1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.7
6 * New command line options
9 This is an alias for the --data-directory option.
11 * GDB supports printing and modifying of variable length automatic arrays
12 as specified in ISO C99.
14 * The ARM simulator now supports instruction level tracing
15 with or without disassembly.
19 GDB now has support for scripting using Guile. Whether this is
20 available is determined at configure time.
21 Guile version 2.0 or greater is required.
22 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
24 * New commands (for set/show, see "New options" below)
28 Invoke CODE by passing it to the Guile interpreter.
32 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
34 info auto-load guile-scripts [regexp]
35 Print the list of automatically loaded Guile scripts.
37 * The source command is now capable of sourcing Guile scripts.
38 This feature is dependent on the debugger being built with Guile support.
42 set print symbol-loading (off|brief|full)
43 show print symbol-loading
44 Control whether to print informational messages when loading symbol
45 information for a file. The default is "full", but when debugging
46 programs with large numbers of shared libraries the amount of output
49 set guile print-stack (none|message|full)
50 show guile print-stack
51 Show a stack trace when an error is encountered in a Guile script.
53 set auto-load guile-scripts (on|off)
54 show auto-load guile-scripts
55 Control auto-loading of Guile script files.
57 maint ada set ignore-descriptive-types (on|off)
58 maint ada show ignore-descriptive-types
59 Control whether the debugger should ignore descriptive types in Ada
60 programs. The default is not to ignore the descriptive types. See
61 the user manual for more details on descriptive types and the intended
64 set auto-connect-native-target
66 Control whether GDB is allowed to automatically connect to the
67 native target for the run, attach, etc. commands when not connected
68 to any target yet. See also "target native" below.
70 set record btrace replay-memory-access (read-only|read-write)
71 show record btrace replay-memory-access
72 Control what memory accesses are allowed during replay.
74 * New features in the GDB remote stub, GDBserver
76 ** New option --debug-format=option1[,option2,...] allows one to add
77 additional text to each output. At present only timestamps
78 are supported: --debug-format=timestamps.
79 Timestamps can also be turned on with the
80 "monitor set debug-format timestamps" command from GDB.
82 * The 'record instruction-history' command now starts counting instructions
83 at one. This also affects the instruction ranges reported by the
84 'record function-call-history' command when given the /i modifier.
86 * The command 'record function-call-history' supports a new modifier '/c' to
87 indent the function names based on their call stack depth.
88 The fields for the '/i' and '/l' modifier have been reordered.
89 The source line range is now prefixed with 'at'.
90 The instruction range is now prefixed with 'inst'.
91 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
92 "record instruction-history" and "list" commands.
94 * The ranges given as arguments to the 'record function-call-history' and
95 'record instruction-history' commands are now inclusive.
97 * The btrace record target now supports the 'record goto' command.
98 For locations inside the execution trace, the back trace is computed
99 based on the information stored in the execution trace.
101 * The btrace record target supports limited reverse execution and replay.
102 The target does not record data and therefore does not allow reading
105 * The "catch syscall" command now works on s390*-linux* targets.
107 * The "compare-sections" command is no longer specific to target
108 remote. It now works with all targets.
110 * All native targets are now consistently called "native".
111 Consequently, the "target child", "target GNU", "target djgpp",
112 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
113 commands have been replaced with "target native". The QNX/NTO port
114 leaves the "procfs" target in place and adds a "native" target for
115 consistency with other ports. The impact on users should be minimal
116 as these commands previously either throwed an error, or were
117 no-ops. The target's name is visible in the output of the following
118 commands: "help target", "info target", "info files", "maint print
121 * The "target native" command now connects to the native target. This
122 can be used to launch native programs even when "set
123 auto-connect-native-target" is set to off.
127 qXfer:btrace:read's annex
128 The qXfer:btrace:read packet supports a new annex 'delta' to read
129 branch trace incrementally.
133 ** Valid Python operations on gdb.Value objects representing
134 structs/classes invoke the corresponding overloaded operators if
138 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
140 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
141 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
142 its alias "share", instead.
144 * The commands "set remotebaud" and "show remotebaud" are no longer
145 supported. Use "set serial baud" and "show serial baud" (respectively)
148 *** Changes in GDB 7.7
150 * Improved support for process record-replay and reverse debugging on
151 arm*-linux* targets. Support for thumb32 and syscall instruction
152 recording has been added.
154 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
156 * GDB now supports Fission DWP file format version 2.
157 http://gcc.gnu.org/wiki/DebugFission
159 * New convenience function "$_isvoid", to check whether an expression
160 is void. A void expression is an expression where the type of the
161 result is "void". For example, some convenience variables may be
162 "void" when evaluated (e.g., "$_exitcode" before the execution of
163 the program being debugged; or an undefined convenience variable).
164 Another example, when calling a function whose return type is
167 * The "maintenance print objfiles" command now takes an optional regexp.
169 * The "catch syscall" command now works on arm*-linux* targets.
171 * GDB now consistently shows "<not saved>" when printing values of
172 registers the debug info indicates have not been saved in the frame
173 and there's nowhere to retrieve them from
174 (callee-saved/call-clobbered registers):
179 (gdb) info registers rax
182 Before, the former would print "<optimized out>", and the latter
183 "*value not available*".
185 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
190 ** Frame filters and frame decorators have been added.
191 ** Temporary breakpoints are now supported.
192 ** Line tables representation has been added.
193 ** New attribute 'parent_type' for gdb.Field objects.
194 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
195 ** New attribute 'name' for gdb.Type objects.
199 Nios II ELF nios2*-*-elf
200 Nios II GNU/Linux nios2*-*-linux
201 Texas Instruments MSP430 msp430*-*-elf
203 * Removed native configurations
205 Support for these a.out NetBSD and OpenBSD obsolete configurations has
206 been removed. ELF variants of these configurations are kept supported.
208 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
209 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
210 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
211 i[34567]86-*-openbsd3.[0-3]
212 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
213 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
214 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
218 Like "catch throw", but catches a re-thrown exception.
220 Renamed from old "maint check-symtabs".
222 Perform consistency checks on symtabs.
224 Expand symtabs matching an optional regexp.
227 Display the details of GDB configure-time options.
229 maint set|show per-command
230 maint set|show per-command space
231 maint set|show per-command time
232 maint set|show per-command symtab
233 Enable display of per-command gdb resource usage.
235 remove-symbol-file FILENAME
236 remove-symbol-file -a ADDRESS
237 Remove a symbol file added via add-symbol-file. The file to remove
238 can be identified by its filename or by an address that lies within
239 the boundaries of this symbol file in memory.
242 info exceptions REGEXP
243 Display the list of Ada exceptions defined in the program being
244 debugged. If provided, only the exceptions whose names match REGEXP
249 set debug symfile off|on
251 Control display of debugging info regarding reading symbol files and
252 symbol tables within those files
254 set print raw frame-arguments
255 show print raw frame-arguments
256 Set/show whether to print frame arguments in raw mode,
257 disregarding any defined pretty-printers.
259 set remote trace-status-packet
260 show remote trace-status-packet
261 Set/show the use of remote protocol qTStatus packet.
265 Control display of debugging messages related to Nios II targets.
269 Control whether target-assisted range stepping is enabled.
271 set startup-with-shell
272 show startup-with-shell
273 Specifies whether Unix child processes are started via a shell or
278 Use the target memory cache for accesses to the code segment. This
279 improves performance of remote debugging (particularly disassembly).
281 * You can now use a literal value 'unlimited' for options that
282 interpret 0 or -1 as meaning "unlimited". E.g., "set
283 trace-buffer-size unlimited" is now an alias for "set
284 trace-buffer-size -1" and "set height unlimited" is now an alias for
287 * The "set debug symtab-create" debugging option of GDB has been changed to
288 accept a verbosity level. 0 means "off", 1 provides basic debugging
289 output, and values of 2 or greater provides more verbose output.
291 * New command-line options
293 Display the details of GDB configure-time options.
295 * The command 'tsave' can now support new option '-ctf' to save trace
296 buffer in Common Trace Format.
298 * Newly installed $prefix/bin/gcore acts as a shell interface for the
301 * GDB now implements the the C++ 'typeid' operator.
303 * The new convenience variable $_exception holds the exception being
304 thrown or caught at an exception-related catchpoint.
306 * The exception-related catchpoints, like "catch throw", now accept a
307 regular expression which can be used to filter exceptions by type.
309 * The new convenience variable $_exitsignal is automatically set to
310 the terminating signal number when the program being debugged dies
311 due to an uncaught signal.
315 ** All MI commands now accept an optional "--language" option.
316 Support for this feature can be verified by using the "-list-features"
317 command, which should contain "language-option".
319 ** The new command -info-gdb-mi-command allows the user to determine
320 whether a GDB/MI command is supported or not.
322 ** The "^error" result record returned when trying to execute an undefined
323 GDB/MI command now provides a variable named "code" whose content is the
324 "undefined-command" error code. Support for this feature can be verified
325 by using the "-list-features" command, which should contain
326 "undefined-command-error-code".
328 ** The -trace-save MI command can optionally save trace buffer in Common
331 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
333 ** The command -data-list-register-values now accepts an optional
334 "--skip-unavailable" option. When used, only the available registers
337 ** The new command -trace-frame-collected dumps collected variables,
338 computed expressions, tvars, memory and registers in a traceframe.
340 ** The commands -stack-list-locals, -stack-list-arguments and
341 -stack-list-variables now accept an option "--skip-unavailable".
342 When used, only the available locals or arguments are displayed.
344 ** The -exec-run command now accepts an optional "--start" option.
345 When used, the command follows the same semantics as the "start"
346 command, stopping the program's execution at the start of its
347 main subprogram. Support for this feature can be verified using
348 the "-list-features" command, which should contain
349 "exec-run-start-option".
351 ** The new commands -catch-assert and -catch-exceptions insert
352 catchpoints stopping the program when Ada exceptions are raised.
354 ** The new command -info-ada-exceptions provides the equivalent of
355 the new "info exceptions" command.
357 * New system-wide configuration scripts
358 A GDB installation now provides scripts suitable for use as system-wide
359 configuration scripts for the following systems:
363 * GDB now supports target-assigned range stepping with remote targets.
364 This improves the performance of stepping source lines by reducing
365 the number of control packets from/to GDB. See "New remote packets"
368 * GDB now understands the element 'tvar' in the XML traceframe info.
369 It has the id of the collected trace state variables.
371 * On S/390 targets that provide the transactional-execution feature,
372 the program interruption transaction diagnostic block (TDB) is now
373 represented as a number of additional "registers" in GDB.
379 The vCont packet supports a new 'r' action, that tells the remote
380 stub to step through an address range itself, without GDB
381 involvemement at each single-step.
383 qXfer:libraries-svr4:read's annex
384 The previously unused annex of the qXfer:libraries-svr4:read packet
385 is now used to support passing an argument list. The remote stub
386 reports support for this argument list to GDB's qSupported query.
387 The defined arguments are "start" and "prev", used to reduce work
388 necessary for library list updating, resulting in significant
391 * New features in the GDB remote stub, GDBserver
393 ** GDBserver now supports target-assisted range stepping. Currently
394 enabled on x86/x86_64 GNU/Linux targets.
396 ** GDBserver now adds element 'tvar' in the XML in the reply to
397 'qXfer:traceframe-info:read'. It has the id of the collected
398 trace state variables.
400 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
403 * New 'z' formatter for printing and examining memory, this displays the
404 value as hexadecimal zero padded on the left to the size of the type.
406 * GDB can now use Windows x64 unwinding data.
408 * The "set remotebaud" command has been replaced by "set serial baud".
409 Similarly, "show remotebaud" has been replaced by "show serial baud".
410 The "set remotebaud" and "show remotebaud" commands are still available
411 to provide backward compatibility with older versions of GDB.
413 *** Changes in GDB 7.6
415 * Target record has been renamed to record-full.
416 Record/replay is now enabled with the "record full" command.
417 This also affects settings that are associated with full record/replay
418 that have been moved from "set/show record" to "set/show record full":
420 set|show record full insn-number-max
421 set|show record full stop-at-limit
422 set|show record full memory-query
424 * A new record target "record-btrace" has been added. The new target
425 uses hardware support to record the control-flow of a process. It
426 does not support replaying the execution, but it implements the
427 below new commands for investigating the recorded execution log.
428 This new recording method can be enabled using:
432 The "record-btrace" target is only available on Intel Atom processors
433 and requires a Linux kernel 2.6.32 or later.
435 * Two new commands have been added for record/replay to give information
436 about the recorded execution without having to replay the execution.
437 The commands are only supported by "record btrace".
439 record instruction-history prints the execution history at
440 instruction granularity
442 record function-call-history prints the execution history at
445 * New native configurations
447 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
448 FreeBSD/powerpc powerpc*-*-freebsd
449 x86_64/Cygwin x86_64-*-cygwin*
450 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
454 ARM AArch64 aarch64*-*-elf
455 ARM AArch64 GNU/Linux aarch64*-*-linux
456 Lynx 178 PowerPC powerpc-*-lynx*178
457 x86_64/Cygwin x86_64-*-cygwin*
458 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
460 * If the configured location of system.gdbinit file (as given by the
461 --with-system-gdbinit option at configure time) is in the
462 data-directory (as specified by --with-gdb-datadir at configure
463 time) or in one of its subdirectories, then GDB will look for the
464 system-wide init file in the directory specified by the
465 --data-directory command-line option.
467 * New command line options:
469 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
470 other initialization files, unlike -nx which disables all of them.
472 * Removed command line options
474 -epoch This was used by the gdb mode in Epoch, an ancient fork of
477 * The 'ptype' and 'whatis' commands now accept an argument to control
480 * 'info proc' now works on some core files.
484 ** Vectors can be created with gdb.Type.vector.
486 ** Python's atexit.register now works in GDB.
488 ** Types can be pretty-printed via a Python API.
490 ** Python 3 is now supported (in addition to Python 2.4 or later)
492 ** New class gdb.Architecture exposes GDB's internal representation
493 of architecture in the Python API.
495 ** New method Frame.architecture returns the gdb.Architecture object
496 corresponding to the frame's architecture.
498 * New Python-based convenience functions:
500 ** $_memeq(buf1, buf2, length)
501 ** $_streq(str1, str2)
503 ** $_regex(str, regex)
505 * The 'cd' command now defaults to using '~' (the home directory) if not
508 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
509 default for GCC since November 2000.
511 * The command 'forward-search' can now be abbreviated as 'fo'.
513 * The command 'info tracepoints' can now display 'installed on target'
514 or 'not installed on target' for each non-pending location of tracepoint.
516 * New configure options
518 --enable-libmcheck/--disable-libmcheck
519 By default, development versions are built with -lmcheck on hosts
520 that support it, in order to help track memory corruption issues.
521 Release versions, on the other hand, are built without -lmcheck
522 by default. The --enable-libmcheck/--disable-libmcheck configure
523 options allow the user to override that default.
524 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
525 This configure option allows the user to build GDB with
526 libbabeltrace using which GDB can read Common Trace Format data.
528 * New commands (for set/show, see "New options" below)
531 Catch signals. This is similar to "handle", but allows commands and
532 conditions to be attached.
535 List the BFDs known to GDB.
537 python-interactive [command]
539 Start a Python interactive prompt, or evaluate the optional command
540 and print the result of expressions.
543 "py" is a new alias for "python".
545 enable type-printer [name]...
546 disable type-printer [name]...
547 Enable or disable type printers.
551 ** For the Renesas Super-H architecture, the "regs" command has been removed
552 (has been deprecated in GDB 7.5), and "info all-registers" should be used
557 set print type methods (on|off)
558 show print type methods
559 Control whether method declarations are displayed by "ptype".
560 The default is to show them.
562 set print type typedefs (on|off)
563 show print type typedefs
564 Control whether typedef definitions are displayed by "ptype".
565 The default is to show them.
567 set filename-display basename|relative|absolute
568 show filename-display
569 Control the way in which filenames is displayed.
570 The default is "relative", which preserves previous behavior.
572 set trace-buffer-size
573 show trace-buffer-size
574 Request target to change the size of trace buffer.
576 set remote trace-buffer-size-packet auto|on|off
577 show remote trace-buffer-size-packet
578 Control the use of the remote protocol `QTBuffer:size' packet.
582 Control display of debugging messages related to ARM AArch64.
585 set debug coff-pe-read
586 show debug coff-pe-read
587 Control display of debugging messages related to reading of COFF/PE
592 Control display of debugging messages related to Mach-O symbols
595 set debug notification
596 show debug notification
597 Control display of debugging info for async remote notification.
601 ** Command parameter changes are now notified using new async record
602 "=cmd-param-changed".
603 ** Trace frame changes caused by command "tfind" are now notified using
604 new async record "=traceframe-changed".
605 ** The creation, deletion and modification of trace state variables
606 are now notified using new async records "=tsv-created",
607 "=tsv-deleted" and "=tsv-modified".
608 ** The start and stop of process record are now notified using new
609 async record "=record-started" and "=record-stopped".
610 ** Memory changes are now notified using new async record
612 ** The data-disassemble command response will include a "fullname" field
613 containing the absolute file name when source has been requested.
614 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
615 command, to allow pattern filling of memory areas.
616 ** New commands "-catch-load"/"-catch-unload" added for intercepting
617 library load/unload events.
618 ** The response to breakpoint commands and breakpoint async records
619 includes an "installed" field containing a boolean state about each
620 non-pending tracepoint location is whether installed on target or not.
621 ** Output of the "-trace-status" command includes a "trace-file" field
622 containing the name of the trace file being examined. This field is
623 optional, and only present when examining a trace file.
624 ** The "fullname" field is now always present along with the "file" field,
625 even if the file cannot be found by GDB.
627 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
628 You must have the LZMA library available when configuring GDB for this
629 feature to be enabled. For more information, see:
630 http://fedoraproject.org/wiki/Features/MiniDebugInfo
635 Set the size of trace buffer. The remote stub reports support for this
636 packet to gdb's qSupported query.
639 Enable Branch Trace Store (BTS)-based branch tracing for the current
640 thread. The remote stub reports support for this packet to gdb's
644 Disable branch tracing for the current thread. The remote stub reports
645 support for this packet to gdb's qSupported query.
648 Read the traced branches for the current thread. The remote stub
649 reports support for this packet to gdb's qSupported query.
651 *** Changes in GDB 7.5
653 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
654 for more x32 ABI info.
656 * GDB now supports access to MIPS DSP registers on Linux targets.
658 * GDB now supports debugging microMIPS binaries.
660 * The "info os" command on GNU/Linux can now display information on
661 several new classes of objects managed by the operating system:
662 "info os procgroups" lists process groups
663 "info os files" lists file descriptors
664 "info os sockets" lists internet-domain sockets
665 "info os shm" lists shared-memory regions
666 "info os semaphores" lists semaphores
667 "info os msg" lists message queues
668 "info os modules" lists loaded kernel modules
670 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
671 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
672 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
673 options and inspect the probe arguments using the new $_probe_arg family
674 of convenience variables. You can obtain more information about SystemTap
675 in <http://sourceware.org/systemtap/>.
677 * GDB now supports reversible debugging on ARM, it allows you to
678 debug basic ARM and THUMB instructions, and provides
679 record/replay support.
681 * The option "symbol-reloading" has been deleted as it is no longer used.
685 ** GDB commands implemented in Python can now be put in command class
688 ** The "maint set python print-stack on|off" is now deleted.
690 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
691 apply "flag enum"-style pretty-printing to any enum.
693 ** gdb.lookup_symbol can now work when there is no current frame.
695 ** gdb.Symbol now has a 'line' attribute, holding the line number in
696 the source at which the symbol was defined.
698 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
699 method 'value'. The former indicates whether the symbol needs a
700 frame in order to compute its value, and the latter computes the
703 ** A new method 'referenced_value' on gdb.Value objects which can
704 dereference pointer as well as C++ reference values.
706 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
707 which return the global and static blocks (as gdb.Block objects),
708 of the underlying symbol table, respectively.
710 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
711 object associated with a PC value.
713 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
714 of the address range occupied by code for the current source line.
716 * Go language support.
717 GDB now supports debugging programs written in the Go programming
720 * GDBserver now supports stdio connections.
721 E.g. (gdb) target remote | ssh myhost gdbserver - hello
723 * The binary "gdbtui" can no longer be built or installed.
724 Use "gdb -tui" instead.
726 * GDB will now print "flag" enums specially. A flag enum is one where
727 all the enumerator values have no bits in common when pairwise
728 "and"ed. When printing a value whose type is a flag enum, GDB will
729 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
730 (gdb) print (enum E) 3
733 * The filename part of a linespec will now match trailing components
734 of a source file name. For example, "break gcc/expr.c:1000" will
735 now set a breakpoint in build/gcc/expr.c, but not
738 * The "info proc" and "generate-core-file" commands will now also
739 work on remote targets connected to GDBserver on Linux.
741 * The command "info catch" has been removed. It has been disabled
744 * The "catch exception" and "catch assert" commands now accept
745 a condition at the end of the command, much like the "break"
746 command does. For instance:
748 (gdb) catch exception Constraint_Error if Barrier = True
750 Previously, it was possible to add a condition to such catchpoints,
751 but it had to be done as a second step, after the catchpoint had been
752 created, using the "condition" command.
754 * The "info static-tracepoint-marker" command will now also work on
755 native Linux targets with in-process agent.
757 * GDB can now set breakpoints on inlined functions.
759 * The .gdb_index section has been updated to include symbols for
760 inlined functions. GDB will ignore older .gdb_index sections by
761 default, which could cause symbol files to be loaded more slowly
762 until their .gdb_index sections can be recreated. The new command
763 "set use-deprecated-index-sections on" will cause GDB to use any older
764 .gdb_index sections it finds. This will restore performance, but the
765 ability to set breakpoints on inlined functions will be lost in symbol
766 files with older .gdb_index sections.
