1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.6
8 Display the details of GDB configure-time options.
10 maint set|show per-command
11 maint set|show per-command space
12 maint set|show per-command time
13 maint set|show per-command symtab
14 Enable display of per-command gdb resource usage.
18 set remote trace-status-packet
19 show remote trace-status-packet
20 Set/show the use of remote protocol qTStatus packet.
22 * New command-line options
24 Display the details of GDB configure-time options.
26 * The command 'tsave' can now support new option '-ctf' to save trace
27 buffer in Common Trace Format.
29 * Newly installed $prefix/bin/gcore acts as a shell interface for the
34 ** The -trace-save MI command can optionally save trace buffer in Common
37 *** Changes in GDB 7.6
39 * Target record has been renamed to record-full.
40 Record/replay is now enabled with the "record full" command.
41 This also affects settings that are associated with full record/replay
42 that have been moved from "set/show record" to "set/show record full":
44 set|show record full insn-number-max
45 set|show record full stop-at-limit
46 set|show record full memory-query
48 * A new record target "record-btrace" has been added. The new target
49 uses hardware support to record the control-flow of a process. It
50 does not support replaying the execution, but it implements the
51 below new commands for investigating the recorded execution log.
52 This new recording method can be enabled using:
56 The "record-btrace" target is only available on Intel Atom processors
57 and requires a Linux kernel 2.6.32 or later.
59 * Two new commands have been added for record/replay to give information
60 about the recorded execution without having to replay the execution.
61 The commands are only supported by "record btrace".
63 record instruction-history prints the execution history at
64 instruction granularity
66 record function-call-history prints the execution history at
69 * New native configurations
71 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
72 FreeBSD/powerpc powerpc*-*-freebsd
73 x86_64/Cygwin x86_64-*-cygwin*
74 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
78 ARM AArch64 aarch64*-*-elf
79 ARM AArch64 GNU/Linux aarch64*-*-linux
80 Lynx 178 PowerPC powerpc-*-lynx*178
81 x86_64/Cygwin x86_64-*-cygwin*
82 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
84 * If the configured location of system.gdbinit file (as given by the
85 --with-system-gdbinit option at configure time) is in the
86 data-directory (as specified by --with-gdb-datadir at configure
87 time) or in one of its subdirectories, then GDB will look for the
88 system-wide init file in the directory specified by the
89 --data-directory command-line option.
91 * New command line options:
93 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
94 other initialization files, unlike -nx which disables all of them.
96 * Removed command line options
98 -epoch This was used by the gdb mode in Epoch, an ancient fork of
101 * The 'ptype' and 'whatis' commands now accept an argument to control
104 * 'info proc' now works on some core files.
108 ** Vectors can be created with gdb.Type.vector.
110 ** Python's atexit.register now works in GDB.
112 ** Types can be pretty-printed via a Python API.
114 ** Python 3 is now supported (in addition to Python 2.4 or later)
116 ** New class gdb.Architecture exposes GDB's internal representation
117 of architecture in the Python API.
119 ** New method Frame.architecture returns the gdb.Architecture object
120 corresponding to the frame's architecture.
122 * New Python-based convenience functions:
124 ** $_memeq(buf1, buf2, length)
125 ** $_streq(str1, str2)
127 ** $_regex(str, regex)
129 * The 'cd' command now defaults to using '~' (the home directory) if not
132 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
133 default for GCC since November 2000.
135 * The command 'forward-search' can now be abbreviated as 'fo'.
137 * The command 'info tracepoints' can now display 'installed on target'
138 or 'not installed on target' for each non-pending location of tracepoint.
140 * New configure options
142 --enable-libmcheck/--disable-libmcheck
143 By default, development versions are built with -lmcheck on hosts
144 that support it, in order to help track memory corruption issues.
145 Release versions, on the other hand, are built without -lmcheck
146 by default. The --enable-libmcheck/--disable-libmcheck configure
147 options allow the user to override that default.
148 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
149 This configure option allows the user to build GDB with
150 libbabeltrace using which GDB can read Common Trace Format data.
152 * New commands (for set/show, see "New options" below)
155 Like "catch throw", but catches a re-thrown exception.
158 Catch signals. This is similar to "handle", but allows commands and
159 conditions to be attached.
162 List the BFDs known to GDB.
164 python-interactive [command]
166 Start a Python interactive prompt, or evaluate the optional command
167 and print the result of expressions.
170 "py" is a new alias for "python".
172 enable type-printer [name]...
173 disable type-printer [name]...
174 Enable or disable type printers.
178 ** For the Renesas Super-H architecture, the "regs" command has been removed
179 (has been deprecated in GDB 7.5), and "info all-registers" should be used
184 set print type methods (on|off)
185 show print type methods
186 Control whether method declarations are displayed by "ptype".
187 The default is to show them.
189 set print type typedefs (on|off)
190 show print type typedefs
191 Control whether typedef definitions are displayed by "ptype".
192 The default is to show them.
194 set filename-display basename|relative|absolute
195 show filename-display
196 Control the way in which filenames is displayed.
197 The default is "relative", which preserves previous behavior.
199 set trace-buffer-size
200 show trace-buffer-size
201 Request target to change the size of trace buffer.
203 set remote trace-buffer-size-packet auto|on|off
204 show remote trace-buffer-size-packet
205 Control the use of the remote protocol `QTBuffer:size' packet.
209 Control display of debugging messages related to ARM AArch64.
212 set debug coff-pe-read
213 show debug coff-pe-read
214 Control display of debugging messages related to reading of COFF/PE
219 Control display of debugging messages related to Mach-O symbols
222 set debug notification
223 show debug notification
224 Control display of debugging info for async remote notification.
228 ** Command parameter changes are now notified using new async record
229 "=cmd-param-changed".
230 ** Trace frame changes caused by command "tfind" are now notified using
231 new async record "=traceframe-changed".
232 ** The creation, deletion and modification of trace state variables
233 are now notified using new async records "=tsv-created",
234 "=tsv-deleted" and "=tsv-modified".
235 ** The start and stop of process record are now notified using new
236 async record "=record-started" and "=record-stopped".
237 ** Memory changes are now notified using new async record
239 ** The data-disassemble command response will include a "fullname" field
240 containing the absolute file name when source has been requested.
241 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
242 command, to allow pattern filling of memory areas.
243 ** New commands "-catch-load"/"-catch-unload" added for intercepting
244 library load/unload events.
245 ** The response to breakpoint commands and breakpoint async records
246 includes an "installed" field containing a boolean state about each
247 non-pending tracepoint location is whether installed on target or not.
248 ** Output of the "-trace-status" command includes a "trace-file" field
249 containing the name of the trace file being examined. This field is
250 optional, and only present when examining a trace file.
251 ** The "fullname" field is now always present along with the "file" field,
252 even if the file cannot be found by GDB.
254 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
255 You must have the LZMA library available when configuring GDB for this
256 feature to be enabled. For more information, see:
257 http://fedoraproject.org/wiki/Features/MiniDebugInfo
262 Set the size of trace buffer. The remote stub reports support for this
263 packet to gdb's qSupported query.
266 Enable Branch Trace Store (BTS)-based branch tracing for the current
267 thread. The remote stub reports support for this packet to gdb's
271 Disable branch tracing for the current thread. The remote stub reports
272 support for this packet to gdb's qSupported query.
275 Read the traced branches for the current thread. The remote stub
276 reports support for this packet to gdb's qSupported query.
278 *** Changes in GDB 7.5
280 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
281 for more x32 ABI info.
283 * GDB now supports access to MIPS DSP registers on Linux targets.
285 * GDB now supports debugging microMIPS binaries.
287 * The "info os" command on GNU/Linux can now display information on
288 several new classes of objects managed by the operating system:
289 "info os procgroups" lists process groups
290 "info os files" lists file descriptors
291 "info os sockets" lists internet-domain sockets
292 "info os shm" lists shared-memory regions
293 "info os semaphores" lists semaphores
294 "info os msg" lists message queues
295 "info os modules" lists loaded kernel modules
297 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
298 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
299 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
300 options and inspect the probe arguments using the new $_probe_arg family
301 of convenience variables. You can obtain more information about SystemTap
302 in <http://sourceware.org/systemtap/>.
304 * GDB now supports reversible debugging on ARM, it allows you to
305 debug basic ARM and THUMB instructions, and provides
306 record/replay support.
308 * The option "symbol-reloading" has been deleted as it is no longer used.
312 ** GDB commands implemented in Python can now be put in command class
315 ** The "maint set python print-stack on|off" is now deleted.
317 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
318 apply "flag enum"-style pretty-printing to any enum.
320 ** gdb.lookup_symbol can now work when there is no current frame.
322 ** gdb.Symbol now has a 'line' attribute, holding the line number in
323 the source at which the symbol was defined.
325 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
326 method 'value'. The former indicates whether the symbol needs a
327 frame in order to compute its value, and the latter computes the
330 ** A new method 'referenced_value' on gdb.Value objects which can
331 dereference pointer as well as C++ reference values.
333 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
334 which return the global and static blocks (as gdb.Block objects),
335 of the underlying symbol table, respectively.
337 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
338 object associated with a PC value.
340 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
341 of the address range occupied by code for the current source line.
343 * Go language support.
344 GDB now supports debugging programs written in the Go programming
347 * GDBserver now supports stdio connections.
348 E.g. (gdb) target remote | ssh myhost gdbserver - hello
350 * The binary "gdbtui" can no longer be built or installed.
351 Use "gdb -tui" instead.
353 * GDB will now print "flag" enums specially. A flag enum is one where
354 all the enumerator values have no bits in common when pairwise
355 "and"ed. When printing a value whose type is a flag enum, GDB will
356 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
357 (gdb) print (enum E) 3
360 * The filename part of a linespec will now match trailing components
361 of a source file name. For example, "break gcc/expr.c:1000" will
362 now set a breakpoint in build/gcc/expr.c, but not
365 * The "info proc" and "generate-core-file" commands will now also
366 work on remote targets connected to GDBserver on Linux.
368 * The command "info catch" has been removed. It has been disabled
371 * The "catch exception" and "catch assert" commands now accept
372 a condition at the end of the command, much like the "break"
373 command does. For instance:
375 (gdb) catch exception Constraint_Error if Barrier = True
377 Previously, it was possible to add a condition to such catchpoints,
378 but it had to be done as a second step, after the catchpoint had been
379 created, using the "condition" command.
381 * The "info static-tracepoint-marker" command will now also work on
382 native Linux targets with in-process agent.
384 * GDB can now set breakpoints on inlined functions.
386 * The .gdb_index section has been updated to include symbols for
387 inlined functions. GDB will ignore older .gdb_index sections by
388 default, which could cause symbol files to be loaded more slowly
389 until their .gdb_index sections can be recreated. The new command
390 "set use-deprecated-index-sections on" will cause GDB to use any older
391 .gdb_index sections it finds. This will restore performance, but the
392 ability to set breakpoints on inlined functions will be lost in symbol
393 files with older .gdb_index sections.
395 The .gdb_index section has also been updated to record more information
396 about each symbol. This speeds up the "info variables", "info functions"
397 and "info types" commands when used with programs having the .gdb_index
398 section, as well as speeding up debugging with shared libraries using
399 the .gdb_index section.
401 * Ada support for GDB/MI Variable Objects has been added.
403 * GDB can now support 'breakpoint always-inserted mode' in 'record'
408 ** New command -info-os is the MI equivalent of "info os".
410 ** Output logs ("set logging" and related) now include MI output.
414 ** "set use-deprecated-index-sections on|off"
415 "show use-deprecated-index-sections on|off"
416 Controls the use of deprecated .gdb_index sections.
418 ** "catch load" and "catch unload" can be used to stop when a shared
419 library is loaded or unloaded, respectively.
421 ** "enable count" can be used to auto-disable a breakpoint after
424 ** "info vtbl" can be used to show the virtual method tables for
425 C++ and Java objects.
427 ** "explore" and its sub commands "explore value" and "explore type"
428 can be used to reccursively explore values and types of
429 expressions. These commands are available only if GDB is
430 configured with '--with-python'.
432 ** "info auto-load" shows status of all kinds of auto-loaded files,
433 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
434 sequences of commands files, "info auto-load python-scripts"
435 shows status of auto-loading Python script files,
436 "info auto-load local-gdbinit" shows status of loading init file
437 (.gdbinit) from current directory and "info auto-load libthread-db" shows
438 status of inferior specific thread debugging shared library loading.
440 ** "info auto-load-scripts", "set auto-load-scripts on|off"
441 and "show auto-load-scripts" commands have been deprecated, use their
442 "info auto-load python-scripts", "set auto-load python-scripts on|off"
443 and "show auto-load python-scripts" counterparts instead.
445 ** "dprintf location,format,args..." creates a dynamic printf, which
446 is basically a breakpoint that does a printf and immediately
447 resumes your program's execution, so it is like a printf that you
448 can insert dynamically at runtime instead of at compiletime.
450 ** "set print symbol"
452 Controls whether GDB attempts to display the symbol, if any,
453 corresponding to addresses it prints. This defaults to "on", but
454 you can set it to "off" to restore GDB's previous behavior.
456 * Deprecated commands
458 ** For the Renesas Super-H architecture, the "regs" command has been
459 deprecated, and "info all-registers" should be used instead.
463 Renesas RL78 rl78-*-elf
464 HP OpenVMS ia64 ia64-hp-openvms*
466 * GDBserver supports evaluation of breakpoint conditions. When
467 support is advertised by GDBserver, GDB may be told to send the
468 breakpoint conditions in bytecode form to GDBserver. GDBserver
469 will only report the breakpoint trigger to GDB when its condition
475 show mips compression
476 Select the compressed ISA encoding used in functions that have no symbol
477 information available. The encoding can be set to either of:
480 and is updated automatically from ELF file flags if available.
482 set breakpoint condition-evaluation
483 show breakpoint condition-evaluation
484 Control whether breakpoint conditions are evaluated by GDB ("host") or by
485 GDBserver ("target"). Default option "auto" chooses the most efficient
487 This option can improve debugger efficiency depending on the speed of the
491 Disable auto-loading globally.
494 Show auto-loading setting of all kinds of auto-loaded files.
496 set auto-load gdb-scripts on|off
497 show auto-load gdb-scripts
498 Control auto-loading of GDB canned sequences of commands files.
500 set auto-load python-scripts on|off
501 show auto-load python-scripts
502 Control auto-loading of Python script files.
504 set auto-load local-gdbinit on|off
505 show auto-load local-gdbinit
506 Control loading of init file (.gdbinit) from current directory.
508 set auto-load libthread-db on|off
509 show auto-load libthread-db
510 Control auto-loading of inferior specific thread debugging shared library.
512 set auto-load scripts-directory <dir1>[:<dir2>...]
513 show auto-load scripts-directory
514 Set a list of directories from which to load auto-loaded scripts.
515 Automatically loaded Python scripts and GDB scripts are located in one
516 of the directories listed by this option.
517 The delimiter (':' above) may differ according to the host platform.
519 set auto-load safe-path <dir1>[:<dir2>...]
520 show auto-load safe-path
521 Set a list of directories from which it is safe to auto-load files.
522 The delimiter (':' above) may differ according to the host platform.
524 set debug auto-load on|off
526 Control display of debugging info for auto-loading the files above.
528 set dprintf-style gdb|call|agent
530 Control the way in which a dynamic printf is performed; "gdb"
531 requests a GDB printf command, while "call" causes dprintf to call a
532 function in the inferior. "agent" requests that the target agent
533 (such as GDBserver) do the printing.
535 set dprintf-function <expr>
536 show dprintf-function
537 set dprintf-channel <expr>
539 Set the function and optional first argument to the call when using
540 the "call" style of dynamic printf.
542 set disconnected-dprintf on|off
543 show disconnected-dprintf
544 Control whether agent-style dynamic printfs continue to be in effect
545 after GDB disconnects.
547 * New configure options
550 Configure default value for the 'set auto-load scripts-directory'
551 setting above. It defaults to '$debugdir:$datadir/auto-load',
552 $debugdir representing global debugging info directories (available
553 via 'show debug-file-directory') and $datadir representing GDB's data
554 directory (available via 'show data-directory').
556 --with-auto-load-safe-path
557 Configure default value for the 'set auto-load safe-path' setting
558 above. It defaults to the --with-auto-load-dir setting.
560 --without-auto-load-safe-path
561 Set 'set auto-load safe-path' to '/', effectively disabling this
566 z0/z1 conditional breakpoints extension
568 The z0/z1 breakpoint insertion packets have been extended to carry
569 a list of conditional expressions over to the remote stub depending on the
570 condition evaluation mode. The use of this extension can be controlled
571 via the "set remote conditional-breakpoints-packet" command.
575 Specify the signals which the remote stub may pass to the debugged
576 program without GDB involvement.
578 * New command line options
580 --init-command=FILE, -ix Like --command, -x but execute it
581 before loading inferior.
582 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
583 execute it before loading inferior.
585 *** Changes in GDB 7.4
587 * GDB now handles ambiguous linespecs more consistently; the existing
588 FILE:LINE support has been expanded to other types of linespecs. A
589 breakpoint will now be set on all matching locations in all
590 inferiors, and locations will be added or removed according to
593 * GDB now allows you to skip uninteresting functions and files when
594 stepping with the "skip function" and "skip file" commands.
596 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
597 and "show remote hardware-watchpoint-length-limit". These allows to
598 set or show the maximum length limit (in bytes) of a remote
599 target hardware watchpoint.
601 This allows e.g. to use "unlimited" hardware watchpoints with the
602 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
603 watchpoints are slower than real hardware watchpoints but are
604 significantly faster than gdb software watchpoints.
608 ** The register_pretty_printer function in module gdb.printing now takes
609 an optional `replace' argument. If True, the new printer replaces any
612 ** The "maint set python print-stack on|off" command has been
613 deprecated and will be deleted in GDB 7.5.
614 A new command: "set python print-stack none|full|message" has
615 replaced it. Additionally, the default for "print-stack" is
616 now "message", which just prints the error message without
619 ** A prompt substitution hook (prompt_hook) is now available to the
622 ** A new Python module, gdb.prompt has been added to the GDB Python
623 modules library. This module provides functionality for
624 escape sequences in prompts (used by set/show
625 extended-prompt). These escape sequences are replaced by their
628 ** Python commands and convenience-functions located in
629 'data-directory'/python/gdb/command and
630 'data-directory'/python/gdb/function are now automatically loaded
633 ** Blocks now provide four new attributes. global_block and
634 static_block will return the global and static blocks
635 respectively. is_static and is_global are boolean attributes
636 that indicate if the block is one of those two types.
638 ** Symbols now provide the "type" attribute, the type of the symbol.
640 ** The "gdb.breakpoint" function has been deprecated in favor of
643 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
644 of a function. This class is based on the "finish" command
645 available in the CLI.
647 ** Type objects for struct and union types now allow access to
648 the fields using standard Python dictionary (mapping) methods.
649 For example, "some_type['myfield']" now works, as does
652 ** A new event "gdb.new_objfile" has been added, triggered by loading a
655 ** A new function, "deep_items" has been added to the gdb.types
656 module in the GDB Python modules library. This function returns
657 an iterator over the fields of a struct or union type. Unlike
658 the standard Python "iteritems" method, it will recursively traverse
659 any anonymous fields.
663 ** "*stopped" events can report several new "reason"s, such as
666 ** Breakpoint changes are now notified using new async records, like
667 "=breakpoint-modified".
669 ** New command -ada-task-info.
671 * libthread-db-search-path now supports two special values: $sdir and $pdir.
672 $sdir specifies the default system locations of shared libraries.
673 $pdir specifies the directory where the libpthread used by the application
676 GDB no longer looks in $sdir and $pdir after it has searched the directories
677 mentioned in libthread-db-search-path. If you want to search those
678 directories, they must be specified in libthread-db-search-path.
679 The default value of libthread-db-search-path on GNU/Linux and Solaris
680 systems is now "$sdir:$pdir".
682 $pdir is not supported by gdbserver, it is currently ignored.
683 $sdir is supported by gdbserver.
685 * New configure option --with-iconv-bin.
686 When using the internationalization support like the one in the GNU C
687 library, GDB will invoke the "iconv" program to get a list of supported
688 character sets. If this program lives in a non-standard location, one can
689 use this option to specify where to find it.
691 * When natively debugging programs on PowerPC BookE processors running
692 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
693 watchpoints, which specify a mask in addition to an address to watch.
