1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.6
8 Like "catch throw", but catches a re-thrown exception.
11 Display the details of GDB configure-time options.
13 maint set|show per-command
14 maint set|show per-command space
15 maint set|show per-command time
16 maint set|show per-command symtab
17 Enable display of per-command gdb resource usage.
21 set remote trace-status-packet
22 show remote trace-status-packet
23 Set/show the use of remote protocol qTStatus packet.
25 * You can now use a literal value 'unlimited' for options that
26 interpret 0 or -1 as meaning "unlimited". E.g., "set
27 trace-buffer-size unlimited" is now an alias for "set
28 trace-buffer-size -1" and "set height unlimited" is now an alias for
31 * New command-line options
33 Display the details of GDB configure-time options.
35 * The command 'tsave' can now support new option '-ctf' to save trace
36 buffer in Common Trace Format.
38 * Newly installed $prefix/bin/gcore acts as a shell interface for the
41 * GDB now implements the the C++ 'typeid' operator.
43 * The new convenience variable $_exception holds the exception being
44 thrown or caught at an exception-related catchpoint.
46 * The exception-related catchpoints, like "catch throw", now accept a
47 regular expression which can be used to filter exceptions by type.
51 ** The -trace-save MI command can optionally save trace buffer in Common
54 *** Changes in GDB 7.6
56 * Target record has been renamed to record-full.
57 Record/replay is now enabled with the "record full" command.
58 This also affects settings that are associated with full record/replay
59 that have been moved from "set/show record" to "set/show record full":
61 set|show record full insn-number-max
62 set|show record full stop-at-limit
63 set|show record full memory-query
65 * A new record target "record-btrace" has been added. The new target
66 uses hardware support to record the control-flow of a process. It
67 does not support replaying the execution, but it implements the
68 below new commands for investigating the recorded execution log.
69 This new recording method can be enabled using:
73 The "record-btrace" target is only available on Intel Atom processors
74 and requires a Linux kernel 2.6.32 or later.
76 * Two new commands have been added for record/replay to give information
77 about the recorded execution without having to replay the execution.
78 The commands are only supported by "record btrace".
80 record instruction-history prints the execution history at
81 instruction granularity
83 record function-call-history prints the execution history at
86 * New native configurations
88 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
89 FreeBSD/powerpc powerpc*-*-freebsd
90 x86_64/Cygwin x86_64-*-cygwin*
91 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
95 ARM AArch64 aarch64*-*-elf
96 ARM AArch64 GNU/Linux aarch64*-*-linux
97 Lynx 178 PowerPC powerpc-*-lynx*178
98 x86_64/Cygwin x86_64-*-cygwin*
99 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
101 * If the configured location of system.gdbinit file (as given by the
102 --with-system-gdbinit option at configure time) is in the
103 data-directory (as specified by --with-gdb-datadir at configure
104 time) or in one of its subdirectories, then GDB will look for the
105 system-wide init file in the directory specified by the
106 --data-directory command-line option.
108 * New command line options:
110 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
111 other initialization files, unlike -nx which disables all of them.
113 * Removed command line options
115 -epoch This was used by the gdb mode in Epoch, an ancient fork of
118 * The 'ptype' and 'whatis' commands now accept an argument to control
121 * 'info proc' now works on some core files.
125 ** Vectors can be created with gdb.Type.vector.
127 ** Python's atexit.register now works in GDB.
129 ** Types can be pretty-printed via a Python API.
131 ** Python 3 is now supported (in addition to Python 2.4 or later)
133 ** New class gdb.Architecture exposes GDB's internal representation
134 of architecture in the Python API.
136 ** New method Frame.architecture returns the gdb.Architecture object
137 corresponding to the frame's architecture.
139 * New Python-based convenience functions:
141 ** $_memeq(buf1, buf2, length)
142 ** $_streq(str1, str2)
144 ** $_regex(str, regex)
146 * The 'cd' command now defaults to using '~' (the home directory) if not
149 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
150 default for GCC since November 2000.
152 * The command 'forward-search' can now be abbreviated as 'fo'.
154 * The command 'info tracepoints' can now display 'installed on target'
155 or 'not installed on target' for each non-pending location of tracepoint.
157 * New configure options
159 --enable-libmcheck/--disable-libmcheck
160 By default, development versions are built with -lmcheck on hosts
161 that support it, in order to help track memory corruption issues.
162 Release versions, on the other hand, are built without -lmcheck
163 by default. The --enable-libmcheck/--disable-libmcheck configure
164 options allow the user to override that default.
165 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
166 This configure option allows the user to build GDB with
167 libbabeltrace using which GDB can read Common Trace Format data.
169 * New commands (for set/show, see "New options" below)
172 Catch signals. This is similar to "handle", but allows commands and
173 conditions to be attached.
176 List the BFDs known to GDB.
178 python-interactive [command]
180 Start a Python interactive prompt, or evaluate the optional command
181 and print the result of expressions.
184 "py" is a new alias for "python".
186 enable type-printer [name]...
187 disable type-printer [name]...
188 Enable or disable type printers.
192 ** For the Renesas Super-H architecture, the "regs" command has been removed
193 (has been deprecated in GDB 7.5), and "info all-registers" should be used
198 set print type methods (on|off)
199 show print type methods
200 Control whether method declarations are displayed by "ptype".
201 The default is to show them.
203 set print type typedefs (on|off)
204 show print type typedefs
205 Control whether typedef definitions are displayed by "ptype".
206 The default is to show them.
208 set filename-display basename|relative|absolute
209 show filename-display
210 Control the way in which filenames is displayed.
211 The default is "relative", which preserves previous behavior.
213 set trace-buffer-size
214 show trace-buffer-size
215 Request target to change the size of trace buffer.
217 set remote trace-buffer-size-packet auto|on|off
218 show remote trace-buffer-size-packet
219 Control the use of the remote protocol `QTBuffer:size' packet.
223 Control display of debugging messages related to ARM AArch64.
226 set debug coff-pe-read
227 show debug coff-pe-read
228 Control display of debugging messages related to reading of COFF/PE
233 Control display of debugging messages related to Mach-O symbols
236 set debug notification
237 show debug notification
238 Control display of debugging info for async remote notification.
242 ** Command parameter changes are now notified using new async record
243 "=cmd-param-changed".
244 ** Trace frame changes caused by command "tfind" are now notified using
245 new async record "=traceframe-changed".
246 ** The creation, deletion and modification of trace state variables
247 are now notified using new async records "=tsv-created",
248 "=tsv-deleted" and "=tsv-modified".
249 ** The start and stop of process record are now notified using new
250 async record "=record-started" and "=record-stopped".
251 ** Memory changes are now notified using new async record
253 ** The data-disassemble command response will include a "fullname" field
254 containing the absolute file name when source has been requested.
255 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
256 command, to allow pattern filling of memory areas.
257 ** New commands "-catch-load"/"-catch-unload" added for intercepting
258 library load/unload events.
259 ** The response to breakpoint commands and breakpoint async records
260 includes an "installed" field containing a boolean state about each
261 non-pending tracepoint location is whether installed on target or not.
262 ** Output of the "-trace-status" command includes a "trace-file" field
263 containing the name of the trace file being examined. This field is
264 optional, and only present when examining a trace file.
265 ** The "fullname" field is now always present along with the "file" field,
266 even if the file cannot be found by GDB.
268 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
269 You must have the LZMA library available when configuring GDB for this
270 feature to be enabled. For more information, see:
271 http://fedoraproject.org/wiki/Features/MiniDebugInfo
276 Set the size of trace buffer. The remote stub reports support for this
277 packet to gdb's qSupported query.
280 Enable Branch Trace Store (BTS)-based branch tracing for the current
281 thread. The remote stub reports support for this packet to gdb's
285 Disable branch tracing for the current thread. The remote stub reports
286 support for this packet to gdb's qSupported query.
289 Read the traced branches for the current thread. The remote stub
290 reports support for this packet to gdb's qSupported query.
292 *** Changes in GDB 7.5
294 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
295 for more x32 ABI info.
297 * GDB now supports access to MIPS DSP registers on Linux targets.
299 * GDB now supports debugging microMIPS binaries.
301 * The "info os" command on GNU/Linux can now display information on
302 several new classes of objects managed by the operating system:
303 "info os procgroups" lists process groups
304 "info os files" lists file descriptors
305 "info os sockets" lists internet-domain sockets
306 "info os shm" lists shared-memory regions
307 "info os semaphores" lists semaphores
308 "info os msg" lists message queues
309 "info os modules" lists loaded kernel modules
311 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
312 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
313 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
314 options and inspect the probe arguments using the new $_probe_arg family
315 of convenience variables. You can obtain more information about SystemTap
316 in <http://sourceware.org/systemtap/>.
318 * GDB now supports reversible debugging on ARM, it allows you to
319 debug basic ARM and THUMB instructions, and provides
320 record/replay support.
322 * The option "symbol-reloading" has been deleted as it is no longer used.
326 ** GDB commands implemented in Python can now be put in command class
329 ** The "maint set python print-stack on|off" is now deleted.
331 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
332 apply "flag enum"-style pretty-printing to any enum.
334 ** gdb.lookup_symbol can now work when there is no current frame.
336 ** gdb.Symbol now has a 'line' attribute, holding the line number in
337 the source at which the symbol was defined.
339 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
340 method 'value'. The former indicates whether the symbol needs a
341 frame in order to compute its value, and the latter computes the
344 ** A new method 'referenced_value' on gdb.Value objects which can
345 dereference pointer as well as C++ reference values.
347 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
348 which return the global and static blocks (as gdb.Block objects),
349 of the underlying symbol table, respectively.
351 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
352 object associated with a PC value.
354 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
355 of the address range occupied by code for the current source line.
357 * Go language support.
358 GDB now supports debugging programs written in the Go programming
361 * GDBserver now supports stdio connections.
362 E.g. (gdb) target remote | ssh myhost gdbserver - hello
364 * The binary "gdbtui" can no longer be built or installed.
365 Use "gdb -tui" instead.
367 * GDB will now print "flag" enums specially. A flag enum is one where
368 all the enumerator values have no bits in common when pairwise
369 "and"ed. When printing a value whose type is a flag enum, GDB will
370 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
371 (gdb) print (enum E) 3
374 * The filename part of a linespec will now match trailing components
375 of a source file name. For example, "break gcc/expr.c:1000" will
376 now set a breakpoint in build/gcc/expr.c, but not
379 * The "info proc" and "generate-core-file" commands will now also
380 work on remote targets connected to GDBserver on Linux.
382 * The command "info catch" has been removed. It has been disabled
385 * The "catch exception" and "catch assert" commands now accept
386 a condition at the end of the command, much like the "break"
387 command does. For instance:
389 (gdb) catch exception Constraint_Error if Barrier = True
391 Previously, it was possible to add a condition to such catchpoints,
392 but it had to be done as a second step, after the catchpoint had been
393 created, using the "condition" command.
395 * The "info static-tracepoint-marker" command will now also work on
396 native Linux targets with in-process agent.
398 * GDB can now set breakpoints on inlined functions.
400 * The .gdb_index section has been updated to include symbols for
401 inlined functions. GDB will ignore older .gdb_index sections by
402 default, which could cause symbol files to be loaded more slowly
403 until their .gdb_index sections can be recreated. The new command
404 "set use-deprecated-index-sections on" will cause GDB to use any older
405 .gdb_index sections it finds. This will restore performance, but the
406 ability to set breakpoints on inlined functions will be lost in symbol
407 files with older .gdb_index sections.
409 The .gdb_index section has also been updated to record more information
410 about each symbol. This speeds up the "info variables", "info functions"
411 and "info types" commands when used with programs having the .gdb_index
412 section, as well as speeding up debugging with shared libraries using
413 the .gdb_index section.
415 * Ada support for GDB/MI Variable Objects has been added.
417 * GDB can now support 'breakpoint always-inserted mode' in 'record'
422 ** New command -info-os is the MI equivalent of "info os".
424 ** Output logs ("set logging" and related) now include MI output.
428 ** "set use-deprecated-index-sections on|off"
429 "show use-deprecated-index-sections on|off"
430 Controls the use of deprecated .gdb_index sections.
432 ** "catch load" and "catch unload" can be used to stop when a shared
433 library is loaded or unloaded, respectively.
435 ** "enable count" can be used to auto-disable a breakpoint after
438 ** "info vtbl" can be used to show the virtual method tables for
439 C++ and Java objects.
441 ** "explore" and its sub commands "explore value" and "explore type"
442 can be used to reccursively explore values and types of
443 expressions. These commands are available only if GDB is
444 configured with '--with-python'.
446 ** "info auto-load" shows status of all kinds of auto-loaded files,
447 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
448 sequences of commands files, "info auto-load python-scripts"
449 shows status of auto-loading Python script files,
450 "info auto-load local-gdbinit" shows status of loading init file
451 (.gdbinit) from current directory and "info auto-load libthread-db" shows
452 status of inferior specific thread debugging shared library loading.
454 ** "info auto-load-scripts", "set auto-load-scripts on|off"
455 and "show auto-load-scripts" commands have been deprecated, use their
456 "info auto-load python-scripts", "set auto-load python-scripts on|off"
457 and "show auto-load python-scripts" counterparts instead.
459 ** "dprintf location,format,args..." creates a dynamic printf, which
460 is basically a breakpoint that does a printf and immediately
461 resumes your program's execution, so it is like a printf that you
462 can insert dynamically at runtime instead of at compiletime.
464 ** "set print symbol"
466 Controls whether GDB attempts to display the symbol, if any,
467 corresponding to addresses it prints. This defaults to "on", but
468 you can set it to "off" to restore GDB's previous behavior.
470 * Deprecated commands
472 ** For the Renesas Super-H architecture, the "regs" command has been
473 deprecated, and "info all-registers" should be used instead.
477 Renesas RL78 rl78-*-elf
478 HP OpenVMS ia64 ia64-hp-openvms*
480 * GDBserver supports evaluation of breakpoint conditions. When
481 support is advertised by GDBserver, GDB may be told to send the
482 breakpoint conditions in bytecode form to GDBserver. GDBserver
483 will only report the breakpoint trigger to GDB when its condition
489 show mips compression
490 Select the compressed ISA encoding used in functions that have no symbol
491 information available. The encoding can be set to either of:
494 and is updated automatically from ELF file flags if available.
496 set breakpoint condition-evaluation
497 show breakpoint condition-evaluation
498 Control whether breakpoint conditions are evaluated by GDB ("host") or by
499 GDBserver ("target"). Default option "auto" chooses the most efficient
501 This option can improve debugger efficiency depending on the speed of the
505 Disable auto-loading globally.
508 Show auto-loading setting of all kinds of auto-loaded files.
510 set auto-load gdb-scripts on|off
511 show auto-load gdb-scripts
512 Control auto-loading of GDB canned sequences of commands files.
514 set auto-load python-scripts on|off
515 show auto-load python-scripts
516 Control auto-loading of Python script files.
518 set auto-load local-gdbinit on|off
519 show auto-load local-gdbinit
520 Control loading of init file (.gdbinit) from current directory.
522 set auto-load libthread-db on|off
523 show auto-load libthread-db
524 Control auto-loading of inferior specific thread debugging shared library.
526 set auto-load scripts-directory <dir1>[:<dir2>...]
527 show auto-load scripts-directory
528 Set a list of directories from which to load auto-loaded scripts.
529 Automatically loaded Python scripts and GDB scripts are located in one
530 of the directories listed by this option.
531 The delimiter (':' above) may differ according to the host platform.
533 set auto-load safe-path <dir1>[:<dir2>...]
534 show auto-load safe-path
535 Set a list of directories from which it is safe to auto-load files.
536 The delimiter (':' above) may differ according to the host platform.
538 set debug auto-load on|off
540 Control display of debugging info for auto-loading the files above.
542 set dprintf-style gdb|call|agent
544 Control the way in which a dynamic printf is performed; "gdb"
545 requests a GDB printf command, while "call" causes dprintf to call a
546 function in the inferior. "agent" requests that the target agent
547 (such as GDBserver) do the printing.
549 set dprintf-function <expr>
550 show dprintf-function
551 set dprintf-channel <expr>
553 Set the function and optional first argument to the call when using
554 the "call" style of dynamic printf.
556 set disconnected-dprintf on|off
557 show disconnected-dprintf
558 Control whether agent-style dynamic printfs continue to be in effect
559 after GDB disconnects.
561 * New configure options
564 Configure default value for the 'set auto-load scripts-directory'
565 setting above. It defaults to '$debugdir:$datadir/auto-load',
566 $debugdir representing global debugging info directories (available
567 via 'show debug-file-directory') and $datadir representing GDB's data
568 directory (available via 'show data-directory').
570 --with-auto-load-safe-path
571 Configure default value for the 'set auto-load safe-path' setting
572 above. It defaults to the --with-auto-load-dir setting.
574 --without-auto-load-safe-path
575 Set 'set auto-load safe-path' to '/', effectively disabling this
580 z0/z1 conditional breakpoints extension
582 The z0/z1 breakpoint insertion packets have been extended to carry
583 a list of conditional expressions over to the remote stub depending on the
584 condition evaluation mode. The use of this extension can be controlled
585 via the "set remote conditional-breakpoints-packet" command.
589 Specify the signals which the remote stub may pass to the debugged
590 program without GDB involvement.
592 * New command line options
594 --init-command=FILE, -ix Like --command, -x but execute it
595 before loading inferior.
596 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
597 execute it before loading inferior.
599 *** Changes in GDB 7.4
601 * GDB now handles ambiguous linespecs more consistently; the existing
602 FILE:LINE support has been expanded to other types of linespecs. A
603 breakpoint will now be set on all matching locations in all
604 inferiors, and locations will be added or removed according to
607 * GDB now allows you to skip uninteresting functions and files when
608 stepping with the "skip function" and "skip file" commands.
610 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
611 and "show remote hardware-watchpoint-length-limit". These allows to
612 set or show the maximum length limit (in bytes) of a remote
613 target hardware watchpoint.
615 This allows e.g. to use "unlimited" hardware watchpoints with the
616 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
617 watchpoints are slower than real hardware watchpoints but are
618 significantly faster than gdb software watchpoints.
622 ** The register_pretty_printer function in module gdb.printing now takes
623 an optional `replace' argument. If True, the new printer replaces any
626 ** The "maint set python print-stack on|off" command has been
627 deprecated and will be deleted in GDB 7.5.
628 A new command: "set python print-stack none|full|message" has
629 replaced it. Additionally, the default for "print-stack" is
630 now "message", which just prints the error message without
633 ** A prompt substitution hook (prompt_hook) is now available to the
636 ** A new Python module, gdb.prompt has been added to the GDB Python
637 modules library. This module provides functionality for
638 escape sequences in prompts (used by set/show
639 extended-prompt). These escape sequences are replaced by their
642 ** Python commands and convenience-functions located in
643 'data-directory'/python/gdb/command and
644 'data-directory'/python/gdb/function are now automatically loaded
647 ** Blocks now provide four new attributes. global_block and
648 static_block will return the global and static blocks
649 respectively. is_static and is_global are boolean attributes
650 that indicate if the block is one of those two types.
652 ** Symbols now provide the "type" attribute, the type of the symbol.
654 ** The "gdb.breakpoint" function has been deprecated in favor of
657 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
658 of a function. This class is based on the "finish" command
659 available in the CLI.
661 ** Type objects for struct and union types now allow access to
662 the fields using standard Python dictionary (mapping) methods.
663 For example, "some_type['myfield']" now works, as does
666 ** A new event "gdb.new_objfile" has been added, triggered by loading a
669 ** A new function, "deep_items" has been added to the gdb.types
670 module in the GDB Python modules library. This function returns
671 an iterator over the fields of a struct or union type. Unlike
672 the standard Python "iteritems" method, it will recursively traverse
673 any anonymous fields.
677 ** "*stopped" events can report several new "reason"s, such as
680 ** Breakpoint changes are now notified using new async records, like
681 "=breakpoint-modified".
683 ** New command -ada-task-info.
685 * libthread-db-search-path now supports two special values: $sdir and $pdir.
686 $sdir specifies the default system locations of shared libraries.
687 $pdir specifies the directory where the libpthread used by the application
690 GDB no longer looks in $sdir and $pdir after it has searched the directories
691 mentioned in libthread-db-search-path. If you want to search those
692 directories, they must be specified in libthread-db-search-path.
693 The default value of libthread-db-search-path on GNU/Linux and Solaris
694 systems is now "$sdir:$pdir".