768 The .gdb_index section has also been updated to record more information
769 about each symbol. This speeds up the "info variables", "info functions"
770 and "info types" commands when used with programs having the .gdb_index
771 section, as well as speeding up debugging with shared libraries using
772 the .gdb_index section.
774 * Ada support for GDB/MI Variable Objects has been added.
776 * GDB can now support 'breakpoint always-inserted mode' in 'record'
781 ** New command -info-os is the MI equivalent of "info os".
783 ** Output logs ("set logging" and related) now include MI output.
787 ** "set use-deprecated-index-sections on|off"
788 "show use-deprecated-index-sections on|off"
789 Controls the use of deprecated .gdb_index sections.
791 ** "catch load" and "catch unload" can be used to stop when a shared
792 library is loaded or unloaded, respectively.
794 ** "enable count" can be used to auto-disable a breakpoint after
797 ** "info vtbl" can be used to show the virtual method tables for
798 C++ and Java objects.
800 ** "explore" and its sub commands "explore value" and "explore type"
801 can be used to recursively explore values and types of
802 expressions. These commands are available only if GDB is
803 configured with '--with-python'.
805 ** "info auto-load" shows status of all kinds of auto-loaded files,
806 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
807 sequences of commands files, "info auto-load python-scripts"
808 shows status of auto-loading Python script files,
809 "info auto-load local-gdbinit" shows status of loading init file
810 (.gdbinit) from current directory and "info auto-load libthread-db" shows
811 status of inferior specific thread debugging shared library loading.
813 ** "info auto-load-scripts", "set auto-load-scripts on|off"
814 and "show auto-load-scripts" commands have been deprecated, use their
815 "info auto-load python-scripts", "set auto-load python-scripts on|off"
816 and "show auto-load python-scripts" counterparts instead.
818 ** "dprintf location,format,args..." creates a dynamic printf, which
819 is basically a breakpoint that does a printf and immediately
820 resumes your program's execution, so it is like a printf that you
821 can insert dynamically at runtime instead of at compiletime.
823 ** "set print symbol"
825 Controls whether GDB attempts to display the symbol, if any,
826 corresponding to addresses it prints. This defaults to "on", but
827 you can set it to "off" to restore GDB's previous behavior.
829 * Deprecated commands
831 ** For the Renesas Super-H architecture, the "regs" command has been
832 deprecated, and "info all-registers" should be used instead.
836 Renesas RL78 rl78-*-elf
837 HP OpenVMS ia64 ia64-hp-openvms*
839 * GDBserver supports evaluation of breakpoint conditions. When
840 support is advertised by GDBserver, GDB may be told to send the
841 breakpoint conditions in bytecode form to GDBserver. GDBserver
842 will only report the breakpoint trigger to GDB when its condition
848 show mips compression
849 Select the compressed ISA encoding used in functions that have no symbol
850 information available. The encoding can be set to either of:
853 and is updated automatically from ELF file flags if available.
855 set breakpoint condition-evaluation
856 show breakpoint condition-evaluation
857 Control whether breakpoint conditions are evaluated by GDB ("host") or by
858 GDBserver ("target"). Default option "auto" chooses the most efficient
860 This option can improve debugger efficiency depending on the speed of the
864 Disable auto-loading globally.
867 Show auto-loading setting of all kinds of auto-loaded files.
869 set auto-load gdb-scripts on|off
870 show auto-load gdb-scripts
871 Control auto-loading of GDB canned sequences of commands files.
873 set auto-load python-scripts on|off
874 show auto-load python-scripts
875 Control auto-loading of Python script files.
877 set auto-load local-gdbinit on|off
878 show auto-load local-gdbinit
879 Control loading of init file (.gdbinit) from current directory.
881 set auto-load libthread-db on|off
882 show auto-load libthread-db
883 Control auto-loading of inferior specific thread debugging shared library.
885 set auto-load scripts-directory <dir1>[:<dir2>...]
886 show auto-load scripts-directory
887 Set a list of directories from which to load auto-loaded scripts.
888 Automatically loaded Python scripts and GDB scripts are located in one
889 of the directories listed by this option.
890 The delimiter (':' above) may differ according to the host platform.
892 set auto-load safe-path <dir1>[:<dir2>...]
893 show auto-load safe-path
894 Set a list of directories from which it is safe to auto-load files.
895 The delimiter (':' above) may differ according to the host platform.
897 set debug auto-load on|off
899 Control display of debugging info for auto-loading the files above.
901 set dprintf-style gdb|call|agent
903 Control the way in which a dynamic printf is performed; "gdb"
904 requests a GDB printf command, while "call" causes dprintf to call a
905 function in the inferior. "agent" requests that the target agent
906 (such as GDBserver) do the printing.
908 set dprintf-function <expr>
909 show dprintf-function
910 set dprintf-channel <expr>
912 Set the function and optional first argument to the call when using
913 the "call" style of dynamic printf.
915 set disconnected-dprintf on|off
916 show disconnected-dprintf
917 Control whether agent-style dynamic printfs continue to be in effect
918 after GDB disconnects.
920 * New configure options
923 Configure default value for the 'set auto-load scripts-directory'
924 setting above. It defaults to '$debugdir:$datadir/auto-load',
925 $debugdir representing global debugging info directories (available
926 via 'show debug-file-directory') and $datadir representing GDB's data
927 directory (available via 'show data-directory').
929 --with-auto-load-safe-path
930 Configure default value for the 'set auto-load safe-path' setting
931 above. It defaults to the --with-auto-load-dir setting.
933 --without-auto-load-safe-path
934 Set 'set auto-load safe-path' to '/', effectively disabling this
939 z0/z1 conditional breakpoints extension
941 The z0/z1 breakpoint insertion packets have been extended to carry
942 a list of conditional expressions over to the remote stub depending on the
943 condition evaluation mode. The use of this extension can be controlled
944 via the "set remote conditional-breakpoints-packet" command.
948 Specify the signals which the remote stub may pass to the debugged
949 program without GDB involvement.
951 * New command line options
953 --init-command=FILE, -ix Like --command, -x but execute it
954 before loading inferior.
955 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
956 execute it before loading inferior.
958 *** Changes in GDB 7.4
960 * GDB now handles ambiguous linespecs more consistently; the existing
961 FILE:LINE support has been expanded to other types of linespecs. A
962 breakpoint will now be set on all matching locations in all
963 inferiors, and locations will be added or removed according to
966 * GDB now allows you to skip uninteresting functions and files when
967 stepping with the "skip function" and "skip file" commands.
969 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
970 and "show remote hardware-watchpoint-length-limit". These allows to
971 set or show the maximum length limit (in bytes) of a remote
972 target hardware watchpoint.
974 This allows e.g. to use "unlimited" hardware watchpoints with the
975 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
976 watchpoints are slower than real hardware watchpoints but are
977 significantly faster than gdb software watchpoints.
981 ** The register_pretty_printer function in module gdb.printing now takes
982 an optional `replace' argument. If True, the new printer replaces any
985 ** The "maint set python print-stack on|off" command has been
986 deprecated and will be deleted in GDB 7.5.
987 A new command: "set python print-stack none|full|message" has
988 replaced it. Additionally, the default for "print-stack" is
989 now "message", which just prints the error message without
992 ** A prompt substitution hook (prompt_hook) is now available to the
995 ** A new Python module, gdb.prompt has been added to the GDB Python
996 modules library. This module provides functionality for
997 escape sequences in prompts (used by set/show
998 extended-prompt). These escape sequences are replaced by their
1001 ** Python commands and convenience-functions located in
1002 'data-directory'/python/gdb/command and
1003 'data-directory'/python/gdb/function are now automatically loaded
1006 ** Blocks now provide four new attributes. global_block and
1007 static_block will return the global and static blocks
1008 respectively. is_static and is_global are boolean attributes
1009 that indicate if the block is one of those two types.
1011 ** Symbols now provide the "type" attribute, the type of the symbol.
1013 ** The "gdb.breakpoint" function has been deprecated in favor of
1016 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1017 of a function. This class is based on the "finish" command
1018 available in the CLI.
1020 ** Type objects for struct and union types now allow access to
1021 the fields using standard Python dictionary (mapping) methods.
1022 For example, "some_type['myfield']" now works, as does
1023 "some_type.items()".
1025 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1028 ** A new function, "deep_items" has been added to the gdb.types
1029 module in the GDB Python modules library. This function returns
1030 an iterator over the fields of a struct or union type. Unlike
1031 the standard Python "iteritems" method, it will recursively traverse
1032 any anonymous fields.
1036 ** "*stopped" events can report several new "reason"s, such as
1039 ** Breakpoint changes are now notified using new async records, like
1040 "=breakpoint-modified".
1042 ** New command -ada-task-info.
1044 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1045 $sdir specifies the default system locations of shared libraries.
1046 $pdir specifies the directory where the libpthread used by the application
1049 GDB no longer looks in $sdir and $pdir after it has searched the directories
1050 mentioned in libthread-db-search-path. If you want to search those
1051 directories, they must be specified in libthread-db-search-path.
1052 The default value of libthread-db-search-path on GNU/Linux and Solaris
1053 systems is now "$sdir:$pdir".
1055 $pdir is not supported by gdbserver, it is currently ignored.
1056 $sdir is supported by gdbserver.
1058 * New configure option --with-iconv-bin.
1059 When using the internationalization support like the one in the GNU C
1060 library, GDB will invoke the "iconv" program to get a list of supported
1061 character sets. If this program lives in a non-standard location, one can
1062 use this option to specify where to find it.
1064 * When natively debugging programs on PowerPC BookE processors running
1065 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1066 watchpoints, which specify a mask in addition to an address to watch.
1067 The mask specifies that some bits of an address (the bits which are
1068 reset in the mask) should be ignored when matching the address accessed
1069 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1070 section in the user manual for more details.
1072 * The new option --once causes GDBserver to stop listening for connections once
1073 the first connection is made. The listening port used by GDBserver will
1074 become available after that.
1076 * New commands "info macros" and "alias" have been added.
1078 * New function parameters suffix @entry specifies value of function parameter
1079 at the time the function got called. Entry values are available only since
1085 "!" is now an alias of the "shell" command.
1086 Note that no space is needed between "!" and SHELL COMMAND.
1090 watch EXPRESSION mask MASK_VALUE
1091 The watch command now supports the mask argument which allows creation
1092 of masked watchpoints, if the current architecture supports this feature.
1094 info auto-load-scripts [REGEXP]
1095 This command was formerly named "maintenance print section-scripts".
1096 It is now generally useful and is no longer a maintenance-only command.
1098 info macro [-all] [--] MACRO
1099 The info macro command has new options `-all' and `--'. The first for
1100 printing all definitions of a macro. The second for explicitly specifying
1101 the end of arguments and the beginning of the macro name in case the macro
1102 name starts with a hyphen.
1104 collect[/s] EXPRESSIONS
1105 The tracepoint collect command now takes an optional modifier "/s"
1106 that directs it to dereference pointer-to-character types and
1107 collect the bytes of memory up to a zero byte. The behavior is
1108 similar to what you see when you use the regular print command on a
1109 string. An optional integer following the "/s" sets a bound on the
1110 number of bytes that will be collected.
1113 The trace start command now interprets any supplied arguments as a
1114 note to be recorded with the trace run, with an effect similar to
1115 setting the variable trace-notes.
1118 The trace stop command now interprets any arguments as a note to be
1119 mentioned along with the tstatus report that the trace was stopped
1120 with a command. The effect is similar to setting the variable
1123 * Tracepoints can now be enabled and disabled at any time after a trace
1124 experiment has been started using the standard "enable" and "disable"
1125 commands. It is now possible to start a trace experiment with no enabled
1126 tracepoints; GDB will display a warning, but will allow the experiment to
1127 begin, assuming that tracepoints will be enabled as needed while the trace
1130 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1131 locations with 4-byte instructions, when they were previously
1132 limited to locations with instructions of 5 bytes or longer.
1136 set debug dwarf2-read
1137 show debug dwarf2-read
1138 Turns on or off display of debugging messages related to reading
1139 DWARF debug info. The default is off.
1141 set debug symtab-create
1142 show debug symtab-create
1143 Turns on or off display of debugging messages related to symbol table
1144 creation. The default is off.
1147 show extended-prompt
1148 Set the GDB prompt, and allow escape sequences to be inserted to
1149 display miscellaneous information (see 'help set extended-prompt'
1150 for the list of sequences). This prompt (and any information
1151 accessed through the escape sequences) is updated every time the
1152 prompt is displayed.
1154 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1155 show print entry-values
1156 Set printing of frame argument values at function entry. In some cases
1157 GDB can determine the value of function argument which was passed by the
1158 function caller, even if the value was modified inside the called function.
1160 set debug entry-values
1161 show debug entry-values
1162 Control display of debugging info for determining frame argument values at
1163 function entry and virtual tail call frames.
1165 set basenames-may-differ
1166 show basenames-may-differ
1167 Set whether a source file may have multiple base names.
1168 (A "base name" is the name of a file with the directory part removed.
1169 Example: The base name of "/home/user/hello.c" is "hello.c".)
1170 If set, GDB will canonicalize file names (e.g., expand symlinks)
1171 before comparing them. Canonicalization is an expensive operation,
1172 but it allows the same file be known by more than one base name.
1173 If not set (the default), all source files are assumed to have just
1174 one base name, and gdb will do file name comparisons more efficiently.
1180 Set a user name and notes for the current and any future trace runs.
1181 This is useful for long-running and/or disconnected traces, to
1182 inform others (or yourself) as to who is running the trace, supply
1183 contact information, or otherwise explain what is going on.
1185 set trace-stop-notes
1186 show trace-stop-notes
1187 Set a note attached to the trace run, that is displayed when the
1188 trace has been stopped by a tstop command. This is useful for
1189 instance as an explanation, if you are stopping a trace run that was
1190 started by someone else.
1192 * New remote packets
1196 Dynamically enable a tracepoint in a started trace experiment.
1200 Dynamically disable a tracepoint in a started trace experiment.
1204 Set the user and notes of the trace run.
1208 Query the current status of a tracepoint.
1212 Query the minimum length of instruction at which a fast tracepoint may
1215 * Dcache size (number of lines) and line-size are now runtime-configurable
1216 via "set dcache line" and "set dcache line-size" commands.
1220 Texas Instruments TMS320C6x tic6x-*-*
1224 Renesas RL78 rl78-*-elf
1226 *** Changes in GDB 7.3.1
1228 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1230 *** Changes in GDB 7.3
1232 * GDB has a new command: "thread find [REGEXP]".
1233 It finds the thread id whose name, target id, or thread extra info
1234 matches the given regular expression.
1236 * The "catch syscall" command now works on mips*-linux* targets.
1238 * The -data-disassemble MI command now supports modes 2 and 3 for
1239 dumping the instruction opcodes.
1241 * New command line options
1243 -data-directory DIR Specify DIR as the "data-directory".
1244 This is mostly for testing purposes.
1246 * The "maint set python auto-load on|off" command has been renamed to
1247 "set auto-load-scripts on|off".
1249 * GDB has a new command: "set directories".
1250 It is like the "dir" command except that it replaces the
1251 source path list instead of augmenting it.
1253 * GDB now understands thread names.
1255 On GNU/Linux, "info threads" will display the thread name as set by
1256 prctl or pthread_setname_np.
1258 There is also a new command, "thread name", which can be used to
1259 assign a name internally for GDB to display.
1262 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1263 has been integrated into GDB.
1267 ** The function gdb.Write now accepts an optional keyword 'stream'.
1268 This keyword, when provided, will direct the output to either
1269 stdout, stderr, or GDB's logging output.
1271 ** Parameters can now be be sub-classed in Python, and in particular
1272 you may implement the get_set_doc and get_show_doc functions.
1273 This improves how Parameter set/show documentation is processed
1274 and allows for more dynamic content.
1276 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1277 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1278 have an is_valid method.
1280 ** Breakpoints can now be sub-classed in Python, and in particular
1281 you may implement a 'stop' function that is executed each time
1282 the inferior reaches that breakpoint.
1284 ** New function gdb.lookup_global_symbol looks up a global symbol.
1286 ** GDB values in Python are now callable if the value represents a
1287 function. For example, if 'some_value' represents a function that
1288 takes two integer parameters and returns a value, you can call
1289 that function like so:
1291 result = some_value (10,20)
1293 ** Module gdb.types has been added.
1294 It contains a collection of utilities for working with gdb.Types objects:
1295 get_basic_type, has_field, make_enum_dict.
1297 ** Module gdb.printing has been added.
1298 It contains utilities for writing and registering pretty-printers.
1299 New classes: PrettyPrinter, SubPrettyPrinter,
1300 RegexpCollectionPrettyPrinter.
1301 New function: register_pretty_printer.
1303 ** New commands "info pretty-printers", "enable pretty-printer" and
1304 "disable pretty-printer" have been added.
1306 ** gdb.parameter("directories") is now available.
1308 ** New function gdb.newest_frame returns the newest frame in the
1311 ** The gdb.InferiorThread class has a new "name" attribute. This
1312 holds the thread's name.
1314 ** Python Support for Inferior events.
1315 Python scripts can add observers to be notified of events
1316 occurring in the process being debugged.
1317 The following events are currently supported:
1318 - gdb.events.cont Continue event.
1319 - gdb.events.exited Inferior exited event.
1320 - gdb.events.stop Signal received, and Breakpoint hit events.
1324 ** GDB now puts template parameters in scope when debugging in an
1325 instantiation. For example, if you have:
1327 template<int X> int func (void) { return X; }
1329 then if you step into func<5>, "print X" will show "5". This
1330 feature requires proper debuginfo support from the compiler; it
1331 was added to GCC 4.5.
1333 ** The motion commands "next", "finish", "until", and "advance" now
1334 work better when exceptions are thrown. In particular, GDB will
1335 no longer lose control of the inferior; instead, the GDB will
1336 stop the inferior at the point at which the exception is caught.
1337 This functionality requires a change in the exception handling
1338 code that was introduced in GCC 4.5.
1340 * GDB now follows GCC's rules on accessing volatile objects when
1341 reading or writing target state during expression evaluation.
1342 One notable difference to prior behavior is that "print x = 0"
1343 no longer generates a read of x; the value of the assignment is
1344 now always taken directly from the value being assigned.
1346 * GDB now has some support for using labels in the program's source in
1347 linespecs. For instance, you can use "advance label" to continue
1348 execution to a label.
1350 * GDB now has support for reading and writing a new .gdb_index
1351 section. This section holds a fast index of DWARF debugging
1352 information and can be used to greatly speed up GDB startup and
1353 operation. See the documentation for `save gdb-index' for details.
1355 * The "watch" command now accepts an optional "-location" argument.
1356 When used, this causes GDB to watch the memory referred to by the
1357 expression. Such a watchpoint is never deleted due to it going out
1360 * GDB now supports thread debugging of core dumps on GNU/Linux.
1362 GDB now activates thread debugging using the libthread_db library
1363 when debugging GNU/Linux core dumps, similarly to when debugging
1364 live processes. As a result, when debugging a core dump file, GDB
1365 is now able to display pthread_t ids of threads. For example, "info
1366 threads" shows the same output as when debugging the process when it
1367 was live. In earlier releases, you'd see something like this:
1370 * 1 LWP 6780 main () at main.c:10
1372 While now you see this:
1375 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1377 It is also now possible to inspect TLS variables when debugging core
1380 When debugging a core dump generated on a machine other than the one
1381 used to run GDB, you may need to point GDB at the correct
1382 libthread_db library with the "set libthread-db-search-path"
1383 command. See the user manual for more details on this command.
1385 * When natively debugging programs on PowerPC BookE processors running
1386 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1387 which stop execution of the inferior whenever it executes an instruction
1388 at any address within the specified range. See the "PowerPC Embedded"
1389 section in the user manual for more details.
1391 * New features in the GDB remote stub, GDBserver
1393 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1394 and i686 LynxOS (version 5.x).
1396 ** GDBserver is now supported on Blackfin Linux.
1398 * New native configurations
1400 ia64 HP-UX ia64-*-hpux*
1404 Analog Devices, Inc. Blackfin Processor bfin-*
1406 * Ada task switching is now supported on sparc-elf targets when
1407 debugging a program using the Ravenscar Profile. For more information,
1408 see the "Tasking Support when using the Ravenscar Profile" section
1409 in the GDB user manual.
1411 * Guile support was removed.
1413 * New features in the GNU simulator
1415 ** The --map-info flag lists all known core mappings.
1417 ** CFI flashes may be simulated via the "cfi" device.
1419 *** Changes in GDB 7.2
1421 * Shared library support for remote targets by default
1423 When GDB is configured for a generic, non-OS specific target, like
1424 for example, --target=arm-eabi or one of the many *-*-elf targets,
1425 GDB now queries remote stubs for loaded shared libraries using the
1426 `qXfer:libraries:read' packet. Previously, shared library support
1427 was always disabled for such configurations.
1431 ** Argument Dependent Lookup (ADL)
1433 In C++ ADL lookup directs function search to the namespaces of its
1434 arguments even if the namespace has not been imported.
1444 Here the compiler will search for `foo' in the namespace of 'b'
1445 and find A::foo. GDB now supports this. This construct is commonly
1446 used in the Standard Template Library for operators.