694 The mask specifies that some bits of an address (the bits which are
695 reset in the mask) should be ignored when matching the address accessed
696 by the inferior against the watchpoint address. See the "PowerPC Embedded"
697 section in the user manual for more details.
699 * The new option --once causes GDBserver to stop listening for connections once
700 the first connection is made. The listening port used by GDBserver will
701 become available after that.
703 * New commands "info macros" and "alias" have been added.
705 * New function parameters suffix @entry specifies value of function parameter
706 at the time the function got called. Entry values are available only since
712 "!" is now an alias of the "shell" command.
713 Note that no space is needed between "!" and SHELL COMMAND.
717 watch EXPRESSION mask MASK_VALUE
718 The watch command now supports the mask argument which allows creation
719 of masked watchpoints, if the current architecture supports this feature.
721 info auto-load-scripts [REGEXP]
722 This command was formerly named "maintenance print section-scripts".
723 It is now generally useful and is no longer a maintenance-only command.
725 info macro [-all] [--] MACRO
726 The info macro command has new options `-all' and `--'. The first for
727 printing all definitions of a macro. The second for explicitly specifying
728 the end of arguments and the beginning of the macro name in case the macro
729 name starts with a hyphen.
731 collect[/s] EXPRESSIONS
732 The tracepoint collect command now takes an optional modifier "/s"
733 that directs it to dereference pointer-to-character types and
734 collect the bytes of memory up to a zero byte. The behavior is
735 similar to what you see when you use the regular print command on a
736 string. An optional integer following the "/s" sets a bound on the
737 number of bytes that will be collected.
740 The trace start command now interprets any supplied arguments as a
741 note to be recorded with the trace run, with an effect similar to
742 setting the variable trace-notes.
745 The trace stop command now interprets any arguments as a note to be
746 mentioned along with the tstatus report that the trace was stopped
747 with a command. The effect is similar to setting the variable
750 * Tracepoints can now be enabled and disabled at any time after a trace
751 experiment has been started using the standard "enable" and "disable"
752 commands. It is now possible to start a trace experiment with no enabled
753 tracepoints; GDB will display a warning, but will allow the experiment to
754 begin, assuming that tracepoints will be enabled as needed while the trace
757 * Fast tracepoints on 32-bit x86-architectures can now be placed at
758 locations with 4-byte instructions, when they were previously
759 limited to locations with instructions of 5 bytes or longer.
763 set debug dwarf2-read
764 show debug dwarf2-read
765 Turns on or off display of debugging messages related to reading
766 DWARF debug info. The default is off.
768 set debug symtab-create
769 show debug symtab-create
770 Turns on or off display of debugging messages related to symbol table
771 creation. The default is off.
775 Set the GDB prompt, and allow escape sequences to be inserted to
776 display miscellaneous information (see 'help set extended-prompt'
777 for the list of sequences). This prompt (and any information
778 accessed through the escape sequences) is updated every time the
781 set print entry-values (both|compact|default|if-needed|no|only|preferred)
782 show print entry-values
783 Set printing of frame argument values at function entry. In some cases
784 GDB can determine the value of function argument which was passed by the
785 function caller, even if the value was modified inside the called function.
787 set debug entry-values
788 show debug entry-values
789 Control display of debugging info for determining frame argument values at
790 function entry and virtual tail call frames.
792 set basenames-may-differ
793 show basenames-may-differ
794 Set whether a source file may have multiple base names.
795 (A "base name" is the name of a file with the directory part removed.
796 Example: The base name of "/home/user/hello.c" is "hello.c".)
797 If set, GDB will canonicalize file names (e.g., expand symlinks)
798 before comparing them. Canonicalization is an expensive operation,
799 but it allows the same file be known by more than one base name.
800 If not set (the default), all source files are assumed to have just
801 one base name, and gdb will do file name comparisons more efficiently.
807 Set a user name and notes for the current and any future trace runs.
808 This is useful for long-running and/or disconnected traces, to
809 inform others (or yourself) as to who is running the trace, supply
810 contact information, or otherwise explain what is going on.
813 show trace-stop-notes
814 Set a note attached to the trace run, that is displayed when the
815 trace has been stopped by a tstop command. This is useful for
816 instance as an explanation, if you are stopping a trace run that was
817 started by someone else.
823 Dynamically enable a tracepoint in a started trace experiment.
827 Dynamically disable a tracepoint in a started trace experiment.
831 Set the user and notes of the trace run.
835 Query the current status of a tracepoint.
839 Query the minimum length of instruction at which a fast tracepoint may
842 * Dcache size (number of lines) and line-size are now runtime-configurable
843 via "set dcache line" and "set dcache line-size" commands.
847 Texas Instruments TMS320C6x tic6x-*-*
851 Renesas RL78 rl78-*-elf
853 *** Changes in GDB 7.3.1
855 * The build failure for NetBSD and OpenBSD targets have now been fixed.
857 *** Changes in GDB 7.3
859 * GDB has a new command: "thread find [REGEXP]".
860 It finds the thread id whose name, target id, or thread extra info
861 matches the given regular expression.
863 * The "catch syscall" command now works on mips*-linux* targets.
865 * The -data-disassemble MI command now supports modes 2 and 3 for
866 dumping the instruction opcodes.
868 * New command line options
870 -data-directory DIR Specify DIR as the "data-directory".
871 This is mostly for testing purposes.
873 * The "maint set python auto-load on|off" command has been renamed to
874 "set auto-load-scripts on|off".
876 * GDB has a new command: "set directories".
877 It is like the "dir" command except that it replaces the
878 source path list instead of augmenting it.
880 * GDB now understands thread names.
882 On GNU/Linux, "info threads" will display the thread name as set by
883 prctl or pthread_setname_np.
885 There is also a new command, "thread name", which can be used to
886 assign a name internally for GDB to display.
889 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
890 has been integrated into GDB.
894 ** The function gdb.Write now accepts an optional keyword 'stream'.
895 This keyword, when provided, will direct the output to either
896 stdout, stderr, or GDB's logging output.
898 ** Parameters can now be be sub-classed in Python, and in particular
899 you may implement the get_set_doc and get_show_doc functions.
900 This improves how Parameter set/show documentation is processed
901 and allows for more dynamic content.
903 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
904 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
905 have an is_valid method.
907 ** Breakpoints can now be sub-classed in Python, and in particular
908 you may implement a 'stop' function that is executed each time
909 the inferior reaches that breakpoint.
911 ** New function gdb.lookup_global_symbol looks up a global symbol.
913 ** GDB values in Python are now callable if the value represents a
914 function. For example, if 'some_value' represents a function that
915 takes two integer parameters and returns a value, you can call
916 that function like so:
918 result = some_value (10,20)
920 ** Module gdb.types has been added.
921 It contains a collection of utilities for working with gdb.Types objects:
922 get_basic_type, has_field, make_enum_dict.
924 ** Module gdb.printing has been added.
925 It contains utilities for writing and registering pretty-printers.
926 New classes: PrettyPrinter, SubPrettyPrinter,
927 RegexpCollectionPrettyPrinter.
928 New function: register_pretty_printer.
930 ** New commands "info pretty-printers", "enable pretty-printer" and
931 "disable pretty-printer" have been added.
933 ** gdb.parameter("directories") is now available.
935 ** New function gdb.newest_frame returns the newest frame in the
938 ** The gdb.InferiorThread class has a new "name" attribute. This
939 holds the thread's name.
941 ** Python Support for Inferior events.
942 Python scripts can add observers to be notified of events
943 occurring in the process being debugged.
944 The following events are currently supported:
945 - gdb.events.cont Continue event.
946 - gdb.events.exited Inferior exited event.
947 - gdb.events.stop Signal received, and Breakpoint hit events.
951 ** GDB now puts template parameters in scope when debugging in an
952 instantiation. For example, if you have:
954 template<int X> int func (void) { return X; }
956 then if you step into func<5>, "print X" will show "5". This
957 feature requires proper debuginfo support from the compiler; it
958 was added to GCC 4.5.
960 ** The motion commands "next", "finish", "until", and "advance" now
961 work better when exceptions are thrown. In particular, GDB will
962 no longer lose control of the inferior; instead, the GDB will
963 stop the inferior at the point at which the exception is caught.
964 This functionality requires a change in the exception handling
965 code that was introduced in GCC 4.5.
967 * GDB now follows GCC's rules on accessing volatile objects when
968 reading or writing target state during expression evaluation.
969 One notable difference to prior behavior is that "print x = 0"
970 no longer generates a read of x; the value of the assignment is
971 now always taken directly from the value being assigned.
973 * GDB now has some support for using labels in the program's source in
974 linespecs. For instance, you can use "advance label" to continue
975 execution to a label.
977 * GDB now has support for reading and writing a new .gdb_index
978 section. This section holds a fast index of DWARF debugging
979 information and can be used to greatly speed up GDB startup and
980 operation. See the documentation for `save gdb-index' for details.
982 * The "watch" command now accepts an optional "-location" argument.
983 When used, this causes GDB to watch the memory referred to by the
984 expression. Such a watchpoint is never deleted due to it going out
987 * GDB now supports thread debugging of core dumps on GNU/Linux.
989 GDB now activates thread debugging using the libthread_db library
990 when debugging GNU/Linux core dumps, similarly to when debugging
991 live processes. As a result, when debugging a core dump file, GDB
992 is now able to display pthread_t ids of threads. For example, "info
993 threads" shows the same output as when debugging the process when it
994 was live. In earlier releases, you'd see something like this:
997 * 1 LWP 6780 main () at main.c:10
999 While now you see this:
1002 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1004 It is also now possible to inspect TLS variables when debugging core
1007 When debugging a core dump generated on a machine other than the one
1008 used to run GDB, you may need to point GDB at the correct
1009 libthread_db library with the "set libthread-db-search-path"
1010 command. See the user manual for more details on this command.
1012 * When natively debugging programs on PowerPC BookE processors running
1013 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1014 which stop execution of the inferior whenever it executes an instruction
1015 at any address within the specified range. See the "PowerPC Embedded"
1016 section in the user manual for more details.
1018 * New features in the GDB remote stub, GDBserver
1020 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1021 and i686 LynxOS (version 5.x).
1023 ** GDBserver is now supported on Blackfin Linux.
1025 * New native configurations
1027 ia64 HP-UX ia64-*-hpux*
1031 Analog Devices, Inc. Blackfin Processor bfin-*
1033 * Ada task switching is now supported on sparc-elf targets when
1034 debugging a program using the Ravenscar Profile. For more information,
1035 see the "Tasking Support when using the Ravenscar Profile" section
1036 in the GDB user manual.
1038 * Guile support was removed.
1040 * New features in the GNU simulator
1042 ** The --map-info flag lists all known core mappings.
1044 ** CFI flashes may be simulated via the "cfi" device.
1046 *** Changes in GDB 7.2
1048 * Shared library support for remote targets by default
1050 When GDB is configured for a generic, non-OS specific target, like
1051 for example, --target=arm-eabi or one of the many *-*-elf targets,
1052 GDB now queries remote stubs for loaded shared libraries using the
1053 `qXfer:libraries:read' packet. Previously, shared library support
1054 was always disabled for such configurations.
1058 ** Argument Dependent Lookup (ADL)
1060 In C++ ADL lookup directs function search to the namespaces of its
1061 arguments even if the namespace has not been imported.
1071 Here the compiler will search for `foo' in the namespace of 'b'
1072 and find A::foo. GDB now supports this. This construct is commonly
1073 used in the Standard Template Library for operators.
1075 ** Improved User Defined Operator Support
1077 In addition to member operators, GDB now supports lookup of operators
1078 defined in a namespace and imported with a `using' directive, operators
1079 defined in the global scope, operators imported implicitly from an
1080 anonymous namespace, and the ADL operators mentioned in the previous
1082 GDB now also supports proper overload resolution for all the previously
1083 mentioned flavors of operators.
1085 ** static const class members
1087 Printing of static const class members that are initialized in the
1088 class definition has been fixed.
1090 * Windows Thread Information Block access.
1092 On Windows targets, GDB now supports displaying the Windows Thread
1093 Information Block (TIB) structure. This structure is visible either
1094 by using the new command `info w32 thread-information-block' or, by
1095 dereferencing the new convenience variable named `$_tlb', a
1096 thread-specific pointer to the TIB. This feature is also supported
1097 when remote debugging using GDBserver.
1099 * Static tracepoints
1101 Static tracepoints are calls in the user program into a tracing
1102 library. One such library is a port of the LTTng kernel tracer to
1103 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1104 When debugging with GDBserver, GDB now supports combining the GDB
1105 tracepoint machinery with such libraries. For example: the user can
1106 use GDB to probe a static tracepoint marker (a call from the user
1107 program into the tracing library) with the new "strace" command (see
1108 "New commands" below). This creates a "static tracepoint" in the
1109 breakpoint list, that can be manipulated with the same feature set
1110 as fast and regular tracepoints. E.g., collect registers, local and
1111 global variables, collect trace state variables, and define
1112 tracepoint conditions. In addition, the user can collect extra
1113 static tracepoint marker specific data, by collecting the new
1114 $_sdata internal variable. When analyzing the trace buffer, you can
1115 inspect $_sdata like any other variable available to GDB. For more
1116 information, see the "Tracepoints" chapter in GDB user manual. New
1117 remote packets have been defined to support static tracepoints, see
1118 the "New remote packets" section below.
1120 * Better reconstruction of tracepoints after disconnected tracing
1122 GDB will attempt to download the original source form of tracepoint
1123 definitions when starting a trace run, and then will upload these
1124 upon reconnection to the target, resulting in a more accurate
1125 reconstruction of the tracepoints that are in use on the target.
1129 You can now exercise direct control over the ways that GDB can
1130 affect your program. For instance, you can disallow the setting of
1131 breakpoints, so that the program can run continuously (assuming
1132 non-stop mode). In addition, the "observer" variable is available
1133 to switch all of the different controls; in observer mode, GDB
1134 cannot affect the target's behavior at all, which is useful for
1135 tasks like diagnosing live systems in the field.
1137 * The new convenience variable $_thread holds the number of the
1140 * New remote packets
1144 Return the address of the Windows Thread Information Block of a given thread.
1148 In response to several of the tracepoint packets, the target may now
1149 also respond with a number of intermediate `qRelocInsn' request
1150 packets before the final result packet, to have GDB handle
1151 relocating an instruction to execute at a different address. This
1152 is particularly useful for stubs that support fast tracepoints. GDB
1153 reports support for this feature in the qSupported packet.
1157 List static tracepoint markers in the target program.
1161 List static tracepoint markers at a given address in the target
1164 qXfer:statictrace:read
1166 Read the static trace data collected (by a `collect $_sdata'
1167 tracepoint action). The remote stub reports support for this packet
1168 to gdb's qSupported query.
1172 Send the current settings of GDB's permission flags.
1176 Send part of the source (textual) form of a tracepoint definition,
1177 which includes location, conditional, and action list.
1179 * The source command now accepts a -s option to force searching for the
1180 script in the source search path even if the script name specifies
1183 * New features in the GDB remote stub, GDBserver
1185 - GDBserver now support tracepoints (including fast tracepoints, and
1186 static tracepoints). The feature is currently supported by the
1187 i386-linux and amd64-linux builds. See the "Tracepoints support
1188 in gdbserver" section in the manual for more information.
1190 GDBserver JIT compiles the tracepoint's conditional agent
1191 expression bytecode into native code whenever possible for low
1192 overhead dynamic tracepoints conditionals. For such tracepoints,
1193 an expression that examines program state is evaluated when the
1194 tracepoint is reached, in order to determine whether to capture
1195 trace data. If the condition is simple and false, processing the
1196 tracepoint finishes very quickly and no data is gathered.
1198 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1199 for static tracepoints support.
1201 - GDBserver now supports x86_64 Windows 64-bit debugging.
1203 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1204 it understands register description.
1206 * The --batch flag now disables pagination and queries.
1208 * X86 general purpose registers
1210 GDB now supports reading/writing byte, word and double-word x86
1211 general purpose registers directly. This means you can use, say,
1212 $ah or $ax to refer, respectively, to the byte register AH and
1213 16-bit word register AX that are actually portions of the 32-bit
1214 register EAX or 64-bit register RAX.
1216 * The `commands' command now accepts a range of breakpoints to modify.
1217 A plain `commands' following a command that creates multiple
1218 breakpoints affects all the breakpoints set by that command. This
1219 applies to breakpoints set by `rbreak', and also applies when a
1220 single `break' command creates multiple breakpoints (e.g.,
1221 breakpoints on overloaded c++ functions).
1223 * The `rbreak' command now accepts a filename specification as part of
1224 its argument, limiting the functions selected by the regex to those
1225 in the specified file.
1227 * Support for remote debugging Windows and SymbianOS shared libraries
1228 from Unix hosts has been improved. Non Windows GDB builds now can
1229 understand target reported file names that follow MS-DOS based file
1230 system semantics, such as file names that include drive letters and
1231 use the backslash character as directory separator. This makes it
1232 possible to transparently use the "set sysroot" and "set
1233 solib-search-path" on Unix hosts to point as host copies of the
1234 target's shared libraries. See the new command "set
1235 target-file-system-kind" described below, and the "Commands to
1236 specify files" section in the user manual for more information.
1240 eval template, expressions...
1241 Convert the values of one or more expressions under the control
1242 of the string template to a command line, and call it.
1244 set target-file-system-kind unix|dos-based|auto
1245 show target-file-system-kind
1246 Set or show the assumed file system kind for target reported file
1249 save breakpoints <filename>
1250 Save all current breakpoint definitions to a file suitable for use
1251 in a later debugging session. To read the saved breakpoint
1252 definitions, use the `source' command.
1254 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1257 info static-tracepoint-markers
1258 Display information about static tracepoint markers in the target.
1260 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1261 Define a static tracepoint by probing a marker at the given
1262 function, line, address, or marker ID.
1266 Enable and disable observer mode.
1268 set may-write-registers on|off
1269 set may-write-memory on|off
1270 set may-insert-breakpoints on|off
1271 set may-insert-tracepoints on|off
1272 set may-insert-fast-tracepoints on|off
1273 set may-interrupt on|off
1274 Set individual permissions for GDB effects on the target. Note that
1275 some of these settings can have undesirable or surprising
1276 consequences, particularly when changed in the middle of a session.
1277 For instance, disabling the writing of memory can prevent
1278 breakpoints from being inserted, cause single-stepping to fail, or
1279 even crash your program, if you disable after breakpoints have been
1280 inserted. However, GDB should not crash.
1282 set record memory-query on|off
1283 show record memory-query
1284 Control whether to stop the inferior if memory changes caused
1285 by an instruction cannot be recorded.
1290 The disassemble command now supports "start,+length" form of two arguments.
1294 ** GDB now provides a new directory location, called the python directory,
1295 where Python scripts written for GDB can be installed. The location
1296 of that directory is <data-directory>/python, where <data-directory>
1297 is the GDB data directory. For more details, see section `Scripting
1298 GDB using Python' in the manual.
1300 ** The GDB Python API now has access to breakpoints, symbols, symbol
1301 tables, program spaces, inferiors, threads and frame's code blocks.
1302 Additionally, GDB Parameters can now be created from the API, and
1303 manipulated via set/show in the CLI.
1305 ** New functions gdb.target_charset, gdb.target_wide_charset,
1306 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1308 ** New exception gdb.GdbError.
1310 ** Pretty-printers are now also looked up in the current program space.
1312 ** Pretty-printers can now be individually enabled and disabled.
1314 ** GDB now looks for names of Python scripts to auto-load in a
1315 special section named `.debug_gdb_scripts', in addition to looking
1316 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1318 * Tracepoint actions were unified with breakpoint commands. In particular,
1319 there are no longer differences in "info break" output for breakpoints and
1320 tracepoints and the "commands" command can be used for both tracepoints and
1321 regular breakpoints.
1325 ARM Symbian arm*-*-symbianelf*
1327 * D language support.
1328 GDB now supports debugging programs written in the D programming
1331 * GDB now supports the extended ptrace interface for PowerPC which is
1332 available since Linux kernel version 2.6.34. This automatically enables
1333 any hardware breakpoints and additional hardware watchpoints available in
1334 the processor. The old ptrace interface exposes just one hardware
1335 watchpoint and no hardware breakpoints.
