1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.8
6 * On resume, GDB now always passes the signal the program had stopped
7 for to the thread the signal was sent to, even if the user changed
8 threads before resuming. Previously GDB would often (but not
9 always) deliver the signal to the thread that happens to be current
12 * Conversely, the "signal" command now consistently delivers the
13 requested signal to the current thread. GDB now asks for
14 confirmation if the program had stopped for a signal and the user
15 switched threads meanwhile.
17 *** Changes in GDB 7.8
19 * New command line options
22 This is an alias for the --data-directory option.
24 * GDB supports printing and modifying of variable length automatic arrays
25 as specified in ISO C99.
27 * The ARM simulator now supports instruction level tracing
28 with or without disassembly.
32 GDB now has support for scripting using Guile. Whether this is
33 available is determined at configure time.
34 Guile version 2.0 or greater is required.
35 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
37 * New commands (for set/show, see "New options" below)
41 Invoke CODE by passing it to the Guile interpreter.
45 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
47 info auto-load guile-scripts [regexp]
48 Print the list of automatically loaded Guile scripts.
50 * The source command is now capable of sourcing Guile scripts.
51 This feature is dependent on the debugger being built with Guile support.
55 set print symbol-loading (off|brief|full)
56 show print symbol-loading
57 Control whether to print informational messages when loading symbol
58 information for a file. The default is "full", but when debugging
59 programs with large numbers of shared libraries the amount of output
62 set guile print-stack (none|message|full)
63 show guile print-stack
64 Show a stack trace when an error is encountered in a Guile script.
66 set auto-load guile-scripts (on|off)
67 show auto-load guile-scripts
68 Control auto-loading of Guile script files.
70 maint ada set ignore-descriptive-types (on|off)
71 maint ada show ignore-descriptive-types
72 Control whether the debugger should ignore descriptive types in Ada
73 programs. The default is not to ignore the descriptive types. See
74 the user manual for more details on descriptive types and the intended
77 set auto-connect-native-target
79 Control whether GDB is allowed to automatically connect to the
80 native target for the run, attach, etc. commands when not connected
81 to any target yet. See also "target native" below.
83 set record btrace replay-memory-access (read-only|read-write)
84 show record btrace replay-memory-access
85 Control what memory accesses are allowed during replay.
87 maint set target-async (on|off)
88 maint show target-async
89 This controls whether GDB targets operate in syncronous or
90 asyncronous mode. Normally the default is asyncronous, if it is
91 available; but this can be changed to more easily debug problems
92 occurring only in syncronous mode.
96 Control whether MI asynchronous mode is preferred. This supersedes
97 "set target-async" of previous GDB versions.
99 * "set target-async" is deprecated as a CLI option and is now an alias
100 for "set mi-async" (only puts MI into async mode).
102 * Background execution commands (e.g., "c&", "s&", etc.) are now
103 possible ``out of the box'' if the target supports them. Previously
104 the user would need to explicitly enable the possibility with the
105 "set target-async on" command.
107 * New features in the GDB remote stub, GDBserver
109 ** New option --debug-format=option1[,option2,...] allows one to add
110 additional text to each output. At present only timestamps
111 are supported: --debug-format=timestamps.
112 Timestamps can also be turned on with the
113 "monitor set debug-format timestamps" command from GDB.
115 * The 'record instruction-history' command now starts counting instructions
116 at one. This also affects the instruction ranges reported by the
117 'record function-call-history' command when given the /i modifier.
119 * The command 'record function-call-history' supports a new modifier '/c' to
120 indent the function names based on their call stack depth.
121 The fields for the '/i' and '/l' modifier have been reordered.
122 The source line range is now prefixed with 'at'.
123 The instruction range is now prefixed with 'inst'.
124 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
125 "record instruction-history" and "list" commands.
127 * The ranges given as arguments to the 'record function-call-history' and
128 'record instruction-history' commands are now inclusive.
130 * The btrace record target now supports the 'record goto' command.
131 For locations inside the execution trace, the back trace is computed
132 based on the information stored in the execution trace.
134 * The btrace record target supports limited reverse execution and replay.
135 The target does not record data and therefore does not allow reading
138 * The "catch syscall" command now works on s390*-linux* targets.
140 * The "compare-sections" command is no longer specific to target
141 remote. It now works with all targets.
143 * All native targets are now consistently called "native".
144 Consequently, the "target child", "target GNU", "target djgpp",
145 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
146 commands have been replaced with "target native". The QNX/NTO port
147 leaves the "procfs" target in place and adds a "native" target for
148 consistency with other ports. The impact on users should be minimal
149 as these commands previously either throwed an error, or were
150 no-ops. The target's name is visible in the output of the following
151 commands: "help target", "info target", "info files", "maint print
154 * The "target native" command now connects to the native target. This
155 can be used to launch native programs even when "set
156 auto-connect-native-target" is set to off.
160 qXfer:btrace:read's annex
161 The qXfer:btrace:read packet supports a new annex 'delta' to read
162 branch trace incrementally.
166 ** Valid Python operations on gdb.Value objects representing
167 structs/classes invoke the corresponding overloaded operators if
169 ** New `Xmethods' feature in the Python API. Xmethods are
170 additional methods or replacements for existing methods of a C++
171 class. This feature is useful for those cases where a method
172 defined in C++ source code could be inlined or optimized out by
173 the compiler, making it unavailable to GDB.
176 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
178 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
179 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
180 its alias "share", instead.
182 * The commands "set remotebaud" and "show remotebaud" are no longer
183 supported. Use "set serial baud" and "show serial baud" (respectively)
188 ** A new option "-gdb-set mi-async" replaces "-gdb-set
189 target-async". The latter is left as a deprecated alias of the
190 former for backward compatibility. If the target supports it,
191 CLI background execution commands are now always possible by
192 default, independently of whether the frontend stated a
193 preference for asynchronous execution with "-gdb-set mi-async".
194 Previously "-gdb-set target-async off" affected both MI execution
195 commands and CLI execution commands.
197 *** Changes in GDB 7.7
199 * Improved support for process record-replay and reverse debugging on
200 arm*-linux* targets. Support for thumb32 and syscall instruction
201 recording has been added.
203 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
205 * GDB now supports Fission DWP file format version 2.
206 http://gcc.gnu.org/wiki/DebugFission
208 * New convenience function "$_isvoid", to check whether an expression
209 is void. A void expression is an expression where the type of the
210 result is "void". For example, some convenience variables may be
211 "void" when evaluated (e.g., "$_exitcode" before the execution of
212 the program being debugged; or an undefined convenience variable).
213 Another example, when calling a function whose return type is
216 * The "maintenance print objfiles" command now takes an optional regexp.
218 * The "catch syscall" command now works on arm*-linux* targets.
220 * GDB now consistently shows "<not saved>" when printing values of
221 registers the debug info indicates have not been saved in the frame
222 and there's nowhere to retrieve them from
223 (callee-saved/call-clobbered registers):
228 (gdb) info registers rax
231 Before, the former would print "<optimized out>", and the latter
232 "*value not available*".
234 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
239 ** Frame filters and frame decorators have been added.
240 ** Temporary breakpoints are now supported.
241 ** Line tables representation has been added.
242 ** New attribute 'parent_type' for gdb.Field objects.
243 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
244 ** New attribute 'name' for gdb.Type objects.
248 Nios II ELF nios2*-*-elf
249 Nios II GNU/Linux nios2*-*-linux
250 Texas Instruments MSP430 msp430*-*-elf
252 * Removed native configurations
254 Support for these a.out NetBSD and OpenBSD obsolete configurations has
255 been removed. ELF variants of these configurations are kept supported.
257 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
258 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
259 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
260 i[34567]86-*-openbsd3.[0-3]
261 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
262 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
263 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
267 Like "catch throw", but catches a re-thrown exception.
269 Renamed from old "maint check-symtabs".
271 Perform consistency checks on symtabs.
273 Expand symtabs matching an optional regexp.
276 Display the details of GDB configure-time options.
278 maint set|show per-command
279 maint set|show per-command space
280 maint set|show per-command time
281 maint set|show per-command symtab
282 Enable display of per-command gdb resource usage.
284 remove-symbol-file FILENAME
285 remove-symbol-file -a ADDRESS
286 Remove a symbol file added via add-symbol-file. The file to remove
287 can be identified by its filename or by an address that lies within
288 the boundaries of this symbol file in memory.
291 info exceptions REGEXP
292 Display the list of Ada exceptions defined in the program being
293 debugged. If provided, only the exceptions whose names match REGEXP
298 set debug symfile off|on
300 Control display of debugging info regarding reading symbol files and
301 symbol tables within those files
303 set print raw frame-arguments
304 show print raw frame-arguments
305 Set/show whether to print frame arguments in raw mode,
306 disregarding any defined pretty-printers.
308 set remote trace-status-packet
309 show remote trace-status-packet
310 Set/show the use of remote protocol qTStatus packet.
314 Control display of debugging messages related to Nios II targets.
318 Control whether target-assisted range stepping is enabled.
320 set startup-with-shell
321 show startup-with-shell
322 Specifies whether Unix child processes are started via a shell or
327 Use the target memory cache for accesses to the code segment. This
328 improves performance of remote debugging (particularly disassembly).
330 * You can now use a literal value 'unlimited' for options that
331 interpret 0 or -1 as meaning "unlimited". E.g., "set
332 trace-buffer-size unlimited" is now an alias for "set
333 trace-buffer-size -1" and "set height unlimited" is now an alias for
336 * The "set debug symtab-create" debugging option of GDB has been changed to
337 accept a verbosity level. 0 means "off", 1 provides basic debugging
338 output, and values of 2 or greater provides more verbose output.
340 * New command-line options
342 Display the details of GDB configure-time options.
344 * The command 'tsave' can now support new option '-ctf' to save trace
345 buffer in Common Trace Format.
347 * Newly installed $prefix/bin/gcore acts as a shell interface for the
350 * GDB now implements the the C++ 'typeid' operator.
352 * The new convenience variable $_exception holds the exception being
353 thrown or caught at an exception-related catchpoint.
355 * The exception-related catchpoints, like "catch throw", now accept a
356 regular expression which can be used to filter exceptions by type.
358 * The new convenience variable $_exitsignal is automatically set to
359 the terminating signal number when the program being debugged dies
360 due to an uncaught signal.
364 ** All MI commands now accept an optional "--language" option.
365 Support for this feature can be verified by using the "-list-features"
366 command, which should contain "language-option".
368 ** The new command -info-gdb-mi-command allows the user to determine
369 whether a GDB/MI command is supported or not.
371 ** The "^error" result record returned when trying to execute an undefined
372 GDB/MI command now provides a variable named "code" whose content is the
373 "undefined-command" error code. Support for this feature can be verified
374 by using the "-list-features" command, which should contain
375 "undefined-command-error-code".
377 ** The -trace-save MI command can optionally save trace buffer in Common
380 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
382 ** The command -data-list-register-values now accepts an optional
383 "--skip-unavailable" option. When used, only the available registers
386 ** The new command -trace-frame-collected dumps collected variables,
387 computed expressions, tvars, memory and registers in a traceframe.
389 ** The commands -stack-list-locals, -stack-list-arguments and
390 -stack-list-variables now accept an option "--skip-unavailable".
391 When used, only the available locals or arguments are displayed.
393 ** The -exec-run command now accepts an optional "--start" option.
394 When used, the command follows the same semantics as the "start"
395 command, stopping the program's execution at the start of its
396 main subprogram. Support for this feature can be verified using
397 the "-list-features" command, which should contain
398 "exec-run-start-option".
400 ** The new commands -catch-assert and -catch-exceptions insert
401 catchpoints stopping the program when Ada exceptions are raised.
403 ** The new command -info-ada-exceptions provides the equivalent of
404 the new "info exceptions" command.
406 * New system-wide configuration scripts
407 A GDB installation now provides scripts suitable for use as system-wide
408 configuration scripts for the following systems:
412 * GDB now supports target-assigned range stepping with remote targets.
413 This improves the performance of stepping source lines by reducing
414 the number of control packets from/to GDB. See "New remote packets"
417 * GDB now understands the element 'tvar' in the XML traceframe info.
418 It has the id of the collected trace state variables.
420 * On S/390 targets that provide the transactional-execution feature,
421 the program interruption transaction diagnostic block (TDB) is now
422 represented as a number of additional "registers" in GDB.
428 The vCont packet supports a new 'r' action, that tells the remote
429 stub to step through an address range itself, without GDB
430 involvemement at each single-step.
432 qXfer:libraries-svr4:read's annex
433 The previously unused annex of the qXfer:libraries-svr4:read packet
434 is now used to support passing an argument list. The remote stub
435 reports support for this argument list to GDB's qSupported query.
436 The defined arguments are "start" and "prev", used to reduce work
437 necessary for library list updating, resulting in significant
440 * New features in the GDB remote stub, GDBserver
442 ** GDBserver now supports target-assisted range stepping. Currently
443 enabled on x86/x86_64 GNU/Linux targets.
445 ** GDBserver now adds element 'tvar' in the XML in the reply to
446 'qXfer:traceframe-info:read'. It has the id of the collected
447 trace state variables.
449 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
452 * New 'z' formatter for printing and examining memory, this displays the
453 value as hexadecimal zero padded on the left to the size of the type.
455 * GDB can now use Windows x64 unwinding data.
457 * The "set remotebaud" command has been replaced by "set serial baud".
458 Similarly, "show remotebaud" has been replaced by "show serial baud".
459 The "set remotebaud" and "show remotebaud" commands are still available
460 to provide backward compatibility with older versions of GDB.
462 *** Changes in GDB 7.6
464 * Target record has been renamed to record-full.
465 Record/replay is now enabled with the "record full" command.
466 This also affects settings that are associated with full record/replay
467 that have been moved from "set/show record" to "set/show record full":
469 set|show record full insn-number-max
470 set|show record full stop-at-limit
471 set|show record full memory-query
473 * A new record target "record-btrace" has been added. The new target
474 uses hardware support to record the control-flow of a process. It
475 does not support replaying the execution, but it implements the
476 below new commands for investigating the recorded execution log.
477 This new recording method can be enabled using:
481 The "record-btrace" target is only available on Intel Atom processors
482 and requires a Linux kernel 2.6.32 or later.
484 * Two new commands have been added for record/replay to give information
485 about the recorded execution without having to replay the execution.
486 The commands are only supported by "record btrace".
488 record instruction-history prints the execution history at
489 instruction granularity
491 record function-call-history prints the execution history at
494 * New native configurations
496 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
497 FreeBSD/powerpc powerpc*-*-freebsd
498 x86_64/Cygwin x86_64-*-cygwin*
499 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
503 ARM AArch64 aarch64*-*-elf
504 ARM AArch64 GNU/Linux aarch64*-*-linux
505 Lynx 178 PowerPC powerpc-*-lynx*178
506 x86_64/Cygwin x86_64-*-cygwin*
507 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
509 * If the configured location of system.gdbinit file (as given by the
510 --with-system-gdbinit option at configure time) is in the
511 data-directory (as specified by --with-gdb-datadir at configure
512 time) or in one of its subdirectories, then GDB will look for the
513 system-wide init file in the directory specified by the
514 --data-directory command-line option.
516 * New command line options:
518 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
519 other initialization files, unlike -nx which disables all of them.
521 * Removed command line options
523 -epoch This was used by the gdb mode in Epoch, an ancient fork of
526 * The 'ptype' and 'whatis' commands now accept an argument to control
529 * 'info proc' now works on some core files.
533 ** Vectors can be created with gdb.Type.vector.
535 ** Python's atexit.register now works in GDB.
537 ** Types can be pretty-printed via a Python API.
539 ** Python 3 is now supported (in addition to Python 2.4 or later)
541 ** New class gdb.Architecture exposes GDB's internal representation
542 of architecture in the Python API.
544 ** New method Frame.architecture returns the gdb.Architecture object
545 corresponding to the frame's architecture.
547 * New Python-based convenience functions:
549 ** $_memeq(buf1, buf2, length)
550 ** $_streq(str1, str2)
552 ** $_regex(str, regex)
554 * The 'cd' command now defaults to using '~' (the home directory) if not
557 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
558 default for GCC since November 2000.
560 * The command 'forward-search' can now be abbreviated as 'fo'.
562 * The command 'info tracepoints' can now display 'installed on target'
563 or 'not installed on target' for each non-pending location of tracepoint.
565 * New configure options
567 --enable-libmcheck/--disable-libmcheck
568 By default, development versions are built with -lmcheck on hosts
569 that support it, in order to help track memory corruption issues.
570 Release versions, on the other hand, are built without -lmcheck
571 by default. The --enable-libmcheck/--disable-libmcheck configure
572 options allow the user to override that default.
573 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
574 This configure option allows the user to build GDB with
575 libbabeltrace using which GDB can read Common Trace Format data.
577 * New commands (for set/show, see "New options" below)
580 Catch signals. This is similar to "handle", but allows commands and
581 conditions to be attached.
584 List the BFDs known to GDB.
586 python-interactive [command]
588 Start a Python interactive prompt, or evaluate the optional command
589 and print the result of expressions.
592 "py" is a new alias for "python".
594 enable type-printer [name]...
595 disable type-printer [name]...
596 Enable or disable type printers.
600 ** For the Renesas Super-H architecture, the "regs" command has been removed
601 (has been deprecated in GDB 7.5), and "info all-registers" should be used
606 set print type methods (on|off)
607 show print type methods
608 Control whether method declarations are displayed by "ptype".
609 The default is to show them.
611 set print type typedefs (on|off)
612 show print type typedefs
613 Control whether typedef definitions are displayed by "ptype".
614 The default is to show them.
616 set filename-display basename|relative|absolute
617 show filename-display
618 Control the way in which filenames is displayed.
619 The default is "relative", which preserves previous behavior.
621 set trace-buffer-size
622 show trace-buffer-size
623 Request target to change the size of trace buffer.
625 set remote trace-buffer-size-packet auto|on|off
626 show remote trace-buffer-size-packet
627 Control the use of the remote protocol `QTBuffer:size' packet.
631 Control display of debugging messages related to ARM AArch64.
634 set debug coff-pe-read
635 show debug coff-pe-read
636 Control display of debugging messages related to reading of COFF/PE
641 Control display of debugging messages related to Mach-O symbols
644 set debug notification
645 show debug notification
646 Control display of debugging info for async remote notification.
650 ** Command parameter changes are now notified using new async record
651 "=cmd-param-changed".
652 ** Trace frame changes caused by command "tfind" are now notified using
653 new async record "=traceframe-changed".
654 ** The creation, deletion and modification of trace state variables
655 are now notified using new async records "=tsv-created",
656 "=tsv-deleted" and "=tsv-modified".
657 ** The start and stop of process record are now notified using new
658 async record "=record-started" and "=record-stopped".
659 ** Memory changes are now notified using new async record
661 ** The data-disassemble command response will include a "fullname" field
662 containing the absolute file name when source has been requested.
663 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
664 command, to allow pattern filling of memory areas.
665 ** New commands "-catch-load"/"-catch-unload" added for intercepting
666 library load/unload events.
667 ** The response to breakpoint commands and breakpoint async records
668 includes an "installed" field containing a boolean state about each
669 non-pending tracepoint location is whether installed on target or not.
670 ** Output of the "-trace-status" command includes a "trace-file" field
671 containing the name of the trace file being examined. This field is
672 optional, and only present when examining a trace file.
673 ** The "fullname" field is now always present along with the "file" field,
674 even if the file cannot be found by GDB.
676 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
677 You must have the LZMA library available when configuring GDB for this
678 feature to be enabled. For more information, see:
679 http://fedoraproject.org/wiki/Features/MiniDebugInfo
684 Set the size of trace buffer. The remote stub reports support for this
685 packet to gdb's qSupported query.
688 Enable Branch Trace Store (BTS)-based branch tracing for the current
689 thread. The remote stub reports support for this packet to gdb's
693 Disable branch tracing for the current thread. The remote stub reports
694 support for this packet to gdb's qSupported query.
697 Read the traced branches for the current thread. The remote stub
698 reports support for this packet to gdb's qSupported query.
700 *** Changes in GDB 7.5
702 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
703 for more x32 ABI info.
705 * GDB now supports access to MIPS DSP registers on Linux targets.
707 * GDB now supports debugging microMIPS binaries.
709 * The "info os" command on GNU/Linux can now display information on
710 several new classes of objects managed by the operating system:
711 "info os procgroups" lists process groups
712 "info os files" lists file descriptors
713 "info os sockets" lists internet-domain sockets
714 "info os shm" lists shared-memory regions
715 "info os semaphores" lists semaphores
716 "info os msg" lists message queues
717 "info os modules" lists loaded kernel modules
719 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
720 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
721 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
722 options and inspect the probe arguments using the new $_probe_arg family
723 of convenience variables. You can obtain more information about SystemTap
724 in <http://sourceware.org/systemtap/>.
726 * GDB now supports reversible debugging on ARM, it allows you to
727 debug basic ARM and THUMB instructions, and provides
728 record/replay support.
730 * The option "symbol-reloading" has been deleted as it is no longer used.
734 ** GDB commands implemented in Python can now be put in command class
737 ** The "maint set python print-stack on|off" is now deleted.
739 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
740 apply "flag enum"-style pretty-printing to any enum.
742 ** gdb.lookup_symbol can now work when there is no current frame.
744 ** gdb.Symbol now has a 'line' attribute, holding the line number in
745 the source at which the symbol was defined.
747 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
748 method 'value'. The former indicates whether the symbol needs a
749 frame in order to compute its value, and the latter computes the
752 ** A new method 'referenced_value' on gdb.Value objects which can
753 dereference pointer as well as C++ reference values.
755 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
756 which return the global and static blocks (as gdb.Block objects),
757 of the underlying symbol table, respectively.
759 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
760 object associated with a PC value.
762 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
763 of the address range occupied by code for the current source line.
765 * Go language support.
