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*".
37 ** Frame filters and frame decorators have been added.
38 ** Temporary breakpoints are now supported.
39 ** Line tables representation has been added.
43 Nios II ELF nios2*-*-elf
44 Nios II GNU/Linux nios2*-*-linux
45 Texas Instruments MSP430 msp430*-*-elf
47 * Removed native configurations
49 Support for these a.out NetBSD and OpenBSD obsolete configurations has
50 been removed. ELF variants of these configurations are kept supported.
52 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
53 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
54 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
55 i[34567]86-*-openbsd3.[0-3]
56 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
57 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
58 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
62 Like "catch throw", but catches a re-thrown exception.
64 Renamed from old "maint check-symtabs".
66 Perform consistency checks on symtabs.
68 Expand symtabs matching an optional regexp.
71 Display the details of GDB configure-time options.
73 maint set|show per-command
74 maint set|show per-command space
75 maint set|show per-command time
76 maint set|show per-command symtab
77 Enable display of per-command gdb resource usage.
79 remove-symbol-file FILENAME
80 remove-symbol-file -a ADDRESS
81 Remove a symbol file added via add-symbol-file. The file to remove
82 can be identified by its filename or by an address that lies within
83 the boundaries of this symbol file in memory.
86 info exceptions REGEXP
87 Display the list of Ada exceptions defined in the program being
88 debugged. If provided, only the exceptions whose names match REGEXP
93 set debug symfile off|on
95 Control display of debugging info regarding reading symbol files and
96 symbol tables within those files
98 set print raw frame-arguments
99 show print raw frame-arguments
100 Set/show whether to print frame arguments in raw mode,
101 disregarding any defined pretty-printers.
103 set remote trace-status-packet
104 show remote trace-status-packet
105 Set/show the use of remote protocol qTStatus packet.
109 Control display of debugging messages related to Nios II targets.
113 Control whether target-assisted range stepping is enabled.
115 set startup-with-shell
116 show startup-with-shell
117 Specifies whether Unix child processes are started via a shell or
122 Use the target memory cache for accesses to the code segment. This
123 improves performance of remote debugging (particularly disassembly).
125 * You can now use a literal value 'unlimited' for options that
126 interpret 0 or -1 as meaning "unlimited". E.g., "set
127 trace-buffer-size unlimited" is now an alias for "set
128 trace-buffer-size -1" and "set height unlimited" is now an alias for
131 * The "set debug symtab-create" debugging option of GDB has been changed to
132 accept a verbosity level. 0 means "off", 1 provides basic debugging
133 output, and values of 2 or greater provides more verbose output.
135 * New command-line options
137 Display the details of GDB configure-time options.
139 * The command 'tsave' can now support new option '-ctf' to save trace
140 buffer in Common Trace Format.
142 * Newly installed $prefix/bin/gcore acts as a shell interface for the
145 * GDB now implements the the C++ 'typeid' operator.
147 * The new convenience variable $_exception holds the exception being
148 thrown or caught at an exception-related catchpoint.
150 * The exception-related catchpoints, like "catch throw", now accept a
151 regular expression which can be used to filter exceptions by type.
153 * The new convenience variable $_exitsignal is automatically set to
154 the terminating signal number when the program being debugged dies
155 due to an uncaught signal.
159 ** All MI commands now accept an optional "--language" option.
161 ** The new command -info-gdb-mi-command allows the user to determine
162 whether a GDB/MI command is supported or not.
164 ** The -trace-save MI command can optionally save trace buffer in Common
167 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
169 ** The command -data-list-register-values now accepts an optional
170 "--skip-unavailable" option. When used, only the available registers
173 ** The new command -trace-frame-collected dumps collected variables,
174 computed expressions, tvars, memory and registers in a traceframe.
176 ** The commands -stack-list-locals, -stack-list-arguments and
177 -stack-list-variables now accept an option "--skip-unavailable".
178 When used, only the available locals or arguments are displayed.
180 ** The -exec-run command now accepts an optional "--start" option.
181 When used, the command follows the same semantics as the "start"
182 command, stopping the program's execution at the start of its
185 ** The new commands -catch-assert and -catch-exceptions insert
186 catchpoints stopping the program when Ada exceptions are raised.
188 ** The new command -info-ada-exceptions provides the equivalent of
189 the new "info exceptions" command.
191 * New system-wide configuration scripts
192 A GDB installation now provides scripts suitable for use as system-wide
193 configuration scripts for the following systems:
197 * GDB now supports target-assigned range stepping with remote targets.
198 This improves the performance of stepping source lines by reducing
199 the number of control packets from/to GDB. See "New remote packets"
202 * GDB now understands the element 'tvar' in the XML traceframe info.
203 It has the id of the collected trace state variables.
205 * On S/390 targets that provide the transactional-execution feature,
206 the program interruption transaction diagnostic block (TDB) is now
207 represented as a number of additional "registers" in GDB.
213 The vCont packet supports a new 'r' action, that tells the remote
214 stub to step through an address range itself, without GDB
215 involvemement at each single-step.
217 qXfer:libraries-svr4:read's annex
218 The previously unused annex of the qXfer:libraries-svr4:read packet
219 is now used to support passing an argument list. The remote stub
220 reports support for this argument list to GDB's qSupported query.
221 The defined arguments are "start" and "prev", used to reduce work
222 necessary for library list updating, resulting in significant
225 * New features in the GDB remote stub, GDBserver
227 ** GDBserver now supports target-assisted range stepping. Currently
228 enabled on x86/x86_64 GNU/Linux targets.
230 ** GDBserver now adds element 'tvar' in the XML in the reply to
231 'qXfer:traceframe-info:read'. It has the id of the collected
232 trace state variables.
234 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
237 * New 'z' formatter for printing and examining memory, this displays the
238 value as hexadecimal zero padded on the left to the size of the type.
240 * GDB can now use Windows x64 unwinding data.
242 * The "set remotebaud" command has been replaced by "set serial baud".
243 Similarly, "show remotebaud" has been replaced by "show serial baud".
244 The "set remotebaud" and "show remotebaud" commands are still available
245 to provide backward compatibility with older versions of GDB.
247 *** Changes in GDB 7.6
249 * Target record has been renamed to record-full.
250 Record/replay is now enabled with the "record full" command.
251 This also affects settings that are associated with full record/replay
252 that have been moved from "set/show record" to "set/show record full":
254 set|show record full insn-number-max
255 set|show record full stop-at-limit
256 set|show record full memory-query
258 * A new record target "record-btrace" has been added. The new target
259 uses hardware support to record the control-flow of a process. It
260 does not support replaying the execution, but it implements the
261 below new commands for investigating the recorded execution log.
262 This new recording method can be enabled using:
266 The "record-btrace" target is only available on Intel Atom processors
267 and requires a Linux kernel 2.6.32 or later.
269 * Two new commands have been added for record/replay to give information
270 about the recorded execution without having to replay the execution.
271 The commands are only supported by "record btrace".
273 record instruction-history prints the execution history at
274 instruction granularity
276 record function-call-history prints the execution history at
279 * New native configurations
281 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
282 FreeBSD/powerpc powerpc*-*-freebsd
283 x86_64/Cygwin x86_64-*-cygwin*
284 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
288 ARM AArch64 aarch64*-*-elf
289 ARM AArch64 GNU/Linux aarch64*-*-linux
290 Lynx 178 PowerPC powerpc-*-lynx*178
291 x86_64/Cygwin x86_64-*-cygwin*
292 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
294 * If the configured location of system.gdbinit file (as given by the
295 --with-system-gdbinit option at configure time) is in the
296 data-directory (as specified by --with-gdb-datadir at configure
297 time) or in one of its subdirectories, then GDB will look for the
298 system-wide init file in the directory specified by the
299 --data-directory command-line option.
301 * New command line options:
303 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
304 other initialization files, unlike -nx which disables all of them.
306 * Removed command line options
308 -epoch This was used by the gdb mode in Epoch, an ancient fork of
311 * The 'ptype' and 'whatis' commands now accept an argument to control
314 * 'info proc' now works on some core files.
318 ** Vectors can be created with gdb.Type.vector.
320 ** Python's atexit.register now works in GDB.
322 ** Types can be pretty-printed via a Python API.
324 ** Python 3 is now supported (in addition to Python 2.4 or later)
326 ** New class gdb.Architecture exposes GDB's internal representation
327 of architecture in the Python API.
329 ** New method Frame.architecture returns the gdb.Architecture object
330 corresponding to the frame's architecture.
332 * New Python-based convenience functions:
334 ** $_memeq(buf1, buf2, length)
335 ** $_streq(str1, str2)
337 ** $_regex(str, regex)
339 * The 'cd' command now defaults to using '~' (the home directory) if not
342 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
343 default for GCC since November 2000.
345 * The command 'forward-search' can now be abbreviated as 'fo'.
347 * The command 'info tracepoints' can now display 'installed on target'
348 or 'not installed on target' for each non-pending location of tracepoint.
350 * New configure options
352 --enable-libmcheck/--disable-libmcheck
353 By default, development versions are built with -lmcheck on hosts
354 that support it, in order to help track memory corruption issues.
355 Release versions, on the other hand, are built without -lmcheck
356 by default. The --enable-libmcheck/--disable-libmcheck configure
357 options allow the user to override that default.
358 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
359 This configure option allows the user to build GDB with
360 libbabeltrace using which GDB can read Common Trace Format data.
362 * New commands (for set/show, see "New options" below)
365 Catch signals. This is similar to "handle", but allows commands and
366 conditions to be attached.
369 List the BFDs known to GDB.
371 python-interactive [command]
373 Start a Python interactive prompt, or evaluate the optional command
374 and print the result of expressions.
377 "py" is a new alias for "python".
379 enable type-printer [name]...
380 disable type-printer [name]...
381 Enable or disable type printers.
385 ** For the Renesas Super-H architecture, the "regs" command has been removed
386 (has been deprecated in GDB 7.5), and "info all-registers" should be used
391 set print type methods (on|off)
392 show print type methods
393 Control whether method declarations are displayed by "ptype".
394 The default is to show them.
396 set print type typedefs (on|off)
397 show print type typedefs
398 Control whether typedef definitions are displayed by "ptype".
399 The default is to show them.
401 set filename-display basename|relative|absolute
402 show filename-display
403 Control the way in which filenames is displayed.
404 The default is "relative", which preserves previous behavior.
406 set trace-buffer-size
407 show trace-buffer-size
408 Request target to change the size of trace buffer.
410 set remote trace-buffer-size-packet auto|on|off
411 show remote trace-buffer-size-packet
412 Control the use of the remote protocol `QTBuffer:size' packet.
416 Control display of debugging messages related to ARM AArch64.
419 set debug coff-pe-read
420 show debug coff-pe-read
421 Control display of debugging messages related to reading of COFF/PE
426 Control display of debugging messages related to Mach-O symbols
429 set debug notification
430 show debug notification
431 Control display of debugging info for async remote notification.
435 ** Command parameter changes are now notified using new async record
436 "=cmd-param-changed".
437 ** Trace frame changes caused by command "tfind" are now notified using
438 new async record "=traceframe-changed".
439 ** The creation, deletion and modification of trace state variables
440 are now notified using new async records "=tsv-created",
441 "=tsv-deleted" and "=tsv-modified".
442 ** The start and stop of process record are now notified using new
443 async record "=record-started" and "=record-stopped".
444 ** Memory changes are now notified using new async record
446 ** The data-disassemble command response will include a "fullname" field
447 containing the absolute file name when source has been requested.
448 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
449 command, to allow pattern filling of memory areas.
450 ** New commands "-catch-load"/"-catch-unload" added for intercepting
451 library load/unload events.
452 ** The response to breakpoint commands and breakpoint async records
453 includes an "installed" field containing a boolean state about each
454 non-pending tracepoint location is whether installed on target or not.
455 ** Output of the "-trace-status" command includes a "trace-file" field
456 containing the name of the trace file being examined. This field is
457 optional, and only present when examining a trace file.
458 ** The "fullname" field is now always present along with the "file" field,
459 even if the file cannot be found by GDB.
461 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
462 You must have the LZMA library available when configuring GDB for this
463 feature to be enabled. For more information, see:
464 http://fedoraproject.org/wiki/Features/MiniDebugInfo
469 Set the size of trace buffer. The remote stub reports support for this
470 packet to gdb's qSupported query.
473 Enable Branch Trace Store (BTS)-based branch tracing for the current
474 thread. The remote stub reports support for this packet to gdb's
478 Disable branch tracing for the current thread. The remote stub reports
479 support for this packet to gdb's qSupported query.
482 Read the traced branches for the current thread. The remote stub
483 reports support for this packet to gdb's qSupported query.
485 *** Changes in GDB 7.5
487 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
488 for more x32 ABI info.
490 * GDB now supports access to MIPS DSP registers on Linux targets.
492 * GDB now supports debugging microMIPS binaries.
494 * The "info os" command on GNU/Linux can now display information on
495 several new classes of objects managed by the operating system:
496 "info os procgroups" lists process groups
497 "info os files" lists file descriptors
498 "info os sockets" lists internet-domain sockets
499 "info os shm" lists shared-memory regions
500 "info os semaphores" lists semaphores
501 "info os msg" lists message queues
502 "info os modules" lists loaded kernel modules
504 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
505 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
506 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
507 options and inspect the probe arguments using the new $_probe_arg family
508 of convenience variables. You can obtain more information about SystemTap
509 in <http://sourceware.org/systemtap/>.
511 * GDB now supports reversible debugging on ARM, it allows you to
512 debug basic ARM and THUMB instructions, and provides
513 record/replay support.
515 * The option "symbol-reloading" has been deleted as it is no longer used.
519 ** GDB commands implemented in Python can now be put in command class
522 ** The "maint set python print-stack on|off" is now deleted.
524 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
525 apply "flag enum"-style pretty-printing to any enum.
527 ** gdb.lookup_symbol can now work when there is no current frame.
529 ** gdb.Symbol now has a 'line' attribute, holding the line number in
530 the source at which the symbol was defined.
532 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
533 method 'value'. The former indicates whether the symbol needs a
534 frame in order to compute its value, and the latter computes the
537 ** A new method 'referenced_value' on gdb.Value objects which can
538 dereference pointer as well as C++ reference values.
540 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
541 which return the global and static blocks (as gdb.Block objects),
542 of the underlying symbol table, respectively.
544 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
545 object associated with a PC value.
547 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
548 of the address range occupied by code for the current source line.
550 * Go language support.
551 GDB now supports debugging programs written in the Go programming
554 * GDBserver now supports stdio connections.
555 E.g. (gdb) target remote | ssh myhost gdbserver - hello
557 * The binary "gdbtui" can no longer be built or installed.
558 Use "gdb -tui" instead.
560 * GDB will now print "flag" enums specially. A flag enum is one where
561 all the enumerator values have no bits in common when pairwise
562 "and"ed. When printing a value whose type is a flag enum, GDB will
563 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
564 (gdb) print (enum E) 3
567 * The filename part of a linespec will now match trailing components
568 of a source file name. For example, "break gcc/expr.c:1000" will
569 now set a breakpoint in build/gcc/expr.c, but not
572 * The "info proc" and "generate-core-file" commands will now also
573 work on remote targets connected to GDBserver on Linux.
575 * The command "info catch" has been removed. It has been disabled
578 * The "catch exception" and "catch assert" commands now accept
579 a condition at the end of the command, much like the "break"
580 command does. For instance:
582 (gdb) catch exception Constraint_Error if Barrier = True
584 Previously, it was possible to add a condition to such catchpoints,
585 but it had to be done as a second step, after the catchpoint had been
586 created, using the "condition" command.
588 * The "info static-tracepoint-marker" command will now also work on
589 native Linux targets with in-process agent.
591 * GDB can now set breakpoints on inlined functions.
593 * The .gdb_index section has been updated to include symbols for
594 inlined functions. GDB will ignore older .gdb_index sections by
595 default, which could cause symbol files to be loaded more slowly
596 until their .gdb_index sections can be recreated. The new command
597 "set use-deprecated-index-sections on" will cause GDB to use any older
598 .gdb_index sections it finds. This will restore performance, but the
599 ability to set breakpoints on inlined functions will be lost in symbol
600 files with older .gdb_index sections.
602 The .gdb_index section has also been updated to record more information
603 about each symbol. This speeds up the "info variables", "info functions"
604 and "info types" commands when used with programs having the .gdb_index
605 section, as well as speeding up debugging with shared libraries using
606 the .gdb_index section.
608 * Ada support for GDB/MI Variable Objects has been added.
610 * GDB can now support 'breakpoint always-inserted mode' in 'record'
615 ** New command -info-os is the MI equivalent of "info os".
617 ** Output logs ("set logging" and related) now include MI output.
621 ** "set use-deprecated-index-sections on|off"
622 "show use-deprecated-index-sections on|off"
623 Controls the use of deprecated .gdb_index sections.
625 ** "catch load" and "catch unload" can be used to stop when a shared
626 library is loaded or unloaded, respectively.
628 ** "enable count" can be used to auto-disable a breakpoint after
631 ** "info vtbl" can be used to show the virtual method tables for
632 C++ and Java objects.
634 ** "explore" and its sub commands "explore value" and "explore type"
635 can be used to recursively explore values and types of
636 expressions. These commands are available only if GDB is
637 configured with '--with-python'.
639 ** "info auto-load" shows status of all kinds of auto-loaded files,
640 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
641 sequences of commands files, "info auto-load python-scripts"
642 shows status of auto-loading Python script files,
643 "info auto-load local-gdbinit" shows status of loading init file
644 (.gdbinit) from current directory and "info auto-load libthread-db" shows
645 status of inferior specific thread debugging shared library loading.
647 ** "info auto-load-scripts", "set auto-load-scripts on|off"
648 and "show auto-load-scripts" commands have been deprecated, use their
649 "info auto-load python-scripts", "set auto-load python-scripts on|off"
650 and "show auto-load python-scripts" counterparts instead.
652 ** "dprintf location,format,args..." creates a dynamic printf, which
653 is basically a breakpoint that does a printf and immediately
654 resumes your program's execution, so it is like a printf that you
655 can insert dynamically at runtime instead of at compiletime.
657 ** "set print symbol"
659 Controls whether GDB attempts to display the symbol, if any,
660 corresponding to addresses it prints. This defaults to "on", but
661 you can set it to "off" to restore GDB's previous behavior.
663 * Deprecated commands
665 ** For the Renesas Super-H architecture, the "regs" command has been
666 deprecated, and "info all-registers" should be used instead.
670 Renesas RL78 rl78-*-elf
671 HP OpenVMS ia64 ia64-hp-openvms*
673 * GDBserver supports evaluation of breakpoint conditions. When
674 support is advertised by GDBserver, GDB may be told to send the
675 breakpoint conditions in bytecode form to GDBserver. GDBserver
676 will only report the breakpoint trigger to GDB when its condition
682 show mips compression
683 Select the compressed ISA encoding used in functions that have no symbol
684 information available. The encoding can be set to either of:
687 and is updated automatically from ELF file flags if available.
689 set breakpoint condition-evaluation
690 show breakpoint condition-evaluation
691 Control whether breakpoint conditions are evaluated by GDB ("host") or by
692 GDBserver ("target"). Default option "auto" chooses the most efficient
694 This option can improve debugger efficiency depending on the speed of the
698 Disable auto-loading globally.
701 Show auto-loading setting of all kinds of auto-loaded files.
703 set auto-load gdb-scripts on|off
704 show auto-load gdb-scripts
705 Control auto-loading of GDB canned sequences of commands files.
707 set auto-load python-scripts on|off
708 show auto-load python-scripts
709 Control auto-loading of Python script files.
711 set auto-load local-gdbinit on|off
712 show auto-load local-gdbinit
713 Control loading of init file (.gdbinit) from current directory.
715 set auto-load libthread-db on|off
716 show auto-load libthread-db
717 Control auto-loading of inferior specific thread debugging shared library.
719 set auto-load scripts-directory <dir1>[:<dir2>...]
720 show auto-load scripts-directory
721 Set a list of directories from which to load auto-loaded scripts.
722 Automatically loaded Python scripts and GDB scripts are located in one
723 of the directories listed by this option.
724 The delimiter (':' above) may differ according to the host platform.
726 set auto-load safe-path <dir1>[:<dir2>...]
727 show auto-load safe-path
728 Set a list of directories from which it is safe to auto-load files.
729 The delimiter (':' above) may differ according to the host platform.
731 set debug auto-load on|off
733 Control display of debugging info for auto-loading the files above.
735 set dprintf-style gdb|call|agent
737 Control the way in which a dynamic printf is performed; "gdb"
738 requests a GDB printf command, while "call" causes dprintf to call a
739 function in the inferior. "agent" requests that the target agent
740 (such as GDBserver) do the printing.
742 set dprintf-function <expr>
743 show dprintf-function
744 set dprintf-channel <expr>
746 Set the function and optional first argument to the call when using
747 the "call" style of dynamic printf.
