-exec-mode new|same
1783 show follow-exec-mode
1784 Control whether GDB reuses the same inferior across an exec call or
1785 creates a new one. This is useful to be able to restart the old
1786 executable after the inferior having done an exec call.
1788 set default-collect EXPR, ...
1789 show default-collect
1790 Define a list of expressions to be collected at each tracepoint.
1791 This is a useful way to ensure essential items are not overlooked,
1792 such as registers or a critical global variable.
1794 set disconnected-tracing
1795 show disconnected-tracing
1796 If set to 1, the target is instructed to continue tracing if it
1797 loses its connection to GDB. If 0, the target is to stop tracing
1800 set circular-trace-buffer
1801 show circular-trace-buffer
1802 If set to on, the target is instructed to use a circular trace buffer
1803 and discard the oldest trace frames instead of stopping the trace due
1804 to a full trace buffer. If set to off, the trace stops when the buffer
1805 fills up. Some targets may not support this.
1807 set script-extension off|soft|strict
1808 show script-extension
1809 If set to "off", the debugger does not perform any script language
1810 recognition, and all sourced files are assumed to be GDB scripts.
1811 If set to "soft" (the default), files are sourced according to
1812 filename extension, falling back to GDB scripts if the first
1814 If set to "strict", files are sourced according to filename extension.
1816 set ada trust-PAD-over-XVS on|off
1817 show ada trust-PAD-over-XVS
1818 If off, activate a workaround against a bug in the debugging information
1819 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1820 the GCC sources for more information about the GNAT encoding and
1821 PAD types in particular). It is always safe to set this option to
1822 off, but this introduces a slight performance penalty. The default
1825 * Python API Improvements
1827 ** GDB provides the new class gdb.LazyString. This is useful in
1828 some pretty-printing cases. The new method gdb.Value.lazy_string
1829 provides a simple way to create objects of this type.
1831 ** The fields returned by gdb.Type.fields now have an
1832 `is_base_class' attribute.
1834 ** The new method gdb.Type.range returns the range of an array type.
1836 ** The new method gdb.parse_and_eval can be used to parse and
1837 evaluate an expression.
1839 * New remote packets
1842 Define a trace state variable.
1845 Get the current value of a trace state variable.
1848 Set desired tracing behavior upon disconnection.
1851 Set the trace buffer to be linear or circular.
1854 Get data about the tracepoints currently in use.
1858 Process record now works correctly with hardware watchpoints.
1860 Multiple bug fixes have been made to the mips-irix port, making it
1861 much more reliable. In particular:
1862 - Debugging threaded applications is now possible again. Previously,
1863 GDB would hang while starting the program, or while waiting for
1864 the program to stop at a breakpoint.
1865 - Attaching to a running process no longer hangs.
1866 - An error occurring while loading a core file has been fixed.
1867 - Changing the value of the PC register now works again. This fixes
1868 problems observed when using the "jump" command, or when calling
1869 a function from GDB, or even when assigning a new value to $pc.
1870 - With the "finish" and "return" commands, the return value for functions
1871 returning a small array is now correctly printed.
1872 - It is now possible to break on shared library code which gets executed
1873 during a shared library init phase (code executed while executing
1874 their .init section). Previously, the breakpoint would have no effect.
1875 - GDB is now able to backtrace through the signal handler for
1876 non-threaded programs.
1878 PIE (Position Independent Executable) programs debugging is now supported.
1879 This includes debugging execution of PIC (Position Independent Code) shared
1880 libraries although for that, it should be possible to run such libraries as an
1883 *** Changes in GDB 7.0
1885 * GDB now has an interface for JIT compilation. Applications that
1886 dynamically generate code can create symbol files in memory and register
1887 them with GDB. For users, the feature should work transparently, and
1888 for JIT developers, the interface is documented in the GDB manual in the
1889 "JIT Compilation Interface" chapter.
1891 * Tracepoints may now be conditional. The syntax is as for
1892 breakpoints; either an "if" clause appended to the "trace" command,
1893 or the "condition" command is available. GDB sends the condition to
1894 the target for evaluation using the same bytecode format as is used
1895 for tracepoint actions.
1897 * The disassemble command now supports: an optional /r modifier, print the
1898 raw instructions in hex as well as in symbolic form, and an optional /m
1899 modifier to print mixed source+assembly.
1901 * Process record and replay
1903 In a architecture environment that supports ``process record and
1904 replay'', ``process record and replay'' target can record a log of
1905 the process execution, and replay it with both forward and reverse
1908 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
1909 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
1910 set execution-direction {forward|reverse}, for targets that support
1913 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
1914 feature is available with a native GDB running on kernel version
1917 * GDB now has support for multi-byte and wide character sets on the
1918 target. Strings whose character type is wchar_t, char16_t, or
1919 char32_t are now correctly printed. GDB supports wide- and unicode-
1920 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
1921 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
1922 `printf'. This feature requires iconv to work properly; if your
1923 system does not have a working iconv, GDB can use GNU libiconv. See
1924 the installation instructions for more information.
1926 * GDB now supports automatic retrieval of shared library files from
1927 remote targets. To use this feature, specify a system root that begins
1928 with the `remote:' prefix, either via the `set sysroot' command or via
1929 the `--with-sysroot' configure-time option.
1931 * "info sharedlibrary" now takes an optional regex of libraries to show,
1932 and it now reports if a shared library has no debugging information.
1934 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
1935 now complete on file names.
1937 * When completing in expressions, gdb will attempt to limit
1938 completions to allowable structure or union fields, where appropriate.
1939 For instance, consider:
1941 # struct example { int f1; double f2; };
1942 # struct example variable;
1945 If the user types TAB at the end of this command line, the available
1946 completions will be "f1" and "f2".
1948 * Inlined functions are now supported. They show up in backtraces, and
1949 the "step", "next", and "finish" commands handle them automatically.
1951 * GDB now supports the token-splicing (##) and stringification (#)
1952 operators when expanding macros. It also supports variable-arity
1955 * GDB now supports inspecting extra signal information, exported by
1956 the new $_siginfo convenience variable. The feature is currently
1957 implemented on linux ARM, i386 and amd64.
1959 * GDB can now display the VFP floating point registers and NEON vector
1960 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
1961 can provide these registers (requires Linux 2.6.30 or later). Remote
1962 and simulator targets may also provide them.
1964 * New remote packets
1967 Search memory for a sequence of bytes.
1970 Turn off `+'/`-' protocol acknowledgments to permit more efficient
1971 operation over reliable transport links. Use of this packet is
1972 controlled by the `set remote noack-packet' command.
1975 Kill the process with the specified process ID. Use this in preference
1976 to `k' when multiprocess protocol extensions are supported.
1979 Obtains additional operating system information
1983 Read or write additional signal information.
1985 * Removed remote protocol undocumented extension
1987 An undocumented extension to the remote protocol's `S' stop reply
1988 packet that permited the stub to pass a process id was removed.
1989 Remote servers should use the `T' stop reply packet instead.
1991 * GDB now supports multiple function calling conventions according to the
1992 DWARF-2 DW_AT_calling_convention function attribute.
1994 * The SH target utilizes the aforementioned change to distinguish between gcc
1995 and Renesas calling convention. It also adds the new CLI commands
1996 `set/show sh calling-convention'.
1998 * GDB can now read compressed debug sections, as produced by GNU gold
1999 with the --compress-debug-sections=zlib flag.
2001 * 64-bit core files are now supported on AIX.
2003 * Thread switching is now supported on Tru64.
2005 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2006 which will be allocated using malloc later in program execution.
2008 * The qXfer:libraries:read remote procotol packet now allows passing a
2009 list of section offsets.
2011 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2012 conditions handling signals delivered during attach or thread creation
2013 have also been fixed.
2015 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2016 From the user's standpoint, all unqualified instances of True and False
2017 are treated as the standard definitions, regardless of context.
2019 * GDB now parses C++ symbol and type names more flexibly. For
2022 template<typename T> class C { };
2025 GDB will now correctly handle all of:
2027 ptype C<char const *>
2028 ptype C<char const*>
2029 ptype C<const char *>
2030 ptype C<const char*>
2032 * New features in the GDB remote stub, gdbserver
2034 - The "--wrapper" command-line argument tells gdbserver to use a
2035 wrapper program to launch programs for debugging.
2037 - On PowerPC and S/390 targets, it is now possible to use a single
2038 gdbserver executable to debug both 32-bit and 64-bit programs.
2039 (This requires gdbserver itself to be built as a 64-bit executable.)
2041 - gdbserver uses the new noack protocol mode for TCP connections to
2042 reduce communications latency, if also supported and enabled in GDB.
2044 - Support for the sparc64-linux-gnu target is now included in
2047 - The amd64-linux build of gdbserver now supports debugging both
2048 32-bit and 64-bit programs.
2050 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2051 now support hardware watchpoints, and will use them automatically
2056 GDB now has support for scripting using Python. Whether this is
2057 available is determined at configure time.
2059 New GDB commands can now be written in Python.
2061 * Ada tasking support
2063 Ada tasks can now be inspected in GDB. The following commands have
2067 Print the list of Ada tasks.
2069 Print detailed information about task number N.
2071 Print the task number of the current task.
2073 Switch the context of debugging to task number N.
2075 * Support for user-defined prefixed commands. The "define" command can
2076 add new commands to existing prefixes, e.g. "target".
2078 * Multi-inferior, multi-process debugging.
2080 GDB now has generalized support for multi-inferior debugging. See
2081 "Debugging Multiple Inferiors" in the manual for more information.
2082 Although availability still depends on target support, the command
2083 set is more uniform now. The GNU/Linux specific multi-forks support
2084 has been migrated to this new framework. This implied some user
2085 visible changes; see "New commands" and also "Removed commands"
2088 * Target descriptions can now describe the target OS ABI. See the
2089 "Target Description Format" section in the user manual for more
2092 * Target descriptions can now describe "compatible" architectures
2093 to indicate that the target can execute applications for a different
2094 architecture in addition to those for the main target architecture.
2095 See the "Target Description Format" section in the user manual for
2098 * Multi-architecture debugging.
2100 GDB now includes general supports for debugging applications on
2101 hybrid systems that use more than one single processor architecture
2102 at the same time. Each such hybrid architecture still requires
2103 specific support to be added. The only hybrid architecture supported
2104 in this version of GDB is the Cell Broadband Engine.
2106 * GDB now supports integrated debugging of Cell/B.E. applications that
2107 use both the PPU and SPU architectures. To enable support for hybrid
2108 Cell/B.E. debugging, you need to configure GDB to support both the
2109 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2110 --enable-targets configure option.
2112 * Non-stop mode debugging.
2114 For some targets, GDB now supports an optional mode of operation in
2115 which you can examine stopped threads while other threads continue
2116 to execute freely. This is referred to as non-stop mode, with the
2117 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2118 section in the user manual for more information.
2120 To be able to support remote non-stop debugging, a remote stub needs
2121 to implement the non-stop mode remote protocol extensions, as
2122 described in the "Remote Non-Stop" section of the user manual. The
2123 GDB remote stub, gdbserver, has been adjusted to support these
2124 extensions on linux targets.
2126 * New commands (for set/show, see "New options" below)
2128 catch syscall [NAME(S) | NUMBER(S)]
2129 Catch system calls. Arguments, which should be names of system
2130 calls or their numbers, mean catch only those syscalls. Without
2131 arguments, every syscall will be caught. When the inferior issues
2132 any of the specified syscalls, GDB will stop and announce the system
2133 call, both when it is called and when its call returns. This
2134 feature is currently available with a native GDB running on the
2135 Linux Kernel, under the following architectures: x86, x86_64,
2136 PowerPC and PowerPC64.
2138 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2140 Search memory for a sequence of bytes.
2142 maint set python print-stack
2143 maint show python print-stack
2144 Show a stack trace when an error is encountered in a Python script.
2147 Invoke CODE by passing it to the Python interpreter.
2152 These allow macros to be defined, undefined, and listed
2156 Show operating system information about processes.
2159 List the inferiors currently under GDB's control.
2162 Switch focus to inferior number NUM.
2165 Detach from inferior number NUM.
2168 Kill inferior number NUM.
2172 set spu stop-on-load
2173 show spu stop-on-load
2174 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2176 set spu auto-flush-cache
2177 show spu auto-flush-cache
2178 Control whether to automatically flush the software-managed cache
2179 during Cell/B.E. debugging.
2181 set sh calling-convention
2182 show sh calling-convention
2183 Control the calling convention used when calling SH target functions.
2186 show debug timestamp
2187 Control display of timestamps with GDB debugging output.
2189 set disassemble-next-line
2190 show disassemble-next-line
2191 Control display of disassembled source lines or instructions when
2194 set remote noack-packet
2195 show remote noack-packet
2196 Set/show the use of remote protocol QStartNoAckMode packet. See above
2197 under "New remote packets."
2199 set remote query-attached-packet
2200 show remote query-attached-packet
2201 Control use of remote protocol `qAttached' (query-attached) packet.
2203 set remote read-siginfo-object
2204 show remote read-siginfo-object
2205 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2208 set remote write-siginfo-object
2209 show remote write-siginfo-object
2210 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2213 set remote reverse-continue
2214 show remote reverse-continue
2215 Control use of remote protocol 'bc' (reverse-continue) packet.
2217 set remote reverse-step
2218 show remote reverse-step
2219 Control use of remote protocol 'bs' (reverse-step) packet.
2221 set displaced-stepping
2222 show displaced-stepping
2223 Control displaced stepping mode. Displaced stepping is a way to
2224 single-step over breakpoints without removing them from the debuggee.
2225 Also known as "out-of-line single-stepping".
2228 show debug displaced
2229 Control display of debugging info for displaced stepping.
2231 maint set internal-error
2232 maint show internal-error
2233 Control what GDB does when an internal error is detected.
2235 maint set internal-warning
2236 maint show internal-warning
2237 Control what GDB does when an internal warning is detected.
2242 Use a wrapper program to launch programs for debugging.
2244 set multiple-symbols (all|ask|cancel)
2245 show multiple-symbols
2246 The value of this variable can be changed to adjust the debugger behavior
2247 when an expression or a breakpoint location contains an ambiguous symbol
2248 name (an overloaded function name, for instance).
2250 set breakpoint always-inserted
2251 show breakpoint always-inserted
2252 Keep breakpoints always inserted in the target, as opposed to inserting
2253 them when resuming the target, and removing them when the target stops.
