1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.7
6 * The 'record instruction-history' command now starts counting instructions
7 at one. This also affects the instruction ranges reported by the
8 'record function-call-history' command when given the /i modifier.
10 * The command 'record function-call-history' supports a new modifier '/c' to
11 indent the function names based on their call stack depth.
12 The fields for the '/i' and '/l' modifier have been reordered.
13 The source line range is now prefixed with 'at'.
14 The instruction range is now prefixed with 'inst'.
15 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
16 "record instruction-history" and "list" commands.
18 * The ranges given as arguments to the 'record function-call-history' and
19 'record instruction-history' commands are now inclusive.
21 * The btrace record target now supports the 'record goto' command.
22 For locations inside the execution trace, the back trace is computed
23 based on the information stored in the execution trace.
25 * The btrace record target supports limited reverse execution and replay.
26 The target does not record data and therefore does not allow reading
31 qXfer:btrace:read's annex
32 The qXfer:btrace:read packet supports a new annex 'delta' to read
33 branch trace incrementally.
35 *** Changes in GDB 7.7
37 * Improved support for process record-replay and reverse debugging on
38 arm*-linux* targets. Support for thumb32 and syscall instruction
39 recording has been added.
41 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
43 * GDB now supports Fission DWP file format version 2.
44 http://gcc.gnu.org/wiki/DebugFission
46 * New convenience function "$_isvoid", to check whether an expression
47 is void. A void expression is an expression where the type of the
48 result is "void". For example, some convenience variables may be
49 "void" when evaluated (e.g., "$_exitcode" before the execution of
50 the program being debugged; or an undefined convenience variable).
51 Another example, when calling a function whose return type is
54 * The "maintenance print objfiles" command now takes an optional regexp.
56 * The "catch syscall" command now works on arm*-linux* targets.
58 * GDB now consistently shows "<not saved>" when printing values of
59 registers the debug info indicates have not been saved in the frame
60 and there's nowhere to retrieve them from
61 (callee-saved/call-clobbered registers):
66 (gdb) info registers rax
69 Before, the former would print "<optimized out>", and the latter
70 "*value not available*".
72 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
77 ** Frame filters and frame decorators have been added.
78 ** Temporary breakpoints are now supported.
79 ** Line tables representation has been added.
80 ** New attribute 'parent_type' for gdb.Field objects.
81 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
82 ** New attribute 'name' for gdb.Type objects.
86 Nios II ELF nios2*-*-elf
87 Nios II GNU/Linux nios2*-*-linux
88 Texas Instruments MSP430 msp430*-*-elf
90 * Removed native configurations
92 Support for these a.out NetBSD and OpenBSD obsolete configurations has
93 been removed. ELF variants of these configurations are kept supported.
95 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
96 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
97 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
98 i[34567]86-*-openbsd3.[0-3]
99 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
100 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
101 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
105 Like "catch throw", but catches a re-thrown exception.
107 Renamed from old "maint check-symtabs".
109 Perform consistency checks on symtabs.
111 Expand symtabs matching an optional regexp.
114 Display the details of GDB configure-time options.
116 maint set|show per-command
117 maint set|show per-command space
118 maint set|show per-command time
119 maint set|show per-command symtab
120 Enable display of per-command gdb resource usage.
122 remove-symbol-file FILENAME
123 remove-symbol-file -a ADDRESS
124 Remove a symbol file added via add-symbol-file. The file to remove
125 can be identified by its filename or by an address that lies within
126 the boundaries of this symbol file in memory.
129 info exceptions REGEXP
130 Display the list of Ada exceptions defined in the program being
131 debugged. If provided, only the exceptions whose names match REGEXP
136 set debug symfile off|on
138 Control display of debugging info regarding reading symbol files and
139 symbol tables within those files
141 set print raw frame-arguments
142 show print raw frame-arguments
143 Set/show whether to print frame arguments in raw mode,
144 disregarding any defined pretty-printers.
146 set remote trace-status-packet
147 show remote trace-status-packet
148 Set/show the use of remote protocol qTStatus packet.
152 Control display of debugging messages related to Nios II targets.
156 Control whether target-assisted range stepping is enabled.
158 set startup-with-shell
159 show startup-with-shell
160 Specifies whether Unix child processes are started via a shell or
165 Use the target memory cache for accesses to the code segment. This
166 improves performance of remote debugging (particularly disassembly).
168 * You can now use a literal value 'unlimited' for options that
169 interpret 0 or -1 as meaning "unlimited". E.g., "set
170 trace-buffer-size unlimited" is now an alias for "set
171 trace-buffer-size -1" and "set height unlimited" is now an alias for
174 * The "set debug symtab-create" debugging option of GDB has been changed to
175 accept a verbosity level. 0 means "off", 1 provides basic debugging
176 output, and values of 2 or greater provides more verbose output.
178 * New command-line options
180 Display the details of GDB configure-time options.
182 * The command 'tsave' can now support new option '-ctf' to save trace
183 buffer in Common Trace Format.
185 * Newly installed $prefix/bin/gcore acts as a shell interface for the
188 * GDB now implements the the C++ 'typeid' operator.
190 * The new convenience variable $_exception holds the exception being
191 thrown or caught at an exception-related catchpoint.
193 * The exception-related catchpoints, like "catch throw", now accept a
194 regular expression which can be used to filter exceptions by type.
196 * The new convenience variable $_exitsignal is automatically set to
197 the terminating signal number when the program being debugged dies
198 due to an uncaught signal.
202 ** All MI commands now accept an optional "--language" option.
203 Support for this feature can be verified by using the "-list-features"
204 command, which should contain "language-option".
206 ** The new command -info-gdb-mi-command allows the user to determine
207 whether a GDB/MI command is supported or not.
209 ** The "^error" result record returned when trying to execute an undefined
210 GDB/MI command now provides a variable named "code" whose content is the
211 "undefined-command" error code. Support for this feature can be verified
212 by using the "-list-features" command, which should contain
213 "undefined-command-error-code".
215 ** The -trace-save MI command can optionally save trace buffer in Common
218 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
220 ** The command -data-list-register-values now accepts an optional
221 "--skip-unavailable" option. When used, only the available registers
224 ** The new command -trace-frame-collected dumps collected variables,
225 computed expressions, tvars, memory and registers in a traceframe.
227 ** The commands -stack-list-locals, -stack-list-arguments and
228 -stack-list-variables now accept an option "--skip-unavailable".
229 When used, only the available locals or arguments are displayed.
231 ** The -exec-run command now accepts an optional "--start" option.
232 When used, the command follows the same semantics as the "start"
233 command, stopping the program's execution at the start of its
234 main subprogram. Support for this feature can be verified using
235 the "-list-features" command, which should contain
236 "exec-run-start-option".
238 ** The new commands -catch-assert and -catch-exceptions insert
239 catchpoints stopping the program when Ada exceptions are raised.
241 ** The new command -info-ada-exceptions provides the equivalent of
242 the new "info exceptions" command.
244 * New system-wide configuration scripts
245 A GDB installation now provides scripts suitable for use as system-wide
246 configuration scripts for the following systems:
250 * GDB now supports target-assigned range stepping with remote targets.
251 This improves the performance of stepping source lines by reducing
252 the number of control packets from/to GDB. See "New remote packets"
255 * GDB now understands the element 'tvar' in the XML traceframe info.
256 It has the id of the collected trace state variables.
258 * On S/390 targets that provide the transactional-execution feature,
259 the program interruption transaction diagnostic block (TDB) is now
260 represented as a number of additional "registers" in GDB.
266 The vCont packet supports a new 'r' action, that tells the remote
267 stub to step through an address range itself, without GDB
268 involvemement at each single-step.
270 qXfer:libraries-svr4:read's annex
271 The previously unused annex of the qXfer:libraries-svr4:read packet
272 is now used to support passing an argument list. The remote stub
273 reports support for this argument list to GDB's qSupported query.
274 The defined arguments are "start" and "prev", used to reduce work
275 necessary for library list updating, resulting in significant
278 * New features in the GDB remote stub, GDBserver
280 ** GDBserver now supports target-assisted range stepping. Currently
281 enabled on x86/x86_64 GNU/Linux targets.
283 ** GDBserver now adds element 'tvar' in the XML in the reply to
284 'qXfer:traceframe-info:read'. It has the id of the collected
285 trace state variables.
287 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
290 * New 'z' formatter for printing and examining memory, this displays the
291 value as hexadecimal zero padded on the left to the size of the type.
293 * GDB can now use Windows x64 unwinding data.
295 * The "set remotebaud" command has been replaced by "set serial baud".
296 Similarly, "show remotebaud" has been replaced by "show serial baud".
297 The "set remotebaud" and "show remotebaud" commands are still available
298 to provide backward compatibility with older versions of GDB.
300 *** Changes in GDB 7.6
302 * Target record has been renamed to record-full.
303 Record/replay is now enabled with the "record full" command.
304 This also affects settings that are associated with full record/replay
305 that have been moved from "set/show record" to "set/show record full":
307 set|show record full insn-number-max
308 set|show record full stop-at-limit
309 set|show record full memory-query
311 * A new record target "record-btrace" has been added. The new target
312 uses hardware support to record the control-flow of a process. It
313 does not support replaying the execution, but it implements the
314 below new commands for investigating the recorded execution log.
315 This new recording method can be enabled using:
319 The "record-btrace" target is only available on Intel Atom processors
320 and requires a Linux kernel 2.6.32 or later.
322 * Two new commands have been added for record/replay to give information
323 about the recorded execution without having to replay the execution.
324 The commands are only supported by "record btrace".
326 record instruction-history prints the execution history at
327 instruction granularity
329 record function-call-history prints the execution history at
332 * New native configurations
334 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
335 FreeBSD/powerpc powerpc*-*-freebsd
336 x86_64/Cygwin x86_64-*-cygwin*
337 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
341 ARM AArch64 aarch64*-*-elf
342 ARM AArch64 GNU/Linux aarch64*-*-linux
343 Lynx 178 PowerPC powerpc-*-lynx*178
344 x86_64/Cygwin x86_64-*-cygwin*
345 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
347 * If the configured location of system.gdbinit file (as given by the
348 --with-system-gdbinit option at configure time) is in the
349 data-directory (as specified by --with-gdb-datadir at configure
350 time) or in one of its subdirectories, then GDB will look for the
351 system-wide init file in the directory specified by the
352 --data-directory command-line option.
354 * New command line options:
356 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
357 other initialization files, unlike -nx which disables all of them.
359 * Removed command line options
361 -epoch This was used by the gdb mode in Epoch, an ancient fork of
364 * The 'ptype' and 'whatis' commands now accept an argument to control
367 * 'info proc' now works on some core files.
371 ** Vectors can be created with gdb.Type.vector.
373 ** Python's atexit.register now works in GDB.
375 ** Types can be pretty-printed via a Python API.
377 ** Python 3 is now supported (in addition to Python 2.4 or later)
379 ** New class gdb.Architecture exposes GDB's internal representation
380 of architecture in the Python API.
382 ** New method Frame.architecture returns the gdb.Architecture object
383 corresponding to the frame's architecture.
385 * New Python-based convenience functions:
387 ** $_memeq(buf1, buf2, length)
388 ** $_streq(str1, str2)
390 ** $_regex(str, regex)
392 * The 'cd' command now defaults to using '~' (the home directory) if not
395 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
396 default for GCC since November 2000.
398 * The command 'forward-search' can now be abbreviated as 'fo'.
400 * The command 'info tracepoints' can now display 'installed on target'
401 or 'not installed on target' for each non-pending location of tracepoint.
403 * New configure options
405 --enable-libmcheck/--disable-libmcheck
406 By default, development versions are built with -lmcheck on hosts
407 that support it, in order to help track memory corruption issues.
408 Release versions, on the other hand, are built without -lmcheck
409 by default. The --enable-libmcheck/--disable-libmcheck configure
410 options allow the user to override that default.
411 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
412 This configure option allows the user to build GDB with
413 libbabeltrace using which GDB can read Common Trace Format data.
415 * New commands (for set/show, see "New options" below)
418 Catch signals. This is similar to "handle", but allows commands and
419 conditions to be attached.
422 List the BFDs known to GDB.
424 python-interactive [command]
426 Start a Python interactive prompt, or evaluate the optional command
427 and print the result of expressions.
430 "py" is a new alias for "python".
432 enable type-printer [name]...
433 disable type-printer [name]...
434 Enable or disable type printers.
438 ** For the Renesas Super-H architecture, the "regs" command has been removed
439 (has been deprecated in GDB 7.5), and "info all-registers" should be used
444 set print type methods (on|off)
445 show print type methods
446 Control whether method declarations are displayed by "ptype".
447 The default is to show them.
449 set print type typedefs (on|off)
450 show print type typedefs
451 Control whether typedef definitions are displayed by "ptype".
452 The default is to show them.
454 set filename-display basename|relative|absolute
455 show filename-display
456 Control the way in which filenames is displayed.
457 The default is "relative", which preserves previous behavior.
459 set trace-buffer-size
460 show trace-buffer-size
461 Request target to change the size of trace buffer.
463 set remote trace-buffer-size-packet auto|on|off
464 show remote trace-buffer-size-packet
465 Control the use of the remote protocol `QTBuffer:size' packet.
469 Control display of debugging messages related to ARM AArch64.
472 set debug coff-pe-read
473 show debug coff-pe-read
474 Control display of debugging messages related to reading of COFF/PE
479 Control display of debugging messages related to Mach-O symbols
482 set debug notification
483 show debug notification
484 Control display of debugging info for async remote notification.
488 ** Command parameter changes are now notified using new async record
489 "=cmd-param-changed".
490 ** Trace frame changes caused by command "tfind" are now notified using
491 new async record "=traceframe-changed".
492 ** The creation, deletion and modification of trace state variables
493 are now notified using new async records "=tsv-created",
494 "=tsv-deleted" and "=tsv-modified".
495 ** The start and stop of process record are now notified using new
496 async record "=record-started" and "=record-stopped".
497 ** Memory changes are now notified using new async record
499 ** The data-disassemble command response will include a "fullname" field
500 containing the absolute file name when source has been requested.
501 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
502 command, to allow pattern filling of memory areas.
503 ** New commands "-catch-load"/"-catch-unload" added for intercepting
504 library load/unload events.
505 ** The response to breakpoint commands and breakpoint async records
506 includes an "installed" field containing a boolean state about each
507 non-pending tracepoint location is whether installed on target or not.
508 ** Output of the "-trace-status" command includes a "trace-file" field
509 containing the name of the trace file being examined. This field is
510 optional, and only present when examining a trace file.
511 ** The "fullname" field is now always present along with the "file" field,
512 even if the file cannot be found by GDB.
514 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
515 You must have the LZMA library available when configuring GDB for this
516 feature to be enabled. For more information, see:
517 http://fedoraproject.org/wiki/Features/MiniDebugInfo
522 Set the size of trace buffer. The remote stub reports support for this
523 packet to gdb's qSupported query.
526 Enable Branch Trace Store (BTS)-based branch tracing for the current
527 thread. The remote stub reports support for this packet to gdb's
531 Disable branch tracing for the current thread. The remote stub reports
532 support for this packet to gdb's qSupported query.
535 Read the traced branches for the current thread. The remote stub
536 reports support for this packet to gdb's qSupported query.
538 *** Changes in GDB 7.5
540 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
541 for more x32 ABI info.
543 * GDB now supports access to MIPS DSP registers on Linux targets.
545 * GDB now supports debugging microMIPS binaries.
547 * The "info os" command on GNU/Linux can now display information on
548 several new classes of objects managed by the operating system:
549 "info os procgroups" lists process groups
550 "info os files" lists file descriptors
551 "info os sockets" lists internet-domain sockets
552 "info os shm" lists shared-memory regions
553 "info os semaphores" lists semaphores
554 "info os msg" lists message queues
555 "info os modules" lists loaded kernel modules
557 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
558 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
559 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
560 options and inspect the probe arguments using the new $_probe_arg family
561 of convenience variables. You can obtain more information about SystemTap
562 in <http://sourceware.org/systemtap/>.
564 * GDB now supports reversible debugging on ARM, it allows you to
565 debug basic ARM and THUMB instructions, and provides
566 record/replay support.
568 * The option "symbol-reloading" has been deleted as it is no longer used.
572 ** GDB commands implemented in Python can now be put in command class
575 ** The "maint set python print-stack on|off" is now deleted.
577 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
578 apply "flag enum"-style pretty-printing to any enum.
580 ** gdb.lookup_symbol can now work when there is no current frame.
582 ** gdb.Symbol now has a 'line' attribute, holding the line number in
583 the source at which the symbol was defined.
585 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
586 method 'value'. The former indicates whether the symbol needs a
587 frame in order to compute its value, and the latter computes the
590 ** A new method 'referenced_value' on gdb.Value objects which can
591 dereference pointer as well as C++ reference values.
593 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
594 which return the global and static blocks (as gdb.Block objects),
595 of the underlying symbol table, respectively.
597 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
598 object associated with a PC value.
600 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
601 of the address range occupied by code for the current source line.
603 * Go language support.
604 GDB now supports debugging programs written in the Go programming
607 * GDBserver now supports stdio connections.
608 E.g. (gdb) target remote | ssh myhost gdbserver - hello
610 * The binary "gdbtui" can no longer be built or installed.
611 Use "gdb -tui" instead.
613 * GDB will now print "flag" enums specially. A flag enum is one where
614 all the enumerator values have no bits in common when pairwise
615 "and"ed. When printing a value whose type is a flag enum, GDB will
616 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
617 (gdb) print (enum E) 3
620 * The filename part of a linespec will now match trailing components
621 of a source file name. For example, "break gcc/expr.c:1000" will
622 now set a breakpoint in build/gcc/expr.c, but not
625 * The "info proc" and "generate-core-file" commands will now also
626 work on remote targets connected to GDBserver on Linux.
628 * The command "info catch" has been removed. It has been disabled
631 * The "catch exception" and "catch assert" commands now accept
632 a condition at the end of the command, much like the "break"
633 command does. For instance:
635 (gdb) catch exception Constraint_Error if Barrier = True
637 Previously, it was possible to add a condition to such catchpoints,
638 but it had to be done as a second step, after the catchpoint had been
639 created, using the "condition" command.
641 * The "info static-tracepoint-marker" command will now also work on
642 native Linux targets with in-process agent.
644 * GDB can now set breakpoints on inlined functions.
646 * The .gdb_index section has been updated to include symbols for
647 inlined functions. GDB will ignore older .gdb_index sections by
648 default, which could cause symbol files to be loaded more slowly
649 until their .gdb_index sections can be recreated. The new command
650 "set use-deprecated-index-sections on" will cause GDB to use any older
651 .gdb_index sections it finds. This will restore performance, but the
652 ability to set breakpoints on inlined functions will be lost in symbol
653 files with older .gdb_index sections.
655 The .gdb_index section has also been updated to record more information
656 about each symbol. This speeds up the "info variables", "info functions"
657 and "info types" commands when used with programs having the .gdb_index
658 section, as well as speeding up debugging with shared libraries using
659 the .gdb_index section.
661 * Ada support for GDB/MI Variable Objects has been added.
663 * GDB can now support 'breakpoint always-inserted mode' in 'record'
668 ** New command -info-os is the MI equivalent of "info os".
670 ** Output logs ("set logging" and related) now include MI output.
674 ** "set use-deprecated-index-sections on|off"
675 "show use-deprecated-index-sections on|off"
676 Controls the use of deprecated .gdb_index sections.
678 ** "catch load" and "catch unload" can be used to stop when a shared
679 library is loaded or unloaded, respectively.
681 ** "enable count" can be used to auto-disable a breakpoint after
684 ** "info vtbl" can be used to show the virtual method tables for
685 C++ and Java objects.
687 ** "explore" and its sub commands "explore value" and "explore type"
688 can be used to recursively explore values and types of
689 expressions. These commands are available only if GDB is
690 configured with '--with-python'.
692 ** "info auto-load" shows status of all kinds of auto-loaded files,
693 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
694 sequences of commands files, "info auto-load python-scripts"
695 shows status of auto-loading Python script files,
696 "info auto-load local-gdbinit" shows status of loading init file
697 (.gdbinit) from current directory and "info auto-load libthread-db" shows
698 status of inferior specific thread debugging shared library loading.
700 ** "info auto-load-scripts", "set auto-load-scripts on|off"
701 and "show auto-load-scripts" commands have been deprecated, use their
702 "info auto-load python-scripts", "set auto-load python-scripts on|off"
703 and "show auto-load python-scripts" counterparts instead.
705 ** "dprintf location,format,args..." creates a dynamic printf, which
706 is basically a breakpoint that does a printf and immediately
707 resumes your program's execution, so it is like a printf that you
708 can insert dynamically at runtime instead of at compiletime.
710 ** "set print symbol"
712 Controls whether GDB attempts to display the symbol, if any,
713 corresponding to addresses it prints. This defaults to "on", but
714 you can set it to "off" to restore GDB's previous behavior.
716 * Deprecated commands
718 ** For the Renesas Super-H architecture, the "regs" command has been
719 deprecated, and "info all-registers" should be used instead.
