1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.8
7 You can now access frame registers from Python scripts.
9 * New Python-based convenience functions:
11 ** $_caller_is(name [, number_of_frames])
12 ** $_caller_matches(regexp [, number_of_frames])
13 ** $_any_caller_is(name [, number_of_frames])
14 ** $_any_caller_matches(regexp [, number_of_frames])
16 * On resume, GDB now always passes the signal the program had stopped
17 for to the thread the signal was sent to, even if the user changed
18 threads before resuming. Previously GDB would often (but not
19 always) deliver the signal to the thread that happens to be current
22 * Conversely, the "signal" command now consistently delivers the
23 requested signal to the current thread. GDB now asks for
24 confirmation if the program had stopped for a signal and the user
25 switched threads meanwhile.
27 *** Changes in GDB 7.8
29 * New command line options
32 This is an alias for the --data-directory option.
34 * GDB supports printing and modifying of variable length automatic arrays
35 as specified in ISO C99.
37 * The ARM simulator now supports instruction level tracing
38 with or without disassembly.
42 GDB now has support for scripting using Guile. Whether this is
43 available is determined at configure time.
44 Guile version 2.0 or greater is required.
45 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
47 * New commands (for set/show, see "New options" below)
51 Invoke CODE by passing it to the Guile interpreter.
55 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
57 info auto-load guile-scripts [regexp]
58 Print the list of automatically loaded Guile scripts.
60 * The source command is now capable of sourcing Guile scripts.
61 This feature is dependent on the debugger being built with Guile support.
65 set print symbol-loading (off|brief|full)
66 show print symbol-loading
67 Control whether to print informational messages when loading symbol
68 information for a file. The default is "full", but when debugging
69 programs with large numbers of shared libraries the amount of output
72 set guile print-stack (none|message|full)
73 show guile print-stack
74 Show a stack trace when an error is encountered in a Guile script.
76 set auto-load guile-scripts (on|off)
77 show auto-load guile-scripts
78 Control auto-loading of Guile script files.
80 maint ada set ignore-descriptive-types (on|off)
81 maint ada show ignore-descriptive-types
82 Control whether the debugger should ignore descriptive types in Ada
83 programs. The default is not to ignore the descriptive types. See
84 the user manual for more details on descriptive types and the intended
87 set auto-connect-native-target
89 Control whether GDB is allowed to automatically connect to the
90 native target for the run, attach, etc. commands when not connected
91 to any target yet. See also "target native" below.
93 set record btrace replay-memory-access (read-only|read-write)
94 show record btrace replay-memory-access
95 Control what memory accesses are allowed during replay.
97 maint set target-async (on|off)
98 maint show target-async
99 This controls whether GDB targets operate in syncronous or
100 asyncronous mode. Normally the default is asyncronous, if it is
101 available; but this can be changed to more easily debug problems
102 occurring only in syncronous mode.
104 set mi-async (on|off)
106 Control whether MI asynchronous mode is preferred. This supersedes
107 "set target-async" of previous GDB versions.
109 * "set target-async" is deprecated as a CLI option and is now an alias
110 for "set mi-async" (only puts MI into async mode).
112 * Background execution commands (e.g., "c&", "s&", etc.) are now
113 possible ``out of the box'' if the target supports them. Previously
114 the user would need to explicitly enable the possibility with the
115 "set target-async on" command.
117 * New features in the GDB remote stub, GDBserver
119 ** New option --debug-format=option1[,option2,...] allows one to add
120 additional text to each output. At present only timestamps
121 are supported: --debug-format=timestamps.
122 Timestamps can also be turned on with the
123 "monitor set debug-format timestamps" command from GDB.
125 * The 'record instruction-history' command now starts counting instructions
126 at one. This also affects the instruction ranges reported by the
127 'record function-call-history' command when given the /i modifier.
129 * The command 'record function-call-history' supports a new modifier '/c' to
130 indent the function names based on their call stack depth.
131 The fields for the '/i' and '/l' modifier have been reordered.
132 The source line range is now prefixed with 'at'.
133 The instruction range is now prefixed with 'inst'.
134 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
135 "record instruction-history" and "list" commands.
137 * The ranges given as arguments to the 'record function-call-history' and
138 'record instruction-history' commands are now inclusive.
140 * The btrace record target now supports the 'record goto' command.
141 For locations inside the execution trace, the back trace is computed
142 based on the information stored in the execution trace.
144 * The btrace record target supports limited reverse execution and replay.
145 The target does not record data and therefore does not allow reading
148 * The "catch syscall" command now works on s390*-linux* targets.
150 * The "compare-sections" command is no longer specific to target
151 remote. It now works with all targets.
153 * All native targets are now consistently called "native".
154 Consequently, the "target child", "target GNU", "target djgpp",
155 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
156 commands have been replaced with "target native". The QNX/NTO port
157 leaves the "procfs" target in place and adds a "native" target for
158 consistency with other ports. The impact on users should be minimal
159 as these commands previously either throwed an error, or were
160 no-ops. The target's name is visible in the output of the following
161 commands: "help target", "info target", "info files", "maint print
164 * The "target native" command now connects to the native target. This
165 can be used to launch native programs even when "set
166 auto-connect-native-target" is set to off.
168 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.
170 * Support for Intel(R) AVX-512 registers on GNU/Linux.
171 Support displaying and modifying Intel(R) AVX-512 registers
172 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
176 qXfer:btrace:read's annex
177 The qXfer:btrace:read packet supports a new annex 'delta' to read
178 branch trace incrementally.
182 ** Valid Python operations on gdb.Value objects representing
183 structs/classes invoke the corresponding overloaded operators if
185 ** New `Xmethods' feature in the Python API. Xmethods are
186 additional methods or replacements for existing methods of a C++
187 class. This feature is useful for those cases where a method
188 defined in C++ source code could be inlined or optimized out by
189 the compiler, making it unavailable to GDB.
192 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
194 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
195 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
196 its alias "share", instead.
198 * The commands "set remotebaud" and "show remotebaud" are no longer
199 supported. Use "set serial baud" and "show serial baud" (respectively)
204 ** A new option "-gdb-set mi-async" replaces "-gdb-set
205 target-async". The latter is left as a deprecated alias of the
206 former for backward compatibility. If the target supports it,
207 CLI background execution commands are now always possible by
208 default, independently of whether the frontend stated a
209 preference for asynchronous execution with "-gdb-set mi-async".
210 Previously "-gdb-set target-async off" affected both MI execution
211 commands and CLI execution commands.
213 *** Changes in GDB 7.7
215 * Improved support for process record-replay and reverse debugging on
216 arm*-linux* targets. Support for thumb32 and syscall instruction
217 recording has been added.
219 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
221 * GDB now supports Fission DWP file format version 2.
222 http://gcc.gnu.org/wiki/DebugFission
224 * New convenience function "$_isvoid", to check whether an expression
225 is void. A void expression is an expression where the type of the
226 result is "void". For example, some convenience variables may be
227 "void" when evaluated (e.g., "$_exitcode" before the execution of
228 the program being debugged; or an undefined convenience variable).
229 Another example, when calling a function whose return type is
232 * The "maintenance print objfiles" command now takes an optional regexp.
234 * The "catch syscall" command now works on arm*-linux* targets.
236 * GDB now consistently shows "<not saved>" when printing values of
237 registers the debug info indicates have not been saved in the frame
238 and there's nowhere to retrieve them from
239 (callee-saved/call-clobbered registers):
244 (gdb) info registers rax
247 Before, the former would print "<optimized out>", and the latter
248 "*value not available*".
250 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
255 ** Frame filters and frame decorators have been added.
256 ** Temporary breakpoints are now supported.
257 ** Line tables representation has been added.
258 ** New attribute 'parent_type' for gdb.Field objects.
259 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
260 ** New attribute 'name' for gdb.Type objects.
264 Nios II ELF nios2*-*-elf
265 Nios II GNU/Linux nios2*-*-linux
266 Texas Instruments MSP430 msp430*-*-elf
268 * Removed native configurations
270 Support for these a.out NetBSD and OpenBSD obsolete configurations has
271 been removed. ELF variants of these configurations are kept supported.
273 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
274 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
275 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
276 i[34567]86-*-openbsd3.[0-3]
277 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
278 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
279 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
283 Like "catch throw", but catches a re-thrown exception.
285 Renamed from old "maint check-symtabs".
287 Perform consistency checks on symtabs.
289 Expand symtabs matching an optional regexp.
292 Display the details of GDB configure-time options.
294 maint set|show per-command
295 maint set|show per-command space
296 maint set|show per-command time
297 maint set|show per-command symtab
298 Enable display of per-command gdb resource usage.
300 remove-symbol-file FILENAME
301 remove-symbol-file -a ADDRESS
302 Remove a symbol file added via add-symbol-file. The file to remove
303 can be identified by its filename or by an address that lies within
304 the boundaries of this symbol file in memory.
307 info exceptions REGEXP
308 Display the list of Ada exceptions defined in the program being
309 debugged. If provided, only the exceptions whose names match REGEXP
314 set debug symfile off|on
316 Control display of debugging info regarding reading symbol files and
317 symbol tables within those files
319 set print raw frame-arguments
320 show print raw frame-arguments
321 Set/show whether to print frame arguments in raw mode,
322 disregarding any defined pretty-printers.
324 set remote trace-status-packet
325 show remote trace-status-packet
326 Set/show the use of remote protocol qTStatus packet.
330 Control display of debugging messages related to Nios II targets.
334 Control whether target-assisted range stepping is enabled.
336 set startup-with-shell
337 show startup-with-shell
338 Specifies whether Unix child processes are started via a shell or
343 Use the target memory cache for accesses to the code segment. This
344 improves performance of remote debugging (particularly disassembly).
346 * You can now use a literal value 'unlimited' for options that
347 interpret 0 or -1 as meaning "unlimited". E.g., "set
348 trace-buffer-size unlimited" is now an alias for "set
349 trace-buffer-size -1" and "set height unlimited" is now an alias for
352 * The "set debug symtab-create" debugging option of GDB has been changed to
353 accept a verbosity level. 0 means "off", 1 provides basic debugging
354 output, and values of 2 or greater provides more verbose output.
356 * New command-line options
358 Display the details of GDB configure-time options.
360 * The command 'tsave' can now support new option '-ctf' to save trace
361 buffer in Common Trace Format.
363 * Newly installed $prefix/bin/gcore acts as a shell interface for the
366 * GDB now implements the the C++ 'typeid' operator.
368 * The new convenience variable $_exception holds the exception being
369 thrown or caught at an exception-related catchpoint.
371 * The exception-related catchpoints, like "catch throw", now accept a
372 regular expression which can be used to filter exceptions by type.
374 * The new convenience variable $_exitsignal is automatically set to
375 the terminating signal number when the program being debugged dies
376 due to an uncaught signal.
380 ** All MI commands now accept an optional "--language" option.
381 Support for this feature can be verified by using the "-list-features"
382 command, which should contain "language-option".
384 ** The new command -info-gdb-mi-command allows the user to determine
385 whether a GDB/MI command is supported or not.
387 ** The "^error" result record returned when trying to execute an undefined
388 GDB/MI command now provides a variable named "code" whose content is the
389 "undefined-command" error code. Support for this feature can be verified
390 by using the "-list-features" command, which should contain
391 "undefined-command-error-code".
393 ** The -trace-save MI command can optionally save trace buffer in Common
396 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
398 ** The command -data-list-register-values now accepts an optional
399 "--skip-unavailable" option. When used, only the available registers
402 ** The new command -trace-frame-collected dumps collected variables,
403 computed expressions, tvars, memory and registers in a traceframe.
405 ** The commands -stack-list-locals, -stack-list-arguments and
406 -stack-list-variables now accept an option "--skip-unavailable".
407 When used, only the available locals or arguments are displayed.
409 ** The -exec-run command now accepts an optional "--start" option.
410 When used, the command follows the same semantics as the "start"
411 command, stopping the program's execution at the start of its
412 main subprogram. Support for this feature can be verified using
413 the "-list-features" command, which should contain
414 "exec-run-start-option".
416 ** The new commands -catch-assert and -catch-exceptions insert
417 catchpoints stopping the program when Ada exceptions are raised.
419 ** The new command -info-ada-exceptions provides the equivalent of
420 the new "info exceptions" command.
422 * New system-wide configuration scripts
423 A GDB installation now provides scripts suitable for use as system-wide
424 configuration scripts for the following systems:
428 * GDB now supports target-assigned range stepping with remote targets.
429 This improves the performance of stepping source lines by reducing
430 the number of control packets from/to GDB. See "New remote packets"
433 * GDB now understands the element 'tvar' in the XML traceframe info.
434 It has the id of the collected trace state variables.
436 * On S/390 targets that provide the transactional-execution feature,
437 the program interruption transaction diagnostic block (TDB) is now
438 represented as a number of additional "registers" in GDB.
444 The vCont packet supports a new 'r' action, that tells the remote
445 stub to step through an address range itself, without GDB
446 involvemement at each single-step.
448 qXfer:libraries-svr4:read's annex
449 The previously unused annex of the qXfer:libraries-svr4:read packet
450 is now used to support passing an argument list. The remote stub
451 reports support for this argument list to GDB's qSupported query.
452 The defined arguments are "start" and "prev", used to reduce work
453 necessary for library list updating, resulting in significant
456 * New features in the GDB remote stub, GDBserver
458 ** GDBserver now supports target-assisted range stepping. Currently
459 enabled on x86/x86_64 GNU/Linux targets.
461 ** GDBserver now adds element 'tvar' in the XML in the reply to
462 'qXfer:traceframe-info:read'. It has the id of the collected
463 trace state variables.
465 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
468 * New 'z' formatter for printing and examining memory, this displays the
469 value as hexadecimal zero padded on the left to the size of the type.
471 * GDB can now use Windows x64 unwinding data.
473 * The "set remotebaud" command has been replaced by "set serial baud".
474 Similarly, "show remotebaud" has been replaced by "show serial baud".
475 The "set remotebaud" and "show remotebaud" commands are still available
476 to provide backward compatibility with older versions of GDB.
478 *** Changes in GDB 7.6
480 * Target record has been renamed to record-full.
481 Record/replay is now enabled with the "record full" command.
482 This also affects settings that are associated with full record/replay
483 that have been moved from "set/show record" to "set/show record full":
485 set|show record full insn-number-max
486 set|show record full stop-at-limit
487 set|show record full memory-query
489 * A new record target "record-btrace" has been added. The new target
490 uses hardware support to record the control-flow of a process. It
491 does not support replaying the execution, but it implements the
492 below new commands for investigating the recorded execution log.
493 This new recording method can be enabled using:
497 The "record-btrace" target is only available on Intel Atom processors
498 and requires a Linux kernel 2.6.32 or later.
500 * Two new commands have been added for record/replay to give information
501 about the recorded execution without having to replay the execution.
502 The commands are only supported by "record btrace".
504 record instruction-history prints the execution history at
505 instruction granularity
507 record function-call-history prints the execution history at
510 * New native configurations
512 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
513 FreeBSD/powerpc powerpc*-*-freebsd
514 x86_64/Cygwin x86_64-*-cygwin*
515 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
519 ARM AArch64 aarch64*-*-elf
520 ARM AArch64 GNU/Linux aarch64*-*-linux
521 Lynx 178 PowerPC powerpc-*-lynx*178
522 x86_64/Cygwin x86_64-*-cygwin*
523 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
525 * If the configured location of system.gdbinit file (as given by the
526 --with-system-gdbinit option at configure time) is in the
527 data-directory (as specified by --with-gdb-datadir at configure
528 time) or in one of its subdirectories, then GDB will look for the
529 system-wide init file in the directory specified by the
530 --data-directory command-line option.
532 * New command line options:
534 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
535 other initialization files, unlike -nx which disables all of them.
537 * Removed command line options
539 -epoch This was used by the gdb mode in Epoch, an ancient fork of
542 * The 'ptype' and 'whatis' commands now accept an argument to control
545 * 'info proc' now works on some core files.
549 ** Vectors can be created with gdb.Type.vector.
551 ** Python's atexit.register now works in GDB.
553 ** Types can be pretty-printed via a Python API.
555 ** Python 3 is now supported (in addition to Python 2.4 or later)
557 ** New class gdb.Architecture exposes GDB's internal representation
558 of architecture in the Python API.
560 ** New method Frame.architecture returns the gdb.Architecture object
561 corresponding to the frame's architecture.
563 * New Python-based convenience functions:
565 ** $_memeq(buf1, buf2, length)
566 ** $_streq(str1, str2)
568 ** $_regex(str, regex)
570 * The 'cd' command now defaults to using '~' (the home directory) if not
573 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
574 default for GCC since November 2000.
576 * The command 'forward-search' can now be abbreviated as 'fo'.
578 * The command 'info tracepoints' can now display 'installed on target'
579 or 'not installed on target' for each non-pending location of tracepoint.
581 * New configure options
583 --enable-libmcheck/--disable-libmcheck
584 By default, development versions are built with -lmcheck on hosts
585 that support it, in order to help track memory corruption issues.
586 Release versions, on the other hand, are built without -lmcheck
587 by default. The --enable-libmcheck/--disable-libmcheck configure
588 options allow the user to override that default.
589 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
590 This configure option allows the user to build GDB with
591 libbabeltrace using which GDB can read Common Trace Format data.
593 * New commands (for set/show, see "New options" below)
596 Catch signals. This is similar to "handle", but allows commands and
597 conditions to be attached.
600 List the BFDs known to GDB.
602 python-interactive [command]
604 Start a Python interactive prompt, or evaluate the optional command
605 and print the result of expressions.
608 "py" is a new alias for "python".
610 enable type-printer [name]...
611 disable type-printer [name]...
612 Enable or disable type printers.
616 ** For the Renesas Super-H architecture, the "regs" command has been removed
617 (has been deprecated in GDB 7.5), and "info all-registers" should be used
622 set print type methods (on|off)
623 show print type methods
624 Control whether method declarations are displayed by "ptype".
625 The default is to show them.
627 set print type typedefs (on|off)
628 show print type typedefs
629 Control whether typedef definitions are displayed by "ptype".
630 The default is to show them.
632 set filename-display basename|relative|absolute
633 show filename-display
634 Control the way in which filenames is displayed.
635 The default is "relative", which preserves previous behavior.
637 set trace-buffer-size
638 show trace-buffer-size
639 Request target to change the size of trace buffer.
641 set remote trace-buffer-size-packet auto|on|off
642 show remote trace-buffer-size-packet
643 Control the use of the remote protocol `QTBuffer:size' packet.
647 Control display of debugging messages related to ARM AArch64.
650 set debug coff-pe-read
651 show debug coff-pe-read
652 Control display of debugging messages related to reading of COFF/PE
657 Control display of debugging messages related to Mach-O symbols
660 set debug notification
661 show debug notification
662 Control display of debugging info for async remote notification.
666 ** Command parameter changes are now notified using new async record
667 "=cmd-param-changed".
668 ** Trace frame changes caused by command "tfind" are now notified using
669 new async record "=traceframe-changed".
670 ** The creation, deletion and modification of trace state variables
671 are now notified using new async records "=tsv-created",
672 "=tsv-deleted" and "=tsv-modified".
673 ** The start and stop of process record are now notified using new
674 async record "=record-started" and "=record-stopped".
675 ** Memory changes are now notified using new async record
677 ** The data-disassemble command response will include a "fullname" field
678 containing the absolute file name when source has been requested.
679 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
680 command, to allow pattern filling of memory areas.
681 ** New commands "-catch-load"/"-catch-unload" added for intercepting
682 library load/unload events.
683 ** The response to breakpoint commands and breakpoint async records
684 includes an "installed" field containing a boolean state about each
685 non-pending tracepoint location is whether installed on target or not.
686 ** Output of the "-trace-status" command includes a "trace-file" field
687 containing the name of the trace file being examined. This field is
688 optional, and only present when examining a trace file.
689 ** The "fullname" field is now always present along with the "file" field,
690 even if the file cannot be found by GDB.
692 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
693 You must have the LZMA library available when configuring GDB for this
694 feature to be enabled. For more information, see:
695 http://fedoraproject.org/wiki/Features/MiniDebugInfo
700 Set the size of trace buffer. The remote stub reports support for this
701 packet to gdb's qSupported query.
704 Enable Branch Trace Store (BTS)-based branch tracing for the current
705 thread. The remote stub reports support for this packet to gdb's
709 Disable branch tracing for the current thread. The remote stub reports
710 support for this packet to gdb's qSupported query.
713 Read the traced branches for the current thread. The remote stub
714 reports support for this packet to gdb's qSupported query.
716 *** Changes in GDB 7.5
718 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
719 for more x32 ABI info.
721 * GDB now supports access to MIPS DSP registers on Linux targets.
723 * GDB now supports debugging microMIPS binaries.
725 * The "info os" command on GNU/Linux can now display information on
726 several new classes of objects managed by the operating system:
727 "info os procgroups" lists process groups
728 "info os files" lists file descriptors
729 "info os sockets" lists internet-domain sockets
730 "info os shm" lists shared-memory regions
731 "info os semaphores" lists semaphores
732 "info os msg" lists message queues
733 "info os modules" lists loaded kernel modules
735 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
736 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
737 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
738 options and inspect the probe arguments using the new $_probe_arg family
739 of convenience variables. You can obtain more information about SystemTap
740 in <http://sourceware.org/systemtap/>.
742 * GDB now supports reversible debugging on ARM, it allows you to
743 debug basic ARM and THUMB instructions, and provides
744 record/replay support.
746 * The option "symbol-reloading" has been deleted as it is no longer used.
750 ** GDB commands implemented in Python can now be put in command class
753 ** The "maint set python print-stack on|off" is now deleted.
755 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
756 apply "flag enum"-style pretty-printing to any enum.
758 ** gdb.lookup_symbol can now work when there is no current frame.
760 ** gdb.Symbol now has a 'line' attribute, holding the line number in
761 the source at which the symbol was defined.