2254 This option can improve debugger performance on slow remote targets.
2256 set arm fallback-mode (arm|thumb|auto)
2257 show arm fallback-mode
2258 set arm force-mode (arm|thumb|auto)
2260 These commands control how ARM GDB determines whether instructions
2261 are ARM or Thumb. The default for both settings is auto, which uses
2262 the current CPSR value for instructions without symbols; previous
2263 versions of GDB behaved as if "set arm fallback-mode arm".
2265 set disable-randomization
2266 show disable-randomization
2267 Standalone programs run with the virtual address space randomization enabled
2268 by default on some platforms. This option keeps the addresses stable across
2269 multiple debugging sessions.
2273 Control whether other threads are stopped or not when some thread hits
2278 Requests that asynchronous execution is enabled in the target, if available.
2279 In this case, it's possible to resume target in the background, and interact
2280 with GDB while the target is running. "show target-async" displays the
2281 current state of asynchronous execution of the target.
2283 set target-wide-charset
2284 show target-wide-charset
2285 The target-wide-charset is the name of the character set that GDB
2286 uses when printing characters whose type is wchar_t.
2288 set tcp auto-retry (on|off)
2290 set tcp connect-timeout
2291 show tcp connect-timeout
2292 These commands allow GDB to retry failed TCP connections to a remote stub
2293 with a specified timeout period; this is useful if the stub is launched
2294 in parallel with GDB but may not be ready to accept connections immediately.
2296 set libthread-db-search-path
2297 show libthread-db-search-path
2298 Control list of directories which GDB will search for appropriate
2301 set schedule-multiple (on|off)
2302 show schedule-multiple
2303 Allow GDB to resume all threads of all processes or only threads of
2304 the current process.
2308 Use more aggressive caching for accesses to the stack. This improves
2309 performance of remote debugging (particularly backtraces) without
2310 affecting correctness.
2312 set interactive-mode (on|off|auto)
2313 show interactive-mode
2314 Control whether GDB runs in interactive mode (on) or not (off).
2315 When in interactive mode, GDB waits for the user to answer all
2316 queries. Otherwise, GDB does not wait and assumes the default
2317 answer. When set to auto (the default), GDB determines which
2318 mode to use based on the stdin settings.
2323 For program forks, this is replaced by the new more generic `info
2324 inferiors' command. To list checkpoints, you can still use the
2325 `info checkpoints' command, which was an alias for the `info forks'
2329 Replaced by the new `inferior' command. To switch between
2330 checkpoints, you can still use the `restart' command, which was an
2331 alias for the `fork' command.
2334 This is removed, since some targets don't have a notion of
2335 processes. To switch between processes, you can still use the
2336 `inferior' command using GDB's own inferior number.
2339 For program forks, this is replaced by the new more generic `kill
2340 inferior' command. To delete a checkpoint, you can still use the
2341 `delete checkpoint' command, which was an alias for the `delete
2345 For program forks, this is replaced by the new more generic `detach
2346 inferior' command. To detach a checkpoint, you can still use the
2347 `detach checkpoint' command, which was an alias for the `detach
2350 * New native configurations
2352 x86/x86_64 Darwin i[34567]86-*-darwin*
2354 x86_64 MinGW x86_64-*-mingw*
2358 Lattice Mico32 lm32-*
2359 x86 DICOS i[34567]86-*-dicos*
2360 x86_64 DICOS x86_64-*-dicos*
2363 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2364 (mingw32ce) debugging.
2370 These commands were actually not implemented on any target.
2372 *** Changes in GDB 6.8
2374 * New native configurations
2376 NetBSD/hppa hppa*-*netbsd*
2377 Xtensa GNU/Linux xtensa*-*-linux*
2381 NetBSD/hppa hppa*-*-netbsd*
2382 Xtensa GNU/Lunux xtensa*-*-linux*
2384 * Change in command line behavior -- corefiles vs. process ids.
2386 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2387 attaching to process NUMBER fails, GDB no longer attempts to open a
2388 core file named NUMBER. Attaching to a program using the -c option
2389 is no longer supported. Instead, use the '-p' or '--pid' options.
2391 * GDB can now be built as a native debugger for debugging Windows x86
2392 (mingw32) Portable Executable (PE) programs.
2394 * Pending breakpoints no longer change their number when their address
2397 * GDB now supports breakpoints with multiple locations,
2398 including breakpoints on C++ constructors, inside C++ templates,
2399 and in inlined functions.
2401 * GDB's ability to debug optimized code has been improved. GDB more
2402 accurately identifies function bodies and lexical blocks that occupy
2403 more than one contiguous range of addresses.
2405 * Target descriptions can now describe registers for PowerPC.
2407 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2408 registers on PowerPC targets.
2410 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2411 targets even when the libthread_db library is not available.
2413 * The GDB remote stub, gdbserver, now supports the new file transfer
2414 commands (remote put, remote get, and remote delete).
2416 * The GDB remote stub, gdbserver, now supports run and attach in
2417 extended-remote mode.
2419 * hppa*64*-*-hpux11* target broken
2420 The debugger is unable to start a program and fails with the following
2421 error: "Error trying to get information about dynamic linker".
2422 The gdb-6.7 release is also affected.
2424 * GDB now supports the --enable-targets= configure option to allow
2425 building a single GDB executable that supports multiple remote
2426 target architectures.
2428 * GDB now supports debugging C and C++ programs which use the
2429 Decimal Floating Point extension. In addition, the PowerPC target
2430 now has a set of pseudo-registers to inspect decimal float values
2431 stored in two consecutive float registers.
2433 * The -break-insert MI command can optionally create pending
2436 * Improved support for debugging Ada
2437 Many improvements to the Ada language support have been made. These
2439 - Better support for Ada2005 interface types
2440 - Improved handling of arrays and slices in general
2441 - Better support for Taft-amendment types
2442 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2444 - Improved command completion in Ada
2447 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2452 set print frame-arguments (all|scalars|none)
2453 show print frame-arguments
2454 The value of this variable can be changed to control which argument
2455 values should be printed by the debugger when displaying a frame.
2460 Transfer files to and from a remote target, and delete remote files.
2467 Transfer files to and from a remote target, and delete remote files.
2469 * New remote packets
2476 Open, close, read, write, and delete files on the remote system.
2479 Attach to an existing process on the remote system, in extended-remote
2483 Run a new process on the remote system, in extended-remote mode.
2485 *** Changes in GDB 6.7
2487 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2488 bfd, libiberty and opcodes, as revealed by static analysis donated by
2489 Coverity, Inc. (http://scan.coverity.com).
2491 * When looking up multiply-defined global symbols, GDB will now prefer the
2492 symbol definition in the current shared library if it was built using the
2493 -Bsymbolic linker option.
2495 * When the Text User Interface (TUI) is not configured, GDB will now
2496 recognize the -tui command-line option and print a message that the TUI
2499 * The GDB remote stub, gdbserver, now has lower overhead for high
2500 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2502 * GDB for MIPS targets now autodetects whether a remote target provides
2503 32-bit or 64-bit register values.
2505 * Support for C++ member pointers has been improved.
2507 * GDB now understands XML target descriptions, which specify the
2508 target's overall architecture. GDB can read a description from
2509 a local file or over the remote serial protocol.
2511 * Vectors of single-byte data use a new integer type which is not
2512 automatically displayed as character or string data.
2514 * The /s format now works with the print command. It displays
2515 arrays of single-byte integers and pointers to single-byte integers
2518 * Target descriptions can now describe target-specific registers,
2519 for architectures which have implemented the support (currently
2520 only ARM, M68K, and MIPS).
2522 * GDB and the GDB remote stub, gdbserver, now support the XScale
2525 * The GDB remote stub, gdbserver, has been updated to support
2526 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2527 has been rewritten to use the standard GDB remote protocol.
2529 * GDB can now step into C++ functions which are called through thunks.
2531 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2533 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2534 layout. It also supports a TextSeg= and DataSeg= response when only
2535 segment base addresses (rather than offsets) are available.
2537 * The /i format now outputs any trailing branch delay slot instructions
2538 immediately following the last instruction within the count specified.
2540 * The GDB remote protocol "T" stop reply packet now supports a
2541 "library" response. Combined with the new "qXfer:libraries:read"
2542 packet, this response allows GDB to debug shared libraries on targets
2543 where the operating system manages the list of loaded libraries (e.g.
2544 Windows and SymbianOS).
2546 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2547 (DLLs) on Windows and Windows CE targets.
2549 * GDB now supports a faster verification that a .debug file matches its binary
2550 according to its build-id signature, if the signature is present.
2556 Enable or disable hardware flow control (RTS/CTS) on the serial port
2557 when debugging using remote targets.
2559 set mem inaccessible-by-default
2560 show mem inaccessible-by-default
2561 If the target supplies a memory map, for instance via the remote
2562 protocol's "qXfer:memory-map:read" packet, setting this variable
2563 prevents GDB from accessing memory outside the memory map. This
2564 is useful for targets with memory mapped registers or which react
2565 badly to accesses of unmapped address space.
2567 set breakpoint auto-hw
2568 show breakpoint auto-hw
2569 If the target supplies a memory map, for instance via the remote
2570 protocol's "qXfer:memory-map:read" packet, setting this variable
2571 lets GDB use hardware breakpoints automatically for memory regions
2572 where it can not use software breakpoints. This covers both the
2573 "break" command and internal breakpoints used for other commands
2574 including "next" and "finish".
2577 catch exception unhandled
2578 Stop the program execution when Ada exceptions are raised.
2581 Stop the program execution when an Ada assertion failed.
2585 Set an alternate system root for target files. This is a more
2586 general version of "set solib-absolute-prefix", which is now
2587 an alias to "set sysroot".
2590 Provide extended SPU facility status information. This set of
2591 commands is available only when debugging the Cell/B.E. SPU
2594 * New native configurations
2596 OpenBSD/sh sh*-*openbsd*
2599 unset tdesc filename
2601 Use the specified local file as an XML target description, and do
2602 not query the target for its built-in description.
2606 OpenBSD/sh sh*-*-openbsd*
2607 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2608 Toshiba Media Processor mep-elf
2610 * New remote packets
2613 Ignore the specified signals; pass them directly to the debugged program
2614 without stopping other threads or reporting them to GDB.
2616 qXfer:features:read:
2617 Read an XML target description from the target, which describes its
2622 Read or write contents of an spufs file on the target system. These
2623 packets are available only on the Cell/B.E. SPU architecture.
2625 qXfer:libraries:read:
2626 Report the loaded shared libraries. Combined with new "T" packet
2627 response, this packet allows GDB to debug shared libraries on
2628 targets where the operating system manages the list of loaded
2629 libraries (e.g. Windows and SymbianOS).
2633 Support for these obsolete configurations has been removed.
2641 i[34567]86-*-lynxos*
2642 i[34567]86-*-netware*
2643 i[34567]86-*-sco3.2v5*
2644 i[34567]86-*-sco3.2v4*
2646 i[34567]86-*-sysv4.2*
2649 i[34567]86-*-unixware2*
2650 i[34567]86-*-unixware*
2659 * Other removed features
2666 Various m68k-only ROM monitors.
2673 Various Renesas ROM monitors and debugging interfaces for SH and
2678 Support for a Macraigor serial interface to on-chip debugging.
2679 GDB does not directly support the newer parallel or USB
2684 A debug information format. The predecessor to DWARF 2 and
2685 DWARF 3, which are still supported.
2687 Support for the HP aCC compiler on HP-UX/PA-RISC
2689 SOM-encapsulated symbolic debugging information, automatic
2690 invocation of pxdb, and the aCC custom C++ ABI. This does not
2691 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2692 with aCC can still be debugged on an assembly level.
2694 MIPS ".pdr" sections
2696 A MIPS-specific format used to describe stack frame layout
2697 in debugging information.
2701 GDB could work with an older version of Guile to debug
2702 the interpreter and Scheme programs running in it.
2704 set mips stack-arg-size
2705 set mips saved-gpreg-size
2707 Use "set mips abi" to control parameter passing for MIPS.
2709 *** Changes in GDB 6.6
2714 Cell Broadband Engine SPU spu-elf
2716 * GDB can now be configured as a cross-debugger targeting native Windows
2717 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2718 running on a Windows system over TCP/IP to debug Windows programs.
2720 * The GDB remote stub, gdbserver, has been updated to support Windows and
2721 Cygwin debugging. Both single-threaded and multi-threaded programs are
2724 * The "set trust-readonly-sections" command works again. This command was
2725 broken in GDB 6.3, 6.4, and 6.5.
2727 * The "load" command now supports writing to flash memory, if the remote
2728 stub provides the required support.
2730 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2731 longer requires symbolic debug information (e.g. DWARF-2).
2736 unset substitute-path
2737 show substitute-path
2738 Manage a list of substitution rules that GDB uses to rewrite the name
2739 of the directories where the sources are located. This can be useful
2740 for instance when the sources were moved to a different location
2741 between compilation and debugging.
2745 Print each CLI command as it is executed. Each command is prefixed with
2746 a number of `+' symbols representing the nesting depth.
2747 The source command now has a `-v' option to enable the same feature.
2751 The ARM Demon monitor support (RDP protocol, "target rdp").
2753 Kernel Object Display, an embedded debugging feature which only worked with
2754 an obsolete version of Cisco IOS.
2756 The 'set download-write-size' and 'show download-write-size' commands.
2758 * New remote packets
2761 Tell a stub about GDB client features, and request remote target features.
2762 The first feature implemented is PacketSize, which allows the target to
2763 specify the size of packets it can handle - to minimize the number of
2764 packets required and improve performance when connected to a remote
2768 Fetch an OS auxilliary vector from the remote stub. This packet is a
2769 more efficient replacement for qPart:auxv:read.
2771 qXfer:memory-map:read:
2772 Fetch a memory map from the remote stub, including information about
2773 RAM, ROM, and flash memory devices.
2778 Erase and program a flash memory device.
2780 * Removed remote packets
2783 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2784 used it, and only gdbserver implemented it.
2786 *** Changes in GDB 6.5
2790 Renesas M32C/M16C m32c-elf
2792 Morpho Technologies ms1 ms1-elf
2796 init-if-undefined Initialize a convenience variable, but
2797 only if it doesn't already have a value.
2799 The following commands are presently only implemented for native GNU/Linux:
2801 checkpoint Save a snapshot of the program state.
2803 restart <n> Return the program state to a
2804 previously saved state.
2806 info checkpoints List currently saved checkpoints.
2808 delete-checkpoint <n> Delete a previously saved checkpoint.
2810 set|show detach-on-fork Tell gdb whether to detach from a newly
2811 forked process, or to keep debugging it.
2813 info forks List forks of the user program that
2814 are available to be debugged.