749 set disconnected-dprintf on|off
750 show disconnected-dprintf
751 Control whether agent-style dynamic printfs continue to be in effect
752 after GDB disconnects.
754 * New configure options
757 Configure default value for the 'set auto-load scripts-directory'
758 setting above. It defaults to '$debugdir:$datadir/auto-load',
759 $debugdir representing global debugging info directories (available
760 via 'show debug-file-directory') and $datadir representing GDB's data
761 directory (available via 'show data-directory').
763 --with-auto-load-safe-path
764 Configure default value for the 'set auto-load safe-path' setting
765 above. It defaults to the --with-auto-load-dir setting.
767 --without-auto-load-safe-path
768 Set 'set auto-load safe-path' to '/', effectively disabling this
773 z0/z1 conditional breakpoints extension
775 The z0/z1 breakpoint insertion packets have been extended to carry
776 a list of conditional expressions over to the remote stub depending on the
777 condition evaluation mode. The use of this extension can be controlled
778 via the "set remote conditional-breakpoints-packet" command.
782 Specify the signals which the remote stub may pass to the debugged
783 program without GDB involvement.
785 * New command line options
787 --init-command=FILE, -ix Like --command, -x but execute it
788 before loading inferior.
789 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
790 execute it before loading inferior.
792 *** Changes in GDB 7.4
794 * GDB now handles ambiguous linespecs more consistently; the existing
795 FILE:LINE support has been expanded to other types of linespecs. A
796 breakpoint will now be set on all matching locations in all
797 inferiors, and locations will be added or removed according to
800 * GDB now allows you to skip uninteresting functions and files when
801 stepping with the "skip function" and "skip file" commands.
803 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
804 and "show remote hardware-watchpoint-length-limit". These allows to
805 set or show the maximum length limit (in bytes) of a remote
806 target hardware watchpoint.
808 This allows e.g. to use "unlimited" hardware watchpoints with the
809 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
810 watchpoints are slower than real hardware watchpoints but are
811 significantly faster than gdb software watchpoints.
815 ** The register_pretty_printer function in module gdb.printing now takes
816 an optional `replace' argument. If True, the new printer replaces any
819 ** The "maint set python print-stack on|off" command has been
820 deprecated and will be deleted in GDB 7.5.
821 A new command: "set python print-stack none|full|message" has
822 replaced it. Additionally, the default for "print-stack" is
823 now "message", which just prints the error message without
826 ** A prompt substitution hook (prompt_hook) is now available to the
829 ** A new Python module, gdb.prompt has been added to the GDB Python
830 modules library. This module provides functionality for
831 escape sequences in prompts (used by set/show
832 extended-prompt). These escape sequences are replaced by their
835 ** Python commands and convenience-functions located in
836 'data-directory'/python/gdb/command and
837 'data-directory'/python/gdb/function are now automatically loaded
840 ** Blocks now provide four new attributes. global_block and
841 static_block will return the global and static blocks
842 respectively. is_static and is_global are boolean attributes
843 that indicate if the block is one of those two types.
845 ** Symbols now provide the "type" attribute, the type of the symbol.
847 ** The "gdb.breakpoint" function has been deprecated in favor of
850 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
851 of a function. This class is based on the "finish" command
852 available in the CLI.
854 ** Type objects for struct and union types now allow access to
855 the fields using standard Python dictionary (mapping) methods.
856 For example, "some_type['myfield']" now works, as does
859 ** A new event "gdb.new_objfile" has been added, triggered by loading a
862 ** A new function, "deep_items" has been added to the gdb.types
863 module in the GDB Python modules library. This function returns
864 an iterator over the fields of a struct or union type. Unlike
865 the standard Python "iteritems" method, it will recursively traverse
866 any anonymous fields.
870 ** "*stopped" events can report several new "reason"s, such as
873 ** Breakpoint changes are now notified using new async records, like
874 "=breakpoint-modified".
876 ** New command -ada-task-info.
878 * libthread-db-search-path now supports two special values: $sdir and $pdir.
879 $sdir specifies the default system locations of shared libraries.
880 $pdir specifies the directory where the libpthread used by the application
883 GDB no longer looks in $sdir and $pdir after it has searched the directories
884 mentioned in libthread-db-search-path. If you want to search those
885 directories, they must be specified in libthread-db-search-path.
886 The default value of libthread-db-search-path on GNU/Linux and Solaris
887 systems is now "$sdir:$pdir".
889 $pdir is not supported by gdbserver, it is currently ignored.
890 $sdir is supported by gdbserver.
892 * New configure option --with-iconv-bin.
893 When using the internationalization support like the one in the GNU C
894 library, GDB will invoke the "iconv" program to get a list of supported
895 character sets. If this program lives in a non-standard location, one can
896 use this option to specify where to find it.
898 * When natively debugging programs on PowerPC BookE processors running
899 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
900 watchpoints, which specify a mask in addition to an address to watch.
901 The mask specifies that some bits of an address (the bits which are
902 reset in the mask) should be ignored when matching the address accessed
903 by the inferior against the watchpoint address. See the "PowerPC Embedded"
904 section in the user manual for more details.
906 * The new option --once causes GDBserver to stop listening for connections once
907 the first connection is made. The listening port used by GDBserver will
908 become available after that.
910 * New commands "info macros" and "alias" have been added.
912 * New function parameters suffix @entry specifies value of function parameter
913 at the time the function got called. Entry values are available only since
919 "!" is now an alias of the "shell" command.
920 Note that no space is needed between "!" and SHELL COMMAND.
924 watch EXPRESSION mask MASK_VALUE
925 The watch command now supports the mask argument which allows creation
926 of masked watchpoints, if the current architecture supports this feature.
928 info auto-load-scripts [REGEXP]
929 This command was formerly named "maintenance print section-scripts".
930 It is now generally useful and is no longer a maintenance-only command.
932 info macro [-all] [--] MACRO
933 The info macro command has new options `-all' and `--'. The first for
934 printing all definitions of a macro. The second for explicitly specifying
935 the end of arguments and the beginning of the macro name in case the macro
936 name starts with a hyphen.
938 collect[/s] EXPRESSIONS
939 The tracepoint collect command now takes an optional modifier "/s"
940 that directs it to dereference pointer-to-character types and
941 collect the bytes of memory up to a zero byte. The behavior is
942 similar to what you see when you use the regular print command on a
943 string. An optional integer following the "/s" sets a bound on the
944 number of bytes that will be collected.
947 The trace start command now interprets any supplied arguments as a
948 note to be recorded with the trace run, with an effect similar to
949 setting the variable trace-notes.
952 The trace stop command now interprets any arguments as a note to be
953 mentioned along with the tstatus report that the trace was stopped
954 with a command. The effect is similar to setting the variable
957 * Tracepoints can now be enabled and disabled at any time after a trace
958 experiment has been started using the standard "enable" and "disable"
959 commands. It is now possible to start a trace experiment with no enabled
960 tracepoints; GDB will display a warning, but will allow the experiment to
961 begin, assuming that tracepoints will be enabled as needed while the trace
964 * Fast tracepoints on 32-bit x86-architectures can now be placed at
965 locations with 4-byte instructions, when they were previously
966 limited to locations with instructions of 5 bytes or longer.
970 set debug dwarf2-read
971 show debug dwarf2-read
972 Turns on or off display of debugging messages related to reading
973 DWARF debug info. The default is off.
975 set debug symtab-create
976 show debug symtab-create
977 Turns on or off display of debugging messages related to symbol table
978 creation. The default is off.
982 Set the GDB prompt, and allow escape sequences to be inserted to
983 display miscellaneous information (see 'help set extended-prompt'
984 for the list of sequences). This prompt (and any information
985 accessed through the escape sequences) is updated every time the
988 set print entry-values (both|compact|default|if-needed|no|only|preferred)
989 show print entry-values
990 Set printing of frame argument values at function entry. In some cases
991 GDB can determine the value of function argument which was passed by the
992 function caller, even if the value was modified inside the called function.
994 set debug entry-values
995 show debug entry-values
996 Control display of debugging info for determining frame argument values at
997 function entry and virtual tail call frames.
999 set basenames-may-differ
1000 show basenames-may-differ
1001 Set whether a source file may have multiple base names.
1002 (A "base name" is the name of a file with the directory part removed.
1003 Example: The base name of "/home/user/hello.c" is "hello.c".)
1004 If set, GDB will canonicalize file names (e.g., expand symlinks)
1005 before comparing them. Canonicalization is an expensive operation,
1006 but it allows the same file be known by more than one base name.
1007 If not set (the default), all source files are assumed to have just
1008 one base name, and gdb will do file name comparisons more efficiently.
1014 Set a user name and notes for the current and any future trace runs.
1015 This is useful for long-running and/or disconnected traces, to
1016 inform others (or yourself) as to who is running the trace, supply
1017 contact information, or otherwise explain what is going on.
1019 set trace-stop-notes
1020 show trace-stop-notes
1021 Set a note attached to the trace run, that is displayed when the
1022 trace has been stopped by a tstop command. This is useful for
1023 instance as an explanation, if you are stopping a trace run that was
1024 started by someone else.
1026 * New remote packets
1030 Dynamically enable a tracepoint in a started trace experiment.
1034 Dynamically disable a tracepoint in a started trace experiment.
1038 Set the user and notes of the trace run.
1042 Query the current status of a tracepoint.
1046 Query the minimum length of instruction at which a fast tracepoint may
1049 * Dcache size (number of lines) and line-size are now runtime-configurable
1050 via "set dcache line" and "set dcache line-size" commands.
1054 Texas Instruments TMS320C6x tic6x-*-*
1058 Renesas RL78 rl78-*-elf
1060 *** Changes in GDB 7.3.1
1062 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1064 *** Changes in GDB 7.3
1066 * GDB has a new command: "thread find [REGEXP]".
1067 It finds the thread id whose name, target id, or thread extra info
1068 matches the given regular expression.
1070 * The "catch syscall" command now works on mips*-linux* targets.
1072 * The -data-disassemble MI command now supports modes 2 and 3 for
1073 dumping the instruction opcodes.
1075 * New command line options
1077 -data-directory DIR Specify DIR as the "data-directory".
1078 This is mostly for testing purposes.
1080 * The "maint set python auto-load on|off" command has been renamed to
1081 "set auto-load-scripts on|off".
1083 * GDB has a new command: "set directories".
1084 It is like the "dir" command except that it replaces the
1085 source path list instead of augmenting it.
1087 * GDB now understands thread names.
1089 On GNU/Linux, "info threads" will display the thread name as set by
1090 prctl or pthread_setname_np.
1092 There is also a new command, "thread name", which can be used to
1093 assign a name internally for GDB to display.
1096 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1097 has been integrated into GDB.
1101 ** The function gdb.Write now accepts an optional keyword 'stream'.
1102 This keyword, when provided, will direct the output to either
1103 stdout, stderr, or GDB's logging output.
1105 ** Parameters can now be be sub-classed in Python, and in particular
1106 you may implement the get_set_doc and get_show_doc functions.
1107 This improves how Parameter set/show documentation is processed
1108 and allows for more dynamic content.
1110 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1111 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1112 have an is_valid method.
1114 ** Breakpoints can now be sub-classed in Python, and in particular
1115 you may implement a 'stop' function that is executed each time
1116 the inferior reaches that breakpoint.
1118 ** New function gdb.lookup_global_symbol looks up a global symbol.
1120 ** GDB values in Python are now callable if the value represents a
1121 function. For example, if 'some_value' represents a function that
1122 takes two integer parameters and returns a value, you can call
1123 that function like so:
1125 result = some_value (10,20)
1127 ** Module gdb.types has been added.
1128 It contains a collection of utilities for working with gdb.Types objects:
1129 get_basic_type, has_field, make_enum_dict.
1131 ** Module gdb.printing has been added.
1132 It contains utilities for writing and registering pretty-printers.
1133 New classes: PrettyPrinter, SubPrettyPrinter,
1134 RegexpCollectionPrettyPrinter.
1135 New function: register_pretty_printer.
1137 ** New commands "info pretty-printers", "enable pretty-printer" and
1138 "disable pretty-printer" have been added.
1140 ** gdb.parameter("directories") is now available.
1142 ** New function gdb.newest_frame returns the newest frame in the
1145 ** The gdb.InferiorThread class has a new "name" attribute. This
1146 holds the thread's name.
1148 ** Python Support for Inferior events.
1149 Python scripts can add observers to be notified of events
1150 occurring in the process being debugged.
1151 The following events are currently supported:
1152 - gdb.events.cont Continue event.
1153 - gdb.events.exited Inferior exited event.
1154 - gdb.events.stop Signal received, and Breakpoint hit events.
1158 ** GDB now puts template parameters in scope when debugging in an
1159 instantiation. For example, if you have:
1161 template<int X> int func (void) { return X; }
1163 then if you step into func<5>, "print X" will show "5". This
1164 feature requires proper debuginfo support from the compiler; it
1165 was added to GCC 4.5.
1167 ** The motion commands "next", "finish", "until", and "advance" now
1168 work better when exceptions are thrown. In particular, GDB will
1169 no longer lose control of the inferior; instead, the GDB will
1170 stop the inferior at the point at which the exception is caught.
1171 This functionality requires a change in the exception handling
1172 code that was introduced in GCC 4.5.
1174 * GDB now follows GCC's rules on accessing volatile objects when
1175 reading or writing target state during expression evaluation.
1176 One notable difference to prior behavior is that "print x = 0"
1177 no longer generates a read of x; the value of the assignment is
1178 now always taken directly from the value being assigned.
1180 * GDB now has some support for using labels in the program's source in
1181 linespecs. For instance, you can use "advance label" to continue
1182 execution to a label.
1184 * GDB now has support for reading and writing a new .gdb_index
1185 section. This section holds a fast index of DWARF debugging
1186 information and can be used to greatly speed up GDB startup and
1187 operation. See the documentation for `save gdb-index' for details.
1189 * The "watch" command now accepts an optional "-location" argument.
1190 When used, this causes GDB to watch the memory referred to by the
1191 expression. Such a watchpoint is never deleted due to it going out
1194 * GDB now supports thread debugging of core dumps on GNU/Linux.
1196 GDB now activates thread debugging using the libthread_db library
1197 when debugging GNU/Linux core dumps, similarly to when debugging
1198 live processes. As a result, when debugging a core dump file, GDB
1199 is now able to display pthread_t ids of threads. For example, "info
1200 threads" shows the same output as when debugging the process when it
1201 was live. In earlier releases, you'd see something like this:
1204 * 1 LWP 6780 main () at main.c:10
1206 While now you see this:
1209 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1211 It is also now possible to inspect TLS variables when debugging core
1214 When debugging a core dump generated on a machine other than the one
1215 used to run GDB, you may need to point GDB at the correct
1216 libthread_db library with the "set libthread-db-search-path"
1217 command. See the user manual for more details on this command.
1219 * When natively debugging programs on PowerPC BookE processors running
1220 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1221 which stop execution of the inferior whenever it executes an instruction
1222 at any address within the specified range. See the "PowerPC Embedded"
1223 section in the user manual for more details.
1225 * New features in the GDB remote stub, GDBserver
1227 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1228 and i686 LynxOS (version 5.x).
1230 ** GDBserver is now supported on Blackfin Linux.
1232 * New native configurations
1234 ia64 HP-UX ia64-*-hpux*
1238 Analog Devices, Inc. Blackfin Processor bfin-*
1240 * Ada task switching is now supported on sparc-elf targets when
1241 debugging a program using the Ravenscar Profile. For more information,
1242 see the "Tasking Support when using the Ravenscar Profile" section
1243 in the GDB user manual.
1245 * Guile support was removed.
1247 * New features in the GNU simulator
1249 ** The --map-info flag lists all known core mappings.
1251 ** CFI flashes may be simulated via the "cfi" device.
1253 *** Changes in GDB 7.2
1255 * Shared library support for remote targets by default
1257 When GDB is configured for a generic, non-OS specific target, like
1258 for example, --target=arm-eabi or one of the many *-*-elf targets,
1259 GDB now queries remote stubs for loaded shared libraries using the
1260 `qXfer:libraries:read' packet. Previously, shared library support
1261 was always disabled for such configurations.
1265 ** Argument Dependent Lookup (ADL)
1267 In C++ ADL lookup directs function search to the namespaces of its
1268 arguments even if the namespace has not been imported.
1278 Here the compiler will search for `foo' in the namespace of 'b'
1279 and find A::foo. GDB now supports this. This construct is commonly
1280 used in the Standard Template Library for operators.
1282 ** Improved User Defined Operator Support
1284 In addition to member operators, GDB now supports lookup of operators
1285 defined in a namespace and imported with a `using' directive, operators
1286 defined in the global scope, operators imported implicitly from an
1287 anonymous namespace, and the ADL operators mentioned in the previous
1289 GDB now also supports proper overload resolution for all the previously
1290 mentioned flavors of operators.
1292 ** static const class members
1294 Printing of static const class members that are initialized in the
1295 class definition has been fixed.
1297 * Windows Thread Information Block access.
1299 On Windows targets, GDB now supports displaying the Windows Thread
1300 Information Block (TIB) structure. This structure is visible either
1301 by using the new command `info w32 thread-information-block' or, by
1302 dereferencing the new convenience variable named `$_tlb', a
1303 thread-specific pointer to the TIB. This feature is also supported
1304 when remote debugging using GDBserver.
1306 * Static tracepoints
1308 Static tracepoints are calls in the user program into a tracing
1309 library. One such library is a port of the LTTng kernel tracer to
1310 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1311 When debugging with GDBserver, GDB now supports combining the GDB
1312 tracepoint machinery with such libraries. For example: the user can
1313 use GDB to probe a static tracepoint marker (a call from the user
1314 program into the tracing library) with the new "strace" command (see
1315 "New commands" below). This creates a "static tracepoint" in the
1316 breakpoint list, that can be manipulated with the same feature set
1317 as fast and regular tracepoints. E.g., collect registers, local and
1318 global variables, collect trace state variables, and define
1319 tracepoint conditions. In addition, the user can collect extra
1320 static tracepoint marker specific data, by collecting the new
1321 $_sdata internal variable. When analyzing the trace buffer, you can
1322 inspect $_sdata like any other variable available to GDB. For more
1323 information, see the "Tracepoints" chapter in GDB user manual. New
1324 remote packets have been defined to support static tracepoints, see
1325 the "New remote packets" section below.
1327 * Better reconstruction of tracepoints after disconnected tracing
1329 GDB will attempt to download the original source form of tracepoint
1330 definitions when starting a trace run, and then will upload these
1331 upon reconnection to the target, resulting in a more accurate
1332 reconstruction of the tracepoints that are in use on the target.
1336 You can now exercise direct control over the ways that GDB can
1337 affect your program. For instance, you can disallow the setting of
1338 breakpoints, so that the program can run continuously (assuming
1339 non-stop mode). In addition, the "observer" variable is available
1340 to switch all of the different controls; in observer mode, GDB
1341 cannot affect the target's behavior at all, which is useful for
1342 tasks like diagnosing live systems in the field.
1344 * The new convenience variable $_thread holds the number of the
1347 * New remote packets
1351 Return the address of the Windows Thread Information Block of a given thread.
1355 In response to several of the tracepoint packets, the target may now
1356 also respond with a number of intermediate `qRelocInsn' request
1357 packets before the final result packet, to have GDB handle
1358 relocating an instruction to execute at a different address. This
1359 is particularly useful for stubs that support fast tracepoints. GDB
1360 reports support for this feature in the qSupported packet.
1364 List static tracepoint markers in the target program.
1368 List static tracepoint markers at a given address in the target
1371 qXfer:statictrace:read
1373 Read the static trace data collected (by a `collect $_sdata'
1374 tracepoint action). The remote stub reports support for this packet
1375 to gdb's qSupported query.
1379 Send the current settings of GDB's permission flags.
1383 Send part of the source (textual) form of a tracepoint definition,
1384 which includes location, conditional, and action list.
1386 * The source command now accepts a -s option to force searching for the
1387 script in the source search path even if the script name specifies
1390 * New features in the GDB remote stub, GDBserver
1392 - GDBserver now support tracepoints (including fast tracepoints, and
1393 static tracepoints). The feature is currently supported by the
1394 i386-linux and amd64-linux builds. See the "Tracepoints support
1395 in gdbserver" section in the manual for more information.
1397 GDBserver JIT compiles the tracepoint's conditional agent
1398 expression bytecode into native code whenever possible for low
1399 overhead dynamic tracepoints conditionals. For such tracepoints,
1400 an expression that examines program state is evaluated when the
1401 tracepoint is reached, in order to determine whether to capture
1402 trace data. If the condition is simple and false, processing the
1403 tracepoint finishes very quickly and no data is gathered.
1405 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1406 for static tracepoints support.
1408 - GDBserver now supports x86_64 Windows 64-bit debugging.
1410 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1411 it understands register description.
1413 * The --batch flag now disables pagination and queries.
