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
29 * The "catch syscall" command now works on s390*-linux* targets.
33 qXfer:btrace:read's annex
34 The qXfer:btrace:read packet supports a new annex 'delta' to read
35 branch trace incrementally.
37 *** Changes in GDB 7.7
39 * Improved support for process record-replay and reverse debugging on
40 arm*-linux* targets. Support for thumb32 and syscall instruction
41 recording has been added.
43 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
45 * GDB now supports Fission DWP file format version 2.
46 http://gcc.gnu.org/wiki/DebugFission
48 * New convenience function "$_isvoid", to check whether an expression
49 is void. A void expression is an expression where the type of the
50 result is "void". For example, some convenience variables may be
51 "void" when evaluated (e.g., "$_exitcode" before the execution of
52 the program being debugged; or an undefined convenience variable).
53 Another example, when calling a function whose return type is
56 * The "maintenance print objfiles" command now takes an optional regexp.
58 * The "catch syscall" command now works on arm*-linux* targets.
60 * GDB now consistently shows "<not saved>" when printing values of
61 registers the debug info indicates have not been saved in the frame
62 and there's nowhere to retrieve them from
63 (callee-saved/call-clobbered registers):
68 (gdb) info registers rax
71 Before, the former would print "<optimized out>", and the latter
72 "*value not available*".
74 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
79 ** Frame filters and frame decorators have been added.
80 ** Temporary breakpoints are now supported.
81 ** Line tables representation has been added.
82 ** New attribute 'parent_type' for gdb.Field objects.
83 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
84 ** New attribute 'name' for gdb.Type objects.
88 Nios II ELF nios2*-*-elf
89 Nios II GNU/Linux nios2*-*-linux
90 Texas Instruments MSP430 msp430*-*-elf
92 * Removed native configurations
94 Support for these a.out NetBSD and OpenBSD obsolete configurations has
95 been removed. ELF variants of these configurations are kept supported.
97 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
98 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
99 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
100 i[34567]86-*-openbsd3.[0-3]
101 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
102 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
103 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
107 Like "catch throw", but catches a re-thrown exception.
109 Renamed from old "maint check-symtabs".
111 Perform consistency checks on symtabs.
113 Expand symtabs matching an optional regexp.
116 Display the details of GDB configure-time options.
118 maint set|show per-command
119 maint set|show per-command space
120 maint set|show per-command time
121 maint set|show per-command symtab
122 Enable display of per-command gdb resource usage.
124 remove-symbol-file FILENAME
125 remove-symbol-file -a ADDRESS
126 Remove a symbol file added via add-symbol-file. The file to remove
127 can be identified by its filename or by an address that lies within
128 the boundaries of this symbol file in memory.
131 info exceptions REGEXP
132 Display the list of Ada exceptions defined in the program being
133 debugged. If provided, only the exceptions whose names match REGEXP
138 set debug symfile off|on
140 Control display of debugging info regarding reading symbol files and
141 symbol tables within those files
143 set print raw frame-arguments
144 show print raw frame-arguments
145 Set/show whether to print frame arguments in raw mode,
146 disregarding any defined pretty-printers.
148 set remote trace-status-packet
149 show remote trace-status-packet
150 Set/show the use of remote protocol qTStatus packet.
154 Control display of debugging messages related to Nios II targets.
158 Control whether target-assisted range stepping is enabled.
160 set startup-with-shell
161 show startup-with-shell
162 Specifies whether Unix child processes are started via a shell or
167 Use the target memory cache for accesses to the code segment. This
168 improves performance of remote debugging (particularly disassembly).
170 * You can now use a literal value 'unlimited' for options that
171 interpret 0 or -1 as meaning "unlimited". E.g., "set
172 trace-buffer-size unlimited" is now an alias for "set
173 trace-buffer-size -1" and "set height unlimited" is now an alias for
176 * The "set debug symtab-create" debugging option of GDB has been changed to
177 accept a verbosity level. 0 means "off", 1 provides basic debugging
178 output, and values of 2 or greater provides more verbose output.
180 * New command-line options
182 Display the details of GDB configure-time options.
184 * The command 'tsave' can now support new option '-ctf' to save trace
185 buffer in Common Trace Format.
187 * Newly installed $prefix/bin/gcore acts as a shell interface for the
190 * GDB now implements the the C++ 'typeid' operator.
192 * The new convenience variable $_exception holds the exception being
193 thrown or caught at an exception-related catchpoint.
195 * The exception-related catchpoints, like "catch throw", now accept a
196 regular expression which can be used to filter exceptions by type.
198 * The new convenience variable $_exitsignal is automatically set to
199 the terminating signal number when the program being debugged dies
200 due to an uncaught signal.
204 ** All MI commands now accept an optional "--language" option.
205 Support for this feature can be verified by using the "-list-features"
206 command, which should contain "language-option".
208 ** The new command -info-gdb-mi-command allows the user to determine
209 whether a GDB/MI command is supported or not.
211 ** The "^error" result record returned when trying to execute an undefined
212 GDB/MI command now provides a variable named "code" whose content is the
213 "undefined-command" error code. Support for this feature can be verified
214 by using the "-list-features" command, which should contain
215 "undefined-command-error-code".
217 ** The -trace-save MI command can optionally save trace buffer in Common
220 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
222 ** The command -data-list-register-values now accepts an optional
223 "--skip-unavailable" option. When used, only the available registers
226 ** The new command -trace-frame-collected dumps collected variables,
227 computed expressions, tvars, memory and registers in a traceframe.
229 ** The commands -stack-list-locals, -stack-list-arguments and
230 -stack-list-variables now accept an option "--skip-unavailable".
231 When used, only the available locals or arguments are displayed.
233 ** The -exec-run command now accepts an optional "--start" option.
234 When used, the command follows the same semantics as the "start"
235 command, stopping the program's execution at the start of its
236 main subprogram. Support for this feature can be verified using
237 the "-list-features" command, which should contain
238 "exec-run-start-option".
240 ** The new commands -catch-assert and -catch-exceptions insert
241 catchpoints stopping the program when Ada exceptions are raised.
243 ** The new command -info-ada-exceptions provides the equivalent of
244 the new "info exceptions" command.
246 * New system-wide configuration scripts
247 A GDB installation now provides scripts suitable for use as system-wide
248 configuration scripts for the following systems:
252 * GDB now supports target-assigned range stepping with remote targets.
253 This improves the performance of stepping source lines by reducing
254 the number of control packets from/to GDB. See "New remote packets"
257 * GDB now understands the element 'tvar' in the XML traceframe info.
258 It has the id of the collected trace state variables.
260 * On S/390 targets that provide the transactional-execution feature,
261 the program interruption transaction diagnostic block (TDB) is now
262 represented as a number of additional "registers" in GDB.
268 The vCont packet supports a new 'r' action, that tells the remote
269 stub to step through an address range itself, without GDB
270 involvemement at each single-step.
272 qXfer:libraries-svr4:read's annex
273 The previously unused annex of the qXfer:libraries-svr4:read packet
274 is now used to support passing an argument list. The remote stub
275 reports support for this argument list to GDB's qSupported query.
276 The defined arguments are "start" and "prev", used to reduce work
277 necessary for library list updating, resulting in significant
280 * New features in the GDB remote stub, GDBserver
282 ** GDBserver now supports target-assisted range stepping. Currently
283 enabled on x86/x86_64 GNU/Linux targets.
285 ** GDBserver now adds element 'tvar' in the XML in the reply to
286 'qXfer:traceframe-info:read'. It has the id of the collected
287 trace state variables.
289 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
292 * New 'z' formatter for printing and examining memory, this displays the
293 value as hexadecimal zero padded on the left to the size of the type.
295 * GDB can now use Windows x64 unwinding data.
297 * The "set remotebaud" command has been replaced by "set serial baud".
298 Similarly, "show remotebaud" has been replaced by "show serial baud".
299 The "set remotebaud" and "show remotebaud" commands are still available
300 to provide backward compatibility with older versions of GDB.
302 *** Changes in GDB 7.6
304 * Target record has been renamed to record-full.
305 Record/replay is now enabled with the "record full" command.
306 This also affects settings that are associated with full record/replay
307 that have been moved from "set/show record" to "set/show record full":
309 set|show record full insn-number-max
310 set|show record full stop-at-limit
311 set|show record full memory-query
313 * A new record target "record-btrace" has been added. The new target
314 uses hardware support to record the control-flow of a process. It
315 does not support replaying the execution, but it implements the
316 below new commands for investigating the recorded execution log.
317 This new recording method can be enabled using:
321 The "record-btrace" target is only available on Intel Atom processors
322 and requires a Linux kernel 2.6.32 or later.
324 * Two new commands have been added for record/replay to give information
325 about the recorded execution without having to replay the execution.
326 The commands are only supported by "record btrace".
328 record instruction-history prints the execution history at
329 instruction granularity
331 record function-call-history prints the execution history at
334 * New native configurations
336 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
337 FreeBSD/powerpc powerpc*-*-freebsd
338 x86_64/Cygwin x86_64-*-cygwin*
339 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
343 ARM AArch64 aarch64*-*-elf
344 ARM AArch64 GNU/Linux aarch64*-*-linux
345 Lynx 178 PowerPC powerpc-*-lynx*178
346 x86_64/Cygwin x86_64-*-cygwin*
347 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
349 * If the configured location of system.gdbinit file (as given by the
350 --with-system-gdbinit option at configure time) is in the
351 data-directory (as specified by --with-gdb-datadir at configure
352 time) or in one of its subdirectories, then GDB will look for the
353 system-wide init file in the directory specified by the
354 --data-directory command-line option.
356 * New command line options:
358 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
359 other initialization files, unlike -nx which disables all of them.
361 * Removed command line options
363 -epoch This was used by the gdb mode in Epoch, an ancient fork of
366 * The 'ptype' and 'whatis' commands now accept an argument to control
369 * 'info proc' now works on some core files.
373 ** Vectors can be created with gdb.Type.vector.
375 ** Python's atexit.register now works in GDB.
377 ** Types can be pretty-printed via a Python API.
379 ** Python 3 is now supported (in addition to Python 2.4 or later)
381 ** New class gdb.Architecture exposes GDB's internal representation
382 of architecture in the Python API.
384 ** New method Frame.architecture returns the gdb.Architecture object
385 corresponding to the frame's architecture.
387 * New Python-based convenience functions:
389 ** $_memeq(buf1, buf2, length)
390 ** $_streq(str1, str2)
392 ** $_regex(str, regex)
394 * The 'cd' command now defaults to using '~' (the home directory) if not
397 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
398 default for GCC since November 2000.
400 * The command 'forward-search' can now be abbreviated as 'fo'.
402 * The command 'info tracepoints' can now display 'installed on target'
403 or 'not installed on target' for each non-pending location of tracepoint.
405 * New configure options
407 --enable-libmcheck/--disable-libmcheck
408 By default, development versions are built with -lmcheck on hosts
409 that support it, in order to help track memory corruption issues.
410 Release versions, on the other hand, are built without -lmcheck
411 by default. The --enable-libmcheck/--disable-libmcheck configure
412 options allow the user to override that default.
413 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
414 This configure option allows the user to build GDB with
415 libbabeltrace using which GDB can read Common Trace Format data.
417 * New commands (for set/show, see "New options" below)
420 Catch signals. This is similar to "handle", but allows commands and
421 conditions to be attached.
424 List the BFDs known to GDB.
426 python-interactive [command]
428 Start a Python interactive prompt, or evaluate the optional command
429 and print the result of expressions.
432 "py" is a new alias for "python".
434 enable type-printer [name]...
435 disable type-printer [name]...
436 Enable or disable type printers.
440 ** For the Renesas Super-H architecture, the "regs" command has been removed
441 (has been deprecated in GDB 7.5), and "info all-registers" should be used
446 set print type methods (on|off)
447 show print type methods
448 Control whether method declarations are displayed by "ptype".
449 The default is to show them.
451 set print type typedefs (on|off)
452 show print type typedefs
453 Control whether typedef definitions are displayed by "ptype".
454 The default is to show them.
456 set filename-display basename|relative|absolute
457 show filename-display
458 Control the way in which filenames is displayed.
459 The default is "relative", which preserves previous behavior.
461 set trace-buffer-size
462 show trace-buffer-size
463 Request target to change the size of trace buffer.
465 set remote trace-buffer-size-packet auto|on|off
466 show remote trace-buffer-size-packet
467 Control the use of the remote protocol `QTBuffer:size' packet.
471 Control display of debugging messages related to ARM AArch64.
474 set debug coff-pe-read
475 show debug coff-pe-read
476 Control display of debugging messages related to reading of COFF/PE
481 Control display of debugging messages related to Mach-O symbols
484 set debug notification
485 show debug notification
486 Control display of debugging info for async remote notification.
490 ** Command parameter changes are now notified using new async record
491 "=cmd-param-changed".
492 ** Trace frame changes caused by command "tfind" are now notified using
493 new async record "=traceframe-changed".
494 ** The creation, deletion and modification of trace state variables
495 are now notified using new async records "=tsv-created",
496 "=tsv-deleted" and "=tsv-modified".
497 ** The start and stop of process record are now notified using new
498 async record "=record-started" and "=record-stopped".
499 ** Memory changes are now notified using new async record
501 ** The data-disassemble command response will include a "fullname" field
502 containing the absolute file name when source has been requested.
503 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
504 command, to allow pattern filling of memory areas.
505 ** New commands "-catch-load"/"-catch-unload" added for intercepting
506 library load/unload events.
507 ** The response to breakpoint commands and breakpoint async records
508 includes an "installed" field containing a boolean state about each
509 non-pending tracepoint location is whether installed on target or not.
510 ** Output of the "-trace-status" command includes a "trace-file" field
511 containing the name of the trace file being examined. This field is
512 optional, and only present when examining a trace file.
513 ** The "fullname" field is now always present along with the "file" field,
514 even if the file cannot be found by GDB.
516 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
517 You must have the LZMA library available when configuring GDB for this
518 feature to be enabled. For more information, see:
519 http://fedoraproject.org/wiki/Features/MiniDebugInfo
524 Set the size of trace buffer. The remote stub reports support for this
525 packet to gdb's qSupported query.
528 Enable Branch Trace Store (BTS)-based branch tracing for the current
529 thread. The remote stub reports support for this packet to gdb's
533 Disable branch tracing for the current thread. The remote stub reports
534 support for this packet to gdb's qSupported query.
537 Read the traced branches for the current thread. The remote stub
538 reports support for this packet to gdb's qSupported query.
540 *** Changes in GDB 7.5
542 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
543 for more x32 ABI info.
545 * GDB now supports access to MIPS DSP registers on Linux targets.
547 * GDB now supports debugging microMIPS binaries.
549 * The "info os" command on GNU/Linux can now display information on
550 several new classes of objects managed by the operating system:
551 "info os procgroups" lists process groups
552 "info os files" lists file descriptors
553 "info os sockets" lists internet-domain sockets
554 "info os shm" lists shared-memory regions
555 "info os semaphores" lists semaphores
556 "info os msg" lists message queues
557 "info os modules" lists loaded kernel modules
559 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
560 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
561 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
562 options and inspect the probe arguments using the new $_probe_arg family
563 of convenience variables. You can obtain more information about SystemTap
564 in <http://sourceware.org/systemtap/>.
566 * GDB now supports reversible debugging on ARM, it allows you to
567 debug basic ARM and THUMB instructions, and provides
568 record/replay support.
570 * The option "symbol-reloading" has been deleted as it is no longer used.
574 ** GDB commands implemented in Python can now be put in command class
577 ** The "maint set python print-stack on|off" is now deleted.
579 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
580 apply "flag enum"-style pretty-printing to any enum.
582 ** gdb.lookup_symbol can now work when there is no current frame.
584 ** gdb.Symbol now has a 'line' attribute, holding the line number in
585 the source at which the symbol was defined.
587 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
588 method 'value'. The former indicates whether the symbol needs a
589 frame in order to compute its value, and the latter computes the
592 ** A new method 'referenced_value' on gdb.Value objects which can
593 dereference pointer as well as C++ reference values.
595 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
596 which return the global and static blocks (as gdb.Block objects),
597 of the underlying symbol table, respectively.
599 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
600 object associated with a PC value.
602 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
603 of the address range occupied by code for the current source line.
605 * Go language support.
606 GDB now supports debugging programs written in the Go programming
609 * GDBserver now supports stdio connections.
610 E.g. (gdb) target remote | ssh myhost gdbserver - hello
612 * The binary "gdbtui" can no longer be built or installed.
613 Use "gdb -tui" instead.
615 * GDB will now print "flag" enums specially. A flag enum is one where
616 all the enumerator values have no bits in common when pairwise
617 "and"ed. When printing a value whose type is a flag enum, GDB will
618 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
619 (gdb) print (enum E) 3
622 * The filename part of a linespec will now match trailing components
623 of a source file name. For example, "break gcc/expr.c:1000" will
624 now set a breakpoint in build/gcc/expr.c, but not
627 * The "info proc" and "generate-core-file" commands will now also
628 work on remote targets connected to GDBserver on Linux.
630 * The command "info catch" has been removed. It has been disabled
633 * The "catch exception" and "catch assert" commands now accept
634 a condition at the end of the command, much like the "break"
635 command does. For instance:
637 (gdb) catch exception Constraint_Error if Barrier = True
639 Previously, it was possible to add a condition to such catchpoints,
640 but it had to be done as a second step, after the catchpoint had been
641 created, using the "condition" command.
643 * The "info static-tracepoint-marker" command will now also work on
644 native Linux targets with in-process agent.
646 * GDB can now set breakpoints on inlined functions.
648 * The .gdb_index section has been updated to include symbols for
649 inlined functions. GDB will ignore older .gdb_index sections by
650 default, which could cause symbol files to be loaded more slowly
651 until their .gdb_index sections can be recreated. The new command
652 "set use-deprecated-index-sections on" will cause GDB to use any older
653 .gdb_index sections it finds. This will restore performance, but the
654 ability to set breakpoints on inlined functions will be lost in symbol
655 files with older .gdb_index sections.
657 The .gdb_index section has also been updated to record more information
658 about each symbol. This speeds up the "info variables", "info functions"
659 and "info types" commands when used with programs having the .gdb_index
660 section, as well as speeding up debugging with shared libraries using
661 the .gdb_index section.
663 * Ada support for GDB/MI Variable Objects has been added.
665 * GDB can now support 'breakpoint always-inserted mode' in 'record'
670 ** New command -info-os is the MI equivalent of "info os".
672 ** Output logs ("set logging" and related) now include MI output.
676 ** "set use-deprecated-index-sections on|off"
677 "show use-deprecated-index-sections on|off"
678 Controls the use of deprecated .gdb_index sections.
680 ** "catch load" and "catch unload" can be used to stop when a shared
681 library is loaded or unloaded, respectively.
683 ** "enable count" can be used to auto-disable a breakpoint after
686 ** "info vtbl" can be used to show the virtual method tables for
687 C++ and Java objects.
689 ** "explore" and its sub commands "explore value" and "explore type"
690 can be used to recursively explore values and types of
691 expressions. These commands are available only if GDB is
692 configured with '--with-python'.
694 ** "info auto-load" shows status of all kinds of auto-loaded files,
695 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
696 sequences of commands files, "info auto-load python-scripts"
697 shows status of auto-loading Python script files,
698 "info auto-load local-gdbinit" shows status of loading init file
699 (.gdbinit) from current directory and "info auto-load libthread-db" shows
700 status of inferior specific thread debugging shared library loading.
702 ** "info auto-load-scripts", "set auto-load-scripts on|off"
703 and "show auto-load-scripts" commands have been deprecated, use their
704 "info auto-load python-scripts", "set auto-load python-scripts on|off"
705 and "show auto-load python-scripts" counterparts instead.
707 ** "dprintf location,format,args..." creates a dynamic printf, which
708 is basically a breakpoint that does a printf and immediately
709 resumes your program's execution, so it is like a printf that you
710 can insert dynamically at runtime instead of at compiletime.
712 ** "set print symbol"
714 Controls whether GDB attempts to display the symbol, if any,
715 corresponding to addresses it prints. This defaults to "on", but
716 you can set it to "off" to restore GDB's previous behavior.
718 * Deprecated commands
720 ** For the Renesas Super-H architecture, the "regs" command has been
721 deprecated, and "info all-registers" should be used instead.
725 Renesas RL78 rl78-*-elf
726 HP OpenVMS ia64 ia64-hp-openvms*
728 * GDBserver supports evaluation of breakpoint conditions. When
729 support is advertised by GDBserver, GDB may be told to send the
730 breakpoint conditions in bytecode form to GDBserver. GDBserver
731 will only report the breakpoint trigger to GDB when its condition
737 show mips compression
738 Select the compressed ISA encoding used in functions that have no symbol
739 information available. The encoding can be set to either of:
742 and is updated automatically from ELF file flags if available.
