1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.6
6 * GDB now supports Fission DWP file format version 2.
7 http://gcc.gnu.org/wiki/DebugFission
9 * New convenience function "$_isvoid", to check whether an expression
10 is void. A void expression is an expression where the type of the
11 result is "void". For example, some convenience variables may be
12 "void" when evaluated (e.g., "$_exitcode" before the execution of
13 the program being debugged; or an undefined convenience variable).
14 Another example, when calling a function whose return type is
17 * The "maintenance print objfiles" command now takes an optional regexp.
19 * The "catch syscall" command now works on arm*-linux* targets.
21 * GDB now consistently shows "<not saved>" when printing values of
22 registers the debug info indicates have not been saved in the frame
23 and there's nowhere to retrieve them from
24 (callee-saved/call-clobbered registers):
29 (gdb) info registers rax
32 Before, the former would print "<optimized out>", and the latter
33 "*value not available*".
35 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
40 ** Frame filters and frame decorators have been added.
41 ** Temporary breakpoints are now supported.
42 ** Line tables representation has been added.
46 Nios II ELF nios2*-*-elf
47 Nios II GNU/Linux nios2*-*-linux
48 Texas Instruments MSP430 msp430*-*-elf
50 * Removed native configurations
52 Support for these a.out NetBSD and OpenBSD obsolete configurations has
53 been removed. ELF variants of these configurations are kept supported.
55 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
56 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
57 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
58 i[34567]86-*-openbsd3.[0-3]
59 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
60 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
61 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
65 Like "catch throw", but catches a re-thrown exception.
67 Renamed from old "maint check-symtabs".
69 Perform consistency checks on symtabs.
71 Expand symtabs matching an optional regexp.
74 Display the details of GDB configure-time options.
76 maint set|show per-command
77 maint set|show per-command space
78 maint set|show per-command time
79 maint set|show per-command symtab
80 Enable display of per-command gdb resource usage.
82 remove-symbol-file FILENAME
83 remove-symbol-file -a ADDRESS
84 Remove a symbol file added via add-symbol-file. The file to remove
85 can be identified by its filename or by an address that lies within
86 the boundaries of this symbol file in memory.
89 info exceptions REGEXP
90 Display the list of Ada exceptions defined in the program being
91 debugged. If provided, only the exceptions whose names match REGEXP
96 set debug symfile off|on
98 Control display of debugging info regarding reading symbol files and
99 symbol tables within those files
101 set print raw frame-arguments
102 show print raw frame-arguments
103 Set/show whether to print frame arguments in raw mode,
104 disregarding any defined pretty-printers.
106 set remote trace-status-packet
107 show remote trace-status-packet
108 Set/show the use of remote protocol qTStatus packet.
112 Control display of debugging messages related to Nios II targets.
116 Control whether target-assisted range stepping is enabled.
118 set startup-with-shell
119 show startup-with-shell
120 Specifies whether Unix child processes are started via a shell or
125 Use the target memory cache for accesses to the code segment. This
126 improves performance of remote debugging (particularly disassembly).
128 * You can now use a literal value 'unlimited' for options that
129 interpret 0 or -1 as meaning "unlimited". E.g., "set
130 trace-buffer-size unlimited" is now an alias for "set
131 trace-buffer-size -1" and "set height unlimited" is now an alias for
134 * The "set debug symtab-create" debugging option of GDB has been changed to
135 accept a verbosity level. 0 means "off", 1 provides basic debugging
136 output, and values of 2 or greater provides more verbose output.
138 * New command-line options
140 Display the details of GDB configure-time options.
142 * The command 'tsave' can now support new option '-ctf' to save trace
143 buffer in Common Trace Format.
145 * Newly installed $prefix/bin/gcore acts as a shell interface for the
148 * GDB now implements the the C++ 'typeid' operator.
150 * The new convenience variable $_exception holds the exception being
151 thrown or caught at an exception-related catchpoint.
153 * The exception-related catchpoints, like "catch throw", now accept a
154 regular expression which can be used to filter exceptions by type.
156 * The new convenience variable $_exitsignal is automatically set to
157 the terminating signal number when the program being debugged dies
158 due to an uncaught signal.
162 ** All MI commands now accept an optional "--language" option.
163 Support for this feature can be verified by using the "-list-features"
164 command, which should contain "language-option".
166 ** The new command -info-gdb-mi-command allows the user to determine
167 whether a GDB/MI command is supported or not.
169 ** The "^error" result record returned when trying to execute an undefined
170 GDB/MI command now provides a variable named "code" whose content is the
171 "undefined-command" error code. Support for this feature can be verified
172 by using the "-list-features" command, which should contain
173 "undefined-command-error-code".
175 ** The -trace-save MI command can optionally save trace buffer in Common
178 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
180 ** The command -data-list-register-values now accepts an optional
181 "--skip-unavailable" option. When used, only the available registers
184 ** The new command -trace-frame-collected dumps collected variables,
185 computed expressions, tvars, memory and registers in a traceframe.
187 ** The commands -stack-list-locals, -stack-list-arguments and
188 -stack-list-variables now accept an option "--skip-unavailable".
189 When used, only the available locals or arguments are displayed.
191 ** The -exec-run command now accepts an optional "--start" option.
192 When used, the command follows the same semantics as the "start"
193 command, stopping the program's execution at the start of its
194 main subprogram. Support for this feature can be verified using
195 the "-list-features" command, which should contain
196 "exec-run-start-option".
198 ** The new commands -catch-assert and -catch-exceptions insert
199 catchpoints stopping the program when Ada exceptions are raised.
201 ** The new command -info-ada-exceptions provides the equivalent of
202 the new "info exceptions" command.
204 * New system-wide configuration scripts
205 A GDB installation now provides scripts suitable for use as system-wide
206 configuration scripts for the following systems:
210 * GDB now supports target-assigned range stepping with remote targets.
211 This improves the performance of stepping source lines by reducing
212 the number of control packets from/to GDB. See "New remote packets"
215 * GDB now understands the element 'tvar' in the XML traceframe info.
216 It has the id of the collected trace state variables.
218 * On S/390 targets that provide the transactional-execution feature,
219 the program interruption transaction diagnostic block (TDB) is now
220 represented as a number of additional "registers" in GDB.
226 The vCont packet supports a new 'r' action, that tells the remote
227 stub to step through an address range itself, without GDB
228 involvemement at each single-step.
230 qXfer:libraries-svr4:read's annex
231 The previously unused annex of the qXfer:libraries-svr4:read packet
232 is now used to support passing an argument list. The remote stub
233 reports support for this argument list to GDB's qSupported query.
234 The defined arguments are "start" and "prev", used to reduce work
235 necessary for library list updating, resulting in significant
238 * New features in the GDB remote stub, GDBserver
240 ** GDBserver now supports target-assisted range stepping. Currently
241 enabled on x86/x86_64 GNU/Linux targets.
243 ** GDBserver now adds element 'tvar' in the XML in the reply to
244 'qXfer:traceframe-info:read'. It has the id of the collected
245 trace state variables.
247 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
250 * New 'z' formatter for printing and examining memory, this displays the
251 value as hexadecimal zero padded on the left to the size of the type.
253 * GDB can now use Windows x64 unwinding data.
255 * The "set remotebaud" command has been replaced by "set serial baud".
256 Similarly, "show remotebaud" has been replaced by "show serial baud".
257 The "set remotebaud" and "show remotebaud" commands are still available
258 to provide backward compatibility with older versions of GDB.
260 *** Changes in GDB 7.6
262 * Target record has been renamed to record-full.
263 Record/replay is now enabled with the "record full" command.
264 This also affects settings that are associated with full record/replay
265 that have been moved from "set/show record" to "set/show record full":
267 set|show record full insn-number-max
268 set|show record full stop-at-limit
269 set|show record full memory-query
271 * A new record target "record-btrace" has been added. The new target
272 uses hardware support to record the control-flow of a process. It
273 does not support replaying the execution, but it implements the
274 below new commands for investigating the recorded execution log.
275 This new recording method can be enabled using:
279 The "record-btrace" target is only available on Intel Atom processors
280 and requires a Linux kernel 2.6.32 or later.
282 * Two new commands have been added for record/replay to give information
283 about the recorded execution without having to replay the execution.
284 The commands are only supported by "record btrace".
286 record instruction-history prints the execution history at
287 instruction granularity
289 record function-call-history prints the execution history at
292 * New native configurations
294 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
295 FreeBSD/powerpc powerpc*-*-freebsd
296 x86_64/Cygwin x86_64-*-cygwin*
297 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
301 ARM AArch64 aarch64*-*-elf
302 ARM AArch64 GNU/Linux aarch64*-*-linux
303 Lynx 178 PowerPC powerpc-*-lynx*178
304 x86_64/Cygwin x86_64-*-cygwin*
305 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
307 * If the configured location of system.gdbinit file (as given by the
308 --with-system-gdbinit option at configure time) is in the
309 data-directory (as specified by --with-gdb-datadir at configure
310 time) or in one of its subdirectories, then GDB will look for the
311 system-wide init file in the directory specified by the
312 --data-directory command-line option.
314 * New command line options:
316 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
317 other initialization files, unlike -nx which disables all of them.
319 * Removed command line options
321 -epoch This was used by the gdb mode in Epoch, an ancient fork of
324 * The 'ptype' and 'whatis' commands now accept an argument to control
327 * 'info proc' now works on some core files.
331 ** Vectors can be created with gdb.Type.vector.
333 ** Python's atexit.register now works in GDB.
335 ** Types can be pretty-printed via a Python API.
337 ** Python 3 is now supported (in addition to Python 2.4 or later)
339 ** New class gdb.Architecture exposes GDB's internal representation
340 of architecture in the Python API.
342 ** New method Frame.architecture returns the gdb.Architecture object
343 corresponding to the frame's architecture.
345 * New Python-based convenience functions:
347 ** $_memeq(buf1, buf2, length)
348 ** $_streq(str1, str2)
350 ** $_regex(str, regex)
352 * The 'cd' command now defaults to using '~' (the home directory) if not
355 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
356 default for GCC since November 2000.
358 * The command 'forward-search' can now be abbreviated as 'fo'.
360 * The command 'info tracepoints' can now display 'installed on target'
361 or 'not installed on target' for each non-pending location of tracepoint.
363 * New configure options
365 --enable-libmcheck/--disable-libmcheck
366 By default, development versions are built with -lmcheck on hosts
367 that support it, in order to help track memory corruption issues.
368 Release versions, on the other hand, are built without -lmcheck
369 by default. The --enable-libmcheck/--disable-libmcheck configure
370 options allow the user to override that default.
371 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
372 This configure option allows the user to build GDB with
373 libbabeltrace using which GDB can read Common Trace Format data.
375 * New commands (for set/show, see "New options" below)
378 Catch signals. This is similar to "handle", but allows commands and
379 conditions to be attached.
382 List the BFDs known to GDB.
384 python-interactive [command]
386 Start a Python interactive prompt, or evaluate the optional command
387 and print the result of expressions.
390 "py" is a new alias for "python".
392 enable type-printer [name]...
393 disable type-printer [name]...
394 Enable or disable type printers.
398 ** For the Renesas Super-H architecture, the "regs" command has been removed
399 (has been deprecated in GDB 7.5), and "info all-registers" should be used
404 set print type methods (on|off)
405 show print type methods
406 Control whether method declarations are displayed by "ptype".
407 The default is to show them.
409 set print type typedefs (on|off)
410 show print type typedefs
411 Control whether typedef definitions are displayed by "ptype".
412 The default is to show them.
414 set filename-display basename|relative|absolute
415 show filename-display
416 Control the way in which filenames is displayed.
417 The default is "relative", which preserves previous behavior.
419 set trace-buffer-size
420 show trace-buffer-size
421 Request target to change the size of trace buffer.
423 set remote trace-buffer-size-packet auto|on|off
424 show remote trace-buffer-size-packet
425 Control the use of the remote protocol `QTBuffer:size' packet.
429 Control display of debugging messages related to ARM AArch64.
432 set debug coff-pe-read
433 show debug coff-pe-read
434 Control display of debugging messages related to reading of COFF/PE
439 Control display of debugging messages related to Mach-O symbols
442 set debug notification
443 show debug notification
444 Control display of debugging info for async remote notification.
448 ** Command parameter changes are now notified using new async record
449 "=cmd-param-changed".
450 ** Trace frame changes caused by command "tfind" are now notified using
451 new async record "=traceframe-changed".
452 ** The creation, deletion and modification of trace state variables
453 are now notified using new async records "=tsv-created",
454 "=tsv-deleted" and "=tsv-modified".
455 ** The start and stop of process record are now notified using new
456 async record "=record-started" and "=record-stopped".
457 ** Memory changes are now notified using new async record
459 ** The data-disassemble command response will include a "fullname" field
460 containing the absolute file name when source has been requested.
461 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
462 command, to allow pattern filling of memory areas.
463 ** New commands "-catch-load"/"-catch-unload" added for intercepting
464 library load/unload events.
465 ** The response to breakpoint commands and breakpoint async records
466 includes an "installed" field containing a boolean state about each
467 non-pending tracepoint location is whether installed on target or not.
468 ** Output of the "-trace-status" command includes a "trace-file" field
469 containing the name of the trace file being examined. This field is
470 optional, and only present when examining a trace file.
471 ** The "fullname" field is now always present along with the "file" field,
472 even if the file cannot be found by GDB.
474 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
475 You must have the LZMA library available when configuring GDB for this
476 feature to be enabled. For more information, see:
477 http://fedoraproject.org/wiki/Features/MiniDebugInfo
482 Set the size of trace buffer. The remote stub reports support for this
483 packet to gdb's qSupported query.
486 Enable Branch Trace Store (BTS)-based branch tracing for the current
487 thread. The remote stub reports support for this packet to gdb's
491 Disable branch tracing for the current thread. The remote stub reports
492 support for this packet to gdb's qSupported query.
495 Read the traced branches for the current thread. The remote stub
496 reports support for this packet to gdb's qSupported query.
498 *** Changes in GDB 7.5
500 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
501 for more x32 ABI info.
503 * GDB now supports access to MIPS DSP registers on Linux targets.
505 * GDB now supports debugging microMIPS binaries.
507 * The "info os" command on GNU/Linux can now display information on
508 several new classes of objects managed by the operating system:
509 "info os procgroups" lists process groups
510 "info os files" lists file descriptors
511 "info os sockets" lists internet-domain sockets
512 "info os shm" lists shared-memory regions
513 "info os semaphores" lists semaphores
514 "info os msg" lists message queues
515 "info os modules" lists loaded kernel modules
517 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
518 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
519 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
520 options and inspect the probe arguments using the new $_probe_arg family
521 of convenience variables. You can obtain more information about SystemTap
522 in <http://sourceware.org/systemtap/>.
524 * GDB now supports reversible debugging on ARM, it allows you to
525 debug basic ARM and THUMB instructions, and provides
526 record/replay support.
528 * The option "symbol-reloading" has been deleted as it is no longer used.
532 ** GDB commands implemented in Python can now be put in command class
535 ** The "maint set python print-stack on|off" is now deleted.
537 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
538 apply "flag enum"-style pretty-printing to any enum.
540 ** gdb.lookup_symbol can now work when there is no current frame.
542 ** gdb.Symbol now has a 'line' attribute, holding the line number in
543 the source at which the symbol was defined.
545 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
546 method 'value'. The former indicates whether the symbol needs a
547 frame in order to compute its value, and the latter computes the
550 ** A new method 'referenced_value' on gdb.Value objects which can
551 dereference pointer as well as C++ reference values.
553 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
554 which return the global and static blocks (as gdb.Block objects),
555 of the underlying symbol table, respectively.
557 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
558 object associated with a PC value.
560 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
561 of the address range occupied by code for the current source line.
563 * Go language support.
564 GDB now supports debugging programs written in the Go programming
567 * GDBserver now supports stdio connections.
568 E.g. (gdb) target remote | ssh myhost gdbserver - hello
570 * The binary "gdbtui" can no longer be built or installed.
571 Use "gdb -tui" instead.
573 * GDB will now print "flag" enums specially. A flag enum is one where
574 all the enumerator values have no bits in common when pairwise
575 "and"ed. When printing a value whose type is a flag enum, GDB will
576 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
577 (gdb) print (enum E) 3
580 * The filename part of a linespec will now match trailing components
581 of a source file name. For example, "break gcc/expr.c:1000" will
582 now set a breakpoint in build/gcc/expr.c, but not
585 * The "info proc" and "generate-core-file" commands will now also
586 work on remote targets connected to GDBserver on Linux.
588 * The command "info catch" has been removed. It has been disabled
591 * The "catch exception" and "catch assert" commands now accept
592 a condition at the end of the command, much like the "break"
593 command does. For instance:
595 (gdb) catch exception Constraint_Error if Barrier = True
597 Previously, it was possible to add a condition to such catchpoints,
598 but it had to be done as a second step, after the catchpoint had been
599 created, using the "condition" command.
601 * The "info static-tracepoint-marker" command will now also work on
602 native Linux targets with in-process agent.
604 * GDB can now set breakpoints on inlined functions.
606 * The .gdb_index section has been updated to include symbols for
607 inlined functions. GDB will ignore older .gdb_index sections by
608 default, which could cause symbol files to be loaded more slowly
609 until their .gdb_index sections can be recreated. The new command
610 "set use-deprecated-index-sections on" will cause GDB to use any older
611 .gdb_index sections it finds. This will restore performance, but the
612 ability to set breakpoints on inlined functions will be lost in symbol
613 files with older .gdb_index sections.
615 The .gdb_index section has also been updated to record more information
616 about each symbol. This speeds up the "info variables", "info functions"
617 and "info types" commands when used with programs having the .gdb_index
618 section, as well as speeding up debugging with shared libraries using
619 the .gdb_index section.
621 * Ada support for GDB/MI Variable Objects has been added.
623 * GDB can now support 'breakpoint always-inserted mode' in 'record'
628 ** New command -info-os is the MI equivalent of "info os".
630 ** Output logs ("set logging" and related) now include MI output.
634 ** "set use-deprecated-index-sections on|off"
635 "show use-deprecated-index-sections on|off"
636 Controls the use of deprecated .gdb_index sections.
638 ** "catch load" and "catch unload" can be used to stop when a shared
639 library is loaded or unloaded, respectively.
641 ** "enable count" can be used to auto-disable a breakpoint after
644 ** "info vtbl" can be used to show the virtual method tables for
645 C++ and Java objects.
647 ** "explore" and its sub commands "explore value" and "explore type"
648 can be used to recursively explore values and types of
649 expressions. These commands are available only if GDB is
650 configured with '--with-python'.
652 ** "info auto-load" shows status of all kinds of auto-loaded files,
653 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
654 sequences of commands files, "info auto-load python-scripts"
655 shows status of auto-loading Python script files,
656 "info auto-load local-gdbinit" shows status of loading init file
657 (.gdbinit) from current directory and "info auto-load libthread-db" shows
658 status of inferior specific thread debugging shared library loading.
660 ** "info auto-load-scripts", "set auto-load-scripts on|off"
661 and "show auto-load-scripts" commands have been deprecated, use their
662 "info auto-load python-scripts", "set auto-load python-scripts on|off"
663 and "show auto-load python-scripts" counterparts instead.
665 ** "dprintf location,format,args..." creates a dynamic printf, which
666 is basically a breakpoint that does a printf and immediately
667 resumes your program's execution, so it is like a printf that you
668 can insert dynamically at runtime instead of at compiletime.
670 ** "set print symbol"
672 Controls whether GDB attempts to display the symbol, if any,
673 corresponding to addresses it prints. This defaults to "on", but
674 you can set it to "off" to restore GDB's previous behavior.
676 * Deprecated commands
678 ** For the Renesas Super-H architecture, the "regs" command has been
679 deprecated, and "info all-registers" should be used instead.
683 Renesas RL78 rl78-*-elf
684 HP OpenVMS ia64 ia64-hp-openvms*
686 * GDBserver supports evaluation of breakpoint conditions. When
687 support is advertised by GDBserver, GDB may be told to send the
688 breakpoint conditions in bytecode form to GDBserver. GDBserver
689 will only report the breakpoint trigger to GDB when its condition
695 show mips compression
696 Select the compressed ISA encoding used in functions that have no symbol
697 information available. The encoding can be set to either of:
700 and is updated automatically from ELF file flags if available.
702 set breakpoint condition-evaluation
703 show breakpoint condition-evaluation
704 Control whether breakpoint conditions are evaluated by GDB ("host") or by
705 GDBserver ("target"). Default option "auto" chooses the most efficient
707 This option can improve debugger efficiency depending on the speed of the
711 Disable auto-loading globally.
714 Show auto-loading setting of all kinds of auto-loaded files.
716 set auto-load gdb-scripts on|off
717 show auto-load gdb-scripts
718 Control auto-loading of GDB canned sequences of commands files.
720 set auto-load python-scripts on|off
721 show auto-load python-scripts
722 Control auto-loading of Python script files.
724 set auto-load local-gdbinit on|off
725 show auto-load local-gdbinit
726 Control loading of init file (.gdbinit) from current directory.
728 set auto-load libthread-db on|off
729 show auto-load libthread-db
730 Control auto-loading of inferior specific thread debugging shared library.
732 set auto-load scripts-directory <dir1>[:<dir2>...]