1448 ** Improved User Defined Operator Support
1450 In addition to member operators, GDB now supports lookup of operators
1451 defined in a namespace and imported with a `using' directive, operators
1452 defined in the global scope, operators imported implicitly from an
1453 anonymous namespace, and the ADL operators mentioned in the previous
1455 GDB now also supports proper overload resolution for all the previously
1456 mentioned flavors of operators.
1458 ** static const class members
1460 Printing of static const class members that are initialized in the
1461 class definition has been fixed.
1463 * Windows Thread Information Block access.
1465 On Windows targets, GDB now supports displaying the Windows Thread
1466 Information Block (TIB) structure. This structure is visible either
1467 by using the new command `info w32 thread-information-block' or, by
1468 dereferencing the new convenience variable named `$_tlb', a
1469 thread-specific pointer to the TIB. This feature is also supported
1470 when remote debugging using GDBserver.
1472 * Static tracepoints
1474 Static tracepoints are calls in the user program into a tracing
1475 library. One such library is a port of the LTTng kernel tracer to
1476 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1477 When debugging with GDBserver, GDB now supports combining the GDB
1478 tracepoint machinery with such libraries. For example: the user can
1479 use GDB to probe a static tracepoint marker (a call from the user
1480 program into the tracing library) with the new "strace" command (see
1481 "New commands" below). This creates a "static tracepoint" in the
1482 breakpoint list, that can be manipulated with the same feature set
1483 as fast and regular tracepoints. E.g., collect registers, local and
1484 global variables, collect trace state variables, and define
1485 tracepoint conditions. In addition, the user can collect extra
1486 static tracepoint marker specific data, by collecting the new
1487 $_sdata internal variable. When analyzing the trace buffer, you can
1488 inspect $_sdata like any other variable available to GDB. For more
1489 information, see the "Tracepoints" chapter in GDB user manual. New
1490 remote packets have been defined to support static tracepoints, see
1491 the "New remote packets" section below.
1493 * Better reconstruction of tracepoints after disconnected tracing
1495 GDB will attempt to download the original source form of tracepoint
1496 definitions when starting a trace run, and then will upload these
1497 upon reconnection to the target, resulting in a more accurate
1498 reconstruction of the tracepoints that are in use on the target.
1502 You can now exercise direct control over the ways that GDB can
1503 affect your program. For instance, you can disallow the setting of
1504 breakpoints, so that the program can run continuously (assuming
1505 non-stop mode). In addition, the "observer" variable is available
1506 to switch all of the different controls; in observer mode, GDB
1507 cannot affect the target's behavior at all, which is useful for
1508 tasks like diagnosing live systems in the field.
1510 * The new convenience variable $_thread holds the number of the
1513 * New remote packets
1517 Return the address of the Windows Thread Information Block of a given thread.
1521 In response to several of the tracepoint packets, the target may now
1522 also respond with a number of intermediate `qRelocInsn' request
1523 packets before the final result packet, to have GDB handle
1524 relocating an instruction to execute at a different address. This
1525 is particularly useful for stubs that support fast tracepoints. GDB
1526 reports support for this feature in the qSupported packet.
1530 List static tracepoint markers in the target program.
1534 List static tracepoint markers at a given address in the target
1537 qXfer:statictrace:read
1539 Read the static trace data collected (by a `collect $_sdata'
1540 tracepoint action). The remote stub reports support for this packet
1541 to gdb's qSupported query.
1545 Send the current settings of GDB's permission flags.
1549 Send part of the source (textual) form of a tracepoint definition,
1550 which includes location, conditional, and action list.
1552 * The source command now accepts a -s option to force searching for the
1553 script in the source search path even if the script name specifies
1556 * New features in the GDB remote stub, GDBserver
1558 - GDBserver now support tracepoints (including fast tracepoints, and
1559 static tracepoints). The feature is currently supported by the
1560 i386-linux and amd64-linux builds. See the "Tracepoints support
1561 in gdbserver" section in the manual for more information.
1563 GDBserver JIT compiles the tracepoint's conditional agent
1564 expression bytecode into native code whenever possible for low
1565 overhead dynamic tracepoints conditionals. For such tracepoints,
1566 an expression that examines program state is evaluated when the
1567 tracepoint is reached, in order to determine whether to capture
1568 trace data. If the condition is simple and false, processing the
1569 tracepoint finishes very quickly and no data is gathered.
1571 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1572 for static tracepoints support.
1574 - GDBserver now supports x86_64 Windows 64-bit debugging.
1576 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1577 it understands register description.
1579 * The --batch flag now disables pagination and queries.
1581 * X86 general purpose registers
1583 GDB now supports reading/writing byte, word and double-word x86
1584 general purpose registers directly. This means you can use, say,
1585 $ah or $ax to refer, respectively, to the byte register AH and
1586 16-bit word register AX that are actually portions of the 32-bit
1587 register EAX or 64-bit register RAX.
1589 * The `commands' command now accepts a range of breakpoints to modify.
1590 A plain `commands' following a command that creates multiple
1591 breakpoints affects all the breakpoints set by that command. This
1592 applies to breakpoints set by `rbreak', and also applies when a
1593 single `break' command creates multiple breakpoints (e.g.,
1594 breakpoints on overloaded c++ functions).
1596 * The `rbreak' command now accepts a filename specification as part of
1597 its argument, limiting the functions selected by the regex to those
1598 in the specified file.
1600 * Support for remote debugging Windows and SymbianOS shared libraries
1601 from Unix hosts has been improved. Non Windows GDB builds now can
1602 understand target reported file names that follow MS-DOS based file
1603 system semantics, such as file names that include drive letters and
1604 use the backslash character as directory separator. This makes it
1605 possible to transparently use the "set sysroot" and "set
1606 solib-search-path" on Unix hosts to point as host copies of the
1607 target's shared libraries. See the new command "set
1608 target-file-system-kind" described below, and the "Commands to
1609 specify files" section in the user manual for more information.
1613 eval template, expressions...
1614 Convert the values of one or more expressions under the control
1615 of the string template to a command line, and call it.
1617 set target-file-system-kind unix|dos-based|auto
1618 show target-file-system-kind
1619 Set or show the assumed file system kind for target reported file
1622 save breakpoints <filename>
1623 Save all current breakpoint definitions to a file suitable for use
1624 in a later debugging session. To read the saved breakpoint
1625 definitions, use the `source' command.
1627 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1630 info static-tracepoint-markers
1631 Display information about static tracepoint markers in the target.
1633 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1634 Define a static tracepoint by probing a marker at the given
1635 function, line, address, or marker ID.
1639 Enable and disable observer mode.
1641 set may-write-registers on|off
1642 set may-write-memory on|off
1643 set may-insert-breakpoints on|off
1644 set may-insert-tracepoints on|off
1645 set may-insert-fast-tracepoints on|off
1646 set may-interrupt on|off
1647 Set individual permissions for GDB effects on the target. Note that
1648 some of these settings can have undesirable or surprising
1649 consequences, particularly when changed in the middle of a session.
1650 For instance, disabling the writing of memory can prevent
1651 breakpoints from being inserted, cause single-stepping to fail, or
1652 even crash your program, if you disable after breakpoints have been
1653 inserted. However, GDB should not crash.
1655 set record memory-query on|off
1656 show record memory-query
1657 Control whether to stop the inferior if memory changes caused
1658 by an instruction cannot be recorded.
1663 The disassemble command now supports "start,+length" form of two arguments.
1667 ** GDB now provides a new directory location, called the python directory,
1668 where Python scripts written for GDB can be installed. The location
1669 of that directory is <data-directory>/python, where <data-directory>
1670 is the GDB data directory. For more details, see section `Scripting
1671 GDB using Python' in the manual.
1673 ** The GDB Python API now has access to breakpoints, symbols, symbol
1674 tables, program spaces, inferiors, threads and frame's code blocks.
1675 Additionally, GDB Parameters can now be created from the API, and
1676 manipulated via set/show in the CLI.
1678 ** New functions gdb.target_charset, gdb.target_wide_charset,
1679 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1681 ** New exception gdb.GdbError.
1683 ** Pretty-printers are now also looked up in the current program space.
1685 ** Pretty-printers can now be individually enabled and disabled.
1687 ** GDB now looks for names of Python scripts to auto-load in a
1688 special section named `.debug_gdb_scripts', in addition to looking
1689 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1691 * Tracepoint actions were unified with breakpoint commands. In particular,
1692 there are no longer differences in "info break" output for breakpoints and
1693 tracepoints and the "commands" command can be used for both tracepoints and
1694 regular breakpoints.
1698 ARM Symbian arm*-*-symbianelf*
1700 * D language support.
1701 GDB now supports debugging programs written in the D programming
1704 * GDB now supports the extended ptrace interface for PowerPC which is
1705 available since Linux kernel version 2.6.34. This automatically enables
1706 any hardware breakpoints and additional hardware watchpoints available in
1707 the processor. The old ptrace interface exposes just one hardware
1708 watchpoint and no hardware breakpoints.
1710 * GDB is now able to use the Data Value Compare (DVC) register available on
1711 embedded PowerPC processors to implement in hardware simple watchpoint
1712 conditions of the form:
1714 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1716 This works in native GDB running on Linux kernels with the extended ptrace
1717 interface mentioned above.
1719 *** Changes in GDB 7.1
1723 ** Namespace Support
1725 GDB now supports importing of namespaces in C++. This enables the
1726 user to inspect variables from imported namespaces. Support for
1727 namepace aliasing has also been added. So, if a namespace is
1728 aliased in the current scope (e.g. namepace C=A; ) the user can
1729 print variables using the alias (e.g. (gdb) print C::x).
1733 All known bugs relating to the printing of virtual base class were
1734 fixed. It is now possible to call overloaded static methods using a
1739 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1740 and reinterpret_cast<> are now handled by the C++ expression parser.
1744 Xilinx MicroBlaze microblaze-*-*
1749 Xilinx MicroBlaze microblaze
1752 * Multi-program debugging.
1754 GDB now has support for multi-program (a.k.a. multi-executable or
1755 multi-exec) debugging. This allows for debugging multiple inferiors
1756 simultaneously each running a different program under the same GDB
1757 session. See "Debugging Multiple Inferiors and Programs" in the
1758 manual for more information. This implied some user visible changes
1759 in the multi-inferior support. For example, "info inferiors" now
1760 lists inferiors that are not running yet or that have exited
1761 already. See also "New commands" and "New options" below.
1763 * New tracing features
1765 GDB's tracepoint facility now includes several new features:
1767 ** Trace state variables
1769 GDB tracepoints now include support for trace state variables, which
1770 are variables managed by the target agent during a tracing
1771 experiment. They are useful for tracepoints that trigger each
1772 other, so for instance one tracepoint can count hits in a variable,
1773 and then a second tracepoint has a condition that is true when the
1774 count reaches a particular value. Trace state variables share the
1775 $-syntax of GDB convenience variables, and can appear in both
1776 tracepoint actions and condition expressions. Use the "tvariable"
1777 command to create, and "info tvariables" to view; see "Trace State
1778 Variables" in the manual for more detail.
1782 GDB now includes an option for defining fast tracepoints, which
1783 targets may implement more efficiently, such as by installing a jump
1784 into the target agent rather than a trap instruction. The resulting
1785 speedup can be by two orders of magnitude or more, although the
1786 tradeoff is that some program locations on some target architectures
1787 might not allow fast tracepoint installation, for instance if the
1788 instruction to be replaced is shorter than the jump. To request a
1789 fast tracepoint, use the "ftrace" command, with syntax identical to
1790 the regular trace command.
1792 ** Disconnected tracing
1794 It is now possible to detach GDB from the target while it is running
1795 a trace experiment, then reconnect later to see how the experiment
1796 is going. In addition, a new variable disconnected-tracing lets you
1797 tell the target agent whether to continue running a trace if the
1798 connection is lost unexpectedly.
1802 GDB now has the ability to save the trace buffer into a file, and
1803 then use that file as a target, similarly to you can do with
1804 corefiles. You can select trace frames, print data that was
1805 collected in them, and use tstatus to display the state of the
1806 tracing run at the moment that it was saved. To create a trace
1807 file, use "tsave <filename>", and to use it, do "target tfile
1810 ** Circular trace buffer
1812 You can ask the target agent to handle the trace buffer as a
1813 circular buffer, discarding the oldest trace frames to make room for
1814 newer ones, by setting circular-trace-buffer to on. This feature may
1815 not be available for all target agents.
1820 The disassemble command, when invoked with two arguments, now requires
1821 the arguments to be comma-separated.
1824 The info variables command now displays variable definitions. Files
1825 which only declare a variable are not shown.
1828 The source command is now capable of sourcing Python scripts.
1829 This feature is dependent on the debugger being build with Python
1832 Related to this enhancement is also the introduction of a new command
1833 "set script-extension" (see below).
1835 * New commands (for set/show, see "New options" below)
1837 record save [<FILENAME>]
1838 Save a file (in core file format) containing the process record
1839 execution log for replay debugging at a later time.
1841 record restore <FILENAME>
1842 Restore the process record execution log that was saved at an
1843 earlier time, for replay debugging.
1845 add-inferior [-copies <N>] [-exec <FILENAME>]
1848 clone-inferior [-copies <N>] [ID]
1849 Make a new inferior ready to execute the same program another
1850 inferior has loaded.
1855 maint info program-spaces
1856 List the program spaces loaded into GDB.
1858 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1859 show remote interrupt-sequence
1860 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1861 as the sequence to the remote target in order to interrupt the execution.
1862 Ctrl-C is a default. Some system prefers BREAK which is high level of
1863 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1864 Magic SysRq g. It is BREAK signal and character 'g'.
1866 set remote interrupt-on-connect [on | off]
1867 show remote interrupt-on-connect
1868 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1869 remote target when gdb connects to it. This is needed when you debug
1872 set remotebreak [on | off]
1874 Deprecated. Use "set/show remote interrupt-sequence" instead.
1876 tvariable $NAME [ = EXP ]
1877 Create or modify a trace state variable.
1880 List trace state variables and their values.
1882 delete tvariable $NAME ...
1883 Delete one or more trace state variables.
1886 Evaluate the given expressions without collecting anything into the
1887 trace buffer. (Valid in tracepoint actions only.)
1889 ftrace FN / FILE:LINE / *ADDR
1890 Define a fast tracepoint at the given function, line, or address.
1892 * New expression syntax
1894 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1895 GDB now parses 0b101010 identically with 42.
1899 set follow-exec-mode new|same
1900 show follow-exec-mode
1901 Control whether GDB reuses the same inferior across an exec call or
1902 creates a new one. This is useful to be able to restart the old
1903 executable after the inferior having done an exec call.
1905 set default-collect EXPR, ...
1906 show default-collect
1907 Define a list of expressions to be collected at each tracepoint.
1908 This is a useful way to ensure essential items are not overlooked,
1909 such as registers or a critical global variable.
1911 set disconnected-tracing
1912 show disconnected-tracing
1913 If set to 1, the target is instructed to continue tracing if it
1914 loses its connection to GDB. If 0, the target is to stop tracing
1917 set circular-trace-buffer
1918 show circular-trace-buffer
1919 If set to on, the target is instructed to use a circular trace buffer
1920 and discard the oldest trace frames instead of stopping the trace due
1921 to a full trace buffer. If set to off, the trace stops when the buffer
1922 fills up. Some targets may not support this.
1924 set script-extension off|soft|strict
1925 show script-extension
1926 If set to "off", the debugger does not perform any script language
1927 recognition, and all sourced files are assumed to be GDB scripts.
1928 If set to "soft" (the default), files are sourced according to
1929 filename extension, falling back to GDB scripts if the first
1931 If set to "strict", files are sourced according to filename extension.
1933 set ada trust-PAD-over-XVS on|off
1934 show ada trust-PAD-over-XVS
1935 If off, activate a workaround against a bug in the debugging information
1936 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1937 the GCC sources for more information about the GNAT encoding and
1938 PAD types in particular). It is always safe to set this option to
1939 off, but this introduces a slight performance penalty. The default
1942 * Python API Improvements
1944 ** GDB provides the new class gdb.LazyString. This is useful in
1945 some pretty-printing cases. The new method gdb.Value.lazy_string
1946 provides a simple way to create objects of this type.
1948 ** The fields returned by gdb.Type.fields now have an
1949 `is_base_class' attribute.
1951 ** The new method gdb.Type.range returns the range of an array type.
1953 ** The new method gdb.parse_and_eval can be used to parse and
1954 evaluate an expression.
1956 * New remote packets
1959 Define a trace state variable.
1962 Get the current value of a trace state variable.
1965 Set desired tracing behavior upon disconnection.
1968 Set the trace buffer to be linear or circular.
1971 Get data about the tracepoints currently in use.
1975 Process record now works correctly with hardware watchpoints.
1977 Multiple bug fixes have been made to the mips-irix port, making it
1978 much more reliable. In particular:
1979 - Debugging threaded applications is now possible again. Previously,
1980 GDB would hang while starting the program, or while waiting for
1981 the program to stop at a breakpoint.
1982 - Attaching to a running process no longer hangs.
1983 - An error occurring while loading a core file has been fixed.
1984 - Changing the value of the PC register now works again. This fixes
1985 problems observed when using the "jump" command, or when calling
1986 a function from GDB, or even when assigning a new value to $pc.
1987 - With the "finish" and "return" commands, the return value for functions
1988 returning a small array is now correctly printed.
1989 - It is now possible to break on shared library code which gets executed
1990 during a shared library init phase (code executed while executing
1991 their .init section). Previously, the breakpoint would have no effect.
1992 - GDB is now able to backtrace through the signal handler for
1993 non-threaded programs.
1995 PIE (Position Independent Executable) programs debugging is now supported.
1996 This includes debugging execution of PIC (Position Independent Code) shared
1997 libraries although for that, it should be possible to run such libraries as an
2000 *** Changes in GDB 7.0
2002 * GDB now has an interface for JIT compilation. Applications that
2003 dynamically generate code can create symbol files in memory and register
2004 them with GDB. For users, the feature should work transparently, and
2005 for JIT developers, the interface is documented in the GDB manual in the
2006 "JIT Compilation Interface" chapter.
2008 * Tracepoints may now be conditional. The syntax is as for
2009 breakpoints; either an "if" clause appended to the "trace" command,
2010 or the "condition" command is available. GDB sends the condition to
2011 the target for evaluation using the same bytecode format as is used
2012 for tracepoint actions.
2014 * The disassemble command now supports: an optional /r modifier, print the
2015 raw instructions in hex as well as in symbolic form, and an optional /m
2016 modifier to print mixed source+assembly.
2018 * Process record and replay
2020 In a architecture environment that supports ``process record and
2021 replay'', ``process record and replay'' target can record a log of
2022 the process execution, and replay it with both forward and reverse
2025 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2026 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2027 set execution-direction {forward|reverse}, for targets that support
2030 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2031 feature is available with a native GDB running on kernel version
2034 * GDB now has support for multi-byte and wide character sets on the
2035 target. Strings whose character type is wchar_t, char16_t, or
2036 char32_t are now correctly printed. GDB supports wide- and unicode-
2037 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2038 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2039 `printf'. This feature requires iconv to work properly; if your
2040 system does not have a working iconv, GDB can use GNU libiconv. See
2041 the installation instructions for more information.
2043 * GDB now supports automatic retrieval of shared library files from
2044 remote targets. To use this feature, specify a system root that begins
2045 with the `remote:' prefix, either via the `set sysroot' command or via
2046 the `--with-sysroot' configure-time option.
2048 * "info sharedlibrary" now takes an optional regex of libraries to show,
2049 and it now reports if a shared library has no debugging information.
2051 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2052 now complete on file names.
2054 * When completing in expressions, gdb will attempt to limit
2055 completions to allowable structure or union fields, where appropriate.
2056 For instance, consider:
2058 # struct example { int f1; double f2; };
2059 # struct example variable;
2062 If the user types TAB at the end of this command line, the available
2063 completions will be "f1" and "f2".
2065 * Inlined functions are now supported. They show up in backtraces, and
2066 the "step", "next", and "finish" commands handle them automatically.
2068 * GDB now supports the token-splicing (##) and stringification (#)
2069 operators when expanding macros. It also supports variable-arity
2072 * GDB now supports inspecting extra signal information, exported by
2073 the new $_siginfo convenience variable. The feature is currently
2074 implemented on linux ARM, i386 and amd64.
2076 * GDB can now display the VFP floating point registers and NEON vector
2077 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2078 can provide these registers (requires Linux 2.6.30 or later). Remote
2079 and simulator targets may also provide them.
2081 * New remote packets
2084 Search memory for a sequence of bytes.
2087 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2088 operation over reliable transport links. Use of this packet is
2089 controlled by the `set remote noack-packet' command.
2092 Kill the process with the specified process ID. Use this in preference
2093 to `k' when multiprocess protocol extensions are supported.
2096 Obtains additional operating system information
2100 Read or write additional signal information.
2102 * Removed remote protocol undocumented extension
2104 An undocumented extension to the remote protocol's `S' stop reply
2105 packet that permited the stub to pass a process id was removed.
2106 Remote servers should use the `T' stop reply packet instead.
2108 * GDB now supports multiple function calling conventions according to the
2109 DWARF-2 DW_AT_calling_convention function attribute.
2111 * The SH target utilizes the aforementioned change to distinguish between gcc
2112 and Renesas calling convention. It also adds the new CLI commands
2113 `set/show sh calling-convention'.
2115 * GDB can now read compressed debug sections, as produced by GNU gold
2116 with the --compress-debug-sections=zlib flag.
2118 * 64-bit core files are now supported on AIX.
2120 * Thread switching is now supported on Tru64.
2122 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2123 which will be allocated using malloc later in program execution.
2125 * The qXfer:libraries:read remote procotol packet now allows passing a
2126 list of section offsets.