1415 * X86 general purpose registers
1417 GDB now supports reading/writing byte, word and double-word x86
1418 general purpose registers directly. This means you can use, say,
1419 $ah or $ax to refer, respectively, to the byte register AH and
1420 16-bit word register AX that are actually portions of the 32-bit
1421 register EAX or 64-bit register RAX.
1423 * The `commands' command now accepts a range of breakpoints to modify.
1424 A plain `commands' following a command that creates multiple
1425 breakpoints affects all the breakpoints set by that command. This
1426 applies to breakpoints set by `rbreak', and also applies when a
1427 single `break' command creates multiple breakpoints (e.g.,
1428 breakpoints on overloaded c++ functions).
1430 * The `rbreak' command now accepts a filename specification as part of
1431 its argument, limiting the functions selected by the regex to those
1432 in the specified file.
1434 * Support for remote debugging Windows and SymbianOS shared libraries
1435 from Unix hosts has been improved. Non Windows GDB builds now can
1436 understand target reported file names that follow MS-DOS based file
1437 system semantics, such as file names that include drive letters and
1438 use the backslash character as directory separator. This makes it
1439 possible to transparently use the "set sysroot" and "set
1440 solib-search-path" on Unix hosts to point as host copies of the
1441 target's shared libraries. See the new command "set
1442 target-file-system-kind" described below, and the "Commands to
1443 specify files" section in the user manual for more information.
1447 eval template, expressions...
1448 Convert the values of one or more expressions under the control
1449 of the string template to a command line, and call it.
1451 set target-file-system-kind unix|dos-based|auto
1452 show target-file-system-kind
1453 Set or show the assumed file system kind for target reported file
1456 save breakpoints <filename>
1457 Save all current breakpoint definitions to a file suitable for use
1458 in a later debugging session. To read the saved breakpoint
1459 definitions, use the `source' command.
1461 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1464 info static-tracepoint-markers
1465 Display information about static tracepoint markers in the target.
1467 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1468 Define a static tracepoint by probing a marker at the given
1469 function, line, address, or marker ID.
1473 Enable and disable observer mode.
1475 set may-write-registers on|off
1476 set may-write-memory on|off
1477 set may-insert-breakpoints on|off
1478 set may-insert-tracepoints on|off
1479 set may-insert-fast-tracepoints on|off
1480 set may-interrupt on|off
1481 Set individual permissions for GDB effects on the target. Note that
1482 some of these settings can have undesirable or surprising
1483 consequences, particularly when changed in the middle of a session.
1484 For instance, disabling the writing of memory can prevent
1485 breakpoints from being inserted, cause single-stepping to fail, or
1486 even crash your program, if you disable after breakpoints have been
1487 inserted. However, GDB should not crash.
1489 set record memory-query on|off
1490 show record memory-query
1491 Control whether to stop the inferior if memory changes caused
1492 by an instruction cannot be recorded.
1497 The disassemble command now supports "start,+length" form of two arguments.
1501 ** GDB now provides a new directory location, called the python directory,
1502 where Python scripts written for GDB can be installed. The location
1503 of that directory is <data-directory>/python, where <data-directory>
1504 is the GDB data directory. For more details, see section `Scripting
1505 GDB using Python' in the manual.
1507 ** The GDB Python API now has access to breakpoints, symbols, symbol
1508 tables, program spaces, inferiors, threads and frame's code blocks.
1509 Additionally, GDB Parameters can now be created from the API, and
1510 manipulated via set/show in the CLI.
1512 ** New functions gdb.target_charset, gdb.target_wide_charset,
1513 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1515 ** New exception gdb.GdbError.
1517 ** Pretty-printers are now also looked up in the current program space.
1519 ** Pretty-printers can now be individually enabled and disabled.
1521 ** GDB now looks for names of Python scripts to auto-load in a
1522 special section named `.debug_gdb_scripts', in addition to looking
1523 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1525 * Tracepoint actions were unified with breakpoint commands. In particular,
1526 there are no longer differences in "info break" output for breakpoints and
1527 tracepoints and the "commands" command can be used for both tracepoints and
1528 regular breakpoints.
1532 ARM Symbian arm*-*-symbianelf*
1534 * D language support.
1535 GDB now supports debugging programs written in the D programming
1538 * GDB now supports the extended ptrace interface for PowerPC which is
1539 available since Linux kernel version 2.6.34. This automatically enables
1540 any hardware breakpoints and additional hardware watchpoints available in
1541 the processor. The old ptrace interface exposes just one hardware
1542 watchpoint and no hardware breakpoints.
1544 * GDB is now able to use the Data Value Compare (DVC) register available on
1545 embedded PowerPC processors to implement in hardware simple watchpoint
1546 conditions of the form:
1548 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1550 This works in native GDB running on Linux kernels with the extended ptrace
1551 interface mentioned above.
1553 *** Changes in GDB 7.1
1557 ** Namespace Support
1559 GDB now supports importing of namespaces in C++. This enables the
1560 user to inspect variables from imported namespaces. Support for
1561 namepace aliasing has also been added. So, if a namespace is
1562 aliased in the current scope (e.g. namepace C=A; ) the user can
1563 print variables using the alias (e.g. (gdb) print C::x).
1567 All known bugs relating to the printing of virtual base class were
1568 fixed. It is now possible to call overloaded static methods using a
1573 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1574 and reinterpret_cast<> are now handled by the C++ expression parser.
1578 Xilinx MicroBlaze microblaze-*-*
1583 Xilinx MicroBlaze microblaze
1586 * Multi-program debugging.
1588 GDB now has support for multi-program (a.k.a. multi-executable or
1589 multi-exec) debugging. This allows for debugging multiple inferiors
1590 simultaneously each running a different program under the same GDB
1591 session. See "Debugging Multiple Inferiors and Programs" in the
1592 manual for more information. This implied some user visible changes
1593 in the multi-inferior support. For example, "info inferiors" now
1594 lists inferiors that are not running yet or that have exited
1595 already. See also "New commands" and "New options" below.
1597 * New tracing features
1599 GDB's tracepoint facility now includes several new features:
1601 ** Trace state variables
1603 GDB tracepoints now include support for trace state variables, which
1604 are variables managed by the target agent during a tracing
1605 experiment. They are useful for tracepoints that trigger each
1606 other, so for instance one tracepoint can count hits in a variable,
1607 and then a second tracepoint has a condition that is true when the
1608 count reaches a particular value. Trace state variables share the
1609 $-syntax of GDB convenience variables, and can appear in both
1610 tracepoint actions and condition expressions. Use the "tvariable"
1611 command to create, and "info tvariables" to view; see "Trace State
1612 Variables" in the manual for more detail.
1616 GDB now includes an option for defining fast tracepoints, which
1617 targets may implement more efficiently, such as by installing a jump
1618 into the target agent rather than a trap instruction. The resulting
1619 speedup can be by two orders of magnitude or more, although the
1620 tradeoff is that some program locations on some target architectures
1621 might not allow fast tracepoint installation, for instance if the
1622 instruction to be replaced is shorter than the jump. To request a
1623 fast tracepoint, use the "ftrace" command, with syntax identical to
1624 the regular trace command.
1626 ** Disconnected tracing
1628 It is now possible to detach GDB from the target while it is running
1629 a trace experiment, then reconnect later to see how the experiment
1630 is going. In addition, a new variable disconnected-tracing lets you
1631 tell the target agent whether to continue running a trace if the
1632 connection is lost unexpectedly.
1636 GDB now has the ability to save the trace buffer into a file, and
1637 then use that file as a target, similarly to you can do with
1638 corefiles. You can select trace frames, print data that was
1639 collected in them, and use tstatus to display the state of the
1640 tracing run at the moment that it was saved. To create a trace
1641 file, use "tsave <filename>", and to use it, do "target tfile
1644 ** Circular trace buffer
1646 You can ask the target agent to handle the trace buffer as a
1647 circular buffer, discarding the oldest trace frames to make room for
1648 newer ones, by setting circular-trace-buffer to on. This feature may
1649 not be available for all target agents.
1654 The disassemble command, when invoked with two arguments, now requires
1655 the arguments to be comma-separated.
1658 The info variables command now displays variable definitions. Files
1659 which only declare a variable are not shown.
1662 The source command is now capable of sourcing Python scripts.
1663 This feature is dependent on the debugger being build with Python
1666 Related to this enhancement is also the introduction of a new command
1667 "set script-extension" (see below).
1669 * New commands (for set/show, see "New options" below)
1671 record save [<FILENAME>]
1672 Save a file (in core file format) containing the process record
1673 execution log for replay debugging at a later time.
1675 record restore <FILENAME>
1676 Restore the process record execution log that was saved at an
1677 earlier time, for replay debugging.
1679 add-inferior [-copies <N>] [-exec <FILENAME>]
1682 clone-inferior [-copies <N>] [ID]
1683 Make a new inferior ready to execute the same program another
1684 inferior has loaded.
1689 maint info program-spaces
1690 List the program spaces loaded into GDB.
1692 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1693 show remote interrupt-sequence
1694 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1695 as the sequence to the remote target in order to interrupt the execution.
1696 Ctrl-C is a default. Some system prefers BREAK which is high level of
1697 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1698 Magic SysRq g. It is BREAK signal and character 'g'.
1700 set remote interrupt-on-connect [on | off]
1701 show remote interrupt-on-connect
1702 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1703 remote target when gdb connects to it. This is needed when you debug
1706 set remotebreak [on | off]
1708 Deprecated. Use "set/show remote interrupt-sequence" instead.
1710 tvariable $NAME [ = EXP ]
1711 Create or modify a trace state variable.
1714 List trace state variables and their values.
1716 delete tvariable $NAME ...
1717 Delete one or more trace state variables.
1720 Evaluate the given expressions without collecting anything into the
1721 trace buffer. (Valid in tracepoint actions only.)
1723 ftrace FN / FILE:LINE / *ADDR
1724 Define a fast tracepoint at the given function, line, or address.
1726 * New expression syntax
1728 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1729 GDB now parses 0b101010 identically with 42.
1733 set follow-exec-mode new|same
1734 show follow-exec-mode
1735 Control whether GDB reuses the same inferior across an exec call or
1736 creates a new one. This is useful to be able to restart the old
1737 executable after the inferior having done an exec call.
1739 set default-collect EXPR, ...
1740 show default-collect
1741 Define a list of expressions to be collected at each tracepoint.
1742 This is a useful way to ensure essential items are not overlooked,
1743 such as registers or a critical global variable.
1745 set disconnected-tracing
1746 show disconnected-tracing
1747 If set to 1, the target is instructed to continue tracing if it
1748 loses its connection to GDB. If 0, the target is to stop tracing
1751 set circular-trace-buffer
1752 show circular-trace-buffer
1753 If set to on, the target is instructed to use a circular trace buffer
1754 and discard the oldest trace frames instead of stopping the trace due
1755 to a full trace buffer. If set to off, the trace stops when the buffer
1756 fills up. Some targets may not support this.
1758 set script-extension off|soft|strict
1759 show script-extension
1760 If set to "off", the debugger does not perform any script language
1761 recognition, and all sourced files are assumed to be GDB scripts.
1762 If set to "soft" (the default), files are sourced according to
1763 filename extension, falling back to GDB scripts if the first
1765 If set to "strict", files are sourced according to filename extension.
1767 set ada trust-PAD-over-XVS on|off
1768 show ada trust-PAD-over-XVS
1769 If off, activate a workaround against a bug in the debugging information
1770 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1771 the GCC sources for more information about the GNAT encoding and
1772 PAD types in particular). It is always safe to set this option to
1773 off, but this introduces a slight performance penalty. The default
1776 * Python API Improvements
1778 ** GDB provides the new class gdb.LazyString. This is useful in
1779 some pretty-printing cases. The new method gdb.Value.lazy_string
1780 provides a simple way to create objects of this type.
1782 ** The fields returned by gdb.Type.fields now have an
1783 `is_base_class' attribute.
1785 ** The new method gdb.Type.range returns the range of an array type.
1787 ** The new method gdb.parse_and_eval can be used to parse and
1788 evaluate an expression.
1790 * New remote packets
1793 Define a trace state variable.
1796 Get the current value of a trace state variable.
1799 Set desired tracing behavior upon disconnection.
1802 Set the trace buffer to be linear or circular.
1805 Get data about the tracepoints currently in use.
1809 Process record now works correctly with hardware watchpoints.
1811 Multiple bug fixes have been made to the mips-irix port, making it
1812 much more reliable. In particular:
1813 - Debugging threaded applications is now possible again. Previously,
1814 GDB would hang while starting the program, or while waiting for
1815 the program to stop at a breakpoint.
1816 - Attaching to a running process no longer hangs.
1817 - An error occurring while loading a core file has been fixed.
1818 - Changing the value of the PC register now works again. This fixes
1819 problems observed when using the "jump" command, or when calling
1820 a function from GDB, or even when assigning a new value to $pc.
1821 - With the "finish" and "return" commands, the return value for functions
1822 returning a small array is now correctly printed.
1823 - It is now possible to break on shared library code which gets executed
1824 during a shared library init phase (code executed while executing
1825 their .init section). Previously, the breakpoint would have no effect.
1826 - GDB is now able to backtrace through the signal handler for
1827 non-threaded programs.
1829 PIE (Position Independent Executable) programs debugging is now supported.
1830 This includes debugging execution of PIC (Position Independent Code) shared
1831 libraries although for that, it should be possible to run such libraries as an
1834 *** Changes in GDB 7.0
1836 * GDB now has an interface for JIT compilation. Applications that
1837 dynamically generate code can create symbol files in memory and register
1838 them with GDB. For users, the feature should work transparently, and
1839 for JIT developers, the interface is documented in the GDB manual in the
1840 "JIT Compilation Interface" chapter.
1842 * Tracepoints may now be conditional. The syntax is as for
1843 breakpoints; either an "if" clause appended to the "trace" command,
1844 or the "condition" command is available. GDB sends the condition to
1845 the target for evaluation using the same bytecode format as is used
1846 for tracepoint actions.
1848 * The disassemble command now supports: an optional /r modifier, print the
1849 raw instructions in hex as well as in symbolic form, and an optional /m
1850 modifier to print mixed source+assembly.
1852 * Process record and replay
1854 In a architecture environment that supports ``process record and
1855 replay'', ``process record and replay'' target can record a log of
1856 the process execution, and replay it with both forward and reverse
1859 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
1860 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
1861 set execution-direction {forward|reverse}, for targets that support
1864 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
1865 feature is available with a native GDB running on kernel version
1868 * GDB now has support for multi-byte and wide character sets on the
1869 target. Strings whose character type is wchar_t, char16_t, or
1870 char32_t are now correctly printed. GDB supports wide- and unicode-
1871 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
1872 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
1873 `printf'. This feature requires iconv to work properly; if your
1874 system does not have a working iconv, GDB can use GNU libiconv. See
1875 the installation instructions for more information.
1877 * GDB now supports automatic retrieval of shared library files from
1878 remote targets. To use this feature, specify a system root that begins
1879 with the `remote:' prefix, either via the `set sysroot' command or via
1880 the `--with-sysroot' configure-time option.
1882 * "info sharedlibrary" now takes an optional regex of libraries to show,
1883 and it now reports if a shared library has no debugging information.
1885 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
1886 now complete on file names.
1888 * When completing in expressions, gdb will attempt to limit
1889 completions to allowable structure or union fields, where appropriate.
1890 For instance, consider:
1892 # struct example { int f1; double f2; };
1893 # struct example variable;
1896 If the user types TAB at the end of this command line, the available
1897 completions will be "f1" and "f2".
1899 * Inlined functions are now supported. They show up in backtraces, and
1900 the "step", "next", and "finish" commands handle them automatically.
1902 * GDB now supports the token-splicing (##) and stringification (#)
1903 operators when expanding macros. It also supports variable-arity
1906 * GDB now supports inspecting extra signal information, exported by
1907 the new $_siginfo convenience variable. The feature is currently
1908 implemented on linux ARM, i386 and amd64.
1910 * GDB can now display the VFP floating point registers and NEON vector
1911 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
1912 can provide these registers (requires Linux 2.6.30 or later). Remote
1913 and simulator targets may also provide them.
1915 * New remote packets
1918 Search memory for a sequence of bytes.
1921 Turn off `+'/`-' protocol acknowledgments to permit more efficient
1922 operation over reliable transport links. Use of this packet is
1923 controlled by the `set remote noack-packet' command.
1926 Kill the process with the specified process ID. Use this in preference
1927 to `k' when multiprocess protocol extensions are supported.
1930 Obtains additional operating system information
1934 Read or write additional signal information.
1936 * Removed remote protocol undocumented extension
1938 An undocumented extension to the remote protocol's `S' stop reply
1939 packet that permited the stub to pass a process id was removed.
1940 Remote servers should use the `T' stop reply packet instead.
1942 * GDB now supports multiple function calling conventions according to the
1943 DWARF-2 DW_AT_calling_convention function attribute.
1945 * The SH target utilizes the aforementioned change to distinguish between gcc
1946 and Renesas calling convention. It also adds the new CLI commands
1947 `set/show sh calling-convention'.
1949 * GDB can now read compressed debug sections, as produced by GNU gold
1950 with the --compress-debug-sections=zlib flag.
1952 * 64-bit core files are now supported on AIX.
1954 * Thread switching is now supported on Tru64.
1956 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
1957 which will be allocated using malloc later in program execution.
1959 * The qXfer:libraries:read remote procotol packet now allows passing a
1960 list of section offsets.
1962 * On GNU/Linux, GDB can now attach to stopped processes. Several race
1963 conditions handling signals delivered during attach or thread creation
1964 have also been fixed.
1966 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
1967 From the user's standpoint, all unqualified instances of True and False
1968 are treated as the standard definitions, regardless of context.
1970 * GDB now parses C++ symbol and type names more flexibly. For
1973 template<typename T> class C { };
1976 GDB will now correctly handle all of:
1978 ptype C<char const *>
1979 ptype C<char const*>
1980 ptype C<const char *>
1981 ptype C<const char*>
1983 * New features in the GDB remote stub, gdbserver
1985 - The "--wrapper" command-line argument tells gdbserver to use a
1986 wrapper program to launch programs for debugging.
1988 - On PowerPC and S/390 targets, it is now possible to use a single
1989 gdbserver executable to debug both 32-bit and 64-bit programs.
1990 (This requires gdbserver itself to be built as a 64-bit executable.)
1992 - gdbserver uses the new noack protocol mode for TCP connections to
1993 reduce communications latency, if also supported and enabled in GDB.
1995 - Support for the sparc64-linux-gnu target is now included in
1998 - The amd64-linux build of gdbserver now supports debugging both
1999 32-bit and 64-bit programs.
2001 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2002 now support hardware watchpoints, and will use them automatically
2007 GDB now has support for scripting using Python. Whether this is
2008 available is determined at configure time.
2010 New GDB commands can now be written in Python.
2012 * Ada tasking support
2014 Ada tasks can now be inspected in GDB. The following commands have
2018 Print the list of Ada tasks.
2020 Print detailed information about task number N.
2022 Print the task number of the current task.
2024 Switch the context of debugging to task number N.
2026 * Support for user-defined prefixed commands. The "define" command can
2027 add new commands to existing prefixes, e.g. "target".
2029 * Multi-inferior, multi-process debugging.
2031 GDB now has generalized support for multi-inferior debugging. See
2032 "Debugging Multiple Inferiors" in the manual for more information.
2033 Although availability still depends on target support, the command
2034 set is more uniform now. The GNU/Linux specific multi-forks support
2035 has been migrated to this new framework. This implied some user
2036 visible changes; see "New commands" and also "Removed commands"
2039 * Target descriptions can now describe the target OS ABI. See the
2040 "Target Description Format" section in the user manual for more
2043 * Target descriptions can now describe "compatible" architectures
2044 to indicate that the target can execute applications for a different
2045 architecture in addition to those for the main target architecture.
2046 See the "Target Description Format" section in the user manual for
2049 * Multi-architecture debugging.
2051 GDB now includes general supports for debugging applications on
2052 hybrid systems that use more than one single processor architecture
2053 at the same time. Each such hybrid architecture still requires
2054 specific support to be added. The only hybrid architecture supported
2055 in this version of GDB is the Cell Broadband Engine.
2057 * GDB now supports integrated debugging of Cell/B.E. applications that
2058 use both the PPU and SPU architectures. To enable support for hybrid
2059 Cell/B.E. debugging, you need to configure GDB to support both the
2060 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2061 --enable-targets configure option.
2063 * Non-stop mode debugging.
2065 For some targets, GDB now supports an optional mode of operation in
2066 which you can examine stopped threads while other threads continue
2067 to execute freely. This is referred to as non-stop mode, with the
2068 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2069 section in the user manual for more information.
2071 To be able to support remote non-stop debugging, a remote stub needs
2072 to implement the non-stop mode remote protocol extensions, as
2073 described in the "Remote Non-Stop" section of the user manual. The
2074 GDB remote stub, gdbserver, has been adjusted to support these
2075 extensions on linux targets.