733 show auto-load scripts-directory
734 Set a list of directories from which to load auto-loaded scripts.
735 Automatically loaded Python scripts and GDB scripts are located in one
736 of the directories listed by this option.
737 The delimiter (':' above) may differ according to the host platform.
739 set auto-load safe-path <dir1>[:<dir2>...]
740 show auto-load safe-path
741 Set a list of directories from which it is safe to auto-load files.
742 The delimiter (':' above) may differ according to the host platform.
744 set debug auto-load on|off
746 Control display of debugging info for auto-loading the files above.
748 set dprintf-style gdb|call|agent
750 Control the way in which a dynamic printf is performed; "gdb"
751 requests a GDB printf command, while "call" causes dprintf to call a
752 function in the inferior. "agent" requests that the target agent
753 (such as GDBserver) do the printing.
755 set dprintf-function <expr>
756 show dprintf-function
757 set dprintf-channel <expr>
759 Set the function and optional first argument to the call when using
760 the "call" style of dynamic printf.
762 set disconnected-dprintf on|off
763 show disconnected-dprintf
764 Control whether agent-style dynamic printfs continue to be in effect
765 after GDB disconnects.
767 * New configure options
770 Configure default value for the 'set auto-load scripts-directory'
771 setting above. It defaults to '$debugdir:$datadir/auto-load',
772 $debugdir representing global debugging info directories (available
773 via 'show debug-file-directory') and $datadir representing GDB's data
774 directory (available via 'show data-directory').
776 --with-auto-load-safe-path
777 Configure default value for the 'set auto-load safe-path' setting
778 above. It defaults to the --with-auto-load-dir setting.
780 --without-auto-load-safe-path
781 Set 'set auto-load safe-path' to '/', effectively disabling this
786 z0/z1 conditional breakpoints extension
788 The z0/z1 breakpoint insertion packets have been extended to carry
789 a list of conditional expressions over to the remote stub depending on the
790 condition evaluation mode. The use of this extension can be controlled
791 via the "set remote conditional-breakpoints-packet" command.
795 Specify the signals which the remote stub may pass to the debugged
796 program without GDB involvement.
798 * New command line options
800 --init-command=FILE, -ix Like --command, -x but execute it
801 before loading inferior.
802 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
803 execute it before loading inferior.
805 *** Changes in GDB 7.4
807 * GDB now handles ambiguous linespecs more consistently; the existing
808 FILE:LINE support has been expanded to other types of linespecs. A
809 breakpoint will now be set on all matching locations in all
810 inferiors, and locations will be added or removed according to
813 * GDB now allows you to skip uninteresting functions and files when
814 stepping with the "skip function" and "skip file" commands.
816 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
817 and "show remote hardware-watchpoint-length-limit". These allows to
818 set or show the maximum length limit (in bytes) of a remote
819 target hardware watchpoint.
821 This allows e.g. to use "unlimited" hardware watchpoints with the
822 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
823 watchpoints are slower than real hardware watchpoints but are
824 significantly faster than gdb software watchpoints.
828 ** The register_pretty_printer function in module gdb.printing now takes
829 an optional `replace' argument. If True, the new printer replaces any
832 ** The "maint set python print-stack on|off" command has been
833 deprecated and will be deleted in GDB 7.5.
834 A new command: "set python print-stack none|full|message" has
835 replaced it. Additionally, the default for "print-stack" is
836 now "message", which just prints the error message without
839 ** A prompt substitution hook (prompt_hook) is now available to the
842 ** A new Python module, gdb.prompt has been added to the GDB Python
843 modules library. This module provides functionality for
844 escape sequences in prompts (used by set/show
845 extended-prompt). These escape sequences are replaced by their
848 ** Python commands and convenience-functions located in
849 'data-directory'/python/gdb/command and
850 'data-directory'/python/gdb/function are now automatically loaded
853 ** Blocks now provide four new attributes. global_block and
854 static_block will return the global and static blocks
855 respectively. is_static and is_global are boolean attributes
856 that indicate if the block is one of those two types.
858 ** Symbols now provide the "type" attribute, the type of the symbol.
860 ** The "gdb.breakpoint" function has been deprecated in favor of
863 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
864 of a function. This class is based on the "finish" command
865 available in the CLI.
867 ** Type objects for struct and union types now allow access to
868 the fields using standard Python dictionary (mapping) methods.
869 For example, "some_type['myfield']" now works, as does
872 ** A new event "gdb.new_objfile" has been added, triggered by loading a
875 ** A new function, "deep_items" has been added to the gdb.types
876 module in the GDB Python modules library. This function returns
877 an iterator over the fields of a struct or union type. Unlike
878 the standard Python "iteritems" method, it will recursively traverse
879 any anonymous fields.
883 ** "*stopped" events can report several new "reason"s, such as
886 ** Breakpoint changes are now notified using new async records, like
887 "=breakpoint-modified".
889 ** New command -ada-task-info.
891 * libthread-db-search-path now supports two special values: $sdir and $pdir.
892 $sdir specifies the default system locations of shared libraries.
893 $pdir specifies the directory where the libpthread used by the application
896 GDB no longer looks in $sdir and $pdir after it has searched the directories
897 mentioned in libthread-db-search-path. If you want to search those
898 directories, they must be specified in libthread-db-search-path.
899 The default value of libthread-db-search-path on GNU/Linux and Solaris
900 systems is now "$sdir:$pdir".
902 $pdir is not supported by gdbserver, it is currently ignored.
903 $sdir is supported by gdbserver.
905 * New configure option --with-iconv-bin.
906 When using the internationalization support like the one in the GNU C
907 library, GDB will invoke the "iconv" program to get a list of supported
908 character sets. If this program lives in a non-standard location, one can
909 use this option to specify where to find it.
911 * When natively debugging programs on PowerPC BookE processors running
912 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
913 watchpoints, which specify a mask in addition to an address to watch.
914 The mask specifies that some bits of an address (the bits which are
915 reset in the mask) should be ignored when matching the address accessed
916 by the inferior against the watchpoint address. See the "PowerPC Embedded"
917 section in the user manual for more details.
919 * The new option --once causes GDBserver to stop listening for connections once
920 the first connection is made. The listening port used by GDBserver will
921 become available after that.
923 * New commands "info macros" and "alias" have been added.
925 * New function parameters suffix @entry specifies value of function parameter
926 at the time the function got called. Entry values are available only since
932 "!" is now an alias of the "shell" command.
933 Note that no space is needed between "!" and SHELL COMMAND.
937 watch EXPRESSION mask MASK_VALUE
938 The watch command now supports the mask argument which allows creation
939 of masked watchpoints, if the current architecture supports this feature.
941 info auto-load-scripts [REGEXP]
942 This command was formerly named "maintenance print section-scripts".
943 It is now generally useful and is no longer a maintenance-only command.
945 info macro [-all] [--] MACRO
946 The info macro command has new options `-all' and `--'. The first for
947 printing all definitions of a macro. The second for explicitly specifying
948 the end of arguments and the beginning of the macro name in case the macro
949 name starts with a hyphen.
951 collect[/s] EXPRESSIONS
952 The tracepoint collect command now takes an optional modifier "/s"
953 that directs it to dereference pointer-to-character types and
954 collect the bytes of memory up to a zero byte. The behavior is
955 similar to what you see when you use the regular print command on a
956 string. An optional integer following the "/s" sets a bound on the
957 number of bytes that will be collected.
960 The trace start command now interprets any supplied arguments as a
961 note to be recorded with the trace run, with an effect similar to
962 setting the variable trace-notes.
965 The trace stop command now interprets any arguments as a note to be
966 mentioned along with the tstatus report that the trace was stopped
967 with a command. The effect is similar to setting the variable
970 * Tracepoints can now be enabled and disabled at any time after a trace
971 experiment has been started using the standard "enable" and "disable"
972 commands. It is now possible to start a trace experiment with no enabled
973 tracepoints; GDB will display a warning, but will allow the experiment to
974 begin, assuming that tracepoints will be enabled as needed while the trace
977 * Fast tracepoints on 32-bit x86-architectures can now be placed at
978 locations with 4-byte instructions, when they were previously
979 limited to locations with instructions of 5 bytes or longer.
983 set debug dwarf2-read
984 show debug dwarf2-read
985 Turns on or off display of debugging messages related to reading
986 DWARF debug info. The default is off.
988 set debug symtab-create
989 show debug symtab-create
990 Turns on or off display of debugging messages related to symbol table
991 creation. The default is off.
995 Set the GDB prompt, and allow escape sequences to be inserted to
996 display miscellaneous information (see 'help set extended-prompt'
997 for the list of sequences). This prompt (and any information
998 accessed through the escape sequences) is updated every time the
1001 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1002 show print entry-values
1003 Set printing of frame argument values at function entry. In some cases
1004 GDB can determine the value of function argument which was passed by the
1005 function caller, even if the value was modified inside the called function.
1007 set debug entry-values
1008 show debug entry-values
1009 Control display of debugging info for determining frame argument values at
1010 function entry and virtual tail call frames.
1012 set basenames-may-differ
1013 show basenames-may-differ
1014 Set whether a source file may have multiple base names.
1015 (A "base name" is the name of a file with the directory part removed.
1016 Example: The base name of "/home/user/hello.c" is "hello.c".)
1017 If set, GDB will canonicalize file names (e.g., expand symlinks)
1018 before comparing them. Canonicalization is an expensive operation,
1019 but it allows the same file be known by more than one base name.
1020 If not set (the default), all source files are assumed to have just
1021 one base name, and gdb will do file name comparisons more efficiently.
1027 Set a user name and notes for the current and any future trace runs.
1028 This is useful for long-running and/or disconnected traces, to
1029 inform others (or yourself) as to who is running the trace, supply
1030 contact information, or otherwise explain what is going on.
1032 set trace-stop-notes
1033 show trace-stop-notes
1034 Set a note attached to the trace run, that is displayed when the
1035 trace has been stopped by a tstop command. This is useful for
1036 instance as an explanation, if you are stopping a trace run that was
1037 started by someone else.
1039 * New remote packets
1043 Dynamically enable a tracepoint in a started trace experiment.
1047 Dynamically disable a tracepoint in a started trace experiment.
1051 Set the user and notes of the trace run.
1055 Query the current status of a tracepoint.
1059 Query the minimum length of instruction at which a fast tracepoint may
1062 * Dcache size (number of lines) and line-size are now runtime-configurable
1063 via "set dcache line" and "set dcache line-size" commands.
1067 Texas Instruments TMS320C6x tic6x-*-*
1071 Renesas RL78 rl78-*-elf
1073 *** Changes in GDB 7.3.1
1075 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1077 *** Changes in GDB 7.3
1079 * GDB has a new command: "thread find [REGEXP]".
1080 It finds the thread id whose name, target id, or thread extra info
1081 matches the given regular expression.
1083 * The "catch syscall" command now works on mips*-linux* targets.
1085 * The -data-disassemble MI command now supports modes 2 and 3 for
1086 dumping the instruction opcodes.
1088 * New command line options
1090 -data-directory DIR Specify DIR as the "data-directory".
1091 This is mostly for testing purposes.
1093 * The "maint set python auto-load on|off" command has been renamed to
1094 "set auto-load-scripts on|off".
1096 * GDB has a new command: "set directories".
1097 It is like the "dir" command except that it replaces the
1098 source path list instead of augmenting it.
1100 * GDB now understands thread names.
1102 On GNU/Linux, "info threads" will display the thread name as set by
1103 prctl or pthread_setname_np.
1105 There is also a new command, "thread name", which can be used to
1106 assign a name internally for GDB to display.
1109 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1110 has been integrated into GDB.
1114 ** The function gdb.Write now accepts an optional keyword 'stream'.
1115 This keyword, when provided, will direct the output to either
1116 stdout, stderr, or GDB's logging output.
1118 ** Parameters can now be be sub-classed in Python, and in particular
1119 you may implement the get_set_doc and get_show_doc functions.
1120 This improves how Parameter set/show documentation is processed
1121 and allows for more dynamic content.
1123 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1124 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1125 have an is_valid method.
1127 ** Breakpoints can now be sub-classed in Python, and in particular
1128 you may implement a 'stop' function that is executed each time
1129 the inferior reaches that breakpoint.
1131 ** New function gdb.lookup_global_symbol looks up a global symbol.
1133 ** GDB values in Python are now callable if the value represents a
1134 function. For example, if 'some_value' represents a function that
1135 takes two integer parameters and returns a value, you can call
1136 that function like so:
1138 result = some_value (10,20)
1140 ** Module gdb.types has been added.
1141 It contains a collection of utilities for working with gdb.Types objects:
1142 get_basic_type, has_field, make_enum_dict.
1144 ** Module gdb.printing has been added.
1145 It contains utilities for writing and registering pretty-printers.
1146 New classes: PrettyPrinter, SubPrettyPrinter,
1147 RegexpCollectionPrettyPrinter.
1148 New function: register_pretty_printer.
1150 ** New commands "info pretty-printers", "enable pretty-printer" and
1151 "disable pretty-printer" have been added.
1153 ** gdb.parameter("directories") is now available.
1155 ** New function gdb.newest_frame returns the newest frame in the
1158 ** The gdb.InferiorThread class has a new "name" attribute. This
1159 holds the thread's name.
1161 ** Python Support for Inferior events.
1162 Python scripts can add observers to be notified of events
1163 occurring in the process being debugged.
1164 The following events are currently supported:
1165 - gdb.events.cont Continue event.
1166 - gdb.events.exited Inferior exited event.
1167 - gdb.events.stop Signal received, and Breakpoint hit events.
1171 ** GDB now puts template parameters in scope when debugging in an
1172 instantiation. For example, if you have:
1174 template<int X> int func (void) { return X; }
1176 then if you step into func<5>, "print X" will show "5". This
1177 feature requires proper debuginfo support from the compiler; it
1178 was added to GCC 4.5.
1180 ** The motion commands "next", "finish", "until", and "advance" now
1181 work better when exceptions are thrown. In particular, GDB will
1182 no longer lose control of the inferior; instead, the GDB will
1183 stop the inferior at the point at which the exception is caught.
1184 This functionality requires a change in the exception handling
1185 code that was introduced in GCC 4.5.
1187 * GDB now follows GCC's rules on accessing volatile objects when
1188 reading or writing target state during expression evaluation.
1189 One notable difference to prior behavior is that "print x = 0"
1190 no longer generates a read of x; the value of the assignment is
1191 now always taken directly from the value being assigned.
1193 * GDB now has some support for using labels in the program's source in
1194 linespecs. For instance, you can use "advance label" to continue
1195 execution to a label.
1197 * GDB now has support for reading and writing a new .gdb_index
1198 section. This section holds a fast index of DWARF debugging
1199 information and can be used to greatly speed up GDB startup and
1200 operation. See the documentation for `save gdb-index' for details.
1202 * The "watch" command now accepts an optional "-location" argument.
1203 When used, this causes GDB to watch the memory referred to by the
1204 expression. Such a watchpoint is never deleted due to it going out
1207 * GDB now supports thread debugging of core dumps on GNU/Linux.
1209 GDB now activates thread debugging using the libthread_db library
1210 when debugging GNU/Linux core dumps, similarly to when debugging
1211 live processes. As a result, when debugging a core dump file, GDB
1212 is now able to display pthread_t ids of threads. For example, "info
1213 threads" shows the same output as when debugging the process when it
1214 was live. In earlier releases, you'd see something like this:
1217 * 1 LWP 6780 main () at main.c:10
1219 While now you see this:
1222 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1224 It is also now possible to inspect TLS variables when debugging core
1227 When debugging a core dump generated on a machine other than the one
1228 used to run GDB, you may need to point GDB at the correct
1229 libthread_db library with the "set libthread-db-search-path"
1230 command. See the user manual for more details on this command.
1232 * When natively debugging programs on PowerPC BookE processors running
1233 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1234 which stop execution of the inferior whenever it executes an instruction
1235 at any address within the specified range. See the "PowerPC Embedded"
1236 section in the user manual for more details.
1238 * New features in the GDB remote stub, GDBserver
1240 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1241 and i686 LynxOS (version 5.x).
1243 ** GDBserver is now supported on Blackfin Linux.
1245 * New native configurations
1247 ia64 HP-UX ia64-*-hpux*
1251 Analog Devices, Inc. Blackfin Processor bfin-*
1253 * Ada task switching is now supported on sparc-elf targets when
1254 debugging a program using the Ravenscar Profile. For more information,
1255 see the "Tasking Support when using the Ravenscar Profile" section
1256 in the GDB user manual.
1258 * Guile support was removed.
1260 * New features in the GNU simulator
1262 ** The --map-info flag lists all known core mappings.
1264 ** CFI flashes may be simulated via the "cfi" device.
1266 *** Changes in GDB 7.2
1268 * Shared library support for remote targets by default
1270 When GDB is configured for a generic, non-OS specific target, like
1271 for example, --target=arm-eabi or one of the many *-*-elf targets,
1272 GDB now queries remote stubs for loaded shared libraries using the
1273 `qXfer:libraries:read' packet. Previously, shared library support
1274 was always disabled for such configurations.
1278 ** Argument Dependent Lookup (ADL)
1280 In C++ ADL lookup directs function search to the namespaces of its
1281 arguments even if the namespace has not been imported.
1291 Here the compiler will search for `foo' in the namespace of 'b'
1292 and find A::foo. GDB now supports this. This construct is commonly
1293 used in the Standard Template Library for operators.
1295 ** Improved User Defined Operator Support
1297 In addition to member operators, GDB now supports lookup of operators
1298 defined in a namespace and imported with a `using' directive, operators
1299 defined in the global scope, operators imported implicitly from an
1300 anonymous namespace, and the ADL operators mentioned in the previous
1302 GDB now also supports proper overload resolution for all the previously
1303 mentioned flavors of operators.
1305 ** static const class members
1307 Printing of static const class members that are initialized in the
1308 class definition has been fixed.
1310 * Windows Thread Information Block access.
1312 On Windows targets, GDB now supports displaying the Windows Thread
1313 Information Block (TIB) structure. This structure is visible either
1314 by using the new command `info w32 thread-information-block' or, by
1315 dereferencing the new convenience variable named `$_tlb', a
1316 thread-specific pointer to the TIB. This feature is also supported
1317 when remote debugging using GDBserver.
1319 * Static tracepoints
1321 Static tracepoints are calls in the user program into a tracing
1322 library. One such library is a port of the LTTng kernel tracer to
1323 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1324 When debugging with GDBserver, GDB now supports combining the GDB
1325 tracepoint machinery with such libraries. For example: the user can
1326 use GDB to probe a static tracepoint marker (a call from the user
1327 program into the tracing library) with the new "strace" command (see
1328 "New commands" below). This creates a "static tracepoint" in the
1329 breakpoint list, that can be manipulated with the same feature set
1330 as fast and regular tracepoints. E.g., collect registers, local and
1331 global variables, collect trace state variables, and define
1332 tracepoint conditions. In addition, the user can collect extra
1333 static tracepoint marker specific data, by collecting the new
1334 $_sdata internal variable. When analyzing the trace buffer, you can
1335 inspect $_sdata like any other variable available to GDB. For more
1336 information, see the "Tracepoints" chapter in GDB user manual. New
1337 remote packets have been defined to support static tracepoints, see
1338 the "New remote packets" section below.
1340 * Better reconstruction of tracepoints after disconnected tracing
1342 GDB will attempt to download the original source form of tracepoint
1343 definitions when starting a trace run, and then will upload these
1344 upon reconnection to the target, resulting in a more accurate
1345 reconstruction of the tracepoints that are in use on the target.
1349 You can now exercise direct control over the ways that GDB can
1350 affect your program. For instance, you can disallow the setting of
1351 breakpoints, so that the program can run continuously (assuming
1352 non-stop mode). In addition, the "observer" variable is available
1353 to switch all of the different controls; in observer mode, GDB
1354 cannot affect the target's behavior at all, which is useful for
1355 tasks like diagnosing live systems in the field.
1357 * The new convenience variable $_thread holds the number of the
1360 * New remote packets
1364 Return the address of the Windows Thread Information Block of a given thread.
1368 In response to several of the tracepoint packets, the target may now
1369 also respond with a number of intermediate `qRelocInsn' request
1370 packets before the final result packet, to have GDB handle
1371 relocating an instruction to execute at a different address. This
1372 is particularly useful for stubs that support fast tracepoints. GDB
1373 reports support for this feature in the qSupported packet.
1377 List static tracepoint markers in the target program.
1381 List static tracepoint markers at a given address in the target
1384 qXfer:statictrace:read
1386 Read the static trace data collected (by a `collect $_sdata'
1387 tracepoint action). The remote stub reports support for this packet
1388 to gdb's qSupported query.
1392 Send the current settings of GDB's permission flags.
1396 Send part of the source (textual) form of a tracepoint definition,
1397 which includes location, conditional, and action list.
