1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.8
6 * GDB now supports hardware watchpoints on x86 GNU Hurd.
9 You can now access frame registers from Python scripts.
11 * New Python-based convenience functions:
13 ** $_caller_is(name [, number_of_frames])
14 ** $_caller_matches(regexp [, number_of_frames])
15 ** $_any_caller_is(name [, number_of_frames])
16 ** $_any_caller_matches(regexp [, number_of_frames])
20 queue-signal signal-name-or-number
21 Queue a signal to be delivered to the thread when it is resumed.
23 * On resume, GDB now always passes the signal the program had stopped
24 for to the thread the signal was sent to, even if the user changed
25 threads before resuming. Previously GDB would often (but not
26 always) deliver the signal to the thread that happens to be current
29 * Conversely, the "signal" command now consistently delivers the
30 requested signal to the current thread. GDB now asks for
31 confirmation if the program had stopped for a signal and the user
32 switched threads meanwhile.
34 *** Changes in GDB 7.8
36 * New command line options
39 This is an alias for the --data-directory option.
41 * GDB supports printing and modifying of variable length automatic arrays
42 as specified in ISO C99.
44 * The ARM simulator now supports instruction level tracing
45 with or without disassembly.
49 GDB now has support for scripting using Guile. Whether this is
50 available is determined at configure time.
51 Guile version 2.0 or greater is required.
52 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
54 * New commands (for set/show, see "New options" below)
58 Invoke CODE by passing it to the Guile interpreter.
62 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
64 info auto-load guile-scripts [regexp]
65 Print the list of automatically loaded Guile scripts.
67 * The source command is now capable of sourcing Guile scripts.
68 This feature is dependent on the debugger being built with Guile support.
72 set print symbol-loading (off|brief|full)
73 show print symbol-loading
74 Control whether to print informational messages when loading symbol
75 information for a file. The default is "full", but when debugging
76 programs with large numbers of shared libraries the amount of output
79 set guile print-stack (none|message|full)
80 show guile print-stack
81 Show a stack trace when an error is encountered in a Guile script.
83 set auto-load guile-scripts (on|off)
84 show auto-load guile-scripts
85 Control auto-loading of Guile script files.
87 maint ada set ignore-descriptive-types (on|off)
88 maint ada show ignore-descriptive-types
89 Control whether the debugger should ignore descriptive types in Ada
90 programs. The default is not to ignore the descriptive types. See
91 the user manual for more details on descriptive types and the intended
94 set auto-connect-native-target
96 Control whether GDB is allowed to automatically connect to the
97 native target for the run, attach, etc. commands when not connected
98 to any target yet. See also "target native" below.
100 set record btrace replay-memory-access (read-only|read-write)
101 show record btrace replay-memory-access
102 Control what memory accesses are allowed during replay.
104 maint set target-async (on|off)
105 maint show target-async
106 This controls whether GDB targets operate in syncronous or
107 asyncronous mode. Normally the default is asyncronous, if it is
108 available; but this can be changed to more easily debug problems
109 occurring only in syncronous mode.
111 set mi-async (on|off)
113 Control whether MI asynchronous mode is preferred. This supersedes
114 "set target-async" of previous GDB versions.
116 * "set target-async" is deprecated as a CLI option and is now an alias
117 for "set mi-async" (only puts MI into async mode).
119 * Background execution commands (e.g., "c&", "s&", etc.) are now
120 possible ``out of the box'' if the target supports them. Previously
121 the user would need to explicitly enable the possibility with the
122 "set target-async on" command.
124 * New features in the GDB remote stub, GDBserver
126 ** New option --debug-format=option1[,option2,...] allows one to add
127 additional text to each output. At present only timestamps
128 are supported: --debug-format=timestamps.
129 Timestamps can also be turned on with the
130 "monitor set debug-format timestamps" command from GDB.
132 * The 'record instruction-history' command now starts counting instructions
133 at one. This also affects the instruction ranges reported by the
134 'record function-call-history' command when given the /i modifier.
136 * The command 'record function-call-history' supports a new modifier '/c' to
137 indent the function names based on their call stack depth.
138 The fields for the '/i' and '/l' modifier have been reordered.
139 The source line range is now prefixed with 'at'.
140 The instruction range is now prefixed with 'inst'.
141 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
142 "record instruction-history" and "list" commands.
144 * The ranges given as arguments to the 'record function-call-history' and
145 'record instruction-history' commands are now inclusive.
147 * The btrace record target now supports the 'record goto' command.
148 For locations inside the execution trace, the back trace is computed
149 based on the information stored in the execution trace.
151 * The btrace record target supports limited reverse execution and replay.
152 The target does not record data and therefore does not allow reading
155 * The "catch syscall" command now works on s390*-linux* targets.
157 * The "compare-sections" command is no longer specific to target
158 remote. It now works with all targets.
160 * All native targets are now consistently called "native".
161 Consequently, the "target child", "target GNU", "target djgpp",
162 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
163 commands have been replaced with "target native". The QNX/NTO port
164 leaves the "procfs" target in place and adds a "native" target for
165 consistency with other ports. The impact on users should be minimal
166 as these commands previously either throwed an error, or were
167 no-ops. The target's name is visible in the output of the following
168 commands: "help target", "info target", "info files", "maint print
171 * The "target native" command now connects to the native target. This
172 can be used to launch native programs even when "set
173 auto-connect-native-target" is set to off.
175 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.
177 * Support for Intel(R) AVX-512 registers on GNU/Linux.
178 Support displaying and modifying Intel(R) AVX-512 registers
179 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
183 qXfer:btrace:read's annex
184 The qXfer:btrace:read packet supports a new annex 'delta' to read
185 branch trace incrementally.
189 ** Valid Python operations on gdb.Value objects representing
190 structs/classes invoke the corresponding overloaded operators if
192 ** New `Xmethods' feature in the Python API. Xmethods are
193 additional methods or replacements for existing methods of a C++
194 class. This feature is useful for those cases where a method
195 defined in C++ source code could be inlined or optimized out by
196 the compiler, making it unavailable to GDB.
199 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
201 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
202 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
203 its alias "share", instead.
205 * The commands "set remotebaud" and "show remotebaud" are no longer
206 supported. Use "set serial baud" and "show serial baud" (respectively)
211 ** A new option "-gdb-set mi-async" replaces "-gdb-set
212 target-async". The latter is left as a deprecated alias of the
213 former for backward compatibility. If the target supports it,
214 CLI background execution commands are now always possible by
215 default, independently of whether the frontend stated a
216 preference for asynchronous execution with "-gdb-set mi-async".
217 Previously "-gdb-set target-async off" affected both MI execution
218 commands and CLI execution commands.
220 *** Changes in GDB 7.7
222 * Improved support for process record-replay and reverse debugging on
223 arm*-linux* targets. Support for thumb32 and syscall instruction
224 recording has been added.
226 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
228 * GDB now supports Fission DWP file format version 2.
229 http://gcc.gnu.org/wiki/DebugFission
231 * New convenience function "$_isvoid", to check whether an expression
232 is void. A void expression is an expression where the type of the
233 result is "void". For example, some convenience variables may be
234 "void" when evaluated (e.g., "$_exitcode" before the execution of
235 the program being debugged; or an undefined convenience variable).
236 Another example, when calling a function whose return type is
239 * The "maintenance print objfiles" command now takes an optional regexp.
241 * The "catch syscall" command now works on arm*-linux* targets.
243 * GDB now consistently shows "<not saved>" when printing values of
244 registers the debug info indicates have not been saved in the frame
245 and there's nowhere to retrieve them from
246 (callee-saved/call-clobbered registers):
251 (gdb) info registers rax
254 Before, the former would print "<optimized out>", and the latter
255 "*value not available*".
257 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
262 ** Frame filters and frame decorators have been added.
263 ** Temporary breakpoints are now supported.
264 ** Line tables representation has been added.
265 ** New attribute 'parent_type' for gdb.Field objects.
266 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
267 ** New attribute 'name' for gdb.Type objects.
271 Nios II ELF nios2*-*-elf
272 Nios II GNU/Linux nios2*-*-linux
273 Texas Instruments MSP430 msp430*-*-elf
275 * Removed native configurations
277 Support for these a.out NetBSD and OpenBSD obsolete configurations has
278 been removed. ELF variants of these configurations are kept supported.
280 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
281 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
282 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
283 i[34567]86-*-openbsd3.[0-3]
284 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
285 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
286 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
290 Like "catch throw", but catches a re-thrown exception.
292 Renamed from old "maint check-symtabs".
294 Perform consistency checks on symtabs.
296 Expand symtabs matching an optional regexp.
299 Display the details of GDB configure-time options.
301 maint set|show per-command
302 maint set|show per-command space
303 maint set|show per-command time
304 maint set|show per-command symtab
305 Enable display of per-command gdb resource usage.
307 remove-symbol-file FILENAME
308 remove-symbol-file -a ADDRESS
309 Remove a symbol file added via add-symbol-file. The file to remove
310 can be identified by its filename or by an address that lies within
311 the boundaries of this symbol file in memory.
314 info exceptions REGEXP
315 Display the list of Ada exceptions defined in the program being
316 debugged. If provided, only the exceptions whose names match REGEXP
321 set debug symfile off|on
323 Control display of debugging info regarding reading symbol files and
324 symbol tables within those files
326 set print raw frame-arguments
327 show print raw frame-arguments
328 Set/show whether to print frame arguments in raw mode,
329 disregarding any defined pretty-printers.
331 set remote trace-status-packet
332 show remote trace-status-packet
333 Set/show the use of remote protocol qTStatus packet.
337 Control display of debugging messages related to Nios II targets.
341 Control whether target-assisted range stepping is enabled.
343 set startup-with-shell
344 show startup-with-shell
345 Specifies whether Unix child processes are started via a shell or
350 Use the target memory cache for accesses to the code segment. This
351 improves performance of remote debugging (particularly disassembly).
353 * You can now use a literal value 'unlimited' for options that
354 interpret 0 or -1 as meaning "unlimited". E.g., "set
355 trace-buffer-size unlimited" is now an alias for "set
356 trace-buffer-size -1" and "set height unlimited" is now an alias for
359 * The "set debug symtab-create" debugging option of GDB has been changed to
360 accept a verbosity level. 0 means "off", 1 provides basic debugging
361 output, and values of 2 or greater provides more verbose output.
363 * New command-line options
365 Display the details of GDB configure-time options.
367 * The command 'tsave' can now support new option '-ctf' to save trace
368 buffer in Common Trace Format.
370 * Newly installed $prefix/bin/gcore acts as a shell interface for the
373 * GDB now implements the the C++ 'typeid' operator.
375 * The new convenience variable $_exception holds the exception being
376 thrown or caught at an exception-related catchpoint.
378 * The exception-related catchpoints, like "catch throw", now accept a
379 regular expression which can be used to filter exceptions by type.
381 * The new convenience variable $_exitsignal is automatically set to
382 the terminating signal number when the program being debugged dies
383 due to an uncaught signal.
387 ** All MI commands now accept an optional "--language" option.
388 Support for this feature can be verified by using the "-list-features"
389 command, which should contain "language-option".
391 ** The new command -info-gdb-mi-command allows the user to determine
392 whether a GDB/MI command is supported or not.
394 ** The "^error" result record returned when trying to execute an undefined
395 GDB/MI command now provides a variable named "code" whose content is the
396 "undefined-command" error code. Support for this feature can be verified
397 by using the "-list-features" command, which should contain
398 "undefined-command-error-code".
400 ** The -trace-save MI command can optionally save trace buffer in Common
403 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
405 ** The command -data-list-register-values now accepts an optional
406 "--skip-unavailable" option. When used, only the available registers
409 ** The new command -trace-frame-collected dumps collected variables,
410 computed expressions, tvars, memory and registers in a traceframe.
412 ** The commands -stack-list-locals, -stack-list-arguments and
413 -stack-list-variables now accept an option "--skip-unavailable".
414 When used, only the available locals or arguments are displayed.
416 ** The -exec-run command now accepts an optional "--start" option.
417 When used, the command follows the same semantics as the "start"
418 command, stopping the program's execution at the start of its
419 main subprogram. Support for this feature can be verified using
420 the "-list-features" command, which should contain
421 "exec-run-start-option".
423 ** The new commands -catch-assert and -catch-exceptions insert
424 catchpoints stopping the program when Ada exceptions are raised.
426 ** The new command -info-ada-exceptions provides the equivalent of
427 the new "info exceptions" command.
429 * New system-wide configuration scripts
430 A GDB installation now provides scripts suitable for use as system-wide
431 configuration scripts for the following systems:
435 * GDB now supports target-assigned range stepping with remote targets.
436 This improves the performance of stepping source lines by reducing
437 the number of control packets from/to GDB. See "New remote packets"
440 * GDB now understands the element 'tvar' in the XML traceframe info.
441 It has the id of the collected trace state variables.
443 * On S/390 targets that provide the transactional-execution feature,
444 the program interruption transaction diagnostic block (TDB) is now
445 represented as a number of additional "registers" in GDB.
451 The vCont packet supports a new 'r' action, that tells the remote
452 stub to step through an address range itself, without GDB
453 involvemement at each single-step.
455 qXfer:libraries-svr4:read's annex
456 The previously unused annex of the qXfer:libraries-svr4:read packet
457 is now used to support passing an argument list. The remote stub
458 reports support for this argument list to GDB's qSupported query.
459 The defined arguments are "start" and "prev", used to reduce work
460 necessary for library list updating, resulting in significant
463 * New features in the GDB remote stub, GDBserver
465 ** GDBserver now supports target-assisted range stepping. Currently
466 enabled on x86/x86_64 GNU/Linux targets.
468 ** GDBserver now adds element 'tvar' in the XML in the reply to
469 'qXfer:traceframe-info:read'. It has the id of the collected
470 trace state variables.
472 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
475 * New 'z' formatter for printing and examining memory, this displays the
476 value as hexadecimal zero padded on the left to the size of the type.
478 * GDB can now use Windows x64 unwinding data.
480 * The "set remotebaud" command has been replaced by "set serial baud".
481 Similarly, "show remotebaud" has been replaced by "show serial baud".
482 The "set remotebaud" and "show remotebaud" commands are still available
483 to provide backward compatibility with older versions of GDB.
485 *** Changes in GDB 7.6
487 * Target record has been renamed to record-full.
488 Record/replay is now enabled with the "record full" command.
489 This also affects settings that are associated with full record/replay
490 that have been moved from "set/show record" to "set/show record full":
492 set|show record full insn-number-max
493 set|show record full stop-at-limit
494 set|show record full memory-query
496 * A new record target "record-btrace" has been added. The new target
497 uses hardware support to record the control-flow of a process. It
498 does not support replaying the execution, but it implements the
499 below new commands for investigating the recorded execution log.
500 This new recording method can be enabled using:
504 The "record-btrace" target is only available on Intel Atom processors
505 and requires a Linux kernel 2.6.32 or later.
507 * Two new commands have been added for record/replay to give information
508 about the recorded execution without having to replay the execution.
509 The commands are only supported by "record btrace".
511 record instruction-history prints the execution history at
512 instruction granularity
514 record function-call-history prints the execution history at
517 * New native configurations
519 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
520 FreeBSD/powerpc powerpc*-*-freebsd
521 x86_64/Cygwin x86_64-*-cygwin*
522 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
526 ARM AArch64 aarch64*-*-elf
527 ARM AArch64 GNU/Linux aarch64*-*-linux
528 Lynx 178 PowerPC powerpc-*-lynx*178
529 x86_64/Cygwin x86_64-*-cygwin*
530 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
532 * If the configured location of system.gdbinit file (as given by the
533 --with-system-gdbinit option at configure time) is in the
534 data-directory (as specified by --with-gdb-datadir at configure
535 time) or in one of its subdirectories, then GDB will look for the
536 system-wide init file in the directory specified by the
537 --data-directory command-line option.
539 * New command line options:
541 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
542 other initialization files, unlike -nx which disables all of them.
544 * Removed command line options
546 -epoch This was used by the gdb mode in Epoch, an ancient fork of
549 * The 'ptype' and 'whatis' commands now accept an argument to control
552 * 'info proc' now works on some core files.
556 ** Vectors can be created with gdb.Type.vector.
558 ** Python's atexit.register now works in GDB.
560 ** Types can be pretty-printed via a Python API.
562 ** Python 3 is now supported (in addition to Python 2.4 or later)
564 ** New class gdb.Architecture exposes GDB's internal representation
565 of architecture in the Python API.
567 ** New method Frame.architecture returns the gdb.Architecture object
568 corresponding to the frame's architecture.
570 * New Python-based convenience functions:
572 ** $_memeq(buf1, buf2, length)
573 ** $_streq(str1, str2)
575 ** $_regex(str, regex)
577 * The 'cd' command now defaults to using '~' (the home directory) if not
580 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
581 default for GCC since November 2000.
583 * The command 'forward-search' can now be abbreviated as 'fo'.
585 * The command 'info tracepoints' can now display 'installed on target'
586 or 'not installed on target' for each non-pending location of tracepoint.
588 * New configure options
590 --enable-libmcheck/--disable-libmcheck
591 By default, development versions are built with -lmcheck on hosts
592 that support it, in order to help track memory corruption issues.
593 Release versions, on the other hand, are built without -lmcheck
594 by default. The --enable-libmcheck/--disable-libmcheck configure
595 options allow the user to override that default.
596 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
597 This configure option allows the user to build GDB with
598 libbabeltrace using which GDB can read Common Trace Format data.
600 * New commands (for set/show, see "New options" below)
603 Catch signals. This is similar to "handle", but allows commands and
604 conditions to be attached.
607 List the BFDs known to GDB.
609 python-interactive [command]
611 Start a Python interactive prompt, or evaluate the optional command
612 and print the result of expressions.
615 "py" is a new alias for "python".
617 enable type-printer [name]...
618 disable type-printer [name]...
619 Enable or disable type printers.
623 ** For the Renesas Super-H architecture, the "regs" command has been removed
624 (has been deprecated in GDB 7.5), and "info all-registers" should be used
629 set print type methods (on|off)
630 show print type methods
631 Control whether method declarations are displayed by "ptype".
632 The default is to show them.
634 set print type typedefs (on|off)
635 show print type typedefs
636 Control whether typedef definitions are displayed by "ptype".
637 The default is to show them.
639 set filename-display basename|relative|absolute
640 show filename-display
641 Control the way in which filenames is displayed.
642 The default is "relative", which preserves previous behavior.
644 set trace-buffer-size
645 show trace-buffer-size
646 Request target to change the size of trace buffer.
648 set remote trace-buffer-size-packet auto|on|off
649 show remote trace-buffer-size-packet
650 Control the use of the remote protocol `QTBuffer:size' packet.
654 Control display of debugging messages related to ARM AArch64.
657 set debug coff-pe-read
658 show debug coff-pe-read
659 Control display of debugging messages related to reading of COFF/PE
664 Control display of debugging messages related to Mach-O symbols
667 set debug notification
668 show debug notification
669 Control display of debugging info for async remote notification.
673 ** Command parameter changes are now notified using new async record
674 "=cmd-param-changed".
675 ** Trace frame changes caused by command "tfind" are now notified using
676 new async record "=traceframe-changed".
677 ** The creation, deletion and modification of trace state variables
678 are now notified using new async records "=tsv-created",
679 "=tsv-deleted" and "=tsv-modified".
680 ** The start and stop of process record are now notified using new
681 async record "=record-started" and "=record-stopped".
682 ** Memory changes are now notified using new async record
684 ** The data-disassemble command response will include a "fullname" field
685 containing the absolute file name when source has been requested.
686 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
687 command, to allow pattern filling of memory areas.
688 ** New commands "-catch-load"/"-catch-unload" added for intercepting
689 library load/unload events.
690 ** The response to breakpoint commands and breakpoint async records
691 includes an "installed" field containing a boolean state about each
692 non-pending tracepoint location is whether installed on target or not.
693 ** Output of the "-trace-status" command includes a "trace-file" field
694 containing the name of the trace file being examined. This field is
695 optional, and only present when examining a trace file.
696 ** The "fullname" field is now always present along with the "file" field,
697 even if the file cannot be found by GDB.
699 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
700 You must have the LZMA library available when configuring GDB for this
701 feature to be enabled. For more information, see:
702 http://fedoraproject.org/wiki/Features/MiniDebugInfo
707 Set the size of trace buffer. The remote stub reports support for this
708 packet to gdb's qSupported query.
711 Enable Branch Trace Store (BTS)-based branch tracing for the current
712 thread. The remote stub reports support for this packet to gdb's
716 Disable branch tracing for the current thread. The remote stub reports
717 support for this packet to gdb's qSupported query.
720 Read the traced branches for the current thread. The remote stub
721 reports support for this packet to gdb's qSupported query.
723 *** Changes in GDB 7.5
725 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
726 for more x32 ABI info.
728 * GDB now supports access to MIPS DSP registers on Linux targets.
730 * GDB now supports debugging microMIPS binaries.
732 * The "info os" command on GNU/Linux can now display information on
733 several new classes of objects managed by the operating system:
734 "info os procgroups" lists process groups
735 "info os files" lists file descriptors
736 "info os sockets" lists internet-domain sockets
737 "info os shm" lists shared-memory regions
738 "info os semaphores" lists semaphores
739 "info os msg" lists message queues
740 "info os modules" lists loaded kernel modules
742 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
743 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
744 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
745 options and inspect the probe arguments using the new $_probe_arg family
746 of convenience variables. You can obtain more information about SystemTap
747 in <http://sourceware.org/systemtap/>.
749 * GDB now supports reversible debugging on ARM, it allows you to
750 debug basic ARM and THUMB instructions, and provides
751 record/replay support.
753 * The option "symbol-reloading" has been deleted as it is no longer used.
757 ** GDB commands implemented in Python can now be put in command class
760 ** The "maint set python print-stack on|off" is now deleted.
762 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
763 apply "flag enum"-style pretty-printing to any enum.