723 Renesas RL78 rl78-*-elf
724 HP OpenVMS ia64 ia64-hp-openvms*
726 * GDBserver supports evaluation of breakpoint conditions. When
727 support is advertised by GDBserver, GDB may be told to send the
728 breakpoint conditions in bytecode form to GDBserver. GDBserver
729 will only report the breakpoint trigger to GDB when its condition
735 show mips compression
736 Select the compressed ISA encoding used in functions that have no symbol
737 information available. The encoding can be set to either of:
740 and is updated automatically from ELF file flags if available.
742 set breakpoint condition-evaluation
743 show breakpoint condition-evaluation
744 Control whether breakpoint conditions are evaluated by GDB ("host") or by
745 GDBserver ("target"). Default option "auto" chooses the most efficient
747 This option can improve debugger efficiency depending on the speed of the
751 Disable auto-loading globally.
754 Show auto-loading setting of all kinds of auto-loaded files.
756 set auto-load gdb-scripts on|off
757 show auto-load gdb-scripts
758 Control auto-loading of GDB canned sequences of commands files.
760 set auto-load python-scripts on|off
761 show auto-load python-scripts
762 Control auto-loading of Python script files.
764 set auto-load local-gdbinit on|off
765 show auto-load local-gdbinit
766 Control loading of init file (.gdbinit) from current directory.
768 set auto-load libthread-db on|off
769 show auto-load libthread-db
770 Control auto-loading of inferior specific thread debugging shared library.
772 set auto-load scripts-directory <dir1>[:<dir2>...]
773 show auto-load scripts-directory
774 Set a list of directories from which to load auto-loaded scripts.
775 Automatically loaded Python scripts and GDB scripts are located in one
776 of the directories listed by this option.
777 The delimiter (':' above) may differ according to the host platform.
779 set auto-load safe-path <dir1>[:<dir2>...]
780 show auto-load safe-path
781 Set a list of directories from which it is safe to auto-load files.
782 The delimiter (':' above) may differ according to the host platform.
784 set debug auto-load on|off
786 Control display of debugging info for auto-loading the files above.
788 set dprintf-style gdb|call|agent
790 Control the way in which a dynamic printf is performed; "gdb"
791 requests a GDB printf command, while "call" causes dprintf to call a
792 function in the inferior. "agent" requests that the target agent
793 (such as GDBserver) do the printing.
795 set dprintf-function <expr>
796 show dprintf-function
797 set dprintf-channel <expr>
799 Set the function and optional first argument to the call when using
800 the "call" style of dynamic printf.
802 set disconnected-dprintf on|off
803 show disconnected-dprintf
804 Control whether agent-style dynamic printfs continue to be in effect
805 after GDB disconnects.
807 * New configure options
810 Configure default value for the 'set auto-load scripts-directory'
811 setting above. It defaults to '$debugdir:$datadir/auto-load',
812 $debugdir representing global debugging info directories (available
813 via 'show debug-file-directory') and $datadir representing GDB's data
814 directory (available via 'show data-directory').
816 --with-auto-load-safe-path
817 Configure default value for the 'set auto-load safe-path' setting
818 above. It defaults to the --with-auto-load-dir setting.
820 --without-auto-load-safe-path
821 Set 'set auto-load safe-path' to '/', effectively disabling this
826 z0/z1 conditional breakpoints extension
828 The z0/z1 breakpoint insertion packets have been extended to carry
829 a list of conditional expressions over to the remote stub depending on the
830 condition evaluation mode. The use of this extension can be controlled
831 via the "set remote conditional-breakpoints-packet" command.
835 Specify the signals which the remote stub may pass to the debugged
836 program without GDB involvement.
838 * New command line options
840 --init-command=FILE, -ix Like --command, -x but execute it
841 before loading inferior.
842 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
843 execute it before loading inferior.
845 *** Changes in GDB 7.4
847 * GDB now handles ambiguous linespecs more consistently; the existing
848 FILE:LINE support has been expanded to other types of linespecs. A
849 breakpoint will now be set on all matching locations in all
850 inferiors, and locations will be added or removed according to
853 * GDB now allows you to skip uninteresting functions and files when
854 stepping with the "skip function" and "skip file" commands.
856 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
857 and "show remote hardware-watchpoint-length-limit". These allows to
858 set or show the maximum length limit (in bytes) of a remote
859 target hardware watchpoint.
861 This allows e.g. to use "unlimited" hardware watchpoints with the
862 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
863 watchpoints are slower than real hardware watchpoints but are
864 significantly faster than gdb software watchpoints.
868 ** The register_pretty_printer function in module gdb.printing now takes
869 an optional `replace' argument. If True, the new printer replaces any
872 ** The "maint set python print-stack on|off" command has been
873 deprecated and will be deleted in GDB 7.5.
874 A new command: "set python print-stack none|full|message" has
875 replaced it. Additionally, the default for "print-stack" is
876 now "message", which just prints the error message without
879 ** A prompt substitution hook (prompt_hook) is now available to the
882 ** A new Python module, gdb.prompt has been added to the GDB Python
883 modules library. This module provides functionality for
884 escape sequences in prompts (used by set/show
885 extended-prompt). These escape sequences are replaced by their
888 ** Python commands and convenience-functions located in
889 'data-directory'/python/gdb/command and
890 'data-directory'/python/gdb/function are now automatically loaded
893 ** Blocks now provide four new attributes. global_block and
894 static_block will return the global and static blocks
895 respectively. is_static and is_global are boolean attributes
896 that indicate if the block is one of those two types.
898 ** Symbols now provide the "type" attribute, the type of the symbol.
900 ** The "gdb.breakpoint" function has been deprecated in favor of
903 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
904 of a function. This class is based on the "finish" command
905 available in the CLI.
907 ** Type objects for struct and union types now allow access to
908 the fields using standard Python dictionary (mapping) methods.
909 For example, "some_type['myfield']" now works, as does
912 ** A new event "gdb.new_objfile" has been added, triggered by loading a
915 ** A new function, "deep_items" has been added to the gdb.types
916 module in the GDB Python modules library. This function returns
917 an iterator over the fields of a struct or union type. Unlike
918 the standard Python "iteritems" method, it will recursively traverse
919 any anonymous fields.
923 ** "*stopped" events can report several new "reason"s, such as
926 ** Breakpoint changes are now notified using new async records, like
927 "=breakpoint-modified".
929 ** New command -ada-task-info.
931 * libthread-db-search-path now supports two special values: $sdir and $pdir.
932 $sdir specifies the default system locations of shared libraries.
933 $pdir specifies the directory where the libpthread used by the application
936 GDB no longer looks in $sdir and $pdir after it has searched the directories
937 mentioned in libthread-db-search-path. If you want to search those
938 directories, they must be specified in libthread-db-search-path.
939 The default value of libthread-db-search-path on GNU/Linux and Solaris
940 systems is now "$sdir:$pdir".
942 $pdir is not supported by gdbserver, it is currently ignored.
943 $sdir is supported by gdbserver.
945 * New configure option --with-iconv-bin.
946 When using the internationalization support like the one in the GNU C
947 library, GDB will invoke the "iconv" program to get a list of supported
948 character sets. If this program lives in a non-standard location, one can
949 use this option to specify where to find it.
951 * When natively debugging programs on PowerPC BookE processors running
952 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
953 watchpoints, which specify a mask in addition to an address to watch.
954 The mask specifies that some bits of an address (the bits which are
955 reset in the mask) should be ignored when matching the address accessed
956 by the inferior against the watchpoint address. See the "PowerPC Embedded"
957 section in the user manual for more details.
959 * The new option --once causes GDBserver to stop listening for connections once
960 the first connection is made. The listening port used by GDBserver will
961 become available after that.
963 * New commands "info macros" and "alias" have been added.
965 * New function parameters suffix @entry specifies value of function parameter
966 at the time the function got called. Entry values are available only since
972 "!" is now an alias of the "shell" command.
973 Note that no space is needed between "!" and SHELL COMMAND.
977 watch EXPRESSION mask MASK_VALUE
978 The watch command now supports the mask argument which allows creation
979 of masked watchpoints, if the current architecture supports this feature.
981 info auto-load-scripts [REGEXP]
982 This command was formerly named "maintenance print section-scripts".
983 It is now generally useful and is no longer a maintenance-only command.
985 info macro [-all] [--] MACRO
986 The info macro command has new options `-all' and `--'. The first for
987 printing all definitions of a macro. The second for explicitly specifying
988 the end of arguments and the beginning of the macro name in case the macro
989 name starts with a hyphen.
991 collect[/s] EXPRESSIONS
992 The tracepoint collect command now takes an optional modifier "/s"
993 that directs it to dereference pointer-to-character types and
994 collect the bytes of memory up to a zero byte. The behavior is
995 similar to what you see when you use the regular print command on a
996 string. An optional integer following the "/s" sets a bound on the
997 number of bytes that will be collected.
1000 The trace start command now interprets any supplied arguments as a
1001 note to be recorded with the trace run, with an effect similar to
1002 setting the variable trace-notes.
1005 The trace stop command now interprets any arguments as a note to be
1006 mentioned along with the tstatus report that the trace was stopped
1007 with a command. The effect is similar to setting the variable
1010 * Tracepoints can now be enabled and disabled at any time after a trace
1011 experiment has been started using the standard "enable" and "disable"
1012 commands. It is now possible to start a trace experiment with no enabled
1013 tracepoints; GDB will display a warning, but will allow the experiment to
1014 begin, assuming that tracepoints will be enabled as needed while the trace
1017 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1018 locations with 4-byte instructions, when they were previously
1019 limited to locations with instructions of 5 bytes or longer.
1023 set debug dwarf2-read
1024 show debug dwarf2-read
1025 Turns on or off display of debugging messages related to reading
1026 DWARF debug info. The default is off.
1028 set debug symtab-create
1029 show debug symtab-create
1030 Turns on or off display of debugging messages related to symbol table
1031 creation. The default is off.
1034 show extended-prompt
1035 Set the GDB prompt, and allow escape sequences to be inserted to
1036 display miscellaneous information (see 'help set extended-prompt'
1037 for the list of sequences). This prompt (and any information
1038 accessed through the escape sequences) is updated every time the
1039 prompt is displayed.
1041 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1042 show print entry-values
1043 Set printing of frame argument values at function entry. In some cases
1044 GDB can determine the value of function argument which was passed by the
1045 function caller, even if the value was modified inside the called function.
1047 set debug entry-values
1048 show debug entry-values
1049 Control display of debugging info for determining frame argument values at
1050 function entry and virtual tail call frames.
1052 set basenames-may-differ
1053 show basenames-may-differ
1054 Set whether a source file may have multiple base names.
1055 (A "base name" is the name of a file with the directory part removed.
1056 Example: The base name of "/home/user/hello.c" is "hello.c".)
1057 If set, GDB will canonicalize file names (e.g., expand symlinks)
1058 before comparing them. Canonicalization is an expensive operation,
1059 but it allows the same file be known by more than one base name.
1060 If not set (the default), all source files are assumed to have just
1061 one base name, and gdb will do file name comparisons more efficiently.
1067 Set a user name and notes for the current and any future trace runs.
1068 This is useful for long-running and/or disconnected traces, to
1069 inform others (or yourself) as to who is running the trace, supply
1070 contact information, or otherwise explain what is going on.
1072 set trace-stop-notes
1073 show trace-stop-notes
1074 Set a note attached to the trace run, that is displayed when the
1075 trace has been stopped by a tstop command. This is useful for
1076 instance as an explanation, if you are stopping a trace run that was
1077 started by someone else.
1079 * New remote packets
1083 Dynamically enable a tracepoint in a started trace experiment.
1087 Dynamically disable a tracepoint in a started trace experiment.
1091 Set the user and notes of the trace run.
1095 Query the current status of a tracepoint.
1099 Query the minimum length of instruction at which a fast tracepoint may
1102 * Dcache size (number of lines) and line-size are now runtime-configurable
1103 via "set dcache line" and "set dcache line-size" commands.
1107 Texas Instruments TMS320C6x tic6x-*-*
1111 Renesas RL78 rl78-*-elf
1113 *** Changes in GDB 7.3.1
1115 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1117 *** Changes in GDB 7.3
1119 * GDB has a new command: "thread find [REGEXP]".
1120 It finds the thread id whose name, target id, or thread extra info
1121 matches the given regular expression.
1123 * The "catch syscall" command now works on mips*-linux* targets.
1125 * The -data-disassemble MI command now supports modes 2 and 3 for
1126 dumping the instruction opcodes.
1128 * New command line options
1130 -data-directory DIR Specify DIR as the "data-directory".
1131 This is mostly for testing purposes.
1133 * The "maint set python auto-load on|off" command has been renamed to
1134 "set auto-load-scripts on|off".
1136 * GDB has a new command: "set directories".
1137 It is like the "dir" command except that it replaces the
1138 source path list instead of augmenting it.
1140 * GDB now understands thread names.
1142 On GNU/Linux, "info threads" will display the thread name as set by
1143 prctl or pthread_setname_np.
1145 There is also a new command, "thread name", which can be used to
1146 assign a name internally for GDB to display.
1149 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1150 has been integrated into GDB.
1154 ** The function gdb.Write now accepts an optional keyword 'stream'.
1155 This keyword, when provided, will direct the output to either
1156 stdout, stderr, or GDB's logging output.
1158 ** Parameters can now be be sub-classed in Python, and in particular
1159 you may implement the get_set_doc and get_show_doc functions.
1160 This improves how Parameter set/show documentation is processed
1161 and allows for more dynamic content.
1163 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1164 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1165 have an is_valid method.
1167 ** Breakpoints can now be sub-classed in Python, and in particular
1168 you may implement a 'stop' function that is executed each time
1169 the inferior reaches that breakpoint.
1171 ** New function gdb.lookup_global_symbol looks up a global symbol.
1173 ** GDB values in Python are now callable if the value represents a
1174 function. For example, if 'some_value' represents a function that
1175 takes two integer parameters and returns a value, you can call
1176 that function like so:
1178 result = some_value (10,20)
1180 ** Module gdb.types has been added.
1181 It contains a collection of utilities for working with gdb.Types objects:
1182 get_basic_type, has_field, make_enum_dict.
1184 ** Module gdb.printing has been added.
1185 It contains utilities for writing and registering pretty-printers.
1186 New classes: PrettyPrinter, SubPrettyPrinter,
1187 RegexpCollectionPrettyPrinter.
1188 New function: register_pretty_printer.
1190 ** New commands "info pretty-printers", "enable pretty-printer" and
1191 "disable pretty-printer" have been added.
1193 ** gdb.parameter("directories") is now available.
1195 ** New function gdb.newest_frame returns the newest frame in the
1198 ** The gdb.InferiorThread class has a new "name" attribute. This
1199 holds the thread's name.
1201 ** Python Support for Inferior events.
1202 Python scripts can add observers to be notified of events
1203 occurring in the process being debugged.
1204 The following events are currently supported:
1205 - gdb.events.cont Continue event.
1206 - gdb.events.exited Inferior exited event.
1207 - gdb.events.stop Signal received, and Breakpoint hit events.
1211 ** GDB now puts template parameters in scope when debugging in an
1212 instantiation. For example, if you have:
1214 template<int X> int func (void) { return X; }
1216 then if you step into func<5>, "print X" will show "5". This
1217 feature requires proper debuginfo support from the compiler; it
1218 was added to GCC 4.5.
1220 ** The motion commands "next", "finish", "until", and "advance" now
1221 work better when exceptions are thrown. In particular, GDB will
1222 no longer lose control of the inferior; instead, the GDB will
1223 stop the inferior at the point at which the exception is caught.
1224 This functionality requires a change in the exception handling
1225 code that was introduced in GCC 4.5.
1227 * GDB now follows GCC's rules on accessing volatile objects when
1228 reading or writing target state during expression evaluation.
1229 One notable difference to prior behavior is that "print x = 0"
1230 no longer generates a read of x; the value of the assignment is
1231 now always taken directly from the value being assigned.
1233 * GDB now has some support for using labels in the program's source in
1234 linespecs. For instance, you can use "advance label" to continue
1235 execution to a label.
1237 * GDB now has support for reading and writing a new .gdb_index
1238 section. This section holds a fast index of DWARF debugging
1239 information and can be used to greatly speed up GDB startup and
1240 operation. See the documentation for `save gdb-index' for details.
1242 * The "watch" command now accepts an optional "-location" argument.
1243 When used, this causes GDB to watch the memory referred to by the
1244 expression. Such a watchpoint is never deleted due to it going out
1247 * GDB now supports thread debugging of core dumps on GNU/Linux.
1249 GDB now activates thread debugging using the libthread_db library
1250 when debugging GNU/Linux core dumps, similarly to when debugging
1251 live processes. As a result, when debugging a core dump file, GDB
1252 is now able to display pthread_t ids of threads. For example, "info
1253 threads" shows the same output as when debugging the process when it
1254 was live. In earlier releases, you'd see something like this:
1257 * 1 LWP 6780 main () at main.c:10
1259 While now you see this:
1262 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1264 It is also now possible to inspect TLS variables when debugging core
1267 When debugging a core dump generated on a machine other than the one
1268 used to run GDB, you may need to point GDB at the correct
1269 libthread_db library with the "set libthread-db-search-path"
1270 command. See the user manual for more details on this command.
1272 * When natively debugging programs on PowerPC BookE processors running
1273 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1274 which stop execution of the inferior whenever it executes an instruction
1275 at any address within the specified range. See the "PowerPC Embedded"
1276 section in the user manual for more details.
1278 * New features in the GDB remote stub, GDBserver
1280 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1281 and i686 LynxOS (version 5.x).
1283 ** GDBserver is now supported on Blackfin Linux.
1285 * New native configurations
1287 ia64 HP-UX ia64-*-hpux*
1291 Analog Devices, Inc. Blackfin Processor bfin-*
1293 * Ada task switching is now supported on sparc-elf targets when
1294 debugging a program using the Ravenscar Profile. For more information,
1295 see the "Tasking Support when using the Ravenscar Profile" section
1296 in the GDB user manual.
1298 * Guile support was removed.
1300 * New features in the GNU simulator
1302 ** The --map-info flag lists all known core mappings.
1304 ** CFI flashes may be simulated via the "cfi" device.
1306 *** Changes in GDB 7.2
1308 * Shared library support for remote targets by default
1310 When GDB is configured for a generic, non-OS specific target, like
1311 for example, --target=arm-eabi or one of the many *-*-elf targets,
1312 GDB now queries remote stubs for loaded shared libraries using the
1313 `qXfer:libraries:read' packet. Previously, shared library support
1314 was always disabled for such configurations.
1318 ** Argument Dependent Lookup (ADL)
1320 In C++ ADL lookup directs function search to the namespaces of its
1321 arguments even if the namespace has not been imported.
1331 Here the compiler will search for `foo' in the namespace of 'b'
1332 and find A::foo. GDB now supports this. This construct is commonly
1333 used in the Standard Template Library for operators.
1335 ** Improved User Defined Operator Support
1337 In addition to member operators, GDB now supports lookup of operators
1338 defined in a namespace and imported with a `using' directive, operators
1339 defined in the global scope, operators imported implicitly from an
1340 anonymous namespace, and the ADL operators mentioned in the previous
1342 GDB now also supports proper overload resolution for all the previously
1343 mentioned flavors of operators.
1345 ** static const class members
1347 Printing of static const class members that are initialized in the
1348 class definition has been fixed.
1350 * Windows Thread Information Block access.
1352 On Windows targets, GDB now supports displaying the Windows Thread
1353 Information Block (TIB) structure. This structure is visible either
1354 by using the new command `info w32 thread-information-block' or, by
1355 dereferencing the new convenience variable named `$_tlb', a
1356 thread-specific pointer to the TIB. This feature is also supported
1357 when remote debugging using GDBserver.
1359 * Static tracepoints
1361 Static tracepoints are calls in the user program into a tracing
1362 library. One such library is a port of the LTTng kernel tracer to
1363 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1364 When debugging with GDBserver, GDB now supports combining the GDB
1365 tracepoint machinery with such libraries. For example: the user can
1366 use GDB to probe a static tracepoint marker (a call from the user
1367 program into the tracing library) with the new "strace" command (see
1368 "New commands" below). This creates a "static tracepoint" in the
1369 breakpoint list, that can be manipulated with the same feature set
1370 as fast and regular tracepoints. E.g., collect registers, local and
1371 global variables, collect trace state variables, and define
1372 tracepoint conditions. In addition, the user can collect extra
1373 static tracepoint marker specific data, by collecting the new
1374 $_sdata internal variable. When analyzing the trace buffer, you can
1375 inspect $_sdata like any other variable available to GDB. For more
1376 information, see the "Tracepoints" chapter in GDB user manual. New
1377 remote packets have been defined to support static tracepoints, see
1378 the "New remote packets" section below.
1380 * Better reconstruction of tracepoints after disconnected tracing
1382 GDB will attempt to download the original source form of tracepoint
1383 definitions when starting a trace run, and then will upload these
1384 upon reconnection to the target, resulting in a more accurate
1385 reconstruction of the tracepoints that are in use on the target.
1389 You can now exercise direct control over the ways that GDB can
1390 affect your program. For instance, you can disallow the setting of
1391 breakpoints, so that the program can run continuously (assuming
1392 non-stop mode). In addition, the "observer" variable is available
1393 to switch all of the different controls; in observer mode, GDB
1394 cannot affect the target's behavior at all, which is useful for
1395 tasks like diagnosing live systems in the field.