2816 fork <n> Switch to debugging one of several
2817 forks of the user program that are
2818 available to be debugged.
2820 delete-fork <n> Delete a fork from the list of forks
2821 that are available to be debugged (and
2822 kill the forked process).
2824 detach-fork <n> Delete a fork from the list of forks
2825 that are available to be debugged (and
2826 allow the process to continue).
2830 Morpho Technologies ms2 ms1-elf
2832 * Improved Windows host support
2834 GDB now builds as a cross debugger hosted on i686-mingw32, including
2835 native console support, and remote communications using either
2836 network sockets or serial ports.
2838 * Improved Modula-2 language support
2840 GDB can now print most types in the Modula-2 syntax. This includes:
2841 basic types, set types, record types, enumerated types, range types,
2842 pointer types and ARRAY types. Procedure var parameters are correctly
2843 printed and hexadecimal addresses and character constants are also
2844 written in the Modula-2 syntax. Best results can be obtained by using
2845 GNU Modula-2 together with the -gdwarf-2 command line option.
2849 The ARM rdi-share module.
2851 The Netware NLM debug server.
2853 *** Changes in GDB 6.4
2855 * New native configurations
2857 OpenBSD/arm arm*-*-openbsd*
2858 OpenBSD/mips64 mips64-*-openbsd*
2862 Morpho Technologies ms1 ms1-elf
2864 * New command line options
2866 --batch-silent As for --batch, but totally silent.
2867 --return-child-result The debugger will exist with the same value
2868 the child (debugged) program exited with.
2869 --eval-command COMMAND, -ex COMMAND
2870 Execute a single GDB CLI command. This may be
2871 specified multiple times and in conjunction
2872 with the --command (-x) option.
2874 * Deprecated commands removed
2876 The following commands, that were deprecated in 2000, have been
2880 set|show arm disassembly-flavor set|show arm disassembler
2881 othernames set arm disassembler
2882 set|show remotedebug set|show debug remote
2883 set|show archdebug set|show debug arch
2884 set|show eventdebug set|show debug event
2887 * New BSD user-level threads support
2889 It is now possible to debug programs using the user-level threads
2890 library on OpenBSD and FreeBSD. Currently supported (target)
2893 FreeBSD/amd64 x86_64-*-freebsd*
2894 FreeBSD/i386 i386-*-freebsd*
2895 OpenBSD/i386 i386-*-openbsd*
2897 Note that the new kernel threads libraries introduced in FreeBSD 5.x
2898 are not yet supported.
2900 * New support for Matsushita MN10300 w/sim added
2901 (Work in progress). mn10300-elf.
2903 * REMOVED configurations and files
2905 VxWorks and the XDR protocol *-*-vxworks
2906 Motorola MCORE mcore-*-*
2907 National Semiconductor NS32000 ns32k-*-*
2909 * New "set print array-indexes" command
2911 After turning this setting "on", GDB prints the index of each element
2912 when displaying arrays. The default is "off" to preserve the previous
2915 * VAX floating point support
2917 GDB now supports the not-quite-ieee VAX F and D floating point formats.
2919 * User-defined command support
2921 In addition to using $arg0..$arg9 for argument passing, it is now possible
2922 to use $argc to determine now many arguments have been passed. See the
2923 section on user-defined commands in the user manual for more information.
2925 *** Changes in GDB 6.3:
2927 * New command line option
2929 GDB now accepts -l followed by a number to set the timeout for remote
2932 * GDB works with GCC -feliminate-dwarf2-dups
2934 GDB now supports a more compact representation of DWARF-2 debug
2935 information using DW_FORM_ref_addr references. These are produced
2936 by GCC with the option -feliminate-dwarf2-dups and also by some
2937 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
2938 to use -feliminate-dwarf2-dups.
2940 * Internationalization
2942 When supported by the host system, GDB will be built with
2943 internationalization (libintl). The task of marking up the sources is
2944 continued, we're looking forward to our first translation.
2948 Initial support for debugging programs compiled with the GNAT
2949 implementation of the Ada programming language has been integrated
2950 into GDB. In this release, support is limited to expression evaluation.
2952 * New native configurations
2954 GNU/Linux/m32r m32r-*-linux-gnu
2958 GDB's remote protocol now includes support for the 'p' packet. This
2959 packet is used to fetch individual registers from a remote inferior.
2961 * END-OF-LIFE registers[] compatibility module
2963 GDB's internal register infrastructure has been completely rewritten.
2964 The new infrastructure making possible the implementation of key new
2965 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
2968 GDB 6.3 will be the last release to include the the registers[]
2969 compatibility module that allowed out-of-date configurations to
2970 continue to work. This change directly impacts the following
2980 powerpc bdm protocol
2982 Unless there is activity to revive these configurations, they will be
2983 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
2985 * OBSOLETE configurations and files
2987 Configurations that have been declared obsolete in this release have
2988 been commented out. Unless there is activity to revive these
2989 configurations, the next release of GDB will have their sources
2990 permanently REMOVED.
2999 *** Changes in GDB 6.2.1:
3001 * MIPS `break main; run' gave an heuristic-fence-post warning
3003 When attempting to run even a simple program, a warning about
3004 heuristic-fence-post being hit would be reported. This problem has
3007 * MIPS IRIX 'long double' crashed GDB
3009 When examining a long double variable, GDB would get a segmentation
3010 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3011 IRIX long double values).
3015 A bug in the VAX stack code was causing problems with the "next"
3016 command. This problem has been fixed.
3018 *** Changes in GDB 6.2:
3020 * Fix for ``many threads''
3022 On GNU/Linux systems that use the NPTL threads library, a program
3023 rapidly creating and deleting threads would confuse GDB leading to the
3026 ptrace: No such process.
3027 thread_db_get_info: cannot get thread info: generic error
3029 This problem has been fixed.
3031 * "-async" and "-noasync" options removed.
3033 Support for the broken "-noasync" option has been removed (it caused
3036 * New ``start'' command.
3038 This command runs the program until the begining of the main procedure.
3040 * New BSD Kernel Data Access Library (libkvm) interface
3042 Using ``target kvm'' it is now possible to debug kernel core dumps and
3043 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3044 platforms. Currently supported (native-only) configurations are:
3046 FreeBSD/amd64 x86_64-*-freebsd*
3047 FreeBSD/i386 i?86-*-freebsd*
3048 NetBSD/i386 i?86-*-netbsd*
3049 NetBSD/m68k m68*-*-netbsd*
3050 NetBSD/sparc sparc-*-netbsd*
3051 OpenBSD/amd64 x86_64-*-openbsd*
3052 OpenBSD/i386 i?86-*-openbsd*
3053 OpenBSD/m68k m68*-openbsd*
3054 OpenBSD/sparc sparc-*-openbsd*
3056 * Signal trampoline code overhauled
3058 Many generic problems with GDB's signal handling code have been fixed.
3059 These include: backtraces through non-contiguous stacks; recognition
3060 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3061 call; backtrace through a signal trampoline; step into and out of
3062 signal handlers; and single-stepping in the signal trampoline.
3064 Please note that kernel bugs are a limiting factor here. These
3065 features have been shown to work on an s390 GNU/Linux system that
3066 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3068 * Cygwin support for DWARF 2 added.
3070 * New native configurations
3072 GNU/Linux/hppa hppa*-*-linux*
3073 OpenBSD/hppa hppa*-*-openbsd*
3074 OpenBSD/m68k m68*-*-openbsd*
3075 OpenBSD/m88k m88*-*-openbsd*
3076 OpenBSD/powerpc powerpc-*-openbsd*
3077 NetBSD/vax vax-*-netbsd*
3078 OpenBSD/vax vax-*-openbsd*
3080 * END-OF-LIFE frame compatibility module
3082 GDB's internal frame infrastructure has been completely rewritten.
3083 The new infrastructure making it possible to support key new features
3084 including DWARF 2 Call Frame Information. To aid in the task of
3085 migrating old configurations to this new infrastructure, a
3086 compatibility module, that allowed old configurations to continue to
3087 work, was also included.
3089 GDB 6.2 will be the last release to include this frame compatibility
3090 module. This change directly impacts the following configurations:
3100 Unless there is activity to revive these configurations, they will be
3101 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3103 * REMOVED configurations and files
3105 Sun 3, running SunOS 3 m68*-*-sunos3*
3106 Sun 3, running SunOS 4 m68*-*-sunos4*
3107 Sun 2, running SunOS 3 m68000-*-sunos3*
3108 Sun 2, running SunOS 4 m68000-*-sunos4*
3109 Motorola 680x0 running LynxOS m68*-*-lynxos*
3110 AT&T 3b1/Unix pc m68*-att-*
3111 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3112 decstation mips-dec-* mips-little-*
3113 riscos mips-*-riscos* mips-*-sysv*
3114 sonymips mips-sony-*
3115 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3117 *** Changes in GDB 6.1.1:
3119 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3121 The TUI (Text-mode User Interface) is now built as part of a default
3122 GDB configuration. It is enabled by either selecting the TUI with the
3123 command line option "-i=tui" or by running the separate "gdbtui"
3124 program. For more information on the TUI, see the manual "Debugging
3127 * Pending breakpoint support (also included in GDB 6.1)
3129 Support has been added to allow you to specify breakpoints in shared
3130 libraries that have not yet been loaded. If a breakpoint location
3131 cannot be found, and the "breakpoint pending" option is set to auto,
3132 GDB queries you if you wish to make the breakpoint pending on a future
3133 shared-library load. If and when GDB resolves the breakpoint symbol,
3134 the pending breakpoint is removed as one or more regular breakpoints
3137 Pending breakpoints are very useful for GCJ Java debugging.
3139 * Fixed ISO-C build problems
3141 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3142 non ISO-C code that stopped them being built using a more strict ISO-C
3143 compiler (e.g., IBM's C compiler).
3145 * Fixed build problem on IRIX 5
3147 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3148 wasn't able to compile compile on an IRIX 5 system.
3150 * Added execute permission to gdb/gdbserver/configure
3152 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3153 permission. This bug would cause configure to fail on a number of
3154 systems (Solaris, IRIX). Ref: server/519.
3156 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3158 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3159 has been updated to use constant array sizes.
3161 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3163 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3164 its generated DWARF Call Frame Info. This encoding was causing GDB to
3165 panic, that panic has been fixed. Ref: gdb/1628.
3167 * Fixed a problem when examining parameters in shared library code.
3169 When examining parameters in optimized shared library code generated
3170 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3171 not available''. GDB now correctly displays the variable's value.
3173 *** Changes in GDB 6.1:
3175 * Removed --with-mmalloc
3177 Support for the mmalloc memory manager has been removed, as it
3178 conflicted with the internal gdb byte cache.
3180 * Changes in AMD64 configurations
3182 The AMD64 target now includes the %cs and %ss registers. As a result
3183 the AMD64 remote protocol has changed; this affects the floating-point
3184 and SSE registers. If you rely on those registers for your debugging,
3185 you should upgrade gdbserver on the remote side.
3187 * Revised SPARC target
3189 The SPARC target has been completely revised, incorporating the
3190 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3191 support for LynxOS and SunOS 4 has been dropped. Calling functions
3192 from within GDB on operating systems with a non-executable stack
3193 (Solaris, OpenBSD) now works.
3197 GDB has a new C++ demangler which does a better job on the mangled
3198 names generated by current versions of g++. It also runs faster, so
3199 with this and other changes gdb should now start faster on large C++
3202 * DWARF 2 Location Expressions
3204 GDB support for location expressions has been extended to support function
3205 arguments and frame bases. Older versions of GDB could crash when they
3208 * C++ nested types and namespaces
3210 GDB's support for nested types and namespaces in C++ has been
3211 improved, especially if you use the DWARF 2 debugging format. (This
3212 is the default for recent versions of GCC on most platforms.)
3213 Specifically, if you have a class "Inner" defined within a class or
3214 namespace "Outer", then GDB realizes that the class's name is
3215 "Outer::Inner", not simply "Inner". This should greatly reduce the
3216 frequency of complaints about not finding RTTI symbols. In addition,
3217 if you are stopped at inside of a function defined within a namespace,
3218 GDB modifies its name lookup accordingly.
3220 * New native configurations
3222 NetBSD/amd64 x86_64-*-netbsd*
3223 OpenBSD/amd64 x86_64-*-openbsd*
3224 OpenBSD/alpha alpha*-*-openbsd*
3225 OpenBSD/sparc sparc-*-openbsd*
3226 OpenBSD/sparc64 sparc64-*-openbsd*
3228 * New debugging protocols
3230 M32R with SDI protocol m32r-*-elf*
3232 * "set prompt-escape-char" command deleted.
3234 The command "set prompt-escape-char" has been deleted. This command,
3235 and its very obscure effet on GDB's prompt, was never documented,
3236 tested, nor mentioned in the NEWS file.
3238 * OBSOLETE configurations and files
3240 Configurations that have been declared obsolete in this release have
3241 been commented out. Unless there is activity to revive these
3242 configurations, the next release of GDB will have their sources
3243 permanently REMOVED.
3245 Sun 3, running SunOS 3 m68*-*-sunos3*
3246 Sun 3, running SunOS 4 m68*-*-sunos4*
3247 Sun 2, running SunOS 3 m68000-*-sunos3*
3248 Sun 2, running SunOS 4 m68000-*-sunos4*
3249 Motorola 680x0 running LynxOS m68*-*-lynxos*
3250 AT&T 3b1/Unix pc m68*-att-*
3251 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3252 decstation mips-dec-* mips-little-*
3253 riscos mips-*-riscos* mips-*-sysv*
3254 sonymips mips-sony-*
3255 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3257 * REMOVED configurations and files
3259 SGI Irix-4.x mips-sgi-irix4 or iris4
3260 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3261 Z8000 simulator z8k-zilog-none or z8ksim
3262 Matsushita MN10200 w/simulator mn10200-*-*
3263 H8/500 simulator h8500-hitachi-hms or h8500hms
3264 HP/PA running BSD hppa*-*-bsd*
3265 HP/PA running OSF/1 hppa*-*-osf*
3266 HP/PA Pro target hppa*-*-pro*
3267 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3268 386BSD i[3456]86-*-bsd*
3269 Sequent family i[3456]86-sequent-sysv4*
3270 i[3456]86-sequent-sysv*
3271 i[3456]86-sequent-bsd*
3272 SPARC running LynxOS sparc-*-lynxos*
3273 SPARC running SunOS 4 sparc-*-sunos4*
3274 Tsqware Sparclet sparclet-*-*
3275 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3277 *** Changes in GDB 6.0:
3281 Support for debugging the Objective-C programming language has been
3282 integrated into GDB.