765 ** gdb.lookup_symbol can now work when there is no current frame.
767 ** gdb.Symbol now has a 'line' attribute, holding the line number in
768 the source at which the symbol was defined.
770 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
771 method 'value'. The former indicates whether the symbol needs a
772 frame in order to compute its value, and the latter computes the
775 ** A new method 'referenced_value' on gdb.Value objects which can
776 dereference pointer as well as C++ reference values.
778 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
779 which return the global and static blocks (as gdb.Block objects),
780 of the underlying symbol table, respectively.
782 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
783 object associated with a PC value.
785 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
786 of the address range occupied by code for the current source line.
788 * Go language support.
789 GDB now supports debugging programs written in the Go programming
792 * GDBserver now supports stdio connections.
793 E.g. (gdb) target remote | ssh myhost gdbserver - hello
795 * The binary "gdbtui" can no longer be built or installed.
796 Use "gdb -tui" instead.
798 * GDB will now print "flag" enums specially. A flag enum is one where
799 all the enumerator values have no bits in common when pairwise
800 "and"ed. When printing a value whose type is a flag enum, GDB will
801 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
802 (gdb) print (enum E) 3
805 * The filename part of a linespec will now match trailing components
806 of a source file name. For example, "break gcc/expr.c:1000" will
807 now set a breakpoint in build/gcc/expr.c, but not
810 * The "info proc" and "generate-core-file" commands will now also
811 work on remote targets connected to GDBserver on Linux.
813 * The command "info catch" has been removed. It has been disabled
816 * The "catch exception" and "catch assert" commands now accept
817 a condition at the end of the command, much like the "break"
818 command does. For instance:
820 (gdb) catch exception Constraint_Error if Barrier = True
822 Previously, it was possible to add a condition to such catchpoints,
823 but it had to be done as a second step, after the catchpoint had been
824 created, using the "condition" command.
826 * The "info static-tracepoint-marker" command will now also work on
827 native Linux targets with in-process agent.
829 * GDB can now set breakpoints on inlined functions.
831 * The .gdb_index section has been updated to include symbols for
832 inlined functions. GDB will ignore older .gdb_index sections by
833 default, which could cause symbol files to be loaded more slowly
834 until their .gdb_index sections can be recreated. The new command
835 "set use-deprecated-index-sections on" will cause GDB to use any older
836 .gdb_index sections it finds. This will restore performance, but the
837 ability to set breakpoints on inlined functions will be lost in symbol
838 files with older .gdb_index sections.
840 The .gdb_index section has also been updated to record more information
841 about each symbol. This speeds up the "info variables", "info functions"
842 and "info types" commands when used with programs having the .gdb_index
843 section, as well as speeding up debugging with shared libraries using
844 the .gdb_index section.
846 * Ada support for GDB/MI Variable Objects has been added.
848 * GDB can now support 'breakpoint always-inserted mode' in 'record'
853 ** New command -info-os is the MI equivalent of "info os".
855 ** Output logs ("set logging" and related) now include MI output.
859 ** "set use-deprecated-index-sections on|off"
860 "show use-deprecated-index-sections on|off"
861 Controls the use of deprecated .gdb_index sections.
863 ** "catch load" and "catch unload" can be used to stop when a shared
864 library is loaded or unloaded, respectively.
866 ** "enable count" can be used to auto-disable a breakpoint after
869 ** "info vtbl" can be used to show the virtual method tables for
870 C++ and Java objects.
872 ** "explore" and its sub commands "explore value" and "explore type"
873 can be used to recursively explore values and types of
874 expressions. These commands are available only if GDB is
875 configured with '--with-python'.
877 ** "info auto-load" shows status of all kinds of auto-loaded files,
878 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
879 sequences of commands files, "info auto-load python-scripts"
880 shows status of auto-loading Python script files,
881 "info auto-load local-gdbinit" shows status of loading init file
882 (.gdbinit) from current directory and "info auto-load libthread-db" shows
883 status of inferior specific thread debugging shared library loading.
885 ** "info auto-load-scripts", "set auto-load-scripts on|off"
886 and "show auto-load-scripts" commands have been deprecated, use their
887 "info auto-load python-scripts", "set auto-load python-scripts on|off"
888 and "show auto-load python-scripts" counterparts instead.
890 ** "dprintf location,format,args..." creates a dynamic printf, which
891 is basically a breakpoint that does a printf and immediately
892 resumes your program's execution, so it is like a printf that you
893 can insert dynamically at runtime instead of at compiletime.
895 ** "set print symbol"
897 Controls whether GDB attempts to display the symbol, if any,
898 corresponding to addresses it prints. This defaults to "on", but
899 you can set it to "off" to restore GDB's previous behavior.
901 * Deprecated commands
903 ** For the Renesas Super-H architecture, the "regs" command has been
904 deprecated, and "info all-registers" should be used instead.
908 Renesas RL78 rl78-*-elf
909 HP OpenVMS ia64 ia64-hp-openvms*
911 * GDBserver supports evaluation of breakpoint conditions. When
912 support is advertised by GDBserver, GDB may be told to send the
913 breakpoint conditions in bytecode form to GDBserver. GDBserver
914 will only report the breakpoint trigger to GDB when its condition
920 show mips compression
921 Select the compressed ISA encoding used in functions that have no symbol
922 information available. The encoding can be set to either of:
925 and is updated automatically from ELF file flags if available.
927 set breakpoint condition-evaluation
928 show breakpoint condition-evaluation
929 Control whether breakpoint conditions are evaluated by GDB ("host") or by
930 GDBserver ("target"). Default option "auto" chooses the most efficient
932 This option can improve debugger efficiency depending on the speed of the
936 Disable auto-loading globally.
939 Show auto-loading setting of all kinds of auto-loaded files.
941 set auto-load gdb-scripts on|off
942 show auto-load gdb-scripts
943 Control auto-loading of GDB canned sequences of commands files.
945 set auto-load python-scripts on|off
946 show auto-load python-scripts
947 Control auto-loading of Python script files.
949 set auto-load local-gdbinit on|off
950 show auto-load local-gdbinit
951 Control loading of init file (.gdbinit) from current directory.
953 set auto-load libthread-db on|off
954 show auto-load libthread-db
955 Control auto-loading of inferior specific thread debugging shared library.
957 set auto-load scripts-directory <dir1>[:<dir2>...]
958 show auto-load scripts-directory
959 Set a list of directories from which to load auto-loaded scripts.
960 Automatically loaded Python scripts and GDB scripts are located in one
961 of the directories listed by this option.
962 The delimiter (':' above) may differ according to the host platform.
964 set auto-load safe-path <dir1>[:<dir2>...]
965 show auto-load safe-path
966 Set a list of directories from which it is safe to auto-load files.
967 The delimiter (':' above) may differ according to the host platform.
969 set debug auto-load on|off
971 Control display of debugging info for auto-loading the files above.
973 set dprintf-style gdb|call|agent
975 Control the way in which a dynamic printf is performed; "gdb"
976 requests a GDB printf command, while "call" causes dprintf to call a
977 function in the inferior. "agent" requests that the target agent
978 (such as GDBserver) do the printing.
980 set dprintf-function <expr>
981 show dprintf-function
982 set dprintf-channel <expr>
984 Set the function and optional first argument to the call when using
985 the "call" style of dynamic printf.
987 set disconnected-dprintf on|off
988 show disconnected-dprintf
989 Control whether agent-style dynamic printfs continue to be in effect
990 after GDB disconnects.
992 * New configure options
995 Configure default value for the 'set auto-load scripts-directory'
996 setting above. It defaults to '$debugdir:$datadir/auto-load',
997 $debugdir representing global debugging info directories (available
998 via 'show debug-file-directory') and $datadir representing GDB's data
999 directory (available via 'show data-directory').
1001 --with-auto-load-safe-path
1002 Configure default value for the 'set auto-load safe-path' setting
1003 above. It defaults to the --with-auto-load-dir setting.
1005 --without-auto-load-safe-path
1006 Set 'set auto-load safe-path' to '/', effectively disabling this
1009 * New remote packets
1011 z0/z1 conditional breakpoints extension
1013 The z0/z1 breakpoint insertion packets have been extended to carry
1014 a list of conditional expressions over to the remote stub depending on the
1015 condition evaluation mode. The use of this extension can be controlled
1016 via the "set remote conditional-breakpoints-packet" command.
1020 Specify the signals which the remote stub may pass to the debugged
1021 program without GDB involvement.
1023 * New command line options
1025 --init-command=FILE, -ix Like --command, -x but execute it
1026 before loading inferior.
1027 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1028 execute it before loading inferior.
1030 *** Changes in GDB 7.4
1032 * GDB now handles ambiguous linespecs more consistently; the existing
1033 FILE:LINE support has been expanded to other types of linespecs. A
1034 breakpoint will now be set on all matching locations in all
1035 inferiors, and locations will be added or removed according to
1038 * GDB now allows you to skip uninteresting functions and files when
1039 stepping with the "skip function" and "skip file" commands.
1041 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1042 and "show remote hardware-watchpoint-length-limit". These allows to
1043 set or show the maximum length limit (in bytes) of a remote
1044 target hardware watchpoint.
1046 This allows e.g. to use "unlimited" hardware watchpoints with the
1047 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1048 watchpoints are slower than real hardware watchpoints but are
1049 significantly faster than gdb software watchpoints.
1053 ** The register_pretty_printer function in module gdb.printing now takes
1054 an optional `replace' argument. If True, the new printer replaces any
1057 ** The "maint set python print-stack on|off" command has been
1058 deprecated and will be deleted in GDB 7.5.
1059 A new command: "set python print-stack none|full|message" has
1060 replaced it. Additionally, the default for "print-stack" is
1061 now "message", which just prints the error message without
1064 ** A prompt substitution hook (prompt_hook) is now available to the
1067 ** A new Python module, gdb.prompt has been added to the GDB Python
1068 modules library. This module provides functionality for
1069 escape sequences in prompts (used by set/show
1070 extended-prompt). These escape sequences are replaced by their
1071 corresponding value.
1073 ** Python commands and convenience-functions located in
1074 'data-directory'/python/gdb/command and
1075 'data-directory'/python/gdb/function are now automatically loaded
1078 ** Blocks now provide four new attributes. global_block and
1079 static_block will return the global and static blocks
1080 respectively. is_static and is_global are boolean attributes
1081 that indicate if the block is one of those two types.
1083 ** Symbols now provide the "type" attribute, the type of the symbol.
1085 ** The "gdb.breakpoint" function has been deprecated in favor of
1088 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1089 of a function. This class is based on the "finish" command
1090 available in the CLI.
1092 ** Type objects for struct and union types now allow access to
1093 the fields using standard Python dictionary (mapping) methods.
1094 For example, "some_type['myfield']" now works, as does
1095 "some_type.items()".
1097 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1100 ** A new function, "deep_items" has been added to the gdb.types
1101 module in the GDB Python modules library. This function returns
1102 an iterator over the fields of a struct or union type. Unlike
1103 the standard Python "iteritems" method, it will recursively traverse
1104 any anonymous fields.
1108 ** "*stopped" events can report several new "reason"s, such as
1111 ** Breakpoint changes are now notified using new async records, like
1112 "=breakpoint-modified".
1114 ** New command -ada-task-info.
1116 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1117 $sdir specifies the default system locations of shared libraries.
1118 $pdir specifies the directory where the libpthread used by the application
1121 GDB no longer looks in $sdir and $pdir after it has searched the directories
1122 mentioned in libthread-db-search-path. If you want to search those
1123 directories, they must be specified in libthread-db-search-path.
1124 The default value of libthread-db-search-path on GNU/Linux and Solaris
1125 systems is now "$sdir:$pdir".
1127 $pdir is not supported by gdbserver, it is currently ignored.
1128 $sdir is supported by gdbserver.
1130 * New configure option --with-iconv-bin.
1131 When using the internationalization support like the one in the GNU C
1132 library, GDB will invoke the "iconv" program to get a list of supported
1133 character sets. If this program lives in a non-standard location, one can
1134 use this option to specify where to find it.
1136 * When natively debugging programs on PowerPC BookE processors running
1137 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1138 watchpoints, which specify a mask in addition to an address to watch.
1139 The mask specifies that some bits of an address (the bits which are
1140 reset in the mask) should be ignored when matching the address accessed
1141 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1142 section in the user manual for more details.
1144 * The new option --once causes GDBserver to stop listening for connections once
1145 the first connection is made. The listening port used by GDBserver will
1146 become available after that.
1148 * New commands "info macros" and "alias" have been added.
1150 * New function parameters suffix @entry specifies value of function parameter
1151 at the time the function got called. Entry values are available only since
1157 "!" is now an alias of the "shell" command.
1158 Note that no space is needed between "!" and SHELL COMMAND.
1162 watch EXPRESSION mask MASK_VALUE
1163 The watch command now supports the mask argument which allows creation
1164 of masked watchpoints, if the current architecture supports this feature.
1166 info auto-load-scripts [REGEXP]
1167 This command was formerly named "maintenance print section-scripts".
1168 It is now generally useful and is no longer a maintenance-only command.
1170 info macro [-all] [--] MACRO
1171 The info macro command has new options `-all' and `--'. The first for
1172 printing all definitions of a macro. The second for explicitly specifying
1173 the end of arguments and the beginning of the macro name in case the macro
1174 name starts with a hyphen.
1176 collect[/s] EXPRESSIONS
1177 The tracepoint collect command now takes an optional modifier "/s"
1178 that directs it to dereference pointer-to-character types and
1179 collect the bytes of memory up to a zero byte. The behavior is
1180 similar to what you see when you use the regular print command on a
1181 string. An optional integer following the "/s" sets a bound on the
1182 number of bytes that will be collected.
1185 The trace start command now interprets any supplied arguments as a
1186 note to be recorded with the trace run, with an effect similar to
1187 setting the variable trace-notes.
1190 The trace stop command now interprets any arguments as a note to be
1191 mentioned along with the tstatus report that the trace was stopped
1192 with a command. The effect is similar to setting the variable
1195 * Tracepoints can now be enabled and disabled at any time after a trace
1196 experiment has been started using the standard "enable" and "disable"
1197 commands. It is now possible to start a trace experiment with no enabled
1198 tracepoints; GDB will display a warning, but will allow the experiment to
1199 begin, assuming that tracepoints will be enabled as needed while the trace
1202 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1203 locations with 4-byte instructions, when they were previously
1204 limited to locations with instructions of 5 bytes or longer.
1208 set debug dwarf2-read
1209 show debug dwarf2-read
1210 Turns on or off display of debugging messages related to reading
1211 DWARF debug info. The default is off.
1213 set debug symtab-create
1214 show debug symtab-create
1215 Turns on or off display of debugging messages related to symbol table
1216 creation. The default is off.
1219 show extended-prompt
1220 Set the GDB prompt, and allow escape sequences to be inserted to
1221 display miscellaneous information (see 'help set extended-prompt'
1222 for the list of sequences). This prompt (and any information
1223 accessed through the escape sequences) is updated every time the
1224 prompt is displayed.
1226 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1227 show print entry-values
1228 Set printing of frame argument values at function entry. In some cases
1229 GDB can determine the value of function argument which was passed by the
1230 function caller, even if the value was modified inside the called function.
1232 set debug entry-values
1233 show debug entry-values
1234 Control display of debugging info for determining frame argument values at
1235 function entry and virtual tail call frames.
1237 set basenames-may-differ
1238 show basenames-may-differ
1239 Set whether a source file may have multiple base names.
1240 (A "base name" is the name of a file with the directory part removed.
1241 Example: The base name of "/home/user/hello.c" is "hello.c".)
1242 If set, GDB will canonicalize file names (e.g., expand symlinks)
1243 before comparing them. Canonicalization is an expensive operation,
1244 but it allows the same file be known by more than one base name.
1245 If not set (the default), all source files are assumed to have just
1246 one base name, and gdb will do file name comparisons more efficiently.
1252 Set a user name and notes for the current and any future trace runs.
1253 This is useful for long-running and/or disconnected traces, to
1254 inform others (or yourself) as to who is running the trace, supply
1255 contact information, or otherwise explain what is going on.
1257 set trace-stop-notes
1258 show trace-stop-notes
1259 Set a note attached to the trace run, that is displayed when the
1260 trace has been stopped by a tstop command. This is useful for
1261 instance as an explanation, if you are stopping a trace run that was
1262 started by someone else.
1264 * New remote packets
1268 Dynamically enable a tracepoint in a started trace experiment.
1272 Dynamically disable a tracepoint in a started trace experiment.
1276 Set the user and notes of the trace run.
1280 Query the current status of a tracepoint.
1284 Query the minimum length of instruction at which a fast tracepoint may
1287 * Dcache size (number of lines) and line-size are now runtime-configurable
1288 via "set dcache line" and "set dcache line-size" commands.
1292 Texas Instruments TMS320C6x tic6x-*-*
1296 Renesas RL78 rl78-*-elf
1298 *** Changes in GDB 7.3.1
1300 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1302 *** Changes in GDB 7.3
1304 * GDB has a new command: "thread find [REGEXP]".
1305 It finds the thread id whose name, target id, or thread extra info
1306 matches the given regular expression.
1308 * The "catch syscall" command now works on mips*-linux* targets.
1310 * The -data-disassemble MI command now supports modes 2 and 3 for
1311 dumping the instruction opcodes.
1313 * New command line options
1315 -data-directory DIR Specify DIR as the "data-directory".
1316 This is mostly for testing purposes.
1318 * The "maint set python auto-load on|off" command has been renamed to
1319 "set auto-load-scripts on|off".
1321 * GDB has a new command: "set directories".
1322 It is like the "dir" command except that it replaces the
1323 source path list instead of augmenting it.
1325 * GDB now understands thread names.
1327 On GNU/Linux, "info threads" will display the thread name as set by
1328 prctl or pthread_setname_np.
1330 There is also a new command, "thread name", which can be used to
1331 assign a name internally for GDB to display.
1334 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1335 has been integrated into GDB.
1339 ** The function gdb.Write now accepts an optional keyword 'stream'.
1340 This keyword, when provided, will direct the output to either
1341 stdout, stderr, or GDB's logging output.
1343 ** Parameters can now be be sub-classed in Python, and in particular
1344 you may implement the get_set_doc and get_show_doc functions.
1345 This improves how Parameter set/show documentation is processed
1346 and allows for more dynamic content.
1348 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1349 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1350 have an is_valid method.
1352 ** Breakpoints can now be sub-classed in Python, and in particular
1353 you may implement a 'stop' function that is executed each time
1354 the inferior reaches that breakpoint.
1356 ** New function gdb.lookup_global_symbol looks up a global symbol.
1358 ** GDB values in Python are now callable if the value represents a
1359 function. For example, if 'some_value' represents a function that
1360 takes two integer parameters and returns a value, you can call
1361 that function like so:
1363 result = some_value (10,20)
1365 ** Module gdb.types has been added.
1366 It contains a collection of utilities for working with gdb.Types objects:
1367 get_basic_type, has_field, make_enum_dict.
1369 ** Module gdb.printing has been added.
1370 It contains utilities for writing and registering pretty-printers.
1371 New classes: PrettyPrinter, SubPrettyPrinter,
1372 RegexpCollectionPrettyPrinter.
1373 New function: register_pretty_printer.
1375 ** New commands "info pretty-printers", "enable pretty-printer" and
1376 "disable pretty-printer" have been added.
1378 ** gdb.parameter("directories") is now available.
1380 ** New function gdb.newest_frame returns the newest frame in the
1383 ** The gdb.InferiorThread class has a new "name" attribute. This
1384 holds the thread's name.
1386 ** Python Support for Inferior events.
1387 Python scripts can add observers to be notified of events
1388 occurring in the process being debugged.
1389 The following events are currently supported:
1390 - gdb.events.cont Continue event.
1391 - gdb.events.exited Inferior exited event.
1392 - gdb.events.stop Signal received, and Breakpoint hit events.
1396 ** GDB now puts template parameters in scope when debugging in an
1397 instantiation. For example, if you have:
1399 template<int X> int func (void) { return X; }
1401 then if you step into func<5>, "print X" will show "5". This
1402 feature requires proper debuginfo support from the compiler; it
1403 was added to GCC 4.5.
1405 ** The motion commands "next", "finish", "until", and "advance" now
1406 work better when exceptions are thrown. In particular, GDB will
1407 no longer lose control of the inferior; instead, the GDB will
1408 stop the inferior at the point at which the exception is caught.
1409 This functionality requires a change in the exception handling
1410 code that was introduced in GCC 4.5.
1412 * GDB now follows GCC's rules on accessing volatile objects when
1413 reading or writing target state during expression evaluation.
1414 One notable difference to prior behavior is that "print x = 0"
1415 no longer generates a read of x; the value of the assignment is
1416 now always taken directly from the value being assigned.
1418 * GDB now has some support for using labels in the program's source in
1419 linespecs. For instance, you can use "advance label" to continue
1420 execution to a label.
1422 * GDB now has support for reading and writing a new .gdb_index
1423 section. This section holds a fast index of DWARF debugging
1424 information and can be used to greatly speed up GDB startup and
1425 operation. See the documentation for `save gdb-index' for details.
1427 * The "watch" command now accepts an optional "-location" argument.
1428 When used, this causes GDB to watch the memory referred to by the
1429 expression. Such a watchpoint is never deleted due to it going out
1432 * GDB now supports thread debugging of core dumps on GNU/Linux.
1434 GDB now activates thread debugging using the libthread_db library
1435 when debugging GNU/Linux core dumps, similarly to when debugging
1436 live processes. As a result, when debugging a core dump file, GDB
1437 is now able to display pthread_t ids of threads. For example, "info
1438 threads" shows the same output as when debugging the process when it
1439 was live. In earlier releases, you'd see something like this:
1442 * 1 LWP 6780 main () at main.c:10
1444 While now you see this:
1447 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1449 It is also now possible to inspect TLS variables when debugging core
1452 When debugging a core dump generated on a machine other than the one
1453 used to run GDB, you may need to point GDB at the correct
1454 libthread_db library with the "set libthread-db-search-path"
1455 command. See the user manual for more details on this command.
