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.
10 ** You can now access frame registers from Python scripts.
11 ** New attribute 'producer' for gdb.Symtab objects.
13 * New Python-based convenience functions:
15 ** $_caller_is(name [, number_of_frames])
16 ** $_caller_matches(regexp [, number_of_frames])
17 ** $_any_caller_is(name [, number_of_frames])
18 ** $_any_caller_matches(regexp [, number_of_frames])
22 queue-signal signal-name-or-number
23 Queue a signal to be delivered to the thread when it is resumed.
25 * On resume, GDB now always passes the signal the program had stopped
26 for to the thread the signal was sent to, even if the user changed
27 threads before resuming. Previously GDB would often (but not
28 always) deliver the signal to the thread that happens to be current
31 * Conversely, the "signal" command now consistently delivers the
32 requested signal to the current thread. GDB now asks for
33 confirmation if the program had stopped for a signal and the user
34 switched threads meanwhile.
36 *** Changes in GDB 7.8
38 * New command line options
41 This is an alias for the --data-directory option.
43 * GDB supports printing and modifying of variable length automatic arrays
44 as specified in ISO C99.
46 * The ARM simulator now supports instruction level tracing
47 with or without disassembly.
51 GDB now has support for scripting using Guile. Whether this is
52 available is determined at configure time.
53 Guile version 2.0 or greater is required.
54 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
56 * New commands (for set/show, see "New options" below)
60 Invoke CODE by passing it to the Guile interpreter.
64 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
66 info auto-load guile-scripts [regexp]
67 Print the list of automatically loaded Guile scripts.
69 * The source command is now capable of sourcing Guile scripts.
70 This feature is dependent on the debugger being built with Guile support.
74 set print symbol-loading (off|brief|full)
75 show print symbol-loading
76 Control whether to print informational messages when loading symbol
77 information for a file. The default is "full", but when debugging
78 programs with large numbers of shared libraries the amount of output
81 set guile print-stack (none|message|full)
82 show guile print-stack
83 Show a stack trace when an error is encountered in a Guile script.
85 set auto-load guile-scripts (on|off)
86 show auto-load guile-scripts
87 Control auto-loading of Guile script files.
89 maint ada set ignore-descriptive-types (on|off)
90 maint ada show ignore-descriptive-types
91 Control whether the debugger should ignore descriptive types in Ada
92 programs. The default is not to ignore the descriptive types. See
93 the user manual for more details on descriptive types and the intended
96 set auto-connect-native-target
98 Control whether GDB is allowed to automatically connect to the
99 native target for the run, attach, etc. commands when not connected
100 to any target yet. See also "target native" below.
102 set record btrace replay-memory-access (read-only|read-write)
103 show record btrace replay-memory-access
104 Control what memory accesses are allowed during replay.
106 maint set target-async (on|off)
107 maint show target-async
108 This controls whether GDB targets operate in syncronous or
109 asyncronous mode. Normally the default is asyncronous, if it is
110 available; but this can be changed to more easily debug problems
111 occurring only in syncronous mode.
113 set mi-async (on|off)
115 Control whether MI asynchronous mode is preferred. This supersedes
116 "set target-async" of previous GDB versions.
118 * "set target-async" is deprecated as a CLI option and is now an alias
119 for "set mi-async" (only puts MI into async mode).
121 * Background execution commands (e.g., "c&", "s&", etc.) are now
122 possible ``out of the box'' if the target supports them. Previously
123 the user would need to explicitly enable the possibility with the
124 "set target-async on" command.
126 * New features in the GDB remote stub, GDBserver
128 ** New option --debug-format=option1[,option2,...] allows one to add
129 additional text to each output. At present only timestamps
130 are supported: --debug-format=timestamps.
131 Timestamps can also be turned on with the
132 "monitor set debug-format timestamps" command from GDB.
134 * The 'record instruction-history' command now starts counting instructions
135 at one. This also affects the instruction ranges reported by the
136 'record function-call-history' command when given the /i modifier.
138 * The command 'record function-call-history' supports a new modifier '/c' to
139 indent the function names based on their call stack depth.
140 The fields for the '/i' and '/l' modifier have been reordered.
141 The source line range is now prefixed with 'at'.
142 The instruction range is now prefixed with 'inst'.
143 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
144 "record instruction-history" and "list" commands.
146 * The ranges given as arguments to the 'record function-call-history' and
147 'record instruction-history' commands are now inclusive.
149 * The btrace record target now supports the 'record goto' command.
150 For locations inside the execution trace, the back trace is computed
151 based on the information stored in the execution trace.
153 * The btrace record target supports limited reverse execution and replay.
154 The target does not record data and therefore does not allow reading
157 * The "catch syscall" command now works on s390*-linux* targets.
159 * The "compare-sections" command is no longer specific to target
160 remote. It now works with all targets.
162 * All native targets are now consistently called "native".
163 Consequently, the "target child", "target GNU", "target djgpp",
164 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
165 commands have been replaced with "target native". The QNX/NTO port
166 leaves the "procfs" target in place and adds a "native" target for
167 consistency with other ports. The impact on users should be minimal
168 as these commands previously either throwed an error, or were
169 no-ops. The target's name is visible in the output of the following
170 commands: "help target", "info target", "info files", "maint print
173 * The "target native" command now connects to the native target. This
174 can be used to launch native programs even when "set
175 auto-connect-native-target" is set to off.
177 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.
179 * Support for Intel(R) AVX-512 registers on GNU/Linux.
180 Support displaying and modifying Intel(R) AVX-512 registers
181 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
185 qXfer:btrace:read's annex
186 The qXfer:btrace:read packet supports a new annex 'delta' to read
187 branch trace incrementally.
191 ** Valid Python operations on gdb.Value objects representing
192 structs/classes invoke the corresponding overloaded operators if
194 ** New `Xmethods' feature in the Python API. Xmethods are
195 additional methods or replacements for existing methods of a C++
196 class. This feature is useful for those cases where a method
197 defined in C++ source code could be inlined or optimized out by
198 the compiler, making it unavailable to GDB.
201 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
203 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
204 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
205 its alias "share", instead.
207 * The commands "set remotebaud" and "show remotebaud" are no longer
208 supported. Use "set serial baud" and "show serial baud" (respectively)
213 ** A new option "-gdb-set mi-async" replaces "-gdb-set
214 target-async". The latter is left as a deprecated alias of the
215 former for backward compatibility. If the target supports it,
216 CLI background execution commands are now always possible by
217 default, independently of whether the frontend stated a
218 preference for asynchronous execution with "-gdb-set mi-async".
219 Previously "-gdb-set target-async off" affected both MI execution
220 commands and CLI execution commands.
222 *** Changes in GDB 7.7
224 * Improved support for process record-replay and reverse debugging on
225 arm*-linux* targets. Support for thumb32 and syscall instruction
226 recording has been added.
228 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
230 * GDB now supports Fission DWP file format version 2.
231 http://gcc.gnu.org/wiki/DebugFission
233 * New convenience function "$_isvoid", to check whether an expression
234 is void. A void expression is an expression where the type of the
235 result is "void". For example, some convenience variables may be
236 "void" when evaluated (e.g., "$_exitcode" before the execution of
237 the program being debugged; or an undefined convenience variable).
238 Another example, when calling a function whose return type is
241 * The "maintenance print objfiles" command now takes an optional regexp.
243 * The "catch syscall" command now works on arm*-linux* targets.
245 * GDB now consistently shows "<not saved>" when printing values of
246 registers the debug info indicates have not been saved in the frame
247 and there's nowhere to retrieve them from
248 (callee-saved/call-clobbered registers):
253 (gdb) info registers rax
256 Before, the former would print "<optimized out>", and the latter
257 "*value not available*".
259 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
264 ** Frame filters and frame decorators have been added.
265 ** Temporary breakpoints are now supported.
266 ** Line tables representation has been added.
267 ** New attribute 'parent_type' for gdb.Field objects.
268 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
269 ** New attribute 'name' for gdb.Type objects.
273 Nios II ELF nios2*-*-elf
274 Nios II GNU/Linux nios2*-*-linux
275 Texas Instruments MSP430 msp430*-*-elf
277 * Removed native configurations
279 Support for these a.out NetBSD and OpenBSD obsolete configurations has
280 been removed. ELF variants of these configurations are kept supported.
282 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
283 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
284 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
285 i[34567]86-*-openbsd3.[0-3]
286 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
287 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
288 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
292 Like "catch throw", but catches a re-thrown exception.
294 Renamed from old "maint check-symtabs".
296 Perform consistency checks on symtabs.
298 Expand symtabs matching an optional regexp.
301 Display the details of GDB configure-time options.
303 maint set|show per-command
304 maint set|show per-command space
305 maint set|show per-command time
306 maint set|show per-command symtab
307 Enable display of per-command gdb resource usage.
309 remove-symbol-file FILENAME
310 remove-symbol-file -a ADDRESS
311 Remove a symbol file added via add-symbol-file. The file to remove
312 can be identified by its filename or by an address that lies within
313 the boundaries of this symbol file in memory.
316 info exceptions REGEXP
317 Display the list of Ada exceptions defined in the program being
318 debugged. If provided, only the exceptions whose names match REGEXP
323 set debug symfile off|on
325 Control display of debugging info regarding reading symbol files and
326 symbol tables within those files
328 set print raw frame-arguments
329 show print raw frame-arguments
330 Set/show whether to print frame arguments in raw mode,
331 disregarding any defined pretty-printers.
333 set remote trace-status-packet
334 show remote trace-status-packet
335 Set/show the use of remote protocol qTStatus packet.
339 Control display of debugging messages related to Nios II targets.
343 Control whether target-assisted range stepping is enabled.
345 set startup-with-shell
346 show startup-with-shell
347 Specifies whether Unix child processes are started via a shell or
352 Use the target memory cache for accesses to the code segment. This
353 improves performance of remote debugging (particularly disassembly).
355 * You can now use a literal value 'unlimited' for options that
356 interpret 0 or -1 as meaning "unlimited". E.g., "set
357 trace-buffer-size unlimited" is now an alias for "set
358 trace-buffer-size -1" and "set height unlimited" is now an alias for
361 * The "set debug symtab-create" debugging option of GDB has been changed to
362 accept a verbosity level. 0 means "off", 1 provides basic debugging
363 output, and values of 2 or greater provides more verbose output.
365 * New command-line options
367 Display the details of GDB configure-time options.
369 * The command 'tsave' can now support new option '-ctf' to save trace
370 buffer in Common Trace Format.
372 * Newly installed $prefix/bin/gcore acts as a shell interface for the
375 * GDB now implements the the C++ 'typeid' operator.
377 * The new convenience variable $_exception holds the exception being
378 thrown or caught at an exception-related catchpoint.
380 * The exception-related catchpoints, like "catch throw", now accept a
381 regular expression which can be used to filter exceptions by type.
383 * The new convenience variable $_exitsignal is automatically set to
384 the terminating signal number when the program being debugged dies
385 due to an uncaught signal.
389 ** All MI commands now accept an optional "--language" option.
390 Support for this feature can be verified by using the "-list-features"
391 command, which should contain "language-option".
393 ** The new command -info-gdb-mi-command allows the user to determine
394 whether a GDB/MI command is supported or not.
396 ** The "^error" result record returned when trying to execute an undefined
397 GDB/MI command now provides a variable named "code" whose content is the
398 "undefined-command" error code. Support for this feature can be verified
399 by using the "-list-features" command, which should contain
400 "undefined-command-error-code".
402 ** The -trace-save MI command can optionally save trace buffer in Common
405 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
407 ** The command -data-list-register-values now accepts an optional
408 "--skip-unavailable" option. When used, only the available registers
411 ** The new command -trace-frame-collected dumps collected variables,
412 computed expressions, tvars, memory and registers in a traceframe.
414 ** The commands -stack-list-locals, -stack-list-arguments and
415 -stack-list-variables now accept an option "--skip-unavailable".
416 When used, only the available locals or arguments are displayed.
418 ** The -exec-run command now accepts an optional "--start" option.
419 When used, the command follows the same semantics as the "start"
420 command, stopping the program's execution at the start of its
421 main subprogram. Support for this feature can be verified using
422 the "-list-features" command, which should contain
423 "exec-run-start-option".
425 ** The new commands -catch-assert and -catch-exceptions insert
426 catchpoints stopping the program when Ada exceptions are raised.
428 ** The new command -info-ada-exceptions provides the equivalent of
429 the new "info exceptions" command.
431 * New system-wide configuration scripts
432 A GDB installation now provides scripts suitable for use as system-wide
433 configuration scripts for the following systems:
437 * GDB now supports target-assigned range stepping with remote targets.
438 This improves the performance of stepping source lines by reducing
439 the number of control packets from/to GDB. See "New remote packets"
442 * GDB now understands the element 'tvar' in the XML traceframe info.
443 It has the id of the collected trace state variables.
445 * On S/390 targets that provide the transactional-execution feature,
446 the program interruption transaction diagnostic block (TDB) is now
447 represented as a number of additional "registers" in GDB.
453 The vCont packet supports a new 'r' action, that tells the remote
454 stub to step through an address range itself, without GDB
455 involvemement at each single-step.
457 qXfer:libraries-svr4:read's annex
458 The previously unused annex of the qXfer:libraries-svr4:read packet
459 is now used to support passing an argument list. The remote stub
460 reports support for this argument list to GDB's qSupported query.
461 The defined arguments are "start" and "prev", used to reduce work
462 necessary for library list updating, resulting in significant
465 * New features in the GDB remote stub, GDBserver
467 ** GDBserver now supports target-assisted range stepping. Currently
468 enabled on x86/x86_64 GNU/Linux targets.
470 ** GDBserver now adds element 'tvar' in the XML in the reply to
471 'qXfer:traceframe-info:read'. It has the id of the collected
472 trace state variables.
474 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
477 * New 'z' formatter for printing and examining memory, this displays the
478 value as hexadecimal zero padded on the left to the size of the type.
480 * GDB can now use Windows x64 unwinding data.
482 * The "set remotebaud" command has been replaced by "set serial baud".
483 Similarly, "show remotebaud" has been replaced by "show serial baud".
484 The "set remotebaud" and "show remotebaud" commands are still available
485 to provide backward compatibility with older versions of GDB.
487 *** Changes in GDB 7.6
489 * Target record has been renamed to record-full.
490 Record/replay is now enabled with the "record full" command.
491 This also affects settings that are associated with full record/replay
492 that have been moved from "set/show record" to "set/show record full":
494 set|show record full insn-number-max
495 set|show record full stop-at-limit
496 set|show record full memory-query
498 * A new record target "record-btrace" has been added. The new target
499 uses hardware support to record the control-flow of a process. It
500 does not support replaying the execution, but it implements the
501 below new commands for investigating the recorded execution log.
502 This new recording method can be enabled using:
506 The "record-btrace" target is only available on Intel Atom processors
507 and requires a Linux kernel 2.6.32 or later.
509 * Two new commands have been added for record/replay to give information
510 about the recorded execution without having to replay the execution.
511 The commands are only supported by "record btrace".
513 record instruction-history prints the execution history at
514 instruction granularity
516 record function-call-history prints the execution history at
519 * New native configurations
521 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
522 FreeBSD/powerpc powerpc*-*-freebsd
523 x86_64/Cygwin x86_64-*-cygwin*
524 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
528 ARM AArch64 aarch64*-*-elf
529 ARM AArch64 GNU/Linux aarch64*-*-linux
530 Lynx 178 PowerPC powerpc-*-lynx*178
531 x86_64/Cygwin x86_64-*-cygwin*
532 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
534 * If the configured location of system.gdbinit file (as given by the
535 --with-system-gdbinit option at configure time) is in the
536 data-directory (as specified by --with-gdb-datadir at configure
537 time) or in one of its subdirectories, then GDB will look for the
538 system-wide init file in the directory specified by the
539 --data-directory command-line option.
541 * New command line options:
543 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
544 other initialization files, unlike -nx which disables all of them.
546 * Removed command line options
548 -epoch This was used by the gdb mode in Epoch, an ancient fork of
551 * The 'ptype' and 'whatis' commands now accept an argument to control
554 * 'info proc' now works on some core files.
558 ** Vectors can be created with gdb.Type.vector.
560 ** Python's atexit.register now works in GDB.
562 ** Types can be pretty-printed via a Python API.
564 ** Python 3 is now supported (in addition to Python 2.4 or later)
566 ** New class gdb.Architecture exposes GDB's internal representation
567 of architecture in the Python API.
569 ** New method Frame.architecture returns the gdb.Architecture object
570 corresponding to the frame's architecture.
572 * New Python-based convenience functions:
574 ** $_memeq(buf1, buf2, length)
575 ** $_streq(str1, str2)
577 ** $_regex(str, regex)
579 * The 'cd' command now defaults to using '~' (the home directory) if not
582 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
583 default for GCC since November 2000.
585 * The command 'forward-search' can now be abbreviated as 'fo'.
587 * The command 'info tracepoints' can now display 'installed on target'
588 or 'not installed on target' for each non-pending location of tracepoint.
590 * New configure options
592 --enable-libmcheck/--disable-libmcheck
593 By default, development versions are built with -lmcheck on hosts
594 that support it, in order to help track memory corruption issues.
595 Release versions, on the other hand, are built without -lmcheck
596 by default. The --enable-libmcheck/--disable-libmcheck configure
597 options allow the user to override that default.
598 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
599 This configure option allows the user to build GDB with
600 libbabeltrace using which GDB can read Common Trace Format data.
602 * New commands (for set/show, see "New options" below)
605 Catch signals. This is similar to "handle", but allows commands and
606 conditions to be attached.
609 List the BFDs known to GDB.
611 python-interactive [command]
613 Start a Python interactive prompt, or evaluate the optional command
614 and print the result of expressions.
617 "py" is a new alias for "python".
619 enable type-printer [name]...
620 disable type-printer [name]...
621 Enable or disable type printers.
625 ** For the Renesas Super-H architecture, the "regs" command has been removed
626 (has been deprecated in GDB 7.5), and "info all-registers" should be used
631 set print type methods (on|off)
632 show print type methods
633 Control whether method declarations are displayed by "ptype".
634 The default is to show them.
636 set print type typedefs (on|off)
637 show print type typedefs
638 Control whether typedef definitions are displayed by "ptype".
639 The default is to show them.
641 set filename-display basename|relative|absolute
642 show filename-display
643 Control the way in which filenames is displayed.
644 The default is "relative", which preserves previous behavior.
646 set trace-buffer-size
647 show trace-buffer-size
648 Request target to change the size of trace buffer.
650 set remote trace-buffer-size-packet auto|on|off
651 show remote trace-buffer-size-packet
652 Control the use of the remote protocol `QTBuffer:size' packet.
656 Control display of debugging messages related to ARM AArch64.
659 set debug coff-pe-read
660 show debug coff-pe-read
661 Control display of debugging messages related to reading of COFF/PE
666 Control display of debugging messages related to Mach-O symbols
669 set debug notification
670 show debug notification
671 Control display of debugging info for async remote notification.
675 ** Command parameter changes are now notified using new async record
676 "=cmd-param-changed".
677 ** Trace frame changes caused by command "tfind" are now notified using
678 new async record "=traceframe-changed".
679 ** The creation, deletion and modification of trace state variables
680 are now notified using new async records "=tsv-created",
681 "=tsv-deleted" and "=tsv-modified".
682 ** The start and stop of process record are now notified using new
683 async record "=record-started" and "=record-stopped".
684 ** Memory changes are now notified using new async record
686 ** The data-disassemble command response will include a "fullname" field
687 containing the absolute file name when source has been requested.
688 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
689 command, to allow pattern filling of memory areas.
690 ** New commands "-catch-load"/"-catch-unload" added for intercepting
691 library load/unload events.
692 ** The response to breakpoint commands and breakpoint async records
693 includes an "installed" field containing a boolean state about each
694 non-pending tracepoint location is whether installed on target or not.
695 ** Output of the "-trace-status" command includes a "trace-file" field
696 containing the name of the trace file being examined. This field is
697 optional, and only present when examining a trace file.
698 ** The "fullname" field is now always present along with the "file" field,
699 even if the file cannot be found by GDB.
701 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
702 You must have the LZMA library available when configuring GDB for this
703 feature to be enabled. For more information, see:
704 http://fedoraproject.org/wiki/Features/MiniDebugInfo
709 Set the size of trace buffer. The remote stub reports support for this
710 packet to gdb's qSupported query.
713 Enable Branch Trace Store (BTS)-based branch tracing for the current
714 thread. The remote stub reports support for this packet to gdb's
718 Disable branch tracing for the current thread. The remote stub reports
719 support for this packet to gdb's qSupported query.
722 Read the traced branches for the current thread. The remote stub
723 reports support for this packet to gdb's qSupported query.
725 *** Changes in GDB 7.5
727 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
728 for more x32 ABI info.
730 * GDB now supports access to MIPS DSP registers on Linux targets.
732 * GDB now supports debugging microMIPS binaries.
734 * The "info os" command on GNU/Linux can now display information on
735 several new classes of objects managed by the operating system:
736 "info os procgroups" lists process groups
737 "info os files" lists file descriptors
738 "info os sockets" lists internet-domain sockets
739 "info os shm" lists shared-memory regions
740 "info os semaphores" lists semaphores
741 "info os msg" lists message queues
742 "info os modules" lists loaded kernel modules
744 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
745 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
746 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
747 options and inspect the probe arguments using the new $_probe_arg family
748 of convenience variables. You can obtain more information about SystemTap
749 in <http://sourceware.org/systemtap/>.
751 * GDB now supports reversible debugging on ARM, it allows you to
752 debug basic ARM and THUMB instructions, and provides
753 record/replay support.
755 * The option "symbol-reloading" has been deleted as it is no longer used.
759 ** GDB commands implemented in Python can now be put in command class
762 ** The "maint set python print-stack on|off" is now deleted.
764 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
765 apply "flag enum"-style pretty-printing to any enum.