1397 * The new convenience variable $_thread holds the number of the
1400 * New remote packets
1404 Return the address of the Windows Thread Information Block of a given thread.
1408 In response to several of the tracepoint packets, the target may now
1409 also respond with a number of intermediate `qRelocInsn' request
1410 packets before the final result packet, to have GDB handle
1411 relocating an instruction to execute at a different address. This
1412 is particularly useful for stubs that support fast tracepoints. GDB
1413 reports support for this feature in the qSupported packet.
1417 List static tracepoint markers in the target program.
1421 List static tracepoint markers at a given address in the target
1424 qXfer:statictrace:read
1426 Read the static trace data collected (by a `collect $_sdata'
1427 tracepoint action). The remote stub reports support for this packet
1428 to gdb's qSupported query.
1432 Send the current settings of GDB's permission flags.
1436 Send part of the source (textual) form of a tracepoint definition,
1437 which includes location, conditional, and action list.
1439 * The source command now accepts a -s option to force searching for the
1440 script in the source search path even if the script name specifies
1443 * New features in the GDB remote stub, GDBserver
1445 - GDBserver now support tracepoints (including fast tracepoints, and
1446 static tracepoints). The feature is currently supported by the
1447 i386-linux and amd64-linux builds. See the "Tracepoints support
1448 in gdbserver" section in the manual for more information.
1450 GDBserver JIT compiles the tracepoint's conditional agent
1451 expression bytecode into native code whenever possible for low
1452 overhead dynamic tracepoints conditionals. For such tracepoints,
1453 an expression that examines program state is evaluated when the
1454 tracepoint is reached, in order to determine whether to capture
1455 trace data. If the condition is simple and false, processing the
1456 tracepoint finishes very quickly and no data is gathered.
1458 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1459 for static tracepoints support.
1461 - GDBserver now supports x86_64 Windows 64-bit debugging.
1463 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1464 it understands register description.
1466 * The --batch flag now disables pagination and queries.
1468 * X86 general purpose registers
1470 GDB now supports reading/writing byte, word and double-word x86
1471 general purpose registers directly. This means you can use, say,
1472 $ah or $ax to refer, respectively, to the byte register AH and
1473 16-bit word register AX that are actually portions of the 32-bit
1474 register EAX or 64-bit register RAX.
1476 * The `commands' command now accepts a range of breakpoints to modify.
1477 A plain `commands' following a command that creates multiple
1478 breakpoints affects all the breakpoints set by that command. This
1479 applies to breakpoints set by `rbreak', and also applies when a
1480 single `break' command creates multiple breakpoints (e.g.,
1481 breakpoints on overloaded c++ functions).
1483 * The `rbreak' command now accepts a filename specification as part of
1484 its argument, limiting the functions selected by the regex to those
1485 in the specified file.
1487 * Support for remote debugging Windows and SymbianOS shared libraries
1488 from Unix hosts has been improved. Non Windows GDB builds now can
1489 understand target reported file names that follow MS-DOS based file
1490 system semantics, such as file names that include drive letters and
1491 use the backslash character as directory separator. This makes it
1492 possible to transparently use the "set sysroot" and "set
1493 solib-search-path" on Unix hosts to point as host copies of the
1494 target's shared libraries. See the new command "set
1495 target-file-system-kind" described below, and the "Commands to
1496 specify files" section in the user manual for more information.
1500 eval template, expressions...
1501 Convert the values of one or more expressions under the control
1502 of the string template to a command line, and call it.
1504 set target-file-system-kind unix|dos-based|auto
1505 show target-file-system-kind
1506 Set or show the assumed file system kind for target reported file
1509 save breakpoints <filename>
1510 Save all current breakpoint definitions to a file suitable for use
1511 in a later debugging session. To read the saved breakpoint
1512 definitions, use the `source' command.
1514 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1517 info static-tracepoint-markers
1518 Display information about static tracepoint markers in the target.
1520 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1521 Define a static tracepoint by probing a marker at the given
1522 function, line, address, or marker ID.
1526 Enable and disable observer mode.
1528 set may-write-registers on|off
1529 set may-write-memory on|off
1530 set may-insert-breakpoints on|off
1531 set may-insert-tracepoints on|off
1532 set may-insert-fast-tracepoints on|off
1533 set may-interrupt on|off
1534 Set individual permissions for GDB effects on the target. Note that
1535 some of these settings can have undesirable or surprising
1536 consequences, particularly when changed in the middle of a session.
1537 For instance, disabling the writing of memory can prevent
1538 breakpoints from being inserted, cause single-stepping to fail, or
1539 even crash your program, if you disable after breakpoints have been
1540 inserted. However, GDB should not crash.
1542 set record memory-query on|off
1543 show record memory-query
1544 Control whether to stop the inferior if memory changes caused
1545 by an instruction cannot be recorded.
1550 The disassemble command now supports "start,+length" form of two arguments.
1554 ** GDB now provides a new directory location, called the python directory,
1555 where Python scripts written for GDB can be installed. The location
1556 of that directory is <data-directory>/python, where <data-directory>
1557 is the GDB data directory. For more details, see section `Scripting
1558 GDB using Python' in the manual.
1560 ** The GDB Python API now has access to breakpoints, symbols, symbol
1561 tables, program spaces, inferiors, threads and frame's code blocks.
1562 Additionally, GDB Parameters can now be created from the API, and
1563 manipulated via set/show in the CLI.
1565 ** New functions gdb.target_charset, gdb.target_wide_charset,
1566 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1568 ** New exception gdb.GdbError.
1570 ** Pretty-printers are now also looked up in the current program space.
1572 ** Pretty-printers can now be individually enabled and disabled.
1574 ** GDB now looks for names of Python scripts to auto-load in a
1575 special section named `.debug_gdb_scripts', in addition to looking
1576 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1578 * Tracepoint actions were unified with breakpoint commands. In particular,
1579 there are no longer differences in "info break" output for breakpoints and
1580 tracepoints and the "commands" command can be used for both tracepoints and
1581 regular breakpoints.
1585 ARM Symbian arm*-*-symbianelf*
1587 * D language support.
1588 GDB now supports debugging programs written in the D programming
1591 * GDB now supports the extended ptrace interface for PowerPC which is
1592 available since Linux kernel version 2.6.34. This automatically enables
1593 any hardware breakpoints and additional hardware watchpoints available in
1594 the processor. The old ptrace interface exposes just one hardware
1595 watchpoint and no hardware breakpoints.
1597 * GDB is now able to use the Data Value Compare (DVC) register available on
1598 embedded PowerPC processors to implement in hardware simple watchpoint
1599 conditions of the form:
1601 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1603 This works in native GDB running on Linux kernels with the extended ptrace
1604 interface mentioned above.
1606 *** Changes in GDB 7.1
1610 ** Namespace Support
1612 GDB now supports importing of namespaces in C++. This enables the
1613 user to inspect variables from imported namespaces. Support for
1614 namepace aliasing has also been added. So, if a namespace is
1615 aliased in the current scope (e.g. namepace C=A; ) the user can
1616 print variables using the alias (e.g. (gdb) print C::x).
1620 All known bugs relating to the printing of virtual base class were
1621 fixed. It is now possible to call overloaded static methods using a
1626 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1627 and reinterpret_cast<> are now handled by the C++ expression parser.
1631 Xilinx MicroBlaze microblaze-*-*
1636 Xilinx MicroBlaze microblaze
1639 * Multi-program debugging.
1641 GDB now has support for multi-program (a.k.a. multi-executable or
1642 multi-exec) debugging. This allows for debugging multiple inferiors
1643 simultaneously each running a different program under the same GDB
1644 session. See "Debugging Multiple Inferiors and Programs" in the
1645 manual for more information. This implied some user visible changes
1646 in the multi-inferior support. For example, "info inferiors" now
1647 lists inferiors that are not running yet or that have exited
1648 already. See also "New commands" and "New options" below.
1650 * New tracing features
1652 GDB's tracepoint facility now includes several new features:
1654 ** Trace state variables
1656 GDB tracepoints now include support for trace state variables, which
1657 are variables managed by the target agent during a tracing
1658 experiment. They are useful for tracepoints that trigger each
1659 other, so for instance one tracepoint can count hits in a variable,
1660 and then a second tracepoint has a condition that is true when the
1661 count reaches a particular value. Trace state variables share the
1662 $-syntax of GDB convenience variables, and can appear in both
1663 tracepoint actions and condition expressions. Use the "tvariable"
1664 command to create, and "info tvariables" to view; see "Trace State
1665 Variables" in the manual for more detail.
1669 GDB now includes an option for defining fast tracepoints, which
1670 targets may implement more efficiently, such as by installing a jump
1671 into the target agent rather than a trap instruction. The resulting
1672 speedup can be by two orders of magnitude or more, although the
1673 tradeoff is that some program locations on some target architectures
1674 might not allow fast tracepoint installation, for instance if the
1675 instruction to be replaced is shorter than the jump. To request a
1676 fast tracepoint, use the "ftrace" command, with syntax identical to
1677 the regular trace command.
1679 ** Disconnected tracing
1681 It is now possible to detach GDB from the target while it is running
1682 a trace experiment, then reconnect later to see how the experiment
1683 is going. In addition, a new variable disconnected-tracing lets you
1684 tell the target agent whether to continue running a trace if the
1685 connection is lost unexpectedly.
1689 GDB now has the ability to save the trace buffer into a file, and
1690 then use that file as a target, similarly to you can do with
1691 corefiles. You can select trace frames, print data that was
1692 collected in them, and use tstatus to display the state of the
1693 tracing run at the moment that it was saved. To create a trace
1694 file, use "tsave <filename>", and to use it, do "target tfile
1697 ** Circular trace buffer
1699 You can ask the target agent to handle the trace buffer as a
1700 circular buffer, discarding the oldest trace frames to make room for
1701 newer ones, by setting circular-trace-buffer to on. This feature may
1702 not be available for all target agents.
1707 The disassemble command, when invoked with two arguments, now requires
1708 the arguments to be comma-separated.
1711 The info variables command now displays variable definitions. Files
1712 which only declare a variable are not shown.
1715 The source command is now capable of sourcing Python scripts.
1716 This feature is dependent on the debugger being build with Python
1719 Related to this enhancement is also the introduction of a new command
1720 "set script-extension" (see below).
1722 * New commands (for set/show, see "New options" below)
1724 record save [<FILENAME>]
1725 Save a file (in core file format) containing the process record
1726 execution log for replay debugging at a later time.
1728 record restore <FILENAME>
1729 Restore the process record execution log that was saved at an
1730 earlier time, for replay debugging.
1732 add-inferior [-copies <N>] [-exec <FILENAME>]
1735 clone-inferior [-copies <N>] [ID]
1736 Make a new inferior ready to execute the same program another
1737 inferior has loaded.
1742 maint info program-spaces
1743 List the program spaces loaded into GDB.
1745 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1746 show remote interrupt-sequence
1747 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1748 as the sequence to the remote target in order to interrupt the execution.
1749 Ctrl-C is a default. Some system prefers BREAK which is high level of
1750 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1751 Magic SysRq g. It is BREAK signal and character 'g'.
1753 set remote interrupt-on-connect [on | off]
1754 show remote interrupt-on-connect
1755 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1756 remote target when gdb connects to it. This is needed when you debug
1759 set remotebreak [on | off]
1761 Deprecated. Use "set/show remote interrupt-sequence" instead.
1763 tvariable $NAME [ = EXP ]
1764 Create or modify a trace state variable.
1767 List trace state variables and their values.
1769 delete tvariable $NAME ...
1770 Delete one or more trace state variables.
1773 Evaluate the given expressions without collecting anything into the
1774 trace buffer. (Valid in tracepoint actions only.)
1776 ftrace FN / FILE:LINE / *ADDR
1777 Define a fast tracepoint at the given function, line, or address.
1779 * New expression syntax
1781 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1782 GDB now parses 0b101010 identically with 42.
1786 set follow-exec-mode new|same
1787 show follow-exec-mode
1788 Control whether GDB reuses the same inferior across an exec call or
1789 creates a new one. This is useful to be able to restart the old
1790 executable after the inferior having done an exec call.
1792 set default-collect EXPR, ...
1793 show default-collect
1794 Define a list of expressions to be collected at each tracepoint.
1795 This is a useful way to ensure essential items are not overlooked,
1796 such as registers or a critical global variable.
1798 set disconnected-tracing
1799 show disconnected-tracing
1800 If set to 1, the target is instructed to continue tracing if it
1801 loses its connection to GDB. If 0, the target is to stop tracing
1804 set circular-trace-buffer
1805 show circular-trace-buffer
1806 If set to on, the target is instructed to use a circular trace buffer
1807 and discard the oldest trace frames instead of stopping the trace due
1808 to a full trace buffer. If set to off, the trace stops when the buffer
1809 fills up. Some targets may not support this.
1811 set script-extension off|soft|strict
1812 show script-extension
1813 If set to "off", the debugger does not perform any script language
1814 recognition, and all sourced files are assumed to be GDB scripts.
1815 If set to "soft" (the default), files are sourced according to
1816 filename extension, falling back to GDB scripts if the first
1818 If set to "strict", files are sourced according to filename extension.
1820 set ada trust-PAD-over-XVS on|off
1821 show ada trust-PAD-over-XVS
1822 If off, activate a workaround against a bug in the debugging information
1823 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1824 the GCC sources for more information about the GNAT encoding and
1825 PAD types in particular). It is always safe to set this option to
1826 off, but this introduces a slight performance penalty. The default
1829 * Python API Improvements
1831 ** GDB provides the new class gdb.LazyString. This is useful in
1832 some pretty-printing cases. The new method gdb.Value.lazy_string
1833 provides a simple way to create objects of this type.
1835 ** The fields returned by gdb.Type.fields now have an
1836 `is_base_class' attribute.
1838 ** The new method gdb.Type.range returns the range of an array type.
1840 ** The new method gdb.parse_and_eval can be used to parse and
1841 evaluate an expression.
1843 * New remote packets
1846 Define a trace state variable.
1849 Get the current value of a trace state variable.
1852 Set desired tracing behavior upon disconnection.
1855 Set the trace buffer to be linear or circular.
1858 Get data about the tracepoints currently in use.
1862 Process record now works correctly with hardware watchpoints.
1864 Multiple bug fixes have been made to the mips-irix port, making it
1865 much more reliable. In particular:
1866 - Debugging threaded applications is now possible again. Previously,
1867 GDB would hang while starting the program, or while waiting for
1868 the program to stop at a breakpoint.
1869 - Attaching to a running process no longer hangs.
1870 - An error occurring while loading a core file has been fixed.
1871 - Changing the value of the PC register now works again. This fixes
1872 problems observed when using the "jump" command, or when calling
1873 a function from GDB, or even when assigning a new value to $pc.
1874 - With the "finish" and "return" commands, the return value for functions
1875 returning a small array is now correctly printed.
1876 - It is now possible to break on shared library code which gets executed
1877 during a shared library init phase (code executed while executing
1878 their .init section). Previously, the breakpoint would have no effect.
1879 - GDB is now able to backtrace through the signal handler for
1880 non-threaded programs.
1882 PIE (Position Independent Executable) programs debugging is now supported.
1883 This includes debugging execution of PIC (Position Independent Code) shared
1884 libraries although for that, it should be possible to run such libraries as an
1887 *** Changes in GDB 7.0
1889 * GDB now has an interface for JIT compilation. Applications that
1890 dynamically generate code can create symbol files in memory and register
1891 them with GDB. For users, the feature should work transparently, and
1892 for JIT developers, the interface is documented in the GDB manual in the
1893 "JIT Compilation Interface" chapter.
1895 * Tracepoints may now be conditional. The syntax is as for
1896 breakpoints; either an "if" clause appended to the "trace" command,
1897 or the "condition" command is available. GDB sends the condition to
1898 the target for evaluation using the same bytecode format as is used
1899 for tracepoint actions.
1901 * The disassemble command now supports: an optional /r modifier, print the
1902 raw instructions in hex as well as in symbolic form, and an optional /m
1903 modifier to print mixed source+assembly.
1905 * Process record and replay
1907 In a architecture environment that supports ``process record and
1908 replay'', ``process record and replay'' target can record a log of
1909 the process execution, and replay it with both forward and reverse
1912 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
1913 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
1914 set execution-direction {forward|reverse}, for targets that support
1917 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
1918 feature is available with a native GDB running on kernel version
1921 * GDB now has support for multi-byte and wide character sets on the
1922 target. Strings whose character type is wchar_t, char16_t, or
1923 char32_t are now correctly printed. GDB supports wide- and unicode-
1924 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
1925 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
1926 `printf'. This feature requires iconv to work properly; if your
1927 system does not have a working iconv, GDB can use GNU libiconv. See
1928 the installation instructions for more information.
1930 * GDB now supports automatic retrieval of shared library files from
1931 remote targets. To use this feature, specify a system root that begins
1932 with the `remote:' prefix, either via the `set sysroot' command or via
1933 the `--with-sysroot' configure-time option.
1935 * "info sharedlibrary" now takes an optional regex of libraries to show,
1936 and it now reports if a shared library has no debugging information.
1938 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
1939 now complete on file names.
1941 * When completing in expressions, gdb will attempt to limit
1942 completions to allowable structure or union fields, where appropriate.
1943 For instance, consider:
1945 # struct example { int f1; double f2; };
1946 # struct example variable;
1949 If the user types TAB at the end of this command line, the available
1950 completions will be "f1" and "f2".
1952 * Inlined functions are now supported. They show up in backtraces, and
1953 the "step", "next", and "finish" commands handle them automatically.
1955 * GDB now supports the token-splicing (##) and stringification (#)
1956 operators when expanding macros. It also supports variable-arity
1959 * GDB now supports inspecting extra signal information, exported by
1960 the new $_siginfo convenience variable. The feature is currently
1961 implemented on linux ARM, i386 and amd64.
1963 * GDB can now display the VFP floating point registers and NEON vector
1964 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
1965 can provide these registers (requires Linux 2.6.30 or later). Remote
1966 and simulator targets may also provide them.
1968 * New remote packets
1971 Search memory for a sequence of bytes.
1974 Turn off `+'/`-' protocol acknowledgments to permit more efficient
1975 operation over reliable transport links. Use of this packet is
1976 controlled by the `set remote noack-packet' command.
1979 Kill the process with the specified process ID. Use this in preference
1980 to `k' when multiprocess protocol extensions are supported.
1983 Obtains additional operating system information
1987 Read or write additional signal information.
1989 * Removed remote protocol undocumented extension
1991 An undocumented extension to the remote protocol's `S' stop reply
1992 packet that permited the stub to pass a process id was removed.
1993 Remote servers should use the `T' stop reply packet instead.
1995 * GDB now supports multiple function calling conventions according to the
1996 DWARF-2 DW_AT_calling_convention function attribute.
1998 * The SH target utilizes the aforementioned change to distinguish between gcc
1999 and Renesas calling convention. It also adds the new CLI commands
2000 `set/show sh calling-convention'.
2002 * GDB can now read compressed debug sections, as produced by GNU gold
2003 with the --compress-debug-sections=zlib flag.
2005 * 64-bit core files are now supported on AIX.
2007 * Thread switching is now supported on Tru64.
2009 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2010 which will be allocated using malloc later in program execution.
2012 * The qXfer:libraries:read remote procotol packet now allows passing a
2013 list of section offsets.
2015 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2016 conditions handling signals delivered during attach or thread creation
2017 have also been fixed.
2019 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2020 From the user's standpoint, all unqualified instances of True and False
2021 are treated as the standard definitions, regardless of context.
2023 * GDB now parses C++ symbol and type names more flexibly. For
2026 template<typename T> class C { };
2029 GDB will now correctly handle all of:
2031 ptype C<char const *>
2032 ptype C<char const*>
2033 ptype C<const char *>
2034 ptype C<const char*>
2036 * New features in the GDB remote stub, gdbserver
2038 - The "--wrapper" command-line argument tells gdbserver to use a
2039 wrapper program to launch programs for debugging.
2041 - On PowerPC and S/390 targets, it is now possible to use a single
2042 gdbserver executable to debug both 32-bit and 64-bit programs.
2043 (This requires gdbserver itself to be built as a 64-bit executable.)
2045 - gdbserver uses the new noack protocol mode for TCP connections to
2046 reduce communications latency, if also supported and enabled in GDB.
2048 - Support for the sparc64-linux-gnu target is now included in
2051 - The amd64-linux build of gdbserver now supports debugging both
2052 32-bit and 64-bit programs.
2054 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2055 now support hardware watchpoints, and will use them automatically
2060 GDB now has support for scripting using Python. Whether this is
2061 available is determined at configure time.
2063 New GDB commands can now be written in Python.
2065 * Ada tasking support
2067 Ada tasks can now be inspected in GDB. The following commands have
2071 Print the list of Ada tasks.
2073 Print detailed information about task number N.
2075 Print the task number of the current task.
2077 Switch the context of debugging to task number N.
2079 * Support for user-defined prefixed commands. The "define" command can
2080 add new commands to existing prefixes, e.g. "target".
2082 * Multi-inferior, multi-process debugging.
2084 GDB now has generalized support for multi-inferior debugging. See
2085 "Debugging Multiple Inferiors" in the manual for more information.
