1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.6
6 * New convenience function "$_isvoid", to check whether an expression
7 is void. A void expression is an expression where the type of the
8 result is "void". For example, some convenience variables may be
9 "void" when evaluated (e.g., "$_exitcode" before the execution of
10 the program being debugged; or an undefined convenience variable).
11 Another example, when calling a function whose return type is
14 * The "maintenance print objfiles" command now takes an optional regexp.
16 * The "catch syscall" command now works on arm*-linux* targets.
20 ** Frame filters and frame decorators have been added.
24 Nios II ELF nios2*-*-elf
25 Nios II GNU/Linux nios2*-*-linux
26 Texas Instruments MSP430 msp430*-*-elf
28 * Removed native configurations
30 Support for these a.out NetBSD and OpenBSD obsolete configurations has
31 been removed. ELF variants of these configurations are kept supported.
33 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
34 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
35 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
36 i[34567]86-*-openbsd3.[0-3]
37 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
38 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
39 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
43 Like "catch throw", but catches a re-thrown exception.
45 Renamed from old "maint check-symtabs".
47 Perform consistency checks on symtabs.
49 Expand symtabs matching an optional regexp.
52 Display the details of GDB configure-time options.
54 maint set|show per-command
55 maint set|show per-command space
56 maint set|show per-command time
57 maint set|show per-command symtab
58 Enable display of per-command gdb resource usage.
62 set print raw frame-arguments
63 show print raw frame-arguments
64 Set/show whether to print frame arguments in raw mode,
65 disregarding any defined pretty-printers.
67 set remote trace-status-packet
68 show remote trace-status-packet
69 Set/show the use of remote protocol qTStatus packet.
73 Control display of debugging messages related to Nios II targets.
77 Control whether target-assisted range stepping is enabled.
79 * You can now use a literal value 'unlimited' for options that
80 interpret 0 or -1 as meaning "unlimited". E.g., "set
81 trace-buffer-size unlimited" is now an alias for "set
82 trace-buffer-size -1" and "set height unlimited" is now an alias for
85 * New command-line options
87 Display the details of GDB configure-time options.
89 * The command 'tsave' can now support new option '-ctf' to save trace
90 buffer in Common Trace Format.
92 * Newly installed $prefix/bin/gcore acts as a shell interface for the
95 * GDB now implements the the C++ 'typeid' operator.
97 * The new convenience variable $_exception holds the exception being
98 thrown or caught at an exception-related catchpoint.
100 * The exception-related catchpoints, like "catch throw", now accept a
101 regular expression which can be used to filter exceptions by type.
105 ** The -trace-save MI command can optionally save trace buffer in Common
108 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
110 ** The command -data-list-register-values now accepts an optional
111 "--skip-unavailable" option. When used, only the available registers
114 ** The new command -trace-frame-collected dumps collected variables,
115 computed expressions, tvars, memory and registers in a traceframe.
117 ** The commands -stack-list-locals, -stack-list-arguments and
118 -stack-list-variables now accept an option "--skip-unavailable".
119 When used, only the available locals or arguments are displayed.
121 * New system-wide configuration scripts
122 A GDB installation now provides scripts suitable for use as system-wide
123 configuration scripts for the following systems:
127 * GDB now supports target-assigned range stepping with remote targets.
128 This improves the performance of stepping source lines by reducing
129 the number of control packets from/to GDB. See "New remote packets"
132 * GDB now understands the element 'tvar' in the XML traceframe info.
133 It has the id of the collected trace state variables.
135 * On S/390 targets that provide the transactional-execution feature,
136 the program interruption transaction diagnostic block (TDB) is now
137 represented as a number of additional "registers" in GDB.
143 The vCont packet supports a new 'r' action, that tells the remote
144 stub to step through an address range itself, without GDB
145 involvemement at each single-step.
147 qXfer:libraries-svr4:read's annex
148 The previously unused annex of the qXfer:libraries-svr4:read packet
149 is now used to support passing an argument list. The remote stub
150 reports support for this argument list to GDB's qSupported query.
151 The defined arguments are "start" and "prev", used to reduce work
152 necessary for library list updating, resulting in significant
155 * New features in the GDB remote stub, GDBserver
157 ** GDBserver now supports target-assisted range stepping. Currently
158 enabled on x86/x86_64 GNU/Linux targets.
160 ** GDBserver now adds element 'tvar' in the XML in the reply to
161 'qXfer:traceframe-info:read'. It has the id of the collected
162 trace state variables.
164 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
167 * New 'z' formatter for printing and examining memory, this displays the
168 value as hexadecimal zero padded on the left to the size of the type.
170 * GDB can now use Windows x64 unwinding data.
172 *** Changes in GDB 7.6
174 * Target record has been renamed to record-full.
175 Record/replay is now enabled with the "record full" command.
176 This also affects settings that are associated with full record/replay
177 that have been moved from "set/show record" to "set/show record full":
179 set|show record full insn-number-max
180 set|show record full stop-at-limit
181 set|show record full memory-query
183 * A new record target "record-btrace" has been added. The new target
184 uses hardware support to record the control-flow of a process. It
185 does not support replaying the execution, but it implements the
186 below new commands for investigating the recorded execution log.
187 This new recording method can be enabled using:
191 The "record-btrace" target is only available on Intel Atom processors
192 and requires a Linux kernel 2.6.32 or later.
194 * Two new commands have been added for record/replay to give information
195 about the recorded execution without having to replay the execution.
196 The commands are only supported by "record btrace".
198 record instruction-history prints the execution history at
199 instruction granularity
201 record function-call-history prints the execution history at
204 * New native configurations
206 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
207 FreeBSD/powerpc powerpc*-*-freebsd
208 x86_64/Cygwin x86_64-*-cygwin*
209 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
213 ARM AArch64 aarch64*-*-elf
214 ARM AArch64 GNU/Linux aarch64*-*-linux
215 Lynx 178 PowerPC powerpc-*-lynx*178
216 x86_64/Cygwin x86_64-*-cygwin*
217 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
219 * If the configured location of system.gdbinit file (as given by the
220 --with-system-gdbinit option at configure time) is in the
221 data-directory (as specified by --with-gdb-datadir at configure
222 time) or in one of its subdirectories, then GDB will look for the
223 system-wide init file in the directory specified by the
224 --data-directory command-line option.
226 * New command line options:
228 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
229 other initialization files, unlike -nx which disables all of them.
231 * Removed command line options
233 -epoch This was used by the gdb mode in Epoch, an ancient fork of
236 * The 'ptype' and 'whatis' commands now accept an argument to control
239 * 'info proc' now works on some core files.
243 ** Vectors can be created with gdb.Type.vector.
245 ** Python's atexit.register now works in GDB.
247 ** Types can be pretty-printed via a Python API.
249 ** Python 3 is now supported (in addition to Python 2.4 or later)
251 ** New class gdb.Architecture exposes GDB's internal representation
252 of architecture in the Python API.
254 ** New method Frame.architecture returns the gdb.Architecture object
255 corresponding to the frame's architecture.
257 * New Python-based convenience functions:
259 ** $_memeq(buf1, buf2, length)
260 ** $_streq(str1, str2)
262 ** $_regex(str, regex)
264 * The 'cd' command now defaults to using '~' (the home directory) if not
267 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
268 default for GCC since November 2000.
270 * The command 'forward-search' can now be abbreviated as 'fo'.
272 * The command 'info tracepoints' can now display 'installed on target'
273 or 'not installed on target' for each non-pending location of tracepoint.
275 * New configure options
277 --enable-libmcheck/--disable-libmcheck
278 By default, development versions are built with -lmcheck on hosts
279 that support it, in order to help track memory corruption issues.
280 Release versions, on the other hand, are built without -lmcheck
281 by default. The --enable-libmcheck/--disable-libmcheck configure
282 options allow the user to override that default.
283 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
284 This configure option allows the user to build GDB with
285 libbabeltrace using which GDB can read Common Trace Format data.
287 * New commands (for set/show, see "New options" below)
290 Catch signals. This is similar to "handle", but allows commands and
291 conditions to be attached.
294 List the BFDs known to GDB.
296 python-interactive [command]
298 Start a Python interactive prompt, or evaluate the optional command
299 and print the result of expressions.
302 "py" is a new alias for "python".
304 enable type-printer [name]...
305 disable type-printer [name]...
306 Enable or disable type printers.
310 ** For the Renesas Super-H architecture, the "regs" command has been removed
311 (has been deprecated in GDB 7.5), and "info all-registers" should be used
316 set print type methods (on|off)
317 show print type methods
318 Control whether method declarations are displayed by "ptype".
319 The default is to show them.
321 set print type typedefs (on|off)
322 show print type typedefs
323 Control whether typedef definitions are displayed by "ptype".
324 The default is to show them.
326 set filename-display basename|relative|absolute
327 show filename-display
328 Control the way in which filenames is displayed.
329 The default is "relative", which preserves previous behavior.
331 set trace-buffer-size
332 show trace-buffer-size
333 Request target to change the size of trace buffer.
335 set remote trace-buffer-size-packet auto|on|off
336 show remote trace-buffer-size-packet
337 Control the use of the remote protocol `QTBuffer:size' packet.
341 Control display of debugging messages related to ARM AArch64.
344 set debug coff-pe-read
345 show debug coff-pe-read
346 Control display of debugging messages related to reading of COFF/PE
351 Control display of debugging messages related to Mach-O symbols
354 set debug notification
355 show debug notification
356 Control display of debugging info for async remote notification.
360 ** Command parameter changes are now notified using new async record
361 "=cmd-param-changed".
362 ** Trace frame changes caused by command "tfind" are now notified using
363 new async record "=traceframe-changed".
364 ** The creation, deletion and modification of trace state variables
365 are now notified using new async records "=tsv-created",
366 "=tsv-deleted" and "=tsv-modified".
367 ** The start and stop of process record are now notified using new
368 async record "=record-started" and "=record-stopped".
369 ** Memory changes are now notified using new async record
371 ** The data-disassemble command response will include a "fullname" field
372 containing the absolute file name when source has been requested.
373 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
374 command, to allow pattern filling of memory areas.
375 ** New commands "-catch-load"/"-catch-unload" added for intercepting
376 library load/unload events.
377 ** The response to breakpoint commands and breakpoint async records
378 includes an "installed" field containing a boolean state about each
379 non-pending tracepoint location is whether installed on target or not.
380 ** Output of the "-trace-status" command includes a "trace-file" field
381 containing the name of the trace file being examined. This field is
382 optional, and only present when examining a trace file.
383 ** The "fullname" field is now always present along with the "file" field,
384 even if the file cannot be found by GDB.
386 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
387 You must have the LZMA library available when configuring GDB for this
388 feature to be enabled. For more information, see:
389 http://fedoraproject.org/wiki/Features/MiniDebugInfo
394 Set the size of trace buffer. The remote stub reports support for this
395 packet to gdb's qSupported query.
398 Enable Branch Trace Store (BTS)-based branch tracing for the current
399 thread. The remote stub reports support for this packet to gdb's
403 Disable branch tracing for the current thread. The remote stub reports
404 support for this packet to gdb's qSupported query.
407 Read the traced branches for the current thread. The remote stub
408 reports support for this packet to gdb's qSupported query.
410 *** Changes in GDB 7.5
412 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
413 for more x32 ABI info.
415 * GDB now supports access to MIPS DSP registers on Linux targets.
417 * GDB now supports debugging microMIPS binaries.
419 * The "info os" command on GNU/Linux can now display information on
420 several new classes of objects managed by the operating system:
421 "info os procgroups" lists process groups
422 "info os files" lists file descriptors
423 "info os sockets" lists internet-domain sockets
424 "info os shm" lists shared-memory regions
425 "info os semaphores" lists semaphores
426 "info os msg" lists message queues
427 "info os modules" lists loaded kernel modules
429 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
430 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
431 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
432 options and inspect the probe arguments using the new $_probe_arg family
433 of convenience variables. You can obtain more information about SystemTap
434 in <http://sourceware.org/systemtap/>.
436 * GDB now supports reversible debugging on ARM, it allows you to
437 debug basic ARM and THUMB instructions, and provides
438 record/replay support.
440 * The option "symbol-reloading" has been deleted as it is no longer used.
444 ** GDB commands implemented in Python can now be put in command class
447 ** The "maint set python print-stack on|off" is now deleted.
449 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
450 apply "flag enum"-style pretty-printing to any enum.
452 ** gdb.lookup_symbol can now work when there is no current frame.
454 ** gdb.Symbol now has a 'line' attribute, holding the line number in
455 the source at which the symbol was defined.
457 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
458 method 'value'. The former indicates whether the symbol needs a
459 frame in order to compute its value, and the latter computes the
462 ** A new method 'referenced_value' on gdb.Value objects which can
463 dereference pointer as well as C++ reference values.
465 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
466 which return the global and static blocks (as gdb.Block objects),
467 of the underlying symbol table, respectively.
469 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
470 object associated with a PC value.
472 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
473 of the address range occupied by code for the current source line.
475 * Go language support.
476 GDB now supports debugging programs written in the Go programming
479 * GDBserver now supports stdio connections.
480 E.g. (gdb) target remote | ssh myhost gdbserver - hello
482 * The binary "gdbtui" can no longer be built or installed.
483 Use "gdb -tui" instead.
485 * GDB will now print "flag" enums specially. A flag enum is one where
486 all the enumerator values have no bits in common when pairwise
487 "and"ed. When printing a value whose type is a flag enum, GDB will
488 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
489 (gdb) print (enum E) 3
492 * The filename part of a linespec will now match trailing components
493 of a source file name. For example, "break gcc/expr.c:1000" will
494 now set a breakpoint in build/gcc/expr.c, but not
497 * The "info proc" and "generate-core-file" commands will now also
498 work on remote targets connected to GDBserver on Linux.
500 * The command "info catch" has been removed. It has been disabled
503 * The "catch exception" and "catch assert" commands now accept
504 a condition at the end of the command, much like the "break"
505 command does. For instance:
507 (gdb) catch exception Constraint_Error if Barrier = True
509 Previously, it was possible to add a condition to such catchpoints,
510 but it had to be done as a second step, after the catchpoint had been
511 created, using the "condition" command.
513 * The "info static-tracepoint-marker" command will now also work on
514 native Linux targets with in-process agent.
516 * GDB can now set breakpoints on inlined functions.
518 * The .gdb_index section has been updated to include symbols for
519 inlined functions. GDB will ignore older .gdb_index sections by
520 default, which could cause symbol files to be loaded more slowly
521 until their .gdb_index sections can be recreated. The new command
522 "set use-deprecated-index-sections on" will cause GDB to use any older
523 .gdb_index sections it finds. This will restore performance, but the
524 ability to set breakpoints on inlined functions will be lost in symbol
525 files with older .gdb_index sections.
527 The .gdb_index section has also been updated to record more information
528 about each symbol. This speeds up the "info variables", "info functions"
529 and "info types" commands when used with programs having the .gdb_index
530 section, as well as speeding up debugging with shared libraries using
531 the .gdb_index section.
533 * Ada support for GDB/MI Variable Objects has been added.
535 * GDB can now support 'breakpoint always-inserted mode' in 'record'
540 ** New command -info-os is the MI equivalent of "info os".
542 ** Output logs ("set logging" and related) now include MI output.
546 ** "set use-deprecated-index-sections on|off"
547 "show use-deprecated-index-sections on|off"
548 Controls the use of deprecated .gdb_index sections.
550 ** "catch load" and "catch unload" can be used to stop when a shared
551 library is loaded or unloaded, respectively.
553 ** "enable count" can be used to auto-disable a breakpoint after
556 ** "info vtbl" can be used to show the virtual method tables for
557 C++ and Java objects.
559 ** "explore" and its sub commands "explore value" and "explore type"
560 can be used to reccursively explore values and types of
561 expressions. These commands are available only if GDB is
562 configured with '--with-python'.
564 ** "info auto-load" shows status of all kinds of auto-loaded files,
565 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
566 sequences of commands files, "info auto-load python-scripts"
567 shows status of auto-loading Python script files,
568 "info auto-load local-gdbinit" shows status of loading init file
569 (.gdbinit) from current directory and "info auto-load libthread-db" shows
570 status of inferior specific thread debugging shared library loading.
572 ** "info auto-load-scripts", "set auto-load-scripts on|off"
573 and "show auto-load-scripts" commands have been deprecated, use their
574 "info auto-load python-scripts", "set auto-load python-scripts on|off"
575 and "show auto-load python-scripts" counterparts instead.
577 ** "dprintf location,format,args..." creates a dynamic printf, which
578 is basically a breakpoint that does a printf and immediately
579 resumes your program's execution, so it is like a printf that you
580 can insert dynamically at runtime instead of at compiletime.
582 ** "set print symbol"
584 Controls whether GDB attempts to display the symbol, if any,
585 corresponding to addresses it prints. This defaults to "on", but
586 you can set it to "off" to restore GDB's previous behavior.
588 * Deprecated commands
590 ** For the Renesas Super-H architecture, the "regs" command has been
591 deprecated, and "info all-registers" should be used instead.
595 Renesas RL78 rl78-*-elf
596 HP OpenVMS ia64 ia64-hp-openvms*
598 * GDBserver supports evaluation of breakpoint conditions. When
599 support is advertised by GDBserver, GDB may be told to send the
600 breakpoint conditions in bytecode form to GDBserver. GDBserver
601 will only report the breakpoint trigger to GDB when its condition
607 show mips compression
608 Select the compressed ISA encoding used in functions that have no symbol
609 information available. The encoding can be set to either of:
612 and is updated automatically from ELF file flags if available.
614 set breakpoint condition-evaluation
615 show breakpoint condition-evaluation
616 Control whether breakpoint conditions are evaluated by GDB ("host") or by
617 GDBserver ("target"). Default option "auto" chooses the most efficient
619 This option can improve debugger efficiency depending on the speed of the
623 Disable auto-loading globally.
626 Show auto-loading setting of all kinds of auto-loaded files.
628 set auto-load gdb-scripts on|off
629 show auto-load gdb-scripts
630 Control auto-loading of GDB canned sequences of commands files.
632 set auto-load python-scripts on|off
633 show auto-load python-scripts
634 Control auto-loading of Python script files.
636 set auto-load local-gdbinit on|off
637 show auto-load local-gdbinit
638 Control loading of init file (.gdbinit) from current directory.
640 set auto-load libthread-db on|off
641 show auto-load libthread-db
642 Control auto-loading of inferior specific thread debugging shared library.
644 set auto-load scripts-directory <dir1>[:<dir2>...]
645 show auto-load scripts-directory
646 Set a list of directories from which to load auto-loaded scripts.
647 Automatically loaded Python scripts and GDB scripts are located in one
648 of the directories listed by this option.
649 The delimiter (':' above) may differ according to the host platform.
651 set auto-load safe-path <dir1>[:<dir2>...]
652 show auto-load safe-path
653 Set a list of directories from which it is safe to auto-load files.
654 The delimiter (':' above) may differ according to the host platform.
656 set debug auto-load on|off
658 Control display of debugging info for auto-loading the files above.
660 set dprintf-style gdb|call|agent
662 Control the way in which a dynamic printf is performed; "gdb"
663 requests a GDB printf command, while "call" causes dprintf to call a
664 function in the inferior. "agent" requests that the target agent
665 (such as GDBserver) do the printing.
667 set dprintf-function <expr>
668 show dprintf-function
669 set dprintf-channel <expr>
671 Set the function and optional first argument to the call when using
672 the "call" style of dynamic printf.
674 set disconnected-dprintf on|off
675 show disconnected-dprintf
676 Control whether agent-style dynamic printfs continue to be in effect
677 after GDB disconnects.
679 * New configure options
682 Configure default value for the 'set auto-load scripts-directory'
683 setting above. It defaults to '$debugdir:$datadir/auto-load',
684 $debugdir representing global debugging info directories (available
685 via 'show debug-file-directory') and $datadir representing GDB's data
686 directory (available via 'show data-directory').
688 --with-auto-load-safe-path
689 Configure default value for the 'set auto-load safe-path' setting
690 above. It defaults to the --with-auto-load-dir setting.
692 --without-auto-load-safe-path
693 Set 'set auto-load safe-path' to '/', effectively disabling this
698 z0/z1 conditional breakpoints extension
700 The z0/z1 breakpoint insertion packets have been extended to carry
701 a list of conditional expressions over to the remote stub depending on the
702 condition evaluation mode. The use of this extension can be controlled
703 via the "set remote conditional-breakpoints-packet" command.
707 Specify the signals which the remote stub may pass to the debugged
708 program without GDB involvement.
710 * New command line options
712 --init-command=FILE, -ix Like --command, -x but execute it
713 before loading inferior.
714 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
715 execute it before loading inferior.