2128 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2129 conditions handling signals delivered during attach or thread creation
2130 have also been fixed.
2132 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2133 From the user's standpoint, all unqualified instances of True and False
2134 are treated as the standard definitions, regardless of context.
2136 * GDB now parses C++ symbol and type names more flexibly. For
2139 template<typename T> class C { };
2142 GDB will now correctly handle all of:
2144 ptype C<char const *>
2145 ptype C<char const*>
2146 ptype C<const char *>
2147 ptype C<const char*>
2149 * New features in the GDB remote stub, gdbserver
2151 - The "--wrapper" command-line argument tells gdbserver to use a
2152 wrapper program to launch programs for debugging.
2154 - On PowerPC and S/390 targets, it is now possible to use a single
2155 gdbserver executable to debug both 32-bit and 64-bit programs.
2156 (This requires gdbserver itself to be built as a 64-bit executable.)
2158 - gdbserver uses the new noack protocol mode for TCP connections to
2159 reduce communications latency, if also supported and enabled in GDB.
2161 - Support for the sparc64-linux-gnu target is now included in
2164 - The amd64-linux build of gdbserver now supports debugging both
2165 32-bit and 64-bit programs.
2167 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2168 now support hardware watchpoints, and will use them automatically
2173 GDB now has support for scripting using Python. Whether this is
2174 available is determined at configure time.
2176 New GDB commands can now be written in Python.
2178 * Ada tasking support
2180 Ada tasks can now be inspected in GDB. The following commands have
2184 Print the list of Ada tasks.
2186 Print detailed information about task number N.
2188 Print the task number of the current task.
2190 Switch the context of debugging to task number N.
2192 * Support for user-defined prefixed commands. The "define" command can
2193 add new commands to existing prefixes, e.g. "target".
2195 * Multi-inferior, multi-process debugging.
2197 GDB now has generalized support for multi-inferior debugging. See
2198 "Debugging Multiple Inferiors" in the manual for more information.
2199 Although availability still depends on target support, the command
2200 set is more uniform now. The GNU/Linux specific multi-forks support
2201 has been migrated to this new framework. This implied some user
2202 visible changes; see "New commands" and also "Removed commands"
2205 * Target descriptions can now describe the target OS ABI. See the
2206 "Target Description Format" section in the user manual for more
2209 * Target descriptions can now describe "compatible" architectures
2210 to indicate that the target can execute applications for a different
2211 architecture in addition to those for the main target architecture.
2212 See the "Target Description Format" section in the user manual for
2215 * Multi-architecture debugging.
2217 GDB now includes general supports for debugging applications on
2218 hybrid systems that use more than one single processor architecture
2219 at the same time. Each such hybrid architecture still requires
2220 specific support to be added. The only hybrid architecture supported
2221 in this version of GDB is the Cell Broadband Engine.
2223 * GDB now supports integrated debugging of Cell/B.E. applications that
2224 use both the PPU and SPU architectures. To enable support for hybrid
2225 Cell/B.E. debugging, you need to configure GDB to support both the
2226 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2227 --enable-targets configure option.
2229 * Non-stop mode debugging.
2231 For some targets, GDB now supports an optional mode of operation in
2232 which you can examine stopped threads while other threads continue
2233 to execute freely. This is referred to as non-stop mode, with the
2234 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2235 section in the user manual for more information.
2237 To be able to support remote non-stop debugging, a remote stub needs
2238 to implement the non-stop mode remote protocol extensions, as
2239 described in the "Remote Non-Stop" section of the user manual. The
2240 GDB remote stub, gdbserver, has been adjusted to support these
2241 extensions on linux targets.
2243 * New commands (for set/show, see "New options" below)
2245 catch syscall [NAME(S) | NUMBER(S)]
2246 Catch system calls. Arguments, which should be names of system
2247 calls or their numbers, mean catch only those syscalls. Without
2248 arguments, every syscall will be caught. When the inferior issues
2249 any of the specified syscalls, GDB will stop and announce the system
2250 call, both when it is called and when its call returns. This
2251 feature is currently available with a native GDB running on the
2252 Linux Kernel, under the following architectures: x86, x86_64,
2253 PowerPC and PowerPC64.
2255 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2257 Search memory for a sequence of bytes.
2259 maint set python print-stack
2260 maint show python print-stack
2261 Show a stack trace when an error is encountered in a Python script.
2264 Invoke CODE by passing it to the Python interpreter.
2269 These allow macros to be defined, undefined, and listed
2273 Show operating system information about processes.
2276 List the inferiors currently under GDB's control.
2279 Switch focus to inferior number NUM.
2282 Detach from inferior number NUM.
2285 Kill inferior number NUM.
2289 set spu stop-on-load
2290 show spu stop-on-load
2291 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2293 set spu auto-flush-cache
2294 show spu auto-flush-cache
2295 Control whether to automatically flush the software-managed cache
2296 during Cell/B.E. debugging.
2298 set sh calling-convention
2299 show sh calling-convention
2300 Control the calling convention used when calling SH target functions.
2303 show debug timestamp
2304 Control display of timestamps with GDB debugging output.
2306 set disassemble-next-line
2307 show disassemble-next-line
2308 Control display of disassembled source lines or instructions when
2311 set remote noack-packet
2312 show remote noack-packet
2313 Set/show the use of remote protocol QStartNoAckMode packet. See above
2314 under "New remote packets."
2316 set remote query-attached-packet
2317 show remote query-attached-packet
2318 Control use of remote protocol `qAttached' (query-attached) packet.
2320 set remote read-siginfo-object
2321 show remote read-siginfo-object
2322 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2325 set remote write-siginfo-object
2326 show remote write-siginfo-object
2327 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2330 set remote reverse-continue
2331 show remote reverse-continue
2332 Control use of remote protocol 'bc' (reverse-continue) packet.
2334 set remote reverse-step
2335 show remote reverse-step
2336 Control use of remote protocol 'bs' (reverse-step) packet.
2338 set displaced-stepping
2339 show displaced-stepping
2340 Control displaced stepping mode. Displaced stepping is a way to
2341 single-step over breakpoints without removing them from the debuggee.
2342 Also known as "out-of-line single-stepping".
2345 show debug displaced
2346 Control display of debugging info for displaced stepping.
2348 maint set internal-error
2349 maint show internal-error
2350 Control what GDB does when an internal error is detected.
2352 maint set internal-warning
2353 maint show internal-warning
2354 Control what GDB does when an internal warning is detected.
2359 Use a wrapper program to launch programs for debugging.
2361 set multiple-symbols (all|ask|cancel)
2362 show multiple-symbols
2363 The value of this variable can be changed to adjust the debugger behavior
2364 when an expression or a breakpoint location contains an ambiguous symbol
2365 name (an overloaded function name, for instance).
2367 set breakpoint always-inserted
2368 show breakpoint always-inserted
2369 Keep breakpoints always inserted in the target, as opposed to inserting
2370 them when resuming the target, and removing them when the target stops.
2371 This option can improve debugger performance on slow remote targets.
2373 set arm fallback-mode (arm|thumb|auto)
2374 show arm fallback-mode
2375 set arm force-mode (arm|thumb|auto)
2377 These commands control how ARM GDB determines whether instructions
2378 are ARM or Thumb. The default for both settings is auto, which uses
2379 the current CPSR value for instructions without symbols; previous
2380 versions of GDB behaved as if "set arm fallback-mode arm".
2382 set disable-randomization
2383 show disable-randomization
2384 Standalone programs run with the virtual address space randomization enabled
2385 by default on some platforms. This option keeps the addresses stable across
2386 multiple debugging sessions.
2390 Control whether other threads are stopped or not when some thread hits
2395 Requests that asynchronous execution is enabled in the target, if available.
2396 In this case, it's possible to resume target in the background, and interact
2397 with GDB while the target is running. "show target-async" displays the
2398 current state of asynchronous execution of the target.
2400 set target-wide-charset
2401 show target-wide-charset
2402 The target-wide-charset is the name of the character set that GDB
2403 uses when printing characters whose type is wchar_t.
2405 set tcp auto-retry (on|off)
2407 set tcp connect-timeout
2408 show tcp connect-timeout
2409 These commands allow GDB to retry failed TCP connections to a remote stub
2410 with a specified timeout period; this is useful if the stub is launched
2411 in parallel with GDB but may not be ready to accept connections immediately.
2413 set libthread-db-search-path
2414 show libthread-db-search-path
2415 Control list of directories which GDB will search for appropriate
2418 set schedule-multiple (on|off)
2419 show schedule-multiple
2420 Allow GDB to resume all threads of all processes or only threads of
2421 the current process.
2425 Use more aggressive caching for accesses to the stack. This improves
2426 performance of remote debugging (particularly backtraces) without
2427 affecting correctness.
2429 set interactive-mode (on|off|auto)
2430 show interactive-mode
2431 Control whether GDB runs in interactive mode (on) or not (off).
2432 When in interactive mode, GDB waits for the user to answer all
2433 queries. Otherwise, GDB does not wait and assumes the default
2434 answer. When set to auto (the default), GDB determines which
2435 mode to use based on the stdin settings.
2440 For program forks, this is replaced by the new more generic `info
2441 inferiors' command. To list checkpoints, you can still use the
2442 `info checkpoints' command, which was an alias for the `info forks'
2446 Replaced by the new `inferior' command. To switch between
2447 checkpoints, you can still use the `restart' command, which was an
2448 alias for the `fork' command.
2451 This is removed, since some targets don't have a notion of
2452 processes. To switch between processes, you can still use the
2453 `inferior' command using GDB's own inferior number.
2456 For program forks, this is replaced by the new more generic `kill
2457 inferior' command. To delete a checkpoint, you can still use the
2458 `delete checkpoint' command, which was an alias for the `delete
2462 For program forks, this is replaced by the new more generic `detach
2463 inferior' command. To detach a checkpoint, you can still use the
2464 `detach checkpoint' command, which was an alias for the `detach
2467 * New native configurations
2469 x86/x86_64 Darwin i[34567]86-*-darwin*
2471 x86_64 MinGW x86_64-*-mingw*
2475 Lattice Mico32 lm32-*
2476 x86 DICOS i[34567]86-*-dicos*
2477 x86_64 DICOS x86_64-*-dicos*
2480 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2481 (mingw32ce) debugging.
2487 These commands were actually not implemented on any target.
2489 *** Changes in GDB 6.8
2491 * New native configurations
2493 NetBSD/hppa hppa*-*netbsd*
2494 Xtensa GNU/Linux xtensa*-*-linux*
2498 NetBSD/hppa hppa*-*-netbsd*
2499 Xtensa GNU/Lunux xtensa*-*-linux*
2501 * Change in command line behavior -- corefiles vs. process ids.
2503 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2504 attaching to process NUMBER fails, GDB no longer attempts to open a
2505 core file named NUMBER. Attaching to a program using the -c option
2506 is no longer supported. Instead, use the '-p' or '--pid' options.
2508 * GDB can now be built as a native debugger for debugging Windows x86
2509 (mingw32) Portable Executable (PE) programs.
2511 * Pending breakpoints no longer change their number when their address
2514 * GDB now supports breakpoints with multiple locations,
2515 including breakpoints on C++ constructors, inside C++ templates,
2516 and in inlined functions.
2518 * GDB's ability to debug optimized code has been improved. GDB more
2519 accurately identifies function bodies and lexical blocks that occupy
2520 more than one contiguous range of addresses.
2522 * Target descriptions can now describe registers for PowerPC.
2524 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2525 registers on PowerPC targets.
2527 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2528 targets even when the libthread_db library is not available.
2530 * The GDB remote stub, gdbserver, now supports the new file transfer
2531 commands (remote put, remote get, and remote delete).
2533 * The GDB remote stub, gdbserver, now supports run and attach in
2534 extended-remote mode.
2536 * hppa*64*-*-hpux11* target broken
2537 The debugger is unable to start a program and fails with the following
2538 error: "Error trying to get information about dynamic linker".
2539 The gdb-6.7 release is also affected.
2541 * GDB now supports the --enable-targets= configure option to allow
2542 building a single GDB executable that supports multiple remote
2543 target architectures.
2545 * GDB now supports debugging C and C++ programs which use the
2546 Decimal Floating Point extension. In addition, the PowerPC target
2547 now has a set of pseudo-registers to inspect decimal float values
2548 stored in two consecutive float registers.
2550 * The -break-insert MI command can optionally create pending
2553 * Improved support for debugging Ada
2554 Many improvements to the Ada language support have been made. These
2556 - Better support for Ada2005 interface types
2557 - Improved handling of arrays and slices in general
2558 - Better support for Taft-amendment types
2559 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2561 - Improved command completion in Ada
2564 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2569 set print frame-arguments (all|scalars|none)
2570 show print frame-arguments
2571 The value of this variable can be changed to control which argument
2572 values should be printed by the debugger when displaying a frame.
2577 Transfer files to and from a remote target, and delete remote files.
2584 Transfer files to and from a remote target, and delete remote files.
2586 * New remote packets
2593 Open, close, read, write, and delete files on the remote system.
2596 Attach to an existing process on the remote system, in extended-remote
2600 Run a new process on the remote system, in extended-remote mode.
2602 *** Changes in GDB 6.7
2604 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2605 bfd, libiberty and opcodes, as revealed by static analysis donated by
2606 Coverity, Inc. (http://scan.coverity.com).
2608 * When looking up multiply-defined global symbols, GDB will now prefer the
2609 symbol definition in the current shared library if it was built using the
2610 -Bsymbolic linker option.
2612 * When the Text User Interface (TUI) is not configured, GDB will now
2613 recognize the -tui command-line option and print a message that the TUI
2616 * The GDB remote stub, gdbserver, now has lower overhead for high
2617 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2619 * GDB for MIPS targets now autodetects whether a remote target provides
2620 32-bit or 64-bit register values.
2622 * Support for C++ member pointers has been improved.
2624 * GDB now understands XML target descriptions, which specify the
2625 target's overall architecture. GDB can read a description from
2626 a local file or over the remote serial protocol.
2628 * Vectors of single-byte data use a new integer type which is not
2629 automatically displayed as character or string data.
2631 * The /s format now works with the print command. It displays
2632 arrays of single-byte integers and pointers to single-byte integers
2635 * Target descriptions can now describe target-specific registers,
2636 for architectures which have implemented the support (currently
2637 only ARM, M68K, and MIPS).
2639 * GDB and the GDB remote stub, gdbserver, now support the XScale
2642 * The GDB remote stub, gdbserver, has been updated to support
2643 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2644 has been rewritten to use the standard GDB remote protocol.
2646 * GDB can now step into C++ functions which are called through thunks.
2648 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2650 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2651 layout. It also supports a TextSeg= and DataSeg= response when only
2652 segment base addresses (rather than offsets) are available.
2654 * The /i format now outputs any trailing branch delay slot instructions
2655 immediately following the last instruction within the count specified.
2657 * The GDB remote protocol "T" stop reply packet now supports a
2658 "library" response. Combined with the new "qXfer:libraries:read"
2659 packet, this response allows GDB to debug shared libraries on targets
2660 where the operating system manages the list of loaded libraries (e.g.
2661 Windows and SymbianOS).
2663 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2664 (DLLs) on Windows and Windows CE targets.
2666 * GDB now supports a faster verification that a .debug file matches its binary
2667 according to its build-id signature, if the signature is present.
2673 Enable or disable hardware flow control (RTS/CTS) on the serial port
2674 when debugging using remote targets.
2676 set mem inaccessible-by-default
2677 show mem inaccessible-by-default
2678 If the target supplies a memory map, for instance via the remote
2679 protocol's "qXfer:memory-map:read" packet, setting this variable
2680 prevents GDB from accessing memory outside the memory map. This
2681 is useful for targets with memory mapped registers or which react
2682 badly to accesses of unmapped address space.
2684 set breakpoint auto-hw
2685 show breakpoint auto-hw
2686 If the target supplies a memory map, for instance via the remote
2687 protocol's "qXfer:memory-map:read" packet, setting this variable
2688 lets GDB use hardware breakpoints automatically for memory regions
2689 where it can not use software breakpoints. This covers both the
2690 "break" command and internal breakpoints used for other commands
2691 including "next" and "finish".
2694 catch exception unhandled
2695 Stop the program execution when Ada exceptions are raised.
2698 Stop the program execution when an Ada assertion failed.
2702 Set an alternate system root for target files. This is a more
2703 general version of "set solib-absolute-prefix", which is now
2704 an alias to "set sysroot".
2707 Provide extended SPU facility status information. This set of
2708 commands is available only when debugging the Cell/B.E. SPU
2711 * New native configurations
2713 OpenBSD/sh sh*-*openbsd*
2716 unset tdesc filename
2718 Use the specified local file as an XML target description, and do
2719 not query the target for its built-in description.
2723 OpenBSD/sh sh*-*-openbsd*
2724 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2725 Toshiba Media Processor mep-elf
2727 * New remote packets
2730 Ignore the specified signals; pass them directly to the debugged program
2731 without stopping other threads or reporting them to GDB.
2733 qXfer:features:read:
2734 Read an XML target description from the target, which describes its
2739 Read or write contents of an spufs file on the target system. These
2740 packets are available only on the Cell/B.E. SPU architecture.
2742 qXfer:libraries:read:
2743 Report the loaded shared libraries. Combined with new "T" packet
2744 response, this packet allows GDB to debug shared libraries on
2745 targets where the operating system manages the list of loaded
2746 libraries (e.g. Windows and SymbianOS).
2750 Support for these obsolete configurations has been removed.
2758 i[34567]86-*-lynxos*
2759 i[34567]86-*-netware*
2760 i[34567]86-*-sco3.2v5*
2761 i[34567]86-*-sco3.2v4*
2763 i[34567]86-*-sysv4.2*
2766 i[34567]86-*-unixware2*
2767 i[34567]86-*-unixware*
2776 * Other removed features
2783 Various m68k-only ROM monitors.
2790 Various Renesas ROM monitors and debugging interfaces for SH and
2795 Support for a Macraigor serial interface to on-chip debugging.
2796 GDB does not directly support the newer parallel or USB
2801 A debug information format. The predecessor to DWARF 2 and
2802 DWARF 3, which are still supported.
2804 Support for the HP aCC compiler on HP-UX/PA-RISC
2806 SOM-encapsulated symbolic debugging information, automatic
2807 invocation of pxdb, and the aCC custom C++ ABI. This does not
2808 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2809 with aCC can still be debugged on an assembly level.
2811 MIPS ".pdr" sections
2813 A MIPS-specific format used to describe stack frame layout
2814 in debugging information.
2818 GDB could work with an older version of Guile to debug
2819 the interpreter and Scheme programs running in it.
2821 set mips stack-arg-size
2822 set mips saved-gpreg-size
2824 Use "set mips abi" to control parameter passing for MIPS.
2826 *** Changes in GDB 6.6
2831 Cell Broadband Engine SPU spu-elf
2833 * GDB can now be configured as a cross-debugger targeting native Windows
2834 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2835 running on a Windows system over TCP/IP to debug Windows programs.
2837 * The GDB remote stub, gdbserver, has been updated to support Windows and
2838 Cygwin debugging. Both single-threaded and multi-threaded programs are
2841 * The "set trust-readonly-sections" command works again. This command was
2842 broken in GDB 6.3, 6.4, and 6.5.
2844 * The "load" command now supports writing to flash memory, if the remote
2845 stub provides the required support.
2847 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2848 longer requires symbolic debug information (e.g. DWARF-2).
2853 unset substitute-path
2854 show substitute-path
2855 Manage a list of substitution rules that GDB uses to rewrite the name
2856 of the directories where the sources are located. This can be useful
2857 for instance when the sources were moved to a different location
2858 between compilation and debugging.
2862 Print each CLI command as it is executed. Each command is prefixed with
2863 a number of `+' symbols representing the nesting depth.
2864 The source command now has a `-v' option to enable the same feature.
2868 The ARM Demon monitor support (RDP protocol, "target rdp").
2870 Kernel Object Display, an embedded debugging feature which only worked with
2871 an obsolete version of Cisco IOS.
2873 The 'set download-write-size' and 'show download-write-size' commands.
2875 * New remote packets
2878 Tell a stub about GDB client features, and request remote target features.
2879 The first feature implemented is PacketSize, which allows the target to
2880 specify the size of packets it can handle - to minimize the number of
2881 packets required and improve performance when connected to a remote
2885 Fetch an OS auxilliary vector from the remote stub. This packet is a
2886 more efficient replacement for qPart:auxv:read.
2888 qXfer:memory-map:read:
2889 Fetch a memory map from the remote stub, including information about
2890 RAM, ROM, and flash memory devices.
2895 Erase and program a flash memory device.
2897 * Removed remote packets
2900 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2901 used it, and only gdbserver implemented it.
2903 *** Changes in GDB 6.5
2907 Renesas M32C/M16C m32c-elf
2909 Morpho Technologies ms1 ms1-elf
2913 init-if-undefined Initialize a convenience variable, but
2914 only if it doesn't already have a value.
2916 The following commands are presently only implemented for native GNU/Linux:
2918 checkpoint Save a snapshot of the program state.
2920 restart <n> Return the program state to a
2921 previously saved state.
2923 info checkpoints List currently saved checkpoints.
2925 delete-checkpoint <n> Delete a previously saved checkpoint.
2927 set|show detach-on-fork Tell gdb whether to detach from a newly
2928 forked process, or to keep debugging it.
2930 info forks List forks of the user program that
2931 are available to be debugged.
2933 fork <n> Switch to debugging one of several
2934 forks of the user program that are
2935 available to be debugged.
2937 delete-fork <n> Delete a fork from the list of forks
2938 that are available to be debugged (and
2939 kill the forked process).