2077 * New commands (for set/show, see "New options" below)
2079 catch syscall [NAME(S) | NUMBER(S)]
2080 Catch system calls. Arguments, which should be names of system
2081 calls or their numbers, mean catch only those syscalls. Without
2082 arguments, every syscall will be caught. When the inferior issues
2083 any of the specified syscalls, GDB will stop and announce the system
2084 call, both when it is called and when its call returns. This
2085 feature is currently available with a native GDB running on the
2086 Linux Kernel, under the following architectures: x86, x86_64,
2087 PowerPC and PowerPC64.
2089 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2091 Search memory for a sequence of bytes.
2093 maint set python print-stack
2094 maint show python print-stack
2095 Show a stack trace when an error is encountered in a Python script.
2098 Invoke CODE by passing it to the Python interpreter.
2103 These allow macros to be defined, undefined, and listed
2107 Show operating system information about processes.
2110 List the inferiors currently under GDB's control.
2113 Switch focus to inferior number NUM.
2116 Detach from inferior number NUM.
2119 Kill inferior number NUM.
2123 set spu stop-on-load
2124 show spu stop-on-load
2125 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2127 set spu auto-flush-cache
2128 show spu auto-flush-cache
2129 Control whether to automatically flush the software-managed cache
2130 during Cell/B.E. debugging.
2132 set sh calling-convention
2133 show sh calling-convention
2134 Control the calling convention used when calling SH target functions.
2137 show debug timestamp
2138 Control display of timestamps with GDB debugging output.
2140 set disassemble-next-line
2141 show disassemble-next-line
2142 Control display of disassembled source lines or instructions when
2145 set remote noack-packet
2146 show remote noack-packet
2147 Set/show the use of remote protocol QStartNoAckMode packet. See above
2148 under "New remote packets."
2150 set remote query-attached-packet
2151 show remote query-attached-packet
2152 Control use of remote protocol `qAttached' (query-attached) packet.
2154 set remote read-siginfo-object
2155 show remote read-siginfo-object
2156 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2159 set remote write-siginfo-object
2160 show remote write-siginfo-object
2161 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2164 set remote reverse-continue
2165 show remote reverse-continue
2166 Control use of remote protocol 'bc' (reverse-continue) packet.
2168 set remote reverse-step
2169 show remote reverse-step
2170 Control use of remote protocol 'bs' (reverse-step) packet.
2172 set displaced-stepping
2173 show displaced-stepping
2174 Control displaced stepping mode. Displaced stepping is a way to
2175 single-step over breakpoints without removing them from the debuggee.
2176 Also known as "out-of-line single-stepping".
2179 show debug displaced
2180 Control display of debugging info for displaced stepping.
2182 maint set internal-error
2183 maint show internal-error
2184 Control what GDB does when an internal error is detected.
2186 maint set internal-warning
2187 maint show internal-warning
2188 Control what GDB does when an internal warning is detected.
2193 Use a wrapper program to launch programs for debugging.
2195 set multiple-symbols (all|ask|cancel)
2196 show multiple-symbols
2197 The value of this variable can be changed to adjust the debugger behavior
2198 when an expression or a breakpoint location contains an ambiguous symbol
2199 name (an overloaded function name, for instance).
2201 set breakpoint always-inserted
2202 show breakpoint always-inserted
2203 Keep breakpoints always inserted in the target, as opposed to inserting
2204 them when resuming the target, and removing them when the target stops.
2205 This option can improve debugger performance on slow remote targets.
2207 set arm fallback-mode (arm|thumb|auto)
2208 show arm fallback-mode
2209 set arm force-mode (arm|thumb|auto)
2211 These commands control how ARM GDB determines whether instructions
2212 are ARM or Thumb. The default for both settings is auto, which uses
2213 the current CPSR value for instructions without symbols; previous
2214 versions of GDB behaved as if "set arm fallback-mode arm".
2216 set disable-randomization
2217 show disable-randomization
2218 Standalone programs run with the virtual address space randomization enabled
2219 by default on some platforms. This option keeps the addresses stable across
2220 multiple debugging sessions.
2224 Control whether other threads are stopped or not when some thread hits
2229 Requests that asynchronous execution is enabled in the target, if available.
2230 In this case, it's possible to resume target in the background, and interact
2231 with GDB while the target is running. "show target-async" displays the
2232 current state of asynchronous execution of the target.
2234 set target-wide-charset
2235 show target-wide-charset
2236 The target-wide-charset is the name of the character set that GDB
2237 uses when printing characters whose type is wchar_t.
2239 set tcp auto-retry (on|off)
2241 set tcp connect-timeout
2242 show tcp connect-timeout
2243 These commands allow GDB to retry failed TCP connections to a remote stub
2244 with a specified timeout period; this is useful if the stub is launched
2245 in parallel with GDB but may not be ready to accept connections immediately.
2247 set libthread-db-search-path
2248 show libthread-db-search-path
2249 Control list of directories which GDB will search for appropriate
2252 set schedule-multiple (on|off)
2253 show schedule-multiple
2254 Allow GDB to resume all threads of all processes or only threads of
2255 the current process.
2259 Use more aggressive caching for accesses to the stack. This improves
2260 performance of remote debugging (particularly backtraces) without
2261 affecting correctness.
2263 set interactive-mode (on|off|auto)
2264 show interactive-mode
2265 Control whether GDB runs in interactive mode (on) or not (off).
2266 When in interactive mode, GDB waits for the user to answer all
2267 queries. Otherwise, GDB does not wait and assumes the default
2268 answer. When set to auto (the default), GDB determines which
2269 mode to use based on the stdin settings.
2274 For program forks, this is replaced by the new more generic `info
2275 inferiors' command. To list checkpoints, you can still use the
2276 `info checkpoints' command, which was an alias for the `info forks'
2280 Replaced by the new `inferior' command. To switch between
2281 checkpoints, you can still use the `restart' command, which was an
2282 alias for the `fork' command.
2285 This is removed, since some targets don't have a notion of
2286 processes. To switch between processes, you can still use the
2287 `inferior' command using GDB's own inferior number.
2290 For program forks, this is replaced by the new more generic `kill
2291 inferior' command. To delete a checkpoint, you can still use the
2292 `delete checkpoint' command, which was an alias for the `delete
2296 For program forks, this is replaced by the new more generic `detach
2297 inferior' command. To detach a checkpoint, you can still use the
2298 `detach checkpoint' command, which was an alias for the `detach
2301 * New native configurations
2303 x86/x86_64 Darwin i[34567]86-*-darwin*
2305 x86_64 MinGW x86_64-*-mingw*
2309 Lattice Mico32 lm32-*
2310 x86 DICOS i[34567]86-*-dicos*
2311 x86_64 DICOS x86_64-*-dicos*
2314 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2315 (mingw32ce) debugging.
2321 These commands were actually not implemented on any target.
2323 *** Changes in GDB 6.8
2325 * New native configurations
2327 NetBSD/hppa hppa*-*netbsd*
2328 Xtensa GNU/Linux xtensa*-*-linux*
2332 NetBSD/hppa hppa*-*-netbsd*
2333 Xtensa GNU/Lunux xtensa*-*-linux*
2335 * Change in command line behavior -- corefiles vs. process ids.
2337 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2338 attaching to process NUMBER fails, GDB no longer attempts to open a
2339 core file named NUMBER. Attaching to a program using the -c option
2340 is no longer supported. Instead, use the '-p' or '--pid' options.
2342 * GDB can now be built as a native debugger for debugging Windows x86
2343 (mingw32) Portable Executable (PE) programs.
2345 * Pending breakpoints no longer change their number when their address
2348 * GDB now supports breakpoints with multiple locations,
2349 including breakpoints on C++ constructors, inside C++ templates,
2350 and in inlined functions.
2352 * GDB's ability to debug optimized code has been improved. GDB more
2353 accurately identifies function bodies and lexical blocks that occupy
2354 more than one contiguous range of addresses.
2356 * Target descriptions can now describe registers for PowerPC.
2358 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2359 registers on PowerPC targets.
2361 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2362 targets even when the libthread_db library is not available.
2364 * The GDB remote stub, gdbserver, now supports the new file transfer
2365 commands (remote put, remote get, and remote delete).
2367 * The GDB remote stub, gdbserver, now supports run and attach in
2368 extended-remote mode.
2370 * hppa*64*-*-hpux11* target broken
2371 The debugger is unable to start a program and fails with the following
2372 error: "Error trying to get information about dynamic linker".
2373 The gdb-6.7 release is also affected.
2375 * GDB now supports the --enable-targets= configure option to allow
2376 building a single GDB executable that supports multiple remote
2377 target architectures.
2379 * GDB now supports debugging C and C++ programs which use the
2380 Decimal Floating Point extension. In addition, the PowerPC target
2381 now has a set of pseudo-registers to inspect decimal float values
2382 stored in two consecutive float registers.
2384 * The -break-insert MI command can optionally create pending
2387 * Improved support for debugging Ada
2388 Many improvements to the Ada language support have been made. These
2390 - Better support for Ada2005 interface types
2391 - Improved handling of arrays and slices in general
2392 - Better support for Taft-amendment types
2393 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2395 - Improved command completion in Ada
2398 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2403 set print frame-arguments (all|scalars|none)
2404 show print frame-arguments
2405 The value of this variable can be changed to control which argument
2406 values should be printed by the debugger when displaying a frame.
2411 Transfer files to and from a remote target, and delete remote files.
2418 Transfer files to and from a remote target, and delete remote files.
2420 * New remote packets
2427 Open, close, read, write, and delete files on the remote system.
2430 Attach to an existing process on the remote system, in extended-remote
2434 Run a new process on the remote system, in extended-remote mode.
2436 *** Changes in GDB 6.7
2438 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2439 bfd, libiberty and opcodes, as revealed by static analysis donated by
2440 Coverity, Inc. (http://scan.coverity.com).
2442 * When looking up multiply-defined global symbols, GDB will now prefer the
2443 symbol definition in the current shared library if it was built using the
2444 -Bsymbolic linker option.
2446 * When the Text User Interface (TUI) is not configured, GDB will now
2447 recognize the -tui command-line option and print a message that the TUI
2450 * The GDB remote stub, gdbserver, now has lower overhead for high
2451 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2453 * GDB for MIPS targets now autodetects whether a remote target provides
2454 32-bit or 64-bit register values.
2456 * Support for C++ member pointers has been improved.
2458 * GDB now understands XML target descriptions, which specify the
2459 target's overall architecture. GDB can read a description from
2460 a local file or over the remote serial protocol.
2462 * Vectors of single-byte data use a new integer type which is not
2463 automatically displayed as character or string data.
2465 * The /s format now works with the print command. It displays
2466 arrays of single-byte integers and pointers to single-byte integers
2469 * Target descriptions can now describe target-specific registers,
2470 for architectures which have implemented the support (currently
2471 only ARM, M68K, and MIPS).
2473 * GDB and the GDB remote stub, gdbserver, now support the XScale
2476 * The GDB remote stub, gdbserver, has been updated to support
2477 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2478 has been rewritten to use the standard GDB remote protocol.
2480 * GDB can now step into C++ functions which are called through thunks.
2482 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2484 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2485 layout. It also supports a TextSeg= and DataSeg= response when only
2486 segment base addresses (rather than offsets) are available.
2488 * The /i format now outputs any trailing branch delay slot instructions
2489 immediately following the last instruction within the count specified.
2491 * The GDB remote protocol "T" stop reply packet now supports a
2492 "library" response. Combined with the new "qXfer:libraries:read"
2493 packet, this response allows GDB to debug shared libraries on targets
2494 where the operating system manages the list of loaded libraries (e.g.
2495 Windows and SymbianOS).
2497 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2498 (DLLs) on Windows and Windows CE targets.
2500 * GDB now supports a faster verification that a .debug file matches its binary
2501 according to its build-id signature, if the signature is present.
2507 Enable or disable hardware flow control (RTS/CTS) on the serial port
2508 when debugging using remote targets.
2510 set mem inaccessible-by-default
2511 show mem inaccessible-by-default
2512 If the target supplies a memory map, for instance via the remote
2513 protocol's "qXfer:memory-map:read" packet, setting this variable
2514 prevents GDB from accessing memory outside the memory map. This
2515 is useful for targets with memory mapped registers or which react
2516 badly to accesses of unmapped address space.
2518 set breakpoint auto-hw
2519 show breakpoint auto-hw
2520 If the target supplies a memory map, for instance via the remote
2521 protocol's "qXfer:memory-map:read" packet, setting this variable
2522 lets GDB use hardware breakpoints automatically for memory regions
2523 where it can not use software breakpoints. This covers both the
2524 "break" command and internal breakpoints used for other commands
2525 including "next" and "finish".
2528 catch exception unhandled
2529 Stop the program execution when Ada exceptions are raised.
2532 Stop the program execution when an Ada assertion failed.
2536 Set an alternate system root for target files. This is a more
2537 general version of "set solib-absolute-prefix", which is now
2538 an alias to "set sysroot".
2541 Provide extended SPU facility status information. This set of
2542 commands is available only when debugging the Cell/B.E. SPU
2545 * New native configurations
2547 OpenBSD/sh sh*-*openbsd*
2550 unset tdesc filename
2552 Use the specified local file as an XML target description, and do
2553 not query the target for its built-in description.
2557 OpenBSD/sh sh*-*-openbsd*
2558 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2559 Toshiba Media Processor mep-elf
2561 * New remote packets
2564 Ignore the specified signals; pass them directly to the debugged program
2565 without stopping other threads or reporting them to GDB.
2567 qXfer:features:read:
2568 Read an XML target description from the target, which describes its
2573 Read or write contents of an spufs file on the target system. These
2574 packets are available only on the Cell/B.E. SPU architecture.
2576 qXfer:libraries:read:
2577 Report the loaded shared libraries. Combined with new "T" packet
2578 response, this packet allows GDB to debug shared libraries on
2579 targets where the operating system manages the list of loaded
2580 libraries (e.g. Windows and SymbianOS).
2584 Support for these obsolete configurations has been removed.
2592 i[34567]86-*-lynxos*
2593 i[34567]86-*-netware*
2594 i[34567]86-*-sco3.2v5*
2595 i[34567]86-*-sco3.2v4*
2597 i[34567]86-*-sysv4.2*
2600 i[34567]86-*-unixware2*
2601 i[34567]86-*-unixware*
2610 * Other removed features
2617 Various m68k-only ROM monitors.
2624 Various Renesas ROM monitors and debugging interfaces for SH and
2629 Support for a Macraigor serial interface to on-chip debugging.
2630 GDB does not directly support the newer parallel or USB
2635 A debug information format. The predecessor to DWARF 2 and
2636 DWARF 3, which are still supported.
2638 Support for the HP aCC compiler on HP-UX/PA-RISC
2640 SOM-encapsulated symbolic debugging information, automatic
2641 invocation of pxdb, and the aCC custom C++ ABI. This does not
2642 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2643 with aCC can still be debugged on an assembly level.
2645 MIPS ".pdr" sections
2647 A MIPS-specific format used to describe stack frame layout
2648 in debugging information.
2652 GDB could work with an older version of Guile to debug
2653 the interpreter and Scheme programs running in it.
2655 set mips stack-arg-size
2656 set mips saved-gpreg-size
2658 Use "set mips abi" to control parameter passing for MIPS.
2660 *** Changes in GDB 6.6
2665 Cell Broadband Engine SPU spu-elf
2667 * GDB can now be configured as a cross-debugger targeting native Windows
2668 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2669 running on a Windows system over TCP/IP to debug Windows programs.
2671 * The GDB remote stub, gdbserver, has been updated to support Windows and
2672 Cygwin debugging. Both single-threaded and multi-threaded programs are
2675 * The "set trust-readonly-sections" command works again. This command was
2676 broken in GDB 6.3, 6.4, and 6.5.
2678 * The "load" command now supports writing to flash memory, if the remote
2679 stub provides the required support.
2681 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2682 longer requires symbolic debug information (e.g. DWARF-2).
2687 unset substitute-path
2688 show substitute-path
2689 Manage a list of substitution rules that GDB uses to rewrite the name
2690 of the directories where the sources are located. This can be useful
2691 for instance when the sources were moved to a different location
2692 between compilation and debugging.
2696 Print each CLI command as it is executed. Each command is prefixed with
2697 a number of `+' symbols representing the nesting depth.
2698 The source command now has a `-v' option to enable the same feature.
2702 The ARM Demon monitor support (RDP protocol, "target rdp").
2704 Kernel Object Display, an embedded debugging feature which only worked with
2705 an obsolete version of Cisco IOS.
2707 The 'set download-write-size' and 'show download-write-size' commands.
2709 * New remote packets
2712 Tell a stub about GDB client features, and request remote target features.
2713 The first feature implemented is PacketSize, which allows the target to
2714 specify the size of packets it can handle - to minimize the number of
2715 packets required and improve performance when connected to a remote
2719 Fetch an OS auxilliary vector from the remote stub. This packet is a
2720 more efficient replacement for qPart:auxv:read.
2722 qXfer:memory-map:read:
2723 Fetch a memory map from the remote stub, including information about
2724 RAM, ROM, and flash memory devices.
2729 Erase and program a flash memory device.
2731 * Removed remote packets
2734 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2735 used it, and only gdbserver implemented it.
2737 *** Changes in GDB 6.5
2741 Renesas M32C/M16C m32c-elf
2743 Morpho Technologies ms1 ms1-elf
2747 init-if-undefined Initialize a convenience variable, but
2748 only if it doesn't already have a value.
2750 The following commands are presently only implemented for native GNU/Linux:
2752 checkpoint Save a snapshot of the program state.
2754 restart <n> Return the program state to a
2755 previously saved state.
2757 info checkpoints List currently saved checkpoints.
2759 delete-checkpoint <n> Delete a previously saved checkpoint.
2761 set|show detach-on-fork Tell gdb whether to detach from a newly
2762 forked process, or to keep debugging it.
2764 info forks List forks of the user program that
2765 are available to be debugged.
2767 fork <n> Switch to debugging one of several
2768 forks of the user program that are
2769 available to be debugged.
2771 delete-fork <n> Delete a fork from the list of forks
2772 that are available to be debugged (and
2773 kill the forked process).
2775 detach-fork <n> Delete a fork from the list of forks
2776 that are available to be debugged (and
2777 allow the process to continue).
2781 Morpho Technologies ms2 ms1-elf
2783 * Improved Windows host support
2785 GDB now builds as a cross debugger hosted on i686-mingw32, including
2786 native console support, and remote communications using either
2787 network sockets or serial ports.
2789 * Improved Modula-2 language support
2791 GDB can now print most types in the Modula-2 syntax. This includes:
2792 basic types, set types, record types, enumerated types, range types,
2793 pointer types and ARRAY types. Procedure var parameters are correctly
2794 printed and hexadecimal addresses and character constants are also
2795 written in the Modula-2 syntax. Best results can be obtained by using
2796 GNU Modula-2 together with the -gdwarf-2 command line option.
2800 The ARM rdi-share module.
2802 The Netware NLM debug server.
2804 *** Changes in GDB 6.4
2806 * New native configurations
2808 OpenBSD/arm arm*-*-openbsd*
2809 OpenBSD/mips64 mips64-*-openbsd*
2813 Morpho Technologies ms1 ms1-elf
2815 * New command line options
2817 --batch-silent As for --batch, but totally silent.
2818 --return-child-result The debugger will exist with the same value
2819 the child (debugged) program exited with.
2820 --eval-command COMMAND, -ex COMMAND
2821 Execute a single GDB CLI command. This may be
2822 specified multiple times and in conjunction
2823 with the --command (-x) option.
2825 * Deprecated commands removed
2827 The following commands, that were deprecated in 2000, have been
2831 set|show arm disassembly-flavor set|show arm disassembler
2832 othernames set arm disassembler
2833 set|show remotedebug set|show debug remote
2834 set|show archdebug set|show debug arch
2835 set|show eventdebug set|show debug event
2838 * New BSD user-level threads support
2840 It is now possible to debug programs using the user-level threads
2841 library on OpenBSD and FreeBSD. Currently supported (target)
2844 FreeBSD/amd64 x86_64-*-freebsd*
2845 FreeBSD/i386 i386-*-freebsd*
2846 OpenBSD/i386 i386-*-openbsd*
2848 Note that the new kernel threads libraries introduced in FreeBSD 5.x
2849 are not yet supported.
2851 * New support for Matsushita MN10300 w/sim added
2852 (Work in progress). mn10300-elf.
2854 * REMOVED configurations and files
2856 VxWorks and the XDR protocol *-*-vxworks
2857 Motorola MCORE mcore-*-*
2858 National Semiconductor NS32000 ns32k-*-*
2860 * New "set print array-indexes" command
2862 After turning this setting "on", GDB prints the index of each element
2863 when displaying arrays. The default is "off" to preserve the previous
2866 * VAX floating point support
2868 GDB now supports the not-quite-ieee VAX F and D floating point formats.
2870 * User-defined command support
2872 In addition to using $arg0..$arg9 for argument passing, it is now possible
2873 to use $argc to determine now many arguments have been passed. See the
2874 section on user-defined commands in the user manual for more information.