696 $pdir is not supported by gdbserver, it is currently ignored.
697 $sdir is supported by gdbserver.
699 * New configure option --with-iconv-bin.
700 When using the internationalization support like the one in the GNU C
701 library, GDB will invoke the "iconv" program to get a list of supported
702 character sets. If this program lives in a non-standard location, one can
703 use this option to specify where to find it.
705 * When natively debugging programs on PowerPC BookE processors running
706 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
707 watchpoints, which specify a mask in addition to an address to watch.
708 The mask specifies that some bits of an address (the bits which are
709 reset in the mask) should be ignored when matching the address accessed
710 by the inferior against the watchpoint address. See the "PowerPC Embedded"
711 section in the user manual for more details.
713 * The new option --once causes GDBserver to stop listening for connections once
714 the first connection is made. The listening port used by GDBserver will
715 become available after that.
717 * New commands "info macros" and "alias" have been added.
719 * New function parameters suffix @entry specifies value of function parameter
720 at the time the function got called. Entry values are available only since
726 "!" is now an alias of the "shell" command.
727 Note that no space is needed between "!" and SHELL COMMAND.
731 watch EXPRESSION mask MASK_VALUE
732 The watch command now supports the mask argument which allows creation
733 of masked watchpoints, if the current architecture supports this feature.
735 info auto-load-scripts [REGEXP]
736 This command was formerly named "maintenance print section-scripts".
737 It is now generally useful and is no longer a maintenance-only command.
739 info macro [-all] [--] MACRO
740 The info macro command has new options `-all' and `--'. The first for
741 printing all definitions of a macro. The second for explicitly specifying
742 the end of arguments and the beginning of the macro name in case the macro
743 name starts with a hyphen.
745 collect[/s] EXPRESSIONS
746 The tracepoint collect command now takes an optional modifier "/s"
747 that directs it to dereference pointer-to-character types and
748 collect the bytes of memory up to a zero byte. The behavior is
749 similar to what you see when you use the regular print command on a
750 string. An optional integer following the "/s" sets a bound on the
751 number of bytes that will be collected.
754 The trace start command now interprets any supplied arguments as a
755 note to be recorded with the trace run, with an effect similar to
756 setting the variable trace-notes.
759 The trace stop command now interprets any arguments as a note to be
760 mentioned along with the tstatus report that the trace was stopped
761 with a command. The effect is similar to setting the variable
764 * Tracepoints can now be enabled and disabled at any time after a trace
765 experiment has been started using the standard "enable" and "disable"
766 commands. It is now possible to start a trace experiment with no enabled
767 tracepoints; GDB will display a warning, but will allow the experiment to
768 begin, assuming that tracepoints will be enabled as needed while the trace
771 * Fast tracepoints on 32-bit x86-architectures can now be placed at
772 locations with 4-byte instructions, when they were previously
773 limited to locations with instructions of 5 bytes or longer.
777 set debug dwarf2-read
778 show debug dwarf2-read
779 Turns on or off display of debugging messages related to reading
780 DWARF debug info. The default is off.
782 set debug symtab-create
783 show debug symtab-create
784 Turns on or off display of debugging messages related to symbol table
785 creation. The default is off.
789 Set the GDB prompt, and allow escape sequences to be inserted to
790 display miscellaneous information (see 'help set extended-prompt'
791 for the list of sequences). This prompt (and any information
792 accessed through the escape sequences) is updated every time the
795 set print entry-values (both|compact|default|if-needed|no|only|preferred)
796 show print entry-values
797 Set printing of frame argument values at function entry. In some cases
798 GDB can determine the value of function argument which was passed by the
799 function caller, even if the value was modified inside the called function.
801 set debug entry-values
802 show debug entry-values
803 Control display of debugging info for determining frame argument values at
804 function entry and virtual tail call frames.
806 set basenames-may-differ
807 show basenames-may-differ
808 Set whether a source file may have multiple base names.
809 (A "base name" is the name of a file with the directory part removed.
810 Example: The base name of "/home/user/hello.c" is "hello.c".)
811 If set, GDB will canonicalize file names (e.g., expand symlinks)
812 before comparing them. Canonicalization is an expensive operation,
813 but it allows the same file be known by more than one base name.
814 If not set (the default), all source files are assumed to have just
815 one base name, and gdb will do file name comparisons more efficiently.
821 Set a user name and notes for the current and any future trace runs.
822 This is useful for long-running and/or disconnected traces, to
823 inform others (or yourself) as to who is running the trace, supply
824 contact information, or otherwise explain what is going on.
827 show trace-stop-notes
828 Set a note attached to the trace run, that is displayed when the
829 trace has been stopped by a tstop command. This is useful for
830 instance as an explanation, if you are stopping a trace run that was
831 started by someone else.
837 Dynamically enable a tracepoint in a started trace experiment.
841 Dynamically disable a tracepoint in a started trace experiment.
845 Set the user and notes of the trace run.
849 Query the current status of a tracepoint.
853 Query the minimum length of instruction at which a fast tracepoint may
856 * Dcache size (number of lines) and line-size are now runtime-configurable
857 via "set dcache line" and "set dcache line-size" commands.
861 Texas Instruments TMS320C6x tic6x-*-*
865 Renesas RL78 rl78-*-elf
867 *** Changes in GDB 7.3.1
869 * The build failure for NetBSD and OpenBSD targets have now been fixed.
871 *** Changes in GDB 7.3
873 * GDB has a new command: "thread find [REGEXP]".
874 It finds the thread id whose name, target id, or thread extra info
875 matches the given regular expression.
877 * The "catch syscall" command now works on mips*-linux* targets.
879 * The -data-disassemble MI command now supports modes 2 and 3 for
880 dumping the instruction opcodes.
882 * New command line options
884 -data-directory DIR Specify DIR as the "data-directory".
885 This is mostly for testing purposes.
887 * The "maint set python auto-load on|off" command has been renamed to
888 "set auto-load-scripts on|off".
890 * GDB has a new command: "set directories".
891 It is like the "dir" command except that it replaces the
892 source path list instead of augmenting it.
894 * GDB now understands thread names.
896 On GNU/Linux, "info threads" will display the thread name as set by
897 prctl or pthread_setname_np.
899 There is also a new command, "thread name", which can be used to
900 assign a name internally for GDB to display.
903 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
904 has been integrated into GDB.
908 ** The function gdb.Write now accepts an optional keyword 'stream'.
909 This keyword, when provided, will direct the output to either
910 stdout, stderr, or GDB's logging output.
912 ** Parameters can now be be sub-classed in Python, and in particular
913 you may implement the get_set_doc and get_show_doc functions.
914 This improves how Parameter set/show documentation is processed
915 and allows for more dynamic content.
917 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
918 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
919 have an is_valid method.
921 ** Breakpoints can now be sub-classed in Python, and in particular
922 you may implement a 'stop' function that is executed each time
923 the inferior reaches that breakpoint.
925 ** New function gdb.lookup_global_symbol looks up a global symbol.
927 ** GDB values in Python are now callable if the value represents a
928 function. For example, if 'some_value' represents a function that
929 takes two integer parameters and returns a value, you can call
930 that function like so:
932 result = some_value (10,20)
934 ** Module gdb.types has been added.
935 It contains a collection of utilities for working with gdb.Types objects:
936 get_basic_type, has_field, make_enum_dict.
938 ** Module gdb.printing has been added.
939 It contains utilities for writing and registering pretty-printers.
940 New classes: PrettyPrinter, SubPrettyPrinter,
941 RegexpCollectionPrettyPrinter.
942 New function: register_pretty_printer.
944 ** New commands "info pretty-printers", "enable pretty-printer" and
945 "disable pretty-printer" have been added.
947 ** gdb.parameter("directories") is now available.
949 ** New function gdb.newest_frame returns the newest frame in the
952 ** The gdb.InferiorThread class has a new "name" attribute. This
953 holds the thread's name.
955 ** Python Support for Inferior events.
956 Python scripts can add observers to be notified of events
957 occurring in the process being debugged.
958 The following events are currently supported:
959 - gdb.events.cont Continue event.
960 - gdb.events.exited Inferior exited event.
961 - gdb.events.stop Signal received, and Breakpoint hit events.
965 ** GDB now puts template parameters in scope when debugging in an
966 instantiation. For example, if you have:
968 template<int X> int func (void) { return X; }
970 then if you step into func<5>, "print X" will show "5". This
971 feature requires proper debuginfo support from the compiler; it
972 was added to GCC 4.5.
974 ** The motion commands "next", "finish", "until", and "advance" now
975 work better when exceptions are thrown. In particular, GDB will
976 no longer lose control of the inferior; instead, the GDB will
977 stop the inferior at the point at which the exception is caught.
978 This functionality requires a change in the exception handling
979 code that was introduced in GCC 4.5.
981 * GDB now follows GCC's rules on accessing volatile objects when
982 reading or writing target state during expression evaluation.
983 One notable difference to prior behavior is that "print x = 0"
984 no longer generates a read of x; the value of the assignment is
985 now always taken directly from the value being assigned.
987 * GDB now has some support for using labels in the program's source in
988 linespecs. For instance, you can use "advance label" to continue
989 execution to a label.
991 * GDB now has support for reading and writing a new .gdb_index
992 section. This section holds a fast index of DWARF debugging
993 information and can be used to greatly speed up GDB startup and
994 operation. See the documentation for `save gdb-index' for details.
996 * The "watch" command now accepts an optional "-location" argument.
997 When used, this causes GDB to watch the memory referred to by the
998 expression. Such a watchpoint is never deleted due to it going out
1001 * GDB now supports thread debugging of core dumps on GNU/Linux.
1003 GDB now activates thread debugging using the libthread_db library
1004 when debugging GNU/Linux core dumps, similarly to when debugging
1005 live processes. As a result, when debugging a core dump file, GDB
1006 is now able to display pthread_t ids of threads. For example, "info
1007 threads" shows the same output as when debugging the process when it
1008 was live. In earlier releases, you'd see something like this:
1011 * 1 LWP 6780 main () at main.c:10
1013 While now you see this:
1016 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1018 It is also now possible to inspect TLS variables when debugging core
1021 When debugging a core dump generated on a machine other than the one
1022 used to run GDB, you may need to point GDB at the correct
1023 libthread_db library with the "set libthread-db-search-path"
1024 command. See the user manual for more details on this command.
1026 * When natively debugging programs on PowerPC BookE processors running
1027 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1028 which stop execution of the inferior whenever it executes an instruction
1029 at any address within the specified range. See the "PowerPC Embedded"
1030 section in the user manual for more details.
1032 * New features in the GDB remote stub, GDBserver
1034 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1035 and i686 LynxOS (version 5.x).
1037 ** GDBserver is now supported on Blackfin Linux.
1039 * New native configurations
1041 ia64 HP-UX ia64-*-hpux*
1045 Analog Devices, Inc. Blackfin Processor bfin-*
1047 * Ada task switching is now supported on sparc-elf targets when
1048 debugging a program using the Ravenscar Profile. For more information,
1049 see the "Tasking Support when using the Ravenscar Profile" section
1050 in the GDB user manual.
1052 * Guile support was removed.
1054 * New features in the GNU simulator
1056 ** The --map-info flag lists all known core mappings.
1058 ** CFI flashes may be simulated via the "cfi" device.
1060 *** Changes in GDB 7.2
1062 * Shared library support for remote targets by default
1064 When GDB is configured for a generic, non-OS specific target, like
1065 for example, --target=arm-eabi or one of the many *-*-elf targets,
1066 GDB now queries remote stubs for loaded shared libraries using the
1067 `qXfer:libraries:read' packet. Previously, shared library support
1068 was always disabled for such configurations.
1072 ** Argument Dependent Lookup (ADL)
1074 In C++ ADL lookup directs function search to the namespaces of its
1075 arguments even if the namespace has not been imported.
1085 Here the compiler will search for `foo' in the namespace of 'b'
1086 and find A::foo. GDB now supports this. This construct is commonly
1087 used in the Standard Template Library for operators.
1089 ** Improved User Defined Operator Support
1091 In addition to member operators, GDB now supports lookup of operators
1092 defined in a namespace and imported with a `using' directive, operators
1093 defined in the global scope, operators imported implicitly from an
1094 anonymous namespace, and the ADL operators mentioned in the previous
1096 GDB now also supports proper overload resolution for all the previously
1097 mentioned flavors of operators.
1099 ** static const class members
1101 Printing of static const class members that are initialized in the
1102 class definition has been fixed.
1104 * Windows Thread Information Block access.
1106 On Windows targets, GDB now supports displaying the Windows Thread
1107 Information Block (TIB) structure. This structure is visible either
1108 by using the new command `info w32 thread-information-block' or, by
1109 dereferencing the new convenience variable named `$_tlb', a
1110 thread-specific pointer to the TIB. This feature is also supported
1111 when remote debugging using GDBserver.
1113 * Static tracepoints
1115 Static tracepoints are calls in the user program into a tracing
1116 library. One such library is a port of the LTTng kernel tracer to
1117 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1118 When debugging with GDBserver, GDB now supports combining the GDB
1119 tracepoint machinery with such libraries. For example: the user can
1120 use GDB to probe a static tracepoint marker (a call from the user
1121 program into the tracing library) with the new "strace" command (see
1122 "New commands" below). This creates a "static tracepoint" in the
1123 breakpoint list, that can be manipulated with the same feature set
1124 as fast and regular tracepoints. E.g., collect registers, local and
1125 global variables, collect trace state variables, and define
1126 tracepoint conditions. In addition, the user can collect extra
1127 static tracepoint marker specific data, by collecting the new
1128 $_sdata internal variable. When analyzing the trace buffer, you can
1129 inspect $_sdata like any other variable available to GDB. For more
1130 information, see the "Tracepoints" chapter in GDB user manual. New
1131 remote packets have been defined to support static tracepoints, see
1132 the "New remote packets" section below.
1134 * Better reconstruction of tracepoints after disconnected tracing
1136 GDB will attempt to download the original source form of tracepoint
1137 definitions when starting a trace run, and then will upload these
1138 upon reconnection to the target, resulting in a more accurate
1139 reconstruction of the tracepoints that are in use on the target.
1143 You can now exercise direct control over the ways that GDB can
1144 affect your program. For instance, you can disallow the setting of
1145 breakpoints, so that the program can run continuously (assuming
1146 non-stop mode). In addition, the "observer" variable is available
1147 to switch all of the different controls; in observer mode, GDB
1148 cannot affect the target's behavior at all, which is useful for
1149 tasks like diagnosing live systems in the field.
1151 * The new convenience variable $_thread holds the number of the
1154 * New remote packets
1158 Return the address of the Windows Thread Information Block of a given thread.
1162 In response to several of the tracepoint packets, the target may now
1163 also respond with a number of intermediate `qRelocInsn' request
1164 packets before the final result packet, to have GDB handle
1165 relocating an instruction to execute at a different address. This
1166 is particularly useful for stubs that support fast tracepoints. GDB
1167 reports support for this feature in the qSupported packet.
1171 List static tracepoint markers in the target program.
1175 List static tracepoint markers at a given address in the target
1178 qXfer:statictrace:read
1180 Read the static trace data collected (by a `collect $_sdata'
1181 tracepoint action). The remote stub reports support for this packet
1182 to gdb's qSupported query.
1186 Send the current settings of GDB's permission flags.
1190 Send part of the source (textual) form of a tracepoint definition,
1191 which includes location, conditional, and action list.
1193 * The source command now accepts a -s option to force searching for the
1194 script in the source search path even if the script name specifies
1197 * New features in the GDB remote stub, GDBserver
1199 - GDBserver now support tracepoints (including fast tracepoints, and
1200 static tracepoints). The feature is currently supported by the
1201 i386-linux and amd64-linux builds. See the "Tracepoints support
1202 in gdbserver" section in the manual for more information.
1204 GDBserver JIT compiles the tracepoint's conditional agent
1205 expression bytecode into native code whenever possible for low
1206 overhead dynamic tracepoints conditionals. For such tracepoints,
1207 an expression that examines program state is evaluated when the
1208 tracepoint is reached, in order to determine whether to capture
1209 trace data. If the condition is simple and false, processing the
1210 tracepoint finishes very quickly and no data is gathered.
1212 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1213 for static tracepoints support.
1215 - GDBserver now supports x86_64 Windows 64-bit debugging.
1217 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1218 it understands register description.
1220 * The --batch flag now disables pagination and queries.
1222 * X86 general purpose registers
1224 GDB now supports reading/writing byte, word and double-word x86
1225 general purpose registers directly. This means you can use, say,
1226 $ah or $ax to refer, respectively, to the byte register AH and
1227 16-bit word register AX that are actually portions of the 32-bit
1228 register EAX or 64-bit register RAX.
1230 * The `commands' command now accepts a range of breakpoints to modify.
1231 A plain `commands' following a command that creates multiple
1232 breakpoints affects all the breakpoints set by that command. This
1233 applies to breakpoints set by `rbreak', and also applies when a
1234 single `break' command creates multiple breakpoints (e.g.,
1235 breakpoints on overloaded c++ functions).
1237 * The `rbreak' command now accepts a filename specification as part of
1238 its argument, limiting the functions selected by the regex to those
1239 in the specified file.
1241 * Support for remote debugging Windows and SymbianOS shared libraries
1242 from Unix hosts has been improved. Non Windows GDB builds now can
1243 understand target reported file names that follow MS-DOS based file
1244 system semantics, such as file names that include drive letters and
1245 use the backslash character as directory separator. This makes it
1246 possible to transparently use the "set sysroot" and "set
1247 solib-search-path" on Unix hosts to point as host copies of the
1248 target's shared libraries. See the new command "set
1249 target-file-system-kind" described below, and the "Commands to
1250 specify files" section in the user manual for more information.
1254 eval template, expressions...
1255 Convert the values of one or more expressions under the control
1256 of the string template to a command line, and call it.
1258 set target-file-system-kind unix|dos-based|auto
1259 show target-file-system-kind
1260 Set or show the assumed file system kind for target reported file
1263 save breakpoints <filename>
1264 Save all current breakpoint definitions to a file suitable for use
1265 in a later debugging session. To read the saved breakpoint
1266 definitions, use the `source' command.
1268 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1271 info static-tracepoint-markers
1272 Display information about static tracepoint markers in the target.
1274 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1275 Define a static tracepoint by probing a marker at the given
1276 function, line, address, or marker ID.
1280 Enable and disable observer mode.
1282 set may-write-registers on|off
1283 set may-write-memory on|off
1284 set may-insert-breakpoints on|off
1285 set may-insert-tracepoints on|off
1286 set may-insert-fast-tracepoints on|off
1287 set may-interrupt on|off
1288 Set individual permissions for GDB effects on the target. Note that
1289 some of these settings can have undesirable or surprising
1290 consequences, particularly when changed in the middle of a session.
1291 For instance, disabling the writing of memory can prevent
1292 breakpoints from being inserted, cause single-stepping to fail, or
1293 even crash your program, if you disable after breakpoints have been
1294 inserted. However, GDB should not crash.
1296 set record memory-query on|off
1297 show record memory-query
1298 Control whether to stop the inferior if memory changes caused
1299 by an instruction cannot be recorded.
1304 The disassemble command now supports "start,+length" form of two arguments.
1308 ** GDB now provides a new directory location, called the python directory,
1309 where Python scripts written for GDB can be installed. The location
1310 of that directory is <data-directory>/python, where <data-directory>
1311 is the GDB data directory. For more details, see section `Scripting
1312 GDB using Python' in the manual.
1314 ** The GDB Python API now has access to breakpoints, symbols, symbol
1315 tables, program spaces, inferiors, threads and frame's code blocks.
1316 Additionally, GDB Parameters can now be created from the API, and
1317 manipulated via set/show in the CLI.
1319 ** New functions gdb.target_charset, gdb.target_wide_charset,
1320 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1322 ** New exception gdb.GdbError.
1324 ** Pretty-printers are now also looked up in the current program space.
1326 ** Pretty-printers can now be individually enabled and disabled.
1328 ** GDB now looks for names of Python scripts to auto-load in a
1329 special section named `.debug_gdb_scripts', in addition to looking
1330 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1332 * Tracepoint actions were unified with breakpoint commands. In particular,
1333 there are no longer differences in "info break" output for breakpoints and
1334 tracepoints and the "commands" command can be used for both tracepoints and
1335 regular breakpoints.
1339 ARM Symbian arm*-*-symbianelf*
1341 * D language support.