2941 detach-fork <n> Delete a fork from the list of forks
2942 that are available to be debugged (and
2943 allow the process to continue).
2947 Morpho Technologies ms2 ms1-elf
2949 * Improved Windows host support
2951 GDB now builds as a cross debugger hosted on i686-mingw32, including
2952 native console support, and remote communications using either
2953 network sockets or serial ports.
2955 * Improved Modula-2 language support
2957 GDB can now print most types in the Modula-2 syntax. This includes:
2958 basic types, set types, record types, enumerated types, range types,
2959 pointer types and ARRAY types. Procedure var parameters are correctly
2960 printed and hexadecimal addresses and character constants are also
2961 written in the Modula-2 syntax. Best results can be obtained by using
2962 GNU Modula-2 together with the -gdwarf-2 command line option.
2966 The ARM rdi-share module.
2968 The Netware NLM debug server.
2970 *** Changes in GDB 6.4
2972 * New native configurations
2974 OpenBSD/arm arm*-*-openbsd*
2975 OpenBSD/mips64 mips64-*-openbsd*
2979 Morpho Technologies ms1 ms1-elf
2981 * New command line options
2983 --batch-silent As for --batch, but totally silent.
2984 --return-child-result The debugger will exist with the same value
2985 the child (debugged) program exited with.
2986 --eval-command COMMAND, -ex COMMAND
2987 Execute a single GDB CLI command. This may be
2988 specified multiple times and in conjunction
2989 with the --command (-x) option.
2991 * Deprecated commands removed
2993 The following commands, that were deprecated in 2000, have been
2997 set|show arm disassembly-flavor set|show arm disassembler
2998 othernames set arm disassembler
2999 set|show remotedebug set|show debug remote
3000 set|show archdebug set|show debug arch
3001 set|show eventdebug set|show debug event
3004 * New BSD user-level threads support
3006 It is now possible to debug programs using the user-level threads
3007 library on OpenBSD and FreeBSD. Currently supported (target)
3010 FreeBSD/amd64 x86_64-*-freebsd*
3011 FreeBSD/i386 i386-*-freebsd*
3012 OpenBSD/i386 i386-*-openbsd*
3014 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3015 are not yet supported.
3017 * New support for Matsushita MN10300 w/sim added
3018 (Work in progress). mn10300-elf.
3020 * REMOVED configurations and files
3022 VxWorks and the XDR protocol *-*-vxworks
3023 Motorola MCORE mcore-*-*
3024 National Semiconductor NS32000 ns32k-*-*
3026 * New "set print array-indexes" command
3028 After turning this setting "on", GDB prints the index of each element
3029 when displaying arrays. The default is "off" to preserve the previous
3032 * VAX floating point support
3034 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3036 * User-defined command support
3038 In addition to using $arg0..$arg9 for argument passing, it is now possible
3039 to use $argc to determine now many arguments have been passed. See the
3040 section on user-defined commands in the user manual for more information.
3042 *** Changes in GDB 6.3:
3044 * New command line option
3046 GDB now accepts -l followed by a number to set the timeout for remote
3049 * GDB works with GCC -feliminate-dwarf2-dups
3051 GDB now supports a more compact representation of DWARF-2 debug
3052 information using DW_FORM_ref_addr references. These are produced
3053 by GCC with the option -feliminate-dwarf2-dups and also by some
3054 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3055 to use -feliminate-dwarf2-dups.
3057 * Internationalization
3059 When supported by the host system, GDB will be built with
3060 internationalization (libintl). The task of marking up the sources is
3061 continued, we're looking forward to our first translation.
3065 Initial support for debugging programs compiled with the GNAT
3066 implementation of the Ada programming language has been integrated
3067 into GDB. In this release, support is limited to expression evaluation.
3069 * New native configurations
3071 GNU/Linux/m32r m32r-*-linux-gnu
3075 GDB's remote protocol now includes support for the 'p' packet. This
3076 packet is used to fetch individual registers from a remote inferior.
3078 * END-OF-LIFE registers[] compatibility module
3080 GDB's internal register infrastructure has been completely rewritten.
3081 The new infrastructure making possible the implementation of key new
3082 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3085 GDB 6.3 will be the last release to include the the registers[]
3086 compatibility module that allowed out-of-date configurations to
3087 continue to work. This change directly impacts the following
3097 powerpc bdm protocol
3099 Unless there is activity to revive these configurations, they will be
3100 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3102 * OBSOLETE configurations and files
3104 Configurations that have been declared obsolete in this release have
3105 been commented out. Unless there is activity to revive these
3106 configurations, the next release of GDB will have their sources
3107 permanently REMOVED.
3116 *** Changes in GDB 6.2.1:
3118 * MIPS `break main; run' gave an heuristic-fence-post warning
3120 When attempting to run even a simple program, a warning about
3121 heuristic-fence-post being hit would be reported. This problem has
3124 * MIPS IRIX 'long double' crashed GDB
3126 When examining a long double variable, GDB would get a segmentation
3127 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3128 IRIX long double values).
3132 A bug in the VAX stack code was causing problems with the "next"
3133 command. This problem has been fixed.
3135 *** Changes in GDB 6.2:
3137 * Fix for ``many threads''
3139 On GNU/Linux systems that use the NPTL threads library, a program
3140 rapidly creating and deleting threads would confuse GDB leading to the
3143 ptrace: No such process.
3144 thread_db_get_info: cannot get thread info: generic error
3146 This problem has been fixed.
3148 * "-async" and "-noasync" options removed.
3150 Support for the broken "-noasync" option has been removed (it caused
3153 * New ``start'' command.
3155 This command runs the program until the begining of the main procedure.
3157 * New BSD Kernel Data Access Library (libkvm) interface
3159 Using ``target kvm'' it is now possible to debug kernel core dumps and
3160 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3161 platforms. Currently supported (native-only) configurations are:
3163 FreeBSD/amd64 x86_64-*-freebsd*
3164 FreeBSD/i386 i?86-*-freebsd*
3165 NetBSD/i386 i?86-*-netbsd*
3166 NetBSD/m68k m68*-*-netbsd*
3167 NetBSD/sparc sparc-*-netbsd*
3168 OpenBSD/amd64 x86_64-*-openbsd*
3169 OpenBSD/i386 i?86-*-openbsd*
3170 OpenBSD/m68k m68*-openbsd*
3171 OpenBSD/sparc sparc-*-openbsd*
3173 * Signal trampoline code overhauled
3175 Many generic problems with GDB's signal handling code have been fixed.
3176 These include: backtraces through non-contiguous stacks; recognition
3177 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3178 call; backtrace through a signal trampoline; step into and out of
3179 signal handlers; and single-stepping in the signal trampoline.
3181 Please note that kernel bugs are a limiting factor here. These
3182 features have been shown to work on an s390 GNU/Linux system that
3183 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3185 * Cygwin support for DWARF 2 added.
3187 * New native configurations
3189 GNU/Linux/hppa hppa*-*-linux*
3190 OpenBSD/hppa hppa*-*-openbsd*
3191 OpenBSD/m68k m68*-*-openbsd*
3192 OpenBSD/m88k m88*-*-openbsd*
3193 OpenBSD/powerpc powerpc-*-openbsd*
3194 NetBSD/vax vax-*-netbsd*
3195 OpenBSD/vax vax-*-openbsd*
3197 * END-OF-LIFE frame compatibility module
3199 GDB's internal frame infrastructure has been completely rewritten.
3200 The new infrastructure making it possible to support key new features
3201 including DWARF 2 Call Frame Information. To aid in the task of
3202 migrating old configurations to this new infrastructure, a
3203 compatibility module, that allowed old configurations to continue to
3204 work, was also included.
3206 GDB 6.2 will be the last release to include this frame compatibility
3207 module. This change directly impacts the following configurations:
3217 Unless there is activity to revive these configurations, they will be
3218 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3220 * REMOVED configurations and files
3222 Sun 3, running SunOS 3 m68*-*-sunos3*
3223 Sun 3, running SunOS 4 m68*-*-sunos4*
3224 Sun 2, running SunOS 3 m68000-*-sunos3*
3225 Sun 2, running SunOS 4 m68000-*-sunos4*
3226 Motorola 680x0 running LynxOS m68*-*-lynxos*
3227 AT&T 3b1/Unix pc m68*-att-*
3228 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3229 decstation mips-dec-* mips-little-*
3230 riscos mips-*-riscos* mips-*-sysv*
3231 sonymips mips-sony-*
3232 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3234 *** Changes in GDB 6.1.1:
3236 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3238 The TUI (Text-mode User Interface) is now built as part of a default
3239 GDB configuration. It is enabled by either selecting the TUI with the
3240 command line option "-i=tui" or by running the separate "gdbtui"
3241 program. For more information on the TUI, see the manual "Debugging
3244 * Pending breakpoint support (also included in GDB 6.1)
3246 Support has been added to allow you to specify breakpoints in shared
3247 libraries that have not yet been loaded. If a breakpoint location
3248 cannot be found, and the "breakpoint pending" option is set to auto,
3249 GDB queries you if you wish to make the breakpoint pending on a future
3250 shared-library load. If and when GDB resolves the breakpoint symbol,
3251 the pending breakpoint is removed as one or more regular breakpoints
3254 Pending breakpoints are very useful for GCJ Java debugging.
3256 * Fixed ISO-C build problems
3258 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3259 non ISO-C code that stopped them being built using a more strict ISO-C
3260 compiler (e.g., IBM's C compiler).
3262 * Fixed build problem on IRIX 5
3264 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3265 wasn't able to compile compile on an IRIX 5 system.
3267 * Added execute permission to gdb/gdbserver/configure
3269 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3270 permission. This bug would cause configure to fail on a number of
3271 systems (Solaris, IRIX). Ref: server/519.
3273 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3275 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3276 has been updated to use constant array sizes.
3278 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3280 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3281 its generated DWARF Call Frame Info. This encoding was causing GDB to
3282 panic, that panic has been fixed. Ref: gdb/1628.
3284 * Fixed a problem when examining parameters in shared library code.
3286 When examining parameters in optimized shared library code generated
3287 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3288 not available''. GDB now correctly displays the variable's value.
3290 *** Changes in GDB 6.1:
3292 * Removed --with-mmalloc
3294 Support for the mmalloc memory manager has been removed, as it
3295 conflicted with the internal gdb byte cache.
3297 * Changes in AMD64 configurations
3299 The AMD64 target now includes the %cs and %ss registers. As a result
3300 the AMD64 remote protocol has changed; this affects the floating-point
3301 and SSE registers. If you rely on those registers for your debugging,
3302 you should upgrade gdbserver on the remote side.
3304 * Revised SPARC target
3306 The SPARC target has been completely revised, incorporating the
3307 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3308 support for LynxOS and SunOS 4 has been dropped. Calling functions
3309 from within GDB on operating systems with a non-executable stack
3310 (Solaris, OpenBSD) now works.
3314 GDB has a new C++ demangler which does a better job on the mangled
3315 names generated by current versions of g++. It also runs faster, so
3316 with this and other changes gdb should now start faster on large C++
3319 * DWARF 2 Location Expressions
3321 GDB support for location expressions has been extended to support function
3322 arguments and frame bases. Older versions of GDB could crash when they
3325 * C++ nested types and namespaces
3327 GDB's support for nested types and namespaces in C++ has been
3328 improved, especially if you use the DWARF 2 debugging format. (This
3329 is the default for recent versions of GCC on most platforms.)
3330 Specifically, if you have a class "Inner" defined within a class or
3331 namespace "Outer", then GDB realizes that the class's name is
3332 "Outer::Inner", not simply "Inner". This should greatly reduce the
3333 frequency of complaints about not finding RTTI symbols. In addition,
3334 if you are stopped at inside of a function defined within a namespace,
3335 GDB modifies its name lookup accordingly.
3337 * New native configurations
3339 NetBSD/amd64 x86_64-*-netbsd*
3340 OpenBSD/amd64 x86_64-*-openbsd*
3341 OpenBSD/alpha alpha*-*-openbsd*
3342 OpenBSD/sparc sparc-*-openbsd*
3343 OpenBSD/sparc64 sparc64-*-openbsd*
3345 * New debugging protocols
3347 M32R with SDI protocol m32r-*-elf*
3349 * "set prompt-escape-char" command deleted.
3351 The command "set prompt-escape-char" has been deleted. This command,
3352 and its very obscure effet on GDB's prompt, was never documented,
3353 tested, nor mentioned in the NEWS file.
3355 * OBSOLETE configurations and files
3357 Configurations that have been declared obsolete in this release have
3358 been commented out. Unless there is activity to revive these
3359 configurations, the next release of GDB will have their sources
3360 permanently REMOVED.
3362 Sun 3, running SunOS 3 m68*-*-sunos3*
3363 Sun 3, running SunOS 4 m68*-*-sunos4*
3364 Sun 2, running SunOS 3 m68000-*-sunos3*
3365 Sun 2, running SunOS 4 m68000-*-sunos4*
3366 Motorola 680x0 running LynxOS m68*-*-lynxos*
3367 AT&T 3b1/Unix pc m68*-att-*
3368 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3369 decstation mips-dec-* mips-little-*
3370 riscos mips-*-riscos* mips-*-sysv*
3371 sonymips mips-sony-*
3372 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3374 * REMOVED configurations and files
3376 SGI Irix-4.x mips-sgi-irix4 or iris4
3377 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3378 Z8000 simulator z8k-zilog-none or z8ksim
3379 Matsushita MN10200 w/simulator mn10200-*-*
3380 H8/500 simulator h8500-hitachi-hms or h8500hms
3381 HP/PA running BSD hppa*-*-bsd*
3382 HP/PA running OSF/1 hppa*-*-osf*
3383 HP/PA Pro target hppa*-*-pro*
3384 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3385 386BSD i[3456]86-*-bsd*
3386 Sequent family i[3456]86-sequent-sysv4*
3387 i[3456]86-sequent-sysv*
3388 i[3456]86-sequent-bsd*
3389 SPARC running LynxOS sparc-*-lynxos*
3390 SPARC running SunOS 4 sparc-*-sunos4*
3391 Tsqware Sparclet sparclet-*-*
3392 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3394 *** Changes in GDB 6.0:
3398 Support for debugging the Objective-C programming language has been
3399 integrated into GDB.
3401 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3403 DWARF 2's Call Frame Information makes available compiler generated
3404 information that more exactly describes the program's run-time stack.
3405 By using this information, GDB is able to provide more robust stack
3408 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3409 have been updated to use a new backtrace mechanism which includes
3410 DWARF 2 CFI support.
3414 GDB's remote protocol has been extended to include support for hosted
3415 file I/O (where the remote target uses GDB's file system). See GDB's
3416 remote protocol documentation for details.
3418 * All targets using the new architecture framework.
3420 All of GDB's targets have been updated to use the new internal
3421 architecture framework. The way is now open for future GDB releases
3422 to include cross-architecture native debugging support (i386 on amd64,
3425 * GNU/Linux's Thread Local Storage (TLS)
3427 GDB now includes support for for the GNU/Linux implementation of
3428 per-thread variables.
3430 * GNU/Linux's Native POSIX Thread Library (NPTL)
3432 GDB's thread code has been updated to work with either the new
3433 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3435 * Separate debug info.
3437 GDB, in conjunction with BINUTILS, now supports a mechanism for
3438 automatically loading debug information from a separate file. Instead
3439 of shipping full debug and non-debug versions of system libraries,
3440 system integrators can now instead ship just the stripped libraries
3441 and optional debug files.
3443 * DWARF 2 Location Expressions
3445 DWARF 2 Location Expressions allow the compiler to more completely
3446 describe the location of variables (even in optimized code) to the
3449 GDB now includes preliminary support for location expressions (support
3450 for DW_OP_piece is still missing).
3454 A number of long standing bugs that caused GDB to die while starting a
3455 Java application have been fixed. GDB's Java support is now
3456 considered "useable".
3458 * GNU/Linux support for fork, vfork, and exec.
3460 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3461 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3464 * GDB supports logging output to a file
3466 There are two new commands, "set logging" and "show logging", which can be
3467 used to capture GDB's output to a file.
3469 * The meaning of "detach" has changed for gdbserver
3471 The "detach" command will now resume the application, as documented. To
3472 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3475 * d10v, m68hc11 `regs' command deprecated
3477 The `info registers' command has been updated so that it displays the
3478 registers using a format identical to the old `regs' command.
3482 A new command, "maint set profile on/off", has been added. This command can
3483 be used to enable or disable profiling while running GDB, to profile a
3484 session or a set of commands. In addition there is a new configure switch,
3485 "--enable-profiling", which will cause GDB to be compiled with profiling
3486 data, for more informative profiling results.
3488 * Default MI syntax changed to "mi2".
3490 The default MI (machine interface) syntax, enabled by the command line
3491 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3492 "mi1", can be enabled by specifying the option "-i=mi1".
3494 Support for the original "mi0" syntax (included in GDB 5.0) has been
3497 Fix for gdb/192: removed extraneous space when displaying frame level.
3498 Fix for gdb/672: update changelist is now output in mi list format.
3499 Fix for gdb/702: a -var-assign that updates the value now shows up
3500 in a subsequent -var-update.
3502 * New native configurations.
3504 FreeBSD/amd64 x86_64-*-freebsd*
3506 * Multi-arched targets.
3508 HP/PA HPUX11 hppa*-*-hpux*
3509 Renesas M32R/D w/simulator m32r-*-elf*
3511 * OBSOLETE configurations and files
3513 Configurations that have been declared obsolete in this release have
3514 been commented out. Unless there is activity to revive these
3515 configurations, the next release of GDB will have their sources
3516 permanently REMOVED.
3518 Z8000 simulator z8k-zilog-none or z8ksim
3519 Matsushita MN10200 w/simulator mn10200-*-*
3520 H8/500 simulator h8500-hitachi-hms or h8500hms
3521 HP/PA running BSD hppa*-*-bsd*
3522 HP/PA running OSF/1 hppa*-*-osf*
3523 HP/PA Pro target hppa*-*-pro*
3524 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3525 Sequent family i[3456]86-sequent-sysv4*
3526 i[3456]86-sequent-sysv*
3527 i[3456]86-sequent-bsd*
3528 Tsqware Sparclet sparclet-*-*
3529 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3531 * REMOVED configurations and files
3534 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3535 IBM AIX PS/2 i[3456]86-*-aix
3536 i386 running Mach 3.0 i[3456]86-*-mach3*
3537 i386 running Mach i[3456]86-*-mach*
3538 i386 running OSF/1 i[3456]86-*osf1mk*
3539 HP/Apollo 68k Family m68*-apollo*-sysv*,
3541 m68*-hp-bsd*, m68*-hp-hpux*
3542 Argonaut Risc Chip (ARC) arc-*-*
3543 Mitsubishi D30V d30v-*-*
3544 Fujitsu FR30 fr30-*-elf*
3545 OS/9000 i[34]86-*-os9k
3546 I960 with MON960 i960-*-coff
3548 * MIPS $fp behavior changed
3550 The convenience variable $fp, for the MIPS, now consistently returns
3551 the address of the current frame's base. Previously, depending on the
3552 context, $fp could refer to either $sp or the current frame's base
3553 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3554 The GNU Source-Level Debugger''.
3556 *** Changes in GDB 5.3:
3558 * GNU/Linux shared library multi-threaded performance improved.
3560 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3561 `/proc', in preference to `ptrace' for memory reads. This may result
3562 in an improvement in the start-up time of multi-threaded, shared
3563 library applications when run under GDB. One GDB user writes: ``loads
3564 shared libs like mad''.
3566 * ``gdbserver'' now supports multi-threaded applications on some targets
3568 Support for debugging multi-threaded applications which use
3569 the GNU/Linux LinuxThreads package has been added for
3570 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3571 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3573 * GDB now supports C/C++ preprocessor macros.
3575 GDB now expands preprocessor macro invocations in C/C++ expressions,
3576 and provides various commands for showing macro definitions and how
3579 The new command `macro expand EXPRESSION' expands any macro
3580 invocations in expression, and shows the result.
3582 The new command `show macro MACRO-NAME' shows the definition of the
3583 macro named MACRO-NAME, and where it was defined.
3585 Most compilers don't include information about macros in the debugging
3586 information by default. In GCC 3.1, for example, you need to compile
3587 your program with the options `-gdwarf-2 -g3'. If the macro
3588 information is present in the executable, GDB will read it.
3590 * Multi-arched targets.
3592 DEC Alpha (partial) alpha*-*-*
3593 DEC VAX (partial) vax-*-*
3595 National Semiconductor NS32000 (partial) ns32k-*-*
3596 Motorola 68000 (partial) m68k-*-*
3597 Motorola MCORE mcore-*-*
3601 Fujitsu FRV architecture added by Red Hat frv*-*-*
3604 * New native configurations
3606 Alpha NetBSD alpha*-*-netbsd*
3607 SH NetBSD sh*-*-netbsdelf*
3608 MIPS NetBSD mips*-*-netbsd*
3609 UltraSPARC NetBSD sparc64-*-netbsd*
3611 * OBSOLETE configurations and files
3613 Configurations that have been declared obsolete in this release have
3614 been commented out. Unless there is activity to revive these
3615 configurations, the next release of GDB will have their sources
3616 permanently REMOVED.
