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 * "breakpoint always-inserted" modes "off" and "auto" merged.
38 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
39 won't remove breakpoints from the target until all threads stop,
40 even in non-stop mode. The "auto" mode has been removed, and "off"
41 is now the default mode.
43 *** Changes in GDB 7.8
45 * New command line options
48 This is an alias for the --data-directory option.
50 * GDB supports printing and modifying of variable length automatic arrays
51 as specified in ISO C99.
53 * The ARM simulator now supports instruction level tracing
54 with or without disassembly.
58 GDB now has support for scripting using Guile. Whether this is
59 available is determined at configure time.
60 Guile version 2.0 or greater is required.
61 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
63 * New commands (for set/show, see "New options" below)
67 Invoke CODE by passing it to the Guile interpreter.
71 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
73 info auto-load guile-scripts [regexp]
74 Print the list of automatically loaded Guile scripts.
76 * The source command is now capable of sourcing Guile scripts.
77 This feature is dependent on the debugger being built with Guile support.
81 set print symbol-loading (off|brief|full)
82 show print symbol-loading
83 Control whether to print informational messages when loading symbol
84 information for a file. The default is "full", but when debugging
85 programs with large numbers of shared libraries the amount of output
88 set guile print-stack (none|message|full)
89 show guile print-stack
90 Show a stack trace when an error is encountered in a Guile script.
92 set auto-load guile-scripts (on|off)
93 show auto-load guile-scripts
94 Control auto-loading of Guile script files.
96 maint ada set ignore-descriptive-types (on|off)
97 maint ada show ignore-descriptive-types
98 Control whether the debugger should ignore descriptive types in Ada
99 programs. The default is not to ignore the descriptive types. See
100 the user manual for more details on descriptive types and the intended
101 usage of this option.
103 set auto-connect-native-target
105 Control whether GDB is allowed to automatically connect to the
106 native target for the run, attach, etc. commands when not connected
107 to any target yet. See also "target native" below.
109 set record btrace replay-memory-access (read-only|read-write)
110 show record btrace replay-memory-access
111 Control what memory accesses are allowed during replay.
113 maint set target-async (on|off)
114 maint show target-async
115 This controls whether GDB targets operate in syncronous or
116 asyncronous mode. Normally the default is asyncronous, if it is
117 available; but this can be changed to more easily debug problems
118 occurring only in syncronous mode.
120 set mi-async (on|off)
122 Control whether MI asynchronous mode is preferred. This supersedes
123 "set target-async" of previous GDB versions.
125 * "set target-async" is deprecated as a CLI option and is now an alias
126 for "set mi-async" (only puts MI into async mode).
128 * Background execution commands (e.g., "c&", "s&", etc.) are now
129 possible ``out of the box'' if the target supports them. Previously
130 the user would need to explicitly enable the possibility with the
131 "set target-async on" command.
133 * New features in the GDB remote stub, GDBserver
135 ** New option --debug-format=option1[,option2,...] allows one to add
136 additional text to each output. At present only timestamps
137 are supported: --debug-format=timestamps.
138 Timestamps can also be turned on with the
139 "monitor set debug-format timestamps" command from GDB.
141 * The 'record instruction-history' command now starts counting instructions
142 at one. This also affects the instruction ranges reported by the
143 'record function-call-history' command when given the /i modifier.
145 * The command 'record function-call-history' supports a new modifier '/c' to
146 indent the function names based on their call stack depth.
147 The fields for the '/i' and '/l' modifier have been reordered.
148 The source line range is now prefixed with 'at'.
149 The instruction range is now prefixed with 'inst'.
150 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
151 "record instruction-history" and "list" commands.
153 * The ranges given as arguments to the 'record function-call-history' and
154 'record instruction-history' commands are now inclusive.
156 * The btrace record target now supports the 'record goto' command.
157 For locations inside the execution trace, the back trace is computed
158 based on the information stored in the execution trace.
160 * The btrace record target supports limited reverse execution and replay.
161 The target does not record data and therefore does not allow reading
164 * The "catch syscall" command now works on s390*-linux* targets.
166 * The "compare-sections" command is no longer specific to target
167 remote. It now works with all targets.
169 * All native targets are now consistently called "native".
170 Consequently, the "target child", "target GNU", "target djgpp",
171 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
172 commands have been replaced with "target native". The QNX/NTO port
173 leaves the "procfs" target in place and adds a "native" target for
174 consistency with other ports. The impact on users should be minimal
175 as these commands previously either throwed an error, or were
176 no-ops. The target's name is visible in the output of the following
177 commands: "help target", "info target", "info files", "maint print
180 * The "target native" command now connects to the native target. This
181 can be used to launch native programs even when "set
182 auto-connect-native-target" is set to off.
184 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.
186 * Support for Intel(R) AVX-512 registers on GNU/Linux.
187 Support displaying and modifying Intel(R) AVX-512 registers
188 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
192 qXfer:btrace:read's annex
193 The qXfer:btrace:read packet supports a new annex 'delta' to read
194 branch trace incrementally.
198 ** Valid Python operations on gdb.Value objects representing
199 structs/classes invoke the corresponding overloaded operators if
201 ** New `Xmethods' feature in the Python API. Xmethods are
202 additional methods or replacements for existing methods of a C++
203 class. This feature is useful for those cases where a method
204 defined in C++ source code could be inlined or optimized out by
205 the compiler, making it unavailable to GDB.
208 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
210 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
211 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
212 its alias "share", instead.
214 * The commands "set remotebaud" and "show remotebaud" are no longer
215 supported. Use "set serial baud" and "show serial baud" (respectively)
220 ** A new option "-gdb-set mi-async" replaces "-gdb-set
221 target-async". The latter is left as a deprecated alias of the
222 former for backward compatibility. If the target supports it,
223 CLI background execution commands are now always possible by
224 default, independently of whether the frontend stated a
225 preference for asynchronous execution with "-gdb-set mi-async".
226 Previously "-gdb-set target-async off" affected both MI execution
227 commands and CLI execution commands.
229 *** Changes in GDB 7.7
231 * Improved support for process record-replay and reverse debugging on
232 arm*-linux* targets. Support for thumb32 and syscall instruction
233 recording has been added.
235 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
237 * GDB now supports Fission DWP file format version 2.
238 http://gcc.gnu.org/wiki/DebugFission
240 * New convenience function "$_isvoid", to check whether an expression
241 is void. A void expression is an expression where the type of the
242 result is "void". For example, some convenience variables may be
243 "void" when evaluated (e.g., "$_exitcode" before the execution of
244 the program being debugged; or an undefined convenience variable).
245 Another example, when calling a function whose return type is
248 * The "maintenance print objfiles" command now takes an optional regexp.
250 * The "catch syscall" command now works on arm*-linux* targets.
252 * GDB now consistently shows "<not saved>" when printing values of
253 registers the debug info indicates have not been saved in the frame
254 and there's nowhere to retrieve them from
255 (callee-saved/call-clobbered registers):
260 (gdb) info registers rax
263 Before, the former would print "<optimized out>", and the latter
264 "*value not available*".
266 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
271 ** Frame filters and frame decorators have been added.
272 ** Temporary breakpoints are now supported.
273 ** Line tables representation has been added.
274 ** New attribute 'parent_type' for gdb.Field objects.
275 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
276 ** New attribute 'name' for gdb.Type objects.
280 Nios II ELF nios2*-*-elf
281 Nios II GNU/Linux nios2*-*-linux
282 Texas Instruments MSP430 msp430*-*-elf
284 * Removed native configurations
286 Support for these a.out NetBSD and OpenBSD obsolete configurations has
287 been removed. ELF variants of these configurations are kept supported.
289 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
290 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
291 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
292 i[34567]86-*-openbsd3.[0-3]
293 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
294 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
295 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
299 Like "catch throw", but catches a re-thrown exception.
301 Renamed from old "maint check-symtabs".
303 Perform consistency checks on symtabs.
305 Expand symtabs matching an optional regexp.
308 Display the details of GDB configure-time options.
310 maint set|show per-command
311 maint set|show per-command space
312 maint set|show per-command time
313 maint set|show per-command symtab
314 Enable display of per-command gdb resource usage.
316 remove-symbol-file FILENAME
317 remove-symbol-file -a ADDRESS
318 Remove a symbol file added via add-symbol-file. The file to remove
319 can be identified by its filename or by an address that lies within
320 the boundaries of this symbol file in memory.
323 info exceptions REGEXP
324 Display the list of Ada exceptions defined in the program being
325 debugged. If provided, only the exceptions whose names match REGEXP
330 set debug symfile off|on
332 Control display of debugging info regarding reading symbol files and
333 symbol tables within those files
335 set print raw frame-arguments
336 show print raw frame-arguments
337 Set/show whether to print frame arguments in raw mode,
338 disregarding any defined pretty-printers.
340 set remote trace-status-packet
341 show remote trace-status-packet
342 Set/show the use of remote protocol qTStatus packet.
346 Control display of debugging messages related to Nios II targets.
350 Control whether target-assisted range stepping is enabled.
352 set startup-with-shell
353 show startup-with-shell
354 Specifies whether Unix child processes are started via a shell or
359 Use the target memory cache for accesses to the code segment. This
360 improves performance of remote debugging (particularly disassembly).
362 * You can now use a literal value 'unlimited' for options that
363 interpret 0 or -1 as meaning "unlimited". E.g., "set
364 trace-buffer-size unlimited" is now an alias for "set
365 trace-buffer-size -1" and "set height unlimited" is now an alias for
368 * The "set debug symtab-create" debugging option of GDB has been changed to
369 accept a verbosity level. 0 means "off", 1 provides basic debugging
370 output, and values of 2 or greater provides more verbose output.
372 * New command-line options
374 Display the details of GDB configure-time options.
376 * The command 'tsave' can now support new option '-ctf' to save trace
377 buffer in Common Trace Format.
379 * Newly installed $prefix/bin/gcore acts as a shell interface for the
382 * GDB now implements the the C++ 'typeid' operator.
384 * The new convenience variable $_exception holds the exception being
385 thrown or caught at an exception-related catchpoint.
387 * The exception-related catchpoints, like "catch throw", now accept a
388 regular expression which can be used to filter exceptions by type.
390 * The new convenience variable $_exitsignal is automatically set to
391 the terminating signal number when the program being debugged dies
392 due to an uncaught signal.
396 ** All MI commands now accept an optional "--language" option.
397 Support for this feature can be verified by using the "-list-features"
398 command, which should contain "language-option".
400 ** The new command -info-gdb-mi-command allows the user to determine
401 whether a GDB/MI command is supported or not.
403 ** The "^error" result record returned when trying to execute an undefined
404 GDB/MI command now provides a variable named "code" whose content is the
405 "undefined-command" error code. Support for this feature can be verified
406 by using the "-list-features" command, which should contain
407 "undefined-command-error-code".
409 ** The -trace-save MI command can optionally save trace buffer in Common
412 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
414 ** The command -data-list-register-values now accepts an optional
415 "--skip-unavailable" option. When used, only the available registers
418 ** The new command -trace-frame-collected dumps collected variables,
419 computed expressions, tvars, memory and registers in a traceframe.
421 ** The commands -stack-list-locals, -stack-list-arguments and
422 -stack-list-variables now accept an option "--skip-unavailable".
423 When used, only the available locals or arguments are displayed.
425 ** The -exec-run command now accepts an optional "--start" option.
426 When used, the command follows the same semantics as the "start"
427 command, stopping the program's execution at the start of its
428 main subprogram. Support for this feature can be verified using
429 the "-list-features" command, which should contain
430 "exec-run-start-option".
432 ** The new commands -catch-assert and -catch-exceptions insert
433 catchpoints stopping the program when Ada exceptions are raised.
435 ** The new command -info-ada-exceptions provides the equivalent of
436 the new "info exceptions" command.
438 * New system-wide configuration scripts
439 A GDB installation now provides scripts suitable for use as system-wide
440 configuration scripts for the following systems:
444 * GDB now supports target-assigned range stepping with remote targets.
445 This improves the performance of stepping source lines by reducing
446 the number of control packets from/to GDB. See "New remote packets"
449 * GDB now understands the element 'tvar' in the XML traceframe info.
450 It has the id of the collected trace state variables.
452 * On S/390 targets that provide the transactional-execution feature,
453 the program interruption transaction diagnostic block (TDB) is now
454 represented as a number of additional "registers" in GDB.
460 The vCont packet supports a new 'r' action, that tells the remote
461 stub to step through an address range itself, without GDB
462 involvemement at each single-step.
464 qXfer:libraries-svr4:read's annex
465 The previously unused annex of the qXfer:libraries-svr4:read packet
466 is now used to support passing an argument list. The remote stub
467 reports support for this argument list to GDB's qSupported query.
468 The defined arguments are "start" and "prev", used to reduce work
469 necessary for library list updating, resulting in significant
472 * New features in the GDB remote stub, GDBserver
474 ** GDBserver now supports target-assisted range stepping. Currently
475 enabled on x86/x86_64 GNU/Linux targets.
477 ** GDBserver now adds element 'tvar' in the XML in the reply to
478 'qXfer:traceframe-info:read'. It has the id of the collected
479 trace state variables.
481 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
484 * New 'z' formatter for printing and examining memory, this displays the
485 value as hexadecimal zero padded on the left to the size of the type.
487 * GDB can now use Windows x64 unwinding data.
489 * The "set remotebaud" command has been replaced by "set serial baud".
490 Similarly, "show remotebaud" has been replaced by "show serial baud".
491 The "set remotebaud" and "show remotebaud" commands are still available
492 to provide backward compatibility with older versions of GDB.
494 *** Changes in GDB 7.6
496 * Target record has been renamed to record-full.
497 Record/replay is now enabled with the "record full" command.
498 This also affects settings that are associated with full record/replay
499 that have been moved from "set/show record" to "set/show record full":
501 set|show record full insn-number-max
502 set|show record full stop-at-limit
503 set|show record full memory-query
505 * A new record target "record-btrace" has been added. The new target
506 uses hardware support to record the control-flow of a process. It
507 does not support replaying the execution, but it implements the
508 below new commands for investigating the recorded execution log.
509 This new recording method can be enabled using:
513 The "record-btrace" target is only available on Intel Atom processors
514 and requires a Linux kernel 2.6.32 or later.
516 * Two new commands have been added for record/replay to give information
517 about the recorded execution without having to replay the execution.
518 The commands are only supported by "record btrace".
520 record instruction-history prints the execution history at
521 instruction granularity
523 record function-call-history prints the execution history at
526 * New native configurations
528 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
529 FreeBSD/powerpc powerpc*-*-freebsd
530 x86_64/Cygwin x86_64-*-cygwin*
531 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
535 ARM AArch64 aarch64*-*-elf
536 ARM AArch64 GNU/Linux aarch64*-*-linux
537 Lynx 178 PowerPC powerpc-*-lynx*178
538 x86_64/Cygwin x86_64-*-cygwin*
539 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
541 * If the configured location of system.gdbinit file (as given by the
542 --with-system-gdbinit option at configure time) is in the
543 data-directory (as specified by --with-gdb-datadir at configure
544 time) or in one of its subdirectories, then GDB will look for the
545 system-wide init file in the directory specified by the
546 --data-directory command-line option.
548 * New command line options:
550 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
551 other initialization files, unlike -nx which disables all of them.
553 * Removed command line options
555 -epoch This was used by the gdb mode in Epoch, an ancient fork of
558 * The 'ptype' and 'whatis' commands now accept an argument to control
561 * 'info proc' now works on some core files.
565 ** Vectors can be created with gdb.Type.vector.
567 ** Python's atexit.register now works in GDB.
569 ** Types can be pretty-printed via a Python API.
571 ** Python 3 is now supported (in addition to Python 2.4 or later)
573 ** New class gdb.Architecture exposes GDB's internal representation
574 of architecture in the Python API.
576 ** New method Frame.architecture returns the gdb.Architecture object
577 corresponding to the frame's architecture.
579 * New Python-based convenience functions:
581 ** $_memeq(buf1, buf2, length)
582 ** $_streq(str1, str2)
584 ** $_regex(str, regex)
586 * The 'cd' command now defaults to using '~' (the home directory) if not
589 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
590 default for GCC since November 2000.
592 * The command 'forward-search' can now be abbreviated as 'fo'.
594 * The command 'info tracepoints' can now display 'installed on target'
595 or 'not installed on target' for each non-pending location of tracepoint.
597 * New configure options
599 --enable-libmcheck/--disable-libmcheck
600 By default, development versions are built with -lmcheck on hosts
601 that support it, in order to help track memory corruption issues.
602 Release versions, on the other hand, are built without -lmcheck
603 by default. The --enable-libmcheck/--disable-libmcheck configure
604 options allow the user to override that default.
605 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
606 This configure option allows the user to build GDB with
607 libbabeltrace using which GDB can read Common Trace Format data.
609 * New commands (for set/show, see "New options" below)
612 Catch signals. This is similar to "handle", but allows commands and
613 conditions to be attached.
616 List the BFDs known to GDB.
618 python-interactive [command]
620 Start a Python interactive prompt, or evaluate the optional command
621 and print the result of expressions.
624 "py" is a new alias for "python".
626 enable type-printer [name]...
627 disable type-printer [name]...
628 Enable or disable type printers.
632 ** For the Renesas Super-H architecture, the "regs" command has been removed
633 (has been deprecated in GDB 7.5), and "info all-registers" should be used
638 set print type methods (on|off)
639 show print type methods
640 Control whether method declarations are displayed by "ptype".
641 The default is to show them.
643 set print type typedefs (on|off)
644 show print type typedefs
645 Control whether typedef definitions are displayed by "ptype".
646 The default is to show them.
648 set filename-display basename|relative|absolute
649 show filename-display
650 Control the way in which filenames is displayed.
651 The default is "relative", which preserves previous behavior.
653 set trace-buffer-size
654 show trace-buffer-size
655 Request target to change the size of trace buffer.
657 set remote trace-buffer-size-packet auto|on|off
658 show remote trace-buffer-size-packet
659 Control the use of the remote protocol `QTBuffer:size' packet.
663 Control display of debugging messages related to ARM AArch64.
666 set debug coff-pe-read
667 show debug coff-pe-read
668 Control display of debugging messages related to reading of COFF/PE
673 Control display of debugging messages related to Mach-O symbols
676 set debug notification
677 show debug notification
678 Control display of debugging info for async remote notification.
682 ** Command parameter changes are now notified using new async record
683 "=cmd-param-changed".
684 ** Trace frame changes caused by command "tfind" are now notified using
685 new async record "=traceframe-changed".
686 ** The creation, deletion and modification of trace state variables
687 are now notified using new async records "=tsv-created",
688 "=tsv-deleted" and "=tsv-modified".
689 ** The start and stop of process record are now notified using new
690 async record "=record-started" and "=record-stopped".
691 ** Memory changes are now notified using new async record
693 ** The data-disassemble command response will include a "fullname" field
694 containing the absolute file name when source has been requested.
695 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
696 command, to allow pattern filling of memory areas.
697 ** New commands "-catch-load"/"-catch-unload" added for intercepting
698 library load/unload events.
699 ** The response to breakpoint commands and breakpoint async records
700 includes an "installed" field containing a boolean state about each
701 non-pending tracepoint location is whether installed on target or not.
702 ** Output of the "-trace-status" command includes a "trace-file" field
703 containing the name of the trace file being examined. This field is
704 optional, and only present when examining a trace file.
705 ** The "fullname" field is now always present along with the "file" field,
706 even if the file cannot be found by GDB.
708 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
709 You must have the LZMA library available when configuring GDB for this
710 feature to be enabled. For more information, see:
711 http://fedoraproject.org/wiki/Features/MiniDebugInfo
716 Set the size of trace buffer. The remote stub reports support for this
717 packet to gdb's qSupported query.
720 Enable Branch Trace Store (BTS)-based branch tracing for the current
721 thread. The remote stub reports support for this packet to gdb's
725 Disable branch tracing for the current thread. The remote stub reports
726 support for this packet to gdb's qSupported query.
729 Read the traced branches for the current thread. The remote stub
730 reports support for this packet to gdb's qSupported query.
732 *** Changes in GDB 7.5
734 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
735 for more x32 ABI info.
737 * GDB now supports access to MIPS DSP registers on Linux targets.
739 * GDB now supports debugging microMIPS binaries.
741 * The "info os" command on GNU/Linux can now display information on
742 several new classes of objects managed by the operating system:
743 "info os procgroups" lists process groups
744 "info os files" lists file descriptors
745 "info os sockets" lists internet-domain sockets
746 "info os shm" lists shared-memory regions
747 "info os semaphores" lists semaphores
748 "info os msg" lists message queues
749 "info os modules" lists loaded kernel modules
751 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
752 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
753 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
754 options and inspect the probe arguments using the new $_probe_arg family
755 of convenience variables. You can obtain more information about SystemTap
756 in <http://sourceware.org/systemtap/>.
758 * GDB now supports reversible debugging on ARM, it allows you to
759 debug basic ARM and THUMB instructions, and provides
760 record/replay support.
762 * The option "symbol-reloading" has been deleted as it is no longer used.
766 ** GDB commands implemented in Python can now be put in command class
769 ** The "maint set python print-stack on|off" is now deleted.
771 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
772 apply "flag enum"-style pretty-printing to any enum.
774 ** gdb.lookup_symbol can now work when there is no current frame.
776 ** gdb.Symbol now has a 'line' attribute, holding the line number in
777 the source at which the symbol was defined.
779 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
780 method 'value'. The former indicates whether the symbol needs a
781 frame in order to compute its value, and the latter computes the
784 ** A new method 'referenced_value' on gdb.Value objects which can
785 dereference pointer as well as C++ reference values.
787 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
788 which return the global and static blocks (as gdb.Block objects),
789 of the underlying symbol table, respectively.
791 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
792 object associated with a PC value.
794 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
795 of the address range occupied by code for the current source line.