763 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
764 method 'value'. The former indicates whether the symbol needs a
765 frame in order to compute its value, and the latter computes the
768 ** A new method 'referenced_value' on gdb.Value objects which can
769 dereference pointer as well as C++ reference values.
771 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
772 which return the global and static blocks (as gdb.Block objects),
773 of the underlying symbol table, respectively.
775 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
776 object associated with a PC value.
778 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
779 of the address range occupied by code for the current source line.
781 * Go language support.
782 GDB now supports debugging programs written in the Go programming
785 * GDBserver now supports stdio connections.
786 E.g. (gdb) target remote | ssh myhost gdbserver - hello
788 * The binary "gdbtui" can no longer be built or installed.
789 Use "gdb -tui" instead.
791 * GDB will now print "flag" enums specially. A flag enum is one where
792 all the enumerator values have no bits in common when pairwise
793 "and"ed. When printing a value whose type is a flag enum, GDB will
794 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
795 (gdb) print (enum E) 3
798 * The filename part of a linespec will now match trailing components
799 of a source file name. For example, "break gcc/expr.c:1000" will
800 now set a breakpoint in build/gcc/expr.c, but not
803 * The "info proc" and "generate-core-file" commands will now also
804 work on remote targets connected to GDBserver on Linux.
806 * The command "info catch" has been removed. It has been disabled
809 * The "catch exception" and "catch assert" commands now accept
810 a condition at the end of the command, much like the "break"
811 command does. For instance:
813 (gdb) catch exception Constraint_Error if Barrier = True
815 Previously, it was possible to add a condition to such catchpoints,
816 but it had to be done as a second step, after the catchpoint had been
817 created, using the "condition" command.
819 * The "info static-tracepoint-marker" command will now also work on
820 native Linux targets with in-process agent.
822 * GDB can now set breakpoints on inlined functions.
824 * The .gdb_index section has been updated to include symbols for
825 inlined functions. GDB will ignore older .gdb_index sections by
826 default, which could cause symbol files to be loaded more slowly
827 until their .gdb_index sections can be recreated. The new command
828 "set use-deprecated-index-sections on" will cause GDB to use any older
829 .gdb_index sections it finds. This will restore performance, but the
830 ability to set breakpoints on inlined functions will be lost in symbol
831 files with older .gdb_index sections.
833 The .gdb_index section has also been updated to record more information
834 about each symbol. This speeds up the "info variables", "info functions"
835 and "info types" commands when used with programs having the .gdb_index
836 section, as well as speeding up debugging with shared libraries using
837 the .gdb_index section.
839 * Ada support for GDB/MI Variable Objects has been added.
841 * GDB can now support 'breakpoint always-inserted mode' in 'record'
846 ** New command -info-os is the MI equivalent of "info os".
848 ** Output logs ("set logging" and related) now include MI output.
852 ** "set use-deprecated-index-sections on|off"
853 "show use-deprecated-index-sections on|off"
854 Controls the use of deprecated .gdb_index sections.
856 ** "catch load" and "catch unload" can be used to stop when a shared
857 library is loaded or unloaded, respectively.
859 ** "enable count" can be used to auto-disable a breakpoint after
862 ** "info vtbl" can be used to show the virtual method tables for
863 C++ and Java objects.
865 ** "explore" and its sub commands "explore value" and "explore type"
866 can be used to recursively explore values and types of
867 expressions. These commands are available only if GDB is
868 configured with '--with-python'.
870 ** "info auto-load" shows status of all kinds of auto-loaded files,
871 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
872 sequences of commands files, "info auto-load python-scripts"
873 shows status of auto-loading Python script files,
874 "info auto-load local-gdbinit" shows status of loading init file
875 (.gdbinit) from current directory and "info auto-load libthread-db" shows
876 status of inferior specific thread debugging shared library loading.
878 ** "info auto-load-scripts", "set auto-load-scripts on|off"
879 and "show auto-load-scripts" commands have been deprecated, use their
880 "info auto-load python-scripts", "set auto-load python-scripts on|off"
881 and "show auto-load python-scripts" counterparts instead.
883 ** "dprintf location,format,args..." creates a dynamic printf, which
884 is basically a breakpoint that does a printf and immediately
885 resumes your program's execution, so it is like a printf that you
886 can insert dynamically at runtime instead of at compiletime.
888 ** "set print symbol"
890 Controls whether GDB attempts to display the symbol, if any,
891 corresponding to addresses it prints. This defaults to "on", but
892 you can set it to "off" to restore GDB's previous behavior.
894 * Deprecated commands
896 ** For the Renesas Super-H architecture, the "regs" command has been
897 deprecated, and "info all-registers" should be used instead.
901 Renesas RL78 rl78-*-elf
902 HP OpenVMS ia64 ia64-hp-openvms*
904 * GDBserver supports evaluation of breakpoint conditions. When
905 support is advertised by GDBserver, GDB may be told to send the
906 breakpoint conditions in bytecode form to GDBserver. GDBserver
907 will only report the breakpoint trigger to GDB when its condition
913 show mips compression
914 Select the compressed ISA encoding used in functions that have no symbol
915 information available. The encoding can be set to either of:
918 and is updated automatically from ELF file flags if available.
920 set breakpoint condition-evaluation
921 show breakpoint condition-evaluation
922 Control whether breakpoint conditions are evaluated by GDB ("host") or by
923 GDBserver ("target"). Default option "auto" chooses the most efficient
925 This option can improve debugger efficiency depending on the speed of the
929 Disable auto-loading globally.
932 Show auto-loading setting of all kinds of auto-loaded files.
934 set auto-load gdb-scripts on|off
935 show auto-load gdb-scripts
936 Control auto-loading of GDB canned sequences of commands files.
938 set auto-load python-scripts on|off
939 show auto-load python-scripts
940 Control auto-loading of Python script files.
942 set auto-load local-gdbinit on|off
943 show auto-load local-gdbinit
944 Control loading of init file (.gdbinit) from current directory.
946 set auto-load libthread-db on|off
947 show auto-load libthread-db
948 Control auto-loading of inferior specific thread debugging shared library.
950 set auto-load scripts-directory <dir1>[:<dir2>...]
951 show auto-load scripts-directory
952 Set a list of directories from which to load auto-loaded scripts.
953 Automatically loaded Python scripts and GDB scripts are located in one
954 of the directories listed by this option.
955 The delimiter (':' above) may differ according to the host platform.
957 set auto-load safe-path <dir1>[:<dir2>...]
958 show auto-load safe-path
959 Set a list of directories from which it is safe to auto-load files.
960 The delimiter (':' above) may differ according to the host platform.
962 set debug auto-load on|off
964 Control display of debugging info for auto-loading the files above.
966 set dprintf-style gdb|call|agent
968 Control the way in which a dynamic printf is performed; "gdb"
969 requests a GDB printf command, while "call" causes dprintf to call a
970 function in the inferior. "agent" requests that the target agent
971 (such as GDBserver) do the printing.
973 set dprintf-function <expr>
974 show dprintf-function
975 set dprintf-channel <expr>
977 Set the function and optional first argument to the call when using
978 the "call" style of dynamic printf.
980 set disconnected-dprintf on|off
981 show disconnected-dprintf
982 Control whether agent-style dynamic printfs continue to be in effect
983 after GDB disconnects.
985 * New configure options
988 Configure default value for the 'set auto-load scripts-directory'
989 setting above. It defaults to '$debugdir:$datadir/auto-load',
990 $debugdir representing global debugging info directories (available
991 via 'show debug-file-directory') and $datadir representing GDB's data
992 directory (available via 'show data-directory').
994 --with-auto-load-safe-path
995 Configure default value for the 'set auto-load safe-path' setting
996 above. It defaults to the --with-auto-load-dir setting.
998 --without-auto-load-safe-path
999 Set 'set auto-load safe-path' to '/', effectively disabling this
1002 * New remote packets
1004 z0/z1 conditional breakpoints extension
1006 The z0/z1 breakpoint insertion packets have been extended to carry
1007 a list of conditional expressions over to the remote stub depending on the
1008 condition evaluation mode. The use of this extension can be controlled
1009 via the "set remote conditional-breakpoints-packet" command.
1013 Specify the signals which the remote stub may pass to the debugged
1014 program without GDB involvement.
1016 * New command line options
1018 --init-command=FILE, -ix Like --command, -x but execute it
1019 before loading inferior.
1020 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1021 execute it before loading inferior.
1023 *** Changes in GDB 7.4
1025 * GDB now handles ambiguous linespecs more consistently; the existing
1026 FILE:LINE support has been expanded to other types of linespecs. A
1027 breakpoint will now be set on all matching locations in all
1028 inferiors, and locations will be added or removed according to
1031 * GDB now allows you to skip uninteresting functions and files when
1032 stepping with the "skip function" and "skip file" commands.
1034 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1035 and "show remote hardware-watchpoint-length-limit". These allows to
1036 set or show the maximum length limit (in bytes) of a remote
1037 target hardware watchpoint.
1039 This allows e.g. to use "unlimited" hardware watchpoints with the
1040 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1041 watchpoints are slower than real hardware watchpoints but are
1042 significantly faster than gdb software watchpoints.
1046 ** The register_pretty_printer function in module gdb.printing now takes
1047 an optional `replace' argument. If True, the new printer replaces any
1050 ** The "maint set python print-stack on|off" command has been
1051 deprecated and will be deleted in GDB 7.5.
1052 A new command: "set python print-stack none|full|message" has
1053 replaced it. Additionally, the default for "print-stack" is
1054 now "message", which just prints the error message without
1057 ** A prompt substitution hook (prompt_hook) is now available to the
1060 ** A new Python module, gdb.prompt has been added to the GDB Python
1061 modules library. This module provides functionality for
1062 escape sequences in prompts (used by set/show
1063 extended-prompt). These escape sequences are replaced by their
1064 corresponding value.
1066 ** Python commands and convenience-functions located in
1067 'data-directory'/python/gdb/command and
1068 'data-directory'/python/gdb/function are now automatically loaded
1071 ** Blocks now provide four new attributes. global_block and
1072 static_block will return the global and static blocks
1073 respectively. is_static and is_global are boolean attributes
1074 that indicate if the block is one of those two types.
1076 ** Symbols now provide the "type" attribute, the type of the symbol.
1078 ** The "gdb.breakpoint" function has been deprecated in favor of
1081 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1082 of a function. This class is based on the "finish" command
1083 available in the CLI.
1085 ** Type objects for struct and union types now allow access to
1086 the fields using standard Python dictionary (mapping) methods.
1087 For example, "some_type['myfield']" now works, as does
1088 "some_type.items()".
1090 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1093 ** A new function, "deep_items" has been added to the gdb.types
1094 module in the GDB Python modules library. This function returns
1095 an iterator over the fields of a struct or union type. Unlike
1096 the standard Python "iteritems" method, it will recursively traverse
1097 any anonymous fields.
1101 ** "*stopped" events can report several new "reason"s, such as
1104 ** Breakpoint changes are now notified using new async records, like
1105 "=breakpoint-modified".
1107 ** New command -ada-task-info.
1109 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1110 $sdir specifies the default system locations of shared libraries.
1111 $pdir specifies the directory where the libpthread used by the application
1114 GDB no longer looks in $sdir and $pdir after it has searched the directories
1115 mentioned in libthread-db-search-path. If you want to search those
1116 directories, they must be specified in libthread-db-search-path.
1117 The default value of libthread-db-search-path on GNU/Linux and Solaris
1118 systems is now "$sdir:$pdir".
1120 $pdir is not supported by gdbserver, it is currently ignored.
1121 $sdir is supported by gdbserver.
1123 * New configure option --with-iconv-bin.
1124 When using the internationalization support like the one in the GNU C
1125 library, GDB will invoke the "iconv" program to get a list of supported
1126 character sets. If this program lives in a non-standard location, one can
1127 use this option to specify where to find it.
1129 * When natively debugging programs on PowerPC BookE processors running
1130 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1131 watchpoints, which specify a mask in addition to an address to watch.
1132 The mask specifies that some bits of an address (the bits which are
1133 reset in the mask) should be ignored when matching the address accessed
1134 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1135 section in the user manual for more details.
1137 * The new option --once causes GDBserver to stop listening for connections once
1138 the first connection is made. The listening port used by GDBserver will
1139 become available after that.
1141 * New commands "info macros" and "alias" have been added.
1143 * New function parameters suffix @entry specifies value of function parameter
1144 at the time the function got called. Entry values are available only since
1150 "!" is now an alias of the "shell" command.
1151 Note that no space is needed between "!" and SHELL COMMAND.
1155 watch EXPRESSION mask MASK_VALUE
1156 The watch command now supports the mask argument which allows creation
1157 of masked watchpoints, if the current architecture supports this feature.
1159 info auto-load-scripts [REGEXP]
1160 This command was formerly named "maintenance print section-scripts".
1161 It is now generally useful and is no longer a maintenance-only command.
1163 info macro [-all] [--] MACRO
1164 The info macro command has new options `-all' and `--'. The first for
1165 printing all definitions of a macro. The second for explicitly specifying
1166 the end of arguments and the beginning of the macro name in case the macro
1167 name starts with a hyphen.
1169 collect[/s] EXPRESSIONS
1170 The tracepoint collect command now takes an optional modifier "/s"
1171 that directs it to dereference pointer-to-character types and
1172 collect the bytes of memory up to a zero byte. The behavior is
1173 similar to what you see when you use the regular print command on a
1174 string. An optional integer following the "/s" sets a bound on the
1175 number of bytes that will be collected.
1178 The trace start command now interprets any supplied arguments as a
1179 note to be recorded with the trace run, with an effect similar to
1180 setting the variable trace-notes.
1183 The trace stop command now interprets any arguments as a note to be
1184 mentioned along with the tstatus report that the trace was stopped
1185 with a command. The effect is similar to setting the variable
1188 * Tracepoints can now be enabled and disabled at any time after a trace
1189 experiment has been started using the standard "enable" and "disable"
1190 commands. It is now possible to start a trace experiment with no enabled
1191 tracepoints; GDB will display a warning, but will allow the experiment to
1192 begin, assuming that tracepoints will be enabled as needed while the trace
1195 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1196 locations with 4-byte instructions, when they were previously
1197 limited to locations with instructions of 5 bytes or longer.
1201 set debug dwarf2-read
1202 show debug dwarf2-read
1203 Turns on or off display of debugging messages related to reading
1204 DWARF debug info. The default is off.
1206 set debug symtab-create
1207 show debug symtab-create
1208 Turns on or off display of debugging messages related to symbol table
1209 creation. The default is off.
1212 show extended-prompt
1213 Set the GDB prompt, and allow escape sequences to be inserted to
1214 display miscellaneous information (see 'help set extended-prompt'
1215 for the list of sequences). This prompt (and any information
1216 accessed through the escape sequences) is updated every time the
1217 prompt is displayed.
1219 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1220 show print entry-values
1221 Set printing of frame argument values at function entry. In some cases
1222 GDB can determine the value of function argument which was passed by the
1223 function caller, even if the value was modified inside the called function.
1225 set debug entry-values
1226 show debug entry-values
1227 Control display of debugging info for determining frame argument values at
1228 function entry and virtual tail call frames.
1230 set basenames-may-differ
1231 show basenames-may-differ
1232 Set whether a source file may have multiple base names.
1233 (A "base name" is the name of a file with the directory part removed.
1234 Example: The base name of "/home/user/hello.c" is "hello.c".)
1235 If set, GDB will canonicalize file names (e.g., expand symlinks)
1236 before comparing them. Canonicalization is an expensive operation,
1237 but it allows the same file be known by more than one base name.
1238 If not set (the default), all source files are assumed to have just
1239 one base name, and gdb will do file name comparisons more efficiently.
1245 Set a user name and notes for the current and any future trace runs.
1246 This is useful for long-running and/or disconnected traces, to
1247 inform others (or yourself) as to who is running the trace, supply
1248 contact information, or otherwise explain what is going on.
1250 set trace-stop-notes
1251 show trace-stop-notes
1252 Set a note attached to the trace run, that is displayed when the
1253 trace has been stopped by a tstop command. This is useful for
1254 instance as an explanation, if you are stopping a trace run that was
1255 started by someone else.
1257 * New remote packets
1261 Dynamically enable a tracepoint in a started trace experiment.
1265 Dynamically disable a tracepoint in a started trace experiment.
1269 Set the user and notes of the trace run.
1273 Query the current status of a tracepoint.
1277 Query the minimum length of instruction at which a fast tracepoint may
1280 * Dcache size (number of lines) and line-size are now runtime-configurable
1281 via "set dcache line" and "set dcache line-size" commands.
1285 Texas Instruments TMS320C6x tic6x-*-*
1289 Renesas RL78 rl78-*-elf
1291 *** Changes in GDB 7.3.1
1293 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1295 *** Changes in GDB 7.3
1297 * GDB has a new command: "thread find [REGEXP]".
1298 It finds the thread id whose name, target id, or thread extra info
1299 matches the given regular expression.
1301 * The "catch syscall" command now works on mips*-linux* targets.
1303 * The -data-disassemble MI command now supports modes 2 and 3 for
1304 dumping the instruction opcodes.
1306 * New command line options
1308 -data-directory DIR Specify DIR as the "data-directory".
1309 This is mostly for testing purposes.
1311 * The "maint set python auto-load on|off" command has been renamed to
1312 "set auto-load-scripts on|off".
1314 * GDB has a new command: "set directories".
1315 It is like the "dir" command except that it replaces the
1316 source path list instead of augmenting it.
1318 * GDB now understands thread names.
1320 On GNU/Linux, "info threads" will display the thread name as set by
1321 prctl or pthread_setname_np.
1323 There is also a new command, "thread name", which can be used to
1324 assign a name internally for GDB to display.
1327 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1328 has been integrated into GDB.
1332 ** The function gdb.Write now accepts an optional keyword 'stream'.
1333 This keyword, when provided, will direct the output to either
1334 stdout, stderr, or GDB's logging output.
1336 ** Parameters can now be be sub-classed in Python, and in particular
1337 you may implement the get_set_doc and get_show_doc functions.
1338 This improves how Parameter set/show documentation is processed
1339 and allows for more dynamic content.
1341 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1342 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1343 have an is_valid method.
1345 ** Breakpoints can now be sub-classed in Python, and in particular
1346 you may implement a 'stop' function that is executed each time
1347 the inferior reaches that breakpoint.
1349 ** New function gdb.lookup_global_symbol looks up a global symbol.
1351 ** GDB values in Python are now callable if the value represents a
1352 function. For example, if 'some_value' represents a function that
1353 takes two integer parameters and returns a value, you can call
1354 that function like so:
1356 result = some_value (10,20)
1358 ** Module gdb.types has been added.
1359 It contains a collection of utilities for working with gdb.Types objects:
1360 get_basic_type, has_field, make_enum_dict.
1362 ** Module gdb.printing has been added.
1363 It contains utilities for writing and registering pretty-printers.
1364 New classes: PrettyPrinter, SubPrettyPrinter,
1365 RegexpCollectionPrettyPrinter.
1366 New function: register_pretty_printer.
1368 ** New commands "info pretty-printers", "enable pretty-printer" and
1369 "disable pretty-printer" have been added.
1371 ** gdb.parameter("directories") is now available.
1373 ** New function gdb.newest_frame returns the newest frame in the
1376 ** The gdb.InferiorThread class has a new "name" attribute. This
1377 holds the thread's name.
1379 ** Python Support for Inferior events.
1380 Python scripts can add observers to be notified of events
1381 occurring in the process being debugged.
1382 The following events are currently supported:
1383 - gdb.events.cont Continue event.
1384 - gdb.events.exited Inferior exited event.
1385 - gdb.events.stop Signal received, and Breakpoint hit events.
1389 ** GDB now puts template parameters in scope when debugging in an
1390 instantiation. For example, if you have:
1392 template<int X> int func (void) { return X; }
1394 then if you step into func<5>, "print X" will show "5". This
1395 feature requires proper debuginfo support from the compiler; it
1396 was added to GCC 4.5.
1398 ** The motion commands "next", "finish", "until", and "advance" now
1399 work better when exceptions are thrown. In particular, GDB will
1400 no longer lose control of the inferior; instead, the GDB will
1401 stop the inferior at the point at which the exception is caught.
1402 This functionality requires a change in the exception handling
1403 code that was introduced in GCC 4.5.
1405 * GDB now follows GCC's rules on accessing volatile objects when
1406 reading or writing target state during expression evaluation.
1407 One notable difference to prior behavior is that "print x = 0"
1408 no longer generates a read of x; the value of the assignment is
1409 now always taken directly from the value being assigned.
1411 * GDB now has some support for using labels in the program's source in
1412 linespecs. For instance, you can use "advance label" to continue
1413 execution to a label.
1415 * GDB now has support for reading and writing a new .gdb_index
1416 section. This section holds a fast index of DWARF debugging
1417 information and can be used to greatly speed up GDB startup and
1418 operation. See the documentation for `save gdb-index' for details.
1420 * The "watch" command now accepts an optional "-location" argument.
1421 When used, this causes GDB to watch the memory referred to by the
1422 expression. Such a watchpoint is never deleted due to it going out
1425 * GDB now supports thread debugging of core dumps on GNU/Linux.
1427 GDB now activates thread debugging using the libthread_db library
1428 when debugging GNU/Linux core dumps, similarly to when debugging
1429 live processes. As a result, when debugging a core dump file, GDB
1430 is now able to display pthread_t ids of threads. For example, "info
1431 threads" shows the same output as when debugging the process when it
1432 was live. In earlier releases, you'd see something like this:
1435 * 1 LWP 6780 main () at main.c:10
1437 While now you see this:
1440 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1442 It is also now possible to inspect TLS variables when debugging core
1445 When debugging a core dump generated on a machine other than the one
1446 used to run GDB, you may need to point GDB at the correct
1447 libthread_db library with the "set libthread-db-search-path"
1448 command. See the user manual for more details on this command.
