1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.7
6 * The 'record instruction-history' command now starts counting instructions
7 at one. This also affects the instruction ranges reported by the
8 'record function-call-history' command when given the /i modifier.
10 * The command 'record function-call-history' supports a new modifier '/c' to
11 indent the function names based on their call stack depth.
12 The fields for the '/i' and '/l' modifier have been reordered.
13 The source line range is now prefixed with 'at'.
14 The instruction range is now prefixed with 'inst'.
15 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
16 "record instruction-history" and "list" commands.
18 * The ranges given as arguments to the 'record function-call-history' and
19 'record instruction-history' commands are now inclusive.
21 *** Changes in GDB 7.7
23 * Improved support for process record-replay and reverse debugging on
24 arm*-linux* targets. Support for thumb32 and syscall instruction
25 recording has been added.
27 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
29 * GDB now supports Fission DWP file format version 2.
30 http://gcc.gnu.org/wiki/DebugFission
32 * New convenience function "$_isvoid", to check whether an expression
33 is void. A void expression is an expression where the type of the
34 result is "void". For example, some convenience variables may be
35 "void" when evaluated (e.g., "$_exitcode" before the execution of
36 the program being debugged; or an undefined convenience variable).
37 Another example, when calling a function whose return type is
40 * The "maintenance print objfiles" command now takes an optional regexp.
42 * The "catch syscall" command now works on arm*-linux* targets.
44 * GDB now consistently shows "<not saved>" when printing values of
45 registers the debug info indicates have not been saved in the frame
46 and there's nowhere to retrieve them from
47 (callee-saved/call-clobbered registers):
52 (gdb) info registers rax
55 Before, the former would print "<optimized out>", and the latter
56 "*value not available*".
58 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
63 ** Frame filters and frame decorators have been added.
64 ** Temporary breakpoints are now supported.
65 ** Line tables representation has been added.
66 ** New attribute 'parent_type' for gdb.Field objects.
67 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
68 ** New attribute 'name' for gdb.Type objects.
72 Nios II ELF nios2*-*-elf
73 Nios II GNU/Linux nios2*-*-linux
74 Texas Instruments MSP430 msp430*-*-elf
76 * Removed native configurations
78 Support for these a.out NetBSD and OpenBSD obsolete configurations has
79 been removed. ELF variants of these configurations are kept supported.
81 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
82 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
83 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
84 i[34567]86-*-openbsd3.[0-3]
85 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
86 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
87 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
91 Like "catch throw", but catches a re-thrown exception.
93 Renamed from old "maint check-symtabs".
95 Perform consistency checks on symtabs.
97 Expand symtabs matching an optional regexp.
100 Display the details of GDB configure-time options.
102 maint set|show per-command
103 maint set|show per-command space
104 maint set|show per-command time
105 maint set|show per-command symtab
106 Enable display of per-command gdb resource usage.
108 remove-symbol-file FILENAME
109 remove-symbol-file -a ADDRESS
110 Remove a symbol file added via add-symbol-file. The file to remove
111 can be identified by its filename or by an address that lies within
112 the boundaries of this symbol file in memory.
115 info exceptions REGEXP
116 Display the list of Ada exceptions defined in the program being
117 debugged. If provided, only the exceptions whose names match REGEXP
122 set debug symfile off|on
124 Control display of debugging info regarding reading symbol files and
125 symbol tables within those files
127 set print raw frame-arguments
128 show print raw frame-arguments
129 Set/show whether to print frame arguments in raw mode,
130 disregarding any defined pretty-printers.
132 set remote trace-status-packet
133 show remote trace-status-packet
134 Set/show the use of remote protocol qTStatus packet.
138 Control display of debugging messages related to Nios II targets.
142 Control whether target-assisted range stepping is enabled.
144 set startup-with-shell
145 show startup-with-shell
146 Specifies whether Unix child processes are started via a shell or
151 Use the target memory cache for accesses to the code segment. This
152 improves performance of remote debugging (particularly disassembly).
154 * You can now use a literal value 'unlimited' for options that
155 interpret 0 or -1 as meaning "unlimited". E.g., "set
156 trace-buffer-size unlimited" is now an alias for "set
157 trace-buffer-size -1" and "set height unlimited" is now an alias for
160 * The "set debug symtab-create" debugging option of GDB has been changed to
161 accept a verbosity level. 0 means "off", 1 provides basic debugging
162 output, and values of 2 or greater provides more verbose output.
164 * New command-line options
166 Display the details of GDB configure-time options.
168 * The command 'tsave' can now support new option '-ctf' to save trace
169 buffer in Common Trace Format.
171 * Newly installed $prefix/bin/gcore acts as a shell interface for the
174 * GDB now implements the the C++ 'typeid' operator.
176 * The new convenience variable $_exception holds the exception being
177 thrown or caught at an exception-related catchpoint.
179 * The exception-related catchpoints, like "catch throw", now accept a
180 regular expression which can be used to filter exceptions by type.
182 * The new convenience variable $_exitsignal is automatically set to
183 the terminating signal number when the program being debugged dies
184 due to an uncaught signal.
188 ** All MI commands now accept an optional "--language" option.
189 Support for this feature can be verified by using the "-list-features"
190 command, which should contain "language-option".
192 ** The new command -info-gdb-mi-command allows the user to determine
193 whether a GDB/MI command is supported or not.
195 ** The "^error" result record returned when trying to execute an undefined
196 GDB/MI command now provides a variable named "code" whose content is the
197 "undefined-command" error code. Support for this feature can be verified
198 by using the "-list-features" command, which should contain
199 "undefined-command-error-code".
201 ** The -trace-save MI command can optionally save trace buffer in Common
204 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
206 ** The command -data-list-register-values now accepts an optional
207 "--skip-unavailable" option. When used, only the available registers
210 ** The new command -trace-frame-collected dumps collected variables,
211 computed expressions, tvars, memory and registers in a traceframe.
213 ** The commands -stack-list-locals, -stack-list-arguments and
214 -stack-list-variables now accept an option "--skip-unavailable".
215 When used, only the available locals or arguments are displayed.
217 ** The -exec-run command now accepts an optional "--start" option.
218 When used, the command follows the same semantics as the "start"
219 command, stopping the program's execution at the start of its
220 main subprogram. Support for this feature can be verified using
221 the "-list-features" command, which should contain
222 "exec-run-start-option".
224 ** The new commands -catch-assert and -catch-exceptions insert
225 catchpoints stopping the program when Ada exceptions are raised.
227 ** The new command -info-ada-exceptions provides the equivalent of
228 the new "info exceptions" command.
230 * New system-wide configuration scripts
231 A GDB installation now provides scripts suitable for use as system-wide
232 configuration scripts for the following systems:
236 * GDB now supports target-assigned range stepping with remote targets.
237 This improves the performance of stepping source lines by reducing
238 the number of control packets from/to GDB. See "New remote packets"
241 * GDB now understands the element 'tvar' in the XML traceframe info.
242 It has the id of the collected trace state variables.
244 * On S/390 targets that provide the transactional-execution feature,
245 the program interruption transaction diagnostic block (TDB) is now
246 represented as a number of additional "registers" in GDB.
252 The vCont packet supports a new 'r' action, that tells the remote
253 stub to step through an address range itself, without GDB
254 involvemement at each single-step.
256 qXfer:libraries-svr4:read's annex
257 The previously unused annex of the qXfer:libraries-svr4:read packet
258 is now used to support passing an argument list. The remote stub
259 reports support for this argument list to GDB's qSupported query.
260 The defined arguments are "start" and "prev", used to reduce work
261 necessary for library list updating, resulting in significant
264 * New features in the GDB remote stub, GDBserver
266 ** GDBserver now supports target-assisted range stepping. Currently
267 enabled on x86/x86_64 GNU/Linux targets.
269 ** GDBserver now adds element 'tvar' in the XML in the reply to
270 'qXfer:traceframe-info:read'. It has the id of the collected
271 trace state variables.
273 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
276 * New 'z' formatter for printing and examining memory, this displays the
277 value as hexadecimal zero padded on the left to the size of the type.
279 * GDB can now use Windows x64 unwinding data.
281 * The "set remotebaud" command has been replaced by "set serial baud".
282 Similarly, "show remotebaud" has been replaced by "show serial baud".
283 The "set remotebaud" and "show remotebaud" commands are still available
284 to provide backward compatibility with older versions of GDB.
286 *** Changes in GDB 7.6
288 * Target record has been renamed to record-full.
289 Record/replay is now enabled with the "record full" command.
290 This also affects settings that are associated with full record/replay
291 that have been moved from "set/show record" to "set/show record full":
293 set|show record full insn-number-max
294 set|show record full stop-at-limit
295 set|show record full memory-query
297 * A new record target "record-btrace" has been added. The new target
298 uses hardware support to record the control-flow of a process. It
299 does not support replaying the execution, but it implements the
300 below new commands for investigating the recorded execution log.
301 This new recording method can be enabled using:
305 The "record-btrace" target is only available on Intel Atom processors
306 and requires a Linux kernel 2.6.32 or later.
308 * Two new commands have been added for record/replay to give information
309 about the recorded execution without having to replay the execution.
310 The commands are only supported by "record btrace".
312 record instruction-history prints the execution history at
313 instruction granularity
315 record function-call-history prints the execution history at
318 * New native configurations
320 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
321 FreeBSD/powerpc powerpc*-*-freebsd
322 x86_64/Cygwin x86_64-*-cygwin*
323 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
327 ARM AArch64 aarch64*-*-elf
328 ARM AArch64 GNU/Linux aarch64*-*-linux
329 Lynx 178 PowerPC powerpc-*-lynx*178
330 x86_64/Cygwin x86_64-*-cygwin*
331 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
333 * If the configured location of system.gdbinit file (as given by the
334 --with-system-gdbinit option at configure time) is in the
335 data-directory (as specified by --with-gdb-datadir at configure
336 time) or in one of its subdirectories, then GDB will look for the
337 system-wide init file in the directory specified by the
338 --data-directory command-line option.
340 * New command line options:
342 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
343 other initialization files, unlike -nx which disables all of them.
345 * Removed command line options
347 -epoch This was used by the gdb mode in Epoch, an ancient fork of
350 * The 'ptype' and 'whatis' commands now accept an argument to control
353 * 'info proc' now works on some core files.
357 ** Vectors can be created with gdb.Type.vector.
359 ** Python's atexit.register now works in GDB.
361 ** Types can be pretty-printed via a Python API.
363 ** Python 3 is now supported (in addition to Python 2.4 or later)
365 ** New class gdb.Architecture exposes GDB's internal representation
366 of architecture in the Python API.
368 ** New method Frame.architecture returns the gdb.Architecture object
369 corresponding to the frame's architecture.
371 * New Python-based convenience functions:
373 ** $_memeq(buf1, buf2, length)
374 ** $_streq(str1, str2)
376 ** $_regex(str, regex)
378 * The 'cd' command now defaults to using '~' (the home directory) if not
381 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
382 default for GCC since November 2000.
384 * The command 'forward-search' can now be abbreviated as 'fo'.
386 * The command 'info tracepoints' can now display 'installed on target'
387 or 'not installed on target' for each non-pending location of tracepoint.
389 * New configure options
391 --enable-libmcheck/--disable-libmcheck
392 By default, development versions are built with -lmcheck on hosts
393 that support it, in order to help track memory corruption issues.
394 Release versions, on the other hand, are built without -lmcheck
395 by default. The --enable-libmcheck/--disable-libmcheck configure
396 options allow the user to override that default.
397 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
398 This configure option allows the user to build GDB with
399 libbabeltrace using which GDB can read Common Trace Format data.
401 * New commands (for set/show, see "New options" below)
404 Catch signals. This is similar to "handle", but allows commands and
405 conditions to be attached.
408 List the BFDs known to GDB.
410 python-interactive [command]
412 Start a Python interactive prompt, or evaluate the optional command
413 and print the result of expressions.
416 "py" is a new alias for "python".
418 enable type-printer [name]...
419 disable type-printer [name]...
420 Enable or disable type printers.
424 ** For the Renesas Super-H architecture, the "regs" command has been removed
425 (has been deprecated in GDB 7.5), and "info all-registers" should be used
430 set print type methods (on|off)
431 show print type methods
432 Control whether method declarations are displayed by "ptype".
433 The default is to show them.
435 set print type typedefs (on|off)
436 show print type typedefs
437 Control whether typedef definitions are displayed by "ptype".
438 The default is to show them.
440 set filename-display basename|relative|absolute
441 show filename-display
442 Control the way in which filenames is displayed.
443 The default is "relative", which preserves previous behavior.
445 set trace-buffer-size
446 show trace-buffer-size
447 Request target to change the size of trace buffer.
449 set remote trace-buffer-size-packet auto|on|off
450 show remote trace-buffer-size-packet
451 Control the use of the remote protocol `QTBuffer:size' packet.
455 Control display of debugging messages related to ARM AArch64.
458 set debug coff-pe-read
459 show debug coff-pe-read
460 Control display of debugging messages related to reading of COFF/PE
465 Control display of debugging messages related to Mach-O symbols
468 set debug notification
469 show debug notification
470 Control display of debugging info for async remote notification.
474 ** Command parameter changes are now notified using new async record
475 "=cmd-param-changed".
476 ** Trace frame changes caused by command "tfind" are now notified using
477 new async record "=traceframe-changed".
478 ** The creation, deletion and modification of trace state variables
479 are now notified using new async records "=tsv-created",
480 "=tsv-deleted" and "=tsv-modified".
481 ** The start and stop of process record are now notified using new
482 async record "=record-started" and "=record-stopped".
483 ** Memory changes are now notified using new async record
485 ** The data-disassemble command response will include a "fullname" field
486 containing the absolute file name when source has been requested.
487 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
488 command, to allow pattern filling of memory areas.
489 ** New commands "-catch-load"/"-catch-unload" added for intercepting
490 library load/unload events.
491 ** The response to breakpoint commands and breakpoint async records
492 includes an "installed" field containing a boolean state about each
493 non-pending tracepoint location is whether installed on target or not.
494 ** Output of the "-trace-status" command includes a "trace-file" field
495 containing the name of the trace file being examined. This field is
496 optional, and only present when examining a trace file.
497 ** The "fullname" field is now always present along with the "file" field,
498 even if the file cannot be found by GDB.
500 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
501 You must have the LZMA library available when configuring GDB for this
502 feature to be enabled. For more information, see:
503 http://fedoraproject.org/wiki/Features/MiniDebugInfo
508 Set the size of trace buffer. The remote stub reports support for this
509 packet to gdb's qSupported query.
512 Enable Branch Trace Store (BTS)-based branch tracing for the current
513 thread. The remote stub reports support for this packet to gdb's
517 Disable branch tracing for the current thread. The remote stub reports
518 support for this packet to gdb's qSupported query.
521 Read the traced branches for the current thread. The remote stub
522 reports support for this packet to gdb's qSupported query.
524 *** Changes in GDB 7.5
526 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
527 for more x32 ABI info.
529 * GDB now supports access to MIPS DSP registers on Linux targets.
531 * GDB now supports debugging microMIPS binaries.
533 * The "info os" command on GNU/Linux can now display information on
534 several new classes of objects managed by the operating system:
535 "info os procgroups" lists process groups
536 "info os files" lists file descriptors
537 "info os sockets" lists internet-domain sockets
538 "info os shm" lists shared-memory regions
539 "info os semaphores" lists semaphores
540 "info os msg" lists message queues
541 "info os modules" lists loaded kernel modules
543 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
544 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
545 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
546 options and inspect the probe arguments using the new $_probe_arg family
547 of convenience variables. You can obtain more information about SystemTap
548 in <http://sourceware.org/systemtap/>.
550 * GDB now supports reversible debugging on ARM, it allows you to
551 debug basic ARM and THUMB instructions, and provides
552 record/replay support.
554 * The option "symbol-reloading" has been deleted as it is no longer used.
558 ** GDB commands implemented in Python can now be put in command class
561 ** The "maint set python print-stack on|off" is now deleted.
563 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
564 apply "flag enum"-style pretty-printing to any enum.
566 ** gdb.lookup_symbol can now work when there is no current frame.
568 ** gdb.Symbol now has a 'line' attribute, holding the line number in
569 the source at which the symbol was defined.
571 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
572 method 'value'. The former indicates whether the symbol needs a
573 frame in order to compute its value, and the latter computes the
576 ** A new method 'referenced_value' on gdb.Value objects which can
577 dereference pointer as well as C++ reference values.
579 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
580 which return the global and static blocks (as gdb.Block objects),
581 of the underlying symbol table, respectively.
583 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
584 object associated with a PC value.
586 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
587 of the address range occupied by code for the current source line.
589 * Go language support.
590 GDB now supports debugging programs written in the Go programming
593 * GDBserver now supports stdio connections.
594 E.g. (gdb) target remote | ssh myhost gdbserver - hello
596 * The binary "gdbtui" can no longer be built or installed.
597 Use "gdb -tui" instead.
599 * GDB will now print "flag" enums specially. A flag enum is one where
600 all the enumerator values have no bits in common when pairwise
601 "and"ed. When printing a value whose type is a flag enum, GDB will
602 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
603 (gdb) print (enum E) 3
606 * The filename part of a linespec will now match trailing components
607 of a source file name. For example, "break gcc/expr.c:1000" will
608 now set a breakpoint in build/gcc/expr.c, but not
611 * The "info proc" and "generate-core-file" commands will now also
612 work on remote targets connected to GDBserver on Linux.
614 * The command "info catch" has been removed. It has been disabled
617 * The "catch exception" and "catch assert" commands now accept
618 a condition at the end of the command, much like the "break"
619 command does. For instance:
621 (gdb) catch exception Constraint_Error if Barrier = True
623 Previously, it was possible to add a condition to such catchpoints,
624 but it had to be done as a second step, after the catchpoint had been
625 created, using the "condition" command.
627 * The "info static-tracepoint-marker" command will now also work on
628 native Linux targets with in-process agent.
630 * GDB can now set breakpoints on inlined functions.
632 * The .gdb_index section has been updated to include symbols for
633 inlined functions. GDB will ignore older .gdb_index sections by
634 default, which could cause symbol files to be loaded more slowly
635 until their .gdb_index sections can be recreated. The new command
636 "set use-deprecated-index-sections on" will cause GDB to use any older
637 .gdb_index sections it finds. This will restore performance, but the
638 ability to set breakpoints on inlined functions will be lost in symbol
639 files with older .gdb_index sections.
641 The .gdb_index section has also been updated to record more information
642 about each symbol. This speeds up the "info variables", "info functions"
643 and "info types" commands when used with programs having the .gdb_index
644 section, as well as speeding up debugging with shared libraries using
645 the .gdb_index section.
647 * Ada support for GDB/MI Variable Objects has been added.
649 * GDB can now support 'breakpoint always-inserted mode' in 'record'
654 ** New command -info-os is the MI equivalent of "info os".
656 ** Output logs ("set logging" and related) now include MI output.
660 ** "set use-deprecated-index-sections on|off"
661 "show use-deprecated-index-sections on|off"
662 Controls the use of deprecated .gdb_index sections.
664 ** "catch load" and "catch unload" can be used to stop when a shared
665 library is loaded or unloaded, respectively.
667 ** "enable count" can be used to auto-disable a breakpoint after
670 ** "info vtbl" can be used to show the virtual method tables for
671 C++ and Java objects.
673 ** "explore" and its sub commands "explore value" and "explore type"
674 can be used to recursively explore values and types of
675 expressions. These commands are available only if GDB is
676 configured with '--with-python'.
678 ** "info auto-load" shows status of all kinds of auto-loaded files,
679 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
680 sequences of commands files, "info auto-load python-scripts"
681 shows status of auto-loading Python script files,
682 "info auto-load local-gdbinit" shows status of loading init file
683 (.gdbinit) from current directory and "info auto-load libthread-db" shows
684 status of inferior specific thread debugging shared library loading.
686 ** "info auto-load-scripts", "set auto-load-scripts on|off"
687 and "show auto-load-scripts" commands have been deprecated, use their
688 "info auto-load python-scripts", "set auto-load python-scripts on|off"
689 and "show auto-load python-scripts" counterparts instead.
691 ** "dprintf location,format,args..." creates a dynamic printf, which
692 is basically a breakpoint that does a printf and immediately
693 resumes your program's execution, so it is like a printf that you
694 can insert dynamically at runtime instead of at compiletime.
696 ** "set print symbol"
698 Controls whether GDB attempts to display the symbol, if any,
699 corresponding to addresses it prints. This defaults to "on", but
700 you can set it to "off" to restore GDB's previous behavior.
702 * Deprecated commands
704 ** For the Renesas Super-H architecture, the "regs" command has been
705 deprecated, and "info all-registers" should be used instead.
709 Renesas RL78 rl78-*-elf
710 HP OpenVMS ia64 ia64-hp-openvms*
712 * GDBserver supports evaluation of breakpoint conditions. When
713 support is advertised by GDBserver, GDB may be told to send the
714 breakpoint conditions in bytecode form to GDBserver. GDBserver
715 will only report the breakpoint trigger to GDB when its condition
721 show mips compression
722 Select the compressed ISA encoding used in functions that have no symbol
723 information available. The encoding can be set to either of:
726 and is updated automatically from ELF file flags if available.