717 *** Changes in GDB 7.4
719 * GDB now handles ambiguous linespecs more consistently; the existing
720 FILE:LINE support has been expanded to other types of linespecs. A
721 breakpoint will now be set on all matching locations in all
722 inferiors, and locations will be added or removed according to
725 * GDB now allows you to skip uninteresting functions and files when
726 stepping with the "skip function" and "skip file" commands.
728 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
729 and "show remote hardware-watchpoint-length-limit". These allows to
730 set or show the maximum length limit (in bytes) of a remote
731 target hardware watchpoint.
733 This allows e.g. to use "unlimited" hardware watchpoints with the
734 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
735 watchpoints are slower than real hardware watchpoints but are
736 significantly faster than gdb software watchpoints.
740 ** The register_pretty_printer function in module gdb.printing now takes
741 an optional `replace' argument. If True, the new printer replaces any
744 ** The "maint set python print-stack on|off" command has been
745 deprecated and will be deleted in GDB 7.5.
746 A new command: "set python print-stack none|full|message" has
747 replaced it. Additionally, the default for "print-stack" is
748 now "message", which just prints the error message without
751 ** A prompt substitution hook (prompt_hook) is now available to the
754 ** A new Python module, gdb.prompt has been added to the GDB Python
755 modules library. This module provides functionality for
756 escape sequences in prompts (used by set/show
757 extended-prompt). These escape sequences are replaced by their
760 ** Python commands and convenience-functions located in
761 'data-directory'/python/gdb/command and
762 'data-directory'/python/gdb/function are now automatically loaded
765 ** Blocks now provide four new attributes. global_block and
766 static_block will return the global and static blocks
767 respectively. is_static and is_global are boolean attributes
768 that indicate if the block is one of those two types.
770 ** Symbols now provide the "type" attribute, the type of the symbol.
772 ** The "gdb.breakpoint" function has been deprecated in favor of
775 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
776 of a function. This class is based on the "finish" command
777 available in the CLI.
779 ** Type objects for struct and union types now allow access to
780 the fields using standard Python dictionary (mapping) methods.
781 For example, "some_type['myfield']" now works, as does
784 ** A new event "gdb.new_objfile" has been added, triggered by loading a
787 ** A new function, "deep_items" has been added to the gdb.types
788 module in the GDB Python modules library. This function returns
789 an iterator over the fields of a struct or union type. Unlike
790 the standard Python "iteritems" method, it will recursively traverse
791 any anonymous fields.
795 ** "*stopped" events can report several new "reason"s, such as
798 ** Breakpoint changes are now notified using new async records, like
799 "=breakpoint-modified".
801 ** New command -ada-task-info.
803 * libthread-db-search-path now supports two special values: $sdir and $pdir.
804 $sdir specifies the default system locations of shared libraries.
805 $pdir specifies the directory where the libpthread used by the application
808 GDB no longer looks in $sdir and $pdir after it has searched the directories
809 mentioned in libthread-db-search-path. If you want to search those
810 directories, they must be specified in libthread-db-search-path.
811 The default value of libthread-db-search-path on GNU/Linux and Solaris
812 systems is now "$sdir:$pdir".
814 $pdir is not supported by gdbserver, it is currently ignored.
815 $sdir is supported by gdbserver.
817 * New configure option --with-iconv-bin.
818 When using the internationalization support like the one in the GNU C
819 library, GDB will invoke the "iconv" program to get a list of supported
820 character sets. If this program lives in a non-standard location, one can
821 use this option to specify where to find it.
823 * When natively debugging programs on PowerPC BookE processors running
824 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
825 watchpoints, which specify a mask in addition to an address to watch.
826 The mask specifies that some bits of an address (the bits which are
827 reset in the mask) should be ignored when matching the address accessed
828 by the inferior against the watchpoint address. See the "PowerPC Embedded"
829 section in the user manual for more details.
831 * The new option --once causes GDBserver to stop listening for connections once
832 the first connection is made. The listening port used by GDBserver will
833 become available after that.
835 * New commands "info macros" and "alias" have been added.
837 * New function parameters suffix @entry specifies value of function parameter
838 at the time the function got called. Entry values are available only since
844 "!" is now an alias of the "shell" command.
845 Note that no space is needed between "!" and SHELL COMMAND.
849 watch EXPRESSION mask MASK_VALUE
850 The watch command now supports the mask argument which allows creation
851 of masked watchpoints, if the current architecture supports this feature.
853 info auto-load-scripts [REGEXP]
854 This command was formerly named "maintenance print section-scripts".
855 It is now generally useful and is no longer a maintenance-only command.
857 info macro [-all] [--] MACRO
858 The info macro command has new options `-all' and `--'. The first for
859 printing all definitions of a macro. The second for explicitly specifying
860 the end of arguments and the beginning of the macro name in case the macro
861 name starts with a hyphen.
863 collect[/s] EXPRESSIONS
864 The tracepoint collect command now takes an optional modifier "/s"
865 that directs it to dereference pointer-to-character types and
866 collect the bytes of memory up to a zero byte. The behavior is
867 similar to what you see when you use the regular print command on a
868 string. An optional integer following the "/s" sets a bound on the
869 number of bytes that will be collected.
872 The trace start command now interprets any supplied arguments as a
873 note to be recorded with the trace run, with an effect similar to
874 setting the variable trace-notes.
877 The trace stop command now interprets any arguments as a note to be
878 mentioned along with the tstatus report that the trace was stopped
879 with a command. The effect is similar to setting the variable
882 * Tracepoints can now be enabled and disabled at any time after a trace
883 experiment has been started using the standard "enable" and "disable"
884 commands. It is now possible to start a trace experiment with no enabled
885 tracepoints; GDB will display a warning, but will allow the experiment to
886 begin, assuming that tracepoints will be enabled as needed while the trace
889 * Fast tracepoints on 32-bit x86-architectures can now be placed at
890 locations with 4-byte instructions, when they were previously
891 limited to locations with instructions of 5 bytes or longer.
895 set debug dwarf2-read
896 show debug dwarf2-read
897 Turns on or off display of debugging messages related to reading
898 DWARF debug info. The default is off.
900 set debug symtab-create
901 show debug symtab-create
902 Turns on or off display of debugging messages related to symbol table
903 creation. The default is off.
907 Set the GDB prompt, and allow escape sequences to be inserted to
908 display miscellaneous information (see 'help set extended-prompt'
909 for the list of sequences). This prompt (and any information
910 accessed through the escape sequences) is updated every time the
913 set print entry-values (both|compact|default|if-needed|no|only|preferred)
914 show print entry-values
915 Set printing of frame argument values at function entry. In some cases
916 GDB can determine the value of function argument which was passed by the
917 function caller, even if the value was modified inside the called function.
919 set debug entry-values
920 show debug entry-values
921 Control display of debugging info for determining frame argument values at
922 function entry and virtual tail call frames.
924 set basenames-may-differ
925 show basenames-may-differ
926 Set whether a source file may have multiple base names.
927 (A "base name" is the name of a file with the directory part removed.
928 Example: The base name of "/home/user/hello.c" is "hello.c".)
929 If set, GDB will canonicalize file names (e.g., expand symlinks)
930 before comparing them. Canonicalization is an expensive operation,
931 but it allows the same file be known by more than one base name.
932 If not set (the default), all source files are assumed to have just
933 one base name, and gdb will do file name comparisons more efficiently.
939 Set a user name and notes for the current and any future trace runs.
940 This is useful for long-running and/or disconnected traces, to
941 inform others (or yourself) as to who is running the trace, supply
942 contact information, or otherwise explain what is going on.
945 show trace-stop-notes
946 Set a note attached to the trace run, that is displayed when the
947 trace has been stopped by a tstop command. This is useful for
948 instance as an explanation, if you are stopping a trace run that was
949 started by someone else.
955 Dynamically enable a tracepoint in a started trace experiment.
959 Dynamically disable a tracepoint in a started trace experiment.
963 Set the user and notes of the trace run.
967 Query the current status of a tracepoint.
971 Query the minimum length of instruction at which a fast tracepoint may
974 * Dcache size (number of lines) and line-size are now runtime-configurable
975 via "set dcache line" and "set dcache line-size" commands.
979 Texas Instruments TMS320C6x tic6x-*-*
983 Renesas RL78 rl78-*-elf
985 *** Changes in GDB 7.3.1
987 * The build failure for NetBSD and OpenBSD targets have now been fixed.
989 *** Changes in GDB 7.3
991 * GDB has a new command: "thread find [REGEXP]".
992 It finds the thread id whose name, target id, or thread extra info
993 matches the given regular expression.
995 * The "catch syscall" command now works on mips*-linux* targets.
997 * The -data-disassemble MI command now supports modes 2 and 3 for
998 dumping the instruction opcodes.
1000 * New command line options
1002 -data-directory DIR Specify DIR as the "data-directory".
1003 This is mostly for testing purposes.
1005 * The "maint set python auto-load on|off" command has been renamed to
1006 "set auto-load-scripts on|off".
1008 * GDB has a new command: "set directories".
1009 It is like the "dir" command except that it replaces the
1010 source path list instead of augmenting it.
1012 * GDB now understands thread names.
1014 On GNU/Linux, "info threads" will display the thread name as set by
1015 prctl or pthread_setname_np.
1017 There is also a new command, "thread name", which can be used to
1018 assign a name internally for GDB to display.
1021 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1022 has been integrated into GDB.
1026 ** The function gdb.Write now accepts an optional keyword 'stream'.
1027 This keyword, when provided, will direct the output to either
1028 stdout, stderr, or GDB's logging output.
1030 ** Parameters can now be be sub-classed in Python, and in particular
1031 you may implement the get_set_doc and get_show_doc functions.
1032 This improves how Parameter set/show documentation is processed
1033 and allows for more dynamic content.
1035 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1036 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1037 have an is_valid method.
1039 ** Breakpoints can now be sub-classed in Python, and in particular
1040 you may implement a 'stop' function that is executed each time
1041 the inferior reaches that breakpoint.
1043 ** New function gdb.lookup_global_symbol looks up a global symbol.
1045 ** GDB values in Python are now callable if the value represents a
1046 function. For example, if 'some_value' represents a function that
1047 takes two integer parameters and returns a value, you can call
1048 that function like so:
1050 result = some_value (10,20)
1052 ** Module gdb.types has been added.
1053 It contains a collection of utilities for working with gdb.Types objects:
1054 get_basic_type, has_field, make_enum_dict.
1056 ** Module gdb.printing has been added.
1057 It contains utilities for writing and registering pretty-printers.
1058 New classes: PrettyPrinter, SubPrettyPrinter,
1059 RegexpCollectionPrettyPrinter.
1060 New function: register_pretty_printer.
1062 ** New commands "info pretty-printers", "enable pretty-printer" and
1063 "disable pretty-printer" have been added.
1065 ** gdb.parameter("directories") is now available.
1067 ** New function gdb.newest_frame returns the newest frame in the
1070 ** The gdb.InferiorThread class has a new "name" attribute. This
1071 holds the thread's name.
1073 ** Python Support for Inferior events.
1074 Python scripts can add observers to be notified of events
1075 occurring in the process being debugged.
1076 The following events are currently supported:
1077 - gdb.events.cont Continue event.
1078 - gdb.events.exited Inferior exited event.
1079 - gdb.events.stop Signal received, and Breakpoint hit events.
1083 ** GDB now puts template parameters in scope when debugging in an
1084 instantiation. For example, if you have:
1086 template<int X> int func (void) { return X; }
1088 then if you step into func<5>, "print X" will show "5". This
1089 feature requires proper debuginfo support from the compiler; it
1090 was added to GCC 4.5.
1092 ** The motion commands "next", "finish", "until", and "advance" now
1093 work better when exceptions are thrown. In particular, GDB will
1094 no longer lose control of the inferior; instead, the GDB will
1095 stop the inferior at the point at which the exception is caught.
1096 This functionality requires a change in the exception handling
1097 code that was introduced in GCC 4.5.
1099 * GDB now follows GCC's rules on accessing volatile objects when
1100 reading or writing target state during expression evaluation.
1101 One notable difference to prior behavior is that "print x = 0"
1102 no longer generates a read of x; the value of the assignment is
1103 now always taken directly from the value being assigned.
1105 * GDB now has some support for using labels in the program's source in
1106 linespecs. For instance, you can use "advance label" to continue
1107 execution to a label.
1109 * GDB now has support for reading and writing a new .gdb_index
1110 section. This section holds a fast index of DWARF debugging
1111 information and can be used to greatly speed up GDB startup and
1112 operation. See the documentation for `save gdb-index' for details.
1114 * The "watch" command now accepts an optional "-location" argument.
1115 When used, this causes GDB to watch the memory referred to by the
1116 expression. Such a watchpoint is never deleted due to it going out
1119 * GDB now supports thread debugging of core dumps on GNU/Linux.
1121 GDB now activates thread debugging using the libthread_db library
1122 when debugging GNU/Linux core dumps, similarly to when debugging
1123 live processes. As a result, when debugging a core dump file, GDB
1124 is now able to display pthread_t ids of threads. For example, "info
1125 threads" shows the same output as when debugging the process when it
1126 was live. In earlier releases, you'd see something like this:
1129 * 1 LWP 6780 main () at main.c:10
1131 While now you see this:
1134 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1136 It is also now possible to inspect TLS variables when debugging core
1139 When debugging a core dump generated on a machine other than the one
1140 used to run GDB, you may need to point GDB at the correct
1141 libthread_db library with the "set libthread-db-search-path"
1142 command. See the user manual for more details on this command.
1144 * When natively debugging programs on PowerPC BookE processors running
1145 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1146 which stop execution of the inferior whenever it executes an instruction
1147 at any address within the specified range. See the "PowerPC Embedded"
1148 section in the user manual for more details.
1150 * New features in the GDB remote stub, GDBserver
1152 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1153 and i686 LynxOS (version 5.x).
1155 ** GDBserver is now supported on Blackfin Linux.
1157 * New native configurations
1159 ia64 HP-UX ia64-*-hpux*
1163 Analog Devices, Inc. Blackfin Processor bfin-*
1165 * Ada task switching is now supported on sparc-elf targets when
1166 debugging a program using the Ravenscar Profile. For more information,
1167 see the "Tasking Support when using the Ravenscar Profile" section
1168 in the GDB user manual.
1170 * Guile support was removed.
1172 * New features in the GNU simulator
1174 ** The --map-info flag lists all known core mappings.
1176 ** CFI flashes may be simulated via the "cfi" device.
1178 *** Changes in GDB 7.2
1180 * Shared library support for remote targets by default
1182 When GDB is configured for a generic, non-OS specific target, like
1183 for example, --target=arm-eabi or one of the many *-*-elf targets,
1184 GDB now queries remote stubs for loaded shared libraries using the
1185 `qXfer:libraries:read' packet. Previously, shared library support
1186 was always disabled for such configurations.
1190 ** Argument Dependent Lookup (ADL)
1192 In C++ ADL lookup directs function search to the namespaces of its
1193 arguments even if the namespace has not been imported.
1203 Here the compiler will search for `foo' in the namespace of 'b'
1204 and find A::foo. GDB now supports this. This construct is commonly
1205 used in the Standard Template Library for operators.
1207 ** Improved User Defined Operator Support
1209 In addition to member operators, GDB now supports lookup of operators
1210 defined in a namespace and imported with a `using' directive, operators
1211 defined in the global scope, operators imported implicitly from an
1212 anonymous namespace, and the ADL operators mentioned in the previous
1214 GDB now also supports proper overload resolution for all the previously
1215 mentioned flavors of operators.
1217 ** static const class members
1219 Printing of static const class members that are initialized in the
1220 class definition has been fixed.
1222 * Windows Thread Information Block access.
1224 On Windows targets, GDB now supports displaying the Windows Thread
1225 Information Block (TIB) structure. This structure is visible either
1226 by using the new command `info w32 thread-information-block' or, by
1227 dereferencing the new convenience variable named `$_tlb', a
1228 thread-specific pointer to the TIB. This feature is also supported
1229 when remote debugging using GDBserver.
1231 * Static tracepoints
1233 Static tracepoints are calls in the user program into a tracing
1234 library. One such library is a port of the LTTng kernel tracer to
1235 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1236 When debugging with GDBserver, GDB now supports combining the GDB
1237 tracepoint machinery with such libraries. For example: the user can
1238 use GDB to probe a static tracepoint marker (a call from the user
1239 program into the tracing library) with the new "strace" command (see
1240 "New commands" below). This creates a "static tracepoint" in the
1241 breakpoint list, that can be manipulated with the same feature set
1242 as fast and regular tracepoints. E.g., collect registers, local and
1243 global variables, collect trace state variables, and define
1244 tracepoint conditions. In addition, the user can collect extra
1245 static tracepoint marker specific data, by collecting the new
1246 $_sdata internal variable. When analyzing the trace buffer, you can
1247 inspect $_sdata like any other variable available to GDB. For more
1248 information, see the "Tracepoints" chapter in GDB user manual. New
1249 remote packets have been defined to support static tracepoints, see
1250 the "New remote packets" section below.
1252 * Better reconstruction of tracepoints after disconnected tracing
1254 GDB will attempt to download the original source form of tracepoint
1255 definitions when starting a trace run, and then will upload these
1256 upon reconnection to the target, resulting in a more accurate
1257 reconstruction of the tracepoints that are in use on the target.
1261 You can now exercise direct control over the ways that GDB can
1262 affect your program. For instance, you can disallow the setting of
1263 breakpoints, so that the program can run continuously (assuming
1264 non-stop mode). In addition, the "observer" variable is available
1265 to switch all of the different controls; in observer mode, GDB
1266 cannot affect the target's behavior at all, which is useful for
1267 tasks like diagnosing live systems in the field.
1269 * The new convenience variable $_thread holds the number of the
1272 * New remote packets
1276 Return the address of the Windows Thread Information Block of a given thread.
1280 In response to several of the tracepoint packets, the target may now
1281 also respond with a number of intermediate `qRelocInsn' request
1282 packets before the final result packet, to have GDB handle
1283 relocating an instruction to execute at a different address. This
1284 is particularly useful for stubs that support fast tracepoints. GDB
1285 reports support for this feature in the qSupported packet.
1289 List static tracepoint markers in the target program.
1293 List static tracepoint markers at a given address in the target
1296 qXfer:statictrace:read
1298 Read the static trace data collected (by a `collect $_sdata'
1299 tracepoint action). The remote stub reports support for this packet
1300 to gdb's qSupported query.
1304 Send the current settings of GDB's permission flags.
1308 Send part of the source (textual) form of a tracepoint definition,
1309 which includes location, conditional, and action list.
1311 * The source command now accepts a -s option to force searching for the
1312 script in the source search path even if the script name specifies
1315 * New features in the GDB remote stub, GDBserver
1317 - GDBserver now support tracepoints (including fast tracepoints, and
1318 static tracepoints). The feature is currently supported by the
1319 i386-linux and amd64-linux builds. See the "Tracepoints support
1320 in gdbserver" section in the manual for more information.
1322 GDBserver JIT compiles the tracepoint's conditional agent
1323 expression bytecode into native code whenever possible for low
1324 overhead dynamic tracepoints conditionals. For such tracepoints,
1325 an expression that examines program state is evaluated when the
1326 tracepoint is reached, in order to determine whether to capture
1327 trace data. If the condition is simple and false, processing the
1328 tracepoint finishes very quickly and no data is gathered.
1330 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1331 for static tracepoints support.
1333 - GDBserver now supports x86_64 Windows 64-bit debugging.
1335 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1336 it understands register description.
1338 * The --batch flag now disables pagination and queries.
1340 * X86 general purpose registers
1342 GDB now supports reading/writing byte, word and double-word x86
1343 general purpose registers directly. This means you can use, say,
1344 $ah or $ax to refer, respectively, to the byte register AH and
1345 16-bit word register AX that are actually portions of the 32-bit
1346 register EAX or 64-bit register RAX.
1348 * The `commands' command now accepts a range of breakpoints to modify.
1349 A plain `commands' following a command that creates multiple
1350 breakpoints affects all the breakpoints set by that command. This
1351 applies to breakpoints set by `rbreak', and also applies when a
1352 single `break' command creates multiple breakpoints (e.g.,
1353 breakpoints on overloaded c++ functions).
1355 * The `rbreak' command now accepts a filename specification as part of
1356 its argument, limiting the functions selected by the regex to those
1357 in the specified file.
1359 * Support for remote debugging Windows and SymbianOS shared libraries
1360 from Unix hosts has been improved. Non Windows GDB builds now can
1361 understand target reported file names that follow MS-DOS based file
1362 system semantics, such as file names that include drive letters and
1363 use the backslash character as directory separator. This makes it
1364 possible to transparently use the "set sysroot" and "set
1365 solib-search-path" on Unix hosts to point as host copies of the
1366 target's shared libraries. See the new command "set
1367 target-file-system-kind" described below, and the "Commands to
1368 specify files" section in the user manual for more information.
1372 eval template, expressions...