797 * Go language support.
798 GDB now supports debugging programs written in the Go programming
801 * GDBserver now supports stdio connections.
802 E.g. (gdb) target remote | ssh myhost gdbserver - hello
804 * The binary "gdbtui" can no longer be built or installed.
805 Use "gdb -tui" instead.
807 * GDB will now print "flag" enums specially. A flag enum is one where
808 all the enumerator values have no bits in common when pairwise
809 "and"ed. When printing a value whose type is a flag enum, GDB will
810 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
811 (gdb) print (enum E) 3
814 * The filename part of a linespec will now match trailing components
815 of a source file name. For example, "break gcc/expr.c:1000" will
816 now set a breakpoint in build/gcc/expr.c, but not
819 * The "info proc" and "generate-core-file" commands will now also
820 work on remote targets connected to GDBserver on Linux.
822 * The command "info catch" has been removed. It has been disabled
825 * The "catch exception" and "catch assert" commands now accept
826 a condition at the end of the command, much like the "break"
827 command does. For instance:
829 (gdb) catch exception Constraint_Error if Barrier = True
831 Previously, it was possible to add a condition to such catchpoints,
832 but it had to be done as a second step, after the catchpoint had been
833 created, using the "condition" command.
835 * The "info static-tracepoint-marker" command will now also work on
836 native Linux targets with in-process agent.
838 * GDB can now set breakpoints on inlined functions.
840 * The .gdb_index section has been updated to include symbols for
841 inlined functions. GDB will ignore older .gdb_index sections by
842 default, which could cause symbol files to be loaded more slowly
843 until their .gdb_index sections can be recreated. The new command
844 "set use-deprecated-index-sections on" will cause GDB to use any older
845 .gdb_index sections it finds. This will restore performance, but the
846 ability to set breakpoints on inlined functions will be lost in symbol
847 files with older .gdb_index sections.
849 The .gdb_index section has also been updated to record more information
850 about each symbol. This speeds up the "info variables", "info functions"
851 and "info types" commands when used with programs having the .gdb_index
852 section, as well as speeding up debugging with shared libraries using
853 the .gdb_index section.
855 * Ada support for GDB/MI Variable Objects has been added.
857 * GDB can now support 'breakpoint always-inserted mode' in 'record'
862 ** New command -info-os is the MI equivalent of "info os".
864 ** Output logs ("set logging" and related) now include MI output.
868 ** "set use-deprecated-index-sections on|off"
869 "show use-deprecated-index-sections on|off"
870 Controls the use of deprecated .gdb_index sections.
872 ** "catch load" and "catch unload" can be used to stop when a shared
873 library is loaded or unloaded, respectively.
875 ** "enable count" can be used to auto-disable a breakpoint after
878 ** "info vtbl" can be used to show the virtual method tables for
879 C++ and Java objects.
881 ** "explore" and its sub commands "explore value" and "explore type"
882 can be used to recursively explore values and types of
883 expressions. These commands are available only if GDB is
884 configured with '--with-python'.
886 ** "info auto-load" shows status of all kinds of auto-loaded files,
887 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
888 sequences of commands files, "info auto-load python-scripts"
889 shows status of auto-loading Python script files,
890 "info auto-load local-gdbinit" shows status of loading init file
891 (.gdbinit) from current directory and "info auto-load libthread-db" shows
892 status of inferior specific thread debugging shared library loading.
894 ** "info auto-load-scripts", "set auto-load-scripts on|off"
895 and "show auto-load-scripts" commands have been deprecated, use their
896 "info auto-load python-scripts", "set auto-load python-scripts on|off"
897 and "show auto-load python-scripts" counterparts instead.
899 ** "dprintf location,format,args..." creates a dynamic printf, which
900 is basically a breakpoint that does a printf and immediately
901 resumes your program's execution, so it is like a printf that you
902 can insert dynamically at runtime instead of at compiletime.
904 ** "set print symbol"
906 Controls whether GDB attempts to display the symbol, if any,
907 corresponding to addresses it prints. This defaults to "on", but
908 you can set it to "off" to restore GDB's previous behavior.
910 * Deprecated commands
912 ** For the Renesas Super-H architecture, the "regs" command has been
913 deprecated, and "info all-registers" should be used instead.
917 Renesas RL78 rl78-*-elf
918 HP OpenVMS ia64 ia64-hp-openvms*
920 * GDBserver supports evaluation of breakpoint conditions. When
921 support is advertised by GDBserver, GDB may be told to send the
922 breakpoint conditions in bytecode form to GDBserver. GDBserver
923 will only report the breakpoint trigger to GDB when its condition
929 show mips compression
930 Select the compressed ISA encoding used in functions that have no symbol
931 information available. The encoding can be set to either of:
934 and is updated automatically from ELF file flags if available.
936 set breakpoint condition-evaluation
937 show breakpoint condition-evaluation
938 Control whether breakpoint conditions are evaluated by GDB ("host") or by
939 GDBserver ("target"). Default option "auto" chooses the most efficient
941 This option can improve debugger efficiency depending on the speed of the
945 Disable auto-loading globally.
948 Show auto-loading setting of all kinds of auto-loaded files.
950 set auto-load gdb-scripts on|off
951 show auto-load gdb-scripts
952 Control auto-loading of GDB canned sequences of commands files.
954 set auto-load python-scripts on|off
955 show auto-load python-scripts
956 Control auto-loading of Python script files.
958 set auto-load local-gdbinit on|off
959 show auto-load local-gdbinit
960 Control loading of init file (.gdbinit) from current directory.
962 set auto-load libthread-db on|off
963 show auto-load libthread-db
964 Control auto-loading of inferior specific thread debugging shared library.
966 set auto-load scripts-directory <dir1>[:<dir2>...]
967 show auto-load scripts-directory
968 Set a list of directories from which to load auto-loaded scripts.
969 Automatically loaded Python scripts and GDB scripts are located in one
970 of the directories listed by this option.
971 The delimiter (':' above) may differ according to the host platform.
973 set auto-load safe-path <dir1>[:<dir2>...]
974 show auto-load safe-path
975 Set a list of directories from which it is safe to auto-load files.
976 The delimiter (':' above) may differ according to the host platform.
978 set debug auto-load on|off
980 Control display of debugging info for auto-loading the files above.
982 set dprintf-style gdb|call|agent
984 Control the way in which a dynamic printf is performed; "gdb"
985 requests a GDB printf command, while "call" causes dprintf to call a
986 function in the inferior. "agent" requests that the target agent
987 (such as GDBserver) do the printing.
989 set dprintf-function <expr>
990 show dprintf-function
991 set dprintf-channel <expr>
993 Set the function and optional first argument to the call when using
994 the "call" style of dynamic printf.
996 set disconnected-dprintf on|off
997 show disconnected-dprintf
998 Control whether agent-style dynamic printfs continue to be in effect
999 after GDB disconnects.
1001 * New configure options
1003 --with-auto-load-dir
1004 Configure default value for the 'set auto-load scripts-directory'
1005 setting above. It defaults to '$debugdir:$datadir/auto-load',
1006 $debugdir representing global debugging info directories (available
1007 via 'show debug-file-directory') and $datadir representing GDB's data
1008 directory (available via 'show data-directory').
1010 --with-auto-load-safe-path
1011 Configure default value for the 'set auto-load safe-path' setting
1012 above. It defaults to the --with-auto-load-dir setting.
1014 --without-auto-load-safe-path
1015 Set 'set auto-load safe-path' to '/', effectively disabling this
1018 * New remote packets
1020 z0/z1 conditional breakpoints extension
1022 The z0/z1 breakpoint insertion packets have been extended to carry
1023 a list of conditional expressions over to the remote stub depending on the
1024 condition evaluation mode. The use of this extension can be controlled
1025 via the "set remote conditional-breakpoints-packet" command.
1029 Specify the signals which the remote stub may pass to the debugged
1030 program without GDB involvement.
1032 * New command line options
1034 --init-command=FILE, -ix Like --command, -x but execute it
1035 before loading inferior.
1036 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1037 execute it before loading inferior.
1039 *** Changes in GDB 7.4
1041 * GDB now handles ambiguous linespecs more consistently; the existing
1042 FILE:LINE support has been expanded to other types of linespecs. A
1043 breakpoint will now be set on all matching locations in all
1044 inferiors, and locations will be added or removed according to
1047 * GDB now allows you to skip uninteresting functions and files when
1048 stepping with the "skip function" and "skip file" commands.
1050 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1051 and "show remote hardware-watchpoint-length-limit". These allows to
1052 set or show the maximum length limit (in bytes) of a remote
1053 target hardware watchpoint.
1055 This allows e.g. to use "unlimited" hardware watchpoints with the
1056 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1057 watchpoints are slower than real hardware watchpoints but are
1058 significantly faster than gdb software watchpoints.
1062 ** The register_pretty_printer function in module gdb.printing now takes
1063 an optional `replace' argument. If True, the new printer replaces any
1066 ** The "maint set python print-stack on|off" command has been
1067 deprecated and will be deleted in GDB 7.5.
1068 A new command: "set python print-stack none|full|message" has
1069 replaced it. Additionally, the default for "print-stack" is
1070 now "message", which just prints the error message without
1073 ** A prompt substitution hook (prompt_hook) is now available to the
1076 ** A new Python module, gdb.prompt has been added to the GDB Python
1077 modules library. This module provides functionality for
1078 escape sequences in prompts (used by set/show
1079 extended-prompt). These escape sequences are replaced by their
1080 corresponding value.
1082 ** Python commands and convenience-functions located in
1083 'data-directory'/python/gdb/command and
1084 'data-directory'/python/gdb/function are now automatically loaded
1087 ** Blocks now provide four new attributes. global_block and
1088 static_block will return the global and static blocks
1089 respectively. is_static and is_global are boolean attributes
1090 that indicate if the block is one of those two types.
1092 ** Symbols now provide the "type" attribute, the type of the symbol.
1094 ** The "gdb.breakpoint" function has been deprecated in favor of
1097 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1098 of a function. This class is based on the "finish" command
1099 available in the CLI.
1101 ** Type objects for struct and union types now allow access to
1102 the fields using standard Python dictionary (mapping) methods.
1103 For example, "some_type['myfield']" now works, as does
1104 "some_type.items()".
1106 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1109 ** A new function, "deep_items" has been added to the gdb.types
1110 module in the GDB Python modules library. This function returns
1111 an iterator over the fields of a struct or union type. Unlike
1112 the standard Python "iteritems" method, it will recursively traverse
1113 any anonymous fields.
1117 ** "*stopped" events can report several new "reason"s, such as
1120 ** Breakpoint changes are now notified using new async records, like
1121 "=breakpoint-modified".
1123 ** New command -ada-task-info.
1125 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1126 $sdir specifies the default system locations of shared libraries.
1127 $pdir specifies the directory where the libpthread used by the application
1130 GDB no longer looks in $sdir and $pdir after it has searched the directories
1131 mentioned in libthread-db-search-path. If you want to search those
1132 directories, they must be specified in libthread-db-search-path.
1133 The default value of libthread-db-search-path on GNU/Linux and Solaris
1134 systems is now "$sdir:$pdir".
1136 $pdir is not supported by gdbserver, it is currently ignored.
1137 $sdir is supported by gdbserver.
1139 * New configure option --with-iconv-bin.
1140 When using the internationalization support like the one in the GNU C
1141 library, GDB will invoke the "iconv" program to get a list of supported
1142 character sets. If this program lives in a non-standard location, one can
1143 use this option to specify where to find it.
1145 * When natively debugging programs on PowerPC BookE processors running
1146 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1147 watchpoints, which specify a mask in addition to an address to watch.
1148 The mask specifies that some bits of an address (the bits which are
1149 reset in the mask) should be ignored when matching the address accessed
1150 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1151 section in the user manual for more details.
1153 * The new option --once causes GDBserver to stop listening for connections once
1154 the first connection is made. The listening port used by GDBserver will
1155 become available after that.
1157 * New commands "info macros" and "alias" have been added.
1159 * New function parameters suffix @entry specifies value of function parameter
1160 at the time the function got called. Entry values are available only since
1166 "!" is now an alias of the "shell" command.
1167 Note that no space is needed between "!" and SHELL COMMAND.
1171 watch EXPRESSION mask MASK_VALUE
1172 The watch command now supports the mask argument which allows creation
1173 of masked watchpoints, if the current architecture supports this feature.
1175 info auto-load-scripts [REGEXP]
1176 This command was formerly named "maintenance print section-scripts".
1177 It is now generally useful and is no longer a maintenance-only command.
1179 info macro [-all] [--] MACRO
1180 The info macro command has new options `-all' and `--'. The first for
1181 printing all definitions of a macro. The second for explicitly specifying
1182 the end of arguments and the beginning of the macro name in case the macro
1183 name starts with a hyphen.
1185 collect[/s] EXPRESSIONS
1186 The tracepoint collect command now takes an optional modifier "/s"
1187 that directs it to dereference pointer-to-character types and
1188 collect the bytes of memory up to a zero byte. The behavior is
1189 similar to what you see when you use the regular print command on a
1190 string. An optional integer following the "/s" sets a bound on the
1191 number of bytes that will be collected.
1194 The trace start command now interprets any supplied arguments as a
1195 note to be recorded with the trace run, with an effect similar to
1196 setting the variable trace-notes.
1199 The trace stop command now interprets any arguments as a note to be
1200 mentioned along with the tstatus report that the trace was stopped
1201 with a command. The effect is similar to setting the variable
1204 * Tracepoints can now be enabled and disabled at any time after a trace
1205 experiment has been started using the standard "enable" and "disable"
1206 commands. It is now possible to start a trace experiment with no enabled
1207 tracepoints; GDB will display a warning, but will allow the experiment to
1208 begin, assuming that tracepoints will be enabled as needed while the trace
1211 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1212 locations with 4-byte instructions, when they were previously
1213 limited to locations with instructions of 5 bytes or longer.
1217 set debug dwarf2-read
1218 show debug dwarf2-read
1219 Turns on or off display of debugging messages related to reading
1220 DWARF debug info. The default is off.
1222 set debug symtab-create
1223 show debug symtab-create
1224 Turns on or off display of debugging messages related to symbol table
1225 creation. The default is off.
1228 show extended-prompt
1229 Set the GDB prompt, and allow escape sequences to be inserted to
1230 display miscellaneous information (see 'help set extended-prompt'
1231 for the list of sequences). This prompt (and any information
1232 accessed through the escape sequences) is updated every time the
1233 prompt is displayed.
1235 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1236 show print entry-values
1237 Set printing of frame argument values at function entry. In some cases
1238 GDB can determine the value of function argument which was passed by the
1239 function caller, even if the value was modified inside the called function.
1241 set debug entry-values
1242 show debug entry-values
1243 Control display of debugging info for determining frame argument values at
1244 function entry and virtual tail call frames.
1246 set basenames-may-differ
1247 show basenames-may-differ
1248 Set whether a source file may have multiple base names.
1249 (A "base name" is the name of a file with the directory part removed.
1250 Example: The base name of "/home/user/hello.c" is "hello.c".)
1251 If set, GDB will canonicalize file names (e.g., expand symlinks)
1252 before comparing them. Canonicalization is an expensive operation,
1253 but it allows the same file be known by more than one base name.
1254 If not set (the default), all source files are assumed to have just
1255 one base name, and gdb will do file name comparisons more efficiently.
1261 Set a user name and notes for the current and any future trace runs.
1262 This is useful for long-running and/or disconnected traces, to
1263 inform others (or yourself) as to who is running the trace, supply
1264 contact information, or otherwise explain what is going on.
1266 set trace-stop-notes
1267 show trace-stop-notes
1268 Set a note attached to the trace run, that is displayed when the
1269 trace has been stopped by a tstop command. This is useful for
1270 instance as an explanation, if you are stopping a trace run that was
1271 started by someone else.
1273 * New remote packets
1277 Dynamically enable a tracepoint in a started trace experiment.
1281 Dynamically disable a tracepoint in a started trace experiment.
1285 Set the user and notes of the trace run.
1289 Query the current status of a tracepoint.
1293 Query the minimum length of instruction at which a fast tracepoint may
1296 * Dcache size (number of lines) and line-size are now runtime-configurable
1297 via "set dcache line" and "set dcache line-size" commands.
1301 Texas Instruments TMS320C6x tic6x-*-*
1305 Renesas RL78 rl78-*-elf
1307 *** Changes in GDB 7.3.1
1309 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1311 *** Changes in GDB 7.3
1313 * GDB has a new command: "thread find [REGEXP]".
1314 It finds the thread id whose name, target id, or thread extra info
1315 matches the given regular expression.
1317 * The "catch syscall" command now works on mips*-linux* targets.
1319 * The -data-disassemble MI command now supports modes 2 and 3 for
1320 dumping the instruction opcodes.
1322 * New command line options
1324 -data-directory DIR Specify DIR as the "data-directory".
1325 This is mostly for testing purposes.
1327 * The "maint set python auto-load on|off" command has been renamed to
1328 "set auto-load-scripts on|off".
1330 * GDB has a new command: "set directories".
1331 It is like the "dir" command except that it replaces the
1332 source path list instead of augmenting it.
1334 * GDB now understands thread names.
1336 On GNU/Linux, "info threads" will display the thread name as set by
1337 prctl or pthread_setname_np.
1339 There is also a new command, "thread name", which can be used to
1340 assign a name internally for GDB to display.
1343 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1344 has been integrated into GDB.
1348 ** The function gdb.Write now accepts an optional keyword 'stream'.
1349 This keyword, when provided, will direct the output to either
1350 stdout, stderr, or GDB's logging output.
1352 ** Parameters can now be be sub-classed in Python, and in particular
1353 you may implement the get_set_doc and get_show_doc functions.
1354 This improves how Parameter set/show documentation is processed
1355 and allows for more dynamic content.
1357 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1358 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1359 have an is_valid method.
1361 ** Breakpoints can now be sub-classed in Python, and in particular
1362 you may implement a 'stop' function that is executed each time
1363 the inferior reaches that breakpoint.
1365 ** New function gdb.lookup_global_symbol looks up a global symbol.
1367 ** GDB values in Python are now callable if the value represents a
1368 function. For example, if 'some_value' represents a function that
1369 takes two integer parameters and returns a value, you can call
1370 that function like so:
1372 result = some_value (10,20)
1374 ** Module gdb.types has been added.
1375 It contains a collection of utilities for working with gdb.Types objects:
1376 get_basic_type, has_field, make_enum_dict.
1378 ** Module gdb.printing has been added.
1379 It contains utilities for writing and registering pretty-printers.
1380 New classes: PrettyPrinter, SubPrettyPrinter,
1381 RegexpCollectionPrettyPrinter.
1382 New function: register_pretty_printer.
1384 ** New commands "info pretty-printers", "enable pretty-printer" and
1385 "disable pretty-printer" have been added.
1387 ** gdb.parameter("directories") is now available.
1389 ** New function gdb.newest_frame returns the newest frame in the
1392 ** The gdb.InferiorThread class has a new "name" attribute. This
1393 holds the thread's name.
1395 ** Python Support for Inferior events.
1396 Python scripts can add observers to be notified of events
1397 occurring in the process being debugged.
1398 The following events are currently supported:
1399 - gdb.events.cont Continue event.
1400 - gdb.events.exited Inferior exited event.
1401 - gdb.events.stop Signal received, and Breakpoint hit events.
1405 ** GDB now puts template parameters in scope when debugging in an
1406 instantiation. For example, if you have:
1408 template<int X> int func (void) { return X; }
1410 then if you step into func<5>, "print X" will show "5". This
1411 feature requires proper debuginfo support from the compiler; it
1412 was added to GCC 4.5.
1414 ** The motion commands "next", "finish", "until", and "advance" now
1415 work better when exceptions are thrown. In particular, GDB will
1416 no longer lose control of the inferior; instead, the GDB will
1417 stop the inferior at the point at which the exception is caught.
1418 This functionality requires a change in the exception handling
1419 code that was introduced in GCC 4.5.
1421 * GDB now follows GCC's rules on accessing volatile objects when
1422 reading or writing target state during expression evaluation.
1423 One notable difference to prior behavior is that "print x = 0"
1424 no longer generates a read of x; the value of the assignment is
1425 now always taken directly from the value being assigned.
1427 * GDB now has some support for using labels in the program's source in
1428 linespecs. For instance, you can use "advance label" to continue
1429 execution to a label.
1431 * GDB now has support for reading and writing a new .gdb_index
1432 section. This section holds a fast index of DWARF debugging
1433 information and can be used to greatly speed up GDB startup and
1434 operation. See the documentation for `save gdb-index' for details.
1436 * The "watch" command now accepts an optional "-location" argument.
1437 When used, this causes GDB to watch the memory referred to by the
1438 expression. Such a watchpoint is never deleted due to it going out
1441 * GDB now supports thread debugging of core dumps on GNU/Linux.
1443 GDB now activates thread debugging using the libthread_db library
1444 when debugging GNU/Linux core dumps, similarly to when debugging
1445 live processes. As a result, when debugging a core dump file, GDB
1446 is now able to display pthread_t ids of threads. For example, "info
1447 threads" shows the same output as when debugging the process when it
1448 was live. In earlier releases, you'd see something like this:
1451 * 1 LWP 6780 main () at main.c:10
1453 While now you see this:
1456 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1458 It is also now possible to inspect TLS variables when debugging core
1461 When debugging a core dump generated on a machine other than the one
1462 used to run GDB, you may need to point GDB at the correct
1463 libthread_db library with the "set libthread-db-search-path"
1464 command. See the user manual for more details on this command.
1466 * When natively debugging programs on PowerPC BookE processors running
1467 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1468 which stop execution of the inferior whenever it executes an instruction
1469 at any address within the specified range. See the "PowerPC Embedded"
1470 section in the user manual for more details.