1450 * When natively debugging programs on PowerPC BookE processors running
1451 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1452 which stop execution of the inferior whenever it executes an instruction
1453 at any address within the specified range. See the "PowerPC Embedded"
1454 section in the user manual for more details.
1456 * New features in the GDB remote stub, GDBserver
1458 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1459 and i686 LynxOS (version 5.x).
1461 ** GDBserver is now supported on Blackfin Linux.
1463 * New native configurations
1465 ia64 HP-UX ia64-*-hpux*
1469 Analog Devices, Inc. Blackfin Processor bfin-*
1471 * Ada task switching is now supported on sparc-elf targets when
1472 debugging a program using the Ravenscar Profile. For more information,
1473 see the "Tasking Support when using the Ravenscar Profile" section
1474 in the GDB user manual.
1476 * Guile support was removed.
1478 * New features in the GNU simulator
1480 ** The --map-info flag lists all known core mappings.
1482 ** CFI flashes may be simulated via the "cfi" device.
1484 *** Changes in GDB 7.2
1486 * Shared library support for remote targets by default
1488 When GDB is configured for a generic, non-OS specific target, like
1489 for example, --target=arm-eabi or one of the many *-*-elf targets,
1490 GDB now queries remote stubs for loaded shared libraries using the
1491 `qXfer:libraries:read' packet. Previously, shared library support
1492 was always disabled for such configurations.
1496 ** Argument Dependent Lookup (ADL)
1498 In C++ ADL lookup directs function search to the namespaces of its
1499 arguments even if the namespace has not been imported.
1509 Here the compiler will search for `foo' in the namespace of 'b'
1510 and find A::foo. GDB now supports this. This construct is commonly
1511 used in the Standard Template Library for operators.
1513 ** Improved User Defined Operator Support
1515 In addition to member operators, GDB now supports lookup of operators
1516 defined in a namespace and imported with a `using' directive, operators
1517 defined in the global scope, operators imported implicitly from an
1518 anonymous namespace, and the ADL operators mentioned in the previous
1520 GDB now also supports proper overload resolution for all the previously
1521 mentioned flavors of operators.
1523 ** static const class members
1525 Printing of static const class members that are initialized in the
1526 class definition has been fixed.
1528 * Windows Thread Information Block access.
1530 On Windows targets, GDB now supports displaying the Windows Thread
1531 Information Block (TIB) structure. This structure is visible either
1532 by using the new command `info w32 thread-information-block' or, by
1533 dereferencing the new convenience variable named `$_tlb', a
1534 thread-specific pointer to the TIB. This feature is also supported
1535 when remote debugging using GDBserver.
1537 * Static tracepoints
1539 Static tracepoints are calls in the user program into a tracing
1540 library. One such library is a port of the LTTng kernel tracer to
1541 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1542 When debugging with GDBserver, GDB now supports combining the GDB
1543 tracepoint machinery with such libraries. For example: the user can
1544 use GDB to probe a static tracepoint marker (a call from the user
1545 program into the tracing library) with the new "strace" command (see
1546 "New commands" below). This creates a "static tracepoint" in the
1547 breakpoint list, that can be manipulated with the same feature set
1548 as fast and regular tracepoints. E.g., collect registers, local and
1549 global variables, collect trace state variables, and define
1550 tracepoint conditions. In addition, the user can collect extra
1551 static tracepoint marker specific data, by collecting the new
1552 $_sdata internal variable. When analyzing the trace buffer, you can
1553 inspect $_sdata like any other variable available to GDB. For more
1554 information, see the "Tracepoints" chapter in GDB user manual. New
1555 remote packets have been defined to support static tracepoints, see
1556 the "New remote packets" section below.
1558 * Better reconstruction of tracepoints after disconnected tracing
1560 GDB will attempt to download the original source form of tracepoint
1561 definitions when starting a trace run, and then will upload these
1562 upon reconnection to the target, resulting in a more accurate
1563 reconstruction of the tracepoints that are in use on the target.
1567 You can now exercise direct control over the ways that GDB can
1568 affect your program. For instance, you can disallow the setting of
1569 breakpoints, so that the program can run continuously (assuming
1570 non-stop mode). In addition, the "observer" variable is available
1571 to switch all of the different controls; in observer mode, GDB
1572 cannot affect the target's behavior at all, which is useful for
1573 tasks like diagnosing live systems in the field.
1575 * The new convenience variable $_thread holds the number of the
1578 * New remote packets
1582 Return the address of the Windows Thread Information Block of a given thread.
1586 In response to several of the tracepoint packets, the target may now
1587 also respond with a number of intermediate `qRelocInsn' request
1588 packets before the final result packet, to have GDB handle
1589 relocating an instruction to execute at a different address. This
1590 is particularly useful for stubs that support fast tracepoints. GDB
1591 reports support for this feature in the qSupported packet.
1595 List static tracepoint markers in the target program.
1599 List static tracepoint markers at a given address in the target
1602 qXfer:statictrace:read
1604 Read the static trace data collected (by a `collect $_sdata'
1605 tracepoint action). The remote stub reports support for this packet
1606 to gdb's qSupported query.
1610 Send the current settings of GDB's permission flags.
1614 Send part of the source (textual) form of a tracepoint definition,
1615 which includes location, conditional, and action list.
1617 * The source command now accepts a -s option to force searching for the
1618 script in the source search path even if the script name specifies
1621 * New features in the GDB remote stub, GDBserver
1623 - GDBserver now support tracepoints (including fast tracepoints, and
1624 static tracepoints). The feature is currently supported by the
1625 i386-linux and amd64-linux builds. See the "Tracepoints support
1626 in gdbserver" section in the manual for more information.
1628 GDBserver JIT compiles the tracepoint's conditional agent
1629 expression bytecode into native code whenever possible for low
1630 overhead dynamic tracepoints conditionals. For such tracepoints,
1631 an expression that examines program state is evaluated when the
1632 tracepoint is reached, in order to determine whether to capture
1633 trace data. If the condition is simple and false, processing the
1634 tracepoint finishes very quickly and no data is gathered.
1636 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1637 for static tracepoints support.
1639 - GDBserver now supports x86_64 Windows 64-bit debugging.
1641 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1642 it understands register description.
1644 * The --batch flag now disables pagination and queries.
1646 * X86 general purpose registers
1648 GDB now supports reading/writing byte, word and double-word x86
1649 general purpose registers directly. This means you can use, say,
1650 $ah or $ax to refer, respectively, to the byte register AH and
1651 16-bit word register AX that are actually portions of the 32-bit
1652 register EAX or 64-bit register RAX.
1654 * The `commands' command now accepts a range of breakpoints to modify.
1655 A plain `commands' following a command that creates multiple
1656 breakpoints affects all the breakpoints set by that command. This
1657 applies to breakpoints set by `rbreak', and also applies when a
1658 single `break' command creates multiple breakpoints (e.g.,
1659 breakpoints on overloaded c++ functions).
1661 * The `rbreak' command now accepts a filename specification as part of
1662 its argument, limiting the functions selected by the regex to those
1663 in the specified file.
1665 * Support for remote debugging Windows and SymbianOS shared libraries
1666 from Unix hosts has been improved. Non Windows GDB builds now can
1667 understand target reported file names that follow MS-DOS based file
1668 system semantics, such as file names that include drive letters and
1669 use the backslash character as directory separator. This makes it
1670 possible to transparently use the "set sysroot" and "set
1671 solib-search-path" on Unix hosts to point as host copies of the
1672 target's shared libraries. See the new command "set
1673 target-file-system-kind" described below, and the "Commands to
1674 specify files" section in the user manual for more information.
1678 eval template, expressions...
1679 Convert the values of one or more expressions under the control
1680 of the string template to a command line, and call it.
1682 set target-file-system-kind unix|dos-based|auto
1683 show target-file-system-kind
1684 Set or show the assumed file system kind for target reported file
1687 save breakpoints <filename>
1688 Save all current breakpoint definitions to a file suitable for use
1689 in a later debugging session. To read the saved breakpoint
1690 definitions, use the `source' command.
1692 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1695 info static-tracepoint-markers
1696 Display information about static tracepoint markers in the target.
1698 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1699 Define a static tracepoint by probing a marker at the given
1700 function, line, address, or marker ID.
1704 Enable and disable observer mode.
1706 set may-write-registers on|off
1707 set may-write-memory on|off
1708 set may-insert-breakpoints on|off
1709 set may-insert-tracepoints on|off
1710 set may-insert-fast-tracepoints on|off
1711 set may-interrupt on|off
1712 Set individual permissions for GDB effects on the target. Note that
1713 some of these settings can have undesirable or surprising
1714 consequences, particularly when changed in the middle of a session.
1715 For instance, disabling the writing of memory can prevent
1716 breakpoints from being inserted, cause single-stepping to fail, or
1717 even crash your program, if you disable after breakpoints have been
1718 inserted. However, GDB should not crash.
1720 set record memory-query on|off
1721 show record memory-query
1722 Control whether to stop the inferior if memory changes caused
1723 by an instruction cannot be recorded.
1728 The disassemble command now supports "start,+length" form of two arguments.
1732 ** GDB now provides a new directory location, called the python directory,
1733 where Python scripts written for GDB can be installed. The location
1734 of that directory is <data-directory>/python, where <data-directory>
1735 is the GDB data directory. For more details, see section `Scripting
1736 GDB using Python' in the manual.
1738 ** The GDB Python API now has access to breakpoints, symbols, symbol
1739 tables, program spaces, inferiors, threads and frame's code blocks.
1740 Additionally, GDB Parameters can now be created from the API, and
1741 manipulated via set/show in the CLI.
1743 ** New functions gdb.target_charset, gdb.target_wide_charset,
1744 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1746 ** New exception gdb.GdbError.
1748 ** Pretty-printers are now also looked up in the current program space.
1750 ** Pretty-printers can now be individually enabled and disabled.
1752 ** GDB now looks for names of Python scripts to auto-load in a
1753 special section named `.debug_gdb_scripts', in addition to looking
1754 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1756 * Tracepoint actions were unified with breakpoint commands. In particular,
1757 there are no longer differences in "info break" output for breakpoints and
1758 tracepoints and the "commands" command can be used for both tracepoints and
1759 regular breakpoints.
1763 ARM Symbian arm*-*-symbianelf*
1765 * D language support.
1766 GDB now supports debugging programs written in the D programming
1769 * GDB now supports the extended ptrace interface for PowerPC which is
1770 available since Linux kernel version 2.6.34. This automatically enables
1771 any hardware breakpoints and additional hardware watchpoints available in
1772 the processor. The old ptrace interface exposes just one hardware
1773 watchpoint and no hardware breakpoints.
1775 * GDB is now able to use the Data Value Compare (DVC) register available on
1776 embedded PowerPC processors to implement in hardware simple watchpoint
1777 conditions of the form:
1779 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1781 This works in native GDB running on Linux kernels with the extended ptrace
1782 interface mentioned above.
1784 *** Changes in GDB 7.1
1788 ** Namespace Support
1790 GDB now supports importing of namespaces in C++. This enables the
1791 user to inspect variables from imported namespaces. Support for
1792 namepace aliasing has also been added. So, if a namespace is
1793 aliased in the current scope (e.g. namepace C=A; ) the user can
1794 print variables using the alias (e.g. (gdb) print C::x).
1798 All known bugs relating to the printing of virtual base class were
1799 fixed. It is now possible to call overloaded static methods using a
1804 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1805 and reinterpret_cast<> are now handled by the C++ expression parser.
1809 Xilinx MicroBlaze microblaze-*-*
1814 Xilinx MicroBlaze microblaze
1817 * Multi-program debugging.
1819 GDB now has support for multi-program (a.k.a. multi-executable or
1820 multi-exec) debugging. This allows for debugging multiple inferiors
1821 simultaneously each running a different program under the same GDB
1822 session. See "Debugging Multiple Inferiors and Programs" in the
1823 manual for more information. This implied some user visible changes
1824 in the multi-inferior support. For example, "info inferiors" now
1825 lists inferiors that are not running yet or that have exited
1826 already. See also "New commands" and "New options" below.
1828 * New tracing features
1830 GDB's tracepoint facility now includes several new features:
1832 ** Trace state variables
1834 GDB tracepoints now include support for trace state variables, which
1835 are variables managed by the target agent during a tracing
1836 experiment. They are useful for tracepoints that trigger each
1837 other, so for instance one tracepoint can count hits in a variable,
1838 and then a second tracepoint has a condition that is true when the
1839 count reaches a particular value. Trace state variables share the
1840 $-syntax of GDB convenience variables, and can appear in both
1841 tracepoint actions and condition expressions. Use the "tvariable"
1842 command to create, and "info tvariables" to view; see "Trace State
1843 Variables" in the manual for more detail.
1847 GDB now includes an option for defining fast tracepoints, which
1848 targets may implement more efficiently, such as by installing a jump
1849 into the target agent rather than a trap instruction. The resulting
1850 speedup can be by two orders of magnitude or more, although the
1851 tradeoff is that some program locations on some target architectures
1852 might not allow fast tracepoint installation, for instance if the
1853 instruction to be replaced is shorter than the jump. To request a
1854 fast tracepoint, use the "ftrace" command, with syntax identical to
1855 the regular trace command.
1857 ** Disconnected tracing
1859 It is now possible to detach GDB from the target while it is running
1860 a trace experiment, then reconnect later to see how the experiment
1861 is going. In addition, a new variable disconnected-tracing lets you
1862 tell the target agent whether to continue running a trace if the
1863 connection is lost unexpectedly.
1867 GDB now has the ability to save the trace buffer into a file, and
1868 then use that file as a target, similarly to you can do with
1869 corefiles. You can select trace frames, print data that was
1870 collected in them, and use tstatus to display the state of the
1871 tracing run at the moment that it was saved. To create a trace
1872 file, use "tsave <filename>", and to use it, do "target tfile
1875 ** Circular trace buffer
1877 You can ask the target agent to handle the trace buffer as a
1878 circular buffer, discarding the oldest trace frames to make room for
1879 newer ones, by setting circular-trace-buffer to on. This feature may
1880 not be available for all target agents.
1885 The disassemble command, when invoked with two arguments, now requires
1886 the arguments to be comma-separated.
1889 The info variables command now displays variable definitions. Files
1890 which only declare a variable are not shown.
1893 The source command is now capable of sourcing Python scripts.
1894 This feature is dependent on the debugger being build with Python
1897 Related to this enhancement is also the introduction of a new command
1898 "set script-extension" (see below).
1900 * New commands (for set/show, see "New options" below)
1902 record save [<FILENAME>]
1903 Save a file (in core file format) containing the process record
1904 execution log for replay debugging at a later time.
1906 record restore <FILENAME>
1907 Restore the process record execution log that was saved at an
1908 earlier time, for replay debugging.
1910 add-inferior [-copies <N>] [-exec <FILENAME>]
1913 clone-inferior [-copies <N>] [ID]
1914 Make a new inferior ready to execute the same program another
1915 inferior has loaded.
1920 maint info program-spaces
1921 List the program spaces loaded into GDB.
1923 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1924 show remote interrupt-sequence
1925 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1926 as the sequence to the remote target in order to interrupt the execution.
1927 Ctrl-C is a default. Some system prefers BREAK which is high level of
1928 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1929 Magic SysRq g. It is BREAK signal and character 'g'.
1931 set remote interrupt-on-connect [on | off]
1932 show remote interrupt-on-connect
1933 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1934 remote target when gdb connects to it. This is needed when you debug
1937 set remotebreak [on | off]
1939 Deprecated. Use "set/show remote interrupt-sequence" instead.
1941 tvariable $NAME [ = EXP ]
1942 Create or modify a trace state variable.
1945 List trace state variables and their values.
1947 delete tvariable $NAME ...
1948 Delete one or more trace state variables.
1951 Evaluate the given expressions without collecting anything into the
1952 trace buffer. (Valid in tracepoint actions only.)
1954 ftrace FN / FILE:LINE / *ADDR
1955 Define a fast tracepoint at the given function, line, or address.
1957 * New expression syntax
1959 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1960 GDB now parses 0b101010 identically with 42.
1964 set follow-exec-mode new|same
1965 show follow-exec-mode
1966 Control whether GDB reuses the same inferior across an exec call or
1967 creates a new one. This is useful to be able to restart the old
1968 executable after the inferior having done an exec call.
1970 set default-collect EXPR, ...
1971 show default-collect
1972 Define a list of expressions to be collected at each tracepoint.
1973 This is a useful way to ensure essential items are not overlooked,
1974 such as registers or a critical global variable.
1976 set disconnected-tracing
1977 show disconnected-tracing
1978 If set to 1, the target is instructed to continue tracing if it
1979 loses its connection to GDB. If 0, the target is to stop tracing
1982 set circular-trace-buffer
1983 show circular-trace-buffer
1984 If set to on, the target is instructed to use a circular trace buffer
1985 and discard the oldest trace frames instead of stopping the trace due
1986 to a full trace buffer. If set to off, the trace stops when the buffer
1987 fills up. Some targets may not support this.
1989 set script-extension off|soft|strict
1990 show script-extension
1991 If set to "off", the debugger does not perform any script language
1992 recognition, and all sourced files are assumed to be GDB scripts.
1993 If set to "soft" (the default), files are sourced according to
1994 filename extension, falling back to GDB scripts if the first
1996 If set to "strict", files are sourced according to filename extension.
1998 set ada trust-PAD-over-XVS on|off
1999 show ada trust-PAD-over-XVS
2000 If off, activate a workaround against a bug in the debugging information
2001 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2002 the GCC sources for more information about the GNAT encoding and
2003 PAD types in particular). It is always safe to set this option to
2004 off, but this introduces a slight performance penalty. The default
2007 * Python API Improvements
2009 ** GDB provides the new class gdb.LazyString. This is useful in
2010 some pretty-printing cases. The new method gdb.Value.lazy_string
2011 provides a simple way to create objects of this type.
2013 ** The fields returned by gdb.Type.fields now have an
2014 `is_base_class' attribute.
2016 ** The new method gdb.Type.range returns the range of an array type.
2018 ** The new method gdb.parse_and_eval can be used to parse and
2019 evaluate an expression.
2021 * New remote packets
2024 Define a trace state variable.
2027 Get the current value of a trace state variable.
2030 Set desired tracing behavior upon disconnection.
2033 Set the trace buffer to be linear or circular.
2036 Get data about the tracepoints currently in use.
2040 Process record now works correctly with hardware watchpoints.
2042 Multiple bug fixes have been made to the mips-irix port, making it
2043 much more reliable. In particular:
2044 - Debugging threaded applications is now possible again. Previously,
2045 GDB would hang while starting the program, or while waiting for
2046 the program to stop at a breakpoint.
2047 - Attaching to a running process no longer hangs.
2048 - An error occurring while loading a core file has been fixed.
2049 - Changing the value of the PC register now works again. This fixes
2050 problems observed when using the "jump" command, or when calling
2051 a function from GDB, or even when assigning a new value to $pc.
2052 - With the "finish" and "return" commands, the return value for functions
2053 returning a small array is now correctly printed.
2054 - It is now possible to break on shared library code which gets executed
2055 during a shared library init phase (code executed while executing
2056 their .init section). Previously, the breakpoint would have no effect.
2057 - GDB is now able to backtrace through the signal handler for
2058 non-threaded programs.
2060 PIE (Position Independent Executable) programs debugging is now supported.
2061 This includes debugging execution of PIC (Position Independent Code) shared
2062 libraries although for that, it should be possible to run such libraries as an
2065 *** Changes in GDB 7.0
2067 * GDB now has an interface for JIT compilation. Applications that
2068 dynamically generate code can create symbol files in memory and register
2069 them with GDB. For users, the feature should work transparently, and
2070 for JIT developers, the interface is documented in the GDB manual in the
2071 "JIT Compilation Interface" chapter.
2073 * Tracepoints may now be conditional. The syntax is as for
2074 breakpoints; either an "if" clause appended to the "trace" command,
2075 or the "condition" command is available. GDB sends the condition to
2076 the target for evaluation using the same bytecode format as is used
2077 for tracepoint actions.
2079 * The disassemble command now supports: an optional /r modifier, print the
2080 raw instructions in hex as well as in symbolic form, and an optional /m
2081 modifier to print mixed source+assembly.
2083 * Process record and replay
2085 In a architecture environment that supports ``process record and
2086 replay'', ``process record and replay'' target can record a log of
2087 the process execution, and replay it with both forward and reverse
2090 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2091 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2092 set execution-direction {forward|reverse}, for targets that support
2095 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2096 feature is available with a native GDB running on kernel version
2099 * GDB now has support for multi-byte and wide character sets on the
2100 target. Strings whose character type is wchar_t, char16_t, or
2101 char32_t are now correctly printed. GDB supports wide- and unicode-
2102 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2103 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2104 `printf'. This feature requires iconv to work properly; if your
2105 system does not have a working iconv, GDB can use GNU libiconv. See
2106 the installation instructions for more information.
2108 * GDB now supports automatic retrieval of shared library files from
2109 remote targets. To use this feature, specify a system root that begins
2110 with the `remote:' prefix, either via the `set sysroot' command or via
2111 the `--with-sysroot' configure-time option.
2113 * "info sharedlibrary" now takes an optional regex of libraries to show,
2114 and it now reports if a shared library has no debugging information.
2116 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2117 now complete on file names.
2119 * When completing in expressions, gdb will attempt to limit
2120 completions to allowable structure or union fields, where appropriate.
2121 For instance, consider:
2123 # struct example { int f1; double f2; };
2124 # struct example variable;
2127 If the user types TAB at the end of this command line, the available
2128 completions will be "f1" and "f2".
2130 * Inlined functions are now supported. They show up in backtraces, and
2131 the "step", "next", and "finish" commands handle them automatically.