1399 * The source command now accepts a -s option to force searching for the
1400 script in the source search path even if the script name specifies
1403 * New features in the GDB remote stub, GDBserver
1405 - GDBserver now support tracepoints (including fast tracepoints, and
1406 static tracepoints). The feature is currently supported by the
1407 i386-linux and amd64-linux builds. See the "Tracepoints support
1408 in gdbserver" section in the manual for more information.
1410 GDBserver JIT compiles the tracepoint's conditional agent
1411 expression bytecode into native code whenever possible for low
1412 overhead dynamic tracepoints conditionals. For such tracepoints,
1413 an expression that examines program state is evaluated when the
1414 tracepoint is reached, in order to determine whether to capture
1415 trace data. If the condition is simple and false, processing the
1416 tracepoint finishes very quickly and no data is gathered.
1418 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1419 for static tracepoints support.
1421 - GDBserver now supports x86_64 Windows 64-bit debugging.
1423 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1424 it understands register description.
1426 * The --batch flag now disables pagination and queries.
1428 * X86 general purpose registers
1430 GDB now supports reading/writing byte, word and double-word x86
1431 general purpose registers directly. This means you can use, say,
1432 $ah or $ax to refer, respectively, to the byte register AH and
1433 16-bit word register AX that are actually portions of the 32-bit
1434 register EAX or 64-bit register RAX.
1436 * The `commands' command now accepts a range of breakpoints to modify.
1437 A plain `commands' following a command that creates multiple
1438 breakpoints affects all the breakpoints set by that command. This
1439 applies to breakpoints set by `rbreak', and also applies when a
1440 single `break' command creates multiple breakpoints (e.g.,
1441 breakpoints on overloaded c++ functions).
1443 * The `rbreak' command now accepts a filename specification as part of
1444 its argument, limiting the functions selected by the regex to those
1445 in the specified file.
1447 * Support for remote debugging Windows and SymbianOS shared libraries
1448 from Unix hosts has been improved. Non Windows GDB builds now can
1449 understand target reported file names that follow MS-DOS based file
1450 system semantics, such as file names that include drive letters and
1451 use the backslash character as directory separator. This makes it
1452 possible to transparently use the "set sysroot" and "set
1453 solib-search-path" on Unix hosts to point as host copies of the
1454 target's shared libraries. See the new command "set
1455 target-file-system-kind" described below, and the "Commands to
1456 specify files" section in the user manual for more information.
1460 eval template, expressions...
1461 Convert the values of one or more expressions under the control
1462 of the string template to a command line, and call it.
1464 set target-file-system-kind unix|dos-based|auto
1465 show target-file-system-kind
1466 Set or show the assumed file system kind for target reported file
1469 save breakpoints <filename>
1470 Save all current breakpoint definitions to a file suitable for use
1471 in a later debugging session. To read the saved breakpoint
1472 definitions, use the `source' command.
1474 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1477 info static-tracepoint-markers
1478 Display information about static tracepoint markers in the target.
1480 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1481 Define a static tracepoint by probing a marker at the given
1482 function, line, address, or marker ID.
1486 Enable and disable observer mode.
1488 set may-write-registers on|off
1489 set may-write-memory on|off
1490 set may-insert-breakpoints on|off
1491 set may-insert-tracepoints on|off
1492 set may-insert-fast-tracepoints on|off
1493 set may-interrupt on|off
1494 Set individual permissions for GDB effects on the target. Note that
1495 some of these settings can have undesirable or surprising
1496 consequences, particularly when changed in the middle of a session.
1497 For instance, disabling the writing of memory can prevent
1498 breakpoints from being inserted, cause single-stepping to fail, or
1499 even crash your program, if you disable after breakpoints have been
1500 inserted. However, GDB should not crash.
1502 set record memory-query on|off
1503 show record memory-query
1504 Control whether to stop the inferior if memory changes caused
1505 by an instruction cannot be recorded.
1510 The disassemble command now supports "start,+length" form of two arguments.
1514 ** GDB now provides a new directory location, called the python directory,
1515 where Python scripts written for GDB can be installed. The location
1516 of that directory is <data-directory>/python, where <data-directory>
1517 is the GDB data directory. For more details, see section `Scripting
1518 GDB using Python' in the manual.
1520 ** The GDB Python API now has access to breakpoints, symbols, symbol
1521 tables, program spaces, inferiors, threads and frame's code blocks.
1522 Additionally, GDB Parameters can now be created from the API, and
1523 manipulated via set/show in the CLI.
1525 ** New functions gdb.target_charset, gdb.target_wide_charset,
1526 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1528 ** New exception gdb.GdbError.
1530 ** Pretty-printers are now also looked up in the current program space.
1532 ** Pretty-printers can now be individually enabled and disabled.
1534 ** GDB now looks for names of Python scripts to auto-load in a
1535 special section named `.debug_gdb_scripts', in addition to looking
1536 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1538 * Tracepoint actions were unified with breakpoint commands. In particular,
1539 there are no longer differences in "info break" output for breakpoints and
1540 tracepoints and the "commands" command can be used for both tracepoints and
1541 regular breakpoints.
1545 ARM Symbian arm*-*-symbianelf*
1547 * D language support.
1548 GDB now supports debugging programs written in the D programming
1551 * GDB now supports the extended ptrace interface for PowerPC which is
1552 available since Linux kernel version 2.6.34. This automatically enables
1553 any hardware breakpoints and additional hardware watchpoints available in
1554 the processor. The old ptrace interface exposes just one hardware
1555 watchpoint and no hardware breakpoints.
1557 * GDB is now able to use the Data Value Compare (DVC) register available on
1558 embedded PowerPC processors to implement in hardware simple watchpoint
1559 conditions of the form:
1561 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1563 This works in native GDB running on Linux kernels with the extended ptrace
1564 interface mentioned above.
1566 *** Changes in GDB 7.1
1570 ** Namespace Support
1572 GDB now supports importing of namespaces in C++. This enables the
1573 user to inspect variables from imported namespaces. Support for
1574 namepace aliasing has also been added. So, if a namespace is
1575 aliased in the current scope (e.g. namepace C=A; ) the user can
1576 print variables using the alias (e.g. (gdb) print C::x).
1580 All known bugs relating to the printing of virtual base class were
1581 fixed. It is now possible to call overloaded static methods using a
1586 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1587 and reinterpret_cast<> are now handled by the C++ expression parser.
1591 Xilinx MicroBlaze microblaze-*-*
1596 Xilinx MicroBlaze microblaze
1599 * Multi-program debugging.
1601 GDB now has support for multi-program (a.k.a. multi-executable or
1602 multi-exec) debugging. This allows for debugging multiple inferiors
1603 simultaneously each running a different program under the same GDB
1604 session. See "Debugging Multiple Inferiors and Programs" in the
1605 manual for more information. This implied some user visible changes
1606 in the multi-inferior support. For example, "info inferiors" now
1607 lists inferiors that are not running yet or that have exited
1608 already. See also "New commands" and "New options" below.
1610 * New tracing features
1612 GDB's tracepoint facility now includes several new features:
1614 ** Trace state variables
1616 GDB tracepoints now include support for trace state variables, which
1617 are variables managed by the target agent during a tracing
1618 experiment. They are useful for tracepoints that trigger each
1619 other, so for instance one tracepoint can count hits in a variable,
1620 and then a second tracepoint has a condition that is true when the
1621 count reaches a particular value. Trace state variables share the
1622 $-syntax of GDB convenience variables, and can appear in both
1623 tracepoint actions and condition expressions. Use the "tvariable"
1624 command to create, and "info tvariables" to view; see "Trace State
1625 Variables" in the manual for more detail.
1629 GDB now includes an option for defining fast tracepoints, which
1630 targets may implement more efficiently, such as by installing a jump
1631 into the target agent rather than a trap instruction. The resulting
1632 speedup can be by two orders of magnitude or more, although the
1633 tradeoff is that some program locations on some target architectures
1634 might not allow fast tracepoint installation, for instance if the
1635 instruction to be replaced is shorter than the jump. To request a
1636 fast tracepoint, use the "ftrace" command, with syntax identical to
1637 the regular trace command.
1639 ** Disconnected tracing
1641 It is now possible to detach GDB from the target while it is running
1642 a trace experiment, then reconnect later to see how the experiment
1643 is going. In addition, a new variable disconnected-tracing lets you
1644 tell the target agent whether to continue running a trace if the
1645 connection is lost unexpectedly.
1649 GDB now has the ability to save the trace buffer into a file, and
1650 then use that file as a target, similarly to you can do with
1651 corefiles. You can select trace frames, print data that was
1652 collected in them, and use tstatus to display the state of the
1653 tracing run at the moment that it was saved. To create a trace
1654 file, use "tsave <filename>", and to use it, do "target tfile
1657 ** Circular trace buffer
1659 You can ask the target agent to handle the trace buffer as a
1660 circular buffer, discarding the oldest trace frames to make room for
1661 newer ones, by setting circular-trace-buffer to on. This feature may
1662 not be available for all target agents.
1667 The disassemble command, when invoked with two arguments, now requires
1668 the arguments to be comma-separated.
1671 The info variables command now displays variable definitions. Files
1672 which only declare a variable are not shown.
1675 The source command is now capable of sourcing Python scripts.
1676 This feature is dependent on the debugger being build with Python
1679 Related to this enhancement is also the introduction of a new command
1680 "set script-extension" (see below).
1682 * New commands (for set/show, see "New options" below)
1684 record save [<FILENAME>]
1685 Save a file (in core file format) containing the process record
1686 execution log for replay debugging at a later time.
1688 record restore <FILENAME>
1689 Restore the process record execution log that was saved at an
1690 earlier time, for replay debugging.
1692 add-inferior [-copies <N>] [-exec <FILENAME>]
1695 clone-inferior [-copies <N>] [ID]
1696 Make a new inferior ready to execute the same program another
1697 inferior has loaded.
1702 maint info program-spaces
1703 List the program spaces loaded into GDB.
1705 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1706 show remote interrupt-sequence
1707 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1708 as the sequence to the remote target in order to interrupt the execution.
1709 Ctrl-C is a default. Some system prefers BREAK which is high level of
1710 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1711 Magic SysRq g. It is BREAK signal and character 'g'.
1713 set remote interrupt-on-connect [on | off]
1714 show remote interrupt-on-connect
1715 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1716 remote target when gdb connects to it. This is needed when you debug
1719 set remotebreak [on | off]
1721 Deprecated. Use "set/show remote interrupt-sequence" instead.
1723 tvariable $NAME [ = EXP ]
1724 Create or modify a trace state variable.
1727 List trace state variables and their values.
1729 delete tvariable $NAME ...
1730 Delete one or more trace state variables.
1733 Evaluate the given expressions without collecting anything into the
1734 trace buffer. (Valid in tracepoint actions only.)
1736 ftrace FN / FILE:LINE / *ADDR
1737 Define a fast tracepoint at the given function, line, or address.
1739 * New expression syntax
1741 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1742 GDB now parses 0b101010 identically with 42.
1746 set follow-exec-mode new|same
1747 show follow-exec-mode
1748 Control whether GDB reuses the same inferior across an exec call or
1749 creates a new one. This is useful to be able to restart the old
1750 executable after the inferior having done an exec call.
1752 set default-collect EXPR, ...
1753 show default-collect
1754 Define a list of expressions to be collected at each tracepoint.
1755 This is a useful way to ensure essential items are not overlooked,
1756 such as registers or a critical global variable.
1758 set disconnected-tracing
1759 show disconnected-tracing
1760 If set to 1, the target is instructed to continue tracing if it
1761 loses its connection to GDB. If 0, the target is to stop tracing
1764 set circular-trace-buffer
1765 show circular-trace-buffer
1766 If set to on, the target is instructed to use a circular trace buffer
1767 and discard the oldest trace frames instead of stopping the trace due
1768 to a full trace buffer. If set to off, the trace stops when the buffer
1769 fills up. Some targets may not support this.
1771 set script-extension off|soft|strict
1772 show script-extension
1773 If set to "off", the debugger does not perform any script language
1774 recognition, and all sourced files are assumed to be GDB scripts.
1775 If set to "soft" (the default), files are sourced according to
1776 filename extension, falling back to GDB scripts if the first
1778 If set to "strict", files are sourced according to filename extension.
1780 set ada trust-PAD-over-XVS on|off
1781 show ada trust-PAD-over-XVS
1782 If off, activate a workaround against a bug in the debugging information
1783 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1784 the GCC sources for more information about the GNAT encoding and
1785 PAD types in particular). It is always safe to set this option to
1786 off, but this introduces a slight performance penalty. The default
1789 * Python API Improvements
1791 ** GDB provides the new class gdb.LazyString. This is useful in
1792 some pretty-printing cases. The new method gdb.Value.lazy_string
1793 provides a simple way to create objects of this type.
1795 ** The fields returned by gdb.Type.fields now have an
1796 `is_base_class' attribute.
1798 ** The new method gdb.Type.range returns the range of an array type.
1800 ** The new method gdb.parse_and_eval can be used to parse and
1801 evaluate an expression.
1803 * New remote packets
1806 Define a trace state variable.
1809 Get the current value of a trace state variable.
1812 Set desired tracing behavior upon disconnection.
1815 Set the trace buffer to be linear or circular.
1818 Get data about the tracepoints currently in use.
1822 Process record now works correctly with hardware watchpoints.
1824 Multiple bug fixes have been made to the mips-irix port, making it
1825 much more reliable. In particular:
1826 - Debugging threaded applications is now possible again. Previously,
1827 GDB would hang while starting the program, or while waiting for
1828 the program to stop at a breakpoint.
1829 - Attaching to a running process no longer hangs.
1830 - An error occurring while loading a core file has been fixed.
1831 - Changing the value of the PC register now works again. This fixes
1832 problems observed when using the "jump" command, or when calling
1833 a function from GDB, or even when assigning a new value to $pc.
1834 - With the "finish" and "return" commands, the return value for functions
1835 returning a small array is now correctly printed.
1836 - It is now possible to break on shared library code which gets executed
1837 during a shared library init phase (code executed while executing
1838 their .init section). Previously, the breakpoint would have no effect.
1839 - GDB is now able to backtrace through the signal handler for
1840 non-threaded programs.
1842 PIE (Position Independent Executable) programs debugging is now supported.
1843 This includes debugging execution of PIC (Position Independent Code) shared
1844 libraries although for that, it should be possible to run such libraries as an
1847 *** Changes in GDB 7.0
1849 * GDB now has an interface for JIT compilation. Applications that
1850 dynamically generate code can create symbol files in memory and register
1851 them with GDB. For users, the feature should work transparently, and
1852 for JIT developers, the interface is documented in the GDB manual in the
1853 "JIT Compilation Interface" chapter.
1855 * Tracepoints may now be conditional. The syntax is as for
1856 breakpoints; either an "if" clause appended to the "trace" command,
1857 or the "condition" command is available. GDB sends the condition to
1858 the target for evaluation using the same bytecode format as is used
1859 for tracepoint actions.
1861 * The disassemble command now supports: an optional /r modifier, print the
1862 raw instructions in hex as well as in symbolic form, and an optional /m
1863 modifier to print mixed source+assembly.
1865 * Process record and replay
1867 In a architecture environment that supports ``process record and
1868 replay'', ``process record and replay'' target can record a log of
1869 the process execution, and replay it with both forward and reverse
1872 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
1873 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
1874 set execution-direction {forward|reverse}, for targets that support
1877 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
1878 feature is available with a native GDB running on kernel version
1881 * GDB now has support for multi-byte and wide character sets on the
1882 target. Strings whose character type is wchar_t, char16_t, or
1883 char32_t are now correctly printed. GDB supports wide- and unicode-
1884 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
1885 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
1886 `printf'. This feature requires iconv to work properly; if your
1887 system does not have a working iconv, GDB can use GNU libiconv. See
1888 the installation instructions for more information.
1890 * GDB now supports automatic retrieval of shared library files from
1891 remote targets. To use this feature, specify a system root that begins
1892 with the `remote:' prefix, either via the `set sysroot' command or via
1893 the `--with-sysroot' configure-time option.
1895 * "info sharedlibrary" now takes an optional regex of libraries to show,
1896 and it now reports if a shared library has no debugging information.
1898 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
1899 now complete on file names.
1901 * When completing in expressions, gdb will attempt to limit
1902 completions to allowable structure or union fields, where appropriate.
1903 For instance, consider:
1905 # struct example { int f1; double f2; };
1906 # struct example variable;
1909 If the user types TAB at the end of this command line, the available
1910 completions will be "f1" and "f2".
1912 * Inlined functions are now supported. They show up in backtraces, and
1913 the "step", "next", and "finish" commands handle them automatically.
1915 * GDB now supports the token-splicing (##) and stringification (#)
1916 operators when expanding macros. It also supports variable-arity
1919 * GDB now supports inspecting extra signal information, exported by
1920 the new $_siginfo convenience variable. The feature is currently
1921 implemented on linux ARM, i386 and amd64.
1923 * GDB can now display the VFP floating point registers and NEON vector
1924 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
1925 can provide these registers (requires Linux 2.6.30 or later). Remote
1926 and simulator targets may also provide them.
1928 * New remote packets
1931 Search memory for a sequence of bytes.
1934 Turn off `+'/`-' protocol acknowledgments to permit more efficient
1935 operation over reliable transport links. Use of this packet is
1936 controlled by the `set remote noack-packet' command.
1939 Kill the process with the specified process ID. Use this in preference
1940 to `k' when multiprocess protocol extensions are supported.
1943 Obtains additional operating system information
1947 Read or write additional signal information.
1949 * Removed remote protocol undocumented extension
1951 An undocumented extension to the remote protocol's `S' stop reply
1952 packet that permited the stub to pass a process id was removed.
1953 Remote servers should use the `T' stop reply packet instead.
1955 * GDB now supports multiple function calling conventions according to the
1956 DWARF-2 DW_AT_calling_convention function attribute.
1958 * The SH target utilizes the aforementioned change to distinguish between gcc
1959 and Renesas calling convention. It also adds the new CLI commands
1960 `set/show sh calling-convention'.
1962 * GDB can now read compressed debug sections, as produced by GNU gold
1963 with the --compress-debug-sections=zlib flag.
1965 * 64-bit core files are now supported on AIX.
1967 * Thread switching is now supported on Tru64.
1969 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
1970 which will be allocated using malloc later in program execution.
1972 * The qXfer:libraries:read remote procotol packet now allows passing a
1973 list of section offsets.
1975 * On GNU/Linux, GDB can now attach to stopped processes. Several race
1976 conditions handling signals delivered during attach or thread creation
1977 have also been fixed.
1979 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
1980 From the user's standpoint, all unqualified instances of True and False
1981 are treated as the standard definitions, regardless of context.
1983 * GDB now parses C++ symbol and type names more flexibly. For
1986 template<typename T> class C { };
1989 GDB will now correctly handle all of:
1991 ptype C<char const *>
1992 ptype C<char const*>
1993 ptype C<const char *>
1994 ptype C<const char*>
1996 * New features in the GDB remote stub, gdbserver
1998 - The "--wrapper" command-line argument tells gdbserver to use a
1999 wrapper program to launch programs for debugging.
2001 - On PowerPC and S/390 targets, it is now possible to use a single
2002 gdbserver executable to debug both 32-bit and 64-bit programs.
2003 (This requires gdbserver itself to be built as a 64-bit executable.)
2005 - gdbserver uses the new noack protocol mode for TCP connections to
2006 reduce communications latency, if also supported and enabled in GDB.
2008 - Support for the sparc64-linux-gnu target is now included in
2011 - The amd64-linux build of gdbserver now supports debugging both
2012 32-bit and 64-bit programs.
2014 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2015 now support hardware watchpoints, and will use them automatically
2020 GDB now has support for scripting using Python. Whether this is
2021 available is determined at configure time.
2023 New GDB commands can now be written in Python.
2025 * Ada tasking support
2027 Ada tasks can now be inspected in GDB. The following commands have
2031 Print the list of Ada tasks.
2033 Print detailed information about task number N.
2035 Print the task number of the current task.
2037 Switch the context of debugging to task number N.
2039 * Support for user-defined prefixed commands. The "define" command can
2040 add new commands to existing prefixes, e.g. "target".
2042 * Multi-inferior, multi-process debugging.
2044 GDB now has generalized support for multi-inferior debugging. See
2045 "Debugging Multiple Inferiors" in the manual for more information.
2046 Although availability still depends on target support, the command
2047 set is more uniform now. The GNU/Linux specific multi-forks support
2048 has been migrated to this new framework. This implied some user
2049 visible changes; see "New commands" and also "Removed commands"
2052 * Target descriptions can now describe the target OS ABI. See the
2053 "Target Description Format" section in the user manual for more
2056 * Target descriptions can now describe "compatible" architectures
2057 to indicate that the target can execute applications for a different
2058 architecture in addition to those for the main target architecture.
2059 See the "Target Description Format" section in the user manual for
2062 * Multi-architecture debugging.