1337 * GDB is now able to use the Data Value Compare (DVC) register available on
1338 embedded PowerPC processors to implement in hardware simple watchpoint
1339 conditions of the form:
1341 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1343 This works in native GDB running on Linux kernels with the extended ptrace
1344 interface mentioned above.
1346 *** Changes in GDB 7.1
1350 ** Namespace Support
1352 GDB now supports importing of namespaces in C++. This enables the
1353 user to inspect variables from imported namespaces. Support for
1354 namepace aliasing has also been added. So, if a namespace is
1355 aliased in the current scope (e.g. namepace C=A; ) the user can
1356 print variables using the alias (e.g. (gdb) print C::x).
1360 All known bugs relating to the printing of virtual base class were
1361 fixed. It is now possible to call overloaded static methods using a
1366 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1367 and reinterpret_cast<> are now handled by the C++ expression parser.
1371 Xilinx MicroBlaze microblaze-*-*
1376 Xilinx MicroBlaze microblaze
1379 * Multi-program debugging.
1381 GDB now has support for multi-program (a.k.a. multi-executable or
1382 multi-exec) debugging. This allows for debugging multiple inferiors
1383 simultaneously each running a different program under the same GDB
1384 session. See "Debugging Multiple Inferiors and Programs" in the
1385 manual for more information. This implied some user visible changes
1386 in the multi-inferior support. For example, "info inferiors" now
1387 lists inferiors that are not running yet or that have exited
1388 already. See also "New commands" and "New options" below.
1390 * New tracing features
1392 GDB's tracepoint facility now includes several new features:
1394 ** Trace state variables
1396 GDB tracepoints now include support for trace state variables, which
1397 are variables managed by the target agent during a tracing
1398 experiment. They are useful for tracepoints that trigger each
1399 other, so for instance one tracepoint can count hits in a variable,
1400 and then a second tracepoint has a condition that is true when the
1401 count reaches a particular value. Trace state variables share the
1402 $-syntax of GDB convenience variables, and can appear in both
1403 tracepoint actions and condition expressions. Use the "tvariable"
1404 command to create, and "info tvariables" to view; see "Trace State
1405 Variables" in the manual for more detail.
1409 GDB now includes an option for defining fast tracepoints, which
1410 targets may implement more efficiently, such as by installing a jump
1411 into the target agent rather than a trap instruction. The resulting
1412 speedup can be by two orders of magnitude or more, although the
1413 tradeoff is that some program locations on some target architectures
1414 might not allow fast tracepoint installation, for instance if the
1415 instruction to be replaced is shorter than the jump. To request a
1416 fast tracepoint, use the "ftrace" command, with syntax identical to
1417 the regular trace command.
1419 ** Disconnected tracing
1421 It is now possible to detach GDB from the target while it is running
1422 a trace experiment, then reconnect later to see how the experiment
1423 is going. In addition, a new variable disconnected-tracing lets you
1424 tell the target agent whether to continue running a trace if the
1425 connection is lost unexpectedly.
1429 GDB now has the ability to save the trace buffer into a file, and
1430 then use that file as a target, similarly to you can do with
1431 corefiles. You can select trace frames, print data that was
1432 collected in them, and use tstatus to display the state of the
1433 tracing run at the moment that it was saved. To create a trace
1434 file, use "tsave <filename>", and to use it, do "target tfile
1437 ** Circular trace buffer
1439 You can ask the target agent to handle the trace buffer as a
1440 circular buffer, discarding the oldest trace frames to make room for
1441 newer ones, by setting circular-trace-buffer to on. This feature may
1442 not be available for all target agents.
1447 The disassemble command, when invoked with two arguments, now requires
1448 the arguments to be comma-separated.
1451 The info variables command now displays variable definitions. Files
1452 which only declare a variable are not shown.
1455 The source command is now capable of sourcing Python scripts.
1456 This feature is dependent on the debugger being build with Python
1459 Related to this enhancement is also the introduction of a new command
1460 "set script-extension" (see below).
1462 * New commands (for set/show, see "New options" below)
1464 record save [<FILENAME>]
1465 Save a file (in core file format) containing the process record
1466 execution log for replay debugging at a later time.
1468 record restore <FILENAME>
1469 Restore the process record execution log that was saved at an
1470 earlier time, for replay debugging.
1472 add-inferior [-copies <N>] [-exec <FILENAME>]
1475 clone-inferior [-copies <N>] [ID]
1476 Make a new inferior ready to execute the same program another
1477 inferior has loaded.
1482 maint info program-spaces
1483 List the program spaces loaded into GDB.
1485 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1486 show remote interrupt-sequence
1487 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1488 as the sequence to the remote target in order to interrupt the execution.
1489 Ctrl-C is a default. Some system prefers BREAK which is high level of
1490 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1491 Magic SysRq g. It is BREAK signal and character 'g'.
1493 set remote interrupt-on-connect [on | off]
1494 show remote interrupt-on-connect
1495 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1496 remote target when gdb connects to it. This is needed when you debug
1499 set remotebreak [on | off]
1501 Deprecated. Use "set/show remote interrupt-sequence" instead.
1503 tvariable $NAME [ = EXP ]
1504 Create or modify a trace state variable.
1507 List trace state variables and their values.
1509 delete tvariable $NAME ...
1510 Delete one or more trace state variables.
1513 Evaluate the given expressions without collecting anything into the
1514 trace buffer. (Valid in tracepoint actions only.)
1516 ftrace FN / FILE:LINE / *ADDR
1517 Define a fast tracepoint at the given function, line, or address.
1519 * New expression syntax
1521 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1522 GDB now parses 0b101010 identically with 42.
1526 set follow-exec-mode new|same
1527 show follow-exec-mode
1528 Control whether GDB reuses the same inferior across an exec call or
1529 creates a new one. This is useful to be able to restart the old
1530 executable after the inferior having done an exec call.
1532 set default-collect EXPR, ...
1533 show default-collect
1534 Define a list of expressions to be collected at each tracepoint.
1535 This is a useful way to ensure essential items are not overlooked,
1536 such as registers or a critical global variable.
1538 set disconnected-tracing
1539 show disconnected-tracing
1540 If set to 1, the target is instructed to continue tracing if it
1541 loses its connection to GDB. If 0, the target is to stop tracing
1544 set circular-trace-buffer
1545 show circular-trace-buffer
1546 If set to on, the target is instructed to use a circular trace buffer
1547 and discard the oldest trace frames instead of stopping the trace due
1548 to a full trace buffer. If set to off, the trace stops when the buffer
1549 fills up. Some targets may not support this.
1551 set script-extension off|soft|strict
1552 show script-extension
1553 If set to "off", the debugger does not perform any script language
1554 recognition, and all sourced files are assumed to be GDB scripts.
1555 If set to "soft" (the default), files are sourced according to
1556 filename extension, falling back to GDB scripts if the first
1558 If set to "strict", files are sourced according to filename extension.
1560 set ada trust-PAD-over-XVS on|off
1561 show ada trust-PAD-over-XVS
1562 If off, activate a workaround against a bug in the debugging information
1563 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1564 the GCC sources for more information about the GNAT encoding and
1565 PAD types in particular). It is always safe to set this option to
1566 off, but this introduces a slight performance penalty. The default
1569 * Python API Improvements
1571 ** GDB provides the new class gdb.LazyString. This is useful in
1572 some pretty-printing cases. The new method gdb.Value.lazy_string
1573 provides a simple way to create objects of this type.
1575 ** The fields returned by gdb.Type.fields now have an
1576 `is_base_class' attribute.
1578 ** The new method gdb.Type.range returns the range of an array type.
1580 ** The new method gdb.parse_and_eval can be used to parse and
1581 evaluate an expression.
1583 * New remote packets
1586 Define a trace state variable.
1589 Get the current value of a trace state variable.
1592 Set desired tracing behavior upon disconnection.
1595 Set the trace buffer to be linear or circular.
1598 Get data about the tracepoints currently in use.
1602 Process record now works correctly with hardware watchpoints.
1604 Multiple bug fixes have been made to the mips-irix port, making it
1605 much more reliable. In particular:
1606 - Debugging threaded applications is now possible again. Previously,
1607 GDB would hang while starting the program, or while waiting for
1608 the program to stop at a breakpoint.
1609 - Attaching to a running process no longer hangs.
1610 - An error occurring while loading a core file has been fixed.
1611 - Changing the value of the PC register now works again. This fixes
1612 problems observed when using the "jump" command, or when calling
1613 a function from GDB, or even when assigning a new value to $pc.
1614 - With the "finish" and "return" commands, the return value for functions
1615 returning a small array is now correctly printed.
1616 - It is now possible to break on shared library code which gets executed
1617 during a shared library init phase (code executed while executing
1618 their .init section). Previously, the breakpoint would have no effect.
1619 - GDB is now able to backtrace through the signal handler for
1620 non-threaded programs.
1622 PIE (Position Independent Executable) programs debugging is now supported.
1623 This includes debugging execution of PIC (Position Independent Code) shared
1624 libraries although for that, it should be possible to run such libraries as an
1627 *** Changes in GDB 7.0
1629 * GDB now has an interface for JIT compilation. Applications that
1630 dynamically generate code can create symbol files in memory and register
1631 them with GDB. For users, the feature should work transparently, and
1632 for JIT developers, the interface is documented in the GDB manual in the
1633 "JIT Compilation Interface" chapter.
1635 * Tracepoints may now be conditional. The syntax is as for
1636 breakpoints; either an "if" clause appended to the "trace" command,
1637 or the "condition" command is available. GDB sends the condition to
1638 the target for evaluation using the same bytecode format as is used
1639 for tracepoint actions.
1641 * The disassemble command now supports: an optional /r modifier, print the
1642 raw instructions in hex as well as in symbolic form, and an optional /m
1643 modifier to print mixed source+assembly.
1645 * Process record and replay
1647 In a architecture environment that supports ``process record and
1648 replay'', ``process record and replay'' target can record a log of
1649 the process execution, and replay it with both forward and reverse
1652 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
1653 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
1654 set execution-direction {forward|reverse}, for targets that support
1657 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
1658 feature is available with a native GDB running on kernel version
1661 * GDB now has support for multi-byte and wide character sets on the
1662 target. Strings whose character type is wchar_t, char16_t, or
1663 char32_t are now correctly printed. GDB supports wide- and unicode-
1664 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
1665 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
1666 `printf'. This feature requires iconv to work properly; if your
1667 system does not have a working iconv, GDB can use GNU libiconv. See
1668 the installation instructions for more information.
1670 * GDB now supports automatic retrieval of shared library files from
1671 remote targets. To use this feature, specify a system root that begins
1672 with the `remote:' prefix, either via the `set sysroot' command or via
1673 the `--with-sysroot' configure-time option.
1675 * "info sharedlibrary" now takes an optional regex of libraries to show,
1676 and it now reports if a shared library has no debugging information.
1678 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
1679 now complete on file names.
1681 * When completing in expressions, gdb will attempt to limit
1682 completions to allowable structure or union fields, where appropriate.
1683 For instance, consider:
1685 # struct example { int f1; double f2; };
1686 # struct example variable;
1689 If the user types TAB at the end of this command line, the available
1690 completions will be "f1" and "f2".
1692 * Inlined functions are now supported. They show up in backtraces, and
1693 the "step", "next", and "finish" commands handle them automatically.
1695 * GDB now supports the token-splicing (##) and stringification (#)
1696 operators when expanding macros. It also supports variable-arity
1699 * GDB now supports inspecting extra signal information, exported by
1700 the new $_siginfo convenience variable. The feature is currently
1701 implemented on linux ARM, i386 and amd64.
1703 * GDB can now display the VFP floating point registers and NEON vector
1704 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
1705 can provide these registers (requires Linux 2.6.30 or later). Remote
1706 and simulator targets may also provide them.
1708 * New remote packets
1711 Search memory for a sequence of bytes.
1714 Turn off `+'/`-' protocol acknowledgments to permit more efficient
1715 operation over reliable transport links. Use of this packet is
1716 controlled by the `set remote noack-packet' command.
1719 Kill the process with the specified process ID. Use this in preference
1720 to `k' when multiprocess protocol extensions are supported.
1723 Obtains additional operating system information
1727 Read or write additional signal information.
1729 * Removed remote protocol undocumented extension
1731 An undocumented extension to the remote protocol's `S' stop reply
1732 packet that permited the stub to pass a process id was removed.
1733 Remote servers should use the `T' stop reply packet instead.
1735 * GDB now supports multiple function calling conventions according to the
1736 DWARF-2 DW_AT_calling_convention function attribute.
1738 * The SH target utilizes the aforementioned change to distinguish between gcc
1739 and Renesas calling convention. It also adds the new CLI commands
1740 `set/show sh calling-convention'.
1742 * GDB can now read compressed debug sections, as produced by GNU gold
1743 with the --compress-debug-sections=zlib flag.
1745 * 64-bit core files are now supported on AIX.
1747 * Thread switching is now supported on Tru64.
1749 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
1750 which will be allocated using malloc later in program execution.
1752 * The qXfer:libraries:read remote procotol packet now allows passing a
1753 list of section offsets.
1755 * On GNU/Linux, GDB can now attach to stopped processes. Several race
1756 conditions handling signals delivered during attach or thread creation
1757 have also been fixed.
1759 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
1760 From the user's standpoint, all unqualified instances of True and False
1761 are treated as the standard definitions, regardless of context.
1763 * GDB now parses C++ symbol and type names more flexibly. For
1766 template<typename T> class C { };
1769 GDB will now correctly handle all of:
1771 ptype C<char const *>
1772 ptype C<char const*>
1773 ptype C<const char *>
1774 ptype C<const char*>
1776 * New features in the GDB remote stub, gdbserver
1778 - The "--wrapper" command-line argument tells gdbserver to use a
1779 wrapper program to launch programs for debugging.
1781 - On PowerPC and S/390 targets, it is now possible to use a single
1782 gdbserver executable to debug both 32-bit and 64-bit programs.
1783 (This requires gdbserver itself to be built as a 64-bit executable.)
1785 - gdbserver uses the new noack protocol mode for TCP connections to
1786 reduce communications latency, if also supported and enabled in GDB.
1788 - Support for the sparc64-linux-gnu target is now included in
1791 - The amd64-linux build of gdbserver now supports debugging both
1792 32-bit and 64-bit programs.
1794 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
1795 now support hardware watchpoints, and will use them automatically
1800 GDB now has support for scripting using Python. Whether this is
1801 available is determined at configure time.
1803 New GDB commands can now be written in Python.
1805 * Ada tasking support
1807 Ada tasks can now be inspected in GDB. The following commands have
1811 Print the list of Ada tasks.
1813 Print detailed information about task number N.
1815 Print the task number of the current task.
1817 Switch the context of debugging to task number N.
1819 * Support for user-defined prefixed commands. The "define" command can
1820 add new commands to existing prefixes, e.g. "target".
1822 * Multi-inferior, multi-process debugging.
1824 GDB now has generalized support for multi-inferior debugging. See
1825 "Debugging Multiple Inferiors" in the manual for more information.
1826 Although availability still depends on target support, the command
1827 set is more uniform now. The GNU/Linux specific multi-forks support
1828 has been migrated to this new framework. This implied some user
1829 visible changes; see "New commands" and also "Removed commands"
1832 * Target descriptions can now describe the target OS ABI. See the
1833 "Target Description Format" section in the user manual for more
1836 * Target descriptions can now describe "compatible" architectures
1837 to indicate that the target can execute applications for a different
1838 architecture in addition to those for the main target architecture.
1839 See the "Target Description Format" section in the user manual for
1842 * Multi-architecture debugging.
1844 GDB now includes general supports for debugging applications on
1845 hybrid systems that use more than one single processor architecture
1846 at the same time. Each such hybrid architecture still requires
1847 specific support to be added. The only hybrid architecture supported
1848 in this version of GDB is the Cell Broadband Engine.
1850 * GDB now supports integrated debugging of Cell/B.E. applications that
1851 use both the PPU and SPU architectures. To enable support for hybrid
1852 Cell/B.E. debugging, you need to configure GDB to support both the
1853 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
1854 --enable-targets configure option.
1856 * Non-stop mode debugging.
1858 For some targets, GDB now supports an optional mode of operation in
1859 which you can examine stopped threads while other threads continue
1860 to execute freely. This is referred to as non-stop mode, with the
1861 old mode referred to as all-stop mode. See the "Non-Stop Mode"
1862 section in the user manual for more information.
1864 To be able to support remote non-stop debugging, a remote stub needs
1865 to implement the non-stop mode remote protocol extensions, as
1866 described in the "Remote Non-Stop" section of the user manual. The
1867 GDB remote stub, gdbserver, has been adjusted to support these
1868 extensions on linux targets.
1870 * New commands (for set/show, see "New options" below)
1872 catch syscall [NAME(S) | NUMBER(S)]
1873 Catch system calls. Arguments, which should be names of system
1874 calls or their numbers, mean catch only those syscalls. Without
1875 arguments, every syscall will be caught. When the inferior issues
1876 any of the specified syscalls, GDB will stop and announce the system
1877 call, both when it is called and when its call returns. This
1878 feature is currently available with a native GDB running on the
1879 Linux Kernel, under the following architectures: x86, x86_64,
1880 PowerPC and PowerPC64.
1882 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
1884 Search memory for a sequence of bytes.
1886 maint set python print-stack
1887 maint show python print-stack
1888 Show a stack trace when an error is encountered in a Python script.
1891 Invoke CODE by passing it to the Python interpreter.
1896 These allow macros to be defined, undefined, and listed
1900 Show operating system information about processes.
1903 List the inferiors currently under GDB's control.
1906 Switch focus to inferior number NUM.
1909 Detach from inferior number NUM.
1912 Kill inferior number NUM.
1916 set spu stop-on-load
1917 show spu stop-on-load
1918 Control whether to stop for new SPE threads during Cell/B.E. debugging.
1920 set spu auto-flush-cache
1921 show spu auto-flush-cache
1922 Control whether to automatically flush the software-managed cache
1923 during Cell/B.E. debugging.
1925 set sh calling-convention
1926 show sh calling-convention
1927 Control the calling convention used when calling SH target functions.
1930 show debug timestamp
1931 Control display of timestamps with GDB debugging output.
1933 set disassemble-next-line
1934 show disassemble-next-line
1935 Control display of disassembled source lines or instructions when
1938 set remote noack-packet
1939 show remote noack-packet
1940 Set/show the use of remote protocol QStartNoAckMode packet. See above
1941 under "New remote packets."
1943 set remote query-attached-packet
1944 show remote query-attached-packet
1945 Control use of remote protocol `qAttached' (query-attached) packet.
1947 set remote read-siginfo-object
1948 show remote read-siginfo-object
1949 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
1952 set remote write-siginfo-object
1953 show remote write-siginfo-object
1954 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
1957 set remote reverse-continue
1958 show remote reverse-continue
1959 Control use of remote protocol 'bc' (reverse-continue) packet.
1961 set remote reverse-step
1962 show remote reverse-step
1963 Control use of remote protocol 'bs' (reverse-step) packet.
1965 set displaced-stepping
1966 show displaced-stepping
1967 Control displaced stepping mode. Displaced stepping is a way to
1968 single-step over breakpoints without removing them from the debuggee.
1969 Also known as "out-of-line single-stepping".
1972 show debug displaced
1973 Control display of debugging info for displaced stepping.
1975 maint set internal-error
1976 maint show internal-error
1977 Control what GDB does when an internal error is detected.
1979 maint set internal-warning
1980 maint show internal-warning
1981 Control what GDB does when an internal warning is detected.
1986 Use a wrapper program to launch programs for debugging.
1988 set multiple-symbols (all|ask|cancel)
1989 show multiple-symbols
1990 The value of this variable can be changed to adjust the debugger behavior
1991 when an expression or a breakpoint location contains an ambiguous symbol
1992 name (an overloaded function name, for instance).
1994 set breakpoint always-inserted
1995 show breakpoint always-inserted
1996 Keep breakpoints always inserted in the target, as opposed to inserting
1997 them when resuming the target, and removing them when the target stops.
1998 This option can improve debugger performance on slow remote targets.
2000 set arm fallback-mode (arm|thumb|auto)
2001 show arm fallback-mode
2002 set arm force-mode (arm|thumb|auto)
2004 These commands control how ARM GDB determines whether instructions
2005 are ARM or Thumb. The default for both settings is auto, which uses
2006 the current CPSR value for instructions without symbols; previous
2007 versions of GDB behaved as if "set arm fallback-mode arm".