1457 * When natively debugging programs on PowerPC BookE processors running
1458 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1459 which stop execution of the inferior whenever it executes an instruction
1460 at any address within the specified range. See the "PowerPC Embedded"
1461 section in the user manual for more details.
1463 * New features in the GDB remote stub, GDBserver
1465 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1466 and i686 LynxOS (version 5.x).
1468 ** GDBserver is now supported on Blackfin Linux.
1470 * New native configurations
1472 ia64 HP-UX ia64-*-hpux*
1476 Analog Devices, Inc. Blackfin Processor bfin-*
1478 * Ada task switching is now supported on sparc-elf targets when
1479 debugging a program using the Ravenscar Profile. For more information,
1480 see the "Tasking Support when using the Ravenscar Profile" section
1481 in the GDB user manual.
1483 * Guile support was removed.
1485 * New features in the GNU simulator
1487 ** The --map-info flag lists all known core mappings.
1489 ** CFI flashes may be simulated via the "cfi" device.
1491 *** Changes in GDB 7.2
1493 * Shared library support for remote targets by default
1495 When GDB is configured for a generic, non-OS specific target, like
1496 for example, --target=arm-eabi or one of the many *-*-elf targets,
1497 GDB now queries remote stubs for loaded shared libraries using the
1498 `qXfer:libraries:read' packet. Previously, shared library support
1499 was always disabled for such configurations.
1503 ** Argument Dependent Lookup (ADL)
1505 In C++ ADL lookup directs function search to the namespaces of its
1506 arguments even if the namespace has not been imported.
1516 Here the compiler will search for `foo' in the namespace of 'b'
1517 and find A::foo. GDB now supports this. This construct is commonly
1518 used in the Standard Template Library for operators.
1520 ** Improved User Defined Operator Support
1522 In addition to member operators, GDB now supports lookup of operators
1523 defined in a namespace and imported with a `using' directive, operators
1524 defined in the global scope, operators imported implicitly from an
1525 anonymous namespace, and the ADL operators mentioned in the previous
1527 GDB now also supports proper overload resolution for all the previously
1528 mentioned flavors of operators.
1530 ** static const class members
1532 Printing of static const class members that are initialized in the
1533 class definition has been fixed.
1535 * Windows Thread Information Block access.
1537 On Windows targets, GDB now supports displaying the Windows Thread
1538 Information Block (TIB) structure. This structure is visible either
1539 by using the new command `info w32 thread-information-block' or, by
1540 dereferencing the new convenience variable named `$_tlb', a
1541 thread-specific pointer to the TIB. This feature is also supported
1542 when remote debugging using GDBserver.
1544 * Static tracepoints
1546 Static tracepoints are calls in the user program into a tracing
1547 library. One such library is a port of the LTTng kernel tracer to
1548 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1549 When debugging with GDBserver, GDB now supports combining the GDB
1550 tracepoint machinery with such libraries. For example: the user can
1551 use GDB to probe a static tracepoint marker (a call from the user
1552 program into the tracing library) with the new "strace" command (see
1553 "New commands" below). This creates a "static tracepoint" in the
1554 breakpoint list, that can be manipulated with the same feature set
1555 as fast and regular tracepoints. E.g., collect registers, local and
1556 global variables, collect trace state variables, and define
1557 tracepoint conditions. In addition, the user can collect extra
1558 static tracepoint marker specific data, by collecting the new
1559 $_sdata internal variable. When analyzing the trace buffer, you can
1560 inspect $_sdata like any other variable available to GDB. For more
1561 information, see the "Tracepoints" chapter in GDB user manual. New
1562 remote packets have been defined to support static tracepoints, see
1563 the "New remote packets" section below.
1565 * Better reconstruction of tracepoints after disconnected tracing
1567 GDB will attempt to download the original source form of tracepoint
1568 definitions when starting a trace run, and then will upload these
1569 upon reconnection to the target, resulting in a more accurate
1570 reconstruction of the tracepoints that are in use on the target.
1574 You can now exercise direct control over the ways that GDB can
1575 affect your program. For instance, you can disallow the setting of
1576 breakpoints, so that the program can run continuously (assuming
1577 non-stop mode). In addition, the "observer" variable is available
1578 to switch all of the different controls; in observer mode, GDB
1579 cannot affect the target's behavior at all, which is useful for
1580 tasks like diagnosing live systems in the field.
1582 * The new convenience variable $_thread holds the number of the
1585 * New remote packets
1589 Return the address of the Windows Thread Information Block of a given thread.
1593 In response to several of the tracepoint packets, the target may now
1594 also respond with a number of intermediate `qRelocInsn' request
1595 packets before the final result packet, to have GDB handle
1596 relocating an instruction to execute at a different address. This
1597 is particularly useful for stubs that support fast tracepoints. GDB
1598 reports support for this feature in the qSupported packet.
1602 List static tracepoint markers in the target program.
1606 List static tracepoint markers at a given address in the target
1609 qXfer:statictrace:read
1611 Read the static trace data collected (by a `collect $_sdata'
1612 tracepoint action). The remote stub reports support for this packet
1613 to gdb's qSupported query.
1617 Send the current settings of GDB's permission flags.
1621 Send part of the source (textual) form of a tracepoint definition,
1622 which includes location, conditional, and action list.
1624 * The source command now accepts a -s option to force searching for the
1625 script in the source search path even if the script name specifies
1628 * New features in the GDB remote stub, GDBserver
1630 - GDBserver now support tracepoints (including fast tracepoints, and
1631 static tracepoints). The feature is currently supported by the
1632 i386-linux and amd64-linux builds. See the "Tracepoints support
1633 in gdbserver" section in the manual for more information.
1635 GDBserver JIT compiles the tracepoint's conditional agent
1636 expression bytecode into native code whenever possible for low
1637 overhead dynamic tracepoints conditionals. For such tracepoints,
1638 an expression that examines program state is evaluated when the
1639 tracepoint is reached, in order to determine whether to capture
1640 trace data. If the condition is simple and false, processing the
1641 tracepoint finishes very quickly and no data is gathered.
1643 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1644 for static tracepoints support.
1646 - GDBserver now supports x86_64 Windows 64-bit debugging.
1648 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1649 it understands register description.
1651 * The --batch flag now disables pagination and queries.
1653 * X86 general purpose registers
1655 GDB now supports reading/writing byte, word and double-word x86
1656 general purpose registers directly. This means you can use, say,
1657 $ah or $ax to refer, respectively, to the byte register AH and
1658 16-bit word register AX that are actually portions of the 32-bit
1659 register EAX or 64-bit register RAX.
1661 * The `commands' command now accepts a range of breakpoints to modify.
1662 A plain `commands' following a command that creates multiple
1663 breakpoints affects all the breakpoints set by that command. This
1664 applies to breakpoints set by `rbreak', and also applies when a
1665 single `break' command creates multiple breakpoints (e.g.,
1666 breakpoints on overloaded c++ functions).
1668 * The `rbreak' command now accepts a filename specification as part of
1669 its argument, limiting the functions selected by the regex to those
1670 in the specified file.
1672 * Support for remote debugging Windows and SymbianOS shared libraries
1673 from Unix hosts has been improved. Non Windows GDB builds now can
1674 understand target reported file names that follow MS-DOS based file
1675 system semantics, such as file names that include drive letters and
1676 use the backslash character as directory separator. This makes it
1677 possible to transparently use the "set sysroot" and "set
1678 solib-search-path" on Unix hosts to point as host copies of the
1679 target's shared libraries. See the new command "set
1680 target-file-system-kind" described below, and the "Commands to
1681 specify files" section in the user manual for more information.
1685 eval template, expressions...
1686 Convert the values of one or more expressions under the control
1687 of the string template to a command line, and call it.
1689 set target-file-system-kind unix|dos-based|auto
1690 show target-file-system-kind
1691 Set or show the assumed file system kind for target reported file
1694 save breakpoints <filename>
1695 Save all current breakpoint definitions to a file suitable for use
1696 in a later debugging session. To read the saved breakpoint
1697 definitions, use the `source' command.
1699 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1702 info static-tracepoint-markers
1703 Display information about static tracepoint markers in the target.
1705 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1706 Define a static tracepoint by probing a marker at the given
1707 function, line, address, or marker ID.
1711 Enable and disable observer mode.
1713 set may-write-registers on|off
1714 set may-write-memory on|off
1715 set may-insert-breakpoints on|off
1716 set may-insert-tracepoints on|off
1717 set may-insert-fast-tracepoints on|off
1718 set may-interrupt on|off
1719 Set individual permissions for GDB effects on the target. Note that
1720 some of these settings can have undesirable or surprising
1721 consequences, particularly when changed in the middle of a session.
1722 For instance, disabling the writing of memory can prevent
1723 breakpoints from being inserted, cause single-stepping to fail, or
1724 even crash your program, if you disable after breakpoints have been
1725 inserted. However, GDB should not crash.
1727 set record memory-query on|off
1728 show record memory-query
1729 Control whether to stop the inferior if memory changes caused
1730 by an instruction cannot be recorded.
1735 The disassemble command now supports "start,+length" form of two arguments.
1739 ** GDB now provides a new directory location, called the python directory,
1740 where Python scripts written for GDB can be installed. The location
1741 of that directory is <data-directory>/python, where <data-directory>
1742 is the GDB data directory. For more details, see section `Scripting
1743 GDB using Python' in the manual.
1745 ** The GDB Python API now has access to breakpoints, symbols, symbol
1746 tables, program spaces, inferiors, threads and frame's code blocks.
1747 Additionally, GDB Parameters can now be created from the API, and
1748 manipulated via set/show in the CLI.
1750 ** New functions gdb.target_charset, gdb.target_wide_charset,
1751 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1753 ** New exception gdb.GdbError.
1755 ** Pretty-printers are now also looked up in the current program space.
1757 ** Pretty-printers can now be individually enabled and disabled.
1759 ** GDB now looks for names of Python scripts to auto-load in a
1760 special section named `.debug_gdb_scripts', in addition to looking
1761 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1763 * Tracepoint actions were unified with breakpoint commands. In particular,
1764 there are no longer differences in "info break" output for breakpoints and
1765 tracepoints and the "commands" command can be used for both tracepoints and
1766 regular breakpoints.
1770 ARM Symbian arm*-*-symbianelf*
1772 * D language support.
1773 GDB now supports debugging programs written in the D programming
1776 * GDB now supports the extended ptrace interface for PowerPC which is
1777 available since Linux kernel version 2.6.34. This automatically enables
1778 any hardware breakpoints and additional hardware watchpoints available in
1779 the processor. The old ptrace interface exposes just one hardware
1780 watchpoint and no hardware breakpoints.
1782 * GDB is now able to use the Data Value Compare (DVC) register available on
1783 embedded PowerPC processors to implement in hardware simple watchpoint
1784 conditions of the form:
1786 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1788 This works in native GDB running on Linux kernels with the extended ptrace
1789 interface mentioned above.
1791 *** Changes in GDB 7.1
1795 ** Namespace Support
1797 GDB now supports importing of namespaces in C++. This enables the
1798 user to inspect variables from imported namespaces. Support for
1799 namepace aliasing has also been added. So, if a namespace is
1800 aliased in the current scope (e.g. namepace C=A; ) the user can
1801 print variables using the alias (e.g. (gdb) print C::x).
1805 All known bugs relating to the printing of virtual base class were
1806 fixed. It is now possible to call overloaded static methods using a
1811 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1812 and reinterpret_cast<> are now handled by the C++ expression parser.
1816 Xilinx MicroBlaze microblaze-*-*
1821 Xilinx MicroBlaze microblaze
1824 * Multi-program debugging.
1826 GDB now has support for multi-program (a.k.a. multi-executable or
1827 multi-exec) debugging. This allows for debugging multiple inferiors
1828 simultaneously each running a different program under the same GDB
1829 session. See "Debugging Multiple Inferiors and Programs" in the
1830 manual for more information. This implied some user visible changes
1831 in the multi-inferior support. For example, "info inferiors" now
1832 lists inferiors that are not running yet or that have exited
1833 already. See also "New commands" and "New options" below.
1835 * New tracing features
1837 GDB's tracepoint facility now includes several new features:
1839 ** Trace state variables
1841 GDB tracepoints now include support for trace state variables, which
1842 are variables managed by the target agent during a tracing
1843 experiment. They are useful for tracepoints that trigger each
1844 other, so for instance one tracepoint can count hits in a variable,
1845 and then a second tracepoint has a condition that is true when the
1846 count reaches a particular value. Trace state variables share the
1847 $-syntax of GDB convenience variables, and can appear in both
1848 tracepoint actions and condition expressions. Use the "tvariable"
1849 command to create, and "info tvariables" to view; see "Trace State
1850 Variables" in the manual for more detail.
1854 GDB now includes an option for defining fast tracepoints, which
1855 targets may implement more efficiently, such as by installing a jump
1856 into the target agent rather than a trap instruction. The resulting
1857 speedup can be by two orders of magnitude or more, although the
1858 tradeoff is that some program locations on some target architectures
1859 might not allow fast tracepoint installation, for instance if the
1860 instruction to be replaced is shorter than the jump. To request a
1861 fast tracepoint, use the "ftrace" command, with syntax identical to
1862 the regular trace command.
1864 ** Disconnected tracing
1866 It is now possible to detach GDB from the target while it is running
1867 a trace experiment, then reconnect later to see how the experiment
1868 is going. In addition, a new variable disconnected-tracing lets you
1869 tell the target agent whether to continue running a trace if the
1870 connection is lost unexpectedly.
1874 GDB now has the ability to save the trace buffer into a file, and
1875 then use that file as a target, similarly to you can do with
1876 corefiles. You can select trace frames, print data that was
1877 collected in them, and use tstatus to display the state of the
1878 tracing run at the moment that it was saved. To create a trace
1879 file, use "tsave <filename>", and to use it, do "target tfile
1882 ** Circular trace buffer
1884 You can ask the target agent to handle the trace buffer as a
1885 circular buffer, discarding the oldest trace frames to make room for
1886 newer ones, by setting circular-trace-buffer to on. This feature may
1887 not be available for all target agents.
1892 The disassemble command, when invoked with two arguments, now requires
1893 the arguments to be comma-separated.
1896 The info variables command now displays variable definitions. Files
1897 which only declare a variable are not shown.
1900 The source command is now capable of sourcing Python scripts.
1901 This feature is dependent on the debugger being build with Python
1904 Related to this enhancement is also the introduction of a new command
1905 "set script-extension" (see below).
1907 * New commands (for set/show, see "New options" below)
1909 record save [<FILENAME>]
1910 Save a file (in core file format) containing the process record
1911 execution log for replay debugging at a later time.
1913 record restore <FILENAME>
1914 Restore the process record execution log that was saved at an
1915 earlier time, for replay debugging.
1917 add-inferior [-copies <N>] [-exec <FILENAME>]
1920 clone-inferior [-copies <N>] [ID]
1921 Make a new inferior ready to execute the same program another
1922 inferior has loaded.
1927 maint info program-spaces
1928 List the program spaces loaded into GDB.
1930 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1931 show remote interrupt-sequence
1932 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1933 as the sequence to the remote target in order to interrupt the execution.
1934 Ctrl-C is a default. Some system prefers BREAK which is high level of
1935 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1936 Magic SysRq g. It is BREAK signal and character 'g'.
1938 set remote interrupt-on-connect [on | off]
1939 show remote interrupt-on-connect
1940 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1941 remote target when gdb connects to it. This is needed when you debug
1944 set remotebreak [on | off]
1946 Deprecated. Use "set/show remote interrupt-sequence" instead.
1948 tvariable $NAME [ = EXP ]
1949 Create or modify a trace state variable.
1952 List trace state variables and their values.
1954 delete tvariable $NAME ...
1955 Delete one or more trace state variables.
1958 Evaluate the given expressions without collecting anything into the
1959 trace buffer. (Valid in tracepoint actions only.)
1961 ftrace FN / FILE:LINE / *ADDR
1962 Define a fast tracepoint at the given function, line, or address.
1964 * New expression syntax
1966 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1967 GDB now parses 0b101010 identically with 42.
1971 set follow-exec-mode new|same
1972 show follow-exec-mode
1973 Control whether GDB reuses the same inferior across an exec call or
1974 creates a new one. This is useful to be able to restart the old
1975 executable after the inferior having done an exec call.
1977 set default-collect EXPR, ...
1978 show default-collect
1979 Define a list of expressions to be collected at each tracepoint.
1980 This is a useful way to ensure essential items are not overlooked,
1981 such as registers or a critical global variable.
1983 set disconnected-tracing
1984 show disconnected-tracing
1985 If set to 1, the target is instructed to continue tracing if it
1986 loses its connection to GDB. If 0, the target is to stop tracing
1989 set circular-trace-buffer
1990 show circular-trace-buffer
1991 If set to on, the target is instructed to use a circular trace buffer
1992 and discard the oldest trace frames instead of stopping the trace due
1993 to a full trace buffer. If set to off, the trace stops when the buffer
1994 fills up. Some targets may not support this.
1996 set script-extension off|soft|strict
1997 show script-extension
1998 If set to "off", the debugger does not perform any script language
1999 recognition, and all sourced files are assumed to be GDB scripts.
2000 If set to "soft" (the default), files are sourced according to
2001 filename extension, falling back to GDB scripts if the first
2003 If set to "strict", files are sourced according to filename extension.
2005 set ada trust-PAD-over-XVS on|off
2006 show ada trust-PAD-over-XVS
2007 If off, activate a workaround against a bug in the debugging information
2008 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2009 the GCC sources for more information about the GNAT encoding and
2010 PAD types in particular). It is always safe to set this option to
2011 off, but this introduces a slight performance penalty. The default
2014 * Python API Improvements
2016 ** GDB provides the new class gdb.LazyString. This is useful in
2017 some pretty-printing cases. The new method gdb.Value.lazy_string
2018 provides a simple way to create objects of this type.
2020 ** The fields returned by gdb.Type.fields now have an
2021 `is_base_class' attribute.
2023 ** The new method gdb.Type.range returns the range of an array type.
2025 ** The new method gdb.parse_and_eval can be used to parse and
2026 evaluate an expression.
2028 * New remote packets
2031 Define a trace state variable.
2034 Get the current value of a trace state variable.
2037 Set desired tracing behavior upon disconnection.
2040 Set the trace buffer to be linear or circular.
2043 Get data about the tracepoints currently in use.
2047 Process record now works correctly with hardware watchpoints.
2049 Multiple bug fixes have been made to the mips-irix port, making it
2050 much more reliable. In particular:
2051 - Debugging threaded applications is now possible again. Previously,
2052 GDB would hang while starting the program, or while waiting for
2053 the program to stop at a breakpoint.
2054 - Attaching to a running process no longer hangs.
2055 - An error occurring while loading a core file has been fixed.
2056 - Changing the value of the PC register now works again. This fixes
2057 problems observed when using the "jump" command, or when calling
2058 a function from GDB, or even when assigning a new value to $pc.
2059 - With the "finish" and "return" commands, the return value for functions
2060 returning a small array is now correctly printed.
2061 - It is now possible to break on shared library code which gets executed
2062 during a shared library init phase (code executed while executing
2063 their .init section). Previously, the breakpoint would have no effect.
2064 - GDB is now able to backtrace through the signal handler for
2065 non-threaded programs.
2067 PIE (Position Independent Executable) programs debugging is now supported.
2068 This includes debugging execution of PIC (Position Independent Code) shared
2069 libraries although for that, it should be possible to run such libraries as an
2072 *** Changes in GDB 7.0
2074 * GDB now has an interface for JIT compilation. Applications that
2075 dynamically generate code can create symbol files in memory and register
2076 them with GDB. For users, the feature should work transparently, and
2077 for JIT developers, the interface is documented in the GDB manual in the
2078 "JIT Compilation Interface" chapter.
2080 * Tracepoints may now be conditional. The syntax is as for
2081 breakpoints; either an "if" clause appended to the "trace" command,
2082 or the "condition" command is available. GDB sends the condition to
2083 the target for evaluation using the same bytecode format as is used
2084 for tracepoint actions.
2086 * The disassemble command now supports: an optional /r modifier, print the
2087 raw instructions in hex as well as in symbolic form, and an optional /m
2088 modifier to print mixed source+assembly.
2090 * Process record and replay
2092 In a architecture environment that supports ``process record and
2093 replay'', ``process record and replay'' target can record a log of
2094 the process execution, and replay it with both forward and reverse
2097 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2098 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2099 set execution-direction {forward|reverse}, for targets that support
2102 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2103 feature is available with a native GDB running on kernel version
2106 * GDB now has support for multi-byte and wide character sets on the
2107 target. Strings whose character type is wchar_t, char16_t, or
2108 char32_t are now correctly printed. GDB supports wide- and unicode-
2109 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2110 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2111 `printf'. This feature requires iconv to work properly; if your
2112 system does not have a working iconv, GDB can use GNU libiconv. See
2113 the installation instructions for more information.
2115 * GDB now supports automatic retrieval of shared library files from
2116 remote targets. To use this feature, specify a system root that begins
2117 with the `remote:' prefix, either via the `set sysroot' command or via
2118 the `--with-sysroot' configure-time option.
2120 * "info sharedlibrary" now takes an optional regex of libraries to show,
2121 and it now reports if a shared library has no debugging information.
2123 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2124 now complete on file names.
2126 * When completing in expressions, gdb will attempt to limit
2127 completions to allowable structure or union fields, where appropriate.
2128 For instance, consider:
2130 # struct example { int f1; double f2; };
2131 # struct example variable;
2134 If the user types TAB at the end of this command line, the available
2135 completions will be "f1" and "f2".
2137 * Inlined functions are now supported. They show up in backtraces, and
2138 the "step", "next", and "finish" commands handle them automatically.