3284 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3286 DWARF 2's Call Frame Information makes available compiler generated
3287 information that more exactly describes the program's run-time stack.
3288 By using this information, GDB is able to provide more robust stack
3291 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3292 have been updated to use a new backtrace mechanism which includes
3293 DWARF 2 CFI support.
3297 GDB's remote protocol has been extended to include support for hosted
3298 file I/O (where the remote target uses GDB's file system). See GDB's
3299 remote protocol documentation for details.
3301 * All targets using the new architecture framework.
3303 All of GDB's targets have been updated to use the new internal
3304 architecture framework. The way is now open for future GDB releases
3305 to include cross-architecture native debugging support (i386 on amd64,
3308 * GNU/Linux's Thread Local Storage (TLS)
3310 GDB now includes support for for the GNU/Linux implementation of
3311 per-thread variables.
3313 * GNU/Linux's Native POSIX Thread Library (NPTL)
3315 GDB's thread code has been updated to work with either the new
3316 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3318 * Separate debug info.
3320 GDB, in conjunction with BINUTILS, now supports a mechanism for
3321 automatically loading debug information from a separate file. Instead
3322 of shipping full debug and non-debug versions of system libraries,
3323 system integrators can now instead ship just the stripped libraries
3324 and optional debug files.
3326 * DWARF 2 Location Expressions
3328 DWARF 2 Location Expressions allow the compiler to more completely
3329 describe the location of variables (even in optimized code) to the
3332 GDB now includes preliminary support for location expressions (support
3333 for DW_OP_piece is still missing).
3337 A number of long standing bugs that caused GDB to die while starting a
3338 Java application have been fixed. GDB's Java support is now
3339 considered "useable".
3341 * GNU/Linux support for fork, vfork, and exec.
3343 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3344 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3347 * GDB supports logging output to a file
3349 There are two new commands, "set logging" and "show logging", which can be
3350 used to capture GDB's output to a file.
3352 * The meaning of "detach" has changed for gdbserver
3354 The "detach" command will now resume the application, as documented. To
3355 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3358 * d10v, m68hc11 `regs' command deprecated
3360 The `info registers' command has been updated so that it displays the
3361 registers using a format identical to the old `regs' command.
3365 A new command, "maint set profile on/off", has been added. This command can
3366 be used to enable or disable profiling while running GDB, to profile a
3367 session or a set of commands. In addition there is a new configure switch,
3368 "--enable-profiling", which will cause GDB to be compiled with profiling
3369 data, for more informative profiling results.
3371 * Default MI syntax changed to "mi2".
3373 The default MI (machine interface) syntax, enabled by the command line
3374 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3375 "mi1", can be enabled by specifying the option "-i=mi1".
3377 Support for the original "mi0" syntax (included in GDB 5.0) has been
3380 Fix for gdb/192: removed extraneous space when displaying frame level.
3381 Fix for gdb/672: update changelist is now output in mi list format.
3382 Fix for gdb/702: a -var-assign that updates the value now shows up
3383 in a subsequent -var-update.
3385 * New native configurations.
3387 FreeBSD/amd64 x86_64-*-freebsd*
3389 * Multi-arched targets.
3391 HP/PA HPUX11 hppa*-*-hpux*
3392 Renesas M32R/D w/simulator m32r-*-elf*
3394 * OBSOLETE configurations and files
3396 Configurations that have been declared obsolete in this release have
3397 been commented out. Unless there is activity to revive these
3398 configurations, the next release of GDB will have their sources
3399 permanently REMOVED.
3401 Z8000 simulator z8k-zilog-none or z8ksim
3402 Matsushita MN10200 w/simulator mn10200-*-*
3403 H8/500 simulator h8500-hitachi-hms or h8500hms
3404 HP/PA running BSD hppa*-*-bsd*
3405 HP/PA running OSF/1 hppa*-*-osf*
3406 HP/PA Pro target hppa*-*-pro*
3407 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3408 Sequent family i[3456]86-sequent-sysv4*
3409 i[3456]86-sequent-sysv*
3410 i[3456]86-sequent-bsd*
3411 Tsqware Sparclet sparclet-*-*
3412 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3414 * REMOVED configurations and files
3417 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3418 IBM AIX PS/2 i[3456]86-*-aix
3419 i386 running Mach 3.0 i[3456]86-*-mach3*
3420 i386 running Mach i[3456]86-*-mach*
3421 i386 running OSF/1 i[3456]86-*osf1mk*
3422 HP/Apollo 68k Family m68*-apollo*-sysv*,
3424 m68*-hp-bsd*, m68*-hp-hpux*
3425 Argonaut Risc Chip (ARC) arc-*-*
3426 Mitsubishi D30V d30v-*-*
3427 Fujitsu FR30 fr30-*-elf*
3428 OS/9000 i[34]86-*-os9k
3429 I960 with MON960 i960-*-coff
3431 * MIPS $fp behavior changed
3433 The convenience variable $fp, for the MIPS, now consistently returns
3434 the address of the current frame's base. Previously, depending on the
3435 context, $fp could refer to either $sp or the current frame's base
3436 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3437 The GNU Source-Level Debugger''.
3439 *** Changes in GDB 5.3:
3441 * GNU/Linux shared library multi-threaded performance improved.
3443 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3444 `/proc', in preference to `ptrace' for memory reads. This may result
3445 in an improvement in the start-up time of multi-threaded, shared
3446 library applications when run under GDB. One GDB user writes: ``loads
3447 shared libs like mad''.
3449 * ``gdbserver'' now supports multi-threaded applications on some targets
3451 Support for debugging multi-threaded applications which use
3452 the GNU/Linux LinuxThreads package has been added for
3453 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3454 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3456 * GDB now supports C/C++ preprocessor macros.
3458 GDB now expands preprocessor macro invocations in C/C++ expressions,
3459 and provides various commands for showing macro definitions and how
3462 The new command `macro expand EXPRESSION' expands any macro
3463 invocations in expression, and shows the result.
3465 The new command `show macro MACRO-NAME' shows the definition of the
3466 macro named MACRO-NAME, and where it was defined.
3468 Most compilers don't include information about macros in the debugging
3469 information by default. In GCC 3.1, for example, you need to compile
3470 your program with the options `-gdwarf-2 -g3'. If the macro
3471 information is present in the executable, GDB will read it.
3473 * Multi-arched targets.
3475 DEC Alpha (partial) alpha*-*-*
3476 DEC VAX (partial) vax-*-*
3478 National Semiconductor NS32000 (partial) ns32k-*-*
3479 Motorola 68000 (partial) m68k-*-*
3480 Motorola MCORE mcore-*-*
3484 Fujitsu FRV architecture added by Red Hat frv*-*-*
3487 * New native configurations
3489 Alpha NetBSD alpha*-*-netbsd*
3490 SH NetBSD sh*-*-netbsdelf*
3491 MIPS NetBSD mips*-*-netbsd*
3492 UltraSPARC NetBSD sparc64-*-netbsd*
3494 * OBSOLETE configurations and files
3496 Configurations that have been declared obsolete in this release have
3497 been commented out. Unless there is activity to revive these
3498 configurations, the next release of GDB will have their sources
3499 permanently REMOVED.
3501 Mitsubishi D30V d30v-*-*
3502 OS/9000 i[34]86-*-os9k
3503 IBM AIX PS/2 i[3456]86-*-aix
3504 Fujitsu FR30 fr30-*-elf*
3505 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3506 Argonaut Risc Chip (ARC) arc-*-*
3507 i386 running Mach 3.0 i[3456]86-*-mach3*
3508 i386 running Mach i[3456]86-*-mach*
3509 i386 running OSF/1 i[3456]86-*osf1mk*
3510 HP/Apollo 68k Family m68*-apollo*-sysv*,
3512 m68*-hp-bsd*, m68*-hp-hpux*
3513 I960 with MON960 i960-*-coff
3515 * OBSOLETE languages
3517 CHILL, a Pascal like language used by telecommunications companies.
3519 * REMOVED configurations and files
3521 AMD 29k family via UDI a29k-amd-udi, udi29k
3522 A29K VxWorks a29k-*-vxworks
3523 AMD 29000 embedded, using EBMON a29k-none-none
3524 AMD 29000 embedded with COFF a29k-none-coff
3525 AMD 29000 embedded with a.out a29k-none-aout
3527 testsuite/gdb.hp/gdb.threads-hp/ directory
3529 * New command "set max-user-call-depth <nnn>"
3531 This command allows the user to limit the call depth of user-defined
3532 commands. The default is 1024.
3534 * Changes in FreeBSD/i386 native debugging.
3536 Support for the "generate-core-file" has been added.
3538 * New commands "dump", "append", and "restore".
3540 These commands allow data to be copied from target memory
3541 to a bfd-format or binary file (dump and append), and back
3542 from a file into memory (restore).
3544 * Improved "next/step" support on multi-processor Alpha Tru64.
3546 The previous single-step mechanism could cause unpredictable problems,
3547 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3548 of a software single-step mechanism prevents this.
3550 *** Changes in GDB 5.2.1:
3558 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3559 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3560 Fix, by Joel Brobecker imported from mainline.
3562 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3563 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3564 Fix, by Fred Fish, imported from mainline.
3566 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3567 Surprisingly enough, it works now.
3568 By Michal Ludvig, imported from mainline.
3570 i386 hardware watchpoint support:
3571 avoid misses on second run for some targets.
3572 By Pierre Muller, imported from mainline.
3574 *** Changes in GDB 5.2:
3576 * New command "set trust-readonly-sections on[off]".
3578 This command is a hint that tells gdb that read-only sections
3579 really are read-only (ie. that their contents will not change).
3580 In this mode, gdb will go to the object file rather than the
3581 target to read memory from read-only sections (such as ".text").
3582 This can be a significant performance improvement on some
3583 (notably embedded) targets.
3585 * New command "generate-core-file" (or "gcore").
3587 This new gdb command allows the user to drop a core file of the child
3588 process state at any time. So far it's been implemented only for
3589 GNU/Linux and Solaris, but should be relatively easily ported to other
3590 hosts. Argument is core file name (defaults to core.<pid>).
3592 * New command line option
3594 GDB now accepts --pid or -p followed by a process id.
3596 * Change in command line behavior -- corefiles vs. process ids.
3598 There is a subtle behavior in the way in which GDB handles
3599 command line arguments. The first non-flag argument is always
3600 a program to debug, but the second non-flag argument may either
3601 be a corefile or a process id. Previously, GDB would attempt to
3602 open the second argument as a corefile, and if that failed, would
3603 issue a superfluous error message and then attempt to attach it as
3604 a process. Now, if the second argument begins with a non-digit,
3605 it will be treated as a corefile. If it begins with a digit,
3606 GDB will attempt to attach it as a process, and if no such process
3607 is found, will then attempt to open it as a corefile.
3609 * Changes in ARM configurations.
3611 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3612 configuration is fully multi-arch.
3614 * New native configurations
3616 ARM NetBSD arm*-*-netbsd*
3617 x86 OpenBSD i[3456]86-*-openbsd*
3618 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3619 Sparc64 running FreeBSD sparc64-*-freebsd*
3623 Sanyo XStormy16 xstormy16-elf
3625 * OBSOLETE configurations and files
3627 Configurations that have been declared obsolete in this release have
3628 been commented out. Unless there is activity to revive these
3629 configurations, the next release of GDB will have their sources
3630 permanently REMOVED.
3632 AMD 29k family via UDI a29k-amd-udi, udi29k
3633 A29K VxWorks a29k-*-vxworks
3634 AMD 29000 embedded, using EBMON a29k-none-none
3635 AMD 29000 embedded with COFF a29k-none-coff
3636 AMD 29000 embedded with a.out a29k-none-aout
3638 testsuite/gdb.hp/gdb.threads-hp/ directory
3640 * REMOVED configurations and files
3642 TI TMS320C80 tic80-*-*
3644 PowerPC Solaris powerpcle-*-solaris*
3645 PowerPC Windows NT powerpcle-*-cygwin32
3646 PowerPC Netware powerpc-*-netware*
3647 Harris/CXUX m88k m88*-harris-cxux*
3648 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3649 ns32k-utek-sysv* ns32k-utek-*
3650 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3651 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3652 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3653 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3654 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3656 * Changes to command line processing
3658 The new `--args' feature can be used to specify command-line arguments
3659 for the inferior from gdb's command line.
3661 * Changes to key bindings
3663 There is a new `operate-and-get-next' function bound to `C-o'.
3665 *** Changes in GDB 5.1.1
3667 Fix compile problem on DJGPP.
3669 Fix a problem with floating-point registers on the i386 being
3672 Fix to stop GDB crashing on .debug_str debug info.
3674 Numerous documentation fixes.
3676 Numerous testsuite fixes.
3678 *** Changes in GDB 5.1:
3680 * New native configurations
3682 Alpha FreeBSD alpha*-*-freebsd*
3683 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3684 MIPS GNU/Linux mips*-*-linux*
3685 MIPS SGI Irix 6.x mips*-sgi-irix6*
3686 ia64 AIX ia64-*-aix*
3687 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3691 Motorola 68HC11 and 68HC12 m68hc11-elf
3693 UltraSparc running GNU/Linux sparc64-*-linux*
3695 * OBSOLETE configurations and files
3697 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3698 Harris/CXUX m88k m88*-harris-cxux*
3699 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3700 ns32k-utek-sysv* ns32k-utek-*
3701 TI TMS320C80 tic80-*-*
3703 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3704 PowerPC Solaris powerpcle-*-solaris*
3705 PowerPC Windows NT powerpcle-*-cygwin32
3706 PowerPC Netware powerpc-*-netware*
3707 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3708 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3709 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3710 Apple Macintosh (MPW) host N/A
3712 stuff.c (Program to stuff files into a specially prepared space in kdb)
3713 kdb-start.c (Main loop for the standalone kernel debugger)
3715 Configurations that have been declared obsolete in this release have
3716 been commented out. Unless there is activity to revive these
3717 configurations, the next release of GDB will have their sources
3718 permanently REMOVED.
3720 * REMOVED configurations and files
3722 Altos 3068 m68*-altos-*
3723 Convex c1-*-*, c2-*-*
3725 ARM RISCix arm-*-* (as host)
3729 * GDB has been converted to ISO C.
3731 GDB's source code has been converted to ISO C. In particular, the
3732 sources are fully protoized, and rely on standard headers being
3737 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3739 * The MI enabled by default.
3741 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3742 revised and enabled by default. Packages which use GDB as a debugging
3743 engine behind a UI or another front end are encouraged to switch to
3744 using the GDB/MI interface, instead of the old annotations interface
3745 which is now deprecated.