1472 * New features in the GDB remote stub, GDBserver
1474 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1475 and i686 LynxOS (version 5.x).
1477 ** GDBserver is now supported on Blackfin Linux.
1479 * New native configurations
1481 ia64 HP-UX ia64-*-hpux*
1485 Analog Devices, Inc. Blackfin Processor bfin-*
1487 * Ada task switching is now supported on sparc-elf targets when
1488 debugging a program using the Ravenscar Profile. For more information,
1489 see the "Tasking Support when using the Ravenscar Profile" section
1490 in the GDB user manual.
1492 * Guile support was removed.
1494 * New features in the GNU simulator
1496 ** The --map-info flag lists all known core mappings.
1498 ** CFI flashes may be simulated via the "cfi" device.
1500 *** Changes in GDB 7.2
1502 * Shared library support for remote targets by default
1504 When GDB is configured for a generic, non-OS specific target, like
1505 for example, --target=arm-eabi or one of the many *-*-elf targets,
1506 GDB now queries remote stubs for loaded shared libraries using the
1507 `qXfer:libraries:read' packet. Previously, shared library support
1508 was always disabled for such configurations.
1512 ** Argument Dependent Lookup (ADL)
1514 In C++ ADL lookup directs function search to the namespaces of its
1515 arguments even if the namespace has not been imported.
1525 Here the compiler will search for `foo' in the namespace of 'b'
1526 and find A::foo. GDB now supports this. This construct is commonly
1527 used in the Standard Template Library for operators.
1529 ** Improved User Defined Operator Support
1531 In addition to member operators, GDB now supports lookup of operators
1532 defined in a namespace and imported with a `using' directive, operators
1533 defined in the global scope, operators imported implicitly from an
1534 anonymous namespace, and the ADL operators mentioned in the previous
1536 GDB now also supports proper overload resolution for all the previously
1537 mentioned flavors of operators.
1539 ** static const class members
1541 Printing of static const class members that are initialized in the
1542 class definition has been fixed.
1544 * Windows Thread Information Block access.
1546 On Windows targets, GDB now supports displaying the Windows Thread
1547 Information Block (TIB) structure. This structure is visible either
1548 by using the new command `info w32 thread-information-block' or, by
1549 dereferencing the new convenience variable named `$_tlb', a
1550 thread-specific pointer to the TIB. This feature is also supported
1551 when remote debugging using GDBserver.
1553 * Static tracepoints
1555 Static tracepoints are calls in the user program into a tracing
1556 library. One such library is a port of the LTTng kernel tracer to
1557 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1558 When debugging with GDBserver, GDB now supports combining the GDB
1559 tracepoint machinery with such libraries. For example: the user can
1560 use GDB to probe a static tracepoint marker (a call from the user
1561 program into the tracing library) with the new "strace" command (see
1562 "New commands" below). This creates a "static tracepoint" in the
1563 breakpoint list, that can be manipulated with the same feature set
1564 as fast and regular tracepoints. E.g., collect registers, local and
1565 global variables, collect trace state variables, and define
1566 tracepoint conditions. In addition, the user can collect extra
1567 static tracepoint marker specific data, by collecting the new
1568 $_sdata internal variable. When analyzing the trace buffer, you can
1569 inspect $_sdata like any other variable available to GDB. For more
1570 information, see the "Tracepoints" chapter in GDB user manual. New
1571 remote packets have been defined to support static tracepoints, see
1572 the "New remote packets" section below.
1574 * Better reconstruction of tracepoints after disconnected tracing
1576 GDB will attempt to download the original source form of tracepoint
1577 definitions when starting a trace run, and then will upload these
1578 upon reconnection to the target, resulting in a more accurate
1579 reconstruction of the tracepoints that are in use on the target.
1583 You can now exercise direct control over the ways that GDB can
1584 affect your program. For instance, you can disallow the setting of
1585 breakpoints, so that the program can run continuously (assuming
1586 non-stop mode). In addition, the "observer" variable is available
1587 to switch all of the different controls; in observer mode, GDB
1588 cannot affect the target's behavior at all, which is useful for
1589 tasks like diagnosing live systems in the field.
1591 * The new convenience variable $_thread holds the number of the
1594 * New remote packets
1598 Return the address of the Windows Thread Information Block of a given thread.
1602 In response to several of the tracepoint packets, the target may now
1603 also respond with a number of intermediate `qRelocInsn' request
1604 packets before the final result packet, to have GDB handle
1605 relocating an instruction to execute at a different address. This
1606 is particularly useful for stubs that support fast tracepoints. GDB
1607 reports support for this feature in the qSupported packet.
1611 List static tracepoint markers in the target program.
1615 List static tracepoint markers at a given address in the target
1618 qXfer:statictrace:read
1620 Read the static trace data collected (by a `collect $_sdata'
1621 tracepoint action). The remote stub reports support for this packet
1622 to gdb's qSupported query.
1626 Send the current settings of GDB's permission flags.
1630 Send part of the source (textual) form of a tracepoint definition,
1631 which includes location, conditional, and action list.
1633 * The source command now accepts a -s option to force searching for the
1634 script in the source search path even if the script name specifies
1637 * New features in the GDB remote stub, GDBserver
1639 - GDBserver now support tracepoints (including fast tracepoints, and
1640 static tracepoints). The feature is currently supported by the
1641 i386-linux and amd64-linux builds. See the "Tracepoints support
1642 in gdbserver" section in the manual for more information.
1644 GDBserver JIT compiles the tracepoint's conditional agent
1645 expression bytecode into native code whenever possible for low
1646 overhead dynamic tracepoints conditionals. For such tracepoints,
1647 an expression that examines program state is evaluated when the
1648 tracepoint is reached, in order to determine whether to capture
1649 trace data. If the condition is simple and false, processing the
1650 tracepoint finishes very quickly and no data is gathered.
1652 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1653 for static tracepoints support.
1655 - GDBserver now supports x86_64 Windows 64-bit debugging.
1657 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1658 it understands register description.
1660 * The --batch flag now disables pagination and queries.
1662 * X86 general purpose registers
1664 GDB now supports reading/writing byte, word and double-word x86
1665 general purpose registers directly. This means you can use, say,
1666 $ah or $ax to refer, respectively, to the byte register AH and
1667 16-bit word register AX that are actually portions of the 32-bit
1668 register EAX or 64-bit register RAX.
1670 * The `commands' command now accepts a range of breakpoints to modify.
1671 A plain `commands' following a command that creates multiple
1672 breakpoints affects all the breakpoints set by that command. This
1673 applies to breakpoints set by `rbreak', and also applies when a
1674 single `break' command creates multiple breakpoints (e.g.,
1675 breakpoints on overloaded c++ functions).
1677 * The `rbreak' command now accepts a filename specification as part of
1678 its argument, limiting the functions selected by the regex to those
1679 in the specified file.
1681 * Support for remote debugging Windows and SymbianOS shared libraries
1682 from Unix hosts has been improved. Non Windows GDB builds now can
1683 understand target reported file names that follow MS-DOS based file
1684 system semantics, such as file names that include drive letters and
1685 use the backslash character as directory separator. This makes it
1686 possible to transparently use the "set sysroot" and "set
1687 solib-search-path" on Unix hosts to point as host copies of the
1688 target's shared libraries. See the new command "set
1689 target-file-system-kind" described below, and the "Commands to
1690 specify files" section in the user manual for more information.
1694 eval template, expressions...
1695 Convert the values of one or more expressions under the control
1696 of the string template to a command line, and call it.
1698 set target-file-system-kind unix|dos-based|auto
1699 show target-file-system-kind
1700 Set or show the assumed file system kind for target reported file
1703 save breakpoints <filename>
1704 Save all current breakpoint definitions to a file suitable for use
1705 in a later debugging session. To read the saved breakpoint
1706 definitions, use the `source' command.
1708 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1711 info static-tracepoint-markers
1712 Display information about static tracepoint markers in the target.
1714 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1715 Define a static tracepoint by probing a marker at the given
1716 function, line, address, or marker ID.
1720 Enable and disable observer mode.
1722 set may-write-registers on|off
1723 set may-write-memory on|off
1724 set may-insert-breakpoints on|off
1725 set may-insert-tracepoints on|off
1726 set may-insert-fast-tracepoints on|off
1727 set may-interrupt on|off
1728 Set individual permissions for GDB effects on the target. Note that
1729 some of these settings can have undesirable or surprising
1730 consequences, particularly when changed in the middle of a session.
1731 For instance, disabling the writing of memory can prevent
1732 breakpoints from being inserted, cause single-stepping to fail, or
1733 even crash your program, if you disable after breakpoints have been
1734 inserted. However, GDB should not crash.
1736 set record memory-query on|off
1737 show record memory-query
1738 Control whether to stop the inferior if memory changes caused
1739 by an instruction cannot be recorded.
1744 The disassemble command now supports "start,+length" form of two arguments.
1748 ** GDB now provides a new directory location, called the python directory,
1749 where Python scripts written for GDB can be installed. The location
1750 of that directory is <data-directory>/python, where <data-directory>
1751 is the GDB data directory. For more details, see section `Scripting
1752 GDB using Python' in the manual.
1754 ** The GDB Python API now has access to breakpoints, symbols, symbol
1755 tables, program spaces, inferiors, threads and frame's code blocks.
1756 Additionally, GDB Parameters can now be created from the API, and
1757 manipulated via set/show in the CLI.
1759 ** New functions gdb.target_charset, gdb.target_wide_charset,
1760 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1762 ** New exception gdb.GdbError.
1764 ** Pretty-printers are now also looked up in the current program space.
1766 ** Pretty-printers can now be individually enabled and disabled.
1768 ** GDB now looks for names of Python scripts to auto-load in a
1769 special section named `.debug_gdb_scripts', in addition to looking
1770 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1772 * Tracepoint actions were unified with breakpoint commands. In particular,
1773 there are no longer differences in "info break" output for breakpoints and
1774 tracepoints and the "commands" command can be used for both tracepoints and
1775 regular breakpoints.
1779 ARM Symbian arm*-*-symbianelf*
1781 * D language support.
1782 GDB now supports debugging programs written in the D programming
1785 * GDB now supports the extended ptrace interface for PowerPC which is
1786 available since Linux kernel version 2.6.34. This automatically enables
1787 any hardware breakpoints and additional hardware watchpoints available in
1788 the processor. The old ptrace interface exposes just one hardware
1789 watchpoint and no hardware breakpoints.
1791 * GDB is now able to use the Data Value Compare (DVC) register available on
1792 embedded PowerPC processors to implement in hardware simple watchpoint
1793 conditions of the form:
1795 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1797 This works in native GDB running on Linux kernels with the extended ptrace
1798 interface mentioned above.
1800 *** Changes in GDB 7.1
1804 ** Namespace Support
1806 GDB now supports importing of namespaces in C++. This enables the
1807 user to inspect variables from imported namespaces. Support for
1808 namepace aliasing has also been added. So, if a namespace is
1809 aliased in the current scope (e.g. namepace C=A; ) the user can
1810 print variables using the alias (e.g. (gdb) print C::x).
1814 All known bugs relating to the printing of virtual base class were
1815 fixed. It is now possible to call overloaded static methods using a
1820 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1821 and reinterpret_cast<> are now handled by the C++ expression parser.
1825 Xilinx MicroBlaze microblaze-*-*
1830 Xilinx MicroBlaze microblaze
1833 * Multi-program debugging.
1835 GDB now has support for multi-program (a.k.a. multi-executable or
1836 multi-exec) debugging. This allows for debugging multiple inferiors
1837 simultaneously each running a different program under the same GDB
1838 session. See "Debugging Multiple Inferiors and Programs" in the
1839 manual for more information. This implied some user visible changes
1840 in the multi-inferior support. For example, "info inferiors" now
1841 lists inferiors that are not running yet or that have exited
1842 already. See also "New commands" and "New options" below.
1844 * New tracing features
1846 GDB's tracepoint facility now includes several new features:
1848 ** Trace state variables
1850 GDB tracepoints now include support for trace state variables, which
1851 are variables managed by the target agent during a tracing
1852 experiment. They are useful for tracepoints that trigger each
1853 other, so for instance one tracepoint can count hits in a variable,
1854 and then a second tracepoint has a condition that is true when the
1855 count reaches a particular value. Trace state variables share the
1856 $-syntax of GDB convenience variables, and can appear in both
1857 tracepoint actions and condition expressions. Use the "tvariable"
1858 command to create, and "info tvariables" to view; see "Trace State
1859 Variables" in the manual for more detail.
1863 GDB now includes an option for defining fast tracepoints, which
1864 targets may implement more efficiently, such as by installing a jump
1865 into the target agent rather than a trap instruction. The resulting
1866 speedup can be by two orders of magnitude or more, although the
1867 tradeoff is that some program locations on some target architectures
1868 might not allow fast tracepoint installation, for instance if the
1869 instruction to be replaced is shorter than the jump. To request a
1870 fast tracepoint, use the "ftrace" command, with syntax identical to
1871 the regular trace command.
1873 ** Disconnected tracing
1875 It is now possible to detach GDB from the target while it is running
1876 a trace experiment, then reconnect later to see how the experiment
1877 is going. In addition, a new variable disconnected-tracing lets you
1878 tell the target agent whether to continue running a trace if the
1879 connection is lost unexpectedly.
1883 GDB now has the ability to save the trace buffer into a file, and
1884 then use that file as a target, similarly to you can do with
1885 corefiles. You can select trace frames, print data that was
1886 collected in them, and use tstatus to display the state of the
1887 tracing run at the moment that it was saved. To create a trace
1888 file, use "tsave <filename>", and to use it, do "target tfile
1891 ** Circular trace buffer
1893 You can ask the target agent to handle the trace buffer as a
1894 circular buffer, discarding the oldest trace frames to make room for
1895 newer ones, by setting circular-trace-buffer to on. This feature may
1896 not be available for all target agents.
1901 The disassemble command, when invoked with two arguments, now requires
1902 the arguments to be comma-separated.
1905 The info variables command now displays variable definitions. Files
1906 which only declare a variable are not shown.
1909 The source command is now capable of sourcing Python scripts.
1910 This feature is dependent on the debugger being build with Python
1913 Related to this enhancement is also the introduction of a new command
1914 "set script-extension" (see below).
1916 * New commands (for set/show, see "New options" below)
1918 record save [<FILENAME>]
1919 Save a file (in core file format) containing the process record
1920 execution log for replay debugging at a later time.
1922 record restore <FILENAME>
1923 Restore the process record execution log that was saved at an
1924 earlier time, for replay debugging.
1926 add-inferior [-copies <N>] [-exec <FILENAME>]
1929 clone-inferior [-copies <N>] [ID]
1930 Make a new inferior ready to execute the same program another
1931 inferior has loaded.
1936 maint info program-spaces
1937 List the program spaces loaded into GDB.
1939 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1940 show remote interrupt-sequence
1941 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1942 as the sequence to the remote target in order to interrupt the execution.
1943 Ctrl-C is a default. Some system prefers BREAK which is high level of
1944 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1945 Magic SysRq g. It is BREAK signal and character 'g'.
1947 set remote interrupt-on-connect [on | off]
1948 show remote interrupt-on-connect
1949 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1950 remote target when gdb connects to it. This is needed when you debug
1953 set remotebreak [on | off]
1955 Deprecated. Use "set/show remote interrupt-sequence" instead.
1957 tvariable $NAME [ = EXP ]
1958 Create or modify a trace state variable.
1961 List trace state variables and their values.
1963 delete tvariable $NAME ...
1964 Delete one or more trace state variables.
1967 Evaluate the given expressions without collecting anything into the
1968 trace buffer. (Valid in tracepoint actions only.)
1970 ftrace FN / FILE:LINE / *ADDR
1971 Define a fast tracepoint at the given function, line, or address.
1973 * New expression syntax
1975 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1976 GDB now parses 0b101010 identically with 42.
1980 set follow-exec-mode new|same
1981 show follow-exec-mode
1982 Control whether GDB reuses the same inferior across an exec call or
1983 creates a new one. This is useful to be able to restart the old
1984 executable after the inferior having done an exec call.
1986 set default-collect EXPR, ...
1987 show default-collect
1988 Define a list of expressions to be collected at each tracepoint.
1989 This is a useful way to ensure essential items are not overlooked,
1990 such as registers or a critical global variable.
1992 set disconnected-tracing
1993 show disconnected-tracing
1994 If set to 1, the target is instructed to continue tracing if it
1995 loses its connection to GDB. If 0, the target is to stop tracing
1998 set circular-trace-buffer
1999 show circular-trace-buffer
2000 If set to on, the target is instructed to use a circular trace buffer
2001 and discard the oldest trace frames instead of stopping the trace due
2002 to a full trace buffer. If set to off, the trace stops when the buffer
2003 fills up. Some targets may not support this.
2005 set script-extension off|soft|strict
2006 show script-extension
2007 If set to "off", the debugger does not perform any script language
2008 recognition, and all sourced files are assumed to be GDB scripts.
2009 If set to "soft" (the default), files are sourced according to
2010 filename extension, falling back to GDB scripts if the first
2012 If set to "strict", files are sourced according to filename extension.
2014 set ada trust-PAD-over-XVS on|off
2015 show ada trust-PAD-over-XVS
2016 If off, activate a workaround against a bug in the debugging information
2017 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2018 the GCC sources for more information about the GNAT encoding and
2019 PAD types in particular). It is always safe to set this option to
2020 off, but this introduces a slight performance penalty. The default
2023 * Python API Improvements
2025 ** GDB provides the new class gdb.LazyString. This is useful in
2026 some pretty-printing cases. The new method gdb.Value.lazy_string
2027 provides a simple way to create objects of this type.
2029 ** The fields returned by gdb.Type.fields now have an
2030 `is_base_class' attribute.
2032 ** The new method gdb.Type.range returns the range of an array type.
2034 ** The new method gdb.parse_and_eval can be used to parse and
2035 evaluate an expression.
2037 * New remote packets
2040 Define a trace state variable.
2043 Get the current value of a trace state variable.
2046 Set desired tracing behavior upon disconnection.
2049 Set the trace buffer to be linear or circular.
2052 Get data about the tracepoints currently in use.
2056 Process record now works correctly with hardware watchpoints.
2058 Multiple bug fixes have been made to the mips-irix port, making it
2059 much more reliable. In particular:
2060 - Debugging threaded applications is now possible again. Previously,
2061 GDB would hang while starting the program, or while waiting for
2062 the program to stop at a breakpoint.
2063 - Attaching to a running process no longer hangs.
2064 - An error occurring while loading a core file has been fixed.
2065 - Changing the value of the PC register now works again. This fixes
2066 problems observed when using the "jump" command, or when calling
2067 a function from GDB, or even when assigning a new value to $pc.
2068 - With the "finish" and "return" commands, the return value for functions
2069 returning a small array is now correctly printed.
2070 - It is now possible to break on shared library code which gets executed
2071 during a shared library init phase (code executed while executing
2072 their .init section). Previously, the breakpoint would have no effect.
2073 - GDB is now able to backtrace through the signal handler for
2074 non-threaded programs.
2076 PIE (Position Independent Executable) programs debugging is now supported.
2077 This includes debugging execution of PIC (Position Independent Code) shared
2078 libraries although for that, it should be possible to run such libraries as an
2081 *** Changes in GDB 7.0
2083 * GDB now has an interface for JIT compilation. Applications that
2084 dynamically generate code can create symbol files in memory and register
2085 them with GDB. For users, the feature should work transparently, and
2086 for JIT developers, the interface is documented in the GDB manual in the
2087 "JIT Compilation Interface" chapter.
2089 * Tracepoints may now be conditional. The syntax is as for
2090 breakpoints; either an "if" clause appended to the "trace" command,
2091 or the "condition" command is available. GDB sends the condition to
2092 the target for evaluation using the same bytecode format as is used
2093 for tracepoint actions.
2095 * The disassemble command now supports: an optional /r modifier, print the
2096 raw instructions in hex as well as in symbolic form, and an optional /m
2097 modifier to print mixed source+assembly.
2099 * Process record and replay
2101 In a architecture environment that supports ``process record and
2102 replay'', ``process record and replay'' target can record a log of
2103 the process execution, and replay it with both forward and reverse
2106 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2107 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2108 set execution-direction {forward|reverse}, for targets that support
2111 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2112 feature is available with a native GDB running on kernel version
2115 * GDB now has support for multi-byte and wide character sets on the
2116 target. Strings whose character type is wchar_t, char16_t, or
2117 char32_t are now correctly printed. GDB supports wide- and unicode-
2118 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2119 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2120 `printf'. This feature requires iconv to work properly; if your
2121 system does not have a working iconv, GDB can use GNU libiconv. See
2122 the installation instructions for more information.
2124 * GDB now supports automatic retrieval of shared library files from
2125 remote targets. To use this feature, specify a system root that begins
2126 with the `remote:' prefix, either via the `set sysroot' command or via
2127 the `--with-sysroot' configure-time option.
2129 * "info sharedlibrary" now takes an optional regex of libraries to show,
2130 and it now reports if a shared library has no debugging information.
2132 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2133 now complete on file names.
2135 * When completing in expressions, gdb will attempt to limit
2136 completions to allowable structure or union fields, where appropriate.
2137 For instance, consider:
2139 # struct example { int f1; double f2; };
2140 # struct example variable;
2143 If the user types TAB at the end of this command line, the available
2144 completions will be "f1" and "f2".
2146 * Inlined functions are now supported. They show up in backtraces, and
2147 the "step", "next", and "finish" commands handle them automatically.
2149 * GDB now supports the token-splicing (##) and stringification (#)
2150 operators when expanding macros. It also supports variable-arity
2153 * GDB now supports inspecting extra signal information, exported by
2154 the new $_siginfo convenience variable. The feature is currently
2155 implemented on linux ARM, i386 and amd64.