2086 Although availability still depends on target support, the command
2087 set is more uniform now. The GNU/Linux specific multi-forks support
2088 has been migrated to this new framework. This implied some user
2089 visible changes; see "New commands" and also "Removed commands"
2092 * Target descriptions can now describe the target OS ABI. See the
2093 "Target Description Format" section in the user manual for more
2096 * Target descriptions can now describe "compatible" architectures
2097 to indicate that the target can execute applications for a different
2098 architecture in addition to those for the main target architecture.
2099 See the "Target Description Format" section in the user manual for
2102 * Multi-architecture debugging.
2104 GDB now includes general supports for debugging applications on
2105 hybrid systems that use more than one single processor architecture
2106 at the same time. Each such hybrid architecture still requires
2107 specific support to be added. The only hybrid architecture supported
2108 in this version of GDB is the Cell Broadband Engine.
2110 * GDB now supports integrated debugging of Cell/B.E. applications that
2111 use both the PPU and SPU architectures. To enable support for hybrid
2112 Cell/B.E. debugging, you need to configure GDB to support both the
2113 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2114 --enable-targets configure option.
2116 * Non-stop mode debugging.
2118 For some targets, GDB now supports an optional mode of operation in
2119 which you can examine stopped threads while other threads continue
2120 to execute freely. This is referred to as non-stop mode, with the
2121 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2122 section in the user manual for more information.
2124 To be able to support remote non-stop debugging, a remote stub needs
2125 to implement the non-stop mode remote protocol extensions, as
2126 described in the "Remote Non-Stop" section of the user manual. The
2127 GDB remote stub, gdbserver, has been adjusted to support these
2128 extensions on linux targets.
2130 * New commands (for set/show, see "New options" below)
2132 catch syscall [NAME(S) | NUMBER(S)]
2133 Catch system calls. Arguments, which should be names of system
2134 calls or their numbers, mean catch only those syscalls. Without
2135 arguments, every syscall will be caught. When the inferior issues
2136 any of the specified syscalls, GDB will stop and announce the system
2137 call, both when it is called and when its call returns. This
2138 feature is currently available with a native GDB running on the
2139 Linux Kernel, under the following architectures: x86, x86_64,
2140 PowerPC and PowerPC64.
2142 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2144 Search memory for a sequence of bytes.
2146 maint set python print-stack
2147 maint show python print-stack
2148 Show a stack trace when an error is encountered in a Python script.
2151 Invoke CODE by passing it to the Python interpreter.
2156 These allow macros to be defined, undefined, and listed
2160 Show operating system information about processes.
2163 List the inferiors currently under GDB's control.
2166 Switch focus to inferior number NUM.
2169 Detach from inferior number NUM.
2172 Kill inferior number NUM.
2176 set spu stop-on-load
2177 show spu stop-on-load
2178 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2180 set spu auto-flush-cache
2181 show spu auto-flush-cache
2182 Control whether to automatically flush the software-managed cache
2183 during Cell/B.E. debugging.
2185 set sh calling-convention
2186 show sh calling-convention
2187 Control the calling convention used when calling SH target functions.
2190 show debug timestamp
2191 Control display of timestamps with GDB debugging output.
2193 set disassemble-next-line
2194 show disassemble-next-line
2195 Control display of disassembled source lines or instructions when
2198 set remote noack-packet
2199 show remote noack-packet
2200 Set/show the use of remote protocol QStartNoAckMode packet. See above
2201 under "New remote packets."
2203 set remote query-attached-packet
2204 show remote query-attached-packet
2205 Control use of remote protocol `qAttached' (query-attached) packet.
2207 set remote read-siginfo-object
2208 show remote read-siginfo-object
2209 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2212 set remote write-siginfo-object
2213 show remote write-siginfo-object
2214 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2217 set remote reverse-continue
2218 show remote reverse-continue
2219 Control use of remote protocol 'bc' (reverse-continue) packet.
2221 set remote reverse-step
2222 show remote reverse-step
2223 Control use of remote protocol 'bs' (reverse-step) packet.
2225 set displaced-stepping
2226 show displaced-stepping
2227 Control displaced stepping mode. Displaced stepping is a way to
2228 single-step over breakpoints without removing them from the debuggee.
2229 Also known as "out-of-line single-stepping".
2232 show debug displaced
2233 Control display of debugging info for displaced stepping.
2235 maint set internal-error
2236 maint show internal-error
2237 Control what GDB does when an internal error is detected.
2239 maint set internal-warning
2240 maint show internal-warning
2241 Control what GDB does when an internal warning is detected.
2246 Use a wrapper program to launch programs for debugging.
2248 set multiple-symbols (all|ask|cancel)
2249 show multiple-symbols
2250 The value of this variable can be changed to adjust the debugger behavior
2251 when an expression or a breakpoint location contains an ambiguous symbol
2252 name (an overloaded function name, for instance).
2254 set breakpoint always-inserted
2255 show breakpoint always-inserted
2256 Keep breakpoints always inserted in the target, as opposed to inserting
2257 them when resuming the target, and removing them when the target stops.
2258 This option can improve debugger performance on slow remote targets.
2260 set arm fallback-mode (arm|thumb|auto)
2261 show arm fallback-mode
2262 set arm force-mode (arm|thumb|auto)
2264 These commands control how ARM GDB determines whether instructions
2265 are ARM or Thumb. The default for both settings is auto, which uses
2266 the current CPSR value for instructions without symbols; previous
2267 versions of GDB behaved as if "set arm fallback-mode arm".
2269 set disable-randomization
2270 show disable-randomization
2271 Standalone programs run with the virtual address space randomization enabled
2272 by default on some platforms. This option keeps the addresses stable across
2273 multiple debugging sessions.
2277 Control whether other threads are stopped or not when some thread hits
2282 Requests that asynchronous execution is enabled in the target, if available.
2283 In this case, it's possible to resume target in the background, and interact
2284 with GDB while the target is running. "show target-async" displays the
2285 current state of asynchronous execution of the target.
2287 set target-wide-charset
2288 show target-wide-charset
2289 The target-wide-charset is the name of the character set that GDB
2290 uses when printing characters whose type is wchar_t.
2292 set tcp auto-retry (on|off)
2294 set tcp connect-timeout
2295 show tcp connect-timeout
2296 These commands allow GDB to retry failed TCP connections to a remote stub
2297 with a specified timeout period; this is useful if the stub is launched
2298 in parallel with GDB but may not be ready to accept connections immediately.
2300 set libthread-db-search-path
2301 show libthread-db-search-path
2302 Control list of directories which GDB will search for appropriate
2305 set schedule-multiple (on|off)
2306 show schedule-multiple
2307 Allow GDB to resume all threads of all processes or only threads of
2308 the current process.
2312 Use more aggressive caching for accesses to the stack. This improves
2313 performance of remote debugging (particularly backtraces) without
2314 affecting correctness.
2316 set interactive-mode (on|off|auto)
2317 show interactive-mode
2318 Control whether GDB runs in interactive mode (on) or not (off).
2319 When in interactive mode, GDB waits for the user to answer all
2320 queries. Otherwise, GDB does not wait and assumes the default
2321 answer. When set to auto (the default), GDB determines which
2322 mode to use based on the stdin settings.
2327 For program forks, this is replaced by the new more generic `info
2328 inferiors' command. To list checkpoints, you can still use the
2329 `info checkpoints' command, which was an alias for the `info forks'
2333 Replaced by the new `inferior' command. To switch between
2334 checkpoints, you can still use the `restart' command, which was an
2335 alias for the `fork' command.
2338 This is removed, since some targets don't have a notion of
2339 processes. To switch between processes, you can still use the
2340 `inferior' command using GDB's own inferior number.
2343 For program forks, this is replaced by the new more generic `kill
2344 inferior' command. To delete a checkpoint, you can still use the
2345 `delete checkpoint' command, which was an alias for the `delete
2349 For program forks, this is replaced by the new more generic `detach
2350 inferior' command. To detach a checkpoint, you can still use the
2351 `detach checkpoint' command, which was an alias for the `detach
2354 * New native configurations
2356 x86/x86_64 Darwin i[34567]86-*-darwin*
2358 x86_64 MinGW x86_64-*-mingw*
2362 Lattice Mico32 lm32-*
2363 x86 DICOS i[34567]86-*-dicos*
2364 x86_64 DICOS x86_64-*-dicos*
2367 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2368 (mingw32ce) debugging.
2374 These commands were actually not implemented on any target.
2376 *** Changes in GDB 6.8
2378 * New native configurations
2380 NetBSD/hppa hppa*-*netbsd*
2381 Xtensa GNU/Linux xtensa*-*-linux*
2385 NetBSD/hppa hppa*-*-netbsd*
2386 Xtensa GNU/Lunux xtensa*-*-linux*
2388 * Change in command line behavior -- corefiles vs. process ids.
2390 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2391 attaching to process NUMBER fails, GDB no longer attempts to open a
2392 core file named NUMBER. Attaching to a program using the -c option
2393 is no longer supported. Instead, use the '-p' or '--pid' options.
2395 * GDB can now be built as a native debugger for debugging Windows x86
2396 (mingw32) Portable Executable (PE) programs.
2398 * Pending breakpoints no longer change their number when their address
2401 * GDB now supports breakpoints with multiple locations,
2402 including breakpoints on C++ constructors, inside C++ templates,
2403 and in inlined functions.
2405 * GDB's ability to debug optimized code has been improved. GDB more
2406 accurately identifies function bodies and lexical blocks that occupy
2407 more than one contiguous range of addresses.
2409 * Target descriptions can now describe registers for PowerPC.
2411 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2412 registers on PowerPC targets.
2414 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2415 targets even when the libthread_db library is not available.
2417 * The GDB remote stub, gdbserver, now supports the new file transfer
2418 commands (remote put, remote get, and remote delete).
2420 * The GDB remote stub, gdbserver, now supports run and attach in
2421 extended-remote mode.
2423 * hppa*64*-*-hpux11* target broken
2424 The debugger is unable to start a program and fails with the following
2425 error: "Error trying to get information about dynamic linker".
2426 The gdb-6.7 release is also affected.
2428 * GDB now supports the --enable-targets= configure option to allow
2429 building a single GDB executable that supports multiple remote
2430 target architectures.
2432 * GDB now supports debugging C and C++ programs which use the
2433 Decimal Floating Point extension. In addition, the PowerPC target
2434 now has a set of pseudo-registers to inspect decimal float values
2435 stored in two consecutive float registers.
2437 * The -break-insert MI command can optionally create pending
2440 * Improved support for debugging Ada
2441 Many improvements to the Ada language support have been made. These
2443 - Better support for Ada2005 interface types
2444 - Improved handling of arrays and slices in general
2445 - Better support for Taft-amendment types
2446 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2448 - Improved command completion in Ada
2451 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2456 set print frame-arguments (all|scalars|none)
2457 show print frame-arguments
2458 The value of this variable can be changed to control which argument
2459 values should be printed by the debugger when displaying a frame.
2464 Transfer files to and from a remote target, and delete remote files.
2471 Transfer files to and from a remote target, and delete remote files.
2473 * New remote packets
2480 Open, close, read, write, and delete files on the remote system.
2483 Attach to an existing process on the remote system, in extended-remote
2487 Run a new process on the remote system, in extended-remote mode.
2489 *** Changes in GDB 6.7
2491 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2492 bfd, libiberty and opcodes, as revealed by static analysis donated by
2493 Coverity, Inc. (http://scan.coverity.com).
2495 * When looking up multiply-defined global symbols, GDB will now prefer the
2496 symbol definition in the current shared library if it was built using the
2497 -Bsymbolic linker option.
2499 * When the Text User Interface (TUI) is not configured, GDB will now
2500 recognize the -tui command-line option and print a message that the TUI
2503 * The GDB remote stub, gdbserver, now has lower overhead for high
2504 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2506 * GDB for MIPS targets now autodetects whether a remote target provides
2507 32-bit or 64-bit register values.
2509 * Support for C++ member pointers has been improved.
2511 * GDB now understands XML target descriptions, which specify the
2512 target's overall architecture. GDB can read a description from
2513 a local file or over the remote serial protocol.
2515 * Vectors of single-byte data use a new integer type which is not
2516 automatically displayed as character or string data.
2518 * The /s format now works with the print command. It displays
2519 arrays of single-byte integers and pointers to single-byte integers
2522 * Target descriptions can now describe target-specific registers,
2523 for architectures which have implemented the support (currently
2524 only ARM, M68K, and MIPS).
2526 * GDB and the GDB remote stub, gdbserver, now support the XScale
2529 * The GDB remote stub, gdbserver, has been updated to support
2530 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2531 has been rewritten to use the standard GDB remote protocol.
2533 * GDB can now step into C++ functions which are called through thunks.
2535 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2537 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2538 layout. It also supports a TextSeg= and DataSeg= response when only
2539 segment base addresses (rather than offsets) are available.
2541 * The /i format now outputs any trailing branch delay slot instructions
2542 immediately following the last instruction within the count specified.
2544 * The GDB remote protocol "T" stop reply packet now supports a
2545 "library" response. Combined with the new "qXfer:libraries:read"
2546 packet, this response allows GDB to debug shared libraries on targets
2547 where the operating system manages the list of loaded libraries (e.g.
2548 Windows and SymbianOS).
2550 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2551 (DLLs) on Windows and Windows CE targets.
2553 * GDB now supports a faster verification that a .debug file matches its binary
2554 according to its build-id signature, if the signature is present.
2560 Enable or disable hardware flow control (RTS/CTS) on the serial port
2561 when debugging using remote targets.
2563 set mem inaccessible-by-default
2564 show mem inaccessible-by-default
2565 If the target supplies a memory map, for instance via the remote
2566 protocol's "qXfer:memory-map:read" packet, setting this variable
2567 prevents GDB from accessing memory outside the memory map. This
2568 is useful for targets with memory mapped registers or which react
2569 badly to accesses of unmapped address space.
2571 set breakpoint auto-hw
2572 show breakpoint auto-hw
2573 If the target supplies a memory map, for instance via the remote
2574 protocol's "qXfer:memory-map:read" packet, setting this variable
2575 lets GDB use hardware breakpoints automatically for memory regions
2576 where it can not use software breakpoints. This covers both the
2577 "break" command and internal breakpoints used for other commands
2578 including "next" and "finish".
2581 catch exception unhandled
2582 Stop the program execution when Ada exceptions are raised.
2585 Stop the program execution when an Ada assertion failed.
2589 Set an alternate system root for target files. This is a more
2590 general version of "set solib-absolute-prefix", which is now
2591 an alias to "set sysroot".
2594 Provide extended SPU facility status information. This set of
2595 commands is available only when debugging the Cell/B.E. SPU
2598 * New native configurations
2600 OpenBSD/sh sh*-*openbsd*
2603 unset tdesc filename
2605 Use the specified local file as an XML target description, and do
2606 not query the target for its built-in description.
2610 OpenBSD/sh sh*-*-openbsd*
2611 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2612 Toshiba Media Processor mep-elf
2614 * New remote packets
2617 Ignore the specified signals; pass them directly to the debugged program
2618 without stopping other threads or reporting them to GDB.
2620 qXfer:features:read:
2621 Read an XML target description from the target, which describes its
2626 Read or write contents of an spufs file on the target system. These
2627 packets are available only on the Cell/B.E. SPU architecture.
2629 qXfer:libraries:read:
2630 Report the loaded shared libraries. Combined with new "T" packet
2631 response, this packet allows GDB to debug shared libraries on
2632 targets where the operating system manages the list of loaded
2633 libraries (e.g. Windows and SymbianOS).
2637 Support for these obsolete configurations has been removed.
2645 i[34567]86-*-lynxos*
2646 i[34567]86-*-netware*
2647 i[34567]86-*-sco3.2v5*
2648 i[34567]86-*-sco3.2v4*
2650 i[34567]86-*-sysv4.2*
2653 i[34567]86-*-unixware2*
2654 i[34567]86-*-unixware*
2663 * Other removed features
2670 Various m68k-only ROM monitors.
2677 Various Renesas ROM monitors and debugging interfaces for SH and
2682 Support for a Macraigor serial interface to on-chip debugging.
2683 GDB does not directly support the newer parallel or USB
2688 A debug information format. The predecessor to DWARF 2 and
2689 DWARF 3, which are still supported.
2691 Support for the HP aCC compiler on HP-UX/PA-RISC
2693 SOM-encapsulated symbolic debugging information, automatic
2694 invocation of pxdb, and the aCC custom C++ ABI. This does not
2695 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2696 with aCC can still be debugged on an assembly level.
2698 MIPS ".pdr" sections
2700 A MIPS-specific format used to describe stack frame layout
2701 in debugging information.
2705 GDB could work with an older version of Guile to debug
2706 the interpreter and Scheme programs running in it.
2708 set mips stack-arg-size
2709 set mips saved-gpreg-size
2711 Use "set mips abi" to control parameter passing for MIPS.
2713 *** Changes in GDB 6.6
2718 Cell Broadband Engine SPU spu-elf
2720 * GDB can now be configured as a cross-debugger targeting native Windows
2721 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2722 running on a Windows system over TCP/IP to debug Windows programs.
2724 * The GDB remote stub, gdbserver, has been updated to support Windows and
2725 Cygwin debugging. Both single-threaded and multi-threaded programs are
2728 * The "set trust-readonly-sections" command works again. This command was
2729 broken in GDB 6.3, 6.4, and 6.5.
2731 * The "load" command now supports writing to flash memory, if the remote
2732 stub provides the required support.
2734 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2735 longer requires symbolic debug information (e.g. DWARF-2).
2740 unset substitute-path
2741 show substitute-path
2742 Manage a list of substitution rules that GDB uses to rewrite the name
2743 of the directories where the sources are located. This can be useful
2744 for instance when the sources were moved to a different location
2745 between compilation and debugging.
2749 Print each CLI command as it is executed. Each command is prefixed with
2750 a number of `+' symbols representing the nesting depth.
2751 The source command now has a `-v' option to enable the same feature.
2755 The ARM Demon monitor support (RDP protocol, "target rdp").
2757 Kernel Object Display, an embedded debugging feature which only worked with
2758 an obsolete version of Cisco IOS.
2760 The 'set download-write-size' and 'show download-write-size' commands.
2762 * New remote packets
2765 Tell a stub about GDB client features, and request remote target features.
2766 The first feature implemented is PacketSize, which allows the target to
2767 specify the size of packets it can handle - to minimize the number of
2768 packets required and improve performance when connected to a remote
2772 Fetch an OS auxilliary vector from the remote stub. This packet is a
2773 more efficient replacement for qPart:auxv:read.
2775 qXfer:memory-map:read:
2776 Fetch a memory map from the remote stub, including information about
2777 RAM, ROM, and flash memory devices.
2782 Erase and program a flash memory device.
2784 * Removed remote packets
2787 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2788 used it, and only gdbserver implemented it.
2790 *** Changes in GDB 6.5
2794 Renesas M32C/M16C m32c-elf
2796 Morpho Technologies ms1 ms1-elf
2800 init-if-undefined Initialize a convenience variable, but
2801 only if it doesn't already have a value.
2803 The following commands are presently only implemented for native GNU/Linux:
2805 checkpoint Save a snapshot of the program state.
2807 restart <n> Return the program state to a
2808 previously saved state.
2810 info checkpoints List currently saved checkpoints.
2812 delete-checkpoint <n> Delete a previously saved checkpoint.
2814 set|show detach-on-fork Tell gdb whether to detach from a newly
2815 forked process, or to keep debugging it.
2817 info forks List forks of the user program that
2818 are available to be debugged.
2820 fork <n> Switch to debugging one of several
2821 forks of the user program that are
2822 available to be debugged.
2824 delete-fork <n> Delete a fork from the list of forks
2825 that are available to be debugged (and
2826 kill the forked process).
2828 detach-fork <n> Delete a fork from the list of forks
2829 that are available to be debugged (and
2830 allow the process to continue).
2834 Morpho Technologies ms2 ms1-elf
2836 * Improved Windows host support
2838 GDB now builds as a cross debugger hosted on i686-mingw32, including
2839 native console support, and remote communications using either
2840 network sockets or serial ports.
2842 * Improved Modula-2 language support
2844 GDB can now print most types in the Modula-2 syntax. This includes:
2845 basic types, set types, record types, enumerated types, range types,
2846 pointer types and ARRAY types. Procedure var parameters are correctly
2847 printed and hexadecimal addresses and character constants are also
2848 written in the Modula-2 syntax. Best results can be obtained by using
2849 GNU Modula-2 together with the -gdwarf-2 command line option.
2853 The ARM rdi-share module.
2855 The Netware NLM debug server.
2857 *** Changes in GDB 6.4
2859 * New native configurations
2861 OpenBSD/arm arm*-*-openbsd*
2862 OpenBSD/mips64 mips64-*-openbsd*
2866 Morpho Technologies ms1 ms1-elf
2868 * New command line options
2870 --batch-silent As for --batch, but totally silent.
2871 --return-child-result The debugger will exist with the same value
2872 the child (debugged) program exited with.
2873 --eval-command COMMAND, -ex COMMAND
2874 Execute a single GDB CLI command. This may be
2875 specified multiple times and in conjunction
2876 with the --command (-x) option.