3747 * Support for debugging Pascal programs.
3749 GDB now includes support for debugging Pascal programs. The following
3750 main features are supported:
3752 - Pascal-specific data types such as sets;
3754 - automatic recognition of Pascal sources based on file-name
3757 - Pascal-style display of data types, variables, and functions;
3759 - a Pascal expression parser.
3761 However, some important features are not yet supported.
3763 - Pascal string operations are not supported at all;
3765 - there are some problems with boolean types;
3767 - Pascal type hexadecimal constants are not supported
3768 because they conflict with the internal variables format;
3770 - support for Pascal objects and classes is not full yet;
3772 - unlike Pascal, GDB is case-sensitive for symbol names.
3774 * Changes in completion.
3776 Commands such as `shell', `run' and `set args', which pass arguments
3777 to inferior programs, now complete on file names, similar to what
3778 users expect at the shell prompt.
3780 Commands which accept locations, such as `disassemble', `print',
3781 `breakpoint', `until', etc. now complete on filenames as well as
3782 program symbols. Thus, if you type "break foob TAB", and the source
3783 files linked into the programs include `foobar.c', that file name will
3784 be one of the candidates for completion. However, file names are not
3785 considered for completion after you typed a colon that delimits a file
3786 name from a name of a function in that file, as in "break foo.c:bar".
3788 `set demangle-style' completes on available demangling styles.
3790 * New platform-independent commands:
3792 It is now possible to define a post-hook for a command as well as a
3793 hook that runs before the command. For more details, see the
3794 documentation of `hookpost' in the GDB manual.
3796 * Changes in GNU/Linux native debugging.
3798 Support for debugging multi-threaded programs has been completely
3799 revised for all platforms except m68k and sparc. You can now debug as
3800 many threads as your system allows you to have.
3802 Attach/detach is supported for multi-threaded programs.
3804 Support for SSE registers was added for x86. This doesn't work for
3805 multi-threaded programs though.
3807 * Changes in MIPS configurations.
3809 Multi-arch support is enabled for all MIPS configurations.
3811 GDB can now be built as native debugger on SGI Irix 6.x systems for
3812 debugging n32 executables. (Debugging 64-bit executables is not yet
3815 * Unified support for hardware watchpoints in all x86 configurations.
3817 Most (if not all) native x86 configurations support hardware-assisted
3818 breakpoints and watchpoints in a unified manner. This support
3819 implements debug register sharing between watchpoints, which allows to
3820 put a virtually infinite number of watchpoints on the same address,
3821 and also supports watching regions up to 16 bytes with several debug
3824 The new maintenance command `maintenance show-debug-regs' toggles
3825 debugging print-outs in functions that insert, remove, and test
3826 watchpoints and hardware breakpoints.
3828 * Changes in the DJGPP native configuration.
3830 New command ``info dos sysinfo'' displays assorted information about
3831 the CPU, OS, memory, and DPMI server.
3833 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3834 display information about segment descriptors stored in GDT, LDT, and
3837 New commands ``info dos pde'' and ``info dos pte'' display entries
3838 from Page Directory and Page Tables (for now works with CWSDPMI only).
3839 New command ``info dos address-pte'' displays the Page Table entry for
3840 a given linear address.
3842 GDB can now pass command lines longer than 126 characters to the
3843 program being debugged (requires an update to the libdbg.a library
3844 which is part of the DJGPP development kit).
3846 DWARF2 debug info is now supported.
3848 It is now possible to `step' and `next' through calls to `longjmp'.
3850 * Changes in documentation.
3852 All GDB documentation was converted to GFDL, the GNU Free
3853 Documentation License.
3855 Tracepoints-related commands are now fully documented in the GDB
3858 TUI, the Text-mode User Interface, is now documented in the manual.
3860 Tracepoints-related commands are now fully documented in the GDB
3863 The "GDB Internals" manual now has an index. It also includes
3864 documentation of `ui_out' functions, GDB coding standards, x86
3865 hardware watchpoints, and memory region attributes.
3867 * GDB's version number moved to ``version.in''
3869 The Makefile variable VERSION has been replaced by the file
3870 ``version.in''. People creating GDB distributions should update the
3871 contents of this file.
3875 GUD support is now a standard part of the EMACS distribution.
3877 *** Changes in GDB 5.0:
3879 * Improved support for debugging FP programs on x86 targets
3881 Unified and much-improved support for debugging floating-point
3882 programs on all x86 targets. In particular, ``info float'' now
3883 displays the FP registers in the same format on all x86 targets, with
3884 greater level of detail.
3886 * Improvements and bugfixes in hardware-assisted watchpoints
3888 It is now possible to watch array elements, struct members, and
3889 bitfields with hardware-assisted watchpoints. Data-read watchpoints
3890 on x86 targets no longer erroneously trigger when the address is
3893 * Improvements in the native DJGPP version of GDB
3895 The distribution now includes all the scripts and auxiliary files
3896 necessary to build the native DJGPP version on MS-DOS/MS-Windows
3897 machines ``out of the box''.
3899 The DJGPP version can now debug programs that use signals. It is
3900 possible to catch signals that happened in the debuggee, deliver
3901 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
3902 would kill the program being debugged.) Programs that hook hardware
3903 interrupts (keyboard, timer, etc.) can also be debugged.
3905 It is now possible to debug DJGPP programs that redirect their
3906 standard handles or switch them to raw (as opposed to cooked) mode, or
3907 even close them. The command ``run < foo > bar'' works as expected,
3908 and ``info terminal'' reports useful information about the debuggee's
3909 terminal, including raw/cooked mode, redirection, etc.
3911 The DJGPP version now uses termios functions for console I/O, which
3912 enables debugging graphics programs. Interrupting GDB with Ctrl-C
3915 DOS-style file names with drive letters are now fully supported by
3918 It is now possible to debug DJGPP programs that switch their working
3919 directory. It is also possible to rerun the debuggee any number of
3920 times without restarting GDB; thus, you can use the same setup,
3921 breakpoints, etc. for many debugging sessions.
3923 * New native configurations
3925 ARM GNU/Linux arm*-*-linux*
3926 PowerPC GNU/Linux powerpc-*-linux*
3930 Motorola MCore mcore-*-*
3931 x86 VxWorks i[3456]86-*-vxworks*
3932 PowerPC VxWorks powerpc-*-vxworks*
3933 TI TMS320C80 tic80-*-*
3935 * OBSOLETE configurations
3937 Altos 3068 m68*-altos-*
3938 Convex c1-*-*, c2-*-*
3940 ARM RISCix arm-*-* (as host)
3943 Configurations that have been declared obsolete will be commented out,
3944 but the code will be left in place. If there is no activity to revive
3945 these configurations before the next release of GDB, the sources will
3946 be permanently REMOVED.
3948 * Gould support removed
3950 Support for the Gould PowerNode and NP1 has been removed.
3952 * New features for SVR4
3954 On SVR4 native platforms (such as Solaris), if you attach to a process
3955 without first loading a symbol file, GDB will now attempt to locate and
3956 load symbols from the running process's executable file.
3958 * Many C++ enhancements
3960 C++ support has been greatly improved. Overload resolution now works properly
3961 in almost all cases. RTTI support is on the way.
3963 * Remote targets can connect to a sub-program
3965 A popen(3) style serial-device has been added. This device starts a
3966 sub-process (such as a stand-alone simulator) and then communicates
3967 with that. The sub-program to run is specified using the syntax
3968 ``|<program> <args>'' vis:
3970 (gdb) set remotedebug 1
3971 (gdb) target extended-remote |mn10300-elf-sim program-args
3973 * MIPS 64 remote protocol
3975 A long standing bug in the mips64 remote protocol where by GDB
3976 expected certain 32 bit registers (ex SR) to be transfered as 32
3977 instead of 64 bits has been fixed.
3979 The command ``set remote-mips64-transfers-32bit-regs on'' has been
3980 added to provide backward compatibility with older versions of GDB.
3982 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
3984 The command ``set remotebinarydownload'' command has been replaced by
3985 ``set remote X-packet''. Other commands in ``set remote'' family
3986 include ``set remote P-packet''.
3988 * Breakpoint commands accept ranges.
3990 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
3991 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
3992 ``tracepoint passcount'' also accepts a range of tracepoints.
3994 * ``apropos'' command added.
3996 The ``apropos'' command searches through command names and
3997 documentation strings, printing out matches, making it much easier to
3998 try to find a command that does what you are looking for.
4002 A new machine oriented interface (MI) has been added to GDB. This
4003 interface is designed for debug environments running GDB as a separate
4004 process. This is part of the long term libGDB project. See the
4005 "GDB/MI" chapter of the GDB manual for further information. It can be
4006 enabled by configuring with:
4008 .../configure --enable-gdbmi
4010 *** Changes in GDB-4.18:
4012 * New native configurations
4014 HP-UX 10.20 hppa*-*-hpux10.20
4015 HP-UX 11.x hppa*-*-hpux11.0*
4016 M68K GNU/Linux m68*-*-linux*
4020 Fujitsu FR30 fr30-*-elf*
4021 Intel StrongARM strongarm-*-*
4022 Mitsubishi D30V d30v-*-*
4024 * OBSOLETE configurations
4026 Gould PowerNode, NP1 np1-*-*, pn-*-*
4028 Configurations that have been declared obsolete will be commented out,
4029 but the code will be left in place. If there is no activity to revive
4030 these configurations before the next release of GDB, the sources will
4031 be permanently REMOVED.
4035 As a compatibility experiment, GDB's source files buildsym.h and
4036 buildsym.c have been converted to pure standard C, no longer
4037 containing any K&R compatibility code. We believe that all systems in
4038 use today either come with a standard C compiler, or have a GCC port
4039 available. If this is not true, please report the affected
4040 configuration to bug-gdb@gnu.org immediately. See the README file for
4041 information about getting a standard C compiler if you don't have one
4046 GDB now uses readline 2.2.
4048 * set extension-language
4050 You can now control the mapping between filename extensions and source
4051 languages by using the `set extension-language' command. For instance,
4052 you can ask GDB to treat .c files as C++ by saying
4053 set extension-language .c c++
4054 The command `info extensions' lists all of the recognized extensions
4055 and their associated languages.
4057 * Setting processor type for PowerPC and RS/6000
4059 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4060 you can use the `set processor' command to specify what variant of the
4061 PowerPC family you are debugging. The command
4065 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4066 following PowerPC and RS6000 variants:
4068 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4069 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4071 403GC IBM PowerPC 403GC
4072 505 Motorola PowerPC 505
4073 860 Motorola PowerPC 860 or 850
4074 601 Motorola PowerPC 601
4075 602 Motorola PowerPC 602
4076 603 Motorola/IBM PowerPC 603 or 603e
4077 604 Motorola PowerPC 604 or 604e
4078 750 Motorola/IBM PowerPC 750 or 750
4080 At the moment, this command just tells GDB what to name the
4081 special-purpose processor registers. Since almost all the affected
4082 registers are inaccessible to user-level programs, this command is
4083 only useful for remote debugging in its present form.
4087 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4088 more extensive support for HP-UX. Added features include shared
4089 library support, kernel threads and hardware watchpoints for 11.00,
4090 support for HP's ANSI C and C++ compilers, and a compatibility mode
4091 for xdb and dbx commands.
4095 HP's donation includes the new concept of catchpoints, which is a
4096 generalization of the old catch command. On HP-UX, it is now possible
4097 to catch exec, fork, and vfork, as well as library loading.
4099 This means that the existing catch command has changed; its first
4100 argument now specifies the type of catch to be set up. See the
4101 output of "help catch" for a list of catchpoint types.
4103 * Debugging across forks
4105 On HP-UX, you can choose which process to debug when a fork() happens
4110 HP has donated a curses-based terminal user interface (TUI). To get
4111 it, build with --enable-tui. Although this can be enabled for any
4112 configuration, at present it only works for native HP debugging.
4114 * GDB remote protocol additions
4116 A new protocol packet 'X' that writes binary data is now available.
4117 Default behavior is to try 'X', then drop back to 'M' if the stub
4118 fails to respond. The settable variable `remotebinarydownload'
4119 allows explicit control over the use of 'X'.
4121 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4122 full 64-bit address. The command
4124 set remoteaddresssize 32
4126 can be used to revert to the old behaviour. For existing remote stubs
4127 the change should not be noticed, as the additional address information
4130 In order to assist in debugging stubs, you may use the maintenance
4131 command `packet' to send any text string to the stub. For instance,
4133 maint packet heythere
4135 sends the packet "$heythere#<checksum>". Note that it is very easy to
4136 disrupt a debugging session by sending the wrong packet at the wrong
4139 The compare-sections command allows you to compare section data on the
4140 target to what is in the executable file without uploading or
4141 downloading, by comparing CRC checksums.
4143 * Tracing can collect general expressions
4145 You may now collect general expressions at tracepoints. This requires
4146 further additions to the target-side stub; see tracepoint.c and
4147 doc/agentexpr.texi for further details.
4149 * mask-address variable for Mips
4151 For Mips targets, you may control the zeroing of the upper 32 bits of
4152 a 64-bit address by entering `set mask-address on'. This is mainly
4153 of interest to users of embedded R4xxx and R5xxx processors.
4155 * Higher serial baud rates
4157 GDB's serial code now allows you to specify baud rates 57600, 115200,
4158 230400, and 460800 baud. (Note that your host system may not be able
4159 to achieve all of these rates.)
4163 The i960 configuration now includes an initial implementation of a
4164 builtin simulator, contributed by Jim Wilson.
4167 *** Changes in GDB-4.17:
4169 * New native configurations
4171 Alpha GNU/Linux alpha*-*-linux*
4172 Unixware 2.x i[3456]86-unixware2*
4173 Irix 6.x mips*-sgi-irix6*
4174 PowerPC GNU/Linux powerpc-*-linux*
4175 PowerPC Solaris powerpcle-*-solaris*
4176 Sparc GNU/Linux sparc-*-linux*
4177 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4181 Argonaut Risc Chip (ARC) arc-*-*
4182 Hitachi H8/300S h8300*-*-*
4183 Matsushita MN10200 w/simulator mn10200-*-*
4184 Matsushita MN10300 w/simulator mn10300-*-*
4185 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4186 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4187 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4188 Mitsubishi D10V w/simulator d10v-*-*
4189 Mitsubishi M32R/D w/simulator m32r-*-elf*
4190 Tsqware Sparclet sparclet-*-*
4191 NEC V850 w/simulator v850-*-*
4193 * New debugging protocols
4195 ARM with RDI protocol arm*-*-*
4196 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4197 DDB and LSI variants of PMON protocol mips*-*-*
4198 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4199 PowerPC with SDS protocol powerpc{,le}-*-eabi
4200 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4204 All configurations can now understand and use the DWARF 2 debugging
4205 format. The choice is automatic, if the symbol file contains DWARF 2
4210 GDB now includes basic Java language support. This support is
4211 only useful with Java compilers that produce native machine code.