728 set breakpoint condition-evaluation
729 show breakpoint condition-evaluation
730 Control whether breakpoint conditions are evaluated by GDB ("host") or by
731 GDBserver ("target"). Default option "auto" chooses the most efficient
733 This option can improve debugger efficiency depending on the speed of the
737 Disable auto-loading globally.
740 Show auto-loading setting of all kinds of auto-loaded files.
742 set auto-load gdb-scripts on|off
743 show auto-load gdb-scripts
744 Control auto-loading of GDB canned sequences of commands files.
746 set auto-load python-scripts on|off
747 show auto-load python-scripts
748 Control auto-loading of Python script files.
750 set auto-load local-gdbinit on|off
751 show auto-load local-gdbinit
752 Control loading of init file (.gdbinit) from current directory.
754 set auto-load libthread-db on|off
755 show auto-load libthread-db
756 Control auto-loading of inferior specific thread debugging shared library.
758 set auto-load scripts-directory <dir1>[:<dir2>...]
759 show auto-load scripts-directory
760 Set a list of directories from which to load auto-loaded scripts.
761 Automatically loaded Python scripts and GDB scripts are located in one
762 of the directories listed by this option.
763 The delimiter (':' above) may differ according to the host platform.
765 set auto-load safe-path <dir1>[:<dir2>...]
766 show auto-load safe-path
767 Set a list of directories from which it is safe to auto-load files.
768 The delimiter (':' above) may differ according to the host platform.
770 set debug auto-load on|off
772 Control display of debugging info for auto-loading the files above.
774 set dprintf-style gdb|call|agent
776 Control the way in which a dynamic printf is performed; "gdb"
777 requests a GDB printf command, while "call" causes dprintf to call a
778 function in the inferior. "agent" requests that the target agent
779 (such as GDBserver) do the printing.
781 set dprintf-function <expr>
782 show dprintf-function
783 set dprintf-channel <expr>
785 Set the function and optional first argument to the call when using
786 the "call" style of dynamic printf.
788 set disconnected-dprintf on|off
789 show disconnected-dprintf
790 Control whether agent-style dynamic printfs continue to be in effect
791 after GDB disconnects.
793 * New configure options
796 Configure default value for the 'set auto-load scripts-directory'
797 setting above. It defaults to '$debugdir:$datadir/auto-load',
798 $debugdir representing global debugging info directories (available
799 via 'show debug-file-directory') and $datadir representing GDB's data
800 directory (available via 'show data-directory').
802 --with-auto-load-safe-path
803 Configure default value for the 'set auto-load safe-path' setting
804 above. It defaults to the --with-auto-load-dir setting.
806 --without-auto-load-safe-path
807 Set 'set auto-load safe-path' to '/', effectively disabling this
812 z0/z1 conditional breakpoints extension
814 The z0/z1 breakpoint insertion packets have been extended to carry
815 a list of conditional expressions over to the remote stub depending on the
816 condition evaluation mode. The use of this extension can be controlled
817 via the "set remote conditional-breakpoints-packet" command.
821 Specify the signals which the remote stub may pass to the debugged
822 program without GDB involvement.
824 * New command line options
826 --init-command=FILE, -ix Like --command, -x but execute it
827 before loading inferior.
828 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
829 execute it before loading inferior.
831 *** Changes in GDB 7.4
833 * GDB now handles ambiguous linespecs more consistently; the existing
834 FILE:LINE support has been expanded to other types of linespecs. A
835 breakpoint will now be set on all matching locations in all
836 inferiors, and locations will be added or removed according to
839 * GDB now allows you to skip uninteresting functions and files when
840 stepping with the "skip function" and "skip file" commands.
842 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
843 and "show remote hardware-watchpoint-length-limit". These allows to
844 set or show the maximum length limit (in bytes) of a remote
845 target hardware watchpoint.
847 This allows e.g. to use "unlimited" hardware watchpoints with the
848 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
849 watchpoints are slower than real hardware watchpoints but are
850 significantly faster than gdb software watchpoints.
854 ** The register_pretty_printer function in module gdb.printing now takes
855 an optional `replace' argument. If True, the new printer replaces any
858 ** The "maint set python print-stack on|off" command has been
859 deprecated and will be deleted in GDB 7.5.
860 A new command: "set python print-stack none|full|message" has
861 replaced it. Additionally, the default for "print-stack" is
862 now "message", which just prints the error message without
865 ** A prompt substitution hook (prompt_hook) is now available to the
868 ** A new Python module, gdb.prompt has been added to the GDB Python
869 modules library. This module provides functionality for
870 escape sequences in prompts (used by set/show
871 extended-prompt). These escape sequences are replaced by their
874 ** Python commands and convenience-functions located in
875 'data-directory'/python/gdb/command and
876 'data-directory'/python/gdb/function are now automatically loaded
879 ** Blocks now provide four new attributes. global_block and
880 static_block will return the global and static blocks
881 respectively. is_static and is_global are boolean attributes
882 that indicate if the block is one of those two types.
884 ** Symbols now provide the "type" attribute, the type of the symbol.
886 ** The "gdb.breakpoint" function has been deprecated in favor of
889 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
890 of a function. This class is based on the "finish" command
891 available in the CLI.
893 ** Type objects for struct and union types now allow access to
894 the fields using standard Python dictionary (mapping) methods.
895 For example, "some_type['myfield']" now works, as does
898 ** A new event "gdb.new_objfile" has been added, triggered by loading a
901 ** A new function, "deep_items" has been added to the gdb.types
902 module in the GDB Python modules library. This function returns
903 an iterator over the fields of a struct or union type. Unlike
904 the standard Python "iteritems" method, it will recursively traverse
905 any anonymous fields.
909 ** "*stopped" events can report several new "reason"s, such as
912 ** Breakpoint changes are now notified using new async records, like
913 "=breakpoint-modified".
915 ** New command -ada-task-info.
917 * libthread-db-search-path now supports two special values: $sdir and $pdir.
918 $sdir specifies the default system locations of shared libraries.
919 $pdir specifies the directory where the libpthread used by the application
922 GDB no longer looks in $sdir and $pdir after it has searched the directories
923 mentioned in libthread-db-search-path. If you want to search those
924 directories, they must be specified in libthread-db-search-path.
925 The default value of libthread-db-search-path on GNU/Linux and Solaris
926 systems is now "$sdir:$pdir".
928 $pdir is not supported by gdbserver, it is currently ignored.
929 $sdir is supported by gdbserver.
931 * New configure option --with-iconv-bin.
932 When using the internationalization support like the one in the GNU C
933 library, GDB will invoke the "iconv" program to get a list of supported
934 character sets. If this program lives in a non-standard location, one can
935 use this option to specify where to find it.
937 * When natively debugging programs on PowerPC BookE processors running
938 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
939 watchpoints, which specify a mask in addition to an address to watch.
940 The mask specifies that some bits of an address (the bits which are
941 reset in the mask) should be ignored when matching the address accessed
942 by the inferior against the watchpoint address. See the "PowerPC Embedded"
943 section in the user manual for more details.
945 * The new option --once causes GDBserver to stop listening for connections once
946 the first connection is made. The listening port used by GDBserver will
947 become available after that.
949 * New commands "info macros" and "alias" have been added.
951 * New function parameters suffix @entry specifies value of function parameter
952 at the time the function got called. Entry values are available only since
958 "!" is now an alias of the "shell" command.
959 Note that no space is needed between "!" and SHELL COMMAND.
963 watch EXPRESSION mask MASK_VALUE
964 The watch command now supports the mask argument which allows creation
965 of masked watchpoints, if the current architecture supports this feature.
967 info auto-load-scripts [REGEXP]
968 This command was formerly named "maintenance print section-scripts".
969 It is now generally useful and is no longer a maintenance-only command.
971 info macro [-all] [--] MACRO
972 The info macro command has new options `-all' and `--'. The first for
973 printing all definitions of a macro. The second for explicitly specifying
974 the end of arguments and the beginning of the macro name in case the macro
975 name starts with a hyphen.
977 collect[/s] EXPRESSIONS
978 The tracepoint collect command now takes an optional modifier "/s"
979 that directs it to dereference pointer-to-character types and
980 collect the bytes of memory up to a zero byte. The behavior is
981 similar to what you see when you use the regular print command on a
982 string. An optional integer following the "/s" sets a bound on the
983 number of bytes that will be collected.
986 The trace start command now interprets any supplied arguments as a
987 note to be recorded with the trace run, with an effect similar to
988 setting the variable trace-notes.
991 The trace stop command now interprets any arguments as a note to be
992 mentioned along with the tstatus report that the trace was stopped
993 with a command. The effect is similar to setting the variable
996 * Tracepoints can now be enabled and disabled at any time after a trace
997 experiment has been started using the standard "enable" and "disable"
998 commands. It is now possible to start a trace experiment with no enabled
999 tracepoints; GDB will display a warning, but will allow the experiment to
1000 begin, assuming that tracepoints will be enabled as needed while the trace
1003 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1004 locations with 4-byte instructions, when they were previously
1005 limited to locations with instructions of 5 bytes or longer.
1009 set debug dwarf2-read
1010 show debug dwarf2-read
1011 Turns on or off display of debugging messages related to reading
1012 DWARF debug info. The default is off.
1014 set debug symtab-create
1015 show debug symtab-create
1016 Turns on or off display of debugging messages related to symbol table
1017 creation. The default is off.
1020 show extended-prompt
1021 Set the GDB prompt, and allow escape sequences to be inserted to
1022 display miscellaneous information (see 'help set extended-prompt'
1023 for the list of sequences). This prompt (and any information
1024 accessed through the escape sequences) is updated every time the
1025 prompt is displayed.
1027 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1028 show print entry-values
1029 Set printing of frame argument values at function entry. In some cases
1030 GDB can determine the value of function argument which was passed by the
1031 function caller, even if the value was modified inside the called function.
1033 set debug entry-values
1034 show debug entry-values
1035 Control display of debugging info for determining frame argument values at
1036 function entry and virtual tail call frames.
1038 set basenames-may-differ
1039 show basenames-may-differ
1040 Set whether a source file may have multiple base names.
1041 (A "base name" is the name of a file with the directory part removed.
1042 Example: The base name of "/home/user/hello.c" is "hello.c".)
1043 If set, GDB will canonicalize file names (e.g., expand symlinks)
1044 before comparing them. Canonicalization is an expensive operation,
1045 but it allows the same file be known by more than one base name.
1046 If not set (the default), all source files are assumed to have just
1047 one base name, and gdb will do file name comparisons more efficiently.
1053 Set a user name and notes for the current and any future trace runs.
1054 This is useful for long-running and/or disconnected traces, to
1055 inform others (or yourself) as to who is running the trace, supply
1056 contact information, or otherwise explain what is going on.
1058 set trace-stop-notes
1059 show trace-stop-notes
1060 Set a note attached to the trace run, that is displayed when the
1061 trace has been stopped by a tstop command. This is useful for
1062 instance as an explanation, if you are stopping a trace run that was
1063 started by someone else.
1065 * New remote packets
1069 Dynamically enable a tracepoint in a started trace experiment.
1073 Dynamically disable a tracepoint in a started trace experiment.
1077 Set the user and notes of the trace run.
1081 Query the current status of a tracepoint.
1085 Query the minimum length of instruction at which a fast tracepoint may
1088 * Dcache size (number of lines) and line-size are now runtime-configurable
1089 via "set dcache line" and "set dcache line-size" commands.
1093 Texas Instruments TMS320C6x tic6x-*-*
1097 Renesas RL78 rl78-*-elf
1099 *** Changes in GDB 7.3.1
1101 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1103 *** Changes in GDB 7.3
1105 * GDB has a new command: "thread find [REGEXP]".
1106 It finds the thread id whose name, target id, or thread extra info
1107 matches the given regular expression.
1109 * The "catch syscall" command now works on mips*-linux* targets.
1111 * The -data-disassemble MI command now supports modes 2 and 3 for
1112 dumping the instruction opcodes.
1114 * New command line options
1116 -data-directory DIR Specify DIR as the "data-directory".
1117 This is mostly for testing purposes.
1119 * The "maint set python auto-load on|off" command has been renamed to
1120 "set auto-load-scripts on|off".
1122 * GDB has a new command: "set directories".
1123 It is like the "dir" command except that it replaces the
1124 source path list instead of augmenting it.
1126 * GDB now understands thread names.
1128 On GNU/Linux, "info threads" will display the thread name as set by
1129 prctl or pthread_setname_np.
1131 There is also a new command, "thread name", which can be used to
1132 assign a name internally for GDB to display.
1135 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1136 has been integrated into GDB.
1140 ** The function gdb.Write now accepts an optional keyword 'stream'.
1141 This keyword, when provided, will direct the output to either
1142 stdout, stderr, or GDB's logging output.
1144 ** Parameters can now be be sub-classed in Python, and in particular
1145 you may implement the get_set_doc and get_show_doc functions.
1146 This improves how Parameter set/show documentation is processed
1147 and allows for more dynamic content.
1149 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1150 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1151 have an is_valid method.
1153 ** Breakpoints can now be sub-classed in Python, and in particular
1154 you may implement a 'stop' function that is executed each time
1155 the inferior reaches that breakpoint.
1157 ** New function gdb.lookup_global_symbol looks up a global symbol.
1159 ** GDB values in Python are now callable if the value represents a
1160 function. For example, if 'some_value' represents a function that
1161 takes two integer parameters and returns a value, you can call
1162 that function like so:
1164 result = some_value (10,20)
1166 ** Module gdb.types has been added.
1167 It contains a collection of utilities for working with gdb.Types objects:
1168 get_basic_type, has_field, make_enum_dict.
1170 ** Module gdb.printing has been added.
1171 It contains utilities for writing and registering pretty-printers.
1172 New classes: PrettyPrinter, SubPrettyPrinter,
1173 RegexpCollectionPrettyPrinter.
1174 New function: register_pretty_printer.
1176 ** New commands "info pretty-printers", "enable pretty-printer" and
1177 "disable pretty-printer" have been added.
1179 ** gdb.parameter("directories") is now available.
1181 ** New function gdb.newest_frame returns the newest frame in the
1184 ** The gdb.InferiorThread class has a new "name" attribute. This
1185 holds the thread's name.
1187 ** Python Support for Inferior events.
1188 Python scripts can add observers to be notified of events
1189 occurring in the process being debugged.
1190 The following events are currently supported:
1191 - gdb.events.cont Continue event.
1192 - gdb.events.exited Inferior exited event.
1193 - gdb.events.stop Signal received, and Breakpoint hit events.
1197 ** GDB now puts template parameters in scope when debugging in an
1198 instantiation. For example, if you have:
1200 template<int X> int func (void) { return X; }
1202 then if you step into func<5>, "print X" will show "5". This
1203 feature requires proper debuginfo support from the compiler; it
1204 was added to GCC 4.5.
1206 ** The motion commands "next", "finish", "until", and "advance" now
1207 work better when exceptions are thrown. In particular, GDB will
1208 no longer lose control of the inferior; instead, the GDB will
1209 stop the inferior at the point at which the exception is caught.
1210 This functionality requires a change in the exception handling
1211 code that was introduced in GCC 4.5.
1213 * GDB now follows GCC's rules on accessing volatile objects when
1214 reading or writing target state during expression evaluation.
1215 One notable difference to prior behavior is that "print x = 0"
1216 no longer generates a read of x; the value of the assignment is
1217 now always taken directly from the value being assigned.
1219 * GDB now has some support for using labels in the program's source in
1220 linespecs. For instance, you can use "advance label" to continue
1221 execution to a label.
1223 * GDB now has support for reading and writing a new .gdb_index
1224 section. This section holds a fast index of DWARF debugging
1225 information and can be used to greatly speed up GDB startup and
1226 operation. See the documentation for `save gdb-index' for details.
1228 * The "watch" command now accepts an optional "-location" argument.
1229 When used, this causes GDB to watch the memory referred to by the
1230 expression. Such a watchpoint is never deleted due to it going out
1233 * GDB now supports thread debugging of core dumps on GNU/Linux.
1235 GDB now activates thread debugging using the libthread_db library
1236 when debugging GNU/Linux core dumps, similarly to when debugging
1237 live processes. As a result, when debugging a core dump file, GDB
1238 is now able to display pthread_t ids of threads. For example, "info
1239 threads" shows the same output as when debugging the process when it
1240 was live. In earlier releases, you'd see something like this:
1243 * 1 LWP 6780 main () at main.c:10
1245 While now you see this:
1248 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1250 It is also now possible to inspect TLS variables when debugging core
1253 When debugging a core dump generated on a machine other than the one
1254 used to run GDB, you may need to point GDB at the correct
1255 libthread_db library with the "set libthread-db-search-path"
1256 command. See the user manual for more details on this command.
1258 * When natively debugging programs on PowerPC BookE processors running
1259 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1260 which stop execution of the inferior whenever it executes an instruction
1261 at any address within the specified range. See the "PowerPC Embedded"
1262 section in the user manual for more details.
1264 * New features in the GDB remote stub, GDBserver
1266 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1267 and i686 LynxOS (version 5.x).
1269 ** GDBserver is now supported on Blackfin Linux.
1271 * New native configurations
1273 ia64 HP-UX ia64-*-hpux*
1277 Analog Devices, Inc. Blackfin Processor bfin-*
1279 * Ada task switching is now supported on sparc-elf targets when
1280 debugging a program using the Ravenscar Profile. For more information,
1281 see the "Tasking Support when using the Ravenscar Profile" section
1282 in the GDB user manual.
1284 * Guile support was removed.
1286 * New features in the GNU simulator
1288 ** The --map-info flag lists all known core mappings.
1290 ** CFI flashes may be simulated via the "cfi" device.
1292 *** Changes in GDB 7.2
1294 * Shared library support for remote targets by default
1296 When GDB is configured for a generic, non-OS specific target, like
1297 for example, --target=arm-eabi or one of the many *-*-elf targets,
1298 GDB now queries remote stubs for loaded shared libraries using the
1299 `qXfer:libraries:read' packet. Previously, shared library support
1300 was always disabled for such configurations.
1304 ** Argument Dependent Lookup (ADL)
1306 In C++ ADL lookup directs function search to the namespaces of its
1307 arguments even if the namespace has not been imported.
1317 Here the compiler will search for `foo' in the namespace of 'b'
1318 and find A::foo. GDB now supports this. This construct is commonly
1319 used in the Standard Template Library for operators.
1321 ** Improved User Defined Operator Support
1323 In addition to member operators, GDB now supports lookup of operators
1324 defined in a namespace and imported with a `using' directive, operators
1325 defined in the global scope, operators imported implicitly from an
1326 anonymous namespace, and the ADL operators mentioned in the previous
1328 GDB now also supports proper overload resolution for all the previously
1329 mentioned flavors of operators.
1331 ** static const class members
1333 Printing of static const class members that are initialized in the
1334 class definition has been fixed.
1336 * Windows Thread Information Block access.
1338 On Windows targets, GDB now supports displaying the Windows Thread
1339 Information Block (TIB) structure. This structure is visible either
1340 by using the new command `info w32 thread-information-block' or, by
1341 dereferencing the new convenience variable named `$_tlb', a
1342 thread-specific pointer to the TIB. This feature is also supported
1343 when remote debugging using GDBserver.
1345 * Static tracepoints
1347 Static tracepoints are calls in the user program into a tracing
1348 library. One such library is a port of the LTTng kernel tracer to
1349 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1350 When debugging with GDBserver, GDB now supports combining the GDB
1351 tracepoint machinery with such libraries. For example: the user can
1352 use GDB to probe a static tracepoint marker (a call from the user
1353 program into the tracing library) with the new "strace" command (see
1354 "New commands" below). This creates a "static tracepoint" in the
1355 breakpoint list, that can be manipulated with the same feature set
1356 as fast and regular tracepoints. E.g., collect registers, local and
1357 global variables, collect trace state variables, and define
1358 tracepoint conditions. In addition, the user can collect extra
1359 static tracepoint marker specific data, by collecting the new
1360 $_sdata internal variable. When analyzing the trace buffer, you can
1361 inspect $_sdata like any other variable available to GDB. For more
1362 information, see the "Tracepoints" chapter in GDB user manual. New
1363 remote packets have been defined to support static tracepoints, see
1364 the "New remote packets" section below.
1366 * Better reconstruction of tracepoints after disconnected tracing
1368 GDB will attempt to download the original source form of tracepoint
1369 definitions when starting a trace run, and then will upload these
1370 upon reconnection to the target, resulting in a more accurate
1371 reconstruction of the tracepoints that are in use on the target.
1375 You can now exercise direct control over the ways that GDB can
1376 affect your program. For instance, you can disallow the setting of
1377 breakpoints, so that the program can run continuously (assuming
1378 non-stop mode). In addition, the "observer" variable is available
1379 to switch all of the different controls; in observer mode, GDB
1380 cannot affect the target's behavior at all, which is useful for
1381 tasks like diagnosing live systems in the field.
1383 * The new convenience variable $_thread holds the number of the
1386 * New remote packets
1390 Return the address of the Windows Thread Information Block of a given thread.
1394 In response to several of the tracepoint packets, the target may now
1395 also respond with a number of intermediate `qRelocInsn' request
1396 packets before the final result packet, to have GDB handle
1397 relocating an instruction to execute at a different address. This
1398 is particularly useful for stubs that support fast tracepoints. GDB
1399 reports support for this feature in the qSupported packet.