2133 * GDB now supports the token-splicing (##) and stringification (#)
2134 operators when expanding macros. It also supports variable-arity
2137 * GDB now supports inspecting extra signal information, exported by
2138 the new $_siginfo convenience variable. The feature is currently
2139 implemented on linux ARM, i386 and amd64.
2141 * GDB can now display the VFP floating point registers and NEON vector
2142 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2143 can provide these registers (requires Linux 2.6.30 or later). Remote
2144 and simulator targets may also provide them.
2146 * New remote packets
2149 Search memory for a sequence of bytes.
2152 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2153 operation over reliable transport links. Use of this packet is
2154 controlled by the `set remote noack-packet' command.
2157 Kill the process with the specified process ID. Use this in preference
2158 to `k' when multiprocess protocol extensions are supported.
2161 Obtains additional operating system information
2165 Read or write additional signal information.
2167 * Removed remote protocol undocumented extension
2169 An undocumented extension to the remote protocol's `S' stop reply
2170 packet that permited the stub to pass a process id was removed.
2171 Remote servers should use the `T' stop reply packet instead.
2173 * GDB now supports multiple function calling conventions according to the
2174 DWARF-2 DW_AT_calling_convention function attribute.
2176 * The SH target utilizes the aforementioned change to distinguish between gcc
2177 and Renesas calling convention. It also adds the new CLI commands
2178 `set/show sh calling-convention'.
2180 * GDB can now read compressed debug sections, as produced by GNU gold
2181 with the --compress-debug-sections=zlib flag.
2183 * 64-bit core files are now supported on AIX.
2185 * Thread switching is now supported on Tru64.
2187 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2188 which will be allocated using malloc later in program execution.
2190 * The qXfer:libraries:read remote procotol packet now allows passing a
2191 list of section offsets.
2193 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2194 conditions handling signals delivered during attach or thread creation
2195 have also been fixed.
2197 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2198 From the user's standpoint, all unqualified instances of True and False
2199 are treated as the standard definitions, regardless of context.
2201 * GDB now parses C++ symbol and type names more flexibly. For
2204 template<typename T> class C { };
2207 GDB will now correctly handle all of:
2209 ptype C<char const *>
2210 ptype C<char const*>
2211 ptype C<const char *>
2212 ptype C<const char*>
2214 * New features in the GDB remote stub, gdbserver
2216 - The "--wrapper" command-line argument tells gdbserver to use a
2217 wrapper program to launch programs for debugging.
2219 - On PowerPC and S/390 targets, it is now possible to use a single
2220 gdbserver executable to debug both 32-bit and 64-bit programs.
2221 (This requires gdbserver itself to be built as a 64-bit executable.)
2223 - gdbserver uses the new noack protocol mode for TCP connections to
2224 reduce communications latency, if also supported and enabled in GDB.
2226 - Support for the sparc64-linux-gnu target is now included in
2229 - The amd64-linux build of gdbserver now supports debugging both
2230 32-bit and 64-bit programs.
2232 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2233 now support hardware watchpoints, and will use them automatically
2238 GDB now has support for scripting using Python. Whether this is
2239 available is determined at configure time.
2241 New GDB commands can now be written in Python.
2243 * Ada tasking support
2245 Ada tasks can now be inspected in GDB. The following commands have
2249 Print the list of Ada tasks.
2251 Print detailed information about task number N.
2253 Print the task number of the current task.
2255 Switch the context of debugging to task number N.
2257 * Support for user-defined prefixed commands. The "define" command can
2258 add new commands to existing prefixes, e.g. "target".
2260 * Multi-inferior, multi-process debugging.
2262 GDB now has generalized support for multi-inferior debugging. See
2263 "Debugging Multiple Inferiors" in the manual for more information.
2264 Although availability still depends on target support, the command
2265 set is more uniform now. The GNU/Linux specific multi-forks support
2266 has been migrated to this new framework. This implied some user
2267 visible changes; see "New commands" and also "Removed commands"
2270 * Target descriptions can now describe the target OS ABI. See the
2271 "Target Description Format" section in the user manual for more
2274 * Target descriptions can now describe "compatible" architectures
2275 to indicate that the target can execute applications for a different
2276 architecture in addition to those for the main target architecture.
2277 See the "Target Description Format" section in the user manual for
2280 * Multi-architecture debugging.
2282 GDB now includes general supports for debugging applications on
2283 hybrid systems that use more than one single processor architecture
2284 at the same time. Each such hybrid architecture still requires
2285 specific support to be added. The only hybrid architecture supported
2286 in this version of GDB is the Cell Broadband Engine.
2288 * GDB now supports integrated debugging of Cell/B.E. applications that
2289 use both the PPU and SPU architectures. To enable support for hybrid
2290 Cell/B.E. debugging, you need to configure GDB to support both the
2291 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2292 --enable-targets configure option.
2294 * Non-stop mode debugging.
2296 For some targets, GDB now supports an optional mode of operation in
2297 which you can examine stopped threads while other threads continue
2298 to execute freely. This is referred to as non-stop mode, with the
2299 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2300 section in the user manual for more information.
2302 To be able to support remote non-stop debugging, a remote stub needs
2303 to implement the non-stop mode remote protocol extensions, as
2304 described in the "Remote Non-Stop" section of the user manual. The
2305 GDB remote stub, gdbserver, has been adjusted to support these
2306 extensions on linux targets.
2308 * New commands (for set/show, see "New options" below)
2310 catch syscall [NAME(S) | NUMBER(S)]
2311 Catch system calls. Arguments, which should be names of system
2312 calls or their numbers, mean catch only those syscalls. Without
2313 arguments, every syscall will be caught. When the inferior issues
2314 any of the specified syscalls, GDB will stop and announce the system
2315 call, both when it is called and when its call returns. This
2316 feature is currently available with a native GDB running on the
2317 Linux Kernel, under the following architectures: x86, x86_64,
2318 PowerPC and PowerPC64.
2320 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2322 Search memory for a sequence of bytes.
2324 maint set python print-stack
2325 maint show python print-stack
2326 Show a stack trace when an error is encountered in a Python script.
2329 Invoke CODE by passing it to the Python interpreter.
2334 These allow macros to be defined, undefined, and listed
2338 Show operating system information about processes.
2341 List the inferiors currently under GDB's control.
2344 Switch focus to inferior number NUM.
2347 Detach from inferior number NUM.
2350 Kill inferior number NUM.
2354 set spu stop-on-load
2355 show spu stop-on-load
2356 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2358 set spu auto-flush-cache
2359 show spu auto-flush-cache
2360 Control whether to automatically flush the software-managed cache
2361 during Cell/B.E. debugging.
2363 set sh calling-convention
2364 show sh calling-convention
2365 Control the calling convention used when calling SH target functions.
2368 show debug timestamp
2369 Control display of timestamps with GDB debugging output.
2371 set disassemble-next-line
2372 show disassemble-next-line
2373 Control display of disassembled source lines or instructions when
2376 set remote noack-packet
2377 show remote noack-packet
2378 Set/show the use of remote protocol QStartNoAckMode packet. See above
2379 under "New remote packets."
2381 set remote query-attached-packet
2382 show remote query-attached-packet
2383 Control use of remote protocol `qAttached' (query-attached) packet.
2385 set remote read-siginfo-object
2386 show remote read-siginfo-object
2387 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2390 set remote write-siginfo-object
2391 show remote write-siginfo-object
2392 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2395 set remote reverse-continue
2396 show remote reverse-continue
2397 Control use of remote protocol 'bc' (reverse-continue) packet.
2399 set remote reverse-step
2400 show remote reverse-step
2401 Control use of remote protocol 'bs' (reverse-step) packet.
2403 set displaced-stepping
2404 show displaced-stepping
2405 Control displaced stepping mode. Displaced stepping is a way to
2406 single-step over breakpoints without removing them from the debuggee.
2407 Also known as "out-of-line single-stepping".
2410 show debug displaced
2411 Control display of debugging info for displaced stepping.
2413 maint set internal-error
2414 maint show internal-error
2415 Control what GDB does when an internal error is detected.
2417 maint set internal-warning
2418 maint show internal-warning
2419 Control what GDB does when an internal warning is detected.
2424 Use a wrapper program to launch programs for debugging.
2426 set multiple-symbols (all|ask|cancel)
2427 show multiple-symbols
2428 The value of this variable can be changed to adjust the debugger behavior
2429 when an expression or a breakpoint location contains an ambiguous symbol
2430 name (an overloaded function name, for instance).
2432 set breakpoint always-inserted
2433 show breakpoint always-inserted
2434 Keep breakpoints always inserted in the target, as opposed to inserting
2435 them when resuming the target, and removing them when the target stops.
2436 This option can improve debugger performance on slow remote targets.
2438 set arm fallback-mode (arm|thumb|auto)
2439 show arm fallback-mode
2440 set arm force-mode (arm|thumb|auto)
2442 These commands control how ARM GDB determines whether instructions
2443 are ARM or Thumb. The default for both settings is auto, which uses
2444 the current CPSR value for instructions without symbols; previous
2445 versions of GDB behaved as if "set arm fallback-mode arm".
2447 set disable-randomization
2448 show disable-randomization
2449 Standalone programs run with the virtual address space randomization enabled
2450 by default on some platforms. This option keeps the addresses stable across
2451 multiple debugging sessions.
2455 Control whether other threads are stopped or not when some thread hits
2460 Requests that asynchronous execution is enabled in the target, if available.
2461 In this case, it's possible to resume target in the background, and interact
2462 with GDB while the target is running. "show target-async" displays the
2463 current state of asynchronous execution of the target.
2465 set target-wide-charset
2466 show target-wide-charset
2467 The target-wide-charset is the name of the character set that GDB
2468 uses when printing characters whose type is wchar_t.
2470 set tcp auto-retry (on|off)
2472 set tcp connect-timeout
2473 show tcp connect-timeout
2474 These commands allow GDB to retry failed TCP connections to a remote stub
2475 with a specified timeout period; this is useful if the stub is launched
2476 in parallel with GDB but may not be ready to accept connections immediately.
2478 set libthread-db-search-path
2479 show libthread-db-search-path
2480 Control list of directories which GDB will search for appropriate
2483 set schedule-multiple (on|off)
2484 show schedule-multiple
2485 Allow GDB to resume all threads of all processes or only threads of
2486 the current process.
2490 Use more aggressive caching for accesses to the stack. This improves
2491 performance of remote debugging (particularly backtraces) without
2492 affecting correctness.
2494 set interactive-mode (on|off|auto)
2495 show interactive-mode
2496 Control whether GDB runs in interactive mode (on) or not (off).
2497 When in interactive mode, GDB waits for the user to answer all
2498 queries. Otherwise, GDB does not wait and assumes the default
2499 answer. When set to auto (the default), GDB determines which
2500 mode to use based on the stdin settings.
2505 For program forks, this is replaced by the new more generic `info
2506 inferiors' command. To list checkpoints, you can still use the
2507 `info checkpoints' command, which was an alias for the `info forks'
2511 Replaced by the new `inferior' command. To switch between
2512 checkpoints, you can still use the `restart' command, which was an
2513 alias for the `fork' command.
2516 This is removed, since some targets don't have a notion of
2517 processes. To switch between processes, you can still use the
2518 `inferior' command using GDB's own inferior number.
2521 For program forks, this is replaced by the new more generic `kill
2522 inferior' command. To delete a checkpoint, you can still use the
2523 `delete checkpoint' command, which was an alias for the `delete
2527 For program forks, this is replaced by the new more generic `detach
2528 inferior' command. To detach a checkpoint, you can still use the
2529 `detach checkpoint' command, which was an alias for the `detach
2532 * New native configurations
2534 x86/x86_64 Darwin i[34567]86-*-darwin*
2536 x86_64 MinGW x86_64-*-mingw*
2540 Lattice Mico32 lm32-*
2541 x86 DICOS i[34567]86-*-dicos*
2542 x86_64 DICOS x86_64-*-dicos*
2545 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2546 (mingw32ce) debugging.
2552 These commands were actually not implemented on any target.
2554 *** Changes in GDB 6.8
2556 * New native configurations
2558 NetBSD/hppa hppa*-*netbsd*
2559 Xtensa GNU/Linux xtensa*-*-linux*
2563 NetBSD/hppa hppa*-*-netbsd*
2564 Xtensa GNU/Lunux xtensa*-*-linux*
2566 * Change in command line behavior -- corefiles vs. process ids.
2568 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2569 attaching to process NUMBER fails, GDB no longer attempts to open a
2570 core file named NUMBER. Attaching to a program using the -c option
2571 is no longer supported. Instead, use the '-p' or '--pid' options.
2573 * GDB can now be built as a native debugger for debugging Windows x86
2574 (mingw32) Portable Executable (PE) programs.
2576 * Pending breakpoints no longer change their number when their address
2579 * GDB now supports breakpoints with multiple locations,
2580 including breakpoints on C++ constructors, inside C++ templates,
2581 and in inlined functions.
2583 * GDB's ability to debug optimized code has been improved. GDB more
2584 accurately identifies function bodies and lexical blocks that occupy
2585 more than one contiguous range of addresses.
2587 * Target descriptions can now describe registers for PowerPC.
2589 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2590 registers on PowerPC targets.
2592 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2593 targets even when the libthread_db library is not available.
2595 * The GDB remote stub, gdbserver, now supports the new file transfer
2596 commands (remote put, remote get, and remote delete).
2598 * The GDB remote stub, gdbserver, now supports run and attach in
2599 extended-remote mode.
2601 * hppa*64*-*-hpux11* target broken
2602 The debugger is unable to start a program and fails with the following
2603 error: "Error trying to get information about dynamic linker".
2604 The gdb-6.7 release is also affected.
2606 * GDB now supports the --enable-targets= configure option to allow
2607 building a single GDB executable that supports multiple remote
2608 target architectures.
2610 * GDB now supports debugging C and C++ programs which use the
2611 Decimal Floating Point extension. In addition, the PowerPC target
2612 now has a set of pseudo-registers to inspect decimal float values
2613 stored in two consecutive float registers.
2615 * The -break-insert MI command can optionally create pending
2618 * Improved support for debugging Ada
2619 Many improvements to the Ada language support have been made. These
2621 - Better support for Ada2005 interface types
2622 - Improved handling of arrays and slices in general
2623 - Better support for Taft-amendment types
2624 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2626 - Improved command completion in Ada
2629 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2634 set print frame-arguments (all|scalars|none)
2635 show print frame-arguments
2636 The value of this variable can be changed to control which argument
2637 values should be printed by the debugger when displaying a frame.
2642 Transfer files to and from a remote target, and delete remote files.
2649 Transfer files to and from a remote target, and delete remote files.
2651 * New remote packets
2658 Open, close, read, write, and delete files on the remote system.
2661 Attach to an existing process on the remote system, in extended-remote
2665 Run a new process on the remote system, in extended-remote mode.
2667 *** Changes in GDB 6.7
2669 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2670 bfd, libiberty and opcodes, as revealed by static analysis donated by
2671 Coverity, Inc. (http://scan.coverity.com).
2673 * When looking up multiply-defined global symbols, GDB will now prefer the
2674 symbol definition in the current shared library if it was built using the
2675 -Bsymbolic linker option.
2677 * When the Text User Interface (TUI) is not configured, GDB will now
2678 recognize the -tui command-line option and print a message that the TUI
2681 * The GDB remote stub, gdbserver, now has lower overhead for high
2682 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2684 * GDB for MIPS targets now autodetects whether a remote target provides
2685 32-bit or 64-bit register values.
2687 * Support for C++ member pointers has been improved.
2689 * GDB now understands XML target descriptions, which specify the
2690 target's overall architecture. GDB can read a description from
2691 a local file or over the remote serial protocol.
2693 * Vectors of single-byte data use a new integer type which is not
2694 automatically displayed as character or string data.
2696 * The /s format now works with the print command. It displays
2697 arrays of single-byte integers and pointers to single-byte integers
2700 * Target descriptions can now describe target-specific registers,
2701 for architectures which have implemented the support (currently
2702 only ARM, M68K, and MIPS).
2704 * GDB and the GDB remote stub, gdbserver, now support the XScale
2707 * The GDB remote stub, gdbserver, has been updated to support
2708 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2709 has been rewritten to use the standard GDB remote protocol.
2711 * GDB can now step into C++ functions which are called through thunks.
2713 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2715 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2716 layout. It also supports a TextSeg= and DataSeg= response when only
2717 segment base addresses (rather than offsets) are available.
2719 * The /i format now outputs any trailing branch delay slot instructions
2720 immediately following the last instruction within the count specified.
2722 * The GDB remote protocol "T" stop reply packet now supports a
2723 "library" response. Combined with the new "qXfer:libraries:read"
2724 packet, this response allows GDB to debug shared libraries on targets
2725 where the operating system manages the list of loaded libraries (e.g.
2726 Windows and SymbianOS).
2728 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2729 (DLLs) on Windows and Windows CE targets.
2731 * GDB now supports a faster verification that a .debug file matches its binary
2732 according to its build-id signature, if the signature is present.
2738 Enable or disable hardware flow control (RTS/CTS) on the serial port
2739 when debugging using remote targets.
2741 set mem inaccessible-by-default
2742 show mem inaccessible-by-default
2743 If the target supplies a memory map, for instance via the remote
2744 protocol's "qXfer:memory-map:read" packet, setting this variable
2745 prevents GDB from accessing memory outside the memory map. This
2746 is useful for targets with memory mapped registers or which react
2747 badly to accesses of unmapped address space.
2749 set breakpoint auto-hw
2750 show breakpoint auto-hw
2751 If the target supplies a memory map, for instance via the remote
2752 protocol's "qXfer:memory-map:read" packet, setting this variable
2753 lets GDB use hardware breakpoints automatically for memory regions
2754 where it can not use software breakpoints. This covers both the
2755 "break" command and internal breakpoints used for other commands
2756 including "next" and "finish".
2759 catch exception unhandled
2760 Stop the program execution when Ada exceptions are raised.
2763 Stop the program execution when an Ada assertion failed.
2767 Set an alternate system root for target files. This is a more
2768 general version of "set solib-absolute-prefix", which is now
2769 an alias to "set sysroot".
2772 Provide extended SPU facility status information. This set of
2773 commands is available only when debugging the Cell/B.E. SPU
2776 * New native configurations
2778 OpenBSD/sh sh*-*openbsd*
2781 unset tdesc filename
2783 Use the specified local file as an XML target description, and do
2784 not query the target for its built-in description.
2788 OpenBSD/sh sh*-*-openbsd*
2789 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2790 Toshiba Media Processor mep-elf
2792 * New remote packets
2795 Ignore the specified signals; pass them directly to the debugged program
2796 without stopping other threads or reporting them to GDB.
2798 qXfer:features:read:
2799 Read an XML target description from the target, which describes its
2804 Read or write contents of an spufs file on the target system. These
2805 packets are available only on the Cell/B.E. SPU architecture.
2807 qXfer:libraries:read:
2808 Report the loaded shared libraries. Combined with new "T" packet
2809 response, this packet allows GDB to debug shared libraries on
2810 targets where the operating system manages the list of loaded
2811 libraries (e.g. Windows and SymbianOS).
2815 Support for these obsolete configurations has been removed.
2823 i[34567]86-*-lynxos*
2824 i[34567]86-*-netware*
2825 i[34567]86-*-sco3.2v5*
2826 i[34567]86-*-sco3.2v4*
2828 i[34567]86-*-sysv4.2*
2831 i[34567]86-*-unixware2*
2832 i[34567]86-*-unixware*
2841 * Other removed features
2848 Various m68k-only ROM monitors.
2855 Various Renesas ROM monitors and debugging interfaces for SH and
2860 Support for a Macraigor serial interface to on-chip debugging.
2861 GDB does not directly support the newer parallel or USB
2866 A debug information format. The predecessor to DWARF 2 and
2867 DWARF 3, which are still supported.
2869 Support for the HP aCC compiler on HP-UX/PA-RISC
2871 SOM-encapsulated symbolic debugging information, automatic
2872 invocation of pxdb, and the aCC custom C++ ABI. This does not
2873 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2874 with aCC can still be debugged on an assembly level.
2876 MIPS ".pdr" sections
2878 A MIPS-specific format used to describe stack frame layout
2879 in debugging information.
2883 GDB could work with an older version of Guile to debug
2884 the interpreter and Scheme programs running in it.
2886 set mips stack-arg-size
2887 set mips saved-gpreg-size
2889 Use "set mips abi" to control parameter passing for MIPS.
2891 *** Changes in GDB 6.6
2896 Cell Broadband Engine SPU spu-elf
2898 * GDB can now be configured as a cross-debugger targeting native Windows
2899 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2900 running on a Windows system over TCP/IP to debug Windows programs.
2902 * The GDB remote stub, gdbserver, has been updated to support Windows and
2903 Cygwin debugging. Both single-threaded and multi-threaded programs are
2906 * The "set trust-readonly-sections" command works again. This command was
2907 broken in GDB 6.3, 6.4, and 6.5.
2909 * The "load" command now supports writing to flash memory, if the remote
2910 stub provides the required support.
2912 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2913 longer requires symbolic debug information (e.g. DWARF-2).
2918 unset substitute-path
2919 show substitute-path
2920 Manage a list of substitution rules that GDB uses to rewrite the name
2921 of the directories where the sources are located. This can be useful
2922 for instance when the sources were moved to a different location
2923 between compilation and debugging.
2927 Print each CLI command as it is executed. Each command is prefixed with
2928 a number of `+' symbols representing the nesting depth.
2929 The source command now has a `-v' option to enable the same feature.
2933 The ARM Demon monitor support (RDP protocol, "target rdp").
2935 Kernel Object Display, an embedded debugging feature which only worked with
2936 an obsolete version of Cisco IOS.
2938 The 'set download-write-size' and 'show download-write-size' commands.
2940 * New remote packets
2943 Tell a stub about GDB client features, and request remote target features.
2944 The first feature implemented is PacketSize, which allows the target to
2945 specify the size of packets it can handle - to minimize the number of
2946 packets required and improve performance when connected to a remote
2950 Fetch an OS auxilliary vector from the remote stub. This packet is a
2951 more efficient replacement for qPart:auxv:read.