4213 * solib-absolute-prefix and solib-search-path
4215 For SunOS and SVR4 shared libraries, you may now set the prefix for
4216 loading absolute shared library symbol files, and the search path for
4217 locating non-absolute shared library symbol files.
4219 * Live range splitting
4221 GDB can now effectively debug code for which GCC has performed live
4222 range splitting as part of its optimization. See gdb/doc/LRS for
4223 more details on the expected format of the stabs information.
4227 GDB's support for the GNU Hurd, including thread debugging, has been
4228 updated to work with current versions of the Hurd.
4232 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4233 instruction set. ARM GDB automatically detects when Thumb
4234 instructions are in use, and adjusts disassembly and backtracing
4239 GDB's MIPS target configurations now handle the MIP16 16-bit
4244 GDB now includes support for overlays; if an executable has been
4245 linked such that multiple sections are based at the same address, GDB
4246 will decide which section to use for symbolic info. You can choose to
4247 control the decision manually, using overlay commands, or implement
4248 additional target-side support and use "overlay load-target" to bring
4249 in the overlay mapping. Do "help overlay" for more detail.
4253 The command "info symbol <address>" displays information about
4254 the symbol at the specified address.
4258 The standard remote protocol now includes an extension that allows
4259 asynchronous collection and display of trace data. This requires
4260 extensive support in the target-side debugging stub. Tracing mode
4261 includes a new interaction mode in GDB and new commands: see the
4262 file tracepoint.c for more details.
4266 Configurations for embedded MIPS now include a simulator contributed
4267 by Cygnus Solutions. The simulator supports the instruction sets
4268 of most MIPS variants.
4272 Sparc configurations may now include the ERC32 simulator contributed
4273 by the European Space Agency. The simulator is not built into
4274 Sparc targets by default; configure with --enable-sim to include it.
4278 For target configurations that may include multiple variants of a
4279 basic architecture (such as MIPS and SH), you may now set the
4280 architecture explicitly. "set arch" sets, "info arch" lists
4281 the possible architectures.
4283 *** Changes in GDB-4.16:
4285 * New native configurations
4287 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4288 M68K NetBSD m68k-*-netbsd*
4289 PowerPC AIX 4.x powerpc-*-aix*
4290 PowerPC MacOS powerpc-*-macos*
4291 PowerPC Windows NT powerpcle-*-cygwin32
4292 RS/6000 AIX 4.x rs6000-*-aix4*
4296 ARM with RDP protocol arm-*-*
4297 I960 with MON960 i960-*-coff
4298 MIPS VxWorks mips*-*-vxworks*
4299 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4300 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4302 Matra Sparclet sparclet-*-*
4306 The powerpc-eabi configuration now includes the PSIM simulator,
4307 contributed by Andrew Cagney, with assistance from Mike Meissner.
4308 PSIM is a very elaborate model of the PowerPC, including not only
4309 basic instruction set execution, but also details of execution unit
4310 performance and I/O hardware. See sim/ppc/README for more details.
4314 GDB now works with Solaris 2.5.
4316 * Windows 95/NT native
4318 GDB will now work as a native debugger on Windows 95 and Windows NT.
4319 To build it from source, you must use the "gnu-win32" environment,
4320 which uses a DLL to emulate enough of Unix to run the GNU tools.
4321 Further information, binaries, and sources are available at
4322 ftp.cygnus.com, under pub/gnu-win32.
4324 * dont-repeat command
4326 If a user-defined command includes the command `dont-repeat', then the
4327 command will not be repeated if the user just types return. This is
4328 useful if the command is time-consuming to run, so that accidental
4329 extra keystrokes don't run the same command many times.
4331 * Send break instead of ^C
4333 The standard remote protocol now includes an option to send a break
4334 rather than a ^C to the target in order to interrupt it. By default,
4335 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4337 * Remote protocol timeout
4339 The standard remote protocol includes a new variable `remotetimeout'
4340 that allows you to set the number of seconds before GDB gives up trying
4341 to read from the target. The default value is 2.
4343 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4345 By default GDB will automatically keep track of objects as they are
4346 loaded and unloaded by the dynamic linker. By using the command `set
4347 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4348 when shared library events occur, thus allowing you to set breakpoints
4349 in shared libraries which are explicitly loaded by the inferior.
4351 Note this feature does not work on hpux8. On hpux9 you must link
4352 /usr/lib/end.o into your program. This feature should work
4353 automatically on hpux10.
4355 * Irix 5.x hardware watchpoint support
4357 Irix 5 configurations now support the use of hardware watchpoints.
4359 * Mips protocol "SYN garbage limit"
4361 When debugging a Mips target using the `target mips' protocol, you
4362 may set the number of characters that GDB will ignore by setting
4363 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4364 every character. The default value is 1050.
4366 * Recording and replaying remote debug sessions
4368 If you set `remotelogfile' to the name of a file, gdb will write to it
4369 a recording of a remote debug session. This recording may then be
4370 replayed back to gdb using "gdbreplay". See gdbserver/README for
4371 details. This is useful when you have a problem with GDB while doing
4372 remote debugging; you can make a recording of the session and send it
4373 to someone else, who can then recreate the problem.
4375 * Speedups for remote debugging
4377 GDB includes speedups for downloading and stepping MIPS systems using
4378 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4379 and more efficient S-record downloading.
4381 * Memory use reductions and statistics collection
4383 GDB now uses less memory and reports statistics about memory usage.
4384 Try the `maint print statistics' command, for example.
4386 *** Changes in GDB-4.15:
4388 * Psymtabs for XCOFF
4390 The symbol reader for AIX GDB now uses partial symbol tables. This
4391 can greatly improve startup time, especially for large executables.
4393 * Remote targets use caching
4395 Remote targets now use a data cache to speed up communication with the
4396 remote side. The data cache could lead to incorrect results because
4397 it doesn't know about volatile variables, thus making it impossible to
4398 debug targets which use memory mapped I/O devices. `set remotecache
4399 off' turns the the data cache off.
4401 * Remote targets may have threads
4403 The standard remote protocol now includes support for multiple threads
4404 in the target system, using new protocol commands 'H' and 'T'. See
4405 gdb/remote.c for details.
4409 If GDB is configured with `--enable-netrom', then it will include
4410 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4411 acts as though it is a bank of ROM on the target board, but you can
4412 write into it over the network. GDB's support consists only of
4413 support for fast loading into the emulated ROM; to debug, you must use
4414 another protocol, such as standard remote protocol. The usual
4415 sequence is something like
4417 target nrom <netrom-hostname>
4419 target remote <netrom-hostname>:1235
4423 GDB now includes support for the Apple Macintosh, as a host only. It
4424 may be run as either an MPW tool or as a standalone application, and
4425 it can debug through the serial port. All the usual GDB commands are
4426 available, but to the target command, you must supply "serial" as the
4427 device type instead of "/dev/ttyXX". See mpw-README in the main
4428 directory for more information on how to build. The MPW configuration
4429 scripts */mpw-config.in support only a few targets, and only the
4430 mips-idt-ecoff target has been tested.
4434 GDB configuration now uses autoconf. This is not user-visible,
4435 but does simplify configuration and building.
4439 GDB now supports hpux10.
4441 *** Changes in GDB-4.14:
4443 * New native configurations
4445 x86 FreeBSD i[345]86-*-freebsd
4446 x86 NetBSD i[345]86-*-netbsd
4447 NS32k NetBSD ns32k-*-netbsd
4448 Sparc NetBSD sparc-*-netbsd
4452 A29K VxWorks a29k-*-vxworks
4453 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4454 CPU32 EST-300 emulator m68*-*-est*
4455 PowerPC ELF powerpc-*-elf
4458 * Alpha OSF/1 support for procfs
4460 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4461 possible to attach to running processes. As the mounting of the /proc
4462 filesystem is optional on the Alpha, GDB automatically determines
4463 the availability of /proc during startup. This can lead to problems
4464 if /proc is unmounted after GDB has been started.
4466 * Arguments to user-defined commands
4468 User commands may accept up to 10 arguments separated by whitespace.
4469 Arguments are accessed within the user command via $arg0..$arg9. A
4472 print $arg0 + $arg1 + $arg2
4474 To execute the command use:
4477 Defines the command "adder" which prints the sum of its three arguments.
4478 Note the arguments are text substitutions, so they may reference variables,
4479 use complex expressions, or even perform inferior function calls.
4481 * New `if' and `while' commands
4483 This makes it possible to write more sophisticated user-defined
4484 commands. Both commands take a single argument, which is the
4485 expression to evaluate, and must be followed by the commands to
4486 execute, one per line, if the expression is nonzero, the list being
4487 terminated by the word `end'. The `if' command list may include an
4488 `else' word, which causes the following commands to be executed only
4489 if the expression is zero.
4491 * Fortran source language mode
4493 GDB now includes partial support for Fortran 77. It will recognize
4494 Fortran programs and can evaluate a subset of Fortran expressions, but
4495 variables and functions may not be handled correctly. GDB will work
4496 with G77, but does not yet know much about symbols emitted by other
4499 * Better HPUX support
4501 Most debugging facilities now work on dynamic executables for HPPAs
4502 running hpux9 or later. You can attach to running dynamically linked
4503 processes, but by default the dynamic libraries will be read-only, so
4504 for instance you won't be able to put breakpoints in them. To change
4505 that behavior do the following before running the program:
4511 This will cause the libraries to be mapped private and read-write.
4512 To revert to the normal behavior, do this:
4518 You cannot set breakpoints or examine data in the library until after
4519 the library is loaded if the function/data symbols do not have
4522 GDB can now also read debug symbols produced by the HP C compiler on
4523 HPPAs (sorry, no C++, Fortran or 68k support).
4525 * Target byte order now dynamically selectable
4527 You can choose which byte order to use with a target system, via the
4528 commands "set endian big" and "set endian little", and you can see the
4529 current setting by using "show endian". You can also give the command
4530 "set endian auto", in which case GDB will use the byte order
4531 associated with the executable. Currently, only embedded MIPS
4532 configurations support dynamic selection of target byte order.
4534 * New DOS host serial code
4536 This version uses DPMI interrupts to handle buffered I/O, so you
4537 no longer need to run asynctsr when debugging boards connected to
4540 *** Changes in GDB-4.13:
4542 * New "complete" command
4544 This lists all the possible completions for the rest of the line, if it
4545 were to be given as a command itself. This is intended for use by emacs.
4547 * Trailing space optional in prompt
4549 "set prompt" no longer adds a space for you after the prompt you set. This
4550 allows you to set a prompt which ends in a space or one that does not.
4552 * Breakpoint hit counts
4554 "info break" now displays a count of the number of times the breakpoint
4555 has been hit. This is especially useful in conjunction with "ignore"; you
4556 can ignore a large number of breakpoint hits, look at the breakpoint info
4557 to see how many times the breakpoint was hit, then run again, ignoring one
4558 less than that number, and this will get you quickly to the last hit of
4561 * Ability to stop printing at NULL character
4563 "set print null-stop" will cause GDB to stop printing the characters of
4564 an array when the first NULL is encountered. This is useful when large
4565 arrays actually contain only short strings.
4567 * Shared library breakpoints
4569 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4570 breakpoints in shared libraries before the executable is run.
4572 * Hardware watchpoints
4574 There is a new hardware breakpoint for the watch command for sparclite
4575 targets. See gdb/sparclite/hw_breakpoint.note.
4577 Hardware watchpoints are also now supported under GNU/Linux.
4581 Annotations have been added. These are for use with graphical interfaces,
4582 and are still experimental. Currently only gdba.el uses these.
4584 * Improved Irix 5 support
4586 GDB now works properly with Irix 5.2.
4588 * Improved HPPA support
4590 GDB now works properly with the latest GCC and GAS.
4592 * New native configurations
4594 Sequent PTX4 i[34]86-sequent-ptx4
4595 HPPA running OSF/1 hppa*-*-osf*
4596 Atari TT running SVR4 m68*-*-sysv4*
4597 RS/6000 LynxOS rs6000-*-lynxos*
4601 OS/9000 i[34]86-*-os9k
4602 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4605 * Hitachi SH7000 and E7000-PC ICE support
4607 There is now support for communicating with the Hitachi E7000-PC ICE.
4608 This is available automatically when GDB is configured for the SH.
4612 As usual, a variety of small fixes and improvements, both generic
4613 and configuration-specific. See the ChangeLog for more detail.
4615 *** Changes in GDB-4.12:
4617 * Irix 5 is now supported
4621 GDB-4.12 on the HPPA has a number of changes which make it unable
4622 to debug the output from the currently released versions of GCC and
4623 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4624 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4625 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4628 *** Changes in GDB-4.11:
4630 * User visible changes:
4634 The "set remotedebug" option is now consistent between the mips remote
4635 target, remote targets using the gdb-specific protocol, UDI (AMD's
4636 debug protocol for the 29k) and the 88k bug monitor. It is now an
4637 integer specifying a debug level (normally 0 or 1, but 2 means more
4638 debugging info for the mips target).
4640 * DEC Alpha native support
4642 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4643 debug info, but GDB works fairly well with the DEC compiler and should
4644 work with a future GCC release. See the README file for a few
4645 Alpha-specific notes.
4647 * Preliminary thread implementation
4649 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4651 * LynxOS native and target support for 386
4653 This release has been hosted on LynxOS 2.2, and also can be configured
4654 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4657 * Improvements in C++ mangling/demangling.
4659 This release has much better g++ debugging, specifically in name
4660 mangling/demangling, virtual function calls, print virtual table,
4661 call methods, ...etc.
4663 *** Changes in GDB-4.10:
4665 * User visible changes:
4667 Remote debugging using the GDB-specific (`target remote') protocol now
4668 supports the `load' command. This is only useful if you have some
4669 other way of getting the stub to the target system, and you can put it
4670 somewhere in memory where it won't get clobbered by the download.
4672 Filename completion now works.
4674 When run under emacs mode, the "info line" command now causes the
4675 arrow to point to the line specified. Also, "info line" prints
4676 addresses in symbolic form (as well as hex).