2876 *** Changes in GDB 6.3:
2878 * New command line option
2880 GDB now accepts -l followed by a number to set the timeout for remote
2883 * GDB works with GCC -feliminate-dwarf2-dups
2885 GDB now supports a more compact representation of DWARF-2 debug
2886 information using DW_FORM_ref_addr references. These are produced
2887 by GCC with the option -feliminate-dwarf2-dups and also by some
2888 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
2889 to use -feliminate-dwarf2-dups.
2891 * Internationalization
2893 When supported by the host system, GDB will be built with
2894 internationalization (libintl). The task of marking up the sources is
2895 continued, we're looking forward to our first translation.
2899 Initial support for debugging programs compiled with the GNAT
2900 implementation of the Ada programming language has been integrated
2901 into GDB. In this release, support is limited to expression evaluation.
2903 * New native configurations
2905 GNU/Linux/m32r m32r-*-linux-gnu
2909 GDB's remote protocol now includes support for the 'p' packet. This
2910 packet is used to fetch individual registers from a remote inferior.
2912 * END-OF-LIFE registers[] compatibility module
2914 GDB's internal register infrastructure has been completely rewritten.
2915 The new infrastructure making possible the implementation of key new
2916 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
2919 GDB 6.3 will be the last release to include the the registers[]
2920 compatibility module that allowed out-of-date configurations to
2921 continue to work. This change directly impacts the following
2931 powerpc bdm protocol
2933 Unless there is activity to revive these configurations, they will be
2934 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
2936 * OBSOLETE configurations and files
2938 Configurations that have been declared obsolete in this release have
2939 been commented out. Unless there is activity to revive these
2940 configurations, the next release of GDB will have their sources
2941 permanently REMOVED.
2950 *** Changes in GDB 6.2.1:
2952 * MIPS `break main; run' gave an heuristic-fence-post warning
2954 When attempting to run even a simple program, a warning about
2955 heuristic-fence-post being hit would be reported. This problem has
2958 * MIPS IRIX 'long double' crashed GDB
2960 When examining a long double variable, GDB would get a segmentation
2961 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
2962 IRIX long double values).
2966 A bug in the VAX stack code was causing problems with the "next"
2967 command. This problem has been fixed.
2969 *** Changes in GDB 6.2:
2971 * Fix for ``many threads''
2973 On GNU/Linux systems that use the NPTL threads library, a program
2974 rapidly creating and deleting threads would confuse GDB leading to the
2977 ptrace: No such process.
2978 thread_db_get_info: cannot get thread info: generic error
2980 This problem has been fixed.
2982 * "-async" and "-noasync" options removed.
2984 Support for the broken "-noasync" option has been removed (it caused
2987 * New ``start'' command.
2989 This command runs the program until the begining of the main procedure.
2991 * New BSD Kernel Data Access Library (libkvm) interface
2993 Using ``target kvm'' it is now possible to debug kernel core dumps and
2994 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
2995 platforms. Currently supported (native-only) configurations are:
2997 FreeBSD/amd64 x86_64-*-freebsd*
2998 FreeBSD/i386 i?86-*-freebsd*
2999 NetBSD/i386 i?86-*-netbsd*
3000 NetBSD/m68k m68*-*-netbsd*
3001 NetBSD/sparc sparc-*-netbsd*
3002 OpenBSD/amd64 x86_64-*-openbsd*
3003 OpenBSD/i386 i?86-*-openbsd*
3004 OpenBSD/m68k m68*-openbsd*
3005 OpenBSD/sparc sparc-*-openbsd*
3007 * Signal trampoline code overhauled
3009 Many generic problems with GDB's signal handling code have been fixed.
3010 These include: backtraces through non-contiguous stacks; recognition
3011 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3012 call; backtrace through a signal trampoline; step into and out of
3013 signal handlers; and single-stepping in the signal trampoline.
3015 Please note that kernel bugs are a limiting factor here. These
3016 features have been shown to work on an s390 GNU/Linux system that
3017 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3019 * Cygwin support for DWARF 2 added.
3021 * New native configurations
3023 GNU/Linux/hppa hppa*-*-linux*
3024 OpenBSD/hppa hppa*-*-openbsd*
3025 OpenBSD/m68k m68*-*-openbsd*
3026 OpenBSD/m88k m88*-*-openbsd*
3027 OpenBSD/powerpc powerpc-*-openbsd*
3028 NetBSD/vax vax-*-netbsd*
3029 OpenBSD/vax vax-*-openbsd*
3031 * END-OF-LIFE frame compatibility module
3033 GDB's internal frame infrastructure has been completely rewritten.
3034 The new infrastructure making it possible to support key new features
3035 including DWARF 2 Call Frame Information. To aid in the task of
3036 migrating old configurations to this new infrastructure, a
3037 compatibility module, that allowed old configurations to continue to
3038 work, was also included.
3040 GDB 6.2 will be the last release to include this frame compatibility
3041 module. This change directly impacts the following configurations:
3051 Unless there is activity to revive these configurations, they will be
3052 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3054 * REMOVED configurations and files
3056 Sun 3, running SunOS 3 m68*-*-sunos3*
3057 Sun 3, running SunOS 4 m68*-*-sunos4*
3058 Sun 2, running SunOS 3 m68000-*-sunos3*
3059 Sun 2, running SunOS 4 m68000-*-sunos4*
3060 Motorola 680x0 running LynxOS m68*-*-lynxos*
3061 AT&T 3b1/Unix pc m68*-att-*
3062 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3063 decstation mips-dec-* mips-little-*
3064 riscos mips-*-riscos* mips-*-sysv*
3065 sonymips mips-sony-*
3066 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3068 *** Changes in GDB 6.1.1:
3070 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3072 The TUI (Text-mode User Interface) is now built as part of a default
3073 GDB configuration. It is enabled by either selecting the TUI with the
3074 command line option "-i=tui" or by running the separate "gdbtui"
3075 program. For more information on the TUI, see the manual "Debugging
3078 * Pending breakpoint support (also included in GDB 6.1)
3080 Support has been added to allow you to specify breakpoints in shared
3081 libraries that have not yet been loaded. If a breakpoint location
3082 cannot be found, and the "breakpoint pending" option is set to auto,
3083 GDB queries you if you wish to make the breakpoint pending on a future
3084 shared-library load. If and when GDB resolves the breakpoint symbol,
3085 the pending breakpoint is removed as one or more regular breakpoints
3088 Pending breakpoints are very useful for GCJ Java debugging.
3090 * Fixed ISO-C build problems
3092 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3093 non ISO-C code that stopped them being built using a more strict ISO-C
3094 compiler (e.g., IBM's C compiler).
3096 * Fixed build problem on IRIX 5
3098 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3099 wasn't able to compile compile on an IRIX 5 system.
3101 * Added execute permission to gdb/gdbserver/configure
3103 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3104 permission. This bug would cause configure to fail on a number of
3105 systems (Solaris, IRIX). Ref: server/519.
3107 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3109 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3110 has been updated to use constant array sizes.
3112 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3114 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3115 its generated DWARF Call Frame Info. This encoding was causing GDB to
3116 panic, that panic has been fixed. Ref: gdb/1628.
3118 * Fixed a problem when examining parameters in shared library code.
3120 When examining parameters in optimized shared library code generated
3121 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3122 not available''. GDB now correctly displays the variable's value.
3124 *** Changes in GDB 6.1:
3126 * Removed --with-mmalloc
3128 Support for the mmalloc memory manager has been removed, as it
3129 conflicted with the internal gdb byte cache.
3131 * Changes in AMD64 configurations
3133 The AMD64 target now includes the %cs and %ss registers. As a result
3134 the AMD64 remote protocol has changed; this affects the floating-point
3135 and SSE registers. If you rely on those registers for your debugging,
3136 you should upgrade gdbserver on the remote side.
3138 * Revised SPARC target
3140 The SPARC target has been completely revised, incorporating the
3141 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3142 support for LynxOS and SunOS 4 has been dropped. Calling functions
3143 from within GDB on operating systems with a non-executable stack
3144 (Solaris, OpenBSD) now works.
3148 GDB has a new C++ demangler which does a better job on the mangled
3149 names generated by current versions of g++. It also runs faster, so
3150 with this and other changes gdb should now start faster on large C++
3153 * DWARF 2 Location Expressions
3155 GDB support for location expressions has been extended to support function
3156 arguments and frame bases. Older versions of GDB could crash when they
3159 * C++ nested types and namespaces
3161 GDB's support for nested types and namespaces in C++ has been
3162 improved, especially if you use the DWARF 2 debugging format. (This
3163 is the default for recent versions of GCC on most platforms.)
3164 Specifically, if you have a class "Inner" defined within a class or
3165 namespace "Outer", then GDB realizes that the class's name is
3166 "Outer::Inner", not simply "Inner". This should greatly reduce the
3167 frequency of complaints about not finding RTTI symbols. In addition,
3168 if you are stopped at inside of a function defined within a namespace,
3169 GDB modifies its name lookup accordingly.
3171 * New native configurations
3173 NetBSD/amd64 x86_64-*-netbsd*
3174 OpenBSD/amd64 x86_64-*-openbsd*
3175 OpenBSD/alpha alpha*-*-openbsd*
3176 OpenBSD/sparc sparc-*-openbsd*
3177 OpenBSD/sparc64 sparc64-*-openbsd*
3179 * New debugging protocols
3181 M32R with SDI protocol m32r-*-elf*
3183 * "set prompt-escape-char" command deleted.
3185 The command "set prompt-escape-char" has been deleted. This command,
3186 and its very obscure effet on GDB's prompt, was never documented,
3187 tested, nor mentioned in the NEWS file.
3189 * OBSOLETE configurations and files
3191 Configurations that have been declared obsolete in this release have
3192 been commented out. Unless there is activity to revive these
3193 configurations, the next release of GDB will have their sources
3194 permanently REMOVED.
3196 Sun 3, running SunOS 3 m68*-*-sunos3*
3197 Sun 3, running SunOS 4 m68*-*-sunos4*
3198 Sun 2, running SunOS 3 m68000-*-sunos3*
3199 Sun 2, running SunOS 4 m68000-*-sunos4*
3200 Motorola 680x0 running LynxOS m68*-*-lynxos*
3201 AT&T 3b1/Unix pc m68*-att-*
3202 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3203 decstation mips-dec-* mips-little-*
3204 riscos mips-*-riscos* mips-*-sysv*
3205 sonymips mips-sony-*
3206 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3208 * REMOVED configurations and files
3210 SGI Irix-4.x mips-sgi-irix4 or iris4
3211 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3212 Z8000 simulator z8k-zilog-none or z8ksim
3213 Matsushita MN10200 w/simulator mn10200-*-*
3214 H8/500 simulator h8500-hitachi-hms or h8500hms
3215 HP/PA running BSD hppa*-*-bsd*
3216 HP/PA running OSF/1 hppa*-*-osf*
3217 HP/PA Pro target hppa*-*-pro*
3218 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3219 386BSD i[3456]86-*-bsd*
3220 Sequent family i[3456]86-sequent-sysv4*
3221 i[3456]86-sequent-sysv*
3222 i[3456]86-sequent-bsd*
3223 SPARC running LynxOS sparc-*-lynxos*
3224 SPARC running SunOS 4 sparc-*-sunos4*
3225 Tsqware Sparclet sparclet-*-*
3226 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3228 *** Changes in GDB 6.0:
3232 Support for debugging the Objective-C programming language has been
3233 integrated into GDB.
3235 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3237 DWARF 2's Call Frame Information makes available compiler generated
3238 information that more exactly describes the program's run-time stack.
3239 By using this information, GDB is able to provide more robust stack
3242 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3243 have been updated to use a new backtrace mechanism which includes
3244 DWARF 2 CFI support.
3248 GDB's remote protocol has been extended to include support for hosted
3249 file I/O (where the remote target uses GDB's file system). See GDB's
3250 remote protocol documentation for details.
3252 * All targets using the new architecture framework.
3254 All of GDB's targets have been updated to use the new internal
3255 architecture framework. The way is now open for future GDB releases
3256 to include cross-architecture native debugging support (i386 on amd64,
3259 * GNU/Linux's Thread Local Storage (TLS)
3261 GDB now includes support for for the GNU/Linux implementation of
3262 per-thread variables.
3264 * GNU/Linux's Native POSIX Thread Library (NPTL)
3266 GDB's thread code has been updated to work with either the new
3267 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3269 * Separate debug info.
3271 GDB, in conjunction with BINUTILS, now supports a mechanism for
3272 automatically loading debug information from a separate file. Instead
3273 of shipping full debug and non-debug versions of system libraries,
3274 system integrators can now instead ship just the stripped libraries
3275 and optional debug files.
3277 * DWARF 2 Location Expressions
3279 DWARF 2 Location Expressions allow the compiler to more completely
3280 describe the location of variables (even in optimized code) to the
3283 GDB now includes preliminary support for location expressions (support
3284 for DW_OP_piece is still missing).
3288 A number of long standing bugs that caused GDB to die while starting a
3289 Java application have been fixed. GDB's Java support is now
3290 considered "useable".
3292 * GNU/Linux support for fork, vfork, and exec.
3294 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3295 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3298 * GDB supports logging output to a file
3300 There are two new commands, "set logging" and "show logging", which can be
3301 used to capture GDB's output to a file.
3303 * The meaning of "detach" has changed for gdbserver
3305 The "detach" command will now resume the application, as documented. To
3306 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3309 * d10v, m68hc11 `regs' command deprecated
3311 The `info registers' command has been updated so that it displays the
3312 registers using a format identical to the old `regs' command.
3316 A new command, "maint set profile on/off", has been added. This command can
3317 be used to enable or disable profiling while running GDB, to profile a
3318 session or a set of commands. In addition there is a new configure switch,
3319 "--enable-profiling", which will cause GDB to be compiled with profiling
3320 data, for more informative profiling results.
3322 * Default MI syntax changed to "mi2".
3324 The default MI (machine interface) syntax, enabled by the command line
3325 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3326 "mi1", can be enabled by specifying the option "-i=mi1".
3328 Support for the original "mi0" syntax (included in GDB 5.0) has been
3331 Fix for gdb/192: removed extraneous space when displaying frame level.
3332 Fix for gdb/672: update changelist is now output in mi list format.
3333 Fix for gdb/702: a -var-assign that updates the value now shows up
3334 in a subsequent -var-update.
3336 * New native configurations.
3338 FreeBSD/amd64 x86_64-*-freebsd*
3340 * Multi-arched targets.
3342 HP/PA HPUX11 hppa*-*-hpux*
3343 Renesas M32R/D w/simulator m32r-*-elf*
3345 * OBSOLETE configurations and files
3347 Configurations that have been declared obsolete in this release have
3348 been commented out. Unless there is activity to revive these
3349 configurations, the next release of GDB will have their sources
3350 permanently REMOVED.
3352 Z8000 simulator z8k-zilog-none or z8ksim
3353 Matsushita MN10200 w/simulator mn10200-*-*
3354 H8/500 simulator h8500-hitachi-hms or h8500hms
3355 HP/PA running BSD hppa*-*-bsd*
3356 HP/PA running OSF/1 hppa*-*-osf*
3357 HP/PA Pro target hppa*-*-pro*
3358 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3359 Sequent family i[3456]86-sequent-sysv4*
3360 i[3456]86-sequent-sysv*
3361 i[3456]86-sequent-bsd*
3362 Tsqware Sparclet sparclet-*-*
3363 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3365 * REMOVED configurations and files
3368 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3369 IBM AIX PS/2 i[3456]86-*-aix
3370 i386 running Mach 3.0 i[3456]86-*-mach3*
3371 i386 running Mach i[3456]86-*-mach*
3372 i386 running OSF/1 i[3456]86-*osf1mk*
3373 HP/Apollo 68k Family m68*-apollo*-sysv*,
3375 m68*-hp-bsd*, m68*-hp-hpux*
3376 Argonaut Risc Chip (ARC) arc-*-*
3377 Mitsubishi D30V d30v-*-*
3378 Fujitsu FR30 fr30-*-elf*
3379 OS/9000 i[34]86-*-os9k
3380 I960 with MON960 i960-*-coff
3382 * MIPS $fp behavior changed
3384 The convenience variable $fp, for the MIPS, now consistently returns
3385 the address of the current frame's base. Previously, depending on the
3386 context, $fp could refer to either $sp or the current frame's base
3387 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3388 The GNU Source-Level Debugger''.
3390 *** Changes in GDB 5.3:
3392 * GNU/Linux shared library multi-threaded performance improved.
3394 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3395 `/proc', in preference to `ptrace' for memory reads. This may result
3396 in an improvement in the start-up time of multi-threaded, shared
3397 library applications when run under GDB. One GDB user writes: ``loads
3398 shared libs like mad''.
3400 * ``gdbserver'' now supports multi-threaded applications on some targets
3402 Support for debugging multi-threaded applications which use
3403 the GNU/Linux LinuxThreads package has been added for
3404 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3405 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3407 * GDB now supports C/C++ preprocessor macros.
3409 GDB now expands preprocessor macro invocations in C/C++ expressions,
3410 and provides various commands for showing macro definitions and how
3413 The new command `macro expand EXPRESSION' expands any macro
3414 invocations in expression, and shows the result.
3416 The new command `show macro MACRO-NAME' shows the definition of the
3417 macro named MACRO-NAME, and where it was defined.
3419 Most compilers don't include information about macros in the debugging
3420 information by default. In GCC 3.1, for example, you need to compile
3421 your program with the options `-gdwarf-2 -g3'. If the macro
3422 information is present in the executable, GDB will read it.
3424 * Multi-arched targets.
3426 DEC Alpha (partial) alpha*-*-*
3427 DEC VAX (partial) vax-*-*
3429 National Semiconductor NS32000 (partial) ns32k-*-*
3430 Motorola 68000 (partial) m68k-*-*
3431 Motorola MCORE mcore-*-*
3435 Fujitsu FRV architecture added by Red Hat frv*-*-*
3438 * New native configurations
3440 Alpha NetBSD alpha*-*-netbsd*
3441 SH NetBSD sh*-*-netbsdelf*
3442 MIPS NetBSD mips*-*-netbsd*
3443 UltraSPARC NetBSD sparc64-*-netbsd*
3445 * OBSOLETE configurations and files
3447 Configurations that have been declared obsolete in this release have
3448 been commented out. Unless there is activity to revive these
3449 configurations, the next release of GDB will have their sources
3450 permanently REMOVED.
3452 Mitsubishi D30V d30v-*-*
3453 OS/9000 i[34]86-*-os9k
3454 IBM AIX PS/2 i[3456]86-*-aix
3455 Fujitsu FR30 fr30-*-elf*
3456 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3457 Argonaut Risc Chip (ARC) arc-*-*
3458 i386 running Mach 3.0 i[3456]86-*-mach3*
3459 i386 running Mach i[3456]86-*-mach*
3460 i386 running OSF/1 i[3456]86-*osf1mk*
3461 HP/Apollo 68k Family m68*-apollo*-sysv*,
3463 m68*-hp-bsd*, m68*-hp-hpux*
3464 I960 with MON960 i960-*-coff
3466 * OBSOLETE languages
3468 CHILL, a Pascal like language used by telecommunications companies.
3470 * REMOVED configurations and files
3472 AMD 29k family via UDI a29k-amd-udi, udi29k
3473 A29K VxWorks a29k-*-vxworks
3474 AMD 29000 embedded, using EBMON a29k-none-none
3475 AMD 29000 embedded with COFF a29k-none-coff
3476 AMD 29000 embedded with a.out a29k-none-aout
3478 testsuite/gdb.hp/gdb.threads-hp/ directory
3480 * New command "set max-user-call-depth <nnn>"
3482 This command allows the user to limit the call depth of user-defined
3483 commands. The default is 1024.
3485 * Changes in FreeBSD/i386 native debugging.
3487 Support for the "generate-core-file" has been added.
3489 * New commands "dump", "append", and "restore".
3491 These commands allow data to be copied from target memory
3492 to a bfd-format or binary file (dump and append), and back
3493 from a file into memory (restore).
3495 * Improved "next/step" support on multi-processor Alpha Tru64.
3497 The previous single-step mechanism could cause unpredictable problems,
3498 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3499 of a software single-step mechanism prevents this.
3501 *** Changes in GDB 5.2.1:
3509 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3510 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3511 Fix, by Joel Brobecker imported from mainline.
3513 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3514 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3515 Fix, by Fred Fish, imported from mainline.
3517 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3518 Surprisingly enough, it works now.
3519 By Michal Ludvig, imported from mainline.
3521 i386 hardware watchpoint support:
3522 avoid misses on second run for some targets.
3523 By Pierre Muller, imported from mainline.
3525 *** Changes in GDB 5.2:
3527 * New command "set trust-readonly-sections on[off]".
3529 This command is a hint that tells gdb that read-only sections
3530 really are read-only (ie. that their contents will not change).
3531 In this mode, gdb will go to the object file rather than the
3532 target to read memory from read-only sections (such as ".text").