1373 Convert the values of one or more expressions under the control
1374 of the string template to a command line, and call it.
1376 set target-file-system-kind unix|dos-based|auto
1377 show target-file-system-kind
1378 Set or show the assumed file system kind for target reported file
1381 save breakpoints <filename>
1382 Save all current breakpoint definitions to a file suitable for use
1383 in a later debugging session. To read the saved breakpoint
1384 definitions, use the `source' command.
1386 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1389 info static-tracepoint-markers
1390 Display information about static tracepoint markers in the target.
1392 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1393 Define a static tracepoint by probing a marker at the given
1394 function, line, address, or marker ID.
1398 Enable and disable observer mode.
1400 set may-write-registers on|off
1401 set may-write-memory on|off
1402 set may-insert-breakpoints on|off
1403 set may-insert-tracepoints on|off
1404 set may-insert-fast-tracepoints on|off
1405 set may-interrupt on|off
1406 Set individual permissions for GDB effects on the target. Note that
1407 some of these settings can have undesirable or surprising
1408 consequences, particularly when changed in the middle of a session.
1409 For instance, disabling the writing of memory can prevent
1410 breakpoints from being inserted, cause single-stepping to fail, or
1411 even crash your program, if you disable after breakpoints have been
1412 inserted. However, GDB should not crash.
1414 set record memory-query on|off
1415 show record memory-query
1416 Control whether to stop the inferior if memory changes caused
1417 by an instruction cannot be recorded.
1422 The disassemble command now supports "start,+length" form of two arguments.
1426 ** GDB now provides a new directory location, called the python directory,
1427 where Python scripts written for GDB can be installed. The location
1428 of that directory is <data-directory>/python, where <data-directory>
1429 is the GDB data directory. For more details, see section `Scripting
1430 GDB using Python' in the manual.
1432 ** The GDB Python API now has access to breakpoints, symbols, symbol
1433 tables, program spaces, inferiors, threads and frame's code blocks.
1434 Additionally, GDB Parameters can now be created from the API, and
1435 manipulated via set/show in the CLI.
1437 ** New functions gdb.target_charset, gdb.target_wide_charset,
1438 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1440 ** New exception gdb.GdbError.
1442 ** Pretty-printers are now also looked up in the current program space.
1444 ** Pretty-printers can now be individually enabled and disabled.
1446 ** GDB now looks for names of Python scripts to auto-load in a
1447 special section named `.debug_gdb_scripts', in addition to looking
1448 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1450 * Tracepoint actions were unified with breakpoint commands. In particular,
1451 there are no longer differences in "info break" output for breakpoints and
1452 tracepoints and the "commands" command can be used for both tracepoints and
1453 regular breakpoints.
1457 ARM Symbian arm*-*-symbianelf*
1459 * D language support.
1460 GDB now supports debugging programs written in the D programming
1463 * GDB now supports the extended ptrace interface for PowerPC which is
1464 available since Linux kernel version 2.6.34. This automatically enables
1465 any hardware breakpoints and additional hardware watchpoints available in
1466 the processor. The old ptrace interface exposes just one hardware
1467 watchpoint and no hardware breakpoints.
1469 * GDB is now able to use the Data Value Compare (DVC) register available on
1470 embedded PowerPC processors to implement in hardware simple watchpoint
1471 conditions of the form:
1473 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1475 This works in native GDB running on Linux kernels with the extended ptrace
1476 interface mentioned above.
1478 *** Changes in GDB 7.1
1482 ** Namespace Support
1484 GDB now supports importing of namespaces in C++. This enables the
1485 user to inspect variables from imported namespaces. Support for
1486 namepace aliasing has also been added. So, if a namespace is
1487 aliased in the current scope (e.g. namepace C=A; ) the user can
1488 print variables using the alias (e.g. (gdb) print C::x).
1492 All known bugs relating to the printing of virtual base class were
1493 fixed. It is now possible to call overloaded static methods using a
1498 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1499 and reinterpret_cast<> are now handled by the C++ expression parser.
1503 Xilinx MicroBlaze microblaze-*-*
1508 Xilinx MicroBlaze microblaze
1511 * Multi-program debugging.
1513 GDB now has support for multi-program (a.k.a. multi-executable or
1514 multi-exec) debugging. This allows for debugging multiple inferiors
1515 simultaneously each running a different program under the same GDB
1516 session. See "Debugging Multiple Inferiors and Programs" in the
1517 manual for more information. This implied some user visible changes
1518 in the multi-inferior support. For example, "info inferiors" now
1519 lists inferiors that are not running yet or that have exited
1520 already. See also "New commands" and "New options" below.
1522 * New tracing features
1524 GDB's tracepoint facility now includes several new features:
1526 ** Trace state variables
1528 GDB tracepoints now include support for trace state variables, which
1529 are variables managed by the target agent during a tracing
1530 experiment. They are useful for tracepoints that trigger each
1531 other, so for instance one tracepoint can count hits in a variable,
1532 and then a second tracepoint has a condition that is true when the
1533 count reaches a particular value. Trace state variables share the
1534 $-syntax of GDB convenience variables, and can appear in both
1535 tracepoint actions and condition expressions. Use the "tvariable"
1536 command to create, and "info tvariables" to view; see "Trace State
1537 Variables" in the manual for more detail.
1541 GDB now includes an option for defining fast tracepoints, which
1542 targets may implement more efficiently, such as by installing a jump
1543 into the target agent rather than a trap instruction. The resulting
1544 speedup can be by two orders of magnitude or more, although the
1545 tradeoff is that some program locations on some target architectures
1546 might not allow fast tracepoint installation, for instance if the
1547 instruction to be replaced is shorter than the jump. To request a
1548 fast tracepoint, use the "ftrace" command, with syntax identical to
1549 the regular trace command.
1551 ** Disconnected tracing
1553 It is now possible to detach GDB from the target while it is running
1554 a trace experiment, then reconnect later to see how the experiment
1555 is going. In addition, a new variable disconnected-tracing lets you
1556 tell the target agent whether to continue running a trace if the
1557 connection is lost unexpectedly.
1561 GDB now has the ability to save the trace buffer into a file, and
1562 then use that file as a target, similarly to you can do with
1563 corefiles. You can select trace frames, print data that was
1564 collected in them, and use tstatus to display the state of the
1565 tracing run at the moment that it was saved. To create a trace
1566 file, use "tsave <filename>", and to use it, do "target tfile
1569 ** Circular trace buffer
1571 You can ask the target agent to handle the trace buffer as a
1572 circular buffer, discarding the oldest trace frames to make room for
1573 newer ones, by setting circular-trace-buffer to on. This feature may
1574 not be available for all target agents.
1579 The disassemble command, when invoked with two arguments, now requires
1580 the arguments to be comma-separated.
1583 The info variables command now displays variable definitions. Files
1584 which only declare a variable are not shown.
1587 The source command is now capable of sourcing Python scripts.
1588 This feature is dependent on the debugger being build with Python
1591 Related to this enhancement is also the introduction of a new command
1592 "set script-extension" (see below).
1594 * New commands (for set/show, see "New options" below)
1596 record save [<FILENAME>]
1597 Save a file (in core file format) containing the process record
1598 execution log for replay debugging at a later time.
1600 record restore <FILENAME>
1601 Restore the process record execution log that was saved at an
1602 earlier time, for replay debugging.
1604 add-inferior [-copies <N>] [-exec <FILENAME>]
1607 clone-inferior [-copies <N>] [ID]
1608 Make a new inferior ready to execute the same program another
1609 inferior has loaded.
1614 maint info program-spaces
1615 List the program spaces loaded into GDB.
1617 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1618 show remote interrupt-sequence
1619 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1620 as the sequence to the remote target in order to interrupt the execution.
1621 Ctrl-C is a default. Some system prefers BREAK which is high level of
1622 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1623 Magic SysRq g. It is BREAK signal and character 'g'.
1625 set remote interrupt-on-connect [on | off]
1626 show remote interrupt-on-connect
1627 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1628 remote target when gdb connects to it. This is needed when you debug
1631 set remotebreak [on | off]
1633 Deprecated. Use "set/show remote interrupt-sequence" instead.
1635 tvariable $NAME [ = EXP ]
1636 Create or modify a trace state variable.
1639 List trace state variables and their values.
1641 delete tvariable $NAME ...
1642 Delete one or more trace state variables.
1645 Evaluate the given expressions without collecting anything into the
1646 trace buffer. (Valid in tracepoint actions only.)
1648 ftrace FN / FILE:LINE / *ADDR
1649 Define a fast tracepoint at the given function, line, or address.
1651 * New expression syntax
1653 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1654 GDB now parses 0b101010 identically with 42.
1658 set follow-exec-mode new|same
1659 show follow-exec-mode
1660 Control whether GDB reuses the same inferior across an exec call or
1661 creates a new one. This is useful to be able to restart the old
1662 executable after the inferior having done an exec call.
1664 set default-collect EXPR, ...
1665 show default-collect
1666 Define a list of expressions to be collected at each tracepoint.
1667 This is a useful way to ensure essential items are not overlooked,
1668 such as registers or a critical global variable.
1670 set disconnected-tracing
1671 show disconnected-tracing
1672 If set to 1, the target is instructed to continue tracing if it
1673 loses its connection to GDB. If 0, the target is to stop tracing
1676 set circular-trace-buffer
1677 show circular-trace-buffer
1678 If set to on, the target is instructed to use a circular trace buffer
1679 and discard the oldest trace frames instead of stopping the trace due
1680 to a full trace buffer. If set to off, the trace stops when the buffer
1681 fills up. Some targets may not support this.
1683 set script-extension off|soft|strict
1684 show script-extension
1685 If set to "off", the debugger does not perform any script language
1686 recognition, and all sourced files are assumed to be GDB scripts.
1687 If set to "soft" (the default), files are sourced according to
1688 filename extension, falling back to GDB scripts if the first
1690 If set to "strict", files are sourced according to filename extension.
1692 set ada trust-PAD-over-XVS on|off
1693 show ada trust-PAD-over-XVS
1694 If off, activate a workaround against a bug in the debugging information
1695 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1696 the GCC sources for more information about the GNAT encoding and
1697 PAD types in particular). It is always safe to set this option to
1698 off, but this introduces a slight performance penalty. The default
1701 * Python API Improvements
1703 ** GDB provides the new class gdb.LazyString. This is useful in
1704 some pretty-printing cases. The new method gdb.Value.lazy_string
1705 provides a simple way to create objects of this type.
1707 ** The fields returned by gdb.Type.fields now have an
1708 `is_base_class' attribute.
1710 ** The new method gdb.Type.range returns the range of an array type.
1712 ** The new method gdb.parse_and_eval can be used to parse and
1713 evaluate an expression.
1715 * New remote packets
1718 Define a trace state variable.
1721 Get the current value of a trace state variable.
1724 Set desired tracing behavior upon disconnection.
1727 Set the trace buffer to be linear or circular.
1730 Get data about the tracepoints currently in use.
1734 Process record now works correctly with hardware watchpoints.
1736 Multiple bug fixes have been made to the mips-irix port, making it
1737 much more reliable. In particular:
1738 - Debugging threaded applications is now possible again. Previously,
1739 GDB would hang while starting the program, or while waiting for
1740 the program to stop at a breakpoint.
1741 - Attaching to a running process no longer hangs.
1742 - An error occurring while loading a core file has been fixed.
1743 - Changing the value of the PC register now works again. This fixes
1744 problems observed when using the "jump" command, or when calling
1745 a function from GDB, or even when assigning a new value to $pc.
1746 - With the "finish" and "return" commands, the return value for functions
1747 returning a small array is now correctly printed.
1748 - It is now possible to break on shared library code which gets executed
1749 during a shared library init phase (code executed while executing
1750 their .init section). Previously, the breakpoint would have no effect.
1751 - GDB is now able to backtrace through the signal handler for
1752 non-threaded programs.
1754 PIE (Position Independent Executable) programs debugging is now supported.
1755 This includes debugging execution of PIC (Position Independent Code) shared
1756 libraries although for that, it should be possible to run such libraries as an
1759 *** Changes in GDB 7.0
1761 * GDB now has an interface for JIT compilation. Applications that
1762 dynamically generate code can create symbol files in memory and register
1763 them with GDB. For users, the feature should work transparently, and
1764 for JIT developers, the interface is documented in the GDB manual in the
1765 "JIT Compilation Interface" chapter.
1767 * Tracepoints may now be conditional. The syntax is as for
1768 breakpoints; either an "if" clause appended to the "trace" command,
1769 or the "condition" command is available. GDB sends the condition to
1770 the target for evaluation using the same bytecode format as is used
1771 for tracepoint actions.
1773 * The disassemble command now supports: an optional /r modifier, print the
1774 raw instructions in hex as well as in symbolic form, and an optional /m
1775 modifier to print mixed source+assembly.
1777 * Process record and replay
1779 In a architecture environment that supports ``process record and
1780 replay'', ``process record and replay'' target can record a log of
1781 the process execution, and replay it with both forward and reverse
1784 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
1785 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
1786 set execution-direction {forward|reverse}, for targets that support
1789 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
1790 feature is available with a native GDB running on kernel version
1793 * GDB now has support for multi-byte and wide character sets on the
1794 target. Strings whose character type is wchar_t, char16_t, or
1795 char32_t are now correctly printed. GDB supports wide- and unicode-
1796 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
1797 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
1798 `printf'. This feature requires iconv to work properly; if your
1799 system does not have a working iconv, GDB can use GNU libiconv. See
1800 the installation instructions for more information.
1802 * GDB now supports automatic retrieval of shared library files from
1803 remote targets. To use this feature, specify a system root that begins
1804 with the `remote:' prefix, either via the `set sysroot' command or via
1805 the `--with-sysroot' configure-time option.
1807 * "info sharedlibrary" now takes an optional regex of libraries to show,
1808 and it now reports if a shared library has no debugging information.
1810 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
1811 now complete on file names.
1813 * When completing in expressions, gdb will attempt to limit
1814 completions to allowable structure or union fields, where appropriate.
1815 For instance, consider:
1817 # struct example { int f1; double f2; };
1818 # struct example variable;
1821 If the user types TAB at the end of this command line, the available
1822 completions will be "f1" and "f2".
1824 * Inlined functions are now supported. They show up in backtraces, and
1825 the "step", "next", and "finish" commands handle them automatically.
1827 * GDB now supports the token-splicing (##) and stringification (#)
1828 operators when expanding macros. It also supports variable-arity
1831 * GDB now supports inspecting extra signal information, exported by
1832 the new $_siginfo convenience variable. The feature is currently
1833 implemented on linux ARM, i386 and amd64.
1835 * GDB can now display the VFP floating point registers and NEON vector
1836 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
1837 can provide these registers (requires Linux 2.6.30 or later). Remote
1838 and simulator targets may also provide them.
1840 * New remote packets
1843 Search memory for a sequence of bytes.
1846 Turn off `+'/`-' protocol acknowledgments to permit more efficient
1847 operation over reliable transport links. Use of this packet is
1848 controlled by the `set remote noack-packet' command.
1851 Kill the process with the specified process ID. Use this in preference
1852 to `k' when multiprocess protocol extensions are supported.
1855 Obtains additional operating system information
1859 Read or write additional signal information.
1861 * Removed remote protocol undocumented extension
1863 An undocumented extension to the remote protocol's `S' stop reply
1864 packet that permited the stub to pass a process id was removed.
1865 Remote servers should use the `T' stop reply packet instead.
1867 * GDB now supports multiple function calling conventions according to the
1868 DWARF-2 DW_AT_calling_convention function attribute.
1870 * The SH target utilizes the aforementioned change to distinguish between gcc
1871 and Renesas calling convention. It also adds the new CLI commands
1872 `set/show sh calling-convention'.
1874 * GDB can now read compressed debug sections, as produced by GNU gold
1875 with the --compress-debug-sections=zlib flag.
1877 * 64-bit core files are now supported on AIX.
1879 * Thread switching is now supported on Tru64.
1881 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
1882 which will be allocated using malloc later in program execution.
1884 * The qXfer:libraries:read remote procotol packet now allows passing a
1885 list of section offsets.
1887 * On GNU/Linux, GDB can now attach to stopped processes. Several race
1888 conditions handling signals delivered during attach or thread creation
1889 have also been fixed.
1891 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
1892 From the user's standpoint, all unqualified instances of True and False
1893 are treated as the standard definitions, regardless of context.
1895 * GDB now parses C++ symbol and type names more flexibly. For
1898 template<typename T> class C { };
1901 GDB will now correctly handle all of:
1903 ptype C<char const *>
1904 ptype C<char const*>
1905 ptype C<const char *>
1906 ptype C<const char*>
1908 * New features in the GDB remote stub, gdbserver
1910 - The "--wrapper" command-line argument tells gdbserver to use a
1911 wrapper program to launch programs for debugging.
1913 - On PowerPC and S/390 targets, it is now possible to use a single
1914 gdbserver executable to debug both 32-bit and 64-bit programs.
1915 (This requires gdbserver itself to be built as a 64-bit executable.)
1917 - gdbserver uses the new noack protocol mode for TCP connections to
1918 reduce communications latency, if also supported and enabled in GDB.
1920 - Support for the sparc64-linux-gnu target is now included in
1923 - The amd64-linux build of gdbserver now supports debugging both
1924 32-bit and 64-bit programs.
1926 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
1927 now support hardware watchpoints, and will use them automatically
1932 GDB now has support for scripting using Python. Whether this is
1933 available is determined at configure time.
1935 New GDB commands can now be written in Python.
1937 * Ada tasking support
1939 Ada tasks can now be inspected in GDB. The following commands have
1943 Print the list of Ada tasks.
1945 Print detailed information about task number N.
1947 Print the task number of the current task.
1949 Switch the context of debugging to task number N.
1951 * Support for user-defined prefixed commands. The "define" command can
1952 add new commands to existing prefixes, e.g. "target".
1954 * Multi-inferior, multi-process debugging.
1956 GDB now has generalized support for multi-inferior debugging. See
1957 "Debugging Multiple Inferiors" in the manual for more information.
1958 Although availability still depends on target support, the command
1959 set is more uniform now. The GNU/Linux specific multi-forks support
1960 has been migrated to this new framework. This implied some user
1961 visible changes; see "New commands" and also "Removed commands"
1964 * Target descriptions can now describe the target OS ABI. See the
1965 "Target Description Format" section in the user manual for more
1968 * Target descriptions can now describe "compatible" architectures
1969 to indicate that the target can execute applications for a different
1970 architecture in addition to those for the main target architecture.
1971 See the "Target Description Format" section in the user manual for
1974 * Multi-architecture debugging.
1976 GDB now includes general supports for debugging applications on
1977 hybrid systems that use more than one single processor architecture
1978 at the same time. Each such hybrid architecture still requires
1979 specific support to be added. The only hybrid architecture supported
1980 in this version of GDB is the Cell Broadband Engine.
1982 * GDB now supports integrated debugging of Cell/B.E. applications that
1983 use both the PPU and SPU architectures. To enable support for hybrid
1984 Cell/B.E. debugging, you need to configure GDB to support both the
1985 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
1986 --enable-targets configure option.
1988 * Non-stop mode debugging.
1990 For some targets, GDB now supports an optional mode of operation in
1991 which you can examine stopped threads while other threads continue
1992 to execute freely. This is referred to as non-stop mode, with the
1993 old mode referred to as all-stop mode. See the "Non-Stop Mode"
1994 section in the user manual for more information.
1996 To be able to support remote non-stop debugging, a remote stub needs
1997 to implement the non-stop mode remote protocol extensions, as
1998 described in the "Remote Non-Stop" section of the user manual. The
1999 GDB remote stub, gdbserver, has been adjusted to support these
2000 extensions on linux targets.
2002 * New commands (for set/show, see "New options" below)
2004 catch syscall [NAME(S) | NUMBER(S)]
2005 Catch system calls. Arguments, which should be names of system
2006 calls or their numbers, mean catch only those syscalls. Without
2007 arguments, every syscall will be caught. When the inferior issues
2008 any of the specified syscalls, GDB will stop and announce the system
2009 call, both when it is called and when its call returns. This
2010 feature is currently available with a native GDB running on the
2011 Linux Kernel, under the following architectures: x86, x86_64,
2012 PowerPC and PowerPC64.
2014 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2016 Search memory for a sequence of bytes.
2018 maint set python print-stack
2019 maint show python print-stack
2020 Show a stack trace when an error is encountered in a Python script.
2023 Invoke CODE by passing it to the Python interpreter.
2028 These allow macros to be defined, undefined, and listed
2032 Show operating system information about processes.
2035 List the inferiors currently under GDB's control.
2038 Switch focus to inferior number NUM.
2041 Detach from inferior number NUM.
2044 Kill inferior number NUM.
2048 set spu stop-on-load
2049 show spu stop-on-load
2050 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2052 set spu auto-flush-cache
2053 show spu auto-flush-cache
2054 Control whether to automatically flush the software-managed cache
2055 during Cell/B.E. debugging.