744 set breakpoint condition-evaluation
745 show breakpoint condition-evaluation
746 Control whether breakpoint conditions are evaluated by GDB ("host") or by
747 GDBserver ("target"). Default option "auto" chooses the most efficient
749 This option can improve debugger efficiency depending on the speed of the
753 Disable auto-loading globally.
756 Show auto-loading setting of all kinds of auto-loaded files.
758 set auto-load gdb-scripts on|off
759 show auto-load gdb-scripts
760 Control auto-loading of GDB canned sequences of commands files.
762 set auto-load python-scripts on|off
763 show auto-load python-scripts
764 Control auto-loading of Python script files.
766 set auto-load local-gdbinit on|off
767 show auto-load local-gdbinit
768 Control loading of init file (.gdbinit) from current directory.
770 set auto-load libthread-db on|off
771 show auto-load libthread-db
772 Control auto-loading of inferior specific thread debugging shared library.
774 set auto-load scripts-directory <dir1>[:<dir2>...]
775 show auto-load scripts-directory
776 Set a list of directories from which to load auto-loaded scripts.
777 Automatically loaded Python scripts and GDB scripts are located in one
778 of the directories listed by this option.
779 The delimiter (':' above) may differ according to the host platform.
781 set auto-load safe-path <dir1>[:<dir2>...]
782 show auto-load safe-path
783 Set a list of directories from which it is safe to auto-load files.
784 The delimiter (':' above) may differ according to the host platform.
786 set debug auto-load on|off
788 Control display of debugging info for auto-loading the files above.
790 set dprintf-style gdb|call|agent
792 Control the way in which a dynamic printf is performed; "gdb"
793 requests a GDB printf command, while "call" causes dprintf to call a
794 function in the inferior. "agent" requests that the target agent
795 (such as GDBserver) do the printing.
797 set dprintf-function <expr>
798 show dprintf-function
799 set dprintf-channel <expr>
801 Set the function and optional first argument to the call when using
802 the "call" style of dynamic printf.
804 set disconnected-dprintf on|off
805 show disconnected-dprintf
806 Control whether agent-style dynamic printfs continue to be in effect
807 after GDB disconnects.
809 * New configure options
812 Configure default value for the 'set auto-load scripts-directory'
813 setting above. It defaults to '$debugdir:$datadir/auto-load',
814 $debugdir representing global debugging info directories (available
815 via 'show debug-file-directory') and $datadir representing GDB's data
816 directory (available via 'show data-directory').
818 --with-auto-load-safe-path
819 Configure default value for the 'set auto-load safe-path' setting
820 above. It defaults to the --with-auto-load-dir setting.
822 --without-auto-load-safe-path
823 Set 'set auto-load safe-path' to '/', effectively disabling this
828 z0/z1 conditional breakpoints extension
830 The z0/z1 breakpoint insertion packets have been extended to carry
831 a list of conditional expressions over to the remote stub depending on the
832 condition evaluation mode. The use of this extension can be controlled
833 via the "set remote conditional-breakpoints-packet" command.
837 Specify the signals which the remote stub may pass to the debugged
838 program without GDB involvement.
840 * New command line options
842 --init-command=FILE, -ix Like --command, -x but execute it
843 before loading inferior.
844 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
845 execute it before loading inferior.
847 *** Changes in GDB 7.4
849 * GDB now handles ambiguous linespecs more consistently; the existing
850 FILE:LINE support has been expanded to other types of linespecs. A
851 breakpoint will now be set on all matching locations in all
852 inferiors, and locations will be added or removed according to
855 * GDB now allows you to skip uninteresting functions and files when
856 stepping with the "skip function" and "skip file" commands.
858 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
859 and "show remote hardware-watchpoint-length-limit". These allows to
860 set or show the maximum length limit (in bytes) of a remote
861 target hardware watchpoint.
863 This allows e.g. to use "unlimited" hardware watchpoints with the
864 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
865 watchpoints are slower than real hardware watchpoints but are
866 significantly faster than gdb software watchpoints.
870 ** The register_pretty_printer function in module gdb.printing now takes
871 an optional `replace' argument. If True, the new printer replaces any
874 ** The "maint set python print-stack on|off" command has been
875 deprecated and will be deleted in GDB 7.5.
876 A new command: "set python print-stack none|full|message" has
877 replaced it. Additionally, the default for "print-stack" is
878 now "message", which just prints the error message without
881 ** A prompt substitution hook (prompt_hook) is now available to the
884 ** A new Python module, gdb.prompt has been added to the GDB Python
885 modules library. This module provides functionality for
886 escape sequences in prompts (used by set/show
887 extended-prompt). These escape sequences are replaced by their
890 ** Python commands and convenience-functions located in
891 'data-directory'/python/gdb/command and
892 'data-directory'/python/gdb/function are now automatically loaded
895 ** Blocks now provide four new attributes. global_block and
896 static_block will return the global and static blocks
897 respectively. is_static and is_global are boolean attributes
898 that indicate if the block is one of those two types.
900 ** Symbols now provide the "type" attribute, the type of the symbol.
902 ** The "gdb.breakpoint" function has been deprecated in favor of
905 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
906 of a function. This class is based on the "finish" command
907 available in the CLI.
909 ** Type objects for struct and union types now allow access to
910 the fields using standard Python dictionary (mapping) methods.
911 For example, "some_type['myfield']" now works, as does
914 ** A new event "gdb.new_objfile" has been added, triggered by loading a
917 ** A new function, "deep_items" has been added to the gdb.types
918 module in the GDB Python modules library. This function returns
919 an iterator over the fields of a struct or union type. Unlike
920 the standard Python "iteritems" method, it will recursively traverse
921 any anonymous fields.
925 ** "*stopped" events can report several new "reason"s, such as
928 ** Breakpoint changes are now notified using new async records, like
929 "=breakpoint-modified".
931 ** New command -ada-task-info.
933 * libthread-db-search-path now supports two special values: $sdir and $pdir.
934 $sdir specifies the default system locations of shared libraries.
935 $pdir specifies the directory where the libpthread used by the application
938 GDB no longer looks in $sdir and $pdir after it has searched the directories
939 mentioned in libthread-db-search-path. If you want to search those
940 directories, they must be specified in libthread-db-search-path.
941 The default value of libthread-db-search-path on GNU/Linux and Solaris
942 systems is now "$sdir:$pdir".
944 $pdir is not supported by gdbserver, it is currently ignored.
945 $sdir is supported by gdbserver.
947 * New configure option --with-iconv-bin.
948 When using the internationalization support like the one in the GNU C
949 library, GDB will invoke the "iconv" program to get a list of supported
950 character sets. If this program lives in a non-standard location, one can
951 use this option to specify where to find it.
953 * When natively debugging programs on PowerPC BookE processors running
954 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
955 watchpoints, which specify a mask in addition to an address to watch.
956 The mask specifies that some bits of an address (the bits which are
957 reset in the mask) should be ignored when matching the address accessed
958 by the inferior against the watchpoint address. See the "PowerPC Embedded"
959 section in the user manual for more details.
961 * The new option --once causes GDBserver to stop listening for connections once
962 the first connection is made. The listening port used by GDBserver will
963 become available after that.
965 * New commands "info macros" and "alias" have been added.
967 * New function parameters suffix @entry specifies value of function parameter
968 at the time the function got called. Entry values are available only since
974 "!" is now an alias of the "shell" command.
975 Note that no space is needed between "!" and SHELL COMMAND.
979 watch EXPRESSION mask MASK_VALUE
980 The watch command now supports the mask argument which allows creation
981 of masked watchpoints, if the current architecture supports this feature.
983 info auto-load-scripts [REGEXP]
984 This command was formerly named "maintenance print section-scripts".
985 It is now generally useful and is no longer a maintenance-only command.
987 info macro [-all] [--] MACRO
988 The info macro command has new options `-all' and `--'. The first for
989 printing all definitions of a macro. The second for explicitly specifying
990 the end of arguments and the beginning of the macro name in case the macro
991 name starts with a hyphen.
993 collect[/s] EXPRESSIONS
994 The tracepoint collect command now takes an optional modifier "/s"
995 that directs it to dereference pointer-to-character types and
996 collect the bytes of memory up to a zero byte. The behavior is
997 similar to what you see when you use the regular print command on a
998 string. An optional integer following the "/s" sets a bound on the
999 number of bytes that will be collected.
1002 The trace start command now interprets any supplied arguments as a
1003 note to be recorded with the trace run, with an effect similar to
1004 setting the variable trace-notes.
1007 The trace stop command now interprets any arguments as a note to be
1008 mentioned along with the tstatus report that the trace was stopped
1009 with a command. The effect is similar to setting the variable
1012 * Tracepoints can now be enabled and disabled at any time after a trace
1013 experiment has been started using the standard "enable" and "disable"
1014 commands. It is now possible to start a trace experiment with no enabled
1015 tracepoints; GDB will display a warning, but will allow the experiment to
1016 begin, assuming that tracepoints will be enabled as needed while the trace
1019 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1020 locations with 4-byte instructions, when they were previously
1021 limited to locations with instructions of 5 bytes or longer.
1025 set debug dwarf2-read
1026 show debug dwarf2-read
1027 Turns on or off display of debugging messages related to reading
1028 DWARF debug info. The default is off.
1030 set debug symtab-create
1031 show debug symtab-create
1032 Turns on or off display of debugging messages related to symbol table
1033 creation. The default is off.
1036 show extended-prompt
1037 Set the GDB prompt, and allow escape sequences to be inserted to
1038 display miscellaneous information (see 'help set extended-prompt'
1039 for the list of sequences). This prompt (and any information
1040 accessed through the escape sequences) is updated every time the
1041 prompt is displayed.
1043 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1044 show print entry-values
1045 Set printing of frame argument values at function entry. In some cases
1046 GDB can determine the value of function argument which was passed by the
1047 function caller, even if the value was modified inside the called function.
1049 set debug entry-values
1050 show debug entry-values
1051 Control display of debugging info for determining frame argument values at
1052 function entry and virtual tail call frames.
1054 set basenames-may-differ
1055 show basenames-may-differ
1056 Set whether a source file may have multiple base names.
1057 (A "base name" is the name of a file with the directory part removed.
1058 Example: The base name of "/home/user/hello.c" is "hello.c".)
1059 If set, GDB will canonicalize file names (e.g., expand symlinks)
1060 before comparing them. Canonicalization is an expensive operation,
1061 but it allows the same file be known by more than one base name.
1062 If not set (the default), all source files are assumed to have just
1063 one base name, and gdb will do file name comparisons more efficiently.
1069 Set a user name and notes for the current and any future trace runs.
1070 This is useful for long-running and/or disconnected traces, to
1071 inform others (or yourself) as to who is running the trace, supply
1072 contact information, or otherwise explain what is going on.
1074 set trace-stop-notes
1075 show trace-stop-notes
1076 Set a note attached to the trace run, that is displayed when the
1077 trace has been stopped by a tstop command. This is useful for
1078 instance as an explanation, if you are stopping a trace run that was
1079 started by someone else.
1081 * New remote packets
1085 Dynamically enable a tracepoint in a started trace experiment.
1089 Dynamically disable a tracepoint in a started trace experiment.
1093 Set the user and notes of the trace run.
1097 Query the current status of a tracepoint.
1101 Query the minimum length of instruction at which a fast tracepoint may
1104 * Dcache size (number of lines) and line-size are now runtime-configurable
1105 via "set dcache line" and "set dcache line-size" commands.
1109 Texas Instruments TMS320C6x tic6x-*-*
1113 Renesas RL78 rl78-*-elf
1115 *** Changes in GDB 7.3.1
1117 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1119 *** Changes in GDB 7.3
1121 * GDB has a new command: "thread find [REGEXP]".
1122 It finds the thread id whose name, target id, or thread extra info
1123 matches the given regular expression.
1125 * The "catch syscall" command now works on mips*-linux* targets.
1127 * The -data-disassemble MI command now supports modes 2 and 3 for
1128 dumping the instruction opcodes.
1130 * New command line options
1132 -data-directory DIR Specify DIR as the "data-directory".
1133 This is mostly for testing purposes.
1135 * The "maint set python auto-load on|off" command has been renamed to
1136 "set auto-load-scripts on|off".
1138 * GDB has a new command: "set directories".
1139 It is like the "dir" command except that it replaces the
1140 source path list instead of augmenting it.
1142 * GDB now understands thread names.
1144 On GNU/Linux, "info threads" will display the thread name as set by
1145 prctl or pthread_setname_np.
1147 There is also a new command, "thread name", which can be used to
1148 assign a name internally for GDB to display.
1151 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1152 has been integrated into GDB.
1156 ** The function gdb.Write now accepts an optional keyword 'stream'.
1157 This keyword, when provided, will direct the output to either
1158 stdout, stderr, or GDB's logging output.
1160 ** Parameters can now be be sub-classed in Python, and in particular
1161 you may implement the get_set_doc and get_show_doc functions.
1162 This improves how Parameter set/show documentation is processed
1163 and allows for more dynamic content.
1165 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1166 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1167 have an is_valid method.
1169 ** Breakpoints can now be sub-classed in Python, and in particular
1170 you may implement a 'stop' function that is executed each time
1171 the inferior reaches that breakpoint.
1173 ** New function gdb.lookup_global_symbol looks up a global symbol.
1175 ** GDB values in Python are now callable if the value represents a
1176 function. For example, if 'some_value' represents a function that
1177 takes two integer parameters and returns a value, you can call
1178 that function like so:
1180 result = some_value (10,20)
1182 ** Module gdb.types has been added.
1183 It contains a collection of utilities for working with gdb.Types objects:
1184 get_basic_type, has_field, make_enum_dict.
1186 ** Module gdb.printing has been added.
1187 It contains utilities for writing and registering pretty-printers.
1188 New classes: PrettyPrinter, SubPrettyPrinter,
1189 RegexpCollectionPrettyPrinter.
1190 New function: register_pretty_printer.
1192 ** New commands "info pretty-printers", "enable pretty-printer" and
1193 "disable pretty-printer" have been added.
1195 ** gdb.parameter("directories") is now available.
1197 ** New function gdb.newest_frame returns the newest frame in the
1200 ** The gdb.InferiorThread class has a new "name" attribute. This
1201 holds the thread's name.
1203 ** Python Support for Inferior events.
1204 Python scripts can add observers to be notified of events
1205 occurring in the process being debugged.
1206 The following events are currently supported:
1207 - gdb.events.cont Continue event.
1208 - gdb.events.exited Inferior exited event.
1209 - gdb.events.stop Signal received, and Breakpoint hit events.
1213 ** GDB now puts template parameters in scope when debugging in an
1214 instantiation. For example, if you have:
1216 template<int X> int func (void) { return X; }
1218 then if you step into func<5>, "print X" will show "5". This
1219 feature requires proper debuginfo support from the compiler; it
1220 was added to GCC 4.5.
1222 ** The motion commands "next", "finish", "until", and "advance" now
1223 work better when exceptions are thrown. In particular, GDB will
1224 no longer lose control of the inferior; instead, the GDB will
1225 stop the inferior at the point at which the exception is caught.
1226 This functionality requires a change in the exception handling
1227 code that was introduced in GCC 4.5.
1229 * GDB now follows GCC's rules on accessing volatile objects when
1230 reading or writing target state during expression evaluation.
1231 One notable difference to prior behavior is that "print x = 0"
1232 no longer generates a read of x; the value of the assignment is
1233 now always taken directly from the value being assigned.
1235 * GDB now has some support for using labels in the program's source in
1236 linespecs. For instance, you can use "advance label" to continue
1237 execution to a label.
1239 * GDB now has support for reading and writing a new .gdb_index
1240 section. This section holds a fast index of DWARF debugging
1241 information and can be used to greatly speed up GDB startup and
1242 operation. See the documentation for `save gdb-index' for details.
1244 * The "watch" command now accepts an optional "-location" argument.
1245 When used, this causes GDB to watch the memory referred to by the
1246 expression. Such a watchpoint is never deleted due to it going out
1249 * GDB now supports thread debugging of core dumps on GNU/Linux.
1251 GDB now activates thread debugging using the libthread_db library
1252 when debugging GNU/Linux core dumps, similarly to when debugging
1253 live processes. As a result, when debugging a core dump file, GDB
1254 is now able to display pthread_t ids of threads. For example, "info
1255 threads" shows the same output as when debugging the process when it
1256 was live. In earlier releases, you'd see something like this:
1259 * 1 LWP 6780 main () at main.c:10
1261 While now you see this:
1264 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1266 It is also now possible to inspect TLS variables when debugging core
1269 When debugging a core dump generated on a machine other than the one
1270 used to run GDB, you may need to point GDB at the correct
1271 libthread_db library with the "set libthread-db-search-path"
1272 command. See the user manual for more details on this command.
1274 * When natively debugging programs on PowerPC BookE processors running
1275 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1276 which stop execution of the inferior whenever it executes an instruction
1277 at any address within the specified range. See the "PowerPC Embedded"
1278 section in the user manual for more details.
1280 * New features in the GDB remote stub, GDBserver
1282 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1283 and i686 LynxOS (version 5.x).
1285 ** GDBserver is now supported on Blackfin Linux.
1287 * New native configurations
1289 ia64 HP-UX ia64-*-hpux*
1293 Analog Devices, Inc. Blackfin Processor bfin-*
1295 * Ada task switching is now supported on sparc-elf targets when
1296 debugging a program using the Ravenscar Profile. For more information,
1297 see the "Tasking Support when using the Ravenscar Profile" section
1298 in the GDB user manual.
1300 * Guile support was removed.
1302 * New features in the GNU simulator
1304 ** The --map-info flag lists all known core mappings.
1306 ** CFI flashes may be simulated via the "cfi" device.
1308 *** Changes in GDB 7.2
1310 * Shared library support for remote targets by default
1312 When GDB is configured for a generic, non-OS specific target, like
1313 for example, --target=arm-eabi or one of the many *-*-elf targets,
1314 GDB now queries remote stubs for loaded shared libraries using the
1315 `qXfer:libraries:read' packet. Previously, shared library support
1316 was always disabled for such configurations.
1320 ** Argument Dependent Lookup (ADL)
1322 In C++ ADL lookup directs function search to the namespaces of its
1323 arguments even if the namespace has not been imported.
1333 Here the compiler will search for `foo' in the namespace of 'b'
1334 and find A::foo. GDB now supports this. This construct is commonly
1335 used in the Standard Template Library for operators.
1337 ** Improved User Defined Operator Support
1339 In addition to member operators, GDB now supports lookup of operators
1340 defined in a namespace and imported with a `using' directive, operators
1341 defined in the global scope, operators imported implicitly from an
1342 anonymous namespace, and the ADL operators mentioned in the previous
1344 GDB now also supports proper overload resolution for all the previously
1345 mentioned flavors of operators.
1347 ** static const class members
1349 Printing of static const class members that are initialized in the
1350 class definition has been fixed.
1352 * Windows Thread Information Block access.
1354 On Windows targets, GDB now supports displaying the Windows Thread
1355 Information Block (TIB) structure. This structure is visible either
1356 by using the new command `info w32 thread-information-block' or, by
1357 dereferencing the new convenience variable named `$_tlb', a
1358 thread-specific pointer to the TIB. This feature is also supported
1359 when remote debugging using GDBserver.
1361 * Static tracepoints
1363 Static tracepoints are calls in the user program into a tracing
1364 library. One such library is a port of the LTTng kernel tracer to
1365 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1366 When debugging with GDBserver, GDB now supports combining the GDB
1367 tracepoint machinery with such libraries. For example: the user can
1368 use GDB to probe a static tracepoint marker (a call from the user
1369 program into the tracing library) with the new "strace" command (see
1370 "New commands" below). This creates a "static tracepoint" in the
1371 breakpoint list, that can be manipulated with the same feature set
1372 as fast and regular tracepoints. E.g., collect registers, local and
1373 global variables, collect trace state variables, and define
1374 tracepoint conditions. In addition, the user can collect extra
1375 static tracepoint marker specific data, by collecting the new
1376 $_sdata internal variable. When analyzing the trace buffer, you can
1377 inspect $_sdata like any other variable available to GDB. For more
1378 information, see the "Tracepoints" chapter in GDB user manual. New
1379 remote packets have been defined to support static tracepoints, see
1380 the "New remote packets" section below.
1382 * Better reconstruction of tracepoints after disconnected tracing
1384 GDB will attempt to download the original source form of tracepoint
1385 definitions when starting a trace run, and then will upload these
1386 upon reconnection to the target, resulting in a more accurate
1387 reconstruction of the tracepoints that are in use on the target.
1391 You can now exercise direct control over the ways that GDB can
1392 affect your program. For instance, you can disallow the setting of
1393 breakpoints, so that the program can run continuously (assuming
1394 non-stop mode). In addition, the "observer" variable is available
1395 to switch all of the different controls; in observer mode, GDB
1396 cannot affect the target's behavior at all, which is useful for
1397 tasks like diagnosing live systems in the field.
1399 * The new convenience variable $_thread holds the number of the
1402 * New remote packets
1406 Return the address of the Windows Thread Information Block of a given thread.
1410 In response to several of the tracepoint packets, the target may now
1411 also respond with a number of intermediate `qRelocInsn' request
1412 packets before the final result packet, to have GDB handle
1413 relocating an instruction to execute at a different address. This
1414 is particularly useful for stubs that support fast tracepoints. GDB
1415 reports support for this feature in the qSupported packet.