2064 GDB now includes general supports for debugging applications on
2065 hybrid systems that use more than one single processor architecture
2066 at the same time. Each such hybrid architecture still requires
2067 specific support to be added. The only hybrid architecture supported
2068 in this version of GDB is the Cell Broadband Engine.
2070 * GDB now supports integrated debugging of Cell/B.E. applications that
2071 use both the PPU and SPU architectures. To enable support for hybrid
2072 Cell/B.E. debugging, you need to configure GDB to support both the
2073 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2074 --enable-targets configure option.
2076 * Non-stop mode debugging.
2078 For some targets, GDB now supports an optional mode of operation in
2079 which you can examine stopped threads while other threads continue
2080 to execute freely. This is referred to as non-stop mode, with the
2081 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2082 section in the user manual for more information.
2084 To be able to support remote non-stop debugging, a remote stub needs
2085 to implement the non-stop mode remote protocol extensions, as
2086 described in the "Remote Non-Stop" section of the user manual. The
2087 GDB remote stub, gdbserver, has been adjusted to support these
2088 extensions on linux targets.
2090 * New commands (for set/show, see "New options" below)
2092 catch syscall [NAME(S) | NUMBER(S)]
2093 Catch system calls. Arguments, which should be names of system
2094 calls or their numbers, mean catch only those syscalls. Without
2095 arguments, every syscall will be caught. When the inferior issues
2096 any of the specified syscalls, GDB will stop and announce the system
2097 call, both when it is called and when its call returns. This
2098 feature is currently available with a native GDB running on the
2099 Linux Kernel, under the following architectures: x86, x86_64,
2100 PowerPC and PowerPC64.
2102 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2104 Search memory for a sequence of bytes.
2106 maint set python print-stack
2107 maint show python print-stack
2108 Show a stack trace when an error is encountered in a Python script.
2111 Invoke CODE by passing it to the Python interpreter.
2116 These allow macros to be defined, undefined, and listed
2120 Show operating system information about processes.
2123 List the inferiors currently under GDB's control.
2126 Switch focus to inferior number NUM.
2129 Detach from inferior number NUM.
2132 Kill inferior number NUM.
2136 set spu stop-on-load
2137 show spu stop-on-load
2138 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2140 set spu auto-flush-cache
2141 show spu auto-flush-cache
2142 Control whether to automatically flush the software-managed cache
2143 during Cell/B.E. debugging.
2145 set sh calling-convention
2146 show sh calling-convention
2147 Control the calling convention used when calling SH target functions.
2150 show debug timestamp
2151 Control display of timestamps with GDB debugging output.
2153 set disassemble-next-line
2154 show disassemble-next-line
2155 Control display of disassembled source lines or instructions when
2158 set remote noack-packet
2159 show remote noack-packet
2160 Set/show the use of remote protocol QStartNoAckMode packet. See above
2161 under "New remote packets."
2163 set remote query-attached-packet
2164 show remote query-attached-packet
2165 Control use of remote protocol `qAttached' (query-attached) packet.
2167 set remote read-siginfo-object
2168 show remote read-siginfo-object
2169 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2172 set remote write-siginfo-object
2173 show remote write-siginfo-object
2174 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2177 set remote reverse-continue
2178 show remote reverse-continue
2179 Control use of remote protocol 'bc' (reverse-continue) packet.
2181 set remote reverse-step
2182 show remote reverse-step
2183 Control use of remote protocol 'bs' (reverse-step) packet.
2185 set displaced-stepping
2186 show displaced-stepping
2187 Control displaced stepping mode. Displaced stepping is a way to
2188 single-step over breakpoints without removing them from the debuggee.
2189 Also known as "out-of-line single-stepping".
2192 show debug displaced
2193 Control display of debugging info for displaced stepping.
2195 maint set internal-error
2196 maint show internal-error
2197 Control what GDB does when an internal error is detected.
2199 maint set internal-warning
2200 maint show internal-warning
2201 Control what GDB does when an internal warning is detected.
2206 Use a wrapper program to launch programs for debugging.
2208 set multiple-symbols (all|ask|cancel)
2209 show multiple-symbols
2210 The value of this variable can be changed to adjust the debugger behavior
2211 when an expression or a breakpoint location contains an ambiguous symbol
2212 name (an overloaded function name, for instance).
2214 set breakpoint always-inserted
2215 show breakpoint always-inserted
2216 Keep breakpoints always inserted in the target, as opposed to inserting
2217 them when resuming the target, and removing them when the target stops.
2218 This option can improve debugger performance on slow remote targets.
2220 set arm fallback-mode (arm|thumb|auto)
2221 show arm fallback-mode
2222 set arm force-mode (arm|thumb|auto)
2224 These commands control how ARM GDB determines whether instructions
2225 are ARM or Thumb. The default for both settings is auto, which uses
2226 the current CPSR value for instructions without symbols; previous
2227 versions of GDB behaved as if "set arm fallback-mode arm".
2229 set disable-randomization
2230 show disable-randomization
2231 Standalone programs run with the virtual address space randomization enabled
2232 by default on some platforms. This option keeps the addresses stable across
2233 multiple debugging sessions.
2237 Control whether other threads are stopped or not when some thread hits
2242 Requests that asynchronous execution is enabled in the target, if available.
2243 In this case, it's possible to resume target in the background, and interact
2244 with GDB while the target is running. "show target-async" displays the
2245 current state of asynchronous execution of the target.
2247 set target-wide-charset
2248 show target-wide-charset
2249 The target-wide-charset is the name of the character set that GDB
2250 uses when printing characters whose type is wchar_t.
2252 set tcp auto-retry (on|off)
2254 set tcp connect-timeout
2255 show tcp connect-timeout
2256 These commands allow GDB to retry failed TCP connections to a remote stub
2257 with a specified timeout period; this is useful if the stub is launched
2258 in parallel with GDB but may not be ready to accept connections immediately.
2260 set libthread-db-search-path
2261 show libthread-db-search-path
2262 Control list of directories which GDB will search for appropriate
2265 set schedule-multiple (on|off)
2266 show schedule-multiple
2267 Allow GDB to resume all threads of all processes or only threads of
2268 the current process.
2272 Use more aggressive caching for accesses to the stack. This improves
2273 performance of remote debugging (particularly backtraces) without
2274 affecting correctness.
2276 set interactive-mode (on|off|auto)
2277 show interactive-mode
2278 Control whether GDB runs in interactive mode (on) or not (off).
2279 When in interactive mode, GDB waits for the user to answer all
2280 queries. Otherwise, GDB does not wait and assumes the default
2281 answer. When set to auto (the default), GDB determines which
2282 mode to use based on the stdin settings.
2287 For program forks, this is replaced by the new more generic `info
2288 inferiors' command. To list checkpoints, you can still use the
2289 `info checkpoints' command, which was an alias for the `info forks'
2293 Replaced by the new `inferior' command. To switch between
2294 checkpoints, you can still use the `restart' command, which was an
2295 alias for the `fork' command.
2298 This is removed, since some targets don't have a notion of
2299 processes. To switch between processes, you can still use the
2300 `inferior' command using GDB's own inferior number.
2303 For program forks, this is replaced by the new more generic `kill
2304 inferior' command. To delete a checkpoint, you can still use the
2305 `delete checkpoint' command, which was an alias for the `delete
2309 For program forks, this is replaced by the new more generic `detach
2310 inferior' command. To detach a checkpoint, you can still use the
2311 `detach checkpoint' command, which was an alias for the `detach
2314 * New native configurations
2316 x86/x86_64 Darwin i[34567]86-*-darwin*
2318 x86_64 MinGW x86_64-*-mingw*
2322 Lattice Mico32 lm32-*
2323 x86 DICOS i[34567]86-*-dicos*
2324 x86_64 DICOS x86_64-*-dicos*
2327 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2328 (mingw32ce) debugging.
2334 These commands were actually not implemented on any target.
2336 *** Changes in GDB 6.8
2338 * New native configurations
2340 NetBSD/hppa hppa*-*netbsd*
2341 Xtensa GNU/Linux xtensa*-*-linux*
2345 NetBSD/hppa hppa*-*-netbsd*
2346 Xtensa GNU/Lunux xtensa*-*-linux*
2348 * Change in command line behavior -- corefiles vs. process ids.
2350 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2351 attaching to process NUMBER fails, GDB no longer attempts to open a
2352 core file named NUMBER. Attaching to a program using the -c option
2353 is no longer supported. Instead, use the '-p' or '--pid' options.
2355 * GDB can now be built as a native debugger for debugging Windows x86
2356 (mingw32) Portable Executable (PE) programs.
2358 * Pending breakpoints no longer change their number when their address
2361 * GDB now supports breakpoints with multiple locations,
2362 including breakpoints on C++ constructors, inside C++ templates,
2363 and in inlined functions.
2365 * GDB's ability to debug optimized code has been improved. GDB more
2366 accurately identifies function bodies and lexical blocks that occupy
2367 more than one contiguous range of addresses.
2369 * Target descriptions can now describe registers for PowerPC.
2371 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2372 registers on PowerPC targets.
2374 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2375 targets even when the libthread_db library is not available.
2377 * The GDB remote stub, gdbserver, now supports the new file transfer
2378 commands (remote put, remote get, and remote delete).
2380 * The GDB remote stub, gdbserver, now supports run and attach in
2381 extended-remote mode.
2383 * hppa*64*-*-hpux11* target broken
2384 The debugger is unable to start a program and fails with the following
2385 error: "Error trying to get information about dynamic linker".
2386 The gdb-6.7 release is also affected.
2388 * GDB now supports the --enable-targets= configure option to allow
2389 building a single GDB executable that supports multiple remote
2390 target architectures.
2392 * GDB now supports debugging C and C++ programs which use the
2393 Decimal Floating Point extension. In addition, the PowerPC target
2394 now has a set of pseudo-registers to inspect decimal float values
2395 stored in two consecutive float registers.
2397 * The -break-insert MI command can optionally create pending
2400 * Improved support for debugging Ada
2401 Many improvements to the Ada language support have been made. These
2403 - Better support for Ada2005 interface types
2404 - Improved handling of arrays and slices in general
2405 - Better support for Taft-amendment types
2406 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2408 - Improved command completion in Ada
2411 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2416 set print frame-arguments (all|scalars|none)
2417 show print frame-arguments
2418 The value of this variable can be changed to control which argument
2419 values should be printed by the debugger when displaying a frame.
2424 Transfer files to and from a remote target, and delete remote files.
2431 Transfer files to and from a remote target, and delete remote files.
2433 * New remote packets
2440 Open, close, read, write, and delete files on the remote system.
2443 Attach to an existing process on the remote system, in extended-remote
2447 Run a new process on the remote system, in extended-remote mode.
2449 *** Changes in GDB 6.7
2451 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2452 bfd, libiberty and opcodes, as revealed by static analysis donated by
2453 Coverity, Inc. (http://scan.coverity.com).
2455 * When looking up multiply-defined global symbols, GDB will now prefer the
2456 symbol definition in the current shared library if it was built using the
2457 -Bsymbolic linker option.
2459 * When the Text User Interface (TUI) is not configured, GDB will now
2460 recognize the -tui command-line option and print a message that the TUI
2463 * The GDB remote stub, gdbserver, now has lower overhead for high
2464 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2466 * GDB for MIPS targets now autodetects whether a remote target provides
2467 32-bit or 64-bit register values.
2469 * Support for C++ member pointers has been improved.
2471 * GDB now understands XML target descriptions, which specify the
2472 target's overall architecture. GDB can read a description from
2473 a local file or over the remote serial protocol.
2475 * Vectors of single-byte data use a new integer type which is not
2476 automatically displayed as character or string data.
2478 * The /s format now works with the print command. It displays
2479 arrays of single-byte integers and pointers to single-byte integers
2482 * Target descriptions can now describe target-specific registers,
2483 for architectures which have implemented the support (currently
2484 only ARM, M68K, and MIPS).
2486 * GDB and the GDB remote stub, gdbserver, now support the XScale
2489 * The GDB remote stub, gdbserver, has been updated to support
2490 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2491 has been rewritten to use the standard GDB remote protocol.
2493 * GDB can now step into C++ functions which are called through thunks.
2495 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2497 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2498 layout. It also supports a TextSeg= and DataSeg= response when only
2499 segment base addresses (rather than offsets) are available.
2501 * The /i format now outputs any trailing branch delay slot instructions
2502 immediately following the last instruction within the count specified.
2504 * The GDB remote protocol "T" stop reply packet now supports a
2505 "library" response. Combined with the new "qXfer:libraries:read"
2506 packet, this response allows GDB to debug shared libraries on targets
2507 where the operating system manages the list of loaded libraries (e.g.
2508 Windows and SymbianOS).
2510 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2511 (DLLs) on Windows and Windows CE targets.
2513 * GDB now supports a faster verification that a .debug file matches its binary
2514 according to its build-id signature, if the signature is present.
2520 Enable or disable hardware flow control (RTS/CTS) on the serial port
2521 when debugging using remote targets.
2523 set mem inaccessible-by-default
2524 show mem inaccessible-by-default
2525 If the target supplies a memory map, for instance via the remote
2526 protocol's "qXfer:memory-map:read" packet, setting this variable
2527 prevents GDB from accessing memory outside the memory map. This
2528 is useful for targets with memory mapped registers or which react
2529 badly to accesses of unmapped address space.
2531 set breakpoint auto-hw
2532 show breakpoint auto-hw
2533 If the target supplies a memory map, for instance via the remote
2534 protocol's "qXfer:memory-map:read" packet, setting this variable
2535 lets GDB use hardware breakpoints automatically for memory regions
2536 where it can not use software breakpoints. This covers both the
2537 "break" command and internal breakpoints used for other commands
2538 including "next" and "finish".
2541 catch exception unhandled
2542 Stop the program execution when Ada exceptions are raised.
2545 Stop the program execution when an Ada assertion failed.
2549 Set an alternate system root for target files. This is a more
2550 general version of "set solib-absolute-prefix", which is now
2551 an alias to "set sysroot".
2554 Provide extended SPU facility status information. This set of
2555 commands is available only when debugging the Cell/B.E. SPU
2558 * New native configurations
2560 OpenBSD/sh sh*-*openbsd*
2563 unset tdesc filename
2565 Use the specified local file as an XML target description, and do
2566 not query the target for its built-in description.
2570 OpenBSD/sh sh*-*-openbsd*
2571 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2572 Toshiba Media Processor mep-elf
2574 * New remote packets
2577 Ignore the specified signals; pass them directly to the debugged program
2578 without stopping other threads or reporting them to GDB.
2580 qXfer:features:read:
2581 Read an XML target description from the target, which describes its
2586 Read or write contents of an spufs file on the target system. These
2587 packets are available only on the Cell/B.E. SPU architecture.
2589 qXfer:libraries:read:
2590 Report the loaded shared libraries. Combined with new "T" packet
2591 response, this packet allows GDB to debug shared libraries on
2592 targets where the operating system manages the list of loaded
2593 libraries (e.g. Windows and SymbianOS).
2597 Support for these obsolete configurations has been removed.
2605 i[34567]86-*-lynxos*
2606 i[34567]86-*-netware*
2607 i[34567]86-*-sco3.2v5*
2608 i[34567]86-*-sco3.2v4*
2610 i[34567]86-*-sysv4.2*
2613 i[34567]86-*-unixware2*
2614 i[34567]86-*-unixware*
2623 * Other removed features
2630 Various m68k-only ROM monitors.
2637 Various Renesas ROM monitors and debugging interfaces for SH and
2642 Support for a Macraigor serial interface to on-chip debugging.
2643 GDB does not directly support the newer parallel or USB
2648 A debug information format. The predecessor to DWARF 2 and
2649 DWARF 3, which are still supported.
2651 Support for the HP aCC compiler on HP-UX/PA-RISC
2653 SOM-encapsulated symbolic debugging information, automatic
2654 invocation of pxdb, and the aCC custom C++ ABI. This does not
2655 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2656 with aCC can still be debugged on an assembly level.
2658 MIPS ".pdr" sections
2660 A MIPS-specific format used to describe stack frame layout
2661 in debugging information.
2665 GDB could work with an older version of Guile to debug
2666 the interpreter and Scheme programs running in it.
2668 set mips stack-arg-size
2669 set mips saved-gpreg-size
2671 Use "set mips abi" to control parameter passing for MIPS.
2673 *** Changes in GDB 6.6
2678 Cell Broadband Engine SPU spu-elf
2680 * GDB can now be configured as a cross-debugger targeting native Windows
2681 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2682 running on a Windows system over TCP/IP to debug Windows programs.
2684 * The GDB remote stub, gdbserver, has been updated to support Windows and
2685 Cygwin debugging. Both single-threaded and multi-threaded programs are
2688 * The "set trust-readonly-sections" command works again. This command was
2689 broken in GDB 6.3, 6.4, and 6.5.
2691 * The "load" command now supports writing to flash memory, if the remote
2692 stub provides the required support.
2694 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2695 longer requires symbolic debug information (e.g. DWARF-2).
2700 unset substitute-path
2701 show substitute-path
2702 Manage a list of substitution rules that GDB uses to rewrite the name
2703 of the directories where the sources are located. This can be useful
2704 for instance when the sources were moved to a different location
2705 between compilation and debugging.
2709 Print each CLI command as it is executed. Each command is prefixed with
2710 a number of `+' symbols representing the nesting depth.
2711 The source command now has a `-v' option to enable the same feature.
2715 The ARM Demon monitor support (RDP protocol, "target rdp").
2717 Kernel Object Display, an embedded debugging feature which only worked with
2718 an obsolete version of Cisco IOS.
2720 The 'set download-write-size' and 'show download-write-size' commands.
2722 * New remote packets
2725 Tell a stub about GDB client features, and request remote target features.
2726 The first feature implemented is PacketSize, which allows the target to
2727 specify the size of packets it can handle - to minimize the number of
2728 packets required and improve performance when connected to a remote
2732 Fetch an OS auxilliary vector from the remote stub. This packet is a
2733 more efficient replacement for qPart:auxv:read.
2735 qXfer:memory-map:read:
2736 Fetch a memory map from the remote stub, including information about
2737 RAM, ROM, and flash memory devices.
2742 Erase and program a flash memory device.
2744 * Removed remote packets
2747 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2748 used it, and only gdbserver implemented it.
2750 *** Changes in GDB 6.5
2754 Renesas M32C/M16C m32c-elf
2756 Morpho Technologies ms1 ms1-elf
2760 init-if-undefined Initialize a convenience variable, but
2761 only if it doesn't already have a value.
2763 The following commands are presently only implemented for native GNU/Linux:
2765 checkpoint Save a snapshot of the program state.
2767 restart <n> Return the program state to a
2768 previously saved state.
2770 info checkpoints List currently saved checkpoints.
2772 delete-checkpoint <n> Delete a previously saved checkpoint.
2774 set|show detach-on-fork Tell gdb whether to detach from a newly
2775 forked process, or to keep debugging it.
2777 info forks List forks of the user program that
2778 are available to be debugged.
2780 fork <n> Switch to debugging one of several
2781 forks of the user program that are
2782 available to be debugged.
2784 delete-fork <n> Delete a fork from the list of forks
2785 that are available to be debugged (and
2786 kill the forked process).
2788 detach-fork <n> Delete a fork from the list of forks
2789 that are available to be debugged (and
2790 allow the process to continue).
2794 Morpho Technologies ms2 ms1-elf
2796 * Improved Windows host support
2798 GDB now builds as a cross debugger hosted on i686-mingw32, including
2799 native console support, and remote communications using either
2800 network sockets or serial ports.
2802 * Improved Modula-2 language support
2804 GDB can now print most types in the Modula-2 syntax. This includes:
2805 basic types, set types, record types, enumerated types, range types,
2806 pointer types and ARRAY types. Procedure var parameters are correctly
2807 printed and hexadecimal addresses and character constants are also
2808 written in the Modula-2 syntax. Best results can be obtained by using
2809 GNU Modula-2 together with the -gdwarf-2 command line option.
2813 The ARM rdi-share module.
2815 The Netware NLM debug server.
2817 *** Changes in GDB 6.4
2819 * New native configurations
2821 OpenBSD/arm arm*-*-openbsd*
2822 OpenBSD/mips64 mips64-*-openbsd*
2826 Morpho Technologies ms1 ms1-elf
2828 * New command line options
2830 --batch-silent As for --batch, but totally silent.
2831 --return-child-result The debugger will exist with the same value
2832 the child (debugged) program exited with.
2833 --eval-command COMMAND, -ex COMMAND
2834 Execute a single GDB CLI command. This may be
2835 specified multiple times and in conjunction
2836 with the --command (-x) option.
2838 * Deprecated commands removed
2840 The following commands, that were deprecated in 2000, have been
2844 set|show arm disassembly-flavor set|show arm disassembler
2845 othernames set arm disassembler
2846 set|show remotedebug set|show debug remote
2847 set|show archdebug set|show debug arch
2848 set|show eventdebug set|show debug event
2851 * New BSD user-level threads support
2853 It is now possible to debug programs using the user-level threads
2854 library on OpenBSD and FreeBSD. Currently supported (target)
2857 FreeBSD/amd64 x86_64-*-freebsd*
2858 FreeBSD/i386 i386-*-freebsd*
2859 OpenBSD/i386 i386-*-openbsd*
2861 Note that the new kernel threads libraries introduced in FreeBSD 5.x
2862 are not yet supported.