2878 * Deprecated commands removed
2880 The following commands, that were deprecated in 2000, have been
2884 set|show arm disassembly-flavor set|show arm disassembler
2885 othernames set arm disassembler
2886 set|show remotedebug set|show debug remote
2887 set|show archdebug set|show debug arch
2888 set|show eventdebug set|show debug event
2891 * New BSD user-level threads support
2893 It is now possible to debug programs using the user-level threads
2894 library on OpenBSD and FreeBSD. Currently supported (target)
2897 FreeBSD/amd64 x86_64-*-freebsd*
2898 FreeBSD/i386 i386-*-freebsd*
2899 OpenBSD/i386 i386-*-openbsd*
2901 Note that the new kernel threads libraries introduced in FreeBSD 5.x
2902 are not yet supported.
2904 * New support for Matsushita MN10300 w/sim added
2905 (Work in progress). mn10300-elf.
2907 * REMOVED configurations and files
2909 VxWorks and the XDR protocol *-*-vxworks
2910 Motorola MCORE mcore-*-*
2911 National Semiconductor NS32000 ns32k-*-*
2913 * New "set print array-indexes" command
2915 After turning this setting "on", GDB prints the index of each element
2916 when displaying arrays. The default is "off" to preserve the previous
2919 * VAX floating point support
2921 GDB now supports the not-quite-ieee VAX F and D floating point formats.
2923 * User-defined command support
2925 In addition to using $arg0..$arg9 for argument passing, it is now possible
2926 to use $argc to determine now many arguments have been passed. See the
2927 section on user-defined commands in the user manual for more information.
2929 *** Changes in GDB 6.3:
2931 * New command line option
2933 GDB now accepts -l followed by a number to set the timeout for remote
2936 * GDB works with GCC -feliminate-dwarf2-dups
2938 GDB now supports a more compact representation of DWARF-2 debug
2939 information using DW_FORM_ref_addr references. These are produced
2940 by GCC with the option -feliminate-dwarf2-dups and also by some
2941 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
2942 to use -feliminate-dwarf2-dups.
2944 * Internationalization
2946 When supported by the host system, GDB will be built with
2947 internationalization (libintl). The task of marking up the sources is
2948 continued, we're looking forward to our first translation.
2952 Initial support for debugging programs compiled with the GNAT
2953 implementation of the Ada programming language has been integrated
2954 into GDB. In this release, support is limited to expression evaluation.
2956 * New native configurations
2958 GNU/Linux/m32r m32r-*-linux-gnu
2962 GDB's remote protocol now includes support for the 'p' packet. This
2963 packet is used to fetch individual registers from a remote inferior.
2965 * END-OF-LIFE registers[] compatibility module
2967 GDB's internal register infrastructure has been completely rewritten.
2968 The new infrastructure making possible the implementation of key new
2969 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
2972 GDB 6.3 will be the last release to include the the registers[]
2973 compatibility module that allowed out-of-date configurations to
2974 continue to work. This change directly impacts the following
2984 powerpc bdm protocol
2986 Unless there is activity to revive these configurations, they will be
2987 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
2989 * OBSOLETE configurations and files
2991 Configurations that have been declared obsolete in this release have
2992 been commented out. Unless there is activity to revive these
2993 configurations, the next release of GDB will have their sources
2994 permanently REMOVED.
3003 *** Changes in GDB 6.2.1:
3005 * MIPS `break main; run' gave an heuristic-fence-post warning
3007 When attempting to run even a simple program, a warning about
3008 heuristic-fence-post being hit would be reported. This problem has
3011 * MIPS IRIX 'long double' crashed GDB
3013 When examining a long double variable, GDB would get a segmentation
3014 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3015 IRIX long double values).
3019 A bug in the VAX stack code was causing problems with the "next"
3020 command. This problem has been fixed.
3022 *** Changes in GDB 6.2:
3024 * Fix for ``many threads''
3026 On GNU/Linux systems that use the NPTL threads library, a program
3027 rapidly creating and deleting threads would confuse GDB leading to the
3030 ptrace: No such process.
3031 thread_db_get_info: cannot get thread info: generic error
3033 This problem has been fixed.
3035 * "-async" and "-noasync" options removed.
3037 Support for the broken "-noasync" option has been removed (it caused
3040 * New ``start'' command.
3042 This command runs the program until the begining of the main procedure.
3044 * New BSD Kernel Data Access Library (libkvm) interface
3046 Using ``target kvm'' it is now possible to debug kernel core dumps and
3047 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3048 platforms. Currently supported (native-only) configurations are:
3050 FreeBSD/amd64 x86_64-*-freebsd*
3051 FreeBSD/i386 i?86-*-freebsd*
3052 NetBSD/i386 i?86-*-netbsd*
3053 NetBSD/m68k m68*-*-netbsd*
3054 NetBSD/sparc sparc-*-netbsd*
3055 OpenBSD/amd64 x86_64-*-openbsd*
3056 OpenBSD/i386 i?86-*-openbsd*
3057 OpenBSD/m68k m68*-openbsd*
3058 OpenBSD/sparc sparc-*-openbsd*
3060 * Signal trampoline code overhauled
3062 Many generic problems with GDB's signal handling code have been fixed.
3063 These include: backtraces through non-contiguous stacks; recognition
3064 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3065 call; backtrace through a signal trampoline; step into and out of
3066 signal handlers; and single-stepping in the signal trampoline.
3068 Please note that kernel bugs are a limiting factor here. These
3069 features have been shown to work on an s390 GNU/Linux system that
3070 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3072 * Cygwin support for DWARF 2 added.
3074 * New native configurations
3076 GNU/Linux/hppa hppa*-*-linux*
3077 OpenBSD/hppa hppa*-*-openbsd*
3078 OpenBSD/m68k m68*-*-openbsd*
3079 OpenBSD/m88k m88*-*-openbsd*
3080 OpenBSD/powerpc powerpc-*-openbsd*
3081 NetBSD/vax vax-*-netbsd*
3082 OpenBSD/vax vax-*-openbsd*
3084 * END-OF-LIFE frame compatibility module
3086 GDB's internal frame infrastructure has been completely rewritten.
3087 The new infrastructure making it possible to support key new features
3088 including DWARF 2 Call Frame Information. To aid in the task of
3089 migrating old configurations to this new infrastructure, a
3090 compatibility module, that allowed old configurations to continue to
3091 work, was also included.
3093 GDB 6.2 will be the last release to include this frame compatibility
3094 module. This change directly impacts the following configurations:
3104 Unless there is activity to revive these configurations, they will be
3105 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3107 * REMOVED configurations and files
3109 Sun 3, running SunOS 3 m68*-*-sunos3*
3110 Sun 3, running SunOS 4 m68*-*-sunos4*
3111 Sun 2, running SunOS 3 m68000-*-sunos3*
3112 Sun 2, running SunOS 4 m68000-*-sunos4*
3113 Motorola 680x0 running LynxOS m68*-*-lynxos*
3114 AT&T 3b1/Unix pc m68*-att-*
3115 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3116 decstation mips-dec-* mips-little-*
3117 riscos mips-*-riscos* mips-*-sysv*
3118 sonymips mips-sony-*
3119 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3121 *** Changes in GDB 6.1.1:
3123 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3125 The TUI (Text-mode User Interface) is now built as part of a default
3126 GDB configuration. It is enabled by either selecting the TUI with the
3127 command line option "-i=tui" or by running the separate "gdbtui"
3128 program. For more information on the TUI, see the manual "Debugging
3131 * Pending breakpoint support (also included in GDB 6.1)
3133 Support has been added to allow you to specify breakpoints in shared
3134 libraries that have not yet been loaded. If a breakpoint location
3135 cannot be found, and the "breakpoint pending" option is set to auto,
3136 GDB queries you if you wish to make the breakpoint pending on a future
3137 shared-library load. If and when GDB resolves the breakpoint symbol,
3138 the pending breakpoint is removed as one or more regular breakpoints
3141 Pending breakpoints are very useful for GCJ Java debugging.
3143 * Fixed ISO-C build problems
3145 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3146 non ISO-C code that stopped them being built using a more strict ISO-C
3147 compiler (e.g., IBM's C compiler).
3149 * Fixed build problem on IRIX 5
3151 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3152 wasn't able to compile compile on an IRIX 5 system.
3154 * Added execute permission to gdb/gdbserver/configure
3156 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3157 permission. This bug would cause configure to fail on a number of
3158 systems (Solaris, IRIX). Ref: server/519.
3160 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3162 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3163 has been updated to use constant array sizes.
3165 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3167 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3168 its generated DWARF Call Frame Info. This encoding was causing GDB to
3169 panic, that panic has been fixed. Ref: gdb/1628.
3171 * Fixed a problem when examining parameters in shared library code.
3173 When examining parameters in optimized shared library code generated
3174 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3175 not available''. GDB now correctly displays the variable's value.
3177 *** Changes in GDB 6.1:
3179 * Removed --with-mmalloc
3181 Support for the mmalloc memory manager has been removed, as it
3182 conflicted with the internal gdb byte cache.
3184 * Changes in AMD64 configurations
3186 The AMD64 target now includes the %cs and %ss registers. As a result
3187 the AMD64 remote protocol has changed; this affects the floating-point
3188 and SSE registers. If you rely on those registers for your debugging,
3189 you should upgrade gdbserver on the remote side.
3191 * Revised SPARC target
3193 The SPARC target has been completely revised, incorporating the
3194 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3195 support for LynxOS and SunOS 4 has been dropped. Calling functions
3196 from within GDB on operating systems with a non-executable stack
3197 (Solaris, OpenBSD) now works.
3201 GDB has a new C++ demangler which does a better job on the mangled
3202 names generated by current versions of g++. It also runs faster, so
3203 with this and other changes gdb should now start faster on large C++
3206 * DWARF 2 Location Expressions
3208 GDB support for location expressions has been extended to support function
3209 arguments and frame bases. Older versions of GDB could crash when they
3212 * C++ nested types and namespaces
3214 GDB's support for nested types and namespaces in C++ has been
3215 improved, especially if you use the DWARF 2 debugging format. (This
3216 is the default for recent versions of GCC on most platforms.)
3217 Specifically, if you have a class "Inner" defined within a class or
3218 namespace "Outer", then GDB realizes that the class's name is
3219 "Outer::Inner", not simply "Inner". This should greatly reduce the
3220 frequency of complaints about not finding RTTI symbols. In addition,
3221 if you are stopped at inside of a function defined within a namespace,
3222 GDB modifies its name lookup accordingly.
3224 * New native configurations
3226 NetBSD/amd64 x86_64-*-netbsd*
3227 OpenBSD/amd64 x86_64-*-openbsd*
3228 OpenBSD/alpha alpha*-*-openbsd*
3229 OpenBSD/sparc sparc-*-openbsd*
3230 OpenBSD/sparc64 sparc64-*-openbsd*
3232 * New debugging protocols
3234 M32R with SDI protocol m32r-*-elf*
3236 * "set prompt-escape-char" command deleted.
3238 The command "set prompt-escape-char" has been deleted. This command,
3239 and its very obscure effet on GDB's prompt, was never documented,
3240 tested, nor mentioned in the NEWS file.
3242 * OBSOLETE configurations and files
3244 Configurations that have been declared obsolete in this release have
3245 been commented out. Unless there is activity to revive these
3246 configurations, the next release of GDB will have their sources
3247 permanently REMOVED.
3249 Sun 3, running SunOS 3 m68*-*-sunos3*
3250 Sun 3, running SunOS 4 m68*-*-sunos4*
3251 Sun 2, running SunOS 3 m68000-*-sunos3*
3252 Sun 2, running SunOS 4 m68000-*-sunos4*
3253 Motorola 680x0 running LynxOS m68*-*-lynxos*
3254 AT&T 3b1/Unix pc m68*-att-*
3255 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3256 decstation mips-dec-* mips-little-*
3257 riscos mips-*-riscos* mips-*-sysv*
3258 sonymips mips-sony-*
3259 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3261 * REMOVED configurations and files
3263 SGI Irix-4.x mips-sgi-irix4 or iris4
3264 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3265 Z8000 simulator z8k-zilog-none or z8ksim
3266 Matsushita MN10200 w/simulator mn10200-*-*
3267 H8/500 simulator h8500-hitachi-hms or h8500hms
3268 HP/PA running BSD hppa*-*-bsd*
3269 HP/PA running OSF/1 hppa*-*-osf*
3270 HP/PA Pro target hppa*-*-pro*
3271 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3272 386BSD i[3456]86-*-bsd*
3273 Sequent family i[3456]86-sequent-sysv4*
3274 i[3456]86-sequent-sysv*
3275 i[3456]86-sequent-bsd*
3276 SPARC running LynxOS sparc-*-lynxos*
3277 SPARC running SunOS 4 sparc-*-sunos4*
3278 Tsqware Sparclet sparclet-*-*
3279 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3281 *** Changes in GDB 6.0:
3285 Support for debugging the Objective-C programming language has been
3286 integrated into GDB.
3288 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3290 DWARF 2's Call Frame Information makes available compiler generated
3291 information that more exactly describes the program's run-time stack.
3292 By using this information, GDB is able to provide more robust stack
3295 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3296 have been updated to use a new backtrace mechanism which includes
3297 DWARF 2 CFI support.
3301 GDB's remote protocol has been extended to include support for hosted
3302 file I/O (where the remote target uses GDB's file system). See GDB's
3303 remote protocol documentation for details.
3305 * All targets using the new architecture framework.
3307 All of GDB's targets have been updated to use the new internal
3308 architecture framework. The way is now open for future GDB releases
3309 to include cross-architecture native debugging support (i386 on amd64,
3312 * GNU/Linux's Thread Local Storage (TLS)
3314 GDB now includes support for for the GNU/Linux implementation of
3315 per-thread variables.
3317 * GNU/Linux's Native POSIX Thread Library (NPTL)
3319 GDB's thread code has been updated to work with either the new
3320 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3322 * Separate debug info.
3324 GDB, in conjunction with BINUTILS, now supports a mechanism for
3325 automatically loading debug information from a separate file. Instead
3326 of shipping full debug and non-debug versions of system libraries,
3327 system integrators can now instead ship just the stripped libraries
3328 and optional debug files.
3330 * DWARF 2 Location Expressions
3332 DWARF 2 Location Expressions allow the compiler to more completely
3333 describe the location of variables (even in optimized code) to the
3336 GDB now includes preliminary support for location expressions (support
3337 for DW_OP_piece is still missing).
3341 A number of long standing bugs that caused GDB to die while starting a
3342 Java application have been fixed. GDB's Java support is now
3343 considered "useable".
3345 * GNU/Linux support for fork, vfork, and exec.
3347 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3348 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3351 * GDB supports logging output to a file
3353 There are two new commands, "set logging" and "show logging", which can be
3354 used to capture GDB's output to a file.
3356 * The meaning of "detach" has changed for gdbserver
3358 The "detach" command will now resume the application, as documented. To
3359 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3362 * d10v, m68hc11 `regs' command deprecated
3364 The `info registers' command has been updated so that it displays the
3365 registers using a format identical to the old `regs' command.
3369 A new command, "maint set profile on/off", has been added. This command can
3370 be used to enable or disable profiling while running GDB, to profile a
3371 session or a set of commands. In addition there is a new configure switch,
3372 "--enable-profiling", which will cause GDB to be compiled with profiling
3373 data, for more informative profiling results.
3375 * Default MI syntax changed to "mi2".
3377 The default MI (machine interface) syntax, enabled by the command line
3378 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3379 "mi1", can be enabled by specifying the option "-i=mi1".
3381 Support for the original "mi0" syntax (included in GDB 5.0) has been
3384 Fix for gdb/192: removed extraneous space when displaying frame level.
3385 Fix for gdb/672: update changelist is now output in mi list format.
3386 Fix for gdb/702: a -var-assign that updates the value now shows up
3387 in a subsequent -var-update.
3389 * New native configurations.
3391 FreeBSD/amd64 x86_64-*-freebsd*
3393 * Multi-arched targets.
3395 HP/PA HPUX11 hppa*-*-hpux*
3396 Renesas M32R/D w/simulator m32r-*-elf*
3398 * OBSOLETE configurations and files
3400 Configurations that have been declared obsolete in this release have
3401 been commented out. Unless there is activity to revive these
3402 configurations, the next release of GDB will have their sources
3403 permanently REMOVED.
3405 Z8000 simulator z8k-zilog-none or z8ksim
3406 Matsushita MN10200 w/simulator mn10200-*-*
3407 H8/500 simulator h8500-hitachi-hms or h8500hms
3408 HP/PA running BSD hppa*-*-bsd*
3409 HP/PA running OSF/1 hppa*-*-osf*
3410 HP/PA Pro target hppa*-*-pro*
3411 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3412 Sequent family i[3456]86-sequent-sysv4*
3413 i[3456]86-sequent-sysv*
3414 i[3456]86-sequent-bsd*
3415 Tsqware Sparclet sparclet-*-*
3416 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3418 * REMOVED configurations and files
3421 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3422 IBM AIX PS/2 i[3456]86-*-aix
3423 i386 running Mach 3.0 i[3456]86-*-mach3*
3424 i386 running Mach i[3456]86-*-mach*
3425 i386 running OSF/1 i[3456]86-*osf1mk*
3426 HP/Apollo 68k Family m68*-apollo*-sysv*,
3428 m68*-hp-bsd*, m68*-hp-hpux*
3429 Argonaut Risc Chip (ARC) arc-*-*
3430 Mitsubishi D30V d30v-*-*
3431 Fujitsu FR30 fr30-*-elf*
3432 OS/9000 i[34]86-*-os9k
3433 I960 with MON960 i960-*-coff
3435 * MIPS $fp behavior changed
3437 The convenience variable $fp, for the MIPS, now consistently returns
3438 the address of the current frame's base. Previously, depending on the
3439 context, $fp could refer to either $sp or the current frame's base
3440 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3441 The GNU Source-Level Debugger''.
3443 *** Changes in GDB 5.3:
3445 * GNU/Linux shared library multi-threaded performance improved.
3447 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3448 `/proc', in preference to `ptrace' for memory reads. This may result
3449 in an improvement in the start-up time of multi-threaded, shared
3450 library applications when run under GDB. One GDB user writes: ``loads
3451 shared libs like mad''.
3453 * ``gdbserver'' now supports multi-threaded applications on some targets
3455 Support for debugging multi-threaded applications which use
3456 the GNU/Linux LinuxThreads package has been added for
3457 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3458 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3460 * GDB now supports C/C++ preprocessor macros.
3462 GDB now expands preprocessor macro invocations in C/C++ expressions,
3463 and provides various commands for showing macro definitions and how
3466 The new command `macro expand EXPRESSION' expands any macro
3467 invocations in expression, and shows the result.
3469 The new command `show macro MACRO-NAME' shows the definition of the
3470 macro named MACRO-NAME, and where it was defined.
3472 Most compilers don't include information about macros in the debugging
3473 information by default. In GCC 3.1, for example, you need to compile
3474 your program with the options `-gdwarf-2 -g3'. If the macro
3475 information is present in the executable, GDB will read it.
3477 * Multi-arched targets.
3479 DEC Alpha (partial) alpha*-*-*
3480 DEC VAX (partial) vax-*-*
3482 National Semiconductor NS32000 (partial) ns32k-*-*
3483 Motorola 68000 (partial) m68k-*-*
3484 Motorola MCORE mcore-*-*
3488 Fujitsu FRV architecture added by Red Hat frv*-*-*
3491 * New native configurations
3493 Alpha NetBSD alpha*-*-netbsd*
3494 SH NetBSD sh*-*-netbsdelf*
3495 MIPS NetBSD mips*-*-netbsd*
3496 UltraSPARC NetBSD sparc64-*-netbsd*
3498 * OBSOLETE configurations and files
3500 Configurations that have been declared obsolete in this release have
3501 been commented out. Unless there is activity to revive these
3502 configurations, the next release of GDB will have their sources
3503 permanently REMOVED.
3505 Mitsubishi D30V d30v-*-*
3506 OS/9000 i[34]86-*-os9k
3507 IBM AIX PS/2 i[3456]86-*-aix
3508 Fujitsu FR30 fr30-*-elf*
3509 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3510 Argonaut Risc Chip (ARC) arc-*-*
3511 i386 running Mach 3.0 i[3456]86-*-mach3*
3512 i386 running Mach i[3456]86-*-mach*
3513 i386 running OSF/1 i[3456]86-*osf1mk*
3514 HP/Apollo 68k Family m68*-apollo*-sysv*,
3516 m68*-hp-bsd*, m68*-hp-hpux*
3517 I960 with MON960 i960-*-coff
3519 * OBSOLETE languages
3521 CHILL, a Pascal like language used by telecommunications companies.
3523 * REMOVED configurations and files
3525 AMD 29k family via UDI a29k-amd-udi, udi29k
3526 A29K VxWorks a29k-*-vxworks
3527 AMD 29000 embedded, using EBMON a29k-none-none
3528 AMD 29000 embedded with COFF a29k-none-coff
3529 AMD 29000 embedded with a.out a29k-none-aout
3531 testsuite/gdb.hp/gdb.threads-hp/ directory
3533 * New command "set max-user-call-depth <nnn>"
3535 This command allows the user to limit the call depth of user-defined
3536 commands. The default is 1024.
3538 * Changes in FreeBSD/i386 native debugging.
3540 Support for the "generate-core-file" has been added.
3542 * New commands "dump", "append", and "restore".