3618 Mitsubishi D30V d30v-*-*
3619 OS/9000 i[34]86-*-os9k
3620 IBM AIX PS/2 i[3456]86-*-aix
3621 Fujitsu FR30 fr30-*-elf*
3622 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3623 Argonaut Risc Chip (ARC) arc-*-*
3624 i386 running Mach 3.0 i[3456]86-*-mach3*
3625 i386 running Mach i[3456]86-*-mach*
3626 i386 running OSF/1 i[3456]86-*osf1mk*
3627 HP/Apollo 68k Family m68*-apollo*-sysv*,
3629 m68*-hp-bsd*, m68*-hp-hpux*
3630 I960 with MON960 i960-*-coff
3632 * OBSOLETE languages
3634 CHILL, a Pascal like language used by telecommunications companies.
3636 * REMOVED configurations and files
3638 AMD 29k family via UDI a29k-amd-udi, udi29k
3639 A29K VxWorks a29k-*-vxworks
3640 AMD 29000 embedded, using EBMON a29k-none-none
3641 AMD 29000 embedded with COFF a29k-none-coff
3642 AMD 29000 embedded with a.out a29k-none-aout
3644 testsuite/gdb.hp/gdb.threads-hp/ directory
3646 * New command "set max-user-call-depth <nnn>"
3648 This command allows the user to limit the call depth of user-defined
3649 commands. The default is 1024.
3651 * Changes in FreeBSD/i386 native debugging.
3653 Support for the "generate-core-file" has been added.
3655 * New commands "dump", "append", and "restore".
3657 These commands allow data to be copied from target memory
3658 to a bfd-format or binary file (dump and append), and back
3659 from a file into memory (restore).
3661 * Improved "next/step" support on multi-processor Alpha Tru64.
3663 The previous single-step mechanism could cause unpredictable problems,
3664 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3665 of a software single-step mechanism prevents this.
3667 *** Changes in GDB 5.2.1:
3675 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3676 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3677 Fix, by Joel Brobecker imported from mainline.
3679 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3680 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3681 Fix, by Fred Fish, imported from mainline.
3683 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3684 Surprisingly enough, it works now.
3685 By Michal Ludvig, imported from mainline.
3687 i386 hardware watchpoint support:
3688 avoid misses on second run for some targets.
3689 By Pierre Muller, imported from mainline.
3691 *** Changes in GDB 5.2:
3693 * New command "set trust-readonly-sections on[off]".
3695 This command is a hint that tells gdb that read-only sections
3696 really are read-only (ie. that their contents will not change).
3697 In this mode, gdb will go to the object file rather than the
3698 target to read memory from read-only sections (such as ".text").
3699 This can be a significant performance improvement on some
3700 (notably embedded) targets.
3702 * New command "generate-core-file" (or "gcore").
3704 This new gdb command allows the user to drop a core file of the child
3705 process state at any time. So far it's been implemented only for
3706 GNU/Linux and Solaris, but should be relatively easily ported to other
3707 hosts. Argument is core file name (defaults to core.<pid>).
3709 * New command line option
3711 GDB now accepts --pid or -p followed by a process id.
3713 * Change in command line behavior -- corefiles vs. process ids.
3715 There is a subtle behavior in the way in which GDB handles
3716 command line arguments. The first non-flag argument is always
3717 a program to debug, but the second non-flag argument may either
3718 be a corefile or a process id. Previously, GDB would attempt to
3719 open the second argument as a corefile, and if that failed, would
3720 issue a superfluous error message and then attempt to attach it as
3721 a process. Now, if the second argument begins with a non-digit,
3722 it will be treated as a corefile. If it begins with a digit,
3723 GDB will attempt to attach it as a process, and if no such process
3724 is found, will then attempt to open it as a corefile.
3726 * Changes in ARM configurations.
3728 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3729 configuration is fully multi-arch.
3731 * New native configurations
3733 ARM NetBSD arm*-*-netbsd*
3734 x86 OpenBSD i[3456]86-*-openbsd*
3735 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3736 Sparc64 running FreeBSD sparc64-*-freebsd*
3740 Sanyo XStormy16 xstormy16-elf
3742 * OBSOLETE configurations and files
3744 Configurations that have been declared obsolete in this release have
3745 been commented out. Unless there is activity to revive these
3746 configurations, the next release of GDB will have their sources
3747 permanently REMOVED.
3749 AMD 29k family via UDI a29k-amd-udi, udi29k
3750 A29K VxWorks a29k-*-vxworks
3751 AMD 29000 embedded, using EBMON a29k-none-none
3752 AMD 29000 embedded with COFF a29k-none-coff
3753 AMD 29000 embedded with a.out a29k-none-aout
3755 testsuite/gdb.hp/gdb.threads-hp/ directory
3757 * REMOVED configurations and files
3759 TI TMS320C80 tic80-*-*
3761 PowerPC Solaris powerpcle-*-solaris*
3762 PowerPC Windows NT powerpcle-*-cygwin32
3763 PowerPC Netware powerpc-*-netware*
3764 Harris/CXUX m88k m88*-harris-cxux*
3765 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3766 ns32k-utek-sysv* ns32k-utek-*
3767 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3768 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3769 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3770 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3771 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3773 * Changes to command line processing
3775 The new `--args' feature can be used to specify command-line arguments
3776 for the inferior from gdb's command line.
3778 * Changes to key bindings
3780 There is a new `operate-and-get-next' function bound to `C-o'.
3782 *** Changes in GDB 5.1.1
3784 Fix compile problem on DJGPP.
3786 Fix a problem with floating-point registers on the i386 being
3789 Fix to stop GDB crashing on .debug_str debug info.
3791 Numerous documentation fixes.
3793 Numerous testsuite fixes.
3795 *** Changes in GDB 5.1:
3797 * New native configurations
3799 Alpha FreeBSD alpha*-*-freebsd*
3800 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3801 MIPS GNU/Linux mips*-*-linux*
3802 MIPS SGI Irix 6.x mips*-sgi-irix6*
3803 ia64 AIX ia64-*-aix*
3804 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3808 Motorola 68HC11 and 68HC12 m68hc11-elf
3810 UltraSparc running GNU/Linux sparc64-*-linux*
3812 * OBSOLETE configurations and files
3814 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3815 Harris/CXUX m88k m88*-harris-cxux*
3816 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3817 ns32k-utek-sysv* ns32k-utek-*
3818 TI TMS320C80 tic80-*-*
3820 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3821 PowerPC Solaris powerpcle-*-solaris*
3822 PowerPC Windows NT powerpcle-*-cygwin32
3823 PowerPC Netware powerpc-*-netware*
3824 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3825 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3826 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3827 Apple Macintosh (MPW) host N/A
3829 stuff.c (Program to stuff files into a specially prepared space in kdb)
3830 kdb-start.c (Main loop for the standalone kernel debugger)
3832 Configurations that have been declared obsolete in this release have
3833 been commented out. Unless there is activity to revive these
3834 configurations, the next release of GDB will have their sources
3835 permanently REMOVED.
3837 * REMOVED configurations and files
3839 Altos 3068 m68*-altos-*
3840 Convex c1-*-*, c2-*-*
3842 ARM RISCix arm-*-* (as host)
3846 * GDB has been converted to ISO C.
3848 GDB's source code has been converted to ISO C. In particular, the
3849 sources are fully protoized, and rely on standard headers being
3854 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3856 * The MI enabled by default.
3858 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3859 revised and enabled by default. Packages which use GDB as a debugging
3860 engine behind a UI or another front end are encouraged to switch to
3861 using the GDB/MI interface, instead of the old annotations interface
3862 which is now deprecated.
3864 * Support for debugging Pascal programs.
3866 GDB now includes support for debugging Pascal programs. The following
3867 main features are supported:
3869 - Pascal-specific data types such as sets;
3871 - automatic recognition of Pascal sources based on file-name
3874 - Pascal-style display of data types, variables, and functions;
3876 - a Pascal expression parser.
3878 However, some important features are not yet supported.
3880 - Pascal string operations are not supported at all;
3882 - there are some problems with boolean types;
3884 - Pascal type hexadecimal constants are not supported
3885 because they conflict with the internal variables format;
3887 - support for Pascal objects and classes is not full yet;
3889 - unlike Pascal, GDB is case-sensitive for symbol names.
3891 * Changes in completion.
3893 Commands such as `shell', `run' and `set args', which pass arguments
3894 to inferior programs, now complete on file names, similar to what
3895 users expect at the shell prompt.
3897 Commands which accept locations, such as `disassemble', `print',
3898 `breakpoint', `until', etc. now complete on filenames as well as
3899 program symbols. Thus, if you type "break foob TAB", and the source
3900 files linked into the programs include `foobar.c', that file name will
3901 be one of the candidates for completion. However, file names are not
3902 considered for completion after you typed a colon that delimits a file
3903 name from a name of a function in that file, as in "break foo.c:bar".
3905 `set demangle-style' completes on available demangling styles.
3907 * New platform-independent commands:
3909 It is now possible to define a post-hook for a command as well as a
3910 hook that runs before the command. For more details, see the
3911 documentation of `hookpost' in the GDB manual.
3913 * Changes in GNU/Linux native debugging.
3915 Support for debugging multi-threaded programs has been completely
3916 revised for all platforms except m68k and sparc. You can now debug as
3917 many threads as your system allows you to have.
3919 Attach/detach is supported for multi-threaded programs.
3921 Support for SSE registers was added for x86. This doesn't work for
3922 multi-threaded programs though.
3924 * Changes in MIPS configurations.
3926 Multi-arch support is enabled for all MIPS configurations.
3928 GDB can now be built as native debugger on SGI Irix 6.x systems for
3929 debugging n32 executables. (Debugging 64-bit executables is not yet
3932 * Unified support for hardware watchpoints in all x86 configurations.
3934 Most (if not all) native x86 configurations support hardware-assisted
3935 breakpoints and watchpoints in a unified manner. This support
3936 implements debug register sharing between watchpoints, which allows to
3937 put a virtually infinite number of watchpoints on the same address,
3938 and also supports watching regions up to 16 bytes with several debug
3941 The new maintenance command `maintenance show-debug-regs' toggles
3942 debugging print-outs in functions that insert, remove, and test
3943 watchpoints and hardware breakpoints.
3945 * Changes in the DJGPP native configuration.
3947 New command ``info dos sysinfo'' displays assorted information about
3948 the CPU, OS, memory, and DPMI server.
3950 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3951 display information about segment descriptors stored in GDT, LDT, and
3954 New commands ``info dos pde'' and ``info dos pte'' display entries
3955 from Page Directory and Page Tables (for now works with CWSDPMI only).
3956 New command ``info dos address-pte'' displays the Page Table entry for
3957 a given linear address.
3959 GDB can now pass command lines longer than 126 characters to the
3960 program being debugged (requires an update to the libdbg.a library
3961 which is part of the DJGPP development kit).
3963 DWARF2 debug info is now supported.
3965 It is now possible to `step' and `next' through calls to `longjmp'.
3967 * Changes in documentation.
3969 All GDB documentation was converted to GFDL, the GNU Free
3970 Documentation License.
3972 Tracepoints-related commands are now fully documented in the GDB
3975 TUI, the Text-mode User Interface, is now documented in the manual.
3977 Tracepoints-related commands are now fully documented in the GDB
3980 The "GDB Internals" manual now has an index. It also includes
3981 documentation of `ui_out' functions, GDB coding standards, x86
3982 hardware watchpoints, and memory region attributes.
3984 * GDB's version number moved to ``version.in''
3986 The Makefile variable VERSION has been replaced by the file
3987 ``version.in''. People creating GDB distributions should update the
3988 contents of this file.
3992 GUD support is now a standard part of the EMACS distribution.
3994 *** Changes in GDB 5.0:
3996 * Improved support for debugging FP programs on x86 targets
3998 Unified and much-improved support for debugging floating-point
3999 programs on all x86 targets. In particular, ``info float'' now
4000 displays the FP registers in the same format on all x86 targets, with
4001 greater level of detail.
4003 * Improvements and bugfixes in hardware-assisted watchpoints
4005 It is now possible to watch array elements, struct members, and
4006 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4007 on x86 targets no longer erroneously trigger when the address is
4010 * Improvements in the native DJGPP version of GDB
4012 The distribution now includes all the scripts and auxiliary files
4013 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4014 machines ``out of the box''.
4016 The DJGPP version can now debug programs that use signals. It is
4017 possible to catch signals that happened in the debuggee, deliver
4018 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4019 would kill the program being debugged.) Programs that hook hardware
4020 interrupts (keyboard, timer, etc.) can also be debugged.
4022 It is now possible to debug DJGPP programs that redirect their
4023 standard handles or switch them to raw (as opposed to cooked) mode, or
4024 even close them. The command ``run < foo > bar'' works as expected,
4025 and ``info terminal'' reports useful information about the debuggee's
4026 terminal, including raw/cooked mode, redirection, etc.
4028 The DJGPP version now uses termios functions for console I/O, which
4029 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4032 DOS-style file names with drive letters are now fully supported by
4035 It is now possible to debug DJGPP programs that switch their working
4036 directory. It is also possible to rerun the debuggee any number of
4037 times without restarting GDB; thus, you can use the same setup,
4038 breakpoints, etc. for many debugging sessions.
4040 * New native configurations
4042 ARM GNU/Linux arm*-*-linux*
4043 PowerPC GNU/Linux powerpc-*-linux*
4047 Motorola MCore mcore-*-*
4048 x86 VxWorks i[3456]86-*-vxworks*
4049 PowerPC VxWorks powerpc-*-vxworks*
4050 TI TMS320C80 tic80-*-*
4052 * OBSOLETE configurations
4054 Altos 3068 m68*-altos-*
4055 Convex c1-*-*, c2-*-*
4057 ARM RISCix arm-*-* (as host)
4060 Configurations that have been declared obsolete will be commented out,
4061 but the code will be left in place. If there is no activity to revive
4062 these configurations before the next release of GDB, the sources will
4063 be permanently REMOVED.
4065 * Gould support removed
4067 Support for the Gould PowerNode and NP1 has been removed.
4069 * New features for SVR4
4071 On SVR4 native platforms (such as Solaris), if you attach to a process
4072 without first loading a symbol file, GDB will now attempt to locate and
4073 load symbols from the running process's executable file.
4075 * Many C++ enhancements
4077 C++ support has been greatly improved. Overload resolution now works properly
4078 in almost all cases. RTTI support is on the way.
4080 * Remote targets can connect to a sub-program
4082 A popen(3) style serial-device has been added. This device starts a
4083 sub-process (such as a stand-alone simulator) and then communicates
4084 with that. The sub-program to run is specified using the syntax
4085 ``|<program> <args>'' vis:
4087 (gdb) set remotedebug 1
4088 (gdb) target extended-remote |mn10300-elf-sim program-args
4090 * MIPS 64 remote protocol
4092 A long standing bug in the mips64 remote protocol where by GDB
4093 expected certain 32 bit registers (ex SR) to be transfered as 32
4094 instead of 64 bits has been fixed.
4096 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4097 added to provide backward compatibility with older versions of GDB.
4099 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4101 The command ``set remotebinarydownload'' command has been replaced by
4102 ``set remote X-packet''. Other commands in ``set remote'' family
4103 include ``set remote P-packet''.
4105 * Breakpoint commands accept ranges.
4107 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4108 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4109 ``tracepoint passcount'' also accepts a range of tracepoints.
4111 * ``apropos'' command added.
4113 The ``apropos'' command searches through command names and
4114 documentation strings, printing out matches, making it much easier to
4115 try to find a command that does what you are looking for.
4119 A new machine oriented interface (MI) has been added to GDB. This
4120 interface is designed for debug environments running GDB as a separate
4121 process. This is part of the long term libGDB project. See the
4122 "GDB/MI" chapter of the GDB manual for further information. It can be
4123 enabled by configuring with:
4125 .../configure --enable-gdbmi
4127 *** Changes in GDB-4.18:
4129 * New native configurations
4131 HP-UX 10.20 hppa*-*-hpux10.20
4132 HP-UX 11.x hppa*-*-hpux11.0*
4133 M68K GNU/Linux m68*-*-linux*
4137 Fujitsu FR30 fr30-*-elf*
4138 Intel StrongARM strongarm-*-*
4139 Mitsubishi D30V d30v-*-*
4141 * OBSOLETE configurations
4143 Gould PowerNode, NP1 np1-*-*, pn-*-*
4145 Configurations that have been declared obsolete will be commented out,
4146 but the code will be left in place. If there is no activity to revive
4147 these configurations before the next release of GDB, the sources will
4148 be permanently REMOVED.
4152 As a compatibility experiment, GDB's source files buildsym.h and
4153 buildsym.c have been converted to pure standard C, no longer
4154 containing any K&R compatibility code. We believe that all systems in
4155 use today either come with a standard C compiler, or have a GCC port
4156 available. If this is not true, please report the affected
4157 configuration to bug-gdb@gnu.org immediately. See the README file for
4158 information about getting a standard C compiler if you don't have one
4163 GDB now uses readline 2.2.
4165 * set extension-language
4167 You can now control the mapping between filename extensions and source
4168 languages by using the `set extension-language' command. For instance,
4169 you can ask GDB to treat .c files as C++ by saying
4170 set extension-language .c c++
4171 The command `info extensions' lists all of the recognized extensions
4172 and their associated languages.
4174 * Setting processor type for PowerPC and RS/6000
4176 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4177 you can use the `set processor' command to specify what variant of the
4178 PowerPC family you are debugging. The command
4182 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4183 following PowerPC and RS6000 variants:
4185 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4186 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4188 403GC IBM PowerPC 403GC
4189 505 Motorola PowerPC 505
4190 860 Motorola PowerPC 860 or 850
4191 601 Motorola PowerPC 601
4192 602 Motorola PowerPC 602
4193 603 Motorola/IBM PowerPC 603 or 603e
4194 604 Motorola PowerPC 604 or 604e
4195 750 Motorola/IBM PowerPC 750 or 750
4197 At the moment, this command just tells GDB what to name the
4198 special-purpose processor registers. Since almost all the affected
4199 registers are inaccessible to user-level programs, this command is
4200 only useful for remote debugging in its present form.
4204 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4205 more extensive support for HP-UX. Added features include shared
4206 library support, kernel threads and hardware watchpoints for 11.00,
4207 support for HP's ANSI C and C++ compilers, and a compatibility mode
4208 for xdb and dbx commands.
4212 HP's donation includes the new concept of catchpoints, which is a
4213 generalization of the old catch command. On HP-UX, it is now possible
4214 to catch exec, fork, and vfork, as well as library loading.
4216 This means that the existing catch command has changed; its first
4217 argument now specifies the type of catch to be set up. See the
4218 output of "help catch" for a list of catchpoint types.
4220 * Debugging across forks
4222 On HP-UX, you can choose which process to debug when a fork() happens
4227 HP has donated a curses-based terminal user interface (TUI). To get
4228 it, build with --enable-tui. Although this can be enabled for any
4229 configuration, at present it only works for native HP debugging.
4231 * GDB remote protocol additions
4233 A new protocol packet 'X' that writes binary data is now available.
4234 Default behavior is to try 'X', then drop back to 'M' if the stub
4235 fails to respond. The settable variable `remotebinarydownload'
4236 allows explicit control over the use of 'X'.
4238 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4239 full 64-bit address. The command
4241 set remoteaddresssize 32
4243 can be used to revert to the old behaviour. For existing remote stubs
4244 the change should not be noticed, as the additional address information
4247 In order to assist in debugging stubs, you may use the maintenance
4248 command `packet' to send any text string to the stub. For instance,
4250 maint packet heythere
4252 sends the packet "$heythere#<checksum>". Note that it is very easy to
4253 disrupt a debugging session by sending the wrong packet at the wrong
4256 The compare-sections command allows you to compare section data on the
4257 target to what is in the executable file without uploading or
4258 downloading, by comparing CRC checksums.
4260 * Tracing can collect general expressions
4262 You may now collect general expressions at tracepoints. This requires
4263 further additions to the target-side stub; see tracepoint.c and
4264 doc/agentexpr.texi for further details.
4266 * mask-address variable for Mips
4268 For Mips targets, you may control the zeroing of the upper 32 bits of
4269 a 64-bit address by entering `set mask-address on'. This is mainly
4270 of interest to users of embedded R4xxx and R5xxx processors.
4272 * Higher serial baud rates
4274 GDB's serial code now allows you to specify baud rates 57600, 115200,
4275 230400, and 460800 baud. (Note that your host system may not be able
4276 to achieve all of these rates.)
4280 The i960 configuration now includes an initial implementation of a
4281 builtin simulator, contributed by Jim Wilson.
4284 *** Changes in GDB-4.17:
4286 * New native configurations
4288 Alpha GNU/Linux alpha*-*-linux*
4289 Unixware 2.x i[3456]86-unixware2*
4290 Irix 6.x mips*-sgi-irix6*
4291 PowerPC GNU/Linux powerpc-*-linux*
4292 PowerPC Solaris powerpcle-*-solaris*
4293 Sparc GNU/Linux sparc-*-linux*
4294 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4298 Argonaut Risc Chip (ARC) arc-*-*
4299 Hitachi H8/300S h8300*-*-*
4300 Matsushita MN10200 w/simulator mn10200-*-*
4301 Matsushita MN10300 w/simulator mn10300-*-*
4302 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4303 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4304 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4305 Mitsubishi D10V w/simulator d10v-*-*
4306 Mitsubishi M32R/D w/simulator m32r-*-elf*
4307 Tsqware Sparclet sparclet-*-*
4308 NEC V850 w/simulator v850-*-*
4310 * New debugging protocols
4312 ARM with RDI protocol arm*-*-*
4313 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4314 DDB and LSI variants of PMON protocol mips*-*-*
4315 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4316 PowerPC with SDS protocol powerpc{,le}-*-eabi
4317 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4321 All configurations can now understand and use the DWARF 2 debugging
4322 format. The choice is automatic, if the symbol file contains DWARF 2
4327 GDB now includes basic Java language support. This support is
4328 only useful with Java compilers that produce native machine code.