2157 * GDB can now display the VFP floating point registers and NEON vector
2158 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2159 can provide these registers (requires Linux 2.6.30 or later). Remote
2160 and simulator targets may also provide them.
2162 * New remote packets
2165 Search memory for a sequence of bytes.
2168 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2169 operation over reliable transport links. Use of this packet is
2170 controlled by the `set remote noack-packet' command.
2173 Kill the process with the specified process ID. Use this in preference
2174 to `k' when multiprocess protocol extensions are supported.
2177 Obtains additional operating system information
2181 Read or write additional signal information.
2183 * Removed remote protocol undocumented extension
2185 An undocumented extension to the remote protocol's `S' stop reply
2186 packet that permited the stub to pass a process id was removed.
2187 Remote servers should use the `T' stop reply packet instead.
2189 * GDB now supports multiple function calling conventions according to the
2190 DWARF-2 DW_AT_calling_convention function attribute.
2192 * The SH target utilizes the aforementioned change to distinguish between gcc
2193 and Renesas calling convention. It also adds the new CLI commands
2194 `set/show sh calling-convention'.
2196 * GDB can now read compressed debug sections, as produced by GNU gold
2197 with the --compress-debug-sections=zlib flag.
2199 * 64-bit core files are now supported on AIX.
2201 * Thread switching is now supported on Tru64.
2203 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2204 which will be allocated using malloc later in program execution.
2206 * The qXfer:libraries:read remote procotol packet now allows passing a
2207 list of section offsets.
2209 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2210 conditions handling signals delivered during attach or thread creation
2211 have also been fixed.
2213 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2214 From the user's standpoint, all unqualified instances of True and False
2215 are treated as the standard definitions, regardless of context.
2217 * GDB now parses C++ symbol and type names more flexibly. For
2220 template<typename T> class C { };
2223 GDB will now correctly handle all of:
2225 ptype C<char const *>
2226 ptype C<char const*>
2227 ptype C<const char *>
2228 ptype C<const char*>
2230 * New features in the GDB remote stub, gdbserver
2232 - The "--wrapper" command-line argument tells gdbserver to use a
2233 wrapper program to launch programs for debugging.
2235 - On PowerPC and S/390 targets, it is now possible to use a single
2236 gdbserver executable to debug both 32-bit and 64-bit programs.
2237 (This requires gdbserver itself to be built as a 64-bit executable.)
2239 - gdbserver uses the new noack protocol mode for TCP connections to
2240 reduce communications latency, if also supported and enabled in GDB.
2242 - Support for the sparc64-linux-gnu target is now included in
2245 - The amd64-linux build of gdbserver now supports debugging both
2246 32-bit and 64-bit programs.
2248 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2249 now support hardware watchpoints, and will use them automatically
2254 GDB now has support for scripting using Python. Whether this is
2255 available is determined at configure time.
2257 New GDB commands can now be written in Python.
2259 * Ada tasking support
2261 Ada tasks can now be inspected in GDB. The following commands have
2265 Print the list of Ada tasks.
2267 Print detailed information about task number N.
2269 Print the task number of the current task.
2271 Switch the context of debugging to task number N.
2273 * Support for user-defined prefixed commands. The "define" command can
2274 add new commands to existing prefixes, e.g. "target".
2276 * Multi-inferior, multi-process debugging.
2278 GDB now has generalized support for multi-inferior debugging. See
2279 "Debugging Multiple Inferiors" in the manual for more information.
2280 Although availability still depends on target support, the command
2281 set is more uniform now. The GNU/Linux specific multi-forks support
2282 has been migrated to this new framework. This implied some user
2283 visible changes; see "New commands" and also "Removed commands"
2286 * Target descriptions can now describe the target OS ABI. See the
2287 "Target Description Format" section in the user manual for more
2290 * Target descriptions can now describe "compatible" architectures
2291 to indicate that the target can execute applications for a different
2292 architecture in addition to those for the main target architecture.
2293 See the "Target Description Format" section in the user manual for
2296 * Multi-architecture debugging.
2298 GDB now includes general supports for debugging applications on
2299 hybrid systems that use more than one single processor architecture
2300 at the same time. Each such hybrid architecture still requires
2301 specific support to be added. The only hybrid architecture supported
2302 in this version of GDB is the Cell Broadband Engine.
2304 * GDB now supports integrated debugging of Cell/B.E. applications that
2305 use both the PPU and SPU architectures. To enable support for hybrid
2306 Cell/B.E. debugging, you need to configure GDB to support both the
2307 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2308 --enable-targets configure option.
2310 * Non-stop mode debugging.
2312 For some targets, GDB now supports an optional mode of operation in
2313 which you can examine stopped threads while other threads continue
2314 to execute freely. This is referred to as non-stop mode, with the
2315 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2316 section in the user manual for more information.
2318 To be able to support remote non-stop debugging, a remote stub needs
2319 to implement the non-stop mode remote protocol extensions, as
2320 described in the "Remote Non-Stop" section of the user manual. The
2321 GDB remote stub, gdbserver, has been adjusted to support these
2322 extensions on linux targets.
2324 * New commands (for set/show, see "New options" below)
2326 catch syscall [NAME(S) | NUMBER(S)]
2327 Catch system calls. Arguments, which should be names of system
2328 calls or their numbers, mean catch only those syscalls. Without
2329 arguments, every syscall will be caught. When the inferior issues
2330 any of the specified syscalls, GDB will stop and announce the system
2331 call, both when it is called and when its call returns. This
2332 feature is currently available with a native GDB running on the
2333 Linux Kernel, under the following architectures: x86, x86_64,
2334 PowerPC and PowerPC64.
2336 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2338 Search memory for a sequence of bytes.
2340 maint set python print-stack
2341 maint show python print-stack
2342 Show a stack trace when an error is encountered in a Python script.
2345 Invoke CODE by passing it to the Python interpreter.
2350 These allow macros to be defined, undefined, and listed
2354 Show operating system information about processes.
2357 List the inferiors currently under GDB's control.
2360 Switch focus to inferior number NUM.
2363 Detach from inferior number NUM.
2366 Kill inferior number NUM.
2370 set spu stop-on-load
2371 show spu stop-on-load
2372 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2374 set spu auto-flush-cache
2375 show spu auto-flush-cache
2376 Control whether to automatically flush the software-managed cache
2377 during Cell/B.E. debugging.
2379 set sh calling-convention
2380 show sh calling-convention
2381 Control the calling convention used when calling SH target functions.
2384 show debug timestamp
2385 Control display of timestamps with GDB debugging output.
2387 set disassemble-next-line
2388 show disassemble-next-line
2389 Control display of disassembled source lines or instructions when
2392 set remote noack-packet
2393 show remote noack-packet
2394 Set/show the use of remote protocol QStartNoAckMode packet. See above
2395 under "New remote packets."
2397 set remote query-attached-packet
2398 show remote query-attached-packet
2399 Control use of remote protocol `qAttached' (query-attached) packet.
2401 set remote read-siginfo-object
2402 show remote read-siginfo-object
2403 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2406 set remote write-siginfo-object
2407 show remote write-siginfo-object
2408 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2411 set remote reverse-continue
2412 show remote reverse-continue
2413 Control use of remote protocol 'bc' (reverse-continue) packet.
2415 set remote reverse-step
2416 show remote reverse-step
2417 Control use of remote protocol 'bs' (reverse-step) packet.
2419 set displaced-stepping
2420 show displaced-stepping
2421 Control displaced stepping mode. Displaced stepping is a way to
2422 single-step over breakpoints without removing them from the debuggee.
2423 Also known as "out-of-line single-stepping".
2426 show debug displaced
2427 Control display of debugging info for displaced stepping.
2429 maint set internal-error
2430 maint show internal-error
2431 Control what GDB does when an internal error is detected.
2433 maint set internal-warning
2434 maint show internal-warning
2435 Control what GDB does when an internal warning is detected.
2440 Use a wrapper program to launch programs for debugging.
2442 set multiple-symbols (all|ask|cancel)
2443 show multiple-symbols
2444 The value of this variable can be changed to adjust the debugger behavior
2445 when an expression or a breakpoint location contains an ambiguous symbol
2446 name (an overloaded function name, for instance).
2448 set breakpoint always-inserted
2449 show breakpoint always-inserted
2450 Keep breakpoints always inserted in the target, as opposed to inserting
2451 them when resuming the target, and removing them when the target stops.
2452 This option can improve debugger performance on slow remote targets.
2454 set arm fallback-mode (arm|thumb|auto)
2455 show arm fallback-mode
2456 set arm force-mode (arm|thumb|auto)
2458 These commands control how ARM GDB determines whether instructions
2459 are ARM or Thumb. The default for both settings is auto, which uses
2460 the current CPSR value for instructions without symbols; previous
2461 versions of GDB behaved as if "set arm fallback-mode arm".
2463 set disable-randomization
2464 show disable-randomization
2465 Standalone programs run with the virtual address space randomization enabled
2466 by default on some platforms. This option keeps the addresses stable across
2467 multiple debugging sessions.
2471 Control whether other threads are stopped or not when some thread hits
2476 Requests that asynchronous execution is enabled in the target, if available.
2477 In this case, it's possible to resume target in the background, and interact
2478 with GDB while the target is running. "show target-async" displays the
2479 current state of asynchronous execution of the target.
2481 set target-wide-charset
2482 show target-wide-charset
2483 The target-wide-charset is the name of the character set that GDB
2484 uses when printing characters whose type is wchar_t.
2486 set tcp auto-retry (on|off)
2488 set tcp connect-timeout
2489 show tcp connect-timeout
2490 These commands allow GDB to retry failed TCP connections to a remote stub
2491 with a specified timeout period; this is useful if the stub is launched
2492 in parallel with GDB but may not be ready to accept connections immediately.
2494 set libthread-db-search-path
2495 show libthread-db-search-path
2496 Control list of directories which GDB will search for appropriate
2499 set schedule-multiple (on|off)
2500 show schedule-multiple
2501 Allow GDB to resume all threads of all processes or only threads of
2502 the current process.
2506 Use more aggressive caching for accesses to the stack. This improves
2507 performance of remote debugging (particularly backtraces) without
2508 affecting correctness.
2510 set interactive-mode (on|off|auto)
2511 show interactive-mode
2512 Control whether GDB runs in interactive mode (on) or not (off).
2513 When in interactive mode, GDB waits for the user to answer all
2514 queries. Otherwise, GDB does not wait and assumes the default
2515 answer. When set to auto (the default), GDB determines which
2516 mode to use based on the stdin settings.
2521 For program forks, this is replaced by the new more generic `info
2522 inferiors' command. To list checkpoints, you can still use the
2523 `info checkpoints' command, which was an alias for the `info forks'
2527 Replaced by the new `inferior' command. To switch between
2528 checkpoints, you can still use the `restart' command, which was an
2529 alias for the `fork' command.
2532 This is removed, since some targets don't have a notion of
2533 processes. To switch between processes, you can still use the
2534 `inferior' command using GDB's own inferior number.
2537 For program forks, this is replaced by the new more generic `kill
2538 inferior' command. To delete a checkpoint, you can still use the
2539 `delete checkpoint' command, which was an alias for the `delete
2543 For program forks, this is replaced by the new more generic `detach
2544 inferior' command. To detach a checkpoint, you can still use the
2545 `detach checkpoint' command, which was an alias for the `detach
2548 * New native configurations
2550 x86/x86_64 Darwin i[34567]86-*-darwin*
2552 x86_64 MinGW x86_64-*-mingw*
2556 Lattice Mico32 lm32-*
2557 x86 DICOS i[34567]86-*-dicos*
2558 x86_64 DICOS x86_64-*-dicos*
2561 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2562 (mingw32ce) debugging.
2568 These commands were actually not implemented on any target.
2570 *** Changes in GDB 6.8
2572 * New native configurations
2574 NetBSD/hppa hppa*-*netbsd*
2575 Xtensa GNU/Linux xtensa*-*-linux*
2579 NetBSD/hppa hppa*-*-netbsd*
2580 Xtensa GNU/Lunux xtensa*-*-linux*
2582 * Change in command line behavior -- corefiles vs. process ids.
2584 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2585 attaching to process NUMBER fails, GDB no longer attempts to open a
2586 core file named NUMBER. Attaching to a program using the -c option
2587 is no longer supported. Instead, use the '-p' or '--pid' options.
2589 * GDB can now be built as a native debugger for debugging Windows x86
2590 (mingw32) Portable Executable (PE) programs.
2592 * Pending breakpoints no longer change their number when their address
2595 * GDB now supports breakpoints with multiple locations,
2596 including breakpoints on C++ constructors, inside C++ templates,
2597 and in inlined functions.
2599 * GDB's ability to debug optimized code has been improved. GDB more
2600 accurately identifies function bodies and lexical blocks that occupy
2601 more than one contiguous range of addresses.
2603 * Target descriptions can now describe registers for PowerPC.
2605 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2606 registers on PowerPC targets.
2608 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2609 targets even when the libthread_db library is not available.
2611 * The GDB remote stub, gdbserver, now supports the new file transfer
2612 commands (remote put, remote get, and remote delete).
2614 * The GDB remote stub, gdbserver, now supports run and attach in
2615 extended-remote mode.
2617 * hppa*64*-*-hpux11* target broken
2618 The debugger is unable to start a program and fails with the following
2619 error: "Error trying to get information about dynamic linker".
2620 The gdb-6.7 release is also affected.
2622 * GDB now supports the --enable-targets= configure option to allow
2623 building a single GDB executable that supports multiple remote
2624 target architectures.
2626 * GDB now supports debugging C and C++ programs which use the
2627 Decimal Floating Point extension. In addition, the PowerPC target
2628 now has a set of pseudo-registers to inspect decimal float values
2629 stored in two consecutive float registers.
2631 * The -break-insert MI command can optionally create pending
2634 * Improved support for debugging Ada
2635 Many improvements to the Ada language support have been made. These
2637 - Better support for Ada2005 interface types
2638 - Improved handling of arrays and slices in general
2639 - Better support for Taft-amendment types
2640 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2642 - Improved command completion in Ada
2645 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2650 set print frame-arguments (all|scalars|none)
2651 show print frame-arguments
2652 The value of this variable can be changed to control which argument
2653 values should be printed by the debugger when displaying a frame.
2658 Transfer files to and from a remote target, and delete remote files.
2665 Transfer files to and from a remote target, and delete remote files.
2667 * New remote packets
2674 Open, close, read, write, and delete files on the remote system.
2677 Attach to an existing process on the remote system, in extended-remote
2681 Run a new process on the remote system, in extended-remote mode.
2683 *** Changes in GDB 6.7
2685 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2686 bfd, libiberty and opcodes, as revealed by static analysis donated by
2687 Coverity, Inc. (http://scan.coverity.com).
2689 * When looking up multiply-defined global symbols, GDB will now prefer the
2690 symbol definition in the current shared library if it was built using the
2691 -Bsymbolic linker option.
2693 * When the Text User Interface (TUI) is not configured, GDB will now
2694 recognize the -tui command-line option and print a message that the TUI
2697 * The GDB remote stub, gdbserver, now has lower overhead for high
2698 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2700 * GDB for MIPS targets now autodetects whether a remote target provides
2701 32-bit or 64-bit register values.
2703 * Support for C++ member pointers has been improved.
2705 * GDB now understands XML target descriptions, which specify the
2706 target's overall architecture. GDB can read a description from
2707 a local file or over the remote serial protocol.
2709 * Vectors of single-byte data use a new integer type which is not
2710 automatically displayed as character or string data.
2712 * The /s format now works with the print command. It displays
2713 arrays of single-byte integers and pointers to single-byte integers
2716 * Target descriptions can now describe target-specific registers,
2717 for architectures which have implemented the support (currently
2718 only ARM, M68K, and MIPS).
2720 * GDB and the GDB remote stub, gdbserver, now support the XScale
2723 * The GDB remote stub, gdbserver, has been updated to support
2724 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2725 has been rewritten to use the standard GDB remote protocol.
2727 * GDB can now step into C++ functions which are called through thunks.
2729 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2731 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2732 layout. It also supports a TextSeg= and DataSeg= response when only
2733 segment base addresses (rather than offsets) are available.
2735 * The /i format now outputs any trailing branch delay slot instructions
2736 immediately following the last instruction within the count specified.
2738 * The GDB remote protocol "T" stop reply packet now supports a
2739 "library" response. Combined with the new "qXfer:libraries:read"
2740 packet, this response allows GDB to debug shared libraries on targets
2741 where the operating system manages the list of loaded libraries (e.g.
2742 Windows and SymbianOS).
2744 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2745 (DLLs) on Windows and Windows CE targets.
2747 * GDB now supports a faster verification that a .debug file matches its binary
2748 according to its build-id signature, if the signature is present.
2754 Enable or disable hardware flow control (RTS/CTS) on the serial port
2755 when debugging using remote targets.
2757 set mem inaccessible-by-default
2758 show mem inaccessible-by-default
2759 If the target supplies a memory map, for instance via the remote
2760 protocol's "qXfer:memory-map:read" packet, setting this variable
2761 prevents GDB from accessing memory outside the memory map. This
2762 is useful for targets with memory mapped registers or which react
2763 badly to accesses of unmapped address space.
2765 set breakpoint auto-hw
2766 show breakpoint auto-hw
2767 If the target supplies a memory map, for instance via the remote
2768 protocol's "qXfer:memory-map:read" packet, setting this variable
2769 lets GDB use hardware breakpoints automatically for memory regions
2770 where it can not use software breakpoints. This covers both the
2771 "break" command and internal breakpoints used for other commands
2772 including "next" and "finish".
2775 catch exception unhandled
2776 Stop the program execution when Ada exceptions are raised.
2779 Stop the program execution when an Ada assertion failed.
2783 Set an alternate system root for target files. This is a more
2784 general version of "set solib-absolute-prefix", which is now
2785 an alias to "set sysroot".
2788 Provide extended SPU facility status information. This set of
2789 commands is available only when debugging the Cell/B.E. SPU
2792 * New native configurations
2794 OpenBSD/sh sh*-*openbsd*
2797 unset tdesc filename
2799 Use the specified local file as an XML target description, and do
2800 not query the target for its built-in description.
2804 OpenBSD/sh sh*-*-openbsd*
2805 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2806 Toshiba Media Processor mep-elf
2808 * New remote packets
2811 Ignore the specified signals; pass them directly to the debugged program
2812 without stopping other threads or reporting them to GDB.
2814 qXfer:features:read:
2815 Read an XML target description from the target, which describes its
2820 Read or write contents of an spufs file on the target system. These
2821 packets are available only on the Cell/B.E. SPU architecture.
2823 qXfer:libraries:read:
2824 Report the loaded shared libraries. Combined with new "T" packet
2825 response, this packet allows GDB to debug shared libraries on
2826 targets where the operating system manages the list of loaded
2827 libraries (e.g. Windows and SymbianOS).
2831 Support for these obsolete configurations has been removed.
2839 i[34567]86-*-lynxos*
2840 i[34567]86-*-netware*
2841 i[34567]86-*-sco3.2v5*
2842 i[34567]86-*-sco3.2v4*
2844 i[34567]86-*-sysv4.2*
2847 i[34567]86-*-unixware2*
2848 i[34567]86-*-unixware*
2857 * Other removed features
2864 Various m68k-only ROM monitors.
2871 Various Renesas ROM monitors and debugging interfaces for SH and
2876 Support for a Macraigor serial interface to on-chip debugging.
2877 GDB does not directly support the newer parallel or USB
2882 A debug information format. The predecessor to DWARF 2 and
2883 DWARF 3, which are still supported.
2885 Support for the HP aCC compiler on HP-UX/PA-RISC
2887 SOM-encapsulated symbolic debugging information, automatic
2888 invocation of pxdb, and the aCC custom C++ ABI. This does not
2889 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2890 with aCC can still be debugged on an assembly level.
2892 MIPS ".pdr" sections
2894 A MIPS-specific format used to describe stack frame layout
2895 in debugging information.
2899 GDB could work with an older version of Guile to debug
2900 the interpreter and Scheme programs running in it.
2902 set mips stack-arg-size
2903 set mips saved-gpreg-size
2905 Use "set mips abi" to control parameter passing for MIPS.
2907 *** Changes in GDB 6.6
2912 Cell Broadband Engine SPU spu-elf
2914 * GDB can now be configured as a cross-debugger targeting native Windows
2915 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2916 running on a Windows system over TCP/IP to debug Windows programs.
2918 * The GDB remote stub, gdbserver, has been updated to support Windows and
2919 Cygwin debugging. Both single-threaded and multi-threaded programs are
2922 * The "set trust-readonly-sections" command works again. This command was
2923 broken in GDB 6.3, 6.4, and 6.5.
2925 * The "load" command now supports writing to flash memory, if the remote
2926 stub provides the required support.
2928 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2929 longer requires symbolic debug information (e.g. DWARF-2).
2934 unset substitute-path
2935 show substitute-path
2936 Manage a list of substitution rules that GDB uses to rewrite the name
2937 of the directories where the sources are located. This can be useful
2938 for instance when the sources were moved to a different location
2939 between compilation and debugging.
2943 Print each CLI command as it is executed. Each command is prefixed with
2944 a number of `+' symbols representing the nesting depth.
2945 The source command now has a `-v' option to enable the same feature.
2949 The ARM Demon monitor support (RDP protocol, "target rdp").
2951 Kernel Object Display, an embedded debugging feature which only worked with
2952 an obsolete version of Cisco IOS.
2954 The 'set download-write-size' and 'show download-write-size' commands.
2956 * New remote packets
2959 Tell a stub about GDB client features, and request remote target features.
2960 The first feature implemented is PacketSize, which allows the target to
2961 specify the size of packets it can handle - to minimize the number of
2962 packets required and improve performance when connected to a remote
2966 Fetch an OS auxilliary vector from the remote stub. This packet is a
2967 more efficient replacement for qPart:auxv:read.