1342 GDB now supports debugging programs written in the D programming
1345 * GDB now supports the extended ptrace interface for PowerPC which is
1346 available since Linux kernel version 2.6.34. This automatically enables
1347 any hardware breakpoints and additional hardware watchpoints available in
1348 the processor. The old ptrace interface exposes just one hardware
1349 watchpoint and no hardware breakpoints.
1351 * GDB is now able to use the Data Value Compare (DVC) register available on
1352 embedded PowerPC processors to implement in hardware simple watchpoint
1353 conditions of the form:
1355 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1357 This works in native GDB running on Linux kernels with the extended ptrace
1358 interface mentioned above.
1360 *** Changes in GDB 7.1
1364 ** Namespace Support
1366 GDB now supports importing of namespaces in C++. This enables the
1367 user to inspect variables from imported namespaces. Support for
1368 namepace aliasing has also been added. So, if a namespace is
1369 aliased in the current scope (e.g. namepace C=A; ) the user can
1370 print variables using the alias (e.g. (gdb) print C::x).
1374 All known bugs relating to the printing of virtual base class were
1375 fixed. It is now possible to call overloaded static methods using a
1380 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1381 and reinterpret_cast<> are now handled by the C++ expression parser.
1385 Xilinx MicroBlaze microblaze-*-*
1390 Xilinx MicroBlaze microblaze
1393 * Multi-program debugging.
1395 GDB now has support for multi-program (a.k.a. multi-executable or
1396 multi-exec) debugging. This allows for debugging multiple inferiors
1397 simultaneously each running a different program under the same GDB
1398 session. See "Debugging Multiple Inferiors and Programs" in the
1399 manual for more information. This implied some user visible changes
1400 in the multi-inferior support. For example, "info inferiors" now
1401 lists inferiors that are not running yet or that have exited
1402 already. See also "New commands" and "New options" below.
1404 * New tracing features
1406 GDB's tracepoint facility now includes several new features:
1408 ** Trace state variables
1410 GDB tracepoints now include support for trace state variables, which
1411 are variables managed by the target agent during a tracing
1412 experiment. They are useful for tracepoints that trigger each
1413 other, so for instance one tracepoint can count hits in a variable,
1414 and then a second tracepoint has a condition that is true when the
1415 count reaches a particular value. Trace state variables share the
1416 $-syntax of GDB convenience variables, and can appear in both
1417 tracepoint actions and condition expressions. Use the "tvariable"
1418 command to create, and "info tvariables" to view; see "Trace State
1419 Variables" in the manual for more detail.
1423 GDB now includes an option for defining fast tracepoints, which
1424 targets may implement more efficiently, such as by installing a jump
1425 into the target agent rather than a trap instruction. The resulting
1426 speedup can be by two orders of magnitude or more, although the
1427 tradeoff is that some program locations on some target architectures
1428 might not allow fast tracepoint installation, for instance if the
1429 instruction to be replaced is shorter than the jump. To request a
1430 fast tracepoint, use the "ftrace" command, with syntax identical to
1431 the regular trace command.
1433 ** Disconnected tracing
1435 It is now possible to detach GDB from the target while it is running
1436 a trace experiment, then reconnect later to see how the experiment
1437 is going. In addition, a new variable disconnected-tracing lets you
1438 tell the target agent whether to continue running a trace if the
1439 connection is lost unexpectedly.
1443 GDB now has the ability to save the trace buffer into a file, and
1444 then use that file as a target, similarly to you can do with
1445 corefiles. You can select trace frames, print data that was
1446 collected in them, and use tstatus to display the state of the
1447 tracing run at the moment that it was saved. To create a trace
1448 file, use "tsave <filename>", and to use it, do "target tfile
1451 ** Circular trace buffer
1453 You can ask the target agent to handle the trace buffer as a
1454 circular buffer, discarding the oldest trace frames to make room for
1455 newer ones, by setting circular-trace-buffer to on. This feature may
1456 not be available for all target agents.
1461 The disassemble command, when invoked with two arguments, now requires
1462 the arguments to be comma-separated.
1465 The info variables command now displays variable definitions. Files
1466 which only declare a variable are not shown.
1469 The source command is now capable of sourcing Python scripts.
1470 This feature is dependent on the debugger being build with Python
1473 Related to this enhancement is also the introduction of a new command
1474 "set script-extension" (see below).
1476 * New commands (for set/show, see "New options" below)
1478 record save [<FILENAME>]
1479 Save a file (in core file format) containing the process record
1480 execution log for replay debugging at a later time.
1482 record restore <FILENAME>
1483 Restore the process record execution log that was saved at an
1484 earlier time, for replay debugging.
1486 add-inferior [-copies <N>] [-exec <FILENAME>]
1489 clone-inferior [-copies <N>] [ID]
1490 Make a new inferior ready to execute the same program another
1491 inferior has loaded.
1496 maint info program-spaces
1497 List the program spaces loaded into GDB.
1499 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1500 show remote interrupt-sequence
1501 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1502 as the sequence to the remote target in order to interrupt the execution.
1503 Ctrl-C is a default. Some system prefers BREAK which is high level of
1504 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1505 Magic SysRq g. It is BREAK signal and character 'g'.
1507 set remote interrupt-on-connect [on | off]
1508 show remote interrupt-on-connect
1509 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1510 remote target when gdb connects to it. This is needed when you debug
1513 set remotebreak [on | off]
1515 Deprecated. Use "set/show remote interrupt-sequence" instead.
1517 tvariable $NAME [ = EXP ]
1518 Create or modify a trace state variable.
1521 List trace state variables and their values.
1523 delete tvariable $NAME ...
1524 Delete one or more trace state variables.
1527 Evaluate the given expressions without collecting anything into the
1528 trace buffer. (Valid in tracepoint actions only.)
1530 ftrace FN / FILE:LINE / *ADDR
1531 Define a fast tracepoint at the given function, line, or address.
1533 * New expression syntax
1535 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1536 GDB now parses 0b101010 identically with 42.
1540 set follow-exec-mode new|same
1541 show follow-exec-mode
1542 Control whether GDB reuses the same inferior across an exec call or
1543 creates a new one. This is useful to be able to restart the old
1544 executable after the inferior having done an exec call.
1546 set default-collect EXPR, ...
1547 show default-collect
1548 Define a list of expressions to be collected at each tracepoint.
1549 This is a useful way to ensure essential items are not overlooked,
1550 such as registers or a critical global variable.
1552 set disconnected-tracing
1553 show disconnected-tracing
1554 If set to 1, the target is instructed to continue tracing if it
1555 loses its connection to GDB. If 0, the target is to stop tracing
1558 set circular-trace-buffer
1559 show circular-trace-buffer
1560 If set to on, the target is instructed to use a circular trace buffer
1561 and discard the oldest trace frames instead of stopping the trace due
1562 to a full trace buffer. If set to off, the trace stops when the buffer
1563 fills up. Some targets may not support this.
1565 set script-extension off|soft|strict
1566 show script-extension
1567 If set to "off", the debugger does not perform any script language
1568 recognition, and all sourced files are assumed to be GDB scripts.
1569 If set to "soft" (the default), files are sourced according to
1570 filename extension, falling back to GDB scripts if the first
1572 If set to "strict", files are sourced according to filename extension.
1574 set ada trust-PAD-over-XVS on|off
1575 show ada trust-PAD-over-XVS
1576 If off, activate a workaround against a bug in the debugging information
1577 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1578 the GCC sources for more information about the GNAT encoding and
1579 PAD types in particular). It is always safe to set this option to
1580 off, but this introduces a slight performance penalty. The default
1583 * Python API Improvements
1585 ** GDB provides the new class gdb.LazyString. This is useful in
1586 some pretty-printing cases. The new method gdb.Value.lazy_string
1587 provides a simple way to create objects of this type.
1589 ** The fields returned by gdb.Type.fields now have an
1590 `is_base_class' attribute.
1592 ** The new method gdb.Type.range returns the range of an array type.
1594 ** The new method gdb.parse_and_eval can be used to parse and
1595 evaluate an expression.
1597 * New remote packets
1600 Define a trace state variable.
1603 Get the current value of a trace state variable.
1606 Set desired tracing behavior upon disconnection.
1609 Set the trace buffer to be linear or circular.
1612 Get data about the tracepoints currently in use.
1616 Process record now works correctly with hardware watchpoints.
1618 Multiple bug fixes have been made to the mips-irix port, making it
1619 much more reliable. In particular:
1620 - Debugging threaded applications is now possible again. Previously,
1621 GDB would hang while starting the program, or while waiting for
1622 the program to stop at a breakpoint.
1623 - Attaching to a running process no longer hangs.
1624 - An error occurring while loading a core file has been fixed.
1625 - Changing the value of the PC register now works again. This fixes
1626 problems observed when using the "jump" command, or when calling
1627 a function from GDB, or even when assigning a new value to $pc.
1628 - With the "finish" and "return" commands, the return value for functions
1629 returning a small array is now correctly printed.
1630 - It is now possible to break on shared library code which gets executed
1631 during a shared library init phase (code executed while executing
1632 their .init section). Previously, the breakpoint would have no effect.
1633 - GDB is now able to backtrace through the signal handler for
1634 non-threaded programs.
1636 PIE (Position Independent Executable) programs debugging is now supported.
1637 This includes debugging execution of PIC (Position Independent Code) shared
1638 libraries although for that, it should be possible to run such libraries as an
1641 *** Changes in GDB 7.0
1643 * GDB now has an interface for JIT compilation. Applications that
1644 dynamically generate code can create symbol files in memory and register
1645 them with GDB. For users, the feature should work transparently, and
1646 for JIT developers, the interface is documented in the GDB manual in the
1647 "JIT Compilation Interface" chapter.
1649 * Tracepoints may now be conditional. The syntax is as for
1650 breakpoints; either an "if" clause appended to the "trace" command,
1651 or the "condition" command is available. GDB sends the condition to
1652 the target for evaluation using the same bytecode format as is used
1653 for tracepoint actions.
1655 * The disassemble command now supports: an optional /r modifier, print the
1656 raw instructions in hex as well as in symbolic form, and an optional /m
1657 modifier to print mixed source+assembly.
1659 * Process record and replay
1661 In a architecture environment that supports ``process record and
1662 replay'', ``process record and replay'' target can record a log of
1663 the process execution, and replay it with both forward and reverse
1666 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
1667 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
1668 set execution-direction {forward|reverse}, for targets that support
1671 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
1672 feature is available with a native GDB running on kernel version
1675 * GDB now has support for multi-byte and wide character sets on the
1676 target. Strings whose character type is wchar_t, char16_t, or
1677 char32_t are now correctly printed. GDB supports wide- and unicode-
1678 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
1679 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
1680 `printf'. This feature requires iconv to work properly; if your
1681 system does not have a working iconv, GDB can use GNU libiconv. See
1682 the installation instructions for more information.
1684 * GDB now supports automatic retrieval of shared library files from
1685 remote targets. To use this feature, specify a system root that begins
1686 with the `remote:' prefix, either via the `set sysroot' command or via
1687 the `--with-sysroot' configure-time option.
1689 * "info sharedlibrary" now takes an optional regex of libraries to show,
1690 and it now reports if a shared library has no debugging information.
1692 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
1693 now complete on file names.
1695 * When completing in expressions, gdb will attempt to limit
1696 completions to allowable structure or union fields, where appropriate.
1697 For instance, consider:
1699 # struct example { int f1; double f2; };
1700 # struct example variable;
1703 If the user types TAB at the end of this command line, the available
1704 completions will be "f1" and "f2".
1706 * Inlined functions are now supported. They show up in backtraces, and
1707 the "step", "next", and "finish" commands handle them automatically.
1709 * GDB now supports the token-splicing (##) and stringification (#)
1710 operators when expanding macros. It also supports variable-arity
1713 * GDB now supports inspecting extra signal information, exported by
1714 the new $_siginfo convenience variable. The feature is currently
1715 implemented on linux ARM, i386 and amd64.
1717 * GDB can now display the VFP floating point registers and NEON vector
1718 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
1719 can provide these registers (requires Linux 2.6.30 or later). Remote
1720 and simulator targets may also provide them.
1722 * New remote packets
1725 Search memory for a sequence of bytes.
1728 Turn off `+'/`-' protocol acknowledgments to permit more efficient
1729 operation over reliable transport links. Use of this packet is
1730 controlled by the `set remote noack-packet' command.
1733 Kill the process with the specified process ID. Use this in preference
1734 to `k' when multiprocess protocol extensions are supported.
1737 Obtains additional operating system information
1741 Read or write additional signal information.
1743 * Removed remote protocol undocumented extension
1745 An undocumented extension to the remote protocol's `S' stop reply
1746 packet that permited the stub to pass a process id was removed.
1747 Remote servers should use the `T' stop reply packet instead.
1749 * GDB now supports multiple function calling conventions according to the
1750 DWARF-2 DW_AT_calling_convention function attribute.
1752 * The SH target utilizes the aforementioned change to distinguish between gcc
1753 and Renesas calling convention. It also adds the new CLI commands
1754 `set/show sh calling-convention'.
1756 * GDB can now read compressed debug sections, as produced by GNU gold
1757 with the --compress-debug-sections=zlib flag.
1759 * 64-bit core files are now supported on AIX.
1761 * Thread switching is now supported on Tru64.
1763 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
1764 which will be allocated using malloc later in program execution.
1766 * The qXfer:libraries:read remote procotol packet now allows passing a
1767 list of section offsets.
1769 * On GNU/Linux, GDB can now attach to stopped processes. Several race
1770 conditions handling signals delivered during attach or thread creation
1771 have also been fixed.
1773 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
1774 From the user's standpoint, all unqualified instances of True and False
1775 are treated as the standard definitions, regardless of context.
1777 * GDB now parses C++ symbol and type names more flexibly. For
1780 template<typename T> class C { };
1783 GDB will now correctly handle all of:
1785 ptype C<char const *>
1786 ptype C<char const*>
1787 ptype C<const char *>
1788 ptype C<const char*>
1790 * New features in the GDB remote stub, gdbserver
1792 - The "--wrapper" command-line argument tells gdbserver to use a
1793 wrapper program to launch programs for debugging.
1795 - On PowerPC and S/390 targets, it is now possible to use a single
1796 gdbserver executable to debug both 32-bit and 64-bit programs.
1797 (This requires gdbserver itself to be built as a 64-bit executable.)
1799 - gdbserver uses the new noack protocol mode for TCP connections to
1800 reduce communications latency, if also supported and enabled in GDB.
1802 - Support for the sparc64-linux-gnu target is now included in
1805 - The amd64-linux build of gdbserver now supports debugging both
1806 32-bit and 64-bit programs.
1808 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
1809 now support hardware watchpoints, and will use them automatically
1814 GDB now has support for scripting using Python. Whether this is
1815 available is determined at configure time.
1817 New GDB commands can now be written in Python.
1819 * Ada tasking support
1821 Ada tasks can now be inspected in GDB. The following commands have
1825 Print the list of Ada tasks.
1827 Print detailed information about task number N.
1829 Print the task number of the current task.
1831 Switch the context of debugging to task number N.
1833 * Support for user-defined prefixed commands. The "define" command can
1834 add new commands to existing prefixes, e.g. "target".
1836 * Multi-inferior, multi-process debugging.
1838 GDB now has generalized support for multi-inferior debugging. See
1839 "Debugging Multiple Inferiors" in the manual for more information.
1840 Although availability still depends on target support, the command
1841 set is more uniform now. The GNU/Linux specific multi-forks support
1842 has been migrated to this new framework. This implied some user
1843 visible changes; see "New commands" and also "Removed commands"
1846 * Target descriptions can now describe the target OS ABI. See the
1847 "Target Description Format" section in the user manual for more
1850 * Target descriptions can now describe "compatible" architectures
1851 to indicate that the target can execute applications for a different
1852 architecture in addition to those for the main target architecture.
1853 See the "Target Description Format" section in the user manual for
1856 * Multi-architecture debugging.
1858 GDB now includes general supports for debugging applications on
1859 hybrid systems that use more than one single processor architecture
1860 at the same time. Each such hybrid architecture still requires
1861 specific support to be added. The only hybrid architecture supported
1862 in this version of GDB is the Cell Broadband Engine.
1864 * GDB now supports integrated debugging of Cell/B.E. applications that
1865 use both the PPU and SPU architectures. To enable support for hybrid
1866 Cell/B.E. debugging, you need to configure GDB to support both the
1867 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
1868 --enable-targets configure option.
1870 * Non-stop mode debugging.
1872 For some targets, GDB now supports an optional mode of operation in
1873 which you can examine stopped threads while other threads continue
1874 to execute freely. This is referred to as non-stop mode, with the
1875 old mode referred to as all-stop mode. See the "Non-Stop Mode"
1876 section in the user manual for more information.
1878 To be able to support remote non-stop debugging, a remote stub needs
1879 to implement the non-stop mode remote protocol extensions, as
1880 described in the "Remote Non-Stop" section of the user manual. The
1881 GDB remote stub, gdbserver, has been adjusted to support these
1882 extensions on linux targets.
1884 * New commands (for set/show, see "New options" below)
1886 catch syscall [NAME(S) | NUMBER(S)]
1887 Catch system calls. Arguments, which should be names of system
1888 calls or their numbers, mean catch only those syscalls. Without
1889 arguments, every syscall will be caught. When the inferior issues
1890 any of the specified syscalls, GDB will stop and announce the system
1891 call, both when it is called and when its call returns. This
1892 feature is currently available with a native GDB running on the
1893 Linux Kernel, under the following architectures: x86, x86_64,
1894 PowerPC and PowerPC64.
1896 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
1898 Search memory for a sequence of bytes.
1900 maint set python print-stack
1901 maint show python print-stack
1902 Show a stack trace when an error is encountered in a Python script.
1905 Invoke CODE by passing it to the Python interpreter.
1910 These allow macros to be defined, undefined, and listed
1914 Show operating system information about processes.
1917 List the inferiors currently under GDB's control.
1920 Switch focus to inferior number NUM.
1923 Detach from inferior number NUM.
1926 Kill inferior number NUM.
1930 set spu stop-on-load
1931 show spu stop-on-load
1932 Control whether to stop for new SPE threads during Cell/B.E. debugging.
1934 set spu auto-flush-cache
1935 show spu auto-flush-cache
1936 Control whether to automatically flush the software-managed cache
1937 during Cell/B.E. debugging.
1939 set sh calling-convention
1940 show sh calling-convention
1941 Control the calling convention used when calling SH target functions.
1944 show debug timestamp
1945 Control display of timestamps with GDB debugging output.
1947 set disassemble-next-line
1948 show disassemble-next-line
1949 Control display of disassembled source lines or instructions when
1952 set remote noack-packet
1953 show remote noack-packet
1954 Set/show the use of remote protocol QStartNoAckMode packet. See above
1955 under "New remote packets."
1957 set remote query-attached-packet
1958 show remote query-attached-packet
1959 Control use of remote protocol `qAttached' (query-attached) packet.
1961 set remote read-siginfo-object
1962 show remote read-siginfo-object
1963 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
1966 set remote write-siginfo-object
1967 show remote write-siginfo-object
1968 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
1971 set remote reverse-continue
1972 show remote reverse-continue
1973 Control use of remote protocol 'bc' (reverse-continue) packet.
1975 set remote reverse-step
1976 show remote reverse-step
1977 Control use of remote protocol 'bs' (reverse-step) packet.
1979 set displaced-stepping
1980 show displaced-stepping
1981 Control displaced stepping mode. Displaced stepping is a way to
1982 single-step over breakpoints without removing them from the debuggee.
1983 Also known as "out-of-line single-stepping".
1986 show debug displaced
1987 Control display of debugging info for displaced stepping.
1989 maint set internal-error
1990 maint show internal-error
1991 Control what GDB does when an internal error is detected.
1993 maint set internal-warning
1994 maint show internal-warning
1995 Control what GDB does when an internal warning is detected.
2000 Use a wrapper program to launch programs for debugging.
2002 set multiple-symbols (all|ask|cancel)
2003 show multiple-symbols
2004 The value of this variable can be changed to adjust the debugger behavior
2005 when an expression or a breakpoint location contains an ambiguous symbol
2006 name (an overloaded function name, for instance).
2008 set breakpoint always-inserted
2009 show breakpoint always-inserted
2010 Keep breakpoints always inserted in the target, as opposed to inserting
2011 them when resuming the target, and removing them when the target stops.