2953 qXfer:memory-map:read:
2954 Fetch a memory map from the remote stub, including information about
2955 RAM, ROM, and flash memory devices.
2960 Erase and program a flash memory device.
2962 * Removed remote packets
2965 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2966 used it, and only gdbserver implemented it.
2968 *** Changes in GDB 6.5
2972 Renesas M32C/M16C m32c-elf
2974 Morpho Technologies ms1 ms1-elf
2978 init-if-undefined Initialize a convenience variable, but
2979 only if it doesn't already have a value.
2981 The following commands are presently only implemented for native GNU/Linux:
2983 checkpoint Save a snapshot of the program state.
2985 restart <n> Return the program state to a
2986 previously saved state.
2988 info checkpoints List currently saved checkpoints.
2990 delete-checkpoint <n> Delete a previously saved checkpoint.
2992 set|show detach-on-fork Tell gdb whether to detach from a newly
2993 forked process, or to keep debugging it.
2995 info forks List forks of the user program that
2996 are available to be debugged.
2998 fork <n> Switch to debugging one of several
2999 forks of the user program that are
3000 available to be debugged.
3002 delete-fork <n> Delete a fork from the list of forks
3003 that are available to be debugged (and
3004 kill the forked process).
3006 detach-fork <n> Delete a fork from the list of forks
3007 that are available to be debugged (and
3008 allow the process to continue).
3012 Morpho Technologies ms2 ms1-elf
3014 * Improved Windows host support
3016 GDB now builds as a cross debugger hosted on i686-mingw32, including
3017 native console support, and remote communications using either
3018 network sockets or serial ports.
3020 * Improved Modula-2 language support
3022 GDB can now print most types in the Modula-2 syntax. This includes:
3023 basic types, set types, record types, enumerated types, range types,
3024 pointer types and ARRAY types. Procedure var parameters are correctly
3025 printed and hexadecimal addresses and character constants are also
3026 written in the Modula-2 syntax. Best results can be obtained by using
3027 GNU Modula-2 together with the -gdwarf-2 command line option.
3031 The ARM rdi-share module.
3033 The Netware NLM debug server.
3035 *** Changes in GDB 6.4
3037 * New native configurations
3039 OpenBSD/arm arm*-*-openbsd*
3040 OpenBSD/mips64 mips64-*-openbsd*
3044 Morpho Technologies ms1 ms1-elf
3046 * New command line options
3048 --batch-silent As for --batch, but totally silent.
3049 --return-child-result The debugger will exist with the same value
3050 the child (debugged) program exited with.
3051 --eval-command COMMAND, -ex COMMAND
3052 Execute a single GDB CLI command. This may be
3053 specified multiple times and in conjunction
3054 with the --command (-x) option.
3056 * Deprecated commands removed
3058 The following commands, that were deprecated in 2000, have been
3062 set|show arm disassembly-flavor set|show arm disassembler
3063 othernames set arm disassembler
3064 set|show remotedebug set|show debug remote
3065 set|show archdebug set|show debug arch
3066 set|show eventdebug set|show debug event
3069 * New BSD user-level threads support
3071 It is now possible to debug programs using the user-level threads
3072 library on OpenBSD and FreeBSD. Currently supported (target)
3075 FreeBSD/amd64 x86_64-*-freebsd*
3076 FreeBSD/i386 i386-*-freebsd*
3077 OpenBSD/i386 i386-*-openbsd*
3079 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3080 are not yet supported.
3082 * New support for Matsushita MN10300 w/sim added
3083 (Work in progress). mn10300-elf.
3085 * REMOVED configurations and files
3087 VxWorks and the XDR protocol *-*-vxworks
3088 Motorola MCORE mcore-*-*
3089 National Semiconductor NS32000 ns32k-*-*
3091 * New "set print array-indexes" command
3093 After turning this setting "on", GDB prints the index of each element
3094 when displaying arrays. The default is "off" to preserve the previous
3097 * VAX floating point support
3099 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3101 * User-defined command support
3103 In addition to using $arg0..$arg9 for argument passing, it is now possible
3104 to use $argc to determine now many arguments have been passed. See the
3105 section on user-defined commands in the user manual for more information.
3107 *** Changes in GDB 6.3:
3109 * New command line option
3111 GDB now accepts -l followed by a number to set the timeout for remote
3114 * GDB works with GCC -feliminate-dwarf2-dups
3116 GDB now supports a more compact representation of DWARF-2 debug
3117 information using DW_FORM_ref_addr references. These are produced
3118 by GCC with the option -feliminate-dwarf2-dups and also by some
3119 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3120 to use -feliminate-dwarf2-dups.
3122 * Internationalization
3124 When supported by the host system, GDB will be built with
3125 internationalization (libintl). The task of marking up the sources is
3126 continued, we're looking forward to our first translation.
3130 Initial support for debugging programs compiled with the GNAT
3131 implementation of the Ada programming language has been integrated
3132 into GDB. In this release, support is limited to expression evaluation.
3134 * New native configurations
3136 GNU/Linux/m32r m32r-*-linux-gnu
3140 GDB's remote protocol now includes support for the 'p' packet. This
3141 packet is used to fetch individual registers from a remote inferior.
3143 * END-OF-LIFE registers[] compatibility module
3145 GDB's internal register infrastructure has been completely rewritten.
3146 The new infrastructure making possible the implementation of key new
3147 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3150 GDB 6.3 will be the last release to include the the registers[]
3151 compatibility module that allowed out-of-date configurations to
3152 continue to work. This change directly impacts the following
3162 powerpc bdm protocol
3164 Unless there is activity to revive these configurations, they will be
3165 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3167 * OBSOLETE configurations and files
3169 Configurations that have been declared obsolete in this release have
3170 been commented out. Unless there is activity to revive these
3171 configurations, the next release of GDB will have their sources
3172 permanently REMOVED.
3181 *** Changes in GDB 6.2.1:
3183 * MIPS `break main; run' gave an heuristic-fence-post warning
3185 When attempting to run even a simple program, a warning about
3186 heuristic-fence-post being hit would be reported. This problem has
3189 * MIPS IRIX 'long double' crashed GDB
3191 When examining a long double variable, GDB would get a segmentation
3192 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3193 IRIX long double values).
3197 A bug in the VAX stack code was causing problems with the "next"
3198 command. This problem has been fixed.
3200 *** Changes in GDB 6.2:
3202 * Fix for ``many threads''
3204 On GNU/Linux systems that use the NPTL threads library, a program
3205 rapidly creating and deleting threads would confuse GDB leading to the
3208 ptrace: No such process.
3209 thread_db_get_info: cannot get thread info: generic error
3211 This problem has been fixed.
3213 * "-async" and "-noasync" options removed.
3215 Support for the broken "-noasync" option has been removed (it caused
3218 * New ``start'' command.
3220 This command runs the program until the begining of the main procedure.
3222 * New BSD Kernel Data Access Library (libkvm) interface
3224 Using ``target kvm'' it is now possible to debug kernel core dumps and
3225 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3226 platforms. Currently supported (native-only) configurations are:
3228 FreeBSD/amd64 x86_64-*-freebsd*
3229 FreeBSD/i386 i?86-*-freebsd*
3230 NetBSD/i386 i?86-*-netbsd*
3231 NetBSD/m68k m68*-*-netbsd*
3232 NetBSD/sparc sparc-*-netbsd*
3233 OpenBSD/amd64 x86_64-*-openbsd*
3234 OpenBSD/i386 i?86-*-openbsd*
3235 OpenBSD/m68k m68*-openbsd*
3236 OpenBSD/sparc sparc-*-openbsd*
3238 * Signal trampoline code overhauled
3240 Many generic problems with GDB's signal handling code have been fixed.
3241 These include: backtraces through non-contiguous stacks; recognition
3242 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3243 call; backtrace through a signal trampoline; step into and out of
3244 signal handlers; and single-stepping in the signal trampoline.
3246 Please note that kernel bugs are a limiting factor here. These
3247 features have been shown to work on an s390 GNU/Linux system that
3248 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3250 * Cygwin support for DWARF 2 added.
3252 * New native configurations
3254 GNU/Linux/hppa hppa*-*-linux*
3255 OpenBSD/hppa hppa*-*-openbsd*
3256 OpenBSD/m68k m68*-*-openbsd*
3257 OpenBSD/m88k m88*-*-openbsd*
3258 OpenBSD/powerpc powerpc-*-openbsd*
3259 NetBSD/vax vax-*-netbsd*
3260 OpenBSD/vax vax-*-openbsd*
3262 * END-OF-LIFE frame compatibility module
3264 GDB's internal frame infrastructure has been completely rewritten.
3265 The new infrastructure making it possible to support key new features
3266 including DWARF 2 Call Frame Information. To aid in the task of
3267 migrating old configurations to this new infrastructure, a
3268 compatibility module, that allowed old configurations to continue to
3269 work, was also included.
3271 GDB 6.2 will be the last release to include this frame compatibility
3272 module. This change directly impacts the following configurations:
3282 Unless there is activity to revive these configurations, they will be
3283 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3285 * REMOVED configurations and files
3287 Sun 3, running SunOS 3 m68*-*-sunos3*
3288 Sun 3, running SunOS 4 m68*-*-sunos4*
3289 Sun 2, running SunOS 3 m68000-*-sunos3*
3290 Sun 2, running SunOS 4 m68000-*-sunos4*
3291 Motorola 680x0 running LynxOS m68*-*-lynxos*
3292 AT&T 3b1/Unix pc m68*-att-*
3293 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3294 decstation mips-dec-* mips-little-*
3295 riscos mips-*-riscos* mips-*-sysv*
3296 sonymips mips-sony-*
3297 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3299 *** Changes in GDB 6.1.1:
3301 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3303 The TUI (Text-mode User Interface) is now built as part of a default
3304 GDB configuration. It is enabled by either selecting the TUI with the
3305 command line option "-i=tui" or by running the separate "gdbtui"
3306 program. For more information on the TUI, see the manual "Debugging
3309 * Pending breakpoint support (also included in GDB 6.1)
3311 Support has been added to allow you to specify breakpoints in shared
3312 libraries that have not yet been loaded. If a breakpoint location
3313 cannot be found, and the "breakpoint pending" option is set to auto,
3314 GDB queries you if you wish to make the breakpoint pending on a future
3315 shared-library load. If and when GDB resolves the breakpoint symbol,
3316 the pending breakpoint is removed as one or more regular breakpoints
3319 Pending breakpoints are very useful for GCJ Java debugging.
3321 * Fixed ISO-C build problems
3323 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3324 non ISO-C code that stopped them being built using a more strict ISO-C
3325 compiler (e.g., IBM's C compiler).
3327 * Fixed build problem on IRIX 5
3329 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3330 wasn't able to compile compile on an IRIX 5 system.
3332 * Added execute permission to gdb/gdbserver/configure
3334 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3335 permission. This bug would cause configure to fail on a number of
3336 systems (Solaris, IRIX). Ref: server/519.
3338 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3340 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3341 has been updated to use constant array sizes.
3343 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3345 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3346 its generated DWARF Call Frame Info. This encoding was causing GDB to
3347 panic, that panic has been fixed. Ref: gdb/1628.
3349 * Fixed a problem when examining parameters in shared library code.
3351 When examining parameters in optimized shared library code generated
3352 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3353 not available''. GDB now correctly displays the variable's value.
3355 *** Changes in GDB 6.1:
3357 * Removed --with-mmalloc
3359 Support for the mmalloc memory manager has been removed, as it
3360 conflicted with the internal gdb byte cache.
3362 * Changes in AMD64 configurations
3364 The AMD64 target now includes the %cs and %ss registers. As a result
3365 the AMD64 remote protocol has changed; this affects the floating-point
3366 and SSE registers. If you rely on those registers for your debugging,
3367 you should upgrade gdbserver on the remote side.
3369 * Revised SPARC target
3371 The SPARC target has been completely revised, incorporating the
3372 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3373 support for LynxOS and SunOS 4 has been dropped. Calling functions
3374 from within GDB on operating systems with a non-executable stack
3375 (Solaris, OpenBSD) now works.
3379 GDB has a new C++ demangler which does a better job on the mangled
3380 names generated by current versions of g++. It also runs faster, so
3381 with this and other changes gdb should now start faster on large C++
3384 * DWARF 2 Location Expressions
3386 GDB support for location expressions has been extended to support function
3387 arguments and frame bases. Older versions of GDB could crash when they
3390 * C++ nested types and namespaces
3392 GDB's support for nested types and namespaces in C++ has been
3393 improved, especially if you use the DWARF 2 debugging format. (This
3394 is the default for recent versions of GCC on most platforms.)
3395 Specifically, if you have a class "Inner" defined within a class or
3396 namespace "Outer", then GDB realizes that the class's name is
3397 "Outer::Inner", not simply "Inner". This should greatly reduce the
3398 frequency of complaints about not finding RTTI symbols. In addition,
3399 if you are stopped at inside of a function defined within a namespace,
3400 GDB modifies its name lookup accordingly.
3402 * New native configurations
3404 NetBSD/amd64 x86_64-*-netbsd*
3405 OpenBSD/amd64 x86_64-*-openbsd*
3406 OpenBSD/alpha alpha*-*-openbsd*
3407 OpenBSD/sparc sparc-*-openbsd*
3408 OpenBSD/sparc64 sparc64-*-openbsd*
3410 * New debugging protocols
3412 M32R with SDI protocol m32r-*-elf*
3414 * "set prompt-escape-char" command deleted.
3416 The command "set prompt-escape-char" has been deleted. This command,
3417 and its very obscure effet on GDB's prompt, was never documented,
3418 tested, nor mentioned in the NEWS file.
3420 * OBSOLETE configurations and files
3422 Configurations that have been declared obsolete in this release have
3423 been commented out. Unless there is activity to revive these
3424 configurations, the next release of GDB will have their sources
3425 permanently REMOVED.
3427 Sun 3, running SunOS 3 m68*-*-sunos3*
3428 Sun 3, running SunOS 4 m68*-*-sunos4*
3429 Sun 2, running SunOS 3 m68000-*-sunos3*
3430 Sun 2, running SunOS 4 m68000-*-sunos4*
3431 Motorola 680x0 running LynxOS m68*-*-lynxos*
3432 AT&T 3b1/Unix pc m68*-att-*
3433 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3434 decstation mips-dec-* mips-little-*
3435 riscos mips-*-riscos* mips-*-sysv*
3436 sonymips mips-sony-*
3437 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3439 * REMOVED configurations and files
3441 SGI Irix-4.x mips-sgi-irix4 or iris4
3442 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3443 Z8000 simulator z8k-zilog-none or z8ksim
3444 Matsushita MN10200 w/simulator mn10200-*-*
3445 H8/500 simulator h8500-hitachi-hms or h8500hms
3446 HP/PA running BSD hppa*-*-bsd*
3447 HP/PA running OSF/1 hppa*-*-osf*
3448 HP/PA Pro target hppa*-*-pro*
3449 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3450 386BSD i[3456]86-*-bsd*
3451 Sequent family i[3456]86-sequent-sysv4*
3452 i[3456]86-sequent-sysv*
3453 i[3456]86-sequent-bsd*
3454 SPARC running LynxOS sparc-*-lynxos*
3455 SPARC running SunOS 4 sparc-*-sunos4*
3456 Tsqware Sparclet sparclet-*-*
3457 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3459 *** Changes in GDB 6.0:
3463 Support for debugging the Objective-C programming language has been
3464 integrated into GDB.
3466 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3468 DWARF 2's Call Frame Information makes available compiler generated
3469 information that more exactly describes the program's run-time stack.
3470 By using this information, GDB is able to provide more robust stack
3473 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3474 have been updated to use a new backtrace mechanism which includes
3475 DWARF 2 CFI support.
3479 GDB's remote protocol has been extended to include support for hosted
3480 file I/O (where the remote target uses GDB's file system). See GDB's
3481 remote protocol documentation for details.
3483 * All targets using the new architecture framework.
3485 All of GDB's targets have been updated to use the new internal
3486 architecture framework. The way is now open for future GDB releases
3487 to include cross-architecture native debugging support (i386 on amd64,
3490 * GNU/Linux's Thread Local Storage (TLS)
3492 GDB now includes support for for the GNU/Linux implementation of
3493 per-thread variables.
3495 * GNU/Linux's Native POSIX Thread Library (NPTL)
3497 GDB's thread code has been updated to work with either the new
3498 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3500 * Separate debug info.
3502 GDB, in conjunction with BINUTILS, now supports a mechanism for
3503 automatically loading debug information from a separate file. Instead
3504 of shipping full debug and non-debug versions of system libraries,
3505 system integrators can now instead ship just the stripped libraries
3506 and optional debug files.
3508 * DWARF 2 Location Expressions
3510 DWARF 2 Location Expressions allow the compiler to more completely
3511 describe the location of variables (even in optimized code) to the
3514 GDB now includes preliminary support for location expressions (support
3515 for DW_OP_piece is still missing).
3519 A number of long standing bugs that caused GDB to die while starting a
3520 Java application have been fixed. GDB's Java support is now
3521 considered "useable".
3523 * GNU/Linux support for fork, vfork, and exec.
3525 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3526 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3529 * GDB supports logging output to a file
3531 There are two new commands, "set logging" and "show logging", which can be
3532 used to capture GDB's output to a file.
3534 * The meaning of "detach" has changed for gdbserver
3536 The "detach" command will now resume the application, as documented. To
3537 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3540 * d10v, m68hc11 `regs' command deprecated
3542 The `info registers' command has been updated so that it displays the
3543 registers using a format identical to the old `regs' command.
3547 A new command, "maint set profile on/off", has been added. This command can
3548 be used to enable or disable profiling while running GDB, to profile a
3549 session or a set of commands. In addition there is a new configure switch,
3550 "--enable-profiling", which will cause GDB to be compiled with profiling
3551 data, for more informative profiling results.
3553 * Default MI syntax changed to "mi2".
3555 The default MI (machine interface) syntax, enabled by the command line
3556 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3557 "mi1", can be enabled by specifying the option "-i=mi1".
3559 Support for the original "mi0" syntax (included in GDB 5.0) has been
3562 Fix for gdb/192: removed extraneous space when displaying frame level.
3563 Fix for gdb/672: update changelist is now output in mi list format.
3564 Fix for gdb/702: a -var-assign that updates the value now shows up
3565 in a subsequent -var-update.
3567 * New native configurations.
3569 FreeBSD/amd64 x86_64-*-freebsd*
3571 * Multi-arched targets.
3573 HP/PA HPUX11 hppa*-*-hpux*
3574 Renesas M32R/D w/simulator m32r-*-elf*
3576 * OBSOLETE configurations and files
3578 Configurations that have been declared obsolete in this release have
3579 been commented out. Unless there is activity to revive these
3580 configurations, the next release of GDB will have their sources
3581 permanently REMOVED.
3583 Z8000 simulator z8k-zilog-none or z8ksim
3584 Matsushita MN10200 w/simulator mn10200-*-*
3585 H8/500 simulator h8500-hitachi-hms or h8500hms
3586 HP/PA running BSD hppa*-*-bsd*
3587 HP/PA running OSF/1 hppa*-*-osf*
3588 HP/PA Pro target hppa*-*-pro*
3589 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3590 Sequent family i[3456]86-sequent-sysv4*
3591 i[3456]86-sequent-sysv*
3592 i[3456]86-sequent-bsd*
3593 Tsqware Sparclet sparclet-*-*
3594 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3596 * REMOVED configurations and files
3599 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3600 IBM AIX PS/2 i[3456]86-*-aix
3601 i386 running Mach 3.0 i[3456]86-*-mach3*
3602 i386 running Mach i[3456]86-*-mach*
3603 i386 running OSF/1 i[3456]86-*osf1mk*
3604 HP/Apollo 68k Family m68*-apollo*-sysv*,
3606 m68*-hp-bsd*, m68*-hp-hpux*
3607 Argonaut Risc Chip (ARC) arc-*-*
3608 Mitsubishi D30V d30v-*-*
3609 Fujitsu FR30 fr30-*-elf*
3610 OS/9000 i[34]86-*-os9k
3611 I960 with MON960 i960-*-coff
3613 * MIPS $fp behavior changed
3615 The convenience variable $fp, for the MIPS, now consistently returns
3616 the address of the current frame's base. Previously, depending on the
3617 context, $fp could refer to either $sp or the current frame's base
3618 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3619 The GNU Source-Level Debugger''.
3621 *** Changes in GDB 5.3:
3623 * GNU/Linux shared library multi-threaded performance improved.
3625 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3626 `/proc', in preference to `ptrace' for memory reads. This may result
3627 in an improvement in the start-up time of multi-threaded, shared
3628 library applications when run under GDB. One GDB user writes: ``loads
3629 shared libs like mad''.
3631 * ``gdbserver'' now supports multi-threaded applications on some targets
3633 Support for debugging multi-threaded applications which use
3634 the GNU/Linux LinuxThreads package has been added for
3635 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3636 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3638 * GDB now supports C/C++ preprocessor macros.
3640 GDB now expands preprocessor macro invocations in C/C++ expressions,
3641 and provides various commands for showing macro definitions and how
3644 The new command `macro expand EXPRESSION' expands any macro
3645 invocations in expression, and shows the result.
3647 The new command `show macro MACRO-NAME' shows the definition of the
3648 macro named MACRO-NAME, and where it was defined.
3650 Most compilers don't include information about macros in the debugging
3651 information by default. In GCC 3.1, for example, you need to compile
3652 your program with the options `-gdwarf-2 -g3'. If the macro
3653 information is present in the executable, GDB will read it.
3655 * Multi-arched targets.