2009 set disable-randomization
2010 show disable-randomization
2011 Standalone programs run with the virtual address space randomization enabled
2012 by default on some platforms. This option keeps the addresses stable across
2013 multiple debugging sessions.
2017 Control whether other threads are stopped or not when some thread hits
2022 Requests that asynchronous execution is enabled in the target, if available.
2023 In this case, it's possible to resume target in the background, and interact
2024 with GDB while the target is running. "show target-async" displays the
2025 current state of asynchronous execution of the target.
2027 set target-wide-charset
2028 show target-wide-charset
2029 The target-wide-charset is the name of the character set that GDB
2030 uses when printing characters whose type is wchar_t.
2032 set tcp auto-retry (on|off)
2034 set tcp connect-timeout
2035 show tcp connect-timeout
2036 These commands allow GDB to retry failed TCP connections to a remote stub
2037 with a specified timeout period; this is useful if the stub is launched
2038 in parallel with GDB but may not be ready to accept connections immediately.
2040 set libthread-db-search-path
2041 show libthread-db-search-path
2042 Control list of directories which GDB will search for appropriate
2045 set schedule-multiple (on|off)
2046 show schedule-multiple
2047 Allow GDB to resume all threads of all processes or only threads of
2048 the current process.
2052 Use more aggressive caching for accesses to the stack. This improves
2053 performance of remote debugging (particularly backtraces) without
2054 affecting correctness.
2056 set interactive-mode (on|off|auto)
2057 show interactive-mode
2058 Control whether GDB runs in interactive mode (on) or not (off).
2059 When in interactive mode, GDB waits for the user to answer all
2060 queries. Otherwise, GDB does not wait and assumes the default
2061 answer. When set to auto (the default), GDB determines which
2062 mode to use based on the stdin settings.
2067 For program forks, this is replaced by the new more generic `info
2068 inferiors' command. To list checkpoints, you can still use the
2069 `info checkpoints' command, which was an alias for the `info forks'
2073 Replaced by the new `inferior' command. To switch between
2074 checkpoints, you can still use the `restart' command, which was an
2075 alias for the `fork' command.
2078 This is removed, since some targets don't have a notion of
2079 processes. To switch between processes, you can still use the
2080 `inferior' command using GDB's own inferior number.
2083 For program forks, this is replaced by the new more generic `kill
2084 inferior' command. To delete a checkpoint, you can still use the
2085 `delete checkpoint' command, which was an alias for the `delete
2089 For program forks, this is replaced by the new more generic `detach
2090 inferior' command. To detach a checkpoint, you can still use the
2091 `detach checkpoint' command, which was an alias for the `detach
2094 * New native configurations
2096 x86/x86_64 Darwin i[34567]86-*-darwin*
2098 x86_64 MinGW x86_64-*-mingw*
2102 Lattice Mico32 lm32-*
2103 x86 DICOS i[34567]86-*-dicos*
2104 x86_64 DICOS x86_64-*-dicos*
2107 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2108 (mingw32ce) debugging.
2114 These commands were actually not implemented on any target.
2116 *** Changes in GDB 6.8
2118 * New native configurations
2120 NetBSD/hppa hppa*-*netbsd*
2121 Xtensa GNU/Linux xtensa*-*-linux*
2125 NetBSD/hppa hppa*-*-netbsd*
2126 Xtensa GNU/Lunux xtensa*-*-linux*
2128 * Change in command line behavior -- corefiles vs. process ids.
2130 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2131 attaching to process NUMBER fails, GDB no longer attempts to open a
2132 core file named NUMBER. Attaching to a program using the -c option
2133 is no longer supported. Instead, use the '-p' or '--pid' options.
2135 * GDB can now be built as a native debugger for debugging Windows x86
2136 (mingw32) Portable Executable (PE) programs.
2138 * Pending breakpoints no longer change their number when their address
2141 * GDB now supports breakpoints with multiple locations,
2142 including breakpoints on C++ constructors, inside C++ templates,
2143 and in inlined functions.
2145 * GDB's ability to debug optimized code has been improved. GDB more
2146 accurately identifies function bodies and lexical blocks that occupy
2147 more than one contiguous range of addresses.
2149 * Target descriptions can now describe registers for PowerPC.
2151 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2152 registers on PowerPC targets.
2154 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2155 targets even when the libthread_db library is not available.
2157 * The GDB remote stub, gdbserver, now supports the new file transfer
2158 commands (remote put, remote get, and remote delete).
2160 * The GDB remote stub, gdbserver, now supports run and attach in
2161 extended-remote mode.
2163 * hppa*64*-*-hpux11* target broken
2164 The debugger is unable to start a program and fails with the following
2165 error: "Error trying to get information about dynamic linker".
2166 The gdb-6.7 release is also affected.
2168 * GDB now supports the --enable-targets= configure option to allow
2169 building a single GDB executable that supports multiple remote
2170 target architectures.
2172 * GDB now supports debugging C and C++ programs which use the
2173 Decimal Floating Point extension. In addition, the PowerPC target
2174 now has a set of pseudo-registers to inspect decimal float values
2175 stored in two consecutive float registers.
2177 * The -break-insert MI command can optionally create pending
2180 * Improved support for debugging Ada
2181 Many improvements to the Ada language support have been made. These
2183 - Better support for Ada2005 interface types
2184 - Improved handling of arrays and slices in general
2185 - Better support for Taft-amendment types
2186 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2188 - Improved command completion in Ada
2191 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2196 set print frame-arguments (all|scalars|none)
2197 show print frame-arguments
2198 The value of this variable can be changed to control which argument
2199 values should be printed by the debugger when displaying a frame.
2204 Transfer files to and from a remote target, and delete remote files.
2211 Transfer files to and from a remote target, and delete remote files.
2213 * New remote packets
2220 Open, close, read, write, and delete files on the remote system.
2223 Attach to an existing process on the remote system, in extended-remote
2227 Run a new process on the remote system, in extended-remote mode.
2229 *** Changes in GDB 6.7
2231 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2232 bfd, libiberty and opcodes, as revealed by static analysis donated by
2233 Coverity, Inc. (http://scan.coverity.com).
2235 * When looking up multiply-defined global symbols, GDB will now prefer the
2236 symbol definition in the current shared library if it was built using the
2237 -Bsymbolic linker option.
2239 * When the Text User Interface (TUI) is not configured, GDB will now
2240 recognize the -tui command-line option and print a message that the TUI
2243 * The GDB remote stub, gdbserver, now has lower overhead for high
2244 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2246 * GDB for MIPS targets now autodetects whether a remote target provides
2247 32-bit or 64-bit register values.
2249 * Support for C++ member pointers has been improved.
2251 * GDB now understands XML target descriptions, which specify the
2252 target's overall architecture. GDB can read a description from
2253 a local file or over the remote serial protocol.
2255 * Vectors of single-byte data use a new integer type which is not
2256 automatically displayed as character or string data.
2258 * The /s format now works with the print command. It displays
2259 arrays of single-byte integers and pointers to single-byte integers
2262 * Target descriptions can now describe target-specific registers,
2263 for architectures which have implemented the support (currently
2264 only ARM, M68K, and MIPS).
2266 * GDB and the GDB remote stub, gdbserver, now support the XScale
2269 * The GDB remote stub, gdbserver, has been updated to support
2270 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2271 has been rewritten to use the standard GDB remote protocol.
2273 * GDB can now step into C++ functions which are called through thunks.
2275 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2277 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2278 layout. It also supports a TextSeg= and DataSeg= response when only
2279 segment base addresses (rather than offsets) are available.
2281 * The /i format now outputs any trailing branch delay slot instructions
2282 immediately following the last instruction within the count specified.
2284 * The GDB remote protocol "T" stop reply packet now supports a
2285 "library" response. Combined with the new "qXfer:libraries:read"
2286 packet, this response allows GDB to debug shared libraries on targets
2287 where the operating system manages the list of loaded libraries (e.g.
2288 Windows and SymbianOS).
2290 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2291 (DLLs) on Windows and Windows CE targets.
2293 * GDB now supports a faster verification that a .debug file matches its binary
2294 according to its build-id signature, if the signature is present.
2300 Enable or disable hardware flow control (RTS/CTS) on the serial port
2301 when debugging using remote targets.
2303 set mem inaccessible-by-default
2304 show mem inaccessible-by-default
2305 If the target supplies a memory map, for instance via the remote
2306 protocol's "qXfer:memory-map:read" packet, setting this variable
2307 prevents GDB from accessing memory outside the memory map. This
2308 is useful for targets with memory mapped registers or which react
2309 badly to accesses of unmapped address space.
2311 set breakpoint auto-hw
2312 show breakpoint auto-hw
2313 If the target supplies a memory map, for instance via the remote
2314 protocol's "qXfer:memory-map:read" packet, setting this variable
2315 lets GDB use hardware breakpoints automatically for memory regions
2316 where it can not use software breakpoints. This covers both the
2317 "break" command and internal breakpoints used for other commands
2318 including "next" and "finish".
2321 catch exception unhandled
2322 Stop the program execution when Ada exceptions are raised.
2325 Stop the program execution when an Ada assertion failed.
2329 Set an alternate system root for target files. This is a more
2330 general version of "set solib-absolute-prefix", which is now
2331 an alias to "set sysroot".
2334 Provide extended SPU facility status information. This set of
2335 commands is available only when debugging the Cell/B.E. SPU
2338 * New native configurations
2340 OpenBSD/sh sh*-*openbsd*
2343 unset tdesc filename
2345 Use the specified local file as an XML target description, and do
2346 not query the target for its built-in description.
2350 OpenBSD/sh sh*-*-openbsd*
2351 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2352 Toshiba Media Processor mep-elf
2354 * New remote packets
2357 Ignore the specified signals; pass them directly to the debugged program
2358 without stopping other threads or reporting them to GDB.
2360 qXfer:features:read:
2361 Read an XML target description from the target, which describes its
2366 Read or write contents of an spufs file on the target system. These
2367 packets are available only on the Cell/B.E. SPU architecture.
2369 qXfer:libraries:read:
2370 Report the loaded shared libraries. Combined with new "T" packet
2371 response, this packet allows GDB to debug shared libraries on
2372 targets where the operating system manages the list of loaded
2373 libraries (e.g. Windows and SymbianOS).
2377 Support for these obsolete configurations has been removed.
2385 i[34567]86-*-lynxos*
2386 i[34567]86-*-netware*
2387 i[34567]86-*-sco3.2v5*
2388 i[34567]86-*-sco3.2v4*
2390 i[34567]86-*-sysv4.2*
2393 i[34567]86-*-unixware2*
2394 i[34567]86-*-unixware*
2403 * Other removed features
2410 Various m68k-only ROM monitors.
2417 Various Renesas ROM monitors and debugging interfaces for SH and
2422 Support for a Macraigor serial interface to on-chip debugging.
2423 GDB does not directly support the newer parallel or USB
2428 A debug information format. The predecessor to DWARF 2 and
2429 DWARF 3, which are still supported.
2431 Support for the HP aCC compiler on HP-UX/PA-RISC
2433 SOM-encapsulated symbolic debugging information, automatic
2434 invocation of pxdb, and the aCC custom C++ ABI. This does not
2435 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2436 with aCC can still be debugged on an assembly level.
2438 MIPS ".pdr" sections
2440 A MIPS-specific format used to describe stack frame layout
2441 in debugging information.
2445 GDB could work with an older version of Guile to debug
2446 the interpreter and Scheme programs running in it.
2448 set mips stack-arg-size
2449 set mips saved-gpreg-size
2451 Use "set mips abi" to control parameter passing for MIPS.
2453 *** Changes in GDB 6.6
2458 Cell Broadband Engine SPU spu-elf
2460 * GDB can now be configured as a cross-debugger targeting native Windows
2461 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2462 running on a Windows system over TCP/IP to debug Windows programs.
2464 * The GDB remote stub, gdbserver, has been updated to support Windows and
2465 Cygwin debugging. Both single-threaded and multi-threaded programs are
2468 * The "set trust-readonly-sections" command works again. This command was
2469 broken in GDB 6.3, 6.4, and 6.5.
2471 * The "load" command now supports writing to flash memory, if the remote
2472 stub provides the required support.
2474 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2475 longer requires symbolic debug information (e.g. DWARF-2).
2480 unset substitute-path
2481 show substitute-path
2482 Manage a list of substitution rules that GDB uses to rewrite the name
2483 of the directories where the sources are located. This can be useful
2484 for instance when the sources were moved to a different location
2485 between compilation and debugging.
2489 Print each CLI command as it is executed. Each command is prefixed with
2490 a number of `+' symbols representing the nesting depth.
2491 The source command now has a `-v' option to enable the same feature.
2495 The ARM Demon monitor support (RDP protocol, "target rdp").
2497 Kernel Object Display, an embedded debugging feature which only worked with
2498 an obsolete version of Cisco IOS.
2500 The 'set download-write-size' and 'show download-write-size' commands.
2502 * New remote packets
2505 Tell a stub about GDB client features, and request remote target features.
2506 The first feature implemented is PacketSize, which allows the target to
2507 specify the size of packets it can handle - to minimize the number of
2508 packets required and improve performance when connected to a remote
2512 Fetch an OS auxilliary vector from the remote stub. This packet is a
2513 more efficient replacement for qPart:auxv:read.
2515 qXfer:memory-map:read:
2516 Fetch a memory map from the remote stub, including information about
2517 RAM, ROM, and flash memory devices.
2522 Erase and program a flash memory device.
2524 * Removed remote packets
2527 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2528 used it, and only gdbserver implemented it.
2530 *** Changes in GDB 6.5
2534 Renesas M32C/M16C m32c-elf
2536 Morpho Technologies ms1 ms1-elf
2540 init-if-undefined Initialize a convenience variable, but
2541 only if it doesn't already have a value.
2543 The following commands are presently only implemented for native GNU/Linux:
2545 checkpoint Save a snapshot of the program state.
2547 restart <n> Return the program state to a
2548 previously saved state.
2550 info checkpoints List currently saved checkpoints.
2552 delete-checkpoint <n> Delete a previously saved checkpoint.
2554 set|show detach-on-fork Tell gdb whether to detach from a newly
2555 forked process, or to keep debugging it.
2557 info forks List forks of the user program that
2558 are available to be debugged.
2560 fork <n> Switch to debugging one of several
2561 forks of the user program that are
2562 available to be debugged.
2564 delete-fork <n> Delete a fork from the list of forks
2565 that are available to be debugged (and
2566 kill the forked process).
2568 detach-fork <n> Delete a fork from the list of forks
2569 that are available to be debugged (and
2570 allow the process to continue).
2574 Morpho Technologies ms2 ms1-elf
2576 * Improved Windows host support
2578 GDB now builds as a cross debugger hosted on i686-mingw32, including
2579 native console support, and remote communications using either
2580 network sockets or serial ports.
2582 * Improved Modula-2 language support
2584 GDB can now print most types in the Modula-2 syntax. This includes:
2585 basic types, set types, record types, enumerated types, range types,
2586 pointer types and ARRAY types. Procedure var parameters are correctly
2587 printed and hexadecimal addresses and character constants are also
2588 written in the Modula-2 syntax. Best results can be obtained by using
2589 GNU Modula-2 together with the -gdwarf-2 command line option.
2593 The ARM rdi-share module.
2595 The Netware NLM debug server.
2597 *** Changes in GDB 6.4
2599 * New native configurations
2601 OpenBSD/arm arm*-*-openbsd*
2602 OpenBSD/mips64 mips64-*-openbsd*
2606 Morpho Technologies ms1 ms1-elf
2608 * New command line options
2610 --batch-silent As for --batch, but totally silent.
2611 --return-child-result The debugger will exist with the same value
2612 the child (debugged) program exited with.
2613 --eval-command COMMAND, -ex COMMAND
2614 Execute a single GDB CLI command. This may be
2615 specified multiple times and in conjunction
2616 with the --command (-x) option.
2618 * Deprecated commands removed
2620 The following commands, that were deprecated in 2000, have been
2624 set|show arm disassembly-flavor set|show arm disassembler
2625 othernames set arm disassembler
2626 set|show remotedebug set|show debug remote
2627 set|show archdebug set|show debug arch
2628 set|show eventdebug set|show debug event
2631 * New BSD user-level threads support
2633 It is now possible to debug programs using the user-level threads
2634 library on OpenBSD and FreeBSD. Currently supported (target)
2637 FreeBSD/amd64 x86_64-*-freebsd*
2638 FreeBSD/i386 i386-*-freebsd*
2639 OpenBSD/i386 i386-*-openbsd*
2641 Note that the new kernel threads libraries introduced in FreeBSD 5.x
2642 are not yet supported.
2644 * New support for Matsushita MN10300 w/sim added
2645 (Work in progress). mn10300-elf.
2647 * REMOVED configurations and files
2649 VxWorks and the XDR protocol *-*-vxworks
2650 Motorola MCORE mcore-*-*
2651 National Semiconductor NS32000 ns32k-*-*
2653 * New "set print array-indexes" command
2655 After turning this setting "on", GDB prints the index of each element
2656 when displaying arrays. The default is "off" to preserve the previous
2659 * VAX floating point support
2661 GDB now supports the not-quite-ieee VAX F and D floating point formats.
2663 * User-defined command support
2665 In addition to using $arg0..$arg9 for argument passing, it is now possible
2666 to use $argc to determine now many arguments have been passed. See the
2667 section on user-defined commands in the user manual for more information.
2669 *** Changes in GDB 6.3:
2671 * New command line option
2673 GDB now accepts -l followed by a number to set the timeout for remote
2676 * GDB works with GCC -feliminate-dwarf2-dups
2678 GDB now supports a more compact representation of DWARF-2 debug
2679 information using DW_FORM_ref_addr references. These are produced
2680 by GCC with the option -feliminate-dwarf2-dups and also by some
2681 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
2682 to use -feliminate-dwarf2-dups.
2684 * Internationalization
2686 When supported by the host system, GDB will be built with
2687 internationalization (libintl). The task of marking up the sources is
2688 continued, we're looking forward to our first translation.
2692 Initial support for debugging programs compiled with the GNAT
2693 implementation of the Ada programming language has been integrated
2694 into GDB. In this release, support is limited to expression evaluation.
2696 * New native configurations
2698 GNU/Linux/m32r m32r-*-linux-gnu
2702 GDB's remote protocol now includes support for the 'p' packet. This
2703 packet is used to fetch individual registers from a remote inferior.
2705 * END-OF-LIFE registers[] compatibility module
2707 GDB's internal register infrastructure has been completely rewritten.
2708 The new infrastructure making possible the implementation of key new
2709 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
2712 GDB 6.3 will be the last release to include the the registers[]
2713 compatibility module that allowed out-of-date configurations to
2714 continue to work. This change directly impacts the following
2724 powerpc bdm protocol
2726 Unless there is activity to revive these configurations, they will be
2727 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
2729 * OBSOLETE configurations and files
2731 Configurations that have been declared obsolete in this release have
2732 been commented out. Unless there is activity to revive these
2733 configurations, the next release of GDB will have their sources
2734 permanently REMOVED.
2743 *** Changes in GDB 6.2.1:
2745 * MIPS `break main; run' gave an heuristic-fence-post warning
2747 When attempting to run even a simple program, a warning about
2748 heuristic-fence-post being hit would be reported. This problem has
2751 * MIPS IRIX 'long double' crashed GDB
2753 When examining a long double variable, GDB would get a segmentation
2754 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
2755 IRIX long double values).
2759 A bug in the VAX stack code was causing problems with the "next"
2760 command. This problem has been fixed.
2762 *** Changes in GDB 6.2:
2764 * Fix for ``many threads''
2766 On GNU/Linux systems that use the NPTL threads library, a program
2767 rapidly creating and deleting threads would confuse GDB leading to the
2770 ptrace: No such process.
2771 thread_db_get_info: cannot get thread info: generic error
2773 This problem has been fixed.
2775 * "-async" and "-noasync" options removed.
2777 Support for the broken "-noasync" option has been removed (it caused
2780 * New ``start'' command.