2864 * New support for Matsushita MN10300 w/sim added
2865 (Work in progress). mn10300-elf.
2867 * REMOVED configurations and files
2869 VxWorks and the XDR protocol *-*-vxworks
2870 Motorola MCORE mcore-*-*
2871 National Semiconductor NS32000 ns32k-*-*
2873 * New "set print array-indexes" command
2875 After turning this setting "on", GDB prints the index of each element
2876 when displaying arrays. The default is "off" to preserve the previous
2879 * VAX floating point support
2881 GDB now supports the not-quite-ieee VAX F and D floating point formats.
2883 * User-defined command support
2885 In addition to using $arg0..$arg9 for argument passing, it is now possible
2886 to use $argc to determine now many arguments have been passed. See the
2887 section on user-defined commands in the user manual for more information.
2889 *** Changes in GDB 6.3:
2891 * New command line option
2893 GDB now accepts -l followed by a number to set the timeout for remote
2896 * GDB works with GCC -feliminate-dwarf2-dups
2898 GDB now supports a more compact representation of DWARF-2 debug
2899 information using DW_FORM_ref_addr references. These are produced
2900 by GCC with the option -feliminate-dwarf2-dups and also by some
2901 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
2902 to use -feliminate-dwarf2-dups.
2904 * Internationalization
2906 When supported by the host system, GDB will be built with
2907 internationalization (libintl). The task of marking up the sources is
2908 continued, we're looking forward to our first translation.
2912 Initial support for debugging programs compiled with the GNAT
2913 implementation of the Ada programming language has been integrated
2914 into GDB. In this release, support is limited to expression evaluation.
2916 * New native configurations
2918 GNU/Linux/m32r m32r-*-linux-gnu
2922 GDB's remote protocol now includes support for the 'p' packet. This
2923 packet is used to fetch individual registers from a remote inferior.
2925 * END-OF-LIFE registers[] compatibility module
2927 GDB's internal register infrastructure has been completely rewritten.
2928 The new infrastructure making possible the implementation of key new
2929 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
2932 GDB 6.3 will be the last release to include the the registers[]
2933 compatibility module that allowed out-of-date configurations to
2934 continue to work. This change directly impacts the following
2944 powerpc bdm protocol
2946 Unless there is activity to revive these configurations, they will be
2947 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
2949 * OBSOLETE configurations and files
2951 Configurations that have been declared obsolete in this release have
2952 been commented out. Unless there is activity to revive these
2953 configurations, the next release of GDB will have their sources
2954 permanently REMOVED.
2963 *** Changes in GDB 6.2.1:
2965 * MIPS `break main; run' gave an heuristic-fence-post warning
2967 When attempting to run even a simple program, a warning about
2968 heuristic-fence-post being hit would be reported. This problem has
2971 * MIPS IRIX 'long double' crashed GDB
2973 When examining a long double variable, GDB would get a segmentation
2974 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
2975 IRIX long double values).
2979 A bug in the VAX stack code was causing problems with the "next"
2980 command. This problem has been fixed.
2982 *** Changes in GDB 6.2:
2984 * Fix for ``many threads''
2986 On GNU/Linux systems that use the NPTL threads library, a program
2987 rapidly creating and deleting threads would confuse GDB leading to the
2990 ptrace: No such process.
2991 thread_db_get_info: cannot get thread info: generic error
2993 This problem has been fixed.
2995 * "-async" and "-noasync" options removed.
2997 Support for the broken "-noasync" option has been removed (it caused
3000 * New ``start'' command.
3002 This command runs the program until the begining of the main procedure.
3004 * New BSD Kernel Data Access Library (libkvm) interface
3006 Using ``target kvm'' it is now possible to debug kernel core dumps and
3007 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3008 platforms. Currently supported (native-only) configurations are:
3010 FreeBSD/amd64 x86_64-*-freebsd*
3011 FreeBSD/i386 i?86-*-freebsd*
3012 NetBSD/i386 i?86-*-netbsd*
3013 NetBSD/m68k m68*-*-netbsd*
3014 NetBSD/sparc sparc-*-netbsd*
3015 OpenBSD/amd64 x86_64-*-openbsd*
3016 OpenBSD/i386 i?86-*-openbsd*
3017 OpenBSD/m68k m68*-openbsd*
3018 OpenBSD/sparc sparc-*-openbsd*
3020 * Signal trampoline code overhauled
3022 Many generic problems with GDB's signal handling code have been fixed.
3023 These include: backtraces through non-contiguous stacks; recognition
3024 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3025 call; backtrace through a signal trampoline; step into and out of
3026 signal handlers; and single-stepping in the signal trampoline.
3028 Please note that kernel bugs are a limiting factor here. These
3029 features have been shown to work on an s390 GNU/Linux system that
3030 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3032 * Cygwin support for DWARF 2 added.
3034 * New native configurations
3036 GNU/Linux/hppa hppa*-*-linux*
3037 OpenBSD/hppa hppa*-*-openbsd*
3038 OpenBSD/m68k m68*-*-openbsd*
3039 OpenBSD/m88k m88*-*-openbsd*
3040 OpenBSD/powerpc powerpc-*-openbsd*
3041 NetBSD/vax vax-*-netbsd*
3042 OpenBSD/vax vax-*-openbsd*
3044 * END-OF-LIFE frame compatibility module
3046 GDB's internal frame infrastructure has been completely rewritten.
3047 The new infrastructure making it possible to support key new features
3048 including DWARF 2 Call Frame Information. To aid in the task of
3049 migrating old configurations to this new infrastructure, a
3050 compatibility module, that allowed old configurations to continue to
3051 work, was also included.
3053 GDB 6.2 will be the last release to include this frame compatibility
3054 module. This change directly impacts the following configurations:
3064 Unless there is activity to revive these configurations, they will be
3065 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3067 * REMOVED configurations and files
3069 Sun 3, running SunOS 3 m68*-*-sunos3*
3070 Sun 3, running SunOS 4 m68*-*-sunos4*
3071 Sun 2, running SunOS 3 m68000-*-sunos3*
3072 Sun 2, running SunOS 4 m68000-*-sunos4*
3073 Motorola 680x0 running LynxOS m68*-*-lynxos*
3074 AT&T 3b1/Unix pc m68*-att-*
3075 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3076 decstation mips-dec-* mips-little-*
3077 riscos mips-*-riscos* mips-*-sysv*
3078 sonymips mips-sony-*
3079 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3081 *** Changes in GDB 6.1.1:
3083 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3085 The TUI (Text-mode User Interface) is now built as part of a default
3086 GDB configuration. It is enabled by either selecting the TUI with the
3087 command line option "-i=tui" or by running the separate "gdbtui"
3088 program. For more information on the TUI, see the manual "Debugging
3091 * Pending breakpoint support (also included in GDB 6.1)
3093 Support has been added to allow you to specify breakpoints in shared
3094 libraries that have not yet been loaded. If a breakpoint location
3095 cannot be found, and the "breakpoint pending" option is set to auto,
3096 GDB queries you if you wish to make the breakpoint pending on a future
3097 shared-library load. If and when GDB resolves the breakpoint symbol,
3098 the pending breakpoint is removed as one or more regular breakpoints
3101 Pending breakpoints are very useful for GCJ Java debugging.
3103 * Fixed ISO-C build problems
3105 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3106 non ISO-C code that stopped them being built using a more strict ISO-C
3107 compiler (e.g., IBM's C compiler).
3109 * Fixed build problem on IRIX 5
3111 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3112 wasn't able to compile compile on an IRIX 5 system.
3114 * Added execute permission to gdb/gdbserver/configure
3116 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3117 permission. This bug would cause configure to fail on a number of
3118 systems (Solaris, IRIX). Ref: server/519.
3120 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3122 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3123 has been updated to use constant array sizes.
3125 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3127 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3128 its generated DWARF Call Frame Info. This encoding was causing GDB to
3129 panic, that panic has been fixed. Ref: gdb/1628.
3131 * Fixed a problem when examining parameters in shared library code.
3133 When examining parameters in optimized shared library code generated
3134 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3135 not available''. GDB now correctly displays the variable's value.
3137 *** Changes in GDB 6.1:
3139 * Removed --with-mmalloc
3141 Support for the mmalloc memory manager has been removed, as it
3142 conflicted with the internal gdb byte cache.
3144 * Changes in AMD64 configurations
3146 The AMD64 target now includes the %cs and %ss registers. As a result
3147 the AMD64 remote protocol has changed; this affects the floating-point
3148 and SSE registers. If you rely on those registers for your debugging,
3149 you should upgrade gdbserver on the remote side.
3151 * Revised SPARC target
3153 The SPARC target has been completely revised, incorporating the
3154 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3155 support for LynxOS and SunOS 4 has been dropped. Calling functions
3156 from within GDB on operating systems with a non-executable stack
3157 (Solaris, OpenBSD) now works.
3161 GDB has a new C++ demangler which does a better job on the mangled
3162 names generated by current versions of g++. It also runs faster, so
3163 with this and other changes gdb should now start faster on large C++
3166 * DWARF 2 Location Expressions
3168 GDB support for location expressions has been extended to support function
3169 arguments and frame bases. Older versions of GDB could crash when they
3172 * C++ nested types and namespaces
3174 GDB's support for nested types and namespaces in C++ has been
3175 improved, especially if you use the DWARF 2 debugging format. (This
3176 is the default for recent versions of GCC on most platforms.)
3177 Specifically, if you have a class "Inner" defined within a class or
3178 namespace "Outer", then GDB realizes that the class's name is
3179 "Outer::Inner", not simply "Inner". This should greatly reduce the
3180 frequency of complaints about not finding RTTI symbols. In addition,
3181 if you are stopped at inside of a function defined within a namespace,
3182 GDB modifies its name lookup accordingly.
3184 * New native configurations
3186 NetBSD/amd64 x86_64-*-netbsd*
3187 OpenBSD/amd64 x86_64-*-openbsd*
3188 OpenBSD/alpha alpha*-*-openbsd*
3189 OpenBSD/sparc sparc-*-openbsd*
3190 OpenBSD/sparc64 sparc64-*-openbsd*
3192 * New debugging protocols
3194 M32R with SDI protocol m32r-*-elf*
3196 * "set prompt-escape-char" command deleted.
3198 The command "set prompt-escape-char" has been deleted. This command,
3199 and its very obscure effet on GDB's prompt, was never documented,
3200 tested, nor mentioned in the NEWS file.
3202 * OBSOLETE configurations and files
3204 Configurations that have been declared obsolete in this release have
3205 been commented out. Unless there is activity to revive these
3206 configurations, the next release of GDB will have their sources
3207 permanently REMOVED.
3209 Sun 3, running SunOS 3 m68*-*-sunos3*
3210 Sun 3, running SunOS 4 m68*-*-sunos4*
3211 Sun 2, running SunOS 3 m68000-*-sunos3*
3212 Sun 2, running SunOS 4 m68000-*-sunos4*
3213 Motorola 680x0 running LynxOS m68*-*-lynxos*
3214 AT&T 3b1/Unix pc m68*-att-*
3215 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3216 decstation mips-dec-* mips-little-*
3217 riscos mips-*-riscos* mips-*-sysv*
3218 sonymips mips-sony-*
3219 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3221 * REMOVED configurations and files
3223 SGI Irix-4.x mips-sgi-irix4 or iris4
3224 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3225 Z8000 simulator z8k-zilog-none or z8ksim
3226 Matsushita MN10200 w/simulator mn10200-*-*
3227 H8/500 simulator h8500-hitachi-hms or h8500hms
3228 HP/PA running BSD hppa*-*-bsd*
3229 HP/PA running OSF/1 hppa*-*-osf*
3230 HP/PA Pro target hppa*-*-pro*
3231 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3232 386BSD i[3456]86-*-bsd*
3233 Sequent family i[3456]86-sequent-sysv4*
3234 i[3456]86-sequent-sysv*
3235 i[3456]86-sequent-bsd*
3236 SPARC running LynxOS sparc-*-lynxos*
3237 SPARC running SunOS 4 sparc-*-sunos4*
3238 Tsqware Sparclet sparclet-*-*
3239 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3241 *** Changes in GDB 6.0:
3245 Support for debugging the Objective-C programming language has been
3246 integrated into GDB.
3248 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3250 DWARF 2's Call Frame Information makes available compiler generated
3251 information that more exactly describes the program's run-time stack.
3252 By using this information, GDB is able to provide more robust stack
3255 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3256 have been updated to use a new backtrace mechanism which includes
3257 DWARF 2 CFI support.
3261 GDB's remote protocol has been extended to include support for hosted
3262 file I/O (where the remote target uses GDB's file system). See GDB's
3263 remote protocol documentation for details.
3265 * All targets using the new architecture framework.
3267 All of GDB's targets have been updated to use the new internal
3268 architecture framework. The way is now open for future GDB releases
3269 to include cross-architecture native debugging support (i386 on amd64,
3272 * GNU/Linux's Thread Local Storage (TLS)
3274 GDB now includes support for for the GNU/Linux implementation of
3275 per-thread variables.
3277 * GNU/Linux's Native POSIX Thread Library (NPTL)
3279 GDB's thread code has been updated to work with either the new
3280 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3282 * Separate debug info.
3284 GDB, in conjunction with BINUTILS, now supports a mechanism for
3285 automatically loading debug information from a separate file. Instead
3286 of shipping full debug and non-debug versions of system libraries,
3287 system integrators can now instead ship just the stripped libraries
3288 and optional debug files.
3290 * DWARF 2 Location Expressions
3292 DWARF 2 Location Expressions allow the compiler to more completely
3293 describe the location of variables (even in optimized code) to the
3296 GDB now includes preliminary support for location expressions (support
3297 for DW_OP_piece is still missing).
3301 A number of long standing bugs that caused GDB to die while starting a
3302 Java application have been fixed. GDB's Java support is now
3303 considered "useable".
3305 * GNU/Linux support for fork, vfork, and exec.
3307 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3308 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3311 * GDB supports logging output to a file
3313 There are two new commands, "set logging" and "show logging", which can be
3314 used to capture GDB's output to a file.
3316 * The meaning of "detach" has changed for gdbserver
3318 The "detach" command will now resume the application, as documented. To
3319 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3322 * d10v, m68hc11 `regs' command deprecated
3324 The `info registers' command has been updated so that it displays the
3325 registers using a format identical to the old `regs' command.
3329 A new command, "maint set profile on/off", has been added. This command can
3330 be used to enable or disable profiling while running GDB, to profile a
3331 session or a set of commands. In addition there is a new configure switch,
3332 "--enable-profiling", which will cause GDB to be compiled with profiling
3333 data, for more informative profiling results.
3335 * Default MI syntax changed to "mi2".
3337 The default MI (machine interface) syntax, enabled by the command line
3338 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3339 "mi1", can be enabled by specifying the option "-i=mi1".
3341 Support for the original "mi0" syntax (included in GDB 5.0) has been
3344 Fix for gdb/192: removed extraneous space when displaying frame level.
3345 Fix for gdb/672: update changelist is now output in mi list format.
3346 Fix for gdb/702: a -var-assign that updates the value now shows up
3347 in a subsequent -var-update.
3349 * New native configurations.
3351 FreeBSD/amd64 x86_64-*-freebsd*
3353 * Multi-arched targets.
3355 HP/PA HPUX11 hppa*-*-hpux*
3356 Renesas M32R/D w/simulator m32r-*-elf*
3358 * OBSOLETE configurations and files
3360 Configurations that have been declared obsolete in this release have
3361 been commented out. Unless there is activity to revive these
3362 configurations, the next release of GDB will have their sources
3363 permanently REMOVED.
3365 Z8000 simulator z8k-zilog-none or z8ksim
3366 Matsushita MN10200 w/simulator mn10200-*-*
3367 H8/500 simulator h8500-hitachi-hms or h8500hms
3368 HP/PA running BSD hppa*-*-bsd*
3369 HP/PA running OSF/1 hppa*-*-osf*
3370 HP/PA Pro target hppa*-*-pro*
3371 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3372 Sequent family i[3456]86-sequent-sysv4*
3373 i[3456]86-sequent-sysv*
3374 i[3456]86-sequent-bsd*
3375 Tsqware Sparclet sparclet-*-*
3376 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3378 * REMOVED configurations and files
3381 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3382 IBM AIX PS/2 i[3456]86-*-aix
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 Argonaut Risc Chip (ARC) arc-*-*
3390 Mitsubishi D30V d30v-*-*
3391 Fujitsu FR30 fr30-*-elf*
3392 OS/9000 i[34]86-*-os9k
3393 I960 with MON960 i960-*-coff
3395 * MIPS $fp behavior changed
3397 The convenience variable $fp, for the MIPS, now consistently returns
3398 the address of the current frame's base. Previously, depending on the
3399 context, $fp could refer to either $sp or the current frame's base
3400 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3401 The GNU Source-Level Debugger''.
3403 *** Changes in GDB 5.3:
3405 * GNU/Linux shared library multi-threaded performance improved.
3407 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3408 `/proc', in preference to `ptrace' for memory reads. This may result
3409 in an improvement in the start-up time of multi-threaded, shared
3410 library applications when run under GDB. One GDB user writes: ``loads
3411 shared libs like mad''.
3413 * ``gdbserver'' now supports multi-threaded applications on some targets
3415 Support for debugging multi-threaded applications which use
3416 the GNU/Linux LinuxThreads package has been added for
3417 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3418 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3420 * GDB now supports C/C++ preprocessor macros.
3422 GDB now expands preprocessor macro invocations in C/C++ expressions,
3423 and provides various commands for showing macro definitions and how
3426 The new command `macro expand EXPRESSION' expands any macro
3427 invocations in expression, and shows the result.
3429 The new command `show macro MACRO-NAME' shows the definition of the
3430 macro named MACRO-NAME, and where it was defined.
3432 Most compilers don't include information about macros in the debugging
3433 information by default. In GCC 3.1, for example, you need to compile
3434 your program with the options `-gdwarf-2 -g3'. If the macro
3435 information is present in the executable, GDB will read it.
3437 * Multi-arched targets.
3439 DEC Alpha (partial) alpha*-*-*
3440 DEC VAX (partial) vax-*-*
3442 National Semiconductor NS32000 (partial) ns32k-*-*
3443 Motorola 68000 (partial) m68k-*-*
3444 Motorola MCORE mcore-*-*
3448 Fujitsu FRV architecture added by Red Hat frv*-*-*
3451 * New native configurations
3453 Alpha NetBSD alpha*-*-netbsd*
3454 SH NetBSD sh*-*-netbsdelf*
3455 MIPS NetBSD mips*-*-netbsd*
3456 UltraSPARC NetBSD sparc64-*-netbsd*
3458 * OBSOLETE configurations and files
3460 Configurations that have been declared obsolete in this release have
3461 been commented out. Unless there is activity to revive these
3462 configurations, the next release of GDB will have their sources
3463 permanently REMOVED.
3465 Mitsubishi D30V d30v-*-*
3466 OS/9000 i[34]86-*-os9k
3467 IBM AIX PS/2 i[3456]86-*-aix
3468 Fujitsu FR30 fr30-*-elf*
3469 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3470 Argonaut Risc Chip (ARC) arc-*-*
3471 i386 running Mach 3.0 i[3456]86-*-mach3*
3472 i386 running Mach i[3456]86-*-mach*
3473 i386 running OSF/1 i[3456]86-*osf1mk*
3474 HP/Apollo 68k Family m68*-apollo*-sysv*,
3476 m68*-hp-bsd*, m68*-hp-hpux*
3477 I960 with MON960 i960-*-coff
3479 * OBSOLETE languages
3481 CHILL, a Pascal like language used by telecommunications companies.
3483 * REMOVED configurations and files
3485 AMD 29k family via UDI a29k-amd-udi, udi29k
3486 A29K VxWorks a29k-*-vxworks
3487 AMD 29000 embedded, using EBMON a29k-none-none
3488 AMD 29000 embedded with COFF a29k-none-coff
3489 AMD 29000 embedded with a.out a29k-none-aout
3491 testsuite/gdb.hp/gdb.threads-hp/ directory
3493 * New command "set max-user-call-depth <nnn>"
3495 This command allows the user to limit the call depth of user-defined
3496 commands. The default is 1024.
3498 * Changes in FreeBSD/i386 native debugging.
3500 Support for the "generate-core-file" has been added.
3502 * New commands "dump", "append", and "restore".
3504 These commands allow data to be copied from target memory
3505 to a bfd-format or binary file (dump and append), and back
3506 from a file into memory (restore).
3508 * Improved "next/step" support on multi-processor Alpha Tru64.
3510 The previous single-step mechanism could cause unpredictable problems,
3511 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3512 of a software single-step mechanism prevents this.
3514 *** Changes in GDB 5.2.1:
3522 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3523 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3524 Fix, by Joel Brobecker imported from mainline.
3526 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3527 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3528 Fix, by Fred Fish, imported from mainline.