4678 All vxworks based targets now support a user settable option, called
4679 vxworks-timeout. This option represents the number of seconds gdb
4680 should wait for responses to rpc's. You might want to use this if
4681 your vxworks target is, perhaps, a slow software simulator or happens
4682 to be on the far side of a thin network line.
4686 This release contains support for using a DEC alpha as a GDB host for
4687 cross debugging. Native alpha debugging is not supported yet.
4690 *** Changes in GDB-4.9:
4694 This is the first GDB release which is accompanied by a matching testsuite.
4695 The testsuite requires installation of dejagnu, which should be available
4696 via ftp from most sites that carry GNU software.
4700 'Cfront' style demangling has had its name changed to 'ARM' style, to
4701 emphasize that it was written from the specifications in the C++ Annotated
4702 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4703 disclaimers, it still generated too much confusion with users attempting to
4704 use gdb with AT&T cfront.
4708 GDB now uses a standard remote interface to a simulator library.
4709 So far, the library contains simulators for the Zilog Z8001/2, the
4710 Hitachi H8/300, H8/500 and Super-H.
4712 * New targets supported
4714 H8/300 simulator h8300-hitachi-hms or h8300hms
4715 H8/500 simulator h8500-hitachi-hms or h8500hms
4716 SH simulator sh-hitachi-hms or sh
4717 Z8000 simulator z8k-zilog-none or z8ksim
4718 IDT MIPS board over serial line mips-idt-ecoff
4720 Cross-debugging to GO32 targets is supported. It requires a custom
4721 version of the i386-stub.c module which is integrated with the
4722 GO32 memory extender.
4724 * New remote protocols
4726 MIPS remote debugging protocol.
4728 * New source languages supported
4730 This version includes preliminary support for Chill, a Pascal like language
4731 used by telecommunications companies. Chill support is also being integrated
4732 into the GNU compiler, but we don't know when it will be publically available.
4735 *** Changes in GDB-4.8:
4737 * HP Precision Architecture supported
4739 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4740 version of this support was available as a set of patches from the
4741 University of Utah. GDB does not support debugging of programs
4742 compiled with the HP compiler, because HP will not document their file
4743 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4744 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4746 Many problems in the preliminary version have been fixed.
4748 * Faster and better demangling
4750 We have improved template demangling and fixed numerous bugs in the GNU style
4751 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4752 character types (wchar_t) are now supported. Demangling of each symbol is now
4753 only done once, and is cached when the symbol table for a file is read in.
4754 This results in a small increase in memory usage for C programs, a moderate
4755 increase in memory usage for C++ programs, and a fantastic speedup in
4758 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4759 from the specifications in the Annotated Reference Manual, which AT&T's
4760 compiler does not actually implement.
4762 * G++ multiple inheritance compiler problem
4764 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4765 inheritance lattices was reworked to properly discover ambiguities. We
4766 recently found an example which causes this new algorithm to fail in a
4767 very subtle way, producing bad debug information for those classes.
4768 The file 'gcc.patch' (in this directory) can be applied to gcc to
4769 circumvent the problem. A future GCC release will contain a complete
4772 The previous G++ debug info problem (mentioned below for the gdb-4.7
4773 release) is fixed in gcc version 2.3.2.
4775 * Improved configure script
4777 The `configure' script will now attempt to guess your system type if
4778 you don't supply a host system type. The old scheme of supplying a
4779 host system triplet is preferable over using this. All the magic is
4780 done in the new `config.guess' script. Examine it for details.
4782 We have also brought our configure script much more in line with the FSF's
4783 version. It now supports the --with-xxx options. In particular,
4784 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4785 The resulting GDB will not be able to read arbitrary object file formats --
4786 only the format ``expected'' to be used on the configured target system.
4787 We hope to make this the default in a future release.
4789 * Documentation improvements
4791 There's new internal documentation on how to modify GDB, and how to
4792 produce clean changes to the code. We implore people to read it
4793 before submitting changes.
4795 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4796 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4797 `info' files are also provided. To build `info' files from scratch,
4798 you will need the latest `makeinfo' release, which will be available in
4799 a future texinfo-X.Y release.
4801 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4802 We're not sure exactly which versions have this problem, but it has
4803 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4804 or better. If that isn't possible, there is a patch in
4805 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4806 around this problem.
4810 GDB now supports array constants that can be used in expressions typed in by
4811 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4812 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4815 The new directory `gdb/sparclite' contains a program that demonstrates
4816 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4818 * New native hosts supported
4820 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4821 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4823 * New targets supported
4825 AMD 29k family via UDI a29k-amd-udi or udi29k
4827 * New file formats supported
4829 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4830 HPUX core files, and SCO 3.2v2 core files.
4834 Attaching to processes now works again; thanks for the many bug reports.
4836 We have also stomped on a bunch of core dumps caused by
4837 printf_filtered("%s") problems.
4839 We eliminated a copyright problem on the rpc and ptrace header files
4840 for VxWorks, which was discovered at the last minute during the 4.7
4841 release. You should now be able to build a VxWorks GDB.
4843 You can now interrupt gdb while an attached process is running. This
4844 will cause the attached process to stop, and give control back to GDB.
4846 We fixed problems caused by using too many file descriptors
4847 for reading symbols from object files and libraries. This was
4848 especially a problem for programs that used many (~100) shared
4851 The `step' command now only enters a subroutine if there is line number
4852 information for the subroutine. Otherwise it acts like the `next'
4853 command. Previously, `step' would enter subroutines if there was
4854 any debugging information about the routine. This avoids problems
4855 when using `cc -g1' on MIPS machines.
4857 * Internal improvements
4859 GDB's internal interfaces have been improved to make it easier to support
4860 debugging of multiple languages in the future.
4862 GDB now uses a common structure for symbol information internally.
4863 Minimal symbols (derived from linkage symbols in object files), partial
4864 symbols (from a quick scan of debug information), and full symbols
4865 contain a common subset of information, making it easier to write
4866 shared code that handles any of them.
4868 * New command line options
4870 We now accept --silent as an alias for --quiet.
4874 The memory-mapped-malloc library is now licensed under the GNU Library
4875 General Public License.
4877 *** Changes in GDB-4.7:
4879 * Host/native/target split
4881 GDB has had some major internal surgery to untangle the support for
4882 hosts and remote targets. Now, when you configure GDB for a remote
4883 target, it will no longer load in all of the support for debugging
4884 local programs on the host. When fully completed and tested, this will
4885 ensure that arbitrary host/target combinations are possible.
4887 The primary conceptual shift is to separate the non-portable code in
4888 GDB into three categories. Host specific code is required any time GDB
4889 is compiled on that host, regardless of the target. Target specific
4890 code relates to the peculiarities of the target, but can be compiled on
4891 any host. Native specific code is everything else: it can only be
4892 built when the host and target are the same system. Child process
4893 handling and core file support are two common `native' examples.
4895 GDB's use of /proc for controlling Unix child processes is now cleaner.
4896 It has been split out into a single module under the `target_ops' vector,
4897 plus two native-dependent functions for each system that uses /proc.
4899 * New hosts supported
4901 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
4902 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4903 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
4905 * New targets supported
4907 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4908 68030 and CPU32 m68030-*-*, m68332-*-*
4910 * New native hosts supported
4912 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4913 (386bsd is not well tested yet)
4914 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
4916 * New file formats supported
4918 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
4919 supports reading of `a.out.adobe' object files, which are an a.out
4920 format extended with minimal information about multiple sections.
4924 `show copying' is the same as the old `info copying'.
4925 `show warranty' is the same as `info warrantee'.
4926 These were renamed for consistency. The old commands continue to work.
4928 `info handle' is a new alias for `info signals'.
4930 You can now define pre-command hooks, which attach arbitrary command
4931 scripts to any command. The commands in the hook will be executed
4932 prior to the user's command. You can also create a hook which will be
4933 executed whenever the program stops. See gdb.texinfo.
4937 We now deal with Cfront style name mangling, and can even extract type
4938 info from mangled symbols. GDB can automatically figure out which
4939 symbol mangling style your C++ compiler uses.
4941 Calling of methods and virtual functions has been improved as well.
4945 The crash that occured when debugging Sun Ansi-C compiled binaries is
4946 fixed. This was due to mishandling of the extra N_SO stabs output
4949 We also finally got Ultrix 4.2 running in house, and fixed core file
4950 support, with help from a dozen people on the net.
4952 John M. Farrell discovered that the reason that single-stepping was so
4953 slow on all of the Mips based platforms (primarily SGI and DEC) was
4954 that we were trying to demangle and lookup a symbol used for internal
4955 purposes on every instruction that was being stepped through. Changing
4956 the name of that symbol so that it couldn't be mistaken for a C++
4957 mangled symbol sped things up a great deal.
4959 Rich Pixley sped up symbol lookups in general by getting much smarter
4960 about when C++ symbol mangling is necessary. This should make symbol
4961 completion (TAB on the command line) much faster. It's not as fast as
4962 we'd like, but it's significantly faster than gdb-4.6.
4966 A new user controllable variable 'call_scratch_address' can
4967 specify the location of a scratch area to be used when GDB
4968 calls a function in the target. This is necessary because the
4969 usual method of putting the scratch area on the stack does not work
4970 in systems that have separate instruction and data spaces.
4972 We integrated changes to support the 29k UDI (Universal Debugger
4973 Interface), but discovered at the last minute that we didn't have all
4974 of the appropriate copyright paperwork. We are working with AMD to
4975 resolve this, and hope to have it available soon.
4979 We have sped up the remote serial line protocol, especially for targets
4980 with lots of registers. It now supports a new `expedited status' ('T')
4981 message which can be used in place of the existing 'S' status message.
4982 This allows the remote stub to send only the registers that GDB
4983 needs to make a quick decision about single-stepping or conditional
4984 breakpoints, eliminating the need to fetch the entire register set for
4985 each instruction being stepped through.
4987 The GDB remote serial protocol now implements a write-through cache for
4988 registers, only re-reading the registers if the target has run.
4990 There is also a new remote serial stub for SPARC processors. You can
4991 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
4992 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
4993 processor with a serial port.
4997 Configure.in files have become much easier to read and modify. A new
4998 `table driven' format makes it more obvious what configurations are
4999 supported, and what files each one uses.
5003 There is a new opcodes library which will eventually contain all of the
5004 disassembly routines and opcode tables. At present, it only contains
5005 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5006 disassembler (binutils/objdump) to share these routines.
5008 The libiberty library is now copylefted under the GNU Library General
5009 Public License. This allows more liberal use, and was done so libg++
5010 can use it. This makes no difference to GDB, since the Library License
5011 grants all the rights from the General Public License.
5015 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5016 reference to the stabs symbol info used by the debugger. It is (as far
5017 as we know) the only published document on this fascinating topic. We
5018 encourage you to read it, compare it to the stabs information on your
5019 system, and send improvements on the document in general (to
5020 bug-gdb@prep.ai.mit.edu).
5022 And, of course, many bugs have been fixed.
5025 *** Changes in GDB-4.6:
5027 * Better support for C++ function names
5029 GDB now accepts as input the "demangled form" of C++ overloaded function
5030 names and member function names, and can do command completion on such names
5031 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5032 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5033 Make use of command completion, it is your friend.
5035 GDB also now accepts a variety of C++ mangled symbol formats. They are
5036 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5037 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5038 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5039 for the list of formats.
5041 * G++ symbol mangling problem
5043 Recent versions of gcc have a bug in how they emit debugging information for
5044 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5045 directory) can be applied to gcc to fix the problem. Alternatively, if you
5046 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5047 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5048 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5051 * New 'maintenance' command
5053 All of the commands related to hacking GDB internals have been moved out of
5054 the main command set, and now live behind the 'maintenance' command. This
5055 can also be abbreviated as 'mt'. The following changes were made:
5057 dump-me -> maintenance dump-me
5058 info all-breakpoints -> maintenance info breakpoints
5059 printmsyms -> maintenance print msyms
5060 printobjfiles -> maintenance print objfiles
5061 printpsyms -> maintenance print psymbols
5062 printsyms -> maintenance print symbols
5064 The following commands are new:
5066 maintenance demangle Call internal GDB demangler routine to
5067 demangle a C++ link name and prints the result.
5068 maintenance print type Print a type chain for a given symbol
5070 * Change to .gdbinit file processing
5072 We now read the $HOME/.gdbinit file before processing the argv arguments
5073 (e.g. reading symbol files or core files). This allows global parameters to
5074 be set, which will apply during the symbol reading. The ./.gdbinit is still
5075 read after argv processing.
5077 * New hosts supported
5079 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5081 GNU/Linux support i386-unknown-linux or linux
5083 We are also including code to support the HP/PA running BSD and HPUX. This
5084 is almost guaranteed not to work, as we didn't have time to test or build it
5085 for this release. We are including it so that the more adventurous (or
5086 masochistic) of you can play with it. We also had major problems with the
5087 fact that the compiler that we got from HP doesn't support the -g option.
5090 * New targets supported
5092 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5094 * More smarts about finding #include files
5096 GDB now remembers the compilation directory for all include files, and for
5097 all files from which C is generated (like yacc and lex sources). This
5098 greatly improves GDB's ability to find yacc/lex sources, and include files,
5099 especially if you are debugging your program from a directory different from
5100 the one that contains your sources.
5102 We also fixed a bug which caused difficulty with listing and setting
5103 breakpoints in include files which contain C code. (In the past, you had to
5104 try twice in order to list an include file that you hadn't looked at before.)
5106 * Interesting infernals change
5108 GDB now deals with arbitrary numbers of sections, where the symbols for each
5109 section must be relocated relative to that section's landing place in the
5110 target's address space. This work was needed to support ELF with embedded
5111 stabs used by Solaris-2.0.
5113 * Bug fixes (of course!)
5115 There have been loads of fixes for the following things:
5116 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5117 i960, stabs, DOS(GO32), procfs, etc...
5119 See the ChangeLog for details.
5121 *** Changes in GDB-4.5:
5123 * New machines supported (host and target)
5125 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5127 SGI Irix-4.x mips-sgi-irix4 or iris4
5129 * New malloc package
5131 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5132 Mmalloc is capable of handling mutiple heaps of memory. It is also
5133 capable of saving a heap to a file, and then mapping it back in later.
5134 This can be used to greatly speedup the startup of GDB by using a
5135 pre-parsed symbol table which lives in a mmalloc managed heap. For
5136 more details, please read mmalloc/mmalloc.texi.
5140 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5141 'help info proc' for details.