767 ** gdb.lookup_symbol can now work when there is no current frame.
769 ** gdb.Symbol now has a 'line' attribute, holding the line number in
770 the source at which the symbol was defined.
772 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
773 method 'value'. The former indicates whether the symbol needs a
774 frame in order to compute its value, and the latter computes the
777 ** A new method 'referenced_value' on gdb.Value objects which can
778 dereference pointer as well as C++ reference values.
780 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
781 which return the global and static blocks (as gdb.Block objects),
782 of the underlying symbol table, respectively.
784 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
785 object associated with a PC value.
787 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
788 of the address range occupied by code for the current source line.
790 * Go language support.
791 GDB now supports debugging programs written in the Go programming
794 * GDBserver now supports stdio connections.
795 E.g. (gdb) target remote | ssh myhost gdbserver - hello
797 * The binary "gdbtui" can no longer be built or installed.
798 Use "gdb -tui" instead.
800 * GDB will now print "flag" enums specially. A flag enum is one where
801 all the enumerator values have no bits in common when pairwise
802 "and"ed. When printing a value whose type is a flag enum, GDB will
803 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
804 (gdb) print (enum E) 3
807 * The filename part of a linespec will now match trailing components
808 of a source file name. For example, "break gcc/expr.c:1000" will
809 now set a breakpoint in build/gcc/expr.c, but not
812 * The "info proc" and "generate-core-file" commands will now also
813 work on remote targets connected to GDBserver on Linux.
815 * The command "info catch" has been removed. It has been disabled
818 * The "catch exception" and "catch assert" commands now accept
819 a condition at the end of the command, much like the "break"
820 command does. For instance:
822 (gdb) catch exception Constraint_Error if Barrier = True
824 Previously, it was possible to add a condition to such catchpoints,
825 but it had to be done as a second step, after the catchpoint had been
826 created, using the "condition" command.
828 * The "info static-tracepoint-marker" command will now also work on
829 native Linux targets with in-process agent.
831 * GDB can now set breakpoints on inlined functions.
833 * The .gdb_index section has been updated to include symbols for
834 inlined functions. GDB will ignore older .gdb_index sections by
835 default, which could cause symbol files to be loaded more slowly
836 until their .gdb_index sections can be recreated. The new command
837 "set use-deprecated-index-sections on" will cause GDB to use any older
838 .gdb_index sections it finds. This will restore performance, but the
839 ability to set breakpoints on inlined functions will be lost in symbol
840 files with older .gdb_index sections.
842 The .gdb_index section has also been updated to record more information
843 about each symbol. This speeds up the "info variables", "info functions"
844 and "info types" commands when used with programs having the .gdb_index
845 section, as well as speeding up debugging with shared libraries using
846 the .gdb_index section.
848 * Ada support for GDB/MI Variable Objects has been added.
850 * GDB can now support 'breakpoint always-inserted mode' in 'record'
855 ** New command -info-os is the MI equivalent of "info os".
857 ** Output logs ("set logging" and related) now include MI output.
861 ** "set use-deprecated-index-sections on|off"
862 "show use-deprecated-index-sections on|off"
863 Controls the use of deprecated .gdb_index sections.
865 ** "catch load" and "catch unload" can be used to stop when a shared
866 library is loaded or unloaded, respectively.
868 ** "enable count" can be used to auto-disable a breakpoint after
871 ** "info vtbl" can be used to show the virtual method tables for
872 C++ and Java objects.
874 ** "explore" and its sub commands "explore value" and "explore type"
875 can be used to recursively explore values and types of
876 expressions. These commands are available only if GDB is
877 configured with '--with-python'.
879 ** "info auto-load" shows status of all kinds of auto-loaded files,
880 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
881 sequences of commands files, "info auto-load python-scripts"
882 shows status of auto-loading Python script files,
883 "info auto-load local-gdbinit" shows status of loading init file
884 (.gdbinit) from current directory and "info auto-load libthread-db" shows
885 status of inferior specific thread debugging shared library loading.
887 ** "info auto-load-scripts", "set auto-load-scripts on|off"
888 and "show auto-load-scripts" commands have been deprecated, use their
889 "info auto-load python-scripts", "set auto-load python-scripts on|off"
890 and "show auto-load python-scripts" counterparts instead.
892 ** "dprintf location,format,args..." creates a dynamic printf, which
893 is basically a breakpoint that does a printf and immediately
894 resumes your program's execution, so it is like a printf that you
895 can insert dynamically at runtime instead of at compiletime.
897 ** "set print symbol"
899 Controls whether GDB attempts to display the symbol, if any,
900 corresponding to addresses it prints. This defaults to "on", but
901 you can set it to "off" to restore GDB's previous behavior.
903 * Deprecated commands
905 ** For the Renesas Super-H architecture, the "regs" command has been
906 deprecated, and "info all-registers" should be used instead.
910 Renesas RL78 rl78-*-elf
911 HP OpenVMS ia64 ia64-hp-openvms*
913 * GDBserver supports evaluation of breakpoint conditions. When
914 support is advertised by GDBserver, GDB may be told to send the
915 breakpoint conditions in bytecode form to GDBserver. GDBserver
916 will only report the breakpoint trigger to GDB when its condition
922 show mips compression
923 Select the compressed ISA encoding used in functions that have no symbol
924 information available. The encoding can be set to either of:
927 and is updated automatically from ELF file flags if available.
929 set breakpoint condition-evaluation
930 show breakpoint condition-evaluation
931 Control whether breakpoint conditions are evaluated by GDB ("host") or by
932 GDBserver ("target"). Default option "auto" chooses the most efficient
934 This option can improve debugger efficiency depending on the speed of the
938 Disable auto-loading globally.
941 Show auto-loading setting of all kinds of auto-loaded files.
943 set auto-load gdb-scripts on|off
944 show auto-load gdb-scripts
945 Control auto-loading of GDB canned sequences of commands files.
947 set auto-load python-scripts on|off
948 show auto-load python-scripts
949 Control auto-loading of Python script files.
951 set auto-load local-gdbinit on|off
952 show auto-load local-gdbinit
953 Control loading of init file (.gdbinit) from current directory.
955 set auto-load libthread-db on|off
956 show auto-load libthread-db
957 Control auto-loading of inferior specific thread debugging shared library.
959 set auto-load scripts-directory <dir1>[:<dir2>...]
960 show auto-load scripts-directory
961 Set a list of directories from which to load auto-loaded scripts.
962 Automatically loaded Python scripts and GDB scripts are located in one
963 of the directories listed by this option.
964 The delimiter (':' above) may differ according to the host platform.
966 set auto-load safe-path <dir1>[:<dir2>...]
967 show auto-load safe-path
968 Set a list of directories from which it is safe to auto-load files.
969 The delimiter (':' above) may differ according to the host platform.
971 set debug auto-load on|off
973 Control display of debugging info for auto-loading the files above.
975 set dprintf-style gdb|call|agent
977 Control the way in which a dynamic printf is performed; "gdb"
978 requests a GDB printf command, while "call" causes dprintf to call a
979 function in the inferior. "agent" requests that the target agent
980 (such as GDBserver) do the printing.
982 set dprintf-function <expr>
983 show dprintf-function
984 set dprintf-channel <expr>
986 Set the function and optional first argument to the call when using
987 the "call" style of dynamic printf.
989 set disconnected-dprintf on|off
990 show disconnected-dprintf
991 Control whether agent-style dynamic printfs continue to be in effect
992 after GDB disconnects.
994 * New configure options
997 Configure default value for the 'set auto-load scripts-directory'
998 setting above. It defaults to '$debugdir:$datadir/auto-load',
999 $debugdir representing global debugging info directories (available
1000 via 'show debug-file-directory') and $datadir representing GDB's data
1001 directory (available via 'show data-directory').
1003 --with-auto-load-safe-path
1004 Configure default value for the 'set auto-load safe-path' setting
1005 above. It defaults to the --with-auto-load-dir setting.
1007 --without-auto-load-safe-path
1008 Set 'set auto-load safe-path' to '/', effectively disabling this
1011 * New remote packets
1013 z0/z1 conditional breakpoints extension
1015 The z0/z1 breakpoint insertion packets have been extended to carry
1016 a list of conditional expressions over to the remote stub depending on the
1017 condition evaluation mode. The use of this extension can be controlled
1018 via the "set remote conditional-breakpoints-packet" command.
1022 Specify the signals which the remote stub may pass to the debugged
1023 program without GDB involvement.
1025 * New command line options
1027 --init-command=FILE, -ix Like --command, -x but execute it
1028 before loading inferior.
1029 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1030 execute it before loading inferior.
1032 *** Changes in GDB 7.4
1034 * GDB now handles ambiguous linespecs more consistently; the existing
1035 FILE:LINE support has been expanded to other types of linespecs. A
1036 breakpoint will now be set on all matching locations in all
1037 inferiors, and locations will be added or removed according to
1040 * GDB now allows you to skip uninteresting functions and files when
1041 stepping with the "skip function" and "skip file" commands.
1043 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1044 and "show remote hardware-watchpoint-length-limit". These allows to
1045 set or show the maximum length limit (in bytes) of a remote
1046 target hardware watchpoint.
1048 This allows e.g. to use "unlimited" hardware watchpoints with the
1049 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1050 watchpoints are slower than real hardware watchpoints but are
1051 significantly faster than gdb software watchpoints.
1055 ** The register_pretty_printer function in module gdb.printing now takes
1056 an optional `replace' argument. If True, the new printer replaces any
1059 ** The "maint set python print-stack on|off" command has been
1060 deprecated and will be deleted in GDB 7.5.
1061 A new command: "set python print-stack none|full|message" has
1062 replaced it. Additionally, the default for "print-stack" is
1063 now "message", which just prints the error message without
1066 ** A prompt substitution hook (prompt_hook) is now available to the
1069 ** A new Python module, gdb.prompt has been added to the GDB Python
1070 modules library. This module provides functionality for
1071 escape sequences in prompts (used by set/show
1072 extended-prompt). These escape sequences are replaced by their
1073 corresponding value.
1075 ** Python commands and convenience-functions located in
1076 'data-directory'/python/gdb/command and
1077 'data-directory'/python/gdb/function are now automatically loaded
1080 ** Blocks now provide four new attributes. global_block and
1081 static_block will return the global and static blocks
1082 respectively. is_static and is_global are boolean attributes
1083 that indicate if the block is one of those two types.
1085 ** Symbols now provide the "type" attribute, the type of the symbol.
1087 ** The "gdb.breakpoint" function has been deprecated in favor of
1090 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1091 of a function. This class is based on the "finish" command
1092 available in the CLI.
1094 ** Type objects for struct and union types now allow access to
1095 the fields using standard Python dictionary (mapping) methods.
1096 For example, "some_type['myfield']" now works, as does
1097 "some_type.items()".
1099 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1102 ** A new function, "deep_items" has been added to the gdb.types
1103 module in the GDB Python modules library. This function returns
1104 an iterator over the fields of a struct or union type. Unlike
1105 the standard Python "iteritems" method, it will recursively traverse
1106 any anonymous fields.
1110 ** "*stopped" events can report several new "reason"s, such as
1113 ** Breakpoint changes are now notified using new async records, like
1114 "=breakpoint-modified".
1116 ** New command -ada-task-info.
1118 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1119 $sdir specifies the default system locations of shared libraries.
1120 $pdir specifies the directory where the libpthread used by the application
1123 GDB no longer looks in $sdir and $pdir after it has searched the directories
1124 mentioned in libthread-db-search-path. If you want to search those
1125 directories, they must be specified in libthread-db-search-path.
1126 The default value of libthread-db-search-path on GNU/Linux and Solaris
1127 systems is now "$sdir:$pdir".
1129 $pdir is not supported by gdbserver, it is currently ignored.
1130 $sdir is supported by gdbserver.
1132 * New configure option --with-iconv-bin.
1133 When using the internationalization support like the one in the GNU C
1134 library, GDB will invoke the "iconv" program to get a list of supported
1135 character sets. If this program lives in a non-standard location, one can
1136 use this option to specify where to find it.
1138 * When natively debugging programs on PowerPC BookE processors running
1139 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1140 watchpoints, which specify a mask in addition to an address to watch.
1141 The mask specifies that some bits of an address (the bits which are
1142 reset in the mask) should be ignored when matching the address accessed
1143 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1144 section in the user manual for more details.
1146 * The new option --once causes GDBserver to stop listening for connections once
1147 the first connection is made. The listening port used by GDBserver will
1148 become available after that.
1150 * New commands "info macros" and "alias" have been added.
1152 * New function parameters suffix @entry specifies value of function parameter
1153 at the time the function got called. Entry values are available only since
1159 "!" is now an alias of the "shell" command.
1160 Note that no space is needed between "!" and SHELL COMMAND.
1164 watch EXPRESSION mask MASK_VALUE
1165 The watch command now supports the mask argument which allows creation
1166 of masked watchpoints, if the current architecture supports this feature.
1168 info auto-load-scripts [REGEXP]
1169 This command was formerly named "maintenance print section-scripts".
1170 It is now generally useful and is no longer a maintenance-only command.
1172 info macro [-all] [--] MACRO
1173 The info macro command has new options `-all' and `--'. The first for
1174 printing all definitions of a macro. The second for explicitly specifying
1175 the end of arguments and the beginning of the macro name in case the macro
1176 name starts with a hyphen.
1178 collect[/s] EXPRESSIONS
1179 The tracepoint collect command now takes an optional modifier "/s"
1180 that directs it to dereference pointer-to-character types and
1181 collect the bytes of memory up to a zero byte. The behavior is
1182 similar to what you see when you use the regular print command on a
1183 string. An optional integer following the "/s" sets a bound on the
1184 number of bytes that will be collected.
1187 The trace start command now interprets any supplied arguments as a
1188 note to be recorded with the trace run, with an effect similar to
1189 setting the variable trace-notes.
1192 The trace stop command now interprets any arguments as a note to be
1193 mentioned along with the tstatus report that the trace was stopped
1194 with a command. The effect is similar to setting the variable
1197 * Tracepoints can now be enabled and disabled at any time after a trace
1198 experiment has been started using the standard "enable" and "disable"
1199 commands. It is now possible to start a trace experiment with no enabled
1200 tracepoints; GDB will display a warning, but will allow the experiment to
1201 begin, assuming that tracepoints will be enabled as needed while the trace
1204 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1205 locations with 4-byte instructions, when they were previously
1206 limited to locations with instructions of 5 bytes or longer.
1210 set debug dwarf2-read
1211 show debug dwarf2-read
1212 Turns on or off display of debugging messages related to reading
1213 DWARF debug info. The default is off.
1215 set debug symtab-create
1216 show debug symtab-create
1217 Turns on or off display of debugging messages related to symbol table
1218 creation. The default is off.
1221 show extended-prompt
1222 Set the GDB prompt, and allow escape sequences to be inserted to
1223 display miscellaneous information (see 'help set extended-prompt'
1224 for the list of sequences). This prompt (and any information
1225 accessed through the escape sequences) is updated every time the
1226 prompt is displayed.
1228 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1229 show print entry-values
1230 Set printing of frame argument values at function entry. In some cases
1231 GDB can determine the value of function argument which was passed by the
1232 function caller, even if the value was modified inside the called function.
1234 set debug entry-values
1235 show debug entry-values
1236 Control display of debugging info for determining frame argument values at
1237 function entry and virtual tail call frames.
1239 set basenames-may-differ
1240 show basenames-may-differ
1241 Set whether a source file may have multiple base names.
1242 (A "base name" is the name of a file with the directory part removed.
1243 Example: The base name of "/home/user/hello.c" is "hello.c".)
1244 If set, GDB will canonicalize file names (e.g., expand symlinks)
1245 before comparing them. Canonicalization is an expensive operation,
1246 but it allows the same file be known by more than one base name.
1247 If not set (the default), all source files are assumed to have just
1248 one base name, and gdb will do file name comparisons more efficiently.
1254 Set a user name and notes for the current and any future trace runs.
1255 This is useful for long-running and/or disconnected traces, to
1256 inform others (or yourself) as to who is running the trace, supply
1257 contact information, or otherwise explain what is going on.
1259 set trace-stop-notes
1260 show trace-stop-notes
1261 Set a note attached to the trace run, that is displayed when the
1262 trace has been stopped by a tstop command. This is useful for
1263 instance as an explanation, if you are stopping a trace run that was
1264 started by someone else.
1266 * New remote packets
1270 Dynamically enable a tracepoint in a started trace experiment.
1274 Dynamically disable a tracepoint in a started trace experiment.
1278 Set the user and notes of the trace run.
1282 Query the current status of a tracepoint.
1286 Query the minimum length of instruction at which a fast tracepoint may
1289 * Dcache size (number of lines) and line-size are now runtime-configurable
1290 via "set dcache line" and "set dcache line-size" commands.
1294 Texas Instruments TMS320C6x tic6x-*-*
1298 Renesas RL78 rl78-*-elf
1300 *** Changes in GDB 7.3.1
1302 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1304 *** Changes in GDB 7.3
1306 * GDB has a new command: "thread find [REGEXP]".
1307 It finds the thread id whose name, target id, or thread extra info
1308 matches the given regular expression.
1310 * The "catch syscall" command now works on mips*-linux* targets.
1312 * The -data-disassemble MI command now supports modes 2 and 3 for
1313 dumping the instruction opcodes.
1315 * New command line options
1317 -data-directory DIR Specify DIR as the "data-directory".
1318 This is mostly for testing purposes.
1320 * The "maint set python auto-load on|off" command has been renamed to
1321 "set auto-load-scripts on|off".
1323 * GDB has a new command: "set directories".
1324 It is like the "dir" command except that it replaces the
1325 source path list instead of augmenting it.
1327 * GDB now understands thread names.
1329 On GNU/Linux, "info threads" will display the thread name as set by
1330 prctl or pthread_setname_np.
1332 There is also a new command, "thread name", which can be used to
1333 assign a name internally for GDB to display.
1336 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1337 has been integrated into GDB.
1341 ** The function gdb.Write now accepts an optional keyword 'stream'.
1342 This keyword, when provided, will direct the output to either
1343 stdout, stderr, or GDB's logging output.
1345 ** Parameters can now be be sub-classed in Python, and in particular
1346 you may implement the get_set_doc and get_show_doc functions.
1347 This improves how Parameter set/show documentation is processed
1348 and allows for more dynamic content.
1350 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1351 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1352 have an is_valid method.
1354 ** Breakpoints can now be sub-classed in Python, and in particular
1355 you may implement a 'stop' function that is executed each time
1356 the inferior reaches that breakpoint.
1358 ** New function gdb.lookup_global_symbol looks up a global symbol.
1360 ** GDB values in Python are now callable if the value represents a
1361 function. For example, if 'some_value' represents a function that
1362 takes two integer parameters and returns a value, you can call
1363 that function like so:
1365 result = some_value (10,20)
1367 ** Module gdb.types has been added.
1368 It contains a collection of utilities for working with gdb.Types objects:
1369 get_basic_type, has_field, make_enum_dict.
1371 ** Module gdb.printing has been added.
1372 It contains utilities for writing and registering pretty-printers.
1373 New classes: PrettyPrinter, SubPrettyPrinter,
1374 RegexpCollectionPrettyPrinter.
1375 New function: register_pretty_printer.
1377 ** New commands "info pretty-printers", "enable pretty-printer" and
1378 "disable pretty-printer" have been added.
1380 ** gdb.parameter("directories") is now available.
1382 ** New function gdb.newest_frame returns the newest frame in the
1385 ** The gdb.InferiorThread class has a new "name" attribute. This
1386 holds the thread's name.
1388 ** Python Support for Inferior events.
1389 Python scripts can add observers to be notified of events
1390 occurring in the process being debugged.
1391 The following events are currently supported:
1392 - gdb.events.cont Continue event.
1393 - gdb.events.exited Inferior exited event.
1394 - gdb.events.stop Signal received, and Breakpoint hit events.
1398 ** GDB now puts template parameters in scope when debugging in an
1399 instantiation. For example, if you have:
1401 template<int X> int func (void) { return X; }
1403 then if you step into func<5>, "print X" will show "5". This
1404 feature requires proper debuginfo support from the compiler; it
1405 was added to GCC 4.5.
1407 ** The motion commands "next", "finish", "until", and "advance" now
1408 work better when exceptions are thrown. In particular, GDB will
1409 no longer lose control of the inferior; instead, the GDB will
1410 stop the inferior at the point at which the exception is caught.
1411 This functionality requires a change in the exception handling
1412 code that was introduced in GCC 4.5.
1414 * GDB now follows GCC's rules on accessing volatile objects when
1415 reading or writing target state during expression evaluation.
1416 One notable difference to prior behavior is that "print x = 0"
1417 no longer generates a read of x; the value of the assignment is
1418 now always taken directly from the value being assigned.
1420 * GDB now has some support for using labels in the program's source in
1421 linespecs. For instance, you can use "advance label" to continue
1422 execution to a label.
1424 * GDB now has support for reading and writing a new .gdb_index
1425 section. This section holds a fast index of DWARF debugging
1426 information and can be used to greatly speed up GDB startup and
1427 operation. See the documentation for `save gdb-index' for details.
1429 * The "watch" command now accepts an optional "-location" argument.
1430 When used, this causes GDB to watch the memory referred to by the
1431 expression. Such a watchpoint is never deleted due to it going out
1434 * GDB now supports thread debugging of core dumps on GNU/Linux.
1436 GDB now activates thread debugging using the libthread_db library
1437 when debugging GNU/Linux core dumps, similarly to when debugging
1438 live processes. As a result, when debugging a core dump file, GDB
1439 is now able to display pthread_t ids of threads. For example, "info
1440 threads" shows the same output as when debugging the process when it
1441 was live. In earlier releases, you'd see something like this:
1444 * 1 LWP 6780 main () at main.c:10
1446 While now you see this:
1449 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1451 It is also now possible to inspect TLS variables when debugging core
1454 When debugging a core dump generated on a machine other than the one
1455 used to run GDB, you may need to point GDB at the correct
1456 libthread_db library with the "set libthread-db-search-path"
1457 command. See the user manual for more details on this command.