766 GDB now supports debugging programs written in the Go programming
769 * GDBserver now supports stdio connections.
770 E.g. (gdb) target remote | ssh myhost gdbserver - hello
772 * The binary "gdbtui" can no longer be built or installed.
773 Use "gdb -tui" instead.
775 * GDB will now print "flag" enums specially. A flag enum is one where
776 all the enumerator values have no bits in common when pairwise
777 "and"ed. When printing a value whose type is a flag enum, GDB will
778 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
779 (gdb) print (enum E) 3
782 * The filename part of a linespec will now match trailing components
783 of a source file name. For example, "break gcc/expr.c:1000" will
784 now set a breakpoint in build/gcc/expr.c, but not
787 * The "info proc" and "generate-core-file" commands will now also
788 work on remote targets connected to GDBserver on Linux.
790 * The command "info catch" has been removed. It has been disabled
793 * The "catch exception" and "catch assert" commands now accept
794 a condition at the end of the command, much like the "break"
795 command does. For instance:
797 (gdb) catch exception Constraint_Error if Barrier = True
799 Previously, it was possible to add a condition to such catchpoints,
800 but it had to be done as a second step, after the catchpoint had been
801 created, using the "condition" command.
803 * The "info static-tracepoint-marker" command will now also work on
804 native Linux targets with in-process agent.
806 * GDB can now set breakpoints on inlined functions.
808 * The .gdb_index section has been updated to include symbols for
809 inlined functions. GDB will ignore older .gdb_index sections by
810 default, which could cause symbol files to be loaded more slowly
811 until their .gdb_index sections can be recreated. The new command
812 "set use-deprecated-index-sections on" will cause GDB to use any older
813 .gdb_index sections it finds. This will restore performance, but the
814 ability to set breakpoints on inlined functions will be lost in symbol
815 files with older .gdb_index sections.
817 The .gdb_index section has also been updated to record more information
818 about each symbol. This speeds up the "info variables", "info functions"
819 and "info types" commands when used with programs having the .gdb_index
820 section, as well as speeding up debugging with shared libraries using
821 the .gdb_index section.
823 * Ada support for GDB/MI Variable Objects has been added.
825 * GDB can now support 'breakpoint always-inserted mode' in 'record'
830 ** New command -info-os is the MI equivalent of "info os".
832 ** Output logs ("set logging" and related) now include MI output.
836 ** "set use-deprecated-index-sections on|off"
837 "show use-deprecated-index-sections on|off"
838 Controls the use of deprecated .gdb_index sections.
840 ** "catch load" and "catch unload" can be used to stop when a shared
841 library is loaded or unloaded, respectively.
843 ** "enable count" can be used to auto-disable a breakpoint after
846 ** "info vtbl" can be used to show the virtual method tables for
847 C++ and Java objects.
849 ** "explore" and its sub commands "explore value" and "explore type"
850 can be used to recursively explore values and types of
851 expressions. These commands are available only if GDB is
852 configured with '--with-python'.
854 ** "info auto-load" shows status of all kinds of auto-loaded files,
855 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
856 sequences of commands files, "info auto-load python-scripts"
857 shows status of auto-loading Python script files,
858 "info auto-load local-gdbinit" shows status of loading init file
859 (.gdbinit) from current directory and "info auto-load libthread-db" shows
860 status of inferior specific thread debugging shared library loading.
862 ** "info auto-load-scripts", "set auto-load-scripts on|off"
863 and "show auto-load-scripts" commands have been deprecated, use their
864 "info auto-load python-scripts", "set auto-load python-scripts on|off"
865 and "show auto-load python-scripts" counterparts instead.
867 ** "dprintf location,format,args..." creates a dynamic printf, which
868 is basically a breakpoint that does a printf and immediately
869 resumes your program's execution, so it is like a printf that you
870 can insert dynamically at runtime instead of at compiletime.
872 ** "set print symbol"
874 Controls whether GDB attempts to display the symbol, if any,
875 corresponding to addresses it prints. This defaults to "on", but
876 you can set it to "off" to restore GDB's previous behavior.
878 * Deprecated commands
880 ** For the Renesas Super-H architecture, the "regs" command has been
881 deprecated, and "info all-registers" should be used instead.
885 Renesas RL78 rl78-*-elf
886 HP OpenVMS ia64 ia64-hp-openvms*
888 * GDBserver supports evaluation of breakpoint conditions. When
889 support is advertised by GDBserver, GDB may be told to send the
890 breakpoint conditions in bytecode form to GDBserver. GDBserver
891 will only report the breakpoint trigger to GDB when its condition
897 show mips compression
898 Select the compressed ISA encoding used in functions that have no symbol
899 information available. The encoding can be set to either of:
902 and is updated automatically from ELF file flags if available.
904 set breakpoint condition-evaluation
905 show breakpoint condition-evaluation
906 Control whether breakpoint conditions are evaluated by GDB ("host") or by
907 GDBserver ("target"). Default option "auto" chooses the most efficient
909 This option can improve debugger efficiency depending on the speed of the
913 Disable auto-loading globally.
916 Show auto-loading setting of all kinds of auto-loaded files.
918 set auto-load gdb-scripts on|off
919 show auto-load gdb-scripts
920 Control auto-loading of GDB canned sequences of commands files.
922 set auto-load python-scripts on|off
923 show auto-load python-scripts
924 Control auto-loading of Python script files.
926 set auto-load local-gdbinit on|off
927 show auto-load local-gdbinit
928 Control loading of init file (.gdbinit) from current directory.
930 set auto-load libthread-db on|off
931 show auto-load libthread-db
932 Control auto-loading of inferior specific thread debugging shared library.
934 set auto-load scripts-directory <dir1>[:<dir2>...]
935 show auto-load scripts-directory
936 Set a list of directories from which to load auto-loaded scripts.
937 Automatically loaded Python scripts and GDB scripts are located in one
938 of the directories listed by this option.
939 The delimiter (':' above) may differ according to the host platform.
941 set auto-load safe-path <dir1>[:<dir2>...]
942 show auto-load safe-path
943 Set a list of directories from which it is safe to auto-load files.
944 The delimiter (':' above) may differ according to the host platform.
946 set debug auto-load on|off
948 Control display of debugging info for auto-loading the files above.
950 set dprintf-style gdb|call|agent
952 Control the way in which a dynamic printf is performed; "gdb"
953 requests a GDB printf command, while "call" causes dprintf to call a
954 function in the inferior. "agent" requests that the target agent
955 (such as GDBserver) do the printing.
957 set dprintf-function <expr>
958 show dprintf-function
959 set dprintf-channel <expr>
961 Set the function and optional first argument to the call when using
962 the "call" style of dynamic printf.
964 set disconnected-dprintf on|off
965 show disconnected-dprintf
966 Control whether agent-style dynamic printfs continue to be in effect
967 after GDB disconnects.
969 * New configure options
972 Configure default value for the 'set auto-load scripts-directory'
973 setting above. It defaults to '$debugdir:$datadir/auto-load',
974 $debugdir representing global debugging info directories (available
975 via 'show debug-file-directory') and $datadir representing GDB's data
976 directory (available via 'show data-directory').
978 --with-auto-load-safe-path
979 Configure default value for the 'set auto-load safe-path' setting
980 above. It defaults to the --with-auto-load-dir setting.
982 --without-auto-load-safe-path
983 Set 'set auto-load safe-path' to '/', effectively disabling this
988 z0/z1 conditional breakpoints extension
990 The z0/z1 breakpoint insertion packets have been extended to carry
991 a list of conditional expressions over to the remote stub depending on the
992 condition evaluation mode. The use of this extension can be controlled
993 via the "set remote conditional-breakpoints-packet" command.
997 Specify the signals which the remote stub may pass to the debugged
998 program without GDB involvement.
1000 * New command line options
1002 --init-command=FILE, -ix Like --command, -x but execute it
1003 before loading inferior.
1004 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1005 execute it before loading inferior.
1007 *** Changes in GDB 7.4
1009 * GDB now handles ambiguous linespecs more consistently; the existing
1010 FILE:LINE support has been expanded to other types of linespecs. A
1011 breakpoint will now be set on all matching locations in all
1012 inferiors, and locations will be added or removed according to
1015 * GDB now allows you to skip uninteresting functions and files when
1016 stepping with the "skip function" and "skip file" commands.
1018 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1019 and "show remote hardware-watchpoint-length-limit". These allows to
1020 set or show the maximum length limit (in bytes) of a remote
1021 target hardware watchpoint.
1023 This allows e.g. to use "unlimited" hardware watchpoints with the
1024 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1025 watchpoints are slower than real hardware watchpoints but are
1026 significantly faster than gdb software watchpoints.
1030 ** The register_pretty_printer function in module gdb.printing now takes
1031 an optional `replace' argument. If True, the new printer replaces any
1034 ** The "maint set python print-stack on|off" command has been
1035 deprecated and will be deleted in GDB 7.5.
1036 A new command: "set python print-stack none|full|message" has
1037 replaced it. Additionally, the default for "print-stack" is
1038 now "message", which just prints the error message without
1041 ** A prompt substitution hook (prompt_hook) is now available to the
1044 ** A new Python module, gdb.prompt has been added to the GDB Python
1045 modules library. This module provides functionality for
1046 escape sequences in prompts (used by set/show
1047 extended-prompt). These escape sequences are replaced by their
1048 corresponding value.
1050 ** Python commands and convenience-functions located in
1051 'data-directory'/python/gdb/command and
1052 'data-directory'/python/gdb/function are now automatically loaded
1055 ** Blocks now provide four new attributes. global_block and
1056 static_block will return the global and static blocks
1057 respectively. is_static and is_global are boolean attributes
1058 that indicate if the block is one of those two types.
1060 ** Symbols now provide the "type" attribute, the type of the symbol.
1062 ** The "gdb.breakpoint" function has been deprecated in favor of
1065 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1066 of a function. This class is based on the "finish" command
1067 available in the CLI.
1069 ** Type objects for struct and union types now allow access to
1070 the fields using standard Python dictionary (mapping) methods.
1071 For example, "some_type['myfield']" now works, as does
1072 "some_type.items()".
1074 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1077 ** A new function, "deep_items" has been added to the gdb.types
1078 module in the GDB Python modules library. This function returns
1079 an iterator over the fields of a struct or union type. Unlike
1080 the standard Python "iteritems" method, it will recursively traverse
1081 any anonymous fields.
1085 ** "*stopped" events can report several new "reason"s, such as
1088 ** Breakpoint changes are now notified using new async records, like
1089 "=breakpoint-modified".
1091 ** New command -ada-task-info.
1093 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1094 $sdir specifies the default system locations of shared libraries.
1095 $pdir specifies the directory where the libpthread used by the application
1098 GDB no longer looks in $sdir and $pdir after it has searched the directories
1099 mentioned in libthread-db-search-path. If you want to search those
1100 directories, they must be specified in libthread-db-search-path.
1101 The default value of libthread-db-search-path on GNU/Linux and Solaris
1102 systems is now "$sdir:$pdir".
1104 $pdir is not supported by gdbserver, it is currently ignored.
1105 $sdir is supported by gdbserver.
1107 * New configure option --with-iconv-bin.
1108 When using the internationalization support like the one in the GNU C
1109 library, GDB will invoke the "iconv" program to get a list of supported
1110 character sets. If this program lives in a non-standard location, one can
1111 use this option to specify where to find it.
1113 * When natively debugging programs on PowerPC BookE processors running
1114 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1115 watchpoints, which specify a mask in addition to an address to watch.
1116 The mask specifies that some bits of an address (the bits which are
1117 reset in the mask) should be ignored when matching the address accessed
1118 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1119 section in the user manual for more details.
1121 * The new option --once causes GDBserver to stop listening for connections once
1122 the first connection is made. The listening port used by GDBserver will
1123 become available after that.
1125 * New commands "info macros" and "alias" have been added.
1127 * New function parameters suffix @entry specifies value of function parameter
1128 at the time the function got called. Entry values are available only since
1134 "!" is now an alias of the "shell" command.
1135 Note that no space is needed between "!" and SHELL COMMAND.
1139 watch EXPRESSION mask MASK_VALUE
1140 The watch command now supports the mask argument which allows creation
1141 of masked watchpoints, if the current architecture supports this feature.
1143 info auto-load-scripts [REGEXP]
1144 This command was formerly named "maintenance print section-scripts".
1145 It is now generally useful and is no longer a maintenance-only command.
1147 info macro [-all] [--] MACRO
1148 The info macro command has new options `-all' and `--'. The first for
1149 printing all definitions of a macro. The second for explicitly specifying
1150 the end of arguments and the beginning of the macro name in case the macro
1151 name starts with a hyphen.
1153 collect[/s] EXPRESSIONS
1154 The tracepoint collect command now takes an optional modifier "/s"
1155 that directs it to dereference pointer-to-character types and
1156 collect the bytes of memory up to a zero byte. The behavior is
1157 similar to what you see when you use the regular print command on a
1158 string. An optional integer following the "/s" sets a bound on the
1159 number of bytes that will be collected.
1162 The trace start command now interprets any supplied arguments as a
1163 note to be recorded with the trace run, with an effect similar to
1164 setting the variable trace-notes.
1167 The trace stop command now interprets any arguments as a note to be
1168 mentioned along with the tstatus report that the trace was stopped
1169 with a command. The effect is similar to setting the variable
1172 * Tracepoints can now be enabled and disabled at any time after a trace
1173 experiment has been started using the standard "enable" and "disable"
1174 commands. It is now possible to start a trace experiment with no enabled
1175 tracepoints; GDB will display a warning, but will allow the experiment to
1176 begin, assuming that tracepoints will be enabled as needed while the trace
1179 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1180 locations with 4-byte instructions, when they were previously
1181 limited to locations with instructions of 5 bytes or longer.
1185 set debug dwarf2-read
1186 show debug dwarf2-read
1187 Turns on or off display of debugging messages related to reading
1188 DWARF debug info. The default is off.
1190 set debug symtab-create
1191 show debug symtab-create
1192 Turns on or off display of debugging messages related to symbol table
1193 creation. The default is off.
1196 show extended-prompt
1197 Set the GDB prompt, and allow escape sequences to be inserted to
1198 display miscellaneous information (see 'help set extended-prompt'
1199 for the list of sequences). This prompt (and any information
1200 accessed through the escape sequences) is updated every time the
1201 prompt is displayed.
1203 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1204 show print entry-values
1205 Set printing of frame argument values at function entry. In some cases
1206 GDB can determine the value of function argument which was passed by the
1207 function caller, even if the value was modified inside the called function.
1209 set debug entry-values
1210 show debug entry-values
1211 Control display of debugging info for determining frame argument values at
1212 function entry and virtual tail call frames.
1214 set basenames-may-differ
1215 show basenames-may-differ
1216 Set whether a source file may have multiple base names.
1217 (A "base name" is the name of a file with the directory part removed.
1218 Example: The base name of "/home/user/hello.c" is "hello.c".)
1219 If set, GDB will canonicalize file names (e.g., expand symlinks)
1220 before comparing them. Canonicalization is an expensive operation,
1221 but it allows the same file be known by more than one base name.
1222 If not set (the default), all source files are assumed to have just
1223 one base name, and gdb will do file name comparisons more efficiently.
1229 Set a user name and notes for the current and any future trace runs.
1230 This is useful for long-running and/or disconnected traces, to
1231 inform others (or yourself) as to who is running the trace, supply
1232 contact information, or otherwise explain what is going on.
1234 set trace-stop-notes
1235 show trace-stop-notes
1236 Set a note attached to the trace run, that is displayed when the
1237 trace has been stopped by a tstop command. This is useful for
1238 instance as an explanation, if you are stopping a trace run that was
1239 started by someone else.
1241 * New remote packets
1245 Dynamically enable a tracepoint in a started trace experiment.
1249 Dynamically disable a tracepoint in a started trace experiment.
1253 Set the user and notes of the trace run.
1257 Query the current status of a tracepoint.
1261 Query the minimum length of instruction at which a fast tracepoint may
1264 * Dcache size (number of lines) and line-size are now runtime-configurable
1265 via "set dcache line" and "set dcache line-size" commands.
1269 Texas Instruments TMS320C6x tic6x-*-*
1273 Renesas RL78 rl78-*-elf
1275 *** Changes in GDB 7.3.1
1277 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1279 *** Changes in GDB 7.3
1281 * GDB has a new command: "thread find [REGEXP]".
1282 It finds the thread id whose name, target id, or thread extra info
1283 matches the given regular expression.
1285 * The "catch syscall" command now works on mips*-linux* targets.
1287 * The -data-disassemble MI command now supports modes 2 and 3 for
1288 dumping the instruction opcodes.
1290 * New command line options
1292 -data-directory DIR Specify DIR as the "data-directory".
1293 This is mostly for testing purposes.
1295 * The "maint set python auto-load on|off" command has been renamed to
1296 "set auto-load-scripts on|off".
1298 * GDB has a new command: "set directories".
1299 It is like the "dir" command except that it replaces the
1300 source path list instead of augmenting it.
1302 * GDB now understands thread names.
1304 On GNU/Linux, "info threads" will display the thread name as set by
1305 prctl or pthread_setname_np.
1307 There is also a new command, "thread name", which can be used to
1308 assign a name internally for GDB to display.
1311 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1312 has been integrated into GDB.
1316 ** The function gdb.Write now accepts an optional keyword 'stream'.
1317 This keyword, when provided, will direct the output to either
1318 stdout, stderr, or GDB's logging output.
1320 ** Parameters can now be be sub-classed in Python, and in particular
1321 you may implement the get_set_doc and get_show_doc functions.
1322 This improves how Parameter set/show documentation is processed
1323 and allows for more dynamic content.
1325 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1326 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1327 have an is_valid method.
1329 ** Breakpoints can now be sub-classed in Python, and in particular
1330 you may implement a 'stop' function that is executed each time
1331 the inferior reaches that breakpoint.
1333 ** New function gdb.lookup_global_symbol looks up a global symbol.
1335 ** GDB values in Python are now callable if the value represents a
1336 function. For example, if 'some_value' represents a function that
1337 takes two integer parameters and returns a value, you can call
1338 that function like so:
1340 result = some_value (10,20)
1342 ** Module gdb.types has been added.
1343 It contains a collection of utilities for working with gdb.Types objects:
1344 get_basic_type, has_field, make_enum_dict.
1346 ** Module gdb.printing has been added.
1347 It contains utilities for writing and registering pretty-printers.
1348 New classes: PrettyPrinter, SubPrettyPrinter,
1349 RegexpCollectionPrettyPrinter.
1350 New function: register_pretty_printer.
1352 ** New commands "info pretty-printers", "enable pretty-printer" and
1353 "disable pretty-printer" have been added.
1355 ** gdb.parameter("directories") is now available.
1357 ** New function gdb.newest_frame returns the newest frame in the
1360 ** The gdb.InferiorThread class has a new "name" attribute. This
1361 holds the thread's name.
1363 ** Python Support for Inferior events.
1364 Python scripts can add observers to be notified of events
1365 occurring in the process being debugged.
1366 The following events are currently supported:
1367 - gdb.events.cont Continue event.
1368 - gdb.events.exited Inferior exited event.
1369 - gdb.events.stop Signal received, and Breakpoint hit events.
1373 ** GDB now puts template parameters in scope when debugging in an
1374 instantiation. For example, if you have:
1376 template<int X> int func (void) { return X; }
1378 then if you step into func<5>, "print X" will show "5". This
1379 feature requires proper debuginfo support from the compiler; it
1380 was added to GCC 4.5.
1382 ** The motion commands "next", "finish", "until", and "advance" now
1383 work better when exceptions are thrown. In particular, GDB will
1384 no longer lose control of the inferior; instead, the GDB will
1385 stop the inferior at the point at which the exception is caught.
1386 This functionality requires a change in the exception handling
1387 code that was introduced in GCC 4.5.
1389 * GDB now follows GCC's rules on accessing volatile objects when
1390 reading or writing target state during expression evaluation.
1391 One notable difference to prior behavior is that "print x = 0"
1392 no longer generates a read of x; the value of the assignment is
1393 now always taken directly from the value being assigned.
1395 * GDB now has some support for using labels in the program's source in
1396 linespecs. For instance, you can use "advance label" to continue
1397 execution to a label.
1399 * GDB now has support for reading and writing a new .gdb_index
1400 section. This section holds a fast index of DWARF debugging
1401 information and can be used to greatly speed up GDB startup and
1402 operation. See the documentation for `save gdb-index' for details.
1404 * The "watch" command now accepts an optional "-location" argument.
1405 When used, this causes GDB to watch the memory referred to by the
1406 expression. Such a watchpoint is never deleted due to it going out
1409 * GDB now supports thread debugging of core dumps on GNU/Linux.
1411 GDB now activates thread debugging using the libthread_db library
1412 when debugging GNU/Linux core dumps, similarly to when debugging
1413 live processes. As a result, when debugging a core dump file, GDB
1414 is now able to display pthread_t ids of threads. For example, "info
1415 threads" shows the same output as when debugging the process when it
1416 was live. In earlier releases, you'd see something like this:
1419 * 1 LWP 6780 main () at main.c:10
1421 While now you see this:
1424 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1426 It is also now possible to inspect TLS variables when debugging core
1429 When debugging a core dump generated on a machine other than the one
1430 used to run GDB, you may need to point GDB at the correct
1431 libthread_db library with the "set libthread-db-search-path"
1432 command. See the user manual for more details on this command.
1434 * When natively debugging programs on PowerPC BookE processors running
1435 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1436 which stop execution of the inferior whenever it executes an instruction
1437 at any address within the specified range. See the "PowerPC Embedded"
1438 section in the user manual for more details.
1440 * New features in the GDB remote stub, GDBserver
1442 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1443 and i686 LynxOS (version 5.x).
1445 ** GDBserver is now supported on Blackfin Linux.