1403 List static tracepoint markers in the target program.
1407 List static tracepoint markers at a given address in the target
1410 qXfer:statictrace:read
1412 Read the static trace data collected (by a `collect $_sdata'
1413 tracepoint action). The remote stub reports support for this packet
1414 to gdb's qSupported query.
1418 Send the current settings of GDB's permission flags.
1422 Send part of the source (textual) form of a tracepoint definition,
1423 which includes location, conditional, and action list.
1425 * The source command now accepts a -s option to force searching for the
1426 script in the source search path even if the script name specifies
1429 * New features in the GDB remote stub, GDBserver
1431 - GDBserver now support tracepoints (including fast tracepoints, and
1432 static tracepoints). The feature is currently supported by the
1433 i386-linux and amd64-linux builds. See the "Tracepoints support
1434 in gdbserver" section in the manual for more information.
1436 GDBserver JIT compiles the tracepoint's conditional agent
1437 expression bytecode into native code whenever possible for low
1438 overhead dynamic tracepoints conditionals. For such tracepoints,
1439 an expression that examines program state is evaluated when the
1440 tracepoint is reached, in order to determine whether to capture
1441 trace data. If the condition is simple and false, processing the
1442 tracepoint finishes very quickly and no data is gathered.
1444 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1445 for static tracepoints support.
1447 - GDBserver now supports x86_64 Windows 64-bit debugging.
1449 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1450 it understands register description.
1452 * The --batch flag now disables pagination and queries.
1454 * X86 general purpose registers
1456 GDB now supports reading/writing byte, word and double-word x86
1457 general purpose registers directly. This means you can use, say,
1458 $ah or $ax to refer, respectively, to the byte register AH and
1459 16-bit word register AX that are actually portions of the 32-bit
1460 register EAX or 64-bit register RAX.
1462 * The `commands' command now accepts a range of breakpoints to modify.
1463 A plain `commands' following a command that creates multiple
1464 breakpoints affects all the breakpoints set by that command. This
1465 applies to breakpoints set by `rbreak', and also applies when a
1466 single `break' command creates multiple breakpoints (e.g.,
1467 breakpoints on overloaded c++ functions).
1469 * The `rbreak' command now accepts a filename specification as part of
1470 its argument, limiting the functions selected by the regex to those
1471 in the specified file.
1473 * Support for remote debugging Windows and SymbianOS shared libraries
1474 from Unix hosts has been improved. Non Windows GDB builds now can
1475 understand target reported file names that follow MS-DOS based file
1476 system semantics, such as file names that include drive letters and
1477 use the backslash character as directory separator. This makes it
1478 possible to transparently use the "set sysroot" and "set
1479 solib-search-path" on Unix hosts to point as host copies of the
1480 target's shared libraries. See the new command "set
1481 target-file-system-kind" described below, and the "Commands to
1482 specify files" section in the user manual for more information.
1486 eval template, expressions...
1487 Convert the values of one or more expressions under the control
1488 of the string template to a command line, and call it.
1490 set target-file-system-kind unix|dos-based|auto
1491 show target-file-system-kind
1492 Set or show the assumed file system kind for target reported file
1495 save breakpoints <filename>
1496 Save all current breakpoint definitions to a file suitable for use
1497 in a later debugging session. To read the saved breakpoint
1498 definitions, use the `source' command.
1500 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1503 info static-tracepoint-markers
1504 Display information about static tracepoint markers in the target.
1506 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1507 Define a static tracepoint by probing a marker at the given
1508 function, line, address, or marker ID.
1512 Enable and disable observer mode.
1514 set may-write-registers on|off
1515 set may-write-memory on|off
1516 set may-insert-breakpoints on|off
1517 set may-insert-tracepoints on|off
1518 set may-insert-fast-tracepoints on|off
1519 set may-interrupt on|off
1520 Set individual permissions for GDB effects on the target. Note that
1521 some of these settings can have undesirable or surprising
1522 consequences, particularly when changed in the middle of a session.
1523 For instance, disabling the writing of memory can prevent
1524 breakpoints from being inserted, cause single-stepping to fail, or
1525 even crash your program, if you disable after breakpoints have been
1526 inserted. However, GDB should not crash.
1528 set record memory-query on|off
1529 show record memory-query
1530 Control whether to stop the inferior if memory changes caused
1531 by an instruction cannot be recorded.
1536 The disassemble command now supports "start,+length" form of two arguments.
1540 ** GDB now provides a new directory location, called the python directory,
1541 where Python scripts written for GDB can be installed. The location
1542 of that directory is <data-directory>/python, where <data-directory>
1543 is the GDB data directory. For more details, see section `Scripting
1544 GDB using Python' in the manual.
1546 ** The GDB Python API now has access to breakpoints, symbols, symbol
1547 tables, program spaces, inferiors, threads and frame's code blocks.
1548 Additionally, GDB Parameters can now be created from the API, and
1549 manipulated via set/show in the CLI.
1551 ** New functions gdb.target_charset, gdb.target_wide_charset,
1552 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1554 ** New exception gdb.GdbError.
1556 ** Pretty-printers are now also looked up in the current program space.
1558 ** Pretty-printers can now be individually enabled and disabled.
1560 ** GDB now looks for names of Python scripts to auto-load in a
1561 special section named `.debug_gdb_scripts', in addition to looking
1562 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1564 * Tracepoint actions were unified with breakpoint commands. In particular,
1565 there are no longer differences in "info break" output for breakpoints and
1566 tracepoints and the "commands" command can be used for both tracepoints and
1567 regular breakpoints.
1571 ARM Symbian arm*-*-symbianelf*
1573 * D language support.
1574 GDB now supports debugging programs written in the D programming
1577 * GDB now supports the extended ptrace interface for PowerPC which is
1578 available since Linux kernel version 2.6.34. This automatically enables
1579 any hardware breakpoints and additional hardware watchpoints available in
1580 the processor. The old ptrace interface exposes just one hardware
1581 watchpoint and no hardware breakpoints.
1583 * GDB is now able to use the Data Value Compare (DVC) register available on
1584 embedded PowerPC processors to implement in hardware simple watchpoint
1585 conditions of the form:
1587 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1589 This works in native GDB running on Linux kernels with the extended ptrace
1590 interface mentioned above.
1592 *** Changes in GDB 7.1
1596 ** Namespace Support
1598 GDB now supports importing of namespaces in C++. This enables the
1599 user to inspect variables from imported namespaces. Support for
1600 namepace aliasing has also been added. So, if a namespace is
1601 aliased in the current scope (e.g. namepace C=A; ) the user can
1602 print variables using the alias (e.g. (gdb) print C::x).
1606 All known bugs relating to the printing of virtual base class were
1607 fixed. It is now possible to call overloaded static methods using a
1612 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1613 and reinterpret_cast<> are now handled by the C++ expression parser.
1617 Xilinx MicroBlaze microblaze-*-*
1622 Xilinx MicroBlaze microblaze
1625 * Multi-program debugging.
1627 GDB now has support for multi-program (a.k.a. multi-executable or
1628 multi-exec) debugging. This allows for debugging multiple inferiors
1629 simultaneously each running a different program under the same GDB
1630 session. See "Debugging Multiple Inferiors and Programs" in the
1631 manual for more information. This implied some user visible changes
1632 in the multi-inferior support. For example, "info inferiors" now
1633 lists inferiors that are not running yet or that have exited
1634 already. See also "New commands" and "New options" below.
1636 * New tracing features
1638 GDB's tracepoint facility now includes several new features:
1640 ** Trace state variables
1642 GDB tracepoints now include support for trace state variables, which
1643 are variables managed by the target agent during a tracing
1644 experiment. They are useful for tracepoints that trigger each
1645 other, so for instance one tracepoint can count hits in a variable,
1646 and then a second tracepoint has a condition that is true when the
1647 count reaches a particular value. Trace state variables share the
1648 $-syntax of GDB convenience variables, and can appear in both
1649 tracepoint actions and condition expressions. Use the "tvariable"
1650 command to create, and "info tvariables" to view; see "Trace State
1651 Variables" in the manual for more detail.
1655 GDB now includes an option for defining fast tracepoints, which
1656 targets may implement more efficiently, such as by installing a jump
1657 into the target agent rather than a trap instruction. The resulting
1658 speedup can be by two orders of magnitude or more, although the
1659 tradeoff is that some program locations on some target architectures
1660 might not allow fast tracepoint installation, for instance if the
1661 instruction to be replaced is shorter than the jump. To request a
1662 fast tracepoint, use the "ftrace" command, with syntax identical to
1663 the regular trace command.
1665 ** Disconnected tracing
1667 It is now possible to detach GDB from the target while it is running
1668 a trace experiment, then reconnect later to see how the experiment
1669 is going. In addition, a new variable disconnected-tracing lets you
1670 tell the target agent whether to continue running a trace if the
1671 connection is lost unexpectedly.
1675 GDB now has the ability to save the trace buffer into a file, and
1676 then use that file as a target, similarly to you can do with
1677 corefiles. You can select trace frames, print data that was
1678 collected in them, and use tstatus to display the state of the
1679 tracing run at the moment that it was saved. To create a trace
1680 file, use "tsave <filename>", and to use it, do "target tfile
1683 ** Circular trace buffer
1685 You can ask the target agent to handle the trace buffer as a
1686 circular buffer, discarding the oldest trace frames to make room for
1687 newer ones, by setting circular-trace-buffer to on. This feature may
1688 not be available for all target agents.
1693 The disassemble command, when invoked with two arguments, now requires
1694 the arguments to be comma-separated.
1697 The info variables command now displays variable definitions. Files
1698 which only declare a variable are not shown.
1701 The source command is now capable of sourcing Python scripts.
1702 This feature is dependent on the debugger being build with Python
1705 Related to this enhancement is also the introduction of a new command
1706 "set script-extension" (see below).
1708 * New commands (for set/show, see "New options" below)
1710 record save [<FILENAME>]
1711 Save a file (in core file format) containing the process record
1712 execution log for replay debugging at a later time.
1714 record restore <FILENAME>
1715 Restore the process record execution log that was saved at an
1716 earlier time, for replay debugging.
1718 add-inferior [-copies <N>] [-exec <FILENAME>]
1721 clone-inferior [-copies <N>] [ID]
1722 Make a new inferior ready to execute the same program another
1723 inferior has loaded.
1728 maint info program-spaces
1729 List the program spaces loaded into GDB.
1731 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1732 show remote interrupt-sequence
1733 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1734 as the sequence to the remote target in order to interrupt the execution.
1735 Ctrl-C is a default. Some system prefers BREAK which is high level of
1736 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1737 Magic SysRq g. It is BREAK signal and character 'g'.
1739 set remote interrupt-on-connect [on | off]
1740 show remote interrupt-on-connect
1741 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1742 remote target when gdb connects to it. This is needed when you debug
1745 set remotebreak [on | off]
1747 Deprecated. Use "set/show remote interrupt-sequence" instead.
1749 tvariable $NAME [ = EXP ]
1750 Create or modify a trace state variable.
1753 List trace state variables and their values.
1755 delete tvariable $NAME ...
1756 Delete one or more trace state variables.
1759 Evaluate the given expressions without collecting anything into the
1760 trace buffer. (Valid in tracepoint actions only.)
1762 ftrace FN / FILE:LINE / *ADDR
1763 Define a fast tracepoint at the given function, line, or address.
1765 * New expression syntax
1767 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1768 GDB now parses 0b101010 identically with 42.
1772 set follow-exec-mode new|same
1773 show follow-exec-mode
1774 Control whether GDB reuses the same inferior across an exec call or
1775 creates a new one. This is useful to be able to restart the old
1776 executable after the inferior having done an exec call.
1778 set default-collect EXPR, ...
1779 show default-collect
1780 Define a list of expressions to be collected at each tracepoint.
1781 This is a useful way to ensure essential items are not overlooked,
1782 such as registers or a critical global variable.
1784 set disconnected-tracing
1785 show disconnected-tracing
1786 If set to 1, the target is instructed to continue tracing if it
1787 loses its connection to GDB. If 0, the target is to stop tracing
1790 set circular-trace-buffer
1791 show circular-trace-buffer
1792 If set to on, the target is instructed to use a circular trace buffer
1793 and discard the oldest trace frames instead of stopping the trace due
1794 to a full trace buffer. If set to off, the trace stops when the buffer
1795 fills up. Some targets may not support this.
1797 set script-extension off|soft|strict
1798 show script-extension
1799 If set to "off", the debugger does not perform any script language
1800 recognition, and all sourced files are assumed to be GDB scripts.
1801 If set to "soft" (the default), files are sourced according to
1802 filename extension, falling back to GDB scripts if the first
1804 If set to "strict", files are sourced according to filename extension.
1806 set ada trust-PAD-over-XVS on|off
1807 show ada trust-PAD-over-XVS
1808 If off, activate a workaround against a bug in the debugging information
1809 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1810 the GCC sources for more information about the GNAT encoding and
1811 PAD types in particular). It is always safe to set this option to
1812 off, but this introduces a slight performance penalty. The default
1815 * Python API Improvements
1817 ** GDB provides the new class gdb.LazyString. This is useful in
1818 some pretty-printing cases. The new method gdb.Value.lazy_string
1819 provides a simple way to create objects of this type.
1821 ** The fields returned by gdb.Type.fields now have an
1822 `is_base_class' attribute.
1824 ** The new method gdb.Type.range returns the range of an array type.
1826 ** The new method gdb.parse_and_eval can be used to parse and
1827 evaluate an expression.
1829 * New remote packets
1832 Define a trace state variable.
1835 Get the current value of a trace state variable.
1838 Set desired tracing behavior upon disconnection.
1841 Set the trace buffer to be linear or circular.
1844 Get data about the tracepoints currently in use.
1848 Process record now works correctly with hardware watchpoints.
1850 Multiple bug fixes have been made to the mips-irix port, making it
1851 much more reliable. In particular:
1852 - Debugging threaded applications is now possible again. Previously,
1853 GDB would hang while starting the program, or while waiting for
1854 the program to stop at a breakpoint.
1855 - Attaching to a running process no longer hangs.
1856 - An error occurring while loading a core file has been fixed.
1857 - Changing the value of the PC register now works again. This fixes
1858 problems observed when using the "jump" command, or when calling
1859 a function from GDB, or even when assigning a new value to $pc.
1860 - With the "finish" and "return" commands, the return value for functions
1861 returning a small array is now correctly printed.
1862 - It is now possible to break on shared library code which gets executed
1863 during a shared library init phase (code executed while executing
1864 their .init section). Previously, the breakpoint would have no effect.
1865 - GDB is now able to backtrace through the signal handler for
1866 non-threaded programs.
1868 PIE (Position Independent Executable) programs debugging is now supported.
1869 This includes debugging execution of PIC (Position Independent Code) shared
1870 libraries although for that, it should be possible to run such libraries as an
1873 *** Changes in GDB 7.0
1875 * GDB now has an interface for JIT compilation. Applications that
1876 dynamically generate code can create symbol files in memory and register
1877 them with GDB. For users, the feature should work transparently, and
1878 for JIT developers, the interface is documented in the GDB manual in the
1879 "JIT Compilation Interface" chapter.
1881 * Tracepoints may now be conditional. The syntax is as for
1882 breakpoints; either an "if" clause appended to the "trace" command,
1883 or the "condition" command is available. GDB sends the condition to
1884 the target for evaluation using the same bytecode format as is used
1885 for tracepoint actions.
1887 * The disassemble command now supports: an optional /r modifier, print the
1888 raw instructions in hex as well as in symbolic form, and an optional /m
1889 modifier to print mixed source+assembly.
1891 * Process record and replay
1893 In a architecture environment that supports ``process record and
1894 replay'', ``process record and replay'' target can record a log of
1895 the process execution, and replay it with both forward and reverse
1898 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
1899 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
1900 set execution-direction {forward|reverse}, for targets that support
1903 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
1904 feature is available with a native GDB running on kernel version
1907 * GDB now has support for multi-byte and wide character sets on the
1908 target. Strings whose character type is wchar_t, char16_t, or
1909 char32_t are now correctly printed. GDB supports wide- and unicode-
1910 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
1911 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
1912 `printf'. This feature requires iconv to work properly; if your
1913 system does not have a working iconv, GDB can use GNU libiconv. See
1914 the installation instructions for more information.
1916 * GDB now supports automatic retrieval of shared library files from
1917 remote targets. To use this feature, specify a system root that begins
1918 with the `remote:' prefix, either via the `set sysroot' command or via
1919 the `--with-sysroot' configure-time option.
1921 * "info sharedlibrary" now takes an optional regex of libraries to show,
1922 and it now reports if a shared library has no debugging information.
1924 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
1925 now complete on file names.
1927 * When completing in expressions, gdb will attempt to limit
1928 completions to allowable structure or union fields, where appropriate.
1929 For instance, consider:
1931 # struct example { int f1; double f2; };
1932 # struct example variable;
1935 If the user types TAB at the end of this command line, the available
1936 completions will be "f1" and "f2".
1938 * Inlined functions are now supported. They show up in backtraces, and
1939 the "step", "next", and "finish" commands handle them automatically.
1941 * GDB now supports the token-splicing (##) and stringification (#)
1942 operators when expanding macros. It also supports variable-arity
1945 * GDB now supports inspecting extra signal information, exported by
1946 the new $_siginfo convenience variable. The feature is currently
1947 implemented on linux ARM, i386 and amd64.
1949 * GDB can now display the VFP floating point registers and NEON vector
1950 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
1951 can provide these registers (requires Linux 2.6.30 or later). Remote
1952 and simulator targets may also provide them.
1954 * New remote packets
1957 Search memory for a sequence of bytes.
1960 Turn off `+'/`-' protocol acknowledgments to permit more efficient
1961 operation over reliable transport links. Use of this packet is
1962 controlled by the `set remote noack-packet' command.
1965 Kill the process with the specified process ID. Use this in preference
1966 to `k' when multiprocess protocol extensions are supported.
1969 Obtains additional operating system information
1973 Read or write additional signal information.
1975 * Removed remote protocol undocumented extension
1977 An undocumented extension to the remote protocol's `S' stop reply
1978 packet that permited the stub to pass a process id was removed.
1979 Remote servers should use the `T' stop reply packet instead.
1981 * GDB now supports multiple function calling conventions according to the
1982 DWARF-2 DW_AT_calling_convention function attribute.
1984 * The SH target utilizes the aforementioned change to distinguish between gcc
1985 and Renesas calling convention. It also adds the new CLI commands
1986 `set/show sh calling-convention'.
1988 * GDB can now read compressed debug sections, as produced by GNU gold
1989 with the --compress-debug-sections=zlib flag.
1991 * 64-bit core files are now supported on AIX.
1993 * Thread switching is now supported on Tru64.
1995 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
1996 which will be allocated using malloc later in program execution.
1998 * The qXfer:libraries:read remote procotol packet now allows passing a
1999 list of section offsets.
2001 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2002 conditions handling signals delivered during attach or thread creation
2003 have also been fixed.
2005 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2006 From the user's standpoint, all unqualified instances of True and False
2007 are treated as the standard definitions, regardless of context.
2009 * GDB now parses C++ symbol and type names more flexibly. For
2012 template<typename T> class C { };
2015 GDB will now correctly handle all of:
2017 ptype C<char const *>
2018 ptype C<char const*>
2019 ptype C<const char *>
2020 ptype C<const char*>
2022 * New features in the GDB remote stub, gdbserver
2024 - The "--wrapper" command-line argument tells gdbserver to use a
2025 wrapper program to launch programs for debugging.
2027 - On PowerPC and S/390 targets, it is now possible to use a single
2028 gdbserver executable to debug both 32-bit and 64-bit programs.
2029 (This requires gdbserver itself to be built as a 64-bit executable.)
2031 - gdbserver uses the new noack protocol mode for TCP connections to
2032 reduce communications latency, if also supported and enabled in GDB.
2034 - Support for the sparc64-linux-gnu target is now included in
2037 - The amd64-linux build of gdbserver now supports debugging both
2038 32-bit and 64-bit programs.
2040 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2041 now support hardware watchpoints, and will use them automatically
2046 GDB now has support for scripting using Python. Whether this is
2047 available is determined at configure time.
2049 New GDB commands can now be written in Python.
2051 * Ada tasking support
2053 Ada tasks can now be inspected in GDB. The following commands have
2057 Print the list of Ada tasks.
2059 Print detailed information about task number N.
2061 Print the task number of the current task.
2063 Switch the context of debugging to task number N.
2065 * Support for user-defined prefixed commands. The "define" command can
2066 add new commands to existing prefixes, e.g. "target".
2068 * Multi-inferior, multi-process debugging.
2070 GDB now has generalized support for multi-inferior debugging. See
2071 "Debugging Multiple Inferiors" in the manual for more information.
2072 Although availability still depends on target support, the command
2073 set is more uniform now. The GNU/Linux specific multi-forks support
2074 has been migrated to this new framework. This implied some user
2075 visible changes; see "New commands" and also "Removed commands"
2078 * Target descriptions can now describe the target OS ABI. See the
2079 "Target Description Format" section in the user manual for more
2082 * Target descriptions can now describe "compatible" architectures
2083 to indicate that the target can execute applications for a different
2084 architecture in addition to those for the main target architecture.