2140 * GDB now supports the token-splicing (##) and stringification (#)
2141 operators when expanding macros. It also supports variable-arity
2144 * GDB now supports inspecting extra signal information, exported by
2145 the new $_siginfo convenience variable. The feature is currently
2146 implemented on linux ARM, i386 and amd64.
2148 * GDB can now display the VFP floating point registers and NEON vector
2149 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2150 can provide these registers (requires Linux 2.6.30 or later). Remote
2151 and simulator targets may also provide them.
2153 * New remote packets
2156 Search memory for a sequence of bytes.
2159 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2160 operation over reliable transport links. Use of this packet is
2161 controlled by the `set remote noack-packet' command.
2164 Kill the process with the specified process ID. Use this in preference
2165 to `k' when multiprocess protocol extensions are supported.
2168 Obtains additional operating system information
2172 Read or write additional signal information.
2174 * Removed remote protocol undocumented extension
2176 An undocumented extension to the remote protocol's `S' stop reply
2177 packet that permited the stub to pass a process id was removed.
2178 Remote servers should use the `T' stop reply packet instead.
2180 * GDB now supports multiple function calling conventions according to the
2181 DWARF-2 DW_AT_calling_convention function attribute.
2183 * The SH target utilizes the aforementioned change to distinguish between gcc
2184 and Renesas calling convention. It also adds the new CLI commands
2185 `set/show sh calling-convention'.
2187 * GDB can now read compressed debug sections, as produced by GNU gold
2188 with the --compress-debug-sections=zlib flag.
2190 * 64-bit core files are now supported on AIX.
2192 * Thread switching is now supported on Tru64.
2194 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2195 which will be allocated using malloc later in program execution.
2197 * The qXfer:libraries:read remote procotol packet now allows passing a
2198 list of section offsets.
2200 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2201 conditions handling signals delivered during attach or thread creation
2202 have also been fixed.
2204 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2205 From the user's standpoint, all unqualified instances of True and False
2206 are treated as the standard definitions, regardless of context.
2208 * GDB now parses C++ symbol and type names more flexibly. For
2211 template<typename T> class C { };
2214 GDB will now correctly handle all of:
2216 ptype C<char const *>
2217 ptype C<char const*>
2218 ptype C<const char *>
2219 ptype C<const char*>
2221 * New features in the GDB remote stub, gdbserver
2223 - The "--wrapper" command-line argument tells gdbserver to use a
2224 wrapper program to launch programs for debugging.
2226 - On PowerPC and S/390 targets, it is now possible to use a single
2227 gdbserver executable to debug both 32-bit and 64-bit programs.
2228 (This requires gdbserver itself to be built as a 64-bit executable.)
2230 - gdbserver uses the new noack protocol mode for TCP connections to
2231 reduce communications latency, if also supported and enabled in GDB.
2233 - Support for the sparc64-linux-gnu target is now included in
2236 - The amd64-linux build of gdbserver now supports debugging both
2237 32-bit and 64-bit programs.
2239 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2240 now support hardware watchpoints, and will use them automatically
2245 GDB now has support for scripting using Python. Whether this is
2246 available is determined at configure time.
2248 New GDB commands can now be written in Python.
2250 * Ada tasking support
2252 Ada tasks can now be inspected in GDB. The following commands have
2256 Print the list of Ada tasks.
2258 Print detailed information about task number N.
2260 Print the task number of the current task.
2262 Switch the context of debugging to task number N.
2264 * Support for user-defined prefixed commands. The "define" command can
2265 add new commands to existing prefixes, e.g. "target".
2267 * Multi-inferior, multi-process debugging.
2269 GDB now has generalized support for multi-inferior debugging. See
2270 "Debugging Multiple Inferiors" in the manual for more information.
2271 Although availability still depends on target support, the command
2272 set is more uniform now. The GNU/Linux specific multi-forks support
2273 has been migrated to this new framework. This implied some user
2274 visible changes; see "New commands" and also "Removed commands"
2277 * Target descriptions can now describe the target OS ABI. See the
2278 "Target Description Format" section in the user manual for more
2281 * Target descriptions can now describe "compatible" architectures
2282 to indicate that the target can execute applications for a different
2283 architecture in addition to those for the main target architecture.
2284 See the "Target Description Format" section in the user manual for
2287 * Multi-architecture debugging.
2289 GDB now includes general supports for debugging applications on
2290 hybrid systems that use more than one single processor architecture
2291 at the same time. Each such hybrid architecture still requires
2292 specific support to be added. The only hybrid architecture supported
2293 in this version of GDB is the Cell Broadband Engine.
2295 * GDB now supports integrated debugging of Cell/B.E. applications that
2296 use both the PPU and SPU architectures. To enable support for hybrid
2297 Cell/B.E. debugging, you need to configure GDB to support both the
2298 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2299 --enable-targets configure option.
2301 * Non-stop mode debugging.
2303 For some targets, GDB now supports an optional mode of operation in
2304 which you can examine stopped threads while other threads continue
2305 to execute freely. This is referred to as non-stop mode, with the
2306 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2307 section in the user manual for more information.
2309 To be able to support remote non-stop debugging, a remote stub needs
2310 to implement the non-stop mode remote protocol extensions, as
2311 described in the "Remote Non-Stop" section of the user manual. The
2312 GDB remote stub, gdbserver, has been adjusted to support these
2313 extensions on linux targets.
2315 * New commands (for set/show, see "New options" below)
2317 catch syscall [NAME(S) | NUMBER(S)]
2318 Catch system calls. Arguments, which should be names of system
2319 calls or their numbers, mean catch only those syscalls. Without
2320 arguments, every syscall will be caught. When the inferior issues
2321 any of the specified syscalls, GDB will stop and announce the system
2322 call, both when it is called and when its call returns. This
2323 feature is currently available with a native GDB running on the
2324 Linux Kernel, under the following architectures: x86, x86_64,
2325 PowerPC and PowerPC64.
2327 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2329 Search memory for a sequence of bytes.
2331 maint set python print-stack
2332 maint show python print-stack
2333 Show a stack trace when an error is encountered in a Python script.
2336 Invoke CODE by passing it to the Python interpreter.
2341 These allow macros to be defined, undefined, and listed
2345 Show operating system information about processes.
2348 List the inferiors currently under GDB's control.
2351 Switch focus to inferior number NUM.
2354 Detach from inferior number NUM.
2357 Kill inferior number NUM.
2361 set spu stop-on-load
2362 show spu stop-on-load
2363 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2365 set spu auto-flush-cache
2366 show spu auto-flush-cache
2367 Control whether to automatically flush the software-managed cache
2368 during Cell/B.E. debugging.
2370 set sh calling-convention
2371 show sh calling-convention
2372 Control the calling convention used when calling SH target functions.
2375 show debug timestamp
2376 Control display of timestamps with GDB debugging output.
2378 set disassemble-next-line
2379 show disassemble-next-line
2380 Control display of disassembled source lines or instructions when
2383 set remote noack-packet
2384 show remote noack-packet
2385 Set/show the use of remote protocol QStartNoAckMode packet. See above
2386 under "New remote packets."
2388 set remote query-attached-packet
2389 show remote query-attached-packet
2390 Control use of remote protocol `qAttached' (query-attached) packet.
2392 set remote read-siginfo-object
2393 show remote read-siginfo-object
2394 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2397 set remote write-siginfo-object
2398 show remote write-siginfo-object
2399 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2402 set remote reverse-continue
2403 show remote reverse-continue
2404 Control use of remote protocol 'bc' (reverse-continue) packet.
2406 set remote reverse-step
2407 show remote reverse-step
2408 Control use of remote protocol 'bs' (reverse-step) packet.
2410 set displaced-stepping
2411 show displaced-stepping
2412 Control displaced stepping mode. Displaced stepping is a way to
2413 single-step over breakpoints without removing them from the debuggee.
2414 Also known as "out-of-line single-stepping".
2417 show debug displaced
2418 Control display of debugging info for displaced stepping.
2420 maint set internal-error
2421 maint show internal-error
2422 Control what GDB does when an internal error is detected.
2424 maint set internal-warning
2425 maint show internal-warning
2426 Control what GDB does when an internal warning is detected.
2431 Use a wrapper program to launch programs for debugging.
2433 set multiple-symbols (all|ask|cancel)
2434 show multiple-symbols
2435 The value of this variable can be changed to adjust the debugger behavior
2436 when an expression or a breakpoint location contains an ambiguous symbol
2437 name (an overloaded function name, for instance).
2439 set breakpoint always-inserted
2440 show breakpoint always-inserted
2441 Keep breakpoints always inserted in the target, as opposed to inserting
2442 them when resuming the target, and removing them when the target stops.
2443 This option can improve debugger performance on slow remote targets.
2445 set arm fallback-mode (arm|thumb|auto)
2446 show arm fallback-mode
2447 set arm force-mode (arm|thumb|auto)
2449 These commands control how ARM GDB determines whether instructions
2450 are ARM or Thumb. The default for both settings is auto, which uses
2451 the current CPSR value for instructions without symbols; previous
2452 versions of GDB behaved as if "set arm fallback-mode arm".
2454 set disable-randomization
2455 show disable-randomization
2456 Standalone programs run with the virtual address space randomization enabled
2457 by default on some platforms. This option keeps the addresses stable across
2458 multiple debugging sessions.
2462 Control whether other threads are stopped or not when some thread hits
2467 Requests that asynchronous execution is enabled in the target, if available.
2468 In this case, it's possible to resume target in the background, and interact
2469 with GDB while the target is running. "show target-async" displays the
2470 current state of asynchronous execution of the target.
2472 set target-wide-charset
2473 show target-wide-charset
2474 The target-wide-charset is the name of the character set that GDB
2475 uses when printing characters whose type is wchar_t.
2477 set tcp auto-retry (on|off)
2479 set tcp connect-timeout
2480 show tcp connect-timeout
2481 These commands allow GDB to retry failed TCP connections to a remote stub
2482 with a specified timeout period; this is useful if the stub is launched
2483 in parallel with GDB but may not be ready to accept connections immediately.
2485 set libthread-db-search-path
2486 show libthread-db-search-path
2487 Control list of directories which GDB will search for appropriate
2490 set schedule-multiple (on|off)
2491 show schedule-multiple
2492 Allow GDB to resume all threads of all processes or only threads of
2493 the current process.
2497 Use more aggressive caching for accesses to the stack. This improves
2498 performance of remote debugging (particularly backtraces) without
2499 affecting correctness.
2501 set interactive-mode (on|off|auto)
2502 show interactive-mode
2503 Control whether GDB runs in interactive mode (on) or not (off).
2504 When in interactive mode, GDB waits for the user to answer all
2505 queries. Otherwise, GDB does not wait and assumes the default
2506 answer. When set to auto (the default), GDB determines which
2507 mode to use based on the stdin settings.
2512 For program forks, this is replaced by the new more generic `info
2513 inferiors' command. To list checkpoints, you can still use the
2514 `info checkpoints' command, which was an alias for the `info forks'
2518 Replaced by the new `inferior' command. To switch between
2519 checkpoints, you can still use the `restart' command, which was an
2520 alias for the `fork' command.
2523 This is removed, since some targets don't have a notion of
2524 processes. To switch between processes, you can still use the
2525 `inferior' command using GDB's own inferior number.
2528 For program forks, this is replaced by the new more generic `kill
2529 inferior' command. To delete a checkpoint, you can still use the
2530 `delete checkpoint' command, which was an alias for the `delete
2534 For program forks, this is replaced by the new more generic `detach
2535 inferior' command. To detach a checkpoint, you can still use the
2536 `detach checkpoint' command, which was an alias for the `detach
2539 * New native configurations
2541 x86/x86_64 Darwin i[34567]86-*-darwin*
2543 x86_64 MinGW x86_64-*-mingw*
2547 Lattice Mico32 lm32-*
2548 x86 DICOS i[34567]86-*-dicos*
2549 x86_64 DICOS x86_64-*-dicos*
2552 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2553 (mingw32ce) debugging.
2559 These commands were actually not implemented on any target.
2561 *** Changes in GDB 6.8
2563 * New native configurations
2565 NetBSD/hppa hppa*-*netbsd*
2566 Xtensa GNU/Linux xtensa*-*-linux*
2570 NetBSD/hppa hppa*-*-netbsd*
2571 Xtensa GNU/Lunux xtensa*-*-linux*
2573 * Change in command line behavior -- corefiles vs. process ids.
2575 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2576 attaching to process NUMBER fails, GDB no longer attempts to open a
2577 core file named NUMBER. Attaching to a program using the -c option
2578 is no longer supported. Instead, use the '-p' or '--pid' options.
2580 * GDB can now be built as a native debugger for debugging Windows x86
2581 (mingw32) Portable Executable (PE) programs.
2583 * Pending breakpoints no longer change their number when their address
2586 * GDB now supports breakpoints with multiple locations,
2587 including breakpoints on C++ constructors, inside C++ templates,
2588 and in inlined functions.
2590 * GDB's ability to debug optimized code has been improved. GDB more
2591 accurately identifies function bodies and lexical blocks that occupy
2592 more than one contiguous range of addresses.
2594 * Target descriptions can now describe registers for PowerPC.
2596 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2597 registers on PowerPC targets.
2599 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2600 targets even when the libthread_db library is not available.
2602 * The GDB remote stub, gdbserver, now supports the new file transfer
2603 commands (remote put, remote get, and remote delete).
2605 * The GDB remote stub, gdbserver, now supports run and attach in
2606 extended-remote mode.
2608 * hppa*64*-*-hpux11* target broken
2609 The debugger is unable to start a program and fails with the following
2610 error: "Error trying to get information about dynamic linker".
2611 The gdb-6.7 release is also affected.
2613 * GDB now supports the --enable-targets= configure option to allow
2614 building a single GDB executable that supports multiple remote
2615 target architectures.
2617 * GDB now supports debugging C and C++ programs which use the
2618 Decimal Floating Point extension. In addition, the PowerPC target
2619 now has a set of pseudo-registers to inspect decimal float values
2620 stored in two consecutive float registers.
2622 * The -break-insert MI command can optionally create pending
2625 * Improved support for debugging Ada
2626 Many improvements to the Ada language support have been made. These
2628 - Better support for Ada2005 interface types
2629 - Improved handling of arrays and slices in general
2630 - Better support for Taft-amendment types
2631 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2633 - Improved command completion in Ada
2636 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2641 set print frame-arguments (all|scalars|none)
2642 show print frame-arguments
2643 The value of this variable can be changed to control which argument
2644 values should be printed by the debugger when displaying a frame.
2649 Transfer files to and from a remote target, and delete remote files.
2656 Transfer files to and from a remote target, and delete remote files.
2658 * New remote packets
2665 Open, close, read, write, and delete files on the remote system.
2668 Attach to an existing process on the remote system, in extended-remote
2672 Run a new process on the remote system, in extended-remote mode.
2674 *** Changes in GDB 6.7
2676 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2677 bfd, libiberty and opcodes, as revealed by static analysis donated by
2678 Coverity, Inc. (http://scan.coverity.com).
2680 * When looking up multiply-defined global symbols, GDB will now prefer the
2681 symbol definition in the current shared library if it was built using the
2682 -Bsymbolic linker option.
2684 * When the Text User Interface (TUI) is not configured, GDB will now
2685 recognize the -tui command-line option and print a message that the TUI
2688 * The GDB remote stub, gdbserver, now has lower overhead for high
2689 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2691 * GDB for MIPS targets now autodetects whether a remote target provides
2692 32-bit or 64-bit register values.
2694 * Support for C++ member pointers has been improved.
2696 * GDB now understands XML target descriptions, which specify the
2697 target's overall architecture. GDB can read a description from
2698 a local file or over the remote serial protocol.
2700 * Vectors of single-byte data use a new integer type which is not
2701 automatically displayed as character or string data.
2703 * The /s format now works with the print command. It displays
2704 arrays of single-byte integers and pointers to single-byte integers
2707 * Target descriptions can now describe target-specific registers,
2708 for architectures which have implemented the support (currently
2709 only ARM, M68K, and MIPS).
2711 * GDB and the GDB remote stub, gdbserver, now support the XScale
2714 * The GDB remote stub, gdbserver, has been updated to support
2715 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2716 has been rewritten to use the standard GDB remote protocol.
2718 * GDB can now step into C++ functions which are called through thunks.
2720 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2722 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2723 layout. It also supports a TextSeg= and DataSeg= response when only
2724 segment base addresses (rather than offsets) are available.
2726 * The /i format now outputs any trailing branch delay slot instructions
2727 immediately following the last instruction within the count specified.
2729 * The GDB remote protocol "T" stop reply packet now supports a
2730 "library" response. Combined with the new "qXfer:libraries:read"
2731 packet, this response allows GDB to debug shared libraries on targets
2732 where the operating system manages the list of loaded libraries (e.g.
2733 Windows and SymbianOS).
2735 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2736 (DLLs) on Windows and Windows CE targets.
2738 * GDB now supports a faster verification that a .debug file matches its binary
2739 according to its build-id signature, if the signature is present.
2745 Enable or disable hardware flow control (RTS/CTS) on the serial port
2746 when debugging using remote targets.
2748 set mem inaccessible-by-default
2749 show mem inaccessible-by-default
2750 If the target supplies a memory map, for instance via the remote
2751 protocol's "qXfer:memory-map:read" packet, setting this variable
2752 prevents GDB from accessing memory outside the memory map. This
2753 is useful for targets with memory mapped registers or which react
2754 badly to accesses of unmapped address space.
2756 set breakpoint auto-hw
2757 show breakpoint auto-hw
2758 If the target supplies a memory map, for instance via the remote
2759 protocol's "qXfer:memory-map:read" packet, setting this variable
2760 lets GDB use hardware breakpoints automatically for memory regions
2761 where it can not use software breakpoints. This covers both the
2762 "break" command and internal breakpoints used for other commands
2763 including "next" and "finish".
2766 catch exception unhandled
2767 Stop the program execution when Ada exceptions are raised.
2770 Stop the program execution when an Ada assertion failed.
2774 Set an alternate system root for target files. This is a more
2775 general version of "set solib-absolute-prefix", which is now
2776 an alias to "set sysroot".
2779 Provide extended SPU facility status information. This set of
2780 commands is available only when debugging the Cell/B.E. SPU
2783 * New native configurations
2785 OpenBSD/sh sh*-*openbsd*
2788 unset tdesc filename
2790 Use the specified local file as an XML target description, and do
2791 not query the target for its built-in description.
2795 OpenBSD/sh sh*-*-openbsd*
2796 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2797 Toshiba Media Processor mep-elf
2799 * New remote packets
2802 Ignore the specified signals; pass them directly to the debugged program
2803 without stopping other threads or reporting them to GDB.
2805 qXfer:features:read:
2806 Read an XML target description from the target, which describes its
2811 Read or write contents of an spufs file on the target system. These
2812 packets are available only on the Cell/B.E. SPU architecture.
2814 qXfer:libraries:read:
2815 Report the loaded shared libraries. Combined with new "T" packet
2816 response, this packet allows GDB to debug shared libraries on
2817 targets where the operating system manages the list of loaded
2818 libraries (e.g. Windows and SymbianOS).
2822 Support for these obsolete configurations has been removed.
2830 i[34567]86-*-lynxos*
2831 i[34567]86-*-netware*
2832 i[34567]86-*-sco3.2v5*
2833 i[34567]86-*-sco3.2v4*
2835 i[34567]86-*-sysv4.2*
2838 i[34567]86-*-unixware2*
2839 i[34567]86-*-unixware*
2848 * Other removed features
2855 Various m68k-only ROM monitors.
2862 Various Renesas ROM monitors and debugging interfaces for SH and
2867 Support for a Macraigor serial interface to on-chip debugging.
2868 GDB does not directly support the newer parallel or USB
2873 A debug information format. The predecessor to DWARF 2 and
2874 DWARF 3, which are still supported.
2876 Support for the HP aCC compiler on HP-UX/PA-RISC
2878 SOM-encapsulated symbolic debugging information, automatic
2879 invocation of pxdb, and the aCC custom C++ ABI. This does not
2880 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2881 with aCC can still be debugged on an assembly level.
2883 MIPS ".pdr" sections
2885 A MIPS-specific format used to describe stack frame layout
2886 in debugging information.
2890 GDB could work with an older version of Guile to debug
2891 the interpreter and Scheme programs running in it.
2893 set mips stack-arg-size
2894 set mips saved-gpreg-size
2896 Use "set mips abi" to control parameter passing for MIPS.
2898 *** Changes in GDB 6.6
2903 Cell Broadband Engine SPU spu-elf
2905 * GDB can now be configured as a cross-debugger targeting native Windows
2906 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2907 running on a Windows system over TCP/IP to debug Windows programs.
2909 * The GDB remote stub, gdbserver, has been updated to support Windows and
2910 Cygwin debugging. Both single-threaded and multi-threaded programs are
2913 * The "set trust-readonly-sections" command works again. This command was
2914 broken in GDB 6.3, 6.4, and 6.5.
2916 * The "load" command now supports writing to flash memory, if the remote
2917 stub provides the required support.
2919 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2920 longer requires symbolic debug information (e.g. DWARF-2).
2925 unset substitute-path
2926 show substitute-path
2927 Manage a list of substitution rules that GDB uses to rewrite the name
2928 of the directories where the sources are located. This can be useful
2929 for instance when the sources were moved to a different location
2930 between compilation and debugging.
2934 Print each CLI command as it is executed. Each command is prefixed with
2935 a number of `+' symbols representing the nesting depth.
2936 The source command now has a `-v' option to enable the same feature.
2940 The ARM Demon monitor support (RDP protocol, "target rdp").
2942 Kernel Object Display, an embedded debugging feature which only worked with
2943 an obsolete version of Cisco IOS.