3533 This can be a significant performance improvement on some
3534 (notably embedded) targets.
3536 * New command "generate-core-file" (or "gcore").
3538 This new gdb command allows the user to drop a core file of the child
3539 process state at any time. So far it's been implemented only for
3540 GNU/Linux and Solaris, but should be relatively easily ported to other
3541 hosts. Argument is core file name (defaults to core.<pid>).
3543 * New command line option
3545 GDB now accepts --pid or -p followed by a process id.
3547 * Change in command line behavior -- corefiles vs. process ids.
3549 There is a subtle behavior in the way in which GDB handles
3550 command line arguments. The first non-flag argument is always
3551 a program to debug, but the second non-flag argument may either
3552 be a corefile or a process id. Previously, GDB would attempt to
3553 open the second argument as a corefile, and if that failed, would
3554 issue a superfluous error message and then attempt to attach it as
3555 a process. Now, if the second argument begins with a non-digit,
3556 it will be treated as a corefile. If it begins with a digit,
3557 GDB will attempt to attach it as a process, and if no such process
3558 is found, will then attempt to open it as a corefile.
3560 * Changes in ARM configurations.
3562 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3563 configuration is fully multi-arch.
3565 * New native configurations
3567 ARM NetBSD arm*-*-netbsd*
3568 x86 OpenBSD i[3456]86-*-openbsd*
3569 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3570 Sparc64 running FreeBSD sparc64-*-freebsd*
3574 Sanyo XStormy16 xstormy16-elf
3576 * OBSOLETE configurations and files
3578 Configurations that have been declared obsolete in this release have
3579 been commented out. Unless there is activity to revive these
3580 configurations, the next release of GDB will have their sources
3581 permanently REMOVED.
3583 AMD 29k family via UDI a29k-amd-udi, udi29k
3584 A29K VxWorks a29k-*-vxworks
3585 AMD 29000 embedded, using EBMON a29k-none-none
3586 AMD 29000 embedded with COFF a29k-none-coff
3587 AMD 29000 embedded with a.out a29k-none-aout
3589 testsuite/gdb.hp/gdb.threads-hp/ directory
3591 * REMOVED configurations and files
3593 TI TMS320C80 tic80-*-*
3595 PowerPC Solaris powerpcle-*-solaris*
3596 PowerPC Windows NT powerpcle-*-cygwin32
3597 PowerPC Netware powerpc-*-netware*
3598 Harris/CXUX m88k m88*-harris-cxux*
3599 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3600 ns32k-utek-sysv* ns32k-utek-*
3601 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3602 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3603 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3604 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3605 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3607 * Changes to command line processing
3609 The new `--args' feature can be used to specify command-line arguments
3610 for the inferior from gdb's command line.
3612 * Changes to key bindings
3614 There is a new `operate-and-get-next' function bound to `C-o'.
3616 *** Changes in GDB 5.1.1
3618 Fix compile problem on DJGPP.
3620 Fix a problem with floating-point registers on the i386 being
3623 Fix to stop GDB crashing on .debug_str debug info.
3625 Numerous documentation fixes.
3627 Numerous testsuite fixes.
3629 *** Changes in GDB 5.1:
3631 * New native configurations
3633 Alpha FreeBSD alpha*-*-freebsd*
3634 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3635 MIPS GNU/Linux mips*-*-linux*
3636 MIPS SGI Irix 6.x mips*-sgi-irix6*
3637 ia64 AIX ia64-*-aix*
3638 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3642 Motorola 68HC11 and 68HC12 m68hc11-elf
3644 UltraSparc running GNU/Linux sparc64-*-linux*
3646 * OBSOLETE configurations and files
3648 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3649 Harris/CXUX m88k m88*-harris-cxux*
3650 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3651 ns32k-utek-sysv* ns32k-utek-*
3652 TI TMS320C80 tic80-*-*
3654 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3655 PowerPC Solaris powerpcle-*-solaris*
3656 PowerPC Windows NT powerpcle-*-cygwin32
3657 PowerPC Netware powerpc-*-netware*
3658 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3659 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3660 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3661 Apple Macintosh (MPW) host N/A
3663 stuff.c (Program to stuff files into a specially prepared space in kdb)
3664 kdb-start.c (Main loop for the standalone kernel debugger)
3666 Configurations that have been declared obsolete in this release have
3667 been commented out. Unless there is activity to revive these
3668 configurations, the next release of GDB will have their sources
3669 permanently REMOVED.
3671 * REMOVED configurations and files
3673 Altos 3068 m68*-altos-*
3674 Convex c1-*-*, c2-*-*
3676 ARM RISCix arm-*-* (as host)
3680 * GDB has been converted to ISO C.
3682 GDB's source code has been converted to ISO C. In particular, the
3683 sources are fully protoized, and rely on standard headers being
3688 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3690 * The MI enabled by default.
3692 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3693 revised and enabled by default. Packages which use GDB as a debugging
3694 engine behind a UI or another front end are encouraged to switch to
3695 using the GDB/MI interface, instead of the old annotations interface
3696 which is now deprecated.
3698 * Support for debugging Pascal programs.
3700 GDB now includes support for debugging Pascal programs. The following
3701 main features are supported:
3703 - Pascal-specific data types such as sets;
3705 - automatic recognition of Pascal sources based on file-name
3708 - Pascal-style display of data types, variables, and functions;
3710 - a Pascal expression parser.
3712 However, some important features are not yet supported.
3714 - Pascal string operations are not supported at all;
3716 - there are some problems with boolean types;
3718 - Pascal type hexadecimal constants are not supported
3719 because they conflict with the internal variables format;
3721 - support for Pascal objects and classes is not full yet;
3723 - unlike Pascal, GDB is case-sensitive for symbol names.
3725 * Changes in completion.
3727 Commands such as `shell', `run' and `set args', which pass arguments
3728 to inferior programs, now complete on file names, similar to what
3729 users expect at the shell prompt.
3731 Commands which accept locations, such as `disassemble', `print',
3732 `breakpoint', `until', etc. now complete on filenames as well as
3733 program symbols. Thus, if you type "break foob TAB", and the source
3734 files linked into the programs include `foobar.c', that file name will
3735 be one of the candidates for completion. However, file names are not
3736 considered for completion after you typed a colon that delimits a file
3737 name from a name of a function in that file, as in "break foo.c:bar".
3739 `set demangle-style' completes on available demangling styles.
3741 * New platform-independent commands:
3743 It is now possible to define a post-hook for a command as well as a
3744 hook that runs before the command. For more details, see the
3745 documentation of `hookpost' in the GDB manual.
3747 * Changes in GNU/Linux native debugging.
3749 Support for debugging multi-threaded programs has been completely
3750 revised for all platforms except m68k and sparc. You can now debug as
3751 many threads as your system allows you to have.
3753 Attach/detach is supported for multi-threaded programs.
3755 Support for SSE registers was added for x86. This doesn't work for
3756 multi-threaded programs though.
3758 * Changes in MIPS configurations.
3760 Multi-arch support is enabled for all MIPS configurations.
3762 GDB can now be built as native debugger on SGI Irix 6.x systems for
3763 debugging n32 executables. (Debugging 64-bit executables is not yet
3766 * Unified support for hardware watchpoints in all x86 configurations.
3768 Most (if not all) native x86 configurations support hardware-assisted
3769 breakpoints and watchpoints in a unified manner. This support
3770 implements debug register sharing between watchpoints, which allows to
3771 put a virtually infinite number of watchpoints on the same address,
3772 and also supports watching regions up to 16 bytes with several debug
3775 The new maintenance command `maintenance show-debug-regs' toggles
3776 debugging print-outs in functions that insert, remove, and test
3777 watchpoints and hardware breakpoints.
3779 * Changes in the DJGPP native configuration.
3781 New command ``info dos sysinfo'' displays assorted information about
3782 the CPU, OS, memory, and DPMI server.
3784 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3785 display information about segment descriptors stored in GDT, LDT, and
3788 New commands ``info dos pde'' and ``info dos pte'' display entries
3789 from Page Directory and Page Tables (for now works with CWSDPMI only).
3790 New command ``info dos address-pte'' displays the Page Table entry for
3791 a given linear address.
3793 GDB can now pass command lines longer than 126 characters to the
3794 program being debugged (requires an update to the libdbg.a library
3795 which is part of the DJGPP development kit).
3797 DWARF2 debug info is now supported.
3799 It is now possible to `step' and `next' through calls to `longjmp'.
3801 * Changes in documentation.
3803 All GDB documentation was converted to GFDL, the GNU Free
3804 Documentation License.
3806 Tracepoints-related commands are now fully documented in the GDB
3809 TUI, the Text-mode User Interface, is now documented in the manual.
3811 Tracepoints-related commands are now fully documented in the GDB
3814 The "GDB Internals" manual now has an index. It also includes
3815 documentation of `ui_out' functions, GDB coding standards, x86
3816 hardware watchpoints, and memory region attributes.
3818 * GDB's version number moved to ``version.in''
3820 The Makefile variable VERSION has been replaced by the file
3821 ``version.in''. People creating GDB distributions should update the
3822 contents of this file.
3826 GUD support is now a standard part of the EMACS distribution.
3828 *** Changes in GDB 5.0:
3830 * Improved support for debugging FP programs on x86 targets
3832 Unified and much-improved support for debugging floating-point
3833 programs on all x86 targets. In particular, ``info float'' now
3834 displays the FP registers in the same format on all x86 targets, with
3835 greater level of detail.
3837 * Improvements and bugfixes in hardware-assisted watchpoints
3839 It is now possible to watch array elements, struct members, and
3840 bitfields with hardware-assisted watchpoints. Data-read watchpoints
3841 on x86 targets no longer erroneously trigger when the address is
3844 * Improvements in the native DJGPP version of GDB
3846 The distribution now includes all the scripts and auxiliary files
3847 necessary to build the native DJGPP version on MS-DOS/MS-Windows
3848 machines ``out of the box''.
3850 The DJGPP version can now debug programs that use signals. It is
3851 possible to catch signals that happened in the debuggee, deliver
3852 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
3853 would kill the program being debugged.) Programs that hook hardware
3854 interrupts (keyboard, timer, etc.) can also be debugged.
3856 It is now possible to debug DJGPP programs that redirect their
3857 standard handles or switch them to raw (as opposed to cooked) mode, or
3858 even close them. The command ``run < foo > bar'' works as expected,
3859 and ``info terminal'' reports useful information about the debuggee's
3860 terminal, including raw/cooked mode, redirection, etc.
3862 The DJGPP version now uses termios functions for console I/O, which
3863 enables debugging graphics programs. Interrupting GDB with Ctrl-C
3866 DOS-style file names with drive letters are now fully supported by
3869 It is now possible to debug DJGPP programs that switch their working
3870 directory. It is also possible to rerun the debuggee any number of
3871 times without restarting GDB; thus, you can use the same setup,
3872 breakpoints, etc. for many debugging sessions.
3874 * New native configurations
3876 ARM GNU/Linux arm*-*-linux*
3877 PowerPC GNU/Linux powerpc-*-linux*
3881 Motorola MCore mcore-*-*
3882 x86 VxWorks i[3456]86-*-vxworks*
3883 PowerPC VxWorks powerpc-*-vxworks*
3884 TI TMS320C80 tic80-*-*
3886 * OBSOLETE configurations
3888 Altos 3068 m68*-altos-*
3889 Convex c1-*-*, c2-*-*
3891 ARM RISCix arm-*-* (as host)
3894 Configurations that have been declared obsolete will be commented out,
3895 but the code will be left in place. If there is no activity to revive
3896 these configurations before the next release of GDB, the sources will
3897 be permanently REMOVED.
3899 * Gould support removed
3901 Support for the Gould PowerNode and NP1 has been removed.
3903 * New features for SVR4
3905 On SVR4 native platforms (such as Solaris), if you attach to a process
3906 without first loading a symbol file, GDB will now attempt to locate and
3907 load symbols from the running process's executable file.
3909 * Many C++ enhancements
3911 C++ support has been greatly improved. Overload resolution now works properly
3912 in almost all cases. RTTI support is on the way.
3914 * Remote targets can connect to a sub-program
3916 A popen(3) style serial-device has been added. This device starts a
3917 sub-process (such as a stand-alone simulator) and then communicates
3918 with that. The sub-program to run is specified using the syntax
3919 ``|<program> <args>'' vis:
3921 (gdb) set remotedebug 1
3922 (gdb) target extended-remote |mn10300-elf-sim program-args
3924 * MIPS 64 remote protocol
3926 A long standing bug in the mips64 remote protocol where by GDB
3927 expected certain 32 bit registers (ex SR) to be transfered as 32
3928 instead of 64 bits has been fixed.
3930 The command ``set remote-mips64-transfers-32bit-regs on'' has been
3931 added to provide backward compatibility with older versions of GDB.
3933 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
3935 The command ``set remotebinarydownload'' command has been replaced by
3936 ``set remote X-packet''. Other commands in ``set remote'' family
3937 include ``set remote P-packet''.
3939 * Breakpoint commands accept ranges.
3941 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
3942 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
3943 ``tracepoint passcount'' also accepts a range of tracepoints.
3945 * ``apropos'' command added.
3947 The ``apropos'' command searches through command names and
3948 documentation strings, printing out matches, making it much easier to
3949 try to find a command that does what you are looking for.
3953 A new machine oriented interface (MI) has been added to GDB. This
3954 interface is designed for debug environments running GDB as a separate
3955 process. This is part of the long term libGDB project. See the
3956 "GDB/MI" chapter of the GDB manual for further information. It can be
3957 enabled by configuring with:
3959 .../configure --enable-gdbmi
3961 *** Changes in GDB-4.18:
3963 * New native configurations
3965 HP-UX 10.20 hppa*-*-hpux10.20
3966 HP-UX 11.x hppa*-*-hpux11.0*
3967 M68K GNU/Linux m68*-*-linux*
3971 Fujitsu FR30 fr30-*-elf*
3972 Intel StrongARM strongarm-*-*
3973 Mitsubishi D30V d30v-*-*
3975 * OBSOLETE configurations
3977 Gould PowerNode, NP1 np1-*-*, pn-*-*
3979 Configurations that have been declared obsolete will be commented out,
3980 but the code will be left in place. If there is no activity to revive
3981 these configurations before the next release of GDB, the sources will
3982 be permanently REMOVED.
3986 As a compatibility experiment, GDB's source files buildsym.h and
3987 buildsym.c have been converted to pure standard C, no longer
3988 containing any K&R compatibility code. We believe that all systems in
3989 use today either come with a standard C compiler, or have a GCC port
3990 available. If this is not true, please report the affected
3991 configuration to bug-gdb@gnu.org immediately. See the README file for
3992 information about getting a standard C compiler if you don't have one
3997 GDB now uses readline 2.2.
3999 * set extension-language
4001 You can now control the mapping between filename extensions and source
4002 languages by using the `set extension-language' command. For instance,
4003 you can ask GDB to treat .c files as C++ by saying
4004 set extension-language .c c++
4005 The command `info extensions' lists all of the recognized extensions
4006 and their associated languages.
4008 * Setting processor type for PowerPC and RS/6000
4010 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4011 you can use the `set processor' command to specify what variant of the
4012 PowerPC family you are debugging. The command
4016 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4017 following PowerPC and RS6000 variants:
4019 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4020 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4022 403GC IBM PowerPC 403GC
4023 505 Motorola PowerPC 505
4024 860 Motorola PowerPC 860 or 850
4025 601 Motorola PowerPC 601
4026 602 Motorola PowerPC 602
4027 603 Motorola/IBM PowerPC 603 or 603e
4028 604 Motorola PowerPC 604 or 604e
4029 750 Motorola/IBM PowerPC 750 or 750
4031 At the moment, this command just tells GDB what to name the
4032 special-purpose processor registers. Since almost all the affected
4033 registers are inaccessible to user-level programs, this command is
4034 only useful for remote debugging in its present form.
4038 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4039 more extensive support for HP-UX. Added features include shared
4040 library support, kernel threads and hardware watchpoints for 11.00,
4041 support for HP's ANSI C and C++ compilers, and a compatibility mode
4042 for xdb and dbx commands.
4046 HP's donation includes the new concept of catchpoints, which is a
4047 generalization of the old catch command. On HP-UX, it is now possible
4048 to catch exec, fork, and vfork, as well as library loading.
4050 This means that the existing catch command has changed; its first
4051 argument now specifies the type of catch to be set up. See the
4052 output of "help catch" for a list of catchpoint types.
4054 * Debugging across forks
4056 On HP-UX, you can choose which process to debug when a fork() happens
4061 HP has donated a curses-based terminal user interface (TUI). To get
4062 it, build with --enable-tui. Although this can be enabled for any
4063 configuration, at present it only works for native HP debugging.
4065 * GDB remote protocol additions
4067 A new protocol packet 'X' that writes binary data is now available.
4068 Default behavior is to try 'X', then drop back to 'M' if the stub
4069 fails to respond. The settable variable `remotebinarydownload'
4070 allows explicit control over the use of 'X'.
4072 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4073 full 64-bit address. The command
4075 set remoteaddresssize 32
4077 can be used to revert to the old behaviour. For existing remote stubs
4078 the change should not be noticed, as the additional address information
4081 In order to assist in debugging stubs, you may use the maintenance
4082 command `packet' to send any text string to the stub. For instance,
4084 maint packet heythere
4086 sends the packet "$heythere#<checksum>". Note that it is very easy to
4087 disrupt a debugging session by sending the wrong packet at the wrong
4090 The compare-sections command allows you to compare section data on the
4091 target to what is in the executable file without uploading or
4092 downloading, by comparing CRC checksums.
4094 * Tracing can collect general expressions
4096 You may now collect general expressions at tracepoints. This requires
4097 further additions to the target-side stub; see tracepoint.c and
4098 doc/agentexpr.texi for further details.
4100 * mask-address variable for Mips
4102 For Mips targets, you may control the zeroing of the upper 32 bits of
4103 a 64-bit address by entering `set mask-address on'. This is mainly
4104 of interest to users of embedded R4xxx and R5xxx processors.
4106 * Higher serial baud rates
4108 GDB's serial code now allows you to specify baud rates 57600, 115200,
4109 230400, and 460800 baud. (Note that your host system may not be able
4110 to achieve all of these rates.)
4114 The i960 configuration now includes an initial implementation of a
4115 builtin simulator, contributed by Jim Wilson.
4118 *** Changes in GDB-4.17:
4120 * New native configurations
4122 Alpha GNU/Linux alpha*-*-linux*
4123 Unixware 2.x i[3456]86-unixware2*
4124 Irix 6.x mips*-sgi-irix6*
4125 PowerPC GNU/Linux powerpc-*-linux*
4126 PowerPC Solaris powerpcle-*-solaris*
4127 Sparc GNU/Linux sparc-*-linux*
4128 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4132 Argonaut Risc Chip (ARC) arc-*-*
4133 Hitachi H8/300S h8300*-*-*
4134 Matsushita MN10200 w/simulator mn10200-*-*
4135 Matsushita MN10300 w/simulator mn10300-*-*
4136 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4137 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4138 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4139 Mitsubishi D10V w/simulator d10v-*-*
4140 Mitsubishi M32R/D w/simulator m32r-*-elf*
4141 Tsqware Sparclet sparclet-*-*
4142 NEC V850 w/simulator v850-*-*
4144 * New debugging protocols
4146 ARM with RDI protocol arm*-*-*
4147 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4148 DDB and LSI variants of PMON protocol mips*-*-*
4149 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4150 PowerPC with SDS protocol powerpc{,le}-*-eabi
4151 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4155 All configurations can now understand and use the DWARF 2 debugging
4156 format. The choice is automatic, if the symbol file contains DWARF 2
4161 GDB now includes basic Java language support. This support is
4162 only useful with Java compilers that produce native machine code.
4164 * solib-absolute-prefix and solib-search-path
4166 For SunOS and SVR4 shared libraries, you may now set the prefix for
4167 loading absolute shared library symbol files, and the search path for
4168 locating non-absolute shared library symbol files.
4170 * Live range splitting
4172 GDB can now effectively debug code for which GCC has performed live
4173 range splitting as part of its optimization. See gdb/doc/LRS for
4174 more details on the expected format of the stabs information.
4178 GDB's support for the GNU Hurd, including thread debugging, has been
4179 updated to work with current versions of the Hurd.
4183 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4184 instruction set. ARM GDB automatically detects when Thumb
4185 instructions are in use, and adjusts disassembly and backtracing
4190 GDB's MIPS target configurations now handle the MIP16 16-bit
4195 GDB now includes support for overlays; if an executable has been
4196 linked such that multiple sections are based at the same address, GDB
4197 will decide which section to use for symbolic info. You can choose to
4198 control the decision manually, using overlay commands, or implement
4199 additional target-side support and use "overlay load-target" to bring
4200 in the overlay mapping. Do "help overlay" for more detail.
4204 The command "info symbol <address>" displays information about
4205 the symbol at the specified address.