1419 List static tracepoint markers in the target program.
1423 List static tracepoint markers at a given address in the target
1426 qXfer:statictrace:read
1428 Read the static trace data collected (by a `collect $_sdata'
1429 tracepoint action). The remote stub reports support for this packet
1430 to gdb's qSupported query.
1434 Send the current settings of GDB's permission flags.
1438 Send part of the source (textual) form of a tracepoint definition,
1439 which includes location, conditional, and action list.
1441 * The source command now accepts a -s option to force searching for the
1442 script in the source search path even if the script name specifies
1445 * New features in the GDB remote stub, GDBserver
1447 - GDBserver now support tracepoints (including fast tracepoints, and
1448 static tracepoints). The feature is currently supported by the
1449 i386-linux and amd64-linux builds. See the "Tracepoints support
1450 in gdbserver" section in the manual for more information.
1452 GDBserver JIT compiles the tracepoint's conditional agent
1453 expression bytecode into native code whenever possible for low
1454 overhead dynamic tracepoints conditionals. For such tracepoints,
1455 an expression that examines program state is evaluated when the
1456 tracepoint is reached, in order to determine whether to capture
1457 trace data. If the condition is simple and false, processing the
1458 tracepoint finishes very quickly and no data is gathered.
1460 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1461 for static tracepoints support.
1463 - GDBserver now supports x86_64 Windows 64-bit debugging.
1465 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1466 it understands register description.
1468 * The --batch flag now disables pagination and queries.
1470 * X86 general purpose registers
1472 GDB now supports reading/writing byte, word and double-word x86
1473 general purpose registers directly. This means you can use, say,
1474 $ah or $ax to refer, respectively, to the byte register AH and
1475 16-bit word register AX that are actually portions of the 32-bit
1476 register EAX or 64-bit register RAX.
1478 * The `commands' command now accepts a range of breakpoints to modify.
1479 A plain `commands' following a command that creates multiple
1480 breakpoints affects all the breakpoints set by that command. This
1481 applies to breakpoints set by `rbreak', and also applies when a
1482 single `break' command creates multiple breakpoints (e.g.,
1483 breakpoints on overloaded c++ functions).
1485 * The `rbreak' command now accepts a filename specification as part of
1486 its argument, limiting the functions selected by the regex to those
1487 in the specified file.
1489 * Support for remote debugging Windows and SymbianOS shared libraries
1490 from Unix hosts has been improved. Non Windows GDB builds now can
1491 understand target reported file names that follow MS-DOS based file
1492 system semantics, such as file names that include drive letters and
1493 use the backslash character as directory separator. This makes it
1494 possible to transparently use the "set sysroot" and "set
1495 solib-search-path" on Unix hosts to point as host copies of the
1496 target's shared libraries. See the new command "set
1497 target-file-system-kind" described below, and the "Commands to
1498 specify files" section in the user manual for more information.
1502 eval template, expressions...
1503 Convert the values of one or more expressions under the control
1504 of the string template to a command line, and call it.
1506 set target-file-system-kind unix|dos-based|auto
1507 show target-file-system-kind
1508 Set or show the assumed file system kind for target reported file
1511 save breakpoints <filename>
1512 Save all current breakpoint definitions to a file suitable for use
1513 in a later debugging session. To read the saved breakpoint
1514 definitions, use the `source' command.
1516 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1519 info static-tracepoint-markers
1520 Display information about static tracepoint markers in the target.
1522 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1523 Define a static tracepoint by probing a marker at the given
1524 function, line, address, or marker ID.
1528 Enable and disable observer mode.
1530 set may-write-registers on|off
1531 set may-write-memory on|off
1532 set may-insert-breakpoints on|off
1533 set may-insert-tracepoints on|off
1534 set may-insert-fast-tracepoints on|off
1535 set may-interrupt on|off
1536 Set individual permissions for GDB effects on the target. Note that
1537 some of these settings can have undesirable or surprising
1538 consequences, particularly when changed in the middle of a session.
1539 For instance, disabling the writing of memory can prevent
1540 breakpoints from being inserted, cause single-stepping to fail, or
1541 even crash your program, if you disable after breakpoints have been
1542 inserted. However, GDB should not crash.
1544 set record memory-query on|off
1545 show record memory-query
1546 Control whether to stop the inferior if memory changes caused
1547 by an instruction cannot be recorded.
1552 The disassemble command now supports "start,+length" form of two arguments.
1556 ** GDB now provides a new directory location, called the python directory,
1557 where Python scripts written for GDB can be installed. The location
1558 of that directory is <data-directory>/python, where <data-directory>
1559 is the GDB data directory. For more details, see section `Scripting
1560 GDB using Python' in the manual.
1562 ** The GDB Python API now has access to breakpoints, symbols, symbol
1563 tables, program spaces, inferiors, threads and frame's code blocks.
1564 Additionally, GDB Parameters can now be created from the API, and
1565 manipulated via set/show in the CLI.
1567 ** New functions gdb.target_charset, gdb.target_wide_charset,
1568 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1570 ** New exception gdb.GdbError.
1572 ** Pretty-printers are now also looked up in the current program space.
1574 ** Pretty-printers can now be individually enabled and disabled.
1576 ** GDB now looks for names of Python scripts to auto-load in a
1577 special section named `.debug_gdb_scripts', in addition to looking
1578 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1580 * Tracepoint actions were unified with breakpoint commands. In particular,
1581 there are no longer differences in "info break" output for breakpoints and
1582 tracepoints and the "commands" command can be used for both tracepoints and
1583 regular breakpoints.
1587 ARM Symbian arm*-*-symbianelf*
1589 * D language support.
1590 GDB now supports debugging programs written in the D programming
1593 * GDB now supports the extended ptrace interface for PowerPC which is
1594 available since Linux kernel version 2.6.34. This automatically enables
1595 any hardware breakpoints and additional hardware watchpoints available in
1596 the processor. The old ptrace interface exposes just one hardware
1597 watchpoint and no hardware breakpoints.
1599 * GDB is now able to use the Data Value Compare (DVC) register available on
1600 embedded PowerPC processors to implement in hardware simple watchpoint
1601 conditions of the form:
1603 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1605 This works in native GDB running on Linux kernels with the extended ptrace
1606 interface mentioned above.
1608 *** Changes in GDB 7.1
1612 ** Namespace Support
1614 GDB now supports importing of namespaces in C++. This enables the
1615 user to inspect variables from imported namespaces. Support for
1616 namepace aliasing has also been added. So, if a namespace is
1617 aliased in the current scope (e.g. namepace C=A; ) the user can
1618 print variables using the alias (e.g. (gdb) print C::x).
1622 All known bugs relating to the printing of virtual base class were
1623 fixed. It is now possible to call overloaded static methods using a
1628 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1629 and reinterpret_cast<> are now handled by the C++ expression parser.
1633 Xilinx MicroBlaze microblaze-*-*
1638 Xilinx MicroBlaze microblaze
1641 * Multi-program debugging.
1643 GDB now has support for multi-program (a.k.a. multi-executable or
1644 multi-exec) debugging. This allows for debugging multiple inferiors
1645 simultaneously each running a different program under the same GDB
1646 session. See "Debugging Multiple Inferiors and Programs" in the
1647 manual for more information. This implied some user visible changes
1648 in the multi-inferior support. For example, "info inferiors" now
1649 lists inferiors that are not running yet or that have exited
1650 already. See also "New commands" and "New options" below.
1652 * New tracing features
1654 GDB's tracepoint facility now includes several new features:
1656 ** Trace state variables
1658 GDB tracepoints now include support for trace state variables, which
1659 are variables managed by the target agent during a tracing
1660 experiment. They are useful for tracepoints that trigger each
1661 other, so for instance one tracepoint can count hits in a variable,
1662 and then a second tracepoint has a condition that is true when the
1663 count reaches a particular value. Trace state variables share the
1664 $-syntax of GDB convenience variables, and can appear in both
1665 tracepoint actions and condition expressions. Use the "tvariable"
1666 command to create, and "info tvariables" to view; see "Trace State
1667 Variables" in the manual for more detail.
1671 GDB now includes an option for defining fast tracepoints, which
1672 targets may implement more efficiently, such as by installing a jump
1673 into the target agent rather than a trap instruction. The resulting
1674 speedup can be by two orders of magnitude or more, although the
1675 tradeoff is that some program locations on some target architectures
1676 might not allow fast tracepoint installation, for instance if the
1677 instruction to be replaced is shorter than the jump. To request a
1678 fast tracepoint, use the "ftrace" command, with syntax identical to
1679 the regular trace command.
1681 ** Disconnected tracing
1683 It is now possible to detach GDB from the target while it is running
1684 a trace experiment, then reconnect later to see how the experiment
1685 is going. In addition, a new variable disconnected-tracing lets you
1686 tell the target agent whether to continue running a trace if the
1687 connection is lost unexpectedly.
1691 GDB now has the ability to save the trace buffer into a file, and
1692 then use that file as a target, similarly to you can do with
1693 corefiles. You can select trace frames, print data that was
1694 collected in them, and use tstatus to display the state of the
1695 tracing run at the moment that it was saved. To create a trace
1696 file, use "tsave <filename>", and to use it, do "target tfile
1699 ** Circular trace buffer
1701 You can ask the target agent to handle the trace buffer as a
1702 circular buffer, discarding the oldest trace frames to make room for
1703 newer ones, by setting circular-trace-buffer to on. This feature may
1704 not be available for all target agents.
1709 The disassemble command, when invoked with two arguments, now requires
1710 the arguments to be comma-separated.
1713 The info variables command now displays variable definitions. Files
1714 which only declare a variable are not shown.
1717 The source command is now capable of sourcing Python scripts.
1718 This feature is dependent on the debugger being build with Python
1721 Related to this enhancement is also the introduction of a new command
1722 "set script-extension" (see below).
1724 * New commands (for set/show, see "New options" below)
1726 record save [<FILENAME>]
1727 Save a file (in core file format) containing the process record
1728 execution log for replay debugging at a later time.
1730 record restore <FILENAME>
1731 Restore the process record execution log that was saved at an
1732 earlier time, for replay debugging.
1734 add-inferior [-copies <N>] [-exec <FILENAME>]
1737 clone-inferior [-copies <N>] [ID]
1738 Make a new inferior ready to execute the same program another
1739 inferior has loaded.
1744 maint info program-spaces
1745 List the program spaces loaded into GDB.
1747 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1748 show remote interrupt-sequence
1749 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1750 as the sequence to the remote target in order to interrupt the execution.
1751 Ctrl-C is a default. Some system prefers BREAK which is high level of
1752 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1753 Magic SysRq g. It is BREAK signal and character 'g'.
1755 set remote interrupt-on-connect [on | off]
1756 show remote interrupt-on-connect
1757 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1758 remote target when gdb connects to it. This is needed when you debug
1761 set remotebreak [on | off]
1763 Deprecated. Use "set/show remote interrupt-sequence" instead.
1765 tvariable $NAME [ = EXP ]
1766 Create or modify a trace state variable.
1769 List trace state variables and their values.
1771 delete tvariable $NAME ...
1772 Delete one or more trace state variables.
1775 Evaluate the given expressions without collecting anything into the
1776 trace buffer. (Valid in tracepoint actions only.)
1778 ftrace FN / FILE:LINE / *ADDR
1779 Define a fast tracepoint at the given function, line, or address.
1781 * New expression syntax
1783 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1784 GDB now parses 0b101010 identically with 42.
1788 set follow-exec-mode new|same
1789 show follow-exec-mode
1790 Control whether GDB reuses the same inferior across an exec call or
1791 creates a new one. This is useful to be able to restart the old
1792 executable after the inferior having done an exec call.
1794 set default-collect EXPR, ...
1795 show default-collect
1796 Define a list of expressions to be collected at each tracepoint.
1797 This is a useful way to ensure essential items are not overlooked,
1798 such as registers or a critical global variable.
1800 set disconnected-tracing
1801 show disconnected-tracing
1802 If set to 1, the target is instructed to continue tracing if it
1803 loses its connection to GDB. If 0, the target is to stop tracing
1806 set circular-trace-buffer
1807 show circular-trace-buffer
1808 If set to on, the target is instructed to use a circular trace buffer
1809 and discard the oldest trace frames instead of stopping the trace due
1810 to a full trace buffer. If set to off, the trace stops when the buffer
1811 fills up. Some targets may not support this.
1813 set script-extension off|soft|strict
1814 show script-extension
1815 If set to "off", the debugger does not perform any script language
1816 recognition, and all sourced files are assumed to be GDB scripts.
1817 If set to "soft" (the default), files are sourced according to
1818 filename extension, falling back to GDB scripts if the first
1820 If set to "strict", files are sourced according to filename extension.
1822 set ada trust-PAD-over-XVS on|off
1823 show ada trust-PAD-over-XVS
1824 If off, activate a workaround against a bug in the debugging information
1825 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1826 the GCC sources for more information about the GNAT encoding and
1827 PAD types in particular). It is always safe to set this option to
1828 off, but this introduces a slight performance penalty. The default
1831 * Python API Improvements
1833 ** GDB provides the new class gdb.LazyString. This is useful in
1834 some pretty-printing cases. The new method gdb.Value.lazy_string
1835 provides a simple way to create objects of this type.
1837 ** The fields returned by gdb.Type.fields now have an
1838 `is_base_class' attribute.
1840 ** The new method gdb.Type.range returns the range of an array type.
1842 ** The new method gdb.parse_and_eval can be used to parse and
1843 evaluate an expression.
1845 * New remote packets
1848 Define a trace state variable.
1851 Get the current value of a trace state variable.
1854 Set desired tracing behavior upon disconnection.
1857 Set the trace buffer to be linear or circular.
1860 Get data about the tracepoints currently in use.
1864 Process record now works correctly with hardware watchpoints.
1866 Multiple bug fixes have been made to the mips-irix port, making it
1867 much more reliable. In particular:
1868 - Debugging threaded applications is now possible again. Previously,
1869 GDB would hang while starting the program, or while waiting for
1870 the program to stop at a breakpoint.
1871 - Attaching to a running process no longer hangs.
1872 - An error occurring while loading a core file has been fixed.
1873 - Changing the value of the PC register now works again. This fixes
1874 problems observed when using the "jump" command, or when calling
1875 a function from GDB, or even when assigning a new value to $pc.
1876 - With the "finish" and "return" commands, the return value for functions
1877 returning a small array is now correctly printed.
1878 - It is now possible to break on shared library code which gets executed
1879 during a shared library init phase (code executed while executing
1880 their .init section). Previously, the breakpoint would have no effect.
1881 - GDB is now able to backtrace through the signal handler for
1882 non-threaded programs.
1884 PIE (Position Independent Executable) programs debugging is now supported.
1885 This includes debugging execution of PIC (Position Independent Code) shared
1886 libraries although for that, it should be possible to run such libraries as an
1889 *** Changes in GDB 7.0
1891 * GDB now has an interface for JIT compilation. Applications that
1892 dynamically generate code can create symbol files in memory and register
1893 them with GDB. For users, the feature should work transparently, and
1894 for JIT developers, the interface is documented in the GDB manual in the
1895 "JIT Compilation Interface" chapter.
1897 * Tracepoints may now be conditional. The syntax is as for
1898 breakpoints; either an "if" clause appended to the "trace" command,
1899 or the "condition" command is available. GDB sends the condition to
1900 the target for evaluation using the same bytecode format as is used
1901 for tracepoint actions.
1903 * The disassemble command now supports: an optional /r modifier, print the
1904 raw instructions in hex as well as in symbolic form, and an optional /m
1905 modifier to print mixed source+assembly.
1907 * Process record and replay
1909 In a architecture environment that supports ``process record and
1910 replay'', ``process record and replay'' target can record a log of
1911 the process execution, and replay it with both forward and reverse
1914 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
1915 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
1916 set execution-direction {forward|reverse}, for targets that support
1919 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
1920 feature is available with a native GDB running on kernel version
1923 * GDB now has support for multi-byte and wide character sets on the
1924 target. Strings whose character type is wchar_t, char16_t, or
1925 char32_t are now correctly printed. GDB supports wide- and unicode-
1926 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
1927 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
1928 `printf'. This feature requires iconv to work properly; if your
1929 system does not have a working iconv, GDB can use GNU libiconv. See
1930 the installation instructions for more information.
1932 * GDB now supports automatic retrieval of shared library files from
1933 remote targets. To use this feature, specify a system root that begins
1934 with the `remote:' prefix, either via the `set sysroot' command or via
1935 the `--with-sysroot' configure-time option.
1937 * "info sharedlibrary" now takes an optional regex of libraries to show,
1938 and it now reports if a shared library has no debugging information.
1940 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
1941 now complete on file names.
1943 * When completing in expressions, gdb will attempt to limit
1944 completions to allowable structure or union fields, where appropriate.
1945 For instance, consider:
1947 # struct example { int f1; double f2; };
1948 # struct example variable;
1951 If the user types TAB at the end of this command line, the available
1952 completions will be "f1" and "f2".
1954 * Inlined functions are now supported. They show up in backtraces, and
1955 the "step", "next", and "finish" commands handle them automatically.
1957 * GDB now supports the token-splicing (##) and stringification (#)
1958 operators when expanding macros. It also supports variable-arity
1961 * GDB now supports inspecting extra signal information, exported by
1962 the new $_siginfo convenience variable. The feature is currently
1963 implemented on linux ARM, i386 and amd64.
1965 * GDB can now display the VFP floating point registers and NEON vector
1966 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
1967 can provide these registers (requires Linux 2.6.30 or later). Remote
1968 and simulator targets may also provide them.
1970 * New remote packets
1973 Search memory for a sequence of bytes.
1976 Turn off `+'/`-' protocol acknowledgments to permit more efficient
1977 operation over reliable transport links. Use of this packet is
1978 controlled by the `set remote noack-packet' command.
1981 Kill the process with the specified process ID. Use this in preference
1982 to `k' when multiprocess protocol extensions are supported.
1985 Obtains additional operating system information
1989 Read or write additional signal information.
1991 * Removed remote protocol undocumented extension
1993 An undocumented extension to the remote protocol's `S' stop reply
1994 packet that permited the stub to pass a process id was removed.
1995 Remote servers should use the `T' stop reply packet instead.
1997 * GDB now supports multiple function calling conventions according to the
1998 DWARF-2 DW_AT_calling_convention function attribute.
2000 * The SH target utilizes the aforementioned change to distinguish between gcc
2001 and Renesas calling convention. It also adds the new CLI commands
2002 `set/show sh calling-convention'.
2004 * GDB can now read compressed debug sections, as produced by GNU gold
2005 with the --compress-debug-sections=zlib flag.
2007 * 64-bit core files are now supported on AIX.
2009 * Thread switching is now supported on Tru64.
2011 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2012 which will be allocated using malloc later in program execution.
2014 * The qXfer:libraries:read remote procotol packet now allows passing a
2015 list of section offsets.
2017 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2018 conditions handling signals delivered during attach or thread creation
2019 have also been fixed.
2021 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2022 From the user's standpoint, all unqualified instances of True and False
2023 are treated as the standard definitions, regardless of context.
2025 * GDB now parses C++ symbol and type names more flexibly. For
2028 template<typename T> class C { };
2031 GDB will now correctly handle all of:
2033 ptype C<char const *>
2034 ptype C<char const*>
2035 ptype C<const char *>
2036 ptype C<const char*>
2038 * New features in the GDB remote stub, gdbserver
2040 - The "--wrapper" command-line argument tells gdbserver to use a
2041 wrapper program to launch programs for debugging.
2043 - On PowerPC and S/390 targets, it is now possible to use a single
2044 gdbserver executable to debug both 32-bit and 64-bit programs.
2045 (This requires gdbserver itself to be built as a 64-bit executable.)
2047 - gdbserver uses the new noack protocol mode for TCP connections to
2048 reduce communications latency, if also supported and enabled in GDB.
2050 - Support for the sparc64-linux-gnu target is now included in
2053 - The amd64-linux build of gdbserver now supports debugging both
2054 32-bit and 64-bit programs.
2056 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2057 now support hardware watchpoints, and will use them automatically
2062 GDB now has support for scripting using Python. Whether this is
2063 available is determined at configure time.
2065 New GDB commands can now be written in Python.
2067 * Ada tasking support
2069 Ada tasks can now be inspected in GDB. The following commands have
2073 Print the list of Ada tasks.
2075 Print detailed information about task number N.
2077 Print the task number of the current task.
2079 Switch the context of debugging to task number N.
2081 * Support for user-defined prefixed commands. The "define" command can
2082 add new commands to existing prefixes, e.g. "target".
2084 * Multi-inferior, multi-process debugging.
2086 GDB now has generalized support for multi-inferior debugging. See
2087 "Debugging Multiple Inferiors" in the manual for more information.
2088 Although availability still depends on target support, the command
2089 set is more uniform now. The GNU/Linux specific multi-forks support
2090 has been migrated to this new framework. This implied some user
2091 visible changes; see "New commands" and also "Removed commands"
2094 * Target descriptions can now describe the target OS ABI. See the
2095 "Target Description Format" section in the user manual for more
2098 * Target descriptions can now describe "compatible" architectures
2099 to indicate that the target can execute applications for a different
2100 architecture in addition to those for the main target architecture.
2101 See the "Target Description Format" section in the user manual for
2104 * Multi-architecture debugging.