5143 * MIPS ecoff symbol table format
5145 The code that reads MIPS symbol table format is now supported on all hosts.
5146 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5149 * File name changes for MS-DOS
5151 Many files in the config directories have been renamed to make it easier to
5152 support GDB on MS-DOSe systems (which have very restrictive file name
5153 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5154 environment) is close to working but has some remaining problems. Note
5155 that debugging of DOS programs is not supported, due to limitations
5156 in the ``operating system'', but it can be used to host cross-debugging.
5158 * Cross byte order fixes
5160 Many fixes have been made to support cross debugging of Sparc and MIPS
5161 targets from hosts whose byte order differs.
5163 * New -mapped and -readnow options
5165 If memory-mapped files are available on your system through the 'mmap'
5166 system call, you can use the -mapped option on the `file' or
5167 `symbol-file' commands to cause GDB to write the symbols from your
5168 program into a reusable file. If the program you are debugging is
5169 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5170 Future GDB debugging sessions will notice the presence of this file,
5171 and will quickly map in symbol information from it, rather than reading
5172 the symbol table from the executable program. Using the '-mapped'
5173 option in a GDB `file' or `symbol-file' command has the same effect as
5174 starting GDB with the '-mapped' command-line option.
5176 You can cause GDB to read the entire symbol table immediately by using
5177 the '-readnow' option with any of the commands that load symbol table
5178 information (or on the GDB command line). This makes the command
5179 slower, but makes future operations faster.
5181 The -mapped and -readnow options are typically combined in order to
5182 build a `fred.syms' file that contains complete symbol information.
5183 A simple GDB invocation to do nothing but build a `.syms' file for future
5186 gdb -batch -nx -mapped -readnow programname
5188 The `.syms' file is specific to the host machine on which GDB is run.
5189 It holds an exact image of GDB's internal symbol table. It cannot be
5190 shared across multiple host platforms.
5192 * longjmp() handling
5194 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5195 siglongjmp() without losing control. This feature has not yet been ported to
5196 all systems. It currently works on many 386 platforms, all MIPS-based
5197 platforms (SGI, DECstation, etc), and Sun3/4.
5201 Preliminary work has been put in to support the new Solaris OS from Sun. At
5202 this time, it can control and debug processes, but it is not capable of
5207 As always, many many bug fixes. The major areas were with g++, and mipsread.
5208 People using the MIPS-based platforms should experience fewer mysterious
5209 crashes and trashed symbol tables.
5211 *** Changes in GDB-4.4:
5213 * New machines supported (host and target)
5215 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5217 BSD Reno on Vax vax-dec-bsd
5218 Ultrix on Vax vax-dec-ultrix
5220 * New machines supported (target)
5222 AMD 29000 embedded, using EBMON a29k-none-none
5226 GDB continues to improve its handling of C++. `References' work better.
5227 The demangler has also been improved, and now deals with symbols mangled as
5228 per the Annotated C++ Reference Guide.
5230 GDB also now handles `stabs' symbol information embedded in MIPS
5231 `ecoff' symbol tables. Since the ecoff format was not easily
5232 extensible to handle new languages such as C++, this appeared to be a
5233 good way to put C++ debugging info into MIPS binaries. This option
5234 will be supported in the GNU C compiler, version 2, when it is
5237 * New features for SVR4
5239 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5240 shared libraries. Debugging dynamically linked programs should present
5241 only minor differences from debugging statically linked programs.
5243 The `info proc' command will print out information about any process
5244 on an SVR4 system (including the one you are debugging). At the moment,
5245 it prints the address mappings of the process.
5247 If you bring up GDB on another SVR4 system, please send mail to
5248 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5250 * Better dynamic linking support in SunOS
5252 Reading symbols from shared libraries which contain debugging symbols
5253 now works properly. However, there remain issues such as automatic
5254 skipping of `transfer vector' code during function calls, which
5255 make it harder to debug code in a shared library, than to debug the
5256 same code linked statically.
5260 GDB is now using the latest `getopt' routines from the FSF. This
5261 version accepts the -- prefix for options with long names. GDB will
5262 continue to accept the old forms (-option and +option) as well.
5263 Various single letter abbreviations for options have been explicity
5264 added to the option table so that they won't get overshadowed in the
5265 future by other options that begin with the same letter.
5269 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5270 Many assorted bugs have been handled. Many more remain to be handled.
5271 See the various ChangeLog files (primarily in gdb and bfd) for details.
5274 *** Changes in GDB-4.3:
5276 * New machines supported (host and target)
5278 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5279 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5280 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5282 * Almost SCO Unix support
5284 We had hoped to support:
5285 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5286 (except for core file support), but we discovered very late in the release
5287 that it has problems with process groups that render gdb unusable. Sorry
5288 about that. I encourage people to fix it and post the fixes.
5290 * Preliminary ELF and DWARF support
5292 GDB can read ELF object files on System V Release 4, and can handle
5293 debugging records for C, in DWARF format, in ELF files. This support
5294 is preliminary. If you bring up GDB on another SVR4 system, please
5295 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5300 GDB now uses the latest `readline' library. One user-visible change
5301 is that two tabs will list possible command completions, which previously
5302 required typing M-? (meta-question mark, or ESC ?).
5306 The `stepi' bug that many of you noticed has been squashed.
5307 Many bugs in C++ have been handled. Many more remain to be handled.
5308 See the various ChangeLog files (primarily in gdb and bfd) for details.
5310 * State of the MIPS world (in case you wondered):
5312 GDB can understand the symbol tables emitted by the compilers
5313 supplied by most vendors of MIPS-based machines, including DEC. These
5314 symbol tables are in a format that essentially nobody else uses.
5316 Some versions of gcc come with an assembler post-processor called
5317 mips-tfile. This program is required if you want to do source-level
5318 debugging of gcc-compiled programs. I believe FSF does not ship
5319 mips-tfile with gcc version 1, but it will eventually come with gcc
5322 Debugging of g++ output remains a problem. g++ version 1.xx does not
5323 really support it at all. (If you're lucky, you should be able to get
5324 line numbers and stack traces to work, but no parameters or local
5325 variables.) With some work it should be possible to improve the
5328 When gcc version 2 is released, you will have somewhat better luck.
5329 However, even then you will get confusing results for inheritance and
5332 We will eventually provide full debugging of g++ output on
5333 DECstations. This will probably involve some kind of stabs-in-ecoff
5334 encapulation, but the details have not been worked out yet.
5337 *** Changes in GDB-4.2:
5339 * Improved configuration
5341 Only one copy of `configure' exists now, and it is not self-modifying.
5342 Porting BFD is simpler.
5346 The `step' and `next' commands now only stop at the first instruction
5347 of a source line. This prevents the multiple stops that used to occur
5348 in switch statements, for-loops, etc. `Step' continues to stop if a
5349 function that has debugging information is called within the line.
5353 Lots of small bugs fixed. More remain.
5355 * New host supported (not target)
5357 Intel 386 PC clone running Mach i386-none-mach
5360 *** Changes in GDB-4.1:
5362 * Multiple source language support
5364 GDB now has internal scaffolding to handle several source languages.
5365 It determines the type of each source file from its filename extension,
5366 and will switch expression parsing and number formatting to match the
5367 language of the function in the currently selected stack frame.
5368 You can also specifically set the language to be used, with
5369 `set language c' or `set language modula-2'.
5373 GDB now has preliminary support for the GNU Modula-2 compiler,
5374 currently under development at the State University of New York at
5375 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5376 continue through the fall of 1991 and into 1992.
5378 Other Modula-2 compilers are currently not supported, and attempting to
5379 debug programs compiled with them will likely result in an error as the
5380 symbol table is read. Feel free to work on it, though!
5382 There are hooks in GDB for strict type checking and range checking,
5383 in the `Modula-2 philosophy', but they do not currently work.
5387 GDB can now write to executable and core files (e.g. patch
5388 a variable's value). You must turn this switch on, specify
5389 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5390 by assigning a new value to a variable. Modifications take
5393 * Automatic SunOS shared library reading
5395 When you run your program, GDB automatically determines where its
5396 shared libraries (if any) have been loaded, and reads their symbols.
5397 The `share' command is no longer needed. This also works when
5398 examining core files.
5402 You can specify the number of lines that the `list' command shows.
5405 * New machines supported (host and target)
5407 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5408 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5409 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5411 * New hosts supported (not targets)
5413 IBM RT/PC: romp-ibm-aix or rtpc
5415 * New targets supported (not hosts)
5417 AMD 29000 embedded with COFF a29k-none-coff
5418 AMD 29000 embedded with a.out a29k-none-aout
5419 Ultracomputer remote kernel debug a29k-nyu-kern
5421 * New remote interfaces
5427 *** Changes in GDB-4.0:
5431 Wide output is wrapped at good places to make the output more readable.
5433 Gdb now supports cross-debugging from a host machine of one type to a
5434 target machine of another type. Communication with the target system
5435 is over serial lines. The ``target'' command handles connecting to the
5436 remote system; the ``load'' command will download a program into the
5437 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5438 also supports debugging of realtime processes running under VxWorks,
5439 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5440 stub on the target system.
5442 New CPUs supported include the AMD 29000 and Intel 960.
5444 GDB now reads object files and symbol tables via a ``binary file''
5445 library, which allows a single copy of GDB to debug programs of multiple
5446 object file types such as a.out and coff.
5448 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5449 refcard.dvi and refcard.ps are available to format it).
5452 * Control-Variable user interface simplified
5454 All variables that control the operation of the debugger can be set
5455 by the ``set'' command, and displayed by the ``show'' command.
5457 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5458 ``Show prompt'' produces the response:
5459 Gdb's prompt is new-gdb=>.
5461 What follows are the NEW set commands. The command ``help set'' will
5462 print a complete list of old and new set commands. ``help set FOO''
5463 will give a longer description of the variable FOO. ``show'' will show
5464 all of the variable descriptions and their current settings.
5466 confirm on/off: Enables warning questions for operations that are
5467 hard to recover from, e.g. rerunning the program while
5468 it is already running. Default is ON.
5470 editing on/off: Enables EMACS style command line editing
5471 of input. Previous lines can be recalled with
5472 control-P, the current line can be edited with control-B,
5473 you can search for commands with control-R, etc.
5476 history filename NAME: NAME is where the gdb command history
5477 will be stored. The default is .gdb_history,
5478 or the value of the environment variable
5481 history size N: The size, in commands, of the command history. The
5482 default is 256, or the value of the environment variable
5485 history save on/off: If this value is set to ON, the history file will
5486 be saved after exiting gdb. If set to OFF, the
5487 file will not be saved. The default is OFF.
5489 history expansion on/off: If this value is set to ON, then csh-like
5490 history expansion will be performed on
5491 command line input. The default is OFF.
5493 radix N: Sets the default radix for input and output. It can be set
5494 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5495 in the current radix, so "set radix 10" is always a no-op.
5497 height N: This integer value is the number of lines on a page. Default
5498 is 24, the current `stty rows'' setting, or the ``li#''
5499 setting from the termcap entry matching the environment
5502 width N: This integer value is the number of characters on a line.
5503 Default is 80, the current `stty cols'' setting, or the ``co#''
5504 setting from the termcap entry matching the environment
5507 Note: ``set screensize'' is obsolete. Use ``set height'' and
5508 ``set width'' instead.
5510 print address on/off: Print memory addresses in various command displays,
5511 such as stack traces and structure values. Gdb looks
5512 more ``symbolic'' if you turn this off; it looks more
5513 ``machine level'' with it on. Default is ON.
5515 print array on/off: Prettyprint arrays. New convenient format! Default
5518 print demangle on/off: Print C++ symbols in "source" form if on,
5521 print asm-demangle on/off: Same, for assembler level printouts
5524 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5527 * Support for Epoch Environment.
5529 The epoch environment is a version of Emacs v18 with windowing. One
5530 new command, ``inspect'', is identical to ``print'', except that if you
5531 are running in the epoch environment, the value is printed in its own
5535 * Support for Shared Libraries
5537 GDB can now debug programs and core files that use SunOS shared libraries.
5538 Symbols from a shared library cannot be referenced
5539 before the shared library has been linked with the program (this
5540 happens after you type ``run'' and before the function main() is entered).
5541 At any time after this linking (including when examining core files
5542 from dynamically linked programs), gdb reads the symbols from each
5543 shared library when you type the ``sharedlibrary'' command.
5544 It can be abbreviated ``share''.
5546 sharedlibrary REGEXP: Load shared object library symbols for files
5547 matching a unix regular expression. No argument
5548 indicates to load symbols for all shared libraries.
5550 info sharedlibrary: Status of loaded shared libraries.
5555 A watchpoint stops execution of a program whenever the value of an
5556 expression changes. Checking for this slows down execution
5557 tremendously whenever you are in the scope of the expression, but is
5558 quite useful for catching tough ``bit-spreader'' or pointer misuse
5559 problems. Some machines such as the 386 have hardware for doing this
5560 more quickly, and future versions of gdb will use this hardware.
5562 watch EXP: Set a watchpoint (breakpoint) for an expression.
5564 info watchpoints: Information about your watchpoints.
5566 delete N: Deletes watchpoint number N (same as breakpoints).
5567 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5568 enable N: Re-enables watchpoint number N (same as breakpoints).
5571 * C++ multiple inheritance
5573 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5576 * C++ exception handling
5578 Gdb now supports limited C++ exception handling. Besides the existing
5579 ability to breakpoint on an exception handler, gdb can breakpoint on
5580 the raising of an exception (before the stack is peeled back to the
5583 catch FOO: If there is a FOO exception handler in the dynamic scope,
5584 set a breakpoint to catch exceptions which may be raised there.
5585 Multiple exceptions (``catch foo bar baz'') may be caught.
5587 info catch: Lists all exceptions which may be caught in the
5588 current stack frame.
5591 * Minor command changes
5593 The command ``call func (arg, arg, ...)'' now acts like the print
5594 command, except it does not print or save a value if the function's result
5595 is void. This is similar to dbx usage.
5597 The ``up'' and ``down'' commands now always print the frame they end up
5598 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5599 frames without printing.
5601 * New directory command
5603 'dir' now adds directories to the FRONT of the source search path.
5604 The path starts off empty. Source files that contain debug information
5605 about the directory in which they were compiled can be found even
5606 with an empty path; Sun CC and GCC include this information. If GDB can't
5607 find your source file in the current directory, type "dir .".
5609 * Configuring GDB for compilation
5611 For normal use, type ``./configure host''. See README or gdb.texinfo
5614 GDB now handles cross debugging. If you are remotely debugging between
5615 two different machines, type ``./configure host -target=targ''.
5616 Host is the machine where GDB will run; targ is the machine
5617 where the program that you are debugging will run.
5619 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.