2945 The 'set download-write-size' and 'show download-write-size' commands.
2947 * New remote packets
2950 Tell a stub about GDB client features, and request remote target features.
2951 The first feature implemented is PacketSize, which allows the target to
2952 specify the size of packets it can handle - to minimize the number of
2953 packets required and improve performance when connected to a remote
2957 Fetch an OS auxilliary vector from the remote stub. This packet is a
2958 more efficient replacement for qPart:auxv:read.
2960 qXfer:memory-map:read:
2961 Fetch a memory map from the remote stub, including information about
2962 RAM, ROM, and flash memory devices.
2967 Erase and program a flash memory device.
2969 * Removed remote packets
2972 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2973 used it, and only gdbserver implemented it.
2975 *** Changes in GDB 6.5
2979 Renesas M32C/M16C m32c-elf
2981 Morpho Technologies ms1 ms1-elf
2985 init-if-undefined Initialize a convenience variable, but
2986 only if it doesn't already have a value.
2988 The following commands are presently only implemented for native GNU/Linux:
2990 checkpoint Save a snapshot of the program state.
2992 restart <n> Return the program state to a
2993 previously saved state.
2995 info checkpoints List currently saved checkpoints.
2997 delete-checkpoint <n> Delete a previously saved checkpoint.
2999 set|show detach-on-fork Tell gdb whether to detach from a newly
3000 forked process, or to keep debugging it.
3002 info forks List forks of the user program that
3003 are available to be debugged.
3005 fork <n> Switch to debugging one of several
3006 forks of the user program that are
3007 available to be debugged.
3009 delete-fork <n> Delete a fork from the list of forks
3010 that are available to be debugged (and
3011 kill the forked process).
3013 detach-fork <n> Delete a fork from the list of forks
3014 that are available to be debugged (and
3015 allow the process to continue).
3019 Morpho Technologies ms2 ms1-elf
3021 * Improved Windows host support
3023 GDB now builds as a cross debugger hosted on i686-mingw32, including
3024 native console support, and remote communications using either
3025 network sockets or serial ports.
3027 * Improved Modula-2 language support
3029 GDB can now print most types in the Modula-2 syntax. This includes:
3030 basic types, set types, record types, enumerated types, range types,
3031 pointer types and ARRAY types. Procedure var parameters are correctly
3032 printed and hexadecimal addresses and character constants are also
3033 written in the Modula-2 syntax. Best results can be obtained by using
3034 GNU Modula-2 together with the -gdwarf-2 command line option.
3038 The ARM rdi-share module.
3040 The Netware NLM debug server.
3042 *** Changes in GDB 6.4
3044 * New native configurations
3046 OpenBSD/arm arm*-*-openbsd*
3047 OpenBSD/mips64 mips64-*-openbsd*
3051 Morpho Technologies ms1 ms1-elf
3053 * New command line options
3055 --batch-silent As for --batch, but totally silent.
3056 --return-child-result The debugger will exist with the same value
3057 the child (debugged) program exited with.
3058 --eval-command COMMAND, -ex COMMAND
3059 Execute a single GDB CLI command. This may be
3060 specified multiple times and in conjunction
3061 with the --command (-x) option.
3063 * Deprecated commands removed
3065 The following commands, that were deprecated in 2000, have been
3069 set|show arm disassembly-flavor set|show arm disassembler
3070 othernames set arm disassembler
3071 set|show remotedebug set|show debug remote
3072 set|show archdebug set|show debug arch
3073 set|show eventdebug set|show debug event
3076 * New BSD user-level threads support
3078 It is now possible to debug programs using the user-level threads
3079 library on OpenBSD and FreeBSD. Currently supported (target)
3082 FreeBSD/amd64 x86_64-*-freebsd*
3083 FreeBSD/i386 i386-*-freebsd*
3084 OpenBSD/i386 i386-*-openbsd*
3086 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3087 are not yet supported.
3089 * New support for Matsushita MN10300 w/sim added
3090 (Work in progress). mn10300-elf.
3092 * REMOVED configurations and files
3094 VxWorks and the XDR protocol *-*-vxworks
3095 Motorola MCORE mcore-*-*
3096 National Semiconductor NS32000 ns32k-*-*
3098 * New "set print array-indexes" command
3100 After turning this setting "on", GDB prints the index of each element
3101 when displaying arrays. The default is "off" to preserve the previous
3104 * VAX floating point support
3106 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3108 * User-defined command support
3110 In addition to using $arg0..$arg9 for argument passing, it is now possible
3111 to use $argc to determine now many arguments have been passed. See the
3112 section on user-defined commands in the user manual for more information.
3114 *** Changes in GDB 6.3:
3116 * New command line option
3118 GDB now accepts -l followed by a number to set the timeout for remote
3121 * GDB works with GCC -feliminate-dwarf2-dups
3123 GDB now supports a more compact representation of DWARF-2 debug
3124 information using DW_FORM_ref_addr references. These are produced
3125 by GCC with the option -feliminate-dwarf2-dups and also by some
3126 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3127 to use -feliminate-dwarf2-dups.
3129 * Internationalization
3131 When supported by the host system, GDB will be built with
3132 internationalization (libintl). The task of marking up the sources is
3133 continued, we're looking forward to our first translation.
3137 Initial support for debugging programs compiled with the GNAT
3138 implementation of the Ada programming language has been integrated
3139 into GDB. In this release, support is limited to expression evaluation.
3141 * New native configurations
3143 GNU/Linux/m32r m32r-*-linux-gnu
3147 GDB's remote protocol now includes support for the 'p' packet. This
3148 packet is used to fetch individual registers from a remote inferior.
3150 * END-OF-LIFE registers[] compatibility module
3152 GDB's internal register infrastructure has been completely rewritten.
3153 The new infrastructure making possible the implementation of key new
3154 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3157 GDB 6.3 will be the last release to include the the registers[]
3158 compatibility module that allowed out-of-date configurations to
3159 continue to work. This change directly impacts the following
3169 powerpc bdm protocol
3171 Unless there is activity to revive these configurations, they will be
3172 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3174 * OBSOLETE configurations and files
3176 Configurations that have been declared obsolete in this release have
3177 been commented out. Unless there is activity to revive these
3178 configurations, the next release of GDB will have their sources
3179 permanently REMOVED.
3188 *** Changes in GDB 6.2.1:
3190 * MIPS `break main; run' gave an heuristic-fence-post warning
3192 When attempting to run even a simple program, a warning about
3193 heuristic-fence-post being hit would be reported. This problem has
3196 * MIPS IRIX 'long double' crashed GDB
3198 When examining a long double variable, GDB would get a segmentation
3199 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3200 IRIX long double values).
3204 A bug in the VAX stack code was causing problems with the "next"
3205 command. This problem has been fixed.
3207 *** Changes in GDB 6.2:
3209 * Fix for ``many threads''
3211 On GNU/Linux systems that use the NPTL threads library, a program
3212 rapidly creating and deleting threads would confuse GDB leading to the
3215 ptrace: No such process.
3216 thread_db_get_info: cannot get thread info: generic error
3218 This problem has been fixed.
3220 * "-async" and "-noasync" options removed.
3222 Support for the broken "-noasync" option has been removed (it caused
3225 * New ``start'' command.
3227 This command runs the program until the begining of the main procedure.
3229 * New BSD Kernel Data Access Library (libkvm) interface
3231 Using ``target kvm'' it is now possible to debug kernel core dumps and
3232 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3233 platforms. Currently supported (native-only) configurations are:
3235 FreeBSD/amd64 x86_64-*-freebsd*
3236 FreeBSD/i386 i?86-*-freebsd*
3237 NetBSD/i386 i?86-*-netbsd*
3238 NetBSD/m68k m68*-*-netbsd*
3239 NetBSD/sparc sparc-*-netbsd*
3240 OpenBSD/amd64 x86_64-*-openbsd*
3241 OpenBSD/i386 i?86-*-openbsd*
3242 OpenBSD/m68k m68*-openbsd*
3243 OpenBSD/sparc sparc-*-openbsd*
3245 * Signal trampoline code overhauled
3247 Many generic problems with GDB's signal handling code have been fixed.
3248 These include: backtraces through non-contiguous stacks; recognition
3249 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3250 call; backtrace through a signal trampoline; step into and out of
3251 signal handlers; and single-stepping in the signal trampoline.
3253 Please note that kernel bugs are a limiting factor here. These
3254 features have been shown to work on an s390 GNU/Linux system that
3255 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3257 * Cygwin support for DWARF 2 added.
3259 * New native configurations
3261 GNU/Linux/hppa hppa*-*-linux*
3262 OpenBSD/hppa hppa*-*-openbsd*
3263 OpenBSD/m68k m68*-*-openbsd*
3264 OpenBSD/m88k m88*-*-openbsd*
3265 OpenBSD/powerpc powerpc-*-openbsd*
3266 NetBSD/vax vax-*-netbsd*
3267 OpenBSD/vax vax-*-openbsd*
3269 * END-OF-LIFE frame compatibility module
3271 GDB's internal frame infrastructure has been completely rewritten.
3272 The new infrastructure making it possible to support key new features
3273 including DWARF 2 Call Frame Information. To aid in the task of
3274 migrating old configurations to this new infrastructure, a
3275 compatibility module, that allowed old configurations to continue to
3276 work, was also included.
3278 GDB 6.2 will be the last release to include this frame compatibility
3279 module. This change directly impacts the following configurations:
3289 Unless there is activity to revive these configurations, they will be
3290 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3292 * REMOVED configurations and files
3294 Sun 3, running SunOS 3 m68*-*-sunos3*
3295 Sun 3, running SunOS 4 m68*-*-sunos4*
3296 Sun 2, running SunOS 3 m68000-*-sunos3*
3297 Sun 2, running SunOS 4 m68000-*-sunos4*
3298 Motorola 680x0 running LynxOS m68*-*-lynxos*
3299 AT&T 3b1/Unix pc m68*-att-*
3300 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3301 decstation mips-dec-* mips-little-*
3302 riscos mips-*-riscos* mips-*-sysv*
3303 sonymips mips-sony-*
3304 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3306 *** Changes in GDB 6.1.1:
3308 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3310 The TUI (Text-mode User Interface) is now built as part of a default
3311 GDB configuration. It is enabled by either selecting the TUI with the
3312 command line option "-i=tui" or by running the separate "gdbtui"
3313 program. For more information on the TUI, see the manual "Debugging
3316 * Pending breakpoint support (also included in GDB 6.1)
3318 Support has been added to allow you to specify breakpoints in shared
3319 libraries that have not yet been loaded. If a breakpoint location
3320 cannot be found, and the "breakpoint pending" option is set to auto,
3321 GDB queries you if you wish to make the breakpoint pending on a future
3322 shared-library load. If and when GDB resolves the breakpoint symbol,
3323 the pending breakpoint is removed as one or more regular breakpoints
3326 Pending breakpoints are very useful for GCJ Java debugging.
3328 * Fixed ISO-C build problems
3330 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3331 non ISO-C code that stopped them being built using a more strict ISO-C
3332 compiler (e.g., IBM's C compiler).
3334 * Fixed build problem on IRIX 5
3336 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3337 wasn't able to compile compile on an IRIX 5 system.
3339 * Added execute permission to gdb/gdbserver/configure
3341 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3342 permission. This bug would cause configure to fail on a number of
3343 systems (Solaris, IRIX). Ref: server/519.
3345 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3347 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3348 has been updated to use constant array sizes.
3350 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3352 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3353 its generated DWARF Call Frame Info. This encoding was causing GDB to
3354 panic, that panic has been fixed. Ref: gdb/1628.
3356 * Fixed a problem when examining parameters in shared library code.
3358 When examining parameters in optimized shared library code generated
3359 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3360 not available''. GDB now correctly displays the variable's value.
3362 *** Changes in GDB 6.1:
3364 * Removed --with-mmalloc
3366 Support for the mmalloc memory manager has been removed, as it
3367 conflicted with the internal gdb byte cache.
3369 * Changes in AMD64 configurations
3371 The AMD64 target now includes the %cs and %ss registers. As a result
3372 the AMD64 remote protocol has changed; this affects the floating-point
3373 and SSE registers. If you rely on those registers for your debugging,
3374 you should upgrade gdbserver on the remote side.
3376 * Revised SPARC target
3378 The SPARC target has been completely revised, incorporating the
3379 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3380 support for LynxOS and SunOS 4 has been dropped. Calling functions
3381 from within GDB on operating systems with a non-executable stack
3382 (Solaris, OpenBSD) now works.
3386 GDB has a new C++ demangler which does a better job on the mangled
3387 names generated by current versions of g++. It also runs faster, so
3388 with this and other changes gdb should now start faster on large C++
3391 * DWARF 2 Location Expressions
3393 GDB support for location expressions has been extended to support function
3394 arguments and frame bases. Older versions of GDB could crash when they
3397 * C++ nested types and namespaces
3399 GDB's support for nested types and namespaces in C++ has been
3400 improved, especially if you use the DWARF 2 debugging format. (This
3401 is the default for recent versions of GCC on most platforms.)
3402 Specifically, if you have a class "Inner" defined within a class or
3403 namespace "Outer", then GDB realizes that the class's name is
3404 "Outer::Inner", not simply "Inner". This should greatly reduce the
3405 frequency of complaints about not finding RTTI symbols. In addition,
3406 if you are stopped at inside of a function defined within a namespace,
3407 GDB modifies its name lookup accordingly.
3409 * New native configurations
3411 NetBSD/amd64 x86_64-*-netbsd*
3412 OpenBSD/amd64 x86_64-*-openbsd*
3413 OpenBSD/alpha alpha*-*-openbsd*
3414 OpenBSD/sparc sparc-*-openbsd*
3415 OpenBSD/sparc64 sparc64-*-openbsd*
3417 * New debugging protocols
3419 M32R with SDI protocol m32r-*-elf*
3421 * "set prompt-escape-char" command deleted.
3423 The command "set prompt-escape-char" has been deleted. This command,
3424 and its very obscure effet on GDB's prompt, was never documented,
3425 tested, nor mentioned in the NEWS file.
3427 * OBSOLETE configurations and files
3429 Configurations that have been declared obsolete in this release have
3430 been commented out. Unless there is activity to revive these
3431 configurations, the next release of GDB will have their sources
3432 permanently REMOVED.
3434 Sun 3, running SunOS 3 m68*-*-sunos3*
3435 Sun 3, running SunOS 4 m68*-*-sunos4*
3436 Sun 2, running SunOS 3 m68000-*-sunos3*
3437 Sun 2, running SunOS 4 m68000-*-sunos4*
3438 Motorola 680x0 running LynxOS m68*-*-lynxos*
3439 AT&T 3b1/Unix pc m68*-att-*
3440 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3441 decstation mips-dec-* mips-little-*
3442 riscos mips-*-riscos* mips-*-sysv*
3443 sonymips mips-sony-*
3444 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3446 * REMOVED configurations and files
3448 SGI Irix-4.x mips-sgi-irix4 or iris4
3449 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3450 Z8000 simulator z8k-zilog-none or z8ksim
3451 Matsushita MN10200 w/simulator mn10200-*-*
3452 H8/500 simulator h8500-hitachi-hms or h8500hms
3453 HP/PA running BSD hppa*-*-bsd*
3454 HP/PA running OSF/1 hppa*-*-osf*
3455 HP/PA Pro target hppa*-*-pro*
3456 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3457 386BSD i[3456]86-*-bsd*
3458 Sequent family i[3456]86-sequent-sysv4*
3459 i[3456]86-sequent-sysv*
3460 i[3456]86-sequent-bsd*
3461 SPARC running LynxOS sparc-*-lynxos*
3462 SPARC running SunOS 4 sparc-*-sunos4*
3463 Tsqware Sparclet sparclet-*-*
3464 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3466 *** Changes in GDB 6.0:
3470 Support for debugging the Objective-C programming language has been
3471 integrated into GDB.
3473 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3475 DWARF 2's Call Frame Information makes available compiler generated
3476 information that more exactly describes the program's run-time stack.
3477 By using this information, GDB is able to provide more robust stack
3480 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3481 have been updated to use a new backtrace mechanism which includes
3482 DWARF 2 CFI support.
3486 GDB's remote protocol has been extended to include support for hosted
3487 file I/O (where the remote target uses GDB's file system). See GDB's
3488 remote protocol documentation for details.
3490 * All targets using the new architecture framework.
3492 All of GDB's targets have been updated to use the new internal
3493 architecture framework. The way is now open for future GDB releases
3494 to include cross-architecture native debugging support (i386 on amd64,
3497 * GNU/Linux's Thread Local Storage (TLS)
3499 GDB now includes support for for the GNU/Linux implementation of
3500 per-thread variables.
3502 * GNU/Linux's Native POSIX Thread Library (NPTL)
3504 GDB's thread code has been updated to work with either the new
3505 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3507 * Separate debug info.
3509 GDB, in conjunction with BINUTILS, now supports a mechanism for
3510 automatically loading debug information from a separate file. Instead
3511 of shipping full debug and non-debug versions of system libraries,
3512 system integrators can now instead ship just the stripped libraries
3513 and optional debug files.
3515 * DWARF 2 Location Expressions
3517 DWARF 2 Location Expressions allow the compiler to more completely
3518 describe the location of variables (even in optimized code) to the
3521 GDB now includes preliminary support for location expressions (support
3522 for DW_OP_piece is still missing).
3526 A number of long standing bugs that caused GDB to die while starting a
3527 Java application have been fixed. GDB's Java support is now
3528 considered "useable".
3530 * GNU/Linux support for fork, vfork, and exec.
3532 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3533 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3536 * GDB supports logging output to a file
3538 There are two new commands, "set logging" and "show logging", which can be
3539 used to capture GDB's output to a file.
3541 * The meaning of "detach" has changed for gdbserver
3543 The "detach" command will now resume the application, as documented. To
3544 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3547 * d10v, m68hc11 `regs' command deprecated
3549 The `info registers' command has been updated so that it displays the
3550 registers using a format identical to the old `regs' command.
3554 A new command, "maint set profile on/off", has been added. This command can
3555 be used to enable or disable profiling while running GDB, to profile a
3556 session or a set of commands. In addition there is a new configure switch,
3557 "--enable-profiling", which will cause GDB to be compiled with profiling
3558 data, for more informative profiling results.
3560 * Default MI syntax changed to "mi2".
3562 The default MI (machine interface) syntax, enabled by the command line
3563 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3564 "mi1", can be enabled by specifying the option "-i=mi1".
3566 Support for the original "mi0" syntax (included in GDB 5.0) has been
3569 Fix for gdb/192: removed extraneous space when displaying frame level.
3570 Fix for gdb/672: update changelist is now output in mi list format.
3571 Fix for gdb/702: a -var-assign that updates the value now shows up
3572 in a subsequent -var-update.
3574 * New native configurations.
3576 FreeBSD/amd64 x86_64-*-freebsd*
3578 * Multi-arched targets.
3580 HP/PA HPUX11 hppa*-*-hpux*
3581 Renesas M32R/D w/simulator m32r-*-elf*
3583 * OBSOLETE configurations and files
3585 Configurations that have been declared obsolete in this release have
3586 been commented out. Unless there is activity to revive these
3587 configurations, the next release of GDB will have their sources
3588 permanently REMOVED.
3590 Z8000 simulator z8k-zilog-none or z8ksim
3591 Matsushita MN10200 w/simulator mn10200-*-*
3592 H8/500 simulator h8500-hitachi-hms or h8500hms
3593 HP/PA running BSD hppa*-*-bsd*
3594 HP/PA running OSF/1 hppa*-*-osf*
3595 HP/PA Pro target hppa*-*-pro*
3596 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3597 Sequent family i[3456]86-sequent-sysv4*
3598 i[3456]86-sequent-sysv*
3599 i[3456]86-sequent-bsd*
3600 Tsqware Sparclet sparclet-*-*
3601 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3603 * REMOVED configurations and files
3606 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3607 IBM AIX PS/2 i[3456]86-*-aix
3608 i386 running Mach 3.0 i[3456]86-*-mach3*
3609 i386 running Mach i[3456]86-*-mach*
3610 i386 running OSF/1 i[3456]86-*osf1mk*
3611 HP/Apollo 68k Family m68*-apollo*-sysv*,
3613 m68*-hp-bsd*, m68*-hp-hpux*
3614 Argonaut Risc Chip (ARC) arc-*-*
3615 Mitsubishi D30V d30v-*-*
3616 Fujitsu FR30 fr30-*-elf*
3617 OS/9000 i[34]86-*-os9k
3618 I960 with MON960 i960-*-coff
3620 * MIPS $fp behavior changed
3622 The convenience variable $fp, for the MIPS, now consistently returns
3623 the address of the current frame's base. Previously, depending on the
3624 context, $fp could refer to either $sp or the current frame's base
3625 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3626 The GNU Source-Level Debugger''.
3628 *** Changes in GDB 5.3:
3630 * GNU/Linux shared library multi-threaded performance improved.
3632 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3633 `/proc', in preference to `ptrace' for memory reads. This may result
3634 in an improvement in the start-up time of multi-threaded, shared
3635 library applications when run under GDB. One GDB user writes: ``loads
3636 shared libs like mad''.
3638 * ``gdbserver'' now supports multi-threaded applications on some targets
3640 Support for debugging multi-threaded applications which use
3641 the GNU/Linux LinuxThreads package has been added for
3642 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3643 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3645 * GDB now supports C/C++ preprocessor macros.
3647 GDB now expands preprocessor macro invocations in C/C++ expressions,
3648 and provides various commands for showing macro definitions and how
3651 The new command `macro expand EXPRESSION' expands any macro
3652 invocations in expression, and shows the result.
3654 The new command `show macro MACRO-NAME' shows the definition of the
3655 macro named MACRO-NAME, and where it was defined.
3657 Most compilers don't include information about macros in the debugging
3658 information by default. In GCC 3.1, for example, you need to compile
3659 your program with the options `-gdwarf-2 -g3'. If the macro
3660 information is present in the executable, GDB will read it.
3662 * Multi-arched targets.