2106 GDB now includes general supports for debugging applications on
2107 hybrid systems that use more than one single processor architecture
2108 at the same time. Each such hybrid architecture still requires
2109 specific support to be added. The only hybrid architecture supported
2110 in this version of GDB is the Cell Broadband Engine.
2112 * GDB now supports integrated debugging of Cell/B.E. applications that
2113 use both the PPU and SPU architectures. To enable support for hybrid
2114 Cell/B.E. debugging, you need to configure GDB to support both the
2115 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2116 --enable-targets configure option.
2118 * Non-stop mode debugging.
2120 For some targets, GDB now supports an optional mode of operation in
2121 which you can examine stopped threads while other threads continue
2122 to execute freely. This is referred to as non-stop mode, with the
2123 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2124 section in the user manual for more information.
2126 To be able to support remote non-stop debugging, a remote stub needs
2127 to implement the non-stop mode remote protocol extensions, as
2128 described in the "Remote Non-Stop" section of the user manual. The
2129 GDB remote stub, gdbserver, has been adjusted to support these
2130 extensions on linux targets.
2132 * New commands (for set/show, see "New options" below)
2134 catch syscall [NAME(S) | NUMBER(S)]
2135 Catch system calls. Arguments, which should be names of system
2136 calls or their numbers, mean catch only those syscalls. Without
2137 arguments, every syscall will be caught. When the inferior issues
2138 any of the specified syscalls, GDB will stop and announce the system
2139 call, both when it is called and when its call returns. This
2140 feature is currently available with a native GDB running on the
2141 Linux Kernel, under the following architectures: x86, x86_64,
2142 PowerPC and PowerPC64.
2144 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2146 Search memory for a sequence of bytes.
2148 maint set python print-stack
2149 maint show python print-stack
2150 Show a stack trace when an error is encountered in a Python script.
2153 Invoke CODE by passing it to the Python interpreter.
2158 These allow macros to be defined, undefined, and listed
2162 Show operating system information about processes.
2165 List the inferiors currently under GDB's control.
2168 Switch focus to inferior number NUM.
2171 Detach from inferior number NUM.
2174 Kill inferior number NUM.
2178 set spu stop-on-load
2179 show spu stop-on-load
2180 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2182 set spu auto-flush-cache
2183 show spu auto-flush-cache
2184 Control whether to automatically flush the software-managed cache
2185 during Cell/B.E. debugging.
2187 set sh calling-convention
2188 show sh calling-convention
2189 Control the calling convention used when calling SH target functions.
2192 show debug timestamp
2193 Control display of timestamps with GDB debugging output.
2195 set disassemble-next-line
2196 show disassemble-next-line
2197 Control display of disassembled source lines or instructions when
2200 set remote noack-packet
2201 show remote noack-packet
2202 Set/show the use of remote protocol QStartNoAckMode packet. See above
2203 under "New remote packets."
2205 set remote query-attached-packet
2206 show remote query-attached-packet
2207 Control use of remote protocol `qAttached' (query-attached) packet.
2209 set remote read-siginfo-object
2210 show remote read-siginfo-object
2211 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2214 set remote write-siginfo-object
2215 show remote write-siginfo-object
2216 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2219 set remote reverse-continue
2220 show remote reverse-continue
2221 Control use of remote protocol 'bc' (reverse-continue) packet.
2223 set remote reverse-step
2224 show remote reverse-step
2225 Control use of remote protocol 'bs' (reverse-step) packet.
2227 set displaced-stepping
2228 show displaced-stepping
2229 Control displaced stepping mode. Displaced stepping is a way to
2230 single-step over breakpoints without removing them from the debuggee.
2231 Also known as "out-of-line single-stepping".
2234 show debug displaced
2235 Control display of debugging info for displaced stepping.
2237 maint set internal-error
2238 maint show internal-error
2239 Control what GDB does when an internal error is detected.
2241 maint set internal-warning
2242 maint show internal-warning
2243 Control what GDB does when an internal warning is detected.
2248 Use a wrapper program to launch programs for debugging.
2250 set multiple-symbols (all|ask|cancel)
2251 show multiple-symbols
2252 The value of this variable can be changed to adjust the debugger behavior
2253 when an expression or a breakpoint location contains an ambiguous symbol
2254 name (an overloaded function name, for instance).
2256 set breakpoint always-inserted
2257 show breakpoint always-inserted
2258 Keep breakpoints always inserted in the target, as opposed to inserting
2259 them when resuming the target, and removing them when the target stops.
2260 This option can improve debugger performance on slow remote targets.
2262 set arm fallback-mode (arm|thumb|auto)
2263 show arm fallback-mode
2264 set arm force-mode (arm|thumb|auto)
2266 These commands control how ARM GDB determines whether instructions
2267 are ARM or Thumb. The default for both settings is auto, which uses
2268 the current CPSR value for instructions without symbols; previous
2269 versions of GDB behaved as if "set arm fallback-mode arm".
2271 set disable-randomization
2272 show disable-randomization
2273 Standalone programs run with the virtual address space randomization enabled
2274 by default on some platforms. This option keeps the addresses stable across
2275 multiple debugging sessions.
2279 Control whether other threads are stopped or not when some thread hits
2284 Requests that asynchronous execution is enabled in the target, if available.
2285 In this case, it's possible to resume target in the background, and interact
2286 with GDB while the target is running. "show target-async" displays the
2287 current state of asynchronous execution of the target.
2289 set target-wide-charset
2290 show target-wide-charset
2291 The target-wide-charset is the name of the character set that GDB
2292 uses when printing characters whose type is wchar_t.
2294 set tcp auto-retry (on|off)
2296 set tcp connect-timeout
2297 show tcp connect-timeout
2298 These commands allow GDB to retry failed TCP connections to a remote stub
2299 with a specified timeout period; this is useful if the stub is launched
2300 in parallel with GDB but may not be ready to accept connections immediately.
2302 set libthread-db-search-path
2303 show libthread-db-search-path
2304 Control list of directories which GDB will search for appropriate
2307 set schedule-multiple (on|off)
2308 show schedule-multiple
2309 Allow GDB to resume all threads of all processes or only threads of
2310 the current process.
2314 Use more aggressive caching for accesses to the stack. This improves
2315 performance of remote debugging (particularly backtraces) without
2316 affecting correctness.
2318 set interactive-mode (on|off|auto)
2319 show interactive-mode
2320 Control whether GDB runs in interactive mode (on) or not (off).
2321 When in interactive mode, GDB waits for the user to answer all
2322 queries. Otherwise, GDB does not wait and assumes the default
2323 answer. When set to auto (the default), GDB determines which
2324 mode to use based on the stdin settings.
2329 For program forks, this is replaced by the new more generic `info
2330 inferiors' command. To list checkpoints, you can still use the
2331 `info checkpoints' command, which was an alias for the `info forks'
2335 Replaced by the new `inferior' command. To switch between
2336 checkpoints, you can still use the `restart' command, which was an
2337 alias for the `fork' command.
2340 This is removed, since some targets don't have a notion of
2341 processes. To switch between processes, you can still use the
2342 `inferior' command using GDB's own inferior number.
2345 For program forks, this is replaced by the new more generic `kill
2346 inferior' command. To delete a checkpoint, you can still use the
2347 `delete checkpoint' command, which was an alias for the `delete
2351 For program forks, this is replaced by the new more generic `detach
2352 inferior' command. To detach a checkpoint, you can still use the
2353 `detach checkpoint' command, which was an alias for the `detach
2356 * New native configurations
2358 x86/x86_64 Darwin i[34567]86-*-darwin*
2360 x86_64 MinGW x86_64-*-mingw*
2364 Lattice Mico32 lm32-*
2365 x86 DICOS i[34567]86-*-dicos*
2366 x86_64 DICOS x86_64-*-dicos*
2369 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2370 (mingw32ce) debugging.
2376 These commands were actually not implemented on any target.
2378 *** Changes in GDB 6.8
2380 * New native configurations
2382 NetBSD/hppa hppa*-*netbsd*
2383 Xtensa GNU/Linux xtensa*-*-linux*
2387 NetBSD/hppa hppa*-*-netbsd*
2388 Xtensa GNU/Lunux xtensa*-*-linux*
2390 * Change in command line behavior -- corefiles vs. process ids.
2392 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2393 attaching to process NUMBER fails, GDB no longer attempts to open a
2394 core file named NUMBER. Attaching to a program using the -c option
2395 is no longer supported. Instead, use the '-p' or '--pid' options.
2397 * GDB can now be built as a native debugger for debugging Windows x86
2398 (mingw32) Portable Executable (PE) programs.
2400 * Pending breakpoints no longer change their number when their address
2403 * GDB now supports breakpoints with multiple locations,
2404 including breakpoints on C++ constructors, inside C++ templates,
2405 and in inlined functions.
2407 * GDB's ability to debug optimized code has been improved. GDB more
2408 accurately identifies function bodies and lexical blocks that occupy
2409 more than one contiguous range of addresses.
2411 * Target descriptions can now describe registers for PowerPC.
2413 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2414 registers on PowerPC targets.
2416 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2417 targets even when the libthread_db library is not available.
2419 * The GDB remote stub, gdbserver, now supports the new file transfer
2420 commands (remote put, remote get, and remote delete).
2422 * The GDB remote stub, gdbserver, now supports run and attach in
2423 extended-remote mode.
2425 * hppa*64*-*-hpux11* target broken
2426 The debugger is unable to start a program and fails with the following
2427 error: "Error trying to get information about dynamic linker".
2428 The gdb-6.7 release is also affected.
2430 * GDB now supports the --enable-targets= configure option to allow
2431 building a single GDB executable that supports multiple remote
2432 target architectures.
2434 * GDB now supports debugging C and C++ programs which use the
2435 Decimal Floating Point extension. In addition, the PowerPC target
2436 now has a set of pseudo-registers to inspect decimal float values
2437 stored in two consecutive float registers.
2439 * The -break-insert MI command can optionally create pending
2442 * Improved support for debugging Ada
2443 Many improvements to the Ada language support have been made. These
2445 - Better support for Ada2005 interface types
2446 - Improved handling of arrays and slices in general
2447 - Better support for Taft-amendment types
2448 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2450 - Improved command completion in Ada
2453 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2458 set print frame-arguments (all|scalars|none)
2459 show print frame-arguments
2460 The value of this variable can be changed to control which argument
2461 values should be printed by the debugger when displaying a frame.
2466 Transfer files to and from a remote target, and delete remote files.
2473 Transfer files to and from a remote target, and delete remote files.
2475 * New remote packets
2482 Open, close, read, write, and delete files on the remote system.
2485 Attach to an existing process on the remote system, in extended-remote
2489 Run a new process on the remote system, in extended-remote mode.
2491 *** Changes in GDB 6.7
2493 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2494 bfd, libiberty and opcodes, as revealed by static analysis donated by
2495 Coverity, Inc. (http://scan.coverity.com).
2497 * When looking up multiply-defined global symbols, GDB will now prefer the
2498 symbol definition in the current shared library if it was built using the
2499 -Bsymbolic linker option.
2501 * When the Text User Interface (TUI) is not configured, GDB will now
2502 recognize the -tui command-line option and print a message that the TUI
2505 * The GDB remote stub, gdbserver, now has lower overhead for high
2506 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2508 * GDB for MIPS targets now autodetects whether a remote target provides
2509 32-bit or 64-bit register values.
2511 * Support for C++ member pointers has been improved.
2513 * GDB now understands XML target descriptions, which specify the
2514 target's overall architecture. GDB can read a description from
2515 a local file or over the remote serial protocol.
2517 * Vectors of single-byte data use a new integer type which is not
2518 automatically displayed as character or string data.
2520 * The /s format now works with the print command. It displays
2521 arrays of single-byte integers and pointers to single-byte integers
2524 * Target descriptions can now describe target-specific registers,
2525 for architectures which have implemented the support (currently
2526 only ARM, M68K, and MIPS).
2528 * GDB and the GDB remote stub, gdbserver, now support the XScale
2531 * The GDB remote stub, gdbserver, has been updated to support
2532 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2533 has been rewritten to use the standard GDB remote protocol.
2535 * GDB can now step into C++ functions which are called through thunks.
2537 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2539 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2540 layout. It also supports a TextSeg= and DataSeg= response when only
2541 segment base addresses (rather than offsets) are available.
2543 * The /i format now outputs any trailing branch delay slot instructions
2544 immediately following the last instruction within the count specified.
2546 * The GDB remote protocol "T" stop reply packet now supports a
2547 "library" response. Combined with the new "qXfer:libraries:read"
2548 packet, this response allows GDB to debug shared libraries on targets
2549 where the operating system manages the list of loaded libraries (e.g.
2550 Windows and SymbianOS).
2552 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2553 (DLLs) on Windows and Windows CE targets.
2555 * GDB now supports a faster verification that a .debug file matches its binary
2556 according to its build-id signature, if the signature is present.
2562 Enable or disable hardware flow control (RTS/CTS) on the serial port
2563 when debugging using remote targets.
2565 set mem inaccessible-by-default
2566 show mem inaccessible-by-default
2567 If the target supplies a memory map, for instance via the remote
2568 protocol's "qXfer:memory-map:read" packet, setting this variable
2569 prevents GDB from accessing memory outside the memory map. This
2570 is useful for targets with memory mapped registers or which react
2571 badly to accesses of unmapped address space.
2573 set breakpoint auto-hw
2574 show breakpoint auto-hw
2575 If the target supplies a memory map, for instance via the remote
2576 protocol's "qXfer:memory-map:read" packet, setting this variable
2577 lets GDB use hardware breakpoints automatically for memory regions
2578 where it can not use software breakpoints. This covers both the
2579 "break" command and internal breakpoints used for other commands
2580 including "next" and "finish".
2583 catch exception unhandled
2584 Stop the program execution when Ada exceptions are raised.
2587 Stop the program execution when an Ada assertion failed.
2591 Set an alternate system root for target files. This is a more
2592 general version of "set solib-absolute-prefix", which is now
2593 an alias to "set sysroot".
2596 Provide extended SPU facility status information. This set of
2597 commands is available only when debugging the Cell/B.E. SPU
2600 * New native configurations
2602 OpenBSD/sh sh*-*openbsd*
2605 unset tdesc filename
2607 Use the specified local file as an XML target description, and do
2608 not query the target for its built-in description.
2612 OpenBSD/sh sh*-*-openbsd*
2613 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2614 Toshiba Media Processor mep-elf
2616 * New remote packets
2619 Ignore the specified signals; pass them directly to the debugged program
2620 without stopping other threads or reporting them to GDB.
2622 qXfer:features:read:
2623 Read an XML target description from the target, which describes its
2628 Read or write contents of an spufs file on the target system. These
2629 packets are available only on the Cell/B.E. SPU architecture.
2631 qXfer:libraries:read:
2632 Report the loaded shared libraries. Combined with new "T" packet
2633 response, this packet allows GDB to debug shared libraries on
2634 targets where the operating system manages the list of loaded
2635 libraries (e.g. Windows and SymbianOS).
2639 Support for these obsolete configurations has been removed.
2647 i[34567]86-*-lynxos*
2648 i[34567]86-*-netware*
2649 i[34567]86-*-sco3.2v5*
2650 i[34567]86-*-sco3.2v4*
2652 i[34567]86-*-sysv4.2*
2655 i[34567]86-*-unixware2*
2656 i[34567]86-*-unixware*
2665 * Other removed features
2672 Various m68k-only ROM monitors.
2679 Various Renesas ROM monitors and debugging interfaces for SH and
2684 Support for a Macraigor serial interface to on-chip debugging.
2685 GDB does not directly support the newer parallel or USB
2690 A debug information format. The predecessor to DWARF 2 and
2691 DWARF 3, which are still supported.
2693 Support for the HP aCC compiler on HP-UX/PA-RISC
2695 SOM-encapsulated symbolic debugging information, automatic
2696 invocation of pxdb, and the aCC custom C++ ABI. This does not
2697 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2698 with aCC can still be debugged on an assembly level.
2700 MIPS ".pdr" sections
2702 A MIPS-specific format used to describe stack frame layout
2703 in debugging information.
2707 GDB could work with an older version of Guile to debug
2708 the interpreter and Scheme programs running in it.
2710 set mips stack-arg-size
2711 set mips saved-gpreg-size
2713 Use "set mips abi" to control parameter passing for MIPS.
2715 *** Changes in GDB 6.6
2720 Cell Broadband Engine SPU spu-elf
2722 * GDB can now be configured as a cross-debugger targeting native Windows
2723 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2724 running on a Windows system over TCP/IP to debug Windows programs.
2726 * The GDB remote stub, gdbserver, has been updated to support Windows and
2727 Cygwin debugging. Both single-threaded and multi-threaded programs are
2730 * The "set trust-readonly-sections" command works again. This command was
2731 broken in GDB 6.3, 6.4, and 6.5.
2733 * The "load" command now supports writing to flash memory, if the remote
2734 stub provides the required support.
2736 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2737 longer requires symbolic debug information (e.g. DWARF-2).
2742 unset substitute-path
2743 show substitute-path
2744 Manage a list of substitution rules that GDB uses to rewrite the name
2745 of the directories where the sources are located. This can be useful
2746 for instance when the sources were moved to a different location
2747 between compilation and debugging.
2751 Print each CLI command as it is executed. Each command is prefixed with
2752 a number of `+' symbols representing the nesting depth.
2753 The source command now has a `-v' option to enable the same feature.
2757 The ARM Demon monitor support (RDP protocol, "target rdp").
2759 Kernel Object Display, an embedded debugging feature which only worked with
2760 an obsolete version of Cisco IOS.
2762 The 'set download-write-size' and 'show download-write-size' commands.
2764 * New remote packets
2767 Tell a stub about GDB client features, and request remote target features.
2768 The first feature implemented is PacketSize, which allows the target to
2769 specify the size of packets it can handle - to minimize the number of
2770 packets required and improve performance when connected to a remote
2774 Fetch an OS auxilliary vector from the remote stub. This packet is a
2775 more efficient replacement for qPart:auxv:read.
2777 qXfer:memory-map:read:
2778 Fetch a memory map from the remote stub, including information about
2779 RAM, ROM, and flash memory devices.
2784 Erase and program a flash memory device.
2786 * Removed remote packets
2789 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2790 used it, and only gdbserver implemented it.
2792 *** Changes in GDB 6.5
2796 Renesas M32C/M16C m32c-elf
2798 Morpho Technologies ms1 ms1-elf
2802 init-if-undefined Initialize a convenience variable, but
2803 only if it doesn't already have a value.
2805 The following commands are presently only implemented for native GNU/Linux:
2807 checkpoint Save a snapshot of the program state.
2809 restart <n> Return the program state to a
2810 previously saved state.
2812 info checkpoints List currently saved checkpoints.
2814 delete-checkpoint <n> Delete a previously saved checkpoint.
2816 set|show detach-on-fork Tell gdb whether to detach from a newly
2817 forked process, or to keep debugging it.
2819 info forks List forks of the user program that
2820 are available to be debugged.
2822 fork <n> Switch to debugging one of several
2823 forks of the user program that are
2824 available to be debugged.
2826 delete-fork <n> Delete a fork from the list of forks
2827 that are available to be debugged (and
2828 kill the forked process).
2830 detach-fork <n> Delete a fork from the list of forks
2831 that are available to be debugged (and
2832 allow the process to continue).
2836 Morpho Technologies ms2 ms1-elf
2838 * Improved Windows host support
2840 GDB now builds as a cross debugger hosted on i686-mingw32, including
2841 native console support, and remote communications using either
2842 network sockets or serial ports.
2844 * Improved Modula-2 language support
2846 GDB can now print most types in the Modula-2 syntax. This includes:
2847 basic types, set types, record types, enumerated types, range types,
2848 pointer types and ARRAY types. Procedure var parameters are correctly
2849 printed and hexadecimal addresses and character constants are also
2850 written in the Modula-2 syntax. Best results can be obtained by using
2851 GNU Modula-2 together with the -gdwarf-2 command line option.
2855 The ARM rdi-share module.
2857 The Netware NLM debug server.
2859 *** Changes in GDB 6.4
2861 * New native configurations
2863 OpenBSD/arm arm*-*-openbsd*
2864 OpenBSD/mips64 mips64-*-openbsd*
2868 Morpho Technologies ms1 ms1-elf
2870 * New command line options
2872 --batch-silent As for --batch, but totally silent.
2873 --return-child-result The debugger will exist with the same value
2874 the child (debugged) program exited with.
2875 --eval-command COMMAND, -ex COMMAND
2876 Execute a single GDB CLI command. This may be
2877 specified multiple times and in conjunction
2878 with the --command (-x) option.
2880 * Deprecated commands removed
2882 The following commands, that were deprecated in 2000, have been
2886 set|show arm disassembly-flavor set|show arm disassembler
2887 othernames set arm disassembler
2888 set|show remotedebug set|show debug remote
2889 set|show archdebug set|show debug arch
2890 set|show eventdebug set|show debug event
2893 * New BSD user-level threads support
2895 It is now possible to debug programs using the user-level threads
2896 library on OpenBSD and FreeBSD. Currently supported (target)
2899 FreeBSD/amd64 x86_64-*-freebsd*
2900 FreeBSD/i386 i386-*-freebsd*
2901 OpenBSD/i386 i386-*-openbsd*
2903 Note that the new kernel threads libraries introduced in FreeBSD 5.x
2904 are not yet supported.