3530 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3531 Surprisingly enough, it works now.
3532 By Michal Ludvig, imported from mainline.
3534 i386 hardware watchpoint support:
3535 avoid misses on second run for some targets.
3536 By Pierre Muller, imported from mainline.
3538 *** Changes in GDB 5.2:
3540 * New command "set trust-readonly-sections on[off]".
3542 This command is a hint that tells gdb that read-only sections
3543 really are read-only (ie. that their contents will not change).
3544 In this mode, gdb will go to the object file rather than the
3545 target to read memory from read-only sections (such as ".text").
3546 This can be a significant performance improvement on some
3547 (notably embedded) targets.
3549 * New command "generate-core-file" (or "gcore").
3551 This new gdb command allows the user to drop a core file of the child
3552 process state at any time. So far it's been implemented only for
3553 GNU/Linux and Solaris, but should be relatively easily ported to other
3554 hosts. Argument is core file name (defaults to core.<pid>).
3556 * New command line option
3558 GDB now accepts --pid or -p followed by a process id.
3560 * Change in command line behavior -- corefiles vs. process ids.
3562 There is a subtle behavior in the way in which GDB handles
3563 command line arguments. The first non-flag argument is always
3564 a program to debug, but the second non-flag argument may either
3565 be a corefile or a process id. Previously, GDB would attempt to
3566 open the second argument as a corefile, and if that failed, would
3567 issue a superfluous error message and then attempt to attach it as
3568 a process. Now, if the second argument begins with a non-digit,
3569 it will be treated as a corefile. If it begins with a digit,
3570 GDB will attempt to attach it as a process, and if no such process
3571 is found, will then attempt to open it as a corefile.
3573 * Changes in ARM configurations.
3575 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3576 configuration is fully multi-arch.
3578 * New native configurations
3580 ARM NetBSD arm*-*-netbsd*
3581 x86 OpenBSD i[3456]86-*-openbsd*
3582 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3583 Sparc64 running FreeBSD sparc64-*-freebsd*
3587 Sanyo XStormy16 xstormy16-elf
3589 * OBSOLETE configurations and files
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 AMD 29k family via UDI a29k-amd-udi, udi29k
3597 A29K VxWorks a29k-*-vxworks
3598 AMD 29000 embedded, using EBMON a29k-none-none
3599 AMD 29000 embedded with COFF a29k-none-coff
3600 AMD 29000 embedded with a.out a29k-none-aout
3602 testsuite/gdb.hp/gdb.threads-hp/ directory
3604 * REMOVED configurations and files
3606 TI TMS320C80 tic80-*-*
3608 PowerPC Solaris powerpcle-*-solaris*
3609 PowerPC Windows NT powerpcle-*-cygwin32
3610 PowerPC Netware powerpc-*-netware*
3611 Harris/CXUX m88k m88*-harris-cxux*
3612 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3613 ns32k-utek-sysv* ns32k-utek-*
3614 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3615 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3616 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3617 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3618 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3620 * Changes to command line processing
3622 The new `--args' feature can be used to specify command-line arguments
3623 for the inferior from gdb's command line.
3625 * Changes to key bindings
3627 There is a new `operate-and-get-next' function bound to `C-o'.
3629 *** Changes in GDB 5.1.1
3631 Fix compile problem on DJGPP.
3633 Fix a problem with floating-point registers on the i386 being
3636 Fix to stop GDB crashing on .debug_str debug info.
3638 Numerous documentation fixes.
3640 Numerous testsuite fixes.
3642 *** Changes in GDB 5.1:
3644 * New native configurations
3646 Alpha FreeBSD alpha*-*-freebsd*
3647 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3648 MIPS GNU/Linux mips*-*-linux*
3649 MIPS SGI Irix 6.x mips*-sgi-irix6*
3650 ia64 AIX ia64-*-aix*
3651 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3655 Motorola 68HC11 and 68HC12 m68hc11-elf
3657 UltraSparc running GNU/Linux sparc64-*-linux*
3659 * OBSOLETE configurations and files
3661 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3662 Harris/CXUX m88k m88*-harris-cxux*
3663 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3664 ns32k-utek-sysv* ns32k-utek-*
3665 TI TMS320C80 tic80-*-*
3667 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3668 PowerPC Solaris powerpcle-*-solaris*
3669 PowerPC Windows NT powerpcle-*-cygwin32
3670 PowerPC Netware powerpc-*-netware*
3671 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3672 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3673 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3674 Apple Macintosh (MPW) host N/A
3676 stuff.c (Program to stuff files into a specially prepared space in kdb)
3677 kdb-start.c (Main loop for the standalone kernel debugger)
3679 Configurations that have been declared obsolete in this release have
3680 been commented out. Unless there is activity to revive these
3681 configurations, the next release of GDB will have their sources
3682 permanently REMOVED.
3684 * REMOVED configurations and files
3686 Altos 3068 m68*-altos-*
3687 Convex c1-*-*, c2-*-*
3689 ARM RISCix arm-*-* (as host)
3693 * GDB has been converted to ISO C.
3695 GDB's source code has been converted to ISO C. In particular, the
3696 sources are fully protoized, and rely on standard headers being
3701 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3703 * The MI enabled by default.
3705 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3706 revised and enabled by default. Packages which use GDB as a debugging
3707 engine behind a UI or another front end are encouraged to switch to
3708 using the GDB/MI interface, instead of the old annotations interface
3709 which is now deprecated.
3711 * Support for debugging Pascal programs.
3713 GDB now includes support for debugging Pascal programs. The following
3714 main features are supported:
3716 - Pascal-specific data types such as sets;
3718 - automatic recognition of Pascal sources based on file-name
3721 - Pascal-style display of data types, variables, and functions;
3723 - a Pascal expression parser.
3725 However, some important features are not yet supported.
3727 - Pascal string operations are not supported at all;
3729 - there are some problems with boolean types;
3731 - Pascal type hexadecimal constants are not supported
3732 because they conflict with the internal variables format;
3734 - support for Pascal objects and classes is not full yet;
3736 - unlike Pascal, GDB is case-sensitive for symbol names.
3738 * Changes in completion.
3740 Commands such as `shell', `run' and `set args', which pass arguments
3741 to inferior programs, now complete on file names, similar to what
3742 users expect at the shell prompt.
3744 Commands which accept locations, such as `disassemble', `print',
3745 `breakpoint', `until', etc. now complete on filenames as well as
3746 program symbols. Thus, if you type "break foob TAB", and the source
3747 files linked into the programs include `foobar.c', that file name will
3748 be one of the candidates for completion. However, file names are not
3749 considered for completion after you typed a colon that delimits a file
3750 name from a name of a function in that file, as in "break foo.c:bar".
3752 `set demangle-style' completes on available demangling styles.
3754 * New platform-independent commands:
3756 It is now possible to define a post-hook for a command as well as a
3757 hook that runs before the command. For more details, see the
3758 documentation of `hookpost' in the GDB manual.
3760 * Changes in GNU/Linux native debugging.
3762 Support for debugging multi-threaded programs has been completely
3763 revised for all platforms except m68k and sparc. You can now debug as
3764 many threads as your system allows you to have.
3766 Attach/detach is supported for multi-threaded programs.
3768 Support for SSE registers was added for x86. This doesn't work for
3769 multi-threaded programs though.
3771 * Changes in MIPS configurations.
3773 Multi-arch support is enabled for all MIPS configurations.
3775 GDB can now be built as native debugger on SGI Irix 6.x systems for
3776 debugging n32 executables. (Debugging 64-bit executables is not yet
3779 * Unified support for hardware watchpoints in all x86 configurations.
3781 Most (if not all) native x86 configurations support hardware-assisted
3782 breakpoints and watchpoints in a unified manner. This support
3783 implements debug register sharing between watchpoints, which allows to
3784 put a virtually infinite number of watchpoints on the same address,
3785 and also supports watching regions up to 16 bytes with several debug
3788 The new maintenance command `maintenance show-debug-regs' toggles
3789 debugging print-outs in functions that insert, remove, and test
3790 watchpoints and hardware breakpoints.
3792 * Changes in the DJGPP native configuration.
3794 New command ``info dos sysinfo'' displays assorted information about
3795 the CPU, OS, memory, and DPMI server.
3797 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3798 display information about segment descriptors stored in GDT, LDT, and
3801 New commands ``info dos pde'' and ``info dos pte'' display entries
3802 from Page Directory and Page Tables (for now works with CWSDPMI only).
3803 New command ``info dos address-pte'' displays the Page Table entry for
3804 a given linear address.
3806 GDB can now pass command lines longer than 126 characters to the
3807 program being debugged (requires an update to the libdbg.a library
3808 which is part of the DJGPP development kit).
3810 DWARF2 debug info is now supported.
3812 It is now possible to `step' and `next' through calls to `longjmp'.
3814 * Changes in documentation.
3816 All GDB documentation was converted to GFDL, the GNU Free
3817 Documentation License.
3819 Tracepoints-related commands are now fully documented in the GDB
3822 TUI, the Text-mode User Interface, is now documented in the manual.
3824 Tracepoints-related commands are now fully documented in the GDB
3827 The "GDB Internals" manual now has an index. It also includes
3828 documentation of `ui_out' functions, GDB coding standards, x86
3829 hardware watchpoints, and memory region attributes.
3831 * GDB's version number moved to ``version.in''
3833 The Makefile variable VERSION has been replaced by the file
3834 ``version.in''. People creating GDB distributions should update the
3835 contents of this file.
3839 GUD support is now a standard part of the EMACS distribution.
3841 *** Changes in GDB 5.0:
3843 * Improved support for debugging FP programs on x86 targets
3845 Unified and much-improved support for debugging floating-point
3846 programs on all x86 targets. In particular, ``info float'' now
3847 displays the FP registers in the same format on all x86 targets, with
3848 greater level of detail.
3850 * Improvements and bugfixes in hardware-assisted watchpoints
3852 It is now possible to watch array elements, struct members, and
3853 bitfields with hardware-assisted watchpoints. Data-read watchpoints
3854 on x86 targets no longer erroneously trigger when the address is
3857 * Improvements in the native DJGPP version of GDB
3859 The distribution now includes all the scripts and auxiliary files
3860 necessary to build the native DJGPP version on MS-DOS/MS-Windows
3861 machines ``out of the box''.
3863 The DJGPP version can now debug programs that use signals. It is
3864 possible to catch signals that happened in the debuggee, deliver
3865 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
3866 would kill the program being debugged.) Programs that hook hardware
3867 interrupts (keyboard, timer, etc.) can also be debugged.
3869 It is now possible to debug DJGPP programs that redirect their
3870 standard handles or switch them to raw (as opposed to cooked) mode, or
3871 even close them. The command ``run < foo > bar'' works as expected,
3872 and ``info terminal'' reports useful information about the debuggee's
3873 terminal, including raw/cooked mode, redirection, etc.
3875 The DJGPP version now uses termios functions for console I/O, which
3876 enables debugging graphics programs. Interrupting GDB with Ctrl-C
3879 DOS-style file names with drive letters are now fully supported by
3882 It is now possible to debug DJGPP programs that switch their working
3883 directory. It is also possible to rerun the debuggee any number of
3884 times without restarting GDB; thus, you can use the same setup,
3885 breakpoints, etc. for many debugging sessions.
3887 * New native configurations
3889 ARM GNU/Linux arm*-*-linux*
3890 PowerPC GNU/Linux powerpc-*-linux*
3894 Motorola MCore mcore-*-*
3895 x86 VxWorks i[3456]86-*-vxworks*
3896 PowerPC VxWorks powerpc-*-vxworks*
3897 TI TMS320C80 tic80-*-*
3899 * OBSOLETE configurations
3901 Altos 3068 m68*-altos-*
3902 Convex c1-*-*, c2-*-*
3904 ARM RISCix arm-*-* (as host)
3907 Configurations that have been declared obsolete will be commented out,
3908 but the code will be left in place. If there is no activity to revive
3909 these configurations before the next release of GDB, the sources will
3910 be permanently REMOVED.
3912 * Gould support removed
3914 Support for the Gould PowerNode and NP1 has been removed.
3916 * New features for SVR4
3918 On SVR4 native platforms (such as Solaris), if you attach to a process
3919 without first loading a symbol file, GDB will now attempt to locate and
3920 load symbols from the running process's executable file.
3922 * Many C++ enhancements
3924 C++ support has been greatly improved. Overload resolution now works properly
3925 in almost all cases. RTTI support is on the way.
3927 * Remote targets can connect to a sub-program
3929 A popen(3) style serial-device has been added. This device starts a
3930 sub-process (such as a stand-alone simulator) and then communicates
3931 with that. The sub-program to run is specified using the syntax
3932 ``|<program> <args>'' vis:
3934 (gdb) set remotedebug 1
3935 (gdb) target extended-remote |mn10300-elf-sim program-args
3937 * MIPS 64 remote protocol
3939 A long standing bug in the mips64 remote protocol where by GDB
3940 expected certain 32 bit registers (ex SR) to be transfered as 32
3941 instead of 64 bits has been fixed.
3943 The command ``set remote-mips64-transfers-32bit-regs on'' has been
3944 added to provide backward compatibility with older versions of GDB.
3946 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
3948 The command ``set remotebinarydownload'' command has been replaced by
3949 ``set remote X-packet''. Other commands in ``set remote'' family
3950 include ``set remote P-packet''.
3952 * Breakpoint commands accept ranges.
3954 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
3955 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
3956 ``tracepoint passcount'' also accepts a range of tracepoints.
3958 * ``apropos'' command added.
3960 The ``apropos'' command searches through command names and
3961 documentation strings, printing out matches, making it much easier to
3962 try to find a command that does what you are looking for.
3966 A new machine oriented interface (MI) has been added to GDB. This
3967 interface is designed for debug environments running GDB as a separate
3968 process. This is part of the long term libGDB project. See the
3969 "GDB/MI" chapter of the GDB manual for further information. It can be
3970 enabled by configuring with:
3972 .../configure --enable-gdbmi
3974 *** Changes in GDB-4.18:
3976 * New native configurations
3978 HP-UX 10.20 hppa*-*-hpux10.20
3979 HP-UX 11.x hppa*-*-hpux11.0*
3980 M68K GNU/Linux m68*-*-linux*
3984 Fujitsu FR30 fr30-*-elf*
3985 Intel StrongARM strongarm-*-*
3986 Mitsubishi D30V d30v-*-*
3988 * OBSOLETE configurations
3990 Gould PowerNode, NP1 np1-*-*, pn-*-*
3992 Configurations that have been declared obsolete will be commented out,
3993 but the code will be left in place. If there is no activity to revive
3994 these configurations before the next release of GDB, the sources will
3995 be permanently REMOVED.
3999 As a compatibility experiment, GDB's source files buildsym.h and
4000 buildsym.c have been converted to pure standard C, no longer
4001 containing any K&R compatibility code. We believe that all systems in
4002 use today either come with a standard C compiler, or have a GCC port
4003 available. If this is not true, please report the affected
4004 configuration to bug-gdb@gnu.org immediately. See the README file for
4005 information about getting a standard C compiler if you don't have one
4010 GDB now uses readline 2.2.
4012 * set extension-language
4014 You can now control the mapping between filename extensions and source
4015 languages by using the `set extension-language' command. For instance,
4016 you can ask GDB to treat .c files as C++ by saying
4017 set extension-language .c c++
4018 The command `info extensions' lists all of the recognized extensions
4019 and their associated languages.
4021 * Setting processor type for PowerPC and RS/6000
4023 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4024 you can use the `set processor' command to specify what variant of the
4025 PowerPC family you are debugging. The command
4029 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4030 following PowerPC and RS6000 variants:
4032 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4033 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4035 403GC IBM PowerPC 403GC
4036 505 Motorola PowerPC 505
4037 860 Motorola PowerPC 860 or 850
4038 601 Motorola PowerPC 601
4039 602 Motorola PowerPC 602
4040 603 Motorola/IBM PowerPC 603 or 603e
4041 604 Motorola PowerPC 604 or 604e
4042 750 Motorola/IBM PowerPC 750 or 750
4044 At the moment, this command just tells GDB what to name the
4045 special-purpose processor registers. Since almost all the affected
4046 registers are inaccessible to user-level programs, this command is
4047 only useful for remote debugging in its present form.
4051 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4052 more extensive support for HP-UX. Added features include shared
4053 library support, kernel threads and hardware watchpoints for 11.00,
4054 support for HP's ANSI C and C++ compilers, and a compatibility mode
4055 for xdb and dbx commands.
4059 HP's donation includes the new concept of catchpoints, which is a
4060 generalization of the old catch command. On HP-UX, it is now possible
4061 to catch exec, fork, and vfork, as well as library loading.
4063 This means that the existing catch command has changed; its first
4064 argument now specifies the type of catch to be set up. See the
4065 output of "help catch" for a list of catchpoint types.
4067 * Debugging across forks
4069 On HP-UX, you can choose which process to debug when a fork() happens
4074 HP has donated a curses-based terminal user interface (TUI). To get
4075 it, build with --enable-tui. Although this can be enabled for any
4076 configuration, at present it only works for native HP debugging.
4078 * GDB remote protocol additions
4080 A new protocol packet 'X' that writes binary data is now available.
4081 Default behavior is to try 'X', then drop back to 'M' if the stub
4082 fails to respond. The settable variable `remotebinarydownload'
4083 allows explicit control over the use of 'X'.
4085 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4086 full 64-bit address. The command
4088 set remoteaddresssize 32
4090 can be used to revert to the old behaviour. For existing remote stubs
4091 the change should not be noticed, as the additional address information
4094 In order to assist in debugging stubs, you may use the maintenance
4095 command `packet' to send any text string to the stub. For instance,
4097 maint packet heythere
4099 sends the packet "$heythere#<checksum>". Note that it is very easy to
4100 disrupt a debugging session by sending the wrong packet at the wrong
4103 The compare-sections command allows you to compare section data on the
4104 target to what is in the executable file without uploading or
4105 downloading, by comparing CRC checksums.
4107 * Tracing can collect general expressions
4109 You may now collect general expressions at tracepoints. This requires
4110 further additions to the target-side stub; see tracepoint.c and
4111 doc/agentexpr.texi for further details.
4113 * mask-address variable for Mips
4115 For Mips targets, you may control the zeroing of the upper 32 bits of
4116 a 64-bit address by entering `set mask-address on'. This is mainly
4117 of interest to users of embedded R4xxx and R5xxx processors.
4119 * Higher serial baud rates
4121 GDB's serial code now allows you to specify baud rates 57600, 115200,
4122 230400, and 460800 baud. (Note that your host system may not be able
4123 to achieve all of these rates.)
4127 The i960 configuration now includes an initial implementation of a
4128 builtin simulator, contributed by Jim Wilson.
4131 *** Changes in GDB-4.17:
4133 * New native configurations
4135 Alpha GNU/Linux alpha*-*-linux*
4136 Unixware 2.x i[3456]86-unixware2*
4137 Irix 6.x mips*-sgi-irix6*
4138 PowerPC GNU/Linux powerpc-*-linux*
4139 PowerPC Solaris powerpcle-*-solaris*
4140 Sparc GNU/Linux sparc-*-linux*
4141 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4145 Argonaut Risc Chip (ARC) arc-*-*
4146 Hitachi H8/300S h8300*-*-*
4147 Matsushita MN10200 w/simulator mn10200-*-*
4148 Matsushita MN10300 w/simulator mn10300-*-*
4149 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4150 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4151 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4152 Mitsubishi D10V w/simulator d10v-*-*
4153 Mitsubishi M32R/D w/simulator m32r-*-elf*
4154 Tsqware Sparclet sparclet-*-*
4155 NEC V850 w/simulator v850-*-*
4157 * New debugging protocols
4159 ARM with RDI protocol arm*-*-*
4160 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4161 DDB and LSI variants of PMON protocol mips*-*-*
4162 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4163 PowerPC with SDS protocol powerpc{,le}-*-eabi
4164 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4168 All configurations can now understand and use the DWARF 2 debugging
4169 format. The choice is automatic, if the symbol file contains DWARF 2
4174 GDB now includes basic Java language support. This support is
4175 only useful with Java compilers that produce native machine code.
4177 * solib-absolute-prefix and solib-search-path
4179 For SunOS and SVR4 shared libraries, you may now set the prefix for
4180 loading absolute shared library symbol files, and the search path for
4181 locating non-absolute shared library symbol files.
4183 * Live range splitting
4185 GDB can now effectively debug code for which GCC has performed live
4186 range splitting as part of its optimization. See gdb/doc/LRS for
4187 more details on the expected format of the stabs information.
4191 GDB's support for the GNU Hurd, including thread debugging, has been
4192 updated to work with current versions of the Hurd.
4196 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4197 instruction set. ARM GDB automatically detects when Thumb
4198 instructions are in use, and adjusts disassembly and backtracing
4203 GDB's MIPS target configurations now handle the MIP16 16-bit
4208 GDB now includes support for overlays; if an executable has been
4209 linked such that multiple sections are based at the same address, GDB
4210 will decide which section to use for symbolic info. You can choose to
4211 control the decision manually, using overlay commands, or implement
4212 additional target-side support and use "overlay load-target" to bring
4213 in the overlay mapping. Do "help overlay" for more detail.