2057 set sh calling-convention
2058 show sh calling-convention
2059 Control the calling convention used when calling SH target functions.
2062 show debug timestamp
2063 Control display of timestamps with GDB debugging output.
2065 set disassemble-next-line
2066 show disassemble-next-line
2067 Control display of disassembled source lines or instructions when
2070 set remote noack-packet
2071 show remote noack-packet
2072 Set/show the use of remote protocol QStartNoAckMode packet. See above
2073 under "New remote packets."
2075 set remote query-attached-packet
2076 show remote query-attached-packet
2077 Control use of remote protocol `qAttached' (query-attached) packet.
2079 set remote read-siginfo-object
2080 show remote read-siginfo-object
2081 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2084 set remote write-siginfo-object
2085 show remote write-siginfo-object
2086 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2089 set remote reverse-continue
2090 show remote reverse-continue
2091 Control use of remote protocol 'bc' (reverse-continue) packet.
2093 set remote reverse-step
2094 show remote reverse-step
2095 Control use of remote protocol 'bs' (reverse-step) packet.
2097 set displaced-stepping
2098 show displaced-stepping
2099 Control displaced stepping mode. Displaced stepping is a way to
2100 single-step over breakpoints without removing them from the debuggee.
2101 Also known as "out-of-line single-stepping".
2104 show debug displaced
2105 Control display of debugging info for displaced stepping.
2107 maint set internal-error
2108 maint show internal-error
2109 Control what GDB does when an internal error is detected.
2111 maint set internal-warning
2112 maint show internal-warning
2113 Control what GDB does when an internal warning is detected.
2118 Use a wrapper program to launch programs for debugging.
2120 set multiple-symbols (all|ask|cancel)
2121 show multiple-symbols
2122 The value of this variable can be changed to adjust the debugger behavior
2123 when an expression or a breakpoint location contains an ambiguous symbol
2124 name (an overloaded function name, for instance).
2126 set breakpoint always-inserted
2127 show breakpoint always-inserted
2128 Keep breakpoints always inserted in the target, as opposed to inserting
2129 them when resuming the target, and removing them when the target stops.
2130 This option can improve debugger performance on slow remote targets.
2132 set arm fallback-mode (arm|thumb|auto)
2133 show arm fallback-mode
2134 set arm force-mode (arm|thumb|auto)
2136 These commands control how ARM GDB determines whether instructions
2137 are ARM or Thumb. The default for both settings is auto, which uses
2138 the current CPSR value for instructions without symbols; previous
2139 versions of GDB behaved as if "set arm fallback-mode arm".
2141 set disable-randomization
2142 show disable-randomization
2143 Standalone programs run with the virtual address space randomization enabled
2144 by default on some platforms. This option keeps the addresses stable across
2145 multiple debugging sessions.
2149 Control whether other threads are stopped or not when some thread hits
2154 Requests that asynchronous execution is enabled in the target, if available.
2155 In this case, it's possible to resume target in the background, and interact
2156 with GDB while the target is running. "show target-async" displays the
2157 current state of asynchronous execution of the target.
2159 set target-wide-charset
2160 show target-wide-charset
2161 The target-wide-charset is the name of the character set that GDB
2162 uses when printing characters whose type is wchar_t.
2164 set tcp auto-retry (on|off)
2166 set tcp connect-timeout
2167 show tcp connect-timeout
2168 These commands allow GDB to retry failed TCP connections to a remote stub
2169 with a specified timeout period; this is useful if the stub is launched
2170 in parallel with GDB but may not be ready to accept connections immediately.
2172 set libthread-db-search-path
2173 show libthread-db-search-path
2174 Control list of directories which GDB will search for appropriate
2177 set schedule-multiple (on|off)
2178 show schedule-multiple
2179 Allow GDB to resume all threads of all processes or only threads of
2180 the current process.
2184 Use more aggressive caching for accesses to the stack. This improves
2185 performance of remote debugging (particularly backtraces) without
2186 affecting correctness.
2188 set interactive-mode (on|off|auto)
2189 show interactive-mode
2190 Control whether GDB runs in interactive mode (on) or not (off).
2191 When in interactive mode, GDB waits for the user to answer all
2192 queries. Otherwise, GDB does not wait and assumes the default
2193 answer. When set to auto (the default), GDB determines which
2194 mode to use based on the stdin settings.
2199 For program forks, this is replaced by the new more generic `info
2200 inferiors' command. To list checkpoints, you can still use the
2201 `info checkpoints' command, which was an alias for the `info forks'
2205 Replaced by the new `inferior' command. To switch between
2206 checkpoints, you can still use the `restart' command, which was an
2207 alias for the `fork' command.
2210 This is removed, since some targets don't have a notion of
2211 processes. To switch between processes, you can still use the
2212 `inferior' command using GDB's own inferior number.
2215 For program forks, this is replaced by the new more generic `kill
2216 inferior' command. To delete a checkpoint, you can still use the
2217 `delete checkpoint' command, which was an alias for the `delete
2221 For program forks, this is replaced by the new more generic `detach
2222 inferior' command. To detach a checkpoint, you can still use the
2223 `detach checkpoint' command, which was an alias for the `detach
2226 * New native configurations
2228 x86/x86_64 Darwin i[34567]86-*-darwin*
2230 x86_64 MinGW x86_64-*-mingw*
2234 Lattice Mico32 lm32-*
2235 x86 DICOS i[34567]86-*-dicos*
2236 x86_64 DICOS x86_64-*-dicos*
2239 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2240 (mingw32ce) debugging.
2246 These commands were actually not implemented on any target.
2248 *** Changes in GDB 6.8
2250 * New native configurations
2252 NetBSD/hppa hppa*-*netbsd*
2253 Xtensa GNU/Linux xtensa*-*-linux*
2257 NetBSD/hppa hppa*-*-netbsd*
2258 Xtensa GNU/Lunux xtensa*-*-linux*
2260 * Change in command line behavior -- corefiles vs. process ids.
2262 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2263 attaching to process NUMBER fails, GDB no longer attempts to open a
2264 core file named NUMBER. Attaching to a program using the -c option
2265 is no longer supported. Instead, use the '-p' or '--pid' options.
2267 * GDB can now be built as a native debugger for debugging Windows x86
2268 (mingw32) Portable Executable (PE) programs.
2270 * Pending breakpoints no longer change their number when their address
2273 * GDB now supports breakpoints with multiple locations,
2274 including breakpoints on C++ constructors, inside C++ templates,
2275 and in inlined functions.
2277 * GDB's ability to debug optimized code has been improved. GDB more
2278 accurately identifies function bodies and lexical blocks that occupy
2279 more than one contiguous range of addresses.
2281 * Target descriptions can now describe registers for PowerPC.
2283 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2284 registers on PowerPC targets.
2286 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2287 targets even when the libthread_db library is not available.
2289 * The GDB remote stub, gdbserver, now supports the new file transfer
2290 commands (remote put, remote get, and remote delete).
2292 * The GDB remote stub, gdbserver, now supports run and attach in
2293 extended-remote mode.
2295 * hppa*64*-*-hpux11* target broken
2296 The debugger is unable to start a program and fails with the following
2297 error: "Error trying to get information about dynamic linker".
2298 The gdb-6.7 release is also affected.
2300 * GDB now supports the --enable-targets= configure option to allow
2301 building a single GDB executable that supports multiple remote
2302 target architectures.
2304 * GDB now supports debugging C and C++ programs which use the
2305 Decimal Floating Point extension. In addition, the PowerPC target
2306 now has a set of pseudo-registers to inspect decimal float values
2307 stored in two consecutive float registers.
2309 * The -break-insert MI command can optionally create pending
2312 * Improved support for debugging Ada
2313 Many improvements to the Ada language support have been made. These
2315 - Better support for Ada2005 interface types
2316 - Improved handling of arrays and slices in general
2317 - Better support for Taft-amendment types
2318 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2320 - Improved command completion in Ada
2323 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2328 set print frame-arguments (all|scalars|none)
2329 show print frame-arguments
2330 The value of this variable can be changed to control which argument
2331 values should be printed by the debugger when displaying a frame.
2336 Transfer files to and from a remote target, and delete remote files.
2343 Transfer files to and from a remote target, and delete remote files.
2345 * New remote packets
2352 Open, close, read, write, and delete files on the remote system.
2355 Attach to an existing process on the remote system, in extended-remote
2359 Run a new process on the remote system, in extended-remote mode.
2361 *** Changes in GDB 6.7
2363 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2364 bfd, libiberty and opcodes, as revealed by static analysis donated by
2365 Coverity, Inc. (http://scan.coverity.com).
2367 * When looking up multiply-defined global symbols, GDB will now prefer the
2368 symbol definition in the current shared library if it was built using the
2369 -Bsymbolic linker option.
2371 * When the Text User Interface (TUI) is not configured, GDB will now
2372 recognize the -tui command-line option and print a message that the TUI
2375 * The GDB remote stub, gdbserver, now has lower overhead for high
2376 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2378 * GDB for MIPS targets now autodetects whether a remote target provides
2379 32-bit or 64-bit register values.
2381 * Support for C++ member pointers has been improved.
2383 * GDB now understands XML target descriptions, which specify the
2384 target's overall architecture. GDB can read a description from
2385 a local file or over the remote serial protocol.
2387 * Vectors of single-byte data use a new integer type which is not
2388 automatically displayed as character or string data.
2390 * The /s format now works with the print command. It displays
2391 arrays of single-byte integers and pointers to single-byte integers
2394 * Target descriptions can now describe target-specific registers,
2395 for architectures which have implemented the support (currently
2396 only ARM, M68K, and MIPS).
2398 * GDB and the GDB remote stub, gdbserver, now support the XScale
2401 * The GDB remote stub, gdbserver, has been updated to support
2402 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2403 has been rewritten to use the standard GDB remote protocol.
2405 * GDB can now step into C++ functions which are called through thunks.
2407 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2409 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2410 layout. It also supports a TextSeg= and DataSeg= response when only
2411 segment base addresses (rather than offsets) are available.
2413 * The /i format now outputs any trailing branch delay slot instructions
2414 immediately following the last instruction within the count specified.
2416 * The GDB remote protocol "T" stop reply packet now supports a
2417 "library" response. Combined with the new "qXfer:libraries:read"
2418 packet, this response allows GDB to debug shared libraries on targets
2419 where the operating system manages the list of loaded libraries (e.g.
2420 Windows and SymbianOS).
2422 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2423 (DLLs) on Windows and Windows CE targets.
2425 * GDB now supports a faster verification that a .debug file matches its binary
2426 according to its build-id signature, if the signature is present.
2432 Enable or disable hardware flow control (RTS/CTS) on the serial port
2433 when debugging using remote targets.
2435 set mem inaccessible-by-default
2436 show mem inaccessible-by-default
2437 If the target supplies a memory map, for instance via the remote
2438 protocol's "qXfer:memory-map:read" packet, setting this variable
2439 prevents GDB from accessing memory outside the memory map. This
2440 is useful for targets with memory mapped registers or which react
2441 badly to accesses of unmapped address space.
2443 set breakpoint auto-hw
2444 show breakpoint auto-hw
2445 If the target supplies a memory map, for instance via the remote
2446 protocol's "qXfer:memory-map:read" packet, setting this variable
2447 lets GDB use hardware breakpoints automatically for memory regions
2448 where it can not use software breakpoints. This covers both the
2449 "break" command and internal breakpoints used for other commands
2450 including "next" and "finish".
2453 catch exception unhandled
2454 Stop the program execution when Ada exceptions are raised.
2457 Stop the program execution when an Ada assertion failed.
2461 Set an alternate system root for target files. This is a more
2462 general version of "set solib-absolute-prefix", which is now
2463 an alias to "set sysroot".
2466 Provide extended SPU facility status information. This set of
2467 commands is available only when debugging the Cell/B.E. SPU
2470 * New native configurations
2472 OpenBSD/sh sh*-*openbsd*
2475 unset tdesc filename
2477 Use the specified local file as an XML target description, and do
2478 not query the target for its built-in description.
2482 OpenBSD/sh sh*-*-openbsd*
2483 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2484 Toshiba Media Processor mep-elf
2486 * New remote packets
2489 Ignore the specified signals; pass them directly to the debugged program
2490 without stopping other threads or reporting them to GDB.
2492 qXfer:features:read:
2493 Read an XML target description from the target, which describes its
2498 Read or write contents of an spufs file on the target system. These
2499 packets are available only on the Cell/B.E. SPU architecture.
2501 qXfer:libraries:read:
2502 Report the loaded shared libraries. Combined with new "T" packet
2503 response, this packet allows GDB to debug shared libraries on
2504 targets where the operating system manages the list of loaded
2505 libraries (e.g. Windows and SymbianOS).
2509 Support for these obsolete configurations has been removed.
2517 i[34567]86-*-lynxos*
2518 i[34567]86-*-netware*
2519 i[34567]86-*-sco3.2v5*
2520 i[34567]86-*-sco3.2v4*
2522 i[34567]86-*-sysv4.2*
2525 i[34567]86-*-unixware2*
2526 i[34567]86-*-unixware*
2535 * Other removed features
2542 Various m68k-only ROM monitors.
2549 Various Renesas ROM monitors and debugging interfaces for SH and
2554 Support for a Macraigor serial interface to on-chip debugging.
2555 GDB does not directly support the newer parallel or USB
2560 A debug information format. The predecessor to DWARF 2 and
2561 DWARF 3, which are still supported.
2563 Support for the HP aCC compiler on HP-UX/PA-RISC
2565 SOM-encapsulated symbolic debugging information, automatic
2566 invocation of pxdb, and the aCC custom C++ ABI. This does not
2567 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2568 with aCC can still be debugged on an assembly level.
2570 MIPS ".pdr" sections
2572 A MIPS-specific format used to describe stack frame layout
2573 in debugging information.
2577 GDB could work with an older version of Guile to debug
2578 the interpreter and Scheme programs running in it.
2580 set mips stack-arg-size
2581 set mips saved-gpreg-size
2583 Use "set mips abi" to control parameter passing for MIPS.
2585 *** Changes in GDB 6.6
2590 Cell Broadband Engine SPU spu-elf
2592 * GDB can now be configured as a cross-debugger targeting native Windows
2593 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2594 running on a Windows system over TCP/IP to debug Windows programs.
2596 * The GDB remote stub, gdbserver, has been updated to support Windows and
2597 Cygwin debugging. Both single-threaded and multi-threaded programs are
2600 * The "set trust-readonly-sections" command works again. This command was
2601 broken in GDB 6.3, 6.4, and 6.5.
2603 * The "load" command now supports writing to flash memory, if the remote
2604 stub provides the required support.
2606 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2607 longer requires symbolic debug information (e.g. DWARF-2).
2612 unset substitute-path
2613 show substitute-path
2614 Manage a list of substitution rules that GDB uses to rewrite the name
2615 of the directories where the sources are located. This can be useful
2616 for instance when the sources were moved to a different location
2617 between compilation and debugging.
2621 Print each CLI command as it is executed. Each command is prefixed with
2622 a number of `+' symbols representing the nesting depth.
2623 The source command now has a `-v' option to enable the same feature.
2627 The ARM Demon monitor support (RDP protocol, "target rdp").
2629 Kernel Object Display, an embedded debugging feature which only worked with
2630 an obsolete version of Cisco IOS.
2632 The 'set download-write-size' and 'show download-write-size' commands.
2634 * New remote packets
2637 Tell a stub about GDB client features, and request remote target features.
2638 The first feature implemented is PacketSize, which allows the target to
2639 specify the size of packets it can handle - to minimize the number of
2640 packets required and improve performance when connected to a remote
2644 Fetch an OS auxilliary vector from the remote stub. This packet is a
2645 more efficient replacement for qPart:auxv:read.
2647 qXfer:memory-map:read:
2648 Fetch a memory map from the remote stub, including information about
2649 RAM, ROM, and flash memory devices.
2654 Erase and program a flash memory device.
2656 * Removed remote packets
2659 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2660 used it, and only gdbserver implemented it.
2662 *** Changes in GDB 6.5
2666 Renesas M32C/M16C m32c-elf
2668 Morpho Technologies ms1 ms1-elf
2672 init-if-undefined Initialize a convenience variable, but
2673 only if it doesn't already have a value.
2675 The following commands are presently only implemented for native GNU/Linux:
2677 checkpoint Save a snapshot of the program state.
2679 restart <n> Return the program state to a
2680 previously saved state.
2682 info checkpoints List currently saved checkpoints.
2684 delete-checkpoint <n> Delete a previously saved checkpoint.
2686 set|show detach-on-fork Tell gdb whether to detach from a newly
2687 forked process, or to keep debugging it.
2689 info forks List forks of the user program that
2690 are available to be debugged.
2692 fork <n> Switch to debugging one of several
2693 forks of the user program that are
2694 available to be debugged.
2696 delete-fork <n> Delete a fork from the list of forks
2697 that are available to be debugged (and
2698 kill the forked process).
2700 detach-fork <n> Delete a fork from the list of forks
2701 that are available to be debugged (and
2702 allow the process to continue).
2706 Morpho Technologies ms2 ms1-elf
2708 * Improved Windows host support
2710 GDB now builds as a cross debugger hosted on i686-mingw32, including
2711 native console support, and remote communications using either
2712 network sockets or serial ports.
2714 * Improved Modula-2 language support
2716 GDB can now print most types in the Modula-2 syntax. This includes:
2717 basic types, set types, record types, enumerated types, range types,
2718 pointer types and ARRAY types. Procedure var parameters are correctly
2719 printed and hexadecimal addresses and character constants are also
2720 written in the Modula-2 syntax. Best results can be obtained by using
2721 GNU Modula-2 together with the -gdwarf-2 command line option.
2725 The ARM rdi-share module.
2727 The Netware NLM debug server.
2729 *** Changes in GDB 6.4
2731 * New native configurations
2733 OpenBSD/arm arm*-*-openbsd*
2734 OpenBSD/mips64 mips64-*-openbsd*
2738 Morpho Technologies ms1 ms1-elf
2740 * New command line options
2742 --batch-silent As for --batch, but totally silent.
2743 --return-child-result The debugger will exist with the same value
2744 the child (debugged) program exited with.
2745 --eval-command COMMAND, -ex COMMAND
2746 Execute a single GDB CLI command. This may be
2747 specified multiple times and in conjunction
2748 with the --command (-x) option.
2750 * Deprecated commands removed
2752 The following commands, that were deprecated in 2000, have been
2756 set|show arm disassembly-flavor set|show arm disassembler
2757 othernames set arm disassembler
2758 set|show remotedebug set|show debug remote
2759 set|show archdebug set|show debug arch
2760 set|show eventdebug set|show debug event
2763 * New BSD user-level threads support
2765 It is now possible to debug programs using the user-level threads
2766 library on OpenBSD and FreeBSD. Currently supported (target)
2769 FreeBSD/amd64 x86_64-*-freebsd*
2770 FreeBSD/i386 i386-*-freebsd*
2771 OpenBSD/i386 i386-*-openbsd*
2773 Note that the new kernel threads libraries introduced in FreeBSD 5.x
2774 are not yet supported.
2776 * New support for Matsushita MN10300 w/sim added
2777 (Work in progress). mn10300-elf.
2779 * REMOVED configurations and files
2781 VxWorks and the XDR protocol *-*-vxworks
2782 Motorola MCORE mcore-*-*
2783 National Semiconductor NS32000 ns32k-*-*
2785 * New "set print array-indexes" command
2787 After turning this setting "on", GDB prints the index of each element
2788 when displaying arrays. The default is "off" to preserve the previous
2791 * VAX floating point support
2793 GDB now supports the not-quite-ieee VAX F and D floating point formats.
2795 * User-defined command support
2797 In addition to using $arg0..$arg9 for argument passing, it is now possible
2798 to use $argc to determine now many arguments have been passed. See the
2799 section on user-defined commands in the user manual for more information.
2801 *** Changes in GDB 6.3:
2803 * New command line option
2805 GDB now accepts -l followed by a number to set the timeout for remote
2808 * GDB works with GCC -feliminate-dwarf2-dups
2810 GDB now supports a more compact representation of DWARF-2 debug
2811 information using DW_FORM_ref_addr references. These are produced
2812 by GCC with the option -feliminate-dwarf2-dups and also by some
2813 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
2814 to use -feliminate-dwarf2-dups.
2816 * Internationalization
2818 When supported by the host system, GDB will be built with
2819 internationalization (libintl). The task of marking up the sources is
2820 continued, we're looking forward to our first translation.
2824 Initial support for debugging programs compiled with the GNAT
2825 implementation of the Ada programming language has been integrated
2826 into GDB. In this release, support is limited to expression evaluation.