4209 The standard remote protocol now includes an extension that allows
4210 asynchronous collection and display of trace data. This requires
4211 extensive support in the target-side debugging stub. Tracing mode
4212 includes a new interaction mode in GDB and new commands: see the
4213 file tracepoint.c for more details.
4217 Configurations for embedded MIPS now include a simulator contributed
4218 by Cygnus Solutions. The simulator supports the instruction sets
4219 of most MIPS variants.
4223 Sparc configurations may now include the ERC32 simulator contributed
4224 by the European Space Agency. The simulator is not built into
4225 Sparc targets by default; configure with --enable-sim to include it.
4229 For target configurations that may include multiple variants of a
4230 basic architecture (such as MIPS and SH), you may now set the
4231 architecture explicitly. "set arch" sets, "info arch" lists
4232 the possible architectures.
4234 *** Changes in GDB-4.16:
4236 * New native configurations
4238 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4239 M68K NetBSD m68k-*-netbsd*
4240 PowerPC AIX 4.x powerpc-*-aix*
4241 PowerPC MacOS powerpc-*-macos*
4242 PowerPC Windows NT powerpcle-*-cygwin32
4243 RS/6000 AIX 4.x rs6000-*-aix4*
4247 ARM with RDP protocol arm-*-*
4248 I960 with MON960 i960-*-coff
4249 MIPS VxWorks mips*-*-vxworks*
4250 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4251 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4253 Matra Sparclet sparclet-*-*
4257 The powerpc-eabi configuration now includes the PSIM simulator,
4258 contributed by Andrew Cagney, with assistance from Mike Meissner.
4259 PSIM is a very elaborate model of the PowerPC, including not only
4260 basic instruction set execution, but also details of execution unit
4261 performance and I/O hardware. See sim/ppc/README for more details.
4265 GDB now works with Solaris 2.5.
4267 * Windows 95/NT native
4269 GDB will now work as a native debugger on Windows 95 and Windows NT.
4270 To build it from source, you must use the "gnu-win32" environment,
4271 which uses a DLL to emulate enough of Unix to run the GNU tools.
4272 Further information, binaries, and sources are available at
4273 ftp.cygnus.com, under pub/gnu-win32.
4275 * dont-repeat command
4277 If a user-defined command includes the command `dont-repeat', then the
4278 command will not be repeated if the user just types return. This is
4279 useful if the command is time-consuming to run, so that accidental
4280 extra keystrokes don't run the same command many times.
4282 * Send break instead of ^C
4284 The standard remote protocol now includes an option to send a break
4285 rather than a ^C to the target in order to interrupt it. By default,
4286 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4288 * Remote protocol timeout
4290 The standard remote protocol includes a new variable `remotetimeout'
4291 that allows you to set the number of seconds before GDB gives up trying
4292 to read from the target. The default value is 2.
4294 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4296 By default GDB will automatically keep track of objects as they are
4297 loaded and unloaded by the dynamic linker. By using the command `set
4298 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4299 when shared library events occur, thus allowing you to set breakpoints
4300 in shared libraries which are explicitly loaded by the inferior.
4302 Note this feature does not work on hpux8. On hpux9 you must link
4303 /usr/lib/end.o into your program. This feature should work
4304 automatically on hpux10.
4306 * Irix 5.x hardware watchpoint support
4308 Irix 5 configurations now support the use of hardware watchpoints.
4310 * Mips protocol "SYN garbage limit"
4312 When debugging a Mips target using the `target mips' protocol, you
4313 may set the number of characters that GDB will ignore by setting
4314 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4315 every character. The default value is 1050.
4317 * Recording and replaying remote debug sessions
4319 If you set `remotelogfile' to the name of a file, gdb will write to it
4320 a recording of a remote debug session. This recording may then be
4321 replayed back to gdb using "gdbreplay". See gdbserver/README for
4322 details. This is useful when you have a problem with GDB while doing
4323 remote debugging; you can make a recording of the session and send it
4324 to someone else, who can then recreate the problem.
4326 * Speedups for remote debugging
4328 GDB includes speedups for downloading and stepping MIPS systems using
4329 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4330 and more efficient S-record downloading.
4332 * Memory use reductions and statistics collection
4334 GDB now uses less memory and reports statistics about memory usage.
4335 Try the `maint print statistics' command, for example.
4337 *** Changes in GDB-4.15:
4339 * Psymtabs for XCOFF
4341 The symbol reader for AIX GDB now uses partial symbol tables. This
4342 can greatly improve startup time, especially for large executables.
4344 * Remote targets use caching
4346 Remote targets now use a data cache to speed up communication with the
4347 remote side. The data cache could lead to incorrect results because
4348 it doesn't know about volatile variables, thus making it impossible to
4349 debug targets which use memory mapped I/O devices. `set remotecache
4350 off' turns the the data cache off.
4352 * Remote targets may have threads
4354 The standard remote protocol now includes support for multiple threads
4355 in the target system, using new protocol commands 'H' and 'T'. See
4356 gdb/remote.c for details.
4360 If GDB is configured with `--enable-netrom', then it will include
4361 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4362 acts as though it is a bank of ROM on the target board, but you can
4363 write into it over the network. GDB's support consists only of
4364 support for fast loading into the emulated ROM; to debug, you must use
4365 another protocol, such as standard remote protocol. The usual
4366 sequence is something like
4368 target nrom <netrom-hostname>
4370 target remote <netrom-hostname>:1235
4374 GDB now includes support for the Apple Macintosh, as a host only. It
4375 may be run as either an MPW tool or as a standalone application, and
4376 it can debug through the serial port. All the usual GDB commands are
4377 available, but to the target command, you must supply "serial" as the
4378 device type instead of "/dev/ttyXX". See mpw-README in the main
4379 directory for more information on how to build. The MPW configuration
4380 scripts */mpw-config.in support only a few targets, and only the
4381 mips-idt-ecoff target has been tested.
4385 GDB configuration now uses autoconf. This is not user-visible,
4386 but does simplify configuration and building.
4390 GDB now supports hpux10.
4392 *** Changes in GDB-4.14:
4394 * New native configurations
4396 x86 FreeBSD i[345]86-*-freebsd
4397 x86 NetBSD i[345]86-*-netbsd
4398 NS32k NetBSD ns32k-*-netbsd
4399 Sparc NetBSD sparc-*-netbsd
4403 A29K VxWorks a29k-*-vxworks
4404 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4405 CPU32 EST-300 emulator m68*-*-est*
4406 PowerPC ELF powerpc-*-elf
4409 * Alpha OSF/1 support for procfs
4411 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4412 possible to attach to running processes. As the mounting of the /proc
4413 filesystem is optional on the Alpha, GDB automatically determines
4414 the availability of /proc during startup. This can lead to problems
4415 if /proc is unmounted after GDB has been started.
4417 * Arguments to user-defined commands
4419 User commands may accept up to 10 arguments separated by whitespace.
4420 Arguments are accessed within the user command via $arg0..$arg9. A
4423 print $arg0 + $arg1 + $arg2
4425 To execute the command use:
4428 Defines the command "adder" which prints the sum of its three arguments.
4429 Note the arguments are text substitutions, so they may reference variables,
4430 use complex expressions, or even perform inferior function calls.
4432 * New `if' and `while' commands
4434 This makes it possible to write more sophisticated user-defined
4435 commands. Both commands take a single argument, which is the
4436 expression to evaluate, and must be followed by the commands to
4437 execute, one per line, if the expression is nonzero, the list being
4438 terminated by the word `end'. The `if' command list may include an
4439 `else' word, which causes the following commands to be executed only
4440 if the expression is zero.
4442 * Fortran source language mode
4444 GDB now includes partial support for Fortran 77. It will recognize
4445 Fortran programs and can evaluate a subset of Fortran expressions, but
4446 variables and functions may not be handled correctly. GDB will work
4447 with G77, but does not yet know much about symbols emitted by other
4450 * Better HPUX support
4452 Most debugging facilities now work on dynamic executables for HPPAs
4453 running hpux9 or later. You can attach to running dynamically linked
4454 processes, but by default the dynamic libraries will be read-only, so
4455 for instance you won't be able to put breakpoints in them. To change
4456 that behavior do the following before running the program:
4462 This will cause the libraries to be mapped private and read-write.
4463 To revert to the normal behavior, do this:
4469 You cannot set breakpoints or examine data in the library until after
4470 the library is loaded if the function/data symbols do not have
4473 GDB can now also read debug symbols produced by the HP C compiler on
4474 HPPAs (sorry, no C++, Fortran or 68k support).
4476 * Target byte order now dynamically selectable
4478 You can choose which byte order to use with a target system, via the
4479 commands "set endian big" and "set endian little", and you can see the
4480 current setting by using "show endian". You can also give the command
4481 "set endian auto", in which case GDB will use the byte order
4482 associated with the executable. Currently, only embedded MIPS
4483 configurations support dynamic selection of target byte order.
4485 * New DOS host serial code
4487 This version uses DPMI interrupts to handle buffered I/O, so you
4488 no longer need to run asynctsr when debugging boards connected to
4491 *** Changes in GDB-4.13:
4493 * New "complete" command
4495 This lists all the possible completions for the rest of the line, if it
4496 were to be given as a command itself. This is intended for use by emacs.
4498 * Trailing space optional in prompt
4500 "set prompt" no longer adds a space for you after the prompt you set. This
4501 allows you to set a prompt which ends in a space or one that does not.
4503 * Breakpoint hit counts
4505 "info break" now displays a count of the number of times the breakpoint
4506 has been hit. This is especially useful in conjunction with "ignore"; you
4507 can ignore a large number of breakpoint hits, look at the breakpoint info
4508 to see how many times the breakpoint was hit, then run again, ignoring one
4509 less than that number, and this will get you quickly to the last hit of
4512 * Ability to stop printing at NULL character
4514 "set print null-stop" will cause GDB to stop printing the characters of
4515 an array when the first NULL is encountered. This is useful when large
4516 arrays actually contain only short strings.
4518 * Shared library breakpoints
4520 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4521 breakpoints in shared libraries before the executable is run.
4523 * Hardware watchpoints
4525 There is a new hardware breakpoint for the watch command for sparclite
4526 targets. See gdb/sparclite/hw_breakpoint.note.
4528 Hardware watchpoints are also now supported under GNU/Linux.
4532 Annotations have been added. These are for use with graphical interfaces,
4533 and are still experimental. Currently only gdba.el uses these.
4535 * Improved Irix 5 support
4537 GDB now works properly with Irix 5.2.
4539 * Improved HPPA support
4541 GDB now works properly with the latest GCC and GAS.
4543 * New native configurations
4545 Sequent PTX4 i[34]86-sequent-ptx4
4546 HPPA running OSF/1 hppa*-*-osf*
4547 Atari TT running SVR4 m68*-*-sysv4*
4548 RS/6000 LynxOS rs6000-*-lynxos*
4552 OS/9000 i[34]86-*-os9k
4553 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4556 * Hitachi SH7000 and E7000-PC ICE support
4558 There is now support for communicating with the Hitachi E7000-PC ICE.
4559 This is available automatically when GDB is configured for the SH.
4563 As usual, a variety of small fixes and improvements, both generic
4564 and configuration-specific. See the ChangeLog for more detail.
4566 *** Changes in GDB-4.12:
4568 * Irix 5 is now supported
4572 GDB-4.12 on the HPPA has a number of changes which make it unable
4573 to debug the output from the currently released versions of GCC and
4574 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4575 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4576 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4579 *** Changes in GDB-4.11:
4581 * User visible changes:
4585 The "set remotedebug" option is now consistent between the mips remote
4586 target, remote targets using the gdb-specific protocol, UDI (AMD's
4587 debug protocol for the 29k) and the 88k bug monitor. It is now an
4588 integer specifying a debug level (normally 0 or 1, but 2 means more
4589 debugging info for the mips target).
4591 * DEC Alpha native support
4593 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4594 debug info, but GDB works fairly well with the DEC compiler and should
4595 work with a future GCC release. See the README file for a few
4596 Alpha-specific notes.
4598 * Preliminary thread implementation
4600 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4602 * LynxOS native and target support for 386
4604 This release has been hosted on LynxOS 2.2, and also can be configured
4605 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4608 * Improvements in C++ mangling/demangling.
4610 This release has much better g++ debugging, specifically in name
4611 mangling/demangling, virtual function calls, print virtual table,
4612 call methods, ...etc.
4614 *** Changes in GDB-4.10:
4616 * User visible changes:
4618 Remote debugging using the GDB-specific (`target remote') protocol now
4619 supports the `load' command. This is only useful if you have some
4620 other way of getting the stub to the target system, and you can put it
4621 somewhere in memory where it won't get clobbered by the download.
4623 Filename completion now works.
4625 When run under emacs mode, the "info line" command now causes the
4626 arrow to point to the line specified. Also, "info line" prints
4627 addresses in symbolic form (as well as hex).
4629 All vxworks based targets now support a user settable option, called
4630 vxworks-timeout. This option represents the number of seconds gdb
4631 should wait for responses to rpc's. You might want to use this if
4632 your vxworks target is, perhaps, a slow software simulator or happens
4633 to be on the far side of a thin network line.
4637 This release contains support for using a DEC alpha as a GDB host for
4638 cross debugging. Native alpha debugging is not supported yet.
4641 *** Changes in GDB-4.9:
4645 This is the first GDB release which is accompanied by a matching testsuite.
4646 The testsuite requires installation of dejagnu, which should be available
4647 via ftp from most sites that carry GNU software.
4651 'Cfront' style demangling has had its name changed to 'ARM' style, to
4652 emphasize that it was written from the specifications in the C++ Annotated
4653 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4654 disclaimers, it still generated too much confusion with users attempting to
4655 use gdb with AT&T cfront.
4659 GDB now uses a standard remote interface to a simulator library.
4660 So far, the library contains simulators for the Zilog Z8001/2, the
4661 Hitachi H8/300, H8/500 and Super-H.
4663 * New targets supported
4665 H8/300 simulator h8300-hitachi-hms or h8300hms
4666 H8/500 simulator h8500-hitachi-hms or h8500hms
4667 SH simulator sh-hitachi-hms or sh
4668 Z8000 simulator z8k-zilog-none or z8ksim
4669 IDT MIPS board over serial line mips-idt-ecoff
4671 Cross-debugging to GO32 targets is supported. It requires a custom
4672 version of the i386-stub.c module which is integrated with the
4673 GO32 memory extender.
4675 * New remote protocols
4677 MIPS remote debugging protocol.
4679 * New source languages supported
4681 This version includes preliminary support for Chill, a Pascal like language
4682 used by telecommunications companies. Chill support is also being integrated
4683 into the GNU compiler, but we don't know when it will be publically available.
4686 *** Changes in GDB-4.8:
4688 * HP Precision Architecture supported
4690 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4691 version of this support was available as a set of patches from the
4692 University of Utah. GDB does not support debugging of programs
4693 compiled with the HP compiler, because HP will not document their file
4694 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4695 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4697 Many problems in the preliminary version have been fixed.
4699 * Faster and better demangling
4701 We have improved template demangling and fixed numerous bugs in the GNU style
4702 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4703 character types (wchar_t) are now supported. Demangling of each symbol is now
4704 only done once, and is cached when the symbol table for a file is read in.
4705 This results in a small increase in memory usage for C programs, a moderate
4706 increase in memory usage for C++ programs, and a fantastic speedup in
4709 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4710 from the specifications in the Annotated Reference Manual, which AT&T's
4711 compiler does not actually implement.
4713 * G++ multiple inheritance compiler problem
4715 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4716 inheritance lattices was reworked to properly discover ambiguities. We
4717 recently found an example which causes this new algorithm to fail in a
4718 very subtle way, producing bad debug information for those classes.
4719 The file 'gcc.patch' (in this directory) can be applied to gcc to
4720 circumvent the problem. A future GCC release will contain a complete
4723 The previous G++ debug info problem (mentioned below for the gdb-4.7
4724 release) is fixed in gcc version 2.3.2.
4726 * Improved configure script
4728 The `configure' script will now attempt to guess your system type if
4729 you don't supply a host system type. The old scheme of supplying a
4730 host system triplet is preferable over using this. All the magic is
4731 done in the new `config.guess' script. Examine it for details.
4733 We have also brought our configure script much more in line with the FSF's
4734 version. It now supports the --with-xxx options. In particular,
4735 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4736 The resulting GDB will not be able to read arbitrary object file formats --
4737 only the format ``expected'' to be used on the configured target system.
4738 We hope to make this the default in a future release.
4740 * Documentation improvements
4742 There's new internal documentation on how to modify GDB, and how to
4743 produce clean changes to the code. We implore people to read it
4744 before submitting changes.
4746 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4747 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4748 `info' files are also provided. To build `info' files from scratch,
4749 you will need the latest `makeinfo' release, which will be available in
4750 a future texinfo-X.Y release.
4752 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4753 We're not sure exactly which versions have this problem, but it has
4754 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4755 or better. If that isn't possible, there is a patch in
4756 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4757 around this problem.
4761 GDB now supports array constants that can be used in expressions typed in by
4762 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4763 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4766 The new directory `gdb/sparclite' contains a program that demonstrates
4767 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4769 * New native hosts supported
4771 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4772 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4774 * New targets supported
4776 AMD 29k family via UDI a29k-amd-udi or udi29k
4778 * New file formats supported
4780 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4781 HPUX core files, and SCO 3.2v2 core files.
4785 Attaching to processes now works again; thanks for the many bug reports.
4787 We have also stomped on a bunch of core dumps caused by
4788 printf_filtered("%s") problems.
4790 We eliminated a copyright problem on the rpc and ptrace header files
4791 for VxWorks, which was discovered at the last minute during the 4.7
4792 release. You should now be able to build a VxWorks GDB.
4794 You can now interrupt gdb while an attached process is running. This
4795 will cause the attached process to stop, and give control back to GDB.
4797 We fixed problems caused by using too many file descriptors
4798 for reading symbols from object files and libraries. This was
4799 especially a problem for programs that used many (~100) shared
4802 The `step' command now only enters a subroutine if there is line number
4803 information for the subroutine. Otherwise it acts like the `next'
4804 command. Previously, `step' would enter subroutines if there was
4805 any debugging information about the routine. This avoids problems
4806 when using `cc -g1' on MIPS machines.
4808 * Internal improvements
4810 GDB's internal interfaces have been improved to make it easier to support
4811 debugging of multiple languages in the future.
4813 GDB now uses a common structure for symbol information internally.
4814 Minimal symbols (derived from linkage symbols in object files), partial
4815 symbols (from a quick scan of debug information), and full symbols
4816 contain a common subset of information, making it easier to write
4817 shared code that handles any of them.
4819 * New command line options
4821 We now accept --silent as an alias for --quiet.
4825 The memory-mapped-malloc library is now licensed under the GNU Library
4826 General Public License.
4828 *** Changes in GDB-4.7:
4830 * Host/native/target split
4832 GDB has had some major internal surgery to untangle the support for
4833 hosts and remote targets. Now, when you configure GDB for a remote
4834 target, it will no longer load in all of the support for debugging
4835 local programs on the host. When fully completed and tested, this will
4836 ensure that arbitrary host/target combinations are possible.
4838 The primary conceptual shift is to separate the non-portable code in
4839 GDB into three categories. Host specific code is required any time GDB
4840 is compiled on that host, regardless of the target. Target specific
4841 code relates to the peculiarities of the target, but can be compiled on
4842 any host. Native specific code is everything else: it can only be
4843 built when the host and target are the same system. Child process
4844 handling and core file support are two common `native' examples.
4846 GDB's use of /proc for controlling Unix child processes is now cleaner.
4847 It has been split out into a single module under the `target_ops' vector,
4848 plus two native-dependent functions for each system that uses /proc.
4850 * New hosts supported
4852 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
4853 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4854 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
4856 * New targets supported
4858 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4859 68030 and CPU32 m68030-*-*, m68332-*-*
4861 * New native hosts supported
4863 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4864 (386bsd is not well tested yet)
4865 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
4867 * New file formats supported
4869 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
4870 supports reading of `a.out.adobe' object files, which are an a.out
4871 format extended with minimal information about multiple sections.
4875 `show copying' is the same as the old `info copying'.
4876 `show warranty' is the same as `info warrantee'.
4877 These were renamed for consistency. The old commands continue to work.
4879 `info handle' is a new alias for `info signals'.
4881 You can now define pre-command hooks, which attach arbitrary command
4882 scripts to any command. The commands in the hook will be executed
4883 prior to the user's command. You can also create a hook which will be
4884 executed whenever the program stops. See gdb.texinfo.
4888 We now deal with Cfront style name mangling, and can even extract type
4889 info from mangled symbols. GDB can automatically figure out which
4890 symbol mangling style your C++ compiler uses.
4892 Calling of methods and virtual functions has been improved as well.
4896 The crash that occured when debugging Sun Ansi-C compiled binaries is
4897 fixed. This was due to mishandling of the extra N_SO stabs output
4900 We also finally got Ultrix 4.2 running in house, and fixed core file
4901 support, with help from a dozen people on the net.