2085 See the "Target Description Format" section in the user manual for
2088 * Multi-architecture debugging.
2090 GDB now includes general supports for debugging applications on
2091 hybrid systems that use more than one single processor architecture
2092 at the same time. Each such hybrid architecture still requires
2093 specific support to be added. The only hybrid architecture supported
2094 in this version of GDB is the Cell Broadband Engine.
2096 * GDB now supports integrated debugging of Cell/B.E. applications that
2097 use both the PPU and SPU architectures. To enable support for hybrid
2098 Cell/B.E. debugging, you need to configure GDB to support both the
2099 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2100 --enable-targets configure option.
2102 * Non-stop mode debugging.
2104 For some targets, GDB now supports an optional mode of operation in
2105 which you can examine stopped threads while other threads continue
2106 to execute freely. This is referred to as non-stop mode, with the
2107 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2108 section in the user manual for more information.
2110 To be able to support remote non-stop debugging, a remote stub needs
2111 to implement the non-stop mode remote protocol extensions, as
2112 described in the "Remote Non-Stop" section of the user manual. The
2113 GDB remote stub, gdbserver, has been adjusted to support these
2114 extensions on linux targets.
2116 * New commands (for set/show, see "New options" below)
2118 catch syscall [NAME(S) | NUMBER(S)]
2119 Catch system calls. Arguments, which should be names of system
2120 calls or their numbers, mean catch only those syscalls. Without
2121 arguments, every syscall will be caught. When the inferior issues
2122 any of the specified syscalls, GDB will stop and announce the system
2123 call, both when it is called and when its call returns. This
2124 feature is currently available with a native GDB running on the
2125 Linux Kernel, under the following architectures: x86, x86_64,
2126 PowerPC and PowerPC64.
2128 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2130 Search memory for a sequence of bytes.
2132 maint set python print-stack
2133 maint show python print-stack
2134 Show a stack trace when an error is encountered in a Python script.
2137 Invoke CODE by passing it to the Python interpreter.
2142 These allow macros to be defined, undefined, and listed
2146 Show operating system information about processes.
2149 List the inferiors currently under GDB's control.
2152 Switch focus to inferior number NUM.
2155 Detach from inferior number NUM.
2158 Kill inferior number NUM.
2162 set spu stop-on-load
2163 show spu stop-on-load
2164 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2166 set spu auto-flush-cache
2167 show spu auto-flush-cache
2168 Control whether to automatically flush the software-managed cache
2169 during Cell/B.E. debugging.
2171 set sh calling-convention
2172 show sh calling-convention
2173 Control the calling convention used when calling SH target functions.
2176 show debug timestamp
2177 Control display of timestamps with GDB debugging output.
2179 set disassemble-next-line
2180 show disassemble-next-line
2181 Control display of disassembled source lines or instructions when
2184 set remote noack-packet
2185 show remote noack-packet
2186 Set/show the use of remote protocol QStartNoAckMode packet. See above
2187 under "New remote packets."
2189 set remote query-attached-packet
2190 show remote query-attached-packet
2191 Control use of remote protocol `qAttached' (query-attached) packet.
2193 set remote read-siginfo-object
2194 show remote read-siginfo-object
2195 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2198 set remote write-siginfo-object
2199 show remote write-siginfo-object
2200 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2203 set remote reverse-continue
2204 show remote reverse-continue
2205 Control use of remote protocol 'bc' (reverse-continue) packet.
2207 set remote reverse-step
2208 show remote reverse-step
2209 Control use of remote protocol 'bs' (reverse-step) packet.
2211 set displaced-stepping
2212 show displaced-stepping
2213 Control displaced stepping mode. Displaced stepping is a way to
2214 single-step over breakpoints without removing them from the debuggee.
2215 Also known as "out-of-line single-stepping".
2218 show debug displaced
2219 Control display of debugging info for displaced stepping.
2221 maint set internal-error
2222 maint show internal-error
2223 Control what GDB does when an internal error is detected.
2225 maint set internal-warning
2226 maint show internal-warning
2227 Control what GDB does when an internal warning is detected.
2232 Use a wrapper program to launch programs for debugging.
2234 set multiple-symbols (all|ask|cancel)
2235 show multiple-symbols
2236 The value of this variable can be changed to adjust the debugger behavior
2237 when an expression or a breakpoint location contains an ambiguous symbol
2238 name (an overloaded function name, for instance).
2240 set breakpoint always-inserted
2241 show breakpoint always-inserted
2242 Keep breakpoints always inserted in the target, as opposed to inserting
2243 them when resuming the target, and removing them when the target stops.
2244 This option can improve debugger performance on slow remote targets.
2246 set arm fallback-mode (arm|thumb|auto)
2247 show arm fallback-mode
2248 set arm force-mode (arm|thumb|auto)
2250 These commands control how ARM GDB determines whether instructions
2251 are ARM or Thumb. The default for both settings is auto, which uses
2252 the current CPSR value for instructions without symbols; previous
2253 versions of GDB behaved as if "set arm fallback-mode arm".
2255 set disable-randomization
2256 show disable-randomization
2257 Standalone programs run with the virtual address space randomization enabled
2258 by default on some platforms. This option keeps the addresses stable across
2259 multiple debugging sessions.
2263 Control whether other threads are stopped or not when some thread hits
2268 Requests that asynchronous execution is enabled in the target, if available.
2269 In this case, it's possible to resume target in the background, and interact
2270 with GDB while the target is running. "show target-async" displays the
2271 current state of asynchronous execution of the target.
2273 set target-wide-charset
2274 show target-wide-charset
2275 The target-wide-charset is the name of the character set that GDB
2276 uses when printing characters whose type is wchar_t.
2278 set tcp auto-retry (on|off)
2280 set tcp connect-timeout
2281 show tcp connect-timeout
2282 These commands allow GDB to retry failed TCP connections to a remote stub
2283 with a specified timeout period; this is useful if the stub is launched
2284 in parallel with GDB but may not be ready to accept connections immediately.
2286 set libthread-db-search-path
2287 show libthread-db-search-path
2288 Control list of directories which GDB will search for appropriate
2291 set schedule-multiple (on|off)
2292 show schedule-multiple
2293 Allow GDB to resume all threads of all processes or only threads of
2294 the current process.
2298 Use more aggressive caching for accesses to the stack. This improves
2299 performance of remote debugging (particularly backtraces) without
2300 affecting correctness.
2302 set interactive-mode (on|off|auto)
2303 show interactive-mode
2304 Control whether GDB runs in interactive mode (on) or not (off).
2305 When in interactive mode, GDB waits for the user to answer all
2306 queries. Otherwise, GDB does not wait and assumes the default
2307 answer. When set to auto (the default), GDB determines which
2308 mode to use based on the stdin settings.
2313 For program forks, this is replaced by the new more generic `info
2314 inferiors' command. To list checkpoints, you can still use the
2315 `info checkpoints' command, which was an alias for the `info forks'
2319 Replaced by the new `inferior' command. To switch between
2320 checkpoints, you can still use the `restart' command, which was an
2321 alias for the `fork' command.
2324 This is removed, since some targets don't have a notion of
2325 processes. To switch between processes, you can still use the
2326 `inferior' command using GDB's own inferior number.
2329 For program forks, this is replaced by the new more generic `kill
2330 inferior' command. To delete a checkpoint, you can still use the
2331 `delete checkpoint' command, which was an alias for the `delete
2335 For program forks, this is replaced by the new more generic `detach
2336 inferior' command. To detach a checkpoint, you can still use the
2337 `detach checkpoint' command, which was an alias for the `detach
2340 * New native configurations
2342 x86/x86_64 Darwin i[34567]86-*-darwin*
2344 x86_64 MinGW x86_64-*-mingw*
2348 Lattice Mico32 lm32-*
2349 x86 DICOS i[34567]86-*-dicos*
2350 x86_64 DICOS x86_64-*-dicos*
2353 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2354 (mingw32ce) debugging.
2360 These commands were actually not implemented on any target.
2362 *** Changes in GDB 6.8
2364 * New native configurations
2366 NetBSD/hppa hppa*-*netbsd*
2367 Xtensa GNU/Linux xtensa*-*-linux*
2371 NetBSD/hppa hppa*-*-netbsd*
2372 Xtensa GNU/Lunux xtensa*-*-linux*
2374 * Change in command line behavior -- corefiles vs. process ids.
2376 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2377 attaching to process NUMBER fails, GDB no longer attempts to open a
2378 core file named NUMBER. Attaching to a program using the -c option
2379 is no longer supported. Instead, use the '-p' or '--pid' options.
2381 * GDB can now be built as a native debugger for debugging Windows x86
2382 (mingw32) Portable Executable (PE) programs.
2384 * Pending breakpoints no longer change their number when their address
2387 * GDB now supports breakpoints with multiple locations,
2388 including breakpoints on C++ constructors, inside C++ templates,
2389 and in inlined functions.
2391 * GDB's ability to debug optimized code has been improved. GDB more
2392 accurately identifies function bodies and lexical blocks that occupy
2393 more than one contiguous range of addresses.
2395 * Target descriptions can now describe registers for PowerPC.
2397 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2398 registers on PowerPC targets.
2400 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2401 targets even when the libthread_db library is not available.
2403 * The GDB remote stub, gdbserver, now supports the new file transfer
2404 commands (remote put, remote get, and remote delete).
2406 * The GDB remote stub, gdbserver, now supports run and attach in
2407 extended-remote mode.
2409 * hppa*64*-*-hpux11* target broken
2410 The debugger is unable to start a program and fails with the following
2411 error: "Error trying to get information about dynamic linker".
2412 The gdb-6.7 release is also affected.
2414 * GDB now supports the --enable-targets= configure option to allow
2415 building a single GDB executable that supports multiple remote
2416 target architectures.
2418 * GDB now supports debugging C and C++ programs which use the
2419 Decimal Floating Point extension. In addition, the PowerPC target
2420 now has a set of pseudo-registers to inspect decimal float values
2421 stored in two consecutive float registers.
2423 * The -break-insert MI command can optionally create pending
2426 * Improved support for debugging Ada
2427 Many improvements to the Ada language support have been made. These
2429 - Better support for Ada2005 interface types
2430 - Improved handling of arrays and slices in general
2431 - Better support for Taft-amendment types
2432 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2434 - Improved command completion in Ada
2437 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2442 set print frame-arguments (all|scalars|none)
2443 show print frame-arguments
2444 The value of this variable can be changed to control which argument
2445 values should be printed by the debugger when displaying a frame.
2450 Transfer files to and from a remote target, and delete remote files.
2457 Transfer files to and from a remote target, and delete remote files.
2459 * New remote packets
2466 Open, close, read, write, and delete files on the remote system.
2469 Attach to an existing process on the remote system, in extended-remote
2473 Run a new process on the remote system, in extended-remote mode.
2475 *** Changes in GDB 6.7
2477 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2478 bfd, libiberty and opcodes, as revealed by static analysis donated by
2479 Coverity, Inc. (http://scan.coverity.com).
2481 * When looking up multiply-defined global symbols, GDB will now prefer the
2482 symbol definition in the current shared library if it was built using the
2483 -Bsymbolic linker option.
2485 * When the Text User Interface (TUI) is not configured, GDB will now
2486 recognize the -tui command-line option and print a message that the TUI
2489 * The GDB remote stub, gdbserver, now has lower overhead for high
2490 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2492 * GDB for MIPS targets now autodetects whether a remote target provides
2493 32-bit or 64-bit register values.
2495 * Support for C++ member pointers has been improved.
2497 * GDB now understands XML target descriptions, which specify the
2498 target's overall architecture. GDB can read a description from
2499 a local file or over the remote serial protocol.
2501 * Vectors of single-byte data use a new integer type which is not
2502 automatically displayed as character or string data.
2504 * The /s format now works with the print command. It displays
2505 arrays of single-byte integers and pointers to single-byte integers
2508 * Target descriptions can now describe target-specific registers,
2509 for architectures which have implemented the support (currently
2510 only ARM, M68K, and MIPS).
2512 * GDB and the GDB remote stub, gdbserver, now support the XScale
2515 * The GDB remote stub, gdbserver, has been updated to support
2516 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2517 has been rewritten to use the standard GDB remote protocol.
2519 * GDB can now step into C++ functions which are called through thunks.
2521 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2523 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2524 layout. It also supports a TextSeg= and DataSeg= response when only
2525 segment base addresses (rather than offsets) are available.
2527 * The /i format now outputs any trailing branch delay slot instructions
2528 immediately following the last instruction within the count specified.
2530 * The GDB remote protocol "T" stop reply packet now supports a
2531 "library" response. Combined with the new "qXfer:libraries:read"
2532 packet, this response allows GDB to debug shared libraries on targets
2533 where the operating system manages the list of loaded libraries (e.g.
2534 Windows and SymbianOS).
2536 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2537 (DLLs) on Windows and Windows CE targets.
2539 * GDB now supports a faster verification that a .debug file matches its binary
2540 according to its build-id signature, if the signature is present.
2546 Enable or disable hardware flow control (RTS/CTS) on the serial port
2547 when debugging using remote targets.
2549 set mem inaccessible-by-default
2550 show mem inaccessible-by-default
2551 If the target supplies a memory map, for instance via the remote
2552 protocol's "qXfer:memory-map:read" packet, setting this variable
2553 prevents GDB from accessing memory outside the memory map. This
2554 is useful for targets with memory mapped registers or which react
2555 badly to accesses of unmapped address space.
2557 set breakpoint auto-hw
2558 show breakpoint auto-hw
2559 If the target supplies a memory map, for instance via the remote
2560 protocol's "qXfer:memory-map:read" packet, setting this variable
2561 lets GDB use hardware breakpoints automatically for memory regions
2562 where it can not use software breakpoints. This covers both the
2563 "break" command and internal breakpoints used for other commands
2564 including "next" and "finish".
2567 catch exception unhandled
2568 Stop the program execution when Ada exceptions are raised.
2571 Stop the program execution when an Ada assertion failed.
2575 Set an alternate system root for target files. This is a more
2576 general version of "set solib-absolute-prefix", which is now
2577 an alias to "set sysroot".
2580 Provide extended SPU facility status information. This set of
2581 commands is available only when debugging the Cell/B.E. SPU
2584 * New native configurations
2586 OpenBSD/sh sh*-*openbsd*
2589 unset tdesc filename
2591 Use the specified local file as an XML target description, and do
2592 not query the target for its built-in description.
2596 OpenBSD/sh sh*-*-openbsd*
2597 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2598 Toshiba Media Processor mep-elf
2600 * New remote packets
2603 Ignore the specified signals; pass them directly to the debugged program
2604 without stopping other threads or reporting them to GDB.
2606 qXfer:features:read:
2607 Read an XML target description from the target, which describes its
2612 Read or write contents of an spufs file on the target system. These
2613 packets are available only on the Cell/B.E. SPU architecture.
2615 qXfer:libraries:read:
2616 Report the loaded shared libraries. Combined with new "T" packet
2617 response, this packet allows GDB to debug shared libraries on
2618 targets where the operating system manages the list of loaded
2619 libraries (e.g. Windows and SymbianOS).
2623 Support for these obsolete configurations has been removed.
2631 i[34567]86-*-lynxos*
2632 i[34567]86-*-netware*
2633 i[34567]86-*-sco3.2v5*
2634 i[34567]86-*-sco3.2v4*
2636 i[34567]86-*-sysv4.2*
2639 i[34567]86-*-unixware2*
2640 i[34567]86-*-unixware*
2649 * Other removed features
2656 Various m68k-only ROM monitors.
2663 Various Renesas ROM monitors and debugging interfaces for SH and
2668 Support for a Macraigor serial interface to on-chip debugging.
2669 GDB does not directly support the newer parallel or USB
2674 A debug information format. The predecessor to DWARF 2 and
2675 DWARF 3, which are still supported.
2677 Support for the HP aCC compiler on HP-UX/PA-RISC
2679 SOM-encapsulated symbolic debugging information, automatic
2680 invocation of pxdb, and the aCC custom C++ ABI. This does not
2681 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2682 with aCC can still be debugged on an assembly level.
2684 MIPS ".pdr" sections
2686 A MIPS-specific format used to describe stack frame layout
2687 in debugging information.
2691 GDB could work with an older version of Guile to debug
2692 the interpreter and Scheme programs running in it.
2694 set mips stack-arg-size
2695 set mips saved-gpreg-size
2697 Use "set mips abi" to control parameter passing for MIPS.
2699 *** Changes in GDB 6.6
2704 Cell Broadband Engine SPU spu-elf
2706 * GDB can now be configured as a cross-debugger targeting native Windows
2707 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2708 running on a Windows system over TCP/IP to debug Windows programs.
2710 * The GDB remote stub, gdbserver, has been updated to support Windows and
2711 Cygwin debugging. Both single-threaded and multi-threaded programs are
2714 * The "set trust-readonly-sections" command works again. This command was
2715 broken in GDB 6.3, 6.4, and 6.5.
2717 * The "load" command now supports writing to flash memory, if the remote
2718 stub provides the required support.
2720 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2721 longer requires symbolic debug information (e.g. DWARF-2).
2726 unset substitute-path
2727 show substitute-path
2728 Manage a list of substitution rules that GDB uses to rewrite the name
2729 of the directories where the sources are located. This can be useful
2730 for instance when the sources were moved to a different location
2731 between compilation and debugging.
2735 Print each CLI command as it is executed. Each command is prefixed with
2736 a number of `+' symbols representing the nesting depth.
2737 The source command now has a `-v' option to enable the same feature.
2741 The ARM Demon monitor support (RDP protocol, "target rdp").
2743 Kernel Object Display, an embedded debugging feature which only worked with
2744 an obsolete version of Cisco IOS.
2746 The 'set download-write-size' and 'show download-write-size' commands.
2748 * New remote packets
2751 Tell a stub about GDB client features, and request remote target features.
2752 The first feature implemented is PacketSize, which allows the target to
2753 specify the size of packets it can handle - to minimize the number of
2754 packets required and improve performance when connected to a remote
2758 Fetch an OS auxilliary vector from the remote stub. This packet is a
2759 more efficient replacement for qPart:auxv:read.
2761 qXfer:memory-map:read:
2762 Fetch a memory map from the remote stub, including information about
2763 RAM, ROM, and flash memory devices.
2768 Erase and program a flash memory device.
2770 * Removed remote packets
2773 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2774 used it, and only gdbserver implemented it.
2776 *** Changes in GDB 6.5
2780 Renesas M32C/M16C m32c-elf
2782 Morpho Technologies ms1 ms1-elf
2786 init-if-undefined Initialize a convenience variable, but
2787 only if it doesn't already have a value.
2789 The following commands are presently only implemented for native GNU/Linux:
2791 checkpoint Save a snapshot of the program state.
2793 restart <n> Return the program state to a
2794 previously saved state.
2796 info checkpoints List currently saved checkpoints.
2798 delete-checkpoint <n> Delete a previously saved checkpoint.
2800 set|show detach-on-fork Tell gdb whether to detach from a newly
2801 forked process, or to keep debugging it.
2803 info forks List forks of the user program that
2804 are available to be debugged.
2806 fork <n> Switch to debugging one of several
2807 forks of the user program that are
2808 available to be debugged.
2810 delete-fork <n> Delete a fork from the list of forks
2811 that are available to be debugged (and
2812 kill the forked process).
2814 detach-fork <n> Delete a fork from the list of forks
2815 that are available to be debugged (and
2816 allow the process to continue).
2820 Morpho Technologies ms2 ms1-elf
2822 * Improved Windows host support
2824 GDB now builds as a cross debugger hosted on i686-mingw32, including
2825 native console support, and remote communications using either
2826 network sockets or serial ports.
2828 * Improved Modula-2 language support
2830 GDB can now print most types in the Modula-2 syntax. This includes:
2831 basic types, set types, record types, enumerated types, range types,
2832 pointer types and ARRAY types. Procedure var parameters are correctly
2833 printed and hexadecimal addresses and character constants are also
2834 written in the Modula-2 syntax. Best results can be obtained by using
2835 GNU Modula-2 together with the -gdwarf-2 command line option.
2839 The ARM rdi-share module.
2841 The Netware NLM debug server.
2843 *** Changes in GDB 6.4
2845 * New native configurations
2847 OpenBSD/arm arm*-*-openbsd*
2848 OpenBSD/mips64 mips64-*-openbsd*
2852 Morpho Technologies ms1 ms1-elf
2854 * New command line options
2856 --batch-silent As for --batch, but totally silent.
2857 --return-child-result The debugger will exist with the same value
2858 the child (debugged) program exited with.
2859 --eval-command COMMAND, -ex COMMAND
2860 Execute a single GDB CLI command. This may be
2861 specified multiple times and in conjunction
2862 with the --command (-x) option.