2782 This command runs the program until the begining of the main procedure.
2784 * New BSD Kernel Data Access Library (libkvm) interface
2786 Using ``target kvm'' it is now possible to debug kernel core dumps and
2787 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
2788 platforms. Currently supported (native-only) configurations are:
2790 FreeBSD/amd64 x86_64-*-freebsd*
2791 FreeBSD/i386 i?86-*-freebsd*
2792 NetBSD/i386 i?86-*-netbsd*
2793 NetBSD/m68k m68*-*-netbsd*
2794 NetBSD/sparc sparc-*-netbsd*
2795 OpenBSD/amd64 x86_64-*-openbsd*
2796 OpenBSD/i386 i?86-*-openbsd*
2797 OpenBSD/m68k m68*-openbsd*
2798 OpenBSD/sparc sparc-*-openbsd*
2800 * Signal trampoline code overhauled
2802 Many generic problems with GDB's signal handling code have been fixed.
2803 These include: backtraces through non-contiguous stacks; recognition
2804 of sa_sigaction signal trampolines; backtrace from a NULL pointer
2805 call; backtrace through a signal trampoline; step into and out of
2806 signal handlers; and single-stepping in the signal trampoline.
2808 Please note that kernel bugs are a limiting factor here. These
2809 features have been shown to work on an s390 GNU/Linux system that
2810 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
2812 * Cygwin support for DWARF 2 added.
2814 * New native configurations
2816 GNU/Linux/hppa hppa*-*-linux*
2817 OpenBSD/hppa hppa*-*-openbsd*
2818 OpenBSD/m68k m68*-*-openbsd*
2819 OpenBSD/m88k m88*-*-openbsd*
2820 OpenBSD/powerpc powerpc-*-openbsd*
2821 NetBSD/vax vax-*-netbsd*
2822 OpenBSD/vax vax-*-openbsd*
2824 * END-OF-LIFE frame compatibility module
2826 GDB's internal frame infrastructure has been completely rewritten.
2827 The new infrastructure making it possible to support key new features
2828 including DWARF 2 Call Frame Information. To aid in the task of
2829 migrating old configurations to this new infrastructure, a
2830 compatibility module, that allowed old configurations to continue to
2831 work, was also included.
2833 GDB 6.2 will be the last release to include this frame compatibility
2834 module. This change directly impacts the following configurations:
2844 Unless there is activity to revive these configurations, they will be
2845 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
2847 * REMOVED configurations and files
2849 Sun 3, running SunOS 3 m68*-*-sunos3*
2850 Sun 3, running SunOS 4 m68*-*-sunos4*
2851 Sun 2, running SunOS 3 m68000-*-sunos3*
2852 Sun 2, running SunOS 4 m68000-*-sunos4*
2853 Motorola 680x0 running LynxOS m68*-*-lynxos*
2854 AT&T 3b1/Unix pc m68*-att-*
2855 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2856 decstation mips-dec-* mips-little-*
2857 riscos mips-*-riscos* mips-*-sysv*
2858 sonymips mips-sony-*
2859 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2861 *** Changes in GDB 6.1.1:
2863 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
2865 The TUI (Text-mode User Interface) is now built as part of a default
2866 GDB configuration. It is enabled by either selecting the TUI with the
2867 command line option "-i=tui" or by running the separate "gdbtui"
2868 program. For more information on the TUI, see the manual "Debugging
2871 * Pending breakpoint support (also included in GDB 6.1)
2873 Support has been added to allow you to specify breakpoints in shared
2874 libraries that have not yet been loaded. If a breakpoint location
2875 cannot be found, and the "breakpoint pending" option is set to auto,
2876 GDB queries you if you wish to make the breakpoint pending on a future
2877 shared-library load. If and when GDB resolves the breakpoint symbol,
2878 the pending breakpoint is removed as one or more regular breakpoints
2881 Pending breakpoints are very useful for GCJ Java debugging.
2883 * Fixed ISO-C build problems
2885 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
2886 non ISO-C code that stopped them being built using a more strict ISO-C
2887 compiler (e.g., IBM's C compiler).
2889 * Fixed build problem on IRIX 5
2891 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
2892 wasn't able to compile compile on an IRIX 5 system.
2894 * Added execute permission to gdb/gdbserver/configure
2896 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
2897 permission. This bug would cause configure to fail on a number of
2898 systems (Solaris, IRIX). Ref: server/519.
2900 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
2902 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
2903 has been updated to use constant array sizes.
2905 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
2907 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
2908 its generated DWARF Call Frame Info. This encoding was causing GDB to
2909 panic, that panic has been fixed. Ref: gdb/1628.
2911 * Fixed a problem when examining parameters in shared library code.
2913 When examining parameters in optimized shared library code generated
2914 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
2915 not available''. GDB now correctly displays the variable's value.
2917 *** Changes in GDB 6.1:
2919 * Removed --with-mmalloc
2921 Support for the mmalloc memory manager has been removed, as it
2922 conflicted with the internal gdb byte cache.
2924 * Changes in AMD64 configurations
2926 The AMD64 target now includes the %cs and %ss registers. As a result
2927 the AMD64 remote protocol has changed; this affects the floating-point
2928 and SSE registers. If you rely on those registers for your debugging,
2929 you should upgrade gdbserver on the remote side.
2931 * Revised SPARC target
2933 The SPARC target has been completely revised, incorporating the
2934 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
2935 support for LynxOS and SunOS 4 has been dropped. Calling functions
2936 from within GDB on operating systems with a non-executable stack
2937 (Solaris, OpenBSD) now works.
2941 GDB has a new C++ demangler which does a better job on the mangled
2942 names generated by current versions of g++. It also runs faster, so
2943 with this and other changes gdb should now start faster on large C++
2946 * DWARF 2 Location Expressions
2948 GDB support for location expressions has been extended to support function
2949 arguments and frame bases. Older versions of GDB could crash when they
2952 * C++ nested types and namespaces
2954 GDB's support for nested types and namespaces in C++ has been
2955 improved, especially if you use the DWARF 2 debugging format. (This
2956 is the default for recent versions of GCC on most platforms.)
2957 Specifically, if you have a class "Inner" defined within a class or
2958 namespace "Outer", then GDB realizes that the class's name is
2959 "Outer::Inner", not simply "Inner". This should greatly reduce the
2960 frequency of complaints about not finding RTTI symbols. In addition,
2961 if you are stopped at inside of a function defined within a namespace,
2962 GDB modifies its name lookup accordingly.
2964 * New native configurations
2966 NetBSD/amd64 x86_64-*-netbsd*
2967 OpenBSD/amd64 x86_64-*-openbsd*
2968 OpenBSD/alpha alpha*-*-openbsd*
2969 OpenBSD/sparc sparc-*-openbsd*
2970 OpenBSD/sparc64 sparc64-*-openbsd*
2972 * New debugging protocols
2974 M32R with SDI protocol m32r-*-elf*
2976 * "set prompt-escape-char" command deleted.
2978 The command "set prompt-escape-char" has been deleted. This command,
2979 and its very obscure effet on GDB's prompt, was never documented,
2980 tested, nor mentioned in the NEWS file.
2982 * OBSOLETE configurations and files
2984 Configurations that have been declared obsolete in this release have
2985 been commented out. Unless there is activity to revive these
2986 configurations, the next release of GDB will have their sources
2987 permanently REMOVED.
2989 Sun 3, running SunOS 3 m68*-*-sunos3*
2990 Sun 3, running SunOS 4 m68*-*-sunos4*
2991 Sun 2, running SunOS 3 m68000-*-sunos3*
2992 Sun 2, running SunOS 4 m68000-*-sunos4*
2993 Motorola 680x0 running LynxOS m68*-*-lynxos*
2994 AT&T 3b1/Unix pc m68*-att-*
2995 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2996 decstation mips-dec-* mips-little-*
2997 riscos mips-*-riscos* mips-*-sysv*
2998 sonymips mips-sony-*
2999 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3001 * REMOVED configurations and files
3003 SGI Irix-4.x mips-sgi-irix4 or iris4
3004 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3005 Z8000 simulator z8k-zilog-none or z8ksim
3006 Matsushita MN10200 w/simulator mn10200-*-*
3007 H8/500 simulator h8500-hitachi-hms or h8500hms
3008 HP/PA running BSD hppa*-*-bsd*
3009 HP/PA running OSF/1 hppa*-*-osf*
3010 HP/PA Pro target hppa*-*-pro*
3011 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3012 386BSD i[3456]86-*-bsd*
3013 Sequent family i[3456]86-sequent-sysv4*
3014 i[3456]86-sequent-sysv*
3015 i[3456]86-sequent-bsd*
3016 SPARC running LynxOS sparc-*-lynxos*
3017 SPARC running SunOS 4 sparc-*-sunos4*
3018 Tsqware Sparclet sparclet-*-*
3019 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3021 *** Changes in GDB 6.0:
3025 Support for debugging the Objective-C programming language has been
3026 integrated into GDB.
3028 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3030 DWARF 2's Call Frame Information makes available compiler generated
3031 information that more exactly describes the program's run-time stack.
3032 By using this information, GDB is able to provide more robust stack
3035 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3036 have been updated to use a new backtrace mechanism which includes
3037 DWARF 2 CFI support.
3041 GDB's remote protocol has been extended to include support for hosted
3042 file I/O (where the remote target uses GDB's file system). See GDB's
3043 remote protocol documentation for details.
3045 * All targets using the new architecture framework.
3047 All of GDB's targets have been updated to use the new internal
3048 architecture framework. The way is now open for future GDB releases
3049 to include cross-architecture native debugging support (i386 on amd64,
3052 * GNU/Linux's Thread Local Storage (TLS)
3054 GDB now includes support for for the GNU/Linux implementation of
3055 per-thread variables.
3057 * GNU/Linux's Native POSIX Thread Library (NPTL)
3059 GDB's thread code has been updated to work with either the new
3060 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3062 * Separate debug info.
3064 GDB, in conjunction with BINUTILS, now supports a mechanism for
3065 automatically loading debug information from a separate file. Instead
3066 of shipping full debug and non-debug versions of system libraries,
3067 system integrators can now instead ship just the stripped libraries
3068 and optional debug files.
3070 * DWARF 2 Location Expressions
3072 DWARF 2 Location Expressions allow the compiler to more completely
3073 describe the location of variables (even in optimized code) to the
3076 GDB now includes preliminary support for location expressions (support
3077 for DW_OP_piece is still missing).
3081 A number of long standing bugs that caused GDB to die while starting a
3082 Java application have been fixed. GDB's Java support is now
3083 considered "useable".
3085 * GNU/Linux support for fork, vfork, and exec.
3087 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3088 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3091 * GDB supports logging output to a file
3093 There are two new commands, "set logging" and "show logging", which can be
3094 used to capture GDB's output to a file.
3096 * The meaning of "detach" has changed for gdbserver
3098 The "detach" command will now resume the application, as documented. To
3099 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3102 * d10v, m68hc11 `regs' command deprecated
3104 The `info registers' command has been updated so that it displays the
3105 registers using a format identical to the old `regs' command.
3109 A new command, "maint set profile on/off", has been added. This command can
3110 be used to enable or disable profiling while running GDB, to profile a
3111 session or a set of commands. In addition there is a new configure switch,
3112 "--enable-profiling", which will cause GDB to be compiled with profiling
3113 data, for more informative profiling results.
3115 * Default MI syntax changed to "mi2".
3117 The default MI (machine interface) syntax, enabled by the command line
3118 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3119 "mi1", can be enabled by specifying the option "-i=mi1".
3121 Support for the original "mi0" syntax (included in GDB 5.0) has been
3124 Fix for gdb/192: removed extraneous space when displaying frame level.
3125 Fix for gdb/672: update changelist is now output in mi list format.
3126 Fix for gdb/702: a -var-assign that updates the value now shows up
3127 in a subsequent -var-update.
3129 * New native configurations.
3131 FreeBSD/amd64 x86_64-*-freebsd*
3133 * Multi-arched targets.
3135 HP/PA HPUX11 hppa*-*-hpux*
3136 Renesas M32R/D w/simulator m32r-*-elf*
3138 * OBSOLETE configurations and files
3140 Configurations that have been declared obsolete in this release have
3141 been commented out. Unless there is activity to revive these
3142 configurations, the next release of GDB will have their sources
3143 permanently REMOVED.
3145 Z8000 simulator z8k-zilog-none or z8ksim
3146 Matsushita MN10200 w/simulator mn10200-*-*
3147 H8/500 simulator h8500-hitachi-hms or h8500hms
3148 HP/PA running BSD hppa*-*-bsd*
3149 HP/PA running OSF/1 hppa*-*-osf*
3150 HP/PA Pro target hppa*-*-pro*
3151 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3152 Sequent family i[3456]86-sequent-sysv4*
3153 i[3456]86-sequent-sysv*
3154 i[3456]86-sequent-bsd*
3155 Tsqware Sparclet sparclet-*-*
3156 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3158 * REMOVED configurations and files
3161 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3162 IBM AIX PS/2 i[3456]86-*-aix
3163 i386 running Mach 3.0 i[3456]86-*-mach3*
3164 i386 running Mach i[3456]86-*-mach*
3165 i386 running OSF/1 i[3456]86-*osf1mk*
3166 HP/Apollo 68k Family m68*-apollo*-sysv*,
3168 m68*-hp-bsd*, m68*-hp-hpux*
3169 Argonaut Risc Chip (ARC) arc-*-*
3170 Mitsubishi D30V d30v-*-*
3171 Fujitsu FR30 fr30-*-elf*
3172 OS/9000 i[34]86-*-os9k
3173 I960 with MON960 i960-*-coff
3175 * MIPS $fp behavior changed
3177 The convenience variable $fp, for the MIPS, now consistently returns
3178 the address of the current frame's base. Previously, depending on the
3179 context, $fp could refer to either $sp or the current frame's base
3180 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3181 The GNU Source-Level Debugger''.
3183 *** Changes in GDB 5.3:
3185 * GNU/Linux shared library multi-threaded performance improved.
3187 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3188 `/proc', in preference to `ptrace' for memory reads. This may result
3189 in an improvement in the start-up time of multi-threaded, shared
3190 library applications when run under GDB. One GDB user writes: ``loads
3191 shared libs like mad''.
3193 * ``gdbserver'' now supports multi-threaded applications on some targets
3195 Support for debugging multi-threaded applications which use
3196 the GNU/Linux LinuxThreads package has been added for
3197 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3198 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3200 * GDB now supports C/C++ preprocessor macros.
3202 GDB now expands preprocessor macro invocations in C/C++ expressions,
3203 and provides various commands for showing macro definitions and how
3206 The new command `macro expand EXPRESSION' expands any macro
3207 invocations in expression, and shows the result.
3209 The new command `show macro MACRO-NAME' shows the definition of the
3210 macro named MACRO-NAME, and where it was defined.
3212 Most compilers don't include information about macros in the debugging
3213 information by default. In GCC 3.1, for example, you need to compile
3214 your program with the options `-gdwarf-2 -g3'. If the macro
3215 information is present in the executable, GDB will read it.
3217 * Multi-arched targets.
3219 DEC Alpha (partial) alpha*-*-*
3220 DEC VAX (partial) vax-*-*
3222 National Semiconductor NS32000 (partial) ns32k-*-*
3223 Motorola 68000 (partial) m68k-*-*
3224 Motorola MCORE mcore-*-*
3228 Fujitsu FRV architecture added by Red Hat frv*-*-*
3231 * New native configurations
3233 Alpha NetBSD alpha*-*-netbsd*
3234 SH NetBSD sh*-*-netbsdelf*
3235 MIPS NetBSD mips*-*-netbsd*
3236 UltraSPARC NetBSD sparc64-*-netbsd*
3238 * OBSOLETE configurations and files
3240 Configurations that have been declared obsolete in this release have
3241 been commented out. Unless there is activity to revive these
3242 configurations, the next release of GDB will have their sources
3243 permanently REMOVED.
3245 Mitsubishi D30V d30v-*-*
3246 OS/9000 i[34]86-*-os9k
3247 IBM AIX PS/2 i[3456]86-*-aix
3248 Fujitsu FR30 fr30-*-elf*
3249 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3250 Argonaut Risc Chip (ARC) arc-*-*
3251 i386 running Mach 3.0 i[3456]86-*-mach3*
3252 i386 running Mach i[3456]86-*-mach*
3253 i386 running OSF/1 i[3456]86-*osf1mk*
3254 HP/Apollo 68k Family m68*-apollo*-sysv*,
3256 m68*-hp-bsd*, m68*-hp-hpux*
3257 I960 with MON960 i960-*-coff
3259 * OBSOLETE languages
3261 CHILL, a Pascal like language used by telecommunications companies.
3263 * REMOVED configurations and files
3265 AMD 29k family via UDI a29k-amd-udi, udi29k
3266 A29K VxWorks a29k-*-vxworks
3267 AMD 29000 embedded, using EBMON a29k-none-none
3268 AMD 29000 embedded with COFF a29k-none-coff
3269 AMD 29000 embedded with a.out a29k-none-aout
3271 testsuite/gdb.hp/gdb.threads-hp/ directory
3273 * New command "set max-user-call-depth <nnn>"
3275 This command allows the user to limit the call depth of user-defined
3276 commands. The default is 1024.
3278 * Changes in FreeBSD/i386 native debugging.
3280 Support for the "generate-core-file" has been added.
3282 * New commands "dump", "append", and "restore".
3284 These commands allow data to be copied from target memory
3285 to a bfd-format or binary file (dump and append), and back
3286 from a file into memory (restore).
3288 * Improved "next/step" support on multi-processor Alpha Tru64.
3290 The previous single-step mechanism could cause unpredictable problems,
3291 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3292 of a software single-step mechanism prevents this.
3294 *** Changes in GDB 5.2.1:
3302 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3303 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3304 Fix, by Joel Brobecker imported from mainline.
3306 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3307 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3308 Fix, by Fred Fish, imported from mainline.
3310 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3311 Surprisingly enough, it works now.
3312 By Michal Ludvig, imported from mainline.
3314 i386 hardware watchpoint support:
3315 avoid misses on second run for some targets.
3316 By Pierre Muller, imported from mainline.
3318 *** Changes in GDB 5.2:
3320 * New command "set trust-readonly-sections on[off]".
3322 This command is a hint that tells gdb that read-only sections
3323 really are read-only (ie. that their contents will not change).
3324 In this mode, gdb will go to the object file rather than the
3325 target to read memory from read-only sections (such as ".text").
3326 This can be a significant performance improvement on some
3327 (notably embedded) targets.
3329 * New command "generate-core-file" (or "gcore").
3331 This new gdb command allows the user to drop a core file of the child
3332 process state at any time. So far it's been implemented only for
3333 GNU/Linux and Solaris, but should be relatively easily ported to other
3334 hosts. Argument is core file name (defaults to core.<pid>).
3336 * New command line option
3338 GDB now accepts --pid or -p followed by a process id.
3340 * Change in command line behavior -- corefiles vs. process ids.
3342 There is a subtle behavior in the way in which GDB handles
3343 command line arguments. The first non-flag argument is always
3344 a program to debug, but the second non-flag argument may either
3345 be a corefile or a process id. Previously, GDB would attempt to
3346 open the second argument as a corefile, and if that failed, would
3347 issue a superfluous error message and then attempt to attach it as
3348 a process. Now, if the second argument begins with a non-digit,
3349 it will be treated as a corefile. If it begins with a digit,
3350 GDB will attempt to attach it as a process, and if no such process
3351 is found, will then attempt to open it as a corefile.
3353 * Changes in ARM configurations.
3355 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3356 configuration is fully multi-arch.
3358 * New native configurations
3360 ARM NetBSD arm*-*-netbsd*
3361 x86 OpenBSD i[3456]86-*-openbsd*
3362 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3363 Sparc64 running FreeBSD sparc64-*-freebsd*
3367 Sanyo XStormy16 xstormy16-elf
3369 * OBSOLETE configurations and files
3371 Configurations that have been declared obsolete in this release have
3372 been commented out. Unless there is activity to revive these
3373 configurations, the next release of GDB will have their sources
3374 permanently REMOVED.
3376 AMD 29k family via UDI a29k-amd-udi, udi29k
3377 A29K VxWorks a29k-*-vxworks
3378 AMD 29000 embedded, using EBMON a29k-none-none
3379 AMD 29000 embedded with COFF a29k-none-coff
3380 AMD 29000 embedded with a.out a29k-none-aout
3382 testsuite/gdb.hp/gdb.threads-hp/ directory
3384 * REMOVED configurations and files
3386 TI TMS320C80 tic80-*-*
3388 PowerPC Solaris powerpcle-*-solaris*
3389 PowerPC Windows NT powerpcle-*-cygwin32
3390 PowerPC Netware powerpc-*-netware*
3391 Harris/CXUX m88k m88*-harris-cxux*
3392 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3393 ns32k-utek-sysv* ns32k-utek-*
3394 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3395 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3396 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3397 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3398 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3400 * Changes to command line processing
3402 The new `--args' feature can be used to specify command-line arguments
3403 for the inferior from gdb's command line.