2906 * New support for Matsushita MN10300 w/sim added
2907 (Work in progress). mn10300-elf.
2909 * REMOVED configurations and files
2911 VxWorks and the XDR protocol *-*-vxworks
2912 Motorola MCORE mcore-*-*
2913 National Semiconductor NS32000 ns32k-*-*
2915 * New "set print array-indexes" command
2917 After turning this setting "on", GDB prints the index of each element
2918 when displaying arrays. The default is "off" to preserve the previous
2921 * VAX floating point support
2923 GDB now supports the not-quite-ieee VAX F and D floating point formats.
2925 * User-defined command support
2927 In addition to using $arg0..$arg9 for argument passing, it is now possible
2928 to use $argc to determine now many arguments have been passed. See the
2929 section on user-defined commands in the user manual for more information.
2931 *** Changes in GDB 6.3:
2933 * New command line option
2935 GDB now accepts -l followed by a number to set the timeout for remote
2938 * GDB works with GCC -feliminate-dwarf2-dups
2940 GDB now supports a more compact representation of DWARF-2 debug
2941 information using DW_FORM_ref_addr references. These are produced
2942 by GCC with the option -feliminate-dwarf2-dups and also by some
2943 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
2944 to use -feliminate-dwarf2-dups.
2946 * Internationalization
2948 When supported by the host system, GDB will be built with
2949 internationalization (libintl). The task of marking up the sources is
2950 continued, we're looking forward to our first translation.
2954 Initial support for debugging programs compiled with the GNAT
2955 implementation of the Ada programming language has been integrated
2956 into GDB. In this release, support is limited to expression evaluation.
2958 * New native configurations
2960 GNU/Linux/m32r m32r-*-linux-gnu
2964 GDB's remote protocol now includes support for the 'p' packet. This
2965 packet is used to fetch individual registers from a remote inferior.
2967 * END-OF-LIFE registers[] compatibility module
2969 GDB's internal register infrastructure has been completely rewritten.
2970 The new infrastructure making possible the implementation of key new
2971 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
2974 GDB 6.3 will be the last release to include the the registers[]
2975 compatibility module that allowed out-of-date configurations to
2976 continue to work. This change directly impacts the following
2986 powerpc bdm protocol
2988 Unless there is activity to revive these configurations, they will be
2989 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
2991 * OBSOLETE configurations and files
2993 Configurations that have been declared obsolete in this release have
2994 been commented out. Unless there is activity to revive these
2995 configurations, the next release of GDB will have their sources
2996 permanently REMOVED.
3005 *** Changes in GDB 6.2.1:
3007 * MIPS `break main; run' gave an heuristic-fence-post warning
3009 When attempting to run even a simple program, a warning about
3010 heuristic-fence-post being hit would be reported. This problem has
3013 * MIPS IRIX 'long double' crashed GDB
3015 When examining a long double variable, GDB would get a segmentation
3016 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3017 IRIX long double values).
3021 A bug in the VAX stack code was causing problems with the "next"
3022 command. This problem has been fixed.
3024 *** Changes in GDB 6.2:
3026 * Fix for ``many threads''
3028 On GNU/Linux systems that use the NPTL threads library, a program
3029 rapidly creating and deleting threads would confuse GDB leading to the
3032 ptrace: No such process.
3033 thread_db_get_info: cannot get thread info: generic error
3035 This problem has been fixed.
3037 * "-async" and "-noasync" options removed.
3039 Support for the broken "-noasync" option has been removed (it caused
3042 * New ``start'' command.
3044 This command runs the program until the begining of the main procedure.
3046 * New BSD Kernel Data Access Library (libkvm) interface
3048 Using ``target kvm'' it is now possible to debug kernel core dumps and
3049 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3050 platforms. Currently supported (native-only) configurations are:
3052 FreeBSD/amd64 x86_64-*-freebsd*
3053 FreeBSD/i386 i?86-*-freebsd*
3054 NetBSD/i386 i?86-*-netbsd*
3055 NetBSD/m68k m68*-*-netbsd*
3056 NetBSD/sparc sparc-*-netbsd*
3057 OpenBSD/amd64 x86_64-*-openbsd*
3058 OpenBSD/i386 i?86-*-openbsd*
3059 OpenBSD/m68k m68*-openbsd*
3060 OpenBSD/sparc sparc-*-openbsd*
3062 * Signal trampoline code overhauled
3064 Many generic problems with GDB's signal handling code have been fixed.
3065 These include: backtraces through non-contiguous stacks; recognition
3066 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3067 call; backtrace through a signal trampoline; step into and out of
3068 signal handlers; and single-stepping in the signal trampoline.
3070 Please note that kernel bugs are a limiting factor here. These
3071 features have been shown to work on an s390 GNU/Linux system that
3072 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3074 * Cygwin support for DWARF 2 added.
3076 * New native configurations
3078 GNU/Linux/hppa hppa*-*-linux*
3079 OpenBSD/hppa hppa*-*-openbsd*
3080 OpenBSD/m68k m68*-*-openbsd*
3081 OpenBSD/m88k m88*-*-openbsd*
3082 OpenBSD/powerpc powerpc-*-openbsd*
3083 NetBSD/vax vax-*-netbsd*
3084 OpenBSD/vax vax-*-openbsd*
3086 * END-OF-LIFE frame compatibility module
3088 GDB's internal frame infrastructure has been completely rewritten.
3089 The new infrastructure making it possible to support key new features
3090 including DWARF 2 Call Frame Information. To aid in the task of
3091 migrating old configurations to this new infrastructure, a
3092 compatibility module, that allowed old configurations to continue to
3093 work, was also included.
3095 GDB 6.2 will be the last release to include this frame compatibility
3096 module. This change directly impacts the following configurations:
3106 Unless there is activity to revive these configurations, they will be
3107 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3109 * REMOVED configurations and files
3111 Sun 3, running SunOS 3 m68*-*-sunos3*
3112 Sun 3, running SunOS 4 m68*-*-sunos4*
3113 Sun 2, running SunOS 3 m68000-*-sunos3*
3114 Sun 2, running SunOS 4 m68000-*-sunos4*
3115 Motorola 680x0 running LynxOS m68*-*-lynxos*
3116 AT&T 3b1/Unix pc m68*-att-*
3117 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3118 decstation mips-dec-* mips-little-*
3119 riscos mips-*-riscos* mips-*-sysv*
3120 sonymips mips-sony-*
3121 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3123 *** Changes in GDB 6.1.1:
3125 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3127 The TUI (Text-mode User Interface) is now built as part of a default
3128 GDB configuration. It is enabled by either selecting the TUI with the
3129 command line option "-i=tui" or by running the separate "gdbtui"
3130 program. For more information on the TUI, see the manual "Debugging
3133 * Pending breakpoint support (also included in GDB 6.1)
3135 Support has been added to allow you to specify breakpoints in shared
3136 libraries that have not yet been loaded. If a breakpoint location
3137 cannot be found, and the "breakpoint pending" option is set to auto,
3138 GDB queries you if you wish to make the breakpoint pending on a future
3139 shared-library load. If and when GDB resolves the breakpoint symbol,
3140 the pending breakpoint is removed as one or more regular breakpoints
3143 Pending breakpoints are very useful for GCJ Java debugging.
3145 * Fixed ISO-C build problems
3147 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3148 non ISO-C code that stopped them being built using a more strict ISO-C
3149 compiler (e.g., IBM's C compiler).
3151 * Fixed build problem on IRIX 5
3153 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3154 wasn't able to compile compile on an IRIX 5 system.
3156 * Added execute permission to gdb/gdbserver/configure
3158 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3159 permission. This bug would cause configure to fail on a number of
3160 systems (Solaris, IRIX). Ref: server/519.
3162 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3164 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3165 has been updated to use constant array sizes.
3167 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3169 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3170 its generated DWARF Call Frame Info. This encoding was causing GDB to
3171 panic, that panic has been fixed. Ref: gdb/1628.
3173 * Fixed a problem when examining parameters in shared library code.
3175 When examining parameters in optimized shared library code generated
3176 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3177 not available''. GDB now correctly displays the variable's value.
3179 *** Changes in GDB 6.1:
3181 * Removed --with-mmalloc
3183 Support for the mmalloc memory manager has been removed, as it
3184 conflicted with the internal gdb byte cache.
3186 * Changes in AMD64 configurations
3188 The AMD64 target now includes the %cs and %ss registers. As a result
3189 the AMD64 remote protocol has changed; this affects the floating-point
3190 and SSE registers. If you rely on those registers for your debugging,
3191 you should upgrade gdbserver on the remote side.
3193 * Revised SPARC target
3195 The SPARC target has been completely revised, incorporating the
3196 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3197 support for LynxOS and SunOS 4 has been dropped. Calling functions
3198 from within GDB on operating systems with a non-executable stack
3199 (Solaris, OpenBSD) now works.
3203 GDB has a new C++ demangler which does a better job on the mangled
3204 names generated by current versions of g++. It also runs faster, so
3205 with this and other changes gdb should now start faster on large C++
3208 * DWARF 2 Location Expressions
3210 GDB support for location expressions has been extended to support function
3211 arguments and frame bases. Older versions of GDB could crash when they
3214 * C++ nested types and namespaces
3216 GDB's support for nested types and namespaces in C++ has been
3217 improved, especially if you use the DWARF 2 debugging format. (This
3218 is the default for recent versions of GCC on most platforms.)
3219 Specifically, if you have a class "Inner" defined within a class or
3220 namespace "Outer", then GDB realizes that the class's name is
3221 "Outer::Inner", not simply "Inner". This should greatly reduce the
3222 frequency of complaints about not finding RTTI symbols. In addition,
3223 if you are stopped at inside of a function defined within a namespace,
3224 GDB modifies its name lookup accordingly.
3226 * New native configurations
3228 NetBSD/amd64 x86_64-*-netbsd*
3229 OpenBSD/amd64 x86_64-*-openbsd*
3230 OpenBSD/alpha alpha*-*-openbsd*
3231 OpenBSD/sparc sparc-*-openbsd*
3232 OpenBSD/sparc64 sparc64-*-openbsd*
3234 * New debugging protocols
3236 M32R with SDI protocol m32r-*-elf*
3238 * "set prompt-escape-char" command deleted.
3240 The command "set prompt-escape-char" has been deleted. This command,
3241 and its very obscure effet on GDB's prompt, was never documented,
3242 tested, nor mentioned in the NEWS file.
3244 * OBSOLETE configurations and files
3246 Configurations that have been declared obsolete in this release have
3247 been commented out. Unless there is activity to revive these
3248 configurations, the next release of GDB will have their sources
3249 permanently REMOVED.
3251 Sun 3, running SunOS 3 m68*-*-sunos3*
3252 Sun 3, running SunOS 4 m68*-*-sunos4*
3253 Sun 2, running SunOS 3 m68000-*-sunos3*
3254 Sun 2, running SunOS 4 m68000-*-sunos4*
3255 Motorola 680x0 running LynxOS m68*-*-lynxos*
3256 AT&T 3b1/Unix pc m68*-att-*
3257 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3258 decstation mips-dec-* mips-little-*
3259 riscos mips-*-riscos* mips-*-sysv*
3260 sonymips mips-sony-*
3261 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3263 * REMOVED configurations and files
3265 SGI Irix-4.x mips-sgi-irix4 or iris4
3266 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3267 Z8000 simulator z8k-zilog-none or z8ksim
3268 Matsushita MN10200 w/simulator mn10200-*-*
3269 H8/500 simulator h8500-hitachi-hms or h8500hms
3270 HP/PA running BSD hppa*-*-bsd*
3271 HP/PA running OSF/1 hppa*-*-osf*
3272 HP/PA Pro target hppa*-*-pro*
3273 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3274 386BSD i[3456]86-*-bsd*
3275 Sequent family i[3456]86-sequent-sysv4*
3276 i[3456]86-sequent-sysv*
3277 i[3456]86-sequent-bsd*
3278 SPARC running LynxOS sparc-*-lynxos*
3279 SPARC running SunOS 4 sparc-*-sunos4*
3280 Tsqware Sparclet sparclet-*-*
3281 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3283 *** Changes in GDB 6.0:
3287 Support for debugging the Objective-C programming language has been
3288 integrated into GDB.
3290 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3292 DWARF 2's Call Frame Information makes available compiler generated
3293 information that more exactly describes the program's run-time stack.
3294 By using this information, GDB is able to provide more robust stack
3297 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3298 have been updated to use a new backtrace mechanism which includes
3299 DWARF 2 CFI support.
3303 GDB's remote protocol has been extended to include support for hosted
3304 file I/O (where the remote target uses GDB's file system). See GDB's
3305 remote protocol documentation for details.
3307 * All targets using the new architecture framework.
3309 All of GDB's targets have been updated to use the new internal
3310 architecture framework. The way is now open for future GDB releases
3311 to include cross-architecture native debugging support (i386 on amd64,
3314 * GNU/Linux's Thread Local Storage (TLS)
3316 GDB now includes support for for the GNU/Linux implementation of
3317 per-thread variables.
3319 * GNU/Linux's Native POSIX Thread Library (NPTL)
3321 GDB's thread code has been updated to work with either the new
3322 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3324 * Separate debug info.
3326 GDB, in conjunction with BINUTILS, now supports a mechanism for
3327 automatically loading debug information from a separate file. Instead
3328 of shipping full debug and non-debug versions of system libraries,
3329 system integrators can now instead ship just the stripped libraries
3330 and optional debug files.
3332 * DWARF 2 Location Expressions
3334 DWARF 2 Location Expressions allow the compiler to more completely
3335 describe the location of variables (even in optimized code) to the
3338 GDB now includes preliminary support for location expressions (support
3339 for DW_OP_piece is still missing).
3343 A number of long standing bugs that caused GDB to die while starting a
3344 Java application have been fixed. GDB's Java support is now
3345 considered "useable".
3347 * GNU/Linux support for fork, vfork, and exec.
3349 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3350 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3353 * GDB supports logging output to a file
3355 There are two new commands, "set logging" and "show logging", which can be
3356 used to capture GDB's output to a file.
3358 * The meaning of "detach" has changed for gdbserver
3360 The "detach" command will now resume the application, as documented. To
3361 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3364 * d10v, m68hc11 `regs' command deprecated
3366 The `info registers' command has been updated so that it displays the
3367 registers using a format identical to the old `regs' command.
3371 A new command, "maint set profile on/off", has been added. This command can
3372 be used to enable or disable profiling while running GDB, to profile a
3373 session or a set of commands. In addition there is a new configure switch,
3374 "--enable-profiling", which will cause GDB to be compiled with profiling
3375 data, for more informative profiling results.
3377 * Default MI syntax changed to "mi2".
3379 The default MI (machine interface) syntax, enabled by the command line
3380 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3381 "mi1", can be enabled by specifying the option "-i=mi1".
3383 Support for the original "mi0" syntax (included in GDB 5.0) has been
3386 Fix for gdb/192: removed extraneous space when displaying frame level.
3387 Fix for gdb/672: update changelist is now output in mi list format.
3388 Fix for gdb/702: a -var-assign that updates the value now shows up
3389 in a subsequent -var-update.
3391 * New native configurations.
3393 FreeBSD/amd64 x86_64-*-freebsd*
3395 * Multi-arched targets.
3397 HP/PA HPUX11 hppa*-*-hpux*
3398 Renesas M32R/D w/simulator m32r-*-elf*
3400 * OBSOLETE configurations and files
3402 Configurations that have been declared obsolete in this release have
3403 been commented out. Unless there is activity to revive these
3404 configurations, the next release of GDB will have their sources
3405 permanently REMOVED.
3407 Z8000 simulator z8k-zilog-none or z8ksim
3408 Matsushita MN10200 w/simulator mn10200-*-*
3409 H8/500 simulator h8500-hitachi-hms or h8500hms
3410 HP/PA running BSD hppa*-*-bsd*
3411 HP/PA running OSF/1 hppa*-*-osf*
3412 HP/PA Pro target hppa*-*-pro*
3413 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3414 Sequent family i[3456]86-sequent-sysv4*
3415 i[3456]86-sequent-sysv*
3416 i[3456]86-sequent-bsd*
3417 Tsqware Sparclet sparclet-*-*
3418 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3420 * REMOVED configurations and files
3423 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3424 IBM AIX PS/2 i[3456]86-*-aix
3425 i386 running Mach 3.0 i[3456]86-*-mach3*
3426 i386 running Mach i[3456]86-*-mach*
3427 i386 running OSF/1 i[3456]86-*osf1mk*
3428 HP/Apollo 68k Family m68*-apollo*-sysv*,
3430 m68*-hp-bsd*, m68*-hp-hpux*
3431 Argonaut Risc Chip (ARC) arc-*-*
3432 Mitsubishi D30V d30v-*-*
3433 Fujitsu FR30 fr30-*-elf*
3434 OS/9000 i[34]86-*-os9k
3435 I960 with MON960 i960-*-coff
3437 * MIPS $fp behavior changed
3439 The convenience variable $fp, for the MIPS, now consistently returns
3440 the address of the current frame's base. Previously, depending on the
3441 context, $fp could refer to either $sp or the current frame's base
3442 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3443 The GNU Source-Level Debugger''.
3445 *** Changes in GDB 5.3:
3447 * GNU/Linux shared library multi-threaded performance improved.
3449 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3450 `/proc', in preference to `ptrace' for memory reads. This may result
3451 in an improvement in the start-up time of multi-threaded, shared
3452 library applications when run under GDB. One GDB user writes: ``loads
3453 shared libs like mad''.
3455 * ``gdbserver'' now supports multi-threaded applications on some targets
3457 Support for debugging multi-threaded applications which use
3458 the GNU/Linux LinuxThreads package has been added for
3459 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3460 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3462 * GDB now supports C/C++ preprocessor macros.
3464 GDB now expands preprocessor macro invocations in C/C++ expressions,
3465 and provides various commands for showing macro definitions and how
3468 The new command `macro expand EXPRESSION' expands any macro
3469 invocations in expression, and shows the result.
3471 The new command `show macro MACRO-NAME' shows the definition of the
3472 macro named MACRO-NAME, and where it was defined.
3474 Most compilers don't include information about macros in the debugging
3475 information by default. In GCC 3.1, for example, you need to compile
3476 your program with the options `-gdwarf-2 -g3'. If the macro
3477 information is present in the executable, GDB will read it.
3479 * Multi-arched targets.
3481 DEC Alpha (partial) alpha*-*-*
3482 DEC VAX (partial) vax-*-*
3484 National Semiconductor NS32000 (partial) ns32k-*-*
3485 Motorola 68000 (partial) m68k-*-*
3486 Motorola MCORE mcore-*-*
3490 Fujitsu FRV architecture added by Red Hat frv*-*-*
3493 * New native configurations
3495 Alpha NetBSD alpha*-*-netbsd*
3496 SH NetBSD sh*-*-netbsdelf*
3497 MIPS NetBSD mips*-*-netbsd*
3498 UltraSPARC NetBSD sparc64-*-netbsd*
3500 * OBSOLETE configurations and files
3502 Configurations that have been declared obsolete in this release have
3503 been commented out. Unless there is activity to revive these
3504 configurations, the next release of GDB will have their sources
3505 permanently REMOVED.
3507 Mitsubishi D30V d30v-*-*
3508 OS/9000 i[34]86-*-os9k
3509 IBM AIX PS/2 i[3456]86-*-aix
3510 Fujitsu FR30 fr30-*-elf*
3511 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3512 Argonaut Risc Chip (ARC) arc-*-*
3513 i386 running Mach 3.0 i[3456]86-*-mach3*
3514 i386 running Mach i[3456]86-*-mach*
3515 i386 running OSF/1 i[3456]86-*osf1mk*
3516 HP/Apollo 68k Family m68*-apollo*-sysv*,
3518 m68*-hp-bsd*, m68*-hp-hpux*
3519 I960 with MON960 i960-*-coff
3521 * OBSOLETE languages
3523 CHILL, a Pascal like language used by telecommunications companies.
3525 * REMOVED configurations and files
3527 AMD 29k family via UDI a29k-amd-udi, udi29k
3528 A29K VxWorks a29k-*-vxworks
3529 AMD 29000 embedded, using EBMON a29k-none-none
3530 AMD 29000 embedded with COFF a29k-none-coff
3531 AMD 29000 embedded with a.out a29k-none-aout
3533 testsuite/gdb.hp/gdb.threads-hp/ directory
3535 * New command "set max-user-call-depth <nnn>"
3537 This command allows the user to limit the call depth of user-defined
3538 commands. The default is 1024.
3540 * Changes in FreeBSD/i386 native debugging.
3542 Support for the "generate-core-file" has been added.
3544 * New commands "dump", "append", and "restore".
3546 These commands allow data to be copied from target memory
3547 to a bfd-format or binary file (dump and append), and back
3548 from a file into memory (restore).
3550 * Improved "next/step" support on multi-processor Alpha Tru64.
3552 The previous single-step mechanism could cause unpredictable problems,
3553 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3554 of a software single-step mechanism prevents this.