2864 * Deprecated commands removed
2866 The following commands, that were deprecated in 2000, have been
2870 set|show arm disassembly-flavor set|show arm disassembler
2871 othernames set arm disassembler
2872 set|show remotedebug set|show debug remote
2873 set|show archdebug set|show debug arch
2874 set|show eventdebug set|show debug event
2877 * New BSD user-level threads support
2879 It is now possible to debug programs using the user-level threads
2880 library on OpenBSD and FreeBSD. Currently supported (target)
2883 FreeBSD/amd64 x86_64-*-freebsd*
2884 FreeBSD/i386 i386-*-freebsd*
2885 OpenBSD/i386 i386-*-openbsd*
2887 Note that the new kernel threads libraries introduced in FreeBSD 5.x
2888 are not yet supported.
2890 * New support for Matsushita MN10300 w/sim added
2891 (Work in progress). mn10300-elf.
2893 * REMOVED configurations and files
2895 VxWorks and the XDR protocol *-*-vxworks
2896 Motorola MCORE mcore-*-*
2897 National Semiconductor NS32000 ns32k-*-*
2899 * New "set print array-indexes" command
2901 After turning this setting "on", GDB prints the index of each element
2902 when displaying arrays. The default is "off" to preserve the previous
2905 * VAX floating point support
2907 GDB now supports the not-quite-ieee VAX F and D floating point formats.
2909 * User-defined command support
2911 In addition to using $arg0..$arg9 for argument passing, it is now possible
2912 to use $argc to determine now many arguments have been passed. See the
2913 section on user-defined commands in the user manual for more information.
2915 *** Changes in GDB 6.3:
2917 * New command line option
2919 GDB now accepts -l followed by a number to set the timeout for remote
2922 * GDB works with GCC -feliminate-dwarf2-dups
2924 GDB now supports a more compact representation of DWARF-2 debug
2925 information using DW_FORM_ref_addr references. These are produced
2926 by GCC with the option -feliminate-dwarf2-dups and also by some
2927 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
2928 to use -feliminate-dwarf2-dups.
2930 * Internationalization
2932 When supported by the host system, GDB will be built with
2933 internationalization (libintl). The task of marking up the sources is
2934 continued, we're looking forward to our first translation.
2938 Initial support for debugging programs compiled with the GNAT
2939 implementation of the Ada programming language has been integrated
2940 into GDB. In this release, support is limited to expression evaluation.
2942 * New native configurations
2944 GNU/Linux/m32r m32r-*-linux-gnu
2948 GDB's remote protocol now includes support for the 'p' packet. This
2949 packet is used to fetch individual registers from a remote inferior.
2951 * END-OF-LIFE registers[] compatibility module
2953 GDB's internal register infrastructure has been completely rewritten.
2954 The new infrastructure making possible the implementation of key new
2955 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
2958 GDB 6.3 will be the last release to include the the registers[]
2959 compatibility module that allowed out-of-date configurations to
2960 continue to work. This change directly impacts the following
2970 powerpc bdm protocol
2972 Unless there is activity to revive these configurations, they will be
2973 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
2975 * OBSOLETE configurations and files
2977 Configurations that have been declared obsolete in this release have
2978 been commented out. Unless there is activity to revive these
2979 configurations, the next release of GDB will have their sources
2980 permanently REMOVED.
2989 *** Changes in GDB 6.2.1:
2991 * MIPS `break main; run' gave an heuristic-fence-post warning
2993 When attempting to run even a simple program, a warning about
2994 heuristic-fence-post being hit would be reported. This problem has
2997 * MIPS IRIX 'long double' crashed GDB
2999 When examining a long double variable, GDB would get a segmentation
3000 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3001 IRIX long double values).
3005 A bug in the VAX stack code was causing problems with the "next"
3006 command. This problem has been fixed.
3008 *** Changes in GDB 6.2:
3010 * Fix for ``many threads''
3012 On GNU/Linux systems that use the NPTL threads library, a program
3013 rapidly creating and deleting threads would confuse GDB leading to the
3016 ptrace: No such process.
3017 thread_db_get_info: cannot get thread info: generic error
3019 This problem has been fixed.
3021 * "-async" and "-noasync" options removed.
3023 Support for the broken "-noasync" option has been removed (it caused
3026 * New ``start'' command.
3028 This command runs the program until the begining of the main procedure.
3030 * New BSD Kernel Data Access Library (libkvm) interface
3032 Using ``target kvm'' it is now possible to debug kernel core dumps and
3033 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3034 platforms. Currently supported (native-only) configurations are:
3036 FreeBSD/amd64 x86_64-*-freebsd*
3037 FreeBSD/i386 i?86-*-freebsd*
3038 NetBSD/i386 i?86-*-netbsd*
3039 NetBSD/m68k m68*-*-netbsd*
3040 NetBSD/sparc sparc-*-netbsd*
3041 OpenBSD/amd64 x86_64-*-openbsd*
3042 OpenBSD/i386 i?86-*-openbsd*
3043 OpenBSD/m68k m68*-openbsd*
3044 OpenBSD/sparc sparc-*-openbsd*
3046 * Signal trampoline code overhauled
3048 Many generic problems with GDB's signal handling code have been fixed.
3049 These include: backtraces through non-contiguous stacks; recognition
3050 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3051 call; backtrace through a signal trampoline; step into and out of
3052 signal handlers; and single-stepping in the signal trampoline.
3054 Please note that kernel bugs are a limiting factor here. These
3055 features have been shown to work on an s390 GNU/Linux system that
3056 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3058 * Cygwin support for DWARF 2 added.
3060 * New native configurations
3062 GNU/Linux/hppa hppa*-*-linux*
3063 OpenBSD/hppa hppa*-*-openbsd*
3064 OpenBSD/m68k m68*-*-openbsd*
3065 OpenBSD/m88k m88*-*-openbsd*
3066 OpenBSD/powerpc powerpc-*-openbsd*
3067 NetBSD/vax vax-*-netbsd*
3068 OpenBSD/vax vax-*-openbsd*
3070 * END-OF-LIFE frame compatibility module
3072 GDB's internal frame infrastructure has been completely rewritten.
3073 The new infrastructure making it possible to support key new features
3074 including DWARF 2 Call Frame Information. To aid in the task of
3075 migrating old configurations to this new infrastructure, a
3076 compatibility module, that allowed old configurations to continue to
3077 work, was also included.
3079 GDB 6.2 will be the last release to include this frame compatibility
3080 module. This change directly impacts the following configurations:
3090 Unless there is activity to revive these configurations, they will be
3091 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3093 * REMOVED configurations and files
3095 Sun 3, running SunOS 3 m68*-*-sunos3*
3096 Sun 3, running SunOS 4 m68*-*-sunos4*
3097 Sun 2, running SunOS 3 m68000-*-sunos3*
3098 Sun 2, running SunOS 4 m68000-*-sunos4*
3099 Motorola 680x0 running LynxOS m68*-*-lynxos*
3100 AT&T 3b1/Unix pc m68*-att-*
3101 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3102 decstation mips-dec-* mips-little-*
3103 riscos mips-*-riscos* mips-*-sysv*
3104 sonymips mips-sony-*
3105 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3107 *** Changes in GDB 6.1.1:
3109 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3111 The TUI (Text-mode User Interface) is now built as part of a default
3112 GDB configuration. It is enabled by either selecting the TUI with the
3113 command line option "-i=tui" or by running the separate "gdbtui"
3114 program. For more information on the TUI, see the manual "Debugging
3117 * Pending breakpoint support (also included in GDB 6.1)
3119 Support has been added to allow you to specify breakpoints in shared
3120 libraries that have not yet been loaded. If a breakpoint location
3121 cannot be found, and the "breakpoint pending" option is set to auto,
3122 GDB queries you if you wish to make the breakpoint pending on a future
3123 shared-library load. If and when GDB resolves the breakpoint symbol,
3124 the pending breakpoint is removed as one or more regular breakpoints
3127 Pending breakpoints are very useful for GCJ Java debugging.
3129 * Fixed ISO-C build problems
3131 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3132 non ISO-C code that stopped them being built using a more strict ISO-C
3133 compiler (e.g., IBM's C compiler).
3135 * Fixed build problem on IRIX 5
3137 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3138 wasn't able to compile compile on an IRIX 5 system.
3140 * Added execute permission to gdb/gdbserver/configure
3142 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3143 permission. This bug would cause configure to fail on a number of
3144 systems (Solaris, IRIX). Ref: server/519.
3146 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3148 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3149 has been updated to use constant array sizes.
3151 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3153 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3154 its generated DWARF Call Frame Info. This encoding was causing GDB to
3155 panic, that panic has been fixed. Ref: gdb/1628.
3157 * Fixed a problem when examining parameters in shared library code.
3159 When examining parameters in optimized shared library code generated
3160 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3161 not available''. GDB now correctly displays the variable's value.
3163 *** Changes in GDB 6.1:
3165 * Removed --with-mmalloc
3167 Support for the mmalloc memory manager has been removed, as it
3168 conflicted with the internal gdb byte cache.
3170 * Changes in AMD64 configurations
3172 The AMD64 target now includes the %cs and %ss registers. As a result
3173 the AMD64 remote protocol has changed; this affects the floating-point
3174 and SSE registers. If you rely on those registers for your debugging,
3175 you should upgrade gdbserver on the remote side.
3177 * Revised SPARC target
3179 The SPARC target has been completely revised, incorporating the
3180 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3181 support for LynxOS and SunOS 4 has been dropped. Calling functions
3182 from within GDB on operating systems with a non-executable stack
3183 (Solaris, OpenBSD) now works.
3187 GDB has a new C++ demangler which does a better job on the mangled
3188 names generated by current versions of g++. It also runs faster, so
3189 with this and other changes gdb should now start faster on large C++
3192 * DWARF 2 Location Expressions
3194 GDB support for location expressions has been extended to support function
3195 arguments and frame bases. Older versions of GDB could crash when they
3198 * C++ nested types and namespaces
3200 GDB's support for nested types and namespaces in C++ has been
3201 improved, especially if you use the DWARF 2 debugging format. (This
3202 is the default for recent versions of GCC on most platforms.)
3203 Specifically, if you have a class "Inner" defined within a class or
3204 namespace "Outer", then GDB realizes that the class's name is
3205 "Outer::Inner", not simply "Inner". This should greatly reduce the
3206 frequency of complaints about not finding RTTI symbols. In addition,
3207 if you are stopped at inside of a function defined within a namespace,
3208 GDB modifies its name lookup accordingly.
3210 * New native configurations
3212 NetBSD/amd64 x86_64-*-netbsd*
3213 OpenBSD/amd64 x86_64-*-openbsd*
3214 OpenBSD/alpha alpha*-*-openbsd*
3215 OpenBSD/sparc sparc-*-openbsd*
3216 OpenBSD/sparc64 sparc64-*-openbsd*
3218 * New debugging protocols
3220 M32R with SDI protocol m32r-*-elf*
3222 * "set prompt-escape-char" command deleted.
3224 The command "set prompt-escape-char" has been deleted. This command,
3225 and its very obscure effet on GDB's prompt, was never documented,
3226 tested, nor mentioned in the NEWS file.
3228 * OBSOLETE configurations and files
3230 Configurations that have been declared obsolete in this release have
3231 been commented out. Unless there is activity to revive these
3232 configurations, the next release of GDB will have their sources
3233 permanently REMOVED.
3235 Sun 3, running SunOS 3 m68*-*-sunos3*
3236 Sun 3, running SunOS 4 m68*-*-sunos4*
3237 Sun 2, running SunOS 3 m68000-*-sunos3*
3238 Sun 2, running SunOS 4 m68000-*-sunos4*
3239 Motorola 680x0 running LynxOS m68*-*-lynxos*
3240 AT&T 3b1/Unix pc m68*-att-*
3241 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3242 decstation mips-dec-* mips-little-*
3243 riscos mips-*-riscos* mips-*-sysv*
3244 sonymips mips-sony-*
3245 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3247 * REMOVED configurations and files
3249 SGI Irix-4.x mips-sgi-irix4 or iris4
3250 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3251 Z8000 simulator z8k-zilog-none or z8ksim
3252 Matsushita MN10200 w/simulator mn10200-*-*
3253 H8/500 simulator h8500-hitachi-hms or h8500hms
3254 HP/PA running BSD hppa*-*-bsd*
3255 HP/PA running OSF/1 hppa*-*-osf*
3256 HP/PA Pro target hppa*-*-pro*
3257 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3258 386BSD i[3456]86-*-bsd*
3259 Sequent family i[3456]86-sequent-sysv4*
3260 i[3456]86-sequent-sysv*
3261 i[3456]86-sequent-bsd*
3262 SPARC running LynxOS sparc-*-lynxos*
3263 SPARC running SunOS 4 sparc-*-sunos4*
3264 Tsqware Sparclet sparclet-*-*
3265 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3267 *** Changes in GDB 6.0:
3271 Support for debugging the Objective-C programming language has been
3272 integrated into GDB.
3274 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3276 DWARF 2's Call Frame Information makes available compiler generated
3277 information that more exactly describes the program's run-time stack.
3278 By using this information, GDB is able to provide more robust stack
3281 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3282 have been updated to use a new backtrace mechanism which includes
3283 DWARF 2 CFI support.
3287 GDB's remote protocol has been extended to include support for hosted
3288 file I/O (where the remote target uses GDB's file system). See GDB's
3289 remote protocol documentation for details.
3291 * All targets using the new architecture framework.
3293 All of GDB's targets have been updated to use the new internal
3294 architecture framework. The way is now open for future GDB releases
3295 to include cross-architecture native debugging support (i386 on amd64,
3298 * GNU/Linux's Thread Local Storage (TLS)
3300 GDB now includes support for for the GNU/Linux implementation of
3301 per-thread variables.
3303 * GNU/Linux's Native POSIX Thread Library (NPTL)
3305 GDB's thread code has been updated to work with either the new
3306 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3308 * Separate debug info.
3310 GDB, in conjunction with BINUTILS, now supports a mechanism for
3311 automatically loading debug information from a separate file. Instead
3312 of shipping full debug and non-debug versions of system libraries,
3313 system integrators can now instead ship just the stripped libraries
3314 and optional debug files.
3316 * DWARF 2 Location Expressions
3318 DWARF 2 Location Expressions allow the compiler to more completely
3319 describe the location of variables (even in optimized code) to the
3322 GDB now includes preliminary support for location expressions (support
3323 for DW_OP_piece is still missing).
3327 A number of long standing bugs that caused GDB to die while starting a
3328 Java application have been fixed. GDB's Java support is now
3329 considered "useable".
3331 * GNU/Linux support for fork, vfork, and exec.
3333 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3334 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3337 * GDB supports logging output to a file
3339 There are two new commands, "set logging" and "show logging", which can be
3340 used to capture GDB's output to a file.
3342 * The meaning of "detach" has changed for gdbserver
3344 The "detach" command will now resume the application, as documented. To
3345 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3348 * d10v, m68hc11 `regs' command deprecated
3350 The `info registers' command has been updated so that it displays the
3351 registers using a format identical to the old `regs' command.
3355 A new command, "maint set profile on/off", has been added. This command can
3356 be used to enable or disable profiling while running GDB, to profile a
3357 session or a set of commands. In addition there is a new configure switch,
3358 "--enable-profiling", which will cause GDB to be compiled with profiling
3359 data, for more informative profiling results.
3361 * Default MI syntax changed to "mi2".
3363 The default MI (machine interface) syntax, enabled by the command line
3364 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3365 "mi1", can be enabled by specifying the option "-i=mi1".
3367 Support for the original "mi0" syntax (included in GDB 5.0) has been
3370 Fix for gdb/192: removed extraneous space when displaying frame level.
3371 Fix for gdb/672: update changelist is now output in mi list format.
3372 Fix for gdb/702: a -var-assign that updates the value now shows up
3373 in a subsequent -var-update.
3375 * New native configurations.
3377 FreeBSD/amd64 x86_64-*-freebsd*
3379 * Multi-arched targets.
3381 HP/PA HPUX11 hppa*-*-hpux*
3382 Renesas M32R/D w/simulator m32r-*-elf*
3384 * OBSOLETE configurations and files
3386 Configurations that have been declared obsolete in this release have
3387 been commented out. Unless there is activity to revive these
3388 configurations, the next release of GDB will have their sources
3389 permanently REMOVED.
3391 Z8000 simulator z8k-zilog-none or z8ksim
3392 Matsushita MN10200 w/simulator mn10200-*-*
3393 H8/500 simulator h8500-hitachi-hms or h8500hms
3394 HP/PA running BSD hppa*-*-bsd*
3395 HP/PA running OSF/1 hppa*-*-osf*
3396 HP/PA Pro target hppa*-*-pro*
3397 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3398 Sequent family i[3456]86-sequent-sysv4*
3399 i[3456]86-sequent-sysv*
3400 i[3456]86-sequent-bsd*
3401 Tsqware Sparclet sparclet-*-*
3402 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3404 * REMOVED configurations and files
3407 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3408 IBM AIX PS/2 i[3456]86-*-aix
3409 i386 running Mach 3.0 i[3456]86-*-mach3*
3410 i386 running Mach i[3456]86-*-mach*
3411 i386 running OSF/1 i[3456]86-*osf1mk*
3412 HP/Apollo 68k Family m68*-apollo*-sysv*,
3414 m68*-hp-bsd*, m68*-hp-hpux*
3415 Argonaut Risc Chip (ARC) arc-*-*
3416 Mitsubishi D30V d30v-*-*
3417 Fujitsu FR30 fr30-*-elf*
3418 OS/9000 i[34]86-*-os9k
3419 I960 with MON960 i960-*-coff
3421 * MIPS $fp behavior changed
3423 The convenience variable $fp, for the MIPS, now consistently returns
3424 the address of the current frame's base. Previously, depending on the
3425 context, $fp could refer to either $sp or the current frame's base
3426 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3427 The GNU Source-Level Debugger''.
3429 *** Changes in GDB 5.3:
3431 * GNU/Linux shared library multi-threaded performance improved.
3433 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3434 `/proc', in preference to `ptrace' for memory reads. This may result
3435 in an improvement in the start-up time of multi-threaded, shared
3436 library applications when run under GDB. One GDB user writes: ``loads
3437 shared libs like mad''.
3439 * ``gdbserver'' now supports multi-threaded applications on some targets
3441 Support for debugging multi-threaded applications which use
3442 the GNU/Linux LinuxThreads package has been added for
3443 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3444 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3446 * GDB now supports C/C++ preprocessor macros.
3448 GDB now expands preprocessor macro invocations in C/C++ expressions,
3449 and provides various commands for showing macro definitions and how
3452 The new command `macro expand EXPRESSION' expands any macro
3453 invocations in expression, and shows the result.
3455 The new command `show macro MACRO-NAME' shows the definition of the
3456 macro named MACRO-NAME, and where it was defined.
3458 Most compilers don't include information about macros in the debugging
3459 information by default. In GCC 3.1, for example, you need to compile
3460 your program with the options `-gdwarf-2 -g3'. If the macro
3461 information is present in the executable, GDB will read it.
3463 * Multi-arched targets.
3465 DEC Alpha (partial) alpha*-*-*
3466 DEC VAX (partial) vax-*-*
3468 National Semiconductor NS32000 (partial) ns32k-*-*
3469 Motorola 68000 (partial) m68k-*-*
3470 Motorola MCORE mcore-*-*
3474 Fujitsu FRV architecture added by Red Hat frv*-*-*
3477 * New native configurations
3479 Alpha NetBSD alpha*-*-netbsd*
3480 SH NetBSD sh*-*-netbsdelf*
3481 MIPS NetBSD mips*-*-netbsd*
3482 UltraSPARC NetBSD sparc64-*-netbsd*
3484 * OBSOLETE configurations and files
3486 Configurations that have been declared obsolete in this release have
3487 been commented out. Unless there is activity to revive these
3488 configurations, the next release of GDB will have their sources
3489 permanently REMOVED.
3491 Mitsubishi D30V d30v-*-*
3492 OS/9000 i[34]86-*-os9k
3493 IBM AIX PS/2 i[3456]86-*-aix
3494 Fujitsu FR30 fr30-*-elf*
3495 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3496 Argonaut Risc Chip (ARC) arc-*-*
3497 i386 running Mach 3.0 i[3456]86-*-mach3*
3498 i386 running Mach i[3456]86-*-mach*
3499 i386 running OSF/1 i[3456]86-*osf1mk*
3500 HP/Apollo 68k Family m68*-apollo*-sysv*,
3502 m68*-hp-bsd*, m68*-hp-hpux*
3503 I960 with MON960 i960-*-coff
3505 * OBSOLETE languages
3507 CHILL, a Pascal like language used by telecommunications companies.
3509 * REMOVED configurations and files
3511 AMD 29k family via UDI a29k-amd-udi, udi29k
3512 A29K VxWorks a29k-*-vxworks
3513 AMD 29000 embedded, using EBMON a29k-none-none
3514 AMD 29000 embedded with COFF a29k-none-coff
3515 AMD 29000 embedded with a.out a29k-none-aout
3517 testsuite/gdb.hp/gdb.threads-hp/ directory
3519 * New command "set max-user-call-depth <nnn>"
3521 This command allows the user to limit the call depth of user-defined
3522 commands. The default is 1024.
3524 * Changes in FreeBSD/i386 native debugging.
3526 Support for the "generate-core-file" has been added.
3528 * New commands "dump", "append", and "restore".
3530 These commands allow data to be copied from target memory
3531 to a bfd-format or binary file (dump and append), and back
3532 from a file into memory (restore).