3664 DEC Alpha (partial) alpha*-*-*
3665 DEC VAX (partial) vax-*-*
3667 National Semiconductor NS32000 (partial) ns32k-*-*
3668 Motorola 68000 (partial) m68k-*-*
3669 Motorola MCORE mcore-*-*
3673 Fujitsu FRV architecture added by Red Hat frv*-*-*
3676 * New native configurations
3678 Alpha NetBSD alpha*-*-netbsd*
3679 SH NetBSD sh*-*-netbsdelf*
3680 MIPS NetBSD mips*-*-netbsd*
3681 UltraSPARC NetBSD sparc64-*-netbsd*
3683 * OBSOLETE configurations and files
3685 Configurations that have been declared obsolete in this release have
3686 been commented out. Unless there is activity to revive these
3687 configurations, the next release of GDB will have their sources
3688 permanently REMOVED.
3690 Mitsubishi D30V d30v-*-*
3691 OS/9000 i[34]86-*-os9k
3692 IBM AIX PS/2 i[3456]86-*-aix
3693 Fujitsu FR30 fr30-*-elf*
3694 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3695 Argonaut Risc Chip (ARC) arc-*-*
3696 i386 running Mach 3.0 i[3456]86-*-mach3*
3697 i386 running Mach i[3456]86-*-mach*
3698 i386 running OSF/1 i[3456]86-*osf1mk*
3699 HP/Apollo 68k Family m68*-apollo*-sysv*,
3701 m68*-hp-bsd*, m68*-hp-hpux*
3702 I960 with MON960 i960-*-coff
3704 * OBSOLETE languages
3706 CHILL, a Pascal like language used by telecommunications companies.
3708 * REMOVED configurations and files
3710 AMD 29k family via UDI a29k-amd-udi, udi29k
3711 A29K VxWorks a29k-*-vxworks
3712 AMD 29000 embedded, using EBMON a29k-none-none
3713 AMD 29000 embedded with COFF a29k-none-coff
3714 AMD 29000 embedded with a.out a29k-none-aout
3716 testsuite/gdb.hp/gdb.threads-hp/ directory
3718 * New command "set max-user-call-depth <nnn>"
3720 This command allows the user to limit the call depth of user-defined
3721 commands. The default is 1024.
3723 * Changes in FreeBSD/i386 native debugging.
3725 Support for the "generate-core-file" has been added.
3727 * New commands "dump", "append", and "restore".
3729 These commands allow data to be copied from target memory
3730 to a bfd-format or binary file (dump and append), and back
3731 from a file into memory (restore).
3733 * Improved "next/step" support on multi-processor Alpha Tru64.
3735 The previous single-step mechanism could cause unpredictable problems,
3736 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3737 of a software single-step mechanism prevents this.
3739 *** Changes in GDB 5.2.1:
3747 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3748 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3749 Fix, by Joel Brobecker imported from mainline.
3751 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3752 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3753 Fix, by Fred Fish, imported from mainline.
3755 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3756 Surprisingly enough, it works now.
3757 By Michal Ludvig, imported from mainline.
3759 i386 hardware watchpoint support:
3760 avoid misses on second run for some targets.
3761 By Pierre Muller, imported from mainline.
3763 *** Changes in GDB 5.2:
3765 * New command "set trust-readonly-sections on[off]".
3767 This command is a hint that tells gdb that read-only sections
3768 really are read-only (ie. that their contents will not change).
3769 In this mode, gdb will go to the object file rather than the
3770 target to read memory from read-only sections (such as ".text").
3771 This can be a significant performance improvement on some
3772 (notably embedded) targets.
3774 * New command "generate-core-file" (or "gcore").
3776 This new gdb command allows the user to drop a core file of the child
3777 process state at any time. So far it's been implemented only for
3778 GNU/Linux and Solaris, but should be relatively easily ported to other
3779 hosts. Argument is core file name (defaults to core.<pid>).
3781 * New command line option
3783 GDB now accepts --pid or -p followed by a process id.
3785 * Change in command line behavior -- corefiles vs. process ids.
3787 There is a subtle behavior in the way in which GDB handles
3788 command line arguments. The first non-flag argument is always
3789 a program to debug, but the second non-flag argument may either
3790 be a corefile or a process id. Previously, GDB would attempt to
3791 open the second argument as a corefile, and if that failed, would
3792 issue a superfluous error message and then attempt to attach it as
3793 a process. Now, if the second argument begins with a non-digit,
3794 it will be treated as a corefile. If it begins with a digit,
3795 GDB will attempt to attach it as a process, and if no such process
3796 is found, will then attempt to open it as a corefile.
3798 * Changes in ARM configurations.
3800 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3801 configuration is fully multi-arch.
3803 * New native configurations
3805 ARM NetBSD arm*-*-netbsd*
3806 x86 OpenBSD i[3456]86-*-openbsd*
3807 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3808 Sparc64 running FreeBSD sparc64-*-freebsd*
3812 Sanyo XStormy16 xstormy16-elf
3814 * OBSOLETE configurations and files
3816 Configurations that have been declared obsolete in this release have
3817 been commented out. Unless there is activity to revive these
3818 configurations, the next release of GDB will have their sources
3819 permanently REMOVED.
3821 AMD 29k family via UDI a29k-amd-udi, udi29k
3822 A29K VxWorks a29k-*-vxworks
3823 AMD 29000 embedded, using EBMON a29k-none-none
3824 AMD 29000 embedded with COFF a29k-none-coff
3825 AMD 29000 embedded with a.out a29k-none-aout
3827 testsuite/gdb.hp/gdb.threads-hp/ directory
3829 * REMOVED configurations and files
3831 TI TMS320C80 tic80-*-*
3833 PowerPC Solaris powerpcle-*-solaris*
3834 PowerPC Windows NT powerpcle-*-cygwin32
3835 PowerPC Netware powerpc-*-netware*
3836 Harris/CXUX m88k m88*-harris-cxux*
3837 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3838 ns32k-utek-sysv* ns32k-utek-*
3839 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3840 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3841 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3842 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3843 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3845 * Changes to command line processing
3847 The new `--args' feature can be used to specify command-line arguments
3848 for the inferior from gdb's command line.
3850 * Changes to key bindings
3852 There is a new `operate-and-get-next' function bound to `C-o'.
3854 *** Changes in GDB 5.1.1
3856 Fix compile problem on DJGPP.
3858 Fix a problem with floating-point registers on the i386 being
3861 Fix to stop GDB crashing on .debug_str debug info.
3863 Numerous documentation fixes.
3865 Numerous testsuite fixes.
3867 *** Changes in GDB 5.1:
3869 * New native configurations
3871 Alpha FreeBSD alpha*-*-freebsd*
3872 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3873 MIPS GNU/Linux mips*-*-linux*
3874 MIPS SGI Irix 6.x mips*-sgi-irix6*
3875 ia64 AIX ia64-*-aix*
3876 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3880 Motorola 68HC11 and 68HC12 m68hc11-elf
3882 UltraSparc running GNU/Linux sparc64-*-linux*
3884 * OBSOLETE configurations and files
3886 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3887 Harris/CXUX m88k m88*-harris-cxux*
3888 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3889 ns32k-utek-sysv* ns32k-utek-*
3890 TI TMS320C80 tic80-*-*
3892 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3893 PowerPC Solaris powerpcle-*-solaris*
3894 PowerPC Windows NT powerpcle-*-cygwin32
3895 PowerPC Netware powerpc-*-netware*
3896 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3897 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3898 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3899 Apple Macintosh (MPW) host N/A
3901 stuff.c (Program to stuff files into a specially prepared space in kdb)
3902 kdb-start.c (Main loop for the standalone kernel debugger)
3904 Configurations that have been declared obsolete in this release have
3905 been commented out. Unless there is activity to revive these
3906 configurations, the next release of GDB will have their sources
3907 permanently REMOVED.
3909 * REMOVED configurations and files
3911 Altos 3068 m68*-altos-*
3912 Convex c1-*-*, c2-*-*
3914 ARM RISCix arm-*-* (as host)
3918 * GDB has been converted to ISO C.
3920 GDB's source code has been converted to ISO C. In particular, the
3921 sources are fully protoized, and rely on standard headers being
3926 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3928 * The MI enabled by default.
3930 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3931 revised and enabled by default. Packages which use GDB as a debugging
3932 engine behind a UI or another front end are encouraged to switch to
3933 using the GDB/MI interface, instead of the old annotations interface
3934 which is now deprecated.
3936 * Support for debugging Pascal programs.
3938 GDB now includes support for debugging Pascal programs. The following
3939 main features are supported:
3941 - Pascal-specific data types such as sets;
3943 - automatic recognition of Pascal sources based on file-name
3946 - Pascal-style display of data types, variables, and functions;
3948 - a Pascal expression parser.
3950 However, some important features are not yet supported.
3952 - Pascal string operations are not supported at all;
3954 - there are some problems with boolean types;
3956 - Pascal type hexadecimal constants are not supported
3957 because they conflict with the internal variables format;
3959 - support for Pascal objects and classes is not full yet;
3961 - unlike Pascal, GDB is case-sensitive for symbol names.
3963 * Changes in completion.
3965 Commands such as `shell', `run' and `set args', which pass arguments
3966 to inferior programs, now complete on file names, similar to what
3967 users expect at the shell prompt.
3969 Commands which accept locations, such as `disassemble', `print',
3970 `breakpoint', `until', etc. now complete on filenames as well as
3971 program symbols. Thus, if you type "break foob TAB", and the source
3972 files linked into the programs include `foobar.c', that file name will
3973 be one of the candidates for completion. However, file names are not
3974 considered for completion after you typed a colon that delimits a file
3975 name from a name of a function in that file, as in "break foo.c:bar".
3977 `set demangle-style' completes on available demangling styles.
3979 * New platform-independent commands:
3981 It is now possible to define a post-hook for a command as well as a
3982 hook that runs before the command. For more details, see the
3983 documentation of `hookpost' in the GDB manual.
3985 * Changes in GNU/Linux native debugging.
3987 Support for debugging multi-threaded programs has been completely
3988 revised for all platforms except m68k and sparc. You can now debug as
3989 many threads as your system allows you to have.
3991 Attach/detach is supported for multi-threaded programs.
3993 Support for SSE registers was added for x86. This doesn't work for
3994 multi-threaded programs though.
3996 * Changes in MIPS configurations.
3998 Multi-arch support is enabled for all MIPS configurations.
4000 GDB can now be built as native debugger on SGI Irix 6.x systems for
4001 debugging n32 executables. (Debugging 64-bit executables is not yet
4004 * Unified support for hardware watchpoints in all x86 configurations.
4006 Most (if not all) native x86 configurations support hardware-assisted
4007 breakpoints and watchpoints in a unified manner. This support
4008 implements debug register sharing between watchpoints, which allows to
4009 put a virtually infinite number of watchpoints on the same address,
4010 and also supports watching regions up to 16 bytes with several debug
4013 The new maintenance command `maintenance show-debug-regs' toggles
4014 debugging print-outs in functions that insert, remove, and test
4015 watchpoints and hardware breakpoints.
4017 * Changes in the DJGPP native configuration.
4019 New command ``info dos sysinfo'' displays assorted information about
4020 the CPU, OS, memory, and DPMI server.
4022 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4023 display information about segment descriptors stored in GDT, LDT, and
4026 New commands ``info dos pde'' and ``info dos pte'' display entries
4027 from Page Directory and Page Tables (for now works with CWSDPMI only).
4028 New command ``info dos address-pte'' displays the Page Table entry for
4029 a given linear address.
4031 GDB can now pass command lines longer than 126 characters to the
4032 program being debugged (requires an update to the libdbg.a library
4033 which is part of the DJGPP development kit).
4035 DWARF2 debug info is now supported.
4037 It is now possible to `step' and `next' through calls to `longjmp'.
4039 * Changes in documentation.
4041 All GDB documentation was converted to GFDL, the GNU Free
4042 Documentation License.
4044 Tracepoints-related commands are now fully documented in the GDB
4047 TUI, the Text-mode User Interface, is now documented in the manual.
4049 Tracepoints-related commands are now fully documented in the GDB
4052 The "GDB Internals" manual now has an index. It also includes
4053 documentation of `ui_out' functions, GDB coding standards, x86
4054 hardware watchpoints, and memory region attributes.
4056 * GDB's version number moved to ``version.in''
4058 The Makefile variable VERSION has been replaced by the file
4059 ``version.in''. People creating GDB distributions should update the
4060 contents of this file.
4064 GUD support is now a standard part of the EMACS distribution.
4066 *** Changes in GDB 5.0:
4068 * Improved support for debugging FP programs on x86 targets
4070 Unified and much-improved support for debugging floating-point
4071 programs on all x86 targets. In particular, ``info float'' now
4072 displays the FP registers in the same format on all x86 targets, with
4073 greater level of detail.
4075 * Improvements and bugfixes in hardware-assisted watchpoints
4077 It is now possible to watch array elements, struct members, and
4078 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4079 on x86 targets no longer erroneously trigger when the address is
4082 * Improvements in the native DJGPP version of GDB
4084 The distribution now includes all the scripts and auxiliary files
4085 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4086 machines ``out of the box''.
4088 The DJGPP version can now debug programs that use signals. It is
4089 possible to catch signals that happened in the debuggee, deliver
4090 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4091 would kill the program being debugged.) Programs that hook hardware
4092 interrupts (keyboard, timer, etc.) can also be debugged.
4094 It is now possible to debug DJGPP programs that redirect their
4095 standard handles or switch them to raw (as opposed to cooked) mode, or
4096 even close them. The command ``run < foo > bar'' works as expected,
4097 and ``info terminal'' reports useful information about the debuggee's
4098 terminal, including raw/cooked mode, redirection, etc.
4100 The DJGPP version now uses termios functions for console I/O, which
4101 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4104 DOS-style file names with drive letters are now fully supported by
4107 It is now possible to debug DJGPP programs that switch their working
4108 directory. It is also possible to rerun the debuggee any number of
4109 times without restarting GDB; thus, you can use the same setup,
4110 breakpoints, etc. for many debugging sessions.
4112 * New native configurations
4114 ARM GNU/Linux arm*-*-linux*
4115 PowerPC GNU/Linux powerpc-*-linux*
4119 Motorola MCore mcore-*-*
4120 x86 VxWorks i[3456]86-*-vxworks*
4121 PowerPC VxWorks powerpc-*-vxworks*
4122 TI TMS320C80 tic80-*-*
4124 * OBSOLETE configurations
4126 Altos 3068 m68*-altos-*
4127 Convex c1-*-*, c2-*-*
4129 ARM RISCix arm-*-* (as host)
4132 Configurations that have been declared obsolete will be commented out,
4133 but the code will be left in place. If there is no activity to revive
4134 these configurations before the next release of GDB, the sources will
4135 be permanently REMOVED.
4137 * Gould support removed
4139 Support for the Gould PowerNode and NP1 has been removed.
4141 * New features for SVR4
4143 On SVR4 native platforms (such as Solaris), if you attach to a process
4144 without first loading a symbol file, GDB will now attempt to locate and
4145 load symbols from the running process's executable file.
4147 * Many C++ enhancements
4149 C++ support has been greatly improved. Overload resolution now works properly
4150 in almost all cases. RTTI support is on the way.
4152 * Remote targets can connect to a sub-program
4154 A popen(3) style serial-device has been added. This device starts a
4155 sub-process (such as a stand-alone simulator) and then communicates
4156 with that. The sub-program to run is specified using the syntax
4157 ``|<program> <args>'' vis:
4159 (gdb) set remotedebug 1
4160 (gdb) target extended-remote |mn10300-elf-sim program-args
4162 * MIPS 64 remote protocol
4164 A long standing bug in the mips64 remote protocol where by GDB
4165 expected certain 32 bit registers (ex SR) to be transfered as 32
4166 instead of 64 bits has been fixed.
4168 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4169 added to provide backward compatibility with older versions of GDB.
4171 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4173 The command ``set remotebinarydownload'' command has been replaced by
4174 ``set remote X-packet''. Other commands in ``set remote'' family
4175 include ``set remote P-packet''.
4177 * Breakpoint commands accept ranges.
4179 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4180 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4181 ``tracepoint passcount'' also accepts a range of tracepoints.
4183 * ``apropos'' command added.
4185 The ``apropos'' command searches through command names and
4186 documentation strings, printing out matches, making it much easier to
4187 try to find a command that does what you are looking for.
4191 A new machine oriented interface (MI) has been added to GDB. This
4192 interface is designed for debug environments running GDB as a separate
4193 process. This is part of the long term libGDB project. See the
4194 "GDB/MI" chapter of the GDB manual for further information. It can be
4195 enabled by configuring with:
4197 .../configure --enable-gdbmi
4199 *** Changes in GDB-4.18:
4201 * New native configurations
4203 HP-UX 10.20 hppa*-*-hpux10.20
4204 HP-UX 11.x hppa*-*-hpux11.0*
4205 M68K GNU/Linux m68*-*-linux*
4209 Fujitsu FR30 fr30-*-elf*
4210 Intel StrongARM strongarm-*-*
4211 Mitsubishi D30V d30v-*-*
4213 * OBSOLETE configurations
4215 Gould PowerNode, NP1 np1-*-*, pn-*-*
4217 Configurations that have been declared obsolete will be commented out,
4218 but the code will be left in place. If there is no activity to revive
4219 these configurations before the next release of GDB, the sources will
4220 be permanently REMOVED.
4224 As a compatibility experiment, GDB's source files buildsym.h and
4225 buildsym.c have been converted to pure standard C, no longer
4226 containing any K&R compatibility code. We believe that all systems in
4227 use today either come with a standard C compiler, or have a GCC port
4228 available. If this is not true, please report the affected
4229 configuration to bug-gdb@gnu.org immediately. See the README file for
4230 information about getting a standard C compiler if you don't have one
4235 GDB now uses readline 2.2.
4237 * set extension-language
4239 You can now control the mapping between filename extensions and source
4240 languages by using the `set extension-language' command. For instance,
4241 you can ask GDB to treat .c files as C++ by saying
4242 set extension-language .c c++
4243 The command `info extensions' lists all of the recognized extensions
4244 and their associated languages.
4246 * Setting processor type for PowerPC and RS/6000
4248 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4249 you can use the `set processor' command to specify what variant of the
4250 PowerPC family you are debugging. The command
4254 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4255 following PowerPC and RS6000 variants:
4257 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4258 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4260 403GC IBM PowerPC 403GC
4261 505 Motorola PowerPC 505
4262 860 Motorola PowerPC 860 or 850
4263 601 Motorola PowerPC 601
4264 602 Motorola PowerPC 602
4265 603 Motorola/IBM PowerPC 603 or 603e
4266 604 Motorola PowerPC 604 or 604e
4267 750 Motorola/IBM PowerPC 750 or 750
4269 At the moment, this command just tells GDB what to name the
4270 special-purpose processor registers. Since almost all the affected
4271 registers are inaccessible to user-level programs, this command is
4272 only useful for remote debugging in its present form.
4276 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4277 more extensive support for HP-UX. Added features include shared
4278 library support, kernel threads and hardware watchpoints for 11.00,
4279 support for HP's ANSI C and C++ compilers, and a compatibility mode
4280 for xdb and dbx commands.
4284 HP's donation includes the new concept of catchpoints, which is a
4285 generalization of the old catch command. On HP-UX, it is now possible
4286 to catch exec, fork, and vfork, as well as library loading.
4288 This means that the existing catch command has changed; its first
4289 argument now specifies the type of catch to be set up. See the
4290 output of "help catch" for a list of catchpoint types.
4292 * Debugging across forks
4294 On HP-UX, you can choose which process to debug when a fork() happens
4299 HP has donated a curses-based terminal user interface (TUI). To get
4300 it, build with --enable-tui. Although this can be enabled for any
4301 configuration, at present it only works for native HP debugging.
4303 * GDB remote protocol additions
4305 A new protocol packet 'X' that writes binary data is now available.
4306 Default behavior is to try 'X', then drop back to 'M' if the stub
4307 fails to respond. The settable variable `remotebinarydownload'
4308 allows explicit control over the use of 'X'.
4310 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4311 full 64-bit address. The command
4313 set remoteaddresssize 32
4315 can be used to revert to the old behaviour. For existing remote stubs
4316 the change should not be noticed, as the additional address information
4319 In order to assist in debugging stubs, you may use the maintenance
4320 command `packet' to send any text string to the stub. For instance,
4322 maint packet heythere
4324 sends the packet "$heythere#<checksum>". Note that it is very easy to
4325 disrupt a debugging session by sending the wrong packet at the wrong
4328 The compare-sections command allows you to compare section data on the
4329 target to what is in the executable file without uploading or
4330 downloading, by comparing CRC checksums.
4332 * Tracing can collect general expressions
4334 You may now collect general expressions at tracepoints. This requires
4335 further additions to the target-side stub; see tracepoint.c and
4336 doc/agentexpr.texi for further details.
4338 * mask-address variable for Mips
4340 For Mips targets, you may control the zeroing of the upper 32 bits of
4341 a 64-bit address by entering `set mask-address on'. This is mainly
4342 of interest to users of embedded R4xxx and R5xxx processors.
4344 * Higher serial baud rates
4346 GDB's serial code now allows you to specify baud rates 57600, 115200,
4347 230400, and 460800 baud. (Note that your host system may not be able
4348 to achieve all of these rates.)
4352 The i960 configuration now includes an initial implementation of a
4353 builtin simulator, contributed by Jim Wilson.