1447 * New native configurations
1449 ia64 HP-UX ia64-*-hpux*
1453 Analog Devices, Inc. Blackfin Processor bfin-*
1455 * Ada task switching is now supported on sparc-elf targets when
1456 debugging a program using the Ravenscar Profile. For more information,
1457 see the "Tasking Support when using the Ravenscar Profile" section
1458 in the GDB user manual.
1460 * Guile support was removed.
1462 * New features in the GNU simulator
1464 ** The --map-info flag lists all known core mappings.
1466 ** CFI flashes may be simulated via the "cfi" device.
1468 *** Changes in GDB 7.2
1470 * Shared library support for remote targets by default
1472 When GDB is configured for a generic, non-OS specific target, like
1473 for example, --target=arm-eabi or one of the many *-*-elf targets,
1474 GDB now queries remote stubs for loaded shared libraries using the
1475 `qXfer:libraries:read' packet. Previously, shared library support
1476 was always disabled for such configurations.
1480 ** Argument Dependent Lookup (ADL)
1482 In C++ ADL lookup directs function search to the namespaces of its
1483 arguments even if the namespace has not been imported.
1493 Here the compiler will search for `foo' in the namespace of 'b'
1494 and find A::foo. GDB now supports this. This construct is commonly
1495 used in the Standard Template Library for operators.
1497 ** Improved User Defined Operator Support
1499 In addition to member operators, GDB now supports lookup of operators
1500 defined in a namespace and imported with a `using' directive, operators
1501 defined in the global scope, operators imported implicitly from an
1502 anonymous namespace, and the ADL operators mentioned in the previous
1504 GDB now also supports proper overload resolution for all the previously
1505 mentioned flavors of operators.
1507 ** static const class members
1509 Printing of static const class members that are initialized in the
1510 class definition has been fixed.
1512 * Windows Thread Information Block access.
1514 On Windows targets, GDB now supports displaying the Windows Thread
1515 Information Block (TIB) structure. This structure is visible either
1516 by using the new command `info w32 thread-information-block' or, by
1517 dereferencing the new convenience variable named `$_tlb', a
1518 thread-specific pointer to the TIB. This feature is also supported
1519 when remote debugging using GDBserver.
1521 * Static tracepoints
1523 Static tracepoints are calls in the user program into a tracing
1524 library. One such library is a port of the LTTng kernel tracer to
1525 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1526 When debugging with GDBserver, GDB now supports combining the GDB
1527 tracepoint machinery with such libraries. For example: the user can
1528 use GDB to probe a static tracepoint marker (a call from the user
1529 program into the tracing library) with the new "strace" command (see
1530 "New commands" below). This creates a "static tracepoint" in the
1531 breakpoint list, that can be manipulated with the same feature set
1532 as fast and regular tracepoints. E.g., collect registers, local and
1533 global variables, collect trace state variables, and define
1534 tracepoint conditions. In addition, the user can collect extra
1535 static tracepoint marker specific data, by collecting the new
1536 $_sdata internal variable. When analyzing the trace buffer, you can
1537 inspect $_sdata like any other variable available to GDB. For more
1538 information, see the "Tracepoints" chapter in GDB user manual. New
1539 remote packets have been defined to support static tracepoints, see
1540 the "New remote packets" section below.
1542 * Better reconstruction of tracepoints after disconnected tracing
1544 GDB will attempt to download the original source form of tracepoint
1545 definitions when starting a trace run, and then will upload these
1546 upon reconnection to the target, resulting in a more accurate
1547 reconstruction of the tracepoints that are in use on the target.
1551 You can now exercise direct control over the ways that GDB can
1552 affect your program. For instance, you can disallow the setting of
1553 breakpoints, so that the program can run continuously (assuming
1554 non-stop mode). In addition, the "observer" variable is available
1555 to switch all of the different controls; in observer mode, GDB
1556 cannot affect the target's behavior at all, which is useful for
1557 tasks like diagnosing live systems in the field.
1559 * The new convenience variable $_thread holds the number of the
1562 * New remote packets
1566 Return the address of the Windows Thread Information Block of a given thread.
1570 In response to several of the tracepoint packets, the target may now
1571 also respond with a number of intermediate `qRelocInsn' request
1572 packets before the final result packet, to have GDB handle
1573 relocating an instruction to execute at a different address. This
1574 is particularly useful for stubs that support fast tracepoints. GDB
1575 reports support for this feature in the qSupported packet.
1579 List static tracepoint markers in the target program.
1583 List static tracepoint markers at a given address in the target
1586 qXfer:statictrace:read
1588 Read the static trace data collected (by a `collect $_sdata'
1589 tracepoint action). The remote stub reports support for this packet
1590 to gdb's qSupported query.
1594 Send the current settings of GDB's permission flags.
1598 Send part of the source (textual) form of a tracepoint definition,
1599 which includes location, conditional, and action list.
1601 * The source command now accepts a -s option to force searching for the
1602 script in the source search path even if the script name specifies
1605 * New features in the GDB remote stub, GDBserver
1607 - GDBserver now support tracepoints (including fast tracepoints, and
1608 static tracepoints). The feature is currently supported by the
1609 i386-linux and amd64-linux builds. See the "Tracepoints support
1610 in gdbserver" section in the manual for more information.
1612 GDBserver JIT compiles the tracepoint's conditional agent
1613 expression bytecode into native code whenever possible for low
1614 overhead dynamic tracepoints conditionals. For such tracepoints,
1615 an expression that examines program state is evaluated when the
1616 tracepoint is reached, in order to determine whether to capture
1617 trace data. If the condition is simple and false, processing the
1618 tracepoint finishes very quickly and no data is gathered.
1620 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1621 for static tracepoints support.
1623 - GDBserver now supports x86_64 Windows 64-bit debugging.
1625 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1626 it understands register description.
1628 * The --batch flag now disables pagination and queries.
1630 * X86 general purpose registers
1632 GDB now supports reading/writing byte, word and double-word x86
1633 general purpose registers directly. This means you can use, say,
1634 $ah or $ax to refer, respectively, to the byte register AH and
1635 16-bit word register AX that are actually portions of the 32-bit
1636 register EAX or 64-bit register RAX.
1638 * The `commands' command now accepts a range of breakpoints to modify.
1639 A plain `commands' following a command that creates multiple
1640 breakpoints affects all the breakpoints set by that command. This
1641 applies to breakpoints set by `rbreak', and also applies when a
1642 single `break' command creates multiple breakpoints (e.g.,
1643 breakpoints on overloaded c++ functions).
1645 * The `rbreak' command now accepts a filename specification as part of
1646 its argument, limiting the functions selected by the regex to those
1647 in the specified file.
1649 * Support for remote debugging Windows and SymbianOS shared libraries
1650 from Unix hosts has been improved. Non Windows GDB builds now can
1651 understand target reported file names that follow MS-DOS based file
1652 system semantics, such as file names that include drive letters and
1653 use the backslash character as directory separator. This makes it
1654 possible to transparently use the "set sysroot" and "set
1655 solib-search-path" on Unix hosts to point as host copies of the
1656 target's shared libraries. See the new command "set
1657 target-file-system-kind" described below, and the "Commands to
1658 specify files" section in the user manual for more information.
1662 eval template, expressions...
1663 Convert the values of one or more expressions under the control
1664 of the string template to a command line, and call it.
1666 set target-file-system-kind unix|dos-based|auto
1667 show target-file-system-kind
1668 Set or show the assumed file system kind for target reported file
1671 save breakpoints <filename>
1672 Save all current breakpoint definitions to a file suitable for use
1673 in a later debugging session. To read the saved breakpoint
1674 definitions, use the `source' command.
1676 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1679 info static-tracepoint-markers
1680 Display information about static tracepoint markers in the target.
1682 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1683 Define a static tracepoint by probing a marker at the given
1684 function, line, address, or marker ID.
1688 Enable and disable observer mode.
1690 set may-write-registers on|off
1691 set may-write-memory on|off
1692 set may-insert-breakpoints on|off
1693 set may-insert-tracepoints on|off
1694 set may-insert-fast-tracepoints on|off
1695 set may-interrupt on|off
1696 Set individual permissions for GDB effects on the target. Note that
1697 some of these settings can have undesirable or surprising
1698 consequences, particularly when changed in the middle of a session.
1699 For instance, disabling the writing of memory can prevent
1700 breakpoints from being inserted, cause single-stepping to fail, or
1701 even crash your program, if you disable after breakpoints have been
1702 inserted. However, GDB should not crash.
1704 set record memory-query on|off
1705 show record memory-query
1706 Control whether to stop the inferior if memory changes caused
1707 by an instruction cannot be recorded.
1712 The disassemble command now supports "start,+length" form of two arguments.
1716 ** GDB now provides a new directory location, called the python directory,
1717 where Python scripts written for GDB can be installed. The location
1718 of that directory is <data-directory>/python, where <data-directory>
1719 is the GDB data directory. For more details, see section `Scripting
1720 GDB using Python' in the manual.
1722 ** The GDB Python API now has access to breakpoints, symbols, symbol
1723 tables, program spaces, inferiors, threads and frame's code blocks.
1724 Additionally, GDB Parameters can now be created from the API, and
1725 manipulated via set/show in the CLI.
1727 ** New functions gdb.target_charset, gdb.target_wide_charset,
1728 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1730 ** New exception gdb.GdbError.
1732 ** Pretty-printers are now also looked up in the current program space.
1734 ** Pretty-printers can now be individually enabled and disabled.
1736 ** GDB now looks for names of Python scripts to auto-load in a
1737 special section named `.debug_gdb_scripts', in addition to looking
1738 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1740 * Tracepoint actions were unified with breakpoint commands. In particular,
1741 there are no longer differences in "info break" output for breakpoints and
1742 tracepoints and the "commands" command can be used for both tracepoints and
1743 regular breakpoints.
1747 ARM Symbian arm*-*-symbianelf*
1749 * D language support.
1750 GDB now supports debugging programs written in the D programming
1753 * GDB now supports the extended ptrace interface for PowerPC which is
1754 available since Linux kernel version 2.6.34. This automatically enables
1755 any hardware breakpoints and additional hardware watchpoints available in
1756 the processor. The old ptrace interface exposes just one hardware
1757 watchpoint and no hardware breakpoints.
1759 * GDB is now able to use the Data Value Compare (DVC) register available on
1760 embedded PowerPC processors to implement in hardware simple watchpoint
1761 conditions of the form:
1763 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1765 This works in native GDB running on Linux kernels with the extended ptrace
1766 interface mentioned above.
1768 *** Changes in GDB 7.1
1772 ** Namespace Support
1774 GDB now supports importing of namespaces in C++. This enables the
1775 user to inspect variables from imported namespaces. Support for
1776 namepace aliasing has also been added. So, if a namespace is
1777 aliased in the current scope (e.g. namepace C=A; ) the user can
1778 print variables using the alias (e.g. (gdb) print C::x).
1782 All known bugs relating to the printing of virtual base class were
1783 fixed. It is now possible to call overloaded static methods using a
1788 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1789 and reinterpret_cast<> are now handled by the C++ expression parser.
1793 Xilinx MicroBlaze microblaze-*-*
1798 Xilinx MicroBlaze microblaze
1801 * Multi-program debugging.
1803 GDB now has support for multi-program (a.k.a. multi-executable or
1804 multi-exec) debugging. This allows for debugging multiple inferiors
1805 simultaneously each running a different program under the same GDB
1806 session. See "Debugging Multiple Inferiors and Programs" in the
1807 manual for more information. This implied some user visible changes
1808 in the multi-inferior support. For example, "info inferiors" now
1809 lists inferiors that are not running yet or that have exited
1810 already. See also "New commands" and "New options" below.
1812 * New tracing features
1814 GDB's tracepoint facility now includes several new features:
1816 ** Trace state variables
1818 GDB tracepoints now include support for trace state variables, which
1819 are variables managed by the target agent during a tracing
1820 experiment. They are useful for tracepoints that trigger each
1821 other, so for instance one tracepoint can count hits in a variable,
1822 and then a second tracepoint has a condition that is true when the
1823 count reaches a particular value. Trace state variables share the
1824 $-syntax of GDB convenience variables, and can appear in both
1825 tracepoint actions and condition expressions. Use the "tvariable"
1826 command to create, and "info tvariables" to view; see "Trace State
1827 Variables" in the manual for more detail.
1831 GDB now includes an option for defining fast tracepoints, which
1832 targets may implement more efficiently, such as by installing a jump
1833 into the target agent rather than a trap instruction. The resulting
1834 speedup can be by two orders of magnitude or more, although the
1835 tradeoff is that some program locations on some target architectures
1836 might not allow fast tracepoint installation, for instance if the
1837 instruction to be replaced is shorter than the jump. To request a
1838 fast tracepoint, use the "ftrace" command, with syntax identical to
1839 the regular trace command.
1841 ** Disconnected tracing
1843 It is now possible to detach GDB from the target while it is running
1844 a trace experiment, then reconnect later to see how the experiment
1845 is going. In addition, a new variable disconnected-tracing lets you
1846 tell the target agent whether to continue running a trace if the
1847 connection is lost unexpectedly.
1851 GDB now has the ability to save the trace buffer into a file, and
1852 then use that file as a target, similarly to you can do with
1853 corefiles. You can select trace frames, print data that was
1854 collected in them, and use tstatus to display the state of the
1855 tracing run at the moment that it was saved. To create a trace
1856 file, use "tsave <filename>", and to use it, do "target tfile
1859 ** Circular trace buffer
1861 You can ask the target agent to handle the trace buffer as a
1862 circular buffer, discarding the oldest trace frames to make room for
1863 newer ones, by setting circular-trace-buffer to on. This feature may
1864 not be available for all target agents.
1869 The disassemble command, when invoked with two arguments, now requires
1870 the arguments to be comma-separated.
1873 The info variables command now displays variable definitions. Files
1874 which only declare a variable are not shown.
1877 The source command is now capable of sourcing Python scripts.
1878 This feature is dependent on the debugger being build with Python
1881 Related to this enhancement is also the introduction of a new command
1882 "set script-extension" (see below).
1884 * New commands (for set/show, see "New options" below)
1886 record save [<FILENAME>]
1887 Save a file (in core file format) containing the process record
1888 execution log for replay debugging at a later time.
1890 record restore <FILENAME>
1891 Restore the process record execution log that was saved at an
1892 earlier time, for replay debugging.
1894 add-inferior [-copies <N>] [-exec <FILENAME>]
1897 clone-inferior [-copies <N>] [ID]
1898 Make a new inferior ready to execute the same program another
1899 inferior has loaded.
1904 maint info program-spaces
1905 List the program spaces loaded into GDB.
1907 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1908 show remote interrupt-sequence
1909 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1910 as the sequence to the remote target in order to interrupt the execution.
1911 Ctrl-C is a default. Some system prefers BREAK which is high level of
1912 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1913 Magic SysRq g. It is BREAK signal and character 'g'.
1915 set remote interrupt-on-connect [on | off]
1916 show remote interrupt-on-connect
1917 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1918 remote target when gdb connects to it. This is needed when you debug
1921 set remotebreak [on | off]
1923 Deprecated. Use "set/show remote interrupt-sequence" instead.
1925 tvariable $NAME [ = EXP ]
1926 Create or modify a trace state variable.
1929 List trace state variables and their values.
1931 delete tvariable $NAME ...
1932 Delete one or more trace state variables.
1935 Evaluate the given expressions without collecting anything into the
1936 trace buffer. (Valid in tracepoint actions only.)
1938 ftrace FN / FILE:LINE / *ADDR
1939 Define a fast tracepoint at the given function, line, or address.
1941 * New expression syntax
1943 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1944 GDB now parses 0b101010 identically with 42.
1948 set follow-exec-mode new|same
1949 show follow-exec-mode
1950 Control whether GDB reuses the same inferior across an exec call or
1951 creates a new one. This is useful to be able to restart the old
1952 executable after the inferior having done an exec call.
1954 set default-collect EXPR, ...
1955 show default-collect
1956 Define a list of expressions to be collected at each tracepoint.
1957 This is a useful way to ensure essential items are not overlooked,
1958 such as registers or a critical global variable.
1960 set disconnected-tracing
1961 show disconnected-tracing
1962 If set to 1, the target is instructed to continue tracing if it
1963 loses its connection to GDB. If 0, the target is to stop tracing
1966 set circular-trace-buffer
1967 show circular-trace-buffer
1968 If set to on, the target is instructed to use a circular trace buffer
1969 and discard the oldest trace frames instead of stopping the trace due
1970 to a full trace buffer. If set to off, the trace stops when the buffer
1971 fills up. Some targets may not support this.
1973 set script-extension off|soft|strict
1974 show script-extension
1975 If set to "off", the debugger does not perform any script language
1976 recognition, and all sourced files are assumed to be GDB scripts.
1977 If set to "soft" (the default), files are sourced according to
1978 filename extension, falling back to GDB scripts if the first
1980 If set to "strict", files are sourced according to filename extension.
1982 set ada trust-PAD-over-XVS on|off
1983 show ada trust-PAD-over-XVS
1984 If off, activate a workaround against a bug in the debugging information
1985 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1986 the GCC sources for more information about the GNAT encoding and
1987 PAD types in particular). It is always safe to set this option to
1988 off, but this introduces a slight performance penalty. The default
1991 * Python API Improvements
1993 ** GDB provides the new class gdb.LazyString. This is useful in
1994 some pretty-printing cases. The new method gdb.Value.lazy_string
1995 provides a simple way to create objects of this type.
1997 ** The fields returned by gdb.Type.fields now have an
1998 `is_base_class' attribute.
2000 ** The new method gdb.Type.range returns the range of an array type.
2002 ** The new method gdb.parse_and_eval can be used to parse and
2003 evaluate an expression.
2005 * New remote packets
2008 Define a trace state variable.
2011 Get the current value of a trace state variable.
2014 Set desired tracing behavior upon disconnection.
2017 Set the trace buffer to be linear or circular.
2020 Get data about the tracepoints currently in use.
2024 Process record now works correctly with hardware watchpoints.
2026 Multiple bug fixes have been made to the mips-irix port, making it
2027 much more reliable. In particular:
2028 - Debugging threaded applications is now possible again. Previously,
2029 GDB would hang while starting the program, or while waiting for
2030 the program to stop at a breakpoint.
2031 - Attaching to a running process no longer hangs.
2032 - An error occurring while loading a core file has been fixed.
2033 - Changing the value of the PC register now works again. This fixes
2034 problems observed when using the "jump" command, or when calling
2035 a function from GDB, or even when assigning a new value to $pc.
2036 - With the "finish" and "return" commands, the return value for functions
2037 returning a small array is now correctly printed.
2038 - It is now possible to break on shared library code which gets executed
2039 during a shared library init phase (code executed while executing
2040 their .init section). Previously, the breakpoint would have no effect.
2041 - GDB is now able to backtrace through the signal handler for
2042 non-threaded programs.
2044 PIE (Position Independent Executable) programs debugging is now supported.
2045 This includes debugging execution of PIC (Position Independent Code) shared
2046 libraries although for that, it should be possible to run such libraries as an
2049 *** Changes in GDB 7.0
2051 * GDB now has an interface for JIT compilation. Applications that
2052 dynamically generate code can create symbol files in memory and register
2053 them with GDB. For users, the feature should work transparently, and
2054 for JIT developers, the interface is documented in the GDB manual in the
2055 "JIT Compilation Interface" chapter.
2057 * Tracepoints may now be conditional. The syntax is as for
2058 breakpoints; either an "if" clause appended to the "trace" command,
2059 or the "condition" command is available. GDB sends the condition to
2060 the target for evaluation using the same bytecode format as is used
2061 for tracepoint actions.
2063 * The disassemble command now supports: an optional /r modifier, print the
2064 raw instructions in hex as well as in symbolic form, and an optional /m
2065 modifier to print mixed source+assembly.
2067 * Process record and replay
2069 In a architecture environment that supports ``process record and
2070 replay'', ``process record and replay'' target can record a log of
2071 the process execution, and replay it with both forward and reverse
2074 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2075 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2076 set execution-direction {forward|reverse}, for targets that support
2079 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2080 feature is available with a native GDB running on kernel version
2083 * GDB now has support for multi-byte and wide character sets on the
2084 target. Strings whose character type is wchar_t, char16_t, or
2085 char32_t are now correctly printed. GDB supports wide- and unicode-
2086 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2087 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2088 `printf'. This feature requires iconv to work properly; if your
2089 system does not have a working iconv, GDB can use GNU libiconv. See
2090 the installation instructions for more information.
2092 * GDB now supports automatic retrieval of shared library files from
2093 remote targets. To use this feature, specify a system root that begins
2094 with the `remote:' prefix, either via the `set sysroot' command or via
2095 the `--with-sysroot' configure-time option.
2097 * "info sharedlibrary" now takes an optional regex of libraries to show,
2098 and it now reports if a shared library has no debugging information.
2100 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2101 now complete on file names.
2103 * When completing in expressions, gdb will attempt to limit
2104 completions to allowable structure or union fields, where appropriate.
2105 For instance, consider:
2107 # struct example { int f1; double f2; };
2108 # struct example variable;
2111 If the user types TAB at the end of this command line, the available
2112 completions will be "f1" and "f2".
2114 * Inlined functions are now supported. They show up in backtraces, and
2115 the "step", "next", and "finish" commands handle them automatically.
2117 * GDB now supports the token-splicing (##) and stringification (#)
2118 operators when expanding macros. It also supports variable-arity
2121 * GDB now supports inspecting extra signal information, exported by
2122 the new $_siginfo convenience variable. The feature is currently
2123 implemented on linux ARM, i386 and amd64.
2125 * GDB can now display the VFP floating point registers and NEON vector
2126 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2127 can provide these registers (requires Linux 2.6.30 or later). Remote
2128 and simulator targets may also provide them.