3657 DEC Alpha (partial) alpha*-*-*
3658 DEC VAX (partial) vax-*-*
3660 National Semiconductor NS32000 (partial) ns32k-*-*
3661 Motorola 68000 (partial) m68k-*-*
3662 Motorola MCORE mcore-*-*
3666 Fujitsu FRV architecture added by Red Hat frv*-*-*
3669 * New native configurations
3671 Alpha NetBSD alpha*-*-netbsd*
3672 SH NetBSD sh*-*-netbsdelf*
3673 MIPS NetBSD mips*-*-netbsd*
3674 UltraSPARC NetBSD sparc64-*-netbsd*
3676 * OBSOLETE configurations and files
3678 Configurations that have been declared obsolete in this release have
3679 been commented out. Unless there is activity to revive these
3680 configurations, the next release of GDB will have their sources
3681 permanently REMOVED.
3683 Mitsubishi D30V d30v-*-*
3684 OS/9000 i[34]86-*-os9k
3685 IBM AIX PS/2 i[3456]86-*-aix
3686 Fujitsu FR30 fr30-*-elf*
3687 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3688 Argonaut Risc Chip (ARC) arc-*-*
3689 i386 running Mach 3.0 i[3456]86-*-mach3*
3690 i386 running Mach i[3456]86-*-mach*
3691 i386 running OSF/1 i[3456]86-*osf1mk*
3692 HP/Apollo 68k Family m68*-apollo*-sysv*,
3694 m68*-hp-bsd*, m68*-hp-hpux*
3695 I960 with MON960 i960-*-coff
3697 * OBSOLETE languages
3699 CHILL, a Pascal like language used by telecommunications companies.
3701 * REMOVED configurations and files
3703 AMD 29k family via UDI a29k-amd-udi, udi29k
3704 A29K VxWorks a29k-*-vxworks
3705 AMD 29000 embedded, using EBMON a29k-none-none
3706 AMD 29000 embedded with COFF a29k-none-coff
3707 AMD 29000 embedded with a.out a29k-none-aout
3709 testsuite/gdb.hp/gdb.threads-hp/ directory
3711 * New command "set max-user-call-depth <nnn>"
3713 This command allows the user to limit the call depth of user-defined
3714 commands. The default is 1024.
3716 * Changes in FreeBSD/i386 native debugging.
3718 Support for the "generate-core-file" has been added.
3720 * New commands "dump", "append", and "restore".
3722 These commands allow data to be copied from target memory
3723 to a bfd-format or binary file (dump and append), and back
3724 from a file into memory (restore).
3726 * Improved "next/step" support on multi-processor Alpha Tru64.
3728 The previous single-step mechanism could cause unpredictable problems,
3729 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3730 of a software single-step mechanism prevents this.
3732 *** Changes in GDB 5.2.1:
3740 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3741 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3742 Fix, by Joel Brobecker imported from mainline.
3744 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3745 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3746 Fix, by Fred Fish, imported from mainline.
3748 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3749 Surprisingly enough, it works now.
3750 By Michal Ludvig, imported from mainline.
3752 i386 hardware watchpoint support:
3753 avoid misses on second run for some targets.
3754 By Pierre Muller, imported from mainline.
3756 *** Changes in GDB 5.2:
3758 * New command "set trust-readonly-sections on[off]".
3760 This command is a hint that tells gdb that read-only sections
3761 really are read-only (ie. that their contents will not change).
3762 In this mode, gdb will go to the object file rather than the
3763 target to read memory from read-only sections (such as ".text").
3764 This can be a significant performance improvement on some
3765 (notably embedded) targets.
3767 * New command "generate-core-file" (or "gcore").
3769 This new gdb command allows the user to drop a core file of the child
3770 process state at any time. So far it's been implemented only for
3771 GNU/Linux and Solaris, but should be relatively easily ported to other
3772 hosts. Argument is core file name (defaults to core.<pid>).
3774 * New command line option
3776 GDB now accepts --pid or -p followed by a process id.
3778 * Change in command line behavior -- corefiles vs. process ids.
3780 There is a subtle behavior in the way in which GDB handles
3781 command line arguments. The first non-flag argument is always
3782 a program to debug, but the second non-flag argument may either
3783 be a corefile or a process id. Previously, GDB would attempt to
3784 open the second argument as a corefile, and if that failed, would
3785 issue a superfluous error message and then attempt to attach it as
3786 a process. Now, if the second argument begins with a non-digit,
3787 it will be treated as a corefile. If it begins with a digit,
3788 GDB will attempt to attach it as a process, and if no such process
3789 is found, will then attempt to open it as a corefile.
3791 * Changes in ARM configurations.
3793 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3794 configuration is fully multi-arch.
3796 * New native configurations
3798 ARM NetBSD arm*-*-netbsd*
3799 x86 OpenBSD i[3456]86-*-openbsd*
3800 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3801 Sparc64 running FreeBSD sparc64-*-freebsd*
3805 Sanyo XStormy16 xstormy16-elf
3807 * OBSOLETE configurations and files
3809 Configurations that have been declared obsolete in this release have
3810 been commented out. Unless there is activity to revive these
3811 configurations, the next release of GDB will have their sources
3812 permanently REMOVED.
3814 AMD 29k family via UDI a29k-amd-udi, udi29k
3815 A29K VxWorks a29k-*-vxworks
3816 AMD 29000 embedded, using EBMON a29k-none-none
3817 AMD 29000 embedded with COFF a29k-none-coff
3818 AMD 29000 embedded with a.out a29k-none-aout
3820 testsuite/gdb.hp/gdb.threads-hp/ directory
3822 * REMOVED configurations and files
3824 TI TMS320C80 tic80-*-*
3826 PowerPC Solaris powerpcle-*-solaris*
3827 PowerPC Windows NT powerpcle-*-cygwin32
3828 PowerPC Netware powerpc-*-netware*
3829 Harris/CXUX m88k m88*-harris-cxux*
3830 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3831 ns32k-utek-sysv* ns32k-utek-*
3832 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3833 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3834 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3835 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3836 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3838 * Changes to command line processing
3840 The new `--args' feature can be used to specify command-line arguments
3841 for the inferior from gdb's command line.
3843 * Changes to key bindings
3845 There is a new `operate-and-get-next' function bound to `C-o'.
3847 *** Changes in GDB 5.1.1
3849 Fix compile problem on DJGPP.
3851 Fix a problem with floating-point registers on the i386 being
3854 Fix to stop GDB crashing on .debug_str debug info.
3856 Numerous documentation fixes.
3858 Numerous testsuite fixes.
3860 *** Changes in GDB 5.1:
3862 * New native configurations
3864 Alpha FreeBSD alpha*-*-freebsd*
3865 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3866 MIPS GNU/Linux mips*-*-linux*
3867 MIPS SGI Irix 6.x mips*-sgi-irix6*
3868 ia64 AIX ia64-*-aix*
3869 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3873 Motorola 68HC11 and 68HC12 m68hc11-elf
3875 UltraSparc running GNU/Linux sparc64-*-linux*
3877 * OBSOLETE configurations and files
3879 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3880 Harris/CXUX m88k m88*-harris-cxux*
3881 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3882 ns32k-utek-sysv* ns32k-utek-*
3883 TI TMS320C80 tic80-*-*
3885 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3886 PowerPC Solaris powerpcle-*-solaris*
3887 PowerPC Windows NT powerpcle-*-cygwin32
3888 PowerPC Netware powerpc-*-netware*
3889 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3890 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3891 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3892 Apple Macintosh (MPW) host N/A
3894 stuff.c (Program to stuff files into a specially prepared space in kdb)
3895 kdb-start.c (Main loop for the standalone kernel debugger)
3897 Configurations that have been declared obsolete in this release have
3898 been commented out. Unless there is activity to revive these
3899 configurations, the next release of GDB will have their sources
3900 permanently REMOVED.
3902 * REMOVED configurations and files
3904 Altos 3068 m68*-altos-*
3905 Convex c1-*-*, c2-*-*
3907 ARM RISCix arm-*-* (as host)
3911 * GDB has been converted to ISO C.
3913 GDB's source code has been converted to ISO C. In particular, the
3914 sources are fully protoized, and rely on standard headers being
3919 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3921 * The MI enabled by default.
3923 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3924 revised and enabled by default. Packages which use GDB as a debugging
3925 engine behind a UI or another front end are encouraged to switch to
3926 using the GDB/MI interface, instead of the old annotations interface
3927 which is now deprecated.
3929 * Support for debugging Pascal programs.
3931 GDB now includes support for debugging Pascal programs. The following
3932 main features are supported:
3934 - Pascal-specific data types such as sets;
3936 - automatic recognition of Pascal sources based on file-name
3939 - Pascal-style display of data types, variables, and functions;
3941 - a Pascal expression parser.
3943 However, some important features are not yet supported.
3945 - Pascal string operations are not supported at all;
3947 - there are some problems with boolean types;
3949 - Pascal type hexadecimal constants are not supported
3950 because they conflict with the internal variables format;
3952 - support for Pascal objects and classes is not full yet;
3954 - unlike Pascal, GDB is case-sensitive for symbol names.
3956 * Changes in completion.
3958 Commands such as `shell', `run' and `set args', which pass arguments
3959 to inferior programs, now complete on file names, similar to what
3960 users expect at the shell prompt.
3962 Commands which accept locations, such as `disassemble', `print',
3963 `breakpoint', `until', etc. now complete on filenames as well as
3964 program symbols. Thus, if you type "break foob TAB", and the source
3965 files linked into the programs include `foobar.c', that file name will
3966 be one of the candidates for completion. However, file names are not
3967 considered for completion after you typed a colon that delimits a file
3968 name from a name of a function in that file, as in "break foo.c:bar".
3970 `set demangle-style' completes on available demangling styles.
3972 * New platform-independent commands:
3974 It is now possible to define a post-hook for a command as well as a
3975 hook that runs before the command. For more details, see the
3976 documentation of `hookpost' in the GDB manual.
3978 * Changes in GNU/Linux native debugging.
3980 Support for debugging multi-threaded programs has been completely
3981 revised for all platforms except m68k and sparc. You can now debug as
3982 many threads as your system allows you to have.
3984 Attach/detach is supported for multi-threaded programs.
3986 Support for SSE registers was added for x86. This doesn't work for
3987 multi-threaded programs though.
3989 * Changes in MIPS configurations.
3991 Multi-arch support is enabled for all MIPS configurations.
3993 GDB can now be built as native debugger on SGI Irix 6.x systems for
3994 debugging n32 executables. (Debugging 64-bit executables is not yet
3997 * Unified support for hardware watchpoints in all x86 configurations.
3999 Most (if not all) native x86 configurations support hardware-assisted
4000 breakpoints and watchpoints in a unified manner. This support
4001 implements debug register sharing between watchpoints, which allows to
4002 put a virtually infinite number of watchpoints on the same address,
4003 and also supports watching regions up to 16 bytes with several debug
4006 The new maintenance command `maintenance show-debug-regs' toggles
4007 debugging print-outs in functions that insert, remove, and test
4008 watchpoints and hardware breakpoints.
4010 * Changes in the DJGPP native configuration.
4012 New command ``info dos sysinfo'' displays assorted information about
4013 the CPU, OS, memory, and DPMI server.
4015 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4016 display information about segment descriptors stored in GDT, LDT, and
4019 New commands ``info dos pde'' and ``info dos pte'' display entries
4020 from Page Directory and Page Tables (for now works with CWSDPMI only).
4021 New command ``info dos address-pte'' displays the Page Table entry for
4022 a given linear address.
4024 GDB can now pass command lines longer than 126 characters to the
4025 program being debugged (requires an update to the libdbg.a library
4026 which is part of the DJGPP development kit).
4028 DWARF2 debug info is now supported.
4030 It is now possible to `step' and `next' through calls to `longjmp'.
4032 * Changes in documentation.
4034 All GDB documentation was converted to GFDL, the GNU Free
4035 Documentation License.
4037 Tracepoints-related commands are now fully documented in the GDB
4040 TUI, the Text-mode User Interface, is now documented in the manual.
4042 Tracepoints-related commands are now fully documented in the GDB
4045 The "GDB Internals" manual now has an index. It also includes
4046 documentation of `ui_out' functions, GDB coding standards, x86
4047 hardware watchpoints, and memory region attributes.
4049 * GDB's version number moved to ``version.in''
4051 The Makefile variable VERSION has been replaced by the file
4052 ``version.in''. People creating GDB distributions should update the
4053 contents of this file.
4057 GUD support is now a standard part of the EMACS distribution.
4059 *** Changes in GDB 5.0:
4061 * Improved support for debugging FP programs on x86 targets
4063 Unified and much-improved support for debugging floating-point
4064 programs on all x86 targets. In particular, ``info float'' now
4065 displays the FP registers in the same format on all x86 targets, with
4066 greater level of detail.
4068 * Improvements and bugfixes in hardware-assisted watchpoints
4070 It is now possible to watch array elements, struct members, and
4071 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4072 on x86 targets no longer erroneously trigger when the address is
4075 * Improvements in the native DJGPP version of GDB
4077 The distribution now includes all the scripts and auxiliary files
4078 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4079 machines ``out of the box''.
4081 The DJGPP version can now debug programs that use signals. It is
4082 possible to catch signals that happened in the debuggee, deliver
4083 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4084 would kill the program being debugged.) Programs that hook hardware
4085 interrupts (keyboard, timer, etc.) can also be debugged.
4087 It is now possible to debug DJGPP programs that redirect their
4088 standard handles or switch them to raw (as opposed to cooked) mode, or
4089 even close them. The command ``run < foo > bar'' works as expected,
4090 and ``info terminal'' reports useful information about the debuggee's
4091 terminal, including raw/cooked mode, redirection, etc.
4093 The DJGPP version now uses termios functions for console I/O, which
4094 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4097 DOS-style file names with drive letters are now fully supported by
4100 It is now possible to debug DJGPP programs that switch their working
4101 directory. It is also possible to rerun the debuggee any number of
4102 times without restarting GDB; thus, you can use the same setup,
4103 breakpoints, etc. for many debugging sessions.
4105 * New native configurations
4107 ARM GNU/Linux arm*-*-linux*
4108 PowerPC GNU/Linux powerpc-*-linux*
4112 Motorola MCore mcore-*-*
4113 x86 VxWorks i[3456]86-*-vxworks*
4114 PowerPC VxWorks powerpc-*-vxworks*
4115 TI TMS320C80 tic80-*-*
4117 * OBSOLETE configurations
4119 Altos 3068 m68*-altos-*
4120 Convex c1-*-*, c2-*-*
4122 ARM RISCix arm-*-* (as host)
4125 Configurations that have been declared obsolete will be commented out,
4126 but the code will be left in place. If there is no activity to revive
4127 these configurations before the next release of GDB, the sources will
4128 be permanently REMOVED.
4130 * Gould support removed
4132 Support for the Gould PowerNode and NP1 has been removed.
4134 * New features for SVR4
4136 On SVR4 native platforms (such as Solaris), if you attach to a process
4137 without first loading a symbol file, GDB will now attempt to locate and
4138 load symbols from the running process's executable file.
4140 * Many C++ enhancements
4142 C++ support has been greatly improved. Overload resolution now works properly
4143 in almost all cases. RTTI support is on the way.
4145 * Remote targets can connect to a sub-program
4147 A popen(3) style serial-device has been added. This device starts a
4148 sub-process (such as a stand-alone simulator) and then communicates
4149 with that. The sub-program to run is specified using the syntax
4150 ``|<program> <args>'' vis:
4152 (gdb) set remotedebug 1
4153 (gdb) target extended-remote |mn10300-elf-sim program-args
4155 * MIPS 64 remote protocol
4157 A long standing bug in the mips64 remote protocol where by GDB
4158 expected certain 32 bit registers (ex SR) to be transfered as 32
4159 instead of 64 bits has been fixed.
4161 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4162 added to provide backward compatibility with older versions of GDB.
4164 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4166 The command ``set remotebinarydownload'' command has been replaced by
4167 ``set remote X-packet''. Other commands in ``set remote'' family
4168 include ``set remote P-packet''.
4170 * Breakpoint commands accept ranges.
4172 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4173 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4174 ``tracepoint passcount'' also accepts a range of tracepoints.
4176 * ``apropos'' command added.
4178 The ``apropos'' command searches through command names and
4179 documentation strings, printing out matches, making it much easier to
4180 try to find a command that does what you are looking for.
4184 A new machine oriented interface (MI) has been added to GDB. This
4185 interface is designed for debug environments running GDB as a separate
4186 process. This is part of the long term libGDB project. See the
4187 "GDB/MI" chapter of the GDB manual for further information. It can be
4188 enabled by configuring with:
4190 .../configure --enable-gdbmi
4192 *** Changes in GDB-4.18:
4194 * New native configurations
4196 HP-UX 10.20 hppa*-*-hpux10.20
4197 HP-UX 11.x hppa*-*-hpux11.0*
4198 M68K GNU/Linux m68*-*-linux*
4202 Fujitsu FR30 fr30-*-elf*
4203 Intel StrongARM strongarm-*-*
4204 Mitsubishi D30V d30v-*-*
4206 * OBSOLETE configurations
4208 Gould PowerNode, NP1 np1-*-*, pn-*-*
4210 Configurations that have been declared obsolete will be commented out,
4211 but the code will be left in place. If there is no activity to revive
4212 these configurations before the next release of GDB, the sources will
4213 be permanently REMOVED.
4217 As a compatibility experiment, GDB's source files buildsym.h and
4218 buildsym.c have been converted to pure standard C, no longer
4219 containing any K&R compatibility code. We believe that all systems in
4220 use today either come with a standard C compiler, or have a GCC port
4221 available. If this is not true, please report the affected
4222 configuration to bug-gdb@gnu.org immediately. See the README file for
4223 information about getting a standard C compiler if you don't have one
4228 GDB now uses readline 2.2.
4230 * set extension-language
4232 You can now control the mapping between filename extensions and source
4233 languages by using the `set extension-language' command. For instance,
4234 you can ask GDB to treat .c files as C++ by saying
4235 set extension-language .c c++
4236 The command `info extensions' lists all of the recognized extensions
4237 and their associated languages.
4239 * Setting processor type for PowerPC and RS/6000
4241 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4242 you can use the `set processor' command to specify what variant of the
4243 PowerPC family you are debugging. The command
4247 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4248 following PowerPC and RS6000 variants:
4250 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4251 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4253 403GC IBM PowerPC 403GC
4254 505 Motorola PowerPC 505
4255 860 Motorola PowerPC 860 or 850
4256 601 Motorola PowerPC 601
4257 602 Motorola PowerPC 602
4258 603 Motorola/IBM PowerPC 603 or 603e
4259 604 Motorola PowerPC 604 or 604e
4260 750 Motorola/IBM PowerPC 750 or 750
4262 At the moment, this command just tells GDB what to name the
4263 special-purpose processor registers. Since almost all the affected
4264 registers are inaccessible to user-level programs, this command is
4265 only useful for remote debugging in its present form.
4269 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4270 more extensive support for HP-UX. Added features include shared
4271 library support, kernel threads and hardware watchpoints for 11.00,
4272 support for HP's ANSI C and C++ compilers, and a compatibility mode
4273 for xdb and dbx commands.
4277 HP's donation includes the new concept of catchpoints, which is a
4278 generalization of the old catch command. On HP-UX, it is now possible
4279 to catch exec, fork, and vfork, as well as library loading.
4281 This means that the existing catch command has changed; its first
4282 argument now specifies the type of catch to be set up. See the
4283 output of "help catch" for a list of catchpoint types.
4285 * Debugging across forks
4287 On HP-UX, you can choose which process to debug when a fork() happens
4292 HP has donated a curses-based terminal user interface (TUI). To get
4293 it, build with --enable-tui. Although this can be enabled for any
4294 configuration, at present it only works for native HP debugging.
4296 * GDB remote protocol additions
4298 A new protocol packet 'X' that writes binary data is now available.
4299 Default behavior is to try 'X', then drop back to 'M' if the stub
4300 fails to respond. The settable variable `remotebinarydownload'
4301 allows explicit control over the use of 'X'.
4303 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4304 full 64-bit address. The command
4306 set remoteaddresssize 32
4308 can be used to revert to the old behaviour. For existing remote stubs
4309 the change should not be noticed, as the additional address information
4312 In order to assist in debugging stubs, you may use the maintenance
4313 command `packet' to send any text string to the stub. For instance,
4315 maint packet heythere
4317 sends the packet "$heythere#<checksum>". Note that it is very easy to
4318 disrupt a debugging session by sending the wrong packet at the wrong
4321 The compare-sections command allows you to compare section data on the
4322 target to what is in the executable file without uploading or
4323 downloading, by comparing CRC checksums.
4325 * Tracing can collect general expressions
4327 You may now collect general expressions at tracepoints. This requires
4328 further additions to the target-side stub; see tracepoint.c and
4329 doc/agentexpr.texi for further details.
4331 * mask-address variable for Mips
4333 For Mips targets, you may control the zeroing of the upper 32 bits of
4334 a 64-bit address by entering `set mask-address on'. This is mainly
4335 of interest to users of embedded R4xxx and R5xxx processors.
4337 * Higher serial baud rates
4339 GDB's serial code now allows you to specify baud rates 57600, 115200,
4340 230400, and 460800 baud. (Note that your host system may not be able
4341 to achieve all of these rates.)
4345 The i960 configuration now includes an initial implementation of a
4346 builtin simulator, contributed by Jim Wilson.