4356 *** Changes in GDB-4.17:
4358 * New native configurations
4360 Alpha GNU/Linux alpha*-*-linux*
4361 Unixware 2.x i[3456]86-unixware2*
4362 Irix 6.x mips*-sgi-irix6*
4363 PowerPC GNU/Linux powerpc-*-linux*
4364 PowerPC Solaris powerpcle-*-solaris*
4365 Sparc GNU/Linux sparc-*-linux*
4366 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4370 Argonaut Risc Chip (ARC) arc-*-*
4371 Hitachi H8/300S h8300*-*-*
4372 Matsushita MN10200 w/simulator mn10200-*-*
4373 Matsushita MN10300 w/simulator mn10300-*-*
4374 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4375 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4376 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4377 Mitsubishi D10V w/simulator d10v-*-*
4378 Mitsubishi M32R/D w/simulator m32r-*-elf*
4379 Tsqware Sparclet sparclet-*-*
4380 NEC V850 w/simulator v850-*-*
4382 * New debugging protocols
4384 ARM with RDI protocol arm*-*-*
4385 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4386 DDB and LSI variants of PMON protocol mips*-*-*
4387 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4388 PowerPC with SDS protocol powerpc{,le}-*-eabi
4389 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4393 All configurations can now understand and use the DWARF 2 debugging
4394 format. The choice is automatic, if the symbol file contains DWARF 2
4399 GDB now includes basic Java language support. This support is
4400 only useful with Java compilers that produce native machine code.
4402 * solib-absolute-prefix and solib-search-path
4404 For SunOS and SVR4 shared libraries, you may now set the prefix for
4405 loading absolute shared library symbol files, and the search path for
4406 locating non-absolute shared library symbol files.
4408 * Live range splitting
4410 GDB can now effectively debug code for which GCC has performed live
4411 range splitting as part of its optimization. See gdb/doc/LRS for
4412 more details on the expected format of the stabs information.
4416 GDB's support for the GNU Hurd, including thread debugging, has been
4417 updated to work with current versions of the Hurd.
4421 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4422 instruction set. ARM GDB automatically detects when Thumb
4423 instructions are in use, and adjusts disassembly and backtracing
4428 GDB's MIPS target configurations now handle the MIP16 16-bit
4433 GDB now includes support for overlays; if an executable has been
4434 linked such that multiple sections are based at the same address, GDB
4435 will decide which section to use for symbolic info. You can choose to
4436 control the decision manually, using overlay commands, or implement
4437 additional target-side support and use "overlay load-target" to bring
4438 in the overlay mapping. Do "help overlay" for more detail.
4442 The command "info symbol <address>" displays information about
4443 the symbol at the specified address.
4447 The standard remote protocol now includes an extension that allows
4448 asynchronous collection and display of trace data. This requires
4449 extensive support in the target-side debugging stub. Tracing mode
4450 includes a new interaction mode in GDB and new commands: see the
4451 file tracepoint.c for more details.
4455 Configurations for embedded MIPS now include a simulator contributed
4456 by Cygnus Solutions. The simulator supports the instruction sets
4457 of most MIPS variants.
4461 Sparc configurations may now include the ERC32 simulator contributed
4462 by the European Space Agency. The simulator is not built into
4463 Sparc targets by default; configure with --enable-sim to include it.
4467 For target configurations that may include multiple variants of a
4468 basic architecture (such as MIPS and SH), you may now set the
4469 architecture explicitly. "set arch" sets, "info arch" lists
4470 the possible architectures.
4472 *** Changes in GDB-4.16:
4474 * New native configurations
4476 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4477 M68K NetBSD m68k-*-netbsd*
4478 PowerPC AIX 4.x powerpc-*-aix*
4479 PowerPC MacOS powerpc-*-macos*
4480 PowerPC Windows NT powerpcle-*-cygwin32
4481 RS/6000 AIX 4.x rs6000-*-aix4*
4485 ARM with RDP protocol arm-*-*
4486 I960 with MON960 i960-*-coff
4487 MIPS VxWorks mips*-*-vxworks*
4488 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4489 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4491 Matra Sparclet sparclet-*-*
4495 The powerpc-eabi configuration now includes the PSIM simulator,
4496 contributed by Andrew Cagney, with assistance from Mike Meissner.
4497 PSIM is a very elaborate model of the PowerPC, including not only
4498 basic instruction set execution, but also details of execution unit
4499 performance and I/O hardware. See sim/ppc/README for more details.
4503 GDB now works with Solaris 2.5.
4505 * Windows 95/NT native
4507 GDB will now work as a native debugger on Windows 95 and Windows NT.
4508 To build it from source, you must use the "gnu-win32" environment,
4509 which uses a DLL to emulate enough of Unix to run the GNU tools.
4510 Further information, binaries, and sources are available at
4511 ftp.cygnus.com, under pub/gnu-win32.
4513 * dont-repeat command
4515 If a user-defined command includes the command `dont-repeat', then the
4516 command will not be repeated if the user just types return. This is
4517 useful if the command is time-consuming to run, so that accidental
4518 extra keystrokes don't run the same command many times.
4520 * Send break instead of ^C
4522 The standard remote protocol now includes an option to send a break
4523 rather than a ^C to the target in order to interrupt it. By default,
4524 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4526 * Remote protocol timeout
4528 The standard remote protocol includes a new variable `remotetimeout'
4529 that allows you to set the number of seconds before GDB gives up trying
4530 to read from the target. The default value is 2.
4532 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4534 By default GDB will automatically keep track of objects as they are
4535 loaded and unloaded by the dynamic linker. By using the command `set
4536 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4537 when shared library events occur, thus allowing you to set breakpoints
4538 in shared libraries which are explicitly loaded by the inferior.
4540 Note this feature does not work on hpux8. On hpux9 you must link
4541 /usr/lib/end.o into your program. This feature should work
4542 automatically on hpux10.
4544 * Irix 5.x hardware watchpoint support
4546 Irix 5 configurations now support the use of hardware watchpoints.
4548 * Mips protocol "SYN garbage limit"
4550 When debugging a Mips target using the `target mips' protocol, you
4551 may set the number of characters that GDB will ignore by setting
4552 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4553 every character. The default value is 1050.
4555 * Recording and replaying remote debug sessions
4557 If you set `remotelogfile' to the name of a file, gdb will write to it
4558 a recording of a remote debug session. This recording may then be
4559 replayed back to gdb using "gdbreplay". See gdbserver/README for
4560 details. This is useful when you have a problem with GDB while doing
4561 remote debugging; you can make a recording of the session and send it
4562 to someone else, who can then recreate the problem.
4564 * Speedups for remote debugging
4566 GDB includes speedups for downloading and stepping MIPS systems using
4567 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4568 and more efficient S-record downloading.
4570 * Memory use reductions and statistics collection
4572 GDB now uses less memory and reports statistics about memory usage.
4573 Try the `maint print statistics' command, for example.
4575 *** Changes in GDB-4.15:
4577 * Psymtabs for XCOFF
4579 The symbol reader for AIX GDB now uses partial symbol tables. This
4580 can greatly improve startup time, especially for large executables.
4582 * Remote targets use caching
4584 Remote targets now use a data cache to speed up communication with the
4585 remote side. The data cache could lead to incorrect results because
4586 it doesn't know about volatile variables, thus making it impossible to
4587 debug targets which use memory mapped I/O devices. `set remotecache
4588 off' turns the the data cache off.
4590 * Remote targets may have threads
4592 The standard remote protocol now includes support for multiple threads
4593 in the target system, using new protocol commands 'H' and 'T'. See
4594 gdb/remote.c for details.
4598 If GDB is configured with `--enable-netrom', then it will include
4599 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4600 acts as though it is a bank of ROM on the target board, but you can
4601 write into it over the network. GDB's support consists only of
4602 support for fast loading into the emulated ROM; to debug, you must use
4603 another protocol, such as standard remote protocol. The usual
4604 sequence is something like
4606 target nrom <netrom-hostname>
4608 target remote <netrom-hostname>:1235
4612 GDB now includes support for the Apple Macintosh, as a host only. It
4613 may be run as either an MPW tool or as a standalone application, and
4614 it can debug through the serial port. All the usual GDB commands are
4615 available, but to the target command, you must supply "serial" as the
4616 device type instead of "/dev/ttyXX". See mpw-README in the main
4617 directory for more information on how to build. The MPW configuration
4618 scripts */mpw-config.in support only a few targets, and only the
4619 mips-idt-ecoff target has been tested.
4623 GDB configuration now uses autoconf. This is not user-visible,
4624 but does simplify configuration and building.
4628 GDB now supports hpux10.
4630 *** Changes in GDB-4.14:
4632 * New native configurations
4634 x86 FreeBSD i[345]86-*-freebsd
4635 x86 NetBSD i[345]86-*-netbsd
4636 NS32k NetBSD ns32k-*-netbsd
4637 Sparc NetBSD sparc-*-netbsd
4641 A29K VxWorks a29k-*-vxworks
4642 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4643 CPU32 EST-300 emulator m68*-*-est*
4644 PowerPC ELF powerpc-*-elf
4647 * Alpha OSF/1 support for procfs
4649 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4650 possible to attach to running processes. As the mounting of the /proc
4651 filesystem is optional on the Alpha, GDB automatically determines
4652 the availability of /proc during startup. This can lead to problems
4653 if /proc is unmounted after GDB has been started.
4655 * Arguments to user-defined commands
4657 User commands may accept up to 10 arguments separated by whitespace.
4658 Arguments are accessed within the user command via $arg0..$arg9. A
4661 print $arg0 + $arg1 + $arg2
4663 To execute the command use:
4666 Defines the command "adder" which prints the sum of its three arguments.
4667 Note the arguments are text substitutions, so they may reference variables,
4668 use complex expressions, or even perform inferior function calls.
4670 * New `if' and `while' commands
4672 This makes it possible to write more sophisticated user-defined
4673 commands. Both commands take a single argument, which is the
4674 expression to evaluate, and must be followed by the commands to
4675 execute, one per line, if the expression is nonzero, the list being
4676 terminated by the word `end'. The `if' command list may include an
4677 `else' word, which causes the following commands to be executed only
4678 if the expression is zero.
4680 * Fortran source language mode
4682 GDB now includes partial support for Fortran 77. It will recognize
4683 Fortran programs and can evaluate a subset of Fortran expressions, but
4684 variables and functions may not be handled correctly. GDB will work
4685 with G77, but does not yet know much about symbols emitted by other
4688 * Better HPUX support
4690 Most debugging facilities now work on dynamic executables for HPPAs
4691 running hpux9 or later. You can attach to running dynamically linked
4692 processes, but by default the dynamic libraries will be read-only, so
4693 for instance you won't be able to put breakpoints in them. To change
4694 that behavior do the following before running the program:
4700 This will cause the libraries to be mapped private and read-write.
4701 To revert to the normal behavior, do this:
4707 You cannot set breakpoints or examine data in the library until after
4708 the library is loaded if the function/data symbols do not have
4711 GDB can now also read debug symbols produced by the HP C compiler on
4712 HPPAs (sorry, no C++, Fortran or 68k support).
4714 * Target byte order now dynamically selectable
4716 You can choose which byte order to use with a target system, via the
4717 commands "set endian big" and "set endian little", and you can see the
4718 current setting by using "show endian". You can also give the command
4719 "set endian auto", in which case GDB will use the byte order
4720 associated with the executable. Currently, only embedded MIPS
4721 configurations support dynamic selection of target byte order.
4723 * New DOS host serial code
4725 This version uses DPMI interrupts to handle buffered I/O, so you
4726 no longer need to run asynctsr when debugging boards connected to
4729 *** Changes in GDB-4.13:
4731 * New "complete" command
4733 This lists all the possible completions for the rest of the line, if it
4734 were to be given as a command itself. This is intended for use by emacs.
4736 * Trailing space optional in prompt
4738 "set prompt" no longer adds a space for you after the prompt you set. This
4739 allows you to set a prompt which ends in a space or one that does not.
4741 * Breakpoint hit counts
4743 "info break" now displays a count of the number of times the breakpoint
4744 has been hit. This is especially useful in conjunction with "ignore"; you
4745 can ignore a large number of breakpoint hits, look at the breakpoint info
4746 to see how many times the breakpoint was hit, then run again, ignoring one
4747 less than that number, and this will get you quickly to the last hit of
4750 * Ability to stop printing at NULL character
4752 "set print null-stop" will cause GDB to stop printing the characters of
4753 an array when the first NULL is encountered. This is useful when large
4754 arrays actually contain only short strings.
4756 * Shared library breakpoints
4758 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4759 breakpoints in shared libraries before the executable is run.
4761 * Hardware watchpoints
4763 There is a new hardware breakpoint for the watch command for sparclite
4764 targets. See gdb/sparclite/hw_breakpoint.note.
4766 Hardware watchpoints are also now supported under GNU/Linux.
4770 Annotations have been added. These are for use with graphical interfaces,
4771 and are still experimental. Currently only gdba.el uses these.
4773 * Improved Irix 5 support
4775 GDB now works properly with Irix 5.2.
4777 * Improved HPPA support
4779 GDB now works properly with the latest GCC and GAS.
4781 * New native configurations
4783 Sequent PTX4 i[34]86-sequent-ptx4
4784 HPPA running OSF/1 hppa*-*-osf*
4785 Atari TT running SVR4 m68*-*-sysv4*
4786 RS/6000 LynxOS rs6000-*-lynxos*
4790 OS/9000 i[34]86-*-os9k
4791 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4794 * Hitachi SH7000 and E7000-PC ICE support
4796 There is now support for communicating with the Hitachi E7000-PC ICE.
4797 This is available automatically when GDB is configured for the SH.
4801 As usual, a variety of small fixes and improvements, both generic
4802 and configuration-specific. See the ChangeLog for more detail.
4804 *** Changes in GDB-4.12:
4806 * Irix 5 is now supported
4810 GDB-4.12 on the HPPA has a number of changes which make it unable
4811 to debug the output from the currently released versions of GCC and
4812 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4813 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4814 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4817 *** Changes in GDB-4.11:
4819 * User visible changes:
4823 The "set remotedebug" option is now consistent between the mips remote
4824 target, remote targets using the gdb-specific protocol, UDI (AMD's
4825 debug protocol for the 29k) and the 88k bug monitor. It is now an
4826 integer specifying a debug level (normally 0 or 1, but 2 means more
4827 debugging info for the mips target).
4829 * DEC Alpha native support
4831 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4832 debug info, but GDB works fairly well with the DEC compiler and should
4833 work with a future GCC release. See the README file for a few
4834 Alpha-specific notes.
4836 * Preliminary thread implementation
4838 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4840 * LynxOS native and target support for 386
4842 This release has been hosted on LynxOS 2.2, and also can be configured
4843 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4846 * Improvements in C++ mangling/demangling.
4848 This release has much better g++ debugging, specifically in name
4849 mangling/demangling, virtual function calls, print virtual table,
4850 call methods, ...etc.
4852 *** Changes in GDB-4.10:
4854 * User visible changes:
4856 Remote debugging using the GDB-specific (`target remote') protocol now
4857 supports the `load' command. This is only useful if you have some
4858 other way of getting the stub to the target system, and you can put it
4859 somewhere in memory where it won't get clobbered by the download.
4861 Filename completion now works.
4863 When run under emacs mode, the "info line" command now causes the
4864 arrow to point to the line specified. Also, "info line" prints
4865 addresses in symbolic form (as well as hex).
4867 All vxworks based targets now support a user settable option, called
4868 vxworks-timeout. This option represents the number of seconds gdb
4869 should wait for responses to rpc's. You might want to use this if
4870 your vxworks target is, perhaps, a slow software simulator or happens
4871 to be on the far side of a thin network line.
4875 This release contains support for using a DEC alpha as a GDB host for
4876 cross debugging. Native alpha debugging is not supported yet.
4879 *** Changes in GDB-4.9:
4883 This is the first GDB release which is accompanied by a matching testsuite.
4884 The testsuite requires installation of dejagnu, which should be available
4885 via ftp from most sites that carry GNU software.
4889 'Cfront' style demangling has had its name changed to 'ARM' style, to
4890 emphasize that it was written from the specifications in the C++ Annotated
4891 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4892 disclaimers, it still generated too much confusion with users attempting to
4893 use gdb with AT&T cfront.
4897 GDB now uses a standard remote interface to a simulator library.
4898 So far, the library contains simulators for the Zilog Z8001/2, the
4899 Hitachi H8/300, H8/500 and Super-H.
4901 * New targets supported
4903 H8/300 simulator h8300-hitachi-hms or h8300hms
4904 H8/500 simulator h8500-hitachi-hms or h8500hms
4905 SH simulator sh-hitachi-hms or sh
4906 Z8000 simulator z8k-zilog-none or z8ksim
4907 IDT MIPS board over serial line mips-idt-ecoff
4909 Cross-debugging to GO32 targets is supported. It requires a custom
4910 version of the i386-stub.c module which is integrated with the
4911 GO32 memory extender.
4913 * New remote protocols
4915 MIPS remote debugging protocol.
4917 * New source languages supported
4919 This version includes preliminary support for Chill, a Pascal like language
4920 used by telecommunications companies. Chill support is also being integrated
4921 into the GNU compiler, but we don't know when it will be publically available.
4924 *** Changes in GDB-4.8:
4926 * HP Precision Architecture supported
4928 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4929 version of this support was available as a set of patches from the
4930 University of Utah. GDB does not support debugging of programs
4931 compiled with the HP compiler, because HP will not document their file
4932 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4933 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4935 Many problems in the preliminary version have been fixed.
4937 * Faster and better demangling
4939 We have improved template demangling and fixed numerous bugs in the GNU style
4940 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4941 character types (wchar_t) are now supported. Demangling of each symbol is now
4942 only done once, and is cached when the symbol table for a file is read in.
4943 This results in a small increase in memory usage for C programs, a moderate
4944 increase in memory usage for C++ programs, and a fantastic speedup in
4947 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4948 from the specifications in the Annotated Reference Manual, which AT&T's
4949 compiler does not actually implement.
4951 * G++ multiple inheritance compiler problem
4953 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4954 inheritance lattices was reworked to properly discover ambiguities. We
4955 recently found an example which causes this new algorithm to fail in a
4956 very subtle way, producing bad debug information for those classes.
4957 The file 'gcc.patch' (in this directory) can be applied to gcc to
4958 circumvent the problem. A future GCC release will contain a complete
4961 The previous G++ debug info problem (mentioned below for the gdb-4.7
4962 release) is fixed in gcc version 2.3.2.
4964 * Improved configure script
4966 The `configure' script will now attempt to guess your system type if
4967 you don't supply a host system type. The old scheme of supplying a
4968 host system triplet is preferable over using this. All the magic is
4969 done in the new `config.guess' script. Examine it for details.
4971 We have also brought our configure script much more in line with the FSF's
4972 version. It now supports the --with-xxx options. In particular,
4973 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4974 The resulting GDB will not be able to read arbitrary object file formats --
4975 only the format ``expected'' to be used on the configured target system.
4976 We hope to make this the default in a future release.
4978 * Documentation improvements
4980 There's new internal documentation on how to modify GDB, and how to
4981 produce clean changes to the code. We implore people to read it
4982 before submitting changes.
4984 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4985 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4986 `info' files are also provided. To build `info' files from scratch,
4987 you will need the latest `makeinfo' release, which will be available in
4988 a future texinfo-X.Y release.
4990 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4991 We're not sure exactly which versions have this problem, but it has
4992 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4993 or better. If that isn't possible, there is a patch in
4994 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4995 around this problem.
4999 GDB now supports array constants that can be used in expressions typed in by
5000 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5001 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5004 The new directory `gdb/sparclite' contains a program that demonstrates
5005 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5007 * New native hosts supported
5009 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5010 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5012 * New targets supported
5014 AMD 29k family via UDI a29k-amd-udi or udi29k
5016 * New file formats supported
5018 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5019 HPUX core files, and SCO 3.2v2 core files.
5023 Attaching to processes now works again; thanks for the many bug reports.
5025 We have also stomped on a bunch of core dumps caused by
5026 printf_filtered("%s") problems.
5028 We eliminated a copyright problem on the rpc and ptrace header files
5029 for VxWorks, which was discovered at the last minute during the 4.7
5030 release. You should now be able to build a VxWorks GDB.
5032 You can now interrupt gdb while an attached process is running. This
5033 will cause the attached process to stop, and give control back to GDB.
5035 We fixed problems caused by using too many file descriptors
5036 for reading symbols from object files and libraries. This was
5037 especially a problem for programs that used many (~100) shared
5040 The `step' command now only enters a subroutine if there is line number
5041 information for the subroutine. Otherwise it acts like the `next'
5042 command. Previously, `step' would enter subroutines if there was
5043 any debugging information about the routine. This avoids problems
5044 when using `cc -g1' on MIPS machines.
5046 * Internal improvements
5048 GDB's internal interfaces have been improved to make it easier to support
5049 debugging of multiple languages in the future.
5051 GDB now uses a common structure for symbol information internally.
5052 Minimal symbols (derived from linkage symbols in object files), partial
5053 symbols (from a quick scan of debug information), and full symbols
5054 contain a common subset of information, making it easier to write
5055 shared code that handles any of them.
5057 * New command line options
5059 We now accept --silent as an alias for --quiet.
5063 The memory-mapped-malloc library is now licensed under the GNU Library
5064 General Public License.
5066 *** Changes in GDB-4.7:
5068 * Host/native/target split
5070 GDB has had some major internal surgery to untangle the support for
5071 hosts and remote targets. Now, when you configure GDB for a remote
5072 target, it will no longer load in all of the support for debugging
5073 local programs on the host. When fully completed and tested, this will
5074 ensure that arbitrary host/target combinations are possible.
5076 The primary conceptual shift is to separate the non-portable code in
5077 GDB into three categories. Host specific code is required any time GDB
5078 is compiled on that host, regardless of the target. Target specific
5079 code relates to the peculiarities of the target, but can be compiled on
5080 any host. Native specific code is everything else: it can only be
5081 built when the host and target are the same system. Child process
5082 handling and core file support are two common `native' examples.
5084 GDB's use of /proc for controlling Unix child processes is now cleaner.
5085 It has been split out into a single module under the `target_ops' vector,
5086 plus two native-dependent functions for each system that uses /proc.