2828 * New native configurations
2830 GNU/Linux/m32r m32r-*-linux-gnu
2834 GDB's remote protocol now includes support for the 'p' packet. This
2835 packet is used to fetch individual registers from a remote inferior.
2837 * END-OF-LIFE registers[] compatibility module
2839 GDB's internal register infrastructure has been completely rewritten.
2840 The new infrastructure making possible the implementation of key new
2841 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
2844 GDB 6.3 will be the last release to include the the registers[]
2845 compatibility module that allowed out-of-date configurations to
2846 continue to work. This change directly impacts the following
2856 powerpc bdm protocol
2858 Unless there is activity to revive these configurations, they will be
2859 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
2861 * OBSOLETE configurations and files
2863 Configurations that have been declared obsolete in this release have
2864 been commented out. Unless there is activity to revive these
2865 configurations, the next release of GDB will have their sources
2866 permanently REMOVED.
2875 *** Changes in GDB 6.2.1:
2877 * MIPS `break main; run' gave an heuristic-fence-post warning
2879 When attempting to run even a simple program, a warning about
2880 heuristic-fence-post being hit would be reported. This problem has
2883 * MIPS IRIX 'long double' crashed GDB
2885 When examining a long double variable, GDB would get a segmentation
2886 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
2887 IRIX long double values).
2891 A bug in the VAX stack code was causing problems with the "next"
2892 command. This problem has been fixed.
2894 *** Changes in GDB 6.2:
2896 * Fix for ``many threads''
2898 On GNU/Linux systems that use the NPTL threads library, a program
2899 rapidly creating and deleting threads would confuse GDB leading to the
2902 ptrace: No such process.
2903 thread_db_get_info: cannot get thread info: generic error
2905 This problem has been fixed.
2907 * "-async" and "-noasync" options removed.
2909 Support for the broken "-noasync" option has been removed (it caused
2912 * New ``start'' command.
2914 This command runs the program until the begining of the main procedure.
2916 * New BSD Kernel Data Access Library (libkvm) interface
2918 Using ``target kvm'' it is now possible to debug kernel core dumps and
2919 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
2920 platforms. Currently supported (native-only) configurations are:
2922 FreeBSD/amd64 x86_64-*-freebsd*
2923 FreeBSD/i386 i?86-*-freebsd*
2924 NetBSD/i386 i?86-*-netbsd*
2925 NetBSD/m68k m68*-*-netbsd*
2926 NetBSD/sparc sparc-*-netbsd*
2927 OpenBSD/amd64 x86_64-*-openbsd*
2928 OpenBSD/i386 i?86-*-openbsd*
2929 OpenBSD/m68k m68*-openbsd*
2930 OpenBSD/sparc sparc-*-openbsd*
2932 * Signal trampoline code overhauled
2934 Many generic problems with GDB's signal handling code have been fixed.
2935 These include: backtraces through non-contiguous stacks; recognition
2936 of sa_sigaction signal trampolines; backtrace from a NULL pointer
2937 call; backtrace through a signal trampoline; step into and out of
2938 signal handlers; and single-stepping in the signal trampoline.
2940 Please note that kernel bugs are a limiting factor here. These
2941 features have been shown to work on an s390 GNU/Linux system that
2942 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
2944 * Cygwin support for DWARF 2 added.
2946 * New native configurations
2948 GNU/Linux/hppa hppa*-*-linux*
2949 OpenBSD/hppa hppa*-*-openbsd*
2950 OpenBSD/m68k m68*-*-openbsd*
2951 OpenBSD/m88k m88*-*-openbsd*
2952 OpenBSD/powerpc powerpc-*-openbsd*
2953 NetBSD/vax vax-*-netbsd*
2954 OpenBSD/vax vax-*-openbsd*
2956 * END-OF-LIFE frame compatibility module
2958 GDB's internal frame infrastructure has been completely rewritten.
2959 The new infrastructure making it possible to support key new features
2960 including DWARF 2 Call Frame Information. To aid in the task of
2961 migrating old configurations to this new infrastructure, a
2962 compatibility module, that allowed old configurations to continue to
2963 work, was also included.
2965 GDB 6.2 will be the last release to include this frame compatibility
2966 module. This change directly impacts the following configurations:
2976 Unless there is activity to revive these configurations, they will be
2977 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
2979 * REMOVED configurations and files
2981 Sun 3, running SunOS 3 m68*-*-sunos3*
2982 Sun 3, running SunOS 4 m68*-*-sunos4*
2983 Sun 2, running SunOS 3 m68000-*-sunos3*
2984 Sun 2, running SunOS 4 m68000-*-sunos4*
2985 Motorola 680x0 running LynxOS m68*-*-lynxos*
2986 AT&T 3b1/Unix pc m68*-att-*
2987 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2988 decstation mips-dec-* mips-little-*
2989 riscos mips-*-riscos* mips-*-sysv*
2990 sonymips mips-sony-*
2991 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2993 *** Changes in GDB 6.1.1:
2995 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
2997 The TUI (Text-mode User Interface) is now built as part of a default
2998 GDB configuration. It is enabled by either selecting the TUI with the
2999 command line option "-i=tui" or by running the separate "gdbtui"
3000 program. For more information on the TUI, see the manual "Debugging
3003 * Pending breakpoint support (also included in GDB 6.1)
3005 Support has been added to allow you to specify breakpoints in shared
3006 libraries that have not yet been loaded. If a breakpoint location
3007 cannot be found, and the "breakpoint pending" option is set to auto,
3008 GDB queries you if you wish to make the breakpoint pending on a future
3009 shared-library load. If and when GDB resolves the breakpoint symbol,
3010 the pending breakpoint is removed as one or more regular breakpoints
3013 Pending breakpoints are very useful for GCJ Java debugging.
3015 * Fixed ISO-C build problems
3017 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3018 non ISO-C code that stopped them being built using a more strict ISO-C
3019 compiler (e.g., IBM's C compiler).
3021 * Fixed build problem on IRIX 5
3023 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3024 wasn't able to compile compile on an IRIX 5 system.
3026 * Added execute permission to gdb/gdbserver/configure
3028 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3029 permission. This bug would cause configure to fail on a number of
3030 systems (Solaris, IRIX). Ref: server/519.
3032 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3034 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3035 has been updated to use constant array sizes.
3037 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3039 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3040 its generated DWARF Call Frame Info. This encoding was causing GDB to
3041 panic, that panic has been fixed. Ref: gdb/1628.
3043 * Fixed a problem when examining parameters in shared library code.
3045 When examining parameters in optimized shared library code generated
3046 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3047 not available''. GDB now correctly displays the variable's value.
3049 *** Changes in GDB 6.1:
3051 * Removed --with-mmalloc
3053 Support for the mmalloc memory manager has been removed, as it
3054 conflicted with the internal gdb byte cache.
3056 * Changes in AMD64 configurations
3058 The AMD64 target now includes the %cs and %ss registers. As a result
3059 the AMD64 remote protocol has changed; this affects the floating-point
3060 and SSE registers. If you rely on those registers for your debugging,
3061 you should upgrade gdbserver on the remote side.
3063 * Revised SPARC target
3065 The SPARC target has been completely revised, incorporating the
3066 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3067 support for LynxOS and SunOS 4 has been dropped. Calling functions
3068 from within GDB on operating systems with a non-executable stack
3069 (Solaris, OpenBSD) now works.
3073 GDB has a new C++ demangler which does a better job on the mangled
3074 names generated by current versions of g++. It also runs faster, so
3075 with this and other changes gdb should now start faster on large C++
3078 * DWARF 2 Location Expressions
3080 GDB support for location expressions has been extended to support function
3081 arguments and frame bases. Older versions of GDB could crash when they
3084 * C++ nested types and namespaces
3086 GDB's support for nested types and namespaces in C++ has been
3087 improved, especially if you use the DWARF 2 debugging format. (This
3088 is the default for recent versions of GCC on most platforms.)
3089 Specifically, if you have a class "Inner" defined within a class or
3090 namespace "Outer", then GDB realizes that the class's name is
3091 "Outer::Inner", not simply "Inner". This should greatly reduce the
3092 frequency of complaints about not finding RTTI symbols. In addition,
3093 if you are stopped at inside of a function defined within a namespace,
3094 GDB modifies its name lookup accordingly.
3096 * New native configurations
3098 NetBSD/amd64 x86_64-*-netbsd*
3099 OpenBSD/amd64 x86_64-*-openbsd*
3100 OpenBSD/alpha alpha*-*-openbsd*
3101 OpenBSD/sparc sparc-*-openbsd*
3102 OpenBSD/sparc64 sparc64-*-openbsd*
3104 * New debugging protocols
3106 M32R with SDI protocol m32r-*-elf*
3108 * "set prompt-escape-char" command deleted.
3110 The command "set prompt-escape-char" has been deleted. This command,
3111 and its very obscure effet on GDB's prompt, was never documented,
3112 tested, nor mentioned in the NEWS file.
3114 * OBSOLETE configurations and files
3116 Configurations that have been declared obsolete in this release have
3117 been commented out. Unless there is activity to revive these
3118 configurations, the next release of GDB will have their sources
3119 permanently REMOVED.
3121 Sun 3, running SunOS 3 m68*-*-sunos3*
3122 Sun 3, running SunOS 4 m68*-*-sunos4*
3123 Sun 2, running SunOS 3 m68000-*-sunos3*
3124 Sun 2, running SunOS 4 m68000-*-sunos4*
3125 Motorola 680x0 running LynxOS m68*-*-lynxos*
3126 AT&T 3b1/Unix pc m68*-att-*
3127 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3128 decstation mips-dec-* mips-little-*
3129 riscos mips-*-riscos* mips-*-sysv*
3130 sonymips mips-sony-*
3131 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3133 * REMOVED configurations and files
3135 SGI Irix-4.x mips-sgi-irix4 or iris4
3136 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3137 Z8000 simulator z8k-zilog-none or z8ksim
3138 Matsushita MN10200 w/simulator mn10200-*-*
3139 H8/500 simulator h8500-hitachi-hms or h8500hms
3140 HP/PA running BSD hppa*-*-bsd*
3141 HP/PA running OSF/1 hppa*-*-osf*
3142 HP/PA Pro target hppa*-*-pro*
3143 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3144 386BSD i[3456]86-*-bsd*
3145 Sequent family i[3456]86-sequent-sysv4*
3146 i[3456]86-sequent-sysv*
3147 i[3456]86-sequent-bsd*
3148 SPARC running LynxOS sparc-*-lynxos*
3149 SPARC running SunOS 4 sparc-*-sunos4*
3150 Tsqware Sparclet sparclet-*-*
3151 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3153 *** Changes in GDB 6.0:
3157 Support for debugging the Objective-C programming language has been
3158 integrated into GDB.
3160 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3162 DWARF 2's Call Frame Information makes available compiler generated
3163 information that more exactly describes the program's run-time stack.
3164 By using this information, GDB is able to provide more robust stack
3167 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3168 have been updated to use a new backtrace mechanism which includes
3169 DWARF 2 CFI support.
3173 GDB's remote protocol has been extended to include support for hosted
3174 file I/O (where the remote target uses GDB's file system). See GDB's
3175 remote protocol documentation for details.
3177 * All targets using the new architecture framework.
3179 All of GDB's targets have been updated to use the new internal
3180 architecture framework. The way is now open for future GDB releases
3181 to include cross-architecture native debugging support (i386 on amd64,
3184 * GNU/Linux's Thread Local Storage (TLS)
3186 GDB now includes support for for the GNU/Linux implementation of
3187 per-thread variables.
3189 * GNU/Linux's Native POSIX Thread Library (NPTL)
3191 GDB's thread code has been updated to work with either the new
3192 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3194 * Separate debug info.
3196 GDB, in conjunction with BINUTILS, now supports a mechanism for
3197 automatically loading debug information from a separate file. Instead
3198 of shipping full debug and non-debug versions of system libraries,
3199 system integrators can now instead ship just the stripped libraries
3200 and optional debug files.
3202 * DWARF 2 Location Expressions
3204 DWARF 2 Location Expressions allow the compiler to more completely
3205 describe the location of variables (even in optimized code) to the
3208 GDB now includes preliminary support for location expressions (support
3209 for DW_OP_piece is still missing).
3213 A number of long standing bugs that caused GDB to die while starting a
3214 Java application have been fixed. GDB's Java support is now
3215 considered "useable".
3217 * GNU/Linux support for fork, vfork, and exec.
3219 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3220 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3223 * GDB supports logging output to a file
3225 There are two new commands, "set logging" and "show logging", which can be
3226 used to capture GDB's output to a file.
3228 * The meaning of "detach" has changed for gdbserver
3230 The "detach" command will now resume the application, as documented. To
3231 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3234 * d10v, m68hc11 `regs' command deprecated
3236 The `info registers' command has been updated so that it displays the
3237 registers using a format identical to the old `regs' command.
3241 A new command, "maint set profile on/off", has been added. This command can
3242 be used to enable or disable profiling while running GDB, to profile a
3243 session or a set of commands. In addition there is a new configure switch,
3244 "--enable-profiling", which will cause GDB to be compiled with profiling
3245 data, for more informative profiling results.
3247 * Default MI syntax changed to "mi2".
3249 The default MI (machine interface) syntax, enabled by the command line
3250 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3251 "mi1", can be enabled by specifying the option "-i=mi1".
3253 Support for the original "mi0" syntax (included in GDB 5.0) has been
3256 Fix for gdb/192: removed extraneous space when displaying frame level.
3257 Fix for gdb/672: update changelist is now output in mi list format.
3258 Fix for gdb/702: a -var-assign that updates the value now shows up
3259 in a subsequent -var-update.
3261 * New native configurations.
3263 FreeBSD/amd64 x86_64-*-freebsd*
3265 * Multi-arched targets.
3267 HP/PA HPUX11 hppa*-*-hpux*
3268 Renesas M32R/D w/simulator m32r-*-elf*
3270 * OBSOLETE configurations and files
3272 Configurations that have been declared obsolete in this release have
3273 been commented out. Unless there is activity to revive these
3274 configurations, the next release of GDB will have their sources
3275 permanently REMOVED.
3277 Z8000 simulator z8k-zilog-none or z8ksim
3278 Matsushita MN10200 w/simulator mn10200-*-*
3279 H8/500 simulator h8500-hitachi-hms or h8500hms
3280 HP/PA running BSD hppa*-*-bsd*
3281 HP/PA running OSF/1 hppa*-*-osf*
3282 HP/PA Pro target hppa*-*-pro*
3283 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3284 Sequent family i[3456]86-sequent-sysv4*
3285 i[3456]86-sequent-sysv*
3286 i[3456]86-sequent-bsd*
3287 Tsqware Sparclet sparclet-*-*
3288 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3290 * REMOVED configurations and files
3293 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3294 IBM AIX PS/2 i[3456]86-*-aix
3295 i386 running Mach 3.0 i[3456]86-*-mach3*
3296 i386 running Mach i[3456]86-*-mach*
3297 i386 running OSF/1 i[3456]86-*osf1mk*
3298 HP/Apollo 68k Family m68*-apollo*-sysv*,
3300 m68*-hp-bsd*, m68*-hp-hpux*
3301 Argonaut Risc Chip (ARC) arc-*-*
3302 Mitsubishi D30V d30v-*-*
3303 Fujitsu FR30 fr30-*-elf*
3304 OS/9000 i[34]86-*-os9k
3305 I960 with MON960 i960-*-coff
3307 * MIPS $fp behavior changed
3309 The convenience variable $fp, for the MIPS, now consistently returns
3310 the address of the current frame's base. Previously, depending on the
3311 context, $fp could refer to either $sp or the current frame's base
3312 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3313 The GNU Source-Level Debugger''.
3315 *** Changes in GDB 5.3:
3317 * GNU/Linux shared library multi-threaded performance improved.
3319 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3320 `/proc', in preference to `ptrace' for memory reads. This may result
3321 in an improvement in the start-up time of multi-threaded, shared
3322 library applications when run under GDB. One GDB user writes: ``loads
3323 shared libs like mad''.
3325 * ``gdbserver'' now supports multi-threaded applications on some targets
3327 Support for debugging multi-threaded applications which use
3328 the GNU/Linux LinuxThreads package has been added for
3329 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3330 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3332 * GDB now supports C/C++ preprocessor macros.
3334 GDB now expands preprocessor macro invocations in C/C++ expressions,
3335 and provides various commands for showing macro definitions and how
3338 The new command `macro expand EXPRESSION' expands any macro
3339 invocations in expression, and shows the result.
3341 The new command `show macro MACRO-NAME' shows the definition of the
3342 macro named MACRO-NAME, and where it was defined.
3344 Most compilers don't include information about macros in the debugging
3345 information by default. In GCC 3.1, for example, you need to compile
3346 your program with the options `-gdwarf-2 -g3'. If the macro
3347 information is present in the executable, GDB will read it.
3349 * Multi-arched targets.
3351 DEC Alpha (partial) alpha*-*-*
3352 DEC VAX (partial) vax-*-*
3354 National Semiconductor NS32000 (partial) ns32k-*-*
3355 Motorola 68000 (partial) m68k-*-*
3356 Motorola MCORE mcore-*-*
3360 Fujitsu FRV architecture added by Red Hat frv*-*-*
3363 * New native configurations
3365 Alpha NetBSD alpha*-*-netbsd*
3366 SH NetBSD sh*-*-netbsdelf*
3367 MIPS NetBSD mips*-*-netbsd*
3368 UltraSPARC NetBSD sparc64-*-netbsd*
3370 * OBSOLETE configurations and files
3372 Configurations that have been declared obsolete in this release have
3373 been commented out. Unless there is activity to revive these
3374 configurations, the next release of GDB will have their sources
3375 permanently REMOVED.
3377 Mitsubishi D30V d30v-*-*
3378 OS/9000 i[34]86-*-os9k
3379 IBM AIX PS/2 i[3456]86-*-aix
3380 Fujitsu FR30 fr30-*-elf*
3381 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3382 Argonaut Risc Chip (ARC) arc-*-*
3383 i386 running Mach 3.0 i[3456]86-*-mach3*
3384 i386 running Mach i[3456]86-*-mach*
3385 i386 running OSF/1 i[3456]86-*osf1mk*
3386 HP/Apollo 68k Family m68*-apollo*-sysv*,
3388 m68*-hp-bsd*, m68*-hp-hpux*
3389 I960 with MON960 i960-*-coff
3391 * OBSOLETE languages
3393 CHILL, a Pascal like language used by telecommunications companies.
3395 * REMOVED configurations and files
3397 AMD 29k family via UDI a29k-amd-udi, udi29k
3398 A29K VxWorks a29k-*-vxworks
3399 AMD 29000 embedded, using EBMON a29k-none-none
3400 AMD 29000 embedded with COFF a29k-none-coff
3401 AMD 29000 embedded with a.out a29k-none-aout
3403 testsuite/gdb.hp/gdb.threads-hp/ directory
3405 * New command "set max-user-call-depth <nnn>"
3407 This command allows the user to limit the call depth of user-defined
3408 commands. The default is 1024.
3410 * Changes in FreeBSD/i386 native debugging.
3412 Support for the "generate-core-file" has been added.
3414 * New commands "dump", "append", and "restore".
3416 These commands allow data to be copied from target memory
3417 to a bfd-format or binary file (dump and append), and back
3418 from a file into memory (restore).
3420 * Improved "next/step" support on multi-processor Alpha Tru64.
3422 The previous single-step mechanism could cause unpredictable problems,
3423 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3424 of a software single-step mechanism prevents this.
3426 *** Changes in GDB 5.2.1:
3434 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3435 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3436 Fix, by Joel Brobecker imported from mainline.
3438 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3439 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3440 Fix, by Fred Fish, imported from mainline.
3442 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3443 Surprisingly enough, it works now.
3444 By Michal Ludvig, imported from mainline.
3446 i386 hardware watchpoint support:
3447 avoid misses on second run for some targets.
3448 By Pierre Muller, imported from mainline.
3450 *** Changes in GDB 5.2:
3452 * New command "set trust-readonly-sections on[off]".
3454 This command is a hint that tells gdb that read-only sections
3455 really are read-only (ie. that their contents will not change).
3456 In this mode, gdb will go to the object file rather than the
3457 target to read memory from read-only sections (such as ".text").
3458 This can be a significant performance improvement on some
3459 (notably embedded) targets.
3461 * New command "generate-core-file" (or "gcore").
3463 This new gdb command allows the user to drop a core file of the child
3464 process state at any time. So far it's been implemented only for
3465 GNU/Linux and Solaris, but should be relatively easily ported to other
3466 hosts. Argument is core file name (defaults to core.<pid>).
3468 * New command line option
3470 GDB now accepts --pid or -p followed by a process id.
3472 * Change in command line behavior -- corefiles vs. process ids.