2969 qXfer:memory-map:read:
2970 Fetch a memory map from the remote stub, including information about
2971 RAM, ROM, and flash memory devices.
2976 Erase and program a flash memory device.
2978 * Removed remote packets
2981 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2982 used it, and only gdbserver implemented it.
2984 *** Changes in GDB 6.5
2988 Renesas M32C/M16C m32c-elf
2990 Morpho Technologies ms1 ms1-elf
2994 init-if-undefined Initialize a convenience variable, but
2995 only if it doesn't already have a value.
2997 The following commands are presently only implemented for native GNU/Linux:
2999 checkpoint Save a snapshot of the program state.
3001 restart <n> Return the program state to a
3002 previously saved state.
3004 info checkpoints List currently saved checkpoints.
3006 delete-checkpoint <n> Delete a previously saved checkpoint.
3008 set|show detach-on-fork Tell gdb whether to detach from a newly
3009 forked process, or to keep debugging it.
3011 info forks List forks of the user program that
3012 are available to be debugged.
3014 fork <n> Switch to debugging one of several
3015 forks of the user program that are
3016 available to be debugged.
3018 delete-fork <n> Delete a fork from the list of forks
3019 that are available to be debugged (and
3020 kill the forked process).
3022 detach-fork <n> Delete a fork from the list of forks
3023 that are available to be debugged (and
3024 allow the process to continue).
3028 Morpho Technologies ms2 ms1-elf
3030 * Improved Windows host support
3032 GDB now builds as a cross debugger hosted on i686-mingw32, including
3033 native console support, and remote communications using either
3034 network sockets or serial ports.
3036 * Improved Modula-2 language support
3038 GDB can now print most types in the Modula-2 syntax. This includes:
3039 basic types, set types, record types, enumerated types, range types,
3040 pointer types and ARRAY types. Procedure var parameters are correctly
3041 printed and hexadecimal addresses and character constants are also
3042 written in the Modula-2 syntax. Best results can be obtained by using
3043 GNU Modula-2 together with the -gdwarf-2 command line option.
3047 The ARM rdi-share module.
3049 The Netware NLM debug server.
3051 *** Changes in GDB 6.4
3053 * New native configurations
3055 OpenBSD/arm arm*-*-openbsd*
3056 OpenBSD/mips64 mips64-*-openbsd*
3060 Morpho Technologies ms1 ms1-elf
3062 * New command line options
3064 --batch-silent As for --batch, but totally silent.
3065 --return-child-result The debugger will exist with the same value
3066 the child (debugged) program exited with.
3067 --eval-command COMMAND, -ex COMMAND
3068 Execute a single GDB CLI command. This may be
3069 specified multiple times and in conjunction
3070 with the --command (-x) option.
3072 * Deprecated commands removed
3074 The following commands, that were deprecated in 2000, have been
3078 set|show arm disassembly-flavor set|show arm disassembler
3079 othernames set arm disassembler
3080 set|show remotedebug set|show debug remote
3081 set|show archdebug set|show debug arch
3082 set|show eventdebug set|show debug event
3085 * New BSD user-level threads support
3087 It is now possible to debug programs using the user-level threads
3088 library on OpenBSD and FreeBSD. Currently supported (target)
3091 FreeBSD/amd64 x86_64-*-freebsd*
3092 FreeBSD/i386 i386-*-freebsd*
3093 OpenBSD/i386 i386-*-openbsd*
3095 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3096 are not yet supported.
3098 * New support for Matsushita MN10300 w/sim added
3099 (Work in progress). mn10300-elf.
3101 * REMOVED configurations and files
3103 VxWorks and the XDR protocol *-*-vxworks
3104 Motorola MCORE mcore-*-*
3105 National Semiconductor NS32000 ns32k-*-*
3107 * New "set print array-indexes" command
3109 After turning this setting "on", GDB prints the index of each element
3110 when displaying arrays. The default is "off" to preserve the previous
3113 * VAX floating point support
3115 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3117 * User-defined command support
3119 In addition to using $arg0..$arg9 for argument passing, it is now possible
3120 to use $argc to determine now many arguments have been passed. See the
3121 section on user-defined commands in the user manual for more information.
3123 *** Changes in GDB 6.3:
3125 * New command line option
3127 GDB now accepts -l followed by a number to set the timeout for remote
3130 * GDB works with GCC -feliminate-dwarf2-dups
3132 GDB now supports a more compact representation of DWARF-2 debug
3133 information using DW_FORM_ref_addr references. These are produced
3134 by GCC with the option -feliminate-dwarf2-dups and also by some
3135 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3136 to use -feliminate-dwarf2-dups.
3138 * Internationalization
3140 When supported by the host system, GDB will be built with
3141 internationalization (libintl). The task of marking up the sources is
3142 continued, we're looking forward to our first translation.
3146 Initial support for debugging programs compiled with the GNAT
3147 implementation of the Ada programming language has been integrated
3148 into GDB. In this release, support is limited to expression evaluation.
3150 * New native configurations
3152 GNU/Linux/m32r m32r-*-linux-gnu
3156 GDB's remote protocol now includes support for the 'p' packet. This
3157 packet is used to fetch individual registers from a remote inferior.
3159 * END-OF-LIFE registers[] compatibility module
3161 GDB's internal register infrastructure has been completely rewritten.
3162 The new infrastructure making possible the implementation of key new
3163 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3166 GDB 6.3 will be the last release to include the the registers[]
3167 compatibility module that allowed out-of-date configurations to
3168 continue to work. This change directly impacts the following
3178 powerpc bdm protocol
3180 Unless there is activity to revive these configurations, they will be
3181 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3183 * OBSOLETE configurations and files
3185 Configurations that have been declared obsolete in this release have
3186 been commented out. Unless there is activity to revive these
3187 configurations, the next release of GDB will have their sources
3188 permanently REMOVED.
3197 *** Changes in GDB 6.2.1:
3199 * MIPS `break main; run' gave an heuristic-fence-post warning
3201 When attempting to run even a simple program, a warning about
3202 heuristic-fence-post being hit would be reported. This problem has
3205 * MIPS IRIX 'long double' crashed GDB
3207 When examining a long double variable, GDB would get a segmentation
3208 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3209 IRIX long double values).
3213 A bug in the VAX stack code was causing problems with the "next"
3214 command. This problem has been fixed.
3216 *** Changes in GDB 6.2:
3218 * Fix for ``many threads''
3220 On GNU/Linux systems that use the NPTL threads library, a program
3221 rapidly creating and deleting threads would confuse GDB leading to the
3224 ptrace: No such process.
3225 thread_db_get_info: cannot get thread info: generic error
3227 This problem has been fixed.
3229 * "-async" and "-noasync" options removed.
3231 Support for the broken "-noasync" option has been removed (it caused
3234 * New ``start'' command.
3236 This command runs the program until the begining of the main procedure.
3238 * New BSD Kernel Data Access Library (libkvm) interface
3240 Using ``target kvm'' it is now possible to debug kernel core dumps and
3241 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3242 platforms. Currently supported (native-only) configurations are:
3244 FreeBSD/amd64 x86_64-*-freebsd*
3245 FreeBSD/i386 i?86-*-freebsd*
3246 NetBSD/i386 i?86-*-netbsd*
3247 NetBSD/m68k m68*-*-netbsd*
3248 NetBSD/sparc sparc-*-netbsd*
3249 OpenBSD/amd64 x86_64-*-openbsd*
3250 OpenBSD/i386 i?86-*-openbsd*
3251 OpenBSD/m68k m68*-openbsd*
3252 OpenBSD/sparc sparc-*-openbsd*
3254 * Signal trampoline code overhauled
3256 Many generic problems with GDB's signal handling code have been fixed.
3257 These include: backtraces through non-contiguous stacks; recognition
3258 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3259 call; backtrace through a signal trampoline; step into and out of
3260 signal handlers; and single-stepping in the signal trampoline.
3262 Please note that kernel bugs are a limiting factor here. These
3263 features have been shown to work on an s390 GNU/Linux system that
3264 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3266 * Cygwin support for DWARF 2 added.
3268 * New native configurations
3270 GNU/Linux/hppa hppa*-*-linux*
3271 OpenBSD/hppa hppa*-*-openbsd*
3272 OpenBSD/m68k m68*-*-openbsd*
3273 OpenBSD/m88k m88*-*-openbsd*
3274 OpenBSD/powerpc powerpc-*-openbsd*
3275 NetBSD/vax vax-*-netbsd*
3276 OpenBSD/vax vax-*-openbsd*
3278 * END-OF-LIFE frame compatibility module
3280 GDB's internal frame infrastructure has been completely rewritten.
3281 The new infrastructure making it possible to support key new features
3282 including DWARF 2 Call Frame Information. To aid in the task of
3283 migrating old configurations to this new infrastructure, a
3284 compatibility module, that allowed old configurations to continue to
3285 work, was also included.
3287 GDB 6.2 will be the last release to include this frame compatibility
3288 module. This change directly impacts the following configurations:
3298 Unless there is activity to revive these configurations, they will be
3299 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3301 * REMOVED configurations and files
3303 Sun 3, running SunOS 3 m68*-*-sunos3*
3304 Sun 3, running SunOS 4 m68*-*-sunos4*
3305 Sun 2, running SunOS 3 m68000-*-sunos3*
3306 Sun 2, running SunOS 4 m68000-*-sunos4*
3307 Motorola 680x0 running LynxOS m68*-*-lynxos*
3308 AT&T 3b1/Unix pc m68*-att-*
3309 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3310 decstation mips-dec-* mips-little-*
3311 riscos mips-*-riscos* mips-*-sysv*
3312 sonymips mips-sony-*
3313 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3315 *** Changes in GDB 6.1.1:
3317 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3319 The TUI (Text-mode User Interface) is now built as part of a default
3320 GDB configuration. It is enabled by either selecting the TUI with the
3321 command line option "-i=tui" or by running the separate "gdbtui"
3322 program. For more information on the TUI, see the manual "Debugging
3325 * Pending breakpoint support (also included in GDB 6.1)
3327 Support has been added to allow you to specify breakpoints in shared
3328 libraries that have not yet been loaded. If a breakpoint location
3329 cannot be found, and the "breakpoint pending" option is set to auto,
3330 GDB queries you if you wish to make the breakpoint pending on a future
3331 shared-library load. If and when GDB resolves the breakpoint symbol,
3332 the pending breakpoint is removed as one or more regular breakpoints
3335 Pending breakpoints are very useful for GCJ Java debugging.
3337 * Fixed ISO-C build problems
3339 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3340 non ISO-C code that stopped them being built using a more strict ISO-C
3341 compiler (e.g., IBM's C compiler).
3343 * Fixed build problem on IRIX 5
3345 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3346 wasn't able to compile compile on an IRIX 5 system.
3348 * Added execute permission to gdb/gdbserver/configure
3350 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3351 permission. This bug would cause configure to fail on a number of
3352 systems (Solaris, IRIX). Ref: server/519.
3354 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3356 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3357 has been updated to use constant array sizes.
3359 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3361 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3362 its generated DWARF Call Frame Info. This encoding was causing GDB to
3363 panic, that panic has been fixed. Ref: gdb/1628.
3365 * Fixed a problem when examining parameters in shared library code.
3367 When examining parameters in optimized shared library code generated
3368 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3369 not available''. GDB now correctly displays the variable's value.
3371 *** Changes in GDB 6.1:
3373 * Removed --with-mmalloc
3375 Support for the mmalloc memory manager has been removed, as it
3376 conflicted with the internal gdb byte cache.
3378 * Changes in AMD64 configurations
3380 The AMD64 target now includes the %cs and %ss registers. As a result
3381 the AMD64 remote protocol has changed; this affects the floating-point
3382 and SSE registers. If you rely on those registers for your debugging,
3383 you should upgrade gdbserver on the remote side.
3385 * Revised SPARC target
3387 The SPARC target has been completely revised, incorporating the
3388 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3389 support for LynxOS and SunOS 4 has been dropped. Calling functions
3390 from within GDB on operating systems with a non-executable stack
3391 (Solaris, OpenBSD) now works.
3395 GDB has a new C++ demangler which does a better job on the mangled
3396 names generated by current versions of g++. It also runs faster, so
3397 with this and other changes gdb should now start faster on large C++
3400 * DWARF 2 Location Expressions
3402 GDB support for location expressions has been extended to support function
3403 arguments and frame bases. Older versions of GDB could crash when they
3406 * C++ nested types and namespaces
3408 GDB's support for nested types and namespaces in C++ has been
3409 improved, especially if you use the DWARF 2 debugging format. (This
3410 is the default for recent versions of GCC on most platforms.)
3411 Specifically, if you have a class "Inner" defined within a class or
3412 namespace "Outer", then GDB realizes that the class's name is
3413 "Outer::Inner", not simply "Inner". This should greatly reduce the
3414 frequency of complaints about not finding RTTI symbols. In addition,
3415 if you are stopped at inside of a function defined within a namespace,
3416 GDB modifies its name lookup accordingly.
3418 * New native configurations
3420 NetBSD/amd64 x86_64-*-netbsd*
3421 OpenBSD/amd64 x86_64-*-openbsd*
3422 OpenBSD/alpha alpha*-*-openbsd*
3423 OpenBSD/sparc sparc-*-openbsd*
3424 OpenBSD/sparc64 sparc64-*-openbsd*
3426 * New debugging protocols
3428 M32R with SDI protocol m32r-*-elf*
3430 * "set prompt-escape-char" command deleted.
3432 The command "set prompt-escape-char" has been deleted. This command,
3433 and its very obscure effet on GDB's prompt, was never documented,
3434 tested, nor mentioned in the NEWS file.
3436 * OBSOLETE configurations and files
3438 Configurations that have been declared obsolete in this release have
3439 been commented out. Unless there is activity to revive these
3440 configurations, the next release of GDB will have their sources
3441 permanently REMOVED.
3443 Sun 3, running SunOS 3 m68*-*-sunos3*
3444 Sun 3, running SunOS 4 m68*-*-sunos4*
3445 Sun 2, running SunOS 3 m68000-*-sunos3*
3446 Sun 2, running SunOS 4 m68000-*-sunos4*
3447 Motorola 680x0 running LynxOS m68*-*-lynxos*
3448 AT&T 3b1/Unix pc m68*-att-*
3449 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3450 decstation mips-dec-* mips-little-*
3451 riscos mips-*-riscos* mips-*-sysv*
3452 sonymips mips-sony-*
3453 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3455 * REMOVED configurations and files
3457 SGI Irix-4.x mips-sgi-irix4 or iris4
3458 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3459 Z8000 simulator z8k-zilog-none or z8ksim
3460 Matsushita MN10200 w/simulator mn10200-*-*
3461 H8/500 simulator h8500-hitachi-hms or h8500hms
3462 HP/PA running BSD hppa*-*-bsd*
3463 HP/PA running OSF/1 hppa*-*-osf*
3464 HP/PA Pro target hppa*-*-pro*
3465 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3466 386BSD i[3456]86-*-bsd*
3467 Sequent family i[3456]86-sequent-sysv4*
3468 i[3456]86-sequent-sysv*
3469 i[3456]86-sequent-bsd*
3470 SPARC running LynxOS sparc-*-lynxos*
3471 SPARC running SunOS 4 sparc-*-sunos4*
3472 Tsqware Sparclet sparclet-*-*
3473 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3475 *** Changes in GDB 6.0:
3479 Support for debugging the Objective-C programming language has been
3480 integrated into GDB.
3482 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3484 DWARF 2's Call Frame Information makes available compiler generated
3485 information that more exactly describes the program's run-time stack.
3486 By using this information, GDB is able to provide more robust stack
3489 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3490 have been updated to use a new backtrace mechanism which includes
3491 DWARF 2 CFI support.
3495 GDB's remote protocol has been extended to include support for hosted
3496 file I/O (where the remote target uses GDB's file system). See GDB's
3497 remote protocol documentation for details.
3499 * All targets using the new architecture framework.
3501 All of GDB's targets have been updated to use the new internal
3502 architecture framework. The way is now open for future GDB releases
3503 to include cross-architecture native debugging support (i386 on amd64,
3506 * GNU/Linux's Thread Local Storage (TLS)
3508 GDB now includes support for for the GNU/Linux implementation of
3509 per-thread variables.
3511 * GNU/Linux's Native POSIX Thread Library (NPTL)
3513 GDB's thread code has been updated to work with either the new
3514 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3516 * Separate debug info.
3518 GDB, in conjunction with BINUTILS, now supports a mechanism for
3519 automatically loading debug information from a separate file. Instead
3520 of shipping full debug and non-debug versions of system libraries,
3521 system integrators can now instead ship just the stripped libraries
3522 and optional debug files.
3524 * DWARF 2 Location Expressions
3526 DWARF 2 Location Expressions allow the compiler to more completely
3527 describe the location of variables (even in optimized code) to the
3530 GDB now includes preliminary support for location expressions (support
3531 for DW_OP_piece is still missing).
3535 A number of long standing bugs that caused GDB to die while starting a
3536 Java application have been fixed. GDB's Java support is now
3537 considered "useable".
3539 * GNU/Linux support for fork, vfork, and exec.
3541 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3542 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3545 * GDB supports logging output to a file
3547 There are two new commands, "set logging" and "show logging", which can be
3548 used to capture GDB's output to a file.
3550 * The meaning of "detach" has changed for gdbserver
3552 The "detach" command will now resume the application, as documented. To
3553 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3556 * d10v, m68hc11 `regs' command deprecated
3558 The `info registers' command has been updated so that it displays the
3559 registers using a format identical to the old `regs' command.
3563 A new command, "maint set profile on/off", has been added. This command can
3564 be used to enable or disable profiling while running GDB, to profile a
3565 session or a set of commands. In addition there is a new configure switch,
3566 "--enable-profiling", which will cause GDB to be compiled with profiling
3567 data, for more informative profiling results.
3569 * Default MI syntax changed to "mi2".
3571 The default MI (machine interface) syntax, enabled by the command line
3572 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3573 "mi1", can be enabled by specifying the option "-i=mi1".
3575 Support for the original "mi0" syntax (included in GDB 5.0) has been
3578 Fix for gdb/192: removed extraneous space when displaying frame level.
3579 Fix for gdb/672: update changelist is now output in mi list format.
3580 Fix for gdb/702: a -var-assign that updates the value now shows up
3581 in a subsequent -var-update.
3583 * New native configurations.
3585 FreeBSD/amd64 x86_64-*-freebsd*
3587 * Multi-arched targets.
3589 HP/PA HPUX11 hppa*-*-hpux*
3590 Renesas M32R/D w/simulator m32r-*-elf*
3592 * OBSOLETE configurations and files
3594 Configurations that have been declared obsolete in this release have
3595 been commented out. Unless there is activity to revive these
3596 configurations, the next release of GDB will have their sources
3597 permanently REMOVED.
3599 Z8000 simulator z8k-zilog-none or z8ksim
3600 Matsushita MN10200 w/simulator mn10200-*-*
3601 H8/500 simulator h8500-hitachi-hms or h8500hms
3602 HP/PA running BSD hppa*-*-bsd*
3603 HP/PA running OSF/1 hppa*-*-osf*
3604 HP/PA Pro target hppa*-*-pro*
3605 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3606 Sequent family i[3456]86-sequent-sysv4*
3607 i[3456]86-sequent-sysv*
3608 i[3456]86-sequent-bsd*
3609 Tsqware Sparclet sparclet-*-*
3610 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3612 * REMOVED configurations and files
3615 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3616 IBM AIX PS/2 i[3456]86-*-aix
3617 i386 running Mach 3.0 i[3456]86-*-mach3*
3618 i386 running Mach i[3456]86-*-mach*
3619 i386 running OSF/1 i[3456]86-*osf1mk*
3620 HP/Apollo 68k Family m68*-apollo*-sysv*,
3622 m68*-hp-bsd*, m68*-hp-hpux*
3623 Argonaut Risc Chip (ARC) arc-*-*
3624 Mitsubishi D30V d30v-*-*
3625 Fujitsu FR30 fr30-*-elf*
3626 OS/9000 i[34]86-*-os9k
3627 I960 with MON960 i960-*-coff
3629 * MIPS $fp behavior changed
3631 The convenience variable $fp, for the MIPS, now consistently returns
3632 the address of the current frame's base. Previously, depending on the
3633 context, $fp could refer to either $sp or the current frame's base
3634 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3635 The GNU Source-Level Debugger''.
3637 *** Changes in GDB 5.3:
3639 * GNU/Linux shared library multi-threaded performance improved.
3641 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3642 `/proc', in preference to `ptrace' for memory reads. This may result
3643 in an improvement in the start-up time of multi-threaded, shared
3644 library applications when run under GDB. One GDB user writes: ``loads
3645 shared libs like mad''.
3647 * ``gdbserver'' now supports multi-threaded applications on some targets
3649 Support for debugging multi-threaded applications which use
3650 the GNU/Linux LinuxThreads package has been added for
3651 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3652 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3654 * GDB now supports C/C++ preprocessor macros.
3656 GDB now expands preprocessor macro invocations in C/C++ expressions,
3657 and provides various commands for showing macro definitions and how
3660 The new command `macro expand EXPRESSION' expands any macro
3661 invocations in expression, and shows the result.
3663 The new command `show macro MACRO-NAME' shows the definition of the
3664 macro named MACRO-NAME, and where it was defined.
3666 Most compilers don't include information about macros in the debugging
3667 information by default. In GCC 3.1, for example, you need to compile
3668 your program with the options `-gdwarf-2 -g3'. If the macro
3669 information is present in the executable, GDB will read it.
3671 * Multi-arched targets.