3534 * Improved "next/step" support on multi-processor Alpha Tru64.
3536 The previous single-step mechanism could cause unpredictable problems,
3537 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3538 of a software single-step mechanism prevents this.
3540 *** Changes in GDB 5.2.1:
3548 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3549 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3550 Fix, by Joel Brobecker imported from mainline.
3552 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3553 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3554 Fix, by Fred Fish, imported from mainline.
3556 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3557 Surprisingly enough, it works now.
3558 By Michal Ludvig, imported from mainline.
3560 i386 hardware watchpoint support:
3561 avoid misses on second run for some targets.
3562 By Pierre Muller, imported from mainline.
3564 *** Changes in GDB 5.2:
3566 * New command "set trust-readonly-sections on[off]".
3568 This command is a hint that tells gdb that read-only sections
3569 really are read-only (ie. that their contents will not change).
3570 In this mode, gdb will go to the object file rather than the
3571 target to read memory from read-only sections (such as ".text").
3572 This can be a significant performance improvement on some
3573 (notably embedded) targets.
3575 * New command "generate-core-file" (or "gcore").
3577 This new gdb command allows the user to drop a core file of the child
3578 process state at any time. So far it's been implemented only for
3579 GNU/Linux and Solaris, but should be relatively easily ported to other
3580 hosts. Argument is core file name (defaults to core.<pid>).
3582 * New command line option
3584 GDB now accepts --pid or -p followed by a process id.
3586 * Change in command line behavior -- corefiles vs. process ids.
3588 There is a subtle behavior in the way in which GDB handles
3589 command line arguments. The first non-flag argument is always
3590 a program to debug, but the second non-flag argument may either
3591 be a corefile or a process id. Previously, GDB would attempt to
3592 open the second argument as a corefile, and if that failed, would
3593 issue a superfluous error message and then attempt to attach it as
3594 a process. Now, if the second argument begins with a non-digit,
3595 it will be treated as a corefile. If it begins with a digit,
3596 GDB will attempt to attach it as a process, and if no such process
3597 is found, will then attempt to open it as a corefile.
3599 * Changes in ARM configurations.
3601 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3602 configuration is fully multi-arch.
3604 * New native configurations
3606 ARM NetBSD arm*-*-netbsd*
3607 x86 OpenBSD i[3456]86-*-openbsd*
3608 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3609 Sparc64 running FreeBSD sparc64-*-freebsd*
3613 Sanyo XStormy16 xstormy16-elf
3615 * OBSOLETE configurations and files
3617 Configurations that have been declared obsolete in this release have
3618 been commented out. Unless there is activity to revive these
3619 configurations, the next release of GDB will have their sources
3620 permanently REMOVED.
3622 AMD 29k family via UDI a29k-amd-udi, udi29k
3623 A29K VxWorks a29k-*-vxworks
3624 AMD 29000 embedded, using EBMON a29k-none-none
3625 AMD 29000 embedded with COFF a29k-none-coff
3626 AMD 29000 embedded with a.out a29k-none-aout
3628 testsuite/gdb.hp/gdb.threads-hp/ directory
3630 * REMOVED configurations and files
3632 TI TMS320C80 tic80-*-*
3634 PowerPC Solaris powerpcle-*-solaris*
3635 PowerPC Windows NT powerpcle-*-cygwin32
3636 PowerPC Netware powerpc-*-netware*
3637 Harris/CXUX m88k m88*-harris-cxux*
3638 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3639 ns32k-utek-sysv* ns32k-utek-*
3640 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3641 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3642 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3643 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3644 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3646 * Changes to command line processing
3648 The new `--args' feature can be used to specify command-line arguments
3649 for the inferior from gdb's command line.
3651 * Changes to key bindings
3653 There is a new `operate-and-get-next' function bound to `C-o'.
3655 *** Changes in GDB 5.1.1
3657 Fix compile problem on DJGPP.
3659 Fix a problem with floating-point registers on the i386 being
3662 Fix to stop GDB crashing on .debug_str debug info.
3664 Numerous documentation fixes.
3666 Numerous testsuite fixes.
3668 *** Changes in GDB 5.1:
3670 * New native configurations
3672 Alpha FreeBSD alpha*-*-freebsd*
3673 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3674 MIPS GNU/Linux mips*-*-linux*
3675 MIPS SGI Irix 6.x mips*-sgi-irix6*
3676 ia64 AIX ia64-*-aix*
3677 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3681 Motorola 68HC11 and 68HC12 m68hc11-elf
3683 UltraSparc running GNU/Linux sparc64-*-linux*
3685 * OBSOLETE configurations and files
3687 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3688 Harris/CXUX m88k m88*-harris-cxux*
3689 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3690 ns32k-utek-sysv* ns32k-utek-*
3691 TI TMS320C80 tic80-*-*
3693 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3694 PowerPC Solaris powerpcle-*-solaris*
3695 PowerPC Windows NT powerpcle-*-cygwin32
3696 PowerPC Netware powerpc-*-netware*
3697 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3698 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3699 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3700 Apple Macintosh (MPW) host N/A
3702 stuff.c (Program to stuff files into a specially prepared space in kdb)
3703 kdb-start.c (Main loop for the standalone kernel debugger)
3705 Configurations that have been declared obsolete in this release have
3706 been commented out. Unless there is activity to revive these
3707 configurations, the next release of GDB will have their sources
3708 permanently REMOVED.
3710 * REMOVED configurations and files
3712 Altos 3068 m68*-altos-*
3713 Convex c1-*-*, c2-*-*
3715 ARM RISCix arm-*-* (as host)
3719 * GDB has been converted to ISO C.
3721 GDB's source code has been converted to ISO C. In particular, the
3722 sources are fully protoized, and rely on standard headers being
3727 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3729 * The MI enabled by default.
3731 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3732 revised and enabled by default. Packages which use GDB as a debugging
3733 engine behind a UI or another front end are encouraged to switch to
3734 using the GDB/MI interface, instead of the old annotations interface
3735 which is now deprecated.
3737 * Support for debugging Pascal programs.
3739 GDB now includes support for debugging Pascal programs. The following
3740 main features are supported:
3742 - Pascal-specific data types such as sets;
3744 - automatic recognition of Pascal sources based on file-name
3747 - Pascal-style display of data types, variables, and functions;
3749 - a Pascal expression parser.
3751 However, some important features are not yet supported.
3753 - Pascal string operations are not supported at all;
3755 - there are some problems with boolean types;
3757 - Pascal type hexadecimal constants are not supported
3758 because they conflict with the internal variables format;
3760 - support for Pascal objects and classes is not full yet;
3762 - unlike Pascal, GDB is case-sensitive for symbol names.
3764 * Changes in completion.
3766 Commands such as `shell', `run' and `set args', which pass arguments
3767 to inferior programs, now complete on file names, similar to what
3768 users expect at the shell prompt.
3770 Commands which accept locations, such as `disassemble', `print',
3771 `breakpoint', `until', etc. now complete on filenames as well as
3772 program symbols. Thus, if you type "break foob TAB", and the source
3773 files linked into the programs include `foobar.c', that file name will
3774 be one of the candidates for completion. However, file names are not
3775 considered for completion after you typed a colon that delimits a file
3776 name from a name of a function in that file, as in "break foo.c:bar".
3778 `set demangle-style' completes on available demangling styles.
3780 * New platform-independent commands:
3782 It is now possible to define a post-hook for a command as well as a
3783 hook that runs before the command. For more details, see the
3784 documentation of `hookpost' in the GDB manual.
3786 * Changes in GNU/Linux native debugging.
3788 Support for debugging multi-threaded programs has been completely
3789 revised for all platforms except m68k and sparc. You can now debug as
3790 many threads as your system allows you to have.
3792 Attach/detach is supported for multi-threaded programs.
3794 Support for SSE registers was added for x86. This doesn't work for
3795 multi-threaded programs though.
3797 * Changes in MIPS configurations.
3799 Multi-arch support is enabled for all MIPS configurations.
3801 GDB can now be built as native debugger on SGI Irix 6.x systems for
3802 debugging n32 executables. (Debugging 64-bit executables is not yet
3805 * Unified support for hardware watchpoints in all x86 configurations.
3807 Most (if not all) native x86 configurations support hardware-assisted
3808 breakpoints and watchpoints in a unified manner. This support
3809 implements debug register sharing between watchpoints, which allows to
3810 put a virtually infinite number of watchpoints on the same address,
3811 and also supports watching regions up to 16 bytes with several debug
3814 The new maintenance command `maintenance show-debug-regs' toggles
3815 debugging print-outs in functions that insert, remove, and test
3816 watchpoints and hardware breakpoints.
3818 * Changes in the DJGPP native configuration.
3820 New command ``info dos sysinfo'' displays assorted information about
3821 the CPU, OS, memory, and DPMI server.
3823 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3824 display information about segment descriptors stored in GDT, LDT, and
3827 New commands ``info dos pde'' and ``info dos pte'' display entries
3828 from Page Directory and Page Tables (for now works with CWSDPMI only).
3829 New command ``info dos address-pte'' displays the Page Table entry for
3830 a given linear address.
3832 GDB can now pass command lines longer than 126 characters to the
3833 program being debugged (requires an update to the libdbg.a library
3834 which is part of the DJGPP development kit).
3836 DWARF2 debug info is now supported.
3838 It is now possible to `step' and `next' through calls to `longjmp'.
3840 * Changes in documentation.
3842 All GDB documentation was converted to GFDL, the GNU Free
3843 Documentation License.
3845 Tracepoints-related commands are now fully documented in the GDB
3848 TUI, the Text-mode User Interface, is now documented in the manual.
3850 Tracepoints-related commands are now fully documented in the GDB
3853 The "GDB Internals" manual now has an index. It also includes
3854 documentation of `ui_out' functions, GDB coding standards, x86
3855 hardware watchpoints, and memory region attributes.
3857 * GDB's version number moved to ``version.in''
3859 The Makefile variable VERSION has been replaced by the file
3860 ``version.in''. People creating GDB distributions should update the
3861 contents of this file.
3865 GUD support is now a standard part of the EMACS distribution.
3867 *** Changes in GDB 5.0:
3869 * Improved support for debugging FP programs on x86 targets
3871 Unified and much-improved support for debugging floating-point
3872 programs on all x86 targets. In particular, ``info float'' now
3873 displays the FP registers in the same format on all x86 targets, with
3874 greater level of detail.
3876 * Improvements and bugfixes in hardware-assisted watchpoints
3878 It is now possible to watch array elements, struct members, and
3879 bitfields with hardware-assisted watchpoints. Data-read watchpoints
3880 on x86 targets no longer erroneously trigger when the address is
3883 * Improvements in the native DJGPP version of GDB
3885 The distribution now includes all the scripts and auxiliary files
3886 necessary to build the native DJGPP version on MS-DOS/MS-Windows
3887 machines ``out of the box''.
3889 The DJGPP version can now debug programs that use signals. It is
3890 possible to catch signals that happened in the debuggee, deliver
3891 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
3892 would kill the program being debugged.) Programs that hook hardware
3893 interrupts (keyboard, timer, etc.) can also be debugged.
3895 It is now possible to debug DJGPP programs that redirect their
3896 standard handles or switch them to raw (as opposed to cooked) mode, or
3897 even close them. The command ``run < foo > bar'' works as expected,
3898 and ``info terminal'' reports useful information about the debuggee's
3899 terminal, including raw/cooked mode, redirection, etc.
3901 The DJGPP version now uses termios functions for console I/O, which
3902 enables debugging graphics programs. Interrupting GDB with Ctrl-C
3905 DOS-style file names with drive letters are now fully supported by
3908 It is now possible to debug DJGPP programs that switch their working
3909 directory. It is also possible to rerun the debuggee any number of
3910 times without restarting GDB; thus, you can use the same setup,
3911 breakpoints, etc. for many debugging sessions.
3913 * New native configurations
3915 ARM GNU/Linux arm*-*-linux*
3916 PowerPC GNU/Linux powerpc-*-linux*
3920 Motorola MCore mcore-*-*
3921 x86 VxWorks i[3456]86-*-vxworks*
3922 PowerPC VxWorks powerpc-*-vxworks*
3923 TI TMS320C80 tic80-*-*
3925 * OBSOLETE configurations
3927 Altos 3068 m68*-altos-*
3928 Convex c1-*-*, c2-*-*
3930 ARM RISCix arm-*-* (as host)
3933 Configurations that have been declared obsolete will be commented out,
3934 but the code will be left in place. If there is no activity to revive
3935 these configurations before the next release of GDB, the sources will
3936 be permanently REMOVED.
3938 * Gould support removed
3940 Support for the Gould PowerNode and NP1 has been removed.
3942 * New features for SVR4
3944 On SVR4 native platforms (such as Solaris), if you attach to a process
3945 without first loading a symbol file, GDB will now attempt to locate and
3946 load symbols from the running process's executable file.
3948 * Many C++ enhancements
3950 C++ support has been greatly improved. Overload resolution now works properly
3951 in almost all cases. RTTI support is on the way.
3953 * Remote targets can connect to a sub-program
3955 A popen(3) style serial-device has been added. This device starts a
3956 sub-process (such as a stand-alone simulator) and then communicates
3957 with that. The sub-program to run is specified using the syntax
3958 ``|<program> <args>'' vis:
3960 (gdb) set remotedebug 1
3961 (gdb) target extended-remote |mn10300-elf-sim program-args
3963 * MIPS 64 remote protocol
3965 A long standing bug in the mips64 remote protocol where by GDB
3966 expected certain 32 bit registers (ex SR) to be transfered as 32
3967 instead of 64 bits has been fixed.
3969 The command ``set remote-mips64-transfers-32bit-regs on'' has been
3970 added to provide backward compatibility with older versions of GDB.
3972 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
3974 The command ``set remotebinarydownload'' command has been replaced by
3975 ``set remote X-packet''. Other commands in ``set remote'' family
3976 include ``set remote P-packet''.
3978 * Breakpoint commands accept ranges.
3980 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
3981 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
3982 ``tracepoint passcount'' also accepts a range of tracepoints.
3984 * ``apropos'' command added.
3986 The ``apropos'' command searches through command names and
3987 documentation strings, printing out matches, making it much easier to
3988 try to find a command that does what you are looking for.
3992 A new machine oriented interface (MI) has been added to GDB. This
3993 interface is designed for debug environments running GDB as a separate
3994 process. This is part of the long term libGDB project. See the
3995 "GDB/MI" chapter of the GDB manual for further information. It can be
3996 enabled by configuring with:
3998 .../configure --enable-gdbmi
4000 *** Changes in GDB-4.18:
4002 * New native configurations
4004 HP-UX 10.20 hppa*-*-hpux10.20
4005 HP-UX 11.x hppa*-*-hpux11.0*
4006 M68K GNU/Linux m68*-*-linux*
4010 Fujitsu FR30 fr30-*-elf*
4011 Intel StrongARM strongarm-*-*
4012 Mitsubishi D30V d30v-*-*
4014 * OBSOLETE configurations
4016 Gould PowerNode, NP1 np1-*-*, pn-*-*
4018 Configurations that have been declared obsolete will be commented out,
4019 but the code will be left in place. If there is no activity to revive
4020 these configurations before the next release of GDB, the sources will
4021 be permanently REMOVED.
4025 As a compatibility experiment, GDB's source files buildsym.h and
4026 buildsym.c have been converted to pure standard C, no longer
4027 containing any K&R compatibility code. We believe that all systems in
4028 use today either come with a standard C compiler, or have a GCC port
4029 available. If this is not true, please report the affected
4030 configuration to bug-gdb@gnu.org immediately. See the README file for
4031 information about getting a standard C compiler if you don't have one
4036 GDB now uses readline 2.2.
4038 * set extension-language
4040 You can now control the mapping between filename extensions and source
4041 languages by using the `set extension-language' command. For instance,
4042 you can ask GDB to treat .c files as C++ by saying
4043 set extension-language .c c++
4044 The command `info extensions' lists all of the recognized extensions
4045 and their associated languages.
4047 * Setting processor type for PowerPC and RS/6000
4049 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4050 you can use the `set processor' command to specify what variant of the
4051 PowerPC family you are debugging. The command
4055 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4056 following PowerPC and RS6000 variants:
4058 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4059 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4061 403GC IBM PowerPC 403GC
4062 505 Motorola PowerPC 505
4063 860 Motorola PowerPC 860 or 850
4064 601 Motorola PowerPC 601
4065 602 Motorola PowerPC 602
4066 603 Motorola/IBM PowerPC 603 or 603e
4067 604 Motorola PowerPC 604 or 604e
4068 750 Motorola/IBM PowerPC 750 or 750
4070 At the moment, this command just tells GDB what to name the
4071 special-purpose processor registers. Since almost all the affected
4072 registers are inaccessible to user-level programs, this command is
4073 only useful for remote debugging in its present form.
4077 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4078 more extensive support for HP-UX. Added features include shared
4079 library support, kernel threads and hardware watchpoints for 11.00,
4080 support for HP's ANSI C and C++ compilers, and a compatibility mode
4081 for xdb and dbx commands.
4085 HP's donation includes the new concept of catchpoints, which is a
4086 generalization of the old catch command. On HP-UX, it is now possible
4087 to catch exec, fork, and vfork, as well as library loading.
4089 This means that the existing catch command has changed; its first
4090 argument now specifies the type of catch to be set up. See the
4091 output of "help catch" for a list of catchpoint types.
4093 * Debugging across forks
4095 On HP-UX, you can choose which process to debug when a fork() happens
4100 HP has donated a curses-based terminal user interface (TUI). To get
4101 it, build with --enable-tui. Although this can be enabled for any
4102 configuration, at present it only works for native HP debugging.
4104 * GDB remote protocol additions
4106 A new protocol packet 'X' that writes binary data is now available.
4107 Default behavior is to try 'X', then drop back to 'M' if the stub
4108 fails to respond. The settable variable `remotebinarydownload'
4109 allows explicit control over the use of 'X'.
4111 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4112 full 64-bit address. The command
4114 set remoteaddresssize 32
4116 can be used to revert to the old behaviour. For existing remote stubs
4117 the change should not be noticed, as the additional address information
4120 In order to assist in debugging stubs, you may use the maintenance
4121 command `packet' to send any text string to the stub. For instance,
4123 maint packet heythere
4125 sends the packet "$heythere#<checksum>". Note that it is very easy to
4126 disrupt a debugging session by sending the wrong packet at the wrong
4129 The compare-sections command allows you to compare section data on the
4130 target to what is in the executable file without uploading or
4131 downloading, by comparing CRC checksums.
4133 * Tracing can collect general expressions
4135 You may now collect general expressions at tracepoints. This requires
4136 further additions to the target-side stub; see tracepoint.c and
4137 doc/agentexpr.texi for further details.
4139 * mask-address variable for Mips
4141 For Mips targets, you may control the zeroing of the upper 32 bits of
4142 a 64-bit address by entering `set mask-address on'. This is mainly
4143 of interest to users of embedded R4xxx and R5xxx processors.
4145 * Higher serial baud rates
4147 GDB's serial code now allows you to specify baud rates 57600, 115200,
4148 230400, and 460800 baud. (Note that your host system may not be able
4149 to achieve all of these rates.)
4153 The i960 configuration now includes an initial implementation of a
4154 builtin simulator, contributed by Jim Wilson.
4157 *** Changes in GDB-4.17:
4159 * New native configurations
4161 Alpha GNU/Linux alpha*-*-linux*
4162 Unixware 2.x i[3456]86-unixware2*
4163 Irix 6.x mips*-sgi-irix6*
4164 PowerPC GNU/Linux powerpc-*-linux*
4165 PowerPC Solaris powerpcle-*-solaris*
4166 Sparc GNU/Linux sparc-*-linux*
4167 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4171 Argonaut Risc Chip (ARC) arc-*-*
4172 Hitachi H8/300S h8300*-*-*
4173 Matsushita MN10200 w/simulator mn10200-*-*
4174 Matsushita MN10300 w/simulator mn10300-*-*
4175 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4176 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4177 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4178 Mitsubishi D10V w/simulator d10v-*-*
4179 Mitsubishi M32R/D w/simulator m32r-*-elf*
4180 Tsqware Sparclet sparclet-*-*
4181 NEC V850 w/simulator v850-*-*
4183 * New debugging protocols
4185 ARM with RDI protocol arm*-*-*
4186 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4187 DDB and LSI variants of PMON protocol mips*-*-*
4188 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4189 PowerPC with SDS protocol powerpc{,le}-*-eabi
4190 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4194 All configurations can now understand and use the DWARF 2 debugging
4195 format. The choice is automatic, if the symbol file contains DWARF 2
4200 GDB now includes basic Java language support. This support is
4201 only useful with Java compilers that produce native machine code.
4203 * solib-absolute-prefix and solib-search-path
4205 For SunOS and SVR4 shared libraries, you may now set the prefix for
4206 loading absolute shared library symbol files, and the search path for
4207 locating non-absolute shared library symbol files.
4209 * Live range splitting
4211 GDB can now effectively debug code for which GCC has performed live
4212 range splitting as part of its optimization. See gdb/doc/LRS for
4213 more details on the expected format of the stabs information.
4217 GDB's support for the GNU Hurd, including thread debugging, has been
4218 updated to work with current versions of the Hurd.