4330 * solib-absolute-prefix and solib-search-path
4332 For SunOS and SVR4 shared libraries, you may now set the prefix for
4333 loading absolute shared library symbol files, and the search path for
4334 locating non-absolute shared library symbol files.
4336 * Live range splitting
4338 GDB can now effectively debug code for which GCC has performed live
4339 range splitting as part of its optimization. See gdb/doc/LRS for
4340 more details on the expected format of the stabs information.
4344 GDB's support for the GNU Hurd, including thread debugging, has been
4345 updated to work with current versions of the Hurd.
4349 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4350 instruction set. ARM GDB automatically detects when Thumb
4351 instructions are in use, and adjusts disassembly and backtracing
4356 GDB's MIPS target configurations now handle the MIP16 16-bit
4361 GDB now includes support for overlays; if an executable has been
4362 linked such that multiple sections are based at the same address, GDB
4363 will decide which section to use for symbolic info. You can choose to
4364 control the decision manually, using overlay commands, or implement
4365 additional target-side support and use "overlay load-target" to bring
4366 in the overlay mapping. Do "help overlay" for more detail.
4370 The command "info symbol <address>" displays information about
4371 the symbol at the specified address.
4375 The standard remote protocol now includes an extension that allows
4376 asynchronous collection and display of trace data. This requires
4377 extensive support in the target-side debugging stub. Tracing mode
4378 includes a new interaction mode in GDB and new commands: see the
4379 file tracepoint.c for more details.
4383 Configurations for embedded MIPS now include a simulator contributed
4384 by Cygnus Solutions. The simulator supports the instruction sets
4385 of most MIPS variants.
4389 Sparc configurations may now include the ERC32 simulator contributed
4390 by the European Space Agency. The simulator is not built into
4391 Sparc targets by default; configure with --enable-sim to include it.
4395 For target configurations that may include multiple variants of a
4396 basic architecture (such as MIPS and SH), you may now set the
4397 architecture explicitly. "set arch" sets, "info arch" lists
4398 the possible architectures.
4400 *** Changes in GDB-4.16:
4402 * New native configurations
4404 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4405 M68K NetBSD m68k-*-netbsd*
4406 PowerPC AIX 4.x powerpc-*-aix*
4407 PowerPC MacOS powerpc-*-macos*
4408 PowerPC Windows NT powerpcle-*-cygwin32
4409 RS/6000 AIX 4.x rs6000-*-aix4*
4413 ARM with RDP protocol arm-*-*
4414 I960 with MON960 i960-*-coff
4415 MIPS VxWorks mips*-*-vxworks*
4416 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4417 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4419 Matra Sparclet sparclet-*-*
4423 The powerpc-eabi configuration now includes the PSIM simulator,
4424 contributed by Andrew Cagney, with assistance from Mike Meissner.
4425 PSIM is a very elaborate model of the PowerPC, including not only
4426 basic instruction set execution, but also details of execution unit
4427 performance and I/O hardware. See sim/ppc/README for more details.
4431 GDB now works with Solaris 2.5.
4433 * Windows 95/NT native
4435 GDB will now work as a native debugger on Windows 95 and Windows NT.
4436 To build it from source, you must use the "gnu-win32" environment,
4437 which uses a DLL to emulate enough of Unix to run the GNU tools.
4438 Further information, binaries, and sources are available at
4439 ftp.cygnus.com, under pub/gnu-win32.
4441 * dont-repeat command
4443 If a user-defined command includes the command `dont-repeat', then the
4444 command will not be repeated if the user just types return. This is
4445 useful if the command is time-consuming to run, so that accidental
4446 extra keystrokes don't run the same command many times.
4448 * Send break instead of ^C
4450 The standard remote protocol now includes an option to send a break
4451 rather than a ^C to the target in order to interrupt it. By default,
4452 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4454 * Remote protocol timeout
4456 The standard remote protocol includes a new variable `remotetimeout'
4457 that allows you to set the number of seconds before GDB gives up trying
4458 to read from the target. The default value is 2.
4460 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4462 By default GDB will automatically keep track of objects as they are
4463 loaded and unloaded by the dynamic linker. By using the command `set
4464 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4465 when shared library events occur, thus allowing you to set breakpoints
4466 in shared libraries which are explicitly loaded by the inferior.
4468 Note this feature does not work on hpux8. On hpux9 you must link
4469 /usr/lib/end.o into your program. This feature should work
4470 automatically on hpux10.
4472 * Irix 5.x hardware watchpoint support
4474 Irix 5 configurations now support the use of hardware watchpoints.
4476 * Mips protocol "SYN garbage limit"
4478 When debugging a Mips target using the `target mips' protocol, you
4479 may set the number of characters that GDB will ignore by setting
4480 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4481 every character. The default value is 1050.
4483 * Recording and replaying remote debug sessions
4485 If you set `remotelogfile' to the name of a file, gdb will write to it
4486 a recording of a remote debug session. This recording may then be
4487 replayed back to gdb using "gdbreplay". See gdbserver/README for
4488 details. This is useful when you have a problem with GDB while doing
4489 remote debugging; you can make a recording of the session and send it
4490 to someone else, who can then recreate the problem.
4492 * Speedups for remote debugging
4494 GDB includes speedups for downloading and stepping MIPS systems using
4495 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4496 and more efficient S-record downloading.
4498 * Memory use reductions and statistics collection
4500 GDB now uses less memory and reports statistics about memory usage.
4501 Try the `maint print statistics' command, for example.
4503 *** Changes in GDB-4.15:
4505 * Psymtabs for XCOFF
4507 The symbol reader for AIX GDB now uses partial symbol tables. This
4508 can greatly improve startup time, especially for large executables.
4510 * Remote targets use caching
4512 Remote targets now use a data cache to speed up communication with the
4513 remote side. The data cache could lead to incorrect results because
4514 it doesn't know about volatile variables, thus making it impossible to
4515 debug targets which use memory mapped I/O devices. `set remotecache
4516 off' turns the the data cache off.
4518 * Remote targets may have threads
4520 The standard remote protocol now includes support for multiple threads
4521 in the target system, using new protocol commands 'H' and 'T'. See
4522 gdb/remote.c for details.
4526 If GDB is configured with `--enable-netrom', then it will include
4527 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4528 acts as though it is a bank of ROM on the target board, but you can
4529 write into it over the network. GDB's support consists only of
4530 support for fast loading into the emulated ROM; to debug, you must use
4531 another protocol, such as standard remote protocol. The usual
4532 sequence is something like
4534 target nrom <netrom-hostname>
4536 target remote <netrom-hostname>:1235
4540 GDB now includes support for the Apple Macintosh, as a host only. It
4541 may be run as either an MPW tool or as a standalone application, and
4542 it can debug through the serial port. All the usual GDB commands are
4543 available, but to the target command, you must supply "serial" as the
4544 device type instead of "/dev/ttyXX". See mpw-README in the main
4545 directory for more information on how to build. The MPW configuration
4546 scripts */mpw-config.in support only a few targets, and only the
4547 mips-idt-ecoff target has been tested.
4551 GDB configuration now uses autoconf. This is not user-visible,
4552 but does simplify configuration and building.
4556 GDB now supports hpux10.
4558 *** Changes in GDB-4.14:
4560 * New native configurations
4562 x86 FreeBSD i[345]86-*-freebsd
4563 x86 NetBSD i[345]86-*-netbsd
4564 NS32k NetBSD ns32k-*-netbsd
4565 Sparc NetBSD sparc-*-netbsd
4569 A29K VxWorks a29k-*-vxworks
4570 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4571 CPU32 EST-300 emulator m68*-*-est*
4572 PowerPC ELF powerpc-*-elf
4575 * Alpha OSF/1 support for procfs
4577 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4578 possible to attach to running processes. As the mounting of the /proc
4579 filesystem is optional on the Alpha, GDB automatically determines
4580 the availability of /proc during startup. This can lead to problems
4581 if /proc is unmounted after GDB has been started.
4583 * Arguments to user-defined commands
4585 User commands may accept up to 10 arguments separated by whitespace.
4586 Arguments are accessed within the user command via $arg0..$arg9. A
4589 print $arg0 + $arg1 + $arg2
4591 To execute the command use:
4594 Defines the command "adder" which prints the sum of its three arguments.
4595 Note the arguments are text substitutions, so they may reference variables,
4596 use complex expressions, or even perform inferior function calls.
4598 * New `if' and `while' commands
4600 This makes it possible to write more sophisticated user-defined
4601 commands. Both commands take a single argument, which is the
4602 expression to evaluate, and must be followed by the commands to
4603 execute, one per line, if the expression is nonzero, the list being
4604 terminated by the word `end'. The `if' command list may include an
4605 `else' word, which causes the following commands to be executed only
4606 if the expression is zero.
4608 * Fortran source language mode
4610 GDB now includes partial support for Fortran 77. It will recognize
4611 Fortran programs and can evaluate a subset of Fortran expressions, but
4612 variables and functions may not be handled correctly. GDB will work
4613 with G77, but does not yet know much about symbols emitted by other
4616 * Better HPUX support
4618 Most debugging facilities now work on dynamic executables for HPPAs
4619 running hpux9 or later. You can attach to running dynamically linked
4620 processes, but by default the dynamic libraries will be read-only, so
4621 for instance you won't be able to put breakpoints in them. To change
4622 that behavior do the following before running the program:
4628 This will cause the libraries to be mapped private and read-write.
4629 To revert to the normal behavior, do this:
4635 You cannot set breakpoints or examine data in the library until after
4636 the library is loaded if the function/data symbols do not have
4639 GDB can now also read debug symbols produced by the HP C compiler on
4640 HPPAs (sorry, no C++, Fortran or 68k support).
4642 * Target byte order now dynamically selectable
4644 You can choose which byte order to use with a target system, via the
4645 commands "set endian big" and "set endian little", and you can see the
4646 current setting by using "show endian". You can also give the command
4647 "set endian auto", in which case GDB will use the byte order
4648 associated with the executable. Currently, only embedded MIPS
4649 configurations support dynamic selection of target byte order.
4651 * New DOS host serial code
4653 This version uses DPMI interrupts to handle buffered I/O, so you
4654 no longer need to run asynctsr when debugging boards connected to
4657 *** Changes in GDB-4.13:
4659 * New "complete" command
4661 This lists all the possible completions for the rest of the line, if it
4662 were to be given as a command itself. This is intended for use by emacs.
4664 * Trailing space optional in prompt
4666 "set prompt" no longer adds a space for you after the prompt you set. This
4667 allows you to set a prompt which ends in a space or one that does not.
4669 * Breakpoint hit counts
4671 "info break" now displays a count of the number of times the breakpoint
4672 has been hit. This is especially useful in conjunction with "ignore"; you
4673 can ignore a large number of breakpoint hits, look at the breakpoint info
4674 to see how many times the breakpoint was hit, then run again, ignoring one
4675 less than that number, and this will get you quickly to the last hit of
4678 * Ability to stop printing at NULL character
4680 "set print null-stop" will cause GDB to stop printing the characters of
4681 an array when the first NULL is encountered. This is useful when large
4682 arrays actually contain only short strings.
4684 * Shared library breakpoints
4686 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4687 breakpoints in shared libraries before the executable is run.
4689 * Hardware watchpoints
4691 There is a new hardware breakpoint for the watch command for sparclite
4692 targets. See gdb/sparclite/hw_breakpoint.note.
4694 Hardware watchpoints are also now supported under GNU/Linux.
4698 Annotations have been added. These are for use with graphical interfaces,
4699 and are still experimental. Currently only gdba.el uses these.
4701 * Improved Irix 5 support
4703 GDB now works properly with Irix 5.2.
4705 * Improved HPPA support
4707 GDB now works properly with the latest GCC and GAS.
4709 * New native configurations
4711 Sequent PTX4 i[34]86-sequent-ptx4
4712 HPPA running OSF/1 hppa*-*-osf*
4713 Atari TT running SVR4 m68*-*-sysv4*
4714 RS/6000 LynxOS rs6000-*-lynxos*
4718 OS/9000 i[34]86-*-os9k
4719 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4722 * Hitachi SH7000 and E7000-PC ICE support
4724 There is now support for communicating with the Hitachi E7000-PC ICE.
4725 This is available automatically when GDB is configured for the SH.
4729 As usual, a variety of small fixes and improvements, both generic
4730 and configuration-specific. See the ChangeLog for more detail.
4732 *** Changes in GDB-4.12:
4734 * Irix 5 is now supported
4738 GDB-4.12 on the HPPA has a number of changes which make it unable
4739 to debug the output from the currently released versions of GCC and
4740 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4741 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4742 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4745 *** Changes in GDB-4.11:
4747 * User visible changes:
4751 The "set remotedebug" option is now consistent between the mips remote
4752 target, remote targets using the gdb-specific protocol, UDI (AMD's
4753 debug protocol for the 29k) and the 88k bug monitor. It is now an
4754 integer specifying a debug level (normally 0 or 1, but 2 means more
4755 debugging info for the mips target).
4757 * DEC Alpha native support
4759 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4760 debug info, but GDB works fairly well with the DEC compiler and should
4761 work with a future GCC release. See the README file for a few
4762 Alpha-specific notes.
4764 * Preliminary thread implementation
4766 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4768 * LynxOS native and target support for 386
4770 This release has been hosted on LynxOS 2.2, and also can be configured
4771 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4774 * Improvements in C++ mangling/demangling.
4776 This release has much better g++ debugging, specifically in name
4777 mangling/demangling, virtual function calls, print virtual table,
4778 call methods, ...etc.
4780 *** Changes in GDB-4.10:
4782 * User visible changes:
4784 Remote debugging using the GDB-specific (`target remote') protocol now
4785 supports the `load' command. This is only useful if you have some
4786 other way of getting the stub to the target system, and you can put it
4787 somewhere in memory where it won't get clobbered by the download.
4789 Filename completion now works.
4791 When run under emacs mode, the "info line" command now causes the
4792 arrow to point to the line specified. Also, "info line" prints
4793 addresses in symbolic form (as well as hex).
4795 All vxworks based targets now support a user settable option, called
4796 vxworks-timeout. This option represents the number of seconds gdb
4797 should wait for responses to rpc's. You might want to use this if
4798 your vxworks target is, perhaps, a slow software simulator or happens
4799 to be on the far side of a thin network line.
4803 This release contains support for using a DEC alpha as a GDB host for
4804 cross debugging. Native alpha debugging is not supported yet.
4807 *** Changes in GDB-4.9:
4811 This is the first GDB release which is accompanied by a matching testsuite.
4812 The testsuite requires installation of dejagnu, which should be available
4813 via ftp from most sites that carry GNU software.
4817 'Cfront' style demangling has had its name changed to 'ARM' style, to
4818 emphasize that it was written from the specifications in the C++ Annotated
4819 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4820 disclaimers, it still generated too much confusion with users attempting to
4821 use gdb with AT&T cfront.
4825 GDB now uses a standard remote interface to a simulator library.
4826 So far, the library contains simulators for the Zilog Z8001/2, the
4827 Hitachi H8/300, H8/500 and Super-H.
4829 * New targets supported
4831 H8/300 simulator h8300-hitachi-hms or h8300hms
4832 H8/500 simulator h8500-hitachi-hms or h8500hms
4833 SH simulator sh-hitachi-hms or sh
4834 Z8000 simulator z8k-zilog-none or z8ksim
4835 IDT MIPS board over serial line mips-idt-ecoff
4837 Cross-debugging to GO32 targets is supported. It requires a custom
4838 version of the i386-stub.c module which is integrated with the
4839 GO32 memory extender.
4841 * New remote protocols
4843 MIPS remote debugging protocol.
4845 * New source languages supported
4847 This version includes preliminary support for Chill, a Pascal like language
4848 used by telecommunications companies. Chill support is also being integrated
4849 into the GNU compiler, but we don't know when it will be publically available.
4852 *** Changes in GDB-4.8:
4854 * HP Precision Architecture supported
4856 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4857 version of this support was available as a set of patches from the
4858 University of Utah. GDB does not support debugging of programs
4859 compiled with the HP compiler, because HP will not document their file
4860 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4861 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4863 Many problems in the preliminary version have been fixed.
4865 * Faster and better demangling
4867 We have improved template demangling and fixed numerous bugs in the GNU style
4868 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4869 character types (wchar_t) are now supported. Demangling of each symbol is now
4870 only done once, and is cached when the symbol table for a file is read in.
4871 This results in a small increase in memory usage for C programs, a moderate
4872 increase in memory usage for C++ programs, and a fantastic speedup in
4875 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4876 from the specifications in the Annotated Reference Manual, which AT&T's
4877 compiler does not actually implement.
4879 * G++ multiple inheritance compiler problem
4881 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4882 inheritance lattices was reworked to properly discover ambiguities. We
4883 recently found an example which causes this new algorithm to fail in a
4884 very subtle way, producing bad debug information for those classes.
4885 The file 'gcc.patch' (in this directory) can be applied to gcc to
4886 circumvent the problem. A future GCC release will contain a complete
4889 The previous G++ debug info problem (mentioned below for the gdb-4.7
4890 release) is fixed in gcc version 2.3.2.
4892 * Improved configure script
4894 The `configure' script will now attempt to guess your system type if
4895 you don't supply a host system type. The old scheme of supplying a
4896 host system triplet is preferable over using this. All the magic is
4897 done in the new `config.guess' script. Examine it for details.
4899 We have also brought our configure script much more in line with the FSF's
4900 version. It now supports the --with-xxx options. In particular,
4901 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4902 The resulting GDB will not be able to read arbitrary object file formats --
4903 only the format ``expected'' to be used on the configured target system.
4904 We hope to make this the default in a future release.
4906 * Documentation improvements
4908 There's new internal documentation on how to modify GDB, and how to
4909 produce clean changes to the code. We implore people to read it
4910 before submitting changes.
4912 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4913 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4914 `info' files are also provided. To build `info' files from scratch,
4915 you will need the latest `makeinfo' release, which will be available in
4916 a future texinfo-X.Y release.
4918 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4919 We're not sure exactly which versions have this problem, but it has
4920 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4921 or better. If that isn't possible, there is a patch in
4922 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4923 around this problem.
4927 GDB now supports array constants that can be used in expressions typed in by
4928 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4929 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4932 The new directory `gdb/sparclite' contains a program that demonstrates
4933 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4935 * New native hosts supported
4937 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4938 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4940 * New targets supported
4942 AMD 29k family via UDI a29k-amd-udi or udi29k
4944 * New file formats supported
4946 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4947 HPUX core files, and SCO 3.2v2 core files.
4951 Attaching to processes now works again; thanks for the many bug reports.
4953 We have also stomped on a bunch of core dumps caused by
4954 printf_filtered("%s") problems.
4956 We eliminated a copyright problem on the rpc and ptrace header files
4957 for VxWorks, which was discovered at the last minute during the 4.7
4958 release. You should now be able to build a VxWorks GDB.
4960 You can now interrupt gdb while an attached process is running. This
4961 will cause the attached process to stop, and give control back to GDB.
4963 We fixed problems caused by using too many file descriptors
4964 for reading symbols from object files and libraries. This was
4965 especially a problem for programs that used many (~100) shared
4968 The `step' command now only enters a subroutine if there is line number
4969 information for the subroutine. Otherwise it acts like the `next'
4970 command. Previously, `step' would enter subroutines if there was
4971 any debugging information about the routine. This avoids problems
4972 when using `cc -g1' on MIPS machines.
4974 * Internal improvements
4976 GDB's internal interfaces have been improved to make it easier to support
4977 debugging of multiple languages in the future.
4979 GDB now uses a common structure for symbol information internally.
4980 Minimal symbols (derived from linkage symbols in object files), partial
4981 symbols (from a quick scan of debug information), and full symbols
4982 contain a common subset of information, making it easier to write
4983 shared code that handles any of them.
4985 * New command line options
4987 We now accept --silent as an alias for --quiet.
4991 The memory-mapped-malloc library is now licensed under the GNU Library
4992 General Public License.
4994 *** Changes in GDB-4.7:
4996 * Host/native/target split
4998 GDB has had some major internal surgery to untangle the support for
4999 hosts and remote targets. Now, when you configure GDB for a remote
5000 target, it will no longer load in all of the support for debugging
5001 local programs on the host. When fully completed and tested, this will
5002 ensure that arbitrary host/target combinations are possible.
5004 The primary conceptual shift is to separate the non-portable code in
5005 GDB into three categories. Host specific code is required any time GDB
5006 is compiled on that host, regardless of the target. Target specific
5007 code relates to the peculiarities of the target, but can be compiled on
5008 any host. Native specific code is everything else: it can only be
5009 built when the host and target are the same system. Child process
5010 handling and core file support are two common `native' examples.
5012 GDB's use of /proc for controlling Unix child processes is now cleaner.
5013 It has been split out into a single module under the `target_ops' vector,
5014 plus two native-dependent functions for each system that uses /proc.
5016 * New hosts supported
5018 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5019 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5020 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5022 * New targets supported
5024 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5025 68030 and CPU32 m68030-*-*, m68332-*-*
5027 * New native hosts supported
5029 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5030 (386bsd is not well tested yet)
5031 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5033 * New file formats supported
5035 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5036 supports reading of `a.out.adobe' object files, which are an a.out
5037 format extended with minimal information about multiple sections.
5041 `show copying' is the same as the old `info copying'.
5042 `show warranty' is the same as `info warrantee'.
5043 These were renamed for consistency. The old commands continue to work.
5045 `info handle' is a new alias for `info signals'.