3673 DEC Alpha (partial) alpha*-*-*
3674 DEC VAX (partial) vax-*-*
3676 National Semiconductor NS32000 (partial) ns32k-*-*
3677 Motorola 68000 (partial) m68k-*-*
3678 Motorola MCORE mcore-*-*
3682 Fujitsu FRV architecture added by Red Hat frv*-*-*
3685 * New native configurations
3687 Alpha NetBSD alpha*-*-netbsd*
3688 SH NetBSD sh*-*-netbsdelf*
3689 MIPS NetBSD mips*-*-netbsd*
3690 UltraSPARC NetBSD sparc64-*-netbsd*
3692 * OBSOLETE configurations and files
3694 Configurations that have been declared obsolete in this release have
3695 been commented out. Unless there is activity to revive these
3696 configurations, the next release of GDB will have their sources
3697 permanently REMOVED.
3699 Mitsubishi D30V d30v-*-*
3700 OS/9000 i[34]86-*-os9k
3701 IBM AIX PS/2 i[3456]86-*-aix
3702 Fujitsu FR30 fr30-*-elf*
3703 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3704 Argonaut Risc Chip (ARC) arc-*-*
3705 i386 running Mach 3.0 i[3456]86-*-mach3*
3706 i386 running Mach i[3456]86-*-mach*
3707 i386 running OSF/1 i[3456]86-*osf1mk*
3708 HP/Apollo 68k Family m68*-apollo*-sysv*,
3710 m68*-hp-bsd*, m68*-hp-hpux*
3711 I960 with MON960 i960-*-coff
3713 * OBSOLETE languages
3715 CHILL, a Pascal like language used by telecommunications companies.
3717 * REMOVED configurations and files
3719 AMD 29k family via UDI a29k-amd-udi, udi29k
3720 A29K VxWorks a29k-*-vxworks
3721 AMD 29000 embedded, using EBMON a29k-none-none
3722 AMD 29000 embedded with COFF a29k-none-coff
3723 AMD 29000 embedded with a.out a29k-none-aout
3725 testsuite/gdb.hp/gdb.threads-hp/ directory
3727 * New command "set max-user-call-depth <nnn>"
3729 This command allows the user to limit the call depth of user-defined
3730 commands. The default is 1024.
3732 * Changes in FreeBSD/i386 native debugging.
3734 Support for the "generate-core-file" has been added.
3736 * New commands "dump", "append", and "restore".
3738 These commands allow data to be copied from target memory
3739 to a bfd-format or binary file (dump and append), and back
3740 from a file into memory (restore).
3742 * Improved "next/step" support on multi-processor Alpha Tru64.
3744 The previous single-step mechanism could cause unpredictable problems,
3745 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3746 of a software single-step mechanism prevents this.
3748 *** Changes in GDB 5.2.1:
3756 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3757 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3758 Fix, by Joel Brobecker imported from mainline.
3760 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3761 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3762 Fix, by Fred Fish, imported from mainline.
3764 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3765 Surprisingly enough, it works now.
3766 By Michal Ludvig, imported from mainline.
3768 i386 hardware watchpoint support:
3769 avoid misses on second run for some targets.
3770 By Pierre Muller, imported from mainline.
3772 *** Changes in GDB 5.2:
3774 * New command "set trust-readonly-sections on[off]".
3776 This command is a hint that tells gdb that read-only sections
3777 really are read-only (ie. that their contents will not change).
3778 In this mode, gdb will go to the object file rather than the
3779 target to read memory from read-only sections (such as ".text").
3780 This can be a significant performance improvement on some
3781 (notably embedded) targets.
3783 * New command "generate-core-file" (or "gcore").
3785 This new gdb command allows the user to drop a core file of the child
3786 process state at any time. So far it's been implemented only for
3787 GNU/Linux and Solaris, but should be relatively easily ported to other
3788 hosts. Argument is core file name (defaults to core.<pid>).
3790 * New command line option
3792 GDB now accepts --pid or -p followed by a process id.
3794 * Change in command line behavior -- corefiles vs. process ids.
3796 There is a subtle behavior in the way in which GDB handles
3797 command line arguments. The first non-flag argument is always
3798 a program to debug, but the second non-flag argument may either
3799 be a corefile or a process id. Previously, GDB would attempt to
3800 open the second argument as a corefile, and if that failed, would
3801 issue a superfluous error message and then attempt to attach it as
3802 a process. Now, if the second argument begins with a non-digit,
3803 it will be treated as a corefile. If it begins with a digit,
3804 GDB will attempt to attach it as a process, and if no such process
3805 is found, will then attempt to open it as a corefile.
3807 * Changes in ARM configurations.
3809 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3810 configuration is fully multi-arch.
3812 * New native configurations
3814 ARM NetBSD arm*-*-netbsd*
3815 x86 OpenBSD i[3456]86-*-openbsd*
3816 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3817 Sparc64 running FreeBSD sparc64-*-freebsd*
3821 Sanyo XStormy16 xstormy16-elf
3823 * OBSOLETE configurations and files
3825 Configurations that have been declared obsolete in this release have
3826 been commented out. Unless there is activity to revive these
3827 configurations, the next release of GDB will have their sources
3828 permanently REMOVED.
3830 AMD 29k family via UDI a29k-amd-udi, udi29k
3831 A29K VxWorks a29k-*-vxworks
3832 AMD 29000 embedded, using EBMON a29k-none-none
3833 AMD 29000 embedded with COFF a29k-none-coff
3834 AMD 29000 embedded with a.out a29k-none-aout
3836 testsuite/gdb.hp/gdb.threads-hp/ directory
3838 * REMOVED configurations and files
3840 TI TMS320C80 tic80-*-*
3842 PowerPC Solaris powerpcle-*-solaris*
3843 PowerPC Windows NT powerpcle-*-cygwin32
3844 PowerPC Netware powerpc-*-netware*
3845 Harris/CXUX m88k m88*-harris-cxux*
3846 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3847 ns32k-utek-sysv* ns32k-utek-*
3848 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3849 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3850 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3851 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3852 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3854 * Changes to command line processing
3856 The new `--args' feature can be used to specify command-line arguments
3857 for the inferior from gdb's command line.
3859 * Changes to key bindings
3861 There is a new `operate-and-get-next' function bound to `C-o'.
3863 *** Changes in GDB 5.1.1
3865 Fix compile problem on DJGPP.
3867 Fix a problem with floating-point registers on the i386 being
3870 Fix to stop GDB crashing on .debug_str debug info.
3872 Numerous documentation fixes.
3874 Numerous testsuite fixes.
3876 *** Changes in GDB 5.1:
3878 * New native configurations
3880 Alpha FreeBSD alpha*-*-freebsd*
3881 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3882 MIPS GNU/Linux mips*-*-linux*
3883 MIPS SGI Irix 6.x mips*-sgi-irix6*
3884 ia64 AIX ia64-*-aix*
3885 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3889 Motorola 68HC11 and 68HC12 m68hc11-elf
3891 UltraSparc running GNU/Linux sparc64-*-linux*
3893 * OBSOLETE configurations and files
3895 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3896 Harris/CXUX m88k m88*-harris-cxux*
3897 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3898 ns32k-utek-sysv* ns32k-utek-*
3899 TI TMS320C80 tic80-*-*
3901 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3902 PowerPC Solaris powerpcle-*-solaris*
3903 PowerPC Windows NT powerpcle-*-cygwin32
3904 PowerPC Netware powerpc-*-netware*
3905 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3906 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3907 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3908 Apple Macintosh (MPW) host N/A
3910 stuff.c (Program to stuff files into a specially prepared space in kdb)
3911 kdb-start.c (Main loop for the standalone kernel debugger)
3913 Configurations that have been declared obsolete in this release have
3914 been commented out. Unless there is activity to revive these
3915 configurations, the next release of GDB will have their sources
3916 permanently REMOVED.
3918 * REMOVED configurations and files
3920 Altos 3068 m68*-altos-*
3921 Convex c1-*-*, c2-*-*
3923 ARM RISCix arm-*-* (as host)
3927 * GDB has been converted to ISO C.
3929 GDB's source code has been converted to ISO C. In particular, the
3930 sources are fully protoized, and rely on standard headers being
3935 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3937 * The MI enabled by default.
3939 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3940 revised and enabled by default. Packages which use GDB as a debugging
3941 engine behind a UI or another front end are encouraged to switch to
3942 using the GDB/MI interface, instead of the old annotations interface
3943 which is now deprecated.
3945 * Support for debugging Pascal programs.
3947 GDB now includes support for debugging Pascal programs. The following
3948 main features are supported:
3950 - Pascal-specific data types such as sets;
3952 - automatic recognition of Pascal sources based on file-name
3955 - Pascal-style display of data types, variables, and functions;
3957 - a Pascal expression parser.
3959 However, some important features are not yet supported.
3961 - Pascal string operations are not supported at all;
3963 - there are some problems with boolean types;
3965 - Pascal type hexadecimal constants are not supported
3966 because they conflict with the internal variables format;
3968 - support for Pascal objects and classes is not full yet;
3970 - unlike Pascal, GDB is case-sensitive for symbol names.
3972 * Changes in completion.
3974 Commands such as `shell', `run' and `set args', which pass arguments
3975 to inferior programs, now complete on file names, similar to what
3976 users expect at the shell prompt.
3978 Commands which accept locations, such as `disassemble', `print',
3979 `breakpoint', `until', etc. now complete on filenames as well as
3980 program symbols. Thus, if you type "break foob TAB", and the source
3981 files linked into the programs include `foobar.c', that file name will
3982 be one of the candidates for completion. However, file names are not
3983 considered for completion after you typed a colon that delimits a file
3984 name from a name of a function in that file, as in "break foo.c:bar".
3986 `set demangle-style' completes on available demangling styles.
3988 * New platform-independent commands:
3990 It is now possible to define a post-hook for a command as well as a
3991 hook that runs before the command. For more details, see the
3992 documentation of `hookpost' in the GDB manual.
3994 * Changes in GNU/Linux native debugging.
3996 Support for debugging multi-threaded programs has been completely
3997 revised for all platforms except m68k and sparc. You can now debug as
3998 many threads as your system allows you to have.
4000 Attach/detach is supported for multi-threaded programs.
4002 Support for SSE registers was added for x86. This doesn't work for
4003 multi-threaded programs though.
4005 * Changes in MIPS configurations.
4007 Multi-arch support is enabled for all MIPS configurations.
4009 GDB can now be built as native debugger on SGI Irix 6.x systems for
4010 debugging n32 executables. (Debugging 64-bit executables is not yet
4013 * Unified support for hardware watchpoints in all x86 configurations.
4015 Most (if not all) native x86 configurations support hardware-assisted
4016 breakpoints and watchpoints in a unified manner. This support
4017 implements debug register sharing between watchpoints, which allows to
4018 put a virtually infinite number of watchpoints on the same address,
4019 and also supports watching regions up to 16 bytes with several debug
4022 The new maintenance command `maintenance show-debug-regs' toggles
4023 debugging print-outs in functions that insert, remove, and test
4024 watchpoints and hardware breakpoints.
4026 * Changes in the DJGPP native configuration.
4028 New command ``info dos sysinfo'' displays assorted information about
4029 the CPU, OS, memory, and DPMI server.
4031 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4032 display information about segment descriptors stored in GDT, LDT, and
4035 New commands ``info dos pde'' and ``info dos pte'' display entries
4036 from Page Directory and Page Tables (for now works with CWSDPMI only).
4037 New command ``info dos address-pte'' displays the Page Table entry for
4038 a given linear address.
4040 GDB can now pass command lines longer than 126 characters to the
4041 program being debugged (requires an update to the libdbg.a library
4042 which is part of the DJGPP development kit).
4044 DWARF2 debug info is now supported.
4046 It is now possible to `step' and `next' through calls to `longjmp'.
4048 * Changes in documentation.
4050 All GDB documentation was converted to GFDL, the GNU Free
4051 Documentation License.
4053 Tracepoints-related commands are now fully documented in the GDB
4056 TUI, the Text-mode User Interface, is now documented in the manual.
4058 Tracepoints-related commands are now fully documented in the GDB
4061 The "GDB Internals" manual now has an index. It also includes
4062 documentation of `ui_out' functions, GDB coding standards, x86
4063 hardware watchpoints, and memory region attributes.
4065 * GDB's version number moved to ``version.in''
4067 The Makefile variable VERSION has been replaced by the file
4068 ``version.in''. People creating GDB distributions should update the
4069 contents of this file.
4073 GUD support is now a standard part of the EMACS distribution.
4075 *** Changes in GDB 5.0:
4077 * Improved support for debugging FP programs on x86 targets
4079 Unified and much-improved support for debugging floating-point
4080 programs on all x86 targets. In particular, ``info float'' now
4081 displays the FP registers in the same format on all x86 targets, with
4082 greater level of detail.
4084 * Improvements and bugfixes in hardware-assisted watchpoints
4086 It is now possible to watch array elements, struct members, and
4087 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4088 on x86 targets no longer erroneously trigger when the address is
4091 * Improvements in the native DJGPP version of GDB
4093 The distribution now includes all the scripts and auxiliary files
4094 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4095 machines ``out of the box''.
4097 The DJGPP version can now debug programs that use signals. It is
4098 possible to catch signals that happened in the debuggee, deliver
4099 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4100 would kill the program being debugged.) Programs that hook hardware
4101 interrupts (keyboard, timer, etc.) can also be debugged.
4103 It is now possible to debug DJGPP programs that redirect their
4104 standard handles or switch them to raw (as opposed to cooked) mode, or
4105 even close them. The command ``run < foo > bar'' works as expected,
4106 and ``info terminal'' reports useful information about the debuggee's
4107 terminal, including raw/cooked mode, redirection, etc.
4109 The DJGPP version now uses termios functions for console I/O, which
4110 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4113 DOS-style file names with drive letters are now fully supported by
4116 It is now possible to debug DJGPP programs that switch their working
4117 directory. It is also possible to rerun the debuggee any number of
4118 times without restarting GDB; thus, you can use the same setup,
4119 breakpoints, etc. for many debugging sessions.
4121 * New native configurations
4123 ARM GNU/Linux arm*-*-linux*
4124 PowerPC GNU/Linux powerpc-*-linux*
4128 Motorola MCore mcore-*-*
4129 x86 VxWorks i[3456]86-*-vxworks*
4130 PowerPC VxWorks powerpc-*-vxworks*
4131 TI TMS320C80 tic80-*-*
4133 * OBSOLETE configurations
4135 Altos 3068 m68*-altos-*
4136 Convex c1-*-*, c2-*-*
4138 ARM RISCix arm-*-* (as host)
4141 Configurations that have been declared obsolete will be commented out,
4142 but the code will be left in place. If there is no activity to revive
4143 these configurations before the next release of GDB, the sources will
4144 be permanently REMOVED.
4146 * Gould support removed
4148 Support for the Gould PowerNode and NP1 has been removed.
4150 * New features for SVR4
4152 On SVR4 native platforms (such as Solaris), if you attach to a process
4153 without first loading a symbol file, GDB will now attempt to locate and
4154 load symbols from the running process's executable file.
4156 * Many C++ enhancements
4158 C++ support has been greatly improved. Overload resolution now works properly
4159 in almost all cases. RTTI support is on the way.
4161 * Remote targets can connect to a sub-program
4163 A popen(3) style serial-device has been added. This device starts a
4164 sub-process (such as a stand-alone simulator) and then communicates
4165 with that. The sub-program to run is specified using the syntax
4166 ``|<program> <args>'' vis:
4168 (gdb) set remotedebug 1
4169 (gdb) target extended-remote |mn10300-elf-sim program-args
4171 * MIPS 64 remote protocol
4173 A long standing bug in the mips64 remote protocol where by GDB
4174 expected certain 32 bit registers (ex SR) to be transfered as 32
4175 instead of 64 bits has been fixed.
4177 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4178 added to provide backward compatibility with older versions of GDB.
4180 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4182 The command ``set remotebinarydownload'' command has been replaced by
4183 ``set remote X-packet''. Other commands in ``set remote'' family
4184 include ``set remote P-packet''.
4186 * Breakpoint commands accept ranges.
4188 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4189 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4190 ``tracepoint passcount'' also accepts a range of tracepoints.
4192 * ``apropos'' command added.
4194 The ``apropos'' command searches through command names and
4195 documentation strings, printing out matches, making it much easier to
4196 try to find a command that does what you are looking for.
4200 A new machine oriented interface (MI) has been added to GDB. This
4201 interface is designed for debug environments running GDB as a separate
4202 process. This is part of the long term libGDB project. See the
4203 "GDB/MI" chapter of the GDB manual for further information. It can be
4204 enabled by configuring with:
4206 .../configure --enable-gdbmi
4208 *** Changes in GDB-4.18:
4210 * New native configurations
4212 HP-UX 10.20 hppa*-*-hpux10.20
4213 HP-UX 11.x hppa*-*-hpux11.0*
4214 M68K GNU/Linux m68*-*-linux*
4218 Fujitsu FR30 fr30-*-elf*
4219 Intel StrongARM strongarm-*-*
4220 Mitsubishi D30V d30v-*-*
4222 * OBSOLETE configurations
4224 Gould PowerNode, NP1 np1-*-*, pn-*-*
4226 Configurations that have been declared obsolete will be commented out,
4227 but the code will be left in place. If there is no activity to revive
4228 these configurations before the next release of GDB, the sources will
4229 be permanently REMOVED.
4233 As a compatibility experiment, GDB's source files buildsym.h and
4234 buildsym.c have been converted to pure standard C, no longer
4235 containing any K&R compatibility code. We believe that all systems in
4236 use today either come with a standard C compiler, or have a GCC port
4237 available. If this is not true, please report the affected
4238 configuration to bug-gdb@gnu.org immediately. See the README file for
4239 information about getting a standard C compiler if you don't have one
4244 GDB now uses readline 2.2.
4246 * set extension-language
4248 You can now control the mapping between filename extensions and source
4249 languages by using the `set extension-language' command. For instance,
4250 you can ask GDB to treat .c files as C++ by saying
4251 set extension-language .c c++
4252 The command `info extensions' lists all of the recognized extensions
4253 and their associated languages.
4255 * Setting processor type for PowerPC and RS/6000
4257 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4258 you can use the `set processor' command to specify what variant of the
4259 PowerPC family you are debugging. The command
4263 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4264 following PowerPC and RS6000 variants:
4266 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4267 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4269 403GC IBM PowerPC 403GC
4270 505 Motorola PowerPC 505
4271 860 Motorola PowerPC 860 or 850
4272 601 Motorola PowerPC 601
4273 602 Motorola PowerPC 602
4274 603 Motorola/IBM PowerPC 603 or 603e
4275 604 Motorola PowerPC 604 or 604e
4276 750 Motorola/IBM PowerPC 750 or 750
4278 At the moment, this command just tells GDB what to name the
4279 special-purpose processor registers. Since almost all the affected
4280 registers are inaccessible to user-level programs, this command is
4281 only useful for remote debugging in its present form.
4285 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4286 more extensive support for HP-UX. Added features include shared
4287 library support, kernel threads and hardware watchpoints for 11.00,
4288 support for HP's ANSI C and C++ compilers, and a compatibility mode
4289 for xdb and dbx commands.
4293 HP's donation includes the new concept of catchpoints, which is a
4294 generalization of the old catch command. On HP-UX, it is now possible
4295 to catch exec, fork, and vfork, as well as library loading.
4297 This means that the existing catch command has changed; its first
4298 argument now specifies the type of catch to be set up. See the
4299 output of "help catch" for a list of catchpoint types.
4301 * Debugging across forks
4303 On HP-UX, you can choose which process to debug when a fork() happens
4308 HP has donated a curses-based terminal user interface (TUI). To get
4309 it, build with --enable-tui. Although this can be enabled for any
4310 configuration, at present it only works for native HP debugging.
4312 * GDB remote protocol additions
4314 A new protocol packet 'X' that writes binary data is now available.
4315 Default behavior is to try 'X', then drop back to 'M' if the stub
4316 fails to respond. The settable variable `remotebinarydownload'
4317 allows explicit control over the use of 'X'.
4319 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4320 full 64-bit address. The command
4322 set remoteaddresssize 32
4324 can be used to revert to the old behaviour. For existing remote stubs
4325 the change should not be noticed, as the additional address information
4328 In order to assist in debugging stubs, you may use the maintenance
4329 command `packet' to send any text string to the stub. For instance,
4331 maint packet heythere
4333 sends the packet "$heythere#<checksum>". Note that it is very easy to
4334 disrupt a debugging session by sending the wrong packet at the wrong
4337 The compare-sections command allows you to compare section data on the
4338 target to what is in the executable file without uploading or
4339 downloading, by comparing CRC checksums.
4341 * Tracing can collect general expressions
4343 You may now collect general expressions at tracepoints. This requires
4344 further additions to the target-side stub; see tracepoint.c and
4345 doc/agentexpr.texi for further details.
4347 * mask-address variable for Mips
4349 For Mips targets, you may control the zeroing of the upper 32 bits of
4350 a 64-bit address by entering `set mask-address on'. This is mainly
4351 of interest to users of embedded R4xxx and R5xxx processors.
4353 * Higher serial baud rates
4355 GDB's serial code now allows you to specify baud rates 57600, 115200,
4356 230400, and 460800 baud. (Note that your host system may not be able
4357 to achieve all of these rates.)
4361 The i960 configuration now includes an initial implementation of a
4362 builtin simulator, contributed by Jim Wilson.