4222 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4223 instruction set. ARM GDB automatically detects when Thumb
4224 instructions are in use, and adjusts disassembly and backtracing
4229 GDB's MIPS target configurations now handle the MIP16 16-bit
4234 GDB now includes support for overlays; if an executable has been
4235 linked such that multiple sections are based at the same address, GDB
4236 will decide which section to use for symbolic info. You can choose to
4237 control the decision manually, using overlay commands, or implement
4238 additional target-side support and use "overlay load-target" to bring
4239 in the overlay mapping. Do "help overlay" for more detail.
4243 The command "info symbol <address>" displays information about
4244 the symbol at the specified address.
4248 The standard remote protocol now includes an extension that allows
4249 asynchronous collection and display of trace data. This requires
4250 extensive support in the target-side debugging stub. Tracing mode
4251 includes a new interaction mode in GDB and new commands: see the
4252 file tracepoint.c for more details.
4256 Configurations for embedded MIPS now include a simulator contributed
4257 by Cygnus Solutions. The simulator supports the instruction sets
4258 of most MIPS variants.
4262 Sparc configurations may now include the ERC32 simulator contributed
4263 by the European Space Agency. The simulator is not built into
4264 Sparc targets by default; configure with --enable-sim to include it.
4268 For target configurations that may include multiple variants of a
4269 basic architecture (such as MIPS and SH), you may now set the
4270 architecture explicitly. "set arch" sets, "info arch" lists
4271 the possible architectures.
4273 *** Changes in GDB-4.16:
4275 * New native configurations
4277 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4278 M68K NetBSD m68k-*-netbsd*
4279 PowerPC AIX 4.x powerpc-*-aix*
4280 PowerPC MacOS powerpc-*-macos*
4281 PowerPC Windows NT powerpcle-*-cygwin32
4282 RS/6000 AIX 4.x rs6000-*-aix4*
4286 ARM with RDP protocol arm-*-*
4287 I960 with MON960 i960-*-coff
4288 MIPS VxWorks mips*-*-vxworks*
4289 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4290 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4292 Matra Sparclet sparclet-*-*
4296 The powerpc-eabi configuration now includes the PSIM simulator,
4297 contributed by Andrew Cagney, with assistance from Mike Meissner.
4298 PSIM is a very elaborate model of the PowerPC, including not only
4299 basic instruction set execution, but also details of execution unit
4300 performance and I/O hardware. See sim/ppc/README for more details.
4304 GDB now works with Solaris 2.5.
4306 * Windows 95/NT native
4308 GDB will now work as a native debugger on Windows 95 and Windows NT.
4309 To build it from source, you must use the "gnu-win32" environment,
4310 which uses a DLL to emulate enough of Unix to run the GNU tools.
4311 Further information, binaries, and sources are available at
4312 ftp.cygnus.com, under pub/gnu-win32.
4314 * dont-repeat command
4316 If a user-defined command includes the command `dont-repeat', then the
4317 command will not be repeated if the user just types return. This is
4318 useful if the command is time-consuming to run, so that accidental
4319 extra keystrokes don't run the same command many times.
4321 * Send break instead of ^C
4323 The standard remote protocol now includes an option to send a break
4324 rather than a ^C to the target in order to interrupt it. By default,
4325 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4327 * Remote protocol timeout
4329 The standard remote protocol includes a new variable `remotetimeout'
4330 that allows you to set the number of seconds before GDB gives up trying
4331 to read from the target. The default value is 2.
4333 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4335 By default GDB will automatically keep track of objects as they are
4336 loaded and unloaded by the dynamic linker. By using the command `set
4337 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4338 when shared library events occur, thus allowing you to set breakpoints
4339 in shared libraries which are explicitly loaded by the inferior.
4341 Note this feature does not work on hpux8. On hpux9 you must link
4342 /usr/lib/end.o into your program. This feature should work
4343 automatically on hpux10.
4345 * Irix 5.x hardware watchpoint support
4347 Irix 5 configurations now support the use of hardware watchpoints.
4349 * Mips protocol "SYN garbage limit"
4351 When debugging a Mips target using the `target mips' protocol, you
4352 may set the number of characters that GDB will ignore by setting
4353 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4354 every character. The default value is 1050.
4356 * Recording and replaying remote debug sessions
4358 If you set `remotelogfile' to the name of a file, gdb will write to it
4359 a recording of a remote debug session. This recording may then be
4360 replayed back to gdb using "gdbreplay". See gdbserver/README for
4361 details. This is useful when you have a problem with GDB while doing
4362 remote debugging; you can make a recording of the session and send it
4363 to someone else, who can then recreate the problem.
4365 * Speedups for remote debugging
4367 GDB includes speedups for downloading and stepping MIPS systems using
4368 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4369 and more efficient S-record downloading.
4371 * Memory use reductions and statistics collection
4373 GDB now uses less memory and reports statistics about memory usage.
4374 Try the `maint print statistics' command, for example.
4376 *** Changes in GDB-4.15:
4378 * Psymtabs for XCOFF
4380 The symbol reader for AIX GDB now uses partial symbol tables. This
4381 can greatly improve startup time, especially for large executables.
4383 * Remote targets use caching
4385 Remote targets now use a data cache to speed up communication with the
4386 remote side. The data cache could lead to incorrect results because
4387 it doesn't know about volatile variables, thus making it impossible to
4388 debug targets which use memory mapped I/O devices. `set remotecache
4389 off' turns the the data cache off.
4391 * Remote targets may have threads
4393 The standard remote protocol now includes support for multiple threads
4394 in the target system, using new protocol commands 'H' and 'T'. See
4395 gdb/remote.c for details.
4399 If GDB is configured with `--enable-netrom', then it will include
4400 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4401 acts as though it is a bank of ROM on the target board, but you can
4402 write into it over the network. GDB's support consists only of
4403 support for fast loading into the emulated ROM; to debug, you must use
4404 another protocol, such as standard remote protocol. The usual
4405 sequence is something like
4407 target nrom <netrom-hostname>
4409 target remote <netrom-hostname>:1235
4413 GDB now includes support for the Apple Macintosh, as a host only. It
4414 may be run as either an MPW tool or as a standalone application, and
4415 it can debug through the serial port. All the usual GDB commands are
4416 available, but to the target command, you must supply "serial" as the
4417 device type instead of "/dev/ttyXX". See mpw-README in the main
4418 directory for more information on how to build. The MPW configuration
4419 scripts */mpw-config.in support only a few targets, and only the
4420 mips-idt-ecoff target has been tested.
4424 GDB configuration now uses autoconf. This is not user-visible,
4425 but does simplify configuration and building.
4429 GDB now supports hpux10.
4431 *** Changes in GDB-4.14:
4433 * New native configurations
4435 x86 FreeBSD i[345]86-*-freebsd
4436 x86 NetBSD i[345]86-*-netbsd
4437 NS32k NetBSD ns32k-*-netbsd
4438 Sparc NetBSD sparc-*-netbsd
4442 A29K VxWorks a29k-*-vxworks
4443 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4444 CPU32 EST-300 emulator m68*-*-est*
4445 PowerPC ELF powerpc-*-elf
4448 * Alpha OSF/1 support for procfs
4450 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4451 possible to attach to running processes. As the mounting of the /proc
4452 filesystem is optional on the Alpha, GDB automatically determines
4453 the availability of /proc during startup. This can lead to problems
4454 if /proc is unmounted after GDB has been started.
4456 * Arguments to user-defined commands
4458 User commands may accept up to 10 arguments separated by whitespace.
4459 Arguments are accessed within the user command via $arg0..$arg9. A
4462 print $arg0 + $arg1 + $arg2
4464 To execute the command use:
4467 Defines the command "adder" which prints the sum of its three arguments.
4468 Note the arguments are text substitutions, so they may reference variables,
4469 use complex expressions, or even perform inferior function calls.
4471 * New `if' and `while' commands
4473 This makes it possible to write more sophisticated user-defined
4474 commands. Both commands take a single argument, which is the
4475 expression to evaluate, and must be followed by the commands to
4476 execute, one per line, if the expression is nonzero, the list being
4477 terminated by the word `end'. The `if' command list may include an
4478 `else' word, which causes the following commands to be executed only
4479 if the expression is zero.
4481 * Fortran source language mode
4483 GDB now includes partial support for Fortran 77. It will recognize
4484 Fortran programs and can evaluate a subset of Fortran expressions, but
4485 variables and functions may not be handled correctly. GDB will work
4486 with G77, but does not yet know much about symbols emitted by other
4489 * Better HPUX support
4491 Most debugging facilities now work on dynamic executables for HPPAs
4492 running hpux9 or later. You can attach to running dynamically linked
4493 processes, but by default the dynamic libraries will be read-only, so
4494 for instance you won't be able to put breakpoints in them. To change
4495 that behavior do the following before running the program:
4501 This will cause the libraries to be mapped private and read-write.
4502 To revert to the normal behavior, do this:
4508 You cannot set breakpoints or examine data in the library until after
4509 the library is loaded if the function/data symbols do not have
4512 GDB can now also read debug symbols produced by the HP C compiler on
4513 HPPAs (sorry, no C++, Fortran or 68k support).
4515 * Target byte order now dynamically selectable
4517 You can choose which byte order to use with a target system, via the
4518 commands "set endian big" and "set endian little", and you can see the
4519 current setting by using "show endian". You can also give the command
4520 "set endian auto", in which case GDB will use the byte order
4521 associated with the executable. Currently, only embedded MIPS
4522 configurations support dynamic selection of target byte order.
4524 * New DOS host serial code
4526 This version uses DPMI interrupts to handle buffered I/O, so you
4527 no longer need to run asynctsr when debugging boards connected to
4530 *** Changes in GDB-4.13:
4532 * New "complete" command
4534 This lists all the possible completions for the rest of the line, if it
4535 were to be given as a command itself. This is intended for use by emacs.
4537 * Trailing space optional in prompt
4539 "set prompt" no longer adds a space for you after the prompt you set. This
4540 allows you to set a prompt which ends in a space or one that does not.
4542 * Breakpoint hit counts
4544 "info break" now displays a count of the number of times the breakpoint
4545 has been hit. This is especially useful in conjunction with "ignore"; you
4546 can ignore a large number of breakpoint hits, look at the breakpoint info
4547 to see how many times the breakpoint was hit, then run again, ignoring one
4548 less than that number, and this will get you quickly to the last hit of
4551 * Ability to stop printing at NULL character
4553 "set print null-stop" will cause GDB to stop printing the characters of
4554 an array when the first NULL is encountered. This is useful when large
4555 arrays actually contain only short strings.
4557 * Shared library breakpoints
4559 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4560 breakpoints in shared libraries before the executable is run.
4562 * Hardware watchpoints
4564 There is a new hardware breakpoint for the watch command for sparclite
4565 targets. See gdb/sparclite/hw_breakpoint.note.
4567 Hardware watchpoints are also now supported under GNU/Linux.
4571 Annotations have been added. These are for use with graphical interfaces,
4572 and are still experimental. Currently only gdba.el uses these.
4574 * Improved Irix 5 support
4576 GDB now works properly with Irix 5.2.
4578 * Improved HPPA support
4580 GDB now works properly with the latest GCC and GAS.
4582 * New native configurations
4584 Sequent PTX4 i[34]86-sequent-ptx4
4585 HPPA running OSF/1 hppa*-*-osf*
4586 Atari TT running SVR4 m68*-*-sysv4*
4587 RS/6000 LynxOS rs6000-*-lynxos*
4591 OS/9000 i[34]86-*-os9k
4592 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4595 * Hitachi SH7000 and E7000-PC ICE support
4597 There is now support for communicating with the Hitachi E7000-PC ICE.
4598 This is available automatically when GDB is configured for the SH.
4602 As usual, a variety of small fixes and improvements, both generic
4603 and configuration-specific. See the ChangeLog for more detail.
4605 *** Changes in GDB-4.12:
4607 * Irix 5 is now supported
4611 GDB-4.12 on the HPPA has a number of changes which make it unable
4612 to debug the output from the currently released versions of GCC and
4613 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4614 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4615 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4618 *** Changes in GDB-4.11:
4620 * User visible changes:
4624 The "set remotedebug" option is now consistent between the mips remote
4625 target, remote targets using the gdb-specific protocol, UDI (AMD's
4626 debug protocol for the 29k) and the 88k bug monitor. It is now an
4627 integer specifying a debug level (normally 0 or 1, but 2 means more
4628 debugging info for the mips target).
4630 * DEC Alpha native support
4632 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4633 debug info, but GDB works fairly well with the DEC compiler and should
4634 work with a future GCC release. See the README file for a few
4635 Alpha-specific notes.
4637 * Preliminary thread implementation
4639 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4641 * LynxOS native and target support for 386
4643 This release has been hosted on LynxOS 2.2, and also can be configured
4644 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4647 * Improvements in C++ mangling/demangling.
4649 This release has much better g++ debugging, specifically in name
4650 mangling/demangling, virtual function calls, print virtual table,
4651 call methods, ...etc.
4653 *** Changes in GDB-4.10:
4655 * User visible changes:
4657 Remote debugging using the GDB-specific (`target remote') protocol now
4658 supports the `load' command. This is only useful if you have some
4659 other way of getting the stub to the target system, and you can put it
4660 somewhere in memory where it won't get clobbered by the download.
4662 Filename completion now works.
4664 When run under emacs mode, the "info line" command now causes the
4665 arrow to point to the line specified. Also, "info line" prints
4666 addresses in symbolic form (as well as hex).
4668 All vxworks based targets now support a user settable option, called
4669 vxworks-timeout. This option represents the number of seconds gdb
4670 should wait for responses to rpc's. You might want to use this if
4671 your vxworks target is, perhaps, a slow software simulator or happens
4672 to be on the far side of a thin network line.
4676 This release contains support for using a DEC alpha as a GDB host for
4677 cross debugging. Native alpha debugging is not supported yet.
4680 *** Changes in GDB-4.9:
4684 This is the first GDB release which is accompanied by a matching testsuite.
4685 The testsuite requires installation of dejagnu, which should be available
4686 via ftp from most sites that carry GNU software.
4690 'Cfront' style demangling has had its name changed to 'ARM' style, to
4691 emphasize that it was written from the specifications in the C++ Annotated
4692 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4693 disclaimers, it still generated too much confusion with users attempting to
4694 use gdb with AT&T cfront.
4698 GDB now uses a standard remote interface to a simulator library.
4699 So far, the library contains simulators for the Zilog Z8001/2, the
4700 Hitachi H8/300, H8/500 and Super-H.
4702 * New targets supported
4704 H8/300 simulator h8300-hitachi-hms or h8300hms
4705 H8/500 simulator h8500-hitachi-hms or h8500hms
4706 SH simulator sh-hitachi-hms or sh
4707 Z8000 simulator z8k-zilog-none or z8ksim
4708 IDT MIPS board over serial line mips-idt-ecoff
4710 Cross-debugging to GO32 targets is supported. It requires a custom
4711 version of the i386-stub.c module which is integrated with the
4712 GO32 memory extender.
4714 * New remote protocols
4716 MIPS remote debugging protocol.
4718 * New source languages supported
4720 This version includes preliminary support for Chill, a Pascal like language
4721 used by telecommunications companies. Chill support is also being integrated
4722 into the GNU compiler, but we don't know when it will be publically available.
4725 *** Changes in GDB-4.8:
4727 * HP Precision Architecture supported
4729 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4730 version of this support was available as a set of patches from the
4731 University of Utah. GDB does not support debugging of programs
4732 compiled with the HP compiler, because HP will not document their file
4733 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4734 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4736 Many problems in the preliminary version have been fixed.
4738 * Faster and better demangling
4740 We have improved template demangling and fixed numerous bugs in the GNU style
4741 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4742 character types (wchar_t) are now supported. Demangling of each symbol is now
4743 only done once, and is cached when the symbol table for a file is read in.
4744 This results in a small increase in memory usage for C programs, a moderate
4745 increase in memory usage for C++ programs, and a fantastic speedup in
4748 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4749 from the specifications in the Annotated Reference Manual, which AT&T's
4750 compiler does not actually implement.
4752 * G++ multiple inheritance compiler problem
4754 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4755 inheritance lattices was reworked to properly discover ambiguities. We
4756 recently found an example which causes this new algorithm to fail in a
4757 very subtle way, producing bad debug information for those classes.
4758 The file 'gcc.patch' (in this directory) can be applied to gcc to
4759 circumvent the problem. A future GCC release will contain a complete
4762 The previous G++ debug info problem (mentioned below for the gdb-4.7
4763 release) is fixed in gcc version 2.3.2.
4765 * Improved configure script
4767 The `configure' script will now attempt to guess your system type if
4768 you don't supply a host system type. The old scheme of supplying a
4769 host system triplet is preferable over using this. All the magic is
4770 done in the new `config.guess' script. Examine it for details.
4772 We have also brought our configure script much more in line with the FSF's
4773 version. It now supports the --with-xxx options. In particular,
4774 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4775 The resulting GDB will not be able to read arbitrary object file formats --
4776 only the format ``expected'' to be used on the configured target system.
4777 We hope to make this the default in a future release.
4779 * Documentation improvements
4781 There's new internal documentation on how to modify GDB, and how to
4782 produce clean changes to the code. We implore people to read it
4783 before submitting changes.
4785 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4786 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4787 `info' files are also provided. To build `info' files from scratch,
4788 you will need the latest `makeinfo' release, which will be available in
4789 a future texinfo-X.Y release.
4791 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4792 We're not sure exactly which versions have this problem, but it has
4793 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4794 or better. If that isn't possible, there is a patch in
4795 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4796 around this problem.
4800 GDB now supports array constants that can be used in expressions typed in by
4801 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4802 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4805 The new directory `gdb/sparclite' contains a program that demonstrates
4806 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4808 * New native hosts supported
4810 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4811 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4813 * New targets supported
4815 AMD 29k family via UDI a29k-amd-udi or udi29k
4817 * New file formats supported
4819 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4820 HPUX core files, and SCO 3.2v2 core files.
4824 Attaching to processes now works again; thanks for the many bug reports.
4826 We have also stomped on a bunch of core dumps caused by
4827 printf_filtered("%s") problems.
4829 We eliminated a copyright problem on the rpc and ptrace header files
4830 for VxWorks, which was discovered at the last minute during the 4.7
4831 release. You should now be able to build a VxWorks GDB.
4833 You can now interrupt gdb while an attached process is running. This
4834 will cause the attached process to stop, and give control back to GDB.
4836 We fixed problems caused by using too many file descriptors
4837 for reading symbols from object files and libraries. This was
4838 especially a problem for programs that used many (~100) shared
4841 The `step' command now only enters a subroutine if there is line number
4842 information for the subroutine. Otherwise it acts like the `next'
4843 command. Previously, `step' would enter subroutines if there was
4844 any debugging information about the routine. This avoids problems
4845 when using `cc -g1' on MIPS machines.
4847 * Internal improvements
4849 GDB's internal interfaces have been improved to make it easier to support
4850 debugging of multiple languages in the future.
4852 GDB now uses a common structure for symbol information internally.
4853 Minimal symbols (derived from linkage symbols in object files), partial
4854 symbols (from a quick scan of debug information), and full symbols
4855 contain a common subset of information, making it easier to write
4856 shared code that handles any of them.
4858 * New command line options
4860 We now accept --silent as an alias for --quiet.
4864 The memory-mapped-malloc library is now licensed under the GNU Library
4865 General Public License.
4867 *** Changes in GDB-4.7:
4869 * Host/native/target split
4871 GDB has had some major internal surgery to untangle the support for
4872 hosts and remote targets. Now, when you configure GDB for a remote
4873 target, it will no longer load in all of the support for debugging
4874 local programs on the host. When fully completed and tested, this will
4875 ensure that arbitrary host/target combinations are possible.
4877 The primary conceptual shift is to separate the non-portable code in
4878 GDB into three categories. Host specific code is required any time GDB
4879 is compiled on that host, regardless of the target. Target specific
4880 code relates to the peculiarities of the target, but can be compiled on
4881 any host. Native specific code is everything else: it can only be
4882 built when the host and target are the same system. Child process
4883 handling and core file support are two common `native' examples.
4885 GDB's use of /proc for controlling Unix child processes is now cleaner.
4886 It has been split out into a single module under the `target_ops' vector,
4887 plus two native-dependent functions for each system that uses /proc.
4889 * New hosts supported
4891 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
4892 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4893 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
4895 * New targets supported
4897 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4898 68030 and CPU32 m68030-*-*, m68332-*-*
4900 * New native hosts supported
4902 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4903 (386bsd is not well tested yet)
4904 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
4906 * New file formats supported
4908 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
4909 supports reading of `a.out.adobe' object files, which are an a.out
4910 format extended with minimal information about multiple sections.
4914 `show copying' is the same as the old `info copying'.
4915 `show warranty' is the same as `info warrantee'.
4916 These were renamed for consistency. The old commands continue to work.
4918 `info handle' is a new alias for `info signals'.
4920 You can now define pre-command hooks, which attach arbitrary command
4921 scripts to any command. The commands in the hook will be executed
4922 prior to the user's command. You can also create a hook which will be
4923 executed whenever the program stops. See gdb.texinfo.
4927 We now deal with Cfront style name mangling, and can even extract type
4928 info from mangled symbols. GDB can automatically figure out which
4929 symbol mangling style your C++ compiler uses.