3556 *** Changes in GDB 5.2.1:
3564 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3565 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3566 Fix, by Joel Brobecker imported from mainline.
3568 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3569 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3570 Fix, by Fred Fish, imported from mainline.
3572 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3573 Surprisingly enough, it works now.
3574 By Michal Ludvig, imported from mainline.
3576 i386 hardware watchpoint support:
3577 avoid misses on second run for some targets.
3578 By Pierre Muller, imported from mainline.
3580 *** Changes in GDB 5.2:
3582 * New command "set trust-readonly-sections on[off]".
3584 This command is a hint that tells gdb that read-only sections
3585 really are read-only (ie. that their contents will not change).
3586 In this mode, gdb will go to the object file rather than the
3587 target to read memory from read-only sections (such as ".text").
3588 This can be a significant performance improvement on some
3589 (notably embedded) targets.
3591 * New command "generate-core-file" (or "gcore").
3593 This new gdb command allows the user to drop a core file of the child
3594 process state at any time. So far it's been implemented only for
3595 GNU/Linux and Solaris, but should be relatively easily ported to other
3596 hosts. Argument is core file name (defaults to core.<pid>).
3598 * New command line option
3600 GDB now accepts --pid or -p followed by a process id.
3602 * Change in command line behavior -- corefiles vs. process ids.
3604 There is a subtle behavior in the way in which GDB handles
3605 command line arguments. The first non-flag argument is always
3606 a program to debug, but the second non-flag argument may either
3607 be a corefile or a process id. Previously, GDB would attempt to
3608 open the second argument as a corefile, and if that failed, would
3609 issue a superfluous error message and then attempt to attach it as
3610 a process. Now, if the second argument begins with a non-digit,
3611 it will be treated as a corefile. If it begins with a digit,
3612 GDB will attempt to attach it as a process, and if no such process
3613 is found, will then attempt to open it as a corefile.
3615 * Changes in ARM configurations.
3617 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3618 configuration is fully multi-arch.
3620 * New native configurations
3622 ARM NetBSD arm*-*-netbsd*
3623 x86 OpenBSD i[3456]86-*-openbsd*
3624 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3625 Sparc64 running FreeBSD sparc64-*-freebsd*
3629 Sanyo XStormy16 xstormy16-elf
3631 * OBSOLETE configurations and files
3633 Configurations that have been declared obsolete in this release have
3634 been commented out. Unless there is activity to revive these
3635 configurations, the next release of GDB will have their sources
3636 permanently REMOVED.
3638 AMD 29k family via UDI a29k-amd-udi, udi29k
3639 A29K VxWorks a29k-*-vxworks
3640 AMD 29000 embedded, using EBMON a29k-none-none
3641 AMD 29000 embedded with COFF a29k-none-coff
3642 AMD 29000 embedded with a.out a29k-none-aout
3644 testsuite/gdb.hp/gdb.threads-hp/ directory
3646 * REMOVED configurations and files
3648 TI TMS320C80 tic80-*-*
3650 PowerPC Solaris powerpcle-*-solaris*
3651 PowerPC Windows NT powerpcle-*-cygwin32
3652 PowerPC Netware powerpc-*-netware*
3653 Harris/CXUX m88k m88*-harris-cxux*
3654 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3655 ns32k-utek-sysv* ns32k-utek-*
3656 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3657 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3658 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3659 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3660 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3662 * Changes to command line processing
3664 The new `--args' feature can be used to specify command-line arguments
3665 for the inferior from gdb's command line.
3667 * Changes to key bindings
3669 There is a new `operate-and-get-next' function bound to `C-o'.
3671 *** Changes in GDB 5.1.1
3673 Fix compile problem on DJGPP.
3675 Fix a problem with floating-point registers on the i386 being
3678 Fix to stop GDB crashing on .debug_str debug info.
3680 Numerous documentation fixes.
3682 Numerous testsuite fixes.
3684 *** Changes in GDB 5.1:
3686 * New native configurations
3688 Alpha FreeBSD alpha*-*-freebsd*
3689 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3690 MIPS GNU/Linux mips*-*-linux*
3691 MIPS SGI Irix 6.x mips*-sgi-irix6*
3692 ia64 AIX ia64-*-aix*
3693 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3697 Motorola 68HC11 and 68HC12 m68hc11-elf
3699 UltraSparc running GNU/Linux sparc64-*-linux*
3701 * OBSOLETE configurations and files
3703 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3704 Harris/CXUX m88k m88*-harris-cxux*
3705 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3706 ns32k-utek-sysv* ns32k-utek-*
3707 TI TMS320C80 tic80-*-*
3709 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3710 PowerPC Solaris powerpcle-*-solaris*
3711 PowerPC Windows NT powerpcle-*-cygwin32
3712 PowerPC Netware powerpc-*-netware*
3713 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3714 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3715 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3716 Apple Macintosh (MPW) host N/A
3718 stuff.c (Program to stuff files into a specially prepared space in kdb)
3719 kdb-start.c (Main loop for the standalone kernel debugger)
3721 Configurations that have been declared obsolete in this release have
3722 been commented out. Unless there is activity to revive these
3723 configurations, the next release of GDB will have their sources
3724 permanently REMOVED.
3726 * REMOVED configurations and files
3728 Altos 3068 m68*-altos-*
3729 Convex c1-*-*, c2-*-*
3731 ARM RISCix arm-*-* (as host)
3735 * GDB has been converted to ISO C.
3737 GDB's source code has been converted to ISO C. In particular, the
3738 sources are fully protoized, and rely on standard headers being
3743 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3745 * The MI enabled by default.
3747 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3748 revised and enabled by default. Packages which use GDB as a debugging
3749 engine behind a UI or another front end are encouraged to switch to
3750 using the GDB/MI interface, instead of the old annotations interface
3751 which is now deprecated.
3753 * Support for debugging Pascal programs.
3755 GDB now includes support for debugging Pascal programs. The following
3756 main features are supported:
3758 - Pascal-specific data types such as sets;
3760 - automatic recognition of Pascal sources based on file-name
3763 - Pascal-style display of data types, variables, and functions;
3765 - a Pascal expression parser.
3767 However, some important features are not yet supported.
3769 - Pascal string operations are not supported at all;
3771 - there are some problems with boolean types;
3773 - Pascal type hexadecimal constants are not supported
3774 because they conflict with the internal variables format;
3776 - support for Pascal objects and classes is not full yet;
3778 - unlike Pascal, GDB is case-sensitive for symbol names.
3780 * Changes in completion.
3782 Commands such as `shell', `run' and `set args', which pass arguments
3783 to inferior programs, now complete on file names, similar to what
3784 users expect at the shell prompt.
3786 Commands which accept locations, such as `disassemble', `print',
3787 `breakpoint', `until', etc. now complete on filenames as well as
3788 program symbols. Thus, if you type "break foob TAB", and the source
3789 files linked into the programs include `foobar.c', that file name will
3790 be one of the candidates for completion. However, file names are not
3791 considered for completion after you typed a colon that delimits a file
3792 name from a name of a function in that file, as in "break foo.c:bar".
3794 `set demangle-style' completes on available demangling styles.
3796 * New platform-independent commands:
3798 It is now possible to define a post-hook for a command as well as a
3799 hook that runs before the command. For more details, see the
3800 documentation of `hookpost' in the GDB manual.
3802 * Changes in GNU/Linux native debugging.
3804 Support for debugging multi-threaded programs has been completely
3805 revised for all platforms except m68k and sparc. You can now debug as
3806 many threads as your system allows you to have.
3808 Attach/detach is supported for multi-threaded programs.
3810 Support for SSE registers was added for x86. This doesn't work for
3811 multi-threaded programs though.
3813 * Changes in MIPS configurations.
3815 Multi-arch support is enabled for all MIPS configurations.
3817 GDB can now be built as native debugger on SGI Irix 6.x systems for
3818 debugging n32 executables. (Debugging 64-bit executables is not yet
3821 * Unified support for hardware watchpoints in all x86 configurations.
3823 Most (if not all) native x86 configurations support hardware-assisted
3824 breakpoints and watchpoints in a unified manner. This support
3825 implements debug register sharing between watchpoints, which allows to
3826 put a virtually infinite number of watchpoints on the same address,
3827 and also supports watching regions up to 16 bytes with several debug
3830 The new maintenance command `maintenance show-debug-regs' toggles
3831 debugging print-outs in functions that insert, remove, and test
3832 watchpoints and hardware breakpoints.
3834 * Changes in the DJGPP native configuration.
3836 New command ``info dos sysinfo'' displays assorted information about
3837 the CPU, OS, memory, and DPMI server.
3839 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3840 display information about segment descriptors stored in GDT, LDT, and
3843 New commands ``info dos pde'' and ``info dos pte'' display entries
3844 from Page Directory and Page Tables (for now works with CWSDPMI only).
3845 New command ``info dos address-pte'' displays the Page Table entry for
3846 a given linear address.
3848 GDB can now pass command lines longer than 126 characters to the
3849 program being debugged (requires an update to the libdbg.a library
3850 which is part of the DJGPP development kit).
3852 DWARF2 debug info is now supported.
3854 It is now possible to `step' and `next' through calls to `longjmp'.
3856 * Changes in documentation.
3858 All GDB documentation was converted to GFDL, the GNU Free
3859 Documentation License.
3861 Tracepoints-related commands are now fully documented in the GDB
3864 TUI, the Text-mode User Interface, is now documented in the manual.
3866 Tracepoints-related commands are now fully documented in the GDB
3869 The "GDB Internals" manual now has an index. It also includes
3870 documentation of `ui_out' functions, GDB coding standards, x86
3871 hardware watchpoints, and memory region attributes.
3873 * GDB's version number moved to ``version.in''
3875 The Makefile variable VERSION has been replaced by the file
3876 ``version.in''. People creating GDB distributions should update the
3877 contents of this file.
3881 GUD support is now a standard part of the EMACS distribution.
3883 *** Changes in GDB 5.0:
3885 * Improved support for debugging FP programs on x86 targets
3887 Unified and much-improved support for debugging floating-point
3888 programs on all x86 targets. In particular, ``info float'' now
3889 displays the FP registers in the same format on all x86 targets, with
3890 greater level of detail.
3892 * Improvements and bugfixes in hardware-assisted watchpoints
3894 It is now possible to watch array elements, struct members, and
3895 bitfields with hardware-assisted watchpoints. Data-read watchpoints
3896 on x86 targets no longer erroneously trigger when the address is
3899 * Improvements in the native DJGPP version of GDB
3901 The distribution now includes all the scripts and auxiliary files
3902 necessary to build the native DJGPP version on MS-DOS/MS-Windows
3903 machines ``out of the box''.
3905 The DJGPP version can now debug programs that use signals. It is
3906 possible to catch signals that happened in the debuggee, deliver
3907 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
3908 would kill the program being debugged.) Programs that hook hardware
3909 interrupts (keyboard, timer, etc.) can also be debugged.
3911 It is now possible to debug DJGPP programs that redirect their
3912 standard handles or switch them to raw (as opposed to cooked) mode, or
3913 even close them. The command ``run < foo > bar'' works as expected,
3914 and ``info terminal'' reports useful information about the debuggee's
3915 terminal, including raw/cooked mode, redirection, etc.
3917 The DJGPP version now uses termios functions for console I/O, which
3918 enables debugging graphics programs. Interrupting GDB with Ctrl-C
3921 DOS-style file names with drive letters are now fully supported by
3924 It is now possible to debug DJGPP programs that switch their working
3925 directory. It is also possible to rerun the debuggee any number of
3926 times without restarting GDB; thus, you can use the same setup,
3927 breakpoints, etc. for many debugging sessions.
3929 * New native configurations
3931 ARM GNU/Linux arm*-*-linux*
3932 PowerPC GNU/Linux powerpc-*-linux*
3936 Motorola MCore mcore-*-*
3937 x86 VxWorks i[3456]86-*-vxworks*
3938 PowerPC VxWorks powerpc-*-vxworks*
3939 TI TMS320C80 tic80-*-*
3941 * OBSOLETE configurations
3943 Altos 3068 m68*-altos-*
3944 Convex c1-*-*, c2-*-*
3946 ARM RISCix arm-*-* (as host)
3949 Configurations that have been declared obsolete will be commented out,
3950 but the code will be left in place. If there is no activity to revive
3951 these configurations before the next release of GDB, the sources will
3952 be permanently REMOVED.
3954 * Gould support removed
3956 Support for the Gould PowerNode and NP1 has been removed.
3958 * New features for SVR4
3960 On SVR4 native platforms (such as Solaris), if you attach to a process
3961 without first loading a symbol file, GDB will now attempt to locate and
3962 load symbols from the running process's executable file.
3964 * Many C++ enhancements
3966 C++ support has been greatly improved. Overload resolution now works properly
3967 in almost all cases. RTTI support is on the way.
3969 * Remote targets can connect to a sub-program
3971 A popen(3) style serial-device has been added. This device starts a
3972 sub-process (such as a stand-alone simulator) and then communicates
3973 with that. The sub-program to run is specified using the syntax
3974 ``|<program> <args>'' vis:
3976 (gdb) set remotedebug 1
3977 (gdb) target extended-remote |mn10300-elf-sim program-args
3979 * MIPS 64 remote protocol
3981 A long standing bug in the mips64 remote protocol where by GDB
3982 expected certain 32 bit registers (ex SR) to be transfered as 32
3983 instead of 64 bits has been fixed.
3985 The command ``set remote-mips64-transfers-32bit-regs on'' has been
3986 added to provide backward compatibility with older versions of GDB.
3988 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
3990 The command ``set remotebinarydownload'' command has been replaced by
3991 ``set remote X-packet''. Other commands in ``set remote'' family
3992 include ``set remote P-packet''.
3994 * Breakpoint commands accept ranges.
3996 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
3997 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
3998 ``tracepoint passcount'' also accepts a range of tracepoints.
4000 * ``apropos'' command added.
4002 The ``apropos'' command searches through command names and
4003 documentation strings, printing out matches, making it much easier to
4004 try to find a command that does what you are looking for.
4008 A new machine oriented interface (MI) has been added to GDB. This
4009 interface is designed for debug environments running GDB as a separate
4010 process. This is part of the long term libGDB project. See the
4011 "GDB/MI" chapter of the GDB manual for further information. It can be
4012 enabled by configuring with:
4014 .../configure --enable-gdbmi
4016 *** Changes in GDB-4.18:
4018 * New native configurations
4020 HP-UX 10.20 hppa*-*-hpux10.20
4021 HP-UX 11.x hppa*-*-hpux11.0*
4022 M68K GNU/Linux m68*-*-linux*
4026 Fujitsu FR30 fr30-*-elf*
4027 Intel StrongARM strongarm-*-*
4028 Mitsubishi D30V d30v-*-*
4030 * OBSOLETE configurations
4032 Gould PowerNode, NP1 np1-*-*, pn-*-*
4034 Configurations that have been declared obsolete will be commented out,
4035 but the code will be left in place. If there is no activity to revive
4036 these configurations before the next release of GDB, the sources will
4037 be permanently REMOVED.
4041 As a compatibility experiment, GDB's source files buildsym.h and
4042 buildsym.c have been converted to pure standard C, no longer
4043 containing any K&R compatibility code. We believe that all systems in
4044 use today either come with a standard C compiler, or have a GCC port
4045 available. If this is not true, please report the affected
4046 configuration to bug-gdb@gnu.org immediately. See the README file for
4047 information about getting a standard C compiler if you don't have one
4052 GDB now uses readline 2.2.
4054 * set extension-language
4056 You can now control the mapping between filename extensions and source
4057 languages by using the `set extension-language' command. For instance,
4058 you can ask GDB to treat .c files as C++ by saying
4059 set extension-language .c c++
4060 The command `info extensions' lists all of the recognized extensions
4061 and their associated languages.
4063 * Setting processor type for PowerPC and RS/6000
4065 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4066 you can use the `set processor' command to specify what variant of the
4067 PowerPC family you are debugging. The command
4071 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4072 following PowerPC and RS6000 variants:
4074 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4075 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4077 403GC IBM PowerPC 403GC
4078 505 Motorola PowerPC 505
4079 860 Motorola PowerPC 860 or 850
4080 601 Motorola PowerPC 601
4081 602 Motorola PowerPC 602
4082 603 Motorola/IBM PowerPC 603 or 603e
4083 604 Motorola PowerPC 604 or 604e
4084 750 Motorola/IBM PowerPC 750 or 750
4086 At the moment, this command just tells GDB what to name the
4087 special-purpose processor registers. Since almost all the affected
4088 registers are inaccessible to user-level programs, this command is
4089 only useful for remote debugging in its present form.
4093 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4094 more extensive support for HP-UX. Added features include shared
4095 library support, kernel threads and hardware watchpoints for 11.00,
4096 support for HP's ANSI C and C++ compilers, and a compatibility mode
4097 for xdb and dbx commands.
4101 HP's donation includes the new concept of catchpoints, which is a
4102 generalization of the old catch command. On HP-UX, it is now possible
4103 to catch exec, fork, and vfork, as well as library loading.
4105 This means that the existing catch command has changed; its first
4106 argument now specifies the type of catch to be set up. See the
4107 output of "help catch" for a list of catchpoint types.
4109 * Debugging across forks
4111 On HP-UX, you can choose which process to debug when a fork() happens
4116 HP has donated a curses-based terminal user interface (TUI). To get
4117 it, build with --enable-tui. Although this can be enabled for any
4118 configuration, at present it only works for native HP debugging.
4120 * GDB remote protocol additions
4122 A new protocol packet 'X' that writes binary data is now available.
4123 Default behavior is to try 'X', then drop back to 'M' if the stub
4124 fails to respond. The settable variable `remotebinarydownload'
4125 allows explicit control over the use of 'X'.
4127 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4128 full 64-bit address. The command
4130 set remoteaddresssize 32
4132 can be used to revert to the old behaviour. For existing remote stubs
4133 the change should not be noticed, as the additional address information
4136 In order to assist in debugging stubs, you may use the maintenance
4137 command `packet' to send any text string to the stub. For instance,
4139 maint packet heythere
4141 sends the packet "$heythere#<checksum>". Note that it is very easy to
4142 disrupt a debugging session by sending the wrong packet at the wrong
4145 The compare-sections command allows you to compare section data on the
4146 target to what is in the executable file without uploading or
4147 downloading, by comparing CRC checksums.
4149 * Tracing can collect general expressions
4151 You may now collect general expressions at tracepoints. This requires
4152 further additions to the target-side stub; see tracepoint.c and
4153 doc/agentexpr.texi for further details.
4155 * mask-address variable for Mips
4157 For Mips targets, you may control the zeroing of the upper 32 bits of
4158 a 64-bit address by entering `set mask-address on'. This is mainly
4159 of interest to users of embedded R4xxx and R5xxx processors.
4161 * Higher serial baud rates
4163 GDB's serial code now allows you to specify baud rates 57600, 115200,
4164 230400, and 460800 baud. (Note that your host system may not be able
4165 to achieve all of these rates.)
4169 The i960 configuration now includes an initial implementation of a
4170 builtin simulator, contributed by Jim Wilson.
4173 *** Changes in GDB-4.17:
4175 * New native configurations
4177 Alpha GNU/Linux alpha*-*-linux*
4178 Unixware 2.x i[3456]86-unixware2*
4179 Irix 6.x mips*-sgi-irix6*
4180 PowerPC GNU/Linux powerpc-*-linux*
4181 PowerPC Solaris powerpcle-*-solaris*
4182 Sparc GNU/Linux sparc-*-linux*
4183 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4187 Argonaut Risc Chip (ARC) arc-*-*
4188 Hitachi H8/300S h8300*-*-*
4189 Matsushita MN10200 w/simulator mn10200-*-*
4190 Matsushita MN10300 w/simulator mn10300-*-*
4191 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4192 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4193 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4194 Mitsubishi D10V w/simulator d10v-*-*
4195 Mitsubishi M32R/D w/simulator m32r-*-elf*
4196 Tsqware Sparclet sparclet-*-*
4197 NEC V850 w/simulator v850-*-*
4199 * New debugging protocols
4201 ARM with RDI protocol arm*-*-*
4202 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4203 DDB and LSI variants of PMON protocol mips*-*-*
4204 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4205 PowerPC with SDS protocol powerpc{,le}-*-eabi
4206 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4210 All configurations can now understand and use the DWARF 2 debugging
4211 format. The choice is automatic, if the symbol file contains DWARF 2
4216 GDB now includes basic Java language support. This support is
4217 only useful with Java compilers that produce native machine code.
4219 * solib-absolute-prefix and solib-search-path
4221 For SunOS and SVR4 shared libraries, you may now set the prefix for
4222 loading absolute shared library symbol files, and the search path for
4223 locating non-absolute shared library symbol files.
4225 * Live range splitting
4227 GDB can now effectively debug code for which GCC has performed live
4228 range splitting as part of its optimization. See gdb/doc/LRS for
4229 more details on the expected format of the stabs information.
4233 GDB's support for the GNU Hurd, including thread debugging, has been
4234 updated to work with current versions of the Hurd.