4365 *** Changes in GDB-4.17:
4367 * New native configurations
4369 Alpha GNU/Linux alpha*-*-linux*
4370 Unixware 2.x i[3456]86-unixware2*
4371 Irix 6.x mips*-sgi-irix6*
4372 PowerPC GNU/Linux powerpc-*-linux*
4373 PowerPC Solaris powerpcle-*-solaris*
4374 Sparc GNU/Linux sparc-*-linux*
4375 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4379 Argonaut Risc Chip (ARC) arc-*-*
4380 Hitachi H8/300S h8300*-*-*
4381 Matsushita MN10200 w/simulator mn10200-*-*
4382 Matsushita MN10300 w/simulator mn10300-*-*
4383 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4384 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4385 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4386 Mitsubishi D10V w/simulator d10v-*-*
4387 Mitsubishi M32R/D w/simulator m32r-*-elf*
4388 Tsqware Sparclet sparclet-*-*
4389 NEC V850 w/simulator v850-*-*
4391 * New debugging protocols
4393 ARM with RDI protocol arm*-*-*
4394 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4395 DDB and LSI variants of PMON protocol mips*-*-*
4396 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4397 PowerPC with SDS protocol powerpc{,le}-*-eabi
4398 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4402 All configurations can now understand and use the DWARF 2 debugging
4403 format. The choice is automatic, if the symbol file contains DWARF 2
4408 GDB now includes basic Java language support. This support is
4409 only useful with Java compilers that produce native machine code.
4411 * solib-absolute-prefix and solib-search-path
4413 For SunOS and SVR4 shared libraries, you may now set the prefix for
4414 loading absolute shared library symbol files, and the search path for
4415 locating non-absolute shared library symbol files.
4417 * Live range splitting
4419 GDB can now effectively debug code for which GCC has performed live
4420 range splitting as part of its optimization. See gdb/doc/LRS for
4421 more details on the expected format of the stabs information.
4425 GDB's support for the GNU Hurd, including thread debugging, has been
4426 updated to work with current versions of the Hurd.
4430 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4431 instruction set. ARM GDB automatically detects when Thumb
4432 instructions are in use, and adjusts disassembly and backtracing
4437 GDB's MIPS target configurations now handle the MIP16 16-bit
4442 GDB now includes support for overlays; if an executable has been
4443 linked such that multiple sections are based at the same address, GDB
4444 will decide which section to use for symbolic info. You can choose to
4445 control the decision manually, using overlay commands, or implement
4446 additional target-side support and use "overlay load-target" to bring
4447 in the overlay mapping. Do "help overlay" for more detail.
4451 The command "info symbol <address>" displays information about
4452 the symbol at the specified address.
4456 The standard remote protocol now includes an extension that allows
4457 asynchronous collection and display of trace data. This requires
4458 extensive support in the target-side debugging stub. Tracing mode
4459 includes a new interaction mode in GDB and new commands: see the
4460 file tracepoint.c for more details.
4464 Configurations for embedded MIPS now include a simulator contributed
4465 by Cygnus Solutions. The simulator supports the instruction sets
4466 of most MIPS variants.
4470 Sparc configurations may now include the ERC32 simulator contributed
4471 by the European Space Agency. The simulator is not built into
4472 Sparc targets by default; configure with --enable-sim to include it.
4476 For target configurations that may include multiple variants of a
4477 basic architecture (such as MIPS and SH), you may now set the
4478 architecture explicitly. "set arch" sets, "info arch" lists
4479 the possible architectures.
4481 *** Changes in GDB-4.16:
4483 * New native configurations
4485 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4486 M68K NetBSD m68k-*-netbsd*
4487 PowerPC AIX 4.x powerpc-*-aix*
4488 PowerPC MacOS powerpc-*-macos*
4489 PowerPC Windows NT powerpcle-*-cygwin32
4490 RS/6000 AIX 4.x rs6000-*-aix4*
4494 ARM with RDP protocol arm-*-*
4495 I960 with MON960 i960-*-coff
4496 MIPS VxWorks mips*-*-vxworks*
4497 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4498 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4500 Matra Sparclet sparclet-*-*
4504 The powerpc-eabi configuration now includes the PSIM simulator,
4505 contributed by Andrew Cagney, with assistance from Mike Meissner.
4506 PSIM is a very elaborate model of the PowerPC, including not only
4507 basic instruction set execution, but also details of execution unit
4508 performance and I/O hardware. See sim/ppc/README for more details.
4512 GDB now works with Solaris 2.5.
4514 * Windows 95/NT native
4516 GDB will now work as a native debugger on Windows 95 and Windows NT.
4517 To build it from source, you must use the "gnu-win32" environment,
4518 which uses a DLL to emulate enough of Unix to run the GNU tools.
4519 Further information, binaries, and sources are available at
4520 ftp.cygnus.com, under pub/gnu-win32.
4522 * dont-repeat command
4524 If a user-defined command includes the command `dont-repeat', then the
4525 command will not be repeated if the user just types return. This is
4526 useful if the command is time-consuming to run, so that accidental
4527 extra keystrokes don't run the same command many times.
4529 * Send break instead of ^C
4531 The standard remote protocol now includes an option to send a break
4532 rather than a ^C to the target in order to interrupt it. By default,
4533 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4535 * Remote protocol timeout
4537 The standard remote protocol includes a new variable `remotetimeout'
4538 that allows you to set the number of seconds before GDB gives up trying
4539 to read from the target. The default value is 2.
4541 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4543 By default GDB will automatically keep track of objects as they are
4544 loaded and unloaded by the dynamic linker. By using the command `set
4545 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4546 when shared library events occur, thus allowing you to set breakpoints
4547 in shared libraries which are explicitly loaded by the inferior.
4549 Note this feature does not work on hpux8. On hpux9 you must link
4550 /usr/lib/end.o into your program. This feature should work
4551 automatically on hpux10.
4553 * Irix 5.x hardware watchpoint support
4555 Irix 5 configurations now support the use of hardware watchpoints.
4557 * Mips protocol "SYN garbage limit"
4559 When debugging a Mips target using the `target mips' protocol, you
4560 may set the number of characters that GDB will ignore by setting
4561 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4562 every character. The default value is 1050.
4564 * Recording and replaying remote debug sessions
4566 If you set `remotelogfile' to the name of a file, gdb will write to it
4567 a recording of a remote debug session. This recording may then be
4568 replayed back to gdb using "gdbreplay". See gdbserver/README for
4569 details. This is useful when you have a problem with GDB while doing
4570 remote debugging; you can make a recording of the session and send it
4571 to someone else, who can then recreate the problem.
4573 * Speedups for remote debugging
4575 GDB includes speedups for downloading and stepping MIPS systems using
4576 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4577 and more efficient S-record downloading.
4579 * Memory use reductions and statistics collection
4581 GDB now uses less memory and reports statistics about memory usage.
4582 Try the `maint print statistics' command, for example.
4584 *** Changes in GDB-4.15:
4586 * Psymtabs for XCOFF
4588 The symbol reader for AIX GDB now uses partial symbol tables. This
4589 can greatly improve startup time, especially for large executables.
4591 * Remote targets use caching
4593 Remote targets now use a data cache to speed up communication with the
4594 remote side. The data cache could lead to incorrect results because
4595 it doesn't know about volatile variables, thus making it impossible to
4596 debug targets which use memory mapped I/O devices. `set remotecache
4597 off' turns the the data cache off.
4599 * Remote targets may have threads
4601 The standard remote protocol now includes support for multiple threads
4602 in the target system, using new protocol commands 'H' and 'T'. See
4603 gdb/remote.c for details.
4607 If GDB is configured with `--enable-netrom', then it will include
4608 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4609 acts as though it is a bank of ROM on the target board, but you can
4610 write into it over the network. GDB's support consists only of
4611 support for fast loading into the emulated ROM; to debug, you must use
4612 another protocol, such as standard remote protocol. The usual
4613 sequence is something like
4615 target nrom <netrom-hostname>
4617 target remote <netrom-hostname>:1235
4621 GDB now includes support for the Apple Macintosh, as a host only. It
4622 may be run as either an MPW tool or as a standalone application, and
4623 it can debug through the serial port. All the usual GDB commands are
4624 available, but to the target command, you must supply "serial" as the
4625 device type instead of "/dev/ttyXX". See mpw-README in the main
4626 directory for more information on how to build. The MPW configuration
4627 scripts */mpw-config.in support only a few targets, and only the
4628 mips-idt-ecoff target has been tested.
4632 GDB configuration now uses autoconf. This is not user-visible,
4633 but does simplify configuration and building.
4637 GDB now supports hpux10.
4639 *** Changes in GDB-4.14:
4641 * New native configurations
4643 x86 FreeBSD i[345]86-*-freebsd
4644 x86 NetBSD i[345]86-*-netbsd
4645 NS32k NetBSD ns32k-*-netbsd
4646 Sparc NetBSD sparc-*-netbsd
4650 A29K VxWorks a29k-*-vxworks
4651 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4652 CPU32 EST-300 emulator m68*-*-est*
4653 PowerPC ELF powerpc-*-elf
4656 * Alpha OSF/1 support for procfs
4658 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4659 possible to attach to running processes. As the mounting of the /proc
4660 filesystem is optional on the Alpha, GDB automatically determines
4661 the availability of /proc during startup. This can lead to problems
4662 if /proc is unmounted after GDB has been started.
4664 * Arguments to user-defined commands
4666 User commands may accept up to 10 arguments separated by whitespace.
4667 Arguments are accessed within the user command via $arg0..$arg9. A
4670 print $arg0 + $arg1 + $arg2
4672 To execute the command use:
4675 Defines the command "adder" which prints the sum of its three arguments.
4676 Note the arguments are text substitutions, so they may reference variables,
4677 use complex expressions, or even perform inferior function calls.
4679 * New `if' and `while' commands
4681 This makes it possible to write more sophisticated user-defined
4682 commands. Both commands take a single argument, which is the
4683 expression to evaluate, and must be followed by the commands to
4684 execute, one per line, if the expression is nonzero, the list being
4685 terminated by the word `end'. The `if' command list may include an
4686 `else' word, which causes the following commands to be executed only
4687 if the expression is zero.
4689 * Fortran source language mode
4691 GDB now includes partial support for Fortran 77. It will recognize
4692 Fortran programs and can evaluate a subset of Fortran expressions, but
4693 variables and functions may not be handled correctly. GDB will work
4694 with G77, but does not yet know much about symbols emitted by other
4697 * Better HPUX support
4699 Most debugging facilities now work on dynamic executables for HPPAs
4700 running hpux9 or later. You can attach to running dynamically linked
4701 processes, but by default the dynamic libraries will be read-only, so
4702 for instance you won't be able to put breakpoints in them. To change
4703 that behavior do the following before running the program:
4709 This will cause the libraries to be mapped private and read-write.
4710 To revert to the normal behavior, do this:
4716 You cannot set breakpoints or examine data in the library until after
4717 the library is loaded if the function/data symbols do not have
4720 GDB can now also read debug symbols produced by the HP C compiler on
4721 HPPAs (sorry, no C++, Fortran or 68k support).
4723 * Target byte order now dynamically selectable
4725 You can choose which byte order to use with a target system, via the
4726 commands "set endian big" and "set endian little", and you can see the
4727 current setting by using "show endian". You can also give the command
4728 "set endian auto", in which case GDB will use the byte order
4729 associated with the executable. Currently, only embedded MIPS
4730 configurations support dynamic selection of target byte order.
4732 * New DOS host serial code
4734 This version uses DPMI interrupts to handle buffered I/O, so you
4735 no longer need to run asynctsr when debugging boards connected to
4738 *** Changes in GDB-4.13:
4740 * New "complete" command
4742 This lists all the possible completions for the rest of the line, if it
4743 were to be given as a command itself. This is intended for use by emacs.
4745 * Trailing space optional in prompt
4747 "set prompt" no longer adds a space for you after the prompt you set. This
4748 allows you to set a prompt which ends in a space or one that does not.
4750 * Breakpoint hit counts
4752 "info break" now displays a count of the number of times the breakpoint
4753 has been hit. This is especially useful in conjunction with "ignore"; you
4754 can ignore a large number of breakpoint hits, look at the breakpoint info
4755 to see how many times the breakpoint was hit, then run again, ignoring one
4756 less than that number, and this will get you quickly to the last hit of
4759 * Ability to stop printing at NULL character
4761 "set print null-stop" will cause GDB to stop printing the characters of
4762 an array when the first NULL is encountered. This is useful when large
4763 arrays actually contain only short strings.
4765 * Shared library breakpoints
4767 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4768 breakpoints in shared libraries before the executable is run.
4770 * Hardware watchpoints
4772 There is a new hardware breakpoint for the watch command for sparclite
4773 targets. See gdb/sparclite/hw_breakpoint.note.
4775 Hardware watchpoints are also now supported under GNU/Linux.
4779 Annotations have been added. These are for use with graphical interfaces,
4780 and are still experimental. Currently only gdba.el uses these.
4782 * Improved Irix 5 support
4784 GDB now works properly with Irix 5.2.
4786 * Improved HPPA support
4788 GDB now works properly with the latest GCC and GAS.
4790 * New native configurations
4792 Sequent PTX4 i[34]86-sequent-ptx4
4793 HPPA running OSF/1 hppa*-*-osf*
4794 Atari TT running SVR4 m68*-*-sysv4*
4795 RS/6000 LynxOS rs6000-*-lynxos*
4799 OS/9000 i[34]86-*-os9k
4800 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4803 * Hitachi SH7000 and E7000-PC ICE support
4805 There is now support for communicating with the Hitachi E7000-PC ICE.
4806 This is available automatically when GDB is configured for the SH.
4810 As usual, a variety of small fixes and improvements, both generic
4811 and configuration-specific. See the ChangeLog for more detail.
4813 *** Changes in GDB-4.12:
4815 * Irix 5 is now supported
4819 GDB-4.12 on the HPPA has a number of changes which make it unable
4820 to debug the output from the currently released versions of GCC and
4821 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4822 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4823 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4826 *** Changes in GDB-4.11:
4828 * User visible changes:
4832 The "set remotedebug" option is now consistent between the mips remote
4833 target, remote targets using the gdb-specific protocol, UDI (AMD's
4834 debug protocol for the 29k) and the 88k bug monitor. It is now an
4835 integer specifying a debug level (normally 0 or 1, but 2 means more
4836 debugging info for the mips target).
4838 * DEC Alpha native support
4840 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4841 debug info, but GDB works fairly well with the DEC compiler and should
4842 work with a future GCC release. See the README file for a few
4843 Alpha-specific notes.
4845 * Preliminary thread implementation
4847 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4849 * LynxOS native and target support for 386
4851 This release has been hosted on LynxOS 2.2, and also can be configured
4852 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4855 * Improvements in C++ mangling/demangling.
4857 This release has much better g++ debugging, specifically in name
4858 mangling/demangling, virtual function calls, print virtual table,
4859 call methods, ...etc.
4861 *** Changes in GDB-4.10:
4863 * User visible changes:
4865 Remote debugging using the GDB-specific (`target remote') protocol now
4866 supports the `load' command. This is only useful if you have some
4867 other way of getting the stub to the target system, and you can put it
4868 somewhere in memory where it won't get clobbered by the download.
4870 Filename completion now works.
4872 When run under emacs mode, the "info line" command now causes the
4873 arrow to point to the line specified. Also, "info line" prints
4874 addresses in symbolic form (as well as hex).
4876 All vxworks based targets now support a user settable option, called
4877 vxworks-timeout. This option represents the number of seconds gdb
4878 should wait for responses to rpc's. You might want to use this if
4879 your vxworks target is, perhaps, a slow software simulator or happens
4880 to be on the far side of a thin network line.
4884 This release contains support for using a DEC alpha as a GDB host for
4885 cross debugging. Native alpha debugging is not supported yet.
4888 *** Changes in GDB-4.9:
4892 This is the first GDB release which is accompanied by a matching testsuite.
4893 The testsuite requires installation of dejagnu, which should be available
4894 via ftp from most sites that carry GNU software.
4898 'Cfront' style demangling has had its name changed to 'ARM' style, to
4899 emphasize that it was written from the specifications in the C++ Annotated
4900 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4901 disclaimers, it still generated too much confusion with users attempting to
4902 use gdb with AT&T cfront.
4906 GDB now uses a standard remote interface to a simulator library.
4907 So far, the library contains simulators for the Zilog Z8001/2, the
4908 Hitachi H8/300, H8/500 and Super-H.
4910 * New targets supported
4912 H8/300 simulator h8300-hitachi-hms or h8300hms
4913 H8/500 simulator h8500-hitachi-hms or h8500hms
4914 SH simulator sh-hitachi-hms or sh
4915 Z8000 simulator z8k-zilog-none or z8ksim
4916 IDT MIPS board over serial line mips-idt-ecoff
4918 Cross-debugging to GO32 targets is supported. It requires a custom
4919 version of the i386-stub.c module which is integrated with the
4920 GO32 memory extender.
4922 * New remote protocols
4924 MIPS remote debugging protocol.
4926 * New source languages supported
4928 This version includes preliminary support for Chill, a Pascal like language
4929 used by telecommunications companies. Chill support is also being integrated
4930 into the GNU compiler, but we don't know when it will be publically available.
4933 *** Changes in GDB-4.8:
4935 * HP Precision Architecture supported
4937 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4938 version of this support was available as a set of patches from the
4939 University of Utah. GDB does not support debugging of programs
4940 compiled with the HP compiler, because HP will not document their file
4941 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4942 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4944 Many problems in the preliminary version have been fixed.
4946 * Faster and better demangling
4948 We have improved template demangling and fixed numerous bugs in the GNU style
4949 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4950 character types (wchar_t) are now supported. Demangling of each symbol is now
4951 only done once, and is cached when the symbol table for a file is read in.
4952 This results in a small increase in memory usage for C programs, a moderate
4953 increase in memory usage for C++ programs, and a fantastic speedup in
4956 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4957 from the specifications in the Annotated Reference Manual, which AT&T's
4958 compiler does not actually implement.
4960 * G++ multiple inheritance compiler problem
4962 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4963 inheritance lattices was reworked to properly discover ambiguities. We
4964 recently found an example which causes this new algorithm to fail in a
4965 very subtle way, producing bad debug information for those classes.
4966 The file 'gcc.patch' (in this directory) can be applied to gcc to
4967 circumvent the problem. A future GCC release will contain a complete
4970 The previous G++ debug info problem (mentioned below for the gdb-4.7
4971 release) is fixed in gcc version 2.3.2.
4973 * Improved configure script
4975 The `configure' script will now attempt to guess your system type if
4976 you don't supply a host system type. The old scheme of supplying a
4977 host system triplet is preferable over using this. All the magic is
4978 done in the new `config.guess' script. Examine it for details.
4980 We have also brought our configure script much more in line with the FSF's
4981 version. It now supports the --with-xxx options. In particular,
4982 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4983 The resulting GDB will not be able to read arbitrary object file formats --
4984 only the format ``expected'' to be used on the configured target system.
4985 We hope to make this the default in a future release.
4987 * Documentation improvements
4989 There's new internal documentation on how to modify GDB, and how to
4990 produce clean changes to the code. We implore people to read it
4991 before submitting changes.
4993 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4994 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4995 `info' files are also provided. To build `info' files from scratch,
4996 you will need the latest `makeinfo' release, which will be available in
4997 a future texinfo-X.Y release.
4999 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5000 We're not sure exactly which versions have this problem, but it has
5001 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5002 or better. If that isn't possible, there is a patch in
5003 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5004 around this problem.
5008 GDB now supports array constants that can be used in expressions typed in by
5009 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5010 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5013 The new directory `gdb/sparclite' contains a program that demonstrates
5014 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5016 * New native hosts supported
5018 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5019 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5021 * New targets supported
5023 AMD 29k family via UDI a29k-amd-udi or udi29k
5025 * New file formats supported
5027 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5028 HPUX core files, and SCO 3.2v2 core files.
5032 Attaching to processes now works again; thanks for the many bug reports.
5034 We have also stomped on a bunch of core dumps caused by
5035 printf_filtered("%s") problems.
5037 We eliminated a copyright problem on the rpc and ptrace header files
5038 for VxWorks, which was discovered at the last minute during the 4.7
5039 release. You should now be able to build a VxWorks GDB.
5041 You can now interrupt gdb while an attached process is running. This
5042 will cause the attached process to stop, and give control back to GDB.
5044 We fixed problems caused by using too many file descriptors
5045 for reading symbols from object files and libraries. This was
5046 especially a problem for programs that used many (~100) shared
5049 The `step' command now only enters a subroutine if there is line number
5050 information for the subroutine. Otherwise it acts like the `next'
5051 command. Previously, `step' would enter subroutines if there was
5052 any debugging information about the routine. This avoids problems
5053 when using `cc -g1' on MIPS machines.
5055 * Internal improvements
5057 GDB's internal interfaces have been improved to make it easier to support
5058 debugging of multiple languages in the future.
5060 GDB now uses a common structure for symbol information internally.
5061 Minimal symbols (derived from linkage symbols in object files), partial
5062 symbols (from a quick scan of debug information), and full symbols
5063 contain a common subset of information, making it easier to write
5064 shared code that handles any of them.
5066 * New command line options
5068 We now accept --silent as an alias for --quiet.
5072 The memory-mapped-malloc library is now licensed under the GNU Library
5073 General Public License.
5075 *** Changes in GDB-4.7:
5077 * Host/native/target split
5079 GDB has had some major internal surgery to untangle the support for
5080 hosts and remote targets. Now, when you configure GDB for a remote
5081 target, it will no longer load in all of the support for debugging
5082 local programs on the host. When fully completed and tested, this will
5083 ensure that arbitrary host/target combinations are possible.
5085 The primary conceptual shift is to separate the non-portable code in
5086 GDB into three categories. Host specific code is required any time GDB
5087 is compiled on that host, regardless of the target. Target specific
5088 code relates to the peculiarities of the target, but can be compiled on
5089 any host. Native specific code is everything else: it can only be
5090 built when the host and target are the same system. Child process
5091 handling and core file support are two common `native' examples.
5093 GDB's use of /proc for controlling Unix child processes is now cleaner.
5094 It has been split out into a single module under the `target_ops' vector,
5095 plus two native-dependent functions for each system that uses /proc.
5097 * New hosts supported
5099 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5100 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5101 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5103 * New targets supported
5105 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5106 68030 and CPU32 m68030-*-*, m68332-*-*
5108 * New native hosts supported
5110 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5111 (386bsd is not well tested yet)
5112 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5114 * New file formats supported
5116 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5117 supports reading of `a.out.adobe' object files, which are an a.out
5118 format extended with minimal information about multiple sections.