2130 * New remote packets
2133 Search memory for a sequence of bytes.
2136 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2137 operation over reliable transport links. Use of this packet is
2138 controlled by the `set remote noack-packet' command.
2141 Kill the process with the specified process ID. Use this in preference
2142 to `k' when multiprocess protocol extensions are supported.
2145 Obtains additional operating system information
2149 Read or write additional signal information.
2151 * Removed remote protocol undocumented extension
2153 An undocumented extension to the remote protocol's `S' stop reply
2154 packet that permited the stub to pass a process id was removed.
2155 Remote servers should use the `T' stop reply packet instead.
2157 * GDB now supports multiple function calling conventions according to the
2158 DWARF-2 DW_AT_calling_convention function attribute.
2160 * The SH target utilizes the aforementioned change to distinguish between gcc
2161 and Renesas calling convention. It also adds the new CLI commands
2162 `set/show sh calling-convention'.
2164 * GDB can now read compressed debug sections, as produced by GNU gold
2165 with the --compress-debug-sections=zlib flag.
2167 * 64-bit core files are now supported on AIX.
2169 * Thread switching is now supported on Tru64.
2171 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2172 which will be allocated using malloc later in program execution.
2174 * The qXfer:libraries:read remote procotol packet now allows passing a
2175 list of section offsets.
2177 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2178 conditions handling signals delivered during attach or thread creation
2179 have also been fixed.
2181 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2182 From the user's standpoint, all unqualified instances of True and False
2183 are treated as the standard definitions, regardless of context.
2185 * GDB now parses C++ symbol and type names more flexibly. For
2188 template<typename T> class C { };
2191 GDB will now correctly handle all of:
2193 ptype C<char const *>
2194 ptype C<char const*>
2195 ptype C<const char *>
2196 ptype C<const char*>
2198 * New features in the GDB remote stub, gdbserver
2200 - The "--wrapper" command-line argument tells gdbserver to use a
2201 wrapper program to launch programs for debugging.
2203 - On PowerPC and S/390 targets, it is now possible to use a single
2204 gdbserver executable to debug both 32-bit and 64-bit programs.
2205 (This requires gdbserver itself to be built as a 64-bit executable.)
2207 - gdbserver uses the new noack protocol mode for TCP connections to
2208 reduce communications latency, if also supported and enabled in GDB.
2210 - Support for the sparc64-linux-gnu target is now included in
2213 - The amd64-linux build of gdbserver now supports debugging both
2214 32-bit and 64-bit programs.
2216 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2217 now support hardware watchpoints, and will use them automatically
2222 GDB now has support for scripting using Python. Whether this is
2223 available is determined at configure time.
2225 New GDB commands can now be written in Python.
2227 * Ada tasking support
2229 Ada tasks can now be inspected in GDB. The following commands have
2233 Print the list of Ada tasks.
2235 Print detailed information about task number N.
2237 Print the task number of the current task.
2239 Switch the context of debugging to task number N.
2241 * Support for user-defined prefixed commands. The "define" command can
2242 add new commands to existing prefixes, e.g. "target".
2244 * Multi-inferior, multi-process debugging.
2246 GDB now has generalized support for multi-inferior debugging. See
2247 "Debugging Multiple Inferiors" in the manual for more information.
2248 Although availability still depends on target support, the command
2249 set is more uniform now. The GNU/Linux specific multi-forks support
2250 has been migrated to this new framework. This implied some user
2251 visible changes; see "New commands" and also "Removed commands"
2254 * Target descriptions can now describe the target OS ABI. See the
2255 "Target Description Format" section in the user manual for more
2258 * Target descriptions can now describe "compatible" architectures
2259 to indicate that the target can execute applications for a different
2260 architecture in addition to those for the main target architecture.
2261 See the "Target Description Format" section in the user manual for
2264 * Multi-architecture debugging.
2266 GDB now includes general supports for debugging applications on
2267 hybrid systems that use more than one single processor architecture
2268 at the same time. Each such hybrid architecture still requires
2269 specific support to be added. The only hybrid architecture supported
2270 in this version of GDB is the Cell Broadband Engine.
2272 * GDB now supports integrated debugging of Cell/B.E. applications that
2273 use both the PPU and SPU architectures. To enable support for hybrid
2274 Cell/B.E. debugging, you need to configure GDB to support both the
2275 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2276 --enable-targets configure option.
2278 * Non-stop mode debugging.
2280 For some targets, GDB now supports an optional mode of operation in
2281 which you can examine stopped threads while other threads continue
2282 to execute freely. This is referred to as non-stop mode, with the
2283 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2284 section in the user manual for more information.
2286 To be able to support remote non-stop debugging, a remote stub needs
2287 to implement the non-stop mode remote protocol extensions, as
2288 described in the "Remote Non-Stop" section of the user manual. The
2289 GDB remote stub, gdbserver, has been adjusted to support these
2290 extensions on linux targets.
2292 * New commands (for set/show, see "New options" below)
2294 catch syscall [NAME(S) | NUMBER(S)]
2295 Catch system calls. Arguments, which should be names of system
2296 calls or their numbers, mean catch only those syscalls. Without
2297 arguments, every syscall will be caught. When the inferior issues
2298 any of the specified syscalls, GDB will stop and announce the system
2299 call, both when it is called and when its call returns. This
2300 feature is currently available with a native GDB running on the
2301 Linux Kernel, under the following architectures: x86, x86_64,
2302 PowerPC and PowerPC64.
2304 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2306 Search memory for a sequence of bytes.
2308 maint set python print-stack
2309 maint show python print-stack
2310 Show a stack trace when an error is encountered in a Python script.
2313 Invoke CODE by passing it to the Python interpreter.
2318 These allow macros to be defined, undefined, and listed
2322 Show operating system information about processes.
2325 List the inferiors currently under GDB's control.
2328 Switch focus to inferior number NUM.
2331 Detach from inferior number NUM.
2334 Kill inferior number NUM.
2338 set spu stop-on-load
2339 show spu stop-on-load
2340 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2342 set spu auto-flush-cache
2343 show spu auto-flush-cache
2344 Control whether to automatically flush the software-managed cache
2345 during Cell/B.E. debugging.
2347 set sh calling-convention
2348 show sh calling-convention
2349 Control the calling convention used when calling SH target functions.
2352 show debug timestamp
2353 Control display of timestamps with GDB debugging output.
2355 set disassemble-next-line
2356 show disassemble-next-line
2357 Control display of disassembled source lines or instructions when
2360 set remote noack-packet
2361 show remote noack-packet
2362 Set/show the use of remote protocol QStartNoAckMode packet. See above
2363 under "New remote packets."
2365 set remote query-attached-packet
2366 show remote query-attached-packet
2367 Control use of remote protocol `qAttached' (query-attached) packet.
2369 set remote read-siginfo-object
2370 show remote read-siginfo-object
2371 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2374 set remote write-siginfo-object
2375 show remote write-siginfo-object
2376 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2379 set remote reverse-continue
2380 show remote reverse-continue
2381 Control use of remote protocol 'bc' (reverse-continue) packet.
2383 set remote reverse-step
2384 show remote reverse-step
2385 Control use of remote protocol 'bs' (reverse-step) packet.
2387 set displaced-stepping
2388 show displaced-stepping
2389 Control displaced stepping mode. Displaced stepping is a way to
2390 single-step over breakpoints without removing them from the debuggee.
2391 Also known as "out-of-line single-stepping".
2394 show debug displaced
2395 Control display of debugging info for displaced stepping.
2397 maint set internal-error
2398 maint show internal-error
2399 Control what GDB does when an internal error is detected.
2401 maint set internal-warning
2402 maint show internal-warning
2403 Control what GDB does when an internal warning is detected.
2408 Use a wrapper program to launch programs for debugging.
2410 set multiple-symbols (all|ask|cancel)
2411 show multiple-symbols
2412 The value of this variable can be changed to adjust the debugger behavior
2413 when an expression or a breakpoint location contains an ambiguous symbol
2414 name (an overloaded function name, for instance).
2416 set breakpoint always-inserted
2417 show breakpoint always-inserted
2418 Keep breakpoints always inserted in the target, as opposed to inserting
2419 them when resuming the target, and removing them when the target stops.
2420 This option can improve debugger performance on slow remote targets.
2422 set arm fallback-mode (arm|thumb|auto)
2423 show arm fallback-mode
2424 set arm force-mode (arm|thumb|auto)
2426 These commands control how ARM GDB determines whether instructions
2427 are ARM or Thumb. The default for both settings is auto, which uses
2428 the current CPSR value for instructions without symbols; previous
2429 versions of GDB behaved as if "set arm fallback-mode arm".
2431 set disable-randomization
2432 show disable-randomization
2433 Standalone programs run with the virtual address space randomization enabled
2434 by default on some platforms. This option keeps the addresses stable across
2435 multiple debugging sessions.
2439 Control whether other threads are stopped or not when some thread hits
2444 Requests that asynchronous execution is enabled in the target, if available.
2445 In this case, it's possible to resume target in the background, and interact
2446 with GDB while the target is running. "show target-async" displays the
2447 current state of asynchronous execution of the target.
2449 set target-wide-charset
2450 show target-wide-charset
2451 The target-wide-charset is the name of the character set that GDB
2452 uses when printing characters whose type is wchar_t.
2454 set tcp auto-retry (on|off)
2456 set tcp connect-timeout
2457 show tcp connect-timeout
2458 These commands allow GDB to retry failed TCP connections to a remote stub
2459 with a specified timeout period; this is useful if the stub is launched
2460 in parallel with GDB but may not be ready to accept connections immediately.
2462 set libthread-db-search-path
2463 show libthread-db-search-path
2464 Control list of directories which GDB will search for appropriate
2467 set schedule-multiple (on|off)
2468 show schedule-multiple
2469 Allow GDB to resume all threads of all processes or only threads of
2470 the current process.
2474 Use more aggressive caching for accesses to the stack. This improves
2475 performance of remote debugging (particularly backtraces) without
2476 affecting correctness.
2478 set interactive-mode (on|off|auto)
2479 show interactive-mode
2480 Control whether GDB runs in interactive mode (on) or not (off).
2481 When in interactive mode, GDB waits for the user to answer all
2482 queries. Otherwise, GDB does not wait and assumes the default
2483 answer. When set to auto (the default), GDB determines which
2484 mode to use based on the stdin settings.
2489 For program forks, this is replaced by the new more generic `info
2490 inferiors' command. To list checkpoints, you can still use the
2491 `info checkpoints' command, which was an alias for the `info forks'
2495 Replaced by the new `inferior' command. To switch between
2496 checkpoints, you can still use the `restart' command, which was an
2497 alias for the `fork' command.
2500 This is removed, since some targets don't have a notion of
2501 processes. To switch between processes, you can still use the
2502 `inferior' command using GDB's own inferior number.
2505 For program forks, this is replaced by the new more generic `kill
2506 inferior' command. To delete a checkpoint, you can still use the
2507 `delete checkpoint' command, which was an alias for the `delete
2511 For program forks, this is replaced by the new more generic `detach
2512 inferior' command. To detach a checkpoint, you can still use the
2513 `detach checkpoint' command, which was an alias for the `detach
2516 * New native configurations
2518 x86/x86_64 Darwin i[34567]86-*-darwin*
2520 x86_64 MinGW x86_64-*-mingw*
2524 Lattice Mico32 lm32-*
2525 x86 DICOS i[34567]86-*-dicos*
2526 x86_64 DICOS x86_64-*-dicos*
2529 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2530 (mingw32ce) debugging.
2536 These commands were actually not implemented on any target.
2538 *** Changes in GDB 6.8
2540 * New native configurations
2542 NetBSD/hppa hppa*-*netbsd*
2543 Xtensa GNU/Linux xtensa*-*-linux*
2547 NetBSD/hppa hppa*-*-netbsd*
2548 Xtensa GNU/Lunux xtensa*-*-linux*
2550 * Change in command line behavior -- corefiles vs. process ids.
2552 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2553 attaching to process NUMBER fails, GDB no longer attempts to open a
2554 core file named NUMBER. Attaching to a program using the -c option
2555 is no longer supported. Instead, use the '-p' or '--pid' options.
2557 * GDB can now be built as a native debugger for debugging Windows x86
2558 (mingw32) Portable Executable (PE) programs.
2560 * Pending breakpoints no longer change their number when their address
2563 * GDB now supports breakpoints with multiple locations,
2564 including breakpoints on C++ constructors, inside C++ templates,
2565 and in inlined functions.
2567 * GDB's ability to debug optimized code has been improved. GDB more
2568 accurately identifies function bodies and lexical blocks that occupy
2569 more than one contiguous range of addresses.
2571 * Target descriptions can now describe registers for PowerPC.
2573 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2574 registers on PowerPC targets.
2576 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2577 targets even when the libthread_db library is not available.
2579 * The GDB remote stub, gdbserver, now supports the new file transfer
2580 commands (remote put, remote get, and remote delete).
2582 * The GDB remote stub, gdbserver, now supports run and attach in
2583 extended-remote mode.
2585 * hppa*64*-*-hpux11* target broken
2586 The debugger is unable to start a program and fails with the following
2587 error: "Error trying to get information about dynamic linker".
2588 The gdb-6.7 release is also affected.
2590 * GDB now supports the --enable-targets= configure option to allow
2591 building a single GDB executable that supports multiple remote
2592 target architectures.
2594 * GDB now supports debugging C and C++ programs which use the
2595 Decimal Floating Point extension. In addition, the PowerPC target
2596 now has a set of pseudo-registers to inspect decimal float values
2597 stored in two consecutive float registers.
2599 * The -break-insert MI command can optionally create pending
2602 * Improved support for debugging Ada
2603 Many improvements to the Ada language support have been made. These
2605 - Better support for Ada2005 interface types
2606 - Improved handling of arrays and slices in general
2607 - Better support for Taft-amendment types
2608 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2610 - Improved command completion in Ada
2613 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2618 set print frame-arguments (all|scalars|none)
2619 show print frame-arguments
2620 The value of this variable can be changed to control which argument
2621 values should be printed by the debugger when displaying a frame.
2626 Transfer files to and from a remote target, and delete remote files.
2633 Transfer files to and from a remote target, and delete remote files.
2635 * New remote packets
2642 Open, close, read, write, and delete files on the remote system.
2645 Attach to an existing process on the remote system, in extended-remote
2649 Run a new process on the remote system, in extended-remote mode.
2651 *** Changes in GDB 6.7
2653 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2654 bfd, libiberty and opcodes, as revealed by static analysis donated by
2655 Coverity, Inc. (http://scan.coverity.com).
2657 * When looking up multiply-defined global symbols, GDB will now prefer the
2658 symbol definition in the current shared library if it was built using the
2659 -Bsymbolic linker option.
2661 * When the Text User Interface (TUI) is not configured, GDB will now
2662 recognize the -tui command-line option and print a message that the TUI
2665 * The GDB remote stub, gdbserver, now has lower overhead for high
2666 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2668 * GDB for MIPS targets now autodetects whether a remote target provides
2669 32-bit or 64-bit register values.
2671 * Support for C++ member pointers has been improved.
2673 * GDB now understands XML target descriptions, which specify the
2674 target's overall architecture. GDB can read a description from
2675 a local file or over the remote serial protocol.
2677 * Vectors of single-byte data use a new integer type which is not
2678 automatically displayed as character or string data.
2680 * The /s format now works with the print command. It displays
2681 arrays of single-byte integers and pointers to single-byte integers
2684 * Target descriptions can now describe target-specific registers,
2685 for architectures which have implemented the support (currently
2686 only ARM, M68K, and MIPS).
2688 * GDB and the GDB remote stub, gdbserver, now support the XScale
2691 * The GDB remote stub, gdbserver, has been updated to support
2692 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2693 has been rewritten to use the standard GDB remote protocol.
2695 * GDB can now step into C++ functions which are called through thunks.
2697 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2699 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2700 layout. It also supports a TextSeg= and DataSeg= response when only
2701 segment base addresses (rather than offsets) are available.
2703 * The /i format now outputs any trailing branch delay slot instructions
2704 immediately following the last instruction within the count specified.
2706 * The GDB remote protocol "T" stop reply packet now supports a
2707 "library" response. Combined with the new "qXfer:libraries:read"
2708 packet, this response allows GDB to debug shared libraries on targets
2709 where the operating system manages the list of loaded libraries (e.g.
2710 Windows and SymbianOS).
2712 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2713 (DLLs) on Windows and Windows CE targets.
2715 * GDB now supports a faster verification that a .debug file matches its binary
2716 according to its build-id signature, if the signature is present.
2722 Enable or disable hardware flow control (RTS/CTS) on the serial port
2723 when debugging using remote targets.
2725 set mem inaccessible-by-default
2726 show mem inaccessible-by-default
2727 If the target supplies a memory map, for instance via the remote
2728 protocol's "qXfer:memory-map:read" packet, setting this variable
2729 prevents GDB from accessing memory outside the memory map. This
2730 is useful for targets with memory mapped registers or which react
2731 badly to accesses of unmapped address space.
2733 set breakpoint auto-hw
2734 show breakpoint auto-hw
2735 If the target supplies a memory map, for instance via the remote
2736 protocol's "qXfer:memory-map:read" packet, setting this variable
2737 lets GDB use hardware breakpoints automatically for memory regions
2738 where it can not use software breakpoints. This covers both the
2739 "break" command and internal breakpoints used for other commands
2740 including "next" and "finish".
2743 catch exception unhandled
2744 Stop the program execution when Ada exceptions are raised.
2747 Stop the program execution when an Ada assertion failed.
2751 Set an alternate system root for target files. This is a more
2752 general version of "set solib-absolute-prefix", which is now
2753 an alias to "set sysroot".
2756 Provide extended SPU facility status information. This set of
2757 commands is available only when debugging the Cell/B.E. SPU
2760 * New native configurations
2762 OpenBSD/sh sh*-*openbsd*
2765 unset tdesc filename
2767 Use the specified local file as an XML target description, and do
2768 not query the target for its built-in description.
2772 OpenBSD/sh sh*-*-openbsd*
2773 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2774 Toshiba Media Processor mep-elf
2776 * New remote packets
2779 Ignore the specified signals; pass them directly to the debugged program
2780 without stopping other threads or reporting them to GDB.
2782 qXfer:features:read:
2783 Read an XML target description from the target, which describes its
2788 Read or write contents of an spufs file on the target system. These
2789 packets are available only on the Cell/B.E. SPU architecture.
2791 qXfer:libraries:read:
2792 Report the loaded shared libraries. Combined with new "T" packet
2793 response, this packet allows GDB to debug shared libraries on
2794 targets where the operating system manages the list of loaded
2795 libraries (e.g. Windows and SymbianOS).
2799 Support for these obsolete configurations has been removed.
2807 i[34567]86-*-lynxos*
2808 i[34567]86-*-netware*
2809 i[34567]86-*-sco3.2v5*
2810 i[34567]86-*-sco3.2v4*
2812 i[34567]86-*-sysv4.2*
2815 i[34567]86-*-unixware2*
2816 i[34567]86-*-unixware*
2825 * Other removed features
2832 Various m68k-only ROM monitors.
2839 Various Renesas ROM monitors and debugging interfaces for SH and
2844 Support for a Macraigor serial interface to on-chip debugging.
2845 GDB does not directly support the newer parallel or USB
2850 A debug information format. The predecessor to DWARF 2 and
2851 DWARF 3, which are still supported.
2853 Support for the HP aCC compiler on HP-UX/PA-RISC
2855 SOM-encapsulated symbolic debugging information, automatic
2856 invocation of pxdb, and the aCC custom C++ ABI. This does not
2857 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2858 with aCC can still be debugged on an assembly level.
2860 MIPS ".pdr" sections
2862 A MIPS-specific format used to describe stack frame layout
2863 in debugging information.
2867 GDB could work with an older version of Guile to debug
2868 the interpreter and Scheme programs running in it.
2870 set mips stack-arg-size
2871 set mips saved-gpreg-size
2873 Use "set mips abi" to control parameter passing for MIPS.
2875 *** Changes in GDB 6.6
2880 Cell Broadband Engine SPU spu-elf
2882 * GDB can now be configured as a cross-debugger targeting native Windows
2883 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2884 running on a Windows system over TCP/IP to debug Windows programs.
2886 * The GDB remote stub, gdbserver, has been updated to support Windows and
2887 Cygwin debugging. Both single-threaded and multi-threaded programs are
2890 * The "set trust-readonly-sections" command works again. This command was
2891 broken in GDB 6.3, 6.4, and 6.5.
2893 * The "load" command now supports writing to flash memory, if the remote
2894 stub provides the required support.
2896 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2897 longer requires symbolic debug information (e.g. DWARF-2).
2902 unset substitute-path
2903 show substitute-path
2904 Manage a list of substitution rules that GDB uses to rewrite the name
2905 of the directories where the sources are located. This can be useful
2906 for instance when the sources were moved to a different location
2907 between compilation and debugging.
2911 Print each CLI command as it is executed. Each command is prefixed with
2912 a number of `+' symbols representing the nesting depth.
2913 The source command now has a `-v' option to enable the same feature.
2917 The ARM Demon monitor support (RDP protocol, "target rdp").
2919 Kernel Object Display, an embedded debugging feature which only worked with
2920 an obsolete version of Cisco IOS.
2922 The 'set download-write-size' and 'show download-write-size' commands.
2924 * New remote packets
2927 Tell a stub about GDB client features, and request remote target features.
2928 The first feature implemented is PacketSize, which allows the target to
2929 specify the size of packets it can handle - to minimize the number of
2930 packets required and improve performance when connected to a remote
2934 Fetch an OS auxilliary vector from the remote stub. This packet is a
2935 more efficient replacement for qPart:auxv:read.
2937 qXfer:memory-map:read:
2938 Fetch a memory map from the remote stub, including information about
2939 RAM, ROM, and flash memory devices.
2944 Erase and program a flash memory device.
2946 * Removed remote packets
2949 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2950 used it, and only gdbserver implemented it.