1459 * When natively debugging programs on PowerPC BookE processors running
1460 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1461 which stop execution of the inferior whenever it executes an instruction
1462 at any address within the specified range. See the "PowerPC Embedded"
1463 section in the user manual for more details.
1465 * New features in the GDB remote stub, GDBserver
1467 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1468 and i686 LynxOS (version 5.x).
1470 ** GDBserver is now supported on Blackfin Linux.
1472 * New native configurations
1474 ia64 HP-UX ia64-*-hpux*
1478 Analog Devices, Inc. Blackfin Processor bfin-*
1480 * Ada task switching is now supported on sparc-elf targets when
1481 debugging a program using the Ravenscar Profile. For more information,
1482 see the "Tasking Support when using the Ravenscar Profile" section
1483 in the GDB user manual.
1485 * Guile support was removed.
1487 * New features in the GNU simulator
1489 ** The --map-info flag lists all known core mappings.
1491 ** CFI flashes may be simulated via the "cfi" device.
1493 *** Changes in GDB 7.2
1495 * Shared library support for remote targets by default
1497 When GDB is configured for a generic, non-OS specific target, like
1498 for example, --target=arm-eabi or one of the many *-*-elf targets,
1499 GDB now queries remote stubs for loaded shared libraries using the
1500 `qXfer:libraries:read' packet. Previously, shared library support
1501 was always disabled for such configurations.
1505 ** Argument Dependent Lookup (ADL)
1507 In C++ ADL lookup directs function search to the namespaces of its
1508 arguments even if the namespace has not been imported.
1518 Here the compiler will search for `foo' in the namespace of 'b'
1519 and find A::foo. GDB now supports this. This construct is commonly
1520 used in the Standard Template Library for operators.
1522 ** Improved User Defined Operator Support
1524 In addition to member operators, GDB now supports lookup of operators
1525 defined in a namespace and imported with a `using' directive, operators
1526 defined in the global scope, operators imported implicitly from an
1527 anonymous namespace, and the ADL operators mentioned in the previous
1529 GDB now also supports proper overload resolution for all the previously
1530 mentioned flavors of operators.
1532 ** static const class members
1534 Printing of static const class members that are initialized in the
1535 class definition has been fixed.
1537 * Windows Thread Information Block access.
1539 On Windows targets, GDB now supports displaying the Windows Thread
1540 Information Block (TIB) structure. This structure is visible either
1541 by using the new command `info w32 thread-information-block' or, by
1542 dereferencing the new convenience variable named `$_tlb', a
1543 thread-specific pointer to the TIB. This feature is also supported
1544 when remote debugging using GDBserver.
1546 * Static tracepoints
1548 Static tracepoints are calls in the user program into a tracing
1549 library. One such library is a port of the LTTng kernel tracer to
1550 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1551 When debugging with GDBserver, GDB now supports combining the GDB
1552 tracepoint machinery with such libraries. For example: the user can
1553 use GDB to probe a static tracepoint marker (a call from the user
1554 program into the tracing library) with the new "strace" command (see
1555 "New commands" below). This creates a "static tracepoint" in the
1556 breakpoint list, that can be manipulated with the same feature set
1557 as fast and regular tracepoints. E.g., collect registers, local and
1558 global variables, collect trace state variables, and define
1559 tracepoint conditions. In addition, the user can collect extra
1560 static tracepoint marker specific data, by collecting the new
1561 $_sdata internal variable. When analyzing the trace buffer, you can
1562 inspect $_sdata like any other variable available to GDB. For more
1563 information, see the "Tracepoints" chapter in GDB user manual. New
1564 remote packets have been defined to support static tracepoints, see
1565 the "New remote packets" section below.
1567 * Better reconstruction of tracepoints after disconnected tracing
1569 GDB will attempt to download the original source form of tracepoint
1570 definitions when starting a trace run, and then will upload these
1571 upon reconnection to the target, resulting in a more accurate
1572 reconstruction of the tracepoints that are in use on the target.
1576 You can now exercise direct control over the ways that GDB can
1577 affect your program. For instance, you can disallow the setting of
1578 breakpoints, so that the program can run continuously (assuming
1579 non-stop mode). In addition, the "observer" variable is available
1580 to switch all of the different controls; in observer mode, GDB
1581 cannot affect the target's behavior at all, which is useful for
1582 tasks like diagnosing live systems in the field.
1584 * The new convenience variable $_thread holds the number of the
1587 * New remote packets
1591 Return the address of the Windows Thread Information Block of a given thread.
1595 In response to several of the tracepoint packets, the target may now
1596 also respond with a number of intermediate `qRelocInsn' request
1597 packets before the final result packet, to have GDB handle
1598 relocating an instruction to execute at a different address. This
1599 is particularly useful for stubs that support fast tracepoints. GDB
1600 reports support for this feature in the qSupported packet.
1604 List static tracepoint markers in the target program.
1608 List static tracepoint markers at a given address in the target
1611 qXfer:statictrace:read
1613 Read the static trace data collected (by a `collect $_sdata'
1614 tracepoint action). The remote stub reports support for this packet
1615 to gdb's qSupported query.
1619 Send the current settings of GDB's permission flags.
1623 Send part of the source (textual) form of a tracepoint definition,
1624 which includes location, conditional, and action list.
1626 * The source command now accepts a -s option to force searching for the
1627 script in the source search path even if the script name specifies
1630 * New features in the GDB remote stub, GDBserver
1632 - GDBserver now support tracepoints (including fast tracepoints, and
1633 static tracepoints). The feature is currently supported by the
1634 i386-linux and amd64-linux builds. See the "Tracepoints support
1635 in gdbserver" section in the manual for more information.
1637 GDBserver JIT compiles the tracepoint's conditional agent
1638 expression bytecode into native code whenever possible for low
1639 overhead dynamic tracepoints conditionals. For such tracepoints,
1640 an expression that examines program state is evaluated when the
1641 tracepoint is reached, in order to determine whether to capture
1642 trace data. If the condition is simple and false, processing the
1643 tracepoint finishes very quickly and no data is gathered.
1645 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1646 for static tracepoints support.
1648 - GDBserver now supports x86_64 Windows 64-bit debugging.
1650 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1651 it understands register description.
1653 * The --batch flag now disables pagination and queries.
1655 * X86 general purpose registers
1657 GDB now supports reading/writing byte, word and double-word x86
1658 general purpose registers directly. This means you can use, say,
1659 $ah or $ax to refer, respectively, to the byte register AH and
1660 16-bit word register AX that are actually portions of the 32-bit
1661 register EAX or 64-bit register RAX.
1663 * The `commands' command now accepts a range of breakpoints to modify.
1664 A plain `commands' following a command that creates multiple
1665 breakpoints affects all the breakpoints set by that command. This
1666 applies to breakpoints set by `rbreak', and also applies when a
1667 single `break' command creates multiple breakpoints (e.g.,
1668 breakpoints on overloaded c++ functions).
1670 * The `rbreak' command now accepts a filename specification as part of
1671 its argument, limiting the functions selected by the regex to those
1672 in the specified file.
1674 * Support for remote debugging Windows and SymbianOS shared libraries
1675 from Unix hosts has been improved. Non Windows GDB builds now can
1676 understand target reported file names that follow MS-DOS based file
1677 system semantics, such as file names that include drive letters and
1678 use the backslash character as directory separator. This makes it
1679 possible to transparently use the "set sysroot" and "set
1680 solib-search-path" on Unix hosts to point as host copies of the
1681 target's shared libraries. See the new command "set
1682 target-file-system-kind" described below, and the "Commands to
1683 specify files" section in the user manual for more information.
1687 eval template, expressions...
1688 Convert the values of one or more expressions under the control
1689 of the string template to a command line, and call it.
1691 set target-file-system-kind unix|dos-based|auto
1692 show target-file-system-kind
1693 Set or show the assumed file system kind for target reported file
1696 save breakpoints <filename>
1697 Save all current breakpoint definitions to a file suitable for use
1698 in a later debugging session. To read the saved breakpoint
1699 definitions, use the `source' command.
1701 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1704 info static-tracepoint-markers
1705 Display information about static tracepoint markers in the target.
1707 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1708 Define a static tracepoint by probing a marker at the given
1709 function, line, address, or marker ID.
1713 Enable and disable observer mode.
1715 set may-write-registers on|off
1716 set may-write-memory on|off
1717 set may-insert-breakpoints on|off
1718 set may-insert-tracepoints on|off
1719 set may-insert-fast-tracepoints on|off
1720 set may-interrupt on|off
1721 Set individual permissions for GDB effects on the target. Note that
1722 some of these settings can have undesirable or surprising
1723 consequences, particularly when changed in the middle of a session.
1724 For instance, disabling the writing of memory can prevent
1725 breakpoints from being inserted, cause single-stepping to fail, or
1726 even crash your program, if you disable after breakpoints have been
1727 inserted. However, GDB should not crash.
1729 set record memory-query on|off
1730 show record memory-query
1731 Control whether to stop the inferior if memory changes caused
1732 by an instruction cannot be recorded.
1737 The disassemble command now supports "start,+length" form of two arguments.
1741 ** GDB now provides a new directory location, called the python directory,
1742 where Python scripts written for GDB can be installed. The location
1743 of that directory is <data-directory>/python, where <data-directory>
1744 is the GDB data directory. For more details, see section `Scripting
1745 GDB using Python' in the manual.
1747 ** The GDB Python API now has access to breakpoints, symbols, symbol
1748 tables, program spaces, inferiors, threads and frame's code blocks.
1749 Additionally, GDB Parameters can now be created from the API, and
1750 manipulated via set/show in the CLI.
1752 ** New functions gdb.target_charset, gdb.target_wide_charset,
1753 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1755 ** New exception gdb.GdbError.
1757 ** Pretty-printers are now also looked up in the current program space.
1759 ** Pretty-printers can now be individually enabled and disabled.
1761 ** GDB now looks for names of Python scripts to auto-load in a
1762 special section named `.debug_gdb_scripts', in addition to looking
1763 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1765 * Tracepoint actions were unified with breakpoint commands. In particular,
1766 there are no longer differences in "info break" output for breakpoints and
1767 tracepoints and the "commands" command can be used for both tracepoints and
1768 regular breakpoints.
1772 ARM Symbian arm*-*-symbianelf*
1774 * D language support.
1775 GDB now supports debugging programs written in the D programming
1778 * GDB now supports the extended ptrace interface for PowerPC which is
1779 available since Linux kernel version 2.6.34. This automatically enables
1780 any hardware breakpoints and additional hardware watchpoints available in
1781 the processor. The old ptrace interface exposes just one hardware
1782 watchpoint and no hardware breakpoints.
1784 * GDB is now able to use the Data Value Compare (DVC) register available on
1785 embedded PowerPC processors to implement in hardware simple watchpoint
1786 conditions of the form:
1788 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1790 This works in native GDB running on Linux kernels with the extended ptrace
1791 interface mentioned above.
1793 *** Changes in GDB 7.1
1797 ** Namespace Support
1799 GDB now supports importing of namespaces in C++. This enables the
1800 user to inspect variables from imported namespaces. Support for
1801 namepace aliasing has also been added. So, if a namespace is
1802 aliased in the current scope (e.g. namepace C=A; ) the user can
1803 print variables using the alias (e.g. (gdb) print C::x).
1807 All known bugs relating to the printing of virtual base class were
1808 fixed. It is now possible to call overloaded static methods using a
1813 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1814 and reinterpret_cast<> are now handled by the C++ expression parser.
1818 Xilinx MicroBlaze microblaze-*-*
1823 Xilinx MicroBlaze microblaze
1826 * Multi-program debugging.
1828 GDB now has support for multi-program (a.k.a. multi-executable or
1829 multi-exec) debugging. This allows for debugging multiple inferiors
1830 simultaneously each running a different program under the same GDB
1831 session. See "Debugging Multiple Inferiors and Programs" in the
1832 manual for more information. This implied some user visible changes
1833 in the multi-inferior support. For example, "info inferiors" now
1834 lists inferiors that are not running yet or that have exited
1835 already. See also "New commands" and "New options" below.
1837 * New tracing features
1839 GDB's tracepoint facility now includes several new features:
1841 ** Trace state variables
1843 GDB tracepoints now include support for trace state variables, which
1844 are variables managed by the target agent during a tracing
1845 experiment. They are useful for tracepoints that trigger each
1846 other, so for instance one tracepoint can count hits in a variable,
1847 and then a second tracepoint has a condition that is true when the
1848 count reaches a particular value. Trace state variables share the
1849 $-syntax of GDB convenience variables, and can appear in both
1850 tracepoint actions and condition expressions. Use the "tvariable"
1851 command to create, and "info tvariables" to view; see "Trace State
1852 Variables" in the manual for more detail.
1856 GDB now includes an option for defining fast tracepoints, which
1857 targets may implement more efficiently, such as by installing a jump
1858 into the target agent rather than a trap instruction. The resulting
1859 speedup can be by two orders of magnitude or more, although the
1860 tradeoff is that some program locations on some target architectures
1861 might not allow fast tracepoint installation, for instance if the
1862 instruction to be replaced is shorter than the jump. To request a
1863 fast tracepoint, use the "ftrace" command, with syntax identical to
1864 the regular trace command.
1866 ** Disconnected tracing
1868 It is now possible to detach GDB from the target while it is running
1869 a trace experiment, then reconnect later to see how the experiment
1870 is going. In addition, a new variable disconnected-tracing lets you
1871 tell the target agent whether to continue running a trace if the
1872 connection is lost unexpectedly.
1876 GDB now has the ability to save the trace buffer into a file, and
1877 then use that file as a target, similarly to you can do with
1878 corefiles. You can select trace frames, print data that was
1879 collected in them, and use tstatus to display the state of the
1880 tracing run at the moment that it was saved. To create a trace
1881 file, use "tsave <filename>", and to use it, do "target tfile
1884 ** Circular trace buffer
1886 You can ask the target agent to handle the trace buffer as a
1887 circular buffer, discarding the oldest trace frames to make room for
1888 newer ones, by setting circular-trace-buffer to on. This feature may
1889 not be available for all target agents.
1894 The disassemble command, when invoked with two arguments, now requires
1895 the arguments to be comma-separated.
1898 The info variables command now displays variable definitions. Files
1899 which only declare a variable are not shown.
1902 The source command is now capable of sourcing Python scripts.
1903 This feature is dependent on the debugger being build with Python
1906 Related to this enhancement is also the introduction of a new command
1907 "set script-extension" (see below).
1909 * New commands (for set/show, see "New options" below)
1911 record save [<FILENAME>]
1912 Save a file (in core file format) containing the process record
1913 execution log for replay debugging at a later time.
1915 record restore <FILENAME>
1916 Restore the process record execution log that was saved at an
1917 earlier time, for replay debugging.
1919 add-inferior [-copies <N>] [-exec <FILENAME>]
1922 clone-inferior [-copies <N>] [ID]
1923 Make a new inferior ready to execute the same program another
1924 inferior has loaded.
1929 maint info program-spaces
1930 List the program spaces loaded into GDB.
1932 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1933 show remote interrupt-sequence
1934 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1935 as the sequence to the remote target in order to interrupt the execution.
1936 Ctrl-C is a default. Some system prefers BREAK which is high level of
1937 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1938 Magic SysRq g. It is BREAK signal and character 'g'.
1940 set remote interrupt-on-connect [on | off]
1941 show remote interrupt-on-connect
1942 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1943 remote target when gdb connects to it. This is needed when you debug
1946 set remotebreak [on | off]
1948 Deprecated. Use "set/show remote interrupt-sequence" instead.
1950 tvariable $NAME [ = EXP ]
1951 Create or modify a trace state variable.
1954 List trace state variables and their values.
1956 delete tvariable $NAME ...
1957 Delete one or more trace state variables.
1960 Evaluate the given expressions without collecting anything into the
1961 trace buffer. (Valid in tracepoint actions only.)
1963 ftrace FN / FILE:LINE / *ADDR
1964 Define a fast tracepoint at the given function, line, or address.
1966 * New expression syntax
1968 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1969 GDB now parses 0b101010 identically with 42.
1973 set follow-exec-mode new|same
1974 show follow-exec-mode
1975 Control whether GDB reuses the same inferior across an exec call or
1976 creates a new one. This is useful to be able to restart the old
1977 executable after the inferior having done an exec call.
1979 set default-collect EXPR, ...
1980 show default-collect
1981 Define a list of expressions to be collected at each tracepoint.
1982 This is a useful way to ensure essential items are not overlooked,
1983 such as registers or a critical global variable.
1985 set disconnected-tracing
1986 show disconnected-tracing
1987 If set to 1, the target is instructed to continue tracing if it
1988 loses its connection to GDB. If 0, the target is to stop tracing
1991 set circular-trace-buffer
1992 show circular-trace-buffer
1993 If set to on, the target is instructed to use a circular trace buffer
1994 and discard the oldest trace frames instead of stopping the trace due
1995 to a full trace buffer. If set to off, the trace stops when the buffer
1996 fills up. Some targets may not support this.
1998 set script-extension off|soft|strict
1999 show script-extension
2000 If set to "off", the debugger does not perform any script language
2001 recognition, and all sourced files are assumed to be GDB scripts.
2002 If set to "soft" (the default), files are sourced according to
2003 filename extension, falling back to GDB scripts if the first
2005 If set to "strict", files are sourced according to filename extension.
2007 set ada trust-PAD-over-XVS on|off
2008 show ada trust-PAD-over-XVS
2009 If off, activate a workaround against a bug in the debugging information
2010 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2011 the GCC sources for more information about the GNAT encoding and
2012 PAD types in particular). It is always safe to set this option to
2013 off, but this introduces a slight performance penalty. The default
2016 * Python API Improvements
2018 ** GDB provides the new class gdb.LazyString. This is useful in
2019 some pretty-printing cases. The new method gdb.Value.lazy_string
2020 provides a simple way to create objects of this type.
2022 ** The fields returned by gdb.Type.fields now have an
2023 `is_base_class' attribute.
2025 ** The new method gdb.Type.range returns the range of an array type.
2027 ** The new method gdb.parse_and_eval can be used to parse and
2028 evaluate an expression.
2030 * New remote packets
2033 Define a trace state variable.
2036 Get the current value of a trace state variable.
2039 Set desired tracing behavior upon disconnection.
2042 Set the trace buffer to be linear or circular.
2045 Get data about the tracepoints currently in use.
2049 Process record now works correctly with hardware watchpoints.
2051 Multiple bug fixes have been made to the mips-irix port, making it
2052 much more reliable. In particular:
2053 - Debugging threaded applications is now possible again. Previously,
2054 GDB would hang while starting the program, or while waiting for
2055 the program to stop at a breakpoint.
2056 - Attaching to a running process no longer hangs.
2057 - An error occurring while loading a core file has been fixed.
2058 - Changing the value of the PC register now works again. This fixes
2059 problems observed when using the "jump" command, or when calling
2060 a function from GDB, or even when assigning a new value to $pc.
2061 - With the "finish" and "return" commands, the return value for functions
2062 returning a small array is now correctly printed.
2063 - It is now possible to break on shared library code which gets executed
2064 during a shared library init phase (code executed while executing
2065 their .init section). Previously, the breakpoint would have no effect.
2066 - GDB is now able to backtrace through the signal handler for
2067 non-threaded programs.
2069 PIE (Position Independent Executable) programs debugging is now supported.
2070 This includes debugging execution of PIC (Position Independent Code) shared
2071 libraries although for that, it should be possible to run such libraries as an
2074 *** Changes in GDB 7.0
2076 * GDB now has an interface for JIT compilation. Applications that
2077 dynamically generate code can create symbol files in memory and register
2078 them with GDB. For users, the feature should work transparently, and
2079 for JIT developers, the interface is documented in the GDB manual in the
2080 "JIT Compilation Interface" chapter.
2082 * Tracepoints may now be conditional. The syntax is as for
2083 breakpoints; either an "if" clause appended to the "trace" command,
2084 or the "condition" command is available. GDB sends the condition to
2085 the target for evaluation using the same bytecode format as is used
2086 for tracepoint actions.
2088 * The disassemble command now supports: an optional /r modifier, print the
2089 raw instructions in hex as well as in symbolic form, and an optional /m
2090 modifier to print mixed source+assembly.
2092 * Process record and replay
2094 In a architecture environment that supports ``process record and
2095 replay'', ``process record and replay'' target can record a log of
2096 the process execution, and replay it with both forward and reverse
2099 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2100 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2101 set execution-direction {forward|reverse}, for targets that support
2104 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2105 feature is available with a native GDB running on kernel version
2108 * GDB now has support for multi-byte and wide character sets on the
2109 target. Strings whose character type is wchar_t, char16_t, or
2110 char32_t are now correctly printed. GDB supports wide- and unicode-
2111 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2112 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2113 `printf'. This feature requires iconv to work properly; if your
2114 system does not have a working iconv, GDB can use GNU libiconv. See
2115 the installation instructions for more information.
2117 * GDB now supports automatic retrieval of shared library files from
2118 remote targets. To use this feature, specify a system root that begins
2119 with the `remote:' prefix, either via the `set sysroot' command or via
2120 the `--with-sysroot' configure-time option.
2122 * "info sharedlibrary" now takes an optional regex of libraries to show,
2123 and it now reports if a shared library has no debugging information.
2125 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2126 now complete on file names.
2128 * When completing in expressions, gdb will attempt to limit
2129 completions to allowable structure or union fields, where appropriate.
2130 For instance, consider:
2132 # struct example { int f1; double f2; };
2133 # struct example variable;
2136 If the user types TAB at the end of this command line, the available
2137 completions will be "f1" and "f2".
2139 * Inlined functions are now supported. They show up in backtraces, and
2140 the "step", "next", and "finish" commands handle them automatically.