2012 This option can improve debugger performance on slow remote targets.
2014 set arm fallback-mode (arm|thumb|auto)
2015 show arm fallback-mode
2016 set arm force-mode (arm|thumb|auto)
2018 These commands control how ARM GDB determines whether instructions
2019 are ARM or Thumb. The default for both settings is auto, which uses
2020 the current CPSR value for instructions without symbols; previous
2021 versions of GDB behaved as if "set arm fallback-mode arm".
2023 set disable-randomization
2024 show disable-randomization
2025 Standalone programs run with the virtual address space randomization enabled
2026 by default on some platforms. This option keeps the addresses stable across
2027 multiple debugging sessions.
2031 Control whether other threads are stopped or not when some thread hits
2036 Requests that asynchronous execution is enabled in the target, if available.
2037 In this case, it's possible to resume target in the background, and interact
2038 with GDB while the target is running. "show target-async" displays the
2039 current state of asynchronous execution of the target.
2041 set target-wide-charset
2042 show target-wide-charset
2043 The target-wide-charset is the name of the character set that GDB
2044 uses when printing characters whose type is wchar_t.
2046 set tcp auto-retry (on|off)
2048 set tcp connect-timeout
2049 show tcp connect-timeout
2050 These commands allow GDB to retry failed TCP connections to a remote stub
2051 with a specified timeout period; this is useful if the stub is launched
2052 in parallel with GDB but may not be ready to accept connections immediately.
2054 set libthread-db-search-path
2055 show libthread-db-search-path
2056 Control list of directories which GDB will search for appropriate
2059 set schedule-multiple (on|off)
2060 show schedule-multiple
2061 Allow GDB to resume all threads of all processes or only threads of
2062 the current process.
2066 Use more aggressive caching for accesses to the stack. This improves
2067 performance of remote debugging (particularly backtraces) without
2068 affecting correctness.
2070 set interactive-mode (on|off|auto)
2071 show interactive-mode
2072 Control whether GDB runs in interactive mode (on) or not (off).
2073 When in interactive mode, GDB waits for the user to answer all
2074 queries. Otherwise, GDB does not wait and assumes the default
2075 answer. When set to auto (the default), GDB determines which
2076 mode to use based on the stdin settings.
2081 For program forks, this is replaced by the new more generic `info
2082 inferiors' command. To list checkpoints, you can still use the
2083 `info checkpoints' command, which was an alias for the `info forks'
2087 Replaced by the new `inferior' command. To switch between
2088 checkpoints, you can still use the `restart' command, which was an
2089 alias for the `fork' command.
2092 This is removed, since some targets don't have a notion of
2093 processes. To switch between processes, you can still use the
2094 `inferior' command using GDB's own inferior number.
2097 For program forks, this is replaced by the new more generic `kill
2098 inferior' command. To delete a checkpoint, you can still use the
2099 `delete checkpoint' command, which was an alias for the `delete
2103 For program forks, this is replaced by the new more generic `detach
2104 inferior' command. To detach a checkpoint, you can still use the
2105 `detach checkpoint' command, which was an alias for the `detach
2108 * New native configurations
2110 x86/x86_64 Darwin i[34567]86-*-darwin*
2112 x86_64 MinGW x86_64-*-mingw*
2116 Lattice Mico32 lm32-*
2117 x86 DICOS i[34567]86-*-dicos*
2118 x86_64 DICOS x86_64-*-dicos*
2121 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2122 (mingw32ce) debugging.
2128 These commands were actually not implemented on any target.
2130 *** Changes in GDB 6.8
2132 * New native configurations
2134 NetBSD/hppa hppa*-*netbsd*
2135 Xtensa GNU/Linux xtensa*-*-linux*
2139 NetBSD/hppa hppa*-*-netbsd*
2140 Xtensa GNU/Lunux xtensa*-*-linux*
2142 * Change in command line behavior -- corefiles vs. process ids.
2144 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2145 attaching to process NUMBER fails, GDB no longer attempts to open a
2146 core file named NUMBER. Attaching to a program using the -c option
2147 is no longer supported. Instead, use the '-p' or '--pid' options.
2149 * GDB can now be built as a native debugger for debugging Windows x86
2150 (mingw32) Portable Executable (PE) programs.
2152 * Pending breakpoints no longer change their number when their address
2155 * GDB now supports breakpoints with multiple locations,
2156 including breakpoints on C++ constructors, inside C++ templates,
2157 and in inlined functions.
2159 * GDB's ability to debug optimized code has been improved. GDB more
2160 accurately identifies function bodies and lexical blocks that occupy
2161 more than one contiguous range of addresses.
2163 * Target descriptions can now describe registers for PowerPC.
2165 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2166 registers on PowerPC targets.
2168 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2169 targets even when the libthread_db library is not available.
2171 * The GDB remote stub, gdbserver, now supports the new file transfer
2172 commands (remote put, remote get, and remote delete).
2174 * The GDB remote stub, gdbserver, now supports run and attach in
2175 extended-remote mode.
2177 * hppa*64*-*-hpux11* target broken
2178 The debugger is unable to start a program and fails with the following
2179 error: "Error trying to get information about dynamic linker".
2180 The gdb-6.7 release is also affected.
2182 * GDB now supports the --enable-targets= configure option to allow
2183 building a single GDB executable that supports multiple remote
2184 target architectures.
2186 * GDB now supports debugging C and C++ programs which use the
2187 Decimal Floating Point extension. In addition, the PowerPC target
2188 now has a set of pseudo-registers to inspect decimal float values
2189 stored in two consecutive float registers.
2191 * The -break-insert MI command can optionally create pending
2194 * Improved support for debugging Ada
2195 Many improvements to the Ada language support have been made. These
2197 - Better support for Ada2005 interface types
2198 - Improved handling of arrays and slices in general
2199 - Better support for Taft-amendment types
2200 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2202 - Improved command completion in Ada
2205 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2210 set print frame-arguments (all|scalars|none)
2211 show print frame-arguments
2212 The value of this variable can be changed to control which argument
2213 values should be printed by the debugger when displaying a frame.
2218 Transfer files to and from a remote target, and delete remote files.
2225 Transfer files to and from a remote target, and delete remote files.
2227 * New remote packets
2234 Open, close, read, write, and delete files on the remote system.
2237 Attach to an existing process on the remote system, in extended-remote
2241 Run a new process on the remote system, in extended-remote mode.
2243 *** Changes in GDB 6.7
2245 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2246 bfd, libiberty and opcodes, as revealed by static analysis donated by
2247 Coverity, Inc. (http://scan.coverity.com).
2249 * When looking up multiply-defined global symbols, GDB will now prefer the
2250 symbol definition in the current shared library if it was built using the
2251 -Bsymbolic linker option.
2253 * When the Text User Interface (TUI) is not configured, GDB will now
2254 recognize the -tui command-line option and print a message that the TUI
2257 * The GDB remote stub, gdbserver, now has lower overhead for high
2258 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2260 * GDB for MIPS targets now autodetects whether a remote target provides
2261 32-bit or 64-bit register values.
2263 * Support for C++ member pointers has been improved.
2265 * GDB now understands XML target descriptions, which specify the
2266 target's overall architecture. GDB can read a description from
2267 a local file or over the remote serial protocol.
2269 * Vectors of single-byte data use a new integer type which is not
2270 automatically displayed as character or string data.
2272 * The /s format now works with the print command. It displays
2273 arrays of single-byte integers and pointers to single-byte integers
2276 * Target descriptions can now describe target-specific registers,
2277 for architectures which have implemented the support (currently
2278 only ARM, M68K, and MIPS).
2280 * GDB and the GDB remote stub, gdbserver, now support the XScale
2283 * The GDB remote stub, gdbserver, has been updated to support
2284 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2285 has been rewritten to use the standard GDB remote protocol.
2287 * GDB can now step into C++ functions which are called through thunks.
2289 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2291 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2292 layout. It also supports a TextSeg= and DataSeg= response when only
2293 segment base addresses (rather than offsets) are available.
2295 * The /i format now outputs any trailing branch delay slot instructions
2296 immediately following the last instruction within the count specified.
2298 * The GDB remote protocol "T" stop reply packet now supports a
2299 "library" response. Combined with the new "qXfer:libraries:read"
2300 packet, this response allows GDB to debug shared libraries on targets
2301 where the operating system manages the list of loaded libraries (e.g.
2302 Windows and SymbianOS).
2304 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2305 (DLLs) on Windows and Windows CE targets.
2307 * GDB now supports a faster verification that a .debug file matches its binary
2308 according to its build-id signature, if the signature is present.
2314 Enable or disable hardware flow control (RTS/CTS) on the serial port
2315 when debugging using remote targets.
2317 set mem inaccessible-by-default
2318 show mem inaccessible-by-default
2319 If the target supplies a memory map, for instance via the remote
2320 protocol's "qXfer:memory-map:read" packet, setting this variable
2321 prevents GDB from accessing memory outside the memory map. This
2322 is useful for targets with memory mapped registers or which react
2323 badly to accesses of unmapped address space.
2325 set breakpoint auto-hw
2326 show breakpoint auto-hw
2327 If the target supplies a memory map, for instance via the remote
2328 protocol's "qXfer:memory-map:read" packet, setting this variable
2329 lets GDB use hardware breakpoints automatically for memory regions
2330 where it can not use software breakpoints. This covers both the
2331 "break" command and internal breakpoints used for other commands
2332 including "next" and "finish".
2335 catch exception unhandled
2336 Stop the program execution when Ada exceptions are raised.
2339 Stop the program execution when an Ada assertion failed.
2343 Set an alternate system root for target files. This is a more
2344 general version of "set solib-absolute-prefix", which is now
2345 an alias to "set sysroot".
2348 Provide extended SPU facility status information. This set of
2349 commands is available only when debugging the Cell/B.E. SPU
2352 * New native configurations
2354 OpenBSD/sh sh*-*openbsd*
2357 unset tdesc filename
2359 Use the specified local file as an XML target description, and do
2360 not query the target for its built-in description.
2364 OpenBSD/sh sh*-*-openbsd*
2365 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2366 Toshiba Media Processor mep-elf
2368 * New remote packets
2371 Ignore the specified signals; pass them directly to the debugged program
2372 without stopping other threads or reporting them to GDB.
2374 qXfer:features:read:
2375 Read an XML target description from the target, which describes its
2380 Read or write contents of an spufs file on the target system. These
2381 packets are available only on the Cell/B.E. SPU architecture.
2383 qXfer:libraries:read:
2384 Report the loaded shared libraries. Combined with new "T" packet
2385 response, this packet allows GDB to debug shared libraries on
2386 targets where the operating system manages the list of loaded
2387 libraries (e.g. Windows and SymbianOS).
2391 Support for these obsolete configurations has been removed.
2399 i[34567]86-*-lynxos*
2400 i[34567]86-*-netware*
2401 i[34567]86-*-sco3.2v5*
2402 i[34567]86-*-sco3.2v4*
2404 i[34567]86-*-sysv4.2*
2407 i[34567]86-*-unixware2*
2408 i[34567]86-*-unixware*
2417 * Other removed features
2424 Various m68k-only ROM monitors.
2431 Various Renesas ROM monitors and debugging interfaces for SH and
2436 Support for a Macraigor serial interface to on-chip debugging.
2437 GDB does not directly support the newer parallel or USB
2442 A debug information format. The predecessor to DWARF 2 and
2443 DWARF 3, which are still supported.
2445 Support for the HP aCC compiler on HP-UX/PA-RISC
2447 SOM-encapsulated symbolic debugging information, automatic
2448 invocation of pxdb, and the aCC custom C++ ABI. This does not
2449 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2450 with aCC can still be debugged on an assembly level.
2452 MIPS ".pdr" sections
2454 A MIPS-specific format used to describe stack frame layout
2455 in debugging information.
2459 GDB could work with an older version of Guile to debug
2460 the interpreter and Scheme programs running in it.
2462 set mips stack-arg-size
2463 set mips saved-gpreg-size
2465 Use "set mips abi" to control parameter passing for MIPS.
2467 *** Changes in GDB 6.6
2472 Cell Broadband Engine SPU spu-elf
2474 * GDB can now be configured as a cross-debugger targeting native Windows
2475 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2476 running on a Windows system over TCP/IP to debug Windows programs.
2478 * The GDB remote stub, gdbserver, has been updated to support Windows and
2479 Cygwin debugging. Both single-threaded and multi-threaded programs are
2482 * The "set trust-readonly-sections" command works again. This command was
2483 broken in GDB 6.3, 6.4, and 6.5.
2485 * The "load" command now supports writing to flash memory, if the remote
2486 stub provides the required support.
2488 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2489 longer requires symbolic debug information (e.g. DWARF-2).
2494 unset substitute-path
2495 show substitute-path
2496 Manage a list of substitution rules that GDB uses to rewrite the name
2497 of the directories where the sources are located. This can be useful
2498 for instance when the sources were moved to a different location
2499 between compilation and debugging.
2503 Print each CLI command as it is executed. Each command is prefixed with
2504 a number of `+' symbols representing the nesting depth.
2505 The source command now has a `-v' option to enable the same feature.
2509 The ARM Demon monitor support (RDP protocol, "target rdp").
2511 Kernel Object Display, an embedded debugging feature which only worked with
2512 an obsolete version of Cisco IOS.
2514 The 'set download-write-size' and 'show download-write-size' commands.
2516 * New remote packets
2519 Tell a stub about GDB client features, and request remote target features.
2520 The first feature implemented is PacketSize, which allows the target to
2521 specify the size of packets it can handle - to minimize the number of
2522 packets required and improve performance when connected to a remote
2526 Fetch an OS auxilliary vector from the remote stub. This packet is a
2527 more efficient replacement for qPart:auxv:read.
2529 qXfer:memory-map:read:
2530 Fetch a memory map from the remote stub, including information about
2531 RAM, ROM, and flash memory devices.
2536 Erase and program a flash memory device.
2538 * Removed remote packets
2541 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2542 used it, and only gdbserver implemented it.
2544 *** Changes in GDB 6.5
2548 Renesas M32C/M16C m32c-elf
2550 Morpho Technologies ms1 ms1-elf
2554 init-if-undefined Initialize a convenience variable, but
2555 only if it doesn't already have a value.
2557 The following commands are presently only implemented for native GNU/Linux:
2559 checkpoint Save a snapshot of the program state.
2561 restart <n> Return the program state to a
2562 previously saved state.
2564 info checkpoints List currently saved checkpoints.
2566 delete-checkpoint <n> Delete a previously saved checkpoint.
2568 set|show detach-on-fork Tell gdb whether to detach from a newly
2569 forked process, or to keep debugging it.
2571 info forks List forks of the user program that
2572 are available to be debugged.
2574 fork <n> Switch to debugging one of several
2575 forks of the user program that are
2576 available to be debugged.
2578 delete-fork <n> Delete a fork from the list of forks
2579 that are available to be debugged (and
2580 kill the forked process).
2582 detach-fork <n> Delete a fork from the list of forks
2583 that are available to be debugged (and
2584 allow the process to continue).
2588 Morpho Technologies ms2 ms1-elf
2590 * Improved Windows host support
2592 GDB now builds as a cross debugger hosted on i686-mingw32, including
2593 native console support, and remote communications using either
2594 network sockets or serial ports.
2596 * Improved Modula-2 language support
2598 GDB can now print most types in the Modula-2 syntax. This includes:
2599 basic types, set types, record types, enumerated types, range types,
2600 pointer types and ARRAY types. Procedure var parameters are correctly
2601 printed and hexadecimal addresses and character constants are also
2602 written in the Modula-2 syntax. Best results can be obtained by using
2603 GNU Modula-2 together with the -gdwarf-2 command line option.
2607 The ARM rdi-share module.
2609 The Netware NLM debug server.
2611 *** Changes in GDB 6.4
2613 * New native configurations
2615 OpenBSD/arm arm*-*-openbsd*
2616 OpenBSD/mips64 mips64-*-openbsd*
2620 Morpho Technologies ms1 ms1-elf
2622 * New command line options
2624 --batch-silent As for --batch, but totally silent.
2625 --return-child-result The debugger will exist with the same value
2626 the child (debugged) program exited with.
2627 --eval-command COMMAND, -ex COMMAND
2628 Execute a single GDB CLI command. This may be
2629 specified multiple times and in conjunction
2630 with the --command (-x) option.
2632 * Deprecated commands removed
2634 The following commands, that were deprecated in 2000, have been
2638 set|show arm disassembly-flavor set|show arm disassembler
2639 othernames set arm disassembler
2640 set|show remotedebug set|show debug remote
2641 set|show archdebug set|show debug arch
2642 set|show eventdebug set|show debug event
2645 * New BSD user-level threads support
2647 It is now possible to debug programs using the user-level threads
2648 library on OpenBSD and FreeBSD. Currently supported (target)
2651 FreeBSD/amd64 x86_64-*-freebsd*
2652 FreeBSD/i386 i386-*-freebsd*
2653 OpenBSD/i386 i386-*-openbsd*
2655 Note that the new kernel threads libraries introduced in FreeBSD 5.x
2656 are not yet supported.
2658 * New support for Matsushita MN10300 w/sim added
2659 (Work in progress). mn10300-elf.
2661 * REMOVED configurations and files
2663 VxWorks and the XDR protocol *-*-vxworks
2664 Motorola MCORE mcore-*-*
2665 National Semiconductor NS32000 ns32k-*-*
2667 * New "set print array-indexes" command
2669 After turning this setting "on", GDB prints the index of each element
2670 when displaying arrays. The default is "off" to preserve the previous
2673 * VAX floating point support
2675 GDB now supports the not-quite-ieee VAX F and D floating point formats.
2677 * User-defined command support
2679 In addition to using $arg0..$arg9 for argument passing, it is now possible
2680 to use $argc to determine now many arguments have been passed. See the
2681 section on user-defined commands in the user manual for more information.
2683 *** Changes in GDB 6.3:
2685 * New command line option
2687 GDB now accepts -l followed by a number to set the timeout for remote
2690 * GDB works with GCC -feliminate-dwarf2-dups
2692 GDB now supports a more compact representation of DWARF-2 debug
2693 information using DW_FORM_ref_addr references. These are produced
2694 by GCC with the option -feliminate-dwarf2-dups and also by some
2695 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
2696 to use -feliminate-dwarf2-dups.
2698 * Internationalization
2700 When supported by the host system, GDB will be built with
2701 internationalization (libintl). The task of marking up the sources is
2702 continued, we're looking forward to our first translation.
2706 Initial support for debugging programs compiled with the GNAT
2707 implementation of the Ada programming language has been integrated
2708 into GDB. In this release, support is limited to expression evaluation.
2710 * New native configurations
2712 GNU/Linux/m32r m32r-*-linux-gnu
2716 GDB's remote protocol now includes support for the 'p' packet. This
2717 packet is used to fetch individual registers from a remote inferior.
2719 * END-OF-LIFE registers[] compatibility module
2721 GDB's internal register infrastructure has been completely rewritten.
2722 The new infrastructure making possible the implementation of key new
2723 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
2726 GDB 6.3 will be the last release to include the the registers[]
2727 compatibility module that allowed out-of-date configurations to
2728 continue to work. This change directly impacts the following
2738 powerpc bdm protocol
2740 Unless there is activity to revive these configurations, they will be
2741 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
2743 * OBSOLETE configurations and files
2745 Configurations that have been declared obsolete in this release have
2746 been commented out. Unless there is activity to revive these
2747 configurations, the next release of GDB will have their sources
2748 permanently REMOVED.
2757 *** Changes in GDB 6.2.1:
2759 * MIPS `break main; run' gave an heuristic-fence-post warning
2761 When attempting to run even a simple program, a warning about
2762 heuristic-fence-post being hit would be reported. This problem has
2765 * MIPS IRIX 'long double' crashed GDB
2767 When examining a long double variable, GDB would get a segmentation
2768 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
2769 IRIX long double values).
2773 A bug in the VAX stack code was causing problems with the "next"
2774 command. This problem has been fixed.
2776 *** Changes in GDB 6.2:
2778 * Fix for ``many threads''
2780 On GNU/Linux systems that use the NPTL threads library, a program
2781 rapidly creating and deleting threads would confuse GDB leading to the
2784 ptrace: No such process.
2785 thread_db_get_info: cannot get thread info: generic error
2787 This problem has been fixed.
2789 * "-async" and "-noasync" options removed.
2791 Support for the broken "-noasync" option has been removed (it caused
2794 * New ``start'' command.