4349 *** Changes in GDB-4.17:
4351 * New native configurations
4353 Alpha GNU/Linux alpha*-*-linux*
4354 Unixware 2.x i[3456]86-unixware2*
4355 Irix 6.x mips*-sgi-irix6*
4356 PowerPC GNU/Linux powerpc-*-linux*
4357 PowerPC Solaris powerpcle-*-solaris*
4358 Sparc GNU/Linux sparc-*-linux*
4359 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4363 Argonaut Risc Chip (ARC) arc-*-*
4364 Hitachi H8/300S h8300*-*-*
4365 Matsushita MN10200 w/simulator mn10200-*-*
4366 Matsushita MN10300 w/simulator mn10300-*-*
4367 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4368 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4369 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4370 Mitsubishi D10V w/simulator d10v-*-*
4371 Mitsubishi M32R/D w/simulator m32r-*-elf*
4372 Tsqware Sparclet sparclet-*-*
4373 NEC V850 w/simulator v850-*-*
4375 * New debugging protocols
4377 ARM with RDI protocol arm*-*-*
4378 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4379 DDB and LSI variants of PMON protocol mips*-*-*
4380 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4381 PowerPC with SDS protocol powerpc{,le}-*-eabi
4382 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4386 All configurations can now understand and use the DWARF 2 debugging
4387 format. The choice is automatic, if the symbol file contains DWARF 2
4392 GDB now includes basic Java language support. This support is
4393 only useful with Java compilers that produce native machine code.
4395 * solib-absolute-prefix and solib-search-path
4397 For SunOS and SVR4 shared libraries, you may now set the prefix for
4398 loading absolute shared library symbol files, and the search path for
4399 locating non-absolute shared library symbol files.
4401 * Live range splitting
4403 GDB can now effectively debug code for which GCC has performed live
4404 range splitting as part of its optimization. See gdb/doc/LRS for
4405 more details on the expected format of the stabs information.
4409 GDB's support for the GNU Hurd, including thread debugging, has been
4410 updated to work with current versions of the Hurd.
4414 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4415 instruction set. ARM GDB automatically detects when Thumb
4416 instructions are in use, and adjusts disassembly and backtracing
4421 GDB's MIPS target configurations now handle the MIP16 16-bit
4426 GDB now includes support for overlays; if an executable has been
4427 linked such that multiple sections are based at the same address, GDB
4428 will decide which section to use for symbolic info. You can choose to
4429 control the decision manually, using overlay commands, or implement
4430 additional target-side support and use "overlay load-target" to bring
4431 in the overlay mapping. Do "help overlay" for more detail.
4435 The command "info symbol <address>" displays information about
4436 the symbol at the specified address.
4440 The standard remote protocol now includes an extension that allows
4441 asynchronous collection and display of trace data. This requires
4442 extensive support in the target-side debugging stub. Tracing mode
4443 includes a new interaction mode in GDB and new commands: see the
4444 file tracepoint.c for more details.
4448 Configurations for embedded MIPS now include a simulator contributed
4449 by Cygnus Solutions. The simulator supports the instruction sets
4450 of most MIPS variants.
4454 Sparc configurations may now include the ERC32 simulator contributed
4455 by the European Space Agency. The simulator is not built into
4456 Sparc targets by default; configure with --enable-sim to include it.
4460 For target configurations that may include multiple variants of a
4461 basic architecture (such as MIPS and SH), you may now set the
4462 architecture explicitly. "set arch" sets, "info arch" lists
4463 the possible architectures.
4465 *** Changes in GDB-4.16:
4467 * New native configurations
4469 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4470 M68K NetBSD m68k-*-netbsd*
4471 PowerPC AIX 4.x powerpc-*-aix*
4472 PowerPC MacOS powerpc-*-macos*
4473 PowerPC Windows NT powerpcle-*-cygwin32
4474 RS/6000 AIX 4.x rs6000-*-aix4*
4478 ARM with RDP protocol arm-*-*
4479 I960 with MON960 i960-*-coff
4480 MIPS VxWorks mips*-*-vxworks*
4481 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4482 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4484 Matra Sparclet sparclet-*-*
4488 The powerpc-eabi configuration now includes the PSIM simulator,
4489 contributed by Andrew Cagney, with assistance from Mike Meissner.
4490 PSIM is a very elaborate model of the PowerPC, including not only
4491 basic instruction set execution, but also details of execution unit
4492 performance and I/O hardware. See sim/ppc/README for more details.
4496 GDB now works with Solaris 2.5.
4498 * Windows 95/NT native
4500 GDB will now work as a native debugger on Windows 95 and Windows NT.
4501 To build it from source, you must use the "gnu-win32" environment,
4502 which uses a DLL to emulate enough of Unix to run the GNU tools.
4503 Further information, binaries, and sources are available at
4504 ftp.cygnus.com, under pub/gnu-win32.
4506 * dont-repeat command
4508 If a user-defined command includes the command `dont-repeat', then the
4509 command will not be repeated if the user just types return. This is
4510 useful if the command is time-consuming to run, so that accidental
4511 extra keystrokes don't run the same command many times.
4513 * Send break instead of ^C
4515 The standard remote protocol now includes an option to send a break
4516 rather than a ^C to the target in order to interrupt it. By default,
4517 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4519 * Remote protocol timeout
4521 The standard remote protocol includes a new variable `remotetimeout'
4522 that allows you to set the number of seconds before GDB gives up trying
4523 to read from the target. The default value is 2.
4525 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4527 By default GDB will automatically keep track of objects as they are
4528 loaded and unloaded by the dynamic linker. By using the command `set
4529 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4530 when shared library events occur, thus allowing you to set breakpoints
4531 in shared libraries which are explicitly loaded by the inferior.
4533 Note this feature does not work on hpux8. On hpux9 you must link
4534 /usr/lib/end.o into your program. This feature should work
4535 automatically on hpux10.
4537 * Irix 5.x hardware watchpoint support
4539 Irix 5 configurations now support the use of hardware watchpoints.
4541 * Mips protocol "SYN garbage limit"
4543 When debugging a Mips target using the `target mips' protocol, you
4544 may set the number of characters that GDB will ignore by setting
4545 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4546 every character. The default value is 1050.
4548 * Recording and replaying remote debug sessions
4550 If you set `remotelogfile' to the name of a file, gdb will write to it
4551 a recording of a remote debug session. This recording may then be
4552 replayed back to gdb using "gdbreplay". See gdbserver/README for
4553 details. This is useful when you have a problem with GDB while doing
4554 remote debugging; you can make a recording of the session and send it
4555 to someone else, who can then recreate the problem.
4557 * Speedups for remote debugging
4559 GDB includes speedups for downloading and stepping MIPS systems using
4560 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4561 and more efficient S-record downloading.
4563 * Memory use reductions and statistics collection
4565 GDB now uses less memory and reports statistics about memory usage.
4566 Try the `maint print statistics' command, for example.
4568 *** Changes in GDB-4.15:
4570 * Psymtabs for XCOFF
4572 The symbol reader for AIX GDB now uses partial symbol tables. This
4573 can greatly improve startup time, especially for large executables.
4575 * Remote targets use caching
4577 Remote targets now use a data cache to speed up communication with the
4578 remote side. The data cache could lead to incorrect results because
4579 it doesn't know about volatile variables, thus making it impossible to
4580 debug targets which use memory mapped I/O devices. `set remotecache
4581 off' turns the the data cache off.
4583 * Remote targets may have threads
4585 The standard remote protocol now includes support for multiple threads
4586 in the target system, using new protocol commands 'H' and 'T'. See
4587 gdb/remote.c for details.
4591 If GDB is configured with `--enable-netrom', then it will include
4592 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4593 acts as though it is a bank of ROM on the target board, but you can
4594 write into it over the network. GDB's support consists only of
4595 support for fast loading into the emulated ROM; to debug, you must use
4596 another protocol, such as standard remote protocol. The usual
4597 sequence is something like
4599 target nrom <netrom-hostname>
4601 target remote <netrom-hostname>:1235
4605 GDB now includes support for the Apple Macintosh, as a host only. It
4606 may be run as either an MPW tool or as a standalone application, and
4607 it can debug through the serial port. All the usual GDB commands are
4608 available, but to the target command, you must supply "serial" as the
4609 device type instead of "/dev/ttyXX". See mpw-README in the main
4610 directory for more information on how to build. The MPW configuration
4611 scripts */mpw-config.in support only a few targets, and only the
4612 mips-idt-ecoff target has been tested.
4616 GDB configuration now uses autoconf. This is not user-visible,
4617 but does simplify configuration and building.
4621 GDB now supports hpux10.
4623 *** Changes in GDB-4.14:
4625 * New native configurations
4627 x86 FreeBSD i[345]86-*-freebsd
4628 x86 NetBSD i[345]86-*-netbsd
4629 NS32k NetBSD ns32k-*-netbsd
4630 Sparc NetBSD sparc-*-netbsd
4634 A29K VxWorks a29k-*-vxworks
4635 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4636 CPU32 EST-300 emulator m68*-*-est*
4637 PowerPC ELF powerpc-*-elf
4640 * Alpha OSF/1 support for procfs
4642 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4643 possible to attach to running processes. As the mounting of the /proc
4644 filesystem is optional on the Alpha, GDB automatically determines
4645 the availability of /proc during startup. This can lead to problems
4646 if /proc is unmounted after GDB has been started.
4648 * Arguments to user-defined commands
4650 User commands may accept up to 10 arguments separated by whitespace.
4651 Arguments are accessed within the user command via $arg0..$arg9. A
4654 print $arg0 + $arg1 + $arg2
4656 To execute the command use:
4659 Defines the command "adder" which prints the sum of its three arguments.
4660 Note the arguments are text substitutions, so they may reference variables,
4661 use complex expressions, or even perform inferior function calls.
4663 * New `if' and `while' commands
4665 This makes it possible to write more sophisticated user-defined
4666 commands. Both commands take a single argument, which is the
4667 expression to evaluate, and must be followed by the commands to
4668 execute, one per line, if the expression is nonzero, the list being
4669 terminated by the word `end'. The `if' command list may include an
4670 `else' word, which causes the following commands to be executed only
4671 if the expression is zero.
4673 * Fortran source language mode
4675 GDB now includes partial support for Fortran 77. It will recognize
4676 Fortran programs and can evaluate a subset of Fortran expressions, but
4677 variables and functions may not be handled correctly. GDB will work
4678 with G77, but does not yet know much about symbols emitted by other
4681 * Better HPUX support
4683 Most debugging facilities now work on dynamic executables for HPPAs
4684 running hpux9 or later. You can attach to running dynamically linked
4685 processes, but by default the dynamic libraries will be read-only, so
4686 for instance you won't be able to put breakpoints in them. To change
4687 that behavior do the following before running the program:
4693 This will cause the libraries to be mapped private and read-write.
4694 To revert to the normal behavior, do this:
4700 You cannot set breakpoints or examine data in the library until after
4701 the library is loaded if the function/data symbols do not have
4704 GDB can now also read debug symbols produced by the HP C compiler on
4705 HPPAs (sorry, no C++, Fortran or 68k support).
4707 * Target byte order now dynamically selectable
4709 You can choose which byte order to use with a target system, via the
4710 commands "set endian big" and "set endian little", and you can see the
4711 current setting by using "show endian". You can also give the command
4712 "set endian auto", in which case GDB will use the byte order
4713 associated with the executable. Currently, only embedded MIPS
4714 configurations support dynamic selection of target byte order.
4716 * New DOS host serial code
4718 This version uses DPMI interrupts to handle buffered I/O, so you
4719 no longer need to run asynctsr when debugging boards connected to
4722 *** Changes in GDB-4.13:
4724 * New "complete" command
4726 This lists all the possible completions for the rest of the line, if it
4727 were to be given as a command itself. This is intended for use by emacs.
4729 * Trailing space optional in prompt
4731 "set prompt" no longer adds a space for you after the prompt you set. This
4732 allows you to set a prompt which ends in a space or one that does not.
4734 * Breakpoint hit counts
4736 "info break" now displays a count of the number of times the breakpoint
4737 has been hit. This is especially useful in conjunction with "ignore"; you
4738 can ignore a large number of breakpoint hits, look at the breakpoint info
4739 to see how many times the breakpoint was hit, then run again, ignoring one
4740 less than that number, and this will get you quickly to the last hit of
4743 * Ability to stop printing at NULL character
4745 "set print null-stop" will cause GDB to stop printing the characters of
4746 an array when the first NULL is encountered. This is useful when large
4747 arrays actually contain only short strings.
4749 * Shared library breakpoints
4751 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4752 breakpoints in shared libraries before the executable is run.
4754 * Hardware watchpoints
4756 There is a new hardware breakpoint for the watch command for sparclite
4757 targets. See gdb/sparclite/hw_breakpoint.note.
4759 Hardware watchpoints are also now supported under GNU/Linux.
4763 Annotations have been added. These are for use with graphical interfaces,
4764 and are still experimental. Currently only gdba.el uses these.
4766 * Improved Irix 5 support
4768 GDB now works properly with Irix 5.2.
4770 * Improved HPPA support
4772 GDB now works properly with the latest GCC and GAS.
4774 * New native configurations
4776 Sequent PTX4 i[34]86-sequent-ptx4
4777 HPPA running OSF/1 hppa*-*-osf*
4778 Atari TT running SVR4 m68*-*-sysv4*
4779 RS/6000 LynxOS rs6000-*-lynxos*
4783 OS/9000 i[34]86-*-os9k
4784 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4787 * Hitachi SH7000 and E7000-PC ICE support
4789 There is now support for communicating with the Hitachi E7000-PC ICE.
4790 This is available automatically when GDB is configured for the SH.
4794 As usual, a variety of small fixes and improvements, both generic
4795 and configuration-specific. See the ChangeLog for more detail.
4797 *** Changes in GDB-4.12:
4799 * Irix 5 is now supported
4803 GDB-4.12 on the HPPA has a number of changes which make it unable
4804 to debug the output from the currently released versions of GCC and
4805 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4806 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4807 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4810 *** Changes in GDB-4.11:
4812 * User visible changes:
4816 The "set remotedebug" option is now consistent between the mips remote
4817 target, remote targets using the gdb-specific protocol, UDI (AMD's
4818 debug protocol for the 29k) and the 88k bug monitor. It is now an
4819 integer specifying a debug level (normally 0 or 1, but 2 means more
4820 debugging info for the mips target).
4822 * DEC Alpha native support
4824 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4825 debug info, but GDB works fairly well with the DEC compiler and should
4826 work with a future GCC release. See the README file for a few
4827 Alpha-specific notes.
4829 * Preliminary thread implementation
4831 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4833 * LynxOS native and target support for 386
4835 This release has been hosted on LynxOS 2.2, and also can be configured
4836 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4839 * Improvements in C++ mangling/demangling.
4841 This release has much better g++ debugging, specifically in name
4842 mangling/demangling, virtual function calls, print virtual table,
4843 call methods, ...etc.
4845 *** Changes in GDB-4.10:
4847 * User visible changes:
4849 Remote debugging using the GDB-specific (`target remote') protocol now
4850 supports the `load' command. This is only useful if you have some
4851 other way of getting the stub to the target system, and you can put it
4852 somewhere in memory where it won't get clobbered by the download.
4854 Filename completion now works.
4856 When run under emacs mode, the "info line" command now causes the
4857 arrow to point to the line specified. Also, "info line" prints
4858 addresses in symbolic form (as well as hex).
4860 All vxworks based targets now support a user settable option, called
4861 vxworks-timeout. This option represents the number of seconds gdb
4862 should wait for responses to rpc's. You might want to use this if
4863 your vxworks target is, perhaps, a slow software simulator or happens
4864 to be on the far side of a thin network line.
4868 This release contains support for using a DEC alpha as a GDB host for
4869 cross debugging. Native alpha debugging is not supported yet.
4872 *** Changes in GDB-4.9:
4876 This is the first GDB release which is accompanied by a matching testsuite.
4877 The testsuite requires installation of dejagnu, which should be available
4878 via ftp from most sites that carry GNU software.
4882 'Cfront' style demangling has had its name changed to 'ARM' style, to
4883 emphasize that it was written from the specifications in the C++ Annotated
4884 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4885 disclaimers, it still generated too much confusion with users attempting to
4886 use gdb with AT&T cfront.
4890 GDB now uses a standard remote interface to a simulator library.
4891 So far, the library contains simulators for the Zilog Z8001/2, the
4892 Hitachi H8/300, H8/500 and Super-H.
4894 * New targets supported
4896 H8/300 simulator h8300-hitachi-hms or h8300hms
4897 H8/500 simulator h8500-hitachi-hms or h8500hms
4898 SH simulator sh-hitachi-hms or sh
4899 Z8000 simulator z8k-zilog-none or z8ksim
4900 IDT MIPS board over serial line mips-idt-ecoff
4902 Cross-debugging to GO32 targets is supported. It requires a custom
4903 version of the i386-stub.c module which is integrated with the
4904 GO32 memory extender.
4906 * New remote protocols
4908 MIPS remote debugging protocol.
4910 * New source languages supported
4912 This version includes preliminary support for Chill, a Pascal like language
4913 used by telecommunications companies. Chill support is also being integrated
4914 into the GNU compiler, but we don't know when it will be publically available.
4917 *** Changes in GDB-4.8:
4919 * HP Precision Architecture supported
4921 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4922 version of this support was available as a set of patches from the
4923 University of Utah. GDB does not support debugging of programs
4924 compiled with the HP compiler, because HP will not document their file
4925 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4926 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4928 Many problems in the preliminary version have been fixed.
4930 * Faster and better demangling
4932 We have improved template demangling and fixed numerous bugs in the GNU style
4933 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4934 character types (wchar_t) are now supported. Demangling of each symbol is now
4935 only done once, and is cached when the symbol table for a file is read in.
4936 This results in a small increase in memory usage for C programs, a moderate
4937 increase in memory usage for C++ programs, and a fantastic speedup in
4940 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4941 from the specifications in the Annotated Reference Manual, which AT&T's
4942 compiler does not actually implement.
4944 * G++ multiple inheritance compiler problem
4946 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4947 inheritance lattices was reworked to properly discover ambiguities. We
4948 recently found an example which causes this new algorithm to fail in a
4949 very subtle way, producing bad debug information for those classes.
4950 The file 'gcc.patch' (in this directory) can be applied to gcc to
4951 circumvent the problem. A future GCC release will contain a complete
4954 The previous G++ debug info problem (mentioned below for the gdb-4.7
4955 release) is fixed in gcc version 2.3.2.
4957 * Improved configure script
4959 The `configure' script will now attempt to guess your system type if
4960 you don't supply a host system type. The old scheme of supplying a
4961 host system triplet is preferable over using this. All the magic is
4962 done in the new `config.guess' script. Examine it for details.
4964 We have also brought our configure script much more in line with the FSF's
4965 version. It now supports the --with-xxx options. In particular,
4966 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4967 The resulting GDB will not be able to read arbitrary object file formats --
4968 only the format ``expected'' to be used on the configured target system.
4969 We hope to make this the default in a future release.
4971 * Documentation improvements
4973 There's new internal documentation on how to modify GDB, and how to
4974 produce clean changes to the code. We implore people to read it
4975 before submitting changes.
4977 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4978 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4979 `info' files are also provided. To build `info' files from scratch,
4980 you will need the latest `makeinfo' release, which will be available in
4981 a future texinfo-X.Y release.
4983 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4984 We're not sure exactly which versions have this problem, but it has
4985 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4986 or better. If that isn't possible, there is a patch in
4987 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4988 around this problem.
4992 GDB now supports array constants that can be used in expressions typed in by
4993 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4994 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4997 The new directory `gdb/sparclite' contains a program that demonstrates
4998 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5000 * New native hosts supported
5002 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5003 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5005 * New targets supported
5007 AMD 29k family via UDI a29k-amd-udi or udi29k
5009 * New file formats supported
5011 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5012 HPUX core files, and SCO 3.2v2 core files.
5016 Attaching to processes now works again; thanks for the many bug reports.
5018 We have also stomped on a bunch of core dumps caused by
5019 printf_filtered("%s") problems.
5021 We eliminated a copyright problem on the rpc and ptrace header files
5022 for VxWorks, which was discovered at the last minute during the 4.7
5023 release. You should now be able to build a VxWorks GDB.
5025 You can now interrupt gdb while an attached process is running. This
5026 will cause the attached process to stop, and give control back to GDB.
5028 We fixed problems caused by using too many file descriptors
5029 for reading symbols from object files and libraries. This was
5030 especially a problem for programs that used many (~100) shared
5033 The `step' command now only enters a subroutine if there is line number
5034 information for the subroutine. Otherwise it acts like the `next'
5035 command. Previously, `step' would enter subroutines if there was
5036 any debugging information about the routine. This avoids problems
5037 when using `cc -g1' on MIPS machines.
5039 * Internal improvements
5041 GDB's internal interfaces have been improved to make it easier to support
5042 debugging of multiple languages in the future.
5044 GDB now uses a common structure for symbol information internally.
5045 Minimal symbols (derived from linkage symbols in object files), partial
5046 symbols (from a quick scan of debug information), and full symbols
5047 contain a common subset of information, making it easier to write
5048 shared code that handles any of them.
5050 * New command line options
5052 We now accept --silent as an alias for --quiet.
5056 The memory-mapped-malloc library is now licensed under the GNU Library
5057 General Public License.
5059 *** Changes in GDB-4.7:
5061 * Host/native/target split
5063 GDB has had some major internal surgery to untangle the support for
5064 hosts and remote targets. Now, when you configure GDB for a remote
5065 target, it will no longer load in all of the support for debugging
5066 local programs on the host. When fully completed and tested, this will
5067 ensure that arbitrary host/target combinations are possible.
5069 The primary conceptual shift is to separate the non-portable code in
5070 GDB into three categories. Host specific code is required any time GDB
5071 is compiled on that host, regardless of the target. Target specific
5072 code relates to the peculiarities of the target, but can be compiled on
5073 any host. Native specific code is everything else: it can only be
5074 built when the host and target are the same system. Child process
5075 handling and core file support are two common `native' examples.
5077 GDB's use of /proc for controlling Unix child processes is now cleaner.
5078 It has been split out into a single module under the `target_ops' vector,
5079 plus two native-dependent functions for each system that uses /proc.