2142 * GDB now supports the token-splicing (##) and stringification (#)
2143 operators when expanding macros. It also supports variable-arity
2146 * GDB now supports inspecting extra signal information, exported by
2147 the new $_siginfo convenience variable. The feature is currently
2148 implemented on linux ARM, i386 and amd64.
2150 * GDB can now display the VFP floating point registers and NEON vector
2151 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2152 can provide these registers (requires Linux 2.6.30 or later). Remote
2153 and simulator targets may also provide them.
2155 * New remote packets
2158 Search memory for a sequence of bytes.
2161 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2162 operation over reliable transport links. Use of this packet is
2163 controlled by the `set remote noack-packet' command.
2166 Kill the process with the specified process ID. Use this in preference
2167 to `k' when multiprocess protocol extensions are supported.
2170 Obtains additional operating system information
2174 Read or write additional signal information.
2176 * Removed remote protocol undocumented extension
2178 An undocumented extension to the remote protocol's `S' stop reply
2179 packet that permited the stub to pass a process id was removed.
2180 Remote servers should use the `T' stop reply packet instead.
2182 * GDB now supports multiple function calling conventions according to the
2183 DWARF-2 DW_AT_calling_convention function attribute.
2185 * The SH target utilizes the aforementioned change to distinguish between gcc
2186 and Renesas calling convention. It also adds the new CLI commands
2187 `set/show sh calling-convention'.
2189 * GDB can now read compressed debug sections, as produced by GNU gold
2190 with the --compress-debug-sections=zlib flag.
2192 * 64-bit core files are now supported on AIX.
2194 * Thread switching is now supported on Tru64.
2196 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2197 which will be allocated using malloc later in program execution.
2199 * The qXfer:libraries:read remote procotol packet now allows passing a
2200 list of section offsets.
2202 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2203 conditions handling signals delivered during attach or thread creation
2204 have also been fixed.
2206 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2207 From the user's standpoint, all unqualified instances of True and False
2208 are treated as the standard definitions, regardless of context.
2210 * GDB now parses C++ symbol and type names more flexibly. For
2213 template<typename T> class C { };
2216 GDB will now correctly handle all of:
2218 ptype C<char const *>
2219 ptype C<char const*>
2220 ptype C<const char *>
2221 ptype C<const char*>
2223 * New features in the GDB remote stub, gdbserver
2225 - The "--wrapper" command-line argument tells gdbserver to use a
2226 wrapper program to launch programs for debugging.
2228 - On PowerPC and S/390 targets, it is now possible to use a single
2229 gdbserver executable to debug both 32-bit and 64-bit programs.
2230 (This requires gdbserver itself to be built as a 64-bit executable.)
2232 - gdbserver uses the new noack protocol mode for TCP connections to
2233 reduce communications latency, if also supported and enabled in GDB.
2235 - Support for the sparc64-linux-gnu target is now included in
2238 - The amd64-linux build of gdbserver now supports debugging both
2239 32-bit and 64-bit programs.
2241 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2242 now support hardware watchpoints, and will use them automatically
2247 GDB now has support for scripting using Python. Whether this is
2248 available is determined at configure time.
2250 New GDB commands can now be written in Python.
2252 * Ada tasking support
2254 Ada tasks can now be inspected in GDB. The following commands have
2258 Print the list of Ada tasks.
2260 Print detailed information about task number N.
2262 Print the task number of the current task.
2264 Switch the context of debugging to task number N.
2266 * Support for user-defined prefixed commands. The "define" command can
2267 add new commands to existing prefixes, e.g. "target".
2269 * Multi-inferior, multi-process debugging.
2271 GDB now has generalized support for multi-inferior debugging. See
2272 "Debugging Multiple Inferiors" in the manual for more information.
2273 Although availability still depends on target support, the command
2274 set is more uniform now. The GNU/Linux specific multi-forks support
2275 has been migrated to this new framework. This implied some user
2276 visible changes; see "New commands" and also "Removed commands"
2279 * Target descriptions can now describe the target OS ABI. See the
2280 "Target Description Format" section in the user manual for more
2283 * Target descriptions can now describe "compatible" architectures
2284 to indicate that the target can execute applications for a different
2285 architecture in addition to those for the main target architecture.
2286 See the "Target Description Format" section in the user manual for
2289 * Multi-architecture debugging.
2291 GDB now includes general supports for debugging applications on
2292 hybrid systems that use more than one single processor architecture
2293 at the same time. Each such hybrid architecture still requires
2294 specific support to be added. The only hybrid architecture supported
2295 in this version of GDB is the Cell Broadband Engine.
2297 * GDB now supports integrated debugging of Cell/B.E. applications that
2298 use both the PPU and SPU architectures. To enable support for hybrid
2299 Cell/B.E. debugging, you need to configure GDB to support both the
2300 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2301 --enable-targets configure option.
2303 * Non-stop mode debugging.
2305 For some targets, GDB now supports an optional mode of operation in
2306 which you can examine stopped threads while other threads continue
2307 to execute freely. This is referred to as non-stop mode, with the
2308 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2309 section in the user manual for more information.
2311 To be able to support remote non-stop debugging, a remote stub needs
2312 to implement the non-stop mode remote protocol extensions, as
2313 described in the "Remote Non-Stop" section of the user manual. The
2314 GDB remote stub, gdbserver, has been adjusted to support these
2315 extensions on linux targets.
2317 * New commands (for set/show, see "New options" below)
2319 catch syscall [NAME(S) | NUMBER(S)]
2320 Catch system calls. Arguments, which should be names of system
2321 calls or their numbers, mean catch only those syscalls. Without
2322 arguments, every syscall will be caught. When the inferior issues
2323 any of the specified syscalls, GDB will stop and announce the system
2324 call, both when it is called and when its call returns. This
2325 feature is currently available with a native GDB running on the
2326 Linux Kernel, under the following architectures: x86, x86_64,
2327 PowerPC and PowerPC64.
2329 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2331 Search memory for a sequence of bytes.
2333 maint set python print-stack
2334 maint show python print-stack
2335 Show a stack trace when an error is encountered in a Python script.
2338 Invoke CODE by passing it to the Python interpreter.
2343 These allow macros to be defined, undefined, and listed
2347 Show operating system information about processes.
2350 List the inferiors currently under GDB's control.
2353 Switch focus to inferior number NUM.
2356 Detach from inferior number NUM.
2359 Kill inferior number NUM.
2363 set spu stop-on-load
2364 show spu stop-on-load
2365 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2367 set spu auto-flush-cache
2368 show spu auto-flush-cache
2369 Control whether to automatically flush the software-managed cache
2370 during Cell/B.E. debugging.
2372 set sh calling-convention
2373 show sh calling-convention
2374 Control the calling convention used when calling SH target functions.
2377 show debug timestamp
2378 Control display of timestamps with GDB debugging output.
2380 set disassemble-next-line
2381 show disassemble-next-line
2382 Control display of disassembled source lines or instructions when
2385 set remote noack-packet
2386 show remote noack-packet
2387 Set/show the use of remote protocol QStartNoAckMode packet. See above
2388 under "New remote packets."
2390 set remote query-attached-packet
2391 show remote query-attached-packet
2392 Control use of remote protocol `qAttached' (query-attached) packet.
2394 set remote read-siginfo-object
2395 show remote read-siginfo-object
2396 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2399 set remote write-siginfo-object
2400 show remote write-siginfo-object
2401 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2404 set remote reverse-continue
2405 show remote reverse-continue
2406 Control use of remote protocol 'bc' (reverse-continue) packet.
2408 set remote reverse-step
2409 show remote reverse-step
2410 Control use of remote protocol 'bs' (reverse-step) packet.
2412 set displaced-stepping
2413 show displaced-stepping
2414 Control displaced stepping mode. Displaced stepping is a way to
2415 single-step over breakpoints without removing them from the debuggee.
2416 Also known as "out-of-line single-stepping".
2419 show debug displaced
2420 Control display of debugging info for displaced stepping.
2422 maint set internal-error
2423 maint show internal-error
2424 Control what GDB does when an internal error is detected.
2426 maint set internal-warning
2427 maint show internal-warning
2428 Control what GDB does when an internal warning is detected.
2433 Use a wrapper program to launch programs for debugging.
2435 set multiple-symbols (all|ask|cancel)
2436 show multiple-symbols
2437 The value of this variable can be changed to adjust the debugger behavior
2438 when an expression or a breakpoint location contains an ambiguous symbol
2439 name (an overloaded function name, for instance).
2441 set breakpoint always-inserted
2442 show breakpoint always-inserted
2443 Keep breakpoints always inserted in the target, as opposed to inserting
2444 them when resuming the target, and removing them when the target stops.
2445 This option can improve debugger performance on slow remote targets.
2447 set arm fallback-mode (arm|thumb|auto)
2448 show arm fallback-mode
2449 set arm force-mode (arm|thumb|auto)
2451 These commands control how ARM GDB determines whether instructions
2452 are ARM or Thumb. The default for both settings is auto, which uses
2453 the current CPSR value for instructions without symbols; previous
2454 versions of GDB behaved as if "set arm fallback-mode arm".
2456 set disable-randomization
2457 show disable-randomization
2458 Standalone programs run with the virtual address space randomization enabled
2459 by default on some platforms. This option keeps the addresses stable across
2460 multiple debugging sessions.
2464 Control whether other threads are stopped or not when some thread hits
2469 Requests that asynchronous execution is enabled in the target, if available.
2470 In this case, it's possible to resume target in the background, and interact
2471 with GDB while the target is running. "show target-async" displays the
2472 current state of asynchronous execution of the target.
2474 set target-wide-charset
2475 show target-wide-charset
2476 The target-wide-charset is the name of the character set that GDB
2477 uses when printing characters whose type is wchar_t.
2479 set tcp auto-retry (on|off)
2481 set tcp connect-timeout
2482 show tcp connect-timeout
2483 These commands allow GDB to retry failed TCP connections to a remote stub
2484 with a specified timeout period; this is useful if the stub is launched
2485 in parallel with GDB but may not be ready to accept connections immediately.
2487 set libthread-db-search-path
2488 show libthread-db-search-path
2489 Control list of directories which GDB will search for appropriate
2492 set schedule-multiple (on|off)
2493 show schedule-multiple
2494 Allow GDB to resume all threads of all processes or only threads of
2495 the current process.
2499 Use more aggressive caching for accesses to the stack. This improves
2500 performance of remote debugging (particularly backtraces) without
2501 affecting correctness.
2503 set interactive-mode (on|off|auto)
2504 show interactive-mode
2505 Control whether GDB runs in interactive mode (on) or not (off).
2506 When in interactive mode, GDB waits for the user to answer all
2507 queries. Otherwise, GDB does not wait and assumes the default
2508 answer. When set to auto (the default), GDB determines which
2509 mode to use based on the stdin settings.
2514 For program forks, this is replaced by the new more generic `info
2515 inferiors' command. To list checkpoints, you can still use the
2516 `info checkpoints' command, which was an alias for the `info forks'
2520 Replaced by the new `inferior' command. To switch between
2521 checkpoints, you can still use the `restart' command, which was an
2522 alias for the `fork' command.
2525 This is removed, since some targets don't have a notion of
2526 processes. To switch between processes, you can still use the
2527 `inferior' command using GDB's own inferior number.
2530 For program forks, this is replaced by the new more generic `kill
2531 inferior' command. To delete a checkpoint, you can still use the
2532 `delete checkpoint' command, which was an alias for the `delete
2536 For program forks, this is replaced by the new more generic `detach
2537 inferior' command. To detach a checkpoint, you can still use the
2538 `detach checkpoint' command, which was an alias for the `detach
2541 * New native configurations
2543 x86/x86_64 Darwin i[34567]86-*-darwin*
2545 x86_64 MinGW x86_64-*-mingw*
2549 Lattice Mico32 lm32-*
2550 x86 DICOS i[34567]86-*-dicos*
2551 x86_64 DICOS x86_64-*-dicos*
2554 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2555 (mingw32ce) debugging.
2561 These commands were actually not implemented on any target.
2563 *** Changes in GDB 6.8
2565 * New native configurations
2567 NetBSD/hppa hppa*-*netbsd*
2568 Xtensa GNU/Linux xtensa*-*-linux*
2572 NetBSD/hppa hppa*-*-netbsd*
2573 Xtensa GNU/Lunux xtensa*-*-linux*
2575 * Change in command line behavior -- corefiles vs. process ids.
2577 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2578 attaching to process NUMBER fails, GDB no longer attempts to open a
2579 core file named NUMBER. Attaching to a program using the -c option
2580 is no longer supported. Instead, use the '-p' or '--pid' options.
2582 * GDB can now be built as a native debugger for debugging Windows x86
2583 (mingw32) Portable Executable (PE) programs.
2585 * Pending breakpoints no longer change their number when their address
2588 * GDB now supports breakpoints with multiple locations,
2589 including breakpoints on C++ constructors, inside C++ templates,
2590 and in inlined functions.
2592 * GDB's ability to debug optimized code has been improved. GDB more
2593 accurately identifies function bodies and lexical blocks that occupy
2594 more than one contiguous range of addresses.
2596 * Target descriptions can now describe registers for PowerPC.
2598 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2599 registers on PowerPC targets.
2601 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2602 targets even when the libthread_db library is not available.
2604 * The GDB remote stub, gdbserver, now supports the new file transfer
2605 commands (remote put, remote get, and remote delete).
2607 * The GDB remote stub, gdbserver, now supports run and attach in
2608 extended-remote mode.
2610 * hppa*64*-*-hpux11* target broken
2611 The debugger is unable to start a program and fails with the following
2612 error: "Error trying to get information about dynamic linker".
2613 The gdb-6.7 release is also affected.
2615 * GDB now supports the --enable-targets= configure option to allow
2616 building a single GDB executable that supports multiple remote
2617 target architectures.
2619 * GDB now supports debugging C and C++ programs which use the
2620 Decimal Floating Point extension. In addition, the PowerPC target
2621 now has a set of pseudo-registers to inspect decimal float values
2622 stored in two consecutive float registers.
2624 * The -break-insert MI command can optionally create pending
2627 * Improved support for debugging Ada
2628 Many improvements to the Ada language support have been made. These
2630 - Better support for Ada2005 interface types
2631 - Improved handling of arrays and slices in general
2632 - Better support for Taft-amendment types
2633 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2635 - Improved command completion in Ada
2638 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2643 set print frame-arguments (all|scalars|none)
2644 show print frame-arguments
2645 The value of this variable can be changed to control which argument
2646 values should be printed by the debugger when displaying a frame.
2651 Transfer files to and from a remote target, and delete remote files.
2658 Transfer files to and from a remote target, and delete remote files.
2660 * New remote packets
2667 Open, close, read, write, and delete files on the remote system.
2670 Attach to an existing process on the remote system, in extended-remote
2674 Run a new process on the remote system, in extended-remote mode.
2676 *** Changes in GDB 6.7
2678 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2679 bfd, libiberty and opcodes, as revealed by static analysis donated by
2680 Coverity, Inc. (http://scan.coverity.com).
2682 * When looking up multiply-defined global symbols, GDB will now prefer the
2683 symbol definition in the current shared library if it was built using the
2684 -Bsymbolic linker option.
2686 * When the Text User Interface (TUI) is not configured, GDB will now
2687 recognize the -tui command-line option and print a message that the TUI
2690 * The GDB remote stub, gdbserver, now has lower overhead for high
2691 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2693 * GDB for MIPS targets now autodetects whether a remote target provides
2694 32-bit or 64-bit register values.
2696 * Support for C++ member pointers has been improved.
2698 * GDB now understands XML target descriptions, which specify the
2699 target's overall architecture. GDB can read a description from
2700 a local file or over the remote serial protocol.
2702 * Vectors of single-byte data use a new integer type which is not
2703 automatically displayed as character or string data.
2705 * The /s format now works with the print command. It displays
2706 arrays of single-byte integers and pointers to single-byte integers
2709 * Target descriptions can now describe target-specific registers,
2710 for architectures which have implemented the support (currently
2711 only ARM, M68K, and MIPS).
2713 * GDB and the GDB remote stub, gdbserver, now support the XScale
2716 * The GDB remote stub, gdbserver, has been updated to support
2717 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2718 has been rewritten to use the standard GDB remote protocol.
2720 * GDB can now step into C++ functions which are called through thunks.
2722 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2724 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2725 layout. It also supports a TextSeg= and DataSeg= response when only
2726 segment base addresses (rather than offsets) are available.
2728 * The /i format now outputs any trailing branch delay slot instructions
2729 immediately following the last instruction within the count specified.
2731 * The GDB remote protocol "T" stop reply packet now supports a
2732 "library" response. Combined with the new "qXfer:libraries:read"
2733 packet, this response allows GDB to debug shared libraries on targets
2734 where the operating system manages the list of loaded libraries (e.g.
2735 Windows and SymbianOS).
2737 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2738 (DLLs) on Windows and Windows CE targets.
2740 * GDB now supports a faster verification that a .debug file matches its binary
2741 according to its build-id signature, if the signature is present.
2747 Enable or disable hardware flow control (RTS/CTS) on the serial port
2748 when debugging using remote targets.
2750 set mem inaccessible-by-default
2751 show mem inaccessible-by-default
2752 If the target supplies a memory map, for instance via the remote
2753 protocol's "qXfer:memory-map:read" packet, setting this variable
2754 prevents GDB from accessing memory outside the memory map. This
2755 is useful for targets with memory mapped registers or which react
2756 badly to accesses of unmapped address space.
2758 set breakpoint auto-hw
2759 show breakpoint auto-hw
2760 If the target supplies a memory map, for instance via the remote
2761 protocol's "qXfer:memory-map:read" packet, setting this variable
2762 lets GDB use hardware breakpoints automatically for memory regions
2763 where it can not use software breakpoints. This covers both the
2764 "break" command and internal breakpoints used for other commands
2765 including "next" and "finish".
2768 catch exception unhandled
2769 Stop the program execution when Ada exceptions are raised.
2772 Stop the program execution when an Ada assertion failed.
2776 Set an alternate system root for target files. This is a more
2777 general version of "set solib-absolute-prefix", which is now
2778 an alias to "set sysroot".
2781 Provide extended SPU facility status information. This set of
2782 commands is available only when debugging the Cell/B.E. SPU
2785 * New native configurations
2787 OpenBSD/sh sh*-*openbsd*
2790 unset tdesc filename
2792 Use the specified local file as an XML target description, and do
2793 not query the target for its built-in description.
2797 OpenBSD/sh sh*-*-openbsd*
2798 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2799 Toshiba Media Processor mep-elf
2801 * New remote packets
2804 Ignore the specified signals; pass them directly to the debugged program
2805 without stopping other threads or reporting them to GDB.
2807 qXfer:features:read:
2808 Read an XML target description from the target, which describes its
2813 Read or write contents of an spufs file on the target system. These
2814 packets are available only on the Cell/B.E. SPU architecture.
2816 qXfer:libraries:read:
2817 Report the loaded shared libraries. Combined with new "T" packet
2818 response, this packet allows GDB to debug shared libraries on
2819 targets where the operating system manages the list of loaded
2820 libraries (e.g. Windows and SymbianOS).
2824 Support for these obsolete configurations has been removed.
2832 i[34567]86-*-lynxos*
2833 i[34567]86-*-netware*
2834 i[34567]86-*-sco3.2v5*
2835 i[34567]86-*-sco3.2v4*
2837 i[34567]86-*-sysv4.2*
2840 i[34567]86-*-unixware2*
2841 i[34567]86-*-unixware*
2850 * Other removed features
2857 Various m68k-only ROM monitors.
2864 Various Renesas ROM monitors and debugging interfaces for SH and
2869 Support for a Macraigor serial interface to on-chip debugging.
2870 GDB does not directly support the newer parallel or USB
2875 A debug information format. The predecessor to DWARF 2 and
2876 DWARF 3, which are still supported.
2878 Support for the HP aCC compiler on HP-UX/PA-RISC
2880 SOM-encapsulated symbolic debugging information, automatic
2881 invocation of pxdb, and the aCC custom C++ ABI. This does not
2882 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2883 with aCC can still be debugged on an assembly level.
2885 MIPS ".pdr" sections
2887 A MIPS-specific format used to describe stack frame layout
2888 in debugging information.
2892 GDB could work with an older version of Guile to debug
2893 the interpreter and Scheme programs running in it.
2895 set mips stack-arg-size
2896 set mips saved-gpreg-size
2898 Use "set mips abi" to control parameter passing for MIPS.
2900 *** Changes in GDB 6.6
2905 Cell Broadband Engine SPU spu-elf
2907 * GDB can now be configured as a cross-debugger targeting native Windows
2908 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2909 running on a Windows system over TCP/IP to debug Windows programs.
2911 * The GDB remote stub, gdbserver, has been updated to support Windows and
2912 Cygwin debugging. Both single-threaded and multi-threaded programs are
2915 * The "set trust-readonly-sections" command works again. This command was
2916 broken in GDB 6.3, 6.4, and 6.5.
2918 * The "load" command now supports writing to flash memory, if the remote
2919 stub provides the required support.
2921 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2922 longer requires symbolic debug information (e.g. DWARF-2).
2927 unset substitute-path
2928 show substitute-path
2929 Manage a list of substitution rules that GDB uses to rewrite the name
2930 of the directories where the sources are located. This can be useful
2931 for instance when the sources were moved to a different location
2932 between compilation and debugging.
2936 Print each CLI command as it is executed. Each command is prefixed with
2937 a number of `+' symbols representing the nesting depth.
2938 The source command now has a `-v' option to enable the same feature.
2942 The ARM Demon monitor support (RDP protocol, "target rdp").
2944 Kernel Object Display, an embedded debugging feature which only worked with
2945 an obsolete version of Cisco IOS.