2796 This command runs the program until the begining of the main procedure.
2798 * New BSD Kernel Data Access Library (libkvm) interface
2800 Using ``target kvm'' it is now possible to debug kernel core dumps and
2801 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
2802 platforms. Currently supported (native-only) configurations are:
2804 FreeBSD/amd64 x86_64-*-freebsd*
2805 FreeBSD/i386 i?86-*-freebsd*
2806 NetBSD/i386 i?86-*-netbsd*
2807 NetBSD/m68k m68*-*-netbsd*
2808 NetBSD/sparc sparc-*-netbsd*
2809 OpenBSD/amd64 x86_64-*-openbsd*
2810 OpenBSD/i386 i?86-*-openbsd*
2811 OpenBSD/m68k m68*-openbsd*
2812 OpenBSD/sparc sparc-*-openbsd*
2814 * Signal trampoline code overhauled
2816 Many generic problems with GDB's signal handling code have been fixed.
2817 These include: backtraces through non-contiguous stacks; recognition
2818 of sa_sigaction signal trampolines; backtrace from a NULL pointer
2819 call; backtrace through a signal trampoline; step into and out of
2820 signal handlers; and single-stepping in the signal trampoline.
2822 Please note that kernel bugs are a limiting factor here. These
2823 features have been shown to work on an s390 GNU/Linux system that
2824 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
2826 * Cygwin support for DWARF 2 added.
2828 * New native configurations
2830 GNU/Linux/hppa hppa*-*-linux*
2831 OpenBSD/hppa hppa*-*-openbsd*
2832 OpenBSD/m68k m68*-*-openbsd*
2833 OpenBSD/m88k m88*-*-openbsd*
2834 OpenBSD/powerpc powerpc-*-openbsd*
2835 NetBSD/vax vax-*-netbsd*
2836 OpenBSD/vax vax-*-openbsd*
2838 * END-OF-LIFE frame compatibility module
2840 GDB's internal frame infrastructure has been completely rewritten.
2841 The new infrastructure making it possible to support key new features
2842 including DWARF 2 Call Frame Information. To aid in the task of
2843 migrating old configurations to this new infrastructure, a
2844 compatibility module, that allowed old configurations to continue to
2845 work, was also included.
2847 GDB 6.2 will be the last release to include this frame compatibility
2848 module. This change directly impacts the following configurations:
2858 Unless there is activity to revive these configurations, they will be
2859 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
2861 * REMOVED configurations and files
2863 Sun 3, running SunOS 3 m68*-*-sunos3*
2864 Sun 3, running SunOS 4 m68*-*-sunos4*
2865 Sun 2, running SunOS 3 m68000-*-sunos3*
2866 Sun 2, running SunOS 4 m68000-*-sunos4*
2867 Motorola 680x0 running LynxOS m68*-*-lynxos*
2868 AT&T 3b1/Unix pc m68*-att-*
2869 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2870 decstation mips-dec-* mips-little-*
2871 riscos mips-*-riscos* mips-*-sysv*
2872 sonymips mips-sony-*
2873 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2875 *** Changes in GDB 6.1.1:
2877 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
2879 The TUI (Text-mode User Interface) is now built as part of a default
2880 GDB configuration. It is enabled by either selecting the TUI with the
2881 command line option "-i=tui" or by running the separate "gdbtui"
2882 program. For more information on the TUI, see the manual "Debugging
2885 * Pending breakpoint support (also included in GDB 6.1)
2887 Support has been added to allow you to specify breakpoints in shared
2888 libraries that have not yet been loaded. If a breakpoint location
2889 cannot be found, and the "breakpoint pending" option is set to auto,
2890 GDB queries you if you wish to make the breakpoint pending on a future
2891 shared-library load. If and when GDB resolves the breakpoint symbol,
2892 the pending breakpoint is removed as one or more regular breakpoints
2895 Pending breakpoints are very useful for GCJ Java debugging.
2897 * Fixed ISO-C build problems
2899 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
2900 non ISO-C code that stopped them being built using a more strict ISO-C
2901 compiler (e.g., IBM's C compiler).
2903 * Fixed build problem on IRIX 5
2905 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
2906 wasn't able to compile compile on an IRIX 5 system.
2908 * Added execute permission to gdb/gdbserver/configure
2910 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
2911 permission. This bug would cause configure to fail on a number of
2912 systems (Solaris, IRIX). Ref: server/519.
2914 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
2916 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
2917 has been updated to use constant array sizes.
2919 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
2921 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
2922 its generated DWARF Call Frame Info. This encoding was causing GDB to
2923 panic, that panic has been fixed. Ref: gdb/1628.
2925 * Fixed a problem when examining parameters in shared library code.
2927 When examining parameters in optimized shared library code generated
2928 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
2929 not available''. GDB now correctly displays the variable's value.
2931 *** Changes in GDB 6.1:
2933 * Removed --with-mmalloc
2935 Support for the mmalloc memory manager has been removed, as it
2936 conflicted with the internal gdb byte cache.
2938 * Changes in AMD64 configurations
2940 The AMD64 target now includes the %cs and %ss registers. As a result
2941 the AMD64 remote protocol has changed; this affects the floating-point
2942 and SSE registers. If you rely on those registers for your debugging,
2943 you should upgrade gdbserver on the remote side.
2945 * Revised SPARC target
2947 The SPARC target has been completely revised, incorporating the
2948 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
2949 support for LynxOS and SunOS 4 has been dropped. Calling functions
2950 from within GDB on operating systems with a non-executable stack
2951 (Solaris, OpenBSD) now works.
2955 GDB has a new C++ demangler which does a better job on the mangled
2956 names generated by current versions of g++. It also runs faster, so
2957 with this and other changes gdb should now start faster on large C++
2960 * DWARF 2 Location Expressions
2962 GDB support for location expressions has been extended to support function
2963 arguments and frame bases. Older versions of GDB could crash when they
2966 * C++ nested types and namespaces
2968 GDB's support for nested types and namespaces in C++ has been
2969 improved, especially if you use the DWARF 2 debugging format. (This
2970 is the default for recent versions of GCC on most platforms.)
2971 Specifically, if you have a class "Inner" defined within a class or
2972 namespace "Outer", then GDB realizes that the class's name is
2973 "Outer::Inner", not simply "Inner". This should greatly reduce the
2974 frequency of complaints about not finding RTTI symbols. In addition,
2975 if you are stopped at inside of a function defined within a namespace,
2976 GDB modifies its name lookup accordingly.
2978 * New native configurations
2980 NetBSD/amd64 x86_64-*-netbsd*
2981 OpenBSD/amd64 x86_64-*-openbsd*
2982 OpenBSD/alpha alpha*-*-openbsd*
2983 OpenBSD/sparc sparc-*-openbsd*
2984 OpenBSD/sparc64 sparc64-*-openbsd*
2986 * New debugging protocols
2988 M32R with SDI protocol m32r-*-elf*
2990 * "set prompt-escape-char" command deleted.
2992 The command "set prompt-escape-char" has been deleted. This command,
2993 and its very obscure effet on GDB's prompt, was never documented,
2994 tested, nor mentioned in the NEWS file.
2996 * OBSOLETE configurations and files
2998 Configurations that have been declared obsolete in this release have
2999 been commented out. Unless there is activity to revive these
3000 configurations, the next release of GDB will have their sources
3001 permanently REMOVED.
3003 Sun 3, running SunOS 3 m68*-*-sunos3*
3004 Sun 3, running SunOS 4 m68*-*-sunos4*
3005 Sun 2, running SunOS 3 m68000-*-sunos3*
3006 Sun 2, running SunOS 4 m68000-*-sunos4*
3007 Motorola 680x0 running LynxOS m68*-*-lynxos*
3008 AT&T 3b1/Unix pc m68*-att-*
3009 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3010 decstation mips-dec-* mips-little-*
3011 riscos mips-*-riscos* mips-*-sysv*
3012 sonymips mips-sony-*
3013 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3015 * REMOVED configurations and files
3017 SGI Irix-4.x mips-sgi-irix4 or iris4
3018 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3019 Z8000 simulator z8k-zilog-none or z8ksim
3020 Matsushita MN10200 w/simulator mn10200-*-*
3021 H8/500 simulator h8500-hitachi-hms or h8500hms
3022 HP/PA running BSD hppa*-*-bsd*
3023 HP/PA running OSF/1 hppa*-*-osf*
3024 HP/PA Pro target hppa*-*-pro*
3025 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3026 386BSD i[3456]86-*-bsd*
3027 Sequent family i[3456]86-sequent-sysv4*
3028 i[3456]86-sequent-sysv*
3029 i[3456]86-sequent-bsd*
3030 SPARC running LynxOS sparc-*-lynxos*
3031 SPARC running SunOS 4 sparc-*-sunos4*
3032 Tsqware Sparclet sparclet-*-*
3033 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3035 *** Changes in GDB 6.0:
3039 Support for debugging the Objective-C programming language has been
3040 integrated into GDB.
3042 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3044 DWARF 2's Call Frame Information makes available compiler generated
3045 information that more exactly describes the program's run-time stack.
3046 By using this information, GDB is able to provide more robust stack
3049 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3050 have been updated to use a new backtrace mechanism which includes
3051 DWARF 2 CFI support.
3055 GDB's remote protocol has been extended to include support for hosted
3056 file I/O (where the remote target uses GDB's file system). See GDB's
3057 remote protocol documentation for details.
3059 * All targets using the new architecture framework.
3061 All of GDB's targets have been updated to use the new internal
3062 architecture framework. The way is now open for future GDB releases
3063 to include cross-architecture native debugging support (i386 on amd64,
3066 * GNU/Linux's Thread Local Storage (TLS)
3068 GDB now includes support for for the GNU/Linux implementation of
3069 per-thread variables.
3071 * GNU/Linux's Native POSIX Thread Library (NPTL)
3073 GDB's thread code has been updated to work with either the new
3074 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3076 * Separate debug info.
3078 GDB, in conjunction with BINUTILS, now supports a mechanism for
3079 automatically loading debug information from a separate file. Instead
3080 of shipping full debug and non-debug versions of system libraries,
3081 system integrators can now instead ship just the stripped libraries
3082 and optional debug files.
3084 * DWARF 2 Location Expressions
3086 DWARF 2 Location Expressions allow the compiler to more completely
3087 describe the location of variables (even in optimized code) to the
3090 GDB now includes preliminary support for location expressions (support
3091 for DW_OP_piece is still missing).
3095 A number of long standing bugs that caused GDB to die while starting a
3096 Java application have been fixed. GDB's Java support is now
3097 considered "useable".
3099 * GNU/Linux support for fork, vfork, and exec.
3101 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3102 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3105 * GDB supports logging output to a file
3107 There are two new commands, "set logging" and "show logging", which can be
3108 used to capture GDB's output to a file.
3110 * The meaning of "detach" has changed for gdbserver
3112 The "detach" command will now resume the application, as documented. To
3113 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3116 * d10v, m68hc11 `regs' command deprecated
3118 The `info registers' command has been updated so that it displays the
3119 registers using a format identical to the old `regs' command.
3123 A new command, "maint set profile on/off", has been added. This command can
3124 be used to enable or disable profiling while running GDB, to profile a
3125 session or a set of commands. In addition there is a new configure switch,
3126 "--enable-profiling", which will cause GDB to be compiled with profiling
3127 data, for more informative profiling results.
3129 * Default MI syntax changed to "mi2".
3131 The default MI (machine interface) syntax, enabled by the command line
3132 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3133 "mi1", can be enabled by specifying the option "-i=mi1".
3135 Support for the original "mi0" syntax (included in GDB 5.0) has been
3138 Fix for gdb/192: removed extraneous space when displaying frame level.
3139 Fix for gdb/672: update changelist is now output in mi list format.
3140 Fix for gdb/702: a -var-assign that updates the value now shows up
3141 in a subsequent -var-update.
3143 * New native configurations.
3145 FreeBSD/amd64 x86_64-*-freebsd*
3147 * Multi-arched targets.
3149 HP/PA HPUX11 hppa*-*-hpux*
3150 Renesas M32R/D w/simulator m32r-*-elf*
3152 * OBSOLETE configurations and files
3154 Configurations that have been declared obsolete in this release have
3155 been commented out. Unless there is activity to revive these
3156 configurations, the next release of GDB will have their sources
3157 permanently REMOVED.
3159 Z8000 simulator z8k-zilog-none or z8ksim
3160 Matsushita MN10200 w/simulator mn10200-*-*
3161 H8/500 simulator h8500-hitachi-hms or h8500hms
3162 HP/PA running BSD hppa*-*-bsd*
3163 HP/PA running OSF/1 hppa*-*-osf*
3164 HP/PA Pro target hppa*-*-pro*
3165 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3166 Sequent family i[3456]86-sequent-sysv4*
3167 i[3456]86-sequent-sysv*
3168 i[3456]86-sequent-bsd*
3169 Tsqware Sparclet sparclet-*-*
3170 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3172 * REMOVED configurations and files
3175 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3176 IBM AIX PS/2 i[3456]86-*-aix
3177 i386 running Mach 3.0 i[3456]86-*-mach3*
3178 i386 running Mach i[3456]86-*-mach*
3179 i386 running OSF/1 i[3456]86-*osf1mk*
3180 HP/Apollo 68k Family m68*-apollo*-sysv*,
3182 m68*-hp-bsd*, m68*-hp-hpux*
3183 Argonaut Risc Chip (ARC) arc-*-*
3184 Mitsubishi D30V d30v-*-*
3185 Fujitsu FR30 fr30-*-elf*
3186 OS/9000 i[34]86-*-os9k
3187 I960 with MON960 i960-*-coff
3189 * MIPS $fp behavior changed
3191 The convenience variable $fp, for the MIPS, now consistently returns
3192 the address of the current frame's base. Previously, depending on the
3193 context, $fp could refer to either $sp or the current frame's base
3194 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3195 The GNU Source-Level Debugger''.
3197 *** Changes in GDB 5.3:
3199 * GNU/Linux shared library multi-threaded performance improved.
3201 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3202 `/proc', in preference to `ptrace' for memory reads. This may result
3203 in an improvement in the start-up time of multi-threaded, shared
3204 library applications when run under GDB. One GDB user writes: ``loads
3205 shared libs like mad''.
3207 * ``gdbserver'' now supports multi-threaded applications on some targets
3209 Support for debugging multi-threaded applications which use
3210 the GNU/Linux LinuxThreads package has been added for
3211 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3212 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3214 * GDB now supports C/C++ preprocessor macros.
3216 GDB now expands preprocessor macro invocations in C/C++ expressions,
3217 and provides various commands for showing macro definitions and how
3220 The new command `macro expand EXPRESSION' expands any macro
3221 invocations in expression, and shows the result.
3223 The new command `show macro MACRO-NAME' shows the definition of the
3224 macro named MACRO-NAME, and where it was defined.
3226 Most compilers don't include information about macros in the debugging
3227 information by default. In GCC 3.1, for example, you need to compile
3228 your program with the options `-gdwarf-2 -g3'. If the macro
3229 information is present in the executable, GDB will read it.
3231 * Multi-arched targets.
3233 DEC Alpha (partial) alpha*-*-*
3234 DEC VAX (partial) vax-*-*
3236 National Semiconductor NS32000 (partial) ns32k-*-*
3237 Motorola 68000 (partial) m68k-*-*
3238 Motorola MCORE mcore-*-*
3242 Fujitsu FRV architecture added by Red Hat frv*-*-*
3245 * New native configurations
3247 Alpha NetBSD alpha*-*-netbsd*
3248 SH NetBSD sh*-*-netbsdelf*
3249 MIPS NetBSD mips*-*-netbsd*
3250 UltraSPARC NetBSD sparc64-*-netbsd*
3252 * OBSOLETE configurations and files
3254 Configurations that have been declared obsolete in this release have
3255 been commented out. Unless there is activity to revive these
3256 configurations, the next release of GDB will have their sources
3257 permanently REMOVED.
3259 Mitsubishi D30V d30v-*-*
3260 OS/9000 i[34]86-*-os9k
3261 IBM AIX PS/2 i[3456]86-*-aix
3262 Fujitsu FR30 fr30-*-elf*
3263 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3264 Argonaut Risc Chip (ARC) arc-*-*
3265 i386 running Mach 3.0 i[3456]86-*-mach3*
3266 i386 running Mach i[3456]86-*-mach*
3267 i386 running OSF/1 i[3456]86-*osf1mk*
3268 HP/Apollo 68k Family m68*-apollo*-sysv*,
3270 m68*-hp-bsd*, m68*-hp-hpux*
3271 I960 with MON960 i960-*-coff
3273 * OBSOLETE languages
3275 CHILL, a Pascal like language used by telecommunications companies.
3277 * REMOVED configurations and files
3279 AMD 29k family via UDI a29k-amd-udi, udi29k
3280 A29K VxWorks a29k-*-vxworks
3281 AMD 29000 embedded, using EBMON a29k-none-none
3282 AMD 29000 embedded with COFF a29k-none-coff
3283 AMD 29000 embedded with a.out a29k-none-aout
3285 testsuite/gdb.hp/gdb.threads-hp/ directory
3287 * New command "set max-user-call-depth <nnn>"
3289 This command allows the user to limit the call depth of user-defined
3290 commands. The default is 1024.
3292 * Changes in FreeBSD/i386 native debugging.
3294 Support for the "generate-core-file" has been added.
3296 * New commands "dump", "append", and "restore".
3298 These commands allow data to be copied from target memory
3299 to a bfd-format or binary file (dump and append), and back
3300 from a file into memory (restore).
3302 * Improved "next/step" support on multi-processor Alpha Tru64.
3304 The previous single-step mechanism could cause unpredictable problems,
3305 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3306 of a software single-step mechanism prevents this.
3308 *** Changes in GDB 5.2.1:
3316 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3317 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3318 Fix, by Joel Brobecker imported from mainline.
3320 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3321 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3322 Fix, by Fred Fish, imported from mainline.
3324 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3325 Surprisingly enough, it works now.
3326 By Michal Ludvig, imported from mainline.
3328 i386 hardware watchpoint support:
3329 avoid misses on second run for some targets.
3330 By Pierre Muller, imported from mainline.
3332 *** Changes in GDB 5.2:
3334 * New command "set trust-readonly-sections on[off]".
3336 This command is a hint that tells gdb that read-only sections
3337 really are read-only (ie. that their contents will not change).
3338 In this mode, gdb will go to the object file rather than the
3339 target to read memory from read-only sections (such as ".text").
3340 This can be a significant performance improvement on some
3341 (notably embedded) targets.
3343 * New command "generate-core-file" (or "gcore").
3345 This new gdb command allows the user to drop a core file of the child
3346 process state at any time. So far it's been implemented only for
3347 GNU/Linux and Solaris, but should be relatively easily ported to other
3348 hosts. Argument is core file name (defaults to core.<pid>).
3350 * New command line option
3352 GDB now accepts --pid or -p followed by a process id.
3354 * Change in command line behavior -- corefiles vs. process ids.
3356 There is a subtle behavior in the way in which GDB handles
3357 command line arguments. The first non-flag argument is always
3358 a program to debug, but the second non-flag argument may either
3359 be a corefile or a process id. Previously, GDB would attempt to
3360 open the second argument as a corefile, and if that failed, would
3361 issue a superfluous error message and then attempt to attach it as
3362 a process. Now, if the second argument begins with a non-digit,
3363 it will be treated as a corefile. If it begins with a digit,
3364 GDB will attempt to attach it as a process, and if no such process
3365 is found, will then attempt to open it as a corefile.
3367 * Changes in ARM configurations.
3369 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3370 configuration is fully multi-arch.
3372 * New native configurations
3374 ARM NetBSD arm*-*-netbsd*
3375 x86 OpenBSD i[3456]86-*-openbsd*
3376 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3377 Sparc64 running FreeBSD sparc64-*-freebsd*
3381 Sanyo XStormy16 xstormy16-elf
3383 * OBSOLETE configurations and files
3385 Configurations that have been declared obsolete in this release have
3386 been commented out. Unless there is activity to revive these
3387 configurations, the next release of GDB will have their sources
3388 permanently REMOVED.