4931 Calling of methods and virtual functions has been improved as well.
4935 The crash that occured when debugging Sun Ansi-C compiled binaries is
4936 fixed. This was due to mishandling of the extra N_SO stabs output
4939 We also finally got Ultrix 4.2 running in house, and fixed core file
4940 support, with help from a dozen people on the net.
4942 John M. Farrell discovered that the reason that single-stepping was so
4943 slow on all of the Mips based platforms (primarily SGI and DEC) was
4944 that we were trying to demangle and lookup a symbol used for internal
4945 purposes on every instruction that was being stepped through. Changing
4946 the name of that symbol so that it couldn't be mistaken for a C++
4947 mangled symbol sped things up a great deal.
4949 Rich Pixley sped up symbol lookups in general by getting much smarter
4950 about when C++ symbol mangling is necessary. This should make symbol
4951 completion (TAB on the command line) much faster. It's not as fast as
4952 we'd like, but it's significantly faster than gdb-4.6.
4956 A new user controllable variable 'call_scratch_address' can
4957 specify the location of a scratch area to be used when GDB
4958 calls a function in the target. This is necessary because the
4959 usual method of putting the scratch area on the stack does not work
4960 in systems that have separate instruction and data spaces.
4962 We integrated changes to support the 29k UDI (Universal Debugger
4963 Interface), but discovered at the last minute that we didn't have all
4964 of the appropriate copyright paperwork. We are working with AMD to
4965 resolve this, and hope to have it available soon.
4969 We have sped up the remote serial line protocol, especially for targets
4970 with lots of registers. It now supports a new `expedited status' ('T')
4971 message which can be used in place of the existing 'S' status message.
4972 This allows the remote stub to send only the registers that GDB
4973 needs to make a quick decision about single-stepping or conditional
4974 breakpoints, eliminating the need to fetch the entire register set for
4975 each instruction being stepped through.
4977 The GDB remote serial protocol now implements a write-through cache for
4978 registers, only re-reading the registers if the target has run.
4980 There is also a new remote serial stub for SPARC processors. You can
4981 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
4982 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
4983 processor with a serial port.
4987 Configure.in files have become much easier to read and modify. A new
4988 `table driven' format makes it more obvious what configurations are
4989 supported, and what files each one uses.
4993 There is a new opcodes library which will eventually contain all of the
4994 disassembly routines and opcode tables. At present, it only contains
4995 Sparc and Z8000 routines. This will allow the assembler, debugger, and
4996 disassembler (binutils/objdump) to share these routines.
4998 The libiberty library is now copylefted under the GNU Library General
4999 Public License. This allows more liberal use, and was done so libg++
5000 can use it. This makes no difference to GDB, since the Library License
5001 grants all the rights from the General Public License.
5005 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5006 reference to the stabs symbol info used by the debugger. It is (as far
5007 as we know) the only published document on this fascinating topic. We
5008 encourage you to read it, compare it to the stabs information on your
5009 system, and send improvements on the document in general (to
5010 bug-gdb@prep.ai.mit.edu).
5012 And, of course, many bugs have been fixed.
5015 *** Changes in GDB-4.6:
5017 * Better support for C++ function names
5019 GDB now accepts as input the "demangled form" of C++ overloaded function
5020 names and member function names, and can do command completion on such names
5021 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5022 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5023 Make use of command completion, it is your friend.
5025 GDB also now accepts a variety of C++ mangled symbol formats. They are
5026 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5027 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5028 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5029 for the list of formats.
5031 * G++ symbol mangling problem
5033 Recent versions of gcc have a bug in how they emit debugging information for
5034 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5035 directory) can be applied to gcc to fix the problem. Alternatively, if you
5036 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5037 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5038 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5041 * New 'maintenance' command
5043 All of the commands related to hacking GDB internals have been moved out of
5044 the main command set, and now live behind the 'maintenance' command. This
5045 can also be abbreviated as 'mt'. The following changes were made:
5047 dump-me -> maintenance dump-me
5048 info all-breakpoints -> maintenance info breakpoints
5049 printmsyms -> maintenance print msyms
5050 printobjfiles -> maintenance print objfiles
5051 printpsyms -> maintenance print psymbols
5052 printsyms -> maintenance print symbols
5054 The following commands are new:
5056 maintenance demangle Call internal GDB demangler routine to
5057 demangle a C++ link name and prints the result.
5058 maintenance print type Print a type chain for a given symbol
5060 * Change to .gdbinit file processing
5062 We now read the $HOME/.gdbinit file before processing the argv arguments
5063 (e.g. reading symbol files or core files). This allows global parameters to
5064 be set, which will apply during the symbol reading. The ./.gdbinit is still
5065 read after argv processing.
5067 * New hosts supported
5069 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5071 GNU/Linux support i386-unknown-linux or linux
5073 We are also including code to support the HP/PA running BSD and HPUX. This
5074 is almost guaranteed not to work, as we didn't have time to test or build it
5075 for this release. We are including it so that the more adventurous (or
5076 masochistic) of you can play with it. We also had major problems with the
5077 fact that the compiler that we got from HP doesn't support the -g option.
5080 * New targets supported
5082 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5084 * More smarts about finding #include files
5086 GDB now remembers the compilation directory for all include files, and for
5087 all files from which C is generated (like yacc and lex sources). This
5088 greatly improves GDB's ability to find yacc/lex sources, and include files,
5089 especially if you are debugging your program from a directory different from
5090 the one that contains your sources.
5092 We also fixed a bug which caused difficulty with listing and setting
5093 breakpoints in include files which contain C code. (In the past, you had to
5094 try twice in order to list an include file that you hadn't looked at before.)
5096 * Interesting infernals change
5098 GDB now deals with arbitrary numbers of sections, where the symbols for each
5099 section must be relocated relative to that section's landing place in the
5100 target's address space. This work was needed to support ELF with embedded
5101 stabs used by Solaris-2.0.
5103 * Bug fixes (of course!)
5105 There have been loads of fixes for the following things:
5106 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5107 i960, stabs, DOS(GO32), procfs, etc...
5109 See the ChangeLog for details.
5111 *** Changes in GDB-4.5:
5113 * New machines supported (host and target)
5115 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5117 SGI Irix-4.x mips-sgi-irix4 or iris4
5119 * New malloc package
5121 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5122 Mmalloc is capable of handling mutiple heaps of memory. It is also
5123 capable of saving a heap to a file, and then mapping it back in later.
5124 This can be used to greatly speedup the startup of GDB by using a
5125 pre-parsed symbol table which lives in a mmalloc managed heap. For
5126 more details, please read mmalloc/mmalloc.texi.
5130 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5131 'help info proc' for details.
5133 * MIPS ecoff symbol table format
5135 The code that reads MIPS symbol table format is now supported on all hosts.
5136 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5139 * File name changes for MS-DOS
5141 Many files in the config directories have been renamed to make it easier to
5142 support GDB on MS-DOSe systems (which have very restrictive file name
5143 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5144 environment) is close to working but has some remaining problems. Note
5145 that debugging of DOS programs is not supported, due to limitations
5146 in the ``operating system'', but it can be used to host cross-debugging.
5148 * Cross byte order fixes
5150 Many fixes have been made to support cross debugging of Sparc and MIPS
5151 targets from hosts whose byte order differs.
5153 * New -mapped and -readnow options
5155 If memory-mapped files are available on your system through the 'mmap'
5156 system call, you can use the -mapped option on the `file' or
5157 `symbol-file' commands to cause GDB to write the symbols from your
5158 program into a reusable file. If the program you are debugging is
5159 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5160 Future GDB debugging sessions will notice the presence of this file,
5161 and will quickly map in symbol information from it, rather than reading
5162 the symbol table from the executable program. Using the '-mapped'
5163 option in a GDB `file' or `symbol-file' command has the same effect as
5164 starting GDB with the '-mapped' command-line option.
5166 You can cause GDB to read the entire symbol table immediately by using
5167 the '-readnow' option with any of the commands that load symbol table
5168 information (or on the GDB command line). This makes the command
5169 slower, but makes future operations faster.
5171 The -mapped and -readnow options are typically combined in order to
5172 build a `fred.syms' file that contains complete symbol information.
5173 A simple GDB invocation to do nothing but build a `.syms' file for future
5176 gdb -batch -nx -mapped -readnow programname
5178 The `.syms' file is specific to the host machine on which GDB is run.
5179 It holds an exact image of GDB's internal symbol table. It cannot be
5180 shared across multiple host platforms.
5182 * longjmp() handling
5184 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5185 siglongjmp() without losing control. This feature has not yet been ported to
5186 all systems. It currently works on many 386 platforms, all MIPS-based
5187 platforms (SGI, DECstation, etc), and Sun3/4.
5191 Preliminary work has been put in to support the new Solaris OS from Sun. At
5192 this time, it can control and debug processes, but it is not capable of
5197 As always, many many bug fixes. The major areas were with g++, and mipsread.
5198 People using the MIPS-based platforms should experience fewer mysterious
5199 crashes and trashed symbol tables.
5201 *** Changes in GDB-4.4:
5203 * New machines supported (host and target)
5205 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5207 BSD Reno on Vax vax-dec-bsd
5208 Ultrix on Vax vax-dec-ultrix
5210 * New machines supported (target)
5212 AMD 29000 embedded, using EBMON a29k-none-none
5216 GDB continues to improve its handling of C++. `References' work better.
5217 The demangler has also been improved, and now deals with symbols mangled as
5218 per the Annotated C++ Reference Guide.
5220 GDB also now handles `stabs' symbol information embedded in MIPS
5221 `ecoff' symbol tables. Since the ecoff format was not easily
5222 extensible to handle new languages such as C++, this appeared to be a
5223 good way to put C++ debugging info into MIPS binaries. This option
5224 will be supported in the GNU C compiler, version 2, when it is
5227 * New features for SVR4
5229 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5230 shared libraries. Debugging dynamically linked programs should present
5231 only minor differences from debugging statically linked programs.
5233 The `info proc' command will print out information about any process
5234 on an SVR4 system (including the one you are debugging). At the moment,
5235 it prints the address mappings of the process.
5237 If you bring up GDB on another SVR4 system, please send mail to
5238 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5240 * Better dynamic linking support in SunOS
5242 Reading symbols from shared libraries which contain debugging symbols
5243 now works properly. However, there remain issues such as automatic
5244 skipping of `transfer vector' code during function calls, which
5245 make it harder to debug code in a shared library, than to debug the
5246 same code linked statically.
5250 GDB is now using the latest `getopt' routines from the FSF. This
5251 version accepts the -- prefix for options with long names. GDB will
5252 continue to accept the old forms (-option and +option) as well.
5253 Various single letter abbreviations for options have been explicity
5254 added to the option table so that they won't get overshadowed in the
5255 future by other options that begin with the same letter.
5259 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5260 Many assorted bugs have been handled. Many more remain to be handled.
5261 See the various ChangeLog files (primarily in gdb and bfd) for details.
5264 *** Changes in GDB-4.3:
5266 * New machines supported (host and target)
5268 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5269 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5270 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5272 * Almost SCO Unix support
5274 We had hoped to support:
5275 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5276 (except for core file support), but we discovered very late in the release
5277 that it has problems with process groups that render gdb unusable. Sorry
5278 about that. I encourage people to fix it and post the fixes.
5280 * Preliminary ELF and DWARF support
5282 GDB can read ELF object files on System V Release 4, and can handle
5283 debugging records for C, in DWARF format, in ELF files. This support
5284 is preliminary. If you bring up GDB on another SVR4 system, please
5285 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5290 GDB now uses the latest `readline' library. One user-visible change
5291 is that two tabs will list possible command completions, which previously
5292 required typing M-? (meta-question mark, or ESC ?).
5296 The `stepi' bug that many of you noticed has been squashed.
5297 Many bugs in C++ have been handled. Many more remain to be handled.
5298 See the various ChangeLog files (primarily in gdb and bfd) for details.
5300 * State of the MIPS world (in case you wondered):
5302 GDB can understand the symbol tables emitted by the compilers
5303 supplied by most vendors of MIPS-based machines, including DEC. These
5304 symbol tables are in a format that essentially nobody else uses.
5306 Some versions of gcc come with an assembler post-processor called
5307 mips-tfile. This program is required if you want to do source-level
5308 debugging of gcc-compiled programs. I believe FSF does not ship
5309 mips-tfile with gcc version 1, but it will eventually come with gcc
5312 Debugging of g++ output remains a problem. g++ version 1.xx does not
5313 really support it at all. (If you're lucky, you should be able to get
5314 line numbers and stack traces to work, but no parameters or local
5315 variables.) With some work it should be possible to improve the
5318 When gcc version 2 is released, you will have somewhat better luck.
5319 However, even then you will get confusing results for inheritance and
5322 We will eventually provide full debugging of g++ output on
5323 DECstations. This will probably involve some kind of stabs-in-ecoff
5324 encapulation, but the details have not been worked out yet.
5327 *** Changes in GDB-4.2:
5329 * Improved configuration
5331 Only one copy of `configure' exists now, and it is not self-modifying.
5332 Porting BFD is simpler.
5336 The `step' and `next' commands now only stop at the first instruction
5337 of a source line. This prevents the multiple stops that used to occur
5338 in switch statements, for-loops, etc. `Step' continues to stop if a
5339 function that has debugging information is called within the line.
5343 Lots of small bugs fixed. More remain.
5345 * New host supported (not target)
5347 Intel 386 PC clone running Mach i386-none-mach
5350 *** Changes in GDB-4.1:
5352 * Multiple source language support
5354 GDB now has internal scaffolding to handle several source languages.
5355 It determines the type of each source file from its filename extension,
5356 and will switch expression parsing and number formatting to match the
5357 language of the function in the currently selected stack frame.
5358 You can also specifically set the language to be used, with
5359 `set language c' or `set language modula-2'.
5363 GDB now has preliminary support for the GNU Modula-2 compiler,
5364 currently under development at the State University of New York at
5365 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5366 continue through the fall of 1991 and into 1992.
5368 Other Modula-2 compilers are currently not supported, and attempting to
5369 debug programs compiled with them will likely result in an error as the
5370 symbol table is read. Feel free to work on it, though!
5372 There are hooks in GDB for strict type checking and range checking,
5373 in the `Modula-2 philosophy', but they do not currently work.
5377 GDB can now write to executable and core files (e.g. patch
5378 a variable's value). You must turn this switch on, specify
5379 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5380 by assigning a new value to a variable. Modifications take
5383 * Automatic SunOS shared library reading
5385 When you run your program, GDB automatically determines where its
5386 shared libraries (if any) have been loaded, and reads their symbols.
5387 The `share' command is no longer needed. This also works when
5388 examining core files.
5392 You can specify the number of lines that the `list' command shows.
5395 * New machines supported (host and target)
5397 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5398 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5399 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5401 * New hosts supported (not targets)
5403 IBM RT/PC: romp-ibm-aix or rtpc
5405 * New targets supported (not hosts)
5407 AMD 29000 embedded with COFF a29k-none-coff
5408 AMD 29000 embedded with a.out a29k-none-aout
5409 Ultracomputer remote kernel debug a29k-nyu-kern
5411 * New remote interfaces
5417 *** Changes in GDB-4.0:
5421 Wide output is wrapped at good places to make the output more readable.
5423 Gdb now supports cross-debugging from a host machine of one type to a
5424 target machine of another type. Communication with the target system
5425 is over serial lines. The ``target'' command handles connecting to the
5426 remote system; the ``load'' command will download a program into the
5427 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5428 also supports debugging of realtime processes running under VxWorks,
5429 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5430 stub on the target system.
5432 New CPUs supported include the AMD 29000 and Intel 960.
5434 GDB now reads object files and symbol tables via a ``binary file''
5435 library, which allows a single copy of GDB to debug programs of multiple
5436 object file types such as a.out and coff.
5438 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5439 refcard.dvi and refcard.ps are available to format it).
5442 * Control-Variable user interface simplified
5444 All variables that control the operation of the debugger can be set
5445 by the ``set'' command, and displayed by the ``show'' command.
5447 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5448 ``Show prompt'' produces the response:
5449 Gdb's prompt is new-gdb=>.
5451 What follows are the NEW set commands. The command ``help set'' will
5452 print a complete list of old and new set commands. ``help set FOO''
5453 will give a longer description of the variable FOO. ``show'' will show
5454 all of the variable descriptions and their current settings.
5456 confirm on/off: Enables warning questions for operations that are
5457 hard to recover from, e.g. rerunning the program while
5458 it is already running. Default is ON.
5460 editing on/off: Enables EMACS style command line editing
5461 of input. Previous lines can be recalled with
5462 control-P, the current line can be edited with control-B,
5463 you can search for commands with control-R, etc.
5466 history filename NAME: NAME is where the gdb command history
5467 will be stored. The default is .gdb_history,
5468 or the value of the environment variable
5471 history size N: The size, in commands, of the command history. The
5472 default is 256, or the value of the environment variable
5475 history save on/off: If this value is set to ON, the history file will
5476 be saved after exiting gdb. If set to OFF, the
5477 file will not be saved. The default is OFF.
5479 history expansion on/off: If this value is set to ON, then csh-like
5480 history expansion will be performed on
5481 command line input. The default is OFF.
5483 radix N: Sets the default radix for input and output. It can be set
5484 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5485 in the current radix, so "set radix 10" is always a no-op.
5487 height N: This integer value is the number of lines on a page. Default
5488 is 24, the current `stty rows'' setting, or the ``li#''
5489 setting from the termcap entry matching the environment
5492 width N: This integer value is the number of characters on a line.
5493 Default is 80, the current `stty cols'' setting, or the ``co#''
5494 setting from the termcap entry matching the environment
5497 Note: ``set screensize'' is obsolete. Use ``set height'' and
5498 ``set width'' instead.
5500 print address on/off: Print memory addresses in various command displays,
5501 such as stack traces and structure values. Gdb looks
5502 more ``symbolic'' if you turn this off; it looks more
5503 ``machine level'' with it on. Default is ON.
5505 print array on/off: Prettyprint arrays. New convenient format! Default
5508 print demangle on/off: Print C++ symbols in "source" form if on,
5511 print asm-demangle on/off: Same, for assembler level printouts
5514 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5517 * Support for Epoch Environment.
5519 The epoch environment is a version of Emacs v18 with windowing. One
5520 new command, ``inspect'', is identical to ``print'', except that if you
5521 are running in the epoch environment, the value is printed in its own
5525 * Support for Shared Libraries
5527 GDB can now debug programs and core files that use SunOS shared libraries.
5528 Symbols from a shared library cannot be referenced
5529 before the shared library has been linked with the program (this
5530 happens after you type ``run'' and before the function main() is entered).
5531 At any time after this linking (including when examining core files
5532 from dynamically linked programs), gdb reads the symbols from each
5533 shared library when you type the ``sharedlibrary'' command.
5534 It can be abbreviated ``share''.
5536 sharedlibrary REGEXP: Load shared object library symbols for files
5537 matching a unix regular expression. No argument
5538 indicates to load symbols for all shared libraries.
5540 info sharedlibrary: Status of loaded shared libraries.
5545 A watchpoint stops execution of a program whenever the value of an
5546 expression changes. Checking for this slows down execution
5547 tremendously whenever you are in the scope of the expression, but is
5548 quite useful for catching tough ``bit-spreader'' or pointer misuse
5549 problems. Some machines such as the 386 have hardware for doing this
5550 more quickly, and future versions of gdb will use this hardware.
5552 watch EXP: Set a watchpoint (breakpoint) for an expression.
5554 info watchpoints: Information about your watchpoints.
5556 delete N: Deletes watchpoint number N (same as breakpoints).
5557 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5558 enable N: Re-enables watchpoint number N (same as breakpoints).
5561 * C++ multiple inheritance
5563 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5566 * C++ exception handling
5568 Gdb now supports limited C++ exception handling. Besides the existing
5569 ability to breakpoint on an exception handler, gdb can breakpoint on
5570 the raising of an exception (before the stack is peeled back to the
5573 catch FOO: If there is a FOO exception handler in the dynamic scope,
5574 set a breakpoint to catch exceptions which may be raised there.
5575 Multiple exceptions (``catch foo bar baz'') may be caught.
5577 info catch: Lists all exceptions which may be caught in the
5578 current stack frame.
5581 * Minor command changes
5583 The command ``call func (arg, arg, ...)'' now acts like the print
5584 command, except it does not print or save a value if the function's result
5585 is void. This is similar to dbx usage.
5587 The ``up'' and ``down'' commands now always print the frame they end up
5588 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5589 frames without printing.
5591 * New directory command
5593 'dir' now adds directories to the FRONT of the source search path.
5594 The path starts off empty. Source files that contain debug information
5595 about the directory in which they were compiled can be found even
5596 with an empty path; Sun CC and GCC include this information. If GDB can't
5597 find your source file in the current directory, type "dir .".
5599 * Configuring GDB for compilation
5601 For normal use, type ``./configure host''. See README or gdb.texinfo
5604 GDB now handles cross debugging. If you are remotely debugging between
5605 two different machines, type ``./configure host -target=targ''.
5606 Host is the machine where GDB will run; targ is the machine
5607 where the program that you are debugging will run.
5609 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.