2947 The 'set download-write-size' and 'show download-write-size' commands.
2949 * New remote packets
2952 Tell a stub about GDB client features, and request remote target features.
2953 The first feature implemented is PacketSize, which allows the target to
2954 specify the size of packets it can handle - to minimize the number of
2955 packets required and improve performance when connected to a remote
2959 Fetch an OS auxilliary vector from the remote stub. This packet is a
2960 more efficient replacement for qPart:auxv:read.
2962 qXfer:memory-map:read:
2963 Fetch a memory map from the remote stub, including information about
2964 RAM, ROM, and flash memory devices.
2969 Erase and program a flash memory device.
2971 * Removed remote packets
2974 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2975 used it, and only gdbserver implemented it.
2977 *** Changes in GDB 6.5
2981 Renesas M32C/M16C m32c-elf
2983 Morpho Technologies ms1 ms1-elf
2987 init-if-undefined Initialize a convenience variable, but
2988 only if it doesn't already have a value.
2990 The following commands are presently only implemented for native GNU/Linux:
2992 checkpoint Save a snapshot of the program state.
2994 restart <n> Return the program state to a
2995 previously saved state.
2997 info checkpoints List currently saved checkpoints.
2999 delete-checkpoint <n> Delete a previously saved checkpoint.
3001 set|show detach-on-fork Tell gdb whether to detach from a newly
3002 forked process, or to keep debugging it.
3004 info forks List forks of the user program that
3005 are available to be debugged.
3007 fork <n> Switch to debugging one of several
3008 forks of the user program that are
3009 available to be debugged.
3011 delete-fork <n> Delete a fork from the list of forks
3012 that are available to be debugged (and
3013 kill the forked process).
3015 detach-fork <n> Delete a fork from the list of forks
3016 that are available to be debugged (and
3017 allow the process to continue).
3021 Morpho Technologies ms2 ms1-elf
3023 * Improved Windows host support
3025 GDB now builds as a cross debugger hosted on i686-mingw32, including
3026 native console support, and remote communications using either
3027 network sockets or serial ports.
3029 * Improved Modula-2 language support
3031 GDB can now print most types in the Modula-2 syntax. This includes:
3032 basic types, set types, record types, enumerated types, range types,
3033 pointer types and ARRAY types. Procedure var parameters are correctly
3034 printed and hexadecimal addresses and character constants are also
3035 written in the Modula-2 syntax. Best results can be obtained by using
3036 GNU Modula-2 together with the -gdwarf-2 command line option.
3040 The ARM rdi-share module.
3042 The Netware NLM debug server.
3044 *** Changes in GDB 6.4
3046 * New native configurations
3048 OpenBSD/arm arm*-*-openbsd*
3049 OpenBSD/mips64 mips64-*-openbsd*
3053 Morpho Technologies ms1 ms1-elf
3055 * New command line options
3057 --batch-silent As for --batch, but totally silent.
3058 --return-child-result The debugger will exist with the same value
3059 the child (debugged) program exited with.
3060 --eval-command COMMAND, -ex COMMAND
3061 Execute a single GDB CLI command. This may be
3062 specified multiple times and in conjunction
3063 with the --command (-x) option.
3065 * Deprecated commands removed
3067 The following commands, that were deprecated in 2000, have been
3071 set|show arm disassembly-flavor set|show arm disassembler
3072 othernames set arm disassembler
3073 set|show remotedebug set|show debug remote
3074 set|show archdebug set|show debug arch
3075 set|show eventdebug set|show debug event
3078 * New BSD user-level threads support
3080 It is now possible to debug programs using the user-level threads
3081 library on OpenBSD and FreeBSD. Currently supported (target)
3084 FreeBSD/amd64 x86_64-*-freebsd*
3085 FreeBSD/i386 i386-*-freebsd*
3086 OpenBSD/i386 i386-*-openbsd*
3088 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3089 are not yet supported.
3091 * New support for Matsushita MN10300 w/sim added
3092 (Work in progress). mn10300-elf.
3094 * REMOVED configurations and files
3096 VxWorks and the XDR protocol *-*-vxworks
3097 Motorola MCORE mcore-*-*
3098 National Semiconductor NS32000 ns32k-*-*
3100 * New "set print array-indexes" command
3102 After turning this setting "on", GDB prints the index of each element
3103 when displaying arrays. The default is "off" to preserve the previous
3106 * VAX floating point support
3108 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3110 * User-defined command support
3112 In addition to using $arg0..$arg9 for argument passing, it is now possible
3113 to use $argc to determine now many arguments have been passed. See the
3114 section on user-defined commands in the user manual for more information.
3116 *** Changes in GDB 6.3:
3118 * New command line option
3120 GDB now accepts -l followed by a number to set the timeout for remote
3123 * GDB works with GCC -feliminate-dwarf2-dups
3125 GDB now supports a more compact representation of DWARF-2 debug
3126 information using DW_FORM_ref_addr references. These are produced
3127 by GCC with the option -feliminate-dwarf2-dups and also by some
3128 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3129 to use -feliminate-dwarf2-dups.
3131 * Internationalization
3133 When supported by the host system, GDB will be built with
3134 internationalization (libintl). The task of marking up the sources is
3135 continued, we're looking forward to our first translation.
3139 Initial support for debugging programs compiled with the GNAT
3140 implementation of the Ada programming language has been integrated
3141 into GDB. In this release, support is limited to expression evaluation.
3143 * New native configurations
3145 GNU/Linux/m32r m32r-*-linux-gnu
3149 GDB's remote protocol now includes support for the 'p' packet. This
3150 packet is used to fetch individual registers from a remote inferior.
3152 * END-OF-LIFE registers[] compatibility module
3154 GDB's internal register infrastructure has been completely rewritten.
3155 The new infrastructure making possible the implementation of key new
3156 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3159 GDB 6.3 will be the last release to include the the registers[]
3160 compatibility module that allowed out-of-date configurations to
3161 continue to work. This change directly impacts the following
3171 powerpc bdm protocol
3173 Unless there is activity to revive these configurations, they will be
3174 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3176 * OBSOLETE configurations and files
3178 Configurations that have been declared obsolete in this release have
3179 been commented out. Unless there is activity to revive these
3180 configurations, the next release of GDB will have their sources
3181 permanently REMOVED.
3190 *** Changes in GDB 6.2.1:
3192 * MIPS `break main; run' gave an heuristic-fence-post warning
3194 When attempting to run even a simple program, a warning about
3195 heuristic-fence-post being hit would be reported. This problem has
3198 * MIPS IRIX 'long double' crashed GDB
3200 When examining a long double variable, GDB would get a segmentation
3201 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3202 IRIX long double values).
3206 A bug in the VAX stack code was causing problems with the "next"
3207 command. This problem has been fixed.
3209 *** Changes in GDB 6.2:
3211 * Fix for ``many threads''
3213 On GNU/Linux systems that use the NPTL threads library, a program
3214 rapidly creating and deleting threads would confuse GDB leading to the
3217 ptrace: No such process.
3218 thread_db_get_info: cannot get thread info: generic error
3220 This problem has been fixed.
3222 * "-async" and "-noasync" options removed.
3224 Support for the broken "-noasync" option has been removed (it caused
3227 * New ``start'' command.
3229 This command runs the program until the begining of the main procedure.
3231 * New BSD Kernel Data Access Library (libkvm) interface
3233 Using ``target kvm'' it is now possible to debug kernel core dumps and
3234 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3235 platforms. Currently supported (native-only) configurations are:
3237 FreeBSD/amd64 x86_64-*-freebsd*
3238 FreeBSD/i386 i?86-*-freebsd*
3239 NetBSD/i386 i?86-*-netbsd*
3240 NetBSD/m68k m68*-*-netbsd*
3241 NetBSD/sparc sparc-*-netbsd*
3242 OpenBSD/amd64 x86_64-*-openbsd*
3243 OpenBSD/i386 i?86-*-openbsd*
3244 OpenBSD/m68k m68*-openbsd*
3245 OpenBSD/sparc sparc-*-openbsd*
3247 * Signal trampoline code overhauled
3249 Many generic problems with GDB's signal handling code have been fixed.
3250 These include: backtraces through non-contiguous stacks; recognition
3251 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3252 call; backtrace through a signal trampoline; step into and out of
3253 signal handlers; and single-stepping in the signal trampoline.
3255 Please note that kernel bugs are a limiting factor here. These
3256 features have been shown to work on an s390 GNU/Linux system that
3257 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3259 * Cygwin support for DWARF 2 added.
3261 * New native configurations
3263 GNU/Linux/hppa hppa*-*-linux*
3264 OpenBSD/hppa hppa*-*-openbsd*
3265 OpenBSD/m68k m68*-*-openbsd*
3266 OpenBSD/m88k m88*-*-openbsd*
3267 OpenBSD/powerpc powerpc-*-openbsd*
3268 NetBSD/vax vax-*-netbsd*
3269 OpenBSD/vax vax-*-openbsd*
3271 * END-OF-LIFE frame compatibility module
3273 GDB's internal frame infrastructure has been completely rewritten.
3274 The new infrastructure making it possible to support key new features
3275 including DWARF 2 Call Frame Information. To aid in the task of
3276 migrating old configurations to this new infrastructure, a
3277 compatibility module, that allowed old configurations to continue to
3278 work, was also included.
3280 GDB 6.2 will be the last release to include this frame compatibility
3281 module. This change directly impacts the following configurations:
3291 Unless there is activity to revive these configurations, they will be
3292 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3294 * REMOVED configurations and files
3296 Sun 3, running SunOS 3 m68*-*-sunos3*
3297 Sun 3, running SunOS 4 m68*-*-sunos4*
3298 Sun 2, running SunOS 3 m68000-*-sunos3*
3299 Sun 2, running SunOS 4 m68000-*-sunos4*
3300 Motorola 680x0 running LynxOS m68*-*-lynxos*
3301 AT&T 3b1/Unix pc m68*-att-*
3302 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3303 decstation mips-dec-* mips-little-*
3304 riscos mips-*-riscos* mips-*-sysv*
3305 sonymips mips-sony-*
3306 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3308 *** Changes in GDB 6.1.1:
3310 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3312 The TUI (Text-mode User Interface) is now built as part of a default
3313 GDB configuration. It is enabled by either selecting the TUI with the
3314 command line option "-i=tui" or by running the separate "gdbtui"
3315 program. For more information on the TUI, see the manual "Debugging
3318 * Pending breakpoint support (also included in GDB 6.1)
3320 Support has been added to allow you to specify breakpoints in shared
3321 libraries that have not yet been loaded. If a breakpoint location
3322 cannot be found, and the "breakpoint pending" option is set to auto,
3323 GDB queries you if you wish to make the breakpoint pending on a future
3324 shared-library load. If and when GDB resolves the breakpoint symbol,
3325 the pending breakpoint is removed as one or more regular breakpoints
3328 Pending breakpoints are very useful for GCJ Java debugging.
3330 * Fixed ISO-C build problems
3332 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3333 non ISO-C code that stopped them being built using a more strict ISO-C
3334 compiler (e.g., IBM's C compiler).
3336 * Fixed build problem on IRIX 5
3338 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3339 wasn't able to compile compile on an IRIX 5 system.
3341 * Added execute permission to gdb/gdbserver/configure
3343 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3344 permission. This bug would cause configure to fail on a number of
3345 systems (Solaris, IRIX). Ref: server/519.
3347 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3349 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3350 has been updated to use constant array sizes.
3352 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3354 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3355 its generated DWARF Call Frame Info. This encoding was causing GDB to
3356 panic, that panic has been fixed. Ref: gdb/1628.
3358 * Fixed a problem when examining parameters in shared library code.
3360 When examining parameters in optimized shared library code generated
3361 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3362 not available''. GDB now correctly displays the variable's value.
3364 *** Changes in GDB 6.1:
3366 * Removed --with-mmalloc
3368 Support for the mmalloc memory manager has been removed, as it
3369 conflicted with the internal gdb byte cache.
3371 * Changes in AMD64 configurations
3373 The AMD64 target now includes the %cs and %ss registers. As a result
3374 the AMD64 remote protocol has changed; this affects the floating-point
3375 and SSE registers. If you rely on those registers for your debugging,
3376 you should upgrade gdbserver on the remote side.
3378 * Revised SPARC target
3380 The SPARC target has been completely revised, incorporating the
3381 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3382 support for LynxOS and SunOS 4 has been dropped. Calling functions
3383 from within GDB on operating systems with a non-executable stack
3384 (Solaris, OpenBSD) now works.
3388 GDB has a new C++ demangler which does a better job on the mangled
3389 names generated by current versions of g++. It also runs faster, so
3390 with this and other changes gdb should now start faster on large C++
3393 * DWARF 2 Location Expressions
3395 GDB support for location expressions has been extended to support function
3396 arguments and frame bases. Older versions of GDB could crash when they
3399 * C++ nested types and namespaces
3401 GDB's support for nested types and namespaces in C++ has been
3402 improved, especially if you use the DWARF 2 debugging format. (This
3403 is the default for recent versions of GCC on most platforms.)
3404 Specifically, if you have a class "Inner" defined within a class or
3405 namespace "Outer", then GDB realizes that the class's name is
3406 "Outer::Inner", not simply "Inner". This should greatly reduce the
3407 frequency of complaints about not finding RTTI symbols. In addition,
3408 if you are stopped at inside of a function defined within a namespace,
3409 GDB modifies its name lookup accordingly.
3411 * New native configurations
3413 NetBSD/amd64 x86_64-*-netbsd*
3414 OpenBSD/amd64 x86_64-*-openbsd*
3415 OpenBSD/alpha alpha*-*-openbsd*
3416 OpenBSD/sparc sparc-*-openbsd*
3417 OpenBSD/sparc64 sparc64-*-openbsd*
3419 * New debugging protocols
3421 M32R with SDI protocol m32r-*-elf*
3423 * "set prompt-escape-char" command deleted.
3425 The command "set prompt-escape-char" has been deleted. This command,
3426 and its very obscure effet on GDB's prompt, was never documented,
3427 tested, nor mentioned in the NEWS file.
3429 * OBSOLETE configurations and files
3431 Configurations that have been declared obsolete in this release have
3432 been commented out. Unless there is activity to revive these
3433 configurations, the next release of GDB will have their sources
3434 permanently REMOVED.
3436 Sun 3, running SunOS 3 m68*-*-sunos3*
3437 Sun 3, running SunOS 4 m68*-*-sunos4*
3438 Sun 2, running SunOS 3 m68000-*-sunos3*
3439 Sun 2, running SunOS 4 m68000-*-sunos4*
3440 Motorola 680x0 running LynxOS m68*-*-lynxos*
3441 AT&T 3b1/Unix pc m68*-att-*
3442 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3443 decstation mips-dec-* mips-little-*
3444 riscos mips-*-riscos* mips-*-sysv*
3445 sonymips mips-sony-*
3446 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3448 * REMOVED configurations and files
3450 SGI Irix-4.x mips-sgi-irix4 or iris4
3451 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3452 Z8000 simulator z8k-zilog-none or z8ksim
3453 Matsushita MN10200 w/simulator mn10200-*-*
3454 H8/500 simulator h8500-hitachi-hms or h8500hms
3455 HP/PA running BSD hppa*-*-bsd*
3456 HP/PA running OSF/1 hppa*-*-osf*
3457 HP/PA Pro target hppa*-*-pro*
3458 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3459 386BSD i[3456]86-*-bsd*
3460 Sequent family i[3456]86-sequent-sysv4*
3461 i[3456]86-sequent-sysv*
3462 i[3456]86-sequent-bsd*
3463 SPARC running LynxOS sparc-*-lynxos*
3464 SPARC running SunOS 4 sparc-*-sunos4*
3465 Tsqware Sparclet sparclet-*-*
3466 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3468 *** Changes in GDB 6.0:
3472 Support for debugging the Objective-C programming language has been
3473 integrated into GDB.
3475 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3477 DWARF 2's Call Frame Information makes available compiler generated
3478 information that more exactly describes the program's run-time stack.
3479 By using this information, GDB is able to provide more robust stack
3482 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3483 have been updated to use a new backtrace mechanism which includes
3484 DWARF 2 CFI support.
3488 GDB's remote protocol has been extended to include support for hosted
3489 file I/O (where the remote target uses GDB's file system). See GDB's
3490 remote protocol documentation for details.
3492 * All targets using the new architecture framework.
3494 All of GDB's targets have been updated to use the new internal
3495 architecture framework. The way is now open for future GDB releases
3496 to include cross-architecture native debugging support (i386 on amd64,
3499 * GNU/Linux's Thread Local Storage (TLS)
3501 GDB now includes support for for the GNU/Linux implementation of
3502 per-thread variables.
3504 * GNU/Linux's Native POSIX Thread Library (NPTL)
3506 GDB's thread code has been updated to work with either the new
3507 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3509 * Separate debug info.
3511 GDB, in conjunction with BINUTILS, now supports a mechanism for
3512 automatically loading debug information from a separate file. Instead
3513 of shipping full debug and non-debug versions of system libraries,
3514 system integrators can now instead ship just the stripped libraries
3515 and optional debug files.
3517 * DWARF 2 Location Expressions
3519 DWARF 2 Location Expressions allow the compiler to more completely
3520 describe the location of variables (even in optimized code) to the
3523 GDB now includes preliminary support for location expressions (support
3524 for DW_OP_piece is still missing).
3528 A number of long standing bugs that caused GDB to die while starting a
3529 Java application have been fixed. GDB's Java support is now
3530 considered "useable".
3532 * GNU/Linux support for fork, vfork, and exec.
3534 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3535 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3538 * GDB supports logging output to a file
3540 There are two new commands, "set logging" and "show logging", which can be
3541 used to capture GDB's output to a file.
3543 * The meaning of "detach" has changed for gdbserver
3545 The "detach" command will now resume the application, as documented. To
3546 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3549 * d10v, m68hc11 `regs' command deprecated
3551 The `info registers' command has been updated so that it displays the
3552 registers using a format identical to the old `regs' command.
3556 A new command, "maint set profile on/off", has been added. This command can
3557 be used to enable or disable profiling while running GDB, to profile a
3558 session or a set of commands. In addition there is a new configure switch,
3559 "--enable-profiling", which will cause GDB to be compiled with profiling
3560 data, for more informative profiling results.
3562 * Default MI syntax changed to "mi2".
3564 The default MI (machine interface) syntax, enabled by the command line
3565 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3566 "mi1", can be enabled by specifying the option "-i=mi1".
3568 Support for the original "mi0" syntax (included in GDB 5.0) has been
3571 Fix for gdb/192: removed extraneous space when displaying frame level.
3572 Fix for gdb/672: update changelist is now output in mi list format.
3573 Fix for gdb/702: a -var-assign that updates the value now shows up
3574 in a subsequent -var-update.
3576 * New native configurations.
3578 FreeBSD/amd64 x86_64-*-freebsd*
3580 * Multi-arched targets.
3582 HP/PA HPUX11 hppa*-*-hpux*
3583 Renesas M32R/D w/simulator m32r-*-elf*
3585 * OBSOLETE configurations and files
3587 Configurations that have been declared obsolete in this release have
3588 been commented out. Unless there is activity to revive these
3589 configurations, the next release of GDB will have their sources
3590 permanently REMOVED.
3592 Z8000 simulator z8k-zilog-none or z8ksim
3593 Matsushita MN10200 w/simulator mn10200-*-*
3594 H8/500 simulator h8500-hitachi-hms or h8500hms
3595 HP/PA running BSD hppa*-*-bsd*
3596 HP/PA running OSF/1 hppa*-*-osf*
3597 HP/PA Pro target hppa*-*-pro*
3598 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3599 Sequent family i[3456]86-sequent-sysv4*
3600 i[3456]86-sequent-sysv*
3601 i[3456]86-sequent-bsd*
3602 Tsqware Sparclet sparclet-*-*
3603 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3605 * REMOVED configurations and files
3608 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3609 IBM AIX PS/2 i[3456]86-*-aix
3610 i386 running Mach 3.0 i[3456]86-*-mach3*
3611 i386 running Mach i[3456]86-*-mach*
3612 i386 running OSF/1 i[3456]86-*osf1mk*
3613 HP/Apollo 68k Family m68*-apollo*-sysv*,
3615 m68*-hp-bsd*, m68*-hp-hpux*
3616 Argonaut Risc Chip (ARC) arc-*-*
3617 Mitsubishi D30V d30v-*-*
3618 Fujitsu FR30 fr30-*-elf*
3619 OS/9000 i[34]86-*-os9k
3620 I960 with MON960 i960-*-coff
3622 * MIPS $fp behavior changed
3624 The convenience variable $fp, for the MIPS, now consistently returns
3625 the address of the current frame's base. Previously, depending on the
3626 context, $fp could refer to either $sp or the current frame's base
3627 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3628 The GNU Source-Level Debugger''.
3630 *** Changes in GDB 5.3:
3632 * GNU/Linux shared library multi-threaded performance improved.
3634 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3635 `/proc', in preference to `ptrace' for memory reads. This may result
3636 in an improvement in the start-up time of multi-threaded, shared
3637 library applications when run under GDB. One GDB user writes: ``loads
3638 shared libs like mad''.
3640 * ``gdbserver'' now supports multi-threaded applications on some targets
3642 Support for debugging multi-threaded applications which use
3643 the GNU/Linux LinuxThreads package has been added for
3644 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3645 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3647 * GDB now supports C/C++ preprocessor macros.
3649 GDB now expands preprocessor macro invocations in C/C++ expressions,
3650 and provides various commands for showing macro definitions and how
3653 The new command `macro expand EXPRESSION' expands any macro
3654 invocations in expression, and shows the result.
3656 The new command `show macro MACRO-NAME' shows the definition of the
3657 macro named MACRO-NAME, and where it was defined.
3659 Most compilers don't include information about macros in the debugging
3660 information by default. In GCC 3.1, for example, you need to compile
3661 your program with the options `-gdwarf-2 -g3'. If the macro
3662 information is present in the executable, GDB will read it.
3664 * Multi-arched targets.