4238 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4239 instruction set. ARM GDB automatically detects when Thumb
4240 instructions are in use, and adjusts disassembly and backtracing
4245 GDB's MIPS target configurations now handle the MIP16 16-bit
4250 GDB now includes support for overlays; if an executable has been
4251 linked such that multiple sections are based at the same address, GDB
4252 will decide which section to use for symbolic info. You can choose to
4253 control the decision manually, using overlay commands, or implement
4254 additional target-side support and use "overlay load-target" to bring
4255 in the overlay mapping. Do "help overlay" for more detail.
4259 The command "info symbol <address>" displays information about
4260 the symbol at the specified address.
4264 The standard remote protocol now includes an extension that allows
4265 asynchronous collection and display of trace data. This requires
4266 extensive support in the target-side debugging stub. Tracing mode
4267 includes a new interaction mode in GDB and new commands: see the
4268 file tracepoint.c for more details.
4272 Configurations for embedded MIPS now include a simulator contributed
4273 by Cygnus Solutions. The simulator supports the instruction sets
4274 of most MIPS variants.
4278 Sparc configurations may now include the ERC32 simulator contributed
4279 by the European Space Agency. The simulator is not built into
4280 Sparc targets by default; configure with --enable-sim to include it.
4284 For target configurations that may include multiple variants of a
4285 basic architecture (such as MIPS and SH), you may now set the
4286 architecture explicitly. "set arch" sets, "info arch" lists
4287 the possible architectures.
4289 *** Changes in GDB-4.16:
4291 * New native configurations
4293 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4294 M68K NetBSD m68k-*-netbsd*
4295 PowerPC AIX 4.x powerpc-*-aix*
4296 PowerPC MacOS powerpc-*-macos*
4297 PowerPC Windows NT powerpcle-*-cygwin32
4298 RS/6000 AIX 4.x rs6000-*-aix4*
4302 ARM with RDP protocol arm-*-*
4303 I960 with MON960 i960-*-coff
4304 MIPS VxWorks mips*-*-vxworks*
4305 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4306 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4308 Matra Sparclet sparclet-*-*
4312 The powerpc-eabi configuration now includes the PSIM simulator,
4313 contributed by Andrew Cagney, with assistance from Mike Meissner.
4314 PSIM is a very elaborate model of the PowerPC, including not only
4315 basic instruction set execution, but also details of execution unit
4316 performance and I/O hardware. See sim/ppc/README for more details.
4320 GDB now works with Solaris 2.5.
4322 * Windows 95/NT native
4324 GDB will now work as a native debugger on Windows 95 and Windows NT.
4325 To build it from source, you must use the "gnu-win32" environment,
4326 which uses a DLL to emulate enough of Unix to run the GNU tools.
4327 Further information, binaries, and sources are available at
4328 ftp.cygnus.com, under pub/gnu-win32.
4330 * dont-repeat command
4332 If a user-defined command includes the command `dont-repeat', then the
4333 command will not be repeated if the user just types return. This is
4334 useful if the command is time-consuming to run, so that accidental
4335 extra keystrokes don't run the same command many times.
4337 * Send break instead of ^C
4339 The standard remote protocol now includes an option to send a break
4340 rather than a ^C to the target in order to interrupt it. By default,
4341 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4343 * Remote protocol timeout
4345 The standard remote protocol includes a new variable `remotetimeout'
4346 that allows you to set the number of seconds before GDB gives up trying
4347 to read from the target. The default value is 2.
4349 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4351 By default GDB will automatically keep track of objects as they are
4352 loaded and unloaded by the dynamic linker. By using the command `set
4353 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4354 when shared library events occur, thus allowing you to set breakpoints
4355 in shared libraries which are explicitly loaded by the inferior.
4357 Note this feature does not work on hpux8. On hpux9 you must link
4358 /usr/lib/end.o into your program. This feature should work
4359 automatically on hpux10.
4361 * Irix 5.x hardware watchpoint support
4363 Irix 5 configurations now support the use of hardware watchpoints.
4365 * Mips protocol "SYN garbage limit"
4367 When debugging a Mips target using the `target mips' protocol, you
4368 may set the number of characters that GDB will ignore by setting
4369 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4370 every character. The default value is 1050.
4372 * Recording and replaying remote debug sessions
4374 If you set `remotelogfile' to the name of a file, gdb will write to it
4375 a recording of a remote debug session. This recording may then be
4376 replayed back to gdb using "gdbreplay". See gdbserver/README for
4377 details. This is useful when you have a problem with GDB while doing
4378 remote debugging; you can make a recording of the session and send it
4379 to someone else, who can then recreate the problem.
4381 * Speedups for remote debugging
4383 GDB includes speedups for downloading and stepping MIPS systems using
4384 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4385 and more efficient S-record downloading.
4387 * Memory use reductions and statistics collection
4389 GDB now uses less memory and reports statistics about memory usage.
4390 Try the `maint print statistics' command, for example.
4392 *** Changes in GDB-4.15:
4394 * Psymtabs for XCOFF
4396 The symbol reader for AIX GDB now uses partial symbol tables. This
4397 can greatly improve startup time, especially for large executables.
4399 * Remote targets use caching
4401 Remote targets now use a data cache to speed up communication with the
4402 remote side. The data cache could lead to incorrect results because
4403 it doesn't know about volatile variables, thus making it impossible to
4404 debug targets which use memory mapped I/O devices. `set remotecache
4405 off' turns the the data cache off.
4407 * Remote targets may have threads
4409 The standard remote protocol now includes support for multiple threads
4410 in the target system, using new protocol commands 'H' and 'T'. See
4411 gdb/remote.c for details.
4415 If GDB is configured with `--enable-netrom', then it will include
4416 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4417 acts as though it is a bank of ROM on the target board, but you can
4418 write into it over the network. GDB's support consists only of
4419 support for fast loading into the emulated ROM; to debug, you must use
4420 another protocol, such as standard remote protocol. The usual
4421 sequence is something like
4423 target nrom <netrom-hostname>
4425 target remote <netrom-hostname>:1235
4429 GDB now includes support for the Apple Macintosh, as a host only. It
4430 may be run as either an MPW tool or as a standalone application, and
4431 it can debug through the serial port. All the usual GDB commands are
4432 available, but to the target command, you must supply "serial" as the
4433 device type instead of "/dev/ttyXX". See mpw-README in the main
4434 directory for more information on how to build. The MPW configuration
4435 scripts */mpw-config.in support only a few targets, and only the
4436 mips-idt-ecoff target has been tested.
4440 GDB configuration now uses autoconf. This is not user-visible,
4441 but does simplify configuration and building.
4445 GDB now supports hpux10.
4447 *** Changes in GDB-4.14:
4449 * New native configurations
4451 x86 FreeBSD i[345]86-*-freebsd
4452 x86 NetBSD i[345]86-*-netbsd
4453 NS32k NetBSD ns32k-*-netbsd
4454 Sparc NetBSD sparc-*-netbsd
4458 A29K VxWorks a29k-*-vxworks
4459 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4460 CPU32 EST-300 emulator m68*-*-est*
4461 PowerPC ELF powerpc-*-elf
4464 * Alpha OSF/1 support for procfs
4466 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4467 possible to attach to running processes. As the mounting of the /proc
4468 filesystem is optional on the Alpha, GDB automatically determines
4469 the availability of /proc during startup. This can lead to problems
4470 if /proc is unmounted after GDB has been started.
4472 * Arguments to user-defined commands
4474 User commands may accept up to 10 arguments separated by whitespace.
4475 Arguments are accessed within the user command via $arg0..$arg9. A
4478 print $arg0 + $arg1 + $arg2
4480 To execute the command use:
4483 Defines the command "adder" which prints the sum of its three arguments.
4484 Note the arguments are text substitutions, so they may reference variables,
4485 use complex expressions, or even perform inferior function calls.
4487 * New `if' and `while' commands
4489 This makes it possible to write more sophisticated user-defined
4490 commands. Both commands take a single argument, which is the
4491 expression to evaluate, and must be followed by the commands to
4492 execute, one per line, if the expression is nonzero, the list being
4493 terminated by the word `end'. The `if' command list may include an
4494 `else' word, which causes the following commands to be executed only
4495 if the expression is zero.
4497 * Fortran source language mode
4499 GDB now includes partial support for Fortran 77. It will recognize
4500 Fortran programs and can evaluate a subset of Fortran expressions, but
4501 variables and functions may not be handled correctly. GDB will work
4502 with G77, but does not yet know much about symbols emitted by other
4505 * Better HPUX support
4507 Most debugging facilities now work on dynamic executables for HPPAs
4508 running hpux9 or later. You can attach to running dynamically linked
4509 processes, but by default the dynamic libraries will be read-only, so
4510 for instance you won't be able to put breakpoints in them. To change
4511 that behavior do the following before running the program:
4517 This will cause the libraries to be mapped private and read-write.
4518 To revert to the normal behavior, do this:
4524 You cannot set breakpoints or examine data in the library until after
4525 the library is loaded if the function/data symbols do not have
4528 GDB can now also read debug symbols produced by the HP C compiler on
4529 HPPAs (sorry, no C++, Fortran or 68k support).
4531 * Target byte order now dynamically selectable
4533 You can choose which byte order to use with a target system, via the
4534 commands "set endian big" and "set endian little", and you can see the
4535 current setting by using "show endian". You can also give the command
4536 "set endian auto", in which case GDB will use the byte order
4537 associated with the executable. Currently, only embedded MIPS
4538 configurations support dynamic selection of target byte order.
4540 * New DOS host serial code
4542 This version uses DPMI interrupts to handle buffered I/O, so you
4543 no longer need to run asynctsr when debugging boards connected to
4546 *** Changes in GDB-4.13:
4548 * New "complete" command
4550 This lists all the possible completions for the rest of the line, if it
4551 were to be given as a command itself. This is intended for use by emacs.
4553 * Trailing space optional in prompt
4555 "set prompt" no longer adds a space for you after the prompt you set. This
4556 allows you to set a prompt which ends in a space or one that does not.
4558 * Breakpoint hit counts
4560 "info break" now displays a count of the number of times the breakpoint
4561 has been hit. This is especially useful in conjunction with "ignore"; you
4562 can ignore a large number of breakpoint hits, look at the breakpoint info
4563 to see how many times the breakpoint was hit, then run again, ignoring one
4564 less than that number, and this will get you quickly to the last hit of
4567 * Ability to stop printing at NULL character
4569 "set print null-stop" will cause GDB to stop printing the characters of
4570 an array when the first NULL is encountered. This is useful when large
4571 arrays actually contain only short strings.
4573 * Shared library breakpoints
4575 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4576 breakpoints in shared libraries before the executable is run.
4578 * Hardware watchpoints
4580 There is a new hardware breakpoint for the watch command for sparclite
4581 targets. See gdb/sparclite/hw_breakpoint.note.
4583 Hardware watchpoints are also now supported under GNU/Linux.
4587 Annotations have been added. These are for use with graphical interfaces,
4588 and are still experimental. Currently only gdba.el uses these.
4590 * Improved Irix 5 support
4592 GDB now works properly with Irix 5.2.
4594 * Improved HPPA support
4596 GDB now works properly with the latest GCC and GAS.
4598 * New native configurations
4600 Sequent PTX4 i[34]86-sequent-ptx4
4601 HPPA running OSF/1 hppa*-*-osf*
4602 Atari TT running SVR4 m68*-*-sysv4*
4603 RS/6000 LynxOS rs6000-*-lynxos*
4607 OS/9000 i[34]86-*-os9k
4608 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4611 * Hitachi SH7000 and E7000-PC ICE support
4613 There is now support for communicating with the Hitachi E7000-PC ICE.
4614 This is available automatically when GDB is configured for the SH.
4618 As usual, a variety of small fixes and improvements, both generic
4619 and configuration-specific. See the ChangeLog for more detail.
4621 *** Changes in GDB-4.12:
4623 * Irix 5 is now supported
4627 GDB-4.12 on the HPPA has a number of changes which make it unable
4628 to debug the output from the currently released versions of GCC and
4629 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4630 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4631 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4634 *** Changes in GDB-4.11:
4636 * User visible changes:
4640 The "set remotedebug" option is now consistent between the mips remote
4641 target, remote targets using the gdb-specific protocol, UDI (AMD's
4642 debug protocol for the 29k) and the 88k bug monitor. It is now an
4643 integer specifying a debug level (normally 0 or 1, but 2 means more
4644 debugging info for the mips target).
4646 * DEC Alpha native support
4648 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4649 debug info, but GDB works fairly well with the DEC compiler and should
4650 work with a future GCC release. See the README file for a few
4651 Alpha-specific notes.
4653 * Preliminary thread implementation
4655 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4657 * LynxOS native and target support for 386
4659 This release has been hosted on LynxOS 2.2, and also can be configured
4660 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4663 * Improvements in C++ mangling/demangling.
4665 This release has much better g++ debugging, specifically in name
4666 mangling/demangling, virtual function calls, print virtual table,
4667 call methods, ...etc.
4669 *** Changes in GDB-4.10:
4671 * User visible changes:
4673 Remote debugging using the GDB-specific (`target remote') protocol now
4674 supports the `load' command. This is only useful if you have some
4675 other way of getting the stub to the target system, and you can put it
4676 somewhere in memory where it won't get clobbered by the download.
4678 Filename completion now works.
4680 When run under emacs mode, the "info line" command now causes the
4681 arrow to point to the line specified. Also, "info line" prints
4682 addresses in symbolic form (as well as hex).
4684 All vxworks based targets now support a user settable option, called
4685 vxworks-timeout. This option represents the number of seconds gdb
4686 should wait for responses to rpc's. You might want to use this if
4687 your vxworks target is, perhaps, a slow software simulator or happens
4688 to be on the far side of a thin network line.
4692 This release contains support for using a DEC alpha as a GDB host for
4693 cross debugging. Native alpha debugging is not supported yet.
4696 *** Changes in GDB-4.9:
4700 This is the first GDB release which is accompanied by a matching testsuite.
4701 The testsuite requires installation of dejagnu, which should be available
4702 via ftp from most sites that carry GNU software.
4706 'Cfront' style demangling has had its name changed to 'ARM' style, to
4707 emphasize that it was written from the specifications in the C++ Annotated
4708 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4709 disclaimers, it still generated too much confusion with users attempting to
4710 use gdb with AT&T cfront.
4714 GDB now uses a standard remote interface to a simulator library.
4715 So far, the library contains simulators for the Zilog Z8001/2, the
4716 Hitachi H8/300, H8/500 and Super-H.
4718 * New targets supported
4720 H8/300 simulator h8300-hitachi-hms or h8300hms
4721 H8/500 simulator h8500-hitachi-hms or h8500hms
4722 SH simulator sh-hitachi-hms or sh
4723 Z8000 simulator z8k-zilog-none or z8ksim
4724 IDT MIPS board over serial line mips-idt-ecoff
4726 Cross-debugging to GO32 targets is supported. It requires a custom
4727 version of the i386-stub.c module which is integrated with the
4728 GO32 memory extender.
4730 * New remote protocols
4732 MIPS remote debugging protocol.
4734 * New source languages supported
4736 This version includes preliminary support for Chill, a Pascal like language
4737 used by telecommunications companies. Chill support is also being integrated
4738 into the GNU compiler, but we don't know when it will be publically available.
4741 *** Changes in GDB-4.8:
4743 * HP Precision Architecture supported
4745 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4746 version of this support was available as a set of patches from the
4747 University of Utah. GDB does not support debugging of programs
4748 compiled with the HP compiler, because HP will not document their file
4749 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4750 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4752 Many problems in the preliminary version have been fixed.
4754 * Faster and better demangling
4756 We have improved template demangling and fixed numerous bugs in the GNU style
4757 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4758 character types (wchar_t) are now supported. Demangling of each symbol is now
4759 only done once, and is cached when the symbol table for a file is read in.
4760 This results in a small increase in memory usage for C programs, a moderate
4761 increase in memory usage for C++ programs, and a fantastic speedup in
4764 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4765 from the specifications in the Annotated Reference Manual, which AT&T's
4766 compiler does not actually implement.
4768 * G++ multiple inheritance compiler problem
4770 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4771 inheritance lattices was reworked to properly discover ambiguities. We
4772 recently found an example which causes this new algorithm to fail in a
4773 very subtle way, producing bad debug information for those classes.
4774 The file 'gcc.patch' (in this directory) can be applied to gcc to
4775 circumvent the problem. A future GCC release will contain a complete
4778 The previous G++ debug info problem (mentioned below for the gdb-4.7
4779 release) is fixed in gcc version 2.3.2.
4781 * Improved configure script
4783 The `configure' script will now attempt to guess your system type if
4784 you don't supply a host system type. The old scheme of supplying a
4785 host system triplet is preferable over using this. All the magic is
4786 done in the new `config.guess' script. Examine it for details.
4788 We have also brought our configure script much more in line with the FSF's
4789 version. It now supports the --with-xxx options. In particular,
4790 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4791 The resulting GDB will not be able to read arbitrary object file formats --
4792 only the format ``expected'' to be used on the configured target system.
4793 We hope to make this the default in a future release.
4795 * Documentation improvements
4797 There's new internal documentation on how to modify GDB, and how to
4798 produce clean changes to the code. We implore people to read it
4799 before submitting changes.
4801 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4802 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4803 `info' files are also provided. To build `info' files from scratch,
4804 you will need the latest `makeinfo' release, which will be available in
4805 a future texinfo-X.Y release.
4807 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4808 We're not sure exactly which versions have this problem, but it has
4809 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4810 or better. If that isn't possible, there is a patch in
4811 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4812 around this problem.
4816 GDB now supports array constants that can be used in expressions typed in by
4817 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4818 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4821 The new directory `gdb/sparclite' contains a program that demonstrates
4822 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4824 * New native hosts supported
4826 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4827 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4829 * New targets supported
4831 AMD 29k family via UDI a29k-amd-udi or udi29k
4833 * New file formats supported
4835 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4836 HPUX core files, and SCO 3.2v2 core files.
4840 Attaching to processes now works again; thanks for the many bug reports.
4842 We have also stomped on a bunch of core dumps caused by
4843 printf_filtered("%s") problems.
4845 We eliminated a copyright problem on the rpc and ptrace header files
4846 for VxWorks, which was discovered at the last minute during the 4.7
4847 release. You should now be able to build a VxWorks GDB.
4849 You can now interrupt gdb while an attached process is running. This
4850 will cause the attached process to stop, and give control back to GDB.
4852 We fixed problems caused by using too many file descriptors
4853 for reading symbols from object files and libraries. This was
4854 especially a problem for programs that used many (~100) shared
4857 The `step' command now only enters a subroutine if there is line number
4858 information for the subroutine. Otherwise it acts like the `next'
4859 command. Previously, `step' would enter subroutines if there was
4860 any debugging information about the routine. This avoids problems
4861 when using `cc -g1' on MIPS machines.
4863 * Internal improvements
4865 GDB's internal interfaces have been improved to make it easier to support
4866 debugging of multiple languages in the future.
4868 GDB now uses a common structure for symbol information internally.
4869 Minimal symbols (derived from linkage symbols in object files), partial
4870 symbols (from a quick scan of debug information), and full symbols
4871 contain a common subset of information, making it easier to write
4872 shared code that handles any of them.
4874 * New command line options
4876 We now accept --silent as an alias for --quiet.
4880 The memory-mapped-malloc library is now licensed under the GNU Library
4881 General Public License.
4883 *** Changes in GDB-4.7:
4885 * Host/native/target split
4887 GDB has had some major internal surgery to untangle the support for
4888 hosts and remote targets. Now, when you configure GDB for a remote
4889 target, it will no longer load in all of the support for debugging
4890 local programs on the host. When fully completed and tested, this will
4891 ensure that arbitrary host/target combinations are possible.
4893 The primary conceptual shift is to separate the non-portable code in
4894 GDB into three categories. Host specific code is required any time GDB
4895 is compiled on that host, regardless of the target. Target specific
4896 code relates to the peculiarities of the target, but can be compiled on
4897 any host. Native specific code is everything else: it can only be
4898 built when the host and target are the same system. Child process
4899 handling and core file support are two common `native' examples.
4901 GDB's use of /proc for controlling Unix child processes is now cleaner.
4902 It has been split out into a single module under the `target_ops' vector,
4903 plus two native-dependent functions for each system that uses /proc.
4905 * New hosts supported
4907 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
4908 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4909 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
4911 * New targets supported
4913 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4914 68030 and CPU32 m68030-*-*, m68332-*-*
4916 * New native hosts supported
4918 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4919 (386bsd is not well tested yet)
4920 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
4922 * New file formats supported
4924 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
4925 supports reading of `a.out.adobe' object files, which are an a.out
4926 format extended with minimal information about multiple sections.
4930 `show copying' is the same as the old `info copying'.
4931 `show warranty' is the same as `info warrantee'.
4932 These were renamed for consistency. The old commands continue to work.
4934 `info handle' is a new alias for `info signals'.
4936 You can now define pre-command hooks, which attach arbitrary command
4937 scripts to any command. The commands in the hook will be executed
4938 prior to the user's command. You can also create a hook which will be
4939 executed whenever the program stops. See gdb.texinfo.