3390 AMD 29k family via UDI a29k-amd-udi, udi29k
3391 A29K VxWorks a29k-*-vxworks
3392 AMD 29000 embedded, using EBMON a29k-none-none
3393 AMD 29000 embedded with COFF a29k-none-coff
3394 AMD 29000 embedded with a.out a29k-none-aout
3396 testsuite/gdb.hp/gdb.threads-hp/ directory
3398 * REMOVED configurations and files
3400 TI TMS320C80 tic80-*-*
3402 PowerPC Solaris powerpcle-*-solaris*
3403 PowerPC Windows NT powerpcle-*-cygwin32
3404 PowerPC Netware powerpc-*-netware*
3405 Harris/CXUX m88k m88*-harris-cxux*
3406 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3407 ns32k-utek-sysv* ns32k-utek-*
3408 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3409 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3410 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3411 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3412 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3414 * Changes to command line processing
3416 The new `--args' feature can be used to specify command-line arguments
3417 for the inferior from gdb's command line.
3419 * Changes to key bindings
3421 There is a new `operate-and-get-next' function bound to `C-o'.
3423 *** Changes in GDB 5.1.1
3425 Fix compile problem on DJGPP.
3427 Fix a problem with floating-point registers on the i386 being
3430 Fix to stop GDB crashing on .debug_str debug info.
3432 Numerous documentation fixes.
3434 Numerous testsuite fixes.
3436 *** Changes in GDB 5.1:
3438 * New native configurations
3440 Alpha FreeBSD alpha*-*-freebsd*
3441 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3442 MIPS GNU/Linux mips*-*-linux*
3443 MIPS SGI Irix 6.x mips*-sgi-irix6*
3444 ia64 AIX ia64-*-aix*
3445 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3449 Motorola 68HC11 and 68HC12 m68hc11-elf
3451 UltraSparc running GNU/Linux sparc64-*-linux*
3453 * OBSOLETE configurations and files
3455 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3456 Harris/CXUX m88k m88*-harris-cxux*
3457 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3458 ns32k-utek-sysv* ns32k-utek-*
3459 TI TMS320C80 tic80-*-*
3461 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3462 PowerPC Solaris powerpcle-*-solaris*
3463 PowerPC Windows NT powerpcle-*-cygwin32
3464 PowerPC Netware powerpc-*-netware*
3465 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3466 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3467 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3468 Apple Macintosh (MPW) host N/A
3470 stuff.c (Program to stuff files into a specially prepared space in kdb)
3471 kdb-start.c (Main loop for the standalone kernel debugger)
3473 Configurations that have been declared obsolete in this release have
3474 been commented out. Unless there is activity to revive these
3475 configurations, the next release of GDB will have their sources
3476 permanently REMOVED.
3478 * REMOVED configurations and files
3480 Altos 3068 m68*-altos-*
3481 Convex c1-*-*, c2-*-*
3483 ARM RISCix arm-*-* (as host)
3487 * GDB has been converted to ISO C.
3489 GDB's source code has been converted to ISO C. In particular, the
3490 sources are fully protoized, and rely on standard headers being
3495 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3497 * The MI enabled by default.
3499 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3500 revised and enabled by default. Packages which use GDB as a debugging
3501 engine behind a UI or another front end are encouraged to switch to
3502 using the GDB/MI interface, instead of the old annotations interface
3503 which is now deprecated.
3505 * Support for debugging Pascal programs.
3507 GDB now includes support for debugging Pascal programs. The following
3508 main features are supported:
3510 - Pascal-specific data types such as sets;
3512 - automatic recognition of Pascal sources based on file-name
3515 - Pascal-style display of data types, variables, and functions;
3517 - a Pascal expression parser.
3519 However, some important features are not yet supported.
3521 - Pascal string operations are not supported at all;
3523 - there are some problems with boolean types;
3525 - Pascal type hexadecimal constants are not supported
3526 because they conflict with the internal variables format;
3528 - support for Pascal objects and classes is not full yet;
3530 - unlike Pascal, GDB is case-sensitive for symbol names.
3532 * Changes in completion.
3534 Commands such as `shell', `run' and `set args', which pass arguments
3535 to inferior programs, now complete on file names, similar to what
3536 users expect at the shell prompt.
3538 Commands which accept locations, such as `disassemble', `print',
3539 `breakpoint', `until', etc. now complete on filenames as well as
3540 program symbols. Thus, if you type "break foob TAB", and the source
3541 files linked into the programs include `foobar.c', that file name will
3542 be one of the candidates for completion. However, file names are not
3543 considered for completion after you typed a colon that delimits a file
3544 name from a name of a function in that file, as in "break foo.c:bar".
3546 `set demangle-style' completes on available demangling styles.
3548 * New platform-independent commands:
3550 It is now possible to define a post-hook for a command as well as a
3551 hook that runs before the command. For more details, see the
3552 documentation of `hookpost' in the GDB manual.
3554 * Changes in GNU/Linux native debugging.
3556 Support for debugging multi-threaded programs has been completely
3557 revised for all platforms except m68k and sparc. You can now debug as
3558 many threads as your system allows you to have.
3560 Attach/detach is supported for multi-threaded programs.
3562 Support for SSE registers was added for x86. This doesn't work for
3563 multi-threaded programs though.
3565 * Changes in MIPS configurations.
3567 Multi-arch support is enabled for all MIPS configurations.
3569 GDB can now be built as native debugger on SGI Irix 6.x systems for
3570 debugging n32 executables. (Debugging 64-bit executables is not yet
3573 * Unified support for hardware watchpoints in all x86 configurations.
3575 Most (if not all) native x86 configurations support hardware-assisted
3576 breakpoints and watchpoints in a unified manner. This support
3577 implements debug register sharing between watchpoints, which allows to
3578 put a virtually infinite number of watchpoints on the same address,
3579 and also supports watching regions up to 16 bytes with several debug
3582 The new maintenance command `maintenance show-debug-regs' toggles
3583 debugging print-outs in functions that insert, remove, and test
3584 watchpoints and hardware breakpoints.
3586 * Changes in the DJGPP native configuration.
3588 New command ``info dos sysinfo'' displays assorted information about
3589 the CPU, OS, memory, and DPMI server.
3591 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3592 display information about segment descriptors stored in GDT, LDT, and
3595 New commands ``info dos pde'' and ``info dos pte'' display entries
3596 from Page Directory and Page Tables (for now works with CWSDPMI only).
3597 New command ``info dos address-pte'' displays the Page Table entry for
3598 a given linear address.
3600 GDB can now pass command lines longer than 126 characters to the
3601 program being debugged (requires an update to the libdbg.a library
3602 which is part of the DJGPP development kit).
3604 DWARF2 debug info is now supported.
3606 It is now possible to `step' and `next' through calls to `longjmp'.
3608 * Changes in documentation.
3610 All GDB documentation was converted to GFDL, the GNU Free
3611 Documentation License.
3613 Tracepoints-related commands are now fully documented in the GDB
3616 TUI, the Text-mode User Interface, is now documented in the manual.
3618 Tracepoints-related commands are now fully documented in the GDB
3621 The "GDB Internals" manual now has an index. It also includes
3622 documentation of `ui_out' functions, GDB coding standards, x86
3623 hardware watchpoints, and memory region attributes.
3625 * GDB's version number moved to ``version.in''
3627 The Makefile variable VERSION has been replaced by the file
3628 ``version.in''. People creating GDB distributions should update the
3629 contents of this file.
3633 GUD support is now a standard part of the EMACS distribution.
3635 *** Changes in GDB 5.0:
3637 * Improved support for debugging FP programs on x86 targets
3639 Unified and much-improved support for debugging floating-point
3640 programs on all x86 targets. In particular, ``info float'' now
3641 displays the FP registers in the same format on all x86 targets, with
3642 greater level of detail.
3644 * Improvements and bugfixes in hardware-assisted watchpoints
3646 It is now possible to watch array elements, struct members, and
3647 bitfields with hardware-assisted watchpoints. Data-read watchpoints
3648 on x86 targets no longer erroneously trigger when the address is
3651 * Improvements in the native DJGPP version of GDB
3653 The distribution now includes all the scripts and auxiliary files
3654 necessary to build the native DJGPP version on MS-DOS/MS-Windows
3655 machines ``out of the box''.
3657 The DJGPP version can now debug programs that use signals. It is
3658 possible to catch signals that happened in the debuggee, deliver
3659 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
3660 would kill the program being debugged.) Programs that hook hardware
3661 interrupts (keyboard, timer, etc.) can also be debugged.
3663 It is now possible to debug DJGPP programs that redirect their
3664 standard handles or switch them to raw (as opposed to cooked) mode, or
3665 even close them. The command ``run < foo > bar'' works as expected,
3666 and ``info terminal'' reports useful information about the debuggee's
3667 terminal, including raw/cooked mode, redirection, etc.
3669 The DJGPP version now uses termios functions for console I/O, which
3670 enables debugging graphics programs. Interrupting GDB with Ctrl-C
3673 DOS-style file names with drive letters are now fully supported by
3676 It is now possible to debug DJGPP programs that switch their working
3677 directory. It is also possible to rerun the debuggee any number of
3678 times without restarting GDB; thus, you can use the same setup,
3679 breakpoints, etc. for many debugging sessions.
3681 * New native configurations
3683 ARM GNU/Linux arm*-*-linux*
3684 PowerPC GNU/Linux powerpc-*-linux*
3688 Motorola MCore mcore-*-*
3689 x86 VxWorks i[3456]86-*-vxworks*
3690 PowerPC VxWorks powerpc-*-vxworks*
3691 TI TMS320C80 tic80-*-*
3693 * OBSOLETE configurations
3695 Altos 3068 m68*-altos-*
3696 Convex c1-*-*, c2-*-*
3698 ARM RISCix arm-*-* (as host)
3701 Configurations that have been declared obsolete will be commented out,
3702 but the code will be left in place. If there is no activity to revive
3703 these configurations before the next release of GDB, the sources will
3704 be permanently REMOVED.
3706 * Gould support removed
3708 Support for the Gould PowerNode and NP1 has been removed.
3710 * New features for SVR4
3712 On SVR4 native platforms (such as Solaris), if you attach to a process
3713 without first loading a symbol file, GDB will now attempt to locate and
3714 load symbols from the running process's executable file.
3716 * Many C++ enhancements
3718 C++ support has been greatly improved. Overload resolution now works properly
3719 in almost all cases. RTTI support is on the way.
3721 * Remote targets can connect to a sub-program
3723 A popen(3) style serial-device has been added. This device starts a
3724 sub-process (such as a stand-alone simulator) and then communicates
3725 with that. The sub-program to run is specified using the syntax
3726 ``|<program> <args>'' vis:
3728 (gdb) set remotedebug 1
3729 (gdb) target extended-remote |mn10300-elf-sim program-args
3731 * MIPS 64 remote protocol
3733 A long standing bug in the mips64 remote protocol where by GDB
3734 expected certain 32 bit registers (ex SR) to be transfered as 32
3735 instead of 64 bits has been fixed.
3737 The command ``set remote-mips64-transfers-32bit-regs on'' has been
3738 added to provide backward compatibility with older versions of GDB.
3740 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
3742 The command ``set remotebinarydownload'' command has been replaced by
3743 ``set remote X-packet''. Other commands in ``set remote'' family
3744 include ``set remote P-packet''.
3746 * Breakpoint commands accept ranges.
3748 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
3749 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
3750 ``tracepoint passcount'' also accepts a range of tracepoints.
3752 * ``apropos'' command added.
3754 The ``apropos'' command searches through command names and
3755 documentation strings, printing out matches, making it much easier to
3756 try to find a command that does what you are looking for.
3760 A new machine oriented interface (MI) has been added to GDB. This
3761 interface is designed for debug environments running GDB as a separate
3762 process. This is part of the long term libGDB project. See the
3763 "GDB/MI" chapter of the GDB manual for further information. It can be
3764 enabled by configuring with:
3766 .../configure --enable-gdbmi
3768 *** Changes in GDB-4.18:
3770 * New native configurations
3772 HP-UX 10.20 hppa*-*-hpux10.20
3773 HP-UX 11.x hppa*-*-hpux11.0*
3774 M68K GNU/Linux m68*-*-linux*
3778 Fujitsu FR30 fr30-*-elf*
3779 Intel StrongARM strongarm-*-*
3780 Mitsubishi D30V d30v-*-*
3782 * OBSOLETE configurations
3784 Gould PowerNode, NP1 np1-*-*, pn-*-*
3786 Configurations that have been declared obsolete will be commented out,
3787 but the code will be left in place. If there is no activity to revive
3788 these configurations before the next release of GDB, the sources will
3789 be permanently REMOVED.
3793 As a compatibility experiment, GDB's source files buildsym.h and
3794 buildsym.c have been converted to pure standard C, no longer
3795 containing any K&R compatibility code. We believe that all systems in
3796 use today either come with a standard C compiler, or have a GCC port
3797 available. If this is not true, please report the affected
3798 configuration to bug-gdb@gnu.org immediately. See the README file for
3799 information about getting a standard C compiler if you don't have one
3804 GDB now uses readline 2.2.
3806 * set extension-language
3808 You can now control the mapping between filename extensions and source
3809 languages by using the `set extension-language' command. For instance,
3810 you can ask GDB to treat .c files as C++ by saying
3811 set extension-language .c c++
3812 The command `info extensions' lists all of the recognized extensions
3813 and their associated languages.
3815 * Setting processor type for PowerPC and RS/6000
3817 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
3818 you can use the `set processor' command to specify what variant of the
3819 PowerPC family you are debugging. The command
3823 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
3824 following PowerPC and RS6000 variants:
3826 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
3827 rs6000 IBM RS6000 ("POWER") architecture, user-level view
3829 403GC IBM PowerPC 403GC
3830 505 Motorola PowerPC 505
3831 860 Motorola PowerPC 860 or 850
3832 601 Motorola PowerPC 601
3833 602 Motorola PowerPC 602
3834 603 Motorola/IBM PowerPC 603 or 603e
3835 604 Motorola PowerPC 604 or 604e
3836 750 Motorola/IBM PowerPC 750 or 750
3838 At the moment, this command just tells GDB what to name the
3839 special-purpose processor registers. Since almost all the affected
3840 registers are inaccessible to user-level programs, this command is
3841 only useful for remote debugging in its present form.
3845 Thanks to a major code donation from Hewlett-Packard, GDB now has much
3846 more extensive support for HP-UX. Added features include shared
3847 library support, kernel threads and hardware watchpoints for 11.00,
3848 support for HP's ANSI C and C++ compilers, and a compatibility mode
3849 for xdb and dbx commands.
3853 HP's donation includes the new concept of catchpoints, which is a
3854 generalization of the old catch command. On HP-UX, it is now possible
3855 to catch exec, fork, and vfork, as well as library loading.
3857 This means that the existing catch command has changed; its first
3858 argument now specifies the type of catch to be set up. See the
3859 output of "help catch" for a list of catchpoint types.
3861 * Debugging across forks
3863 On HP-UX, you can choose which process to debug when a fork() happens
3868 HP has donated a curses-based terminal user interface (TUI). To get
3869 it, build with --enable-tui. Although this can be enabled for any
3870 configuration, at present it only works for native HP debugging.
3872 * GDB remote protocol additions
3874 A new protocol packet 'X' that writes binary data is now available.
3875 Default behavior is to try 'X', then drop back to 'M' if the stub
3876 fails to respond. The settable variable `remotebinarydownload'
3877 allows explicit control over the use of 'X'.
3879 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
3880 full 64-bit address. The command
3882 set remoteaddresssize 32
3884 can be used to revert to the old behaviour. For existing remote stubs
3885 the change should not be noticed, as the additional address information
3888 In order to assist in debugging stubs, you may use the maintenance
3889 command `packet' to send any text string to the stub. For instance,
3891 maint packet heythere
3893 sends the packet "$heythere#<checksum>". Note that it is very easy to
3894 disrupt a debugging session by sending the wrong packet at the wrong
3897 The compare-sections command allows you to compare section data on the
3898 target to what is in the executable file without uploading or
3899 downloading, by comparing CRC checksums.
3901 * Tracing can collect general expressions
3903 You may now collect general expressions at tracepoints. This requires
3904 further additions to the target-side stub; see tracepoint.c and
3905 doc/agentexpr.texi for further details.
3907 * mask-address variable for Mips
3909 For Mips targets, you may control the zeroing of the upper 32 bits of
3910 a 64-bit address by entering `set mask-address on'. This is mainly
3911 of interest to users of embedded R4xxx and R5xxx processors.
3913 * Higher serial baud rates
3915 GDB's serial code now allows you to specify baud rates 57600, 115200,
3916 230400, and 460800 baud. (Note that your host system may not be able
3917 to achieve all of these rates.)
3921 The i960 configuration now includes an initial implementation of a
3922 builtin simulator, contributed by Jim Wilson.
3925 *** Changes in GDB-4.17:
3927 * New native configurations
3929 Alpha GNU/Linux alpha*-*-linux*
3930 Unixware 2.x i[3456]86-unixware2*
3931 Irix 6.x mips*-sgi-irix6*
3932 PowerPC GNU/Linux powerpc-*-linux*
3933 PowerPC Solaris powerpcle-*-solaris*
3934 Sparc GNU/Linux sparc-*-linux*
3935 Motorola sysV68 R3V7.1 m68k-motorola-sysv
3939 Argonaut Risc Chip (ARC) arc-*-*
3940 Hitachi H8/300S h8300*-*-*
3941 Matsushita MN10200 w/simulator mn10200-*-*
3942 Matsushita MN10300 w/simulator mn10300-*-*
3943 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
3944 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
3945 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
3946 Mitsubishi D10V w/simulator d10v-*-*
3947 Mitsubishi M32R/D w/simulator m32r-*-elf*
3948 Tsqware Sparclet sparclet-*-*
3949 NEC V850 w/simulator v850-*-*
3951 * New debugging protocols
3953 ARM with RDI protocol arm*-*-*
3954 M68K with dBUG monitor m68*-*-{aout,coff,elf}
3955 DDB and LSI variants of PMON protocol mips*-*-*
3956 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
3957 PowerPC with SDS protocol powerpc{,le}-*-eabi
3958 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
3962 All configurations can now understand and use the DWARF 2 debugging
3963 format. The choice is automatic, if the symbol file contains DWARF 2
3968 GDB now includes basic Java language support. This support is
3969 only useful with Java compilers that produce native machine code.
3971 * solib-absolute-prefix and solib-search-path
3973 For SunOS and SVR4 shared libraries, you may now set the prefix for
3974 loading absolute shared library symbol files, and the search path for
3975 locating non-absolute shared library symbol files.
3977 * Live range splitting
3979 GDB can now effectively debug code for which GCC has performed live
3980 range splitting as part of its optimization. See gdb/doc/LRS for
3981 more details on the expected format of the stabs information.
3985 GDB's support for the GNU Hurd, including thread debugging, has been
3986 updated to work with current versions of the Hurd.
3990 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
3991 instruction set. ARM GDB automatically detects when Thumb
3992 instructions are in use, and adjusts disassembly and backtracing
3997 GDB's MIPS target configurations now handle the MIP16 16-bit
4002 GDB now includes support for overlays; if an executable has been
4003 linked such that multiple sections are based at the same address, GDB
4004 will decide which section to use for symbolic info. You can choose to
4005 control the decision manually, using overlay commands, or implement
4006 additional target-side support and use "overlay load-target" to bring
4007 in the overlay mapping. Do "help overlay" for more detail.
4011 The command "info symbol <address>" displays information about
4012 the symbol at the specified address.
4016 The standard remote protocol now includes an extension that allows
4017 asynchronous collection and display of trace data. This requires
4018 extensive support in the target-side debugging stub. Tracing mode
4019 includes a new interaction mode in GDB and new commands: see the
4020 file tracepoint.c for more details.
4024 Configurations for embedded MIPS now include a simulator contributed
4025 by Cygnus Solutions. The simulator supports the instruction sets
4026 of most MIPS variants.
4030 Sparc configurations may now include the ERC32 simulator contributed
4031 by the European Space Agency. The simulator is not built into
4032 Sparc targets by default; configure with --enable-sim to include it.
4036 For target configurations that may include multiple variants of a
4037 basic architecture (such as MIPS and SH), you may now set the
4038 architecture explicitly. "set arch" sets, "info arch" lists
4039 the possible architectures.
4041 *** Changes in GDB-4.16:
4043 * New native configurations
4045 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4046 M68K NetBSD m68k-*-netbsd*
4047 PowerPC AIX 4.x powerpc-*-aix*
4048 PowerPC MacOS powerpc-*-macos*
4049 PowerPC Windows NT powerpcle-*-cygwin32
4050 RS/6000 AIX 4.x rs6000-*-aix4*
4054 ARM with RDP protocol arm-*-*
4055 I960 with MON960 i960-*-coff
4056 MIPS VxWorks mips*-*-vxworks*
4057 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4058 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4060 Matra Sparclet sparclet-*-*
4064 The powerpc-eabi configuration now includes the PSIM simulator,
4065 contributed by Andrew Cagney, with assistance from Mike Meissner.