3666 DEC Alpha (partial) alpha*-*-*
3667 DEC VAX (partial) vax-*-*
3669 National Semiconductor NS32000 (partial) ns32k-*-*
3670 Motorola 68000 (partial) m68k-*-*
3671 Motorola MCORE mcore-*-*
3675 Fujitsu FRV architecture added by Red Hat frv*-*-*
3678 * New native configurations
3680 Alpha NetBSD alpha*-*-netbsd*
3681 SH NetBSD sh*-*-netbsdelf*
3682 MIPS NetBSD mips*-*-netbsd*
3683 UltraSPARC NetBSD sparc64-*-netbsd*
3685 * OBSOLETE configurations and files
3687 Configurations that have been declared obsolete in this release have
3688 been commented out. Unless there is activity to revive these
3689 configurations, the next release of GDB will have their sources
3690 permanently REMOVED.
3692 Mitsubishi D30V d30v-*-*
3693 OS/9000 i[34]86-*-os9k
3694 IBM AIX PS/2 i[3456]86-*-aix
3695 Fujitsu FR30 fr30-*-elf*
3696 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3697 Argonaut Risc Chip (ARC) arc-*-*
3698 i386 running Mach 3.0 i[3456]86-*-mach3*
3699 i386 running Mach i[3456]86-*-mach*
3700 i386 running OSF/1 i[3456]86-*osf1mk*
3701 HP/Apollo 68k Family m68*-apollo*-sysv*,
3703 m68*-hp-bsd*, m68*-hp-hpux*
3704 I960 with MON960 i960-*-coff
3706 * OBSOLETE languages
3708 CHILL, a Pascal like language used by telecommunications companies.
3710 * REMOVED configurations and files
3712 AMD 29k family via UDI a29k-amd-udi, udi29k
3713 A29K VxWorks a29k-*-vxworks
3714 AMD 29000 embedded, using EBMON a29k-none-none
3715 AMD 29000 embedded with COFF a29k-none-coff
3716 AMD 29000 embedded with a.out a29k-none-aout
3718 testsuite/gdb.hp/gdb.threads-hp/ directory
3720 * New command "set max-user-call-depth <nnn>"
3722 This command allows the user to limit the call depth of user-defined
3723 commands. The default is 1024.
3725 * Changes in FreeBSD/i386 native debugging.
3727 Support for the "generate-core-file" has been added.
3729 * New commands "dump", "append", and "restore".
3731 These commands allow data to be copied from target memory
3732 to a bfd-format or binary file (dump and append), and back
3733 from a file into memory (restore).
3735 * Improved "next/step" support on multi-processor Alpha Tru64.
3737 The previous single-step mechanism could cause unpredictable problems,
3738 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3739 of a software single-step mechanism prevents this.
3741 *** Changes in GDB 5.2.1:
3749 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3750 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3751 Fix, by Joel Brobecker imported from mainline.
3753 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3754 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3755 Fix, by Fred Fish, imported from mainline.
3757 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3758 Surprisingly enough, it works now.
3759 By Michal Ludvig, imported from mainline.
3761 i386 hardware watchpoint support:
3762 avoid misses on second run for some targets.
3763 By Pierre Muller, imported from mainline.
3765 *** Changes in GDB 5.2:
3767 * New command "set trust-readonly-sections on[off]".
3769 This command is a hint that tells gdb that read-only sections
3770 really are read-only (ie. that their contents will not change).
3771 In this mode, gdb will go to the object file rather than the
3772 target to read memory from read-only sections (such as ".text").
3773 This can be a significant performance improvement on some
3774 (notably embedded) targets.
3776 * New command "generate-core-file" (or "gcore").
3778 This new gdb command allows the user to drop a core file of the child
3779 process state at any time. So far it's been implemented only for
3780 GNU/Linux and Solaris, but should be relatively easily ported to other
3781 hosts. Argument is core file name (defaults to core.<pid>).
3783 * New command line option
3785 GDB now accepts --pid or -p followed by a process id.
3787 * Change in command line behavior -- corefiles vs. process ids.
3789 There is a subtle behavior in the way in which GDB handles
3790 command line arguments. The first non-flag argument is always
3791 a program to debug, but the second non-flag argument may either
3792 be a corefile or a process id. Previously, GDB would attempt to
3793 open the second argument as a corefile, and if that failed, would
3794 issue a superfluous error message and then attempt to attach it as
3795 a process. Now, if the second argument begins with a non-digit,
3796 it will be treated as a corefile. If it begins with a digit,
3797 GDB will attempt to attach it as a process, and if no such process
3798 is found, will then attempt to open it as a corefile.
3800 * Changes in ARM configurations.
3802 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3803 configuration is fully multi-arch.
3805 * New native configurations
3807 ARM NetBSD arm*-*-netbsd*
3808 x86 OpenBSD i[3456]86-*-openbsd*
3809 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3810 Sparc64 running FreeBSD sparc64-*-freebsd*
3814 Sanyo XStormy16 xstormy16-elf
3816 * OBSOLETE configurations and files
3818 Configurations that have been declared obsolete in this release have
3819 been commented out. Unless there is activity to revive these
3820 configurations, the next release of GDB will have their sources
3821 permanently REMOVED.
3823 AMD 29k family via UDI a29k-amd-udi, udi29k
3824 A29K VxWorks a29k-*-vxworks
3825 AMD 29000 embedded, using EBMON a29k-none-none
3826 AMD 29000 embedded with COFF a29k-none-coff
3827 AMD 29000 embedded with a.out a29k-none-aout
3829 testsuite/gdb.hp/gdb.threads-hp/ directory
3831 * REMOVED configurations and files
3833 TI TMS320C80 tic80-*-*
3835 PowerPC Solaris powerpcle-*-solaris*
3836 PowerPC Windows NT powerpcle-*-cygwin32
3837 PowerPC Netware powerpc-*-netware*
3838 Harris/CXUX m88k m88*-harris-cxux*
3839 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3840 ns32k-utek-sysv* ns32k-utek-*
3841 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3842 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3843 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3844 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3845 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3847 * Changes to command line processing
3849 The new `--args' feature can be used to specify command-line arguments
3850 for the inferior from gdb's command line.
3852 * Changes to key bindings
3854 There is a new `operate-and-get-next' function bound to `C-o'.
3856 *** Changes in GDB 5.1.1
3858 Fix compile problem on DJGPP.
3860 Fix a problem with floating-point registers on the i386 being
3863 Fix to stop GDB crashing on .debug_str debug info.
3865 Numerous documentation fixes.
3867 Numerous testsuite fixes.
3869 *** Changes in GDB 5.1:
3871 * New native configurations
3873 Alpha FreeBSD alpha*-*-freebsd*
3874 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3875 MIPS GNU/Linux mips*-*-linux*
3876 MIPS SGI Irix 6.x mips*-sgi-irix6*
3877 ia64 AIX ia64-*-aix*
3878 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3882 Motorola 68HC11 and 68HC12 m68hc11-elf
3884 UltraSparc running GNU/Linux sparc64-*-linux*
3886 * OBSOLETE configurations and files
3888 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3889 Harris/CXUX m88k m88*-harris-cxux*
3890 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3891 ns32k-utek-sysv* ns32k-utek-*
3892 TI TMS320C80 tic80-*-*
3894 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3895 PowerPC Solaris powerpcle-*-solaris*
3896 PowerPC Windows NT powerpcle-*-cygwin32
3897 PowerPC Netware powerpc-*-netware*
3898 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3899 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3900 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3901 Apple Macintosh (MPW) host N/A
3903 stuff.c (Program to stuff files into a specially prepared space in kdb)
3904 kdb-start.c (Main loop for the standalone kernel debugger)
3906 Configurations that have been declared obsolete in this release have
3907 been commented out. Unless there is activity to revive these
3908 configurations, the next release of GDB will have their sources
3909 permanently REMOVED.
3911 * REMOVED configurations and files
3913 Altos 3068 m68*-altos-*
3914 Convex c1-*-*, c2-*-*
3916 ARM RISCix arm-*-* (as host)
3920 * GDB has been converted to ISO C.
3922 GDB's source code has been converted to ISO C. In particular, the
3923 sources are fully protoized, and rely on standard headers being
3928 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3930 * The MI enabled by default.
3932 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3933 revised and enabled by default. Packages which use GDB as a debugging
3934 engine behind a UI or another front end are encouraged to switch to
3935 using the GDB/MI interface, instead of the old annotations interface
3936 which is now deprecated.
3938 * Support for debugging Pascal programs.
3940 GDB now includes support for debugging Pascal programs. The following
3941 main features are supported:
3943 - Pascal-specific data types such as sets;
3945 - automatic recognition of Pascal sources based on file-name
3948 - Pascal-style display of data types, variables, and functions;
3950 - a Pascal expression parser.
3952 However, some important features are not yet supported.
3954 - Pascal string operations are not supported at all;
3956 - there are some problems with boolean types;
3958 - Pascal type hexadecimal constants are not supported
3959 because they conflict with the internal variables format;
3961 - support for Pascal objects and classes is not full yet;
3963 - unlike Pascal, GDB is case-sensitive for symbol names.
3965 * Changes in completion.
3967 Commands such as `shell', `run' and `set args', which pass arguments
3968 to inferior programs, now complete on file names, similar to what
3969 users expect at the shell prompt.
3971 Commands which accept locations, such as `disassemble', `print',
3972 `breakpoint', `until', etc. now complete on filenames as well as
3973 program symbols. Thus, if you type "break foob TAB", and the source
3974 files linked into the programs include `foobar.c', that file name will
3975 be one of the candidates for completion. However, file names are not
3976 considered for completion after you typed a colon that delimits a file
3977 name from a name of a function in that file, as in "break foo.c:bar".
3979 `set demangle-style' completes on available demangling styles.
3981 * New platform-independent commands:
3983 It is now possible to define a post-hook for a command as well as a
3984 hook that runs before the command. For more details, see the
3985 documentation of `hookpost' in the GDB manual.
3987 * Changes in GNU/Linux native debugging.
3989 Support for debugging multi-threaded programs has been completely
3990 revised for all platforms except m68k and sparc. You can now debug as
3991 many threads as your system allows you to have.
3993 Attach/detach is supported for multi-threaded programs.
3995 Support for SSE registers was added for x86. This doesn't work for
3996 multi-threaded programs though.
3998 * Changes in MIPS configurations.
4000 Multi-arch support is enabled for all MIPS configurations.
4002 GDB can now be built as native debugger on SGI Irix 6.x systems for
4003 debugging n32 executables. (Debugging 64-bit executables is not yet
4006 * Unified support for hardware watchpoints in all x86 configurations.
4008 Most (if not all) native x86 configurations support hardware-assisted
4009 breakpoints and watchpoints in a unified manner. This support
4010 implements debug register sharing between watchpoints, which allows to
4011 put a virtually infinite number of watchpoints on the same address,
4012 and also supports watching regions up to 16 bytes with several debug
4015 The new maintenance command `maintenance show-debug-regs' toggles
4016 debugging print-outs in functions that insert, remove, and test
4017 watchpoints and hardware breakpoints.
4019 * Changes in the DJGPP native configuration.
4021 New command ``info dos sysinfo'' displays assorted information about
4022 the CPU, OS, memory, and DPMI server.
4024 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4025 display information about segment descriptors stored in GDT, LDT, and
4028 New commands ``info dos pde'' and ``info dos pte'' display entries
4029 from Page Directory and Page Tables (for now works with CWSDPMI only).
4030 New command ``info dos address-pte'' displays the Page Table entry for
4031 a given linear address.
4033 GDB can now pass command lines longer than 126 characters to the
4034 program being debugged (requires an update to the libdbg.a library
4035 which is part of the DJGPP development kit).
4037 DWARF2 debug info is now supported.
4039 It is now possible to `step' and `next' through calls to `longjmp'.
4041 * Changes in documentation.
4043 All GDB documentation was converted to GFDL, the GNU Free
4044 Documentation License.
4046 Tracepoints-related commands are now fully documented in the GDB
4049 TUI, the Text-mode User Interface, is now documented in the manual.
4051 Tracepoints-related commands are now fully documented in the GDB
4054 The "GDB Internals" manual now has an index. It also includes
4055 documentation of `ui_out' functions, GDB coding standards, x86
4056 hardware watchpoints, and memory region attributes.
4058 * GDB's version number moved to ``version.in''
4060 The Makefile variable VERSION has been replaced by the file
4061 ``version.in''. People creating GDB distributions should update the
4062 contents of this file.
4066 GUD support is now a standard part of the EMACS distribution.
4068 *** Changes in GDB 5.0:
4070 * Improved support for debugging FP programs on x86 targets
4072 Unified and much-improved support for debugging floating-point
4073 programs on all x86 targets. In particular, ``info float'' now
4074 displays the FP registers in the same format on all x86 targets, with
4075 greater level of detail.
4077 * Improvements and bugfixes in hardware-assisted watchpoints
4079 It is now possible to watch array elements, struct members, and
4080 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4081 on x86 targets no longer erroneously trigger when the address is
4084 * Improvements in the native DJGPP version of GDB
4086 The distribution now includes all the scripts and auxiliary files
4087 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4088 machines ``out of the box''.
4090 The DJGPP version can now debug programs that use signals. It is
4091 possible to catch signals that happened in the debuggee, deliver
4092 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4093 would kill the program being debugged.) Programs that hook hardware
4094 interrupts (keyboard, timer, etc.) can also be debugged.
4096 It is now possible to debug DJGPP programs that redirect their
4097 standard handles or switch them to raw (as opposed to cooked) mode, or
4098 even close them. The command ``run < foo > bar'' works as expected,
4099 and ``info terminal'' reports useful information about the debuggee's
4100 terminal, including raw/cooked mode, redirection, etc.
4102 The DJGPP version now uses termios functions for console I/O, which
4103 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4106 DOS-style file names with drive letters are now fully supported by
4109 It is now possible to debug DJGPP programs that switch their working
4110 directory. It is also possible to rerun the debuggee any number of
4111 times without restarting GDB; thus, you can use the same setup,
4112 breakpoints, etc. for many debugging sessions.
4114 * New native configurations
4116 ARM GNU/Linux arm*-*-linux*
4117 PowerPC GNU/Linux powerpc-*-linux*
4121 Motorola MCore mcore-*-*
4122 x86 VxWorks i[3456]86-*-vxworks*
4123 PowerPC VxWorks powerpc-*-vxworks*
4124 TI TMS320C80 tic80-*-*
4126 * OBSOLETE configurations
4128 Altos 3068 m68*-altos-*
4129 Convex c1-*-*, c2-*-*
4131 ARM RISCix arm-*-* (as host)
4134 Configurations that have been declared obsolete will be commented out,
4135 but the code will be left in place. If there is no activity to revive
4136 these configurations before the next release of GDB, the sources will
4137 be permanently REMOVED.
4139 * Gould support removed
4141 Support for the Gould PowerNode and NP1 has been removed.
4143 * New features for SVR4
4145 On SVR4 native platforms (such as Solaris), if you attach to a process
4146 without first loading a symbol file, GDB will now attempt to locate and
4147 load symbols from the running process's executable file.
4149 * Many C++ enhancements
4151 C++ support has been greatly improved. Overload resolution now works properly
4152 in almost all cases. RTTI support is on the way.
4154 * Remote targets can connect to a sub-program
4156 A popen(3) style serial-device has been added. This device starts a
4157 sub-process (such as a stand-alone simulator) and then communicates
4158 with that. The sub-program to run is specified using the syntax
4159 ``|<program> <args>'' vis:
4161 (gdb) set remotedebug 1
4162 (gdb) target extended-remote |mn10300-elf-sim program-args
4164 * MIPS 64 remote protocol
4166 A long standing bug in the mips64 remote protocol where by GDB
4167 expected certain 32 bit registers (ex SR) to be transfered as 32
4168 instead of 64 bits has been fixed.
4170 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4171 added to provide backward compatibility with older versions of GDB.
4173 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4175 The command ``set remotebinarydownload'' command has been replaced by
4176 ``set remote X-packet''. Other commands in ``set remote'' family
4177 include ``set remote P-packet''.
4179 * Breakpoint commands accept ranges.
4181 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4182 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4183 ``tracepoint passcount'' also accepts a range of tracepoints.
4185 * ``apropos'' command added.
4187 The ``apropos'' command searches through command names and
4188 documentation strings, printing out matches, making it much easier to
4189 try to find a command that does what you are looking for.
4193 A new machine oriented interface (MI) has been added to GDB. This
4194 interface is designed for debug environments running GDB as a separate
4195 process. This is part of the long term libGDB project. See the
4196 "GDB/MI" chapter of the GDB manual for further information. It can be
4197 enabled by configuring with:
4199 .../configure --enable-gdbmi
4201 *** Changes in GDB-4.18:
4203 * New native configurations
4205 HP-UX 10.20 hppa*-*-hpux10.20
4206 HP-UX 11.x hppa*-*-hpux11.0*
4207 M68K GNU/Linux m68*-*-linux*
4211 Fujitsu FR30 fr30-*-elf*
4212 Intel StrongARM strongarm-*-*
4213 Mitsubishi D30V d30v-*-*
4215 * OBSOLETE configurations
4217 Gould PowerNode, NP1 np1-*-*, pn-*-*
4219 Configurations that have been declared obsolete will be commented out,
4220 but the code will be left in place. If there is no activity to revive
4221 these configurations before the next release of GDB, the sources will
4222 be permanently REMOVED.
4226 As a compatibility experiment, GDB's source files buildsym.h and
4227 buildsym.c have been converted to pure standard C, no longer
4228 containing any K&R compatibility code. We believe that all systems in
4229 use today either come with a standard C compiler, or have a GCC port
4230 available. If this is not true, please report the affected
4231 configuration to bug-gdb@gnu.org immediately. See the README file for
4232 information about getting a standard C compiler if you don't have one
4237 GDB now uses readline 2.2.
4239 * set extension-language
4241 You can now control the mapping between filename extensions and source
4242 languages by using the `set extension-language' command. For instance,
4243 you can ask GDB to treat .c files as C++ by saying
4244 set extension-language .c c++
4245 The command `info extensions' lists all of the recognized extensions
4246 and their associated languages.
4248 * Setting processor type for PowerPC and RS/6000
4250 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4251 you can use the `set processor' command to specify what variant of the
4252 PowerPC family you are debugging. The command
4256 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4257 following PowerPC and RS6000 variants:
4259 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4260 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4262 403GC IBM PowerPC 403GC
4263 505 Motorola PowerPC 505
4264 860 Motorola PowerPC 860 or 850
4265 601 Motorola PowerPC 601
4266 602 Motorola PowerPC 602
4267 603 Motorola/IBM PowerPC 603 or 603e
4268 604 Motorola PowerPC 604 or 604e
4269 750 Motorola/IBM PowerPC 750 or 750
4271 At the moment, this command just tells GDB what to name the
4272 special-purpose processor registers. Since almost all the affected
4273 registers are inaccessible to user-level programs, this command is
4274 only useful for remote debugging in its present form.
4278 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4279 more extensive support for HP-UX. Added features include shared
4280 library support, kernel threads and hardware watchpoints for 11.00,
4281 support for HP's ANSI C and C++ compilers, and a compatibility mode
4282 for xdb and dbx commands.
4286 HP's donation includes the new concept of catchpoints, which is a
4287 generalization of the old catch command. On HP-UX, it is now possible
4288 to catch exec, fork, and vfork, as well as library loading.
4290 This means that the existing catch command has changed; its first
4291 argument now specifies the type of catch to be set up. See the
4292 output of "help catch" for a list of catchpoint types.
4294 * Debugging across forks
4296 On HP-UX, you can choose which process to debug when a fork() happens
4301 HP has donated a curses-based terminal user interface (TUI). To get
4302 it, build with --enable-tui. Although this can be enabled for any
4303 configuration, at present it only works for native HP debugging.
4305 * GDB remote protocol additions
4307 A new protocol packet 'X' that writes binary data is now available.
4308 Default behavior is to try 'X', then drop back to 'M' if the stub
4309 fails to respond. The settable variable `remotebinarydownload'
4310 allows explicit control over the use of 'X'.
4312 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4313 full 64-bit address. The command
4315 set remoteaddresssize 32
4317 can be used to revert to the old behaviour. For existing remote stubs
4318 the change should not be noticed, as the additional address information
4321 In order to assist in debugging stubs, you may use the maintenance
4322 command `packet' to send any text string to the stub. For instance,
4324 maint packet heythere
4326 sends the packet "$heythere#<checksum>". Note that it is very easy to
4327 disrupt a debugging session by sending the wrong packet at the wrong
4330 The compare-sections command allows you to compare section data on the
4331 target to what is in the executable file without uploading or
4332 downloading, by comparing CRC checksums.
4334 * Tracing can collect general expressions
4336 You may now collect general expressions at tracepoints. This requires
4337 further additions to the target-side stub; see tracepoint.c and
4338 doc/agentexpr.texi for further details.
4340 * mask-address variable for Mips
4342 For Mips targets, you may control the zeroing of the upper 32 bits of
4343 a 64-bit address by entering `set mask-address on'. This is mainly
4344 of interest to users of embedded R4xxx and R5xxx processors.
4346 * Higher serial baud rates
4348 GDB's serial code now allows you to specify baud rates 57600, 115200,
4349 230400, and 460800 baud. (Note that your host system may not be able
4350 to achieve all of these rates.)
4354 The i960 configuration now includes an initial implementation of a
4355 builtin simulator, contributed by Jim Wilson.