5081 * New hosts supported
5083 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5084 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5085 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5087 * New targets supported
5089 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5090 68030 and CPU32 m68030-*-*, m68332-*-*
5092 * New native hosts supported
5094 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5095 (386bsd is not well tested yet)
5096 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5098 * New file formats supported
5100 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5101 supports reading of `a.out.adobe' object files, which are an a.out
5102 format extended with minimal information about multiple sections.
5106 `show copying' is the same as the old `info copying'.
5107 `show warranty' is the same as `info warrantee'.
5108 These were renamed for consistency. The old commands continue to work.
5110 `info handle' is a new alias for `info signals'.
5112 You can now define pre-command hooks, which attach arbitrary command
5113 scripts to any command. The commands in the hook will be executed
5114 prior to the user's command. You can also create a hook which will be
5115 executed whenever the program stops. See gdb.texinfo.
5119 We now deal with Cfront style name mangling, and can even extract type
5120 info from mangled symbols. GDB can automatically figure out which
5121 symbol mangling style your C++ compiler uses.
5123 Calling of methods and virtual functions has been improved as well.
5127 The crash that occured when debugging Sun Ansi-C compiled binaries is
5128 fixed. This was due to mishandling of the extra N_SO stabs output
5131 We also finally got Ultrix 4.2 running in house, and fixed core file
5132 support, with help from a dozen people on the net.
5134 John M. Farrell discovered that the reason that single-stepping was so
5135 slow on all of the Mips based platforms (primarily SGI and DEC) was
5136 that we were trying to demangle and lookup a symbol used for internal
5137 purposes on every instruction that was being stepped through. Changing
5138 the name of that symbol so that it couldn't be mistaken for a C++
5139 mangled symbol sped things up a great deal.
5141 Rich Pixley sped up symbol lookups in general by getting much smarter
5142 about when C++ symbol mangling is necessary. This should make symbol
5143 completion (TAB on the command line) much faster. It's not as fast as
5144 we'd like, but it's significantly faster than gdb-4.6.
5148 A new user controllable variable 'call_scratch_address' can
5149 specify the location of a scratch area to be used when GDB
5150 calls a function in the target. This is necessary because the
5151 usual method of putting the scratch area on the stack does not work
5152 in systems that have separate instruction and data spaces.
5154 We integrated changes to support the 29k UDI (Universal Debugger
5155 Interface), but discovered at the last minute that we didn't have all
5156 of the appropriate copyright paperwork. We are working with AMD to
5157 resolve this, and hope to have it available soon.
5161 We have sped up the remote serial line protocol, especially for targets
5162 with lots of registers. It now supports a new `expedited status' ('T')
5163 message which can be used in place of the existing 'S' status message.
5164 This allows the remote stub to send only the registers that GDB
5165 needs to make a quick decision about single-stepping or conditional
5166 breakpoints, eliminating the need to fetch the entire register set for
5167 each instruction being stepped through.
5169 The GDB remote serial protocol now implements a write-through cache for
5170 registers, only re-reading the registers if the target has run.
5172 There is also a new remote serial stub for SPARC processors. You can
5173 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5174 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5175 processor with a serial port.
5179 Configure.in files have become much easier to read and modify. A new
5180 `table driven' format makes it more obvious what configurations are
5181 supported, and what files each one uses.
5185 There is a new opcodes library which will eventually contain all of the
5186 disassembly routines and opcode tables. At present, it only contains
5187 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5188 disassembler (binutils/objdump) to share these routines.
5190 The libiberty library is now copylefted under the GNU Library General
5191 Public License. This allows more liberal use, and was done so libg++
5192 can use it. This makes no difference to GDB, since the Library License
5193 grants all the rights from the General Public License.
5197 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5198 reference to the stabs symbol info used by the debugger. It is (as far
5199 as we know) the only published document on this fascinating topic. We
5200 encourage you to read it, compare it to the stabs information on your
5201 system, and send improvements on the document in general (to
5202 bug-gdb@prep.ai.mit.edu).
5204 And, of course, many bugs have been fixed.
5207 *** Changes in GDB-4.6:
5209 * Better support for C++ function names
5211 GDB now accepts as input the "demangled form" of C++ overloaded function
5212 names and member function names, and can do command completion on such names
5213 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5214 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5215 Make use of command completion, it is your friend.
5217 GDB also now accepts a variety of C++ mangled symbol formats. They are
5218 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5219 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5220 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5221 for the list of formats.
5223 * G++ symbol mangling problem
5225 Recent versions of gcc have a bug in how they emit debugging information for
5226 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5227 directory) can be applied to gcc to fix the problem. Alternatively, if you
5228 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5229 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5230 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5233 * New 'maintenance' command
5235 All of the commands related to hacking GDB internals have been moved out of
5236 the main command set, and now live behind the 'maintenance' command. This
5237 can also be abbreviated as 'mt'. The following changes were made:
5239 dump-me -> maintenance dump-me
5240 info all-breakpoints -> maintenance info breakpoints
5241 printmsyms -> maintenance print msyms
5242 printobjfiles -> maintenance print objfiles
5243 printpsyms -> maintenance print psymbols
5244 printsyms -> maintenance print symbols
5246 The following commands are new:
5248 maintenance demangle Call internal GDB demangler routine to
5249 demangle a C++ link name and prints the result.
5250 maintenance print type Print a type chain for a given symbol
5252 * Change to .gdbinit file processing
5254 We now read the $HOME/.gdbinit file before processing the argv arguments
5255 (e.g. reading symbol files or core files). This allows global parameters to
5256 be set, which will apply during the symbol reading. The ./.gdbinit is still
5257 read after argv processing.
5259 * New hosts supported
5261 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5263 GNU/Linux support i386-unknown-linux or linux
5265 We are also including code to support the HP/PA running BSD and HPUX. This
5266 is almost guaranteed not to work, as we didn't have time to test or build it
5267 for this release. We are including it so that the more adventurous (or
5268 masochistic) of you can play with it. We also had major problems with the
5269 fact that the compiler that we got from HP doesn't support the -g option.
5272 * New targets supported
5274 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5276 * More smarts about finding #include files
5278 GDB now remembers the compilation directory for all include files, and for
5279 all files from which C is generated (like yacc and lex sources). This
5280 greatly improves GDB's ability to find yacc/lex sources, and include files,
5281 especially if you are debugging your program from a directory different from
5282 the one that contains your sources.
5284 We also fixed a bug which caused difficulty with listing and setting
5285 breakpoints in include files which contain C code. (In the past, you had to
5286 try twice in order to list an include file that you hadn't looked at before.)
5288 * Interesting infernals change
5290 GDB now deals with arbitrary numbers of sections, where the symbols for each
5291 section must be relocated relative to that section's landing place in the
5292 target's address space. This work was needed to support ELF with embedded
5293 stabs used by Solaris-2.0.
5295 * Bug fixes (of course!)
5297 There have been loads of fixes for the following things:
5298 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5299 i960, stabs, DOS(GO32), procfs, etc...
5301 See the ChangeLog for details.
5303 *** Changes in GDB-4.5:
5305 * New machines supported (host and target)
5307 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5309 SGI Irix-4.x mips-sgi-irix4 or iris4
5311 * New malloc package
5313 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5314 Mmalloc is capable of handling mutiple heaps of memory. It is also
5315 capable of saving a heap to a file, and then mapping it back in later.
5316 This can be used to greatly speedup the startup of GDB by using a
5317 pre-parsed symbol table which lives in a mmalloc managed heap. For
5318 more details, please read mmalloc/mmalloc.texi.
5322 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5323 'help info proc' for details.
5325 * MIPS ecoff symbol table format
5327 The code that reads MIPS symbol table format is now supported on all hosts.
5328 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5331 * File name changes for MS-DOS
5333 Many files in the config directories have been renamed to make it easier to
5334 support GDB on MS-DOSe systems (which have very restrictive file name
5335 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5336 environment) is close to working but has some remaining problems. Note
5337 that debugging of DOS programs is not supported, due to limitations
5338 in the ``operating system'', but it can be used to host cross-debugging.
5340 * Cross byte order fixes
5342 Many fixes have been made to support cross debugging of Sparc and MIPS
5343 targets from hosts whose byte order differs.
5345 * New -mapped and -readnow options
5347 If memory-mapped files are available on your system through the 'mmap'
5348 system call, you can use the -mapped option on the `file' or
5349 `symbol-file' commands to cause GDB to write the symbols from your
5350 program into a reusable file. If the program you are debugging is
5351 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5352 Future GDB debugging sessions will notice the presence of this file,
5353 and will quickly map in symbol information from it, rather than reading
5354 the symbol table from the executable program. Using the '-mapped'
5355 option in a GDB `file' or `symbol-file' command has the same effect as
5356 starting GDB with the '-mapped' command-line option.
5358 You can cause GDB to read the entire symbol table immediately by using
5359 the '-readnow' option with any of the commands that load symbol table
5360 information (or on the GDB command line). This makes the command
5361 slower, but makes future operations faster.
5363 The -mapped and -readnow options are typically combined in order to
5364 build a `fred.syms' file that contains complete symbol information.
5365 A simple GDB invocation to do nothing but build a `.syms' file for future
5368 gdb -batch -nx -mapped -readnow programname
5370 The `.syms' file is specific to the host machine on which GDB is run.
5371 It holds an exact image of GDB's internal symbol table. It cannot be
5372 shared across multiple host platforms.
5374 * longjmp() handling
5376 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5377 siglongjmp() without losing control. This feature has not yet been ported to
5378 all systems. It currently works on many 386 platforms, all MIPS-based
5379 platforms (SGI, DECstation, etc), and Sun3/4.
5383 Preliminary work has been put in to support the new Solaris OS from Sun. At
5384 this time, it can control and debug processes, but it is not capable of
5389 As always, many many bug fixes. The major areas were with g++, and mipsread.
5390 People using the MIPS-based platforms should experience fewer mysterious
5391 crashes and trashed symbol tables.
5393 *** Changes in GDB-4.4:
5395 * New machines supported (host and target)
5397 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5399 BSD Reno on Vax vax-dec-bsd
5400 Ultrix on Vax vax-dec-ultrix
5402 * New machines supported (target)
5404 AMD 29000 embedded, using EBMON a29k-none-none
5408 GDB continues to improve its handling of C++. `References' work better.
5409 The demangler has also been improved, and now deals with symbols mangled as
5410 per the Annotated C++ Reference Guide.
5412 GDB also now handles `stabs' symbol information embedded in MIPS
5413 `ecoff' symbol tables. Since the ecoff format was not easily
5414 extensible to handle new languages such as C++, this appeared to be a
5415 good way to put C++ debugging info into MIPS binaries. This option
5416 will be supported in the GNU C compiler, version 2, when it is
5419 * New features for SVR4
5421 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5422 shared libraries. Debugging dynamically linked programs should present
5423 only minor differences from debugging statically linked programs.
5425 The `info proc' command will print out information about any process
5426 on an SVR4 system (including the one you are debugging). At the moment,
5427 it prints the address mappings of the process.
5429 If you bring up GDB on another SVR4 system, please send mail to
5430 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5432 * Better dynamic linking support in SunOS
5434 Reading symbols from shared libraries which contain debugging symbols
5435 now works properly. However, there remain issues such as automatic
5436 skipping of `transfer vector' code during function calls, which
5437 make it harder to debug code in a shared library, than to debug the
5438 same code linked statically.
5442 GDB is now using the latest `getopt' routines from the FSF. This
5443 version accepts the -- prefix for options with long names. GDB will
5444 continue to accept the old forms (-option and +option) as well.
5445 Various single letter abbreviations for options have been explicity
5446 added to the option table so that they won't get overshadowed in the
5447 future by other options that begin with the same letter.
5451 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5452 Many assorted bugs have been handled. Many more remain to be handled.
5453 See the various ChangeLog files (primarily in gdb and bfd) for details.
5456 *** Changes in GDB-4.3:
5458 * New machines supported (host and target)
5460 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5461 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5462 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5464 * Almost SCO Unix support
5466 We had hoped to support:
5467 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5468 (except for core file support), but we discovered very late in the release
5469 that it has problems with process groups that render gdb unusable. Sorry
5470 about that. I encourage people to fix it and post the fixes.
5472 * Preliminary ELF and DWARF support
5474 GDB can read ELF object files on System V Release 4, and can handle
5475 debugging records for C, in DWARF format, in ELF files. This support
5476 is preliminary. If you bring up GDB on another SVR4 system, please
5477 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5482 GDB now uses the latest `readline' library. One user-visible change
5483 is that two tabs will list possible command completions, which previously
5484 required typing M-? (meta-question mark, or ESC ?).
5488 The `stepi' bug that many of you noticed has been squashed.
5489 Many bugs in C++ have been handled. Many more remain to be handled.
5490 See the various ChangeLog files (primarily in gdb and bfd) for details.
5492 * State of the MIPS world (in case you wondered):
5494 GDB can understand the symbol tables emitted by the compilers
5495 supplied by most vendors of MIPS-based machines, including DEC. These
5496 symbol tables are in a format that essentially nobody else uses.
5498 Some versions of gcc come with an assembler post-processor called
5499 mips-tfile. This program is required if you want to do source-level
5500 debugging of gcc-compiled programs. I believe FSF does not ship
5501 mips-tfile with gcc version 1, but it will eventually come with gcc
5504 Debugging of g++ output remains a problem. g++ version 1.xx does not
5505 really support it at all. (If you're lucky, you should be able to get
5506 line numbers and stack traces to work, but no parameters or local
5507 variables.) With some work it should be possible to improve the
5510 When gcc version 2 is released, you will have somewhat better luck.
5511 However, even then you will get confusing results for inheritance and
5514 We will eventually provide full debugging of g++ output on
5515 DECstations. This will probably involve some kind of stabs-in-ecoff
5516 encapulation, but the details have not been worked out yet.
5519 *** Changes in GDB-4.2:
5521 * Improved configuration
5523 Only one copy of `configure' exists now, and it is not self-modifying.
5524 Porting BFD is simpler.
5528 The `step' and `next' commands now only stop at the first instruction
5529 of a source line. This prevents the multiple stops that used to occur
5530 in switch statements, for-loops, etc. `Step' continues to stop if a
5531 function that has debugging information is called within the line.
5535 Lots of small bugs fixed. More remain.
5537 * New host supported (not target)
5539 Intel 386 PC clone running Mach i386-none-mach
5542 *** Changes in GDB-4.1:
5544 * Multiple source language support
5546 GDB now has internal scaffolding to handle several source languages.
5547 It determines the type of each source file from its filename extension,
5548 and will switch expression parsing and number formatting to match the
5549 language of the function in the currently selected stack frame.
5550 You can also specifically set the language to be used, with
5551 `set language c' or `set language modula-2'.
5555 GDB now has preliminary support for the GNU Modula-2 compiler,
5556 currently under development at the State University of New York at
5557 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5558 continue through the fall of 1991 and into 1992.
5560 Other Modula-2 compilers are currently not supported, and attempting to
5561 debug programs compiled with them will likely result in an error as the
5562 symbol table is read. Feel free to work on it, though!
5564 There are hooks in GDB for strict type checking and range checking,
5565 in the `Modula-2 philosophy', but they do not currently work.
5569 GDB can now write to executable and core files (e.g. patch
5570 a variable's value). You must turn this switch on, specify
5571 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5572 by assigning a new value to a variable. Modifications take
5575 * Automatic SunOS shared library reading
5577 When you run your program, GDB automatically determines where its
5578 shared libraries (if any) have been loaded, and reads their symbols.
5579 The `share' command is no longer needed. This also works when
5580 examining core files.
5584 You can specify the number of lines that the `list' command shows.
5587 * New machines supported (host and target)
5589 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5590 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5591 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5593 * New hosts supported (not targets)
5595 IBM RT/PC: romp-ibm-aix or rtpc
5597 * New targets supported (not hosts)
5599 AMD 29000 embedded with COFF a29k-none-coff
5600 AMD 29000 embedded with a.out a29k-none-aout
5601 Ultracomputer remote kernel debug a29k-nyu-kern
5603 * New remote interfaces
5609 *** Changes in GDB-4.0:
5613 Wide output is wrapped at good places to make the output more readable.
5615 Gdb now supports cross-debugging from a host machine of one type to a
5616 target machine of another type. Communication with the target system
5617 is over serial lines. The ``target'' command handles connecting to the
5618 remote system; the ``load'' command will download a program into the
5619 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5620 also supports debugging of realtime processes running under VxWorks,
5621 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5622 stub on the target system.
5624 New CPUs supported include the AMD 29000 and Intel 960.
5626 GDB now reads object files and symbol tables via a ``binary file''
5627 library, which allows a single copy of GDB to debug programs of multiple
5628 object file types such as a.out and coff.
5630 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5631 refcard.dvi and refcard.ps are available to format it).
5634 * Control-Variable user interface simplified
5636 All variables that control the operation of the debugger can be set
5637 by the ``set'' command, and displayed by the ``show'' command.
5639 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5640 ``Show prompt'' produces the response:
5641 Gdb's prompt is new-gdb=>.
5643 What follows are the NEW set commands. The command ``help set'' will
5644 print a complete list of old and new set commands. ``help set FOO''
5645 will give a longer description of the variable FOO. ``show'' will show
5646 all of the variable descriptions and their current settings.
5648 confirm on/off: Enables warning questions for operations that are
5649 hard to recover from, e.g. rerunning the program while
5650 it is already running. Default is ON.
5652 editing on/off: Enables EMACS style command line editing
5653 of input. Previous lines can be recalled with
5654 control-P, the current line can be edited with control-B,
5655 you can search for commands with control-R, etc.
5658 history filename NAME: NAME is where the gdb command history
5659 will be stored. The default is .gdb_history,
5660 or the value of the environment variable
5663 history size N: The size, in commands, of the command history. The
5664 default is 256, or the value of the environment variable
5667 history save on/off: If this value is set to ON, the history file will
5668 be saved after exiting gdb. If set to OFF, the
5669 file will not be saved. The default is OFF.
5671 history expansion on/off: If this value is set to ON, then csh-like
5672 history expansion will be performed on
5673 command line input. The default is OFF.
5675 radix N: Sets the default radix for input and output. It can be set
5676 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5677 in the current radix, so "set radix 10" is always a no-op.
5679 height N: This integer value is the number of lines on a page. Default
5680 is 24, the current `stty rows'' setting, or the ``li#''
5681 setting from the termcap entry matching the environment
5684 width N: This integer value is the number of characters on a line.
5685 Default is 80, the current `stty cols'' setting, or the ``co#''
5686 setting from the termcap entry matching the environment
5689 Note: ``set screensize'' is obsolete. Use ``set height'' and
5690 ``set width'' instead.
5692 print address on/off: Print memory addresses in various command displays,
5693 such as stack traces and structure values. Gdb looks
5694 more ``symbolic'' if you turn this off; it looks more
5695 ``machine level'' with it on. Default is ON.
5697 print array on/off: Prettyprint arrays. New convenient format! Default
5700 print demangle on/off: Print C++ symbols in "source" form if on,
5703 print asm-demangle on/off: Same, for assembler level printouts
5706 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5709 * Support for Epoch Environment.
5711 The epoch environment is a version of Emacs v18 with windowing. One
5712 new command, ``inspect'', is identical to ``print'', except that if you
5713 are running in the epoch environment, the value is printed in its own
5717 * Support for Shared Libraries
5719 GDB can now debug programs and core files that use SunOS shared libraries.
5720 Symbols from a shared library cannot be referenced
5721 before the shared library has been linked with the program (this
5722 happens after you type ``run'' and before the function main() is entered).
5723 At any time after this linking (including when examining core files
5724 from dynamically linked programs), gdb reads the symbols from each
5725 shared library when you type the ``sharedlibrary'' command.
5726 It can be abbreviated ``share''.
5728 sharedlibrary REGEXP: Load shared object library symbols for files
5729 matching a unix regular expression. No argument
5730 indicates to load symbols for all shared libraries.
5732 info sharedlibrary: Status of loaded shared libraries.
5737 A watchpoint stops execution of a program whenever the value of an
5738 expression changes. Checking for this slows down execution
5739 tremendously whenever you are in the scope of the expression, but is
5740 quite useful for catching tough ``bit-spreader'' or pointer misuse
5741 problems. Some machines such as the 386 have hardware for doing this
5742 more quickly, and future versions of gdb will use this hardware.
5744 watch EXP: Set a watchpoint (breakpoint) for an expression.
5746 info watchpoints: Information about your watchpoints.
5748 delete N: Deletes watchpoint number N (same as breakpoints).
5749 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5750 enable N: Re-enables watchpoint number N (same as breakpoints).
5753 * C++ multiple inheritance
5755 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5758 * C++ exception handling
5760 Gdb now supports limited C++ exception handling. Besides the existing
5761 ability to breakpoint on an exception handler, gdb can breakpoint on
5762 the raising of an exception (before the stack is peeled back to the
5765 catch FOO: If there is a FOO exception handler in the dynamic scope,
5766 set a breakpoint to catch exceptions which may be raised there.
5767 Multiple exceptions (``catch foo bar baz'') may be caught.
5769 info catch: Lists all exceptions which may be caught in the
5770 current stack frame.
5773 * Minor command changes
5775 The command ``call func (arg, arg, ...)'' now acts like the print
5776 command, except it does not print or save a value if the function's result
5777 is void. This is similar to dbx usage.
5779 The ``up'' and ``down'' commands now always print the frame they end up
5780 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5781 frames without printing.
5783 * New directory command
5785 'dir' now adds directories to the FRONT of the source search path.
5786 The path starts off empty. Source files that contain debug information
5787 about the directory in which they were compiled can be found even
5788 with an empty path; Sun CC and GCC include this information. If GDB can't
5789 find your source file in the current directory, type "dir .".
5791 * Configuring GDB for compilation
5793 For normal use, type ``./configure host''. See README or gdb.texinfo
5796 GDB now handles cross debugging. If you are remotely debugging between
5797 two different machines, type ``./configure host -target=targ''.
5798 Host is the machine where GDB will run; targ is the machine
5799 where the program that you are debugging will run.