4217 The command "info symbol <address>" displays information about
4218 the symbol at the specified address.
4222 The standard remote protocol now includes an extension that allows
4223 asynchronous collection and display of trace data. This requires
4224 extensive support in the target-side debugging stub. Tracing mode
4225 includes a new interaction mode in GDB and new commands: see the
4226 file tracepoint.c for more details.
4230 Configurations for embedded MIPS now include a simulator contributed
4231 by Cygnus Solutions. The simulator supports the instruction sets
4232 of most MIPS variants.
4236 Sparc configurations may now include the ERC32 simulator contributed
4237 by the European Space Agency. The simulator is not built into
4238 Sparc targets by default; configure with --enable-sim to include it.
4242 For target configurations that may include multiple variants of a
4243 basic architecture (such as MIPS and SH), you may now set the
4244 architecture explicitly. "set arch" sets, "info arch" lists
4245 the possible architectures.
4247 *** Changes in GDB-4.16:
4249 * New native configurations
4251 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4252 M68K NetBSD m68k-*-netbsd*
4253 PowerPC AIX 4.x powerpc-*-aix*
4254 PowerPC MacOS powerpc-*-macos*
4255 PowerPC Windows NT powerpcle-*-cygwin32
4256 RS/6000 AIX 4.x rs6000-*-aix4*
4260 ARM with RDP protocol arm-*-*
4261 I960 with MON960 i960-*-coff
4262 MIPS VxWorks mips*-*-vxworks*
4263 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4264 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4266 Matra Sparclet sparclet-*-*
4270 The powerpc-eabi configuration now includes the PSIM simulator,
4271 contributed by Andrew Cagney, with assistance from Mike Meissner.
4272 PSIM is a very elaborate model of the PowerPC, including not only
4273 basic instruction set execution, but also details of execution unit
4274 performance and I/O hardware. See sim/ppc/README for more details.
4278 GDB now works with Solaris 2.5.
4280 * Windows 95/NT native
4282 GDB will now work as a native debugger on Windows 95 and Windows NT.
4283 To build it from source, you must use the "gnu-win32" environment,
4284 which uses a DLL to emulate enough of Unix to run the GNU tools.
4285 Further information, binaries, and sources are available at
4286 ftp.cygnus.com, under pub/gnu-win32.
4288 * dont-repeat command
4290 If a user-defined command includes the command `dont-repeat', then the
4291 command will not be repeated if the user just types return. This is
4292 useful if the command is time-consuming to run, so that accidental
4293 extra keystrokes don't run the same command many times.
4295 * Send break instead of ^C
4297 The standard remote protocol now includes an option to send a break
4298 rather than a ^C to the target in order to interrupt it. By default,
4299 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4301 * Remote protocol timeout
4303 The standard remote protocol includes a new variable `remotetimeout'
4304 that allows you to set the number of seconds before GDB gives up trying
4305 to read from the target. The default value is 2.
4307 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4309 By default GDB will automatically keep track of objects as they are
4310 loaded and unloaded by the dynamic linker. By using the command `set
4311 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4312 when shared library events occur, thus allowing you to set breakpoints
4313 in shared libraries which are explicitly loaded by the inferior.
4315 Note this feature does not work on hpux8. On hpux9 you must link
4316 /usr/lib/end.o into your program. This feature should work
4317 automatically on hpux10.
4319 * Irix 5.x hardware watchpoint support
4321 Irix 5 configurations now support the use of hardware watchpoints.
4323 * Mips protocol "SYN garbage limit"
4325 When debugging a Mips target using the `target mips' protocol, you
4326 may set the number of characters that GDB will ignore by setting
4327 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4328 every character. The default value is 1050.
4330 * Recording and replaying remote debug sessions
4332 If you set `remotelogfile' to the name of a file, gdb will write to it
4333 a recording of a remote debug session. This recording may then be
4334 replayed back to gdb using "gdbreplay". See gdbserver/README for
4335 details. This is useful when you have a problem with GDB while doing
4336 remote debugging; you can make a recording of the session and send it
4337 to someone else, who can then recreate the problem.
4339 * Speedups for remote debugging
4341 GDB includes speedups for downloading and stepping MIPS systems using
4342 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4343 and more efficient S-record downloading.
4345 * Memory use reductions and statistics collection
4347 GDB now uses less memory and reports statistics about memory usage.
4348 Try the `maint print statistics' command, for example.
4350 *** Changes in GDB-4.15:
4352 * Psymtabs for XCOFF
4354 The symbol reader for AIX GDB now uses partial symbol tables. This
4355 can greatly improve startup time, especially for large executables.
4357 * Remote targets use caching
4359 Remote targets now use a data cache to speed up communication with the
4360 remote side. The data cache could lead to incorrect results because
4361 it doesn't know about volatile variables, thus making it impossible to
4362 debug targets which use memory mapped I/O devices. `set remotecache
4363 off' turns the the data cache off.
4365 * Remote targets may have threads
4367 The standard remote protocol now includes support for multiple threads
4368 in the target system, using new protocol commands 'H' and 'T'. See
4369 gdb/remote.c for details.
4373 If GDB is configured with `--enable-netrom', then it will include
4374 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4375 acts as though it is a bank of ROM on the target board, but you can
4376 write into it over the network. GDB's support consists only of
4377 support for fast loading into the emulated ROM; to debug, you must use
4378 another protocol, such as standard remote protocol. The usual
4379 sequence is something like
4381 target nrom <netrom-hostname>
4383 target remote <netrom-hostname>:1235
4387 GDB now includes support for the Apple Macintosh, as a host only. It
4388 may be run as either an MPW tool or as a standalone application, and
4389 it can debug through the serial port. All the usual GDB commands are
4390 available, but to the target command, you must supply "serial" as the
4391 device type instead of "/dev/ttyXX". See mpw-README in the main
4392 directory for more information on how to build. The MPW configuration
4393 scripts */mpw-config.in support only a few targets, and only the
4394 mips-idt-ecoff target has been tested.
4398 GDB configuration now uses autoconf. This is not user-visible,
4399 but does simplify configuration and building.
4403 GDB now supports hpux10.
4405 *** Changes in GDB-4.14:
4407 * New native configurations
4409 x86 FreeBSD i[345]86-*-freebsd
4410 x86 NetBSD i[345]86-*-netbsd
4411 NS32k NetBSD ns32k-*-netbsd
4412 Sparc NetBSD sparc-*-netbsd
4416 A29K VxWorks a29k-*-vxworks
4417 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4418 CPU32 EST-300 emulator m68*-*-est*
4419 PowerPC ELF powerpc-*-elf
4422 * Alpha OSF/1 support for procfs
4424 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4425 possible to attach to running processes. As the mounting of the /proc
4426 filesystem is optional on the Alpha, GDB automatically determines
4427 the availability of /proc during startup. This can lead to problems
4428 if /proc is unmounted after GDB has been started.
4430 * Arguments to user-defined commands
4432 User commands may accept up to 10 arguments separated by whitespace.
4433 Arguments are accessed within the user command via $arg0..$arg9. A
4436 print $arg0 + $arg1 + $arg2
4438 To execute the command use:
4441 Defines the command "adder" which prints the sum of its three arguments.
4442 Note the arguments are text substitutions, so they may reference variables,
4443 use complex expressions, or even perform inferior function calls.
4445 * New `if' and `while' commands
4447 This makes it possible to write more sophisticated user-defined
4448 commands. Both commands take a single argument, which is the
4449 expression to evaluate, and must be followed by the commands to
4450 execute, one per line, if the expression is nonzero, the list being
4451 terminated by the word `end'. The `if' command list may include an
4452 `else' word, which causes the following commands to be executed only
4453 if the expression is zero.
4455 * Fortran source language mode
4457 GDB now includes partial support for Fortran 77. It will recognize
4458 Fortran programs and can evaluate a subset of Fortran expressions, but
4459 variables and functions may not be handled correctly. GDB will work
4460 with G77, but does not yet know much about symbols emitted by other
4463 * Better HPUX support
4465 Most debugging facilities now work on dynamic executables for HPPAs
4466 running hpux9 or later. You can attach to running dynamically linked
4467 processes, but by default the dynamic libraries will be read-only, so
4468 for instance you won't be able to put breakpoints in them. To change
4469 that behavior do the following before running the program:
4475 This will cause the libraries to be mapped private and read-write.
4476 To revert to the normal behavior, do this:
4482 You cannot set breakpoints or examine data in the library until after
4483 the library is loaded if the function/data symbols do not have
4486 GDB can now also read debug symbols produced by the HP C compiler on
4487 HPPAs (sorry, no C++, Fortran or 68k support).
4489 * Target byte order now dynamically selectable
4491 You can choose which byte order to use with a target system, via the
4492 commands "set endian big" and "set endian little", and you can see the
4493 current setting by using "show endian". You can also give the command
4494 "set endian auto", in which case GDB will use the byte order
4495 associated with the executable. Currently, only embedded MIPS
4496 configurations support dynamic selection of target byte order.
4498 * New DOS host serial code
4500 This version uses DPMI interrupts to handle buffered I/O, so you
4501 no longer need to run asynctsr when debugging boards connected to
4504 *** Changes in GDB-4.13:
4506 * New "complete" command
4508 This lists all the possible completions for the rest of the line, if it
4509 were to be given as a command itself. This is intended for use by emacs.
4511 * Trailing space optional in prompt
4513 "set prompt" no longer adds a space for you after the prompt you set. This
4514 allows you to set a prompt which ends in a space or one that does not.
4516 * Breakpoint hit counts
4518 "info break" now displays a count of the number of times the breakpoint
4519 has been hit. This is especially useful in conjunction with "ignore"; you
4520 can ignore a large number of breakpoint hits, look at the breakpoint info
4521 to see how many times the breakpoint was hit, then run again, ignoring one
4522 less than that number, and this will get you quickly to the last hit of
4525 * Ability to stop printing at NULL character
4527 "set print null-stop" will cause GDB to stop printing the characters of
4528 an array when the first NULL is encountered. This is useful when large
4529 arrays actually contain only short strings.
4531 * Shared library breakpoints
4533 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4534 breakpoints in shared libraries before the executable is run.
4536 * Hardware watchpoints
4538 There is a new hardware breakpoint for the watch command for sparclite
4539 targets. See gdb/sparclite/hw_breakpoint.note.
4541 Hardware watchpoints are also now supported under GNU/Linux.
4545 Annotations have been added. These are for use with graphical interfaces,
4546 and are still experimental. Currently only gdba.el uses these.
4548 * Improved Irix 5 support
4550 GDB now works properly with Irix 5.2.
4552 * Improved HPPA support
4554 GDB now works properly with the latest GCC and GAS.
4556 * New native configurations
4558 Sequent PTX4 i[34]86-sequent-ptx4
4559 HPPA running OSF/1 hppa*-*-osf*
4560 Atari TT running SVR4 m68*-*-sysv4*
4561 RS/6000 LynxOS rs6000-*-lynxos*
4565 OS/9000 i[34]86-*-os9k
4566 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4569 * Hitachi SH7000 and E7000-PC ICE support
4571 There is now support for communicating with the Hitachi E7000-PC ICE.
4572 This is available automatically when GDB is configured for the SH.
4576 As usual, a variety of small fixes and improvements, both generic
4577 and configuration-specific. See the ChangeLog for more detail.
4579 *** Changes in GDB-4.12:
4581 * Irix 5 is now supported
4585 GDB-4.12 on the HPPA has a number of changes which make it unable
4586 to debug the output from the currently released versions of GCC and
4587 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4588 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4589 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4592 *** Changes in GDB-4.11:
4594 * User visible changes:
4598 The "set remotedebug" option is now consistent between the mips remote
4599 target, remote targets using the gdb-specific protocol, UDI (AMD's
4600 debug protocol for the 29k) and the 88k bug monitor. It is now an
4601 integer specifying a debug level (normally 0 or 1, but 2 means more
4602 debugging info for the mips target).
4604 * DEC Alpha native support
4606 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4607 debug info, but GDB works fairly well with the DEC compiler and should
4608 work with a future GCC release. See the README file for a few
4609 Alpha-specific notes.
4611 * Preliminary thread implementation
4613 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4615 * LynxOS native and target support for 386
4617 This release has been hosted on LynxOS 2.2, and also can be configured
4618 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4621 * Improvements in C++ mangling/demangling.
4623 This release has much better g++ debugging, specifically in name
4624 mangling/demangling, virtual function calls, print virtual table,
4625 call methods, ...etc.
4627 *** Changes in GDB-4.10:
4629 * User visible changes:
4631 Remote debugging using the GDB-specific (`target remote') protocol now
4632 supports the `load' command. This is only useful if you have some
4633 other way of getting the stub to the target system, and you can put it
4634 somewhere in memory where it won't get clobbered by the download.
4636 Filename completion now works.
4638 When run under emacs mode, the "info line" command now causes the
4639 arrow to point to the line specified. Also, "info line" prints
4640 addresses in symbolic form (as well as hex).
4642 All vxworks based targets now support a user settable option, called
4643 vxworks-timeout. This option represents the number of seconds gdb
4644 should wait for responses to rpc's. You might want to use this if
4645 your vxworks target is, perhaps, a slow software simulator or happens
4646 to be on the far side of a thin network line.
4650 This release contains support for using a DEC alpha as a GDB host for
4651 cross debugging. Native alpha debugging is not supported yet.
4654 *** Changes in GDB-4.9:
4658 This is the first GDB release which is accompanied by a matching testsuite.
4659 The testsuite requires installation of dejagnu, which should be available
4660 via ftp from most sites that carry GNU software.
4664 'Cfront' style demangling has had its name changed to 'ARM' style, to
4665 emphasize that it was written from the specifications in the C++ Annotated
4666 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4667 disclaimers, it still generated too much confusion with users attempting to
4668 use gdb with AT&T cfront.
4672 GDB now uses a standard remote interface to a simulator library.
4673 So far, the library contains simulators for the Zilog Z8001/2, the
4674 Hitachi H8/300, H8/500 and Super-H.
4676 * New targets supported
4678 H8/300 simulator h8300-hitachi-hms or h8300hms
4679 H8/500 simulator h8500-hitachi-hms or h8500hms
4680 SH simulator sh-hitachi-hms or sh
4681 Z8000 simulator z8k-zilog-none or z8ksim
4682 IDT MIPS board over serial line mips-idt-ecoff
4684 Cross-debugging to GO32 targets is supported. It requires a custom
4685 version of the i386-stub.c module which is integrated with the
4686 GO32 memory extender.
4688 * New remote protocols
4690 MIPS remote debugging protocol.
4692 * New source languages supported
4694 This version includes preliminary support for Chill, a Pascal like language
4695 used by telecommunications companies. Chill support is also being integrated
4696 into the GNU compiler, but we don't know when it will be publically available.
4699 *** Changes in GDB-4.8:
4701 * HP Precision Architecture supported
4703 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4704 version of this support was available as a set of patches from the
4705 University of Utah. GDB does not support debugging of programs
4706 compiled with the HP compiler, because HP will not document their file
4707 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4708 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4710 Many problems in the preliminary version have been fixed.
4712 * Faster and better demangling
4714 We have improved template demangling and fixed numerous bugs in the GNU style
4715 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4716 character types (wchar_t) are now supported. Demangling of each symbol is now
4717 only done once, and is cached when the symbol table for a file is read in.
4718 This results in a small increase in memory usage for C programs, a moderate
4719 increase in memory usage for C++ programs, and a fantastic speedup in
4722 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4723 from the specifications in the Annotated Reference Manual, which AT&T's
4724 compiler does not actually implement.
4726 * G++ multiple inheritance compiler problem
4728 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4729 inheritance lattices was reworked to properly discover ambiguities. We
4730 recently found an example which causes this new algorithm to fail in a
4731 very subtle way, producing bad debug information for those classes.
4732 The file 'gcc.patch' (in this directory) can be applied to gcc to
4733 circumvent the problem. A future GCC release will contain a complete
4736 The previous G++ debug info problem (mentioned below for the gdb-4.7
4737 release) is fixed in gcc version 2.3.2.
4739 * Improved configure script
4741 The `configure' script will now attempt to guess your system type if
4742 you don't supply a host system type. The old scheme of supplying a
4743 host system triplet is preferable over using this. All the magic is
4744 done in the new `config.guess' script. Examine it for details.
4746 We have also brought our configure script much more in line with the FSF's
4747 version. It now supports the --with-xxx options. In particular,
4748 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4749 The resulting GDB will not be able to read arbitrary object file formats --
4750 only the format ``expected'' to be used on the configured target system.
4751 We hope to make this the default in a future release.
4753 * Documentation improvements
4755 There's new internal documentation on how to modify GDB, and how to
4756 produce clean changes to the code. We implore people to read it
4757 before submitting changes.
4759 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4760 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4761 `info' files are also provided. To build `info' files from scratch,
4762 you will need the latest `makeinfo' release, which will be available in
4763 a future texinfo-X.Y release.
4765 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4766 We're not sure exactly which versions have this problem, but it has
4767 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4768 or better. If that isn't possible, there is a patch in
4769 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4770 around this problem.
4774 GDB now supports array constants that can be used in expressions typed in by
4775 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4776 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4779 The new directory `gdb/sparclite' contains a program that demonstrates
4780 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4782 * New native hosts supported
4784 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4785 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4787 * New targets supported
4789 AMD 29k family via UDI a29k-amd-udi or udi29k
4791 * New file formats supported
4793 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4794 HPUX core files, and SCO 3.2v2 core files.
4798 Attaching to processes now works again; thanks for the many bug reports.
4800 We have also stomped on a bunch of core dumps caused by
4801 printf_filtered("%s") problems.
4803 We eliminated a copyright problem on the rpc and ptrace header files
4804 for VxWorks, which was discovered at the last minute during the 4.7
4805 release. You should now be able to build a VxWorks GDB.
4807 You can now interrupt gdb while an attached process is running. This
4808 will cause the attached process to stop, and give control back to GDB.
4810 We fixed problems caused by using too many file descriptors
4811 for reading symbols from object files and libraries. This was
4812 especially a problem for programs that used many (~100) shared
4815 The `step' command now only enters a subroutine if there is line number
4816 information for the subroutine. Otherwise it acts like the `next'
4817 command. Previously, `step' would enter subroutines if there was
4818 any debugging information about the routine. This avoids problems
4819 when using `cc -g1' on MIPS machines.
4821 * Internal improvements
4823 GDB's internal interfaces have been improved to make it easier to support
4824 debugging of multiple languages in the future.
4826 GDB now uses a common structure for symbol information internally.
4827 Minimal symbols (derived from linkage symbols in object files), partial
4828 symbols (from a quick scan of debug information), and full symbols
4829 contain a common subset of information, making it easier to write
4830 shared code that handles any of them.
4832 * New command line options
4834 We now accept --silent as an alias for --quiet.
4838 The memory-mapped-malloc library is now licensed under the GNU Library
4839 General Public License.
4841 *** Changes in GDB-4.7:
4843 * Host/native/target split
4845 GDB has had some major internal surgery to untangle the support for
4846 hosts and remote targets. Now, when you configure GDB for a remote
4847 target, it will no longer load in all of the support for debugging
4848 local programs on the host. When fully completed and tested, this will
4849 ensure that arbitrary host/target combinations are possible.
4851 The primary conceptual shift is to separate the non-portable code in
4852 GDB into three categories. Host specific code is required any time GDB
4853 is compiled on that host, regardless of the target. Target specific
4854 code relates to the peculiarities of the target, but can be compiled on
4855 any host. Native specific code is everything else: it can only be
4856 built when the host and target are the same system. Child process
4857 handling and core file support are two common `native' examples.
4859 GDB's use of /proc for controlling Unix child processes is now cleaner.
4860 It has been split out into a single module under the `target_ops' vector,
4861 plus two native-dependent functions for each system that uses /proc.
4863 * New hosts supported
4865 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
4866 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4867 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
4869 * New targets supported
4871 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4872 68030 and CPU32 m68030-*-*, m68332-*-*
4874 * New native hosts supported
4876 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4877 (386bsd is not well tested yet)
4878 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
4880 * New file formats supported
4882 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
4883 supports reading of `a.out.adobe' object files, which are an a.out
4884 format extended with minimal information about multiple sections.
4888 `show copying' is the same as the old `info copying'.
4889 `show warranty' is the same as `info warrantee'.
4890 These were renamed for consistency. The old commands continue to work.
4892 `info handle' is a new alias for `info signals'.
4894 You can now define pre-command hooks, which attach arbitrary command
4895 scripts to any command. The commands in the hook will be executed
4896 prior to the user's command. You can also create a hook which will be
4897 executed whenever the program stops. See gdb.texinfo.
4901 We now deal with Cfront style name mangling, and can even extract type
4902 info from mangled symbols. GDB can automatically figure out which
4903 symbol mangling style your C++ compiler uses.