3544 These commands allow data to be copied from target memory
3545 to a bfd-format or binary file (dump and append), and back
3546 from a file into memory (restore).
3548 * Improved "next/step" support on multi-processor Alpha Tru64.
3550 The previous single-step mechanism could cause unpredictable problems,
3551 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3552 of a software single-step mechanism prevents this.
3554 *** Changes in GDB 5.2.1:
3562 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3563 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3564 Fix, by Joel Brobecker imported from mainline.
3566 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3567 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3568 Fix, by Fred Fish, imported from mainline.
3570 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3571 Surprisingly enough, it works now.
3572 By Michal Ludvig, imported from mainline.
3574 i386 hardware watchpoint support:
3575 avoid misses on second run for some targets.
3576 By Pierre Muller, imported from mainline.
3578 *** Changes in GDB 5.2:
3580 * New command "set trust-readonly-sections on[off]".
3582 This command is a hint that tells gdb that read-only sections
3583 really are read-only (ie. that their contents will not change).
3584 In this mode, gdb will go to the object file rather than the
3585 target to read memory from read-only sections (such as ".text").
3586 This can be a significant performance improvement on some
3587 (notably embedded) targets.
3589 * New command "generate-core-file" (or "gcore").
3591 This new gdb command allows the user to drop a core file of the child
3592 process state at any time. So far it's been implemented only for
3593 GNU/Linux and Solaris, but should be relatively easily ported to other
3594 hosts. Argument is core file name (defaults to core.<pid>).
3596 * New command line option
3598 GDB now accepts --pid or -p followed by a process id.
3600 * Change in command line behavior -- corefiles vs. process ids.
3602 There is a subtle behavior in the way in which GDB handles
3603 command line arguments. The first non-flag argument is always
3604 a program to debug, but the second non-flag argument may either
3605 be a corefile or a process id. Previously, GDB would attempt to
3606 open the second argument as a corefile, and if that failed, would
3607 issue a superfluous error message and then attempt to attach it as
3608 a process. Now, if the second argument begins with a non-digit,
3609 it will be treated as a corefile. If it begins with a digit,
3610 GDB will attempt to attach it as a process, and if no such process
3611 is found, will then attempt to open it as a corefile.
3613 * Changes in ARM configurations.
3615 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3616 configuration is fully multi-arch.
3618 * New native configurations
3620 ARM NetBSD arm*-*-netbsd*
3621 x86 OpenBSD i[3456]86-*-openbsd*
3622 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3623 Sparc64 running FreeBSD sparc64-*-freebsd*
3627 Sanyo XStormy16 xstormy16-elf
3629 * OBSOLETE configurations and files
3631 Configurations that have been declared obsolete in this release have
3632 been commented out. Unless there is activity to revive these
3633 configurations, the next release of GDB will have their sources
3634 permanently REMOVED.
3636 AMD 29k family via UDI a29k-amd-udi, udi29k
3637 A29K VxWorks a29k-*-vxworks
3638 AMD 29000 embedded, using EBMON a29k-none-none
3639 AMD 29000 embedded with COFF a29k-none-coff
3640 AMD 29000 embedded with a.out a29k-none-aout
3642 testsuite/gdb.hp/gdb.threads-hp/ directory
3644 * REMOVED configurations and files
3646 TI TMS320C80 tic80-*-*
3648 PowerPC Solaris powerpcle-*-solaris*
3649 PowerPC Windows NT powerpcle-*-cygwin32
3650 PowerPC Netware powerpc-*-netware*
3651 Harris/CXUX m88k m88*-harris-cxux*
3652 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3653 ns32k-utek-sysv* ns32k-utek-*
3654 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3655 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3656 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3657 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3658 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3660 * Changes to command line processing
3662 The new `--args' feature can be used to specify command-line arguments
3663 for the inferior from gdb's command line.
3665 * Changes to key bindings
3667 There is a new `operate-and-get-next' function bound to `C-o'.
3669 *** Changes in GDB 5.1.1
3671 Fix compile problem on DJGPP.
3673 Fix a problem with floating-point registers on the i386 being
3676 Fix to stop GDB crashing on .debug_str debug info.
3678 Numerous documentation fixes.
3680 Numerous testsuite fixes.
3682 *** Changes in GDB 5.1:
3684 * New native configurations
3686 Alpha FreeBSD alpha*-*-freebsd*
3687 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3688 MIPS GNU/Linux mips*-*-linux*
3689 MIPS SGI Irix 6.x mips*-sgi-irix6*
3690 ia64 AIX ia64-*-aix*
3691 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3695 Motorola 68HC11 and 68HC12 m68hc11-elf
3697 UltraSparc running GNU/Linux sparc64-*-linux*
3699 * OBSOLETE configurations and files
3701 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3702 Harris/CXUX m88k m88*-harris-cxux*
3703 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3704 ns32k-utek-sysv* ns32k-utek-*
3705 TI TMS320C80 tic80-*-*
3707 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3708 PowerPC Solaris powerpcle-*-solaris*
3709 PowerPC Windows NT powerpcle-*-cygwin32
3710 PowerPC Netware powerpc-*-netware*
3711 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3712 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3713 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3714 Apple Macintosh (MPW) host N/A
3716 stuff.c (Program to stuff files into a specially prepared space in kdb)
3717 kdb-start.c (Main loop for the standalone kernel debugger)
3719 Configurations that have been declared obsolete in this release have
3720 been commented out. Unless there is activity to revive these
3721 configurations, the next release of GDB will have their sources
3722 permanently REMOVED.
3724 * REMOVED configurations and files
3726 Altos 3068 m68*-altos-*
3727 Convex c1-*-*, c2-*-*
3729 ARM RISCix arm-*-* (as host)
3733 * GDB has been converted to ISO C.
3735 GDB's source code has been converted to ISO C. In particular, the
3736 sources are fully protoized, and rely on standard headers being
3741 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3743 * The MI enabled by default.
3745 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3746 revised and enabled by default. Packages which use GDB as a debugging
3747 engine behind a UI or another front end are encouraged to switch to
3748 using the GDB/MI interface, instead of the old annotations interface
3749 which is now deprecated.
3751 * Support for debugging Pascal programs.
3753 GDB now includes support for debugging Pascal programs. The following
3754 main features are supported:
3756 - Pascal-specific data types such as sets;
3758 - automatic recognition of Pascal sources based on file-name
3761 - Pascal-style display of data types, variables, and functions;
3763 - a Pascal expression parser.
3765 However, some important features are not yet supported.
3767 - Pascal string operations are not supported at all;
3769 - there are some problems with boolean types;
3771 - Pascal type hexadecimal constants are not supported
3772 because they conflict with the internal variables format;
3774 - support for Pascal objects and classes is not full yet;
3776 - unlike Pascal, GDB is case-sensitive for symbol names.
3778 * Changes in completion.
3780 Commands such as `shell', `run' and `set args', which pass arguments
3781 to inferior programs, now complete on file names, similar to what
3782 users expect at the shell prompt.
3784 Commands which accept locations, such as `disassemble', `print',
3785 `breakpoint', `until', etc. now complete on filenames as well as
3786 program symbols. Thus, if you type "break foob TAB", and the source
3787 files linked into the programs include `foobar.c', that file name will
3788 be one of the candidates for completion. However, file names are not
3789 considered for completion after you typed a colon that delimits a file
3790 name from a name of a function in that file, as in "break foo.c:bar".
3792 `set demangle-style' completes on available demangling styles.
3794 * New platform-independent commands:
3796 It is now possible to define a post-hook for a command as well as a
3797 hook that runs before the command. For more details, see the
3798 documentation of `hookpost' in the GDB manual.
3800 * Changes in GNU/Linux native debugging.
3802 Support for debugging multi-threaded programs has been completely
3803 revised for all platforms except m68k and sparc. You can now debug as
3804 many threads as your system allows you to have.
3806 Attach/detach is supported for multi-threaded programs.
3808 Support for SSE registers was added for x86. This doesn't work for
3809 multi-threaded programs though.
3811 * Changes in MIPS configurations.
3813 Multi-arch support is enabled for all MIPS configurations.
3815 GDB can now be built as native debugger on SGI Irix 6.x systems for
3816 debugging n32 executables. (Debugging 64-bit executables is not yet
3819 * Unified support for hardware watchpoints in all x86 configurations.
3821 Most (if not all) native x86 configurations support hardware-assisted
3822 breakpoints and watchpoints in a unified manner. This support
3823 implements debug register sharing between watchpoints, which allows to
3824 put a virtually infinite number of watchpoints on the same address,
3825 and also supports watching regions up to 16 bytes with several debug
3828 The new maintenance command `maintenance show-debug-regs' toggles
3829 debugging print-outs in functions that insert, remove, and test
3830 watchpoints and hardware breakpoints.
3832 * Changes in the DJGPP native configuration.
3834 New command ``info dos sysinfo'' displays assorted information about
3835 the CPU, OS, memory, and DPMI server.
3837 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3838 display information about segment descriptors stored in GDT, LDT, and
3841 New commands ``info dos pde'' and ``info dos pte'' display entries
3842 from Page Directory and Page Tables (for now works with CWSDPMI only).
3843 New command ``info dos address-pte'' displays the Page Table entry for
3844 a given linear address.
3846 GDB can now pass command lines longer than 126 characters to the
3847 program being debugged (requires an update to the libdbg.a library
3848 which is part of the DJGPP development kit).
3850 DWARF2 debug info is now supported.
3852 It is now possible to `step' and `next' through calls to `longjmp'.
3854 * Changes in documentation.
3856 All GDB documentation was converted to GFDL, the GNU Free
3857 Documentation License.
3859 Tracepoints-related commands are now fully documented in the GDB
3862 TUI, the Text-mode User Interface, is now documented in the manual.
3864 Tracepoints-related commands are now fully documented in the GDB
3867 The "GDB Internals" manual now has an index. It also includes
3868 documentation of `ui_out' functions, GDB coding standards, x86
3869 hardware watchpoints, and memory region attributes.
3871 * GDB's version number moved to ``version.in''
3873 The Makefile variable VERSION has been replaced by the file
3874 ``version.in''. People creating GDB distributions should update the
3875 contents of this file.
3879 GUD support is now a standard part of the EMACS distribution.
3881 *** Changes in GDB 5.0:
3883 * Improved support for debugging FP programs on x86 targets
3885 Unified and much-improved support for debugging floating-point
3886 programs on all x86 targets. In particular, ``info float'' now
3887 displays the FP registers in the same format on all x86 targets, with
3888 greater level of detail.
3890 * Improvements and bugfixes in hardware-assisted watchpoints
3892 It is now possible to watch array elements, struct members, and
3893 bitfields with hardware-assisted watchpoints. Data-read watchpoints
3894 on x86 targets no longer erroneously trigger when the address is
3897 * Improvements in the native DJGPP version of GDB
3899 The distribution now includes all the scripts and auxiliary files
3900 necessary to build the native DJGPP version on MS-DOS/MS-Windows
3901 machines ``out of the box''.
3903 The DJGPP version can now debug programs that use signals. It is
3904 possible to catch signals that happened in the debuggee, deliver
3905 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
3906 would kill the program being debugged.) Programs that hook hardware
3907 interrupts (keyboard, timer, etc.) can also be debugged.
3909 It is now possible to debug DJGPP programs that redirect their
3910 standard handles or switch them to raw (as opposed to cooked) mode, or
3911 even close them. The command ``run < foo > bar'' works as expected,
3912 and ``info terminal'' reports useful information about the debuggee's
3913 terminal, including raw/cooked mode, redirection, etc.
3915 The DJGPP version now uses termios functions for console I/O, which
3916 enables debugging graphics programs. Interrupting GDB with Ctrl-C
3919 DOS-style file names with drive letters are now fully supported by
3922 It is now possible to debug DJGPP programs that switch their working
3923 directory. It is also possible to rerun the debuggee any number of
3924 times without restarting GDB; thus, you can use the same setup,
3925 breakpoints, etc. for many debugging sessions.
3927 * New native configurations
3929 ARM GNU/Linux arm*-*-linux*
3930 PowerPC GNU/Linux powerpc-*-linux*
3934 Motorola MCore mcore-*-*
3935 x86 VxWorks i[3456]86-*-vxworks*
3936 PowerPC VxWorks powerpc-*-vxworks*
3937 TI TMS320C80 tic80-*-*
3939 * OBSOLETE configurations
3941 Altos 3068 m68*-altos-*
3942 Convex c1-*-*, c2-*-*
3944 ARM RISCix arm-*-* (as host)
3947 Configurations that have been declared obsolete will be commented out,
3948 but the code will be left in place. If there is no activity to revive
3949 these configurations before the next release of GDB, the sources will
3950 be permanently REMOVED.
3952 * Gould support removed
3954 Support for the Gould PowerNode and NP1 has been removed.
3956 * New features for SVR4
3958 On SVR4 native platforms (such as Solaris), if you attach to a process
3959 without first loading a symbol file, GDB will now attempt to locate and
3960 load symbols from the running process's executable file.
3962 * Many C++ enhancements
3964 C++ support has been greatly improved. Overload resolution now works properly
3965 in almost all cases. RTTI support is on the way.
3967 * Remote targets can connect to a sub-program
3969 A popen(3) style serial-device has been added. This device starts a
3970 sub-process (such as a stand-alone simulator) and then communicates
3971 with that. The sub-program to run is specified using the syntax
3972 ``|<program> <args>'' vis:
3974 (gdb) set remotedebug 1
3975 (gdb) target extended-remote |mn10300-elf-sim program-args
3977 * MIPS 64 remote protocol
3979 A long standing bug in the mips64 remote protocol where by GDB
3980 expected certain 32 bit registers (ex SR) to be transfered as 32
3981 instead of 64 bits has been fixed.
3983 The command ``set remote-mips64-transfers-32bit-regs on'' has been
3984 added to provide backward compatibility with older versions of GDB.
3986 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
3988 The command ``set remotebinarydownload'' command has been replaced by
3989 ``set remote X-packet''. Other commands in ``set remote'' family
3990 include ``set remote P-packet''.
3992 * Breakpoint commands accept ranges.
3994 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
3995 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
3996 ``tracepoint passcount'' also accepts a range of tracepoints.
3998 * ``apropos'' command added.
4000 The ``apropos'' command searches through command names and
4001 documentation strings, printing out matches, making it much easier to
4002 try to find a command that does what you are looking for.
4006 A new machine oriented interface (MI) has been added to GDB. This
4007 interface is designed for debug environments running GDB as a separate
4008 process. This is part of the long term libGDB project. See the
4009 "GDB/MI" chapter of the GDB manual for further information. It can be
4010 enabled by configuring with:
4012 .../configure --enable-gdbmi
4014 *** Changes in GDB-4.18:
4016 * New native configurations
4018 HP-UX 10.20 hppa*-*-hpux10.20
4019 HP-UX 11.x hppa*-*-hpux11.0*
4020 M68K GNU/Linux m68*-*-linux*
4024 Fujitsu FR30 fr30-*-elf*
4025 Intel StrongARM strongarm-*-*
4026 Mitsubishi D30V d30v-*-*
4028 * OBSOLETE configurations
4030 Gould PowerNode, NP1 np1-*-*, pn-*-*
4032 Configurations that have been declared obsolete will be commented out,
4033 but the code will be left in place. If there is no activity to revive
4034 these configurations before the next release of GDB, the sources will
4035 be permanently REMOVED.
4039 As a compatibility experiment, GDB's source files buildsym.h and
4040 buildsym.c have been converted to pure standard C, no longer
4041 containing any K&R compatibility code. We believe that all systems in
4042 use today either come with a standard C compiler, or have a GCC port
4043 available. If this is not true, please report the affected
4044 configuration to bug-gdb@gnu.org immediately. See the README file for
4045 information about getting a standard C compiler if you don't have one
4050 GDB now uses readline 2.2.
4052 * set extension-language
4054 You can now control the mapping between filename extensions and source
4055 languages by using the `set extension-language' command. For instance,
4056 you can ask GDB to treat .c files as C++ by saying
4057 set extension-language .c c++
4058 The command `info extensions' lists all of the recognized extensions
4059 and their associated languages.
4061 * Setting processor type for PowerPC and RS/6000
4063 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4064 you can use the `set processor' command to specify what variant of the
4065 PowerPC family you are debugging. The command
4069 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4070 following PowerPC and RS6000 variants:
4072 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4073 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4075 403GC IBM PowerPC 403GC
4076 505 Motorola PowerPC 505
4077 860 Motorola PowerPC 860 or 850
4078 601 Motorola PowerPC 601
4079 602 Motorola PowerPC 602
4080 603 Motorola/IBM PowerPC 603 or 603e
4081 604 Motorola PowerPC 604 or 604e
4082 750 Motorola/IBM PowerPC 750 or 750
4084 At the moment, this command just tells GDB what to name the
4085 special-purpose processor registers. Since almost all the affected
4086 registers are inaccessible to user-level programs, this command is
4087 only useful for remote debugging in its present form.
4091 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4092 more extensive support for HP-UX. Added features include shared
4093 library support, kernel threads and hardware watchpoints for 11.00,
4094 support for HP's ANSI C and C++ compilers, and a compatibility mode
4095 for xdb and dbx commands.
4099 HP's donation includes the new concept of catchpoints, which is a
4100 generalization of the old catch command. On HP-UX, it is now possible
4101 to catch exec, fork, and vfork, as well as library loading.
4103 This means that the existing catch command has changed; its first
4104 argument now specifies the type of catch to be set up. See the
4105 output of "help catch" for a list of catchpoint types.
4107 * Debugging across forks
4109 On HP-UX, you can choose which process to debug when a fork() happens
4114 HP has donated a curses-based terminal user interface (TUI). To get
4115 it, build with --enable-tui. Although this can be enabled for any
4116 configuration, at present it only works for native HP debugging.
4118 * GDB remote protocol additions
4120 A new protocol packet 'X' that writes binary data is now available.
4121 Default behavior is to try 'X', then drop back to 'M' if the stub
4122 fails to respond. The settable variable `remotebinarydownload'
4123 allows explicit control over the use of 'X'.
4125 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4126 full 64-bit address. The command
4128 set remoteaddresssize 32
4130 can be used to revert to the old behaviour. For existing remote stubs
4131 the change should not be noticed, as the additional address information
4134 In order to assist in debugging stubs, you may use the maintenance
4135 command `packet' to send any text string to the stub. For instance,
4137 maint packet heythere
4139 sends the packet "$heythere#<checksum>". Note that it is very easy to
4140 disrupt a debugging session by sending the wrong packet at the wrong
4143 The compare-sections command allows you to compare section data on the
4144 target to what is in the executable file without uploading or
4145 downloading, by comparing CRC checksums.
4147 * Tracing can collect general expressions
4149 You may now collect general expressions at tracepoints. This requires
4150 further additions to the target-side stub; see tracepoint.c and
4151 doc/agentexpr.texi for further details.
4153 * mask-address variable for Mips
4155 For Mips targets, you may control the zeroing of the upper 32 bits of
4156 a 64-bit address by entering `set mask-address on'. This is mainly
4157 of interest to users of embedded R4xxx and R5xxx processors.
4159 * Higher serial baud rates
4161 GDB's serial code now allows you to specify baud rates 57600, 115200,
4162 230400, and 460800 baud. (Note that your host system may not be able
4163 to achieve all of these rates.)
4167 The i960 configuration now includes an initial implementation of a
4168 builtin simulator, contributed by Jim Wilson.
4171 *** Changes in GDB-4.17:
4173 * New native configurations
4175 Alpha GNU/Linux alpha*-*-linux*
4176 Unixware 2.x i[3456]86-unixware2*
4177 Irix 6.x mips*-sgi-irix6*
4178 PowerPC GNU/Linux powerpc-*-linux*
4179 PowerPC Solaris powerpcle-*-solaris*
4180 Sparc GNU/Linux sparc-*-linux*
4181 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4185 Argonaut Risc Chip (ARC) arc-*-*
4186 Hitachi H8/300S h8300*-*-*
4187 Matsushita MN10200 w/simulator mn10200-*-*
4188 Matsushita MN10300 w/simulator mn10300-*-*
4189 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4190 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4191 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4192 Mitsubishi D10V w/simulator d10v-*-*
4193 Mitsubishi M32R/D w/simulator m32r-*-elf*
4194 Tsqware Sparclet sparclet-*-*
4195 NEC V850 w/simulator v850-*-*
4197 * New debugging protocols
4199 ARM with RDI protocol arm*-*-*
4200 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4201 DDB and LSI variants of PMON protocol mips*-*-*
4202 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4203 PowerPC with SDS protocol powerpc{,le}-*-eabi
4204 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4208 All configurations can now understand and use the DWARF 2 debugging
4209 format. The choice is automatic, if the symbol file contains DWARF 2
4214 GDB now includes basic Java language support. This support is
4215 only useful with Java compilers that produce native machine code.
4217 * solib-absolute-prefix and solib-search-path
4219 For SunOS and SVR4 shared libraries, you may now set the prefix for
4220 loading absolute shared library symbol files, and the search path for
4221 locating non-absolute shared library symbol files.
4223 * Live range splitting
4225 GDB can now effectively debug code for which GCC has performed live
4226 range splitting as part of its optimization. See gdb/doc/LRS for
4227 more details on the expected format of the stabs information.