2952 *** Changes in GDB 6.5
2956 Renesas M32C/M16C m32c-elf
2958 Morpho Technologies ms1 ms1-elf
2962 init-if-undefined Initialize a convenience variable, but
2963 only if it doesn't already have a value.
2965 The following commands are presently only implemented for native GNU/Linux:
2967 checkpoint Save a snapshot of the program state.
2969 restart <n> Return the program state to a
2970 previously saved state.
2972 info checkpoints List currently saved checkpoints.
2974 delete-checkpoint <n> Delete a previously saved checkpoint.
2976 set|show detach-on-fork Tell gdb whether to detach from a newly
2977 forked process, or to keep debugging it.
2979 info forks List forks of the user program that
2980 are available to be debugged.
2982 fork <n> Switch to debugging one of several
2983 forks of the user program that are
2984 available to be debugged.
2986 delete-fork <n> Delete a fork from the list of forks
2987 that are available to be debugged (and
2988 kill the forked process).
2990 detach-fork <n> Delete a fork from the list of forks
2991 that are available to be debugged (and
2992 allow the process to continue).
2996 Morpho Technologies ms2 ms1-elf
2998 * Improved Windows host support
3000 GDB now builds as a cross debugger hosted on i686-mingw32, including
3001 native console support, and remote communications using either
3002 network sockets or serial ports.
3004 * Improved Modula-2 language support
3006 GDB can now print most types in the Modula-2 syntax. This includes:
3007 basic types, set types, record types, enumerated types, range types,
3008 pointer types and ARRAY types. Procedure var parameters are correctly
3009 printed and hexadecimal addresses and character constants are also
3010 written in the Modula-2 syntax. Best results can be obtained by using
3011 GNU Modula-2 together with the -gdwarf-2 command line option.
3015 The ARM rdi-share module.
3017 The Netware NLM debug server.
3019 *** Changes in GDB 6.4
3021 * New native configurations
3023 OpenBSD/arm arm*-*-openbsd*
3024 OpenBSD/mips64 mips64-*-openbsd*
3028 Morpho Technologies ms1 ms1-elf
3030 * New command line options
3032 --batch-silent As for --batch, but totally silent.
3033 --return-child-result The debugger will exist with the same value
3034 the child (debugged) program exited with.
3035 --eval-command COMMAND, -ex COMMAND
3036 Execute a single GDB CLI command. This may be
3037 specified multiple times and in conjunction
3038 with the --command (-x) option.
3040 * Deprecated commands removed
3042 The following commands, that were deprecated in 2000, have been
3046 set|show arm disassembly-flavor set|show arm disassembler
3047 othernames set arm disassembler
3048 set|show remotedebug set|show debug remote
3049 set|show archdebug set|show debug arch
3050 set|show eventdebug set|show debug event
3053 * New BSD user-level threads support
3055 It is now possible to debug programs using the user-level threads
3056 library on OpenBSD and FreeBSD. Currently supported (target)
3059 FreeBSD/amd64 x86_64-*-freebsd*
3060 FreeBSD/i386 i386-*-freebsd*
3061 OpenBSD/i386 i386-*-openbsd*
3063 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3064 are not yet supported.
3066 * New support for Matsushita MN10300 w/sim added
3067 (Work in progress). mn10300-elf.
3069 * REMOVED configurations and files
3071 VxWorks and the XDR protocol *-*-vxworks
3072 Motorola MCORE mcore-*-*
3073 National Semiconductor NS32000 ns32k-*-*
3075 * New "set print array-indexes" command
3077 After turning this setting "on", GDB prints the index of each element
3078 when displaying arrays. The default is "off" to preserve the previous
3081 * VAX floating point support
3083 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3085 * User-defined command support
3087 In addition to using $arg0..$arg9 for argument passing, it is now possible
3088 to use $argc to determine now many arguments have been passed. See the
3089 section on user-defined commands in the user manual for more information.
3091 *** Changes in GDB 6.3:
3093 * New command line option
3095 GDB now accepts -l followed by a number to set the timeout for remote
3098 * GDB works with GCC -feliminate-dwarf2-dups
3100 GDB now supports a more compact representation of DWARF-2 debug
3101 information using DW_FORM_ref_addr references. These are produced
3102 by GCC with the option -feliminate-dwarf2-dups and also by some
3103 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3104 to use -feliminate-dwarf2-dups.
3106 * Internationalization
3108 When supported by the host system, GDB will be built with
3109 internationalization (libintl). The task of marking up the sources is
3110 continued, we're looking forward to our first translation.
3114 Initial support for debugging programs compiled with the GNAT
3115 implementation of the Ada programming language has been integrated
3116 into GDB. In this release, support is limited to expression evaluation.
3118 * New native configurations
3120 GNU/Linux/m32r m32r-*-linux-gnu
3124 GDB's remote protocol now includes support for the 'p' packet. This
3125 packet is used to fetch individual registers from a remote inferior.
3127 * END-OF-LIFE registers[] compatibility module
3129 GDB's internal register infrastructure has been completely rewritten.
3130 The new infrastructure making possible the implementation of key new
3131 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3134 GDB 6.3 will be the last release to include the the registers[]
3135 compatibility module that allowed out-of-date configurations to
3136 continue to work. This change directly impacts the following
3146 powerpc bdm protocol
3148 Unless there is activity to revive these configurations, they will be
3149 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3151 * OBSOLETE configurations and files
3153 Configurations that have been declared obsolete in this release have
3154 been commented out. Unless there is activity to revive these
3155 configurations, the next release of GDB will have their sources
3156 permanently REMOVED.
3165 *** Changes in GDB 6.2.1:
3167 * MIPS `break main; run' gave an heuristic-fence-post warning
3169 When attempting to run even a simple program, a warning about
3170 heuristic-fence-post being hit would be reported. This problem has
3173 * MIPS IRIX 'long double' crashed GDB
3175 When examining a long double variable, GDB would get a segmentation
3176 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3177 IRIX long double values).
3181 A bug in the VAX stack code was causing problems with the "next"
3182 command. This problem has been fixed.
3184 *** Changes in GDB 6.2:
3186 * Fix for ``many threads''
3188 On GNU/Linux systems that use the NPTL threads library, a program
3189 rapidly creating and deleting threads would confuse GDB leading to the
3192 ptrace: No such process.
3193 thread_db_get_info: cannot get thread info: generic error
3195 This problem has been fixed.
3197 * "-async" and "-noasync" options removed.
3199 Support for the broken "-noasync" option has been removed (it caused
3202 * New ``start'' command.
3204 This command runs the program until the begining of the main procedure.
3206 * New BSD Kernel Data Access Library (libkvm) interface
3208 Using ``target kvm'' it is now possible to debug kernel core dumps and
3209 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3210 platforms. Currently supported (native-only) configurations are:
3212 FreeBSD/amd64 x86_64-*-freebsd*
3213 FreeBSD/i386 i?86-*-freebsd*
3214 NetBSD/i386 i?86-*-netbsd*
3215 NetBSD/m68k m68*-*-netbsd*
3216 NetBSD/sparc sparc-*-netbsd*
3217 OpenBSD/amd64 x86_64-*-openbsd*
3218 OpenBSD/i386 i?86-*-openbsd*
3219 OpenBSD/m68k m68*-openbsd*
3220 OpenBSD/sparc sparc-*-openbsd*
3222 * Signal trampoline code overhauled
3224 Many generic problems with GDB's signal handling code have been fixed.
3225 These include: backtraces through non-contiguous stacks; recognition
3226 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3227 call; backtrace through a signal trampoline; step into and out of
3228 signal handlers; and single-stepping in the signal trampoline.
3230 Please note that kernel bugs are a limiting factor here. These
3231 features have been shown to work on an s390 GNU/Linux system that
3232 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3234 * Cygwin support for DWARF 2 added.
3236 * New native configurations
3238 GNU/Linux/hppa hppa*-*-linux*
3239 OpenBSD/hppa hppa*-*-openbsd*
3240 OpenBSD/m68k m68*-*-openbsd*
3241 OpenBSD/m88k m88*-*-openbsd*
3242 OpenBSD/powerpc powerpc-*-openbsd*
3243 NetBSD/vax vax-*-netbsd*
3244 OpenBSD/vax vax-*-openbsd*
3246 * END-OF-LIFE frame compatibility module
3248 GDB's internal frame infrastructure has been completely rewritten.
3249 The new infrastructure making it possible to support key new features
3250 including DWARF 2 Call Frame Information. To aid in the task of
3251 migrating old configurations to this new infrastructure, a
3252 compatibility module, that allowed old configurations to continue to
3253 work, was also included.
3255 GDB 6.2 will be the last release to include this frame compatibility
3256 module. This change directly impacts the following configurations:
3266 Unless there is activity to revive these configurations, they will be
3267 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3269 * REMOVED configurations and files
3271 Sun 3, running SunOS 3 m68*-*-sunos3*
3272 Sun 3, running SunOS 4 m68*-*-sunos4*
3273 Sun 2, running SunOS 3 m68000-*-sunos3*
3274 Sun 2, running SunOS 4 m68000-*-sunos4*
3275 Motorola 680x0 running LynxOS m68*-*-lynxos*
3276 AT&T 3b1/Unix pc m68*-att-*
3277 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3278 decstation mips-dec-* mips-little-*
3279 riscos mips-*-riscos* mips-*-sysv*
3280 sonymips mips-sony-*
3281 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3283 *** Changes in GDB 6.1.1:
3285 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3287 The TUI (Text-mode User Interface) is now built as part of a default
3288 GDB configuration. It is enabled by either selecting the TUI with the
3289 command line option "-i=tui" or by running the separate "gdbtui"
3290 program. For more information on the TUI, see the manual "Debugging
3293 * Pending breakpoint support (also included in GDB 6.1)
3295 Support has been added to allow you to specify breakpoints in shared
3296 libraries that have not yet been loaded. If a breakpoint location
3297 cannot be found, and the "breakpoint pending" option is set to auto,
3298 GDB queries you if you wish to make the breakpoint pending on a future
3299 shared-library load. If and when GDB resolves the breakpoint symbol,
3300 the pending breakpoint is removed as one or more regular breakpoints
3303 Pending breakpoints are very useful for GCJ Java debugging.
3305 * Fixed ISO-C build problems
3307 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3308 non ISO-C code that stopped them being built using a more strict ISO-C
3309 compiler (e.g., IBM's C compiler).
3311 * Fixed build problem on IRIX 5
3313 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3314 wasn't able to compile compile on an IRIX 5 system.
3316 * Added execute permission to gdb/gdbserver/configure
3318 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3319 permission. This bug would cause configure to fail on a number of
3320 systems (Solaris, IRIX). Ref: server/519.
3322 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3324 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3325 has been updated to use constant array sizes.
3327 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3329 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3330 its generated DWARF Call Frame Info. This encoding was causing GDB to
3331 panic, that panic has been fixed. Ref: gdb/1628.
3333 * Fixed a problem when examining parameters in shared library code.
3335 When examining parameters in optimized shared library code generated
3336 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3337 not available''. GDB now correctly displays the variable's value.
3339 *** Changes in GDB 6.1:
3341 * Removed --with-mmalloc
3343 Support for the mmalloc memory manager has been removed, as it
3344 conflicted with the internal gdb byte cache.
3346 * Changes in AMD64 configurations
3348 The AMD64 target now includes the %cs and %ss registers. As a result
3349 the AMD64 remote protocol has changed; this affects the floating-point
3350 and SSE registers. If you rely on those registers for your debugging,
3351 you should upgrade gdbserver on the remote side.
3353 * Revised SPARC target
3355 The SPARC target has been completely revised, incorporating the
3356 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3357 support for LynxOS and SunOS 4 has been dropped. Calling functions
3358 from within GDB on operating systems with a non-executable stack
3359 (Solaris, OpenBSD) now works.
3363 GDB has a new C++ demangler which does a better job on the mangled
3364 names generated by current versions of g++. It also runs faster, so
3365 with this and other changes gdb should now start faster on large C++
3368 * DWARF 2 Location Expressions
3370 GDB support for location expressions has been extended to support function
3371 arguments and frame bases. Older versions of GDB could crash when they
3374 * C++ nested types and namespaces
3376 GDB's support for nested types and namespaces in C++ has been
3377 improved, especially if you use the DWARF 2 debugging format. (This
3378 is the default for recent versions of GCC on most platforms.)
3379 Specifically, if you have a class "Inner" defined within a class or
3380 namespace "Outer", then GDB realizes that the class's name is
3381 "Outer::Inner", not simply "Inner". This should greatly reduce the
3382 frequency of complaints about not finding RTTI symbols. In addition,
3383 if you are stopped at inside of a function defined within a namespace,
3384 GDB modifies its name lookup accordingly.
3386 * New native configurations
3388 NetBSD/amd64 x86_64-*-netbsd*
3389 OpenBSD/amd64 x86_64-*-openbsd*
3390 OpenBSD/alpha alpha*-*-openbsd*
3391 OpenBSD/sparc sparc-*-openbsd*
3392 OpenBSD/sparc64 sparc64-*-openbsd*
3394 * New debugging protocols
3396 M32R with SDI protocol m32r-*-elf*
3398 * "set prompt-escape-char" command deleted.
3400 The command "set prompt-escape-char" has been deleted. This command,
3401 and its very obscure effet on GDB's prompt, was never documented,
3402 tested, nor mentioned in the NEWS file.
3404 * OBSOLETE configurations and files
3406 Configurations that have been declared obsolete in this release have
3407 been commented out. Unless there is activity to revive these
3408 configurations, the next release of GDB will have their sources
3409 permanently REMOVED.
3411 Sun 3, running SunOS 3 m68*-*-sunos3*
3412 Sun 3, running SunOS 4 m68*-*-sunos4*
3413 Sun 2, running SunOS 3 m68000-*-sunos3*
3414 Sun 2, running SunOS 4 m68000-*-sunos4*
3415 Motorola 680x0 running LynxOS m68*-*-lynxos*
3416 AT&T 3b1/Unix pc m68*-att-*
3417 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3418 decstation mips-dec-* mips-little-*
3419 riscos mips-*-riscos* mips-*-sysv*
3420 sonymips mips-sony-*
3421 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3423 * REMOVED configurations and files
3425 SGI Irix-4.x mips-sgi-irix4 or iris4
3426 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3427 Z8000 simulator z8k-zilog-none or z8ksim
3428 Matsushita MN10200 w/simulator mn10200-*-*
3429 H8/500 simulator h8500-hitachi-hms or h8500hms
3430 HP/PA running BSD hppa*-*-bsd*
3431 HP/PA running OSF/1 hppa*-*-osf*
3432 HP/PA Pro target hppa*-*-pro*
3433 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3434 386BSD i[3456]86-*-bsd*
3435 Sequent family i[3456]86-sequent-sysv4*
3436 i[3456]86-sequent-sysv*
3437 i[3456]86-sequent-bsd*
3438 SPARC running LynxOS sparc-*-lynxos*
3439 SPARC running SunOS 4 sparc-*-sunos4*
3440 Tsqware Sparclet sparclet-*-*
3441 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3443 *** Changes in GDB 6.0:
3447 Support for debugging the Objective-C programming language has been
3448 integrated into GDB.
3450 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3452 DWARF 2's Call Frame Information makes available compiler generated
3453 information that more exactly describes the program's run-time stack.
3454 By using this information, GDB is able to provide more robust stack
3457 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3458 have been updated to use a new backtrace mechanism which includes
3459 DWARF 2 CFI support.
3463 GDB's remote protocol has been extended to include support for hosted
3464 file I/O (where the remote target uses GDB's file system). See GDB's
3465 remote protocol documentation for details.
3467 * All targets using the new architecture framework.
3469 All of GDB's targets have been updated to use the new internal
3470 architecture framework. The way is now open for future GDB releases
3471 to include cross-architecture native debugging support (i386 on amd64,
3474 * GNU/Linux's Thread Local Storage (TLS)
3476 GDB now includes support for for the GNU/Linux implementation of
3477 per-thread variables.
3479 * GNU/Linux's Native POSIX Thread Library (NPTL)
3481 GDB's thread code has been updated to work with either the new
3482 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3484 * Separate debug info.
3486 GDB, in conjunction with BINUTILS, now supports a mechanism for
3487 automatically loading debug information from a separate file. Instead
3488 of shipping full debug and non-debug versions of system libraries,
3489 system integrators can now instead ship just the stripped libraries
3490 and optional debug files.
3492 * DWARF 2 Location Expressions
3494 DWARF 2 Location Expressions allow the compiler to more completely
3495 describe the location of variables (even in optimized code) to the
3498 GDB now includes preliminary support for location expressions (support
3499 for DW_OP_piece is still missing).
3503 A number of long standing bugs that caused GDB to die while starting a
3504 Java application have been fixed. GDB's Java support is now
3505 considered "useable".
3507 * GNU/Linux support for fork, vfork, and exec.
3509 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3510 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3513 * GDB supports logging output to a file
3515 There are two new commands, "set logging" and "show logging", which can be
3516 used to capture GDB's output to a file.
3518 * The meaning of "detach" has changed for gdbserver
3520 The "detach" command will now resume the application, as documented. To
3521 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3524 * d10v, m68hc11 `regs' command deprecated
3526 The `info registers' command has been updated so that it displays the
3527 registers using a format identical to the old `regs' command.
3531 A new command, "maint set profile on/off", has been added. This command can
3532 be used to enable or disable profiling while running GDB, to profile a
3533 session or a set of commands. In addition there is a new configure switch,
3534 "--enable-profiling", which will cause GDB to be compiled with profiling
3535 data, for more informative profiling results.
3537 * Default MI syntax changed to "mi2".
3539 The default MI (machine interface) syntax, enabled by the command line
3540 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3541 "mi1", can be enabled by specifying the option "-i=mi1".
3543 Support for the original "mi0" syntax (included in GDB 5.0) has been
3546 Fix for gdb/192: removed extraneous space when displaying frame level.
3547 Fix for gdb/672: update changelist is now output in mi list format.
3548 Fix for gdb/702: a -var-assign that updates the value now shows up
3549 in a subsequent -var-update.
3551 * New native configurations.
3553 FreeBSD/amd64 x86_64-*-freebsd*
3555 * Multi-arched targets.
3557 HP/PA HPUX11 hppa*-*-hpux*
3558 Renesas M32R/D w/simulator m32r-*-elf*
3560 * OBSOLETE configurations and files
3562 Configurations that have been declared obsolete in this release have
3563 been commented out. Unless there is activity to revive these
3564 configurations, the next release of GDB will have their sources
3565 permanently REMOVED.
3567 Z8000 simulator z8k-zilog-none or z8ksim
3568 Matsushita MN10200 w/simulator mn10200-*-*
3569 H8/500 simulator h8500-hitachi-hms or h8500hms
3570 HP/PA running BSD hppa*-*-bsd*
3571 HP/PA running OSF/1 hppa*-*-osf*
3572 HP/PA Pro target hppa*-*-pro*
3573 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3574 Sequent family i[3456]86-sequent-sysv4*
3575 i[3456]86-sequent-sysv*
3576 i[3456]86-sequent-bsd*
3577 Tsqware Sparclet sparclet-*-*
3578 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3580 * REMOVED configurations and files
3583 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3584 IBM AIX PS/2 i[3456]86-*-aix
3585 i386 running Mach 3.0 i[3456]86-*-mach3*
3586 i386 running Mach i[3456]86-*-mach*
3587 i386 running OSF/1 i[3456]86-*osf1mk*
3588 HP/Apollo 68k Family m68*-apollo*-sysv*,
3590 m68*-hp-bsd*, m68*-hp-hpux*
3591 Argonaut Risc Chip (ARC) arc-*-*
3592 Mitsubishi D30V d30v-*-*
3593 Fujitsu FR30 fr30-*-elf*
3594 OS/9000 i[34]86-*-os9k
3595 I960 with MON960 i960-*-coff
3597 * MIPS $fp behavior changed
3599 The convenience variable $fp, for the MIPS, now consistently returns
3600 the address of the current frame's base. Previously, depending on the
3601 context, $fp could refer to either $sp or the current frame's base
3602 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3603 The GNU Source-Level Debugger''.
3605 *** Changes in GDB 5.3:
3607 * GNU/Linux shared library multi-threaded performance improved.
3609 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3610 `/proc', in preference to `ptrace' for memory reads. This may result
3611 in an improvement in the start-up time of multi-threaded, shared
3612 library applications when run under GDB. One GDB user writes: ``loads
3613 shared libs like mad''.
3615 * ``gdbserver'' now supports multi-threaded applications on some targets
3617 Support for debugging multi-threaded applications which use
3618 the GNU/Linux LinuxThreads package has been added for
3619 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3620 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3622 * GDB now supports C/C++ preprocessor macros.
3624 GDB now expands preprocessor macro invocations in C/C++ expressions,
3625 and provides various commands for showing macro definitions and how
3628 The new command `macro expand EXPRESSION' expands any macro
3629 invocations in expression, and shows the result.
3631 The new command `show macro MACRO-NAME' shows the definition of the
3632 macro named MACRO-NAME, and where it was defined.
3634 Most compilers don't include information about macros in the debugging
3635 information by default. In GCC 3.1, for example, you need to compile
3636 your program with the options `-gdwarf-2 -g3'. If the macro
3637 information is present in the executable, GDB will read it.
3639 * Multi-arched targets.
3641 DEC Alpha (partial) alpha*-*-*
3642 DEC VAX (partial) vax-*-*
3644 National Semiconductor NS32000 (partial) ns32k-*-*
3645 Motorola 68000 (partial) m68k-*-*
3646 Motorola MCORE mcore-*-*
3650 Fujitsu FRV architecture added by Red Hat frv*-*-*
3653 * New native configurations
3655 Alpha NetBSD alpha*-*-netbsd*
3656 SH NetBSD sh*-*-netbsdelf*
3657 MIPS NetBSD mips*-*-netbsd*
3658 UltraSPARC NetBSD sparc64-*-netbsd*
3660 * OBSOLETE configurations and files
3662 Configurations that have been declared obsolete in this release have
3663 been commented out. Unless there is activity to revive these
3664 configurations, the next release of GDB will have their sources
3665 permanently REMOVED.