3474 There is a subtle behavior in the way in which GDB handles
3475 command line arguments. The first non-flag argument is always
3476 a program to debug, but the second non-flag argument may either
3477 be a corefile or a process id. Previously, GDB would attempt to
3478 open the second argument as a corefile, and if that failed, would
3479 issue a superfluous error message and then attempt to attach it as
3480 a process. Now, if the second argument begins with a non-digit,
3481 it will be treated as a corefile. If it begins with a digit,
3482 GDB will attempt to attach it as a process, and if no such process
3483 is found, will then attempt to open it as a corefile.
3485 * Changes in ARM configurations.
3487 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3488 configuration is fully multi-arch.
3490 * New native configurations
3492 ARM NetBSD arm*-*-netbsd*
3493 x86 OpenBSD i[3456]86-*-openbsd*
3494 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3495 Sparc64 running FreeBSD sparc64-*-freebsd*
3499 Sanyo XStormy16 xstormy16-elf
3501 * OBSOLETE configurations and files
3503 Configurations that have been declared obsolete in this release have
3504 been commented out. Unless there is activity to revive these
3505 configurations, the next release of GDB will have their sources
3506 permanently REMOVED.
3508 AMD 29k family via UDI a29k-amd-udi, udi29k
3509 A29K VxWorks a29k-*-vxworks
3510 AMD 29000 embedded, using EBMON a29k-none-none
3511 AMD 29000 embedded with COFF a29k-none-coff
3512 AMD 29000 embedded with a.out a29k-none-aout
3514 testsuite/gdb.hp/gdb.threads-hp/ directory
3516 * REMOVED configurations and files
3518 TI TMS320C80 tic80-*-*
3520 PowerPC Solaris powerpcle-*-solaris*
3521 PowerPC Windows NT powerpcle-*-cygwin32
3522 PowerPC Netware powerpc-*-netware*
3523 Harris/CXUX m88k m88*-harris-cxux*
3524 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3525 ns32k-utek-sysv* ns32k-utek-*
3526 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3527 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3528 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3529 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3530 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3532 * Changes to command line processing
3534 The new `--args' feature can be used to specify command-line arguments
3535 for the inferior from gdb's command line.
3537 * Changes to key bindings
3539 There is a new `operate-and-get-next' function bound to `C-o'.
3541 *** Changes in GDB 5.1.1
3543 Fix compile problem on DJGPP.
3545 Fix a problem with floating-point registers on the i386 being
3548 Fix to stop GDB crashing on .debug_str debug info.
3550 Numerous documentation fixes.
3552 Numerous testsuite fixes.
3554 *** Changes in GDB 5.1:
3556 * New native configurations
3558 Alpha FreeBSD alpha*-*-freebsd*
3559 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3560 MIPS GNU/Linux mips*-*-linux*
3561 MIPS SGI Irix 6.x mips*-sgi-irix6*
3562 ia64 AIX ia64-*-aix*
3563 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3567 Motorola 68HC11 and 68HC12 m68hc11-elf
3569 UltraSparc running GNU/Linux sparc64-*-linux*
3571 * OBSOLETE configurations and files
3573 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3574 Harris/CXUX m88k m88*-harris-cxux*
3575 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3576 ns32k-utek-sysv* ns32k-utek-*
3577 TI TMS320C80 tic80-*-*
3579 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3580 PowerPC Solaris powerpcle-*-solaris*
3581 PowerPC Windows NT powerpcle-*-cygwin32
3582 PowerPC Netware powerpc-*-netware*
3583 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3584 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3585 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3586 Apple Macintosh (MPW) host N/A
3588 stuff.c (Program to stuff files into a specially prepared space in kdb)
3589 kdb-start.c (Main loop for the standalone kernel debugger)
3591 Configurations that have been declared obsolete in this release have
3592 been commented out. Unless there is activity to revive these
3593 configurations, the next release of GDB will have their sources
3594 permanently REMOVED.
3596 * REMOVED configurations and files
3598 Altos 3068 m68*-altos-*
3599 Convex c1-*-*, c2-*-*
3601 ARM RISCix arm-*-* (as host)
3605 * GDB has been converted to ISO C.
3607 GDB's source code has been converted to ISO C. In particular, the
3608 sources are fully protoized, and rely on standard headers being
3613 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3615 * The MI enabled by default.
3617 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3618 revised and enabled by default. Packages which use GDB as a debugging
3619 engine behind a UI or another front end are encouraged to switch to
3620 using the GDB/MI interface, instead of the old annotations interface
3621 which is now deprecated.
3623 * Support for debugging Pascal programs.
3625 GDB now includes support for debugging Pascal programs. The following
3626 main features are supported:
3628 - Pascal-specific data types such as sets;
3630 - automatic recognition of Pascal sources based on file-name
3633 - Pascal-style display of data types, variables, and functions;
3635 - a Pascal expression parser.
3637 However, some important features are not yet supported.
3639 - Pascal string operations are not supported at all;
3641 - there are some problems with boolean types;
3643 - Pascal type hexadecimal constants are not supported
3644 because they conflict with the internal variables format;
3646 - support for Pascal objects and classes is not full yet;
3648 - unlike Pascal, GDB is case-sensitive for symbol names.
3650 * Changes in completion.
3652 Commands such as `shell', `run' and `set args', which pass arguments
3653 to inferior programs, now complete on file names, similar to what
3654 users expect at the shell prompt.
3656 Commands which accept locations, such as `disassemble', `print',
3657 `breakpoint', `until', etc. now complete on filenames as well as
3658 program symbols. Thus, if you type "break foob TAB", and the source
3659 files linked into the programs include `foobar.c', that file name will
3660 be one of the candidates for completion. However, file names are not
3661 considered for completion after you typed a colon that delimits a file
3662 name from a name of a function in that file, as in "break foo.c:bar".
3664 `set demangle-style' completes on available demangling styles.
3666 * New platform-independent commands:
3668 It is now possible to define a post-hook for a command as well as a
3669 hook that runs before the command. For more details, see the
3670 documentation of `hookpost' in the GDB manual.
3672 * Changes in GNU/Linux native debugging.
3674 Support for debugging multi-threaded programs has been completely
3675 revised for all platforms except m68k and sparc. You can now debug as
3676 many threads as your system allows you to have.
3678 Attach/detach is supported for multi-threaded programs.
3680 Support for SSE registers was added for x86. This doesn't work for
3681 multi-threaded programs though.
3683 * Changes in MIPS configurations.
3685 Multi-arch support is enabled for all MIPS configurations.
3687 GDB can now be built as native debugger on SGI Irix 6.x systems for
3688 debugging n32 executables. (Debugging 64-bit executables is not yet
3691 * Unified support for hardware watchpoints in all x86 configurations.
3693 Most (if not all) native x86 configurations support hardware-assisted
3694 breakpoints and watchpoints in a unified manner. This support
3695 implements debug register sharing between watchpoints, which allows to
3696 put a virtually infinite number of watchpoints on the same address,
3697 and also supports watching regions up to 16 bytes with several debug
3700 The new maintenance command `maintenance show-debug-regs' toggles
3701 debugging print-outs in functions that insert, remove, and test
3702 watchpoints and hardware breakpoints.
3704 * Changes in the DJGPP native configuration.
3706 New command ``info dos sysinfo'' displays assorted information about
3707 the CPU, OS, memory, and DPMI server.
3709 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3710 display information about segment descriptors stored in GDT, LDT, and
3713 New commands ``info dos pde'' and ``info dos pte'' display entries
3714 from Page Directory and Page Tables (for now works with CWSDPMI only).
3715 New command ``info dos address-pte'' displays the Page Table entry for
3716 a given linear address.
3718 GDB can now pass command lines longer than 126 characters to the
3719 program being debugged (requires an update to the libdbg.a library
3720 which is part of the DJGPP development kit).
3722 DWARF2 debug info is now supported.
3724 It is now possible to `step' and `next' through calls to `longjmp'.
3726 * Changes in documentation.
3728 All GDB documentation was converted to GFDL, the GNU Free
3729 Documentation License.
3731 Tracepoints-related commands are now fully documented in the GDB
3734 TUI, the Text-mode User Interface, is now documented in the manual.
3736 Tracepoints-related commands are now fully documented in the GDB
3739 The "GDB Internals" manual now has an index. It also includes
3740 documentation of `ui_out' functions, GDB coding standards, x86
3741 hardware watchpoints, and memory region attributes.
3743 * GDB's version number moved to ``version.in''
3745 The Makefile variable VERSION has been replaced by the file
3746 ``version.in''. People creating GDB distributions should update the
3747 contents of this file.
3751 GUD support is now a standard part of the EMACS distribution.
3753 *** Changes in GDB 5.0:
3755 * Improved support for debugging FP programs on x86 targets
3757 Unified and much-improved support for debugging floating-point
3758 programs on all x86 targets. In particular, ``info float'' now
3759 displays the FP registers in the same format on all x86 targets, with
3760 greater level of detail.
3762 * Improvements and bugfixes in hardware-assisted watchpoints
3764 It is now possible to watch array elements, struct members, and
3765 bitfields with hardware-assisted watchpoints. Data-read watchpoints
3766 on x86 targets no longer erroneously trigger when the address is
3769 * Improvements in the native DJGPP version of GDB
3771 The distribution now includes all the scripts and auxiliary files
3772 necessary to build the native DJGPP version on MS-DOS/MS-Windows
3773 machines ``out of the box''.
3775 The DJGPP version can now debug programs that use signals. It is
3776 possible to catch signals that happened in the debuggee, deliver
3777 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
3778 would kill the program being debugged.) Programs that hook hardware
3779 interrupts (keyboard, timer, etc.) can also be debugged.
3781 It is now possible to debug DJGPP programs that redirect their
3782 standard handles or switch them to raw (as opposed to cooked) mode, or
3783 even close them. The command ``run < foo > bar'' works as expected,
3784 and ``info terminal'' reports useful information about the debuggee's
3785 terminal, including raw/cooked mode, redirection, etc.
3787 The DJGPP version now uses termios functions for console I/O, which
3788 enables debugging graphics programs. Interrupting GDB with Ctrl-C
3791 DOS-style file names with drive letters are now fully supported by
3794 It is now possible to debug DJGPP programs that switch their working
3795 directory. It is also possible to rerun the debuggee any number of
3796 times without restarting GDB; thus, you can use the same setup,
3797 breakpoints, etc. for many debugging sessions.
3799 * New native configurations
3801 ARM GNU/Linux arm*-*-linux*
3802 PowerPC GNU/Linux powerpc-*-linux*
3806 Motorola MCore mcore-*-*
3807 x86 VxWorks i[3456]86-*-vxworks*
3808 PowerPC VxWorks powerpc-*-vxworks*
3809 TI TMS320C80 tic80-*-*
3811 * OBSOLETE configurations
3813 Altos 3068 m68*-altos-*
3814 Convex c1-*-*, c2-*-*
3816 ARM RISCix arm-*-* (as host)
3819 Configurations that have been declared obsolete will be commented out,
3820 but the code will be left in place. If there is no activity to revive
3821 these configurations before the next release of GDB, the sources will
3822 be permanently REMOVED.
3824 * Gould support removed
3826 Support for the Gould PowerNode and NP1 has been removed.
3828 * New features for SVR4
3830 On SVR4 native platforms (such as Solaris), if you attach to a process
3831 without first loading a symbol file, GDB will now attempt to locate and
3832 load symbols from the running process's executable file.
3834 * Many C++ enhancements
3836 C++ support has been greatly improved. Overload resolution now works properly
3837 in almost all cases. RTTI support is on the way.
3839 * Remote targets can connect to a sub-program
3841 A popen(3) style serial-device has been added. This device starts a
3842 sub-process (such as a stand-alone simulator) and then communicates
3843 with that. The sub-program to run is specified using the syntax
3844 ``|<program> <args>'' vis:
3846 (gdb) set remotedebug 1
3847 (gdb) target extended-remote |mn10300-elf-sim program-args
3849 * MIPS 64 remote protocol
3851 A long standing bug in the mips64 remote protocol where by GDB
3852 expected certain 32 bit registers (ex SR) to be transfered as 32
3853 instead of 64 bits has been fixed.
3855 The command ``set remote-mips64-transfers-32bit-regs on'' has been
3856 added to provide backward compatibility with older versions of GDB.
3858 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
3860 The command ``set remotebinarydownload'' command has been replaced by
3861 ``set remote X-packet''. Other commands in ``set remote'' family
3862 include ``set remote P-packet''.
3864 * Breakpoint commands accept ranges.
3866 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
3867 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
3868 ``tracepoint passcount'' also accepts a range of tracepoints.
3870 * ``apropos'' command added.
3872 The ``apropos'' command searches through command names and
3873 documentation strings, printing out matches, making it much easier to
3874 try to find a command that does what you are looking for.
3878 A new machine oriented interface (MI) has been added to GDB. This
3879 interface is designed for debug environments running GDB as a separate
3880 process. This is part of the long term libGDB project. See the
3881 "GDB/MI" chapter of the GDB manual for further information. It can be
3882 enabled by configuring with:
3884 .../configure --enable-gdbmi
3886 *** Changes in GDB-4.18:
3888 * New native configurations
3890 HP-UX 10.20 hppa*-*-hpux10.20
3891 HP-UX 11.x hppa*-*-hpux11.0*
3892 M68K GNU/Linux m68*-*-linux*
3896 Fujitsu FR30 fr30-*-elf*
3897 Intel StrongARM strongarm-*-*
3898 Mitsubishi D30V d30v-*-*
3900 * OBSOLETE configurations
3902 Gould PowerNode, NP1 np1-*-*, pn-*-*
3904 Configurations that have been declared obsolete will be commented out,
3905 but the code will be left in place. If there is no activity to revive
3906 these configurations before the next release of GDB, the sources will
3907 be permanently REMOVED.
3911 As a compatibility experiment, GDB's source files buildsym.h and
3912 buildsym.c have been converted to pure standard C, no longer
3913 containing any K&R compatibility code. We believe that all systems in
3914 use today either come with a standard C compiler, or have a GCC port
3915 available. If this is not true, please report the affected
3916 configuration to bug-gdb@gnu.org immediately. See the README file for
3917 information about getting a standard C compiler if you don't have one
3922 GDB now uses readline 2.2.
3924 * set extension-language
3926 You can now control the mapping between filename extensions and source
3927 languages by using the `set extension-language' command. For instance,
3928 you can ask GDB to treat .c files as C++ by saying
3929 set extension-language .c c++
3930 The command `info extensions' lists all of the recognized extensions
3931 and their associated languages.
3933 * Setting processor type for PowerPC and RS/6000
3935 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
3936 you can use the `set processor' command to specify what variant of the
3937 PowerPC family you are debugging. The command
3941 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
3942 following PowerPC and RS6000 variants:
3944 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
3945 rs6000 IBM RS6000 ("POWER") architecture, user-level view
3947 403GC IBM PowerPC 403GC
3948 505 Motorola PowerPC 505
3949 860 Motorola PowerPC 860 or 850
3950 601 Motorola PowerPC 601
3951 602 Motorola PowerPC 602
3952 603 Motorola/IBM PowerPC 603 or 603e
3953 604 Motorola PowerPC 604 or 604e
3954 750 Motorola/IBM PowerPC 750 or 750
3956 At the moment, this command just tells GDB what to name the
3957 special-purpose processor registers. Since almost all the affected
3958 registers are inaccessible to user-level programs, this command is
3959 only useful for remote debugging in its present form.
3963 Thanks to a major code donation from Hewlett-Packard, GDB now has much
3964 more extensive support for HP-UX. Added features include shared
3965 library support, kernel threads and hardware watchpoints for 11.00,
3966 support for HP's ANSI C and C++ compilers, and a compatibility mode
3967 for xdb and dbx commands.
3971 HP's donation includes the new concept of catchpoints, which is a
3972 generalization of the old catch command. On HP-UX, it is now possible
3973 to catch exec, fork, and vfork, as well as library loading.
3975 This means that the existing catch command has changed; its first
3976 argument now specifies the type of catch to be set up. See the
3977 output of "help catch" for a list of catchpoint types.
3979 * Debugging across forks
3981 On HP-UX, you can choose which process to debug when a fork() happens
3986 HP has donated a curses-based terminal user interface (TUI). To get
3987 it, build with --enable-tui. Although this can be enabled for any
3988 configuration, at present it only works for native HP debugging.
3990 * GDB remote protocol additions
3992 A new protocol packet 'X' that writes binary data is now available.
3993 Default behavior is to try 'X', then drop back to 'M' if the stub
3994 fails to respond. The settable variable `remotebinarydownload'
3995 allows explicit control over the use of 'X'.
3997 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
3998 full 64-bit address. The command
4000 set remoteaddresssize 32
4002 can be used to revert to the old behaviour. For existing remote stubs
4003 the change should not be noticed, as the additional address information
4006 In order to assist in debugging stubs, you may use the maintenance
4007 command `packet' to send any text string to the stub. For instance,
4009 maint packet heythere
4011 sends the packet "$heythere#<checksum>". Note that it is very easy to
4012 disrupt a debugging session by sending the wrong packet at the wrong
4015 The compare-sections command allows you to compare section data on the
4016 target to what is in the executable file without uploading or
4017 downloading, by comparing CRC checksums.
4019 * Tracing can collect general expressions
4021 You may now collect general expressions at tracepoints. This requires
4022 further additions to the target-side stub; see tracepoint.c and
4023 doc/agentexpr.texi for further details.
4025 * mask-address variable for Mips
4027 For Mips targets, you may control the zeroing of the upper 32 bits of
4028 a 64-bit address by entering `set mask-address on'. This is mainly
4029 of interest to users of embedded R4xxx and R5xxx processors.
4031 * Higher serial baud rates
4033 GDB's serial code now allows you to specify baud rates 57600, 115200,
4034 230400, and 460800 baud. (Note that your host system may not be able
4035 to achieve all of these rates.)
4039 The i960 configuration now includes an initial implementation of a
4040 builtin simulator, contributed by Jim Wilson.
4043 *** Changes in GDB-4.17:
4045 * New native configurations
4047 Alpha GNU/Linux alpha*-*-linux*
4048 Unixware 2.x i[3456]86-unixware2*
4049 Irix 6.x mips*-sgi-irix6*
4050 PowerPC GNU/Linux powerpc-*-linux*
4051 PowerPC Solaris powerpcle-*-solaris*
4052 Sparc GNU/Linux sparc-*-linux*
4053 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4057 Argonaut Risc Chip (ARC) arc-*-*
4058 Hitachi H8/300S h8300*-*-*
4059 Matsushita MN10200 w/simulator mn10200-*-*
4060 Matsushita MN10300 w/simulator mn10300-*-*
4061 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4062 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4063 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4064 Mitsubishi D10V w/simulator d10v-*-*
4065 Mitsubishi M32R/D w/simulator m32r-*-elf*
4066 Tsqware Sparclet sparclet-*-*
4067 NEC V850 w/simulator v850-*-*
4069 * New debugging protocols
4071 ARM with RDI protocol arm*-*-*
4072 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4073 DDB and LSI variants of PMON protocol mips*-*-*
4074 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4075 PowerPC with SDS protocol powerpc{,le}-*-eabi
4076 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4080 All configurations can now understand and use the DWARF 2 debugging
4081 format. The choice is automatic, if the symbol file contains DWARF 2
4086 GDB now includes basic Java language support. This support is
4087 only useful with Java compilers that produce native machine code.
4089 * solib-absolute-prefix and solib-search-path
4091 For SunOS and SVR4 shared libraries, you may now set the prefix for
4092 loading absolute shared library symbol files, and the search path for
4093 locating non-absolute shared library symbol files.
4095 * Live range splitting
4097 GDB can now effectively debug code for which GCC has performed live
4098 range splitting as part of its optimization. See gdb/doc/LRS for
4099 more details on the expected format of the stabs information.
4103 GDB's support for the GNU Hurd, including thread debugging, has been
4104 updated to work with current versions of the Hurd.
4108 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4109 instruction set. ARM GDB automatically detects when Thumb
4110 instructions are in use, and adjusts disassembly and backtracing
4115 GDB's MIPS target configurations now handle the MIP16 16-bit
4120 GDB now includes support for overlays; if an executable has been
4121 linked such that multiple sections are based at the same address, GDB
4122 will decide which section to use for symbolic info. You can choose to
4123 control the decision manually, using overlay commands, or implement
4124 additional target-side support and use "overlay load-target" to bring
4125 in the overlay mapping. Do "help overlay" for more detail.
4129 The command "info symbol <address>" displays information about
4130 the symbol at the specified address.
4134 The standard remote protocol now includes an extension that allows
4135 asynchronous collection and display of trace data. This requires
4136 extensive support in the target-side debugging stub. Tracing mode
4137 includes a new interaction mode in GDB and new commands: see the
4138 file tracepoint.c for more details.
4142 Configurations for embedded MIPS now include a simulator contributed
4143 by Cygnus Solutions. The simulator supports the instruction sets
4144 of most MIPS variants.