4231 GDB's support for the GNU Hurd, including thread debugging, has been
4232 updated to work with current versions of the Hurd.
4236 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4237 instruction set. ARM GDB automatically detects when Thumb
4238 instructions are in use, and adjusts disassembly and backtracing
4243 GDB's MIPS target configurations now handle the MIP16 16-bit
4248 GDB now includes support for overlays; if an executable has been
4249 linked such that multiple sections are based at the same address, GDB
4250 will decide which section to use for symbolic info. You can choose to
4251 control the decision manually, using overlay commands, or implement
4252 additional target-side support and use "overlay load-target" to bring
4253 in the overlay mapping. Do "help overlay" for more detail.
4257 The command "info symbol <address>" displays information about
4258 the symbol at the specified address.
4262 The standard remote protocol now includes an extension that allows
4263 asynchronous collection and display of trace data. This requires
4264 extensive support in the target-side debugging stub. Tracing mode
4265 includes a new interaction mode in GDB and new commands: see the
4266 file tracepoint.c for more details.
4270 Configurations for embedded MIPS now include a simulator contributed
4271 by Cygnus Solutions. The simulator supports the instruction sets
4272 of most MIPS variants.
4276 Sparc configurations may now include the ERC32 simulator contributed
4277 by the European Space Agency. The simulator is not built into
4278 Sparc targets by default; configure with --enable-sim to include it.
4282 For target configurations that may include multiple variants of a
4283 basic architecture (such as MIPS and SH), you may now set the
4284 architecture explicitly. "set arch" sets, "info arch" lists
4285 the possible architectures.
4287 *** Changes in GDB-4.16:
4289 * New native configurations
4291 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4292 M68K NetBSD m68k-*-netbsd*
4293 PowerPC AIX 4.x powerpc-*-aix*
4294 PowerPC MacOS powerpc-*-macos*
4295 PowerPC Windows NT powerpcle-*-cygwin32
4296 RS/6000 AIX 4.x rs6000-*-aix4*
4300 ARM with RDP protocol arm-*-*
4301 I960 with MON960 i960-*-coff
4302 MIPS VxWorks mips*-*-vxworks*
4303 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4304 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4306 Matra Sparclet sparclet-*-*
4310 The powerpc-eabi configuration now includes the PSIM simulator,
4311 contributed by Andrew Cagney, with assistance from Mike Meissner.
4312 PSIM is a very elaborate model of the PowerPC, including not only
4313 basic instruction set execution, but also details of execution unit
4314 performance and I/O hardware. See sim/ppc/README for more details.
4318 GDB now works with Solaris 2.5.
4320 * Windows 95/NT native
4322 GDB will now work as a native debugger on Windows 95 and Windows NT.
4323 To build it from source, you must use the "gnu-win32" environment,
4324 which uses a DLL to emulate enough of Unix to run the GNU tools.
4325 Further information, binaries, and sources are available at
4326 ftp.cygnus.com, under pub/gnu-win32.
4328 * dont-repeat command
4330 If a user-defined command includes the command `dont-repeat', then the
4331 command will not be repeated if the user just types return. This is
4332 useful if the command is time-consuming to run, so that accidental
4333 extra keystrokes don't run the same command many times.
4335 * Send break instead of ^C
4337 The standard remote protocol now includes an option to send a break
4338 rather than a ^C to the target in order to interrupt it. By default,
4339 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4341 * Remote protocol timeout
4343 The standard remote protocol includes a new variable `remotetimeout'
4344 that allows you to set the number of seconds before GDB gives up trying
4345 to read from the target. The default value is 2.
4347 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4349 By default GDB will automatically keep track of objects as they are
4350 loaded and unloaded by the dynamic linker. By using the command `set
4351 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4352 when shared library events occur, thus allowing you to set breakpoints
4353 in shared libraries which are explicitly loaded by the inferior.
4355 Note this feature does not work on hpux8. On hpux9 you must link
4356 /usr/lib/end.o into your program. This feature should work
4357 automatically on hpux10.
4359 * Irix 5.x hardware watchpoint support
4361 Irix 5 configurations now support the use of hardware watchpoints.
4363 * Mips protocol "SYN garbage limit"
4365 When debugging a Mips target using the `target mips' protocol, you
4366 may set the number of characters that GDB will ignore by setting
4367 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4368 every character. The default value is 1050.
4370 * Recording and replaying remote debug sessions
4372 If you set `remotelogfile' to the name of a file, gdb will write to it
4373 a recording of a remote debug session. This recording may then be
4374 replayed back to gdb using "gdbreplay". See gdbserver/README for
4375 details. This is useful when you have a problem with GDB while doing
4376 remote debugging; you can make a recording of the session and send it
4377 to someone else, who can then recreate the problem.
4379 * Speedups for remote debugging
4381 GDB includes speedups for downloading and stepping MIPS systems using
4382 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4383 and more efficient S-record downloading.
4385 * Memory use reductions and statistics collection
4387 GDB now uses less memory and reports statistics about memory usage.
4388 Try the `maint print statistics' command, for example.
4390 *** Changes in GDB-4.15:
4392 * Psymtabs for XCOFF
4394 The symbol reader for AIX GDB now uses partial symbol tables. This
4395 can greatly improve startup time, especially for large executables.
4397 * Remote targets use caching
4399 Remote targets now use a data cache to speed up communication with the
4400 remote side. The data cache could lead to incorrect results because
4401 it doesn't know about volatile variables, thus making it impossible to
4402 debug targets which use memory mapped I/O devices. `set remotecache
4403 off' turns the the data cache off.
4405 * Remote targets may have threads
4407 The standard remote protocol now includes support for multiple threads
4408 in the target system, using new protocol commands 'H' and 'T'. See
4409 gdb/remote.c for details.
4413 If GDB is configured with `--enable-netrom', then it will include
4414 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4415 acts as though it is a bank of ROM on the target board, but you can
4416 write into it over the network. GDB's support consists only of
4417 support for fast loading into the emulated ROM; to debug, you must use
4418 another protocol, such as standard remote protocol. The usual
4419 sequence is something like
4421 target nrom <netrom-hostname>
4423 target remote <netrom-hostname>:1235
4427 GDB now includes support for the Apple Macintosh, as a host only. It
4428 may be run as either an MPW tool or as a standalone application, and
4429 it can debug through the serial port. All the usual GDB commands are
4430 available, but to the target command, you must supply "serial" as the
4431 device type instead of "/dev/ttyXX". See mpw-README in the main
4432 directory for more information on how to build. The MPW configuration
4433 scripts */mpw-config.in support only a few targets, and only the
4434 mips-idt-ecoff target has been tested.
4438 GDB configuration now uses autoconf. This is not user-visible,
4439 but does simplify configuration and building.
4443 GDB now supports hpux10.
4445 *** Changes in GDB-4.14:
4447 * New native configurations
4449 x86 FreeBSD i[345]86-*-freebsd
4450 x86 NetBSD i[345]86-*-netbsd
4451 NS32k NetBSD ns32k-*-netbsd
4452 Sparc NetBSD sparc-*-netbsd
4456 A29K VxWorks a29k-*-vxworks
4457 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4458 CPU32 EST-300 emulator m68*-*-est*
4459 PowerPC ELF powerpc-*-elf
4462 * Alpha OSF/1 support for procfs
4464 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4465 possible to attach to running processes. As the mounting of the /proc
4466 filesystem is optional on the Alpha, GDB automatically determines
4467 the availability of /proc during startup. This can lead to problems
4468 if /proc is unmounted after GDB has been started.
4470 * Arguments to user-defined commands
4472 User commands may accept up to 10 arguments separated by whitespace.
4473 Arguments are accessed within the user command via $arg0..$arg9. A
4476 print $arg0 + $arg1 + $arg2
4478 To execute the command use:
4481 Defines the command "adder" which prints the sum of its three arguments.
4482 Note the arguments are text substitutions, so they may reference variables,
4483 use complex expressions, or even perform inferior function calls.
4485 * New `if' and `while' commands
4487 This makes it possible to write more sophisticated user-defined
4488 commands. Both commands take a single argument, which is the
4489 expression to evaluate, and must be followed by the commands to
4490 execute, one per line, if the expression is nonzero, the list being
4491 terminated by the word `end'. The `if' command list may include an
4492 `else' word, which causes the following commands to be executed only
4493 if the expression is zero.
4495 * Fortran source language mode
4497 GDB now includes partial support for Fortran 77. It will recognize
4498 Fortran programs and can evaluate a subset of Fortran expressions, but
4499 variables and functions may not be handled correctly. GDB will work
4500 with G77, but does not yet know much about symbols emitted by other
4503 * Better HPUX support
4505 Most debugging facilities now work on dynamic executables for HPPAs
4506 running hpux9 or later. You can attach to running dynamically linked
4507 processes, but by default the dynamic libraries will be read-only, so
4508 for instance you won't be able to put breakpoints in them. To change
4509 that behavior do the following before running the program:
4515 This will cause the libraries to be mapped private and read-write.
4516 To revert to the normal behavior, do this:
4522 You cannot set breakpoints or examine data in the library until after
4523 the library is loaded if the function/data symbols do not have
4526 GDB can now also read debug symbols produced by the HP C compiler on
4527 HPPAs (sorry, no C++, Fortran or 68k support).
4529 * Target byte order now dynamically selectable
4531 You can choose which byte order to use with a target system, via the
4532 commands "set endian big" and "set endian little", and you can see the
4533 current setting by using "show endian". You can also give the command
4534 "set endian auto", in which case GDB will use the byte order
4535 associated with the executable. Currently, only embedded MIPS
4536 configurations support dynamic selection of target byte order.
4538 * New DOS host serial code
4540 This version uses DPMI interrupts to handle buffered I/O, so you
4541 no longer need to run asynctsr when debugging boards connected to
4544 *** Changes in GDB-4.13:
4546 * New "complete" command
4548 This lists all the possible completions for the rest of the line, if it
4549 were to be given as a command itself. This is intended for use by emacs.
4551 * Trailing space optional in prompt
4553 "set prompt" no longer adds a space for you after the prompt you set. This
4554 allows you to set a prompt which ends in a space or one that does not.
4556 * Breakpoint hit counts
4558 "info break" now displays a count of the number of times the breakpoint
4559 has been hit. This is especially useful in conjunction with "ignore"; you
4560 can ignore a large number of breakpoint hits, look at the breakpoint info
4561 to see how many times the breakpoint was hit, then run again, ignoring one
4562 less than that number, and this will get you quickly to the last hit of
4565 * Ability to stop printing at NULL character
4567 "set print null-stop" will cause GDB to stop printing the characters of
4568 an array when the first NULL is encountered. This is useful when large
4569 arrays actually contain only short strings.
4571 * Shared library breakpoints
4573 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4574 breakpoints in shared libraries before the executable is run.
4576 * Hardware watchpoints
4578 There is a new hardware breakpoint for the watch command for sparclite
4579 targets. See gdb/sparclite/hw_breakpoint.note.
4581 Hardware watchpoints are also now supported under GNU/Linux.
4585 Annotations have been added. These are for use with graphical interfaces,
4586 and are still experimental. Currently only gdba.el uses these.
4588 * Improved Irix 5 support
4590 GDB now works properly with Irix 5.2.
4592 * Improved HPPA support
4594 GDB now works properly with the latest GCC and GAS.
4596 * New native configurations
4598 Sequent PTX4 i[34]86-sequent-ptx4
4599 HPPA running OSF/1 hppa*-*-osf*
4600 Atari TT running SVR4 m68*-*-sysv4*
4601 RS/6000 LynxOS rs6000-*-lynxos*
4605 OS/9000 i[34]86-*-os9k
4606 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4609 * Hitachi SH7000 and E7000-PC ICE support
4611 There is now support for communicating with the Hitachi E7000-PC ICE.
4612 This is available automatically when GDB is configured for the SH.
4616 As usual, a variety of small fixes and improvements, both generic
4617 and configuration-specific. See the ChangeLog for more detail.
4619 *** Changes in GDB-4.12:
4621 * Irix 5 is now supported
4625 GDB-4.12 on the HPPA has a number of changes which make it unable
4626 to debug the output from the currently released versions of GCC and
4627 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4628 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4629 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4632 *** Changes in GDB-4.11:
4634 * User visible changes:
4638 The "set remotedebug" option is now consistent between the mips remote
4639 target, remote targets using the gdb-specific protocol, UDI (AMD's
4640 debug protocol for the 29k) and the 88k bug monitor. It is now an
4641 integer specifying a debug level (normally 0 or 1, but 2 means more
4642 debugging info for the mips target).
4644 * DEC Alpha native support
4646 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4647 debug info, but GDB works fairly well with the DEC compiler and should
4648 work with a future GCC release. See the README file for a few
4649 Alpha-specific notes.
4651 * Preliminary thread implementation
4653 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4655 * LynxOS native and target support for 386
4657 This release has been hosted on LynxOS 2.2, and also can be configured
4658 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4661 * Improvements in C++ mangling/demangling.
4663 This release has much better g++ debugging, specifically in name
4664 mangling/demangling, virtual function calls, print virtual table,
4665 call methods, ...etc.
4667 *** Changes in GDB-4.10:
4669 * User visible changes:
4671 Remote debugging using the GDB-specific (`target remote') protocol now
4672 supports the `load' command. This is only useful if you have some
4673 other way of getting the stub to the target system, and you can put it
4674 somewhere in memory where it won't get clobbered by the download.
4676 Filename completion now works.
4678 When run under emacs mode, the "info line" command now causes the
4679 arrow to point to the line specified. Also, "info line" prints
4680 addresses in symbolic form (as well as hex).
4682 All vxworks based targets now support a user settable option, called
4683 vxworks-timeout. This option represents the number of seconds gdb
4684 should wait for responses to rpc's. You might want to use this if
4685 your vxworks target is, perhaps, a slow software simulator or happens
4686 to be on the far side of a thin network line.
4690 This release contains support for using a DEC alpha as a GDB host for
4691 cross debugging. Native alpha debugging is not supported yet.
4694 *** Changes in GDB-4.9:
4698 This is the first GDB release which is accompanied by a matching testsuite.
4699 The testsuite requires installation of dejagnu, which should be available
4700 via ftp from most sites that carry GNU software.
4704 'Cfront' style demangling has had its name changed to 'ARM' style, to
4705 emphasize that it was written from the specifications in the C++ Annotated
4706 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4707 disclaimers, it still generated too much confusion with users attempting to
4708 use gdb with AT&T cfront.
4712 GDB now uses a standard remote interface to a simulator library.
4713 So far, the library contains simulators for the Zilog Z8001/2, the
4714 Hitachi H8/300, H8/500 and Super-H.
4716 * New targets supported
4718 H8/300 simulator h8300-hitachi-hms or h8300hms
4719 H8/500 simulator h8500-hitachi-hms or h8500hms
4720 SH simulator sh-hitachi-hms or sh
4721 Z8000 simulator z8k-zilog-none or z8ksim
4722 IDT MIPS board over serial line mips-idt-ecoff
4724 Cross-debugging to GO32 targets is supported. It requires a custom
4725 version of the i386-stub.c module which is integrated with the
4726 GO32 memory extender.
4728 * New remote protocols
4730 MIPS remote debugging protocol.
4732 * New source languages supported
4734 This version includes preliminary support for Chill, a Pascal like language
4735 used by telecommunications companies. Chill support is also being integrated
4736 into the GNU compiler, but we don't know when it will be publically available.
4739 *** Changes in GDB-4.8:
4741 * HP Precision Architecture supported
4743 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4744 version of this support was available as a set of patches from the
4745 University of Utah. GDB does not support debugging of programs
4746 compiled with the HP compiler, because HP will not document their file
4747 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4748 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4750 Many problems in the preliminary version have been fixed.
4752 * Faster and better demangling
4754 We have improved template demangling and fixed numerous bugs in the GNU style
4755 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4756 character types (wchar_t) are now supported. Demangling of each symbol is now
4757 only done once, and is cached when the symbol table for a file is read in.
4758 This results in a small increase in memory usage for C programs, a moderate
4759 increase in memory usage for C++ programs, and a fantastic speedup in
4762 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4763 from the specifications in the Annotated Reference Manual, which AT&T's
4764 compiler does not actually implement.
4766 * G++ multiple inheritance compiler problem
4768 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4769 inheritance lattices was reworked to properly discover ambiguities. We
4770 recently found an example which causes this new algorithm to fail in a
4771 very subtle way, producing bad debug information for those classes.
4772 The file 'gcc.patch' (in this directory) can be applied to gcc to
4773 circumvent the problem. A future GCC release will contain a complete
4776 The previous G++ debug info problem (mentioned below for the gdb-4.7
4777 release) is fixed in gcc version 2.3.2.
4779 * Improved configure script
4781 The `configure' script will now attempt to guess your system type if
4782 you don't supply a host system type. The old scheme of supplying a
4783 host system triplet is preferable over using this. All the magic is
4784 done in the new `config.guess' script. Examine it for details.
4786 We have also brought our configure script much more in line with the FSF's
4787 version. It now supports the --with-xxx options. In particular,
4788 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4789 The resulting GDB will not be able to read arbitrary object file formats --
4790 only the format ``expected'' to be used on the configured target system.
4791 We hope to make this the default in a future release.
4793 * Documentation improvements
4795 There's new internal documentation on how to modify GDB, and how to
4796 produce clean changes to the code. We implore people to read it
4797 before submitting changes.
4799 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4800 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4801 `info' files are also provided. To build `info' files from scratch,
4802 you will need the latest `makeinfo' release, which will be available in
4803 a future texinfo-X.Y release.
4805 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4806 We're not sure exactly which versions have this problem, but it has
4807 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4808 or better. If that isn't possible, there is a patch in
4809 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4810 around this problem.
4814 GDB now supports array constants that can be used in expressions typed in by
4815 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4816 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4819 The new directory `gdb/sparclite' contains a program that demonstrates
4820 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4822 * New native hosts supported
4824 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4825 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4827 * New targets supported
4829 AMD 29k family via UDI a29k-amd-udi or udi29k
4831 * New file formats supported
4833 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4834 HPUX core files, and SCO 3.2v2 core files.
4838 Attaching to processes now works again; thanks for the many bug reports.
4840 We have also stomped on a bunch of core dumps caused by
4841 printf_filtered("%s") problems.
4843 We eliminated a copyright problem on the rpc and ptrace header files
4844 for VxWorks, which was discovered at the last minute during the 4.7
4845 release. You should now be able to build a VxWorks GDB.
4847 You can now interrupt gdb while an attached process is running. This
4848 will cause the attached process to stop, and give control back to GDB.
4850 We fixed problems caused by using too many file descriptors
4851 for reading symbols from object files and libraries. This was
4852 especially a problem for programs that used many (~100) shared
4855 The `step' command now only enters a subroutine if there is line number
4856 information for the subroutine. Otherwise it acts like the `next'
4857 command. Previously, `step' would enter subroutines if there was
4858 any debugging information about the routine. This avoids problems
4859 when using `cc -g1' on MIPS machines.
4861 * Internal improvements
4863 GDB's internal interfaces have been improved to make it easier to support
4864 debugging of multiple languages in the future.
4866 GDB now uses a common structure for symbol information internally.
4867 Minimal symbols (derived from linkage symbols in object files), partial
4868 symbols (from a quick scan of debug information), and full symbols
4869 contain a common subset of information, making it easier to write
4870 shared code that handles any of them.
4872 * New command line options
4874 We now accept --silent as an alias for --quiet.
4878 The memory-mapped-malloc library is now licensed under the GNU Library
4879 General Public License.
4881 *** Changes in GDB-4.7:
4883 * Host/native/target split
4885 GDB has had some major internal surgery to untangle the support for
4886 hosts and remote targets. Now, when you configure GDB for a remote
4887 target, it will no longer load in all of the support for debugging
4888 local programs on the host. When fully completed and tested, this will
4889 ensure that arbitrary host/target combinations are possible.
4891 The primary conceptual shift is to separate the non-portable code in
4892 GDB into three categories. Host specific code is required any time GDB
4893 is compiled on that host, regardless of the target. Target specific
4894 code relates to the peculiarities of the target, but can be compiled on
4895 any host. Native specific code is everything else: it can only be
4896 built when the host and target are the same system. Child process
4897 handling and core file support are two common `native' examples.
4899 GDB's use of /proc for controlling Unix child processes is now cleaner.
4900 It has been split out into a single module under the `target_ops' vector,
4901 plus two native-dependent functions for each system that uses /proc.
4903 * New hosts supported
4905 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
4906 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4907 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
4909 * New targets supported
4911 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4912 68030 and CPU32 m68030-*-*, m68332-*-*
4914 * New native hosts supported
4916 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4917 (386bsd is not well tested yet)
4918 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
4920 * New file formats supported
4922 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
4923 supports reading of `a.out.adobe' object files, which are an a.out
4924 format extended with minimal information about multiple sections.
4928 `show copying' is the same as the old `info copying'.
4929 `show warranty' is the same as `info warrantee'.
4930 These were renamed for consistency. The old commands continue to work.
4932 `info handle' is a new alias for `info signals'.
4934 You can now define pre-command hooks, which attach arbitrary command
4935 scripts to any command. The commands in the hook will be executed
4936 prior to the user's command. You can also create a hook which will be
4937 executed whenever the program stops. See gdb.texinfo.