3667 Mitsubishi D30V d30v-*-*
3668 OS/9000 i[34]86-*-os9k
3669 IBM AIX PS/2 i[3456]86-*-aix
3670 Fujitsu FR30 fr30-*-elf*
3671 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3672 Argonaut Risc Chip (ARC) arc-*-*
3673 i386 running Mach 3.0 i[3456]86-*-mach3*
3674 i386 running Mach i[3456]86-*-mach*
3675 i386 running OSF/1 i[3456]86-*osf1mk*
3676 HP/Apollo 68k Family m68*-apollo*-sysv*,
3678 m68*-hp-bsd*, m68*-hp-hpux*
3679 I960 with MON960 i960-*-coff
3681 * OBSOLETE languages
3683 CHILL, a Pascal like language used by telecommunications companies.
3685 * REMOVED configurations and files
3687 AMD 29k family via UDI a29k-amd-udi, udi29k
3688 A29K VxWorks a29k-*-vxworks
3689 AMD 29000 embedded, using EBMON a29k-none-none
3690 AMD 29000 embedded with COFF a29k-none-coff
3691 AMD 29000 embedded with a.out a29k-none-aout
3693 testsuite/gdb.hp/gdb.threads-hp/ directory
3695 * New command "set max-user-call-depth <nnn>"
3697 This command allows the user to limit the call depth of user-defined
3698 commands. The default is 1024.
3700 * Changes in FreeBSD/i386 native debugging.
3702 Support for the "generate-core-file" has been added.
3704 * New commands "dump", "append", and "restore".
3706 These commands allow data to be copied from target memory
3707 to a bfd-format or binary file (dump and append), and back
3708 from a file into memory (restore).
3710 * Improved "next/step" support on multi-processor Alpha Tru64.
3712 The previous single-step mechanism could cause unpredictable problems,
3713 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3714 of a software single-step mechanism prevents this.
3716 *** Changes in GDB 5.2.1:
3724 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3725 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3726 Fix, by Joel Brobecker imported from mainline.
3728 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3729 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3730 Fix, by Fred Fish, imported from mainline.
3732 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3733 Surprisingly enough, it works now.
3734 By Michal Ludvig, imported from mainline.
3736 i386 hardware watchpoint support:
3737 avoid misses on second run for some targets.
3738 By Pierre Muller, imported from mainline.
3740 *** Changes in GDB 5.2:
3742 * New command "set trust-readonly-sections on[off]".
3744 This command is a hint that tells gdb that read-only sections
3745 really are read-only (ie. that their contents will not change).
3746 In this mode, gdb will go to the object file rather than the
3747 target to read memory from read-only sections (such as ".text").
3748 This can be a significant performance improvement on some
3749 (notably embedded) targets.
3751 * New command "generate-core-file" (or "gcore").
3753 This new gdb command allows the user to drop a core file of the child
3754 process state at any time. So far it's been implemented only for
3755 GNU/Linux and Solaris, but should be relatively easily ported to other
3756 hosts. Argument is core file name (defaults to core.<pid>).
3758 * New command line option
3760 GDB now accepts --pid or -p followed by a process id.
3762 * Change in command line behavior -- corefiles vs. process ids.
3764 There is a subtle behavior in the way in which GDB handles
3765 command line arguments. The first non-flag argument is always
3766 a program to debug, but the second non-flag argument may either
3767 be a corefile or a process id. Previously, GDB would attempt to
3768 open the second argument as a corefile, and if that failed, would
3769 issue a superfluous error message and then attempt to attach it as
3770 a process. Now, if the second argument begins with a non-digit,
3771 it will be treated as a corefile. If it begins with a digit,
3772 GDB will attempt to attach it as a process, and if no such process
3773 is found, will then attempt to open it as a corefile.
3775 * Changes in ARM configurations.
3777 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3778 configuration is fully multi-arch.
3780 * New native configurations
3782 ARM NetBSD arm*-*-netbsd*
3783 x86 OpenBSD i[3456]86-*-openbsd*
3784 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3785 Sparc64 running FreeBSD sparc64-*-freebsd*
3789 Sanyo XStormy16 xstormy16-elf
3791 * OBSOLETE configurations and files
3793 Configurations that have been declared obsolete in this release have
3794 been commented out. Unless there is activity to revive these
3795 configurations, the next release of GDB will have their sources
3796 permanently REMOVED.
3798 AMD 29k family via UDI a29k-amd-udi, udi29k
3799 A29K VxWorks a29k-*-vxworks
3800 AMD 29000 embedded, using EBMON a29k-none-none
3801 AMD 29000 embedded with COFF a29k-none-coff
3802 AMD 29000 embedded with a.out a29k-none-aout
3804 testsuite/gdb.hp/gdb.threads-hp/ directory
3806 * REMOVED configurations and files
3808 TI TMS320C80 tic80-*-*
3810 PowerPC Solaris powerpcle-*-solaris*
3811 PowerPC Windows NT powerpcle-*-cygwin32
3812 PowerPC Netware powerpc-*-netware*
3813 Harris/CXUX m88k m88*-harris-cxux*
3814 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3815 ns32k-utek-sysv* ns32k-utek-*
3816 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3817 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3818 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3819 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3820 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3822 * Changes to command line processing
3824 The new `--args' feature can be used to specify command-line arguments
3825 for the inferior from gdb's command line.
3827 * Changes to key bindings
3829 There is a new `operate-and-get-next' function bound to `C-o'.
3831 *** Changes in GDB 5.1.1
3833 Fix compile problem on DJGPP.
3835 Fix a problem with floating-point registers on the i386 being
3838 Fix to stop GDB crashing on .debug_str debug info.
3840 Numerous documentation fixes.
3842 Numerous testsuite fixes.
3844 *** Changes in GDB 5.1:
3846 * New native configurations
3848 Alpha FreeBSD alpha*-*-freebsd*
3849 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3850 MIPS GNU/Linux mips*-*-linux*
3851 MIPS SGI Irix 6.x mips*-sgi-irix6*
3852 ia64 AIX ia64-*-aix*
3853 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3857 Motorola 68HC11 and 68HC12 m68hc11-elf
3859 UltraSparc running GNU/Linux sparc64-*-linux*
3861 * OBSOLETE configurations and files
3863 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3864 Harris/CXUX m88k m88*-harris-cxux*
3865 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3866 ns32k-utek-sysv* ns32k-utek-*
3867 TI TMS320C80 tic80-*-*
3869 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3870 PowerPC Solaris powerpcle-*-solaris*
3871 PowerPC Windows NT powerpcle-*-cygwin32
3872 PowerPC Netware powerpc-*-netware*
3873 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3874 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3875 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3876 Apple Macintosh (MPW) host N/A
3878 stuff.c (Program to stuff files into a specially prepared space in kdb)
3879 kdb-start.c (Main loop for the standalone kernel debugger)
3881 Configurations that have been declared obsolete in this release have
3882 been commented out. Unless there is activity to revive these
3883 configurations, the next release of GDB will have their sources
3884 permanently REMOVED.
3886 * REMOVED configurations and files
3888 Altos 3068 m68*-altos-*
3889 Convex c1-*-*, c2-*-*
3891 ARM RISCix arm-*-* (as host)
3895 * GDB has been converted to ISO C.
3897 GDB's source code has been converted to ISO C. In particular, the
3898 sources are fully protoized, and rely on standard headers being
3903 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3905 * The MI enabled by default.
3907 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3908 revised and enabled by default. Packages which use GDB as a debugging
3909 engine behind a UI or another front end are encouraged to switch to
3910 using the GDB/MI interface, instead of the old annotations interface
3911 which is now deprecated.
3913 * Support for debugging Pascal programs.
3915 GDB now includes support for debugging Pascal programs. The following
3916 main features are supported:
3918 - Pascal-specific data types such as sets;
3920 - automatic recognition of Pascal sources based on file-name
3923 - Pascal-style display of data types, variables, and functions;
3925 - a Pascal expression parser.
3927 However, some important features are not yet supported.
3929 - Pascal string operations are not supported at all;
3931 - there are some problems with boolean types;
3933 - Pascal type hexadecimal constants are not supported
3934 because they conflict with the internal variables format;
3936 - support for Pascal objects and classes is not full yet;
3938 - unlike Pascal, GDB is case-sensitive for symbol names.
3940 * Changes in completion.
3942 Commands such as `shell', `run' and `set args', which pass arguments
3943 to inferior programs, now complete on file names, similar to what
3944 users expect at the shell prompt.
3946 Commands which accept locations, such as `disassemble', `print',
3947 `breakpoint', `until', etc. now complete on filenames as well as
3948 program symbols. Thus, if you type "break foob TAB", and the source
3949 files linked into the programs include `foobar.c', that file name will
3950 be one of the candidates for completion. However, file names are not
3951 considered for completion after you typed a colon that delimits a file
3952 name from a name of a function in that file, as in "break foo.c:bar".
3954 `set demangle-style' completes on available demangling styles.
3956 * New platform-independent commands:
3958 It is now possible to define a post-hook for a command as well as a
3959 hook that runs before the command. For more details, see the
3960 documentation of `hookpost' in the GDB manual.
3962 * Changes in GNU/Linux native debugging.
3964 Support for debugging multi-threaded programs has been completely
3965 revised for all platforms except m68k and sparc. You can now debug as
3966 many threads as your system allows you to have.
3968 Attach/detach is supported for multi-threaded programs.
3970 Support for SSE registers was added for x86. This doesn't work for
3971 multi-threaded programs though.
3973 * Changes in MIPS configurations.
3975 Multi-arch support is enabled for all MIPS configurations.
3977 GDB can now be built as native debugger on SGI Irix 6.x systems for
3978 debugging n32 executables. (Debugging 64-bit executables is not yet
3981 * Unified support for hardware watchpoints in all x86 configurations.
3983 Most (if not all) native x86 configurations support hardware-assisted
3984 breakpoints and watchpoints in a unified manner. This support
3985 implements debug register sharing between watchpoints, which allows to
3986 put a virtually infinite number of watchpoints on the same address,
3987 and also supports watching regions up to 16 bytes with several debug
3990 The new maintenance command `maintenance show-debug-regs' toggles
3991 debugging print-outs in functions that insert, remove, and test
3992 watchpoints and hardware breakpoints.
3994 * Changes in the DJGPP native configuration.
3996 New command ``info dos sysinfo'' displays assorted information about
3997 the CPU, OS, memory, and DPMI server.
3999 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4000 display information about segment descriptors stored in GDT, LDT, and
4003 New commands ``info dos pde'' and ``info dos pte'' display entries
4004 from Page Directory and Page Tables (for now works with CWSDPMI only).
4005 New command ``info dos address-pte'' displays the Page Table entry for
4006 a given linear address.
4008 GDB can now pass command lines longer than 126 characters to the
4009 program being debugged (requires an update to the libdbg.a library
4010 which is part of the DJGPP development kit).
4012 DWARF2 debug info is now supported.
4014 It is now possible to `step' and `next' through calls to `longjmp'.
4016 * Changes in documentation.
4018 All GDB documentation was converted to GFDL, the GNU Free
4019 Documentation License.
4021 Tracepoints-related commands are now fully documented in the GDB
4024 TUI, the Text-mode User Interface, is now documented in the manual.
4026 Tracepoints-related commands are now fully documented in the GDB
4029 The "GDB Internals" manual now has an index. It also includes
4030 documentation of `ui_out' functions, GDB coding standards, x86
4031 hardware watchpoints, and memory region attributes.
4033 * GDB's version number moved to ``version.in''
4035 The Makefile variable VERSION has been replaced by the file
4036 ``version.in''. People creating GDB distributions should update the
4037 contents of this file.
4041 GUD support is now a standard part of the EMACS distribution.
4043 *** Changes in GDB 5.0:
4045 * Improved support for debugging FP programs on x86 targets
4047 Unified and much-improved support for debugging floating-point
4048 programs on all x86 targets. In particular, ``info float'' now
4049 displays the FP registers in the same format on all x86 targets, with
4050 greater level of detail.
4052 * Improvements and bugfixes in hardware-assisted watchpoints
4054 It is now possible to watch array elements, struct members, and
4055 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4056 on x86 targets no longer erroneously trigger when the address is
4059 * Improvements in the native DJGPP version of GDB
4061 The distribution now includes all the scripts and auxiliary files
4062 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4063 machines ``out of the box''.
4065 The DJGPP version can now debug programs that use signals. It is
4066 possible to catch signals that happened in the debuggee, deliver
4067 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4068 would kill the program being debugged.) Programs that hook hardware
4069 interrupts (keyboard, timer, etc.) can also be debugged.
4071 It is now possible to debug DJGPP programs that redirect their
4072 standard handles or switch them to raw (as opposed to cooked) mode, or
4073 even close them. The command ``run < foo > bar'' works as expected,
4074 and ``info terminal'' reports useful information about the debuggee's
4075 terminal, including raw/cooked mode, redirection, etc.
4077 The DJGPP version now uses termios functions for console I/O, which
4078 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4081 DOS-style file names with drive letters are now fully supported by
4084 It is now possible to debug DJGPP programs that switch their working
4085 directory. It is also possible to rerun the debuggee any number of
4086 times without restarting GDB; thus, you can use the same setup,
4087 breakpoints, etc. for many debugging sessions.
4089 * New native configurations
4091 ARM GNU/Linux arm*-*-linux*
4092 PowerPC GNU/Linux powerpc-*-linux*
4096 Motorola MCore mcore-*-*
4097 x86 VxWorks i[3456]86-*-vxworks*
4098 PowerPC VxWorks powerpc-*-vxworks*
4099 TI TMS320C80 tic80-*-*
4101 * OBSOLETE configurations
4103 Altos 3068 m68*-altos-*
4104 Convex c1-*-*, c2-*-*
4106 ARM RISCix arm-*-* (as host)
4109 Configurations that have been declared obsolete will be commented out,
4110 but the code will be left in place. If there is no activity to revive
4111 these configurations before the next release of GDB, the sources will
4112 be permanently REMOVED.
4114 * Gould support removed
4116 Support for the Gould PowerNode and NP1 has been removed.
4118 * New features for SVR4
4120 On SVR4 native platforms (such as Solaris), if you attach to a process
4121 without first loading a symbol file, GDB will now attempt to locate and
4122 load symbols from the running process's executable file.
4124 * Many C++ enhancements
4126 C++ support has been greatly improved. Overload resolution now works properly
4127 in almost all cases. RTTI support is on the way.
4129 * Remote targets can connect to a sub-program
4131 A popen(3) style serial-device has been added. This device starts a
4132 sub-process (such as a stand-alone simulator) and then communicates
4133 with that. The sub-program to run is specified using the syntax
4134 ``|<program> <args>'' vis:
4136 (gdb) set remotedebug 1
4137 (gdb) target extended-remote |mn10300-elf-sim program-args
4139 * MIPS 64 remote protocol
4141 A long standing bug in the mips64 remote protocol where by GDB
4142 expected certain 32 bit registers (ex SR) to be transfered as 32
4143 instead of 64 bits has been fixed.
4145 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4146 added to provide backward compatibility with older versions of GDB.
4148 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4150 The command ``set remotebinarydownload'' command has been replaced by
4151 ``set remote X-packet''. Other commands in ``set remote'' family
4152 include ``set remote P-packet''.
4154 * Breakpoint commands accept ranges.
4156 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4157 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4158 ``tracepoint passcount'' also accepts a range of tracepoints.
4160 * ``apropos'' command added.
4162 The ``apropos'' command searches through command names and
4163 documentation strings, printing out matches, making it much easier to
4164 try to find a command that does what you are looking for.
4168 A new machine oriented interface (MI) has been added to GDB. This
4169 interface is designed for debug environments running GDB as a separate
4170 process. This is part of the long term libGDB project. See the
4171 "GDB/MI" chapter of the GDB manual for further information. It can be
4172 enabled by configuring with:
4174 .../configure --enable-gdbmi
4176 *** Changes in GDB-4.18:
4178 * New native configurations
4180 HP-UX 10.20 hppa*-*-hpux10.20
4181 HP-UX 11.x hppa*-*-hpux11.0*
4182 M68K GNU/Linux m68*-*-linux*
4186 Fujitsu FR30 fr30-*-elf*
4187 Intel StrongARM strongarm-*-*
4188 Mitsubishi D30V d30v-*-*
4190 * OBSOLETE configurations
4192 Gould PowerNode, NP1 np1-*-*, pn-*-*
4194 Configurations that have been declared obsolete will be commented out,
4195 but the code will be left in place. If there is no activity to revive
4196 these configurations before the next release of GDB, the sources will
4197 be permanently REMOVED.
4201 As a compatibility experiment, GDB's source files buildsym.h and
4202 buildsym.c have been converted to pure standard C, no longer
4203 containing any K&R compatibility code. We believe that all systems in
4204 use today either come with a standard C compiler, or have a GCC port
4205 available. If this is not true, please report the affected
4206 configuration to bug-gdb@gnu.org immediately. See the README file for
4207 information about getting a standard C compiler if you don't have one
4212 GDB now uses readline 2.2.
4214 * set extension-language
4216 You can now control the mapping between filename extensions and source
4217 languages by using the `set extension-language' command. For instance,
4218 you can ask GDB to treat .c files as C++ by saying
4219 set extension-language .c c++
4220 The command `info extensions' lists all of the recognized extensions
4221 and their associated languages.
4223 * Setting processor type for PowerPC and RS/6000
4225 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4226 you can use the `set processor' command to specify what variant of the
4227 PowerPC family you are debugging. The command
4231 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4232 following PowerPC and RS6000 variants:
4234 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4235 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4237 403GC IBM PowerPC 403GC
4238 505 Motorola PowerPC 505
4239 860 Motorola PowerPC 860 or 850
4240 601 Motorola PowerPC 601
4241 602 Motorola PowerPC 602
4242 603 Motorola/IBM PowerPC 603 or 603e
4243 604 Motorola PowerPC 604 or 604e
4244 750 Motorola/IBM PowerPC 750 or 750
4246 At the moment, this command just tells GDB what to name the
4247 special-purpose processor registers. Since almost all the affected
4248 registers are inaccessible to user-level programs, this command is
4249 only useful for remote debugging in its present form.
4253 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4254 more extensive support for HP-UX. Added features include shared
4255 library support, kernel threads and hardware watchpoints for 11.00,
4256 support for HP's ANSI C and C++ compilers, and a compatibility mode
4257 for xdb and dbx commands.
4261 HP's donation includes the new concept of catchpoints, which is a
4262 generalization of the old catch command. On HP-UX, it is now possible
4263 to catch exec, fork, and vfork, as well as library loading.
4265 This means that the existing catch command has changed; its first
4266 argument now specifies the type of catch to be set up. See the
4267 output of "help catch" for a list of catchpoint types.
4269 * Debugging across forks
4271 On HP-UX, you can choose which process to debug when a fork() happens
4276 HP has donated a curses-based terminal user interface (TUI). To get
4277 it, build with --enable-tui. Although this can be enabled for any
4278 configuration, at present it only works for native HP debugging.
4280 * GDB remote protocol additions
4282 A new protocol packet 'X' that writes binary data is now available.
4283 Default behavior is to try 'X', then drop back to 'M' if the stub
4284 fails to respond. The settable variable `remotebinarydownload'
4285 allows explicit control over the use of 'X'.
4287 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4288 full 64-bit address. The command
4290 set remoteaddresssize 32
4292 can be used to revert to the old behaviour. For existing remote stubs
4293 the change should not be noticed, as the additional address information
4296 In order to assist in debugging stubs, you may use the maintenance
4297 command `packet' to send any text string to the stub. For instance,
4299 maint packet heythere
4301 sends the packet "$heythere#<checksum>". Note that it is very easy to
4302 disrupt a debugging session by sending the wrong packet at the wrong
4305 The compare-sections command allows you to compare section data on the
4306 target to what is in the executable file without uploading or
4307 downloading, by comparing CRC checksums.
4309 * Tracing can collect general expressions
4311 You may now collect general expressions at tracepoints. This requires
4312 further additions to the target-side stub; see tracepoint.c and
4313 doc/agentexpr.texi for further details.
4315 * mask-address variable for Mips
4317 For Mips targets, you may control the zeroing of the upper 32 bits of
4318 a 64-bit address by entering `set mask-address on'. This is mainly
4319 of interest to users of embedded R4xxx and R5xxx processors.
4321 * Higher serial baud rates
4323 GDB's serial code now allows you to specify baud rates 57600, 115200,
4324 230400, and 460800 baud. (Note that your host system may not be able
4325 to achieve all of these rates.)
4329 The i960 configuration now includes an initial implementation of a
4330 builtin simulator, contributed by Jim Wilson.
4333 *** Changes in GDB-4.17:
4335 * New native configurations
4337 Alpha GNU/Linux alpha*-*-linux*
4338 Unixware 2.x i[3456]86-unixware2*
4339 Irix 6.x mips*-sgi-irix6*
4340 PowerPC GNU/Linux powerpc-*-linux*
4341 PowerPC Solaris powerpcle-*-solaris*
4342 Sparc GNU/Linux sparc-*-linux*
4343 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4347 Argonaut Risc Chip (ARC) arc-*-*
4348 Hitachi H8/300S h8300*-*-*
4349 Matsushita MN10200 w/simulator mn10200-*-*
4350 Matsushita MN10300 w/simulator mn10300-*-*
4351 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4352 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4353 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4354 Mitsubishi D10V w/simulator d10v-*-*
4355 Mitsubishi M32R/D w/simulator m32r-*-elf*
4356 Tsqware Sparclet sparclet-*-*
4357 NEC V850 w/simulator v850-*-*
4359 * New debugging protocols
4361 ARM with RDI protocol arm*-*-*
4362 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4363 DDB and LSI variants of PMON protocol mips*-*-*
4364 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4365 PowerPC with SDS protocol powerpc{,le}-*-eabi
4366 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4370 All configurations can now understand and use the DWARF 2 debugging
4371 format. The choice is automatic, if the symbol file contains DWARF 2
4376 GDB now includes basic Java language support. This support is
4377 only useful with Java compilers that produce native machine code.