4066 PSIM is a very elaborate model of the PowerPC, including not only
4067 basic instruction set execution, but also details of execution unit
4068 performance and I/O hardware. See sim/ppc/README for more details.
4072 GDB now works with Solaris 2.5.
4074 * Windows 95/NT native
4076 GDB will now work as a native debugger on Windows 95 and Windows NT.
4077 To build it from source, you must use the "gnu-win32" environment,
4078 which uses a DLL to emulate enough of Unix to run the GNU tools.
4079 Further information, binaries, and sources are available at
4080 ftp.cygnus.com, under pub/gnu-win32.
4082 * dont-repeat command
4084 If a user-defined command includes the command `dont-repeat', then the
4085 command will not be repeated if the user just types return. This is
4086 useful if the command is time-consuming to run, so that accidental
4087 extra keystrokes don't run the same command many times.
4089 * Send break instead of ^C
4091 The standard remote protocol now includes an option to send a break
4092 rather than a ^C to the target in order to interrupt it. By default,
4093 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4095 * Remote protocol timeout
4097 The standard remote protocol includes a new variable `remotetimeout'
4098 that allows you to set the number of seconds before GDB gives up trying
4099 to read from the target. The default value is 2.
4101 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4103 By default GDB will automatically keep track of objects as they are
4104 loaded and unloaded by the dynamic linker. By using the command `set
4105 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4106 when shared library events occur, thus allowing you to set breakpoints
4107 in shared libraries which are explicitly loaded by the inferior.
4109 Note this feature does not work on hpux8. On hpux9 you must link
4110 /usr/lib/end.o into your program. This feature should work
4111 automatically on hpux10.
4113 * Irix 5.x hardware watchpoint support
4115 Irix 5 configurations now support the use of hardware watchpoints.
4117 * Mips protocol "SYN garbage limit"
4119 When debugging a Mips target using the `target mips' protocol, you
4120 may set the number of characters that GDB will ignore by setting
4121 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4122 every character. The default value is 1050.
4124 * Recording and replaying remote debug sessions
4126 If you set `remotelogfile' to the name of a file, gdb will write to it
4127 a recording of a remote debug session. This recording may then be
4128 replayed back to gdb using "gdbreplay". See gdbserver/README for
4129 details. This is useful when you have a problem with GDB while doing
4130 remote debugging; you can make a recording of the session and send it
4131 to someone else, who can then recreate the problem.
4133 * Speedups for remote debugging
4135 GDB includes speedups for downloading and stepping MIPS systems using
4136 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4137 and more efficient S-record downloading.
4139 * Memory use reductions and statistics collection
4141 GDB now uses less memory and reports statistics about memory usage.
4142 Try the `maint print statistics' command, for example.
4144 *** Changes in GDB-4.15:
4146 * Psymtabs for XCOFF
4148 The symbol reader for AIX GDB now uses partial symbol tables. This
4149 can greatly improve startup time, especially for large executables.
4151 * Remote targets use caching
4153 Remote targets now use a data cache to speed up communication with the
4154 remote side. The data cache could lead to incorrect results because
4155 it doesn't know about volatile variables, thus making it impossible to
4156 debug targets which use memory mapped I/O devices. `set remotecache
4157 off' turns the the data cache off.
4159 * Remote targets may have threads
4161 The standard remote protocol now includes support for multiple threads
4162 in the target system, using new protocol commands 'H' and 'T'. See
4163 gdb/remote.c for details.
4167 If GDB is configured with `--enable-netrom', then it will include
4168 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4169 acts as though it is a bank of ROM on the target board, but you can
4170 write into it over the network. GDB's support consists only of
4171 support for fast loading into the emulated ROM; to debug, you must use
4172 another protocol, such as standard remote protocol. The usual
4173 sequence is something like
4175 target nrom <netrom-hostname>
4177 target remote <netrom-hostname>:1235
4181 GDB now includes support for the Apple Macintosh, as a host only. It
4182 may be run as either an MPW tool or as a standalone application, and
4183 it can debug through the serial port. All the usual GDB commands are
4184 available, but to the target command, you must supply "serial" as the
4185 device type instead of "/dev/ttyXX". See mpw-README in the main
4186 directory for more information on how to build. The MPW configuration
4187 scripts */mpw-config.in support only a few targets, and only the
4188 mips-idt-ecoff target has been tested.
4192 GDB configuration now uses autoconf. This is not user-visible,
4193 but does simplify configuration and building.
4197 GDB now supports hpux10.
4199 *** Changes in GDB-4.14:
4201 * New native configurations
4203 x86 FreeBSD i[345]86-*-freebsd
4204 x86 NetBSD i[345]86-*-netbsd
4205 NS32k NetBSD ns32k-*-netbsd
4206 Sparc NetBSD sparc-*-netbsd
4210 A29K VxWorks a29k-*-vxworks
4211 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4212 CPU32 EST-300 emulator m68*-*-est*
4213 PowerPC ELF powerpc-*-elf
4216 * Alpha OSF/1 support for procfs
4218 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4219 possible to attach to running processes. As the mounting of the /proc
4220 filesystem is optional on the Alpha, GDB automatically determines
4221 the availability of /proc during startup. This can lead to problems
4222 if /proc is unmounted after GDB has been started.
4224 * Arguments to user-defined commands
4226 User commands may accept up to 10 arguments separated by whitespace.
4227 Arguments are accessed within the user command via $arg0..$arg9. A
4230 print $arg0 + $arg1 + $arg2
4232 To execute the command use:
4235 Defines the command "adder" which prints the sum of its three arguments.
4236 Note the arguments are text substitutions, so they may reference variables,
4237 use complex expressions, or even perform inferior function calls.
4239 * New `if' and `while' commands
4241 This makes it possible to write more sophisticated user-defined
4242 commands. Both commands take a single argument, which is the
4243 expression to evaluate, and must be followed by the commands to
4244 execute, one per line, if the expression is nonzero, the list being
4245 terminated by the word `end'. The `if' command list may include an
4246 `else' word, which causes the following commands to be executed only
4247 if the expression is zero.
4249 * Fortran source language mode
4251 GDB now includes partial support for Fortran 77. It will recognize
4252 Fortran programs and can evaluate a subset of Fortran expressions, but
4253 variables and functions may not be handled correctly. GDB will work
4254 with G77, but does not yet know much about symbols emitted by other
4257 * Better HPUX support
4259 Most debugging facilities now work on dynamic executables for HPPAs
4260 running hpux9 or later. You can attach to running dynamically linked
4261 processes, but by default the dynamic libraries will be read-only, so
4262 for instance you won't be able to put breakpoints in them. To change
4263 that behavior do the following before running the program:
4269 This will cause the libraries to be mapped private and read-write.
4270 To revert to the normal behavior, do this:
4276 You cannot set breakpoints or examine data in the library until after
4277 the library is loaded if the function/data symbols do not have
4280 GDB can now also read debug symbols produced by the HP C compiler on
4281 HPPAs (sorry, no C++, Fortran or 68k support).
4283 * Target byte order now dynamically selectable
4285 You can choose which byte order to use with a target system, via the
4286 commands "set endian big" and "set endian little", and you can see the
4287 current setting by using "show endian". You can also give the command
4288 "set endian auto", in which case GDB will use the byte order
4289 associated with the executable. Currently, only embedded MIPS
4290 configurations support dynamic selection of target byte order.
4292 * New DOS host serial code
4294 This version uses DPMI interrupts to handle buffered I/O, so you
4295 no longer need to run asynctsr when debugging boards connected to
4298 *** Changes in GDB-4.13:
4300 * New "complete" command
4302 This lists all the possible completions for the rest of the line, if it
4303 were to be given as a command itself. This is intended for use by emacs.
4305 * Trailing space optional in prompt
4307 "set prompt" no longer adds a space for you after the prompt you set. This
4308 allows you to set a prompt which ends in a space or one that does not.
4310 * Breakpoint hit counts
4312 "info break" now displays a count of the number of times the breakpoint
4313 has been hit. This is especially useful in conjunction with "ignore"; you
4314 can ignore a large number of breakpoint hits, look at the breakpoint info
4315 to see how many times the breakpoint was hit, then run again, ignoring one
4316 less than that number, and this will get you quickly to the last hit of
4319 * Ability to stop printing at NULL character
4321 "set print null-stop" will cause GDB to stop printing the characters of
4322 an array when the first NULL is encountered. This is useful when large
4323 arrays actually contain only short strings.
4325 * Shared library breakpoints
4327 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4328 breakpoints in shared libraries before the executable is run.
4330 * Hardware watchpoints
4332 There is a new hardware breakpoint for the watch command for sparclite
4333 targets. See gdb/sparclite/hw_breakpoint.note.
4335 Hardware watchpoints are also now supported under GNU/Linux.
4339 Annotations have been added. These are for use with graphical interfaces,
4340 and are still experimental. Currently only gdba.el uses these.
4342 * Improved Irix 5 support
4344 GDB now works properly with Irix 5.2.
4346 * Improved HPPA support
4348 GDB now works properly with the latest GCC and GAS.
4350 * New native configurations
4352 Sequent PTX4 i[34]86-sequent-ptx4
4353 HPPA running OSF/1 hppa*-*-osf*
4354 Atari TT running SVR4 m68*-*-sysv4*
4355 RS/6000 LynxOS rs6000-*-lynxos*
4359 OS/9000 i[34]86-*-os9k
4360 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4363 * Hitachi SH7000 and E7000-PC ICE support
4365 There is now support for communicating with the Hitachi E7000-PC ICE.
4366 This is available automatically when GDB is configured for the SH.
4370 As usual, a variety of small fixes and improvements, both generic
4371 and configuration-specific. See the ChangeLog for more detail.
4373 *** Changes in GDB-4.12:
4375 * Irix 5 is now supported
4379 GDB-4.12 on the HPPA has a number of changes which make it unable
4380 to debug the output from the currently released versions of GCC and
4381 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4382 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4383 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4386 *** Changes in GDB-4.11:
4388 * User visible changes:
4392 The "set remotedebug" option is now consistent between the mips remote
4393 target, remote targets using the gdb-specific protocol, UDI (AMD's
4394 debug protocol for the 29k) and the 88k bug monitor. It is now an
4395 integer specifying a debug level (normally 0 or 1, but 2 means more
4396 debugging info for the mips target).
4398 * DEC Alpha native support
4400 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4401 debug info, but GDB works fairly well with the DEC compiler and should
4402 work with a future GCC release. See the README file for a few
4403 Alpha-specific notes.
4405 * Preliminary thread implementation
4407 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4409 * LynxOS native and target support for 386
4411 This release has been hosted on LynxOS 2.2, and also can be configured
4412 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4415 * Improvements in C++ mangling/demangling.
4417 This release has much better g++ debugging, specifically in name
4418 mangling/demangling, virtual function calls, print virtual table,
4419 call methods, ...etc.
4421 *** Changes in GDB-4.10:
4423 * User visible changes:
4425 Remote debugging using the GDB-specific (`target remote') protocol now
4426 supports the `load' command. This is only useful if you have some
4427 other way of getting the stub to the target system, and you can put it
4428 somewhere in memory where it won't get clobbered by the download.
4430 Filename completion now works.
4432 When run under emacs mode, the "info line" command now causes the
4433 arrow to point to the line specified. Also, "info line" prints
4434 addresses in symbolic form (as well as hex).
4436 All vxworks based targets now support a user settable option, called
4437 vxworks-timeout. This option represents the number of seconds gdb
4438 should wait for responses to rpc's. You might want to use this if
4439 your vxworks target is, perhaps, a slow software simulator or happens
4440 to be on the far side of a thin network line.
4444 This release contains support for using a DEC alpha as a GDB host for
4445 cross debugging. Native alpha debugging is not supported yet.
4448 *** Changes in GDB-4.9:
4452 This is the first GDB release which is accompanied by a matching testsuite.
4453 The testsuite requires installation of dejagnu, which should be available
4454 via ftp from most sites that carry GNU software.
4458 'Cfront' style demangling has had its name changed to 'ARM' style, to
4459 emphasize that it was written from the specifications in the C++ Annotated
4460 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4461 disclaimers, it still generated too much confusion with users attempting to
4462 use gdb with AT&T cfront.
4466 GDB now uses a standard remote interface to a simulator library.
4467 So far, the library contains simulators for the Zilog Z8001/2, the
4468 Hitachi H8/300, H8/500 and Super-H.
4470 * New targets supported
4472 H8/300 simulator h8300-hitachi-hms or h8300hms
4473 H8/500 simulator h8500-hitachi-hms or h8500hms
4474 SH simulator sh-hitachi-hms or sh
4475 Z8000 simulator z8k-zilog-none or z8ksim
4476 IDT MIPS board over serial line mips-idt-ecoff
4478 Cross-debugging to GO32 targets is supported. It requires a custom
4479 version of the i386-stub.c module which is integrated with the
4480 GO32 memory extender.
4482 * New remote protocols
4484 MIPS remote debugging protocol.
4486 * New source languages supported
4488 This version includes preliminary support for Chill, a Pascal like language
4489 used by telecommunications companies. Chill support is also being integrated
4490 into the GNU compiler, but we don't know when it will be publically available.
4493 *** Changes in GDB-4.8:
4495 * HP Precision Architecture supported
4497 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4498 version of this support was available as a set of patches from the
4499 University of Utah. GDB does not support debugging of programs
4500 compiled with the HP compiler, because HP will not document their file
4501 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4502 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4504 Many problems in the preliminary version have been fixed.
4506 * Faster and better demangling
4508 We have improved template demangling and fixed numerous bugs in the GNU style
4509 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4510 character types (wchar_t) are now supported. Demangling of each symbol is now
4511 only done once, and is cached when the symbol table for a file is read in.
4512 This results in a small increase in memory usage for C programs, a moderate
4513 increase in memory usage for C++ programs, and a fantastic speedup in
4516 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4517 from the specifications in the Annotated Reference Manual, which AT&T's
4518 compiler does not actually implement.
4520 * G++ multiple inheritance compiler problem
4522 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4523 inheritance lattices was reworked to properly discover ambiguities. We
4524 recently found an example which causes this new algorithm to fail in a
4525 very subtle way, producing bad debug information for those classes.
4526 The file 'gcc.patch' (in this directory) can be applied to gcc to
4527 circumvent the problem. A future GCC release will contain a complete
4530 The previous G++ debug info problem (mentioned below for the gdb-4.7
4531 release) is fixed in gcc version 2.3.2.
4533 * Improved configure script
4535 The `configure' script will now attempt to guess your system type if
4536 you don't supply a host system type. The old scheme of supplying a
4537 host system triplet is preferable over using this. All the magic is
4538 done in the new `config.guess' script. Examine it for details.
4540 We have also brought our configure script much more in line with the FSF's
4541 version. It now supports the --with-xxx options. In particular,
4542 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4543 The resulting GDB will not be able to read arbitrary object file formats --
4544 only the format ``expected'' to be used on the configured target system.
4545 We hope to make this the default in a future release.
4547 * Documentation improvements
4549 There's new internal documentation on how to modify GDB, and how to
4550 produce clean changes to the code. We implore people to read it
4551 before submitting changes.
4553 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4554 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4555 `info' files are also provided. To build `info' files from scratch,
4556 you will need the latest `makeinfo' release, which will be available in
4557 a future texinfo-X.Y release.
4559 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4560 We're not sure exactly which versions have this problem, but it has
4561 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4562 or better. If that isn't possible, there is a patch in
4563 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4564 around this problem.
4568 GDB now supports array constants that can be used in expressions typed in by
4569 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4570 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4573 The new directory `gdb/sparclite' contains a program that demonstrates
4574 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4576 * New native hosts supported
4578 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4579 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4581 * New targets supported
4583 AMD 29k family via UDI a29k-amd-udi or udi29k
4585 * New file formats supported
4587 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4588 HPUX core files, and SCO 3.2v2 core files.
4592 Attaching to processes now works again; thanks for the many bug reports.
4594 We have also stomped on a bunch of core dumps caused by
4595 printf_filtered("%s") problems.
4597 We eliminated a copyright problem on the rpc and ptrace header files
4598 for VxWorks, which was discovered at the last minute during the 4.7
4599 release. You should now be able to build a VxWorks GDB.
4601 You can now interrupt gdb while an attached process is running. This
4602 will cause the attached process to stop, and give control back to GDB.
4604 We fixed problems caused by using too many file descriptors
4605 for reading symbols from object files and libraries. This was
4606 especially a problem for programs that used many (~100) shared
4609 The `step' command now only enters a subroutine if there is line number
4610 information for the subroutine. Otherwise it acts like the `next'
4611 command. Previously, `step' would enter subroutines if there was
4612 any debugging information about the routine. This avoids problems
4613 when using `cc -g1' on MIPS machines.
4615 * Internal improvements
4617 GDB's internal interfaces have been improved to make it easier to support
4618 debugging of multiple languages in the future.
4620 GDB now uses a common structure for symbol information internally.
4621 Minimal symbols (derived from linkage symbols in object files), partial
4622 symbols (from a quick scan of debug information), and full symbols
4623 contain a common subset of information, making it easier to write
4624 shared code that handles any of them.
4626 * New command line options
4628 We now accept --silent as an alias for --quiet.
4632 The memory-mapped-malloc library is now licensed under the GNU Library
4633 General Public License.
4635 *** Changes in GDB-4.7:
4637 * Host/native/target split
4639 GDB has had some major internal surgery to untangle the support for
4640 hosts and remote targets. Now, when you configure GDB for a remote
4641 target, it will no longer load in all of the support for debugging
4642 local programs on the host. When fully completed and tested, this will
4643 ensure that arbitrary host/target combinations are possible.
4645 The primary conceptual shift is to separate the non-portable code in
4646 GDB into three categories. Host specific code is required any time GDB
4647 is compiled on that host, regardless of the target. Target specific
4648 code relates to the peculiarities of the target, but can be compiled on
4649 any host. Native specific code is everything else: it can only be
4650 built when the host and target are the same system. Child process
4651 handling and core file support are two common `native' examples.
4653 GDB's use of /proc for controlling Unix child processes is now cleaner.
4654 It has been split out into a single module under the `target_ops' vector,
4655 plus two native-dependent functions for each system that uses /proc.
4657 * New hosts supported
4659 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
4660 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4661 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
4663 * New targets supported
4665 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4666 68030 and CPU32 m68030-*-*, m68332-*-*
4668 * New native hosts supported
4670 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4671 (386bsd is not well tested yet)
4672 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
4674 * New file formats supported
4676 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
4677 supports reading of `a.out.adobe' object files, which are an a.out
4678 format extended with minimal information about multiple sections.
4682 `show copying' is the same as the old `info copying'.
4683 `show warranty' is the same as `info warrantee'.
4684 These were renamed for consistency. The old commands continue to work.
4686 `info handle' is a new alias for `info signals'.
4688 You can now define pre-command hooks, which attach arbitrary command
4689 scripts to any command. The commands in the hook will be executed
4690 prior to the user's command. You can also create a hook which will be
4691 executed whenever the program stops. See gdb.texinfo.
4695 We now deal with Cfront style name mangling, and can even extract type
4696 info from mangled symbols. GDB can automatically figure out which
4697 symbol mangling style your C++ compiler uses.
4699 Calling of methods and virtual functions has been improved as well.
4703 The crash that occured when debugging Sun Ansi-C compiled binaries is
4704 fixed. This was due to mishandling of the extra N_SO stabs output
4707 We also finally got Ultrix 4.2 running in house, and fixed core file
4708 support, with help from a dozen people on the net.
4710 John M. Farrell discovered that the reason that single-stepping was so
4711 slow on all of the Mips based platforms (primarily SGI and DEC) was
4712 that we were trying to demangle and lookup a symbol used for internal
4713 purposes on every instruction that was being stepped through. Changing
4714 the name of that symbol so that it couldn't be mistaken for a C++
4715 mangled symbol sped things up a great deal.
4717 Rich Pixley sped up symbol lookups in general by getting much smarter
4718 about when C++ symbol mangling is necessary. This should make symbol
4719 completion (TAB on the command line) much faster. It's not as fast as
4720 we'd like, but it's significantly faster than gdb-4.6.