4903 John M. Farrell discovered that the reason that single-stepping was so
4904 slow on all of the Mips based platforms (primarily SGI and DEC) was
4905 that we were trying to demangle and lookup a symbol used for internal
4906 purposes on every instruction that was being stepped through. Changing
4907 the name of that symbol so that it couldn't be mistaken for a C++
4908 mangled symbol sped things up a great deal.
4910 Rich Pixley sped up symbol lookups in general by getting much smarter
4911 about when C++ symbol mangling is necessary. This should make symbol
4912 completion (TAB on the command line) much faster. It's not as fast as
4913 we'd like, but it's significantly faster than gdb-4.6.
4917 A new user controllable variable 'call_scratch_address' can
4918 specify the location of a scratch area to be used when GDB
4919 calls a function in the target. This is necessary because the
4920 usual method of putting the scratch area on the stack does not work
4921 in systems that have separate instruction and data spaces.
4923 We integrated changes to support the 29k UDI (Universal Debugger
4924 Interface), but discovered at the last minute that we didn't have all
4925 of the appropriate copyright paperwork. We are working with AMD to
4926 resolve this, and hope to have it available soon.
4930 We have sped up the remote serial line protocol, especially for targets
4931 with lots of registers. It now supports a new `expedited status' ('T')
4932 message which can be used in place of the existing 'S' status message.
4933 This allows the remote stub to send only the registers that GDB
4934 needs to make a quick decision about single-stepping or conditional
4935 breakpoints, eliminating the need to fetch the entire register set for
4936 each instruction being stepped through.
4938 The GDB remote serial protocol now implements a write-through cache for
4939 registers, only re-reading the registers if the target has run.
4941 There is also a new remote serial stub for SPARC processors. You can
4942 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
4943 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
4944 processor with a serial port.
4948 Configure.in files have become much easier to read and modify. A new
4949 `table driven' format makes it more obvious what configurations are
4950 supported, and what files each one uses.
4954 There is a new opcodes library which will eventually contain all of the
4955 disassembly routines and opcode tables. At present, it only contains
4956 Sparc and Z8000 routines. This will allow the assembler, debugger, and
4957 disassembler (binutils/objdump) to share these routines.
4959 The libiberty library is now copylefted under the GNU Library General
4960 Public License. This allows more liberal use, and was done so libg++
4961 can use it. This makes no difference to GDB, since the Library License
4962 grants all the rights from the General Public License.
4966 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
4967 reference to the stabs symbol info used by the debugger. It is (as far
4968 as we know) the only published document on this fascinating topic. We
4969 encourage you to read it, compare it to the stabs information on your
4970 system, and send improvements on the document in general (to
4971 bug-gdb@prep.ai.mit.edu).
4973 And, of course, many bugs have been fixed.
4976 *** Changes in GDB-4.6:
4978 * Better support for C++ function names
4980 GDB now accepts as input the "demangled form" of C++ overloaded function
4981 names and member function names, and can do command completion on such names
4982 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
4983 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
4984 Make use of command completion, it is your friend.
4986 GDB also now accepts a variety of C++ mangled symbol formats. They are
4987 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
4988 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
4989 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
4990 for the list of formats.
4992 * G++ symbol mangling problem
4994 Recent versions of gcc have a bug in how they emit debugging information for
4995 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
4996 directory) can be applied to gcc to fix the problem. Alternatively, if you
4997 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
4998 usual symptom is difficulty with setting breakpoints on methods. GDB complains
4999 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5002 * New 'maintenance' command
5004 All of the commands related to hacking GDB internals have been moved out of
5005 the main command set, and now live behind the 'maintenance' command. This
5006 can also be abbreviated as 'mt'. The following changes were made:
5008 dump-me -> maintenance dump-me
5009 info all-breakpoints -> maintenance info breakpoints
5010 printmsyms -> maintenance print msyms
5011 printobjfiles -> maintenance print objfiles
5012 printpsyms -> maintenance print psymbols
5013 printsyms -> maintenance print symbols
5015 The following commands are new:
5017 maintenance demangle Call internal GDB demangler routine to
5018 demangle a C++ link name and prints the result.
5019 maintenance print type Print a type chain for a given symbol
5021 * Change to .gdbinit file processing
5023 We now read the $HOME/.gdbinit file before processing the argv arguments
5024 (e.g. reading symbol files or core files). This allows global parameters to
5025 be set, which will apply during the symbol reading. The ./.gdbinit is still
5026 read after argv processing.
5028 * New hosts supported
5030 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5032 GNU/Linux support i386-unknown-linux or linux
5034 We are also including code to support the HP/PA running BSD and HPUX. This
5035 is almost guaranteed not to work, as we didn't have time to test or build it
5036 for this release. We are including it so that the more adventurous (or
5037 masochistic) of you can play with it. We also had major problems with the
5038 fact that the compiler that we got from HP doesn't support the -g option.
5041 * New targets supported
5043 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5045 * More smarts about finding #include files
5047 GDB now remembers the compilation directory for all include files, and for
5048 all files from which C is generated (like yacc and lex sources). This
5049 greatly improves GDB's ability to find yacc/lex sources, and include files,
5050 especially if you are debugging your program from a directory different from
5051 the one that contains your sources.
5053 We also fixed a bug which caused difficulty with listing and setting
5054 breakpoints in include files which contain C code. (In the past, you had to
5055 try twice in order to list an include file that you hadn't looked at before.)
5057 * Interesting infernals change
5059 GDB now deals with arbitrary numbers of sections, where the symbols for each
5060 section must be relocated relative to that section's landing place in the
5061 target's address space. This work was needed to support ELF with embedded
5062 stabs used by Solaris-2.0.
5064 * Bug fixes (of course!)
5066 There have been loads of fixes for the following things:
5067 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5068 i960, stabs, DOS(GO32), procfs, etc...
5070 See the ChangeLog for details.
5072 *** Changes in GDB-4.5:
5074 * New machines supported (host and target)
5076 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5078 SGI Irix-4.x mips-sgi-irix4 or iris4
5080 * New malloc package
5082 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5083 Mmalloc is capable of handling mutiple heaps of memory. It is also
5084 capable of saving a heap to a file, and then mapping it back in later.
5085 This can be used to greatly speedup the startup of GDB by using a
5086 pre-parsed symbol table which lives in a mmalloc managed heap. For
5087 more details, please read mmalloc/mmalloc.texi.
5091 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5092 'help info proc' for details.
5094 * MIPS ecoff symbol table format
5096 The code that reads MIPS symbol table format is now supported on all hosts.
5097 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5100 * File name changes for MS-DOS
5102 Many files in the config directories have been renamed to make it easier to
5103 support GDB on MS-DOSe systems (which have very restrictive file name
5104 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5105 environment) is close to working but has some remaining problems. Note
5106 that debugging of DOS programs is not supported, due to limitations
5107 in the ``operating system'', but it can be used to host cross-debugging.
5109 * Cross byte order fixes
5111 Many fixes have been made to support cross debugging of Sparc and MIPS
5112 targets from hosts whose byte order differs.
5114 * New -mapped and -readnow options
5116 If memory-mapped files are available on your system through the 'mmap'
5117 system call, you can use the -mapped option on the `file' or
5118 `symbol-file' commands to cause GDB to write the symbols from your
5119 program into a reusable file. If the program you are debugging is
5120 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5121 Future GDB debugging sessions will notice the presence of this file,
5122 and will quickly map in symbol information from it, rather than reading
5123 the symbol table from the executable program. Using the '-mapped'
5124 option in a GDB `file' or `symbol-file' command has the same effect as
5125 starting GDB with the '-mapped' command-line option.
5127 You can cause GDB to read the entire symbol table immediately by using
5128 the '-readnow' option with any of the commands that load symbol table
5129 information (or on the GDB command line). This makes the command
5130 slower, but makes future operations faster.
5132 The -mapped and -readnow options are typically combined in order to
5133 build a `fred.syms' file that contains complete symbol information.
5134 A simple GDB invocation to do nothing but build a `.syms' file for future
5137 gdb -batch -nx -mapped -readnow programname
5139 The `.syms' file is specific to the host machine on which GDB is run.
5140 It holds an exact image of GDB's internal symbol table. It cannot be
5141 shared across multiple host platforms.
5143 * longjmp() handling
5145 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5146 siglongjmp() without losing control. This feature has not yet been ported to
5147 all systems. It currently works on many 386 platforms, all MIPS-based
5148 platforms (SGI, DECstation, etc), and Sun3/4.
5152 Preliminary work has been put in to support the new Solaris OS from Sun. At
5153 this time, it can control and debug processes, but it is not capable of
5158 As always, many many bug fixes. The major areas were with g++, and mipsread.
5159 People using the MIPS-based platforms should experience fewer mysterious
5160 crashes and trashed symbol tables.
5162 *** Changes in GDB-4.4:
5164 * New machines supported (host and target)
5166 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5168 BSD Reno on Vax vax-dec-bsd
5169 Ultrix on Vax vax-dec-ultrix
5171 * New machines supported (target)
5173 AMD 29000 embedded, using EBMON a29k-none-none
5177 GDB continues to improve its handling of C++. `References' work better.
5178 The demangler has also been improved, and now deals with symbols mangled as
5179 per the Annotated C++ Reference Guide.
5181 GDB also now handles `stabs' symbol information embedded in MIPS
5182 `ecoff' symbol tables. Since the ecoff format was not easily
5183 extensible to handle new languages such as C++, this appeared to be a
5184 good way to put C++ debugging info into MIPS binaries. This option
5185 will be supported in the GNU C compiler, version 2, when it is
5188 * New features for SVR4
5190 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5191 shared libraries. Debugging dynamically linked programs should present
5192 only minor differences from debugging statically linked programs.
5194 The `info proc' command will print out information about any process
5195 on an SVR4 system (including the one you are debugging). At the moment,
5196 it prints the address mappings of the process.
5198 If you bring up GDB on another SVR4 system, please send mail to
5199 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5201 * Better dynamic linking support in SunOS
5203 Reading symbols from shared libraries which contain debugging symbols
5204 now works properly. However, there remain issues such as automatic
5205 skipping of `transfer vector' code during function calls, which
5206 make it harder to debug code in a shared library, than to debug the
5207 same code linked statically.
5211 GDB is now using the latest `getopt' routines from the FSF. This
5212 version accepts the -- prefix for options with long names. GDB will
5213 continue to accept the old forms (-option and +option) as well.
5214 Various single letter abbreviations for options have been explicity
5215 added to the option table so that they won't get overshadowed in the
5216 future by other options that begin with the same letter.
5220 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5221 Many assorted bugs have been handled. Many more remain to be handled.
5222 See the various ChangeLog files (primarily in gdb and bfd) for details.
5225 *** Changes in GDB-4.3:
5227 * New machines supported (host and target)
5229 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5230 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5231 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5233 * Almost SCO Unix support
5235 We had hoped to support:
5236 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5237 (except for core file support), but we discovered very late in the release
5238 that it has problems with process groups that render gdb unusable. Sorry
5239 about that. I encourage people to fix it and post the fixes.
5241 * Preliminary ELF and DWARF support
5243 GDB can read ELF object files on System V Release 4, and can handle
5244 debugging records for C, in DWARF format, in ELF files. This support
5245 is preliminary. If you bring up GDB on another SVR4 system, please
5246 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5251 GDB now uses the latest `readline' library. One user-visible change
5252 is that two tabs will list possible command completions, which previously
5253 required typing M-? (meta-question mark, or ESC ?).
5257 The `stepi' bug that many of you noticed has been squashed.
5258 Many bugs in C++ have been handled. Many more remain to be handled.
5259 See the various ChangeLog files (primarily in gdb and bfd) for details.
5261 * State of the MIPS world (in case you wondered):
5263 GDB can understand the symbol tables emitted by the compilers
5264 supplied by most vendors of MIPS-based machines, including DEC. These
5265 symbol tables are in a format that essentially nobody else uses.
5267 Some versions of gcc come with an assembler post-processor called
5268 mips-tfile. This program is required if you want to do source-level
5269 debugging of gcc-compiled programs. I believe FSF does not ship
5270 mips-tfile with gcc version 1, but it will eventually come with gcc
5273 Debugging of g++ output remains a problem. g++ version 1.xx does not
5274 really support it at all. (If you're lucky, you should be able to get
5275 line numbers and stack traces to work, but no parameters or local
5276 variables.) With some work it should be possible to improve the
5279 When gcc version 2 is released, you will have somewhat better luck.
5280 However, even then you will get confusing results for inheritance and
5283 We will eventually provide full debugging of g++ output on
5284 DECstations. This will probably involve some kind of stabs-in-ecoff
5285 encapulation, but the details have not been worked out yet.
5288 *** Changes in GDB-4.2:
5290 * Improved configuration
5292 Only one copy of `configure' exists now, and it is not self-modifying.
5293 Porting BFD is simpler.
5297 The `step' and `next' commands now only stop at the first instruction
5298 of a source line. This prevents the multiple stops that used to occur
5299 in switch statements, for-loops, etc. `Step' continues to stop if a
5300 function that has debugging information is called within the line.
5304 Lots of small bugs fixed. More remain.
5306 * New host supported (not target)
5308 Intel 386 PC clone running Mach i386-none-mach
5311 *** Changes in GDB-4.1:
5313 * Multiple source language support
5315 GDB now has internal scaffolding to handle several source languages.
5316 It determines the type of each source file from its filename extension,
5317 and will switch expression parsing and number formatting to match the
5318 language of the function in the currently selected stack frame.
5319 You can also specifically set the language to be used, with
5320 `set language c' or `set language modula-2'.
5324 GDB now has preliminary support for the GNU Modula-2 compiler,
5325 currently under development at the State University of New York at
5326 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5327 continue through the fall of 1991 and into 1992.
5329 Other Modula-2 compilers are currently not supported, and attempting to
5330 debug programs compiled with them will likely result in an error as the
5331 symbol table is read. Feel free to work on it, though!
5333 There are hooks in GDB for strict type checking and range checking,
5334 in the `Modula-2 philosophy', but they do not currently work.
5338 GDB can now write to executable and core files (e.g. patch
5339 a variable's value). You must turn this switch on, specify
5340 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5341 by assigning a new value to a variable. Modifications take
5344 * Automatic SunOS shared library reading
5346 When you run your program, GDB automatically determines where its
5347 shared libraries (if any) have been loaded, and reads their symbols.
5348 The `share' command is no longer needed. This also works when
5349 examining core files.
5353 You can specify the number of lines that the `list' command shows.
5356 * New machines supported (host and target)
5358 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5359 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5360 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5362 * New hosts supported (not targets)
5364 IBM RT/PC: romp-ibm-aix or rtpc
5366 * New targets supported (not hosts)
5368 AMD 29000 embedded with COFF a29k-none-coff
5369 AMD 29000 embedded with a.out a29k-none-aout
5370 Ultracomputer remote kernel debug a29k-nyu-kern
5372 * New remote interfaces
5378 *** Changes in GDB-4.0:
5382 Wide output is wrapped at good places to make the output more readable.
5384 Gdb now supports cross-debugging from a host machine of one type to a
5385 target machine of another type. Communication with the target system
5386 is over serial lines. The ``target'' command handles connecting to the
5387 remote system; the ``load'' command will download a program into the
5388 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5389 also supports debugging of realtime processes running under VxWorks,
5390 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5391 stub on the target system.
5393 New CPUs supported include the AMD 29000 and Intel 960.
5395 GDB now reads object files and symbol tables via a ``binary file''
5396 library, which allows a single copy of GDB to debug programs of multiple
5397 object file types such as a.out and coff.
5399 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5400 refcard.dvi and refcard.ps are available to format it).
5403 * Control-Variable user interface simplified
5405 All variables that control the operation of the debugger can be set
5406 by the ``set'' command, and displayed by the ``show'' command.
5408 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5409 ``Show prompt'' produces the response:
5410 Gdb's prompt is new-gdb=>.
5412 What follows are the NEW set commands. The command ``help set'' will
5413 print a complete list of old and new set commands. ``help set FOO''
5414 will give a longer description of the variable FOO. ``show'' will show
5415 all of the variable descriptions and their current settings.
5417 confirm on/off: Enables warning questions for operations that are
5418 hard to recover from, e.g. rerunning the program while
5419 it is already running. Default is ON.
5421 editing on/off: Enables EMACS style command line editing
5422 of input. Previous lines can be recalled with
5423 control-P, the current line can be edited with control-B,
5424 you can search for commands with control-R, etc.
5427 history filename NAME: NAME is where the gdb command history
5428 will be stored. The default is .gdb_history,
5429 or the value of the environment variable
5432 history size N: The size, in commands, of the command history. The
5433 default is 256, or the value of the environment variable
5436 history save on/off: If this value is set to ON, the history file will
5437 be saved after exiting gdb. If set to OFF, the
5438 file will not be saved. The default is OFF.
5440 history expansion on/off: If this value is set to ON, then csh-like
5441 history expansion will be performed on
5442 command line input. The default is OFF.
5444 radix N: Sets the default radix for input and output. It can be set
5445 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5446 in the current radix, so "set radix 10" is always a no-op.
5448 height N: This integer value is the number of lines on a page. Default
5449 is 24, the current `stty rows'' setting, or the ``li#''
5450 setting from the termcap entry matching the environment
5453 width N: This integer value is the number of characters on a line.
5454 Default is 80, the current `stty cols'' setting, or the ``co#''
5455 setting from the termcap entry matching the environment
5458 Note: ``set screensize'' is obsolete. Use ``set height'' and
5459 ``set width'' instead.
5461 print address on/off: Print memory addresses in various command displays,
5462 such as stack traces and structure values. Gdb looks
5463 more ``symbolic'' if you turn this off; it looks more
5464 ``machine level'' with it on. Default is ON.
5466 print array on/off: Prettyprint arrays. New convenient format! Default
5469 print demangle on/off: Print C++ symbols in "source" form if on,
5472 print asm-demangle on/off: Same, for assembler level printouts
5475 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5478 * Support for Epoch Environment.
5480 The epoch environment is a version of Emacs v18 with windowing. One
5481 new command, ``inspect'', is identical to ``print'', except that if you
5482 are running in the epoch environment, the value is printed in its own
5486 * Support for Shared Libraries
5488 GDB can now debug programs and core files that use SunOS shared libraries.
5489 Symbols from a shared library cannot be referenced
5490 before the shared library has been linked with the program (this
5491 happens after you type ``run'' and before the function main() is entered).
5492 At any time after this linking (including when examining core files
5493 from dynamically linked programs), gdb reads the symbols from each
5494 shared library when you type the ``sharedlibrary'' command.
5495 It can be abbreviated ``share''.
5497 sharedlibrary REGEXP: Load shared object library symbols for files
5498 matching a unix regular expression. No argument
5499 indicates to load symbols for all shared libraries.
5501 info sharedlibrary: Status of loaded shared libraries.
5506 A watchpoint stops execution of a program whenever the value of an
5507 expression changes. Checking for this slows down execution
5508 tremendously whenever you are in the scope of the expression, but is
5509 quite useful for catching tough ``bit-spreader'' or pointer misuse
5510 problems. Some machines such as the 386 have hardware for doing this
5511 more quickly, and future versions of gdb will use this hardware.
5513 watch EXP: Set a watchpoint (breakpoint) for an expression.
5515 info watchpoints: Information about your watchpoints.
5517 delete N: Deletes watchpoint number N (same as breakpoints).
5518 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5519 enable N: Re-enables watchpoint number N (same as breakpoints).
5522 * C++ multiple inheritance
5524 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5527 * C++ exception handling
5529 Gdb now supports limited C++ exception handling. Besides the existing
5530 ability to breakpoint on an exception handler, gdb can breakpoint on
5531 the raising of an exception (before the stack is peeled back to the
5534 catch FOO: If there is a FOO exception handler in the dynamic scope,
5535 set a breakpoint to catch exceptions which may be raised there.
5536 Multiple exceptions (``catch foo bar baz'') may be caught.
5538 info catch: Lists all exceptions which may be caught in the
5539 current stack frame.
5542 * Minor command changes
5544 The command ``call func (arg, arg, ...)'' now acts like the print
5545 command, except it does not print or save a value if the function's result
5546 is void. This is similar to dbx usage.
5548 The ``up'' and ``down'' commands now always print the frame they end up
5549 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5550 frames without printing.
5552 * New directory command
5554 'dir' now adds directories to the FRONT of the source search path.
5555 The path starts off empty. Source files that contain debug information
5556 about the directory in which they were compiled can be found even
5557 with an empty path; Sun CC and GCC include this information. If GDB can't
5558 find your source file in the current directory, type "dir .".
5560 * Configuring GDB for compilation
5562 For normal use, type ``./configure host''. See README or gdb.texinfo
5565 GDB now handles cross debugging. If you are remotely debugging between
5566 two different machines, type ``./configure host -target=targ''.
5567 Host is the machine where GDB will run; targ is the machine
5568 where the program that you are debugging will run.