4905 Calling of methods and virtual functions has been improved as well.
4909 The crash that occured when debugging Sun Ansi-C compiled binaries is
4910 fixed. This was due to mishandling of the extra N_SO stabs output
4913 We also finally got Ultrix 4.2 running in house, and fixed core file
4914 support, with help from a dozen people on the net.
4916 John M. Farrell discovered that the reason that single-stepping was so
4917 slow on all of the Mips based platforms (primarily SGI and DEC) was
4918 that we were trying to demangle and lookup a symbol used for internal
4919 purposes on every instruction that was being stepped through. Changing
4920 the name of that symbol so that it couldn't be mistaken for a C++
4921 mangled symbol sped things up a great deal.
4923 Rich Pixley sped up symbol lookups in general by getting much smarter
4924 about when C++ symbol mangling is necessary. This should make symbol
4925 completion (TAB on the command line) much faster. It's not as fast as
4926 we'd like, but it's significantly faster than gdb-4.6.
4930 A new user controllable variable 'call_scratch_address' can
4931 specify the location of a scratch area to be used when GDB
4932 calls a function in the target. This is necessary because the
4933 usual method of putting the scratch area on the stack does not work
4934 in systems that have separate instruction and data spaces.
4936 We integrated changes to support the 29k UDI (Universal Debugger
4937 Interface), but discovered at the last minute that we didn't have all
4938 of the appropriate copyright paperwork. We are working with AMD to
4939 resolve this, and hope to have it available soon.
4943 We have sped up the remote serial line protocol, especially for targets
4944 with lots of registers. It now supports a new `expedited status' ('T')
4945 message which can be used in place of the existing 'S' status message.
4946 This allows the remote stub to send only the registers that GDB
4947 needs to make a quick decision about single-stepping or conditional
4948 breakpoints, eliminating the need to fetch the entire register set for
4949 each instruction being stepped through.
4951 The GDB remote serial protocol now implements a write-through cache for
4952 registers, only re-reading the registers if the target has run.
4954 There is also a new remote serial stub for SPARC processors. You can
4955 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
4956 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
4957 processor with a serial port.
4961 Configure.in files have become much easier to read and modify. A new
4962 `table driven' format makes it more obvious what configurations are
4963 supported, and what files each one uses.
4967 There is a new opcodes library which will eventually contain all of the
4968 disassembly routines and opcode tables. At present, it only contains
4969 Sparc and Z8000 routines. This will allow the assembler, debugger, and
4970 disassembler (binutils/objdump) to share these routines.
4972 The libiberty library is now copylefted under the GNU Library General
4973 Public License. This allows more liberal use, and was done so libg++
4974 can use it. This makes no difference to GDB, since the Library License
4975 grants all the rights from the General Public License.
4979 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
4980 reference to the stabs symbol info used by the debugger. It is (as far
4981 as we know) the only published document on this fascinating topic. We
4982 encourage you to read it, compare it to the stabs information on your
4983 system, and send improvements on the document in general (to
4984 bug-gdb@prep.ai.mit.edu).
4986 And, of course, many bugs have been fixed.
4989 *** Changes in GDB-4.6:
4991 * Better support for C++ function names
4993 GDB now accepts as input the "demangled form" of C++ overloaded function
4994 names and member function names, and can do command completion on such names
4995 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
4996 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
4997 Make use of command completion, it is your friend.
4999 GDB also now accepts a variety of C++ mangled symbol formats. They are
5000 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5001 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5002 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5003 for the list of formats.
5005 * G++ symbol mangling problem
5007 Recent versions of gcc have a bug in how they emit debugging information for
5008 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5009 directory) can be applied to gcc to fix the problem. Alternatively, if you
5010 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5011 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5012 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5015 * New 'maintenance' command
5017 All of the commands related to hacking GDB internals have been moved out of
5018 the main command set, and now live behind the 'maintenance' command. This
5019 can also be abbreviated as 'mt'. The following changes were made:
5021 dump-me -> maintenance dump-me
5022 info all-breakpoints -> maintenance info breakpoints
5023 printmsyms -> maintenance print msyms
5024 printobjfiles -> maintenance print objfiles
5025 printpsyms -> maintenance print psymbols
5026 printsyms -> maintenance print symbols
5028 The following commands are new:
5030 maintenance demangle Call internal GDB demangler routine to
5031 demangle a C++ link name and prints the result.
5032 maintenance print type Print a type chain for a given symbol
5034 * Change to .gdbinit file processing
5036 We now read the $HOME/.gdbinit file before processing the argv arguments
5037 (e.g. reading symbol files or core files). This allows global parameters to
5038 be set, which will apply during the symbol reading. The ./.gdbinit is still
5039 read after argv processing.
5041 * New hosts supported
5043 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5045 GNU/Linux support i386-unknown-linux or linux
5047 We are also including code to support the HP/PA running BSD and HPUX. This
5048 is almost guaranteed not to work, as we didn't have time to test or build it
5049 for this release. We are including it so that the more adventurous (or
5050 masochistic) of you can play with it. We also had major problems with the
5051 fact that the compiler that we got from HP doesn't support the -g option.
5054 * New targets supported
5056 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5058 * More smarts about finding #include files
5060 GDB now remembers the compilation directory for all include files, and for
5061 all files from which C is generated (like yacc and lex sources). This
5062 greatly improves GDB's ability to find yacc/lex sources, and include files,
5063 especially if you are debugging your program from a directory different from
5064 the one that contains your sources.
5066 We also fixed a bug which caused difficulty with listing and setting
5067 breakpoints in include files which contain C code. (In the past, you had to
5068 try twice in order to list an include file that you hadn't looked at before.)
5070 * Interesting infernals change
5072 GDB now deals with arbitrary numbers of sections, where the symbols for each
5073 section must be relocated relative to that section's landing place in the
5074 target's address space. This work was needed to support ELF with embedded
5075 stabs used by Solaris-2.0.
5077 * Bug fixes (of course!)
5079 There have been loads of fixes for the following things:
5080 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5081 i960, stabs, DOS(GO32), procfs, etc...
5083 See the ChangeLog for details.
5085 *** Changes in GDB-4.5:
5087 * New machines supported (host and target)
5089 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5091 SGI Irix-4.x mips-sgi-irix4 or iris4
5093 * New malloc package
5095 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5096 Mmalloc is capable of handling mutiple heaps of memory. It is also
5097 capable of saving a heap to a file, and then mapping it back in later.
5098 This can be used to greatly speedup the startup of GDB by using a
5099 pre-parsed symbol table which lives in a mmalloc managed heap. For
5100 more details, please read mmalloc/mmalloc.texi.
5104 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5105 'help info proc' for details.
5107 * MIPS ecoff symbol table format
5109 The code that reads MIPS symbol table format is now supported on all hosts.
5110 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5113 * File name changes for MS-DOS
5115 Many files in the config directories have been renamed to make it easier to
5116 support GDB on MS-DOSe systems (which have very restrictive file name
5117 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5118 environment) is close to working but has some remaining problems. Note
5119 that debugging of DOS programs is not supported, due to limitations
5120 in the ``operating system'', but it can be used to host cross-debugging.
5122 * Cross byte order fixes
5124 Many fixes have been made to support cross debugging of Sparc and MIPS
5125 targets from hosts whose byte order differs.
5127 * New -mapped and -readnow options
5129 If memory-mapped files are available on your system through the 'mmap'
5130 system call, you can use the -mapped option on the `file' or
5131 `symbol-file' commands to cause GDB to write the symbols from your
5132 program into a reusable file. If the program you are debugging is
5133 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5134 Future GDB debugging sessions will notice the presence of this file,
5135 and will quickly map in symbol information from it, rather than reading
5136 the symbol table from the executable program. Using the '-mapped'
5137 option in a GDB `file' or `symbol-file' command has the same effect as
5138 starting GDB with the '-mapped' command-line option.
5140 You can cause GDB to read the entire symbol table immediately by using
5141 the '-readnow' option with any of the commands that load symbol table
5142 information (or on the GDB command line). This makes the command
5143 slower, but makes future operations faster.
5145 The -mapped and -readnow options are typically combined in order to
5146 build a `fred.syms' file that contains complete symbol information.
5147 A simple GDB invocation to do nothing but build a `.syms' file for future
5150 gdb -batch -nx -mapped -readnow programname
5152 The `.syms' file is specific to the host machine on which GDB is run.
5153 It holds an exact image of GDB's internal symbol table. It cannot be
5154 shared across multiple host platforms.
5156 * longjmp() handling
5158 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5159 siglongjmp() without losing control. This feature has not yet been ported to
5160 all systems. It currently works on many 386 platforms, all MIPS-based
5161 platforms (SGI, DECstation, etc), and Sun3/4.
5165 Preliminary work has been put in to support the new Solaris OS from Sun. At
5166 this time, it can control and debug processes, but it is not capable of
5171 As always, many many bug fixes. The major areas were with g++, and mipsread.
5172 People using the MIPS-based platforms should experience fewer mysterious
5173 crashes and trashed symbol tables.
5175 *** Changes in GDB-4.4:
5177 * New machines supported (host and target)
5179 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5181 BSD Reno on Vax vax-dec-bsd
5182 Ultrix on Vax vax-dec-ultrix
5184 * New machines supported (target)
5186 AMD 29000 embedded, using EBMON a29k-none-none
5190 GDB continues to improve its handling of C++. `References' work better.
5191 The demangler has also been improved, and now deals with symbols mangled as
5192 per the Annotated C++ Reference Guide.
5194 GDB also now handles `stabs' symbol information embedded in MIPS
5195 `ecoff' symbol tables. Since the ecoff format was not easily
5196 extensible to handle new languages such as C++, this appeared to be a
5197 good way to put C++ debugging info into MIPS binaries. This option
5198 will be supported in the GNU C compiler, version 2, when it is
5201 * New features for SVR4
5203 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5204 shared libraries. Debugging dynamically linked programs should present
5205 only minor differences from debugging statically linked programs.
5207 The `info proc' command will print out information about any process
5208 on an SVR4 system (including the one you are debugging). At the moment,
5209 it prints the address mappings of the process.
5211 If you bring up GDB on another SVR4 system, please send mail to
5212 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5214 * Better dynamic linking support in SunOS
5216 Reading symbols from shared libraries which contain debugging symbols
5217 now works properly. However, there remain issues such as automatic
5218 skipping of `transfer vector' code during function calls, which
5219 make it harder to debug code in a shared library, than to debug the
5220 same code linked statically.
5224 GDB is now using the latest `getopt' routines from the FSF. This
5225 version accepts the -- prefix for options with long names. GDB will
5226 continue to accept the old forms (-option and +option) as well.
5227 Various single letter abbreviations for options have been explicity
5228 added to the option table so that they won't get overshadowed in the
5229 future by other options that begin with the same letter.
5233 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5234 Many assorted bugs have been handled. Many more remain to be handled.
5235 See the various ChangeLog files (primarily in gdb and bfd) for details.
5238 *** Changes in GDB-4.3:
5240 * New machines supported (host and target)
5242 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5243 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5244 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5246 * Almost SCO Unix support
5248 We had hoped to support:
5249 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5250 (except for core file support), but we discovered very late in the release
5251 that it has problems with process groups that render gdb unusable. Sorry
5252 about that. I encourage people to fix it and post the fixes.
5254 * Preliminary ELF and DWARF support
5256 GDB can read ELF object files on System V Release 4, and can handle
5257 debugging records for C, in DWARF format, in ELF files. This support
5258 is preliminary. If you bring up GDB on another SVR4 system, please
5259 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5264 GDB now uses the latest `readline' library. One user-visible change
5265 is that two tabs will list possible command completions, which previously
5266 required typing M-? (meta-question mark, or ESC ?).
5270 The `stepi' bug that many of you noticed has been squashed.
5271 Many bugs in C++ have been handled. Many more remain to be handled.
5272 See the various ChangeLog files (primarily in gdb and bfd) for details.
5274 * State of the MIPS world (in case you wondered):
5276 GDB can understand the symbol tables emitted by the compilers
5277 supplied by most vendors of MIPS-based machines, including DEC. These
5278 symbol tables are in a format that essentially nobody else uses.
5280 Some versions of gcc come with an assembler post-processor called
5281 mips-tfile. This program is required if you want to do source-level
5282 debugging of gcc-compiled programs. I believe FSF does not ship
5283 mips-tfile with gcc version 1, but it will eventually come with gcc
5286 Debugging of g++ output remains a problem. g++ version 1.xx does not
5287 really support it at all. (If you're lucky, you should be able to get
5288 line numbers and stack traces to work, but no parameters or local
5289 variables.) With some work it should be possible to improve the
5292 When gcc version 2 is released, you will have somewhat better luck.
5293 However, even then you will get confusing results for inheritance and
5296 We will eventually provide full debugging of g++ output on
5297 DECstations. This will probably involve some kind of stabs-in-ecoff
5298 encapulation, but the details have not been worked out yet.
5301 *** Changes in GDB-4.2:
5303 * Improved configuration
5305 Only one copy of `configure' exists now, and it is not self-modifying.
5306 Porting BFD is simpler.
5310 The `step' and `next' commands now only stop at the first instruction
5311 of a source line. This prevents the multiple stops that used to occur
5312 in switch statements, for-loops, etc. `Step' continues to stop if a
5313 function that has debugging information is called within the line.
5317 Lots of small bugs fixed. More remain.
5319 * New host supported (not target)
5321 Intel 386 PC clone running Mach i386-none-mach
5324 *** Changes in GDB-4.1:
5326 * Multiple source language support
5328 GDB now has internal scaffolding to handle several source languages.
5329 It determines the type of each source file from its filename extension,
5330 and will switch expression parsing and number formatting to match the
5331 language of the function in the currently selected stack frame.
5332 You can also specifically set the language to be used, with
5333 `set language c' or `set language modula-2'.
5337 GDB now has preliminary support for the GNU Modula-2 compiler,
5338 currently under development at the State University of New York at
5339 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5340 continue through the fall of 1991 and into 1992.
5342 Other Modula-2 compilers are currently not supported, and attempting to
5343 debug programs compiled with them will likely result in an error as the
5344 symbol table is read. Feel free to work on it, though!
5346 There are hooks in GDB for strict type checking and range checking,
5347 in the `Modula-2 philosophy', but they do not currently work.
5351 GDB can now write to executable and core files (e.g. patch
5352 a variable's value). You must turn this switch on, specify
5353 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5354 by assigning a new value to a variable. Modifications take
5357 * Automatic SunOS shared library reading
5359 When you run your program, GDB automatically determines where its
5360 shared libraries (if any) have been loaded, and reads their symbols.
5361 The `share' command is no longer needed. This also works when
5362 examining core files.
5366 You can specify the number of lines that the `list' command shows.
5369 * New machines supported (host and target)
5371 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5372 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5373 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5375 * New hosts supported (not targets)
5377 IBM RT/PC: romp-ibm-aix or rtpc
5379 * New targets supported (not hosts)
5381 AMD 29000 embedded with COFF a29k-none-coff
5382 AMD 29000 embedded with a.out a29k-none-aout
5383 Ultracomputer remote kernel debug a29k-nyu-kern
5385 * New remote interfaces
5391 *** Changes in GDB-4.0:
5395 Wide output is wrapped at good places to make the output more readable.
5397 Gdb now supports cross-debugging from a host machine of one type to a
5398 target machine of another type. Communication with the target system
5399 is over serial lines. The ``target'' command handles connecting to the
5400 remote system; the ``load'' command will download a program into the
5401 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5402 also supports debugging of realtime processes running under VxWorks,
5403 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5404 stub on the target system.
5406 New CPUs supported include the AMD 29000 and Intel 960.
5408 GDB now reads object files and symbol tables via a ``binary file''
5409 library, which allows a single copy of GDB to debug programs of multiple
5410 object file types such as a.out and coff.
5412 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5413 refcard.dvi and refcard.ps are available to format it).
5416 * Control-Variable user interface simplified
5418 All variables that control the operation of the debugger can be set
5419 by the ``set'' command, and displayed by the ``show'' command.
5421 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5422 ``Show prompt'' produces the response:
5423 Gdb's prompt is new-gdb=>.
5425 What follows are the NEW set commands. The command ``help set'' will
5426 print a complete list of old and new set commands. ``help set FOO''
5427 will give a longer description of the variable FOO. ``show'' will show
5428 all of the variable descriptions and their current settings.
5430 confirm on/off: Enables warning questions for operations that are
5431 hard to recover from, e.g. rerunning the program while
5432 it is already running. Default is ON.
5434 editing on/off: Enables EMACS style command line editing
5435 of input. Previous lines can be recalled with
5436 control-P, the current line can be edited with control-B,
5437 you can search for commands with control-R, etc.
5440 history filename NAME: NAME is where the gdb command history
5441 will be stored. The default is .gdb_history,
5442 or the value of the environment variable
5445 history size N: The size, in commands, of the command history. The
5446 default is 256, or the value of the environment variable
5449 history save on/off: If this value is set to ON, the history file will
5450 be saved after exiting gdb. If set to OFF, the
5451 file will not be saved. The default is OFF.
5453 history expansion on/off: If this value is set to ON, then csh-like
5454 history expansion will be performed on
5455 command line input. The default is OFF.
5457 radix N: Sets the default radix for input and output. It can be set
5458 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5459 in the current radix, so "set radix 10" is always a no-op.
5461 height N: This integer value is the number of lines on a page. Default
5462 is 24, the current `stty rows'' setting, or the ``li#''
5463 setting from the termcap entry matching the environment
5466 width N: This integer value is the number of characters on a line.
5467 Default is 80, the current `stty cols'' setting, or the ``co#''
5468 setting from the termcap entry matching the environment
5471 Note: ``set screensize'' is obsolete. Use ``set height'' and
5472 ``set width'' instead.
5474 print address on/off: Print memory addresses in various command displays,
5475 such as stack traces and structure values. Gdb looks
5476 more ``symbolic'' if you turn this off; it looks more
5477 ``machine level'' with it on. Default is ON.
5479 print array on/off: Prettyprint arrays. New convenient format! Default
5482 print demangle on/off: Print C++ symbols in "source" form if on,
5485 print asm-demangle on/off: Same, for assembler level printouts
5488 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5491 * Support for Epoch Environment.
5493 The epoch environment is a version of Emacs v18 with windowing. One
5494 new command, ``inspect'', is identical to ``print'', except that if you
5495 are running in the epoch environment, the value is printed in its own
5499 * Support for Shared Libraries
5501 GDB can now debug programs and core files that use SunOS shared libraries.
5502 Symbols from a shared library cannot be referenced
5503 before the shared library has been linked with the program (this
5504 happens after you type ``run'' and before the function main() is entered).
5505 At any time after this linking (including when examining core files
5506 from dynamically linked programs), gdb reads the symbols from each
5507 shared library when you type the ``sharedlibrary'' command.
5508 It can be abbreviated ``share''.
5510 sharedlibrary REGEXP: Load shared object library symbols for files
5511 matching a unix regular expression. No argument
5512 indicates to load symbols for all shared libraries.
5514 info sharedlibrary: Status of loaded shared libraries.
5519 A watchpoint stops execution of a program whenever the value of an
5520 expression changes. Checking for this slows down execution
5521 tremendously whenever you are in the scope of the expression, but is
5522 quite useful for catching tough ``bit-spreader'' or pointer misuse
5523 problems. Some machines such as the 386 have hardware for doing this
5524 more quickly, and future versions of gdb will use this hardware.
5526 watch EXP: Set a watchpoint (breakpoint) for an expression.
5528 info watchpoints: Information about your watchpoints.
5530 delete N: Deletes watchpoint number N (same as breakpoints).
5531 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5532 enable N: Re-enables watchpoint number N (same as breakpoints).
5535 * C++ multiple inheritance
5537 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5540 * C++ exception handling
5542 Gdb now supports limited C++ exception handling. Besides the existing
5543 ability to breakpoint on an exception handler, gdb can breakpoint on
5544 the raising of an exception (before the stack is peeled back to the
5547 catch FOO: If there is a FOO exception handler in the dynamic scope,
5548 set a breakpoint to catch exceptions which may be raised there.
5549 Multiple exceptions (``catch foo bar baz'') may be caught.
5551 info catch: Lists all exceptions which may be caught in the
5552 current stack frame.
5555 * Minor command changes
5557 The command ``call func (arg, arg, ...)'' now acts like the print
5558 command, except it does not print or save a value if the function's result
5559 is void. This is similar to dbx usage.
5561 The ``up'' and ``down'' commands now always print the frame they end up
5562 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5563 frames without printing.
5565 * New directory command
5567 'dir' now adds directories to the FRONT of the source search path.
5568 The path starts off empty. Source files that contain debug information
5569 about the directory in which they were compiled can be found even
5570 with an empty path; Sun CC and GCC include this information. If GDB can't
5571 find your source file in the current directory, type "dir .".
5573 * Configuring GDB for compilation
5575 For normal use, type ``./configure host''. See README or gdb.texinfo
5578 GDB now handles cross debugging. If you are remotely debugging between
5579 two different machines, type ``./configure host -target=targ''.
5580 Host is the machine where GDB will run; targ is the machine
5581 where the program that you are debugging will run.
5583 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.