4358 *** Changes in GDB-4.17:
4360 * New native configurations
4362 Alpha GNU/Linux alpha*-*-linux*
4363 Unixware 2.x i[3456]86-unixware2*
4364 Irix 6.x mips*-sgi-irix6*
4365 PowerPC GNU/Linux powerpc-*-linux*
4366 PowerPC Solaris powerpcle-*-solaris*
4367 Sparc GNU/Linux sparc-*-linux*
4368 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4372 Argonaut Risc Chip (ARC) arc-*-*
4373 Hitachi H8/300S h8300*-*-*
4374 Matsushita MN10200 w/simulator mn10200-*-*
4375 Matsushita MN10300 w/simulator mn10300-*-*
4376 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4377 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4378 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4379 Mitsubishi D10V w/simulator d10v-*-*
4380 Mitsubishi M32R/D w/simulator m32r-*-elf*
4381 Tsqware Sparclet sparclet-*-*
4382 NEC V850 w/simulator v850-*-*
4384 * New debugging protocols
4386 ARM with RDI protocol arm*-*-*
4387 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4388 DDB and LSI variants of PMON protocol mips*-*-*
4389 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4390 PowerPC with SDS protocol powerpc{,le}-*-eabi
4391 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4395 All configurations can now understand and use the DWARF 2 debugging
4396 format. The choice is automatic, if the symbol file contains DWARF 2
4401 GDB now includes basic Java language support. This support is
4402 only useful with Java compilers that produce native machine code.
4404 * solib-absolute-prefix and solib-search-path
4406 For SunOS and SVR4 shared libraries, you may now set the prefix for
4407 loading absolute shared library symbol files, and the search path for
4408 locating non-absolute shared library symbol files.
4410 * Live range splitting
4412 GDB can now effectively debug code for which GCC has performed live
4413 range splitting as part of its optimization. See gdb/doc/LRS for
4414 more details on the expected format of the stabs information.
4418 GDB's support for the GNU Hurd, including thread debugging, has been
4419 updated to work with current versions of the Hurd.
4423 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4424 instruction set. ARM GDB automatically detects when Thumb
4425 instructions are in use, and adjusts disassembly and backtracing
4430 GDB's MIPS target configurations now handle the MIP16 16-bit
4435 GDB now includes support for overlays; if an executable has been
4436 linked such that multiple sections are based at the same address, GDB
4437 will decide which section to use for symbolic info. You can choose to
4438 control the decision manually, using overlay commands, or implement
4439 additional target-side support and use "overlay load-target" to bring
4440 in the overlay mapping. Do "help overlay" for more detail.
4444 The command "info symbol <address>" displays information about
4445 the symbol at the specified address.
4449 The standard remote protocol now includes an extension that allows
4450 asynchronous collection and display of trace data. This requires
4451 extensive support in the target-side debugging stub. Tracing mode
4452 includes a new interaction mode in GDB and new commands: see the
4453 file tracepoint.c for more details.
4457 Configurations for embedded MIPS now include a simulator contributed
4458 by Cygnus Solutions. The simulator supports the instruction sets
4459 of most MIPS variants.
4463 Sparc configurations may now include the ERC32 simulator contributed
4464 by the European Space Agency. The simulator is not built into
4465 Sparc targets by default; configure with --enable-sim to include it.
4469 For target configurations that may include multiple variants of a
4470 basic architecture (such as MIPS and SH), you may now set the
4471 architecture explicitly. "set arch" sets, "info arch" lists
4472 the possible architectures.
4474 *** Changes in GDB-4.16:
4476 * New native configurations
4478 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4479 M68K NetBSD m68k-*-netbsd*
4480 PowerPC AIX 4.x powerpc-*-aix*
4481 PowerPC MacOS powerpc-*-macos*
4482 PowerPC Windows NT powerpcle-*-cygwin32
4483 RS/6000 AIX 4.x rs6000-*-aix4*
4487 ARM with RDP protocol arm-*-*
4488 I960 with MON960 i960-*-coff
4489 MIPS VxWorks mips*-*-vxworks*
4490 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4491 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4493 Matra Sparclet sparclet-*-*
4497 The powerpc-eabi configuration now includes the PSIM simulator,
4498 contributed by Andrew Cagney, with assistance from Mike Meissner.
4499 PSIM is a very elaborate model of the PowerPC, including not only
4500 basic instruction set execution, but also details of execution unit
4501 performance and I/O hardware. See sim/ppc/README for more details.
4505 GDB now works with Solaris 2.5.
4507 * Windows 95/NT native
4509 GDB will now work as a native debugger on Windows 95 and Windows NT.
4510 To build it from source, you must use the "gnu-win32" environment,
4511 which uses a DLL to emulate enough of Unix to run the GNU tools.
4512 Further information, binaries, and sources are available at
4513 ftp.cygnus.com, under pub/gnu-win32.
4515 * dont-repeat command
4517 If a user-defined command includes the command `dont-repeat', then the
4518 command will not be repeated if the user just types return. This is
4519 useful if the command is time-consuming to run, so that accidental
4520 extra keystrokes don't run the same command many times.
4522 * Send break instead of ^C
4524 The standard remote protocol now includes an option to send a break
4525 rather than a ^C to the target in order to interrupt it. By default,
4526 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4528 * Remote protocol timeout
4530 The standard remote protocol includes a new variable `remotetimeout'
4531 that allows you to set the number of seconds before GDB gives up trying
4532 to read from the target. The default value is 2.
4534 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4536 By default GDB will automatically keep track of objects as they are
4537 loaded and unloaded by the dynamic linker. By using the command `set
4538 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4539 when shared library events occur, thus allowing you to set breakpoints
4540 in shared libraries which are explicitly loaded by the inferior.
4542 Note this feature does not work on hpux8. On hpux9 you must link
4543 /usr/lib/end.o into your program. This feature should work
4544 automatically on hpux10.
4546 * Irix 5.x hardware watchpoint support
4548 Irix 5 configurations now support the use of hardware watchpoints.
4550 * Mips protocol "SYN garbage limit"
4552 When debugging a Mips target using the `target mips' protocol, you
4553 may set the number of characters that GDB will ignore by setting
4554 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4555 every character. The default value is 1050.
4557 * Recording and replaying remote debug sessions
4559 If you set `remotelogfile' to the name of a file, gdb will write to it
4560 a recording of a remote debug session. This recording may then be
4561 replayed back to gdb using "gdbreplay". See gdbserver/README for
4562 details. This is useful when you have a problem with GDB while doing
4563 remote debugging; you can make a recording of the session and send it
4564 to someone else, who can then recreate the problem.
4566 * Speedups for remote debugging
4568 GDB includes speedups for downloading and stepping MIPS systems using
4569 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4570 and more efficient S-record downloading.
4572 * Memory use reductions and statistics collection
4574 GDB now uses less memory and reports statistics about memory usage.
4575 Try the `maint print statistics' command, for example.
4577 *** Changes in GDB-4.15:
4579 * Psymtabs for XCOFF
4581 The symbol reader for AIX GDB now uses partial symbol tables. This
4582 can greatly improve startup time, especially for large executables.
4584 * Remote targets use caching
4586 Remote targets now use a data cache to speed up communication with the
4587 remote side. The data cache could lead to incorrect results because
4588 it doesn't know about volatile variables, thus making it impossible to
4589 debug targets which use memory mapped I/O devices. `set remotecache
4590 off' turns the the data cache off.
4592 * Remote targets may have threads
4594 The standard remote protocol now includes support for multiple threads
4595 in the target system, using new protocol commands 'H' and 'T'. See
4596 gdb/remote.c for details.
4600 If GDB is configured with `--enable-netrom', then it will include
4601 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4602 acts as though it is a bank of ROM on the target board, but you can
4603 write into it over the network. GDB's support consists only of
4604 support for fast loading into the emulated ROM; to debug, you must use
4605 another protocol, such as standard remote protocol. The usual
4606 sequence is something like
4608 target nrom <netrom-hostname>
4610 target remote <netrom-hostname>:1235
4614 GDB now includes support for the Apple Macintosh, as a host only. It
4615 may be run as either an MPW tool or as a standalone application, and
4616 it can debug through the serial port. All the usual GDB commands are
4617 available, but to the target command, you must supply "serial" as the
4618 device type instead of "/dev/ttyXX". See mpw-README in the main
4619 directory for more information on how to build. The MPW configuration
4620 scripts */mpw-config.in support only a few targets, and only the
4621 mips-idt-ecoff target has been tested.
4625 GDB configuration now uses autoconf. This is not user-visible,
4626 but does simplify configuration and building.
4630 GDB now supports hpux10.
4632 *** Changes in GDB-4.14:
4634 * New native configurations
4636 x86 FreeBSD i[345]86-*-freebsd
4637 x86 NetBSD i[345]86-*-netbsd
4638 NS32k NetBSD ns32k-*-netbsd
4639 Sparc NetBSD sparc-*-netbsd
4643 A29K VxWorks a29k-*-vxworks
4644 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4645 CPU32 EST-300 emulator m68*-*-est*
4646 PowerPC ELF powerpc-*-elf
4649 * Alpha OSF/1 support for procfs
4651 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4652 possible to attach to running processes. As the mounting of the /proc
4653 filesystem is optional on the Alpha, GDB automatically determines
4654 the availability of /proc during startup. This can lead to problems
4655 if /proc is unmounted after GDB has been started.
4657 * Arguments to user-defined commands
4659 User commands may accept up to 10 arguments separated by whitespace.
4660 Arguments are accessed within the user command via $arg0..$arg9. A
4663 print $arg0 + $arg1 + $arg2
4665 To execute the command use:
4668 Defines the command "adder" which prints the sum of its three arguments.
4669 Note the arguments are text substitutions, so they may reference variables,
4670 use complex expressions, or even perform inferior function calls.
4672 * New `if' and `while' commands
4674 This makes it possible to write more sophisticated user-defined
4675 commands. Both commands take a single argument, which is the
4676 expression to evaluate, and must be followed by the commands to
4677 execute, one per line, if the expression is nonzero, the list being
4678 terminated by the word `end'. The `if' command list may include an
4679 `else' word, which causes the following commands to be executed only
4680 if the expression is zero.
4682 * Fortran source language mode
4684 GDB now includes partial support for Fortran 77. It will recognize
4685 Fortran programs and can evaluate a subset of Fortran expressions, but
4686 variables and functions may not be handled correctly. GDB will work
4687 with G77, but does not yet know much about symbols emitted by other
4690 * Better HPUX support
4692 Most debugging facilities now work on dynamic executables for HPPAs
4693 running hpux9 or later. You can attach to running dynamically linked
4694 processes, but by default the dynamic libraries will be read-only, so
4695 for instance you won't be able to put breakpoints in them. To change
4696 that behavior do the following before running the program:
4702 This will cause the libraries to be mapped private and read-write.
4703 To revert to the normal behavior, do this:
4709 You cannot set breakpoints or examine data in the library until after
4710 the library is loaded if the function/data symbols do not have
4713 GDB can now also read debug symbols produced by the HP C compiler on
4714 HPPAs (sorry, no C++, Fortran or 68k support).
4716 * Target byte order now dynamically selectable
4718 You can choose which byte order to use with a target system, via the
4719 commands "set endian big" and "set endian little", and you can see the
4720 current setting by using "show endian". You can also give the command
4721 "set endian auto", in which case GDB will use the byte order
4722 associated with the executable. Currently, only embedded MIPS
4723 configurations support dynamic selection of target byte order.
4725 * New DOS host serial code
4727 This version uses DPMI interrupts to handle buffered I/O, so you
4728 no longer need to run asynctsr when debugging boards connected to
4731 *** Changes in GDB-4.13:
4733 * New "complete" command
4735 This lists all the possible completions for the rest of the line, if it
4736 were to be given as a command itself. This is intended for use by emacs.
4738 * Trailing space optional in prompt
4740 "set prompt" no longer adds a space for you after the prompt you set. This
4741 allows you to set a prompt which ends in a space or one that does not.
4743 * Breakpoint hit counts
4745 "info break" now displays a count of the number of times the breakpoint
4746 has been hit. This is especially useful in conjunction with "ignore"; you
4747 can ignore a large number of breakpoint hits, look at the breakpoint info
4748 to see how many times the breakpoint was hit, then run again, ignoring one
4749 less than that number, and this will get you quickly to the last hit of
4752 * Ability to stop printing at NULL character
4754 "set print null-stop" will cause GDB to stop printing the characters of
4755 an array when the first NULL is encountered. This is useful when large
4756 arrays actually contain only short strings.
4758 * Shared library breakpoints
4760 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4761 breakpoints in shared libraries before the executable is run.
4763 * Hardware watchpoints
4765 There is a new hardware breakpoint for the watch command for sparclite
4766 targets. See gdb/sparclite/hw_breakpoint.note.
4768 Hardware watchpoints are also now supported under GNU/Linux.
4772 Annotations have been added. These are for use with graphical interfaces,
4773 and are still experimental. Currently only gdba.el uses these.
4775 * Improved Irix 5 support
4777 GDB now works properly with Irix 5.2.
4779 * Improved HPPA support
4781 GDB now works properly with the latest GCC and GAS.
4783 * New native configurations
4785 Sequent PTX4 i[34]86-sequent-ptx4
4786 HPPA running OSF/1 hppa*-*-osf*
4787 Atari TT running SVR4 m68*-*-sysv4*
4788 RS/6000 LynxOS rs6000-*-lynxos*
4792 OS/9000 i[34]86-*-os9k
4793 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4796 * Hitachi SH7000 and E7000-PC ICE support
4798 There is now support for communicating with the Hitachi E7000-PC ICE.
4799 This is available automatically when GDB is configured for the SH.
4803 As usual, a variety of small fixes and improvements, both generic
4804 and configuration-specific. See the ChangeLog for more detail.
4806 *** Changes in GDB-4.12:
4808 * Irix 5 is now supported
4812 GDB-4.12 on the HPPA has a number of changes which make it unable
4813 to debug the output from the currently released versions of GCC and
4814 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4815 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4816 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4819 *** Changes in GDB-4.11:
4821 * User visible changes:
4825 The "set remotedebug" option is now consistent between the mips remote
4826 target, remote targets using the gdb-specific protocol, UDI (AMD's
4827 debug protocol for the 29k) and the 88k bug monitor. It is now an
4828 integer specifying a debug level (normally 0 or 1, but 2 means more
4829 debugging info for the mips target).
4831 * DEC Alpha native support
4833 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4834 debug info, but GDB works fairly well with the DEC compiler and should
4835 work with a future GCC release. See the README file for a few
4836 Alpha-specific notes.
4838 * Preliminary thread implementation
4840 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4842 * LynxOS native and target support for 386
4844 This release has been hosted on LynxOS 2.2, and also can be configured
4845 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4848 * Improvements in C++ mangling/demangling.
4850 This release has much better g++ debugging, specifically in name
4851 mangling/demangling, virtual function calls, print virtual table,
4852 call methods, ...etc.
4854 *** Changes in GDB-4.10:
4856 * User visible changes:
4858 Remote debugging using the GDB-specific (`target remote') protocol now
4859 supports the `load' command. This is only useful if you have some
4860 other way of getting the stub to the target system, and you can put it
4861 somewhere in memory where it won't get clobbered by the download.
4863 Filename completion now works.
4865 When run under emacs mode, the "info line" command now causes the
4866 arrow to point to the line specified. Also, "info line" prints
4867 addresses in symbolic form (as well as hex).
4869 All vxworks based targets now support a user settable option, called
4870 vxworks-timeout. This option represents the number of seconds gdb
4871 should wait for responses to rpc's. You might want to use this if
4872 your vxworks target is, perhaps, a slow software simulator or happens
4873 to be on the far side of a thin network line.
4877 This release contains support for using a DEC alpha as a GDB host for
4878 cross debugging. Native alpha debugging is not supported yet.
4881 *** Changes in GDB-4.9:
4885 This is the first GDB release which is accompanied by a matching testsuite.
4886 The testsuite requires installation of dejagnu, which should be available
4887 via ftp from most sites that carry GNU software.
4891 'Cfront' style demangling has had its name changed to 'ARM' style, to
4892 emphasize that it was written from the specifications in the C++ Annotated
4893 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4894 disclaimers, it still generated too much confusion with users attempting to
4895 use gdb with AT&T cfront.
4899 GDB now uses a standard remote interface to a simulator library.
4900 So far, the library contains simulators for the Zilog Z8001/2, the
4901 Hitachi H8/300, H8/500 and Super-H.
4903 * New targets supported
4905 H8/300 simulator h8300-hitachi-hms or h8300hms
4906 H8/500 simulator h8500-hitachi-hms or h8500hms
4907 SH simulator sh-hitachi-hms or sh
4908 Z8000 simulator z8k-zilog-none or z8ksim
4909 IDT MIPS board over serial line mips-idt-ecoff
4911 Cross-debugging to GO32 targets is supported. It requires a custom
4912 version of the i386-stub.c module which is integrated with the
4913 GO32 memory extender.
4915 * New remote protocols
4917 MIPS remote debugging protocol.
4919 * New source languages supported
4921 This version includes preliminary support for Chill, a Pascal like language
4922 used by telecommunications companies. Chill support is also being integrated
4923 into the GNU compiler, but we don't know when it will be publically available.
4926 *** Changes in GDB-4.8:
4928 * HP Precision Architecture supported
4930 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4931 version of this support was available as a set of patches from the
4932 University of Utah. GDB does not support debugging of programs
4933 compiled with the HP compiler, because HP will not document their file
4934 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4935 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4937 Many problems in the preliminary version have been fixed.
4939 * Faster and better demangling
4941 We have improved template demangling and fixed numerous bugs in the GNU style
4942 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4943 character types (wchar_t) are now supported. Demangling of each symbol is now
4944 only done once, and is cached when the symbol table for a file is read in.
4945 This results in a small increase in memory usage for C programs, a moderate
4946 increase in memory usage for C++ programs, and a fantastic speedup in
4949 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4950 from the specifications in the Annotated Reference Manual, which AT&T's
4951 compiler does not actually implement.
4953 * G++ multiple inheritance compiler problem
4955 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4956 inheritance lattices was reworked to properly discover ambiguities. We
4957 recently found an example which causes this new algorithm to fail in a
4958 very subtle way, producing bad debug information for those classes.
4959 The file 'gcc.patch' (in this directory) can be applied to gcc to
4960 circumvent the problem. A future GCC release will contain a complete
4963 The previous G++ debug info problem (mentioned below for the gdb-4.7
4964 release) is fixed in gcc version 2.3.2.
4966 * Improved configure script
4968 The `configure' script will now attempt to guess your system type if
4969 you don't supply a host system type. The old scheme of supplying a
4970 host system triplet is preferable over using this. All the magic is
4971 done in the new `config.guess' script. Examine it for details.
4973 We have also brought our configure script much more in line with the FSF's
4974 version. It now supports the --with-xxx options. In particular,
4975 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4976 The resulting GDB will not be able to read arbitrary object file formats --
4977 only the format ``expected'' to be used on the configured target system.
4978 We hope to make this the default in a future release.
4980 * Documentation improvements
4982 There's new internal documentation on how to modify GDB, and how to
4983 produce clean changes to the code. We implore people to read it
4984 before submitting changes.
4986 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4987 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4988 `info' files are also provided. To build `info' files from scratch,
4989 you will need the latest `makeinfo' release, which will be available in
4990 a future texinfo-X.Y release.
4992 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4993 We're not sure exactly which versions have this problem, but it has
4994 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4995 or better. If that isn't possible, there is a patch in
4996 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4997 around this problem.
5001 GDB now supports array constants that can be used in expressions typed in by
5002 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5003 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5006 The new directory `gdb/sparclite' contains a program that demonstrates
5007 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5009 * New native hosts supported
5011 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5012 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5014 * New targets supported
5016 AMD 29k family via UDI a29k-amd-udi or udi29k
5018 * New file formats supported
5020 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5021 HPUX core files, and SCO 3.2v2 core files.
5025 Attaching to processes now works again; thanks for the many bug reports.
5027 We have also stomped on a bunch of core dumps caused by
5028 printf_filtered("%s") problems.
5030 We eliminated a copyright problem on the rpc and ptrace header files
5031 for VxWorks, which was discovered at the last minute during the 4.7
5032 release. You should now be able to build a VxWorks GDB.
5034 You can now interrupt gdb while an attached process is running. This
5035 will cause the attached process to stop, and give control back to GDB.
5037 We fixed problems caused by using too many file descriptors
5038 for reading symbols from object files and libraries. This was
5039 especially a problem for programs that used many (~100) shared
5042 The `step' command now only enters a subroutine if there is line number
5043 information for the subroutine. Otherwise it acts like the `next'
5044 command. Previously, `step' would enter subroutines if there was
5045 any debugging information about the routine. This avoids problems
5046 when using `cc -g1' on MIPS machines.
5048 * Internal improvements
5050 GDB's internal interfaces have been improved to make it easier to support
5051 debugging of multiple languages in the future.
5053 GDB now uses a common structure for symbol information internally.
5054 Minimal symbols (derived from linkage symbols in object files), partial
5055 symbols (from a quick scan of debug information), and full symbols
5056 contain a common subset of information, making it easier to write
5057 shared code that handles any of them.
5059 * New command line options
5061 We now accept --silent as an alias for --quiet.
5065 The memory-mapped-malloc library is now licensed under the GNU Library
5066 General Public License.
5068 *** Changes in GDB-4.7:
5070 * Host/native/target split
5072 GDB has had some major internal surgery to untangle the support for
5073 hosts and remote targets. Now, when you configure GDB for a remote
5074 target, it will no longer load in all of the support for debugging
5075 local programs on the host. When fully completed and tested, this will
5076 ensure that arbitrary host/target combinations are possible.
5078 The primary conceptual shift is to separate the non-portable code in
5079 GDB into three categories. Host specific code is required any time GDB
5080 is compiled on that host, regardless of the target. Target specific
5081 code relates to the peculiarities of the target, but can be compiled on
5082 any host. Native specific code is everything else: it can only be
5083 built when the host and target are the same system. Child process
5084 handling and core file support are two common `native' examples.
5086 GDB's use of /proc for controlling Unix child processes is now cleaner.
5087 It has been split out into a single module under the `target_ops' vector,
5088 plus two native-dependent functions for each system that uses /proc.