4148 Sparc configurations may now include the ERC32 simulator contributed
4149 by the European Space Agency. The simulator is not built into
4150 Sparc targets by default; configure with --enable-sim to include it.
4154 For target configurations that may include multiple variants of a
4155 basic architecture (such as MIPS and SH), you may now set the
4156 architecture explicitly. "set arch" sets, "info arch" lists
4157 the possible architectures.
4159 *** Changes in GDB-4.16:
4161 * New native configurations
4163 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4164 M68K NetBSD m68k-*-netbsd*
4165 PowerPC AIX 4.x powerpc-*-aix*
4166 PowerPC MacOS powerpc-*-macos*
4167 PowerPC Windows NT powerpcle-*-cygwin32
4168 RS/6000 AIX 4.x rs6000-*-aix4*
4172 ARM with RDP protocol arm-*-*
4173 I960 with MON960 i960-*-coff
4174 MIPS VxWorks mips*-*-vxworks*
4175 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4176 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4178 Matra Sparclet sparclet-*-*
4182 The powerpc-eabi configuration now includes the PSIM simulator,
4183 contributed by Andrew Cagney, with assistance from Mike Meissner.
4184 PSIM is a very elaborate model of the PowerPC, including not only
4185 basic instruction set execution, but also details of execution unit
4186 performance and I/O hardware. See sim/ppc/README for more details.
4190 GDB now works with Solaris 2.5.
4192 * Windows 95/NT native
4194 GDB will now work as a native debugger on Windows 95 and Windows NT.
4195 To build it from source, you must use the "gnu-win32" environment,
4196 which uses a DLL to emulate enough of Unix to run the GNU tools.
4197 Further information, binaries, and sources are available at
4198 ftp.cygnus.com, under pub/gnu-win32.
4200 * dont-repeat command
4202 If a user-defined command includes the command `dont-repeat', then the
4203 command will not be repeated if the user just types return. This is
4204 useful if the command is time-consuming to run, so that accidental
4205 extra keystrokes don't run the same command many times.
4207 * Send break instead of ^C
4209 The standard remote protocol now includes an option to send a break
4210 rather than a ^C to the target in order to interrupt it. By default,
4211 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4213 * Remote protocol timeout
4215 The standard remote protocol includes a new variable `remotetimeout'
4216 that allows you to set the number of seconds before GDB gives up trying
4217 to read from the target. The default value is 2.
4219 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4221 By default GDB will automatically keep track of objects as they are
4222 loaded and unloaded by the dynamic linker. By using the command `set
4223 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4224 when shared library events occur, thus allowing you to set breakpoints
4225 in shared libraries which are explicitly loaded by the inferior.
4227 Note this feature does not work on hpux8. On hpux9 you must link
4228 /usr/lib/end.o into your program. This feature should work
4229 automatically on hpux10.
4231 * Irix 5.x hardware watchpoint support
4233 Irix 5 configurations now support the use of hardware watchpoints.
4235 * Mips protocol "SYN garbage limit"
4237 When debugging a Mips target using the `target mips' protocol, you
4238 may set the number of characters that GDB will ignore by setting
4239 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4240 every character. The default value is 1050.
4242 * Recording and replaying remote debug sessions
4244 If you set `remotelogfile' to the name of a file, gdb will write to it
4245 a recording of a remote debug session. This recording may then be
4246 replayed back to gdb using "gdbreplay". See gdbserver/README for
4247 details. This is useful when you have a problem with GDB while doing
4248 remote debugging; you can make a recording of the session and send it
4249 to someone else, who can then recreate the problem.
4251 * Speedups for remote debugging
4253 GDB includes speedups for downloading and stepping MIPS systems using
4254 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4255 and more efficient S-record downloading.
4257 * Memory use reductions and statistics collection
4259 GDB now uses less memory and reports statistics about memory usage.
4260 Try the `maint print statistics' command, for example.
4262 *** Changes in GDB-4.15:
4264 * Psymtabs for XCOFF
4266 The symbol reader for AIX GDB now uses partial symbol tables. This
4267 can greatly improve startup time, especially for large executables.
4269 * Remote targets use caching
4271 Remote targets now use a data cache to speed up communication with the
4272 remote side. The data cache could lead to incorrect results because
4273 it doesn't know about volatile variables, thus making it impossible to
4274 debug targets which use memory mapped I/O devices. `set remotecache
4275 off' turns the the data cache off.
4277 * Remote targets may have threads
4279 The standard remote protocol now includes support for multiple threads
4280 in the target system, using new protocol commands 'H' and 'T'. See
4281 gdb/remote.c for details.
4285 If GDB is configured with `--enable-netrom', then it will include
4286 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4287 acts as though it is a bank of ROM on the target board, but you can
4288 write into it over the network. GDB's support consists only of
4289 support for fast loading into the emulated ROM; to debug, you must use
4290 another protocol, such as standard remote protocol. The usual
4291 sequence is something like
4293 target nrom <netrom-hostname>
4295 target remote <netrom-hostname>:1235
4299 GDB now includes support for the Apple Macintosh, as a host only. It
4300 may be run as either an MPW tool or as a standalone application, and
4301 it can debug through the serial port. All the usual GDB commands are
4302 available, but to the target command, you must supply "serial" as the
4303 device type instead of "/dev/ttyXX". See mpw-README in the main
4304 directory for more information on how to build. The MPW configuration
4305 scripts */mpw-config.in support only a few targets, and only the
4306 mips-idt-ecoff target has been tested.
4310 GDB configuration now uses autoconf. This is not user-visible,
4311 but does simplify configuration and building.
4315 GDB now supports hpux10.
4317 *** Changes in GDB-4.14:
4319 * New native configurations
4321 x86 FreeBSD i[345]86-*-freebsd
4322 x86 NetBSD i[345]86-*-netbsd
4323 NS32k NetBSD ns32k-*-netbsd
4324 Sparc NetBSD sparc-*-netbsd
4328 A29K VxWorks a29k-*-vxworks
4329 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4330 CPU32 EST-300 emulator m68*-*-est*
4331 PowerPC ELF powerpc-*-elf
4334 * Alpha OSF/1 support for procfs
4336 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4337 possible to attach to running processes. As the mounting of the /proc
4338 filesystem is optional on the Alpha, GDB automatically determines
4339 the availability of /proc during startup. This can lead to problems
4340 if /proc is unmounted after GDB has been started.
4342 * Arguments to user-defined commands
4344 User commands may accept up to 10 arguments separated by whitespace.
4345 Arguments are accessed within the user command via $arg0..$arg9. A
4348 print $arg0 + $arg1 + $arg2
4350 To execute the command use:
4353 Defines the command "adder" which prints the sum of its three arguments.
4354 Note the arguments are text substitutions, so they may reference variables,
4355 use complex expressions, or even perform inferior function calls.
4357 * New `if' and `while' commands
4359 This makes it possible to write more sophisticated user-defined
4360 commands. Both commands take a single argument, which is the
4361 expression to evaluate, and must be followed by the commands to
4362 execute, one per line, if the expression is nonzero, the list being
4363 terminated by the word `end'. The `if' command list may include an
4364 `else' word, which causes the following commands to be executed only
4365 if the expression is zero.
4367 * Fortran source language mode
4369 GDB now includes partial support for Fortran 77. It will recognize
4370 Fortran programs and can evaluate a subset of Fortran expressions, but
4371 variables and functions may not be handled correctly. GDB will work
4372 with G77, but does not yet know much about symbols emitted by other
4375 * Better HPUX support
4377 Most debugging facilities now work on dynamic executables for HPPAs
4378 running hpux9 or later. You can attach to running dynamically linked
4379 processes, but by default the dynamic libraries will be read-only, so
4380 for instance you won't be able to put breakpoints in them. To change
4381 that behavior do the following before running the program:
4387 This will cause the libraries to be mapped private and read-write.
4388 To revert to the normal behavior, do this:
4394 You cannot set breakpoints or examine data in the library until after
4395 the library is loaded if the function/data symbols do not have
4398 GDB can now also read debug symbols produced by the HP C compiler on
4399 HPPAs (sorry, no C++, Fortran or 68k support).
4401 * Target byte order now dynamically selectable
4403 You can choose which byte order to use with a target system, via the
4404 commands "set endian big" and "set endian little", and you can see the
4405 current setting by using "show endian". You can also give the command
4406 "set endian auto", in which case GDB will use the byte order
4407 associated with the executable. Currently, only embedded MIPS
4408 configurations support dynamic selection of target byte order.
4410 * New DOS host serial code
4412 This version uses DPMI interrupts to handle buffered I/O, so you
4413 no longer need to run asynctsr when debugging boards connected to
4416 *** Changes in GDB-4.13:
4418 * New "complete" command
4420 This lists all the possible completions for the rest of the line, if it
4421 were to be given as a command itself. This is intended for use by emacs.
4423 * Trailing space optional in prompt
4425 "set prompt" no longer adds a space for you after the prompt you set. This
4426 allows you to set a prompt which ends in a space or one that does not.
4428 * Breakpoint hit counts
4430 "info break" now displays a count of the number of times the breakpoint
4431 has been hit. This is especially useful in conjunction with "ignore"; you
4432 can ignore a large number of breakpoint hits, look at the breakpoint info
4433 to see how many times the breakpoint was hit, then run again, ignoring one
4434 less than that number, and this will get you quickly to the last hit of
4437 * Ability to stop printing at NULL character
4439 "set print null-stop" will cause GDB to stop printing the characters of
4440 an array when the first NULL is encountered. This is useful when large
4441 arrays actually contain only short strings.
4443 * Shared library breakpoints
4445 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4446 breakpoints in shared libraries before the executable is run.
4448 * Hardware watchpoints
4450 There is a new hardware breakpoint for the watch command for sparclite
4451 targets. See gdb/sparclite/hw_breakpoint.note.
4453 Hardware watchpoints are also now supported under GNU/Linux.
4457 Annotations have been added. These are for use with graphical interfaces,
4458 and are still experimental. Currently only gdba.el uses these.
4460 * Improved Irix 5 support
4462 GDB now works properly with Irix 5.2.
4464 * Improved HPPA support
4466 GDB now works properly with the latest GCC and GAS.
4468 * New native configurations
4470 Sequent PTX4 i[34]86-sequent-ptx4
4471 HPPA running OSF/1 hppa*-*-osf*
4472 Atari TT running SVR4 m68*-*-sysv4*
4473 RS/6000 LynxOS rs6000-*-lynxos*
4477 OS/9000 i[34]86-*-os9k
4478 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4481 * Hitachi SH7000 and E7000-PC ICE support
4483 There is now support for communicating with the Hitachi E7000-PC ICE.
4484 This is available automatically when GDB is configured for the SH.
4488 As usual, a variety of small fixes and improvements, both generic
4489 and configuration-specific. See the ChangeLog for more detail.
4491 *** Changes in GDB-4.12:
4493 * Irix 5 is now supported
4497 GDB-4.12 on the HPPA has a number of changes which make it unable
4498 to debug the output from the currently released versions of GCC and
4499 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4500 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4501 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4504 *** Changes in GDB-4.11:
4506 * User visible changes:
4510 The "set remotedebug" option is now consistent between the mips remote
4511 target, remote targets using the gdb-specific protocol, UDI (AMD's
4512 debug protocol for the 29k) and the 88k bug monitor. It is now an
4513 integer specifying a debug level (normally 0 or 1, but 2 means more
4514 debugging info for the mips target).
4516 * DEC Alpha native support
4518 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4519 debug info, but GDB works fairly well with the DEC compiler and should
4520 work with a future GCC release. See the README file for a few
4521 Alpha-specific notes.
4523 * Preliminary thread implementation
4525 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4527 * LynxOS native and target support for 386
4529 This release has been hosted on LynxOS 2.2, and also can be configured
4530 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4533 * Improvements in C++ mangling/demangling.
4535 This release has much better g++ debugging, specifically in name
4536 mangling/demangling, virtual function calls, print virtual table,
4537 call methods, ...etc.
4539 *** Changes in GDB-4.10:
4541 * User visible changes:
4543 Remote debugging using the GDB-specific (`target remote') protocol now
4544 supports the `load' command. This is only useful if you have some
4545 other way of getting the stub to the target system, and you can put it
4546 somewhere in memory where it won't get clobbered by the download.
4548 Filename completion now works.
4550 When run under emacs mode, the "info line" command now causes the
4551 arrow to point to the line specified. Also, "info line" prints
4552 addresses in symbolic form (as well as hex).
4554 All vxworks based targets now support a user settable option, called
4555 vxworks-timeout. This option represents the number of seconds gdb
4556 should wait for responses to rpc's. You might want to use this if
4557 your vxworks target is, perhaps, a slow software simulator or happens
4558 to be on the far side of a thin network line.
4562 This release contains support for using a DEC alpha as a GDB host for
4563 cross debugging. Native alpha debugging is not supported yet.
4566 *** Changes in GDB-4.9:
4570 This is the first GDB release which is accompanied by a matching testsuite.
4571 The testsuite requires installation of dejagnu, which should be available
4572 via ftp from most sites that carry GNU software.
4576 'Cfront' style demangling has had its name changed to 'ARM' style, to
4577 emphasize that it was written from the specifications in the C++ Annotated
4578 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4579 disclaimers, it still generated too much confusion with users attempting to
4580 use gdb with AT&T cfront.
4584 GDB now uses a standard remote interface to a simulator library.
4585 So far, the library contains simulators for the Zilog Z8001/2, the
4586 Hitachi H8/300, H8/500 and Super-H.
4588 * New targets supported
4590 H8/300 simulator h8300-hitachi-hms or h8300hms
4591 H8/500 simulator h8500-hitachi-hms or h8500hms
4592 SH simulator sh-hitachi-hms or sh
4593 Z8000 simulator z8k-zilog-none or z8ksim
4594 IDT MIPS board over serial line mips-idt-ecoff
4596 Cross-debugging to GO32 targets is supported. It requires a custom
4597 version of the i386-stub.c module which is integrated with the
4598 GO32 memory extender.
4600 * New remote protocols
4602 MIPS remote debugging protocol.
4604 * New source languages supported
4606 This version includes preliminary support for Chill, a Pascal like language
4607 used by telecommunications companies. Chill support is also being integrated
4608 into the GNU compiler, but we don't know when it will be publically available.
4611 *** Changes in GDB-4.8:
4613 * HP Precision Architecture supported
4615 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4616 version of this support was available as a set of patches from the
4617 University of Utah. GDB does not support debugging of programs
4618 compiled with the HP compiler, because HP will not document their file
4619 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4620 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4622 Many problems in the preliminary version have been fixed.
4624 * Faster and better demangling
4626 We have improved template demangling and fixed numerous bugs in the GNU style
4627 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4628 character types (wchar_t) are now supported. Demangling of each symbol is now
4629 only done once, and is cached when the symbol table for a file is read in.
4630 This results in a small increase in memory usage for C programs, a moderate
4631 increase in memory usage for C++ programs, and a fantastic speedup in
4634 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4635 from the specifications in the Annotated Reference Manual, which AT&T's
4636 compiler does not actually implement.
4638 * G++ multiple inheritance compiler problem
4640 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4641 inheritance lattices was reworked to properly discover ambiguities. We
4642 recently found an example which causes this new algorithm to fail in a
4643 very subtle way, producing bad debug information for those classes.
4644 The file 'gcc.patch' (in this directory) can be applied to gcc to
4645 circumvent the problem. A future GCC release will contain a complete
4648 The previous G++ debug info problem (mentioned below for the gdb-4.7
4649 release) is fixed in gcc version 2.3.2.
4651 * Improved configure script
4653 The `configure' script will now attempt to guess your system type if
4654 you don't supply a host system type. The old scheme of supplying a
4655 host system triplet is preferable over using this. All the magic is
4656 done in the new `config.guess' script. Examine it for details.
4658 We have also brought our configure script much more in line with the FSF's
4659 version. It now supports the --with-xxx options. In particular,
4660 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4661 The resulting GDB will not be able to read arbitrary object file formats --
4662 only the format ``expected'' to be used on the configured target system.
4663 We hope to make this the default in a future release.
4665 * Documentation improvements
4667 There's new internal documentation on how to modify GDB, and how to
4668 produce clean changes to the code. We implore people to read it
4669 before submitting changes.
4671 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4672 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4673 `info' files are also provided. To build `info' files from scratch,
4674 you will need the latest `makeinfo' release, which will be available in
4675 a future texinfo-X.Y release.
4677 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4678 We're not sure exactly which versions have this problem, but it has
4679 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4680 or better. If that isn't possible, there is a patch in
4681 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4682 around this problem.
4686 GDB now supports array constants that can be used in expressions typed in by
4687 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4688 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4691 The new directory `gdb/sparclite' contains a program that demonstrates
4692 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4694 * New native hosts supported
4696 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4697 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4699 * New targets supported
4701 AMD 29k family via UDI a29k-amd-udi or udi29k
4703 * New file formats supported
4705 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4706 HPUX core files, and SCO 3.2v2 core files.
4710 Attaching to processes now works again; thanks for the many bug reports.
4712 We have also stomped on a bunch of core dumps caused by
4713 printf_filtered("%s") problems.
4715 We eliminated a copyright problem on the rpc and ptrace header files
4716 for VxWorks, which was discovered at the last minute during the 4.7
4717 release. You should now be able to build a VxWorks GDB.
4719 You can now interrupt gdb while an attached process is running. This
4720 will cause the attached process to stop, and give control back to GDB.
4722 We fixed problems caused by using too many file descriptors
4723 for reading symbols from object files and libraries. This was
4724 especially a problem for programs that used many (~100) shared
4727 The `step' command now only enters a subroutine if there is line number
4728 information for the subroutine. Otherwise it acts like the `next'
4729 command. Previously, `step' would enter subroutines if there was
4730 any debugging information about the routine. This avoids problems
4731 when using `cc -g1' on MIPS machines.
4733 * Internal improvements
4735 GDB's internal interfaces have been improved to make it easier to support
4736 debugging of multiple languages in the future.
4738 GDB now uses a common structure for symbol information internally.
4739 Minimal symbols (derived from linkage symbols in object files), partial
4740 symbols (from a quick scan of debug information), and full symbols
4741 contain a common subset of information, making it easier to write
4742 shared code that handles any of them.
4744 * New command line options
4746 We now accept --silent as an alias for --quiet.
4750 The memory-mapped-malloc library is now licensed under the GNU Library
4751 General Public License.
4753 *** Changes in GDB-4.7:
4755 * Host/native/target split
4757 GDB has had some major internal surgery to untangle the support for
4758 hosts and remote targets. Now, when you configure GDB for a remote
4759 target, it will no longer load in all of the support for debugging
4760 local programs on the host. When fully completed and tested, this will
4761 ensure that arbitrary host/target combinations are possible.
4763 The primary conceptual shift is to separate the non-portable code in
4764 GDB into three categories. Host specific code is required any time GDB
4765 is compiled on that host, regardless of the target. Target specific
4766 code relates to the peculiarities of the target, but can be compiled on
4767 any host. Native specific code is everything else: it can only be
4768 built when the host and target are the same system. Child process
4769 handling and core file support are two common `native' examples.
4771 GDB's use of /proc for controlling Unix child processes is now cleaner.
4772 It has been split out into a single module under the `target_ops' vector,
4773 plus two native-dependent functions for each system that uses /proc.
4775 * New hosts supported
4777 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
4778 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4779 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
4781 * New targets supported
4783 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4784 68030 and CPU32 m68030-*-*, m68332-*-*
4786 * New native hosts supported
4788 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4789 (386bsd is not well tested yet)
4790 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
4792 * New file formats supported
4794 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
4795 supports reading of `a.out.adobe' object files, which are an a.out
4796 format extended with minimal information about multiple sections.
4800 `show copying' is the same as the old `info copying'.
4801 `show warranty' is the same as `info warrantee'.
4802 These were renamed for consistency. The old commands continue to work.
4804 `info handle' is a new alias for `info signals'.
4806 You can now define pre-command hooks, which attach arbitrary command
4807 scripts to any command. The commands in the hook will be executed
4808 prior to the user's command. You can also create a hook which will be
4809 executed whenever the program stops. See gdb.texinfo.
4813 We now deal with Cfront style name mangling, and can even extract type
4814 info from mangled symbols. GDB can automatically figure out which
4815 symbol mangling style your C++ compiler uses.
4817 Calling of methods and virtual functions has been improved as well.
4821 The crash that occured when debugging Sun Ansi-C compiled binaries is
4822 fixed. This was due to mishandling of the extra N_SO stabs output
4825 We also finally got Ultrix 4.2 running in house, and fixed core file
4826 support, with help from a dozen people on the net.
4828 John M. Farrell discovered that the reason that single-stepping was so
4829 slow on all of the Mips based platforms (primarily SGI and DEC) was
4830 that we were trying to demangle and lookup a symbol used for internal
4831 purposes on every instruction that was being stepped through. Changing
4832 the name of that symbol so that it couldn't be mistaken for a C++
4833 mangled symbol sped things up a great deal.