5088 * New hosts supported
5090 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5091 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5092 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5094 * New targets supported
5096 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5097 68030 and CPU32 m68030-*-*, m68332-*-*
5099 * New native hosts supported
5101 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5102 (386bsd is not well tested yet)
5103 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5105 * New file formats supported
5107 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5108 supports reading of `a.out.adobe' object files, which are an a.out
5109 format extended with minimal information about multiple sections.
5113 `show copying' is the same as the old `info copying'.
5114 `show warranty' is the same as `info warrantee'.
5115 These were renamed for consistency. The old commands continue to work.
5117 `info handle' is a new alias for `info signals'.
5119 You can now define pre-command hooks, which attach arbitrary command
5120 scripts to any command. The commands in the hook will be executed
5121 prior to the user's command. You can also create a hook which will be
5122 executed whenever the program stops. See gdb.texinfo.
5126 We now deal with Cfront style name mangling, and can even extract type
5127 info from mangled symbols. GDB can automatically figure out which
5128 symbol mangling style your C++ compiler uses.
5130 Calling of methods and virtual functions has been improved as well.
5134 The crash that occured when debugging Sun Ansi-C compiled binaries is
5135 fixed. This was due to mishandling of the extra N_SO stabs output
5138 We also finally got Ultrix 4.2 running in house, and fixed core file
5139 support, with help from a dozen people on the net.
5141 John M. Farrell discovered that the reason that single-stepping was so
5142 slow on all of the Mips based platforms (primarily SGI and DEC) was
5143 that we were trying to demangle and lookup a symbol used for internal
5144 purposes on every instruction that was being stepped through. Changing
5145 the name of that symbol so that it couldn't be mistaken for a C++
5146 mangled symbol sped things up a great deal.
5148 Rich Pixley sped up symbol lookups in general by getting much smarter
5149 about when C++ symbol mangling is necessary. This should make symbol
5150 completion (TAB on the command line) much faster. It's not as fast as
5151 we'd like, but it's significantly faster than gdb-4.6.
5155 A new user controllable variable 'call_scratch_address' can
5156 specify the location of a scratch area to be used when GDB
5157 calls a function in the target. This is necessary because the
5158 usual method of putting the scratch area on the stack does not work
5159 in systems that have separate instruction and data spaces.
5161 We integrated changes to support the 29k UDI (Universal Debugger
5162 Interface), but discovered at the last minute that we didn't have all
5163 of the appropriate copyright paperwork. We are working with AMD to
5164 resolve this, and hope to have it available soon.
5168 We have sped up the remote serial line protocol, especially for targets
5169 with lots of registers. It now supports a new `expedited status' ('T')
5170 message which can be used in place of the existing 'S' status message.
5171 This allows the remote stub to send only the registers that GDB
5172 needs to make a quick decision about single-stepping or conditional
5173 breakpoints, eliminating the need to fetch the entire register set for
5174 each instruction being stepped through.
5176 The GDB remote serial protocol now implements a write-through cache for
5177 registers, only re-reading the registers if the target has run.
5179 There is also a new remote serial stub for SPARC processors. You can
5180 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5181 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5182 processor with a serial port.
5186 Configure.in files have become much easier to read and modify. A new
5187 `table driven' format makes it more obvious what configurations are
5188 supported, and what files each one uses.
5192 There is a new opcodes library which will eventually contain all of the
5193 disassembly routines and opcode tables. At present, it only contains
5194 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5195 disassembler (binutils/objdump) to share these routines.
5197 The libiberty library is now copylefted under the GNU Library General
5198 Public License. This allows more liberal use, and was done so libg++
5199 can use it. This makes no difference to GDB, since the Library License
5200 grants all the rights from the General Public License.
5204 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5205 reference to the stabs symbol info used by the debugger. It is (as far
5206 as we know) the only published document on this fascinating topic. We
5207 encourage you to read it, compare it to the stabs information on your
5208 system, and send improvements on the document in general (to
5209 bug-gdb@prep.ai.mit.edu).
5211 And, of course, many bugs have been fixed.
5214 *** Changes in GDB-4.6:
5216 * Better support for C++ function names
5218 GDB now accepts as input the "demangled form" of C++ overloaded function
5219 names and member function names, and can do command completion on such names
5220 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5221 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5222 Make use of command completion, it is your friend.
5224 GDB also now accepts a variety of C++ mangled symbol formats. They are
5225 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5226 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5227 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5228 for the list of formats.
5230 * G++ symbol mangling problem
5232 Recent versions of gcc have a bug in how they emit debugging information for
5233 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5234 directory) can be applied to gcc to fix the problem. Alternatively, if you
5235 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5236 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5237 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5240 * New 'maintenance' command
5242 All of the commands related to hacking GDB internals have been moved out of
5243 the main command set, and now live behind the 'maintenance' command. This
5244 can also be abbreviated as 'mt'. The following changes were made:
5246 dump-me -> maintenance dump-me
5247 info all-breakpoints -> maintenance info breakpoints
5248 printmsyms -> maintenance print msyms
5249 printobjfiles -> maintenance print objfiles
5250 printpsyms -> maintenance print psymbols
5251 printsyms -> maintenance print symbols
5253 The following commands are new:
5255 maintenance demangle Call internal GDB demangler routine to
5256 demangle a C++ link name and prints the result.
5257 maintenance print type Print a type chain for a given symbol
5259 * Change to .gdbinit file processing
5261 We now read the $HOME/.gdbinit file before processing the argv arguments
5262 (e.g. reading symbol files or core files). This allows global parameters to
5263 be set, which will apply during the symbol reading. The ./.gdbinit is still
5264 read after argv processing.
5266 * New hosts supported
5268 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5270 GNU/Linux support i386-unknown-linux or linux
5272 We are also including code to support the HP/PA running BSD and HPUX. This
5273 is almost guaranteed not to work, as we didn't have time to test or build it
5274 for this release. We are including it so that the more adventurous (or
5275 masochistic) of you can play with it. We also had major problems with the
5276 fact that the compiler that we got from HP doesn't support the -g option.
5279 * New targets supported
5281 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5283 * More smarts about finding #include files
5285 GDB now remembers the compilation directory for all include files, and for
5286 all files from which C is generated (like yacc and lex sources). This
5287 greatly improves GDB's ability to find yacc/lex sources, and include files,
5288 especially if you are debugging your program from a directory different from
5289 the one that contains your sources.
5291 We also fixed a bug which caused difficulty with listing and setting
5292 breakpoints in include files which contain C code. (In the past, you had to
5293 try twice in order to list an include file that you hadn't looked at before.)
5295 * Interesting infernals change
5297 GDB now deals with arbitrary numbers of sections, where the symbols for each
5298 section must be relocated relative to that section's landing place in the
5299 target's address space. This work was needed to support ELF with embedded
5300 stabs used by Solaris-2.0.
5302 * Bug fixes (of course!)
5304 There have been loads of fixes for the following things:
5305 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5306 i960, stabs, DOS(GO32), procfs, etc...
5308 See the ChangeLog for details.
5310 *** Changes in GDB-4.5:
5312 * New machines supported (host and target)
5314 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5316 SGI Irix-4.x mips-sgi-irix4 or iris4
5318 * New malloc package
5320 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5321 Mmalloc is capable of handling mutiple heaps of memory. It is also
5322 capable of saving a heap to a file, and then mapping it back in later.
5323 This can be used to greatly speedup the startup of GDB by using a
5324 pre-parsed symbol table which lives in a mmalloc managed heap. For
5325 more details, please read mmalloc/mmalloc.texi.
5329 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5330 'help info proc' for details.
5332 * MIPS ecoff symbol table format
5334 The code that reads MIPS symbol table format is now supported on all hosts.
5335 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5338 * File name changes for MS-DOS
5340 Many files in the config directories have been renamed to make it easier to
5341 support GDB on MS-DOSe systems (which have very restrictive file name
5342 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5343 environment) is close to working but has some remaining problems. Note
5344 that debugging of DOS programs is not supported, due to limitations
5345 in the ``operating system'', but it can be used to host cross-debugging.
5347 * Cross byte order fixes
5349 Many fixes have been made to support cross debugging of Sparc and MIPS
5350 targets from hosts whose byte order differs.
5352 * New -mapped and -readnow options
5354 If memory-mapped files are available on your system through the 'mmap'
5355 system call, you can use the -mapped option on the `file' or
5356 `symbol-file' commands to cause GDB to write the symbols from your
5357 program into a reusable file. If the program you are debugging is
5358 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5359 Future GDB debugging sessions will notice the presence of this file,
5360 and will quickly map in symbol information from it, rather than reading
5361 the symbol table from the executable program. Using the '-mapped'
5362 option in a GDB `file' or `symbol-file' command has the same effect as
5363 starting GDB with the '-mapped' command-line option.
5365 You can cause GDB to read the entire symbol table immediately by using
5366 the '-readnow' option with any of the commands that load symbol table
5367 information (or on the GDB command line). This makes the command
5368 slower, but makes future operations faster.
5370 The -mapped and -readnow options are typically combined in order to
5371 build a `fred.syms' file that contains complete symbol information.
5372 A simple GDB invocation to do nothing but build a `.syms' file for future
5375 gdb -batch -nx -mapped -readnow programname
5377 The `.syms' file is specific to the host machine on which GDB is run.
5378 It holds an exact image of GDB's internal symbol table. It cannot be
5379 shared across multiple host platforms.
5381 * longjmp() handling
5383 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5384 siglongjmp() without losing control. This feature has not yet been ported to
5385 all systems. It currently works on many 386 platforms, all MIPS-based
5386 platforms (SGI, DECstation, etc), and Sun3/4.
5390 Preliminary work has been put in to support the new Solaris OS from Sun. At
5391 this time, it can control and debug processes, but it is not capable of
5396 As always, many many bug fixes. The major areas were with g++, and mipsread.
5397 People using the MIPS-based platforms should experience fewer mysterious
5398 crashes and trashed symbol tables.
5400 *** Changes in GDB-4.4:
5402 * New machines supported (host and target)
5404 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5406 BSD Reno on Vax vax-dec-bsd
5407 Ultrix on Vax vax-dec-ultrix
5409 * New machines supported (target)
5411 AMD 29000 embedded, using EBMON a29k-none-none
5415 GDB continues to improve its handling of C++. `References' work better.
5416 The demangler has also been improved, and now deals with symbols mangled as
5417 per the Annotated C++ Reference Guide.
5419 GDB also now handles `stabs' symbol information embedded in MIPS
5420 `ecoff' symbol tables. Since the ecoff format was not easily
5421 extensible to handle new languages such as C++, this appeared to be a
5422 good way to put C++ debugging info into MIPS binaries. This option
5423 will be supported in the GNU C compiler, version 2, when it is
5426 * New features for SVR4
5428 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5429 shared libraries. Debugging dynamically linked programs should present
5430 only minor differences from debugging statically linked programs.
5432 The `info proc' command will print out information about any process
5433 on an SVR4 system (including the one you are debugging). At the moment,
5434 it prints the address mappings of the process.
5436 If you bring up GDB on another SVR4 system, please send mail to
5437 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5439 * Better dynamic linking support in SunOS
5441 Reading symbols from shared libraries which contain debugging symbols
5442 now works properly. However, there remain issues such as automatic
5443 skipping of `transfer vector' code during function calls, which
5444 make it harder to debug code in a shared library, than to debug the
5445 same code linked statically.
5449 GDB is now using the latest `getopt' routines from the FSF. This
5450 version accepts the -- prefix for options with long names. GDB will
5451 continue to accept the old forms (-option and +option) as well.
5452 Various single letter abbreviations for options have been explicity
5453 added to the option table so that they won't get overshadowed in the
5454 future by other options that begin with the same letter.
5458 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5459 Many assorted bugs have been handled. Many more remain to be handled.
5460 See the various ChangeLog files (primarily in gdb and bfd) for details.
5463 *** Changes in GDB-4.3:
5465 * New machines supported (host and target)
5467 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5468 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5469 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5471 * Almost SCO Unix support
5473 We had hoped to support:
5474 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5475 (except for core file support), but we discovered very late in the release
5476 that it has problems with process groups that render gdb unusable. Sorry
5477 about that. I encourage people to fix it and post the fixes.
5479 * Preliminary ELF and DWARF support
5481 GDB can read ELF object files on System V Release 4, and can handle
5482 debugging records for C, in DWARF format, in ELF files. This support
5483 is preliminary. If you bring up GDB on another SVR4 system, please
5484 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5489 GDB now uses the latest `readline' library. One user-visible change
5490 is that two tabs will list possible command completions, which previously
5491 required typing M-? (meta-question mark, or ESC ?).
5495 The `stepi' bug that many of you noticed has been squashed.
5496 Many bugs in C++ have been handled. Many more remain to be handled.
5497 See the various ChangeLog files (primarily in gdb and bfd) for details.
5499 * State of the MIPS world (in case you wondered):
5501 GDB can understand the symbol tables emitted by the compilers
5502 supplied by most vendors of MIPS-based machines, including DEC. These
5503 symbol tables are in a format that essentially nobody else uses.
5505 Some versions of gcc come with an assembler post-processor called
5506 mips-tfile. This program is required if you want to do source-level
5507 debugging of gcc-compiled programs. I believe FSF does not ship
5508 mips-tfile with gcc version 1, but it will eventually come with gcc
5511 Debugging of g++ output remains a problem. g++ version 1.xx does not
5512 really support it at all. (If you're lucky, you should be able to get
5513 line numbers and stack traces to work, but no parameters or local
5514 variables.) With some work it should be possible to improve the
5517 When gcc version 2 is released, you will have somewhat better luck.
5518 However, even then you will get confusing results for inheritance and
5521 We will eventually provide full debugging of g++ output on
5522 DECstations. This will probably involve some kind of stabs-in-ecoff
5523 encapulation, but the details have not been worked out yet.
5526 *** Changes in GDB-4.2:
5528 * Improved configuration
5530 Only one copy of `configure' exists now, and it is not self-modifying.
5531 Porting BFD is simpler.
5535 The `step' and `next' commands now only stop at the first instruction
5536 of a source line. This prevents the multiple stops that used to occur
5537 in switch statements, for-loops, etc. `Step' continues to stop if a
5538 function that has debugging information is called within the line.
5542 Lots of small bugs fixed. More remain.
5544 * New host supported (not target)
5546 Intel 386 PC clone running Mach i386-none-mach
5549 *** Changes in GDB-4.1:
5551 * Multiple source language support
5553 GDB now has internal scaffolding to handle several source languages.
5554 It determines the type of each source file from its filename extension,
5555 and will switch expression parsing and number formatting to match the
5556 language of the function in the currently selected stack frame.
5557 You can also specifically set the language to be used, with
5558 `set language c' or `set language modula-2'.
5562 GDB now has preliminary support for the GNU Modula-2 compiler,
5563 currently under development at the State University of New York at
5564 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5565 continue through the fall of 1991 and into 1992.
5567 Other Modula-2 compilers are currently not supported, and attempting to
5568 debug programs compiled with them will likely result in an error as the
5569 symbol table is read. Feel free to work on it, though!
5571 There are hooks in GDB for strict type checking and range checking,
5572 in the `Modula-2 philosophy', but they do not currently work.
5576 GDB can now write to executable and core files (e.g. patch
5577 a variable's value). You must turn this switch on, specify
5578 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5579 by assigning a new value to a variable. Modifications take
5582 * Automatic SunOS shared library reading
5584 When you run your program, GDB automatically determines where its
5585 shared libraries (if any) have been loaded, and reads their symbols.
5586 The `share' command is no longer needed. This also works when
5587 examining core files.
5591 You can specify the number of lines that the `list' command shows.
5594 * New machines supported (host and target)
5596 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5597 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5598 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5600 * New hosts supported (not targets)
5602 IBM RT/PC: romp-ibm-aix or rtpc
5604 * New targets supported (not hosts)
5606 AMD 29000 embedded with COFF a29k-none-coff
5607 AMD 29000 embedded with a.out a29k-none-aout
5608 Ultracomputer remote kernel debug a29k-nyu-kern
5610 * New remote interfaces
5616 *** Changes in GDB-4.0:
5620 Wide output is wrapped at good places to make the output more readable.
5622 Gdb now supports cross-debugging from a host machine of one type to a
5623 target machine of another type. Communication with the target system
5624 is over serial lines. The ``target'' command handles connecting to the
5625 remote system; the ``load'' command will download a program into the
5626 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5627 also supports debugging of realtime processes running under VxWorks,
5628 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5629 stub on the target system.
5631 New CPUs supported include the AMD 29000 and Intel 960.
5633 GDB now reads object files and symbol tables via a ``binary file''
5634 library, which allows a single copy of GDB to debug programs of multiple
5635 object file types such as a.out and coff.
5637 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5638 refcard.dvi and refcard.ps are available to format it).
5641 * Control-Variable user interface simplified
5643 All variables that control the operation of the debugger can be set
5644 by the ``set'' command, and displayed by the ``show'' command.
5646 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5647 ``Show prompt'' produces the response:
5648 Gdb's prompt is new-gdb=>.
5650 What follows are the NEW set commands. The command ``help set'' will
5651 print a complete list of old and new set commands. ``help set FOO''
5652 will give a longer description of the variable FOO. ``show'' will show
5653 all of the variable descriptions and their current settings.
5655 confirm on/off: Enables warning questions for operations that are
5656 hard to recover from, e.g. rerunning the program while
5657 it is already running. Default is ON.
5659 editing on/off: Enables EMACS style command line editing
5660 of input. Previous lines can be recalled with
5661 control-P, the current line can be edited with control-B,
5662 you can search for commands with control-R, etc.
5665 history filename NAME: NAME is where the gdb command history
5666 will be stored. The default is .gdb_history,
5667 or the value of the environment variable
5670 history size N: The size, in commands, of the command history. The
5671 default is 256, or the value of the environment variable
5674 history save on/off: If this value is set to ON, the history file will
5675 be saved after exiting gdb. If set to OFF, the
5676 file will not be saved. The default is OFF.
5678 history expansion on/off: If this value is set to ON, then csh-like
5679 history expansion will be performed on
5680 command line input. The default is OFF.
5682 radix N: Sets the default radix for input and output. It can be set
5683 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5684 in the current radix, so "set radix 10" is always a no-op.
5686 height N: This integer value is the number of lines on a page. Default
5687 is 24, the current `stty rows'' setting, or the ``li#''
5688 setting from the termcap entry matching the environment
5691 width N: This integer value is the number of characters on a line.
5692 Default is 80, the current `stty cols'' setting, or the ``co#''
5693 setting from the termcap entry matching the environment
5696 Note: ``set screensize'' is obsolete. Use ``set height'' and
5697 ``set width'' instead.
5699 print address on/off: Print memory addresses in various command displays,
5700 such as stack traces and structure values. Gdb looks
5701 more ``symbolic'' if you turn this off; it looks more
5702 ``machine level'' with it on. Default is ON.
5704 print array on/off: Prettyprint arrays. New convenient format! Default
5707 print demangle on/off: Print C++ symbols in "source" form if on,
5710 print asm-demangle on/off: Same, for assembler level printouts
5713 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5716 * Support for Epoch Environment.
5718 The epoch environment is a version of Emacs v18 with windowing. One
5719 new command, ``inspect'', is identical to ``print'', except that if you
5720 are running in the epoch environment, the value is printed in its own
5724 * Support for Shared Libraries
5726 GDB can now debug programs and core files that use SunOS shared libraries.
5727 Symbols from a shared library cannot be referenced
5728 before the shared library has been linked with the program (this
5729 happens after you type ``run'' and before the function main() is entered).
5730 At any time after this linking (including when examining core files
5731 from dynamically linked programs), gdb reads the symbols from each
5732 shared library when you type the ``sharedlibrary'' command.
5733 It can be abbreviated ``share''.
5735 sharedlibrary REGEXP: Load shared object library symbols for files
5736 matching a unix regular expression. No argument
5737 indicates to load symbols for all shared libraries.
5739 info sharedlibrary: Status of loaded shared libraries.
5744 A watchpoint stops execution of a program whenever the value of an
5745 expression changes. Checking for this slows down execution
5746 tremendously whenever you are in the scope of the expression, but is
5747 quite useful for catching tough ``bit-spreader'' or pointer misuse
5748 problems. Some machines such as the 386 have hardware for doing this
5749 more quickly, and future versions of gdb will use this hardware.
5751 watch EXP: Set a watchpoint (breakpoint) for an expression.
5753 info watchpoints: Information about your watchpoints.
5755 delete N: Deletes watchpoint number N (same as breakpoints).
5756 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5757 enable N: Re-enables watchpoint number N (same as breakpoints).
5760 * C++ multiple inheritance
5762 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5765 * C++ exception handling
5767 Gdb now supports limited C++ exception handling. Besides the existing
5768 ability to breakpoint on an exception handler, gdb can breakpoint on
5769 the raising of an exception (before the stack is peeled back to the
5772 catch FOO: If there is a FOO exception handler in the dynamic scope,
5773 set a breakpoint to catch exceptions which may be raised there.
5774 Multiple exceptions (``catch foo bar baz'') may be caught.
5776 info catch: Lists all exceptions which may be caught in the
5777 current stack frame.
5780 * Minor command changes
5782 The command ``call func (arg, arg, ...)'' now acts like the print
5783 command, except it does not print or save a value if the function's result
5784 is void. This is similar to dbx usage.
5786 The ``up'' and ``down'' commands now always print the frame they end up
5787 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5788 frames without printing.
5790 * New directory command
5792 'dir' now adds directories to the FRONT of the source search path.
5793 The path starts off empty. Source files that contain debug information
5794 about the directory in which they were compiled can be found even
5795 with an empty path; Sun CC and GCC include this information. If GDB can't
5796 find your source file in the current directory, type "dir .".
5798 * Configuring GDB for compilation
5800 For normal use, type ``./configure host''. See README or gdb.texinfo
5803 GDB now handles cross debugging. If you are remotely debugging between
5804 two different machines, type ``./configure host -target=targ''.
5805 Host is the machine where GDB will run; targ is the machine
5806 where the program that you are debugging will run.