3405 * Changes to key bindings
3407 There is a new `operate-and-get-next' function bound to `C-o'.
3409 *** Changes in GDB 5.1.1
3411 Fix compile problem on DJGPP.
3413 Fix a problem with floating-point registers on the i386 being
3416 Fix to stop GDB crashing on .debug_str debug info.
3418 Numerous documentation fixes.
3420 Numerous testsuite fixes.
3422 *** Changes in GDB 5.1:
3424 * New native configurations
3426 Alpha FreeBSD alpha*-*-freebsd*
3427 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3428 MIPS GNU/Linux mips*-*-linux*
3429 MIPS SGI Irix 6.x mips*-sgi-irix6*
3430 ia64 AIX ia64-*-aix*
3431 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3435 Motorola 68HC11 and 68HC12 m68hc11-elf
3437 UltraSparc running GNU/Linux sparc64-*-linux*
3439 * OBSOLETE configurations and files
3441 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3442 Harris/CXUX m88k m88*-harris-cxux*
3443 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3444 ns32k-utek-sysv* ns32k-utek-*
3445 TI TMS320C80 tic80-*-*
3447 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3448 PowerPC Solaris powerpcle-*-solaris*
3449 PowerPC Windows NT powerpcle-*-cygwin32
3450 PowerPC Netware powerpc-*-netware*
3451 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3452 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3453 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3454 Apple Macintosh (MPW) host N/A
3456 stuff.c (Program to stuff files into a specially prepared space in kdb)
3457 kdb-start.c (Main loop for the standalone kernel debugger)
3459 Configurations that have been declared obsolete in this release have
3460 been commented out. Unless there is activity to revive these
3461 configurations, the next release of GDB will have their sources
3462 permanently REMOVED.
3464 * REMOVED configurations and files
3466 Altos 3068 m68*-altos-*
3467 Convex c1-*-*, c2-*-*
3469 ARM RISCix arm-*-* (as host)
3473 * GDB has been converted to ISO C.
3475 GDB's source code has been converted to ISO C. In particular, the
3476 sources are fully protoized, and rely on standard headers being
3481 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3483 * The MI enabled by default.
3485 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3486 revised and enabled by default. Packages which use GDB as a debugging
3487 engine behind a UI or another front end are encouraged to switch to
3488 using the GDB/MI interface, instead of the old annotations interface
3489 which is now deprecated.
3491 * Support for debugging Pascal programs.
3493 GDB now includes support for debugging Pascal programs. The following
3494 main features are supported:
3496 - Pascal-specific data types such as sets;
3498 - automatic recognition of Pascal sources based on file-name
3501 - Pascal-style display of data types, variables, and functions;
3503 - a Pascal expression parser.
3505 However, some important features are not yet supported.
3507 - Pascal string operations are not supported at all;
3509 - there are some problems with boolean types;
3511 - Pascal type hexadecimal constants are not supported
3512 because they conflict with the internal variables format;
3514 - support for Pascal objects and classes is not full yet;
3516 - unlike Pascal, GDB is case-sensitive for symbol names.
3518 * Changes in completion.
3520 Commands such as `shell', `run' and `set args', which pass arguments
3521 to inferior programs, now complete on file names, similar to what
3522 users expect at the shell prompt.
3524 Commands which accept locations, such as `disassemble', `print',
3525 `breakpoint', `until', etc. now complete on filenames as well as
3526 program symbols. Thus, if you type "break foob TAB", and the source
3527 files linked into the programs include `foobar.c', that file name will
3528 be one of the candidates for completion. However, file names are not
3529 considered for completion after you typed a colon that delimits a file
3530 name from a name of a function in that file, as in "break foo.c:bar".
3532 `set demangle-style' completes on available demangling styles.
3534 * New platform-independent commands:
3536 It is now possible to define a post-hook for a command as well as a
3537 hook that runs before the command. For more details, see the
3538 documentation of `hookpost' in the GDB manual.
3540 * Changes in GNU/Linux native debugging.
3542 Support for debugging multi-threaded programs has been completely
3543 revised for all platforms except m68k and sparc. You can now debug as
3544 many threads as your system allows you to have.
3546 Attach/detach is supported for multi-threaded programs.
3548 Support for SSE registers was added for x86. This doesn't work for
3549 multi-threaded programs though.
3551 * Changes in MIPS configurations.
3553 Multi-arch support is enabled for all MIPS configurations.
3555 GDB can now be built as native debugger on SGI Irix 6.x systems for
3556 debugging n32 executables. (Debugging 64-bit executables is not yet
3559 * Unified support for hardware watchpoints in all x86 configurations.
3561 Most (if not all) native x86 configurations support hardware-assisted
3562 breakpoints and watchpoints in a unified manner. This support
3563 implements debug register sharing between watchpoints, which allows to
3564 put a virtually infinite number of watchpoints on the same address,
3565 and also supports watching regions up to 16 bytes with several debug
3568 The new maintenance command `maintenance show-debug-regs' toggles
3569 debugging print-outs in functions that insert, remove, and test
3570 watchpoints and hardware breakpoints.
3572 * Changes in the DJGPP native configuration.
3574 New command ``info dos sysinfo'' displays assorted information about
3575 the CPU, OS, memory, and DPMI server.
3577 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3578 display information about segment descriptors stored in GDT, LDT, and
3581 New commands ``info dos pde'' and ``info dos pte'' display entries
3582 from Page Directory and Page Tables (for now works with CWSDPMI only).
3583 New command ``info dos address-pte'' displays the Page Table entry for
3584 a given linear address.
3586 GDB can now pass command lines longer than 126 characters to the
3587 program being debugged (requires an update to the libdbg.a library
3588 which is part of the DJGPP development kit).
3590 DWARF2 debug info is now supported.
3592 It is now possible to `step' and `next' through calls to `longjmp'.
3594 * Changes in documentation.
3596 All GDB documentation was converted to GFDL, the GNU Free
3597 Documentation License.
3599 Tracepoints-related commands are now fully documented in the GDB
3602 TUI, the Text-mode User Interface, is now documented in the manual.
3604 Tracepoints-related commands are now fully documented in the GDB
3607 The "GDB Internals" manual now has an index. It also includes
3608 documentation of `ui_out' functions, GDB coding standards, x86
3609 hardware watchpoints, and memory region attributes.
3611 * GDB's version number moved to ``version.in''
3613 The Makefile variable VERSION has been replaced by the file
3614 ``version.in''. People creating GDB distributions should update the
3615 contents of this file.
3619 GUD support is now a standard part of the EMACS distribution.
3621 *** Changes in GDB 5.0:
3623 * Improved support for debugging FP programs on x86 targets
3625 Unified and much-improved support for debugging floating-point
3626 programs on all x86 targets. In particular, ``info float'' now
3627 displays the FP registers in the same format on all x86 targets, with
3628 greater level of detail.
3630 * Improvements and bugfixes in hardware-assisted watchpoints
3632 It is now possible to watch array elements, struct members, and
3633 bitfields with hardware-assisted watchpoints. Data-read watchpoints
3634 on x86 targets no longer erroneously trigger when the address is
3637 * Improvements in the native DJGPP version of GDB
3639 The distribution now includes all the scripts and auxiliary files
3640 necessary to build the native DJGPP version on MS-DOS/MS-Windows
3641 machines ``out of the box''.
3643 The DJGPP version can now debug programs that use signals. It is
3644 possible to catch signals that happened in the debuggee, deliver
3645 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
3646 would kill the program being debugged.) Programs that hook hardware
3647 interrupts (keyboard, timer, etc.) can also be debugged.
3649 It is now possible to debug DJGPP programs that redirect their
3650 standard handles or switch them to raw (as opposed to cooked) mode, or
3651 even close them. The command ``run < foo > bar'' works as expected,
3652 and ``info terminal'' reports useful information about the debuggee's
3653 terminal, including raw/cooked mode, redirection, etc.
3655 The DJGPP version now uses termios functions for console I/O, which
3656 enables debugging graphics programs. Interrupting GDB with Ctrl-C
3659 DOS-style file names with drive letters are now fully supported by
3662 It is now possible to debug DJGPP programs that switch their working
3663 directory. It is also possible to rerun the debuggee any number of
3664 times without restarting GDB; thus, you can use the same setup,
3665 breakpoints, etc. for many debugging sessions.
3667 * New native configurations
3669 ARM GNU/Linux arm*-*-linux*
3670 PowerPC GNU/Linux powerpc-*-linux*
3674 Motorola MCore mcore-*-*
3675 x86 VxWorks i[3456]86-*-vxworks*
3676 PowerPC VxWorks powerpc-*-vxworks*
3677 TI TMS320C80 tic80-*-*
3679 * OBSOLETE configurations
3681 Altos 3068 m68*-altos-*
3682 Convex c1-*-*, c2-*-*
3684 ARM RISCix arm-*-* (as host)
3687 Configurations that have been declared obsolete will be commented out,
3688 but the code will be left in place. If there is no activity to revive
3689 these configurations before the next release of GDB, the sources will
3690 be permanently REMOVED.
3692 * Gould support removed
3694 Support for the Gould PowerNode and NP1 has been removed.
3696 * New features for SVR4
3698 On SVR4 native platforms (such as Solaris), if you attach to a process
3699 without first loading a symbol file, GDB will now attempt to locate and
3700 load symbols from the running process's executable file.
3702 * Many C++ enhancements
3704 C++ support has been greatly improved. Overload resolution now works properly
3705 in almost all cases. RTTI support is on the way.
3707 * Remote targets can connect to a sub-program
3709 A popen(3) style serial-device has been added. This device starts a
3710 sub-process (such as a stand-alone simulator) and then communicates
3711 with that. The sub-program to run is specified using the syntax
3712 ``|<program> <args>'' vis:
3714 (gdb) set remotedebug 1
3715 (gdb) target extended-remote |mn10300-elf-sim program-args
3717 * MIPS 64 remote protocol
3719 A long standing bug in the mips64 remote protocol where by GDB
3720 expected certain 32 bit registers (ex SR) to be transfered as 32
3721 instead of 64 bits has been fixed.
3723 The command ``set remote-mips64-transfers-32bit-regs on'' has been
3724 added to provide backward compatibility with older versions of GDB.
3726 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
3728 The command ``set remotebinarydownload'' command has been replaced by
3729 ``set remote X-packet''. Other commands in ``set remote'' family
3730 include ``set remote P-packet''.
3732 * Breakpoint commands accept ranges.
3734 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
3735 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
3736 ``tracepoint passcount'' also accepts a range of tracepoints.
3738 * ``apropos'' command added.
3740 The ``apropos'' command searches through command names and
3741 documentation strings, printing out matches, making it much easier to
3742 try to find a command that does what you are looking for.
3746 A new machine oriented interface (MI) has been added to GDB. This
3747 interface is designed for debug environments running GDB as a separate
3748 process. This is part of the long term libGDB project. See the
3749 "GDB/MI" chapter of the GDB manual for further information. It can be
3750 enabled by configuring with:
3752 .../configure --enable-gdbmi
3754 *** Changes in GDB-4.18:
3756 * New native configurations
3758 HP-UX 10.20 hppa*-*-hpux10.20
3759 HP-UX 11.x hppa*-*-hpux11.0*
3760 M68K GNU/Linux m68*-*-linux*
3764 Fujitsu FR30 fr30-*-elf*
3765 Intel StrongARM strongarm-*-*
3766 Mitsubishi D30V d30v-*-*
3768 * OBSOLETE configurations
3770 Gould PowerNode, NP1 np1-*-*, pn-*-*
3772 Configurations that have been declared obsolete will be commented out,
3773 but the code will be left in place. If there is no activity to revive
3774 these configurations before the next release of GDB, the sources will
3775 be permanently REMOVED.
3779 As a compatibility experiment, GDB's source files buildsym.h and
3780 buildsym.c have been converted to pure standard C, no longer
3781 containing any K&R compatibility code. We believe that all systems in
3782 use today either come with a standard C compiler, or have a GCC port
3783 available. If this is not true, please report the affected
3784 configuration to bug-gdb@gnu.org immediately. See the README file for
3785 information about getting a standard C compiler if you don't have one
3790 GDB now uses readline 2.2.
3792 * set extension-language
3794 You can now control the mapping between filename extensions and source
3795 languages by using the `set extension-language' command. For instance,
3796 you can ask GDB to treat .c files as C++ by saying
3797 set extension-language .c c++
3798 The command `info extensions' lists all of the recognized extensions
3799 and their associated languages.
3801 * Setting processor type for PowerPC and RS/6000
3803 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
3804 you can use the `set processor' command to specify what variant of the
3805 PowerPC family you are debugging. The command
3809 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
3810 following PowerPC and RS6000 variants:
3812 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
3813 rs6000 IBM RS6000 ("POWER") architecture, user-level view
3815 403GC IBM PowerPC 403GC
3816 505 Motorola PowerPC 505
3817 860 Motorola PowerPC 860 or 850
3818 601 Motorola PowerPC 601
3819 602 Motorola PowerPC 602
3820 603 Motorola/IBM PowerPC 603 or 603e
3821 604 Motorola PowerPC 604 or 604e
3822 750 Motorola/IBM PowerPC 750 or 750
3824 At the moment, this command just tells GDB what to name the
3825 special-purpose processor registers. Since almost all the affected
3826 registers are inaccessible to user-level programs, this command is
3827 only useful for remote debugging in its present form.
3831 Thanks to a major code donation from Hewlett-Packard, GDB now has much
3832 more extensive support for HP-UX. Added features include shared
3833 library support, kernel threads and hardware watchpoints for 11.00,
3834 support for HP's ANSI C and C++ compilers, and a compatibility mode
3835 for xdb and dbx commands.
3839 HP's donation includes the new concept of catchpoints, which is a
3840 generalization of the old catch command. On HP-UX, it is now possible
3841 to catch exec, fork, and vfork, as well as library loading.
3843 This means that the existing catch command has changed; its first
3844 argument now specifies the type of catch to be set up. See the
3845 output of "help catch" for a list of catchpoint types.
3847 * Debugging across forks
3849 On HP-UX, you can choose which process to debug when a fork() happens
3854 HP has donated a curses-based terminal user interface (TUI). To get
3855 it, build with --enable-tui. Although this can be enabled for any
3856 configuration, at present it only works for native HP debugging.
3858 * GDB remote protocol additions
3860 A new protocol packet 'X' that writes binary data is now available.
3861 Default behavior is to try 'X', then drop back to 'M' if the stub
3862 fails to respond. The settable variable `remotebinarydownload'
3863 allows explicit control over the use of 'X'.
3865 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
3866 full 64-bit address. The command
3868 set remoteaddresssize 32
3870 can be used to revert to the old behaviour. For existing remote stubs
3871 the change should not be noticed, as the additional address information
3874 In order to assist in debugging stubs, you may use the maintenance
3875 command `packet' to send any text string to the stub. For instance,
3877 maint packet heythere
3879 sends the packet "$heythere#<checksum>". Note that it is very easy to
3880 disrupt a debugging session by sending the wrong packet at the wrong
3883 The compare-sections command allows you to compare section data on the
3884 target to what is in the executable file without uploading or
3885 downloading, by comparing CRC checksums.
3887 * Tracing can collect general expressions
3889 You may now collect general expressions at tracepoints. This requires
3890 further additions to the target-side stub; see tracepoint.c and
3891 doc/agentexpr.texi for further details.
3893 * mask-address variable for Mips
3895 For Mips targets, you may control the zeroing of the upper 32 bits of
3896 a 64-bit address by entering `set mask-address on'. This is mainly
3897 of interest to users of embedded R4xxx and R5xxx processors.
3899 * Higher serial baud rates
3901 GDB's serial code now allows you to specify baud rates 57600, 115200,
3902 230400, and 460800 baud. (Note that your host system may not be able
3903 to achieve all of these rates.)
3907 The i960 configuration now includes an initial implementation of a
3908 builtin simulator, contributed by Jim Wilson.
3911 *** Changes in GDB-4.17:
3913 * New native configurations
3915 Alpha GNU/Linux alpha*-*-linux*
3916 Unixware 2.x i[3456]86-unixware2*
3917 Irix 6.x mips*-sgi-irix6*
3918 PowerPC GNU/Linux powerpc-*-linux*
3919 PowerPC Solaris powerpcle-*-solaris*
3920 Sparc GNU/Linux sparc-*-linux*
3921 Motorola sysV68 R3V7.1 m68k-motorola-sysv
3925 Argonaut Risc Chip (ARC) arc-*-*
3926 Hitachi H8/300S h8300*-*-*
3927 Matsushita MN10200 w/simulator mn10200-*-*
3928 Matsushita MN10300 w/simulator mn10300-*-*
3929 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
3930 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
3931 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
3932 Mitsubishi D10V w/simulator d10v-*-*
3933 Mitsubishi M32R/D w/simulator m32r-*-elf*
3934 Tsqware Sparclet sparclet-*-*
3935 NEC V850 w/simulator v850-*-*
3937 * New debugging protocols
3939 ARM with RDI protocol arm*-*-*
3940 M68K with dBUG monitor m68*-*-{aout,coff,elf}
3941 DDB and LSI variants of PMON protocol mips*-*-*
3942 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
3943 PowerPC with SDS protocol powerpc{,le}-*-eabi
3944 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
3948 All configurations can now understand and use the DWARF 2 debugging
3949 format. The choice is automatic, if the symbol file contains DWARF 2
3954 GDB now includes basic Java language support. This support is
3955 only useful with Java compilers that produce native machine code.
3957 * solib-absolute-prefix and solib-search-path
3959 For SunOS and SVR4 shared libraries, you may now set the prefix for
3960 loading absolute shared library symbol files, and the search path for
3961 locating non-absolute shared library symbol files.
3963 * Live range splitting
3965 GDB can now effectively debug code for which GCC has performed live
3966 range splitting as part of its optimization. See gdb/doc/LRS for
3967 more details on the expected format of the stabs information.
3971 GDB's support for the GNU Hurd, including thread debugging, has been
3972 updated to work with current versions of the Hurd.
3976 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
3977 instruction set. ARM GDB automatically detects when Thumb
3978 instructions are in use, and adjusts disassembly and backtracing
3983 GDB's MIPS target configurations now handle the MIP16 16-bit
3988 GDB now includes support for overlays; if an executable has been
3989 linked such that multiple sections are based at the same address, GDB
3990 will decide which section to use for symbolic info. You can choose to
3991 control the decision manually, using overlay commands, or implement
3992 additional target-side support and use "overlay load-target" to bring
3993 in the overlay mapping. Do "help overlay" for more detail.
3997 The command "info symbol <address>" displays information about
3998 the symbol at the specified address.
4002 The standard remote protocol now includes an extension that allows
4003 asynchronous collection and display of trace data. This requires
4004 extensive support in the target-side debugging stub. Tracing mode
4005 includes a new interaction mode in GDB and new commands: see the
4006 file tracepoint.c for more details.
4010 Configurations for embedded MIPS now include a simulator contributed
4011 by Cygnus Solutions. The simulator supports the instruction sets
4012 of most MIPS variants.
4016 Sparc configurations may now include the ERC32 simulator contributed
4017 by the European Space Agency. The simulator is not built into
4018 Sparc targets by default; configure with --enable-sim to include it.
4022 For target configurations that may include multiple variants of a
4023 basic architecture (such as MIPS and SH), you may now set the
4024 architecture explicitly. "set arch" sets, "info arch" lists
4025 the possible architectures.
4027 *** Changes in GDB-4.16:
4029 * New native configurations
4031 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4032 M68K NetBSD m68k-*-netbsd*
4033 PowerPC AIX 4.x powerpc-*-aix*
4034 PowerPC MacOS powerpc-*-macos*
4035 PowerPC Windows NT powerpcle-*-cygwin32
4036 RS/6000 AIX 4.x rs6000-*-aix4*
4040 ARM with RDP protocol arm-*-*
4041 I960 with MON960 i960-*-coff
4042 MIPS VxWorks mips*-*-vxworks*
4043 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4044 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4046 Matra Sparclet sparclet-*-*
4050 The powerpc-eabi configuration now includes the PSIM simulator,
4051 contributed by Andrew Cagney, with assistance from Mike Meissner.