4835 Rich Pixley sped up symbol lookups in general by getting much smarter
4836 about when C++ symbol mangling is necessary. This should make symbol
4837 completion (TAB on the command line) much faster. It's not as fast as
4838 we'd like, but it's significantly faster than gdb-4.6.
4842 A new user controllable variable 'call_scratch_address' can
4843 specify the location of a scratch area to be used when GDB
4844 calls a function in the target. This is necessary because the
4845 usual method of putting the scratch area on the stack does not work
4846 in systems that have separate instruction and data spaces.
4848 We integrated changes to support the 29k UDI (Universal Debugger
4849 Interface), but discovered at the last minute that we didn't have all
4850 of the appropriate copyright paperwork. We are working with AMD to
4851 resolve this, and hope to have it available soon.
4855 We have sped up the remote serial line protocol, especially for targets
4856 with lots of registers. It now supports a new `expedited status' ('T')
4857 message which can be used in place of the existing 'S' status message.
4858 This allows the remote stub to send only the registers that GDB
4859 needs to make a quick decision about single-stepping or conditional
4860 breakpoints, eliminating the need to fetch the entire register set for
4861 each instruction being stepped through.
4863 The GDB remote serial protocol now implements a write-through cache for
4864 registers, only re-reading the registers if the target has run.
4866 There is also a new remote serial stub for SPARC processors. You can
4867 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
4868 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
4869 processor with a serial port.
4873 Configure.in files have become much easier to read and modify. A new
4874 `table driven' format makes it more obvious what configurations are
4875 supported, and what files each one uses.
4879 There is a new opcodes library which will eventually contain all of the
4880 disassembly routines and opcode tables. At present, it only contains
4881 Sparc and Z8000 routines. This will allow the assembler, debugger, and
4882 disassembler (binutils/objdump) to share these routines.
4884 The libiberty library is now copylefted under the GNU Library General
4885 Public License. This allows more liberal use, and was done so libg++
4886 can use it. This makes no difference to GDB, since the Library License
4887 grants all the rights from the General Public License.
4891 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
4892 reference to the stabs symbol info used by the debugger. It is (as far
4893 as we know) the only published document on this fascinating topic. We
4894 encourage you to read it, compare it to the stabs information on your
4895 system, and send improvements on the document in general (to
4896 bug-gdb@prep.ai.mit.edu).
4898 And, of course, many bugs have been fixed.
4901 *** Changes in GDB-4.6:
4903 * Better support for C++ function names
4905 GDB now accepts as input the "demangled form" of C++ overloaded function
4906 names and member function names, and can do command completion on such names
4907 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
4908 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
4909 Make use of command completion, it is your friend.
4911 GDB also now accepts a variety of C++ mangled symbol formats. They are
4912 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
4913 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
4914 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
4915 for the list of formats.
4917 * G++ symbol mangling problem
4919 Recent versions of gcc have a bug in how they emit debugging information for
4920 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
4921 directory) can be applied to gcc to fix the problem. Alternatively, if you
4922 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
4923 usual symptom is difficulty with setting breakpoints on methods. GDB complains
4924 about the method being non-existent. (We believe that version 2.2.2 of GCC has
4927 * New 'maintenance' command
4929 All of the commands related to hacking GDB internals have been moved out of
4930 the main command set, and now live behind the 'maintenance' command. This
4931 can also be abbreviated as 'mt'. The following changes were made:
4933 dump-me -> maintenance dump-me
4934 info all-breakpoints -> maintenance info breakpoints
4935 printmsyms -> maintenance print msyms
4936 printobjfiles -> maintenance print objfiles
4937 printpsyms -> maintenance print psymbols
4938 printsyms -> maintenance print symbols
4940 The following commands are new:
4942 maintenance demangle Call internal GDB demangler routine to
4943 demangle a C++ link name and prints the result.
4944 maintenance print type Print a type chain for a given symbol
4946 * Change to .gdbinit file processing
4948 We now read the $HOME/.gdbinit file before processing the argv arguments
4949 (e.g. reading symbol files or core files). This allows global parameters to
4950 be set, which will apply during the symbol reading. The ./.gdbinit is still
4951 read after argv processing.
4953 * New hosts supported
4955 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
4957 GNU/Linux support i386-unknown-linux or linux
4959 We are also including code to support the HP/PA running BSD and HPUX. This
4960 is almost guaranteed not to work, as we didn't have time to test or build it
4961 for this release. We are including it so that the more adventurous (or
4962 masochistic) of you can play with it. We also had major problems with the
4963 fact that the compiler that we got from HP doesn't support the -g option.
4966 * New targets supported
4968 Hitachi H8/300 h8300-hitachi-hms or h8300hms
4970 * More smarts about finding #include files
4972 GDB now remembers the compilation directory for all include files, and for
4973 all files from which C is generated (like yacc and lex sources). This
4974 greatly improves GDB's ability to find yacc/lex sources, and include files,
4975 especially if you are debugging your program from a directory different from
4976 the one that contains your sources.
4978 We also fixed a bug which caused difficulty with listing and setting
4979 breakpoints in include files which contain C code. (In the past, you had to
4980 try twice in order to list an include file that you hadn't looked at before.)
4982 * Interesting infernals change
4984 GDB now deals with arbitrary numbers of sections, where the symbols for each
4985 section must be relocated relative to that section's landing place in the
4986 target's address space. This work was needed to support ELF with embedded
4987 stabs used by Solaris-2.0.
4989 * Bug fixes (of course!)
4991 There have been loads of fixes for the following things:
4992 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
4993 i960, stabs, DOS(GO32), procfs, etc...
4995 See the ChangeLog for details.
4997 *** Changes in GDB-4.5:
4999 * New machines supported (host and target)
5001 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5003 SGI Irix-4.x mips-sgi-irix4 or iris4
5005 * New malloc package
5007 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5008 Mmalloc is capable of handling mutiple heaps of memory. It is also
5009 capable of saving a heap to a file, and then mapping it back in later.
5010 This can be used to greatly speedup the startup of GDB by using a
5011 pre-parsed symbol table which lives in a mmalloc managed heap. For
5012 more details, please read mmalloc/mmalloc.texi.
5016 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5017 'help info proc' for details.
5019 * MIPS ecoff symbol table format
5021 The code that reads MIPS symbol table format is now supported on all hosts.
5022 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5025 * File name changes for MS-DOS
5027 Many files in the config directories have been renamed to make it easier to
5028 support GDB on MS-DOSe systems (which have very restrictive file name
5029 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5030 environment) is close to working but has some remaining problems. Note
5031 that debugging of DOS programs is not supported, due to limitations
5032 in the ``operating system'', but it can be used to host cross-debugging.
5034 * Cross byte order fixes
5036 Many fixes have been made to support cross debugging of Sparc and MIPS
5037 targets from hosts whose byte order differs.
5039 * New -mapped and -readnow options
5041 If memory-mapped files are available on your system through the 'mmap'
5042 system call, you can use the -mapped option on the `file' or
5043 `symbol-file' commands to cause GDB to write the symbols from your
5044 program into a reusable file. If the program you are debugging is
5045 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5046 Future GDB debugging sessions will notice the presence of this file,
5047 and will quickly map in symbol information from it, rather than reading
5048 the symbol table from the executable program. Using the '-mapped'
5049 option in a GDB `file' or `symbol-file' command has the same effect as
5050 starting GDB with the '-mapped' command-line option.
5052 You can cause GDB to read the entire symbol table immediately by using
5053 the '-readnow' option with any of the commands that load symbol table
5054 information (or on the GDB command line). This makes the command
5055 slower, but makes future operations faster.
5057 The -mapped and -readnow options are typically combined in order to
5058 build a `fred.syms' file that contains complete symbol information.
5059 A simple GDB invocation to do nothing but build a `.syms' file for future
5062 gdb -batch -nx -mapped -readnow programname
5064 The `.syms' file is specific to the host machine on which GDB is run.
5065 It holds an exact image of GDB's internal symbol table. It cannot be
5066 shared across multiple host platforms.
5068 * longjmp() handling
5070 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5071 siglongjmp() without losing control. This feature has not yet been ported to
5072 all systems. It currently works on many 386 platforms, all MIPS-based
5073 platforms (SGI, DECstation, etc), and Sun3/4.
5077 Preliminary work has been put in to support the new Solaris OS from Sun. At
5078 this time, it can control and debug processes, but it is not capable of
5083 As always, many many bug fixes. The major areas were with g++, and mipsread.
5084 People using the MIPS-based platforms should experience fewer mysterious
5085 crashes and trashed symbol tables.
5087 *** Changes in GDB-4.4:
5089 * New machines supported (host and target)
5091 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5093 BSD Reno on Vax vax-dec-bsd
5094 Ultrix on Vax vax-dec-ultrix
5096 * New machines supported (target)
5098 AMD 29000 embedded, using EBMON a29k-none-none
5102 GDB continues to improve its handling of C++. `References' work better.
5103 The demangler has also been improved, and now deals with symbols mangled as
5104 per the Annotated C++ Reference Guide.
5106 GDB also now handles `stabs' symbol information embedded in MIPS
5107 `ecoff' symbol tables. Since the ecoff format was not easily
5108 extensible to handle new languages such as C++, this appeared to be a
5109 good way to put C++ debugging info into MIPS binaries. This option
5110 will be supported in the GNU C compiler, version 2, when it is
5113 * New features for SVR4
5115 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5116 shared libraries. Debugging dynamically linked programs should present
5117 only minor differences from debugging statically linked programs.
5119 The `info proc' command will print out information about any process
5120 on an SVR4 system (including the one you are debugging). At the moment,
5121 it prints the address mappings of the process.
5123 If you bring up GDB on another SVR4 system, please send mail to
5124 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5126 * Better dynamic linking support in SunOS
5128 Reading symbols from shared libraries which contain debugging symbols
5129 now works properly. However, there remain issues such as automatic
5130 skipping of `transfer vector' code during function calls, which
5131 make it harder to debug code in a shared library, than to debug the
5132 same code linked statically.
5136 GDB is now using the latest `getopt' routines from the FSF. This
5137 version accepts the -- prefix for options with long names. GDB will
5138 continue to accept the old forms (-option and +option) as well.
5139 Various single letter abbreviations for options have been explicity
5140 added to the option table so that they won't get overshadowed in the
5141 future by other options that begin with the same letter.
5145 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5146 Many assorted bugs have been handled. Many more remain to be handled.
5147 See the various ChangeLog files (primarily in gdb and bfd) for details.
5150 *** Changes in GDB-4.3:
5152 * New machines supported (host and target)
5154 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5155 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5156 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5158 * Almost SCO Unix support
5160 We had hoped to support:
5161 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5162 (except for core file support), but we discovered very late in the release
5163 that it has problems with process groups that render gdb unusable. Sorry
5164 about that. I encourage people to fix it and post the fixes.
5166 * Preliminary ELF and DWARF support
5168 GDB can read ELF object files on System V Release 4, and can handle
5169 debugging records for C, in DWARF format, in ELF files. This support
5170 is preliminary. If you bring up GDB on another SVR4 system, please
5171 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5176 GDB now uses the latest `readline' library. One user-visible change
5177 is that two tabs will list possible command completions, which previously
5178 required typing M-? (meta-question mark, or ESC ?).
5182 The `stepi' bug that many of you noticed has been squashed.
5183 Many bugs in C++ have been handled. Many more remain to be handled.
5184 See the various ChangeLog files (primarily in gdb and bfd) for details.
5186 * State of the MIPS world (in case you wondered):
5188 GDB can understand the symbol tables emitted by the compilers
5189 supplied by most vendors of MIPS-based machines, including DEC. These
5190 symbol tables are in a format that essentially nobody else uses.
5192 Some versions of gcc come with an assembler post-processor called
5193 mips-tfile. This program is required if you want to do source-level
5194 debugging of gcc-compiled programs. I believe FSF does not ship
5195 mips-tfile with gcc version 1, but it will eventually come with gcc
5198 Debugging of g++ output remains a problem. g++ version 1.xx does not
5199 really support it at all. (If you're lucky, you should be able to get
5200 line numbers and stack traces to work, but no parameters or local
5201 variables.) With some work it should be possible to improve the
5204 When gcc version 2 is released, you will have somewhat better luck.
5205 However, even then you will get confusing results for inheritance and
5208 We will eventually provide full debugging of g++ output on
5209 DECstations. This will probably involve some kind of stabs-in-ecoff
5210 encapulation, but the details have not been worked out yet.
5213 *** Changes in GDB-4.2:
5215 * Improved configuration
5217 Only one copy of `configure' exists now, and it is not self-modifying.
5218 Porting BFD is simpler.
5222 The `step' and `next' commands now only stop at the first instruction
5223 of a source line. This prevents the multiple stops that used to occur
5224 in switch statements, for-loops, etc. `Step' continues to stop if a
5225 function that has debugging information is called within the line.
5229 Lots of small bugs fixed. More remain.
5231 * New host supported (not target)
5233 Intel 386 PC clone running Mach i386-none-mach
5236 *** Changes in GDB-4.1:
5238 * Multiple source language support
5240 GDB now has internal scaffolding to handle several source languages.
5241 It determines the type of each source file from its filename extension,
5242 and will switch expression parsing and number formatting to match the
5243 language of the function in the currently selected stack frame.
5244 You can also specifically set the language to be used, with
5245 `set language c' or `set language modula-2'.
5249 GDB now has preliminary support for the GNU Modula-2 compiler,
5250 currently under development at the State University of New York at
5251 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5252 continue through the fall of 1991 and into 1992.
5254 Other Modula-2 compilers are currently not supported, and attempting to
5255 debug programs compiled with them will likely result in an error as the
5256 symbol table is read. Feel free to work on it, though!
5258 There are hooks in GDB for strict type checking and range checking,
5259 in the `Modula-2 philosophy', but they do not currently work.
5263 GDB can now write to executable and core files (e.g. patch
5264 a variable's value). You must turn this switch on, specify
5265 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5266 by assigning a new value to a variable. Modifications take
5269 * Automatic SunOS shared library reading
5271 When you run your program, GDB automatically determines where its
5272 shared libraries (if any) have been loaded, and reads their symbols.
5273 The `share' command is no longer needed. This also works when
5274 examining core files.
5278 You can specify the number of lines that the `list' command shows.
5281 * New machines supported (host and target)
5283 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5284 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5285 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5287 * New hosts supported (not targets)
5289 IBM RT/PC: romp-ibm-aix or rtpc
5291 * New targets supported (not hosts)
5293 AMD 29000 embedded with COFF a29k-none-coff
5294 AMD 29000 embedded with a.out a29k-none-aout
5295 Ultracomputer remote kernel debug a29k-nyu-kern
5297 * New remote interfaces
5303 *** Changes in GDB-4.0:
5307 Wide output is wrapped at good places to make the output more readable.
5309 Gdb now supports cross-debugging from a host machine of one type to a
5310 target machine of another type. Communication with the target system
5311 is over serial lines. The ``target'' command handles connecting to the
5312 remote system; the ``load'' command will download a program into the
5313 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5314 also supports debugging of realtime processes running under VxWorks,
5315 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5316 stub on the target system.
5318 New CPUs supported include the AMD 29000 and Intel 960.
5320 GDB now reads object files and symbol tables via a ``binary file''
5321 library, which allows a single copy of GDB to debug programs of multiple
5322 object file types such as a.out and coff.
5324 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5325 refcard.dvi and refcard.ps are available to format it).
5328 * Control-Variable user interface simplified
5330 All variables that control the operation of the debugger can be set
5331 by the ``set'' command, and displayed by the ``show'' command.
5333 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5334 ``Show prompt'' produces the response:
5335 Gdb's prompt is new-gdb=>.
5337 What follows are the NEW set commands. The command ``help set'' will
5338 print a complete list of old and new set commands. ``help set FOO''
5339 will give a longer description of the variable FOO. ``show'' will show
5340 all of the variable descriptions and their current settings.
5342 confirm on/off: Enables warning questions for operations that are
5343 hard to recover from, e.g. rerunning the program while
5344 it is already running. Default is ON.
5346 editing on/off: Enables EMACS style command line editing
5347 of input. Previous lines can be recalled with
5348 control-P, the current line can be edited with control-B,
5349 you can search for commands with control-R, etc.
5352 history filename NAME: NAME is where the gdb command history
5353 will be stored. The default is .gdb_history,
5354 or the value of the environment variable
5357 history size N: The size, in commands, of the command history. The
5358 default is 256, or the value of the environment variable
5361 history save on/off: If this value is set to ON, the history file will
5362 be saved after exiting gdb. If set to OFF, the
5363 file will not be saved. The default is OFF.
5365 history expansion on/off: If this value is set to ON, then csh-like
5366 history expansion will be performed on
5367 command line input. The default is OFF.
5369 radix N: Sets the default radix for input and output. It can be set
5370 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5371 in the current radix, so "set radix 10" is always a no-op.
5373 height N: This integer value is the number of lines on a page. Default
5374 is 24, the current `stty rows'' setting, or the ``li#''
5375 setting from the termcap entry matching the environment
5378 width N: This integer value is the number of characters on a line.
5379 Default is 80, the current `stty cols'' setting, or the ``co#''
5380 setting from the termcap entry matching the environment
5383 Note: ``set screensize'' is obsolete. Use ``set height'' and
5384 ``set width'' instead.
5386 print address on/off: Print memory addresses in various command displays,
5387 such as stack traces and structure values. Gdb looks
5388 more ``symbolic'' if you turn this off; it looks more
5389 ``machine level'' with it on. Default is ON.
5391 print array on/off: Prettyprint arrays. New convenient format! Default
5394 print demangle on/off: Print C++ symbols in "source" form if on,
5397 print asm-demangle on/off: Same, for assembler level printouts
5400 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5403 * Support for Epoch Environment.
5405 The epoch environment is a version of Emacs v18 with windowing. One
5406 new command, ``inspect'', is identical to ``print'', except that if you
5407 are running in the epoch environment, the value is printed in its own
5411 * Support for Shared Libraries
5413 GDB can now debug programs and core files that use SunOS shared libraries.
5414 Symbols from a shared library cannot be referenced
5415 before the shared library has been linked with the program (this
5416 happens after you type ``run'' and before the function main() is entered).
5417 At any time after this linking (including when examining core files
5418 from dynamically linked programs), gdb reads the symbols from each
5419 shared library when you type the ``sharedlibrary'' command.
5420 It can be abbreviated ``share''.
5422 sharedlibrary REGEXP: Load shared object library symbols for files
5423 matching a unix regular expression. No argument
5424 indicates to load symbols for all shared libraries.
5426 info sharedlibrary: Status of loaded shared libraries.
5431 A watchpoint stops execution of a program whenever the value of an
5432 expression changes. Checking for this slows down execution
5433 tremendously whenever you are in the scope of the expression, but is
5434 quite useful for catching tough ``bit-spreader'' or pointer misuse
5435 problems. Some machines such as the 386 have hardware for doing this
5436 more quickly, and future versions of gdb will use this hardware.
5438 watch EXP: Set a watchpoint (breakpoint) for an expression.
5440 info watchpoints: Information about your watchpoints.
5442 delete N: Deletes watchpoint number N (same as breakpoints).
5443 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5444 enable N: Re-enables watchpoint number N (same as breakpoints).
5447 * C++ multiple inheritance
5449 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5452 * C++ exception handling
5454 Gdb now supports limited C++ exception handling. Besides the existing
5455 ability to breakpoint on an exception handler, gdb can breakpoint on
5456 the raising of an exception (before the stack is peeled back to the
5459 catch FOO: If there is a FOO exception handler in the dynamic scope,
5460 set a breakpoint to catch exceptions which may be raised there.
5461 Multiple exceptions (``catch foo bar baz'') may be caught.
5463 info catch: Lists all exceptions which may be caught in the
5464 current stack frame.
5467 * Minor command changes
5469 The command ``call func (arg, arg, ...)'' now acts like the print
5470 command, except it does not print or save a value if the function's result
5471 is void. This is similar to dbx usage.
5473 The ``up'' and ``down'' commands now always print the frame they end up
5474 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5475 frames without printing.
5477 * New directory command
5479 'dir' now adds directories to the FRONT of the source search path.
5480 The path starts off empty. Source files that contain debug information
5481 about the directory in which they were compiled can be found even
5482 with an empty path; Sun CC and GCC include this information. If GDB can't
5483 find your source file in the current directory, type "dir .".
5485 * Configuring GDB for compilation
5487 For normal use, type ``./configure host''. See README or gdb.texinfo
5490 GDB now handles cross debugging. If you are remotely debugging between
5491 two different machines, type ``./configure host -target=targ''.
5492 Host is the machine where GDB will run; targ is the machine
5493 where the program that you are debugging will run.