4941 We now deal with Cfront style name mangling, and can even extract type
4942 info from mangled symbols. GDB can automatically figure out which
4943 symbol mangling style your C++ compiler uses.
4945 Calling of methods and virtual functions has been improved as well.
4949 The crash that occured when debugging Sun Ansi-C compiled binaries is
4950 fixed. This was due to mishandling of the extra N_SO stabs output
4953 We also finally got Ultrix 4.2 running in house, and fixed core file
4954 support, with help from a dozen people on the net.
4956 John M. Farrell discovered that the reason that single-stepping was so
4957 slow on all of the Mips based platforms (primarily SGI and DEC) was
4958 that we were trying to demangle and lookup a symbol used for internal
4959 purposes on every instruction that was being stepped through. Changing
4960 the name of that symbol so that it couldn't be mistaken for a C++
4961 mangled symbol sped things up a great deal.
4963 Rich Pixley sped up symbol lookups in general by getting much smarter
4964 about when C++ symbol mangling is necessary. This should make symbol
4965 completion (TAB on the command line) much faster. It's not as fast as
4966 we'd like, but it's significantly faster than gdb-4.6.
4970 A new user controllable variable 'call_scratch_address' can
4971 specify the location of a scratch area to be used when GDB
4972 calls a function in the target. This is necessary because the
4973 usual method of putting the scratch area on the stack does not work
4974 in systems that have separate instruction and data spaces.
4976 We integrated changes to support the 29k UDI (Universal Debugger
4977 Interface), but discovered at the last minute that we didn't have all
4978 of the appropriate copyright paperwork. We are working with AMD to
4979 resolve this, and hope to have it available soon.
4983 We have sped up the remote serial line protocol, especially for targets
4984 with lots of registers. It now supports a new `expedited status' ('T')
4985 message which can be used in place of the existing 'S' status message.
4986 This allows the remote stub to send only the registers that GDB
4987 needs to make a quick decision about single-stepping or conditional
4988 breakpoints, eliminating the need to fetch the entire register set for
4989 each instruction being stepped through.
4991 The GDB remote serial protocol now implements a write-through cache for
4992 registers, only re-reading the registers if the target has run.
4994 There is also a new remote serial stub for SPARC processors. You can
4995 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
4996 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
4997 processor with a serial port.
5001 Configure.in files have become much easier to read and modify. A new
5002 `table driven' format makes it more obvious what configurations are
5003 supported, and what files each one uses.
5007 There is a new opcodes library which will eventually contain all of the
5008 disassembly routines and opcode tables. At present, it only contains
5009 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5010 disassembler (binutils/objdump) to share these routines.
5012 The libiberty library is now copylefted under the GNU Library General
5013 Public License. This allows more liberal use, and was done so libg++
5014 can use it. This makes no difference to GDB, since the Library License
5015 grants all the rights from the General Public License.
5019 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5020 reference to the stabs symbol info used by the debugger. It is (as far
5021 as we know) the only published document on this fascinating topic. We
5022 encourage you to read it, compare it to the stabs information on your
5023 system, and send improvements on the document in general (to
5024 bug-gdb@prep.ai.mit.edu).
5026 And, of course, many bugs have been fixed.
5029 *** Changes in GDB-4.6:
5031 * Better support for C++ function names
5033 GDB now accepts as input the "demangled form" of C++ overloaded function
5034 names and member function names, and can do command completion on such names
5035 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5036 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5037 Make use of command completion, it is your friend.
5039 GDB also now accepts a variety of C++ mangled symbol formats. They are
5040 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5041 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5042 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5043 for the list of formats.
5045 * G++ symbol mangling problem
5047 Recent versions of gcc have a bug in how they emit debugging information for
5048 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5049 directory) can be applied to gcc to fix the problem. Alternatively, if you
5050 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5051 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5052 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5055 * New 'maintenance' command
5057 All of the commands related to hacking GDB internals have been moved out of
5058 the main command set, and now live behind the 'maintenance' command. This
5059 can also be abbreviated as 'mt'. The following changes were made:
5061 dump-me -> maintenance dump-me
5062 info all-breakpoints -> maintenance info breakpoints
5063 printmsyms -> maintenance print msyms
5064 printobjfiles -> maintenance print objfiles
5065 printpsyms -> maintenance print psymbols
5066 printsyms -> maintenance print symbols
5068 The following commands are new:
5070 maintenance demangle Call internal GDB demangler routine to
5071 demangle a C++ link name and prints the result.
5072 maintenance print type Print a type chain for a given symbol
5074 * Change to .gdbinit file processing
5076 We now read the $HOME/.gdbinit file before processing the argv arguments
5077 (e.g. reading symbol files or core files). This allows global parameters to
5078 be set, which will apply during the symbol reading. The ./.gdbinit is still
5079 read after argv processing.
5081 * New hosts supported
5083 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5085 GNU/Linux support i386-unknown-linux or linux
5087 We are also including code to support the HP/PA running BSD and HPUX. This
5088 is almost guaranteed not to work, as we didn't have time to test or build it
5089 for this release. We are including it so that the more adventurous (or
5090 masochistic) of you can play with it. We also had major problems with the
5091 fact that the compiler that we got from HP doesn't support the -g option.
5094 * New targets supported
5096 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5098 * More smarts about finding #include files
5100 GDB now remembers the compilation directory for all include files, and for
5101 all files from which C is generated (like yacc and lex sources). This
5102 greatly improves GDB's ability to find yacc/lex sources, and include files,
5103 especially if you are debugging your program from a directory different from
5104 the one that contains your sources.
5106 We also fixed a bug which caused difficulty with listing and setting
5107 breakpoints in include files which contain C code. (In the past, you had to
5108 try twice in order to list an include file that you hadn't looked at before.)
5110 * Interesting infernals change
5112 GDB now deals with arbitrary numbers of sections, where the symbols for each
5113 section must be relocated relative to that section's landing place in the
5114 target's address space. This work was needed to support ELF with embedded
5115 stabs used by Solaris-2.0.
5117 * Bug fixes (of course!)
5119 There have been loads of fixes for the following things:
5120 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5121 i960, stabs, DOS(GO32), procfs, etc...
5123 See the ChangeLog for details.
5125 *** Changes in GDB-4.5:
5127 * New machines supported (host and target)
5129 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5131 SGI Irix-4.x mips-sgi-irix4 or iris4
5133 * New malloc package
5135 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5136 Mmalloc is capable of handling mutiple heaps of memory. It is also
5137 capable of saving a heap to a file, and then mapping it back in later.
5138 This can be used to greatly speedup the startup of GDB by using a
5139 pre-parsed symbol table which lives in a mmalloc managed heap. For
5140 more details, please read mmalloc/mmalloc.texi.
5144 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5145 'help info proc' for details.
5147 * MIPS ecoff symbol table format
5149 The code that reads MIPS symbol table format is now supported on all hosts.
5150 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5153 * File name changes for MS-DOS
5155 Many files in the config directories have been renamed to make it easier to
5156 support GDB on MS-DOSe systems (which have very restrictive file name
5157 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5158 environment) is close to working but has some remaining problems. Note
5159 that debugging of DOS programs is not supported, due to limitations
5160 in the ``operating system'', but it can be used to host cross-debugging.
5162 * Cross byte order fixes
5164 Many fixes have been made to support cross debugging of Sparc and MIPS
5165 targets from hosts whose byte order differs.
5167 * New -mapped and -readnow options
5169 If memory-mapped files are available on your system through the 'mmap'
5170 system call, you can use the -mapped option on the `file' or
5171 `symbol-file' commands to cause GDB to write the symbols from your
5172 program into a reusable file. If the program you are debugging is
5173 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5174 Future GDB debugging sessions will notice the presence of this file,
5175 and will quickly map in symbol information from it, rather than reading
5176 the symbol table from the executable program. Using the '-mapped'
5177 option in a GDB `file' or `symbol-file' command has the same effect as
5178 starting GDB with the '-mapped' command-line option.
5180 You can cause GDB to read the entire symbol table immediately by using
5181 the '-readnow' option with any of the commands that load symbol table
5182 information (or on the GDB command line). This makes the command
5183 slower, but makes future operations faster.
5185 The -mapped and -readnow options are typically combined in order to
5186 build a `fred.syms' file that contains complete symbol information.
5187 A simple GDB invocation to do nothing but build a `.syms' file for future
5190 gdb -batch -nx -mapped -readnow programname
5192 The `.syms' file is specific to the host machine on which GDB is run.
5193 It holds an exact image of GDB's internal symbol table. It cannot be
5194 shared across multiple host platforms.
5196 * longjmp() handling
5198 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5199 siglongjmp() without losing control. This feature has not yet been ported to
5200 all systems. It currently works on many 386 platforms, all MIPS-based
5201 platforms (SGI, DECstation, etc), and Sun3/4.
5205 Preliminary work has been put in to support the new Solaris OS from Sun. At
5206 this time, it can control and debug processes, but it is not capable of
5211 As always, many many bug fixes. The major areas were with g++, and mipsread.
5212 People using the MIPS-based platforms should experience fewer mysterious
5213 crashes and trashed symbol tables.
5215 *** Changes in GDB-4.4:
5217 * New machines supported (host and target)
5219 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5221 BSD Reno on Vax vax-dec-bsd
5222 Ultrix on Vax vax-dec-ultrix
5224 * New machines supported (target)
5226 AMD 29000 embedded, using EBMON a29k-none-none
5230 GDB continues to improve its handling of C++. `References' work better.
5231 The demangler has also been improved, and now deals with symbols mangled as
5232 per the Annotated C++ Reference Guide.
5234 GDB also now handles `stabs' symbol information embedded in MIPS
5235 `ecoff' symbol tables. Since the ecoff format was not easily
5236 extensible to handle new languages such as C++, this appeared to be a
5237 good way to put C++ debugging info into MIPS binaries. This option
5238 will be supported in the GNU C compiler, version 2, when it is
5241 * New features for SVR4
5243 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5244 shared libraries. Debugging dynamically linked programs should present
5245 only minor differences from debugging statically linked programs.
5247 The `info proc' command will print out information about any process
5248 on an SVR4 system (including the one you are debugging). At the moment,
5249 it prints the address mappings of the process.
5251 If you bring up GDB on another SVR4 system, please send mail to
5252 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5254 * Better dynamic linking support in SunOS
5256 Reading symbols from shared libraries which contain debugging symbols
5257 now works properly. However, there remain issues such as automatic
5258 skipping of `transfer vector' code during function calls, which
5259 make it harder to debug code in a shared library, than to debug the
5260 same code linked statically.
5264 GDB is now using the latest `getopt' routines from the FSF. This
5265 version accepts the -- prefix for options with long names. GDB will
5266 continue to accept the old forms (-option and +option) as well.
5267 Various single letter abbreviations for options have been explicity
5268 added to the option table so that they won't get overshadowed in the
5269 future by other options that begin with the same letter.
5273 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5274 Many assorted bugs have been handled. Many more remain to be handled.
5275 See the various ChangeLog files (primarily in gdb and bfd) for details.
5278 *** Changes in GDB-4.3:
5280 * New machines supported (host and target)
5282 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5283 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5284 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5286 * Almost SCO Unix support
5288 We had hoped to support:
5289 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5290 (except for core file support), but we discovered very late in the release
5291 that it has problems with process groups that render gdb unusable. Sorry
5292 about that. I encourage people to fix it and post the fixes.
5294 * Preliminary ELF and DWARF support
5296 GDB can read ELF object files on System V Release 4, and can handle
5297 debugging records for C, in DWARF format, in ELF files. This support
5298 is preliminary. If you bring up GDB on another SVR4 system, please
5299 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5304 GDB now uses the latest `readline' library. One user-visible change
5305 is that two tabs will list possible command completions, which previously
5306 required typing M-? (meta-question mark, or ESC ?).
5310 The `stepi' bug that many of you noticed has been squashed.
5311 Many bugs in C++ have been handled. Many more remain to be handled.
5312 See the various ChangeLog files (primarily in gdb and bfd) for details.
5314 * State of the MIPS world (in case you wondered):
5316 GDB can understand the symbol tables emitted by the compilers
5317 supplied by most vendors of MIPS-based machines, including DEC. These
5318 symbol tables are in a format that essentially nobody else uses.
5320 Some versions of gcc come with an assembler post-processor called
5321 mips-tfile. This program is required if you want to do source-level
5322 debugging of gcc-compiled programs. I believe FSF does not ship
5323 mips-tfile with gcc version 1, but it will eventually come with gcc
5326 Debugging of g++ output remains a problem. g++ version 1.xx does not
5327 really support it at all. (If you're lucky, you should be able to get
5328 line numbers and stack traces to work, but no parameters or local
5329 variables.) With some work it should be possible to improve the
5332 When gcc version 2 is released, you will have somewhat better luck.
5333 However, even then you will get confusing results for inheritance and
5336 We will eventually provide full debugging of g++ output on
5337 DECstations. This will probably involve some kind of stabs-in-ecoff
5338 encapulation, but the details have not been worked out yet.
5341 *** Changes in GDB-4.2:
5343 * Improved configuration
5345 Only one copy of `configure' exists now, and it is not self-modifying.
5346 Porting BFD is simpler.
5350 The `step' and `next' commands now only stop at the first instruction
5351 of a source line. This prevents the multiple stops that used to occur
5352 in switch statements, for-loops, etc. `Step' continues to stop if a
5353 function that has debugging information is called within the line.
5357 Lots of small bugs fixed. More remain.
5359 * New host supported (not target)
5361 Intel 386 PC clone running Mach i386-none-mach
5364 *** Changes in GDB-4.1:
5366 * Multiple source language support
5368 GDB now has internal scaffolding to handle several source languages.
5369 It determines the type of each source file from its filename extension,
5370 and will switch expression parsing and number formatting to match the
5371 language of the function in the currently selected stack frame.
5372 You can also specifically set the language to be used, with
5373 `set language c' or `set language modula-2'.
5377 GDB now has preliminary support for the GNU Modula-2 compiler,
5378 currently under development at the State University of New York at
5379 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5380 continue through the fall of 1991 and into 1992.
5382 Other Modula-2 compilers are currently not supported, and attempting to
5383 debug programs compiled with them will likely result in an error as the
5384 symbol table is read. Feel free to work on it, though!
5386 There are hooks in GDB for strict type checking and range checking,
5387 in the `Modula-2 philosophy', but they do not currently work.
5391 GDB can now write to executable and core files (e.g. patch
5392 a variable's value). You must turn this switch on, specify
5393 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5394 by assigning a new value to a variable. Modifications take
5397 * Automatic SunOS shared library reading
5399 When you run your program, GDB automatically determines where its
5400 shared libraries (if any) have been loaded, and reads their symbols.
5401 The `share' command is no longer needed. This also works when
5402 examining core files.
5406 You can specify the number of lines that the `list' command shows.
5409 * New machines supported (host and target)
5411 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5412 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5413 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5415 * New hosts supported (not targets)
5417 IBM RT/PC: romp-ibm-aix or rtpc
5419 * New targets supported (not hosts)
5421 AMD 29000 embedded with COFF a29k-none-coff
5422 AMD 29000 embedded with a.out a29k-none-aout
5423 Ultracomputer remote kernel debug a29k-nyu-kern
5425 * New remote interfaces
5431 *** Changes in GDB-4.0:
5435 Wide output is wrapped at good places to make the output more readable.
5437 Gdb now supports cross-debugging from a host machine of one type to a
5438 target machine of another type. Communication with the target system
5439 is over serial lines. The ``target'' command handles connecting to the
5440 remote system; the ``load'' command will download a program into the
5441 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5442 also supports debugging of realtime processes running under VxWorks,
5443 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5444 stub on the target system.
5446 New CPUs supported include the AMD 29000 and Intel 960.
5448 GDB now reads object files and symbol tables via a ``binary file''
5449 library, which allows a single copy of GDB to debug programs of multiple
5450 object file types such as a.out and coff.
5452 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5453 refcard.dvi and refcard.ps are available to format it).
5456 * Control-Variable user interface simplified
5458 All variables that control the operation of the debugger can be set
5459 by the ``set'' command, and displayed by the ``show'' command.
5461 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5462 ``Show prompt'' produces the response:
5463 Gdb's prompt is new-gdb=>.
5465 What follows are the NEW set commands. The command ``help set'' will
5466 print a complete list of old and new set commands. ``help set FOO''
5467 will give a longer description of the variable FOO. ``show'' will show
5468 all of the variable descriptions and their current settings.
5470 confirm on/off: Enables warning questions for operations that are
5471 hard to recover from, e.g. rerunning the program while
5472 it is already running. Default is ON.
5474 editing on/off: Enables EMACS style command line editing
5475 of input. Previous lines can be recalled with
5476 control-P, the current line can be edited with control-B,
5477 you can search for commands with control-R, etc.
5480 history filename NAME: NAME is where the gdb command history
5481 will be stored. The default is .gdb_history,
5482 or the value of the environment variable
5485 history size N: The size, in commands, of the command history. The
5486 default is 256, or the value of the environment variable
5489 history save on/off: If this value is set to ON, the history file will
5490 be saved after exiting gdb. If set to OFF, the
5491 file will not be saved. The default is OFF.
5493 history expansion on/off: If this value is set to ON, then csh-like
5494 history expansion will be performed on
5495 command line input. The default is OFF.
5497 radix N: Sets the default radix for input and output. It can be set
5498 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5499 in the current radix, so "set radix 10" is always a no-op.
5501 height N: This integer value is the number of lines on a page. Default
5502 is 24, the current `stty rows'' setting, or the ``li#''
5503 setting from the termcap entry matching the environment
5506 width N: This integer value is the number of characters on a line.
5507 Default is 80, the current `stty cols'' setting, or the ``co#''
5508 setting from the termcap entry matching the environment
5511 Note: ``set screensize'' is obsolete. Use ``set height'' and
5512 ``set width'' instead.
5514 print address on/off: Print memory addresses in various command displays,
5515 such as stack traces and structure values. Gdb looks
5516 more ``symbolic'' if you turn this off; it looks more
5517 ``machine level'' with it on. Default is ON.
5519 print array on/off: Prettyprint arrays. New convenient format! Default
5522 print demangle on/off: Print C++ symbols in "source" form if on,
5525 print asm-demangle on/off: Same, for assembler level printouts
5528 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5531 * Support for Epoch Environment.
5533 The epoch environment is a version of Emacs v18 with windowing. One
5534 new command, ``inspect'', is identical to ``print'', except that if you
5535 are running in the epoch environment, the value is printed in its own
5539 * Support for Shared Libraries
5541 GDB can now debug programs and core files that use SunOS shared libraries.
5542 Symbols from a shared library cannot be referenced
5543 before the shared library has been linked with the program (this
5544 happens after you type ``run'' and before the function main() is entered).
5545 At any time after this linking (including when examining core files
5546 from dynamically linked programs), gdb reads the symbols from each
5547 shared library when you type the ``sharedlibrary'' command.
5548 It can be abbreviated ``share''.
5550 sharedlibrary REGEXP: Load shared object library symbols for files
5551 matching a unix regular expression. No argument
5552 indicates to load symbols for all shared libraries.
5554 info sharedlibrary: Status of loaded shared libraries.
5559 A watchpoint stops execution of a program whenever the value of an
5560 expression changes. Checking for this slows down execution
5561 tremendously whenever you are in the scope of the expression, but is
5562 quite useful for catching tough ``bit-spreader'' or pointer misuse
5563 problems. Some machines such as the 386 have hardware for doing this
5564 more quickly, and future versions of gdb will use this hardware.
5566 watch EXP: Set a watchpoint (breakpoint) for an expression.
5568 info watchpoints: Information about your watchpoints.
5570 delete N: Deletes watchpoint number N (same as breakpoints).
5571 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5572 enable N: Re-enables watchpoint number N (same as breakpoints).
5575 * C++ multiple inheritance
5577 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5580 * C++ exception handling
5582 Gdb now supports limited C++ exception handling. Besides the existing
5583 ability to breakpoint on an exception handler, gdb can breakpoint on
5584 the raising of an exception (before the stack is peeled back to the
5587 catch FOO: If there is a FOO exception handler in the dynamic scope,
5588 set a breakpoint to catch exceptions which may be raised there.
5589 Multiple exceptions (``catch foo bar baz'') may be caught.
5591 info catch: Lists all exceptions which may be caught in the
5592 current stack frame.
5595 * Minor command changes
5597 The command ``call func (arg, arg, ...)'' now acts like the print
5598 command, except it does not print or save a value if the function's result
5599 is void. This is similar to dbx usage.
5601 The ``up'' and ``down'' commands now always print the frame they end up
5602 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5603 frames without printing.
5605 * New directory command
5607 'dir' now adds directories to the FRONT of the source search path.
5608 The path starts off empty. Source files that contain debug information
5609 about the directory in which they were compiled can be found even
5610 with an empty path; Sun CC and GCC include this information. If GDB can't
5611 find your source file in the current directory, type "dir .".
5613 * Configuring GDB for compilation
5615 For normal use, type ``./configure host''. See README or gdb.texinfo
5618 GDB now handles cross debugging. If you are remotely debugging between
5619 two different machines, type ``./configure host -target=targ''.
5620 Host is the machine where GDB will run; targ is the machine
5621 where the program that you are debugging will run.
5623 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.