4052 PSIM is a very elaborate model of the PowerPC, including not only
4053 basic instruction set execution, but also details of execution unit
4054 performance and I/O hardware. See sim/ppc/README for more details.
4058 GDB now works with Solaris 2.5.
4060 * Windows 95/NT native
4062 GDB will now work as a native debugger on Windows 95 and Windows NT.
4063 To build it from source, you must use the "gnu-win32" environment,
4064 which uses a DLL to emulate enough of Unix to run the GNU tools.
4065 Further information, binaries, and sources are available at
4066 ftp.cygnus.com, under pub/gnu-win32.
4068 * dont-repeat command
4070 If a user-defined command includes the command `dont-repeat', then the
4071 command will not be repeated if the user just types return. This is
4072 useful if the command is time-consuming to run, so that accidental
4073 extra keystrokes don't run the same command many times.
4075 * Send break instead of ^C
4077 The standard remote protocol now includes an option to send a break
4078 rather than a ^C to the target in order to interrupt it. By default,
4079 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4081 * Remote protocol timeout
4083 The standard remote protocol includes a new variable `remotetimeout'
4084 that allows you to set the number of seconds before GDB gives up trying
4085 to read from the target. The default value is 2.
4087 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4089 By default GDB will automatically keep track of objects as they are
4090 loaded and unloaded by the dynamic linker. By using the command `set
4091 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4092 when shared library events occur, thus allowing you to set breakpoints
4093 in shared libraries which are explicitly loaded by the inferior.
4095 Note this feature does not work on hpux8. On hpux9 you must link
4096 /usr/lib/end.o into your program. This feature should work
4097 automatically on hpux10.
4099 * Irix 5.x hardware watchpoint support
4101 Irix 5 configurations now support the use of hardware watchpoints.
4103 * Mips protocol "SYN garbage limit"
4105 When debugging a Mips target using the `target mips' protocol, you
4106 may set the number of characters that GDB will ignore by setting
4107 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4108 every character. The default value is 1050.
4110 * Recording and replaying remote debug sessions
4112 If you set `remotelogfile' to the name of a file, gdb will write to it
4113 a recording of a remote debug session. This recording may then be
4114 replayed back to gdb using "gdbreplay". See gdbserver/README for
4115 details. This is useful when you have a problem with GDB while doing
4116 remote debugging; you can make a recording of the session and send it
4117 to someone else, who can then recreate the problem.
4119 * Speedups for remote debugging
4121 GDB includes speedups for downloading and stepping MIPS systems using
4122 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4123 and more efficient S-record downloading.
4125 * Memory use reductions and statistics collection
4127 GDB now uses less memory and reports statistics about memory usage.
4128 Try the `maint print statistics' command, for example.
4130 *** Changes in GDB-4.15:
4132 * Psymtabs for XCOFF
4134 The symbol reader for AIX GDB now uses partial symbol tables. This
4135 can greatly improve startup time, especially for large executables.
4137 * Remote targets use caching
4139 Remote targets now use a data cache to speed up communication with the
4140 remote side. The data cache could lead to incorrect results because
4141 it doesn't know about volatile variables, thus making it impossible to
4142 debug targets which use memory mapped I/O devices. `set remotecache
4143 off' turns the the data cache off.
4145 * Remote targets may have threads
4147 The standard remote protocol now includes support for multiple threads
4148 in the target system, using new protocol commands 'H' and 'T'. See
4149 gdb/remote.c for details.
4153 If GDB is configured with `--enable-netrom', then it will include
4154 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4155 acts as though it is a bank of ROM on the target board, but you can
4156 write into it over the network. GDB's support consists only of
4157 support for fast loading into the emulated ROM; to debug, you must use
4158 another protocol, such as standard remote protocol. The usual
4159 sequence is something like
4161 target nrom <netrom-hostname>
4163 target remote <netrom-hostname>:1235
4167 GDB now includes support for the Apple Macintosh, as a host only. It
4168 may be run as either an MPW tool or as a standalone application, and
4169 it can debug through the serial port. All the usual GDB commands are
4170 available, but to the target command, you must supply "serial" as the
4171 device type instead of "/dev/ttyXX". See mpw-README in the main
4172 directory for more information on how to build. The MPW configuration
4173 scripts */mpw-config.in support only a few targets, and only the
4174 mips-idt-ecoff target has been tested.
4178 GDB configuration now uses autoconf. This is not user-visible,
4179 but does simplify configuration and building.
4183 GDB now supports hpux10.
4185 *** Changes in GDB-4.14:
4187 * New native configurations
4189 x86 FreeBSD i[345]86-*-freebsd
4190 x86 NetBSD i[345]86-*-netbsd
4191 NS32k NetBSD ns32k-*-netbsd
4192 Sparc NetBSD sparc-*-netbsd
4196 A29K VxWorks a29k-*-vxworks
4197 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4198 CPU32 EST-300 emulator m68*-*-est*
4199 PowerPC ELF powerpc-*-elf
4202 * Alpha OSF/1 support for procfs
4204 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4205 possible to attach to running processes. As the mounting of the /proc
4206 filesystem is optional on the Alpha, GDB automatically determines
4207 the availability of /proc during startup. This can lead to problems
4208 if /proc is unmounted after GDB has been started.
4210 * Arguments to user-defined commands
4212 User commands may accept up to 10 arguments separated by whitespace.
4213 Arguments are accessed within the user command via $arg0..$arg9. A
4216 print $arg0 + $arg1 + $arg2
4218 To execute the command use:
4221 Defines the command "adder" which prints the sum of its three arguments.
4222 Note the arguments are text substitutions, so they may reference variables,
4223 use complex expressions, or even perform inferior function calls.
4225 * New `if' and `while' commands
4227 This makes it possible to write more sophisticated user-defined
4228 commands. Both commands take a single argument, which is the
4229 expression to evaluate, and must be followed by the commands to
4230 execute, one per line, if the expression is nonzero, the list being
4231 terminated by the word `end'. The `if' command list may include an
4232 `else' word, which causes the following commands to be executed only
4233 if the expression is zero.
4235 * Fortran source language mode
4237 GDB now includes partial support for Fortran 77. It will recognize
4238 Fortran programs and can evaluate a subset of Fortran expressions, but
4239 variables and functions may not be handled correctly. GDB will work
4240 with G77, but does not yet know much about symbols emitted by other
4243 * Better HPUX support
4245 Most debugging facilities now work on dynamic executables for HPPAs
4246 running hpux9 or later. You can attach to running dynamically linked
4247 processes, but by default the dynamic libraries will be read-only, so
4248 for instance you won't be able to put breakpoints in them. To change
4249 that behavior do the following before running the program:
4255 This will cause the libraries to be mapped private and read-write.
4256 To revert to the normal behavior, do this:
4262 You cannot set breakpoints or examine data in the library until after
4263 the library is loaded if the function/data symbols do not have
4266 GDB can now also read debug symbols produced by the HP C compiler on
4267 HPPAs (sorry, no C++, Fortran or 68k support).
4269 * Target byte order now dynamically selectable
4271 You can choose which byte order to use with a target system, via the
4272 commands "set endian big" and "set endian little", and you can see the
4273 current setting by using "show endian". You can also give the command
4274 "set endian auto", in which case GDB will use the byte order
4275 associated with the executable. Currently, only embedded MIPS
4276 configurations support dynamic selection of target byte order.
4278 * New DOS host serial code
4280 This version uses DPMI interrupts to handle buffered I/O, so you
4281 no longer need to run asynctsr when debugging boards connected to
4284 *** Changes in GDB-4.13:
4286 * New "complete" command
4288 This lists all the possible completions for the rest of the line, if it
4289 were to be given as a command itself. This is intended for use by emacs.
4291 * Trailing space optional in prompt
4293 "set prompt" no longer adds a space for you after the prompt you set. This
4294 allows you to set a prompt which ends in a space or one that does not.
4296 * Breakpoint hit counts
4298 "info break" now displays a count of the number of times the breakpoint
4299 has been hit. This is especially useful in conjunction with "ignore"; you
4300 can ignore a large number of breakpoint hits, look at the breakpoint info
4301 to see how many times the breakpoint was hit, then run again, ignoring one
4302 less than that number, and this will get you quickly to the last hit of
4305 * Ability to stop printing at NULL character
4307 "set print null-stop" will cause GDB to stop printing the characters of
4308 an array when the first NULL is encountered. This is useful when large
4309 arrays actually contain only short strings.
4311 * Shared library breakpoints
4313 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4314 breakpoints in shared libraries before the executable is run.
4316 * Hardware watchpoints
4318 There is a new hardware breakpoint for the watch command for sparclite
4319 targets. See gdb/sparclite/hw_breakpoint.note.
4321 Hardware watchpoints are also now supported under GNU/Linux.
4325 Annotations have been added. These are for use with graphical interfaces,
4326 and are still experimental. Currently only gdba.el uses these.
4328 * Improved Irix 5 support
4330 GDB now works properly with Irix 5.2.
4332 * Improved HPPA support
4334 GDB now works properly with the latest GCC and GAS.
4336 * New native configurations
4338 Sequent PTX4 i[34]86-sequent-ptx4
4339 HPPA running OSF/1 hppa*-*-osf*
4340 Atari TT running SVR4 m68*-*-sysv4*
4341 RS/6000 LynxOS rs6000-*-lynxos*
4345 OS/9000 i[34]86-*-os9k
4346 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4349 * Hitachi SH7000 and E7000-PC ICE support
4351 There is now support for communicating with the Hitachi E7000-PC ICE.
4352 This is available automatically when GDB is configured for the SH.
4356 As usual, a variety of small fixes and improvements, both generic
4357 and configuration-specific. See the ChangeLog for more detail.
4359 *** Changes in GDB-4.12:
4361 * Irix 5 is now supported
4365 GDB-4.12 on the HPPA has a number of changes which make it unable
4366 to debug the output from the currently released versions of GCC and
4367 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4368 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4369 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4372 *** Changes in GDB-4.11:
4374 * User visible changes:
4378 The "set remotedebug" option is now consistent between the mips remote
4379 target, remote targets using the gdb-specific protocol, UDI (AMD's
4380 debug protocol for the 29k) and the 88k bug monitor. It is now an
4381 integer specifying a debug level (normally 0 or 1, but 2 means more
4382 debugging info for the mips target).
4384 * DEC Alpha native support
4386 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4387 debug info, but GDB works fairly well with the DEC compiler and should
4388 work with a future GCC release. See the README file for a few
4389 Alpha-specific notes.
4391 * Preliminary thread implementation
4393 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4395 * LynxOS native and target support for 386
4397 This release has been hosted on LynxOS 2.2, and also can be configured
4398 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4401 * Improvements in C++ mangling/demangling.
4403 This release has much better g++ debugging, specifically in name
4404 mangling/demangling, virtual function calls, print virtual table,
4405 call methods, ...etc.
4407 *** Changes in GDB-4.10:
4409 * User visible changes:
4411 Remote debugging using the GDB-specific (`target remote') protocol now
4412 supports the `load' command. This is only useful if you have some
4413 other way of getting the stub to the target system, and you can put it
4414 somewhere in memory where it won't get clobbered by the download.
4416 Filename completion now works.
4418 When run under emacs mode, the "info line" command now causes the
4419 arrow to point to the line specified. Also, "info line" prints
4420 addresses in symbolic form (as well as hex).
4422 All vxworks based targets now support a user settable option, called
4423 vxworks-timeout. This option represents the number of seconds gdb
4424 should wait for responses to rpc's. You might want to use this if
4425 your vxworks target is, perhaps, a slow software simulator or happens
4426 to be on the far side of a thin network line.
4430 This release contains support for using a DEC alpha as a GDB host for
4431 cross debugging. Native alpha debugging is not supported yet.
4434 *** Changes in GDB-4.9:
4438 This is the first GDB release which is accompanied by a matching testsuite.
4439 The testsuite requires installation of dejagnu, which should be available
4440 via ftp from most sites that carry GNU software.
4444 'Cfront' style demangling has had its name changed to 'ARM' style, to
4445 emphasize that it was written from the specifications in the C++ Annotated
4446 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4447 disclaimers, it still generated too much confusion with users attempting to
4448 use gdb with AT&T cfront.
4452 GDB now uses a standard remote interface to a simulator library.
4453 So far, the library contains simulators for the Zilog Z8001/2, the
4454 Hitachi H8/300, H8/500 and Super-H.
4456 * New targets supported
4458 H8/300 simulator h8300-hitachi-hms or h8300hms
4459 H8/500 simulator h8500-hitachi-hms or h8500hms
4460 SH simulator sh-hitachi-hms or sh
4461 Z8000 simulator z8k-zilog-none or z8ksim
4462 IDT MIPS board over serial line mips-idt-ecoff
4464 Cross-debugging to GO32 targets is supported. It requires a custom
4465 version of the i386-stub.c module which is integrated with the
4466 GO32 memory extender.
4468 * New remote protocols
4470 MIPS remote debugging protocol.
4472 * New source languages supported
4474 This version includes preliminary support for Chill, a Pascal like language
4475 used by telecommunications companies. Chill support is also being integrated
4476 into the GNU compiler, but we don't know when it will be publically available.
4479 *** Changes in GDB-4.8:
4481 * HP Precision Architecture supported
4483 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4484 version of this support was available as a set of patches from the
4485 University of Utah. GDB does not support debugging of programs
4486 compiled with the HP compiler, because HP will not document their file
4487 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4488 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4490 Many problems in the preliminary version have been fixed.
4492 * Faster and better demangling
4494 We have improved template demangling and fixed numerous bugs in the GNU style
4495 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4496 character types (wchar_t) are now supported. Demangling of each symbol is now
4497 only done once, and is cached when the symbol table for a file is read in.
4498 This results in a small increase in memory usage for C programs, a moderate
4499 increase in memory usage for C++ programs, and a fantastic speedup in
4502 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4503 from the specifications in the Annotated Reference Manual, which AT&T's
4504 compiler does not actually implement.
4506 * G++ multiple inheritance compiler problem
4508 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4509 inheritance lattices was reworked to properly discover ambiguities. We
4510 recently found an example which causes this new algorithm to fail in a
4511 very subtle way, producing bad debug information for those classes.
4512 The file 'gcc.patch' (in this directory) can be applied to gcc to
4513 circumvent the problem. A future GCC release will contain a complete
4516 The previous G++ debug info problem (mentioned below for the gdb-4.7
4517 release) is fixed in gcc version 2.3.2.
4519 * Improved configure script
4521 The `configure' script will now attempt to guess your system type if
4522 you don't supply a host system type. The old scheme of supplying a
4523 host system triplet is preferable over using this. All the magic is
4524 done in the new `config.guess' script. Examine it for details.
4526 We have also brought our configure script much more in line with the FSF's
4527 version. It now supports the --with-xxx options. In particular,
4528 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4529 The resulting GDB will not be able to read arbitrary object file formats --
4530 only the format ``expected'' to be used on the configured target system.
4531 We hope to make this the default in a future release.
4533 * Documentation improvements
4535 There's new internal documentation on how to modify GDB, and how to
4536 produce clean changes to the code. We implore people to read it
4537 before submitting changes.
4539 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4540 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4541 `info' files are also provided. To build `info' files from scratch,
4542 you will need the latest `makeinfo' release, which will be available in
4543 a future texinfo-X.Y release.
4545 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4546 We're not sure exactly which versions have this problem, but it has
4547 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4548 or better. If that isn't possible, there is a patch in
4549 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4550 around this problem.
4554 GDB now supports array constants that can be used in expressions typed in by
4555 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4556 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4559 The new directory `gdb/sparclite' contains a program that demonstrates
4560 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4562 * New native hosts supported
4564 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4565 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4567 * New targets supported
4569 AMD 29k family via UDI a29k-amd-udi or udi29k
4571 * New file formats supported
4573 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4574 HPUX core files, and SCO 3.2v2 core files.
4578 Attaching to processes now works again; thanks for the many bug reports.
4580 We have also stomped on a bunch of core dumps caused by
4581 printf_filtered("%s") problems.
4583 We eliminated a copyright problem on the rpc and ptrace header files
4584 for VxWorks, which was discovered at the last minute during the 4.7
4585 release. You should now be able to build a VxWorks GDB.
4587 You can now interrupt gdb while an attached process is running. This
4588 will cause the attached process to stop, and give control back to GDB.
4590 We fixed problems caused by using too many file descriptors
4591 for reading symbols from object files and libraries. This was
4592 especially a problem for programs that used many (~100) shared
4595 The `step' command now only enters a subroutine if there is line number
4596 information for the subroutine. Otherwise it acts like the `next'
4597 command. Previously, `step' would enter subroutines if there was
4598 any debugging information about the routine. This avoids problems
4599 when using `cc -g1' on MIPS machines.
4601 * Internal improvements
4603 GDB's internal interfaces have been improved to make it easier to support
4604 debugging of multiple languages in the future.
4606 GDB now uses a common structure for symbol information internally.
4607 Minimal symbols (derived from linkage symbols in object files), partial
4608 symbols (from a quick scan of debug information), and full symbols
4609 contain a common subset of information, making it easier to write
4610 shared code that handles any of them.
4612 * New command line options
4614 We now accept --silent as an alias for --quiet.
4618 The memory-mapped-malloc library is now licensed under the GNU Library
4619 General Public License.
4621 *** Changes in GDB-4.7:
4623 * Host/native/target split
4625 GDB has had some major internal surgery to untangle the support for
4626 hosts and remote targets. Now, when you configure GDB for a remote
4627 target, it will no longer load in all of the support for debugging
4628 local programs on the host. When fully completed and tested, this will
4629 ensure that arbitrary host/target combinations are possible.
4631 The primary conceptual shift is to separate the non-portable code in
4632 GDB into three categories. Host specific code is required any time GDB
4633 is compiled on that host, regardless of the target. Target specific
4634 code relates to the peculiarities of the target, but can be compiled on
4635 any host. Native specific code is everything else: it can only be
4636 built when the host and target are the same system. Child process
4637 handling and core file support are two common `native' examples.
4639 GDB's use of /proc for controlling Unix child processes is now cleaner.
4640 It has been split out into a single module under the `target_ops' vector,
4641 plus two native-dependent functions for each system that uses /proc.
4643 * New hosts supported
4645 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
4646 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4647 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
4649 * New targets supported
4651 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4652 68030 and CPU32 m68030-*-*, m68332-*-*
4654 * New native hosts supported
4656 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4657 (386bsd is not well tested yet)
4658 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
4660 * New file formats supported
4662 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
4663 supports reading of `a.out.adobe' object files, which are an a.out
4664 format extended with minimal information about multiple sections.
4668 `show copying' is the same as the old `info copying'.
4669 `show warranty' is the same as `info warrantee'.
4670 These were renamed for consistency. The old commands continue to work.
4672 `info handle' is a new alias for `info signals'.
4674 You can now define pre-command hooks, which attach arbitrary command
4675 scripts to any command. The commands in the hook will be executed
4676 prior to the user's command. You can also create a hook which will be
4677 executed whenever the program stops. See gdb.texinfo.
4681 We now deal with Cfront style name mangling, and can even extract type
4682 info from mangled symbols. GDB can automatically figure out which
4683 symbol mangling style your C++ compiler uses.
4685 Calling of methods and virtual functions has been improved as well.
4689 The crash that occured when debugging Sun Ansi-C compiled binaries is
4690 fixed. This was due to mishandling of the extra N_SO stabs output
4693 We also finally got Ultrix 4.2 running in house, and fixed core file
4694 support, with help from a dozen people on the net.
4696 John M. Farrell discovered that the reason that single-stepping was so
4697 slow on all of the Mips based platforms (primarily SGI and DEC) was
4698 that we were trying to demangle and lookup a symbol used for internal
4699 purposes on every instruction that was being stepped through. Changing
4700 the name of that symbol so that it couldn't be mistaken for a C++
4701 mangled symbol sped things up a great deal.
4703 Rich Pixley sped up symbol lookups in general by getting much smarter
4704 about when C++ symbol mangling is necessary. This should make symbol
4705 completion (TAB on the command line) much faster. It's not as fast as
4706 we'd like, but it's significantly faster than gdb-4.6.
4710 A new user controllable variable 'call_scratch_address' can
4711 specify the location of a scratch area to be used when GDB
4712 calls a function in the target. This is necessary because the
4713 usual method of putting the scratch area on the stack does not work
4714 in systems that have separate instruction and data spaces.