4724 A new user controllable variable 'call_scratch_address' can
4725 specify the location of a scratch area to be used when GDB
4726 calls a function in the target. This is necessary because the
4727 usual method of putting the scratch area on the stack does not work
4728 in systems that have separate instruction and data spaces.
4730 We integrated changes to support the 29k UDI (Universal Debugger
4731 Interface), but discovered at the last minute that we didn't have all
4732 of the appropriate copyright paperwork. We are working with AMD to
4733 resolve this, and hope to have it available soon.
4737 We have sped up the remote serial line protocol, especially for targets
4738 with lots of registers. It now supports a new `expedited status' ('T')
4739 message which can be used in place of the existing 'S' status message.
4740 This allows the remote stub to send only the registers that GDB
4741 needs to make a quick decision about single-stepping or conditional
4742 breakpoints, eliminating the need to fetch the entire register set for
4743 each instruction being stepped through.
4745 The GDB remote serial protocol now implements a write-through cache for
4746 registers, only re-reading the registers if the target has run.
4748 There is also a new remote serial stub for SPARC processors. You can
4749 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
4750 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
4751 processor with a serial port.
4755 Configure.in files have become much easier to read and modify. A new
4756 `table driven' format makes it more obvious what configurations are
4757 supported, and what files each one uses.
4761 There is a new opcodes library which will eventually contain all of the
4762 disassembly routines and opcode tables. At present, it only contains
4763 Sparc and Z8000 routines. This will allow the assembler, debugger, and
4764 disassembler (binutils/objdump) to share these routines.
4766 The libiberty library is now copylefted under the GNU Library General
4767 Public License. This allows more liberal use, and was done so libg++
4768 can use it. This makes no difference to GDB, since the Library License
4769 grants all the rights from the General Public License.
4773 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
4774 reference to the stabs symbol info used by the debugger. It is (as far
4775 as we know) the only published document on this fascinating topic. We
4776 encourage you to read it, compare it to the stabs information on your
4777 system, and send improvements on the document in general (to
4778 bug-gdb@prep.ai.mit.edu).
4780 And, of course, many bugs have been fixed.
4783 *** Changes in GDB-4.6:
4785 * Better support for C++ function names
4787 GDB now accepts as input the "demangled form" of C++ overloaded function
4788 names and member function names, and can do command completion on such names
4789 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
4790 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
4791 Make use of command completion, it is your friend.
4793 GDB also now accepts a variety of C++ mangled symbol formats. They are
4794 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
4795 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
4796 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
4797 for the list of formats.
4799 * G++ symbol mangling problem
4801 Recent versions of gcc have a bug in how they emit debugging information for
4802 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
4803 directory) can be applied to gcc to fix the problem. Alternatively, if you
4804 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
4805 usual symptom is difficulty with setting breakpoints on methods. GDB complains
4806 about the method being non-existent. (We believe that version 2.2.2 of GCC has
4809 * New 'maintenance' command
4811 All of the commands related to hacking GDB internals have been moved out of
4812 the main command set, and now live behind the 'maintenance' command. This
4813 can also be abbreviated as 'mt'. The following changes were made:
4815 dump-me -> maintenance dump-me
4816 info all-breakpoints -> maintenance info breakpoints
4817 printmsyms -> maintenance print msyms
4818 printobjfiles -> maintenance print objfiles
4819 printpsyms -> maintenance print psymbols
4820 printsyms -> maintenance print symbols
4822 The following commands are new:
4824 maintenance demangle Call internal GDB demangler routine to
4825 demangle a C++ link name and prints the result.
4826 maintenance print type Print a type chain for a given symbol
4828 * Change to .gdbinit file processing
4830 We now read the $HOME/.gdbinit file before processing the argv arguments
4831 (e.g. reading symbol files or core files). This allows global parameters to
4832 be set, which will apply during the symbol reading. The ./.gdbinit is still
4833 read after argv processing.
4835 * New hosts supported
4837 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
4839 GNU/Linux support i386-unknown-linux or linux
4841 We are also including code to support the HP/PA running BSD and HPUX. This
4842 is almost guaranteed not to work, as we didn't have time to test or build it
4843 for this release. We are including it so that the more adventurous (or
4844 masochistic) of you can play with it. We also had major problems with the
4845 fact that the compiler that we got from HP doesn't support the -g option.
4848 * New targets supported
4850 Hitachi H8/300 h8300-hitachi-hms or h8300hms
4852 * More smarts about finding #include files
4854 GDB now remembers the compilation directory for all include files, and for
4855 all files from which C is generated (like yacc and lex sources). This
4856 greatly improves GDB's ability to find yacc/lex sources, and include files,
4857 especially if you are debugging your program from a directory different from
4858 the one that contains your sources.
4860 We also fixed a bug which caused difficulty with listing and setting
4861 breakpoints in include files which contain C code. (In the past, you had to
4862 try twice in order to list an include file that you hadn't looked at before.)
4864 * Interesting infernals change
4866 GDB now deals with arbitrary numbers of sections, where the symbols for each
4867 section must be relocated relative to that section's landing place in the
4868 target's address space. This work was needed to support ELF with embedded
4869 stabs used by Solaris-2.0.
4871 * Bug fixes (of course!)
4873 There have been loads of fixes for the following things:
4874 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
4875 i960, stabs, DOS(GO32), procfs, etc...
4877 See the ChangeLog for details.
4879 *** Changes in GDB-4.5:
4881 * New machines supported (host and target)
4883 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
4885 SGI Irix-4.x mips-sgi-irix4 or iris4
4887 * New malloc package
4889 GDB now uses a new memory manager called mmalloc, based on gmalloc.
4890 Mmalloc is capable of handling mutiple heaps of memory. It is also
4891 capable of saving a heap to a file, and then mapping it back in later.
4892 This can be used to greatly speedup the startup of GDB by using a
4893 pre-parsed symbol table which lives in a mmalloc managed heap. For
4894 more details, please read mmalloc/mmalloc.texi.
4898 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
4899 'help info proc' for details.
4901 * MIPS ecoff symbol table format
4903 The code that reads MIPS symbol table format is now supported on all hosts.
4904 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
4907 * File name changes for MS-DOS
4909 Many files in the config directories have been renamed to make it easier to
4910 support GDB on MS-DOSe systems (which have very restrictive file name
4911 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
4912 environment) is close to working but has some remaining problems. Note
4913 that debugging of DOS programs is not supported, due to limitations
4914 in the ``operating system'', but it can be used to host cross-debugging.
4916 * Cross byte order fixes
4918 Many fixes have been made to support cross debugging of Sparc and MIPS
4919 targets from hosts whose byte order differs.
4921 * New -mapped and -readnow options
4923 If memory-mapped files are available on your system through the 'mmap'
4924 system call, you can use the -mapped option on the `file' or
4925 `symbol-file' commands to cause GDB to write the symbols from your
4926 program into a reusable file. If the program you are debugging is
4927 called `/path/fred', the mapped symbol file will be `./fred.syms'.
4928 Future GDB debugging sessions will notice the presence of this file,
4929 and will quickly map in symbol information from it, rather than reading
4930 the symbol table from the executable program. Using the '-mapped'
4931 option in a GDB `file' or `symbol-file' command has the same effect as
4932 starting GDB with the '-mapped' command-line option.
4934 You can cause GDB to read the entire symbol table immediately by using
4935 the '-readnow' option with any of the commands that load symbol table
4936 information (or on the GDB command line). This makes the command
4937 slower, but makes future operations faster.
4939 The -mapped and -readnow options are typically combined in order to
4940 build a `fred.syms' file that contains complete symbol information.
4941 A simple GDB invocation to do nothing but build a `.syms' file for future
4944 gdb -batch -nx -mapped -readnow programname
4946 The `.syms' file is specific to the host machine on which GDB is run.
4947 It holds an exact image of GDB's internal symbol table. It cannot be
4948 shared across multiple host platforms.
4950 * longjmp() handling
4952 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
4953 siglongjmp() without losing control. This feature has not yet been ported to
4954 all systems. It currently works on many 386 platforms, all MIPS-based
4955 platforms (SGI, DECstation, etc), and Sun3/4.
4959 Preliminary work has been put in to support the new Solaris OS from Sun. At
4960 this time, it can control and debug processes, but it is not capable of
4965 As always, many many bug fixes. The major areas were with g++, and mipsread.
4966 People using the MIPS-based platforms should experience fewer mysterious
4967 crashes and trashed symbol tables.
4969 *** Changes in GDB-4.4:
4971 * New machines supported (host and target)
4973 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4975 BSD Reno on Vax vax-dec-bsd
4976 Ultrix on Vax vax-dec-ultrix
4978 * New machines supported (target)
4980 AMD 29000 embedded, using EBMON a29k-none-none
4984 GDB continues to improve its handling of C++. `References' work better.
4985 The demangler has also been improved, and now deals with symbols mangled as
4986 per the Annotated C++ Reference Guide.
4988 GDB also now handles `stabs' symbol information embedded in MIPS
4989 `ecoff' symbol tables. Since the ecoff format was not easily
4990 extensible to handle new languages such as C++, this appeared to be a
4991 good way to put C++ debugging info into MIPS binaries. This option
4992 will be supported in the GNU C compiler, version 2, when it is
4995 * New features for SVR4
4997 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
4998 shared libraries. Debugging dynamically linked programs should present
4999 only minor differences from debugging statically linked programs.
5001 The `info proc' command will print out information about any process
5002 on an SVR4 system (including the one you are debugging). At the moment,
5003 it prints the address mappings of the process.
5005 If you bring up GDB on another SVR4 system, please send mail to
5006 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5008 * Better dynamic linking support in SunOS
5010 Reading symbols from shared libraries which contain debugging symbols
5011 now works properly. However, there remain issues such as automatic
5012 skipping of `transfer vector' code during function calls, which
5013 make it harder to debug code in a shared library, than to debug the
5014 same code linked statically.
5018 GDB is now using the latest `getopt' routines from the FSF. This
5019 version accepts the -- prefix for options with long names. GDB will
5020 continue to accept the old forms (-option and +option) as well.
5021 Various single letter abbreviations for options have been explicity
5022 added to the option table so that they won't get overshadowed in the
5023 future by other options that begin with the same letter.
5027 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5028 Many assorted bugs have been handled. Many more remain to be handled.
5029 See the various ChangeLog files (primarily in gdb and bfd) for details.
5032 *** Changes in GDB-4.3:
5034 * New machines supported (host and target)
5036 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5037 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5038 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5040 * Almost SCO Unix support
5042 We had hoped to support:
5043 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5044 (except for core file support), but we discovered very late in the release
5045 that it has problems with process groups that render gdb unusable. Sorry
5046 about that. I encourage people to fix it and post the fixes.
5048 * Preliminary ELF and DWARF support
5050 GDB can read ELF object files on System V Release 4, and can handle
5051 debugging records for C, in DWARF format, in ELF files. This support
5052 is preliminary. If you bring up GDB on another SVR4 system, please
5053 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5058 GDB now uses the latest `readline' library. One user-visible change
5059 is that two tabs will list possible command completions, which previously
5060 required typing M-? (meta-question mark, or ESC ?).
5064 The `stepi' bug that many of you noticed has been squashed.
5065 Many bugs in C++ have been handled. Many more remain to be handled.
5066 See the various ChangeLog files (primarily in gdb and bfd) for details.
5068 * State of the MIPS world (in case you wondered):
5070 GDB can understand the symbol tables emitted by the compilers
5071 supplied by most vendors of MIPS-based machines, including DEC. These
5072 symbol tables are in a format that essentially nobody else uses.
5074 Some versions of gcc come with an assembler post-processor called
5075 mips-tfile. This program is required if you want to do source-level
5076 debugging of gcc-compiled programs. I believe FSF does not ship
5077 mips-tfile with gcc version 1, but it will eventually come with gcc
5080 Debugging of g++ output remains a problem. g++ version 1.xx does not
5081 really support it at all. (If you're lucky, you should be able to get
5082 line numbers and stack traces to work, but no parameters or local
5083 variables.) With some work it should be possible to improve the
5086 When gcc version 2 is released, you will have somewhat better luck.
5087 However, even then you will get confusing results for inheritance and
5090 We will eventually provide full debugging of g++ output on
5091 DECstations. This will probably involve some kind of stabs-in-ecoff
5092 encapulation, but the details have not been worked out yet.
5095 *** Changes in GDB-4.2:
5097 * Improved configuration
5099 Only one copy of `configure' exists now, and it is not self-modifying.
5100 Porting BFD is simpler.
5104 The `step' and `next' commands now only stop at the first instruction
5105 of a source line. This prevents the multiple stops that used to occur
5106 in switch statements, for-loops, etc. `Step' continues to stop if a
5107 function that has debugging information is called within the line.
5111 Lots of small bugs fixed. More remain.
5113 * New host supported (not target)
5115 Intel 386 PC clone running Mach i386-none-mach
5118 *** Changes in GDB-4.1:
5120 * Multiple source language support
5122 GDB now has internal scaffolding to handle several source languages.
5123 It determines the type of each source file from its filename extension,
5124 and will switch expression parsing and number formatting to match the
5125 language of the function in the currently selected stack frame.
5126 You can also specifically set the language to be used, with
5127 `set language c' or `set language modula-2'.
5131 GDB now has preliminary support for the GNU Modula-2 compiler,
5132 currently under development at the State University of New York at
5133 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5134 continue through the fall of 1991 and into 1992.
5136 Other Modula-2 compilers are currently not supported, and attempting to
5137 debug programs compiled with them will likely result in an error as the
5138 symbol table is read. Feel free to work on it, though!
5140 There are hooks in GDB for strict type checking and range checking,
5141 in the `Modula-2 philosophy', but they do not currently work.
5145 GDB can now write to executable and core files (e.g. patch
5146 a variable's value). You must turn this switch on, specify
5147 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5148 by assigning a new value to a variable. Modifications take
5151 * Automatic SunOS shared library reading
5153 When you run your program, GDB automatically determines where its
5154 shared libraries (if any) have been loaded, and reads their symbols.
5155 The `share' command is no longer needed. This also works when
5156 examining core files.
5160 You can specify the number of lines that the `list' command shows.
5163 * New machines supported (host and target)
5165 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5166 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5167 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5169 * New hosts supported (not targets)
5171 IBM RT/PC: romp-ibm-aix or rtpc
5173 * New targets supported (not hosts)
5175 AMD 29000 embedded with COFF a29k-none-coff
5176 AMD 29000 embedded with a.out a29k-none-aout
5177 Ultracomputer remote kernel debug a29k-nyu-kern
5179 * New remote interfaces
5185 *** Changes in GDB-4.0:
5189 Wide output is wrapped at good places to make the output more readable.
5191 Gdb now supports cross-debugging from a host machine of one type to a
5192 target machine of another type. Communication with the target system
5193 is over serial lines. The ``target'' command handles connecting to the
5194 remote system; the ``load'' command will download a program into the
5195 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5196 also supports debugging of realtime processes running under VxWorks,
5197 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5198 stub on the target system.
5200 New CPUs supported include the AMD 29000 and Intel 960.
5202 GDB now reads object files and symbol tables via a ``binary file''
5203 library, which allows a single copy of GDB to debug programs of multiple
5204 object file types such as a.out and coff.
5206 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5207 refcard.dvi and refcard.ps are available to format it).
5210 * Control-Variable user interface simplified
5212 All variables that control the operation of the debugger can be set
5213 by the ``set'' command, and displayed by the ``show'' command.
5215 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5216 ``Show prompt'' produces the response:
5217 Gdb's prompt is new-gdb=>.
5219 What follows are the NEW set commands. The command ``help set'' will
5220 print a complete list of old and new set commands. ``help set FOO''
5221 will give a longer description of the variable FOO. ``show'' will show
5222 all of the variable descriptions and their current settings.
5224 confirm on/off: Enables warning questions for operations that are
5225 hard to recover from, e.g. rerunning the program while
5226 it is already running. Default is ON.
5228 editing on/off: Enables EMACS style command line editing
5229 of input. Previous lines can be recalled with
5230 control-P, the current line can be edited with control-B,
5231 you can search for commands with control-R, etc.
5234 history filename NAME: NAME is where the gdb command history
5235 will be stored. The default is .gdb_history,
5236 or the value of the environment variable
5239 history size N: The size, in commands, of the command history. The
5240 default is 256, or the value of the environment variable
5243 history save on/off: If this value is set to ON, the history file will
5244 be saved after exiting gdb. If set to OFF, the
5245 file will not be saved. The default is OFF.
5247 history expansion on/off: If this value is set to ON, then csh-like
5248 history expansion will be performed on
5249 command line input. The default is OFF.
5251 radix N: Sets the default radix for input and output. It can be set
5252 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5253 in the current radix, so "set radix 10" is always a no-op.
5255 height N: This integer value is the number of lines on a page. Default
5256 is 24, the current `stty rows'' setting, or the ``li#''
5257 setting from the termcap entry matching the environment
5260 width N: This integer value is the number of characters on a line.
5261 Default is 80, the current `stty cols'' setting, or the ``co#''
5262 setting from the termcap entry matching the environment
5265 Note: ``set screensize'' is obsolete. Use ``set height'' and
5266 ``set width'' instead.
5268 print address on/off: Print memory addresses in various command displays,
5269 such as stack traces and structure values. Gdb looks
5270 more ``symbolic'' if you turn this off; it looks more
5271 ``machine level'' with it on. Default is ON.
5273 print array on/off: Prettyprint arrays. New convenient format! Default
5276 print demangle on/off: Print C++ symbols in "source" form if on,
5279 print asm-demangle on/off: Same, for assembler level printouts
5282 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5285 * Support for Epoch Environment.
5287 The epoch environment is a version of Emacs v18 with windowing. One
5288 new command, ``inspect'', is identical to ``print'', except that if you
5289 are running in the epoch environment, the value is printed in its own
5293 * Support for Shared Libraries
5295 GDB can now debug programs and core files that use SunOS shared libraries.
5296 Symbols from a shared library cannot be referenced
5297 before the shared library has been linked with the program (this
5298 happens after you type ``run'' and before the function main() is entered).
5299 At any time after this linking (including when examining core files
5300 from dynamically linked programs), gdb reads the symbols from each
5301 shared library when you type the ``sharedlibrary'' command.
5302 It can be abbreviated ``share''.
5304 sharedlibrary REGEXP: Load shared object library symbols for files
5305 matching a unix regular expression. No argument
5306 indicates to load symbols for all shared libraries.
5308 info sharedlibrary: Status of loaded shared libraries.
5313 A watchpoint stops execution of a program whenever the value of an
5314 expression changes. Checking for this slows down execution
5315 tremendously whenever you are in the scope of the expression, but is
5316 quite useful for catching tough ``bit-spreader'' or pointer misuse
5317 problems. Some machines such as the 386 have hardware for doing this
5318 more quickly, and future versions of gdb will use this hardware.
5320 watch EXP: Set a watchpoint (breakpoint) for an expression.
5322 info watchpoints: Information about your watchpoints.
5324 delete N: Deletes watchpoint number N (same as breakpoints).
5325 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5326 enable N: Re-enables watchpoint number N (same as breakpoints).
5329 * C++ multiple inheritance
5331 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5334 * C++ exception handling
5336 Gdb now supports limited C++ exception handling. Besides the existing
5337 ability to breakpoint on an exception handler, gdb can breakpoint on
5338 the raising of an exception (before the stack is peeled back to the
5341 catch FOO: If there is a FOO exception handler in the dynamic scope,
5342 set a breakpoint to catch exceptions which may be raised there.
5343 Multiple exceptions (``catch foo bar baz'') may be caught.
5345 info catch: Lists all exceptions which may be caught in the
5346 current stack frame.
5349 * Minor command changes
5351 The command ``call func (arg, arg, ...)'' now acts like the print
5352 command, except it does not print or save a value if the function's result
5353 is void. This is similar to dbx usage.
5355 The ``up'' and ``down'' commands now always print the frame they end up
5356 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5357 frames without printing.
5359 * New directory command
5361 'dir' now adds directories to the FRONT of the source search path.
5362 The path starts off empty. Source files that contain debug information
5363 about the directory in which they were compiled can be found even
5364 with an empty path; Sun CC and GCC include this information. If GDB can't
5365 find your source file in the current directory, type "dir .".
5367 * Configuring GDB for compilation
5369 For normal use, type ``./configure host''. See README or gdb.texinfo
5372 GDB now handles cross debugging. If you are remotely debugging between
5373 two different machines, type ``./configure host -target=targ''.
5374 Host is the machine where GDB will run; targ is the machine
5375 where the program that you are debugging will run.