4379 * solib-absolute-prefix and solib-search-path
4381 For SunOS and SVR4 shared libraries, you may now set the prefix for
4382 loading absolute shared library symbol files, and the search path for
4383 locating non-absolute shared library symbol files.
4385 * Live range splitting
4387 GDB can now effectively debug code for which GCC has performed live
4388 range splitting as part of its optimization. See gdb/doc/LRS for
4389 more details on the expected format of the stabs information.
4393 GDB's support for the GNU Hurd, including thread debugging, has been
4394 updated to work with current versions of the Hurd.
4398 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4399 instruction set. ARM GDB automatically detects when Thumb
4400 instructions are in use, and adjusts disassembly and backtracing
4405 GDB's MIPS target configurations now handle the MIP16 16-bit
4410 GDB now includes support for overlays; if an executable has been
4411 linked such that multiple sections are based at the same address, GDB
4412 will decide which section to use for symbolic info. You can choose to
4413 control the decision manually, using overlay commands, or implement
4414 additional target-side support and use "overlay load-target" to bring
4415 in the overlay mapping. Do "help overlay" for more detail.
4419 The command "info symbol <address>" displays information about
4420 the symbol at the specified address.
4424 The standard remote protocol now includes an extension that allows
4425 asynchronous collection and display of trace data. This requires
4426 extensive support in the target-side debugging stub. Tracing mode
4427 includes a new interaction mode in GDB and new commands: see the
4428 file tracepoint.c for more details.
4432 Configurations for embedded MIPS now include a simulator contributed
4433 by Cygnus Solutions. The simulator supports the instruction sets
4434 of most MIPS variants.
4438 Sparc configurations may now include the ERC32 simulator contributed
4439 by the European Space Agency. The simulator is not built into
4440 Sparc targets by default; configure with --enable-sim to include it.
4444 For target configurations that may include multiple variants of a
4445 basic architecture (such as MIPS and SH), you may now set the
4446 architecture explicitly. "set arch" sets, "info arch" lists
4447 the possible architectures.
4449 *** Changes in GDB-4.16:
4451 * New native configurations
4453 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4454 M68K NetBSD m68k-*-netbsd*
4455 PowerPC AIX 4.x powerpc-*-aix*
4456 PowerPC MacOS powerpc-*-macos*
4457 PowerPC Windows NT powerpcle-*-cygwin32
4458 RS/6000 AIX 4.x rs6000-*-aix4*
4462 ARM with RDP protocol arm-*-*
4463 I960 with MON960 i960-*-coff
4464 MIPS VxWorks mips*-*-vxworks*
4465 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4466 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4468 Matra Sparclet sparclet-*-*
4472 The powerpc-eabi configuration now includes the PSIM simulator,
4473 contributed by Andrew Cagney, with assistance from Mike Meissner.
4474 PSIM is a very elaborate model of the PowerPC, including not only
4475 basic instruction set execution, but also details of execution unit
4476 performance and I/O hardware. See sim/ppc/README for more details.
4480 GDB now works with Solaris 2.5.
4482 * Windows 95/NT native
4484 GDB will now work as a native debugger on Windows 95 and Windows NT.
4485 To build it from source, you must use the "gnu-win32" environment,
4486 which uses a DLL to emulate enough of Unix to run the GNU tools.
4487 Further information, binaries, and sources are available at
4488 ftp.cygnus.com, under pub/gnu-win32.
4490 * dont-repeat command
4492 If a user-defined command includes the command `dont-repeat', then the
4493 command will not be repeated if the user just types return. This is
4494 useful if the command is time-consuming to run, so that accidental
4495 extra keystrokes don't run the same command many times.
4497 * Send break instead of ^C
4499 The standard remote protocol now includes an option to send a break
4500 rather than a ^C to the target in order to interrupt it. By default,
4501 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4503 * Remote protocol timeout
4505 The standard remote protocol includes a new variable `remotetimeout'
4506 that allows you to set the number of seconds before GDB gives up trying
4507 to read from the target. The default value is 2.
4509 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4511 By default GDB will automatically keep track of objects as they are
4512 loaded and unloaded by the dynamic linker. By using the command `set
4513 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4514 when shared library events occur, thus allowing you to set breakpoints
4515 in shared libraries which are explicitly loaded by the inferior.
4517 Note this feature does not work on hpux8. On hpux9 you must link
4518 /usr/lib/end.o into your program. This feature should work
4519 automatically on hpux10.
4521 * Irix 5.x hardware watchpoint support
4523 Irix 5 configurations now support the use of hardware watchpoints.
4525 * Mips protocol "SYN garbage limit"
4527 When debugging a Mips target using the `target mips' protocol, you
4528 may set the number of characters that GDB will ignore by setting
4529 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4530 every character. The default value is 1050.
4532 * Recording and replaying remote debug sessions
4534 If you set `remotelogfile' to the name of a file, gdb will write to it
4535 a recording of a remote debug session. This recording may then be
4536 replayed back to gdb using "gdbreplay". See gdbserver/README for
4537 details. This is useful when you have a problem with GDB while doing
4538 remote debugging; you can make a recording of the session and send it
4539 to someone else, who can then recreate the problem.
4541 * Speedups for remote debugging
4543 GDB includes speedups for downloading and stepping MIPS systems using
4544 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4545 and more efficient S-record downloading.
4547 * Memory use reductions and statistics collection
4549 GDB now uses less memory and reports statistics about memory usage.
4550 Try the `maint print statistics' command, for example.
4552 *** Changes in GDB-4.15:
4554 * Psymtabs for XCOFF
4556 The symbol reader for AIX GDB now uses partial symbol tables. This
4557 can greatly improve startup time, especially for large executables.
4559 * Remote targets use caching
4561 Remote targets now use a data cache to speed up communication with the
4562 remote side. The data cache could lead to incorrect results because
4563 it doesn't know about volatile variables, thus making it impossible to
4564 debug targets which use memory mapped I/O devices. `set remotecache
4565 off' turns the the data cache off.
4567 * Remote targets may have threads
4569 The standard remote protocol now includes support for multiple threads
4570 in the target system, using new protocol commands 'H' and 'T'. See
4571 gdb/remote.c for details.
4575 If GDB is configured with `--enable-netrom', then it will include
4576 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4577 acts as though it is a bank of ROM on the target board, but you can
4578 write into it over the network. GDB's support consists only of
4579 support for fast loading into the emulated ROM; to debug, you must use
4580 another protocol, such as standard remote protocol. The usual
4581 sequence is something like
4583 target nrom <netrom-hostname>
4585 target remote <netrom-hostname>:1235
4589 GDB now includes support for the Apple Macintosh, as a host only. It
4590 may be run as either an MPW tool or as a standalone application, and
4591 it can debug through the serial port. All the usual GDB commands are
4592 available, but to the target command, you must supply "serial" as the
4593 device type instead of "/dev/ttyXX". See mpw-README in the main
4594 directory for more information on how to build. The MPW configuration
4595 scripts */mpw-config.in support only a few targets, and only the
4596 mips-idt-ecoff target has been tested.
4600 GDB configuration now uses autoconf. This is not user-visible,
4601 but does simplify configuration and building.
4605 GDB now supports hpux10.
4607 *** Changes in GDB-4.14:
4609 * New native configurations
4611 x86 FreeBSD i[345]86-*-freebsd
4612 x86 NetBSD i[345]86-*-netbsd
4613 NS32k NetBSD ns32k-*-netbsd
4614 Sparc NetBSD sparc-*-netbsd
4618 A29K VxWorks a29k-*-vxworks
4619 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4620 CPU32 EST-300 emulator m68*-*-est*
4621 PowerPC ELF powerpc-*-elf
4624 * Alpha OSF/1 support for procfs
4626 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4627 possible to attach to running processes. As the mounting of the /proc
4628 filesystem is optional on the Alpha, GDB automatically determines
4629 the availability of /proc during startup. This can lead to problems
4630 if /proc is unmounted after GDB has been started.
4632 * Arguments to user-defined commands
4634 User commands may accept up to 10 arguments separated by whitespace.
4635 Arguments are accessed within the user command via $arg0..$arg9. A
4638 print $arg0 + $arg1 + $arg2
4640 To execute the command use:
4643 Defines the command "adder" which prints the sum of its three arguments.
4644 Note the arguments are text substitutions, so they may reference variables,
4645 use complex expressions, or even perform inferior function calls.
4647 * New `if' and `while' commands
4649 This makes it possible to write more sophisticated user-defined
4650 commands. Both commands take a single argument, which is the
4651 expression to evaluate, and must be followed by the commands to
4652 execute, one per line, if the expression is nonzero, the list being
4653 terminated by the word `end'. The `if' command list may include an
4654 `else' word, which causes the following commands to be executed only
4655 if the expression is zero.
4657 * Fortran source language mode
4659 GDB now includes partial support for Fortran 77. It will recognize
4660 Fortran programs and can evaluate a subset of Fortran expressions, but
4661 variables and functions may not be handled correctly. GDB will work
4662 with G77, but does not yet know much about symbols emitted by other
4665 * Better HPUX support
4667 Most debugging facilities now work on dynamic executables for HPPAs
4668 running hpux9 or later. You can attach to running dynamically linked
4669 processes, but by default the dynamic libraries will be read-only, so
4670 for instance you won't be able to put breakpoints in them. To change
4671 that behavior do the following before running the program:
4677 This will cause the libraries to be mapped private and read-write.
4678 To revert to the normal behavior, do this:
4684 You cannot set breakpoints or examine data in the library until after
4685 the library is loaded if the function/data symbols do not have
4688 GDB can now also read debug symbols produced by the HP C compiler on
4689 HPPAs (sorry, no C++, Fortran or 68k support).
4691 * Target byte order now dynamically selectable
4693 You can choose which byte order to use with a target system, via the
4694 commands "set endian big" and "set endian little", and you can see the
4695 current setting by using "show endian". You can also give the command
4696 "set endian auto", in which case GDB will use the byte order
4697 associated with the executable. Currently, only embedded MIPS
4698 configurations support dynamic selection of target byte order.
4700 * New DOS host serial code
4702 This version uses DPMI interrupts to handle buffered I/O, so you
4703 no longer need to run asynctsr when debugging boards connected to
4706 *** Changes in GDB-4.13:
4708 * New "complete" command
4710 This lists all the possible completions for the rest of the line, if it
4711 were to be given as a command itself. This is intended for use by emacs.
4713 * Trailing space optional in prompt
4715 "set prompt" no longer adds a space for you after the prompt you set. This
4716 allows you to set a prompt which ends in a space or one that does not.
4718 * Breakpoint hit counts
4720 "info break" now displays a count of the number of times the breakpoint
4721 has been hit. This is especially useful in conjunction with "ignore"; you
4722 can ignore a large number of breakpoint hits, look at the breakpoint info
4723 to see how many times the breakpoint was hit, then run again, ignoring one
4724 less than that number, and this will get you quickly to the last hit of
4727 * Ability to stop printing at NULL character
4729 "set print null-stop" will cause GDB to stop printing the characters of
4730 an array when the first NULL is encountered. This is useful when large
4731 arrays actually contain only short strings.
4733 * Shared library breakpoints
4735 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4736 breakpoints in shared libraries before the executable is run.
4738 * Hardware watchpoints
4740 There is a new hardware breakpoint for the watch command for sparclite
4741 targets. See gdb/sparclite/hw_breakpoint.note.
4743 Hardware watchpoints are also now supported under GNU/Linux.
4747 Annotations have been added. These are for use with graphical interfaces,
4748 and are still experimental. Currently only gdba.el uses these.
4750 * Improved Irix 5 support
4752 GDB now works properly with Irix 5.2.
4754 * Improved HPPA support
4756 GDB now works properly with the latest GCC and GAS.
4758 * New native configurations
4760 Sequent PTX4 i[34]86-sequent-ptx4
4761 HPPA running OSF/1 hppa*-*-osf*
4762 Atari TT running SVR4 m68*-*-sysv4*
4763 RS/6000 LynxOS rs6000-*-lynxos*
4767 OS/9000 i[34]86-*-os9k
4768 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4771 * Hitachi SH7000 and E7000-PC ICE support
4773 There is now support for communicating with the Hitachi E7000-PC ICE.
4774 This is available automatically when GDB is configured for the SH.
4778 As usual, a variety of small fixes and improvements, both generic
4779 and configuration-specific. See the ChangeLog for more detail.
4781 *** Changes in GDB-4.12:
4783 * Irix 5 is now supported
4787 GDB-4.12 on the HPPA has a number of changes which make it unable
4788 to debug the output from the currently released versions of GCC and
4789 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4790 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4791 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4794 *** Changes in GDB-4.11:
4796 * User visible changes:
4800 The "set remotedebug" option is now consistent between the mips remote
4801 target, remote targets using the gdb-specific protocol, UDI (AMD's
4802 debug protocol for the 29k) and the 88k bug monitor. It is now an
4803 integer specifying a debug level (normally 0 or 1, but 2 means more
4804 debugging info for the mips target).
4806 * DEC Alpha native support
4808 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4809 debug info, but GDB works fairly well with the DEC compiler and should
4810 work with a future GCC release. See the README file for a few
4811 Alpha-specific notes.
4813 * Preliminary thread implementation
4815 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4817 * LynxOS native and target support for 386
4819 This release has been hosted on LynxOS 2.2, and also can be configured
4820 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4823 * Improvements in C++ mangling/demangling.
4825 This release has much better g++ debugging, specifically in name
4826 mangling/demangling, virtual function calls, print virtual table,
4827 call methods, ...etc.
4829 *** Changes in GDB-4.10:
4831 * User visible changes:
4833 Remote debugging using the GDB-specific (`target remote') protocol now
4834 supports the `load' command. This is only useful if you have some
4835 other way of getting the stub to the target system, and you can put it
4836 somewhere in memory where it won't get clobbered by the download.
4838 Filename completion now works.
4840 When run under emacs mode, the "info line" command now causes the
4841 arrow to point to the line specified. Also, "info line" prints
4842 addresses in symbolic form (as well as hex).
4844 All vxworks based targets now support a user settable option, called
4845 vxworks-timeout. This option represents the number of seconds gdb
4846 should wait for responses to rpc's. You might want to use this if
4847 your vxworks target is, perhaps, a slow software simulator or happens
4848 to be on the far side of a thin network line.
4852 This release contains support for using a DEC alpha as a GDB host for
4853 cross debugging. Native alpha debugging is not supported yet.
4856 *** Changes in GDB-4.9:
4860 This is the first GDB release which is accompanied by a matching testsuite.
4861 The testsuite requires installation of dejagnu, which should be available
4862 via ftp from most sites that carry GNU software.
4866 'Cfront' style demangling has had its name changed to 'ARM' style, to
4867 emphasize that it was written from the specifications in the C++ Annotated
4868 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4869 disclaimers, it still generated too much confusion with users attempting to
4870 use gdb with AT&T cfront.
4874 GDB now uses a standard remote interface to a simulator library.
4875 So far, the library contains simulators for the Zilog Z8001/2, the
4876 Hitachi H8/300, H8/500 and Super-H.
4878 * New targets supported
4880 H8/300 simulator h8300-hitachi-hms or h8300hms
4881 H8/500 simulator h8500-hitachi-hms or h8500hms
4882 SH simulator sh-hitachi-hms or sh
4883 Z8000 simulator z8k-zilog-none or z8ksim
4884 IDT MIPS board over serial line mips-idt-ecoff
4886 Cross-debugging to GO32 targets is supported. It requires a custom
4887 version of the i386-stub.c module which is integrated with the
4888 GO32 memory extender.
4890 * New remote protocols
4892 MIPS remote debugging protocol.
4894 * New source languages supported
4896 This version includes preliminary support for Chill, a Pascal like language
4897 used by telecommunications companies. Chill support is also being integrated
4898 into the GNU compiler, but we don't know when it will be publically available.
4901 *** Changes in GDB-4.8:
4903 * HP Precision Architecture supported
4905 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4906 version of this support was available as a set of patches from the
4907 University of Utah. GDB does not support debugging of programs
4908 compiled with the HP compiler, because HP will not document their file
4909 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4910 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4912 Many problems in the preliminary version have been fixed.
4914 * Faster and better demangling
4916 We have improved template demangling and fixed numerous bugs in the GNU style
4917 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4918 character types (wchar_t) are now supported. Demangling of each symbol is now
4919 only done once, and is cached when the symbol table for a file is read in.
4920 This results in a small increase in memory usage for C programs, a moderate
4921 increase in memory usage for C++ programs, and a fantastic speedup in
4924 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4925 from the specifications in the Annotated Reference Manual, which AT&T's
4926 compiler does not actually implement.
4928 * G++ multiple inheritance compiler problem
4930 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4931 inheritance lattices was reworked to properly discover ambiguities. We
4932 recently found an example which causes this new algorithm to fail in a
4933 very subtle way, producing bad debug information for those classes.
4934 The file 'gcc.patch' (in this directory) can be applied to gcc to
4935 circumvent the problem. A future GCC release will contain a complete
4938 The previous G++ debug info problem (mentioned below for the gdb-4.7
4939 release) is fixed in gcc version 2.3.2.
4941 * Improved configure script
4943 The `configure' script will now attempt to guess your system type if
4944 you don't supply a host system type. The old scheme of supplying a
4945 host system triplet is preferable over using this. All the magic is
4946 done in the new `config.guess' script. Examine it for details.
4948 We have also brought our configure script much more in line with the FSF's
4949 version. It now supports the --with-xxx options. In particular,
4950 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4951 The resulting GDB will not be able to read arbitrary object file formats --
4952 only the format ``expected'' to be used on the configured target system.
4953 We hope to make this the default in a future release.
4955 * Documentation improvements
4957 There's new internal documentation on how to modify GDB, and how to
4958 produce clean changes to the code. We implore people to read it
4959 before submitting changes.
4961 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4962 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4963 `info' files are also provided. To build `info' files from scratch,
4964 you will need the latest `makeinfo' release, which will be available in
4965 a future texinfo-X.Y release.
4967 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4968 We're not sure exactly which versions have this problem, but it has
4969 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4970 or better. If that isn't possible, there is a patch in
4971 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4972 around this problem.
4976 GDB now supports array constants that can be used in expressions typed in by
4977 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4978 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4981 The new directory `gdb/sparclite' contains a program that demonstrates
4982 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4984 * New native hosts supported
4986 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4987 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4989 * New targets supported
4991 AMD 29k family via UDI a29k-amd-udi or udi29k
4993 * New file formats supported
4995 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4996 HPUX core files, and SCO 3.2v2 core files.
5000 Attaching to processes now works again; thanks for the many bug reports.
5002 We have also stomped on a bunch of core dumps caused by
5003 printf_filtered("%s") problems.
5005 We eliminated a copyright problem on the rpc and ptrace header files
5006 for VxWorks, which was discovered at the last minute during the 4.7
5007 release. You should now be able to build a VxWorks GDB.
5009 You can now interrupt gdb while an attached process is running. This
5010 will cause the attached process to stop, and give control back to GDB.
5012 We fixed problems caused by using too many file descriptors
5013 for reading symbols from object files and libraries. This was
5014 especially a problem for programs that used many (~100) shared
5017 The `step' command now only enters a subroutine if there is line number
5018 information for the subroutine. Otherwise it acts like the `next'
5019 command. Previously, `step' would enter subroutines if there was
5020 any debugging information about the routine. This avoids problems
5021 when using `cc -g1' on MIPS machines.
5023 * Internal improvements
5025 GDB's internal interfaces have been improved to make it easier to support
5026 debugging of multiple languages in the future.
5028 GDB now uses a common structure for symbol information internally.
5029 Minimal symbols (derived from linkage symbols in object files), partial
5030 symbols (from a quick scan of debug information), and full symbols
5031 contain a common subset of information, making it easier to write
5032 shared code that handles any of them.
5034 * New command line options
5036 We now accept --silent as an alias for --quiet.
5040 The memory-mapped-malloc library is now licensed under the GNU Library
5041 General Public License.
5043 *** Changes in GDB-4.7:
5045 * Host/native/target split
5047 GDB has had some major internal surgery to untangle the support for
5048 hosts and remote targets. Now, when you configure GDB for a remote
5049 target, it will no longer load in all of the support for debugging
5050 local programs on the host. When fully completed and tested, this will
5051 ensure that arbitrary host/target combinations are possible.
5053 The primary conceptual shift is to separate the non-portable code in
5054 GDB into three categories. Host specific code is required any time GDB
5055 is compiled on that host, regardless of the target. Target specific
5056 code relates to the peculiarities of the target, but can be compiled on
5057 any host. Native specific code is everything else: it can only be
5058 built when the host and target are the same system. Child process
5059 handling and core file support are two common `native' examples.
5061 GDB's use of /proc for controlling Unix child processes is now cleaner.
5062 It has been split out into a single module under the `target_ops' vector,
5063 plus two native-dependent functions for each system that uses /proc.
5065 * New hosts supported
5067 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5068 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5069 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5071 * New targets supported
5073 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5074 68030 and CPU32 m68030-*-*, m68332-*-*
5076 * New native hosts supported
5078 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5079 (386bsd is not well tested yet)
5080 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5082 * New file formats supported
5084 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5085 supports reading of `a.out.adobe' object files, which are an a.out
5086 format extended with minimal information about multiple sections.
5090 `show copying' is the same as the old `info copying'.