5047 You can now define pre-command hooks, which attach arbitrary command
5048 scripts to any command. The commands in the hook will be executed
5049 prior to the user's command. You can also create a hook which will be
5050 executed whenever the program stops. See gdb.texinfo.
5054 We now deal with Cfront style name mangling, and can even extract type
5055 info from mangled symbols. GDB can automatically figure out which
5056 symbol mangling style your C++ compiler uses.
5058 Calling of methods and virtual functions has been improved as well.
5062 The crash that occured when debugging Sun Ansi-C compiled binaries is
5063 fixed. This was due to mishandling of the extra N_SO stabs output
5066 We also finally got Ultrix 4.2 running in house, and fixed core file
5067 support, with help from a dozen people on the net.
5069 John M. Farrell discovered that the reason that single-stepping was so
5070 slow on all of the Mips based platforms (primarily SGI and DEC) was
5071 that we were trying to demangle and lookup a symbol used for internal
5072 purposes on every instruction that was being stepped through. Changing
5073 the name of that symbol so that it couldn't be mistaken for a C++
5074 mangled symbol sped things up a great deal.
5076 Rich Pixley sped up symbol lookups in general by getting much smarter
5077 about when C++ symbol mangling is necessary. This should make symbol
5078 completion (TAB on the command line) much faster. It's not as fast as
5079 we'd like, but it's significantly faster than gdb-4.6.
5083 A new user controllable variable 'call_scratch_address' can
5084 specify the location of a scratch area to be used when GDB
5085 calls a function in the target. This is necessary because the
5086 usual method of putting the scratch area on the stack does not work
5087 in systems that have separate instruction and data spaces.
5089 We integrated changes to support the 29k UDI (Universal Debugger
5090 Interface), but discovered at the last minute that we didn't have all
5091 of the appropriate copyright paperwork. We are working with AMD to
5092 resolve this, and hope to have it available soon.
5096 We have sped up the remote serial line protocol, especially for targets
5097 with lots of registers. It now supports a new `expedited status' ('T')
5098 message which can be used in place of the existing 'S' status message.
5099 This allows the remote stub to send only the registers that GDB
5100 needs to make a quick decision about single-stepping or conditional
5101 breakpoints, eliminating the need to fetch the entire register set for
5102 each instruction being stepped through.
5104 The GDB remote serial protocol now implements a write-through cache for
5105 registers, only re-reading the registers if the target has run.
5107 There is also a new remote serial stub for SPARC processors. You can
5108 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5109 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5110 processor with a serial port.
5114 Configure.in files have become much easier to read and modify. A new
5115 `table driven' format makes it more obvious what configurations are
5116 supported, and what files each one uses.
5120 There is a new opcodes library which will eventually contain all of the
5121 disassembly routines and opcode tables. At present, it only contains
5122 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5123 disassembler (binutils/objdump) to share these routines.
5125 The libiberty library is now copylefted under the GNU Library General
5126 Public License. This allows more liberal use, and was done so libg++
5127 can use it. This makes no difference to GDB, since the Library License
5128 grants all the rights from the General Public License.
5132 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5133 reference to the stabs symbol info used by the debugger. It is (as far
5134 as we know) the only published document on this fascinating topic. We
5135 encourage you to read it, compare it to the stabs information on your
5136 system, and send improvements on the document in general (to
5137 bug-gdb@prep.ai.mit.edu).
5139 And, of course, many bugs have been fixed.
5142 *** Changes in GDB-4.6:
5144 * Better support for C++ function names
5146 GDB now accepts as input the "demangled form" of C++ overloaded function
5147 names and member function names, and can do command completion on such names
5148 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5149 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5150 Make use of command completion, it is your friend.
5152 GDB also now accepts a variety of C++ mangled symbol formats. They are
5153 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5154 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5155 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5156 for the list of formats.
5158 * G++ symbol mangling problem
5160 Recent versions of gcc have a bug in how they emit debugging information for
5161 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5162 directory) can be applied to gcc to fix the problem. Alternatively, if you
5163 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5164 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5165 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5168 * New 'maintenance' command
5170 All of the commands related to hacking GDB internals have been moved out of
5171 the main command set, and now live behind the 'maintenance' command. This
5172 can also be abbreviated as 'mt'. The following changes were made:
5174 dump-me -> maintenance dump-me
5175 info all-breakpoints -> maintenance info breakpoints
5176 printmsyms -> maintenance print msyms
5177 printobjfiles -> maintenance print objfiles
5178 printpsyms -> maintenance print psymbols
5179 printsyms -> maintenance print symbols
5181 The following commands are new:
5183 maintenance demangle Call internal GDB demangler routine to
5184 demangle a C++ link name and prints the result.
5185 maintenance print type Print a type chain for a given symbol
5187 * Change to .gdbinit file processing
5189 We now read the $HOME/.gdbinit file before processing the argv arguments
5190 (e.g. reading symbol files or core files). This allows global parameters to
5191 be set, which will apply during the symbol reading. The ./.gdbinit is still
5192 read after argv processing.
5194 * New hosts supported
5196 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5198 GNU/Linux support i386-unknown-linux or linux
5200 We are also including code to support the HP/PA running BSD and HPUX. This
5201 is almost guaranteed not to work, as we didn't have time to test or build it
5202 for this release. We are including it so that the more adventurous (or
5203 masochistic) of you can play with it. We also had major problems with the
5204 fact that the compiler that we got from HP doesn't support the -g option.
5207 * New targets supported
5209 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5211 * More smarts about finding #include files
5213 GDB now remembers the compilation directory for all include files, and for
5214 all files from which C is generated (like yacc and lex sources). This
5215 greatly improves GDB's ability to find yacc/lex sources, and include files,
5216 especially if you are debugging your program from a directory different from
5217 the one that contains your sources.
5219 We also fixed a bug which caused difficulty with listing and setting
5220 breakpoints in include files which contain C code. (In the past, you had to
5221 try twice in order to list an include file that you hadn't looked at before.)
5223 * Interesting infernals change
5225 GDB now deals with arbitrary numbers of sections, where the symbols for each
5226 section must be relocated relative to that section's landing place in the
5227 target's address space. This work was needed to support ELF with embedded
5228 stabs used by Solaris-2.0.
5230 * Bug fixes (of course!)
5232 There have been loads of fixes for the following things:
5233 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5234 i960, stabs, DOS(GO32), procfs, etc...
5236 See the ChangeLog for details.
5238 *** Changes in GDB-4.5:
5240 * New machines supported (host and target)
5242 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5244 SGI Irix-4.x mips-sgi-irix4 or iris4
5246 * New malloc package
5248 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5249 Mmalloc is capable of handling mutiple heaps of memory. It is also
5250 capable of saving a heap to a file, and then mapping it back in later.
5251 This can be used to greatly speedup the startup of GDB by using a
5252 pre-parsed symbol table which lives in a mmalloc managed heap. For
5253 more details, please read mmalloc/mmalloc.texi.
5257 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5258 'help info proc' for details.
5260 * MIPS ecoff symbol table format
5262 The code that reads MIPS symbol table format is now supported on all hosts.
5263 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5266 * File name changes for MS-DOS
5268 Many files in the config directories have been renamed to make it easier to
5269 support GDB on MS-DOSe systems (which have very restrictive file name
5270 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5271 environment) is close to working but has some remaining problems. Note
5272 that debugging of DOS programs is not supported, due to limitations
5273 in the ``operating system'', but it can be used to host cross-debugging.
5275 * Cross byte order fixes
5277 Many fixes have been made to support cross debugging of Sparc and MIPS
5278 targets from hosts whose byte order differs.
5280 * New -mapped and -readnow options
5282 If memory-mapped files are available on your system through the 'mmap'
5283 system call, you can use the -mapped option on the `file' or
5284 `symbol-file' commands to cause GDB to write the symbols from your
5285 program into a reusable file. If the program you are debugging is
5286 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5287 Future GDB debugging sessions will notice the presence of this file,
5288 and will quickly map in symbol information from it, rather than reading
5289 the symbol table from the executable program. Using the '-mapped'
5290 option in a GDB `file' or `symbol-file' command has the same effect as
5291 starting GDB with the '-mapped' command-line option.
5293 You can cause GDB to read the entire symbol table immediately by using
5294 the '-readnow' option with any of the commands that load symbol table
5295 information (or on the GDB command line). This makes the command
5296 slower, but makes future operations faster.
5298 The -mapped and -readnow options are typically combined in order to
5299 build a `fred.syms' file that contains complete symbol information.
5300 A simple GDB invocation to do nothing but build a `.syms' file for future
5303 gdb -batch -nx -mapped -readnow programname
5305 The `.syms' file is specific to the host machine on which GDB is run.
5306 It holds an exact image of GDB's internal symbol table. It cannot be
5307 shared across multiple host platforms.
5309 * longjmp() handling
5311 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5312 siglongjmp() without losing control. This feature has not yet been ported to
5313 all systems. It currently works on many 386 platforms, all MIPS-based
5314 platforms (SGI, DECstation, etc), and Sun3/4.
5318 Preliminary work has been put in to support the new Solaris OS from Sun. At
5319 this time, it can control and debug processes, but it is not capable of
5324 As always, many many bug fixes. The major areas were with g++, and mipsread.
5325 People using the MIPS-based platforms should experience fewer mysterious
5326 crashes and trashed symbol tables.
5328 *** Changes in GDB-4.4:
5330 * New machines supported (host and target)
5332 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5334 BSD Reno on Vax vax-dec-bsd
5335 Ultrix on Vax vax-dec-ultrix
5337 * New machines supported (target)
5339 AMD 29000 embedded, using EBMON a29k-none-none
5343 GDB continues to improve its handling of C++. `References' work better.
5344 The demangler has also been improved, and now deals with symbols mangled as
5345 per the Annotated C++ Reference Guide.
5347 GDB also now handles `stabs' symbol information embedded in MIPS
5348 `ecoff' symbol tables. Since the ecoff format was not easily
5349 extensible to handle new languages such as C++, this appeared to be a
5350 good way to put C++ debugging info into MIPS binaries. This option
5351 will be supported in the GNU C compiler, version 2, when it is
5354 * New features for SVR4
5356 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5357 shared libraries. Debugging dynamically linked programs should present
5358 only minor differences from debugging statically linked programs.
5360 The `info proc' command will print out information about any process
5361 on an SVR4 system (including the one you are debugging). At the moment,
5362 it prints the address mappings of the process.
5364 If you bring up GDB on another SVR4 system, please send mail to
5365 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5367 * Better dynamic linking support in SunOS
5369 Reading symbols from shared libraries which contain debugging symbols
5370 now works properly. However, there remain issues such as automatic
5371 skipping of `transfer vector' code during function calls, which
5372 make it harder to debug code in a shared library, than to debug the
5373 same code linked statically.
5377 GDB is now using the latest `getopt' routines from the FSF. This
5378 version accepts the -- prefix for options with long names. GDB will
5379 continue to accept the old forms (-option and +option) as well.
5380 Various single letter abbreviations for options have been explicity
5381 added to the option table so that they won't get overshadowed in the
5382 future by other options that begin with the same letter.
5386 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5387 Many assorted bugs have been handled. Many more remain to be handled.
5388 See the various ChangeLog files (primarily in gdb and bfd) for details.
5391 *** Changes in GDB-4.3:
5393 * New machines supported (host and target)
5395 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5396 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5397 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5399 * Almost SCO Unix support
5401 We had hoped to support:
5402 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5403 (except for core file support), but we discovered very late in the release
5404 that it has problems with process groups that render gdb unusable. Sorry
5405 about that. I encourage people to fix it and post the fixes.
5407 * Preliminary ELF and DWARF support
5409 GDB can read ELF object files on System V Release 4, and can handle
5410 debugging records for C, in DWARF format, in ELF files. This support
5411 is preliminary. If you bring up GDB on another SVR4 system, please
5412 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5417 GDB now uses the latest `readline' library. One user-visible change
5418 is that two tabs will list possible command completions, which previously
5419 required typing M-? (meta-question mark, or ESC ?).
5423 The `stepi' bug that many of you noticed has been squashed.
5424 Many bugs in C++ have been handled. Many more remain to be handled.
5425 See the various ChangeLog files (primarily in gdb and bfd) for details.
5427 * State of the MIPS world (in case you wondered):
5429 GDB can understand the symbol tables emitted by the compilers
5430 supplied by most vendors of MIPS-based machines, including DEC. These
5431 symbol tables are in a format that essentially nobody else uses.
5433 Some versions of gcc come with an assembler post-processor called
5434 mips-tfile. This program is required if you want to do source-level
5435 debugging of gcc-compiled programs. I believe FSF does not ship
5436 mips-tfile with gcc version 1, but it will eventually come with gcc
5439 Debugging of g++ output remains a problem. g++ version 1.xx does not
5440 really support it at all. (If you're lucky, you should be able to get
5441 line numbers and stack traces to work, but no parameters or local
5442 variables.) With some work it should be possible to improve the
5445 When gcc version 2 is released, you will have somewhat better luck.
5446 However, even then you will get confusing results for inheritance and
5449 We will eventually provide full debugging of g++ output on
5450 DECstations. This will probably involve some kind of stabs-in-ecoff
5451 encapulation, but the details have not been worked out yet.
5454 *** Changes in GDB-4.2:
5456 * Improved configuration
5458 Only one copy of `configure' exists now, and it is not self-modifying.
5459 Porting BFD is simpler.
5463 The `step' and `next' commands now only stop at the first instruction
5464 of a source line. This prevents the multiple stops that used to occur
5465 in switch statements, for-loops, etc. `Step' continues to stop if a
5466 function that has debugging information is called within the line.
5470 Lots of small bugs fixed. More remain.
5472 * New host supported (not target)
5474 Intel 386 PC clone running Mach i386-none-mach
5477 *** Changes in GDB-4.1:
5479 * Multiple source language support
5481 GDB now has internal scaffolding to handle several source languages.
5482 It determines the type of each source file from its filename extension,
5483 and will switch expression parsing and number formatting to match the
5484 language of the function in the currently selected stack frame.
5485 You can also specifically set the language to be used, with
5486 `set language c' or `set language modula-2'.
5490 GDB now has preliminary support for the GNU Modula-2 compiler,
5491 currently under development at the State University of New York at
5492 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5493 continue through the fall of 1991 and into 1992.
5495 Other Modula-2 compilers are currently not supported, and attempting to
5496 debug programs compiled with them will likely result in an error as the
5497 symbol table is read. Feel free to work on it, though!
5499 There are hooks in GDB for strict type checking and range checking,
5500 in the `Modula-2 philosophy', but they do not currently work.
5504 GDB can now write to executable and core files (e.g. patch
5505 a variable's value). You must turn this switch on, specify
5506 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5507 by assigning a new value to a variable. Modifications take
5510 * Automatic SunOS shared library reading
5512 When you run your program, GDB automatically determines where its
5513 shared libraries (if any) have been loaded, and reads their symbols.
5514 The `share' command is no longer needed. This also works when
5515 examining core files.
5519 You can specify the number of lines that the `list' command shows.
5522 * New machines supported (host and target)
5524 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5525 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5526 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5528 * New hosts supported (not targets)
5530 IBM RT/PC: romp-ibm-aix or rtpc
5532 * New targets supported (not hosts)
5534 AMD 29000 embedded with COFF a29k-none-coff
5535 AMD 29000 embedded with a.out a29k-none-aout
5536 Ultracomputer remote kernel debug a29k-nyu-kern
5538 * New remote interfaces
5544 *** Changes in GDB-4.0:
5548 Wide output is wrapped at good places to make the output more readable.
5550 Gdb now supports cross-debugging from a host machine of one type to a
5551 target machine of another type. Communication with the target system
5552 is over serial lines. The ``target'' command handles connecting to the
5553 remote system; the ``load'' command will download a program into the
5554 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5555 also supports debugging of realtime processes running under VxWorks,
5556 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5557 stub on the target system.
5559 New CPUs supported include the AMD 29000 and Intel 960.
5561 GDB now reads object files and symbol tables via a ``binary file''
5562 library, which allows a single copy of GDB to debug programs of multiple
5563 object file types such as a.out and coff.
5565 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5566 refcard.dvi and refcard.ps are available to format it).
5569 * Control-Variable user interface simplified
5571 All variables that control the operation of the debugger can be set
5572 by the ``set'' command, and displayed by the ``show'' command.
5574 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5575 ``Show prompt'' produces the response:
5576 Gdb's prompt is new-gdb=>.
5578 What follows are the NEW set commands. The command ``help set'' will
5579 print a complete list of old and new set commands. ``help set FOO''
5580 will give a longer description of the variable FOO. ``show'' will show
5581 all of the variable descriptions and their current settings.
5583 confirm on/off: Enables warning questions for operations that are
5584 hard to recover from, e.g. rerunning the program while
5585 it is already running. Default is ON.
5587 editing on/off: Enables EMACS style command line editing
5588 of input. Previous lines can be recalled with
5589 control-P, the current line can be edited with control-B,
5590 you can search for commands with control-R, etc.
5593 history filename NAME: NAME is where the gdb command history
5594 will be stored. The default is .gdb_history,
5595 or the value of the environment variable
5598 history size N: The size, in commands, of the command history. The
5599 default is 256, or the value of the environment variable
5602 history save on/off: If this value is set to ON, the history file will
5603 be saved after exiting gdb. If set to OFF, the
5604 file will not be saved. The default is OFF.
5606 history expansion on/off: If this value is set to ON, then csh-like
5607 history expansion will be performed on
5608 command line input. The default is OFF.
5610 radix N: Sets the default radix for input and output. It can be set
5611 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5612 in the current radix, so "set radix 10" is always a no-op.
5614 height N: This integer value is the number of lines on a page. Default
5615 is 24, the current `stty rows'' setting, or the ``li#''
5616 setting from the termcap entry matching the environment
5619 width N: This integer value is the number of characters on a line.
5620 Default is 80, the current `stty cols'' setting, or the ``co#''
5621 setting from the termcap entry matching the environment
5624 Note: ``set screensize'' is obsolete. Use ``set height'' and
5625 ``set width'' instead.
5627 print address on/off: Print memory addresses in various command displays,
5628 such as stack traces and structure values. Gdb looks
5629 more ``symbolic'' if you turn this off; it looks more
5630 ``machine level'' with it on. Default is ON.
5632 print array on/off: Prettyprint arrays. New convenient format! Default
5635 print demangle on/off: Print C++ symbols in "source" form if on,
5638 print asm-demangle on/off: Same, for assembler level printouts
5641 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5644 * Support for Epoch Environment.
5646 The epoch environment is a version of Emacs v18 with windowing. One
5647 new command, ``inspect'', is identical to ``print'', except that if you
5648 are running in the epoch environment, the value is printed in its own
5652 * Support for Shared Libraries
5654 GDB can now debug programs and core files that use SunOS shared libraries.
5655 Symbols from a shared library cannot be referenced
5656 before the shared library has been linked with the program (this
5657 happens after you type ``run'' and before the function main() is entered).
5658 At any time after this linking (including when examining core files
5659 from dynamically linked programs), gdb reads the symbols from each
5660 shared library when you type the ``sharedlibrary'' command.
5661 It can be abbreviated ``share''.
5663 sharedlibrary REGEXP: Load shared object library symbols for files
5664 matching a unix regular expression. No argument
5665 indicates to load symbols for all shared libraries.
5667 info sharedlibrary: Status of loaded shared libraries.
5672 A watchpoint stops execution of a program whenever the value of an
5673 expression changes. Checking for this slows down execution
5674 tremendously whenever you are in the scope of the expression, but is
5675 quite useful for catching tough ``bit-spreader'' or pointer misuse
5676 problems. Some machines such as the 386 have hardware for doing this
5677 more quickly, and future versions of gdb will use this hardware.
5679 watch EXP: Set a watchpoint (breakpoint) for an expression.
5681 info watchpoints: Information about your watchpoints.
5683 delete N: Deletes watchpoint number N (same as breakpoints).
5684 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5685 enable N: Re-enables watchpoint number N (same as breakpoints).
5688 * C++ multiple inheritance
5690 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5693 * C++ exception handling
5695 Gdb now supports limited C++ exception handling. Besides the existing
5696 ability to breakpoint on an exception handler, gdb can breakpoint on
5697 the raising of an exception (before the stack is peeled back to the
5700 catch FOO: If there is a FOO exception handler in the dynamic scope,
5701 set a breakpoint to catch exceptions which may be raised there.
5702 Multiple exceptions (``catch foo bar baz'') may be caught.
5704 info catch: Lists all exceptions which may be caught in the
5705 current stack frame.
5708 * Minor command changes
5710 The command ``call func (arg, arg, ...)'' now acts like the print
5711 command, except it does not print or save a value if the function's result
5712 is void. This is similar to dbx usage.
5714 The ``up'' and ``down'' commands now always print the frame they end up
5715 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5716 frames without printing.
5718 * New directory command
5720 'dir' now adds directories to the FRONT of the source search path.
5721 The path starts off empty. Source files that contain debug information
5722 about the directory in which they were compiled can be found even
5723 with an empty path; Sun CC and GCC include this information. If GDB can't
5724 find your source file in the current directory, type "dir .".
5726 * Configuring GDB for compilation
5728 For normal use, type ``./configure host''. See README or gdb.texinfo
5731 GDB now handles cross debugging. If you are remotely debugging between
5732 two different machines, type ``./configure host -target=targ''.
5733 Host is the machine where GDB will run; targ is the machine
5734 where the program that you are debugging will run.
5736 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.
5738 * Support for Intel(R) AVX-512 registers on GNU/Linux.
5740 Support displaying and modifying Intel(R) AVX-512 registers $zmm0 - $zmm31 and
5741 $k0 - $k7 on GNU/Linux.