4716 We integrated changes to support the 29k UDI (Universal Debugger
4717 Interface), but discovered at the last minute that we didn't have all
4718 of the appropriate copyright paperwork. We are working with AMD to
4719 resolve this, and hope to have it available soon.
4723 We have sped up the remote serial line protocol, especially for targets
4724 with lots of registers. It now supports a new `expedited status' ('T')
4725 message which can be used in place of the existing 'S' status message.
4726 This allows the remote stub to send only the registers that GDB
4727 needs to make a quick decision about single-stepping or conditional
4728 breakpoints, eliminating the need to fetch the entire register set for
4729 each instruction being stepped through.
4731 The GDB remote serial protocol now implements a write-through cache for
4732 registers, only re-reading the registers if the target has run.
4734 There is also a new remote serial stub for SPARC processors. You can
4735 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
4736 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
4737 processor with a serial port.
4741 Configure.in files have become much easier to read and modify. A new
4742 `table driven' format makes it more obvious what configurations are
4743 supported, and what files each one uses.
4747 There is a new opcodes library which will eventually contain all of the
4748 disassembly routines and opcode tables. At present, it only contains
4749 Sparc and Z8000 routines. This will allow the assembler, debugger, and
4750 disassembler (binutils/objdump) to share these routines.
4752 The libiberty library is now copylefted under the GNU Library General
4753 Public License. This allows more liberal use, and was done so libg++
4754 can use it. This makes no difference to GDB, since the Library License
4755 grants all the rights from the General Public License.
4759 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
4760 reference to the stabs symbol info used by the debugger. It is (as far
4761 as we know) the only published document on this fascinating topic. We
4762 encourage you to read it, compare it to the stabs information on your
4763 system, and send improvements on the document in general (to
4764 bug-gdb@prep.ai.mit.edu).
4766 And, of course, many bugs have been fixed.
4769 *** Changes in GDB-4.6:
4771 * Better support for C++ function names
4773 GDB now accepts as input the "demangled form" of C++ overloaded function
4774 names and member function names, and can do command completion on such names
4775 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
4776 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
4777 Make use of command completion, it is your friend.
4779 GDB also now accepts a variety of C++ mangled symbol formats. They are
4780 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
4781 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
4782 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
4783 for the list of formats.
4785 * G++ symbol mangling problem
4787 Recent versions of gcc have a bug in how they emit debugging information for
4788 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
4789 directory) can be applied to gcc to fix the problem. Alternatively, if you
4790 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
4791 usual symptom is difficulty with setting breakpoints on methods. GDB complains
4792 about the method being non-existent. (We believe that version 2.2.2 of GCC has
4795 * New 'maintenance' command
4797 All of the commands related to hacking GDB internals have been moved out of
4798 the main command set, and now live behind the 'maintenance' command. This
4799 can also be abbreviated as 'mt'. The following changes were made:
4801 dump-me -> maintenance dump-me
4802 info all-breakpoints -> maintenance info breakpoints
4803 printmsyms -> maintenance print msyms
4804 printobjfiles -> maintenance print objfiles
4805 printpsyms -> maintenance print psymbols
4806 printsyms -> maintenance print symbols
4808 The following commands are new:
4810 maintenance demangle Call internal GDB demangler routine to
4811 demangle a C++ link name and prints the result.
4812 maintenance print type Print a type chain for a given symbol
4814 * Change to .gdbinit file processing
4816 We now read the $HOME/.gdbinit file before processing the argv arguments
4817 (e.g. reading symbol files or core files). This allows global parameters to
4818 be set, which will apply during the symbol reading. The ./.gdbinit is still
4819 read after argv processing.
4821 * New hosts supported
4823 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
4825 GNU/Linux support i386-unknown-linux or linux
4827 We are also including code to support the HP/PA running BSD and HPUX. This
4828 is almost guaranteed not to work, as we didn't have time to test or build it
4829 for this release. We are including it so that the more adventurous (or
4830 masochistic) of you can play with it. We also had major problems with the
4831 fact that the compiler that we got from HP doesn't support the -g option.
4834 * New targets supported
4836 Hitachi H8/300 h8300-hitachi-hms or h8300hms
4838 * More smarts about finding #include files
4840 GDB now remembers the compilation directory for all include files, and for
4841 all files from which C is generated (like yacc and lex sources). This
4842 greatly improves GDB's ability to find yacc/lex sources, and include files,
4843 especially if you are debugging your program from a directory different from
4844 the one that contains your sources.
4846 We also fixed a bug which caused difficulty with listing and setting
4847 breakpoints in include files which contain C code. (In the past, you had to
4848 try twice in order to list an include file that you hadn't looked at before.)
4850 * Interesting infernals change
4852 GDB now deals with arbitrary numbers of sections, where the symbols for each
4853 section must be relocated relative to that section's landing place in the
4854 target's address space. This work was needed to support ELF with embedded
4855 stabs used by Solaris-2.0.
4857 * Bug fixes (of course!)
4859 There have been loads of fixes for the following things:
4860 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
4861 i960, stabs, DOS(GO32), procfs, etc...
4863 See the ChangeLog for details.
4865 *** Changes in GDB-4.5:
4867 * New machines supported (host and target)
4869 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
4871 SGI Irix-4.x mips-sgi-irix4 or iris4
4873 * New malloc package
4875 GDB now uses a new memory manager called mmalloc, based on gmalloc.
4876 Mmalloc is capable of handling mutiple heaps of memory. It is also
4877 capable of saving a heap to a file, and then mapping it back in later.
4878 This can be used to greatly speedup the startup of GDB by using a
4879 pre-parsed symbol table which lives in a mmalloc managed heap. For
4880 more details, please read mmalloc/mmalloc.texi.
4884 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
4885 'help info proc' for details.
4887 * MIPS ecoff symbol table format
4889 The code that reads MIPS symbol table format is now supported on all hosts.
4890 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
4893 * File name changes for MS-DOS
4895 Many files in the config directories have been renamed to make it easier to
4896 support GDB on MS-DOSe systems (which have very restrictive file name
4897 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
4898 environment) is close to working but has some remaining problems. Note
4899 that debugging of DOS programs is not supported, due to limitations
4900 in the ``operating system'', but it can be used to host cross-debugging.
4902 * Cross byte order fixes
4904 Many fixes have been made to support cross debugging of Sparc and MIPS
4905 targets from hosts whose byte order differs.
4907 * New -mapped and -readnow options
4909 If memory-mapped files are available on your system through the 'mmap'
4910 system call, you can use the -mapped option on the `file' or
4911 `symbol-file' commands to cause GDB to write the symbols from your
4912 program into a reusable file. If the program you are debugging is
4913 called `/path/fred', the mapped symbol file will be `./fred.syms'.
4914 Future GDB debugging sessions will notice the presence of this file,
4915 and will quickly map in symbol information from it, rather than reading
4916 the symbol table from the executable program. Using the '-mapped'
4917 option in a GDB `file' or `symbol-file' command has the same effect as
4918 starting GDB with the '-mapped' command-line option.
4920 You can cause GDB to read the entire symbol table immediately by using
4921 the '-readnow' option with any of the commands that load symbol table
4922 information (or on the GDB command line). This makes the command
4923 slower, but makes future operations faster.
4925 The -mapped and -readnow options are typically combined in order to
4926 build a `fred.syms' file that contains complete symbol information.
4927 A simple GDB invocation to do nothing but build a `.syms' file for future
4930 gdb -batch -nx -mapped -readnow programname
4932 The `.syms' file is specific to the host machine on which GDB is run.
4933 It holds an exact image of GDB's internal symbol table. It cannot be
4934 shared across multiple host platforms.
4936 * longjmp() handling
4938 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
4939 siglongjmp() without losing control. This feature has not yet been ported to
4940 all systems. It currently works on many 386 platforms, all MIPS-based
4941 platforms (SGI, DECstation, etc), and Sun3/4.
4945 Preliminary work has been put in to support the new Solaris OS from Sun. At
4946 this time, it can control and debug processes, but it is not capable of
4951 As always, many many bug fixes. The major areas were with g++, and mipsread.
4952 People using the MIPS-based platforms should experience fewer mysterious
4953 crashes and trashed symbol tables.
4955 *** Changes in GDB-4.4:
4957 * New machines supported (host and target)
4959 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4961 BSD Reno on Vax vax-dec-bsd
4962 Ultrix on Vax vax-dec-ultrix
4964 * New machines supported (target)
4966 AMD 29000 embedded, using EBMON a29k-none-none
4970 GDB continues to improve its handling of C++. `References' work better.
4971 The demangler has also been improved, and now deals with symbols mangled as
4972 per the Annotated C++ Reference Guide.
4974 GDB also now handles `stabs' symbol information embedded in MIPS
4975 `ecoff' symbol tables. Since the ecoff format was not easily
4976 extensible to handle new languages such as C++, this appeared to be a
4977 good way to put C++ debugging info into MIPS binaries. This option
4978 will be supported in the GNU C compiler, version 2, when it is
4981 * New features for SVR4
4983 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
4984 shared libraries. Debugging dynamically linked programs should present
4985 only minor differences from debugging statically linked programs.
4987 The `info proc' command will print out information about any process
4988 on an SVR4 system (including the one you are debugging). At the moment,
4989 it prints the address mappings of the process.
4991 If you bring up GDB on another SVR4 system, please send mail to
4992 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
4994 * Better dynamic linking support in SunOS
4996 Reading symbols from shared libraries which contain debugging symbols
4997 now works properly. However, there remain issues such as automatic
4998 skipping of `transfer vector' code during function calls, which
4999 make it harder to debug code in a shared library, than to debug the
5000 same code linked statically.
5004 GDB is now using the latest `getopt' routines from the FSF. This
5005 version accepts the -- prefix for options with long names. GDB will
5006 continue to accept the old forms (-option and +option) as well.
5007 Various single letter abbreviations for options have been explicity
5008 added to the option table so that they won't get overshadowed in the
5009 future by other options that begin with the same letter.
5013 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5014 Many assorted bugs have been handled. Many more remain to be handled.
5015 See the various ChangeLog files (primarily in gdb and bfd) for details.
5018 *** Changes in GDB-4.3:
5020 * New machines supported (host and target)
5022 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5023 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5024 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5026 * Almost SCO Unix support
5028 We had hoped to support:
5029 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5030 (except for core file support), but we discovered very late in the release
5031 that it has problems with process groups that render gdb unusable. Sorry
5032 about that. I encourage people to fix it and post the fixes.
5034 * Preliminary ELF and DWARF support
5036 GDB can read ELF object files on System V Release 4, and can handle
5037 debugging records for C, in DWARF format, in ELF files. This support
5038 is preliminary. If you bring up GDB on another SVR4 system, please
5039 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5044 GDB now uses the latest `readline' library. One user-visible change
5045 is that two tabs will list possible command completions, which previously
5046 required typing M-? (meta-question mark, or ESC ?).
5050 The `stepi' bug that many of you noticed has been squashed.
5051 Many bugs in C++ have been handled. Many more remain to be handled.
5052 See the various ChangeLog files (primarily in gdb and bfd) for details.
5054 * State of the MIPS world (in case you wondered):
5056 GDB can understand the symbol tables emitted by the compilers
5057 supplied by most vendors of MIPS-based machines, including DEC. These
5058 symbol tables are in a format that essentially nobody else uses.
5060 Some versions of gcc come with an assembler post-processor called
5061 mips-tfile. This program is required if you want to do source-level
5062 debugging of gcc-compiled programs. I believe FSF does not ship
5063 mips-tfile with gcc version 1, but it will eventually come with gcc
5066 Debugging of g++ output remains a problem. g++ version 1.xx does not
5067 really support it at all. (If you're lucky, you should be able to get
5068 line numbers and stack traces to work, but no parameters or local
5069 variables.) With some work it should be possible to improve the
5072 When gcc version 2 is released, you will have somewhat better luck.
5073 However, even then you will get confusing results for inheritance and
5076 We will eventually provide full debugging of g++ output on
5077 DECstations. This will probably involve some kind of stabs-in-ecoff
5078 encapulation, but the details have not been worked out yet.
5081 *** Changes in GDB-4.2:
5083 * Improved configuration
5085 Only one copy of `configure' exists now, and it is not self-modifying.
5086 Porting BFD is simpler.
5090 The `step' and `next' commands now only stop at the first instruction
5091 of a source line. This prevents the multiple stops that used to occur
5092 in switch statements, for-loops, etc. `Step' continues to stop if a
5093 function that has debugging information is called within the line.
5097 Lots of small bugs fixed. More remain.
5099 * New host supported (not target)
5101 Intel 386 PC clone running Mach i386-none-mach
5104 *** Changes in GDB-4.1:
5106 * Multiple source language support
5108 GDB now has internal scaffolding to handle several source languages.
5109 It determines the type of each source file from its filename extension,
5110 and will switch expression parsing and number formatting to match the
5111 language of the function in the currently selected stack frame.
5112 You can also specifically set the language to be used, with
5113 `set language c' or `set language modula-2'.
5117 GDB now has preliminary support for the GNU Modula-2 compiler,
5118 currently under development at the State University of New York at
5119 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5120 continue through the fall of 1991 and into 1992.
5122 Other Modula-2 compilers are currently not supported, and attempting to
5123 debug programs compiled with them will likely result in an error as the
5124 symbol table is read. Feel free to work on it, though!
5126 There are hooks in GDB for strict type checking and range checking,
5127 in the `Modula-2 philosophy', but they do not currently work.
5131 GDB can now write to executable and core files (e.g. patch
5132 a variable's value). You must turn this switch on, specify
5133 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5134 by assigning a new value to a variable. Modifications take
5137 * Automatic SunOS shared library reading
5139 When you run your program, GDB automatically determines where its
5140 shared libraries (if any) have been loaded, and reads their symbols.
5141 The `share' command is no longer needed. This also works when
5142 examining core files.
5146 You can specify the number of lines that the `list' command shows.
5149 * New machines supported (host and target)
5151 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5152 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5153 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5155 * New hosts supported (not targets)
5157 IBM RT/PC: romp-ibm-aix or rtpc
5159 * New targets supported (not hosts)
5161 AMD 29000 embedded with COFF a29k-none-coff
5162 AMD 29000 embedded with a.out a29k-none-aout
5163 Ultracomputer remote kernel debug a29k-nyu-kern
5165 * New remote interfaces
5171 *** Changes in GDB-4.0:
5175 Wide output is wrapped at good places to make the output more readable.
5177 Gdb now supports cross-debugging from a host machine of one type to a
5178 target machine of another type. Communication with the target system
5179 is over serial lines. The ``target'' command handles connecting to the
5180 remote system; the ``load'' command will download a program into the
5181 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5182 also supports debugging of realtime processes running under VxWorks,
5183 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5184 stub on the target system.
5186 New CPUs supported include the AMD 29000 and Intel 960.
5188 GDB now reads object files and symbol tables via a ``binary file''
5189 library, which allows a single copy of GDB to debug programs of multiple
5190 object file types such as a.out and coff.
5192 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5193 refcard.dvi and refcard.ps are available to format it).
5196 * Control-Variable user interface simplified
5198 All variables that control the operation of the debugger can be set
5199 by the ``set'' command, and displayed by the ``show'' command.
5201 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5202 ``Show prompt'' produces the response:
5203 Gdb's prompt is new-gdb=>.
5205 What follows are the NEW set commands. The command ``help set'' will
5206 print a complete list of old and new set commands. ``help set FOO''
5207 will give a longer description of the variable FOO. ``show'' will show
5208 all of the variable descriptions and their current settings.
5210 confirm on/off: Enables warning questions for operations that are
5211 hard to recover from, e.g. rerunning the program while
5212 it is already running. Default is ON.
5214 editing on/off: Enables EMACS style command line editing
5215 of input. Previous lines can be recalled with
5216 control-P, the current line can be edited with control-B,
5217 you can search for commands with control-R, etc.
5220 history filename NAME: NAME is where the gdb command history
5221 will be stored. The default is .gdb_history,
5222 or the value of the environment variable
5225 history size N: The size, in commands, of the command history. The
5226 default is 256, or the value of the environment variable
5229 history save on/off: If this value is set to ON, the history file will
5230 be saved after exiting gdb. If set to OFF, the
5231 file will not be saved. The default is OFF.
5233 history expansion on/off: If this value is set to ON, then csh-like
5234 history expansion will be performed on
5235 command line input. The default is OFF.
5237 radix N: Sets the default radix for input and output. It can be set
5238 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5239 in the current radix, so "set radix 10" is always a no-op.
5241 height N: This integer value is the number of lines on a page. Default
5242 is 24, the current `stty rows'' setting, or the ``li#''
5243 setting from the termcap entry matching the environment
5246 width N: This integer value is the number of characters on a line.
5247 Default is 80, the current `stty cols'' setting, or the ``co#''
5248 setting from the termcap entry matching the environment
5251 Note: ``set screensize'' is obsolete. Use ``set height'' and
5252 ``set width'' instead.
5254 print address on/off: Print memory addresses in various command displays,
5255 such as stack traces and structure values. Gdb looks
5256 more ``symbolic'' if you turn this off; it looks more
5257 ``machine level'' with it on. Default is ON.
5259 print array on/off: Prettyprint arrays. New convenient format! Default
5262 print demangle on/off: Print C++ symbols in "source" form if on,
5265 print asm-demangle on/off: Same, for assembler level printouts
5268 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5271 * Support for Epoch Environment.
5273 The epoch environment is a version of Emacs v18 with windowing. One
5274 new command, ``inspect'', is identical to ``print'', except that if you
5275 are running in the epoch environment, the value is printed in its own
5279 * Support for Shared Libraries
5281 GDB can now debug programs and core files that use SunOS shared libraries.
5282 Symbols from a shared library cannot be referenced
5283 before the shared library has been linked with the program (this
5284 happens after you type ``run'' and before the function main() is entered).
5285 At any time after this linking (including when examining core files
5286 from dynamically linked programs), gdb reads the symbols from each
5287 shared library when you type the ``sharedlibrary'' command.
5288 It can be abbreviated ``share''.
5290 sharedlibrary REGEXP: Load shared object library symbols for files
5291 matching a unix regular expression. No argument
5292 indicates to load symbols for all shared libraries.
5294 info sharedlibrary: Status of loaded shared libraries.
5299 A watchpoint stops execution of a program whenever the value of an
5300 expression changes. Checking for this slows down execution
5301 tremendously whenever you are in the scope of the expression, but is
5302 quite useful for catching tough ``bit-spreader'' or pointer misuse
5303 problems. Some machines such as the 386 have hardware for doing this
5304 more quickly, and future versions of gdb will use this hardware.
5306 watch EXP: Set a watchpoint (breakpoint) for an expression.
5308 info watchpoints: Information about your watchpoints.
5310 delete N: Deletes watchpoint number N (same as breakpoints).
5311 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5312 enable N: Re-enables watchpoint number N (same as breakpoints).
5315 * C++ multiple inheritance
5317 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5320 * C++ exception handling
5322 Gdb now supports limited C++ exception handling. Besides the existing
5323 ability to breakpoint on an exception handler, gdb can breakpoint on
5324 the raising of an exception (before the stack is peeled back to the
5327 catch FOO: If there is a FOO exception handler in the dynamic scope,
5328 set a breakpoint to catch exceptions which may be raised there.
5329 Multiple exceptions (``catch foo bar baz'') may be caught.
5331 info catch: Lists all exceptions which may be caught in the
5332 current stack frame.
5335 * Minor command changes
5337 The command ``call func (arg, arg, ...)'' now acts like the print
5338 command, except it does not print or save a value if the function's result
5339 is void. This is similar to dbx usage.
5341 The ``up'' and ``down'' commands now always print the frame they end up
5342 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5343 frames without printing.
5345 * New directory command
5347 'dir' now adds directories to the FRONT of the source search path.
5348 The path starts off empty. Source files that contain debug information
5349 about the directory in which they were compiled can be found even
5350 with an empty path; Sun CC and GCC include this information. If GDB can't
5351 find your source file in the current directory, type "dir .".
5353 * Configuring GDB for compilation
5355 For normal use, type ``./configure host''. See README or gdb.texinfo
5358 GDB now handles cross debugging. If you are remotely debugging between
5359 two different machines, type ``./configure host -target=targ''.
5360 Host is the machine where GDB will run; targ is the machine
5361 where the program that you are debugging will run.