5091 `show warranty' is the same as `info warrantee'.
5092 These were renamed for consistency. The old commands continue to work.
5094 `info handle' is a new alias for `info signals'.
5096 You can now define pre-command hooks, which attach arbitrary command
5097 scripts to any command. The commands in the hook will be executed
5098 prior to the user's command. You can also create a hook which will be
5099 executed whenever the program stops. See gdb.texinfo.
5103 We now deal with Cfront style name mangling, and can even extract type
5104 info from mangled symbols. GDB can automatically figure out which
5105 symbol mangling style your C++ compiler uses.
5107 Calling of methods and virtual functions has been improved as well.
5111 The crash that occured when debugging Sun Ansi-C compiled binaries is
5112 fixed. This was due to mishandling of the extra N_SO stabs output
5115 We also finally got Ultrix 4.2 running in house, and fixed core file
5116 support, with help from a dozen people on the net.
5118 John M. Farrell discovered that the reason that single-stepping was so
5119 slow on all of the Mips based platforms (primarily SGI and DEC) was
5120 that we were trying to demangle and lookup a symbol used for internal
5121 purposes on every instruction that was being stepped through. Changing
5122 the name of that symbol so that it couldn't be mistaken for a C++
5123 mangled symbol sped things up a great deal.
5125 Rich Pixley sped up symbol lookups in general by getting much smarter
5126 about when C++ symbol mangling is necessary. This should make symbol
5127 completion (TAB on the command line) much faster. It's not as fast as
5128 we'd like, but it's significantly faster than gdb-4.6.
5132 A new user controllable variable 'call_scratch_address' can
5133 specify the location of a scratch area to be used when GDB
5134 calls a function in the target. This is necessary because the
5135 usual method of putting the scratch area on the stack does not work
5136 in systems that have separate instruction and data spaces.
5138 We integrated changes to support the 29k UDI (Universal Debugger
5139 Interface), but discovered at the last minute that we didn't have all
5140 of the appropriate copyright paperwork. We are working with AMD to
5141 resolve this, and hope to have it available soon.
5145 We have sped up the remote serial line protocol, especially for targets
5146 with lots of registers. It now supports a new `expedited status' ('T')
5147 message which can be used in place of the existing 'S' status message.
5148 This allows the remote stub to send only the registers that GDB
5149 needs to make a quick decision about single-stepping or conditional
5150 breakpoints, eliminating the need to fetch the entire register set for
5151 each instruction being stepped through.
5153 The GDB remote serial protocol now implements a write-through cache for
5154 registers, only re-reading the registers if the target has run.
5156 There is also a new remote serial stub for SPARC processors. You can
5157 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5158 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5159 processor with a serial port.
5163 Configure.in files have become much easier to read and modify. A new
5164 `table driven' format makes it more obvious what configurations are
5165 supported, and what files each one uses.
5169 There is a new opcodes library which will eventually contain all of the
5170 disassembly routines and opcode tables. At present, it only contains
5171 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5172 disassembler (binutils/objdump) to share these routines.
5174 The libiberty library is now copylefted under the GNU Library General
5175 Public License. This allows more liberal use, and was done so libg++
5176 can use it. This makes no difference to GDB, since the Library License
5177 grants all the rights from the General Public License.
5181 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5182 reference to the stabs symbol info used by the debugger. It is (as far
5183 as we know) the only published document on this fascinating topic. We
5184 encourage you to read it, compare it to the stabs information on your
5185 system, and send improvements on the document in general (to
5186 bug-gdb@prep.ai.mit.edu).
5188 And, of course, many bugs have been fixed.
5191 *** Changes in GDB-4.6:
5193 * Better support for C++ function names
5195 GDB now accepts as input the "demangled form" of C++ overloaded function
5196 names and member function names, and can do command completion on such names
5197 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5198 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5199 Make use of command completion, it is your friend.
5201 GDB also now accepts a variety of C++ mangled symbol formats. They are
5202 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5203 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5204 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5205 for the list of formats.
5207 * G++ symbol mangling problem
5209 Recent versions of gcc have a bug in how they emit debugging information for
5210 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5211 directory) can be applied to gcc to fix the problem. Alternatively, if you
5212 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5213 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5214 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5217 * New 'maintenance' command
5219 All of the commands related to hacking GDB internals have been moved out of
5220 the main command set, and now live behind the 'maintenance' command. This
5221 can also be abbreviated as 'mt'. The following changes were made:
5223 dump-me -> maintenance dump-me
5224 info all-breakpoints -> maintenance info breakpoints
5225 printmsyms -> maintenance print msyms
5226 printobjfiles -> maintenance print objfiles
5227 printpsyms -> maintenance print psymbols
5228 printsyms -> maintenance print symbols
5230 The following commands are new:
5232 maintenance demangle Call internal GDB demangler routine to
5233 demangle a C++ link name and prints the result.
5234 maintenance print type Print a type chain for a given symbol
5236 * Change to .gdbinit file processing
5238 We now read the $HOME/.gdbinit file before processing the argv arguments
5239 (e.g. reading symbol files or core files). This allows global parameters to
5240 be set, which will apply during the symbol reading. The ./.gdbinit is still
5241 read after argv processing.
5243 * New hosts supported
5245 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5247 GNU/Linux support i386-unknown-linux or linux
5249 We are also including code to support the HP/PA running BSD and HPUX. This
5250 is almost guaranteed not to work, as we didn't have time to test or build it
5251 for this release. We are including it so that the more adventurous (or
5252 masochistic) of you can play with it. We also had major problems with the
5253 fact that the compiler that we got from HP doesn't support the -g option.
5256 * New targets supported
5258 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5260 * More smarts about finding #include files
5262 GDB now remembers the compilation directory for all include files, and for
5263 all files from which C is generated (like yacc and lex sources). This
5264 greatly improves GDB's ability to find yacc/lex sources, and include files,
5265 especially if you are debugging your program from a directory different from
5266 the one that contains your sources.
5268 We also fixed a bug which caused difficulty with listing and setting
5269 breakpoints in include files which contain C code. (In the past, you had to
5270 try twice in order to list an include file that you hadn't looked at before.)
5272 * Interesting infernals change
5274 GDB now deals with arbitrary numbers of sections, where the symbols for each
5275 section must be relocated relative to that section's landing place in the
5276 target's address space. This work was needed to support ELF with embedded
5277 stabs used by Solaris-2.0.
5279 * Bug fixes (of course!)
5281 There have been loads of fixes for the following things:
5282 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5283 i960, stabs, DOS(GO32), procfs, etc...
5285 See the ChangeLog for details.
5287 *** Changes in GDB-4.5:
5289 * New machines supported (host and target)
5291 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5293 SGI Irix-4.x mips-sgi-irix4 or iris4
5295 * New malloc package
5297 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5298 Mmalloc is capable of handling mutiple heaps of memory. It is also
5299 capable of saving a heap to a file, and then mapping it back in later.
5300 This can be used to greatly speedup the startup of GDB by using a
5301 pre-parsed symbol table which lives in a mmalloc managed heap. For
5302 more details, please read mmalloc/mmalloc.texi.
5306 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5307 'help info proc' for details.
5309 * MIPS ecoff symbol table format
5311 The code that reads MIPS symbol table format is now supported on all hosts.
5312 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5315 * File name changes for MS-DOS
5317 Many files in the config directories have been renamed to make it easier to
5318 support GDB on MS-DOSe systems (which have very restrictive file name
5319 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5320 environment) is close to working but has some remaining problems. Note
5321 that debugging of DOS programs is not supported, due to limitations
5322 in the ``operating system'', but it can be used to host cross-debugging.
5324 * Cross byte order fixes
5326 Many fixes have been made to support cross debugging of Sparc and MIPS
5327 targets from hosts whose byte order differs.
5329 * New -mapped and -readnow options
5331 If memory-mapped files are available on your system through the 'mmap'
5332 system call, you can use the -mapped option on the `file' or
5333 `symbol-file' commands to cause GDB to write the symbols from your
5334 program into a reusable file. If the program you are debugging is
5335 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5336 Future GDB debugging sessions will notice the presence of this file,
5337 and will quickly map in symbol information from it, rather than reading
5338 the symbol table from the executable program. Using the '-mapped'
5339 option in a GDB `file' or `symbol-file' command has the same effect as
5340 starting GDB with the '-mapped' command-line option.
5342 You can cause GDB to read the entire symbol table immediately by using
5343 the '-readnow' option with any of the commands that load symbol table
5344 information (or on the GDB command line). This makes the command
5345 slower, but makes future operations faster.
5347 The -mapped and -readnow options are typically combined in order to
5348 build a `fred.syms' file that contains complete symbol information.
5349 A simple GDB invocation to do nothing but build a `.syms' file for future
5352 gdb -batch -nx -mapped -readnow programname
5354 The `.syms' file is specific to the host machine on which GDB is run.
5355 It holds an exact image of GDB's internal symbol table. It cannot be
5356 shared across multiple host platforms.
5358 * longjmp() handling
5360 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5361 siglongjmp() without losing control. This feature has not yet been ported to
5362 all systems. It currently works on many 386 platforms, all MIPS-based
5363 platforms (SGI, DECstation, etc), and Sun3/4.
5367 Preliminary work has been put in to support the new Solaris OS from Sun. At
5368 this time, it can control and debug processes, but it is not capable of
5373 As always, many many bug fixes. The major areas were with g++, and mipsread.
5374 People using the MIPS-based platforms should experience fewer mysterious
5375 crashes and trashed symbol tables.
5377 *** Changes in GDB-4.4:
5379 * New machines supported (host and target)
5381 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5383 BSD Reno on Vax vax-dec-bsd
5384 Ultrix on Vax vax-dec-ultrix
5386 * New machines supported (target)
5388 AMD 29000 embedded, using EBMON a29k-none-none
5392 GDB continues to improve its handling of C++. `References' work better.
5393 The demangler has also been improved, and now deals with symbols mangled as
5394 per the Annotated C++ Reference Guide.
5396 GDB also now handles `stabs' symbol information embedded in MIPS
5397 `ecoff' symbol tables. Since the ecoff format was not easily
5398 extensible to handle new languages such as C++, this appeared to be a
5399 good way to put C++ debugging info into MIPS binaries. This option
5400 will be supported in the GNU C compiler, version 2, when it is
5403 * New features for SVR4
5405 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5406 shared libraries. Debugging dynamically linked programs should present
5407 only minor differences from debugging statically linked programs.
5409 The `info proc' command will print out information about any process
5410 on an SVR4 system (including the one you are debugging). At the moment,
5411 it prints the address mappings of the process.
5413 If you bring up GDB on another SVR4 system, please send mail to
5414 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5416 * Better dynamic linking support in SunOS
5418 Reading symbols from shared libraries which contain debugging symbols
5419 now works properly. However, there remain issues such as automatic
5420 skipping of `transfer vector' code during function calls, which
5421 make it harder to debug code in a shared library, than to debug the
5422 same code linked statically.
5426 GDB is now using the latest `getopt' routines from the FSF. This
5427 version accepts the -- prefix for options with long names. GDB will
5428 continue to accept the old forms (-option and +option) as well.
5429 Various single letter abbreviations for options have been explicity
5430 added to the option table so that they won't get overshadowed in the
5431 future by other options that begin with the same letter.
5435 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5436 Many assorted bugs have been handled. Many more remain to be handled.
5437 See the various ChangeLog files (primarily in gdb and bfd) for details.
5440 *** Changes in GDB-4.3:
5442 * New machines supported (host and target)
5444 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5445 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5446 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5448 * Almost SCO Unix support
5450 We had hoped to support:
5451 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5452 (except for core file support), but we discovered very late in the release
5453 that it has problems with process groups that render gdb unusable. Sorry
5454 about that. I encourage people to fix it and post the fixes.
5456 * Preliminary ELF and DWARF support
5458 GDB can read ELF object files on System V Release 4, and can handle
5459 debugging records for C, in DWARF format, in ELF files. This support
5460 is preliminary. If you bring up GDB on another SVR4 system, please
5461 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5466 GDB now uses the latest `readline' library. One user-visible change
5467 is that two tabs will list possible command completions, which previously
5468 required typing M-? (meta-question mark, or ESC ?).
5472 The `stepi' bug that many of you noticed has been squashed.
5473 Many bugs in C++ have been handled. Many more remain to be handled.
5474 See the various ChangeLog files (primarily in gdb and bfd) for details.
5476 * State of the MIPS world (in case you wondered):
5478 GDB can understand the symbol tables emitted by the compilers
5479 supplied by most vendors of MIPS-based machines, including DEC. These
5480 symbol tables are in a format that essentially nobody else uses.
5482 Some versions of gcc come with an assembler post-processor called
5483 mips-tfile. This program is required if you want to do source-level
5484 debugging of gcc-compiled programs. I believe FSF does not ship
5485 mips-tfile with gcc version 1, but it will eventually come with gcc
5488 Debugging of g++ output remains a problem. g++ version 1.xx does not
5489 really support it at all. (If you're lucky, you should be able to get
5490 line numbers and stack traces to work, but no parameters or local
5491 variables.) With some work it should be possible to improve the
5494 When gcc version 2 is released, you will have somewhat better luck.
5495 However, even then you will get confusing results for inheritance and
5498 We will eventually provide full debugging of g++ output on
5499 DECstations. This will probably involve some kind of stabs-in-ecoff
5500 encapulation, but the details have not been worked out yet.
5503 *** Changes in GDB-4.2:
5505 * Improved configuration
5507 Only one copy of `configure' exists now, and it is not self-modifying.
5508 Porting BFD is simpler.
5512 The `step' and `next' commands now only stop at the first instruction
5513 of a source line. This prevents the multiple stops that used to occur
5514 in switch statements, for-loops, etc. `Step' continues to stop if a
5515 function that has debugging information is called within the line.
5519 Lots of small bugs fixed. More remain.
5521 * New host supported (not target)
5523 Intel 386 PC clone running Mach i386-none-mach
5526 *** Changes in GDB-4.1:
5528 * Multiple source language support
5530 GDB now has internal scaffolding to handle several source languages.
5531 It determines the type of each source file from its filename extension,
5532 and will switch expression parsing and number formatting to match the
5533 language of the function in the currently selected stack frame.
5534 You can also specifically set the language to be used, with
5535 `set language c' or `set language modula-2'.
5539 GDB now has preliminary support for the GNU Modula-2 compiler,
5540 currently under development at the State University of New York at
5541 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5542 continue through the fall of 1991 and into 1992.
5544 Other Modula-2 compilers are currently not supported, and attempting to
5545 debug programs compiled with them will likely result in an error as the
5546 symbol table is read. Feel free to work on it, though!
5548 There are hooks in GDB for strict type checking and range checking,
5549 in the `Modula-2 philosophy', but they do not currently work.
5553 GDB can now write to executable and core files (e.g. patch
5554 a variable's value). You must turn this switch on, specify
5555 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5556 by assigning a new value to a variable. Modifications take
5559 * Automatic SunOS shared library reading
5561 When you run your program, GDB automatically determines where its
5562 shared libraries (if any) have been loaded, and reads their symbols.
5563 The `share' command is no longer needed. This also works when
5564 examining core files.
5568 You can specify the number of lines that the `list' command shows.
5571 * New machines supported (host and target)
5573 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5574 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5575 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5577 * New hosts supported (not targets)
5579 IBM RT/PC: romp-ibm-aix or rtpc
5581 * New targets supported (not hosts)
5583 AMD 29000 embedded with COFF a29k-none-coff
5584 AMD 29000 embedded with a.out a29k-none-aout
5585 Ultracomputer remote kernel debug a29k-nyu-kern
5587 * New remote interfaces
5593 *** Changes in GDB-4.0:
5597 Wide output is wrapped at good places to make the output more readable.
5599 Gdb now supports cross-debugging from a host machine of one type to a
5600 target machine of another type. Communication with the target system
5601 is over serial lines. The ``target'' command handles connecting to the
5602 remote system; the ``load'' command will download a program into the
5603 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5604 also supports debugging of realtime processes running under VxWorks,
5605 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5606 stub on the target system.
5608 New CPUs supported include the AMD 29000 and Intel 960.
5610 GDB now reads object files and symbol tables via a ``binary file''
5611 library, which allows a single copy of GDB to debug programs of multiple
5612 object file types such as a.out and coff.
5614 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5615 refcard.dvi and refcard.ps are available to format it).
5618 * Control-Variable user interface simplified
5620 All variables that control the operation of the debugger can be set
5621 by the ``set'' command, and displayed by the ``show'' command.
5623 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5624 ``Show prompt'' produces the response:
5625 Gdb's prompt is new-gdb=>.
5627 What follows are the NEW set commands. The command ``help set'' will
5628 print a complete list of old and new set commands. ``help set FOO''
5629 will give a longer description of the variable FOO. ``show'' will show
5630 all of the variable descriptions and their current settings.
5632 confirm on/off: Enables warning questions for operations that are
5633 hard to recover from, e.g. rerunning the program while
5634 it is already running. Default is ON.
5636 editing on/off: Enables EMACS style command line editing
5637 of input. Previous lines can be recalled with
5638 control-P, the current line can be edited with control-B,
5639 you can search for commands with control-R, etc.
5642 history filename NAME: NAME is where the gdb command history
5643 will be stored. The default is .gdb_history,
5644 or the value of the environment variable
5647 history size N: The size, in commands, of the command history. The
5648 default is 256, or the value of the environment variable
5651 history save on/off: If this value is set to ON, the history file will
5652 be saved after exiting gdb. If set to OFF, the
5653 file will not be saved. The default is OFF.
5655 history expansion on/off: If this value is set to ON, then csh-like
5656 history expansion will be performed on
5657 command line input. The default is OFF.
5659 radix N: Sets the default radix for input and output. It can be set
5660 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5661 in the current radix, so "set radix 10" is always a no-op.
5663 height N: This integer value is the number of lines on a page. Default
5664 is 24, the current `stty rows'' setting, or the ``li#''
5665 setting from the termcap entry matching the environment
5668 width N: This integer value is the number of characters on a line.
5669 Default is 80, the current `stty cols'' setting, or the ``co#''
5670 setting from the termcap entry matching the environment
5673 Note: ``set screensize'' is obsolete. Use ``set height'' and
5674 ``set width'' instead.
5676 print address on/off: Print memory addresses in various command displays,
5677 such as stack traces and structure values. Gdb looks
5678 more ``symbolic'' if you turn this off; it looks more
5679 ``machine level'' with it on. Default is ON.
5681 print array on/off: Prettyprint arrays. New convenient format! Default
5684 print demangle on/off: Print C++ symbols in "source" form if on,
5687 print asm-demangle on/off: Same, for assembler level printouts
5690 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5693 * Support for Epoch Environment.
5695 The epoch environment is a version of Emacs v18 with windowing. One
5696 new command, ``inspect'', is identical to ``print'', except that if you
5697 are running in the epoch environment, the value is printed in its own
5701 * Support for Shared Libraries
5703 GDB can now debug programs and core files that use SunOS shared libraries.
5704 Symbols from a shared library cannot be referenced
5705 before the shared library has been linked with the program (this
5706 happens after you type ``run'' and before the function main() is entered).
5707 At any time after this linking (including when examining core files
5708 from dynamically linked programs), gdb reads the symbols from each
5709 shared library when you type the ``sharedlibrary'' command.
5710 It can be abbreviated ``share''.
5712 sharedlibrary REGEXP: Load shared object library symbols for files
5713 matching a unix regular expression. No argument
5714 indicates to load symbols for all shared libraries.
5716 info sharedlibrary: Status of loaded shared libraries.
5721 A watchpoint stops execution of a program whenever the value of an
5722 expression changes. Checking for this slows down execution
5723 tremendously whenever you are in the scope of the expression, but is
5724 quite useful for catching tough ``bit-spreader'' or pointer misuse
5725 problems. Some machines such as the 386 have hardware for doing this
5726 more quickly, and future versions of gdb will use this hardware.
5728 watch EXP: Set a watchpoint (breakpoint) for an expression.
5730 info watchpoints: Information about your watchpoints.
5732 delete N: Deletes watchpoint number N (same as breakpoints).
5733 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5734 enable N: Re-enables watchpoint number N (same as breakpoints).
5737 * C++ multiple inheritance
5739 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5742 * C++ exception handling
5744 Gdb now supports limited C++ exception handling. Besides the existing
5745 ability to breakpoint on an exception handler, gdb can breakpoint on
5746 the raising of an exception (before the stack is peeled back to the
5749 catch FOO: If there is a FOO exception handler in the dynamic scope,
5750 set a breakpoint to catch exceptions which may be raised there.
5751 Multiple exceptions (``catch foo bar baz'') may be caught.
5753 info catch: Lists all exceptions which may be caught in the
5754 current stack frame.
5757 * Minor command changes
5759 The command ``call func (arg, arg, ...)'' now acts like the print
5760 command, except it does not print or save a value if the function's result
5761 is void. This is similar to dbx usage.
5763 The ``up'' and ``down'' commands now always print the frame they end up
5764 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5765 frames without printing.
5767 * New directory command
5769 'dir' now adds directories to the FRONT of the source search path.
5770 The path starts off empty. Source files that contain debug information
5771 about the directory in which they were compiled can be found even
5772 with an empty path; Sun CC and GCC include this information. If GDB can't
5773 find your source file in the current directory, type "dir .".
5775 * Configuring GDB for compilation
5777 For normal use, type ``./configure host''. See README or gdb.texinfo
5780 GDB now handles cross debugging. If you are remotely debugging between
5781 two different machines, type ``./configure host -target=targ''.
5782 Host is the machine where GDB will run; targ is the machine
5783 where the program that you are debugging will run.
5785 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.
5787 * Support for Intel(R) AVX-512 registers on GNU/Linux.
5789 Support displaying and modifying Intel(R) AVX-512 registers $zmm0 - $zmm31 and
5790 $k0 - $k7 on GNU/Linux.