5090 * New hosts supported
5092 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5093 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5094 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5096 * New targets supported
5098 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5099 68030 and CPU32 m68030-*-*, m68332-*-*
5101 * New native hosts supported
5103 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5104 (386bsd is not well tested yet)
5105 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5107 * New file formats supported
5109 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5110 supports reading of `a.out.adobe' object files, which are an a.out
5111 format extended with minimal information about multiple sections.
5115 `show copying' is the same as the old `info copying'.
5116 `show warranty' is the same as `info warrantee'.
5117 These were renamed for consistency. The old commands continue to work.
5119 `info handle' is a new alias for `info signals'.
5121 You can now define pre-command hooks, which attach arbitrary command
5122 scripts to any command. The commands in the hook will be executed
5123 prior to the user's command. You can also create a hook which will be
5124 executed whenever the program stops. See gdb.texinfo.
5128 We now deal with Cfront style name mangling, and can even extract type
5129 info from mangled symbols. GDB can automatically figure out which
5130 symbol mangling style your C++ compiler uses.
5132 Calling of methods and virtual functions has been improved as well.
5136 The crash that occured when debugging Sun Ansi-C compiled binaries is
5137 fixed. This was due to mishandling of the extra N_SO stabs output
5140 We also finally got Ultrix 4.2 running in house, and fixed core file
5141 support, with help from a dozen people on the net.
5143 John M. Farrell discovered that the reason that single-stepping was so
5144 slow on all of the Mips based platforms (primarily SGI and DEC) was
5145 that we were trying to demangle and lookup a symbol used for internal
5146 purposes on every instruction that was being stepped through. Changing
5147 the name of that symbol so that it couldn't be mistaken for a C++
5148 mangled symbol sped things up a great deal.
5150 Rich Pixley sped up symbol lookups in general by getting much smarter
5151 about when C++ symbol mangling is necessary. This should make symbol
5152 completion (TAB on the command line) much faster. It's not as fast as
5153 we'd like, but it's significantly faster than gdb-4.6.
5157 A new user controllable variable 'call_scratch_address' can
5158 specify the location of a scratch area to be used when GDB
5159 calls a function in the target. This is necessary because the
5160 usual method of putting the scratch area on the stack does not work
5161 in systems that have separate instruction and data spaces.
5163 We integrated changes to support the 29k UDI (Universal Debugger
5164 Interface), but discovered at the last minute that we didn't have all
5165 of the appropriate copyright paperwork. We are working with AMD to
5166 resolve this, and hope to have it available soon.
5170 We have sped up the remote serial line protocol, especially for targets
5171 with lots of registers. It now supports a new `expedited status' ('T')
5172 message which can be used in place of the existing 'S' status message.
5173 This allows the remote stub to send only the registers that GDB
5174 needs to make a quick decision about single-stepping or conditional
5175 breakpoints, eliminating the need to fetch the entire register set for
5176 each instruction being stepped through.
5178 The GDB remote serial protocol now implements a write-through cache for
5179 registers, only re-reading the registers if the target has run.
5181 There is also a new remote serial stub for SPARC processors. You can
5182 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5183 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5184 processor with a serial port.
5188 Configure.in files have become much easier to read and modify. A new
5189 `table driven' format makes it more obvious what configurations are
5190 supported, and what files each one uses.
5194 There is a new opcodes library which will eventually contain all of the
5195 disassembly routines and opcode tables. At present, it only contains
5196 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5197 disassembler (binutils/objdump) to share these routines.
5199 The libiberty library is now copylefted under the GNU Library General
5200 Public License. This allows more liberal use, and was done so libg++
5201 can use it. This makes no difference to GDB, since the Library License
5202 grants all the rights from the General Public License.
5206 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5207 reference to the stabs symbol info used by the debugger. It is (as far
5208 as we know) the only published document on this fascinating topic. We
5209 encourage you to read it, compare it to the stabs information on your
5210 system, and send improvements on the document in general (to
5211 bug-gdb@prep.ai.mit.edu).
5213 And, of course, many bugs have been fixed.
5216 *** Changes in GDB-4.6:
5218 * Better support for C++ function names
5220 GDB now accepts as input the "demangled form" of C++ overloaded function
5221 names and member function names, and can do command completion on such names
5222 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5223 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5224 Make use of command completion, it is your friend.
5226 GDB also now accepts a variety of C++ mangled symbol formats. They are
5227 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5228 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5229 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5230 for the list of formats.
5232 * G++ symbol mangling problem
5234 Recent versions of gcc have a bug in how they emit debugging information for
5235 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5236 directory) can be applied to gcc to fix the problem. Alternatively, if you
5237 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5238 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5239 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5242 * New 'maintenance' command
5244 All of the commands related to hacking GDB internals have been moved out of
5245 the main command set, and now live behind the 'maintenance' command. This
5246 can also be abbreviated as 'mt'. The following changes were made:
5248 dump-me -> maintenance dump-me
5249 info all-breakpoints -> maintenance info breakpoints
5250 printmsyms -> maintenance print msyms
5251 printobjfiles -> maintenance print objfiles
5252 printpsyms -> maintenance print psymbols
5253 printsyms -> maintenance print symbols
5255 The following commands are new:
5257 maintenance demangle Call internal GDB demangler routine to
5258 demangle a C++ link name and prints the result.
5259 maintenance print type Print a type chain for a given symbol
5261 * Change to .gdbinit file processing
5263 We now read the $HOME/.gdbinit file before processing the argv arguments
5264 (e.g. reading symbol files or core files). This allows global parameters to
5265 be set, which will apply during the symbol reading. The ./.gdbinit is still
5266 read after argv processing.
5268 * New hosts supported
5270 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5272 GNU/Linux support i386-unknown-linux or linux
5274 We are also including code to support the HP/PA running BSD and HPUX. This
5275 is almost guaranteed not to work, as we didn't have time to test or build it
5276 for this release. We are including it so that the more adventurous (or
5277 masochistic) of you can play with it. We also had major problems with the
5278 fact that the compiler that we got from HP doesn't support the -g option.
5281 * New targets supported
5283 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5285 * More smarts about finding #include files
5287 GDB now remembers the compilation directory for all include files, and for
5288 all files from which C is generated (like yacc and lex sources). This
5289 greatly improves GDB's ability to find yacc/lex sources, and include files,
5290 especially if you are debugging your program from a directory different from
5291 the one that contains your sources.
5293 We also fixed a bug which caused difficulty with listing and setting
5294 breakpoints in include files which contain C code. (In the past, you had to
5295 try twice in order to list an include file that you hadn't looked at before.)
5297 * Interesting infernals change
5299 GDB now deals with arbitrary numbers of sections, where the symbols for each
5300 section must be relocated relative to that section's landing place in the
5301 target's address space. This work was needed to support ELF with embedded
5302 stabs used by Solaris-2.0.
5304 * Bug fixes (of course!)
5306 There have been loads of fixes for the following things:
5307 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5308 i960, stabs, DOS(GO32), procfs, etc...
5310 See the ChangeLog for details.
5312 *** Changes in GDB-4.5:
5314 * New machines supported (host and target)
5316 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5318 SGI Irix-4.x mips-sgi-irix4 or iris4
5320 * New malloc package
5322 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5323 Mmalloc is capable of handling mutiple heaps of memory. It is also
5324 capable of saving a heap to a file, and then mapping it back in later.
5325 This can be used to greatly speedup the startup of GDB by using a
5326 pre-parsed symbol table which lives in a mmalloc managed heap. For
5327 more details, please read mmalloc/mmalloc.texi.
5331 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5332 'help info proc' for details.
5334 * MIPS ecoff symbol table format
5336 The code that reads MIPS symbol table format is now supported on all hosts.
5337 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5340 * File name changes for MS-DOS
5342 Many files in the config directories have been renamed to make it easier to
5343 support GDB on MS-DOSe systems (which have very restrictive file name
5344 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5345 environment) is close to working but has some remaining problems. Note
5346 that debugging of DOS programs is not supported, due to limitations
5347 in the ``operating system'', but it can be used to host cross-debugging.
5349 * Cross byte order fixes
5351 Many fixes have been made to support cross debugging of Sparc and MIPS
5352 targets from hosts whose byte order differs.
5354 * New -mapped and -readnow options
5356 If memory-mapped files are available on your system through the 'mmap'
5357 system call, you can use the -mapped option on the `file' or
5358 `symbol-file' commands to cause GDB to write the symbols from your
5359 program into a reusable file. If the program you are debugging is
5360 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5361 Future GDB debugging sessions will notice the presence of this file,
5362 and will quickly map in symbol information from it, rather than reading
5363 the symbol table from the executable program. Using the '-mapped'
5364 option in a GDB `file' or `symbol-file' command has the same effect as
5365 starting GDB with the '-mapped' command-line option.
5367 You can cause GDB to read the entire symbol table immediately by using
5368 the '-readnow' option with any of the commands that load symbol table
5369 information (or on the GDB command line). This makes the command
5370 slower, but makes future operations faster.
5372 The -mapped and -readnow options are typically combined in order to
5373 build a `fred.syms' file that contains complete symbol information.
5374 A simple GDB invocation to do nothing but build a `.syms' file for future
5377 gdb -batch -nx -mapped -readnow programname
5379 The `.syms' file is specific to the host machine on which GDB is run.
5380 It holds an exact image of GDB's internal symbol table. It cannot be
5381 shared across multiple host platforms.
5383 * longjmp() handling
5385 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5386 siglongjmp() without losing control. This feature has not yet been ported to
5387 all systems. It currently works on many 386 platforms, all MIPS-based
5388 platforms (SGI, DECstation, etc), and Sun3/4.
5392 Preliminary work has been put in to support the new Solaris OS from Sun. At
5393 this time, it can control and debug processes, but it is not capable of
5398 As always, many many bug fixes. The major areas were with g++, and mipsread.
5399 People using the MIPS-based platforms should experience fewer mysterious
5400 crashes and trashed symbol tables.
5402 *** Changes in GDB-4.4:
5404 * New machines supported (host and target)
5406 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5408 BSD Reno on Vax vax-dec-bsd
5409 Ultrix on Vax vax-dec-ultrix
5411 * New machines supported (target)
5413 AMD 29000 embedded, using EBMON a29k-none-none
5417 GDB continues to improve its handling of C++. `References' work better.
5418 The demangler has also been improved, and now deals with symbols mangled as
5419 per the Annotated C++ Reference Guide.
5421 GDB also now handles `stabs' symbol information embedded in MIPS
5422 `ecoff' symbol tables. Since the ecoff format was not easily
5423 extensible to handle new languages such as C++, this appeared to be a
5424 good way to put C++ debugging info into MIPS binaries. This option
5425 will be supported in the GNU C compiler, version 2, when it is
5428 * New features for SVR4
5430 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5431 shared libraries. Debugging dynamically linked programs should present
5432 only minor differences from debugging statically linked programs.
5434 The `info proc' command will print out information about any process
5435 on an SVR4 system (including the one you are debugging). At the moment,
5436 it prints the address mappings of the process.
5438 If you bring up GDB on another SVR4 system, please send mail to
5439 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5441 * Better dynamic linking support in SunOS
5443 Reading symbols from shared libraries which contain debugging symbols
5444 now works properly. However, there remain issues such as automatic
5445 skipping of `transfer vector' code during function calls, which
5446 make it harder to debug code in a shared library, than to debug the
5447 same code linked statically.
5451 GDB is now using the latest `getopt' routines from the FSF. This
5452 version accepts the -- prefix for options with long names. GDB will
5453 continue to accept the old forms (-option and +option) as well.
5454 Various single letter abbreviations for options have been explicity
5455 added to the option table so that they won't get overshadowed in the
5456 future by other options that begin with the same letter.
5460 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5461 Many assorted bugs have been handled. Many more remain to be handled.
5462 See the various ChangeLog files (primarily in gdb and bfd) for details.
5465 *** Changes in GDB-4.3:
5467 * New machines supported (host and target)
5469 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5470 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5471 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5473 * Almost SCO Unix support
5475 We had hoped to support:
5476 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5477 (except for core file support), but we discovered very late in the release
5478 that it has problems with process groups that render gdb unusable. Sorry
5479 about that. I encourage people to fix it and post the fixes.
5481 * Preliminary ELF and DWARF support
5483 GDB can read ELF object files on System V Release 4, and can handle
5484 debugging records for C, in DWARF format, in ELF files. This support
5485 is preliminary. If you bring up GDB on another SVR4 system, please
5486 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5491 GDB now uses the latest `readline' library. One user-visible change
5492 is that two tabs will list possible command completions, which previously
5493 required typing M-? (meta-question mark, or ESC ?).
5497 The `stepi' bug that many of you noticed has been squashed.
5498 Many bugs in C++ have been handled. Many more remain to be handled.
5499 See the various ChangeLog files (primarily in gdb and bfd) for details.
5501 * State of the MIPS world (in case you wondered):
5503 GDB can understand the symbol tables emitted by the compilers
5504 supplied by most vendors of MIPS-based machines, including DEC. These
5505 symbol tables are in a format that essentially nobody else uses.
5507 Some versions of gcc come with an assembler post-processor called
5508 mips-tfile. This program is required if you want to do source-level
5509 debugging of gcc-compiled programs. I believe FSF does not ship
5510 mips-tfile with gcc version 1, but it will eventually come with gcc
5513 Debugging of g++ output remains a problem. g++ version 1.xx does not
5514 really support it at all. (If you're lucky, you should be able to get
5515 line numbers and stack traces to work, but no parameters or local
5516 variables.) With some work it should be possible to improve the
5519 When gcc version 2 is released, you will have somewhat better luck.
5520 However, even then you will get confusing results for inheritance and
5523 We will eventually provide full debugging of g++ output on
5524 DECstations. This will probably involve some kind of stabs-in-ecoff
5525 encapulation, but the details have not been worked out yet.
5528 *** Changes in GDB-4.2:
5530 * Improved configuration
5532 Only one copy of `configure' exists now, and it is not self-modifying.
5533 Porting BFD is simpler.
5537 The `step' and `next' commands now only stop at the first instruction
5538 of a source line. This prevents the multiple stops that used to occur
5539 in switch statements, for-loops, etc. `Step' continues to stop if a
5540 function that has debugging information is called within the line.
5544 Lots of small bugs fixed. More remain.
5546 * New host supported (not target)
5548 Intel 386 PC clone running Mach i386-none-mach
5551 *** Changes in GDB-4.1:
5553 * Multiple source language support
5555 GDB now has internal scaffolding to handle several source languages.
5556 It determines the type of each source file from its filename extension,
5557 and will switch expression parsing and number formatting to match the
5558 language of the function in the currently selected stack frame.
5559 You can also specifically set the language to be used, with
5560 `set language c' or `set language modula-2'.
5564 GDB now has preliminary support for the GNU Modula-2 compiler,
5565 currently under development at the State University of New York at
5566 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5567 continue through the fall of 1991 and into 1992.
5569 Other Modula-2 compilers are currently not supported, and attempting to
5570 debug programs compiled with them will likely result in an error as the
5571 symbol table is read. Feel free to work on it, though!
5573 There are hooks in GDB for strict type checking and range checking,
5574 in the `Modula-2 philosophy', but they do not currently work.
5578 GDB can now write to executable and core files (e.g. patch
5579 a variable's value). You must turn this switch on, specify
5580 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5581 by assigning a new value to a variable. Modifications take
5584 * Automatic SunOS shared library reading
5586 When you run your program, GDB automatically determines where its
5587 shared libraries (if any) have been loaded, and reads their symbols.
5588 The `share' command is no longer needed. This also works when
5589 examining core files.
5593 You can specify the number of lines that the `list' command shows.
5596 * New machines supported (host and target)
5598 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5599 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5600 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5602 * New hosts supported (not targets)
5604 IBM RT/PC: romp-ibm-aix or rtpc
5606 * New targets supported (not hosts)
5608 AMD 29000 embedded with COFF a29k-none-coff
5609 AMD 29000 embedded with a.out a29k-none-aout
5610 Ultracomputer remote kernel debug a29k-nyu-kern
5612 * New remote interfaces
5618 *** Changes in GDB-4.0:
5622 Wide output is wrapped at good places to make the output more readable.
5624 Gdb now supports cross-debugging from a host machine of one type to a
5625 target machine of another type. Communication with the target system
5626 is over serial lines. The ``target'' command handles connecting to the
5627 remote system; the ``load'' command will download a program into the
5628 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5629 also supports debugging of realtime processes running under VxWorks,
5630 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5631 stub on the target system.
5633 New CPUs supported include the AMD 29000 and Intel 960.
5635 GDB now reads object files and symbol tables via a ``binary file''
5636 library, which allows a single copy of GDB to debug programs of multiple
5637 object file types such as a.out and coff.
5639 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5640 refcard.dvi and refcard.ps are available to format it).
5643 * Control-Variable user interface simplified
5645 All variables that control the operation of the debugger can be set
5646 by the ``set'' command, and displayed by the ``show'' command.
5648 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5649 ``Show prompt'' produces the response:
5650 Gdb's prompt is new-gdb=>.
5652 What follows are the NEW set commands. The command ``help set'' will
5653 print a complete list of old and new set commands. ``help set FOO''
5654 will give a longer description of the variable FOO. ``show'' will show
5655 all of the variable descriptions and their current settings.
5657 confirm on/off: Enables warning questions for operations that are
5658 hard to recover from, e.g. rerunning the program while
5659 it is already running. Default is ON.
5661 editing on/off: Enables EMACS style command line editing
5662 of input. Previous lines can be recalled with
5663 control-P, the current line can be edited with control-B,
5664 you can search for commands with control-R, etc.
5667 history filename NAME: NAME is where the gdb command history
5668 will be stored. The default is .gdb_history,
5669 or the value of the environment variable
5672 history size N: The size, in commands, of the command history. The
5673 default is 256, or the value of the environment variable
5676 history save on/off: If this value is set to ON, the history file will
5677 be saved after exiting gdb. If set to OFF, the
5678 file will not be saved. The default is OFF.
5680 history expansion on/off: If this value is set to ON, then csh-like
5681 history expansion will be performed on
5682 command line input. The default is OFF.
5684 radix N: Sets the default radix for input and output. It can be set
5685 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5686 in the current radix, so "set radix 10" is always a no-op.
5688 height N: This integer value is the number of lines on a page. Default
5689 is 24, the current `stty rows'' setting, or the ``li#''
5690 setting from the termcap entry matching the environment
5693 width N: This integer value is the number of characters on a line.
5694 Default is 80, the current `stty cols'' setting, or the ``co#''
5695 setting from the termcap entry matching the environment
5698 Note: ``set screensize'' is obsolete. Use ``set height'' and
5699 ``set width'' instead.
5701 print address on/off: Print memory addresses in various command displays,
5702 such as stack traces and structure values. Gdb looks
5703 more ``symbolic'' if you turn this off; it looks more
5704 ``machine level'' with it on. Default is ON.
5706 print array on/off: Prettyprint arrays. New convenient format! Default
5709 print demangle on/off: Print C++ symbols in "source" form if on,
5712 print asm-demangle on/off: Same, for assembler level printouts
5715 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5718 * Support for Epoch Environment.
5720 The epoch environment is a version of Emacs v18 with windowing. One
5721 new command, ``inspect'', is identical to ``print'', except that if you
5722 are running in the epoch environment, the value is printed in its own
5726 * Support for Shared Libraries
5728 GDB can now debug programs and core files that use SunOS shared libraries.
5729 Symbols from a shared library cannot be referenced
5730 before the shared library has been linked with the program (this
5731 happens after you type ``run'' and before the function main() is entered).
5732 At any time after this linking (including when examining core files
5733 from dynamically linked programs), gdb reads the symbols from each
5734 shared library when you type the ``sharedlibrary'' command.
5735 It can be abbreviated ``share''.
5737 sharedlibrary REGEXP: Load shared object library symbols for files
5738 matching a unix regular expression. No argument
5739 indicates to load symbols for all shared libraries.
5741 info sharedlibrary: Status of loaded shared libraries.
5746 A watchpoint stops execution of a program whenever the value of an
5747 expression changes. Checking for this slows down execution
5748 tremendously whenever you are in the scope of the expression, but is
5749 quite useful for catching tough ``bit-spreader'' or pointer misuse
5750 problems. Some machines such as the 386 have hardware for doing this
5751 more quickly, and future versions of gdb will use this hardware.
5753 watch EXP: Set a watchpoint (breakpoint) for an expression.
5755 info watchpoints: Information about your watchpoints.
5757 delete N: Deletes watchpoint number N (same as breakpoints).
5758 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5759 enable N: Re-enables watchpoint number N (same as breakpoints).
5762 * C++ multiple inheritance
5764 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5767 * C++ exception handling
5769 Gdb now supports limited C++ exception handling. Besides the existing
5770 ability to breakpoint on an exception handler, gdb can breakpoint on
5771 the raising of an exception (before the stack is peeled back to the
5774 catch FOO: If there is a FOO exception handler in the dynamic scope,
5775 set a breakpoint to catch exceptions which may be raised there.
5776 Multiple exceptions (``catch foo bar baz'') may be caught.
5778 info catch: Lists all exceptions which may be caught in the
5779 current stack frame.
5782 * Minor command changes
5784 The command ``call func (arg, arg, ...)'' now acts like the print
5785 command, except it does not print or save a value if the function's result
5786 is void. This is similar to dbx usage.
5788 The ``up'' and ``down'' commands now always print the frame they end up
5789 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5790 frames without printing.
5792 * New directory command
5794 'dir' now adds directories to the FRONT of the source search path.
5795 The path starts off empty. Source files that contain debug information
5796 about the directory in which they were compiled can be found even
5797 with an empty path; Sun CC and GCC include this information. If GDB can't
5798 find your source file in the current directory, type "dir .".
5800 * Configuring GDB for compilation
5802 For normal use, type ``./configure host''. See README or gdb.texinfo
5805 GDB now handles cross debugging. If you are remotely debugging between
5806 two different machines, type ``./configure host -target=targ''.
5807 Host is the machine where GDB will run; targ is the machine
5808 where the program that you are debugging will run.