4943 We now deal with Cfront style name mangling, and can even extract type
4944 info from mangled symbols. GDB can automatically figure out which
4945 symbol mangling style your C++ compiler uses.
4947 Calling of methods and virtual functions has been improved as well.
4951 The crash that occured when debugging Sun Ansi-C compiled binaries is
4952 fixed. This was due to mishandling of the extra N_SO stabs output
4955 We also finally got Ultrix 4.2 running in house, and fixed core file
4956 support, with help from a dozen people on the net.
4958 John M. Farrell discovered that the reason that single-stepping was so
4959 slow on all of the Mips based platforms (primarily SGI and DEC) was
4960 that we were trying to demangle and lookup a symbol used for internal
4961 purposes on every instruction that was being stepped through. Changing
4962 the name of that symbol so that it couldn't be mistaken for a C++
4963 mangled symbol sped things up a great deal.
4965 Rich Pixley sped up symbol lookups in general by getting much smarter
4966 about when C++ symbol mangling is necessary. This should make symbol
4967 completion (TAB on the command line) much faster. It's not as fast as
4968 we'd like, but it's significantly faster than gdb-4.6.
4972 A new user controllable variable 'call_scratch_address' can
4973 specify the location of a scratch area to be used when GDB
4974 calls a function in the target. This is necessary because the
4975 usual method of putting the scratch area on the stack does not work
4976 in systems that have separate instruction and data spaces.
4978 We integrated changes to support the 29k UDI (Universal Debugger
4979 Interface), but discovered at the last minute that we didn't have all
4980 of the appropriate copyright paperwork. We are working with AMD to
4981 resolve this, and hope to have it available soon.
4985 We have sped up the remote serial line protocol, especially for targets
4986 with lots of registers. It now supports a new `expedited status' ('T')
4987 message which can be used in place of the existing 'S' status message.
4988 This allows the remote stub to send only the registers that GDB
4989 needs to make a quick decision about single-stepping or conditional
4990 breakpoints, eliminating the need to fetch the entire register set for
4991 each instruction being stepped through.
4993 The GDB remote serial protocol now implements a write-through cache for
4994 registers, only re-reading the registers if the target has run.
4996 There is also a new remote serial stub for SPARC processors. You can
4997 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
4998 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
4999 processor with a serial port.
5003 Configure.in files have become much easier to read and modify. A new
5004 `table driven' format makes it more obvious what configurations are
5005 supported, and what files each one uses.
5009 There is a new opcodes library which will eventually contain all of the
5010 disassembly routines and opcode tables. At present, it only contains
5011 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5012 disassembler (binutils/objdump) to share these routines.
5014 The libiberty library is now copylefted under the GNU Library General
5015 Public License. This allows more liberal use, and was done so libg++
5016 can use it. This makes no difference to GDB, since the Library License
5017 grants all the rights from the General Public License.
5021 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5022 reference to the stabs symbol info used by the debugger. It is (as far
5023 as we know) the only published document on this fascinating topic. We
5024 encourage you to read it, compare it to the stabs information on your
5025 system, and send improvements on the document in general (to
5026 bug-gdb@prep.ai.mit.edu).
5028 And, of course, many bugs have been fixed.
5031 *** Changes in GDB-4.6:
5033 * Better support for C++ function names
5035 GDB now accepts as input the "demangled form" of C++ overloaded function
5036 names and member function names, and can do command completion on such names
5037 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5038 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5039 Make use of command completion, it is your friend.
5041 GDB also now accepts a variety of C++ mangled symbol formats. They are
5042 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5043 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5044 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5045 for the list of formats.
5047 * G++ symbol mangling problem
5049 Recent versions of gcc have a bug in how they emit debugging information for
5050 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5051 directory) can be applied to gcc to fix the problem. Alternatively, if you
5052 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5053 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5054 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5057 * New 'maintenance' command
5059 All of the commands related to hacking GDB internals have been moved out of
5060 the main command set, and now live behind the 'maintenance' command. This
5061 can also be abbreviated as 'mt'. The following changes were made:
5063 dump-me -> maintenance dump-me
5064 info all-breakpoints -> maintenance info breakpoints
5065 printmsyms -> maintenance print msyms
5066 printobjfiles -> maintenance print objfiles
5067 printpsyms -> maintenance print psymbols
5068 printsyms -> maintenance print symbols
5070 The following commands are new:
5072 maintenance demangle Call internal GDB demangler routine to
5073 demangle a C++ link name and prints the result.
5074 maintenance print type Print a type chain for a given symbol
5076 * Change to .gdbinit file processing
5078 We now read the $HOME/.gdbinit file before processing the argv arguments
5079 (e.g. reading symbol files or core files). This allows global parameters to
5080 be set, which will apply during the symbol reading. The ./.gdbinit is still
5081 read after argv processing.
5083 * New hosts supported
5085 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5087 GNU/Linux support i386-unknown-linux or linux
5089 We are also including code to support the HP/PA running BSD and HPUX. This
5090 is almost guaranteed not to work, as we didn't have time to test or build it
5091 for this release. We are including it so that the more adventurous (or
5092 masochistic) of you can play with it. We also had major problems with the
5093 fact that the compiler that we got from HP doesn't support the -g option.
5096 * New targets supported
5098 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5100 * More smarts about finding #include files
5102 GDB now remembers the compilation directory for all include files, and for
5103 all files from which C is generated (like yacc and lex sources). This
5104 greatly improves GDB's ability to find yacc/lex sources, and include files,
5105 especially if you are debugging your program from a directory different from
5106 the one that contains your sources.
5108 We also fixed a bug which caused difficulty with listing and setting
5109 breakpoints in include files which contain C code. (In the past, you had to
5110 try twice in order to list an include file that you hadn't looked at before.)
5112 * Interesting infernals change
5114 GDB now deals with arbitrary numbers of sections, where the symbols for each
5115 section must be relocated relative to that section's landing place in the
5116 target's address space. This work was needed to support ELF with embedded
5117 stabs used by Solaris-2.0.
5119 * Bug fixes (of course!)
5121 There have been loads of fixes for the following things:
5122 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5123 i960, stabs, DOS(GO32), procfs, etc...
5125 See the ChangeLog for details.
5127 *** Changes in GDB-4.5:
5129 * New machines supported (host and target)
5131 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5133 SGI Irix-4.x mips-sgi-irix4 or iris4
5135 * New malloc package
5137 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5138 Mmalloc is capable of handling mutiple heaps of memory. It is also
5139 capable of saving a heap to a file, and then mapping it back in later.
5140 This can be used to greatly speedup the startup of GDB by using a
5141 pre-parsed symbol table which lives in a mmalloc managed heap. For
5142 more details, please read mmalloc/mmalloc.texi.
5146 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5147 'help info proc' for details.
5149 * MIPS ecoff symbol table format
5151 The code that reads MIPS symbol table format is now supported on all hosts.
5152 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5155 * File name changes for MS-DOS
5157 Many files in the config directories have been renamed to make it easier to
5158 support GDB on MS-DOSe systems (which have very restrictive file name
5159 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5160 environment) is close to working but has some remaining problems. Note
5161 that debugging of DOS programs is not supported, due to limitations
5162 in the ``operating system'', but it can be used to host cross-debugging.
5164 * Cross byte order fixes
5166 Many fixes have been made to support cross debugging of Sparc and MIPS
5167 targets from hosts whose byte order differs.
5169 * New -mapped and -readnow options
5171 If memory-mapped files are available on your system through the 'mmap'
5172 system call, you can use the -mapped option on the `file' or
5173 `symbol-file' commands to cause GDB to write the symbols from your
5174 program into a reusable file. If the program you are debugging is
5175 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5176 Future GDB debugging sessions will notice the presence of this file,
5177 and will quickly map in symbol information from it, rather than reading
5178 the symbol table from the executable program. Using the '-mapped'
5179 option in a GDB `file' or `symbol-file' command has the same effect as
5180 starting GDB with the '-mapped' command-line option.
5182 You can cause GDB to read the entire symbol table immediately by using
5183 the '-readnow' option with any of the commands that load symbol table
5184 information (or on the GDB command line). This makes the command
5185 slower, but makes future operations faster.
5187 The -mapped and -readnow options are typically combined in order to
5188 build a `fred.syms' file that contains complete symbol information.
5189 A simple GDB invocation to do nothing but build a `.syms' file for future
5192 gdb -batch -nx -mapped -readnow programname
5194 The `.syms' file is specific to the host machine on which GDB is run.
5195 It holds an exact image of GDB's internal symbol table. It cannot be
5196 shared across multiple host platforms.
5198 * longjmp() handling
5200 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5201 siglongjmp() without losing control. This feature has not yet been ported to
5202 all systems. It currently works on many 386 platforms, all MIPS-based
5203 platforms (SGI, DECstation, etc), and Sun3/4.
5207 Preliminary work has been put in to support the new Solaris OS from Sun. At
5208 this time, it can control and debug processes, but it is not capable of
5213 As always, many many bug fixes. The major areas were with g++, and mipsread.
5214 People using the MIPS-based platforms should experience fewer mysterious
5215 crashes and trashed symbol tables.
5217 *** Changes in GDB-4.4:
5219 * New machines supported (host and target)
5221 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5223 BSD Reno on Vax vax-dec-bsd
5224 Ultrix on Vax vax-dec-ultrix
5226 * New machines supported (target)
5228 AMD 29000 embedded, using EBMON a29k-none-none
5232 GDB continues to improve its handling of C++. `References' work better.
5233 The demangler has also been improved, and now deals with symbols mangled as
5234 per the Annotated C++ Reference Guide.
5236 GDB also now handles `stabs' symbol information embedded in MIPS
5237 `ecoff' symbol tables. Since the ecoff format was not easily
5238 extensible to handle new languages such as C++, this appeared to be a
5239 good way to put C++ debugging info into MIPS binaries. This option
5240 will be supported in the GNU C compiler, version 2, when it is
5243 * New features for SVR4
5245 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5246 shared libraries. Debugging dynamically linked programs should present
5247 only minor differences from debugging statically linked programs.
5249 The `info proc' command will print out information about any process
5250 on an SVR4 system (including the one you are debugging). At the moment,
5251 it prints the address mappings of the process.
5253 If you bring up GDB on another SVR4 system, please send mail to
5254 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5256 * Better dynamic linking support in SunOS
5258 Reading symbols from shared libraries which contain debugging symbols
5259 now works properly. However, there remain issues such as automatic
5260 skipping of `transfer vector' code during function calls, which
5261 make it harder to debug code in a shared library, than to debug the
5262 same code linked statically.
5266 GDB is now using the latest `getopt' routines from the FSF. This
5267 version accepts the -- prefix for options with long names. GDB will
5268 continue to accept the old forms (-option and +option) as well.
5269 Various single letter abbreviations for options have been explicity
5270 added to the option table so that they won't get overshadowed in the
5271 future by other options that begin with the same letter.
5275 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5276 Many assorted bugs have been handled. Many more remain to be handled.
5277 See the various ChangeLog files (primarily in gdb and bfd) for details.
5280 *** Changes in GDB-4.3:
5282 * New machines supported (host and target)
5284 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5285 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5286 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5288 * Almost SCO Unix support
5290 We had hoped to support:
5291 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5292 (except for core file support), but we discovered very late in the release
5293 that it has problems with process groups that render gdb unusable. Sorry
5294 about that. I encourage people to fix it and post the fixes.
5296 * Preliminary ELF and DWARF support
5298 GDB can read ELF object files on System V Release 4, and can handle
5299 debugging records for C, in DWARF format, in ELF files. This support
5300 is preliminary. If you bring up GDB on another SVR4 system, please
5301 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5306 GDB now uses the latest `readline' library. One user-visible change
5307 is that two tabs will list possible command completions, which previously
5308 required typing M-? (meta-question mark, or ESC ?).
5312 The `stepi' bug that many of you noticed has been squashed.
5313 Many bugs in C++ have been handled. Many more remain to be handled.
5314 See the various ChangeLog files (primarily in gdb and bfd) for details.
5316 * State of the MIPS world (in case you wondered):
5318 GDB can understand the symbol tables emitted by the compilers
5319 supplied by most vendors of MIPS-based machines, including DEC. These
5320 symbol tables are in a format that essentially nobody else uses.
5322 Some versions of gcc come with an assembler post-processor called
5323 mips-tfile. This program is required if you want to do source-level
5324 debugging of gcc-compiled programs. I believe FSF does not ship
5325 mips-tfile with gcc version 1, but it will eventually come with gcc
5328 Debugging of g++ output remains a problem. g++ version 1.xx does not
5329 really support it at all. (If you're lucky, you should be able to get
5330 line numbers and stack traces to work, but no parameters or local
5331 variables.) With some work it should be possible to improve the
5334 When gcc version 2 is released, you will have somewhat better luck.
5335 However, even then you will get confusing results for inheritance and
5338 We will eventually provide full debugging of g++ output on
5339 DECstations. This will probably involve some kind of stabs-in-ecoff
5340 encapulation, but the details have not been worked out yet.
5343 *** Changes in GDB-4.2:
5345 * Improved configuration
5347 Only one copy of `configure' exists now, and it is not self-modifying.
5348 Porting BFD is simpler.
5352 The `step' and `next' commands now only stop at the first instruction
5353 of a source line. This prevents the multiple stops that used to occur
5354 in switch statements, for-loops, etc. `Step' continues to stop if a
5355 function that has debugging information is called within the line.
5359 Lots of small bugs fixed. More remain.
5361 * New host supported (not target)
5363 Intel 386 PC clone running Mach i386-none-mach
5366 *** Changes in GDB-4.1:
5368 * Multiple source language support
5370 GDB now has internal scaffolding to handle several source languages.
5371 It determines the type of each source file from its filename extension,
5372 and will switch expression parsing and number formatting to match the
5373 language of the function in the currently selected stack frame.
5374 You can also specifically set the language to be used, with
5375 `set language c' or `set language modula-2'.
5379 GDB now has preliminary support for the GNU Modula-2 compiler,
5380 currently under development at the State University of New York at
5381 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5382 continue through the fall of 1991 and into 1992.
5384 Other Modula-2 compilers are currently not supported, and attempting to
5385 debug programs compiled with them will likely result in an error as the
5386 symbol table is read. Feel free to work on it, though!
5388 There are hooks in GDB for strict type checking and range checking,
5389 in the `Modula-2 philosophy', but they do not currently work.
5393 GDB can now write to executable and core files (e.g. patch
5394 a variable's value). You must turn this switch on, specify
5395 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5396 by assigning a new value to a variable. Modifications take
5399 * Automatic SunOS shared library reading
5401 When you run your program, GDB automatically determines where its
5402 shared libraries (if any) have been loaded, and reads their symbols.
5403 The `share' command is no longer needed. This also works when
5404 examining core files.
5408 You can specify the number of lines that the `list' command shows.
5411 * New machines supported (host and target)
5413 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5414 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5415 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5417 * New hosts supported (not targets)
5419 IBM RT/PC: romp-ibm-aix or rtpc
5421 * New targets supported (not hosts)
5423 AMD 29000 embedded with COFF a29k-none-coff
5424 AMD 29000 embedded with a.out a29k-none-aout
5425 Ultracomputer remote kernel debug a29k-nyu-kern
5427 * New remote interfaces
5433 *** Changes in GDB-4.0:
5437 Wide output is wrapped at good places to make the output more readable.
5439 Gdb now supports cross-debugging from a host machine of one type to a
5440 target machine of another type. Communication with the target system
5441 is over serial lines. The ``target'' command handles connecting to the
5442 remote system; the ``load'' command will download a program into the
5443 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5444 also supports debugging of realtime processes running under VxWorks,
5445 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5446 stub on the target system.
5448 New CPUs supported include the AMD 29000 and Intel 960.
5450 GDB now reads object files and symbol tables via a ``binary file''
5451 library, which allows a single copy of GDB to debug programs of multiple
5452 object file types such as a.out and coff.
5454 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5455 refcard.dvi and refcard.ps are available to format it).
5458 * Control-Variable user interface simplified
5460 All variables that control the operation of the debugger can be set
5461 by the ``set'' command, and displayed by the ``show'' command.
5463 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5464 ``Show prompt'' produces the response:
5465 Gdb's prompt is new-gdb=>.
5467 What follows are the NEW set commands. The command ``help set'' will
5468 print a complete list of old and new set commands. ``help set FOO''
5469 will give a longer description of the variable FOO. ``show'' will show
5470 all of the variable descriptions and their current settings.
5472 confirm on/off: Enables warning questions for operations that are
5473 hard to recover from, e.g. rerunning the program while
5474 it is already running. Default is ON.
5476 editing on/off: Enables EMACS style command line editing
5477 of input. Previous lines can be recalled with
5478 control-P, the current line can be edited with control-B,
5479 you can search for commands with control-R, etc.
5482 history filename NAME: NAME is where the gdb command history
5483 will be stored. The default is .gdb_history,
5484 or the value of the environment variable
5487 history size N: The size, in commands, of the command history. The
5488 default is 256, or the value of the environment variable
5491 history save on/off: If this value is set to ON, the history file will
5492 be saved after exiting gdb. If set to OFF, the
5493 file will not be saved. The default is OFF.
5495 history expansion on/off: If this value is set to ON, then csh-like
5496 history expansion will be performed on
5497 command line input. The default is OFF.
5499 radix N: Sets the default radix for input and output. It can be set
5500 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5501 in the current radix, so "set radix 10" is always a no-op.
5503 height N: This integer value is the number of lines on a page. Default
5504 is 24, the current `stty rows'' setting, or the ``li#''
5505 setting from the termcap entry matching the environment
5508 width N: This integer value is the number of characters on a line.
5509 Default is 80, the current `stty cols'' setting, or the ``co#''
5510 setting from the termcap entry matching the environment
5513 Note: ``set screensize'' is obsolete. Use ``set height'' and
5514 ``set width'' instead.
5516 print address on/off: Print memory addresses in various command displays,
5517 such as stack traces and structure values. Gdb looks
5518 more ``symbolic'' if you turn this off; it looks more
5519 ``machine level'' with it on. Default is ON.
5521 print array on/off: Prettyprint arrays. New convenient format! Default
5524 print demangle on/off: Print C++ symbols in "source" form if on,
5527 print asm-demangle on/off: Same, for assembler level printouts
5530 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5533 * Support for Epoch Environment.
5535 The epoch environment is a version of Emacs v18 with windowing. One
5536 new command, ``inspect'', is identical to ``print'', except that if you
5537 are running in the epoch environment, the value is printed in its own
5541 * Support for Shared Libraries
5543 GDB can now debug programs and core files that use SunOS shared libraries.
5544 Symbols from a shared library cannot be referenced
5545 before the shared library has been linked with the program (this
5546 happens after you type ``run'' and before the function main() is entered).
5547 At any time after this linking (including when examining core files
5548 from dynamically linked programs), gdb reads the symbols from each
5549 shared library when you type the ``sharedlibrary'' command.
5550 It can be abbreviated ``share''.
5552 sharedlibrary REGEXP: Load shared object library symbols for files
5553 matching a unix regular expression. No argument
5554 indicates to load symbols for all shared libraries.
5556 info sharedlibrary: Status of loaded shared libraries.
5561 A watchpoint stops execution of a program whenever the value of an
5562 expression changes. Checking for this slows down execution
5563 tremendously whenever you are in the scope of the expression, but is
5564 quite useful for catching tough ``bit-spreader'' or pointer misuse
5565 problems. Some machines such as the 386 have hardware for doing this
5566 more quickly, and future versions of gdb will use this hardware.
5568 watch EXP: Set a watchpoint (breakpoint) for an expression.
5570 info watchpoints: Information about your watchpoints.
5572 delete N: Deletes watchpoint number N (same as breakpoints).
5573 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5574 enable N: Re-enables watchpoint number N (same as breakpoints).
5577 * C++ multiple inheritance
5579 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5582 * C++ exception handling
5584 Gdb now supports limited C++ exception handling. Besides the existing
5585 ability to breakpoint on an exception handler, gdb can breakpoint on
5586 the raising of an exception (before the stack is peeled back to the
5589 catch FOO: If there is a FOO exception handler in the dynamic scope,
5590 set a breakpoint to catch exceptions which may be raised there.
5591 Multiple exceptions (``catch foo bar baz'') may be caught.
5593 info catch: Lists all exceptions which may be caught in the
5594 current stack frame.
5597 * Minor command changes
5599 The command ``call func (arg, arg, ...)'' now acts like the print
5600 command, except it does not print or save a value if the function's result
5601 is void. This is similar to dbx usage.
5603 The ``up'' and ``down'' commands now always print the frame they end up
5604 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5605 frames without printing.
5607 * New directory command
5609 'dir' now adds directories to the FRONT of the source search path.
5610 The path starts off empty. Source files that contain debug information
5611 about the directory in which they were compiled can be found even
5612 with an empty path; Sun CC and GCC include this information. If GDB can't
5613 find your source file in the current directory, type "dir .".
5615 * Configuring GDB for compilation
5617 For normal use, type ``./configure host''. See README or gdb.texinfo
5620 GDB now handles cross debugging. If you are remotely debugging between
5621 two different machines, type ``./configure host -target=targ''.
5622 Host is the machine where GDB will run; targ is the machine
5623 where the program that you are debugging will run.
5625 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.