5122 `show copying' is the same as the old `info copying'.
5123 `show warranty' is the same as `info warrantee'.
5124 These were renamed for consistency. The old commands continue to work.
5126 `info handle' is a new alias for `info signals'.
5128 You can now define pre-command hooks, which attach arbitrary command
5129 scripts to any command. The commands in the hook will be executed
5130 prior to the user's command. You can also create a hook which will be
5131 executed whenever the program stops. See gdb.texinfo.
5135 We now deal with Cfront style name mangling, and can even extract type
5136 info from mangled symbols. GDB can automatically figure out which
5137 symbol mangling style your C++ compiler uses.
5139 Calling of methods and virtual functions has been improved as well.
5143 The crash that occured when debugging Sun Ansi-C compiled binaries is
5144 fixed. This was due to mishandling of the extra N_SO stabs output
5147 We also finally got Ultrix 4.2 running in house, and fixed core file
5148 support, with help from a dozen people on the net.
5150 John M. Farrell discovered that the reason that single-stepping was so
5151 slow on all of the Mips based platforms (primarily SGI and DEC) was
5152 that we were trying to demangle and lookup a symbol used for internal
5153 purposes on every instruction that was being stepped through. Changing
5154 the name of that symbol so that it couldn't be mistaken for a C++
5155 mangled symbol sped things up a great deal.
5157 Rich Pixley sped up symbol lookups in general by getting much smarter
5158 about when C++ symbol mangling is necessary. This should make symbol
5159 completion (TAB on the command line) much faster. It's not as fast as
5160 we'd like, but it's significantly faster than gdb-4.6.
5164 A new user controllable variable 'call_scratch_address' can
5165 specify the location of a scratch area to be used when GDB
5166 calls a function in the target. This is necessary because the
5167 usual method of putting the scratch area on the stack does not work
5168 in systems that have separate instruction and data spaces.
5170 We integrated changes to support the 29k UDI (Universal Debugger
5171 Interface), but discovered at the last minute that we didn't have all
5172 of the appropriate copyright paperwork. We are working with AMD to
5173 resolve this, and hope to have it available soon.
5177 We have sped up the remote serial line protocol, especially for targets
5178 with lots of registers. It now supports a new `expedited status' ('T')
5179 message which can be used in place of the existing 'S' status message.
5180 This allows the remote stub to send only the registers that GDB
5181 needs to make a quick decision about single-stepping or conditional
5182 breakpoints, eliminating the need to fetch the entire register set for
5183 each instruction being stepped through.
5185 The GDB remote serial protocol now implements a write-through cache for
5186 registers, only re-reading the registers if the target has run.
5188 There is also a new remote serial stub for SPARC processors. You can
5189 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5190 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5191 processor with a serial port.
5195 Configure.in files have become much easier to read and modify. A new
5196 `table driven' format makes it more obvious what configurations are
5197 supported, and what files each one uses.
5201 There is a new opcodes library which will eventually contain all of the
5202 disassembly routines and opcode tables. At present, it only contains
5203 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5204 disassembler (binutils/objdump) to share these routines.
5206 The libiberty library is now copylefted under the GNU Library General
5207 Public License. This allows more liberal use, and was done so libg++
5208 can use it. This makes no difference to GDB, since the Library License
5209 grants all the rights from the General Public License.
5213 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5214 reference to the stabs symbol info used by the debugger. It is (as far
5215 as we know) the only published document on this fascinating topic. We
5216 encourage you to read it, compare it to the stabs information on your
5217 system, and send improvements on the document in general (to
5218 bug-gdb@prep.ai.mit.edu).
5220 And, of course, many bugs have been fixed.
5223 *** Changes in GDB-4.6:
5225 * Better support for C++ function names
5227 GDB now accepts as input the "demangled form" of C++ overloaded function
5228 names and member function names, and can do command completion on such names
5229 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5230 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5231 Make use of command completion, it is your friend.
5233 GDB also now accepts a variety of C++ mangled symbol formats. They are
5234 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5235 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5236 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5237 for the list of formats.
5239 * G++ symbol mangling problem
5241 Recent versions of gcc have a bug in how they emit debugging information for
5242 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5243 directory) can be applied to gcc to fix the problem. Alternatively, if you
5244 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5245 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5246 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5249 * New 'maintenance' command
5251 All of the commands related to hacking GDB internals have been moved out of
5252 the main command set, and now live behind the 'maintenance' command. This
5253 can also be abbreviated as 'mt'. The following changes were made:
5255 dump-me -> maintenance dump-me
5256 info all-breakpoints -> maintenance info breakpoints
5257 printmsyms -> maintenance print msyms
5258 printobjfiles -> maintenance print objfiles
5259 printpsyms -> maintenance print psymbols
5260 printsyms -> maintenance print symbols
5262 The following commands are new:
5264 maintenance demangle Call internal GDB demangler routine to
5265 demangle a C++ link name and prints the result.
5266 maintenance print type Print a type chain for a given symbol
5268 * Change to .gdbinit file processing
5270 We now read the $HOME/.gdbinit file before processing the argv arguments
5271 (e.g. reading symbol files or core files). This allows global parameters to
5272 be set, which will apply during the symbol reading. The ./.gdbinit is still
5273 read after argv processing.
5275 * New hosts supported
5277 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5279 GNU/Linux support i386-unknown-linux or linux
5281 We are also including code to support the HP/PA running BSD and HPUX. This
5282 is almost guaranteed not to work, as we didn't have time to test or build it
5283 for this release. We are including it so that the more adventurous (or
5284 masochistic) of you can play with it. We also had major problems with the
5285 fact that the compiler that we got from HP doesn't support the -g option.
5288 * New targets supported
5290 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5292 * More smarts about finding #include files
5294 GDB now remembers the compilation directory for all include files, and for
5295 all files from which C is generated (like yacc and lex sources). This
5296 greatly improves GDB's ability to find yacc/lex sources, and include files,
5297 especially if you are debugging your program from a directory different from
5298 the one that contains your sources.
5300 We also fixed a bug which caused difficulty with listing and setting
5301 breakpoints in include files which contain C code. (In the past, you had to
5302 try twice in order to list an include file that you hadn't looked at before.)
5304 * Interesting infernals change
5306 GDB now deals with arbitrary numbers of sections, where the symbols for each
5307 section must be relocated relative to that section's landing place in the
5308 target's address space. This work was needed to support ELF with embedded
5309 stabs used by Solaris-2.0.
5311 * Bug fixes (of course!)
5313 There have been loads of fixes for the following things:
5314 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5315 i960, stabs, DOS(GO32), procfs, etc...
5317 See the ChangeLog for details.
5319 *** Changes in GDB-4.5:
5321 * New machines supported (host and target)
5323 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5325 SGI Irix-4.x mips-sgi-irix4 or iris4
5327 * New malloc package
5329 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5330 Mmalloc is capable of handling mutiple heaps of memory. It is also
5331 capable of saving a heap to a file, and then mapping it back in later.
5332 This can be used to greatly speedup the startup of GDB by using a
5333 pre-parsed symbol table which lives in a mmalloc managed heap. For
5334 more details, please read mmalloc/mmalloc.texi.
5338 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5339 'help info proc' for details.
5341 * MIPS ecoff symbol table format
5343 The code that reads MIPS symbol table format is now supported on all hosts.
5344 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5347 * File name changes for MS-DOS
5349 Many files in the config directories have been renamed to make it easier to
5350 support GDB on MS-DOSe systems (which have very restrictive file name
5351 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5352 environment) is close to working but has some remaining problems. Note
5353 that debugging of DOS programs is not supported, due to limitations
5354 in the ``operating system'', but it can be used to host cross-debugging.
5356 * Cross byte order fixes
5358 Many fixes have been made to support cross debugging of Sparc and MIPS
5359 targets from hosts whose byte order differs.
5361 * New -mapped and -readnow options
5363 If memory-mapped files are available on your system through the 'mmap'
5364 system call, you can use the -mapped option on the `file' or
5365 `symbol-file' commands to cause GDB to write the symbols from your
5366 program into a reusable file. If the program you are debugging is
5367 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5368 Future GDB debugging sessions will notice the presence of this file,
5369 and will quickly map in symbol information from it, rather than reading
5370 the symbol table from the executable program. Using the '-mapped'
5371 option in a GDB `file' or `symbol-file' command has the same effect as
5372 starting GDB with the '-mapped' command-line option.
5374 You can cause GDB to read the entire symbol table immediately by using
5375 the '-readnow' option with any of the commands that load symbol table
5376 information (or on the GDB command line). This makes the command
5377 slower, but makes future operations faster.
5379 The -mapped and -readnow options are typically combined in order to
5380 build a `fred.syms' file that contains complete symbol information.
5381 A simple GDB invocation to do nothing but build a `.syms' file for future
5384 gdb -batch -nx -mapped -readnow programname
5386 The `.syms' file is specific to the host machine on which GDB is run.
5387 It holds an exact image of GDB's internal symbol table. It cannot be
5388 shared across multiple host platforms.
5390 * longjmp() handling
5392 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5393 siglongjmp() without losing control. This feature has not yet been ported to
5394 all systems. It currently works on many 386 platforms, all MIPS-based
5395 platforms (SGI, DECstation, etc), and Sun3/4.
5399 Preliminary work has been put in to support the new Solaris OS from Sun. At
5400 this time, it can control and debug processes, but it is not capable of
5405 As always, many many bug fixes. The major areas were with g++, and mipsread.
5406 People using the MIPS-based platforms should experience fewer mysterious
5407 crashes and trashed symbol tables.
5409 *** Changes in GDB-4.4:
5411 * New machines supported (host and target)
5413 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5415 BSD Reno on Vax vax-dec-bsd
5416 Ultrix on Vax vax-dec-ultrix
5418 * New machines supported (target)
5420 AMD 29000 embedded, using EBMON a29k-none-none
5424 GDB continues to improve its handling of C++. `References' work better.
5425 The demangler has also been improved, and now deals with symbols mangled as
5426 per the Annotated C++ Reference Guide.
5428 GDB also now handles `stabs' symbol information embedded in MIPS
5429 `ecoff' symbol tables. Since the ecoff format was not easily
5430 extensible to handle new languages such as C++, this appeared to be a
5431 good way to put C++ debugging info into MIPS binaries. This option
5432 will be supported in the GNU C compiler, version 2, when it is
5435 * New features for SVR4
5437 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5438 shared libraries. Debugging dynamically linked programs should present
5439 only minor differences from debugging statically linked programs.
5441 The `info proc' command will print out information about any process
5442 on an SVR4 system (including the one you are debugging). At the moment,
5443 it prints the address mappings of the process.
5445 If you bring up GDB on another SVR4 system, please send mail to
5446 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5448 * Better dynamic linking support in SunOS
5450 Reading symbols from shared libraries which contain debugging symbols
5451 now works properly. However, there remain issues such as automatic
5452 skipping of `transfer vector' code during function calls, which
5453 make it harder to debug code in a shared library, than to debug the
5454 same code linked statically.
5458 GDB is now using the latest `getopt' routines from the FSF. This
5459 version accepts the -- prefix for options with long names. GDB will
5460 continue to accept the old forms (-option and +option) as well.
5461 Various single letter abbreviations for options have been explicity
5462 added to the option table so that they won't get overshadowed in the
5463 future by other options that begin with the same letter.
5467 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5468 Many assorted bugs have been handled. Many more remain to be handled.
5469 See the various ChangeLog files (primarily in gdb and bfd) for details.
5472 *** Changes in GDB-4.3:
5474 * New machines supported (host and target)
5476 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5477 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5478 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5480 * Almost SCO Unix support
5482 We had hoped to support:
5483 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5484 (except for core file support), but we discovered very late in the release
5485 that it has problems with process groups that render gdb unusable. Sorry
5486 about that. I encourage people to fix it and post the fixes.
5488 * Preliminary ELF and DWARF support
5490 GDB can read ELF object files on System V Release 4, and can handle
5491 debugging records for C, in DWARF format, in ELF files. This support
5492 is preliminary. If you bring up GDB on another SVR4 system, please
5493 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5498 GDB now uses the latest `readline' library. One user-visible change
5499 is that two tabs will list possible command completions, which previously
5500 required typing M-? (meta-question mark, or ESC ?).
5504 The `stepi' bug that many of you noticed has been squashed.
5505 Many bugs in C++ have been handled. Many more remain to be handled.
5506 See the various ChangeLog files (primarily in gdb and bfd) for details.
5508 * State of the MIPS world (in case you wondered):
5510 GDB can understand the symbol tables emitted by the compilers
5511 supplied by most vendors of MIPS-based machines, including DEC. These
5512 symbol tables are in a format that essentially nobody else uses.
5514 Some versions of gcc come with an assembler post-processor called
5515 mips-tfile. This program is required if you want to do source-level
5516 debugging of gcc-compiled programs. I believe FSF does not ship
5517 mips-tfile with gcc version 1, but it will eventually come with gcc
5520 Debugging of g++ output remains a problem. g++ version 1.xx does not
5521 really support it at all. (If you're lucky, you should be able to get
5522 line numbers and stack traces to work, but no parameters or local
5523 variables.) With some work it should be possible to improve the
5526 When gcc version 2 is released, you will have somewhat better luck.
5527 However, even then you will get confusing results for inheritance and
5530 We will eventually provide full debugging of g++ output on
5531 DECstations. This will probably involve some kind of stabs-in-ecoff
5532 encapulation, but the details have not been worked out yet.
5535 *** Changes in GDB-4.2:
5537 * Improved configuration
5539 Only one copy of `configure' exists now, and it is not self-modifying.
5540 Porting BFD is simpler.
5544 The `step' and `next' commands now only stop at the first instruction
5545 of a source line. This prevents the multiple stops that used to occur
5546 in switch statements, for-loops, etc. `Step' continues to stop if a
5547 function that has debugging information is called within the line.
5551 Lots of small bugs fixed. More remain.
5553 * New host supported (not target)
5555 Intel 386 PC clone running Mach i386-none-mach
5558 *** Changes in GDB-4.1:
5560 * Multiple source language support
5562 GDB now has internal scaffolding to handle several source languages.
5563 It determines the type of each source file from its filename extension,
5564 and will switch expression parsing and number formatting to match the
5565 language of the function in the currently selected stack frame.
5566 You can also specifically set the language to be used, with
5567 `set language c' or `set language modula-2'.
5571 GDB now has preliminary support for the GNU Modula-2 compiler,
5572 currently under development at the State University of New York at
5573 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5574 continue through the fall of 1991 and into 1992.
5576 Other Modula-2 compilers are currently not supported, and attempting to
5577 debug programs compiled with them will likely result in an error as the
5578 symbol table is read. Feel free to work on it, though!
5580 There are hooks in GDB for strict type checking and range checking,
5581 in the `Modula-2 philosophy', but they do not currently work.
5585 GDB can now write to executable and core files (e.g. patch
5586 a variable's value). You must turn this switch on, specify
5587 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5588 by assigning a new value to a variable. Modifications take
5591 * Automatic SunOS shared library reading
5593 When you run your program, GDB automatically determines where its
5594 shared libraries (if any) have been loaded, and reads their symbols.
5595 The `share' command is no longer needed. This also works when
5596 examining core files.
5600 You can specify the number of lines that the `list' command shows.
5603 * New machines supported (host and target)
5605 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5606 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5607 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5609 * New hosts supported (not targets)
5611 IBM RT/PC: romp-ibm-aix or rtpc
5613 * New targets supported (not hosts)
5615 AMD 29000 embedded with COFF a29k-none-coff
5616 AMD 29000 embedded with a.out a29k-none-aout
5617 Ultracomputer remote kernel debug a29k-nyu-kern
5619 * New remote interfaces
5625 *** Changes in GDB-4.0:
5629 Wide output is wrapped at good places to make the output more readable.
5631 Gdb now supports cross-debugging from a host machine of one type to a
5632 target machine of another type. Communication with the target system
5633 is over serial lines. The ``target'' command handles connecting to the
5634 remote system; the ``load'' command will download a program into the
5635 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5636 also supports debugging of realtime processes running under VxWorks,
5637 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5638 stub on the target system.
5640 New CPUs supported include the AMD 29000 and Intel 960.
5642 GDB now reads object files and symbol tables via a ``binary file''
5643 library, which allows a single copy of GDB to debug programs of multiple
5644 object file types such as a.out and coff.
5646 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5647 refcard.dvi and refcard.ps are available to format it).
5650 * Control-Variable user interface simplified
5652 All variables that control the operation of the debugger can be set
5653 by the ``set'' command, and displayed by the ``show'' command.
5655 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5656 ``Show prompt'' produces the response:
5657 Gdb's prompt is new-gdb=>.
5659 What follows are the NEW set commands. The command ``help set'' will
5660 print a complete list of old and new set commands. ``help set FOO''
5661 will give a longer description of the variable FOO. ``show'' will show
5662 all of the variable descriptions and their current settings.
5664 confirm on/off: Enables warning questions for operations that are
5665 hard to recover from, e.g. rerunning the program while
5666 it is already running. Default is ON.
5668 editing on/off: Enables EMACS style command line editing
5669 of input. Previous lines can be recalled with
5670 control-P, the current line can be edited with control-B,
5671 you can search for commands with control-R, etc.
5674 history filename NAME: NAME is where the gdb command history
5675 will be stored. The default is .gdb_history,
5676 or the value of the environment variable
5679 history size N: The size, in commands, of the command history. The
5680 default is 256, or the value of the environment variable
5683 history save on/off: If this value is set to ON, the history file will
5684 be saved after exiting gdb. If set to OFF, the
5685 file will not be saved. The default is OFF.
5687 history expansion on/off: If this value is set to ON, then csh-like
5688 history expansion will be performed on
5689 command line input. The default is OFF.
5691 radix N: Sets the default radix for input and output. It can be set
5692 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5693 in the current radix, so "set radix 10" is always a no-op.
5695 height N: This integer value is the number of lines on a page. Default
5696 is 24, the current `stty rows'' setting, or the ``li#''
5697 setting from the termcap entry matching the environment
5700 width N: This integer value is the number of characters on a line.
5701 Default is 80, the current `stty cols'' setting, or the ``co#''
5702 setting from the termcap entry matching the environment
5705 Note: ``set screensize'' is obsolete. Use ``set height'' and
5706 ``set width'' instead.
5708 print address on/off: Print memory addresses in various command displays,
5709 such as stack traces and structure values. Gdb looks
5710 more ``symbolic'' if you turn this off; it looks more
5711 ``machine level'' with it on. Default is ON.
5713 print array on/off: Prettyprint arrays. New convenient format! Default
5716 print demangle on/off: Print C++ symbols in "source" form if on,
5719 print asm-demangle on/off: Same, for assembler level printouts
5722 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5725 * Support for Epoch Environment.
5727 The epoch environment is a version of Emacs v18 with windowing. One
5728 new command, ``inspect'', is identical to ``print'', except that if you
5729 are running in the epoch environment, the value is printed in its own
5733 * Support for Shared Libraries
5735 GDB can now debug programs and core files that use SunOS shared libraries.
5736 Symbols from a shared library cannot be referenced
5737 before the shared library has been linked with the program (this
5738 happens after you type ``run'' and before the function main() is entered).
5739 At any time after this linking (including when examining core files
5740 from dynamically linked programs), gdb reads the symbols from each
5741 shared library when you type the ``sharedlibrary'' command.
5742 It can be abbreviated ``share''.
5744 sharedlibrary REGEXP: Load shared object library symbols for files
5745 matching a unix regular expression. No argument
5746 indicates to load symbols for all shared libraries.
5748 info sharedlibrary: Status of loaded shared libraries.
5753 A watchpoint stops execution of a program whenever the value of an
5754 expression changes. Checking for this slows down execution
5755 tremendously whenever you are in the scope of the expression, but is
5756 quite useful for catching tough ``bit-spreader'' or pointer misuse
5757 problems. Some machines such as the 386 have hardware for doing this
5758 more quickly, and future versions of gdb will use this hardware.
5760 watch EXP: Set a watchpoint (breakpoint) for an expression.
5762 info watchpoints: Information about your watchpoints.
5764 delete N: Deletes watchpoint number N (same as breakpoints).
5765 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5766 enable N: Re-enables watchpoint number N (same as breakpoints).
5769 * C++ multiple inheritance
5771 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5774 * C++ exception handling
5776 Gdb now supports limited C++ exception handling. Besides the existing
5777 ability to breakpoint on an exception handler, gdb can breakpoint on
5778 the raising of an exception (before the stack is peeled back to the
5781 catch FOO: If there is a FOO exception handler in the dynamic scope,
5782 set a breakpoint to catch exceptions which may be raised there.
5783 Multiple exceptions (``catch foo bar baz'') may be caught.
5785 info catch: Lists all exceptions which may be caught in the
5786 current stack frame.
5789 * Minor command changes
5791 The command ``call func (arg, arg, ...)'' now acts like the print
5792 command, except it does not print or save a value if the function's result
5793 is void. This is similar to dbx usage.
5795 The ``up'' and ``down'' commands now always print the frame they end up
5796 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5797 frames without printing.
5799 * New directory command
5801 'dir' now adds directories to the FRONT of the source search path.
5802 The path starts off empty. Source files that contain debug information
5803 about the directory in which they were compiled can be found even
5804 with an empty path; Sun CC and GCC include this information. If GDB can't
5805 find your source file in the current directory, type "dir .".
5807 * Configuring GDB for compilation
5809 For normal use, type ``./configure host''. See README or gdb.texinfo
5812 GDB now handles cross debugging. If you are remotely debugging between
5813 two different machines, type ``./configure host -target=targ''.
5814 Host is the machine where GDB will run; targ is the machine
5